KoreaScience (Korea)

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UK PubMed Central (United Kingdom)

BackgroundVisual neurons respond essentially to luminance variations occurring within their receptive fields. In primary visual cortex, each neuron is a filter for stimulus features...Full Text Available

International Nuclear Information System (INIS)

Neuronal cell death induced by oxidative stress is correlated with numerous neurodegenerative diseases, including Alzheimer's disease (AD), Parkinson's disease (PD), and stroke. The causes of sporadic forms of age-related neurodegenerative diseases are still unknown. Recently, a correlation between paraquat exposure and neurodegenerative diseases has been observed. Paraquat, a nonselective herbicide, was once widely used in North America and is still routinely used in Taiwan. We have used differentiated Human Neuroblastoma (SHSY-5Y) cells as an in vitro model to study the mechanism of cell death induced by paraquat. We observed that paraquat-induced oxidative stress in differentiated SHSY-5Y cells as indicated by an increase in the production of cellular reactive oxygen species (ROS). Furthermore, apoptosis was evident as indicated by cellular and nuclear morphology and DNA fragmentation. Interestingly, ...

International Nuclear Information System (INIS)

Short communication.

UK PubMed Central (United Kingdom)

The receptive field of a neuron reflects its function. For example, for parallel fiber (PF) inputs in C3 zone the cerebellar cortex, the excitatory and inhibitory receptive fields of a Purkinje cell...Full Text Available

British Library Electronic Table of Contents (United Kingdom)

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

UK PubMed Central (United Kingdom)

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

Science.gov (United States)

Compounds isolated from Magnolia officinalis such as magnolol, honokiol and obovatol exhibit several pharmacological effects on CNS including depressant, anxiolytic and anticonvulsant effects, as well as neuroprotective effects against chemical and heat damages. Recently, honokiol was found to have a neurotrophic effect in fetal rat cortical neurons. In the present study, we show that 4-O-methylhonokiol, a novel compound from Magnolia officinalis, promotes neurite outgrowth in a concentration- dependent manner in rat embryonic neuronal cells. In parallel with the neurite outgrowth activity, the expression of neurite outgrowth marker proteins is also increased by treatment with 4-O-methylhonokiol. We also found that 4-O-methylhonokiol promotes the release of NGF and BDNF into cell culture medium. In addition, lower concentration of 4-O-methylhonokiol (1 and 2 lM) further enhanced neurite outgrowth and expression of neurite ...

UK PubMed Central (United Kingdom)

Since Src kinase inhibitors decrease brain injury produced by intracerebral hemorrhage (ICH) and thrombin is activated following ICH, this study determined whether Src kinase inhibitors decrease...Full Text Available

UK PubMed Central (United Kingdom)

Place fields of hippocampal pyramidal cells expand asymmetrically when adult rats repeatedly follow the same route. This behaviorally-induced expression of neuronal plasticity utilizes an NMDA_R-dependent,...Full Text Available

UK PubMed Central (United Kingdom)

BackgroundMultiple sclerosis (MS) is the endpoint of a complex and still poorly understood process which results in inflammation, demyelination and axonal and neuronal degeneration....Full Text Available

UK PubMed Central (United Kingdom)

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

UK PubMed Central (United Kingdom)

This study explored the effects of propofol on c-Fos and Egr-1 in neuroblastoma (N2A) cells. We demonstrate that propofol induced the expression of c-Fos and Egr-1 within 30 and 60 min of exposure...Full Text Available

Science.gov (United States)

... a rotating mirror Q-switch or an acousto-optic Q-switch. The former ... Q-switch up to 2000 pps. The Q-switched output bean, is predominantly ...

UK PubMed Central (United Kingdom)

The CNS is a unique organ due to its limited capacity for immune surveillance. As macrophages of the CNS, microglia represent a population originally known for the ability to assist neuronal stability,...Full Text Available

UK PubMed Central (United Kingdom)

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

DEFF Research Database (Denmark)

Efflux of dopamine through the dopamine transporter (DAT) is critical for the psychostimulatory properties of amphetamines, but the underlying mechanism is unclear. Here we show that Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) plays a key role in this efflux. CaMKIIalpha bound to the distal C terminus of DAT and colocalized with DAT in dopaminergic neurons. CaMKIIalpha stimulated dopamine efflux via DAT in response to amphetamine in heterologous cells and in dopaminergic neurons. CaMKIIalpha phosphorylated serines in the distal N terminus of DAT in vitro, and mutation of these serines eliminated the stimulatory effects of CaMKIIalpha. A mutation of the DAT C terminus impairing CaMKIIalpha binding also impaired amphetamine-induced dopamine efflux. An in vivo role for CaMKII was supported by chronoamperometry measurements showing reduced amphetamine-induced dopamine efflux in response to the ...

British Library Electronic Table of Contents (United Kingdom)

Precocious puberty is a significant child health problem, especially in girls, because 95% of cases are idiopathic. Our earlier studies demonstrated that low-dose levels of manganese (Mn) caused precocious puberty via stimulating the secretion of luteinizing hormone-releasing hormone (LHRH). Because glial-neuronal communications are important for the activation of LHRH secretion at puberty, we investigated the effects of prepubertal Mn exposure on specific glial-derived puberty-related genes known to affect neuronal LHRH release. Animals were supplemented with MnCl2 (10 mg/kg) or saline by gastric gavage from day 12 until day 22 or day 29, then decapitated, and brains removed. The site of LHRH release is the medial basal hypothalamus (MBH), and tissues from this area were analyzed by real-...

Energy Technology Data Exchange (ETDEWEB)

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.

DEFF Research Database (Denmark)

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.

UK PubMed Central (United Kingdom)

Neurons are born throughout adulthood in the hippocampus and show enhanced plasticity compared to mature neurons. However, there are conflicting reports on whether or not young neurons contribute...Full Text Available

International Nuclear Information System (INIS)

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.

International Nuclear Information System (INIS)

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 ...

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The regional concentrations of nine radiochemicals were measured in rat brain after induction of cerebral ischemia to identify tracers concentrated by brain undergoing selective neuronal necrosis. Transient (30 minute) forebrain ischemia was produced in the rat; 24 hours after cerebral recirculation the radiochemicals were injected intravenously and allowed to circulate for 5 hours. The brain concentrations of the radiochemicals in dissected regions were determined by scintillation counting. Forebrain ischemia of this nature will produce extensive injury to striatal neurons but will spare the great majority of neocortical neurons at 24 hours. The regional concentrations of these radiochemicals varied considerably in both control and ischemic animals. In postischemic animals, 4 radionuclides (/sup 63/Ni, /sup 99/TcO/sub 4/, /sup 22/Na, and (/sup 3/H)tetracycline) were concentrated in the irreversibly ...

UK PubMed Central (United Kingdom)

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

UK PubMed Central (United Kingdom)

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

UK PubMed Central (United Kingdom)

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

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

UK PubMed Central (United Kingdom)

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

UK PubMed Central (United Kingdom)

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

Energy Technology Data Exchange (ETDEWEB)

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 ...

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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.

International Nuclear Information System (INIS)

Isolation and expansion of neural stem cells (NSCs) of human origin are crucial for successful development of cell therapy approaches in neurodegenerative diseases. Different epigenetic and genetic immortalization strategies have been established for long-term maintenance and expansion of these cells in vitro. Here we report the generation of a new, clonal NSC (hc-NSC) line, derived from human fetal cortical tissue, based on v-myc immortalization. Using immunocytochemistry, we show that these cells retain the characteristics of NSCs after more than 50 passages. Under proliferation conditions, when supplemented with epidermal and basic fibroblast growth factors, the hc-NSCs expressed neural stem/progenitor cell markers like nestin, vimentin and Sox2. When growth factors were withdrawn, proliferation and expression of v-myc and telomerase were dramatically reduced, and the hc-NSCs differentiated into glia and neurons (mostly glutamatergic and GABAergic, as well as ...

International Nuclear Information System (INIS)

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.

UK PubMed Central (United Kingdom)

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

UK PubMed Central (United Kingdom)

The thalamic reticular nucleus (TRN) consists of GABA-containing neurons that form reciprocal synaptic connections with thalamic relay nuclei. Excitatory synaptic innervation of TRN neurons arises from...Full Text Available

UK PubMed Central (United Kingdom)

Feedback controls of estrogen in LHRH-1 neurons play a pivotal role in reproductive function. However, the mechanism of estrogen action in LHRH-1 neurons is still unclear. In the present study, the...Full Text Available

UK PubMed Central (United Kingdom)

Dopaminergic neurons of the ventral midbrain fire high frequency bursts when animals are presented with unexpected rewards, or stimuli that predict reward. To identify the afferents that can...Full Text Available

Science.gov (United States)

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, ...

International Nuclear Information System (INIS)

Cadmium is a non-essential heavy metal found abundantly in the environment. Children of women exposed to cadmium during pregnancy display lower motor and perceptual abilities. High cadmium body burden in children is also related to impaired intelligence and lowered school achievement. However, little is known about the molecular and cellular basis of developmental neurotoxicity in the sensitive early life stages of animals. In this study, we explore neurological deficits caused by cadmium during early embryonic stages in zebrafish by examining regionalization of the neural tube, pattern formation and cell fate determination, commitment of proneural genes and induction of neurogenesis. We show that cadmium-treated embryos developed a smaller head with unclear boundaries between the brain subdivisions, particularly in the mid-hindbrain region. Embryos display normal anterior to posterior regionalization; however, the commitment of neural progenitor cells was affected by cadmium. We ...

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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 ...

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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.

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

British Library Electronic Table of Contents (United Kingdom)

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...

CERN Document Server

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.

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

DEFF Research Database (Denmark)

Udgivelsesdato: 1991-null

KoreaScience (Korea)

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

British Library Electronic Table of Contents (United Kingdom)

Nerve growth factor (NGF), a survival factor for neurons enforces pain by sensitizing nociceptors. Also in the pancreas, NGF was associated with pain and it can stimulate the proliferation of pancreatic cancer cells. Hepatic stellate cells (HSC) respond to NGF with apoptosis. Transforming growth factor (TGF)-b, one of the strongest pro-fibrogenic activators of pancreatic stellate cells (PSC) induced NGF and its two receptors in an immortalized human cell line (ihPSC) and primary rat PSC (prPSC) as determined by RT-PCR, western blot, and immunofluorescence. In contrast to HSC, PSC expressed both NGF receptors, although p75NTR expression was weak in prPSC. In contrast to ihPSC TGF-b activated both Smad signaling cascades in prPSC. NGF secretion was diminished by the activin-like kinase (ALK)...

Energy Technology Data Exchange (ETDEWEB)

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 ...

International Nuclear Information System (INIS)

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 ...

International Nuclear Information System (INIS)

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.

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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.

International Nuclear Information System (INIS)

The work scope of 'Biological Research for the Radiation Protection' had contained the research about ornithine decarboxylase and its controlling proteins, thioredoxin, peroxiredoxin, S-adenosymethionine decarboxylase, and glutamate decarboxylase 67KD effect on the cell death triggered ionizing radiation and H_2O_2(toxic agents). In this study, to elucidate the role of these proteins in the ionizing radiation (or H_2O_2)-induced apoptotic cell death, we utilized sensesed (or antisensed) cells, which overexpress (or down-regulate) RNAs associated with these proteins biosynthesis, and investigated the effects of these genes on the cytotoxicity caused by ionizing radiation and H_2O_2(or paraquat). We also investigated whether genisteine(or thiamine) may enhance the cytotoxic efficacy of tumor cells caused by ionizing radiation (may enhance the preventing effect radiation or paraquat-induced damage) because such compounds are ...

Energy Technology Data Exchange (ETDEWEB)

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.).

UK PubMed Central (United Kingdom)

Although acetylated α-tubulin is known to be a marker of stable microtubules in neurons, precise factors that regulate α-tubulin acetylation are, to date, largely unknown. Therefore,...Full Text Available

UK PubMed Central (United Kingdom)

We have constructed a deletion-mutant rabies virus encoding EGFP and find it to be an excellent tool for studying detailed morphology and physiology of neurons projecting to injection sites...Full Text Available

UK PubMed Central (United Kingdom)

Sensory neurons in aging mammals undergo changes in anatomy, physiology and gene expression that correlate with reduced sensory perception. In this study we compared young and aged mice to identify...Full Text Available

UK PubMed Central (United Kingdom)

1. Previous studies have shown that electrical stimulation (ES) of the guinea-pig cochlea causes a neurally mediated increase in cochlear blood flow (CBF). It is known that the centrifugal neuronal...Full Text Available

UK PubMed Central (United Kingdom)

PurposeThe size of neuronal populations is modulated by gene variants that influence cell production and survival, in turn influencing neuronal connectivity, function,...Full Text Available

UK PubMed Central (United Kingdom)

Neuronal death is known to trigger reactive microgliosis. However, little is known regarding the manner by which microglia are activated by injured neurons and how microgliosis participates...Full Text Available

UK PubMed Central (United Kingdom)

A fundamental property of neuronal networks in Ammon’s horn is that each area is comprised of a single glutamatergic cell population and various types of GABAergic neurons. Here we describe...Full Text Available

UK PubMed Central (United Kingdom)

Phox2b-expressing neurons of the retrotrapezoid nucleus (RTN) located in the ventrolateral brainstem are sensitive to changes in PCO₂/pH, have excitatory projections...Full Text Available

UK PubMed Central (United Kingdom)

The mitogen-activated protein kinase/extracellular regulated kinase (MAPK/ERK) pathway plays a key role in mediating estrogen actions in the brain and neuronal sensitization during inflammation....Full Text Available

UK PubMed Central (United Kingdom)

New neurons are generated in the granule cell layer of the dentate gyrus (GCL) throughout adulthood. This process is modulated by many environmental and neurochemical factors. We previously...Full Text Available

International Nuclear Information System (INIS)

Radiation-induced enteritis is a well-recognized sequel of therapeutic irradiation. Therefore we examined the radioprotective properties of Punica granatum peel extract (PPE) on the oxidative damage in the ileum. Rats were exposed to a single whole-body X-ray irradiation of 800 cGy. Irradiated rats were pretreated orally with saline or PPE (50 mg/kg/day) for 10 days before irradiation and the following 10 days, while control rats received saline or PPE but no irradiation. Then plasma and ileum samples were obtained. Irradiation caused a decrease in glutathione and total antioxidant capacity, which was accompanied by increases in malondialdehyde levels, myeloperoxidase activity, collagen content of the tissue with a concomitant increase 8-hydroxy-2'-deoxyguanosine (an index of oxidative DNA damage). Similarly, pro-inflammatory cytokines (TNF-?, IL-1? and IL-6) and lactate dehydrogenase were elevated in irradiated groups as ...

Science.gov (United States)

Prairie (Microtus ochrogaster) and meadow voles (M. pennsylvanicus) are closely related species that differ in life strategy and social behaviors, and thus provide an excellent comparative model for the study of neuronal and hormonal mechanisms underlying behavior. In the present study using the elevated plus maze (EPM) test, we found that male prairie voles entered the open arms of the EPM more and remained there longer, and showed a higher level of overall locomotor activity than did male meadow voles. In addition, two weeks of social isolation induced an increase in open arm entries in prairie, but not meadow, voles. Prairie voles also had a higher level of circulating corticosterone compared to meadow voles, and the EPM test increased circulating corticosterone in prairie voles. Finally, social isolation coupled with the EPM test influenced Fos-immunoreactive expression in several brain areas, including the medial preoptic area, ...

British Library Electronic Table of Contents (United Kingdom)

Action potentials from the brain control the activity of spinal neural networks to produce, by as yet unknown mechanisms, a variety of motor behaviors. Particularly lacking are details on how identified descending neurons integrate diverse sensory inputs to generate specific locomotor patterns. We have examined the operations of the principal neurons in an intriguing midbrain nucleus, the nucleus of the medial longitudinal fasciculus (nMLF), in the larval zebrafish. The nMLF is the most rostral grouping of neurons that projects from the brain well into the spinal cord of teleost fishes, yet there is little direct physiological data available regarding its function. We report here that a distinct set of large, individually-identifiable neurons in nMLF (the MeL and MeM neurons) are activated...

International Nuclear Information System (INIS)

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

Energy Technology Data Exchange (ETDEWEB)

Greenhouse-effect induced climate change repercussions will, via the catchment areas of big rivers, eventually arrive in amplified form at the far downstream coastal zones of the world. In the coastal zone these imported problems will add to the locally exerted climate change effects, while the climate change induced sea-level rise will attack the coastal zone from the other side, both by flooding and by saline groundwater intrusion. These multiple problems will hit the coastal zone, which is already under increasing stress. The combined threats require fast and massive support for national Coastal Zone Management capabilities, which could help to limit the damage and to support planning for sustainable development. Recommendations are presented to facilitate implementation of Coastal Zone Management units in all coastal countries by the year 2000.

International Nuclear Information System (INIS)

The point at which the common final pathway for induction of cancer by chemical carcinogens and ionizing radiation has not been identified. Although common molecular targets are suggested by recent findings about the role of oncogenes, the mechanism by which the deposition of radiation energy and the formation of adducts or other DNA lesions induced by chemicals affects the changes in the relevant targets may be quite different. The damage to DNA that plays no part in the transformation events, but that influences the stability of the genome, and therefore, the probability of subsequent changes that influence tumorigenesis may be more readily induced by some agents than others. Similarly, the degree of cytotoxic effects that disrupt tissue integrity and increase the probability of expression of initiated cells may be dependent on the type of carcinogen. Also, evidence was presented that repair of the initial lesions could ...

Energy Technology Data Exchange (ETDEWEB)

We report on recent studies of the effects of 50 keV focused ion beam (FIB) exposure on MOS transistors. We demonstrate that the changes in value of transistor parameters (such as threshold voltage, V{sub t}) are essentially the same for exposure to a Ga+ ion beam at 30 and 50 keV under the same exposure conditions. We characterize the effects of FIB exposure on test transistors fabricated in both 0.5 {micro}m and 0.225 {micro}m technologies from two different vendors. We report on the effectiveness of overlying metal layers in screening MOS transistors from FIB-induced damage and examine the importance of ion dose rate and the physical dimensions of the exposed area.

International Nuclear Information System (INIS)

The post (neutron) -irradiation high-temperature tensile and creep-rupture properties, deformation and fracture characteristics of austenitic alloys, particularly solution annealed Type 316 steel, are surveyed and correlated with the damage structures developed as a function of irradiation temperature (and dose). The mechanisms proposed to explain the irradiation-induced changes in properties and behaviour are summarised. The factors responsible for the observed differences in the post-irradiation and 'in-reactor' creep-rupture properties and behaviour of an austenitic steel are discussed in terms of the helium gas and stress driven growth of small intergranular bubbles and the atom plating associated with their growth and coalescence. (author).

Energy Technology Data Exchange (ETDEWEB)

White beam Laue micro-diffraction was performed on directionally solidified, single-crystal Mo pillars in the as-grown state, after focused ion beam (FIB) milling and after pre-straining. The Laue diffraction peaks from the as-grown pillars are very sharp and show no broadening, similar to those from single-crystal Si wafers. Significant broadening and streaking of the peaks occurred after FIB milling and pre-straining, indicative of the damage these treatments induce in the nearly perfect crystal structure of the directionally solidified Mo pillars.

Science.gov (United States)

Snake envenomation employs three well integrated strategies: prey immobilization via hypotension, prey immobilization via paralysis, and prey digestion. Purines (adenosine, guanosine and inosine) evidently play a central role in the envenomation strategies of most advanced snakes. Purines constitute the perfect multifunctional toxins, participating simultaneously in all three envenomation strategies. Because they are endogenous regulatory compounds in all vertebrates, it is impossible for any prey organism to develop resistance to them. Purine generation from endogenous precursors in the prey explains the presence of many hitherto unexplained enzyme activities in snake venoms: 5'-nucleotidase, endonucleases (including ribonuclease), phosphodiesterase, ATPase, ADPase, phosphomonoesterase, and NADase. Phospholipases A(2), cytotoxins, myotoxins, and heparinase also participate in purine liberation, in addition to their better known functions. Adenosine contributes to prey immobilization ...

Energy Technology Data Exchange (ETDEWEB)

To determine if barbiturates would protect brain at high doses of radiation, survival rates in rats that received whole-brain x-irradiation during pentobarbital- or lidocaine-induced anesthesia were compared with those of control animals that received no medication and of animals anesthetized with ketamine. The animals were shielded so that respiratory and digestive tissues would not be damaged by the radiation. Survival rates in rats that received whole-brain irradiation as a single 7500-rad dose under pentobarbital- or lidocaine-induced anesthesia was increased from between from 0% and 20% to between 45% and 69% over the 40 days of observation compared with the other two groups (p less than 0.007). Ketamine anesthesia provided no protection. There were no notable differential effects upon non-neural tissues, suggesting that pentobarbital afforded protection through modulation of ambient neural activity during radiation ...

International Nuclear Information System (INIS)

Studies have linked cell phone radiation to health problems such as headaches, high blood pressure, cancer and more. There is a latency period for most diseases and it may take years and more studies before the required weight of evidence is established. But the effects are cumulative and precautions should be taken now before it is too late. The aim of the present study was to investigate if supplementation with antioxidants would protect heart and liver tissues from harmful radiation emitted by cell phone. Thirty two male albino rats were randomly divided into four equal groups: I- Control, II- Antioxidants treated group, III- 950 MHz EMR, IV- 950 MHz EMR + antioxidants. A 950 MHz EMR radiation (217-Hz pulse rate, 2-W maximum peak power, SAR Specific Absorption Rate"1.6 W/Kg) was applied to groups III and IV 60 min/day, for 30 days using an experimental exposure device. Antioxidants supplement (Vitamins A, E and C + Se) was administered to rats daily, by gavages, during the period of ...

UK PubMed Central (United Kingdom)

SUMMARYHomeostatic synaptic plasticity is a negative feedback mechanism neurons use to offset excessive excitation or inhibition by adjusting their synaptic strengths. Recent...Full Text Available

British Library Electronic Table of Contents (United Kingdom)

SummaryPrimary visual cortex recombines inputs from magnocellular (M) and parvocellular (P) streams to create functionally specialized outputs. Understanding these input-output relationships is complicated by the fact that layer 4B, which provides outputs to dorsal visual areas, contains multiple cell types. Using a modified rabies virus that expresses green fluorescent protein, we show that layer 4B neurons projecting to MT are a majority spiny stellate, whereas those projecting to V2 are overwhelmingly pyramidal. Regardless of cell type, MT-projecting neurons have larger cell bodies, more dendritic length, and are deeper within layer 4B. Furthermore, MT-projecting pyramidal neurons are located preferentially underneath cytochrome oxidase blobs, indicating that MT-projecting neurons of bo...

UK PubMed Central (United Kingdom)

The processes of neuronal outgrowth and guidance have typically been studied in classic 2D cell culture systems that do not recapitulate topographical cues present in the in vivo extracellular matrix...Full Text Available

British Library Electronic Table of Contents (United Kingdom)

Nitric oxide (NO) is a gas produced through the action of nitric oxide synthase that acts as a neurotransmitter in the central nervous system (CNS) of adult gastropod mollusks. There are no known reports of the presence of NOS-containing neurons and glial cells in young and adult Megalobulimus abbreviatus. Therefore, NADPH-d histochemistry was employed to map the nitrergic distribution in the CNS of young and adult snails in an attempt to identify any transient enzymatic activity in the developing CNS. Reaction was observed in neurons and fibers in all CNS ganglia of both age groups, but in the pedal and cerebral ganglia, positive neurons were more intense than in other ganglia, forming clusters symmetrically located in both paired ganglia. However, neuronal NADPH-d activity in the mesocer...

Science.gov (United States)

The field of stem cell research was revolutionized with the advent of induced pluripotent stem cells. By reprogramming somatic cells to pluripotent stem cells, most ethical concerns associated with the use of embryonic stem cells are overcome, such that many hopes from the stem cell field now seem a step closer to reality. Several methods and cell sources have been described to create induced pluripotent stem cells and we discuss their characteristics in terms of feasibility and efficiency. From these cells, cardiac progenitors and cardiomyocytes can be derived by several protocols and most recent advances as well as remaining limitations are being discussed. However in the short time period this technology has been around, evidence emerges that induced pluripotent stem cells may be more prone to genetic defects and maintain an epigenetic memory and thus may not be entirely the same as embryonic stem cells. Despite the lack ...

Energy Technology Data Exchange (ETDEWEB)

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.

Energy Technology Data Exchange (ETDEWEB)

Spice extracts under the form of essential oils were tested for their efficiency to increase the relative radiosensitivity of Listeria monocytogenes and Escherichia coli O157H7 in culture media. The two pathogens were treated by gamma-irradiation alone or in combination with oregano essential oil to evaluate their mechanism of action. The membrane murein composition, and the intracellular and extracellular concentration of ATP was determined. The bacterial strains were treated with two irradiation doses: 1.2 kGy to induce cell damage and 3.5 kGy to cause cell death for L. monocytogenes. A dose of 0.4 kGy to induce cell damages, 1.1 kGy to obtain viable but nonculturable (VBNC) state and 1.3 kGy to obtain a lethal dose was also applied on E. coli O157H7. Oregano essential oil was used at 0.020% and 0.025% (w/v), which is the minimum inhibitory concentration (MIC) for L. monocytogenes. For E. coli O157H7, ...

International Nuclear Information System (INIS)

Full text of publication follows: Understanding the dynamic irradiation effects on silica glasses is important for developing the diagnostic systems used in fusion and fission environments. While fundamental defects having an un-pared electron such as the E' center have been extensively studied, the neutral oxygen deficiency defects have been insufficiently clarified for lack of the detection methods. The ion induced luminescence is one of the probes that can be used to detect non-paramagnetic defects, and to observe creation and annihilation behavior dynamically. In the present study, we examined the characteristics of the ion induced luminescence such as energy, fluence flux and temperature dependence of the luminescence efficiency to analyze damage process quantitatively. Samples of SiO2 glasses were commercially available fused and synthesized silica glasses, produced by Toshiba Ceramics, Co. Ltd.. A thin films of SiO2 ...

International Nuclear Information System (INIS)

The effect of swelling of crystalline Ge irradiated at room temperature with 30 keV Ga"+ focused ion beam (FIB) was studied by means of in situ FIB imaging, atomic force microscopy (AFM) and transmission electron microscopy (TEM). The swelling occurred in the surface region of amorphous damage layer which was formed during ion irradiation. The degree of swelling reaches values up to 10 times for an implantation dose of #approx#10"1"7 ions/cm"2. Cross-secitonal TEM examination showed that the swelling is due to formation of a porous layer with a honeycomb structure. (author). 8 refs., 4 figs.

British Library Electronic Table of Contents (United Kingdom)

A better understanding of the immune processes in the pathogenesis and progression of prostate cancer (CaP) may point the way towards improved treatment modalities. The challenge is to amplify immune responses to combat tumour escape mechanisms. Infection and inflammation may have a role in prostate carcinogenesis, including the newly discovered xenotropic murine leukaemia virus (XMRV). These inflammatory states damage defence mechanisms and induce a high proliferative state favouring further mutation and impaired immune surveillance. With this knowledge we are able to explore the use of immunotherapy to rejuvenate the immune system in combating CaP. Recently Sipuleucel-T, an immunotherapeutic agent for metastatic androgen independent CaP, has resulted in improved survival and might be the...

Energy Technology Data Exchange (ETDEWEB)

The authors examined the effects of large escapements of sockeye salmon in to the Kenai River and into Red and Akalura Lakes on Kodiak Island. Estimated smolt numbers outmigrating from the Kenai River decreased from 30 million in 1989 to under 500,000 in 1992. Decreased overwintering survival of age-0 juvenile sockeye salmon rearing in Skilak and Kenai lakes is the major contributor to this decline. Preliminary examination of limnological data from Skilak and Kenai Lakes provided no obvious explanation for this major decline in winter survival of juvenile sockeye. Due to differences in diel vertical migration of zooplankton among glacial lakes on the Kenai Peninsula with varying planktivores levels, the authors hypothesize that behavioral changes of zooplankton induced by predation may be a major contributor to the juvenile sockeye decline.

International Nuclear Information System (INIS)

We have investigated the diffusion of Sb in Si in the presence of defects injected by high-energy implantation of Si ions at room temperature. MeV ion implantation increases the concentrations of vacancies, which induce transient-enhanced diffusion of Sb deposited in Si. We observed a significant enhancement of Sb diffusion. Secondary ions mass spectroscopy has been performed on the implanted samples before and after annealing. Rutherford-backscattering spectrometry has been used to characterize the high-energy implantation damage. By fitting diffusion profiles to a linear diffusive model, information about atomic scale diffusion of Sb, i.e. the generation rate of mobile state Sb and its mean migration length were extracted.

UK PubMed Central (United Kingdom)

SUMMARYWe recorded Ca²⁺ current and intracellular Ca²⁺ ([Ca²⁺]_i) in isolated adult rat dorsal root ganglion (DRG) neurons at 20 and...Full Text Available

International Nuclear Information System (INIS)

We examined the effect of the trophic protein, nerve growth factor (NGF), on cultures of fetal rat neostriatum and basal forebrain-medial septal area (BF-MS) to define its role in brain development. Treatment of cultures with NGF resulted in an increase in the specific activity of the cholinergic enzyme choline acetyltransferase (CAT) in both brain areas. CAT was immunocytochemically localized to neurons. In the BF-MS, NGF treatment elicited a marked increase in staining intensity and an apparent increase in the number of CAT-positive neurons. Moreover, treatment of BF-MS cultures with NGF increased the activity of acetylcholinesterase, suggesting that the cholinergic neuron as a whole was affected. To begin defining mechanisms of action of NGF in the BF-MS, we detected NGF receptors by two independent methods. Receptors were localized to two different cellular populations: neuron-like cells, and ...

UK PubMed Central (United Kingdom)

Intracellular recordings were made from 1022 somatic lumbar dorsal root ganglion (DRG) neurones in anaesthetized adult rats, classified from dorsal root conduction velocities (CVs) as C, Aδ...Full Text Available

UK PubMed Central (United Kingdom)

Gonadotropin–releasing hormone (GnRH) neurons are the central regulators of reproduction. GABAergic transmission plays a critical role in pubertal activation of pulsatile GnRH secretion....Full Text Available

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

International Nuclear Information System (INIS)

The gender-specific expression pattern of aromatase and 5alpha-reductases (5alpha-R) during brain development provides neurons the right amount of estradiol and DHT to induce a dimorphic organization of the structure. Polychlorinated biphenyls (PCBs) are endocrine disruptive pollutants; exposure to PCBs through placental transfer and breast-feeding may adversely affect the organizational action of sex steroid, resulting in long-term alteration of reproductive neuroendocrinology. The study was aimed at: a) evaluating the hypothalamic expression of aromatase, 5alpha-R1 and 5alpha-R2 in fetuses (GD20), infant (PN12), weaning (PN21) and young adult (PN60) male and female rats exposed to PCBs during development; b) correlating these parameters with the time of testicular descent, puberty onset, estrous cyclicity and copulatory behavior; c) evaluating possible alterations of some non reproductive behaviors (locomotion, learning and memory, ...

International Nuclear Information System (INIS)

In this paper, we report the systematic investigation on the melt characteristics of silicon during laser thermal processing (LTP) of amorphous silicon (a-Si) gates on ultrathin gate oxides. LTP is used to reduce the gate depletion effect in advanced semiconductor devices. The influence of implantation-induced damage and chemical inhomogeneities on the melt behavior of ion-implanted a-Si is studied using in situ time-resolved reflectance (TRR) measurements and ex situ secondary ion mass spectrometry. The results from TRR measurements indicate the presence of a buried melt for a-Si implanted with B"+ at a subamorphizing dose. In contrast, such a melt behavior is not observed during LTP of undoped a-Si and a-Si implanted with As"+ at an amorphizing dose. We attribute the marked difference in the melt characteristics to the competitive effects between compositional inhomogeneities and the extent of amorphization in the a-Si layer. It should be ...

Energy Technology Data Exchange (ETDEWEB)

Experiments were performed to investigate the involvement of the cell membrane in the excision DNA repair process in Escherichia coli. Two membrane-binding drugs, procaine and phenethyl alcohol (PEA), inhibited liquid-holding recovery (LBR) in u.v.-irradiated E. coli wild-type and recA strains. In uvrB and polA strains where, after u.v.-irradiation, LHR was absent the two drugs had no effect. Both drugs markedly reduced the removal of u.v.-induced thymine dimers in the DNA of wild-type cells (H/r30). Analysis by alkaline sucrose gradients revealed that PEA inhibited the incision step in excision repair. In contrast, procaine had no effect on incision but apparently inhibited the late steps in excision repair. PEA dissociated DNA from the cell membrane, whereas procaine did not. The results suggest that the two drugs PEA and procaine inhibit LHR and the excision repair process operating on u.v.-induced damage in E. coli by ...

Energy Technology Data Exchange (ETDEWEB)

For most cells there exists an optimum cooling rate. Both supraoptimal rates and suboptimal rates can be very damaging. The optimal rate varies enormously from less than or equal to 1/sup 0/C/min for mammalian preimplantation embryos to greater than or equal to 800/sup 0/C/min for the human red cell. Death at supraoptimal rates is the result of the formation of intracellular ice and its recrystallization during warming. Intracellular ice occurs when cells are cooled too rapidly to allow them to equilibrate by the osmotic withdrawal of intracellular water. The definition of too rapid depends chiefly on the size of the cell and its permeability to water. Death at suboptimal rates is a consequence of the major alterations in aqueous solutions produced by ice formation. The chief effects are a major reduction in the fraction of the solution remaining unfrozen at a given temperature and a major increase in the solute concentration of that fraction. Presumably, slow ...

International Nuclear Information System (INIS)

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

International Nuclear Information System (INIS)

An artificial neural network can be used as an intelligent controller to control non-linear, dynamic system through learning. It can easily accommodate non-linearities and time dependencies. Most common multi-layer feed-forward neural networks have drawbacks of large number of neurons and hidden layers required to deal with complex problems and require large training time. To overcome these drawbacks, a generalized neuron based non-linear controller has been developed and illustrated as a power system stabilizer. Studies on a five-machine power system show that the proposed controller can significantly improve the dynamic performance and provide good damping of the power system over a wide operating range.

British Library Electronic Table of Contents (United Kingdom)

Reduced systems such as brain slices offer a powerful approach to study the physiology of auditory neurons in great detail. However, when studying auditory nuclei in reduced systems such as brain slices, especially highly active auditory brain stem nuclei, one has to be aware that the unphysiological lack of activity in the reduced system compared to the in-vivo situation has a number of important effects on the neurons under investigation, and thus on the data that are measured. Most importantly, the lack of chronic activity in the slice preparation has important effects on the properties of short-term plasticity of the synapses. The main purpose of this article is to discuss how spontaneous activity in auditory neurons, or the lack thereof, can affect the data measured.

DEFF Research Database (Denmark)

We study the spike statistics of neurons in a network with dynamically balanced excitation and inhibition. Our model, intended to represent a generic cortical column, comprises randomly connected excitatory and inhibitory leaky integrate-and-fire neurons, driven by excitatory input from an external population. The high connectivity permits a mean field description in which synaptic currents can be treated as gaussian noise, the mean and autocorrelation function of which are calculated self-consistently from the firing statistics of single model neurons. Within this description, a wide range of Fano factors is possible. We find that the irregularity of spike trains is controlled mainly by the strength of the synapses relative to the difference between the firing threshold and the postfiring reset level of the membrane potential. For moderately strong synapses, we find spike statistics very similar to those observed in ...

UK PubMed Central (United Kingdom)

BackgroundChanges in ionic concentration have a fundamental effect on numerous physiological processes. For example, IP₃-gated thapsigargin sensitive intracellular calcium...Full Text Available

UK PubMed Central (United Kingdom)

Tuberous Sclerosis Complex (TSC) is a neurogenetic disorder caused by loss-of-function mutations in either the TSC1 or TSC2 genes and frequently results in...Full Text Available

UK PubMed Central (United Kingdom)

The functional outcome after stroke is unpredictable; it is not accurately predicted by clinical pictures upon hospital admission. The presence of apoptotic neurons in the ischemic penumbra and perihematoma...Full Text Available

UK PubMed Central (United Kingdom)

Understanding the mechanisms whereby information encoded within patterns of action potentials is deciphered by neurons is central to cognitive psychology. The multiprotein complexes formed by...Full Text Available

UK PubMed Central (United Kingdom)

Deep brain stimulation of the subthalamic nucleus (STN-DBS) is efficacious in treating the motor symptoms of Parkinson’s disease (PD). However, the impact of STN-DBS on the progression...Full Text Available

UK PubMed Central (United Kingdom)

The neuronal networks in spinal cord can produce a diverse array of motor behaviors. In aquatic vertebrates such as fishes and tadpoles, these include escape behaviors, swimming across a range...Full Text Available

UK PubMed Central (United Kingdom)

The Pde6b^rd10 (rd10) mouse has a moderate rate of photoreceptor degeneration and serves as a valuable model for human autosomal recessive retinitis pigmentosa...Full Text Available

UK PubMed Central (United Kingdom)

Previous studies in several different trigeminal nerve injury/inflammation models indicated that the hyperexcitability of primary afferent neurons contributes to the pain pathway underlying mechanical...Full Text Available

UK PubMed Central (United Kingdom)

Ionotropic P2X and metabotropic P2Y purinergic receptors are expressed in the central nervous system and participate in the synaptic process particularly associated with acetylcholine, GABA, and glutamate...Full Text Available

UK PubMed Central (United Kingdom)

Neonatal bacterial infection in rats alters the responses to a variety of subsequent challenges later in life. Here we explored the effects of neonatal bacterial infection on a subsequent drug...Full Text Available

UK PubMed Central (United Kingdom)

Spike-timing-dependent plasticity (STDP), a form of Hebbian plasticity, is inherently stabilizing. Whether and how GABAergic inhibition influences STDP is not well understood. Using a model neuron driven...Full Text Available

UK PubMed Central (United Kingdom)

Auditory fear conditioning with tone bursts followed by electric leg stimulation activates neurons not only in the auditory and somatosensory systems but also in many other regions of the brain and...Full Text Available

UK PubMed Central (United Kingdom)

BackgroundHuman immunodeficiency virus type 1 (HIV-1) infection frequently causes neurologic disease, which is the result of viral replication and activation of macrophages and microglia...Full Text Available

UK PubMed Central (United Kingdom)

1. The effects of stimulation of atrial receptors on hypothalamic neurosecretory cells were investigated in anaesthetized dogs and cats. Atrial receptors were activated by stretching the left and the...Full Text Available

UK PubMed Central (United Kingdom)

Rapid place encoding by hippocampal neurons, as reflected by place-related firing, has been intensely studied, whereas the substrates that translate hippocampal place codes into behavior have received...Full Text Available

Science.gov (United States)

... ions. MATERIALS AND METHODS Cell Culture Culture of NT2/D1 cells was carried out as described previously (18, 19). NT2 cells were plated at a density of 2. ... ...

UK PubMed Central (United Kingdom)

In mammals, adult neurogenesis has been extensively studied in the dentate gyrus of the hippocampus and subventricular zone. However, newly proliferated neurons have also been documented in...Full Text Available

UK PubMed Central (United Kingdom)

While estrogen (E2) is thought to play an important role in age-related cognitive decline, neuronal plasticity, as well as the pathogenesis of Alzheimer disease (AD), the mechanisms by which...Full Text Available

UK PubMed Central (United Kingdom)

Despite their wide use, the physiological relevance of organotypic slices remains controversial. Such cultures are prepared at 5 days postnatal. Although some local circuitry remains intact, they develop...Full Text Available

UK PubMed Central (United Kingdom)

Proprioceptive sensory signals inform the CNS of the consequences of motor acts, but effective motor planning involves internal neural systems capable of anticipating actual sensory feedback....Full Text Available

UK PubMed Central (United Kingdom)

BackgroundAntibodies against gonadotropin-releasing hormone (GnRH) and gastrointestinal dysmotility have been found after treatment with GnRH analogues. The aim of this study was...Full Text Available

UK PubMed Central (United Kingdom)

BackgroundGATA-2 is a transcription factor required for hematopoietic stem cell survival as well as for neuronal development in vertebrates. It has been shown that specific expression...Full Text Available

UK PubMed Central (United Kingdom)

The primary method for neuronal communication involves the extracellular release of small molecules that are packaged in secretory vesicles. We have developed a platform to separate, lyse, and...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Iodine-131 MIBG, a radiolabeled adrenergic neuron-blocking agent, decreased rapidly from the heart and liver of patients with adrenergic dysfunction and pheochromocytoma when compared with eight controls. However, there was no significant difference in the rate of (/sup 131/I)MIBG decrease in these organs between controls and patients in the intervals subsequent to 4 hr. These findings suggest that adrenergic neuronal uptake of (/sup 131/I)MIBG in these organs is smaller in the patients than in the controls. Measurements of time-activity relationships of radioiodinated MIBG may be useful for assessment of adrenergic function of these organs and thus of generalized disorders of adrenergic innervation.

International Nuclear Information System (INIS)

The role of the HCR system in the repair of prelethal lesions induced by UV light, #gamma# radiation and alkylating agents was studied in the Bacillus subtilis SPP1 phage, its heat sensitive mutants (N3, N73 nad ts_1) and corresponding infectious DNA. The survival of phages and their transfecting DNA after treatment with UV light is substantially higher in hcr"+ cells than in hcr cells, the differences being more striking in intact phages than in their transfecting DNA's. Repair inhibitors reduce survival in hcr"+ cells: caffeine lowers the survival of UV-irradiated phage SPP1 in exponentially growing hcr"+ cells but has no effect on its survival in competent hcr"+ cells; acriflavin and ethidium bromide decrease the survival of the UV-irradiated SPP1 phage in both exponentially growing and competent hcr"+ cells to the level of survival observed in hcr cells; moreover, ethidium bromide lowers the number of infective centres in hcr"+ cells of the UV-irradiated DNA of ...

UK PubMed Central (United Kingdom)

Candida albicans frequently causes superficial infections by invading and damaging epithelial cells, but may also cause systemic infections by...Full Text Available

Science.gov (United States)

... The revised work plan emphasized the research priorities of preharvest rodent damage to rice, the importance of postharvest food losses to rodents ...

Energy Technology Data Exchange (ETDEWEB)

Radiation Damage Calculations for the FUBR and BEATRIX Irradiations of Lithium Compunds in EBR-II and FFTF

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Short communication

International Nuclear Information System (INIS)

Transmission electron microscope (TEM) specimens are today routinely prepared using focussed ion beam (FIB) instruments. Specifically, the lift-out method has become an increasingly popular technique and involves removing thin cross-sections from site-specific locations and transferring them to a TEM grid. This lift-out process can either be performed ex situ or in situ. The latter is mainly carried out on combined dual-beam FIB and scanning electron microscope (SEM) systems whereas conventional single-beam instruments often are limited to the traditional ex situ method. It is nevertheless desirable to enhance the capabilities of existing single-beam instruments to allow for in situ lift-out preparation to be performed since this technique offers a number of advantages over the older ex situ method. A single-beam FIB instrument was therefore modified to incorporate an in situ micromanipulator fitted with a tungsten needle, which can be attached to a cut-out FIB section using ion beam ...

Energy Technology Data Exchange (ETDEWEB)

During rolling contact fatigue of the inner rings of ball bearings three stages of material response can be distinguished, in terms of the volume that is plastically deformed upon overrolling. After a first stage of material strengthening during which a decrease occurs for the volume that is deformed plastically, an effectively stationary, second stage is entered which is eventually succeeded by a third stage exhibiting a pronounced increase of the volume that is deformed plastically upon overrolling, which leads to failure. It is suggested that carbon diffusion induced by local temperature peaks occurring at the moment of overrolling is the key mechanism leading to fatigue damage. The amount of decomposed retained austenite is a useful, practical parameter to assess fatigue life. It is shown that published ideas about the role of certain components of residual stress in enhancing fatigue life are not correct and that the so-called ...

International Nuclear Information System (INIS)

Total-dose irradiation seriously damages MOS devices and their circuit performance. Threshold voltage shifts, transconductance degradation and increase in off-state leakage current are generally observed for irradiated devices. These instabilities are essentially due to positive and/or negative charge trapping in SiO_2 and interface trap generation at the SiO_2/Si interface. Radiation hardening of CMOS VLSIs is to eliminate these trapping effects, and for this purpose, special considerations for fabrication processes and layout design are necessary. In this paper, basic mechanisms for radiation-induced charge trapping and related effects on MOS devices are reviewed. Also discussed are radiation-hardening technologies from both fabrication-process and layout-design viewpoints. Using these technologies, 1 #mu#m radiation-hard CMOS gate arrays have been successfully developed. Experimental data taken for 2k-gate test chips indicate that radiation ...

International Nuclear Information System (INIS)

Ethidium bromide (EB) and ultraviolet light (UV) in combination are known to produce a synergistic induction of 'petite' mutants in yeast. Two other agents were combined with EB, 3-Carbethoxypsoralene (3 CPs) activated by 365 nm light or #gamma# rays. EB in combination with 3 CPs also resulted in an enhanced production of 'petite' mutants. After the photoaddition of 3 CPs in exponential phase cells, recovery of the 'petite' mutation during dark liquid holding was inhibited by the presence of EB producing an enhanced number of 'petite' mutants. The behavior of mitochondrial antibiotic resistance markers after individual and combined treatments with EB and 3 CPs indicates a random loss of markers after EB and a preferential loss of a certain region for the 3 CPs photoaddition. The combination of the two agents leads to an additivity of total drug marker losses rather than a synergistic loss. The combination of EB with #gamma# rays produced no enhancement in 'petite' induction. A ...

Science.gov (United States)

The goal of the present study is to elucidate the effect of lipid domain formation on activities of Naja naja atra and Bungarus multicinctus phospholipase A(2) (PLA(2)) enzymes. Sphingomyelin inhibited enzymatic activity and membrane-damaging activity of PLA(2) against egg yolk phosphatidylcholine (EYPC), while cholesterol and cholesterol sulfate abrogated the inhibitory effect of sphingomyelin. The ability of cholesterol and cholesterol sulfate to abolish the inhibitory effect of sphingomyelin was closely related to their capacity to induce domain formation in EYPC/sphingomyelin vesicles. Laurdan fluorescence measurement revealed that membrane packing of EYPC/sphingomyelin vesicles was differently affected by cholesterol and cholesterol sulfate. Unlike cholesterol, cholesterol sulfate was unable to promote domain formation in dipalmitoylphosphatidylcholine (DPPC) vesicles. Cholesterol increased but cholesterol sulfate reduced PLA(2) activity ...

Energy Technology Data Exchange (ETDEWEB)

The plastic displacements around Knoop indentations made in hard titanium/aluminum multilayered films on soft aluminum alloy substrates have been studied. Indentations were cross-sectioned and imaged using the focused-ion-beam (FIB) milling and high-resolution scanning electron microscopy (SEM), respectively. The FIB milling method has the advantage of removing material in a localized region without producing mechanical damage to the specimen. The micrographs of the cross-sectioned indentations indicate that most of the plastic deformation around the indentation is dominated by the soft aluminum substrate. There is a very small change in the multilayered film thickness around the indentation{emdash}less than 10{percent}. The plastic deformation of the thin film resembles a membrane being deflected by a localized pressure gradient across the membrane. Stress-induced voids are also observed in the multilayered film, especially in the area around ...

Energy Technology Data Exchange (ETDEWEB)

A fractographic and numerical approach is presented to analyze hydrogen-plasticity interactions in pearlitic steel and to elucidate the main hydrogen transport mechanism in this material under triaxial stress states produced by notches. Fractographic analysis showed that the microdamage produced by the hydrogen was clearly detectable by scanning electron microscopy (SEM), through a specific microscopic topography associated with hydrogen effects (tearing topography surface or TTS). Numerical computations obtained by using an elastic-plastic finite element program gave the progressive spreading of the plastic zone, closely associated with the movement of dislocations. In the majority of cases, the plastic zone (PZ) clearly exceeds the hydrogen affected region (TTS) and has no relation with it. In some tests, however, the hydrogen-induced micro-damage surpasses the only region in which there is dislocation movement, and in this case the net ...

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

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This paper overviews the general features of computer program 'HEC-5, Simulation of Flood Control and Conservation Systems', with emphasis on the capabilities of the most recent release of HEC-5, Version 7.2, dated March 1991. HEC-5 can simulate the essential features and operation goals and constraints of simple or complex systems with simulation intervals ranging from minutes to one month. Single event flood analysis and period of record conservation analysis may be accomplished with the model. Flood control analysis includes balanced system operation for downstream damage centers with consideration of forecasted local flows and hydrologic routing. In addition, induced surcharge operation based on spillway gate regulation schedules can be simulated. Hydropower analysis may include run-of-river, peaking, and pumped storage plants as well as system power operation. Water supply simulation can include reservoir and downstream ...

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Aluminum nitride has been proposed as electrically insulating coating in connection with blankets made of vanadium alloys. Irradiations were performed with an applied DC electric field of 100 kV/m, using a 104 MeV {alpha}-particle beam. The dose achieved were 0.1 dpa at 300 C, 0.05 dpa at 400 C, and 0.06 dpa at 500 C. The out-of-beam conductivity {sigma}{sub 0} decreased at all temperatures employed during early stage of irradiation. Before 0.02 dpa had been reached, {sigma}{sub 0} dropped to low values of typically (2-4) x 10{sup -11} ({Omega} m){sup -1}. Although a moderate increase can be observed during further irradiation, {sigma}{sub 0} remained below the initial value of the unirradiated specimen for all temperatures. That is, there is no significant evidence for radiation induced electrical degradation. The in-beam conductivity {sigma}, measured continuously during irradiation, also decreased by at least one order of magnitude. Relevant ...

Energy Technology Data Exchange (ETDEWEB)

Tensile specimens of the normalized and tempered fully martensitic steel DIN 1.4914 were helium implanted up to 340 appm within the temperature range 300-720/sup 0/C using a 104 MeV alpha particle beam. The high He/damage ratio of 1850 appm He/dpa allowed to determine the effect of helium on material properties. After irradiation tensile strength and ductility were investigated mainly at test temperatures equal to the irradiation temperatures. While short time irradiations with helium contents up to 100 appm have shown no visible effect on the tensile behaviour at all temperatures investigated, long time irradiations reduced the material strength at irradiation temperatures above about 440/sup 0/C. This irradiation induced softening obscured the predicted minor hardening effect of the observed He-bubbles completely and increases with irradiation time and temperature. The fracture mode of helium-implanted and control specimens is found to remain ...

Science.gov (United States)

Current antidotal regimens for organophosphorus compound (OP) poisoning consist of a combination of pretreatment with a spontaneously reactivating AChE inhibitor such as pyridostigmine bromide, and postexposure therapy with anticholinergic drugs such as atropine sulfate and oximes such as 2-PAM chloride (Gray, 1984). Although these antidotal regimens are effective in preventing lethality of animals from OP poisoning, they do not prevent postexposure incapacitation, convulsions, performance deficits, or, in many cases, permanent brain damage (Dunn and Sidell, 1989). These problems stimulated the development of enzyme bioscavengers as a pretreatment to sequester highly toxic OPs before they reach their physiological targets. Several studies over the last two decades have demonstrated that exogenously administered human serum butyrylcholinesterase (Hu BChE) can be used successfully as a safe, efficacious, and single prophylactic treatment to counteract the toxicity of ...

International Nuclear Information System (INIS)

Exposure of cells to light of less than 320 nanometers wavelengths may lead to lethal lesions and perhaps carcinogenesis. Many organisms have evolved mechanisms to repair U.V. light-induced damage. Organisms such as deep-sea bacteria are presumably never exposed to U.V. light and perhaps occasionally to visible from bioluminescence. Thus, the repair of U.V. damage in deep-sea bacterial DNA might be inefficient and repair by photoreactivation unlikely. The bacteria utilized in this investigation are temperature sensitive and barophilic. Four deep-sea isolates were chosen for this study: PE-36 from 3584 m, CNPT-3 from 5782 m, HS-34 from 5682 m, and MT-41 from 10,476 m, all are from the North Pacific ocean. The deep-sea extends from 1100 m to depths greater than 7000 m. It is a region of relatively uniform conditions. The temperature ranges from 5 to -1"0C. There is no solar light in the deep-sea. Deep-sea bacteria are ...

International Nuclear Information System (INIS)

Space particles act on semiconductor devices by creating charges (electrons, holes) in the silicon and the silicon dioxide, and by creating displacement damage. These primary phenomena alter the electrical parameters of MOS and bipolar devices (threshold voltage V_t, mobility #mu#, conductivity #sigma#, current gain #beta#). The dose rate is not important in space (a few rad (Si)/h) but as the durations of space expeditions are on average from seven to twelve years, the total dose is an aggravating factor in the behaviour of the electrical parameters and also in device operation. The total dose effect from the beginning of charge creation (ionization) to the parameter shifts is reviewed. One can note that this effect is permanent because there will almost always be charge creation in space. Another important phenomenon is called the Single Event Upset (S.E.U.) and caused by the heavy ions and the protons which come from the galactic rays. The consequence of S.E.U. ...

International Nuclear Information System (INIS)

The radiation-induced microstructural changes have been studied by cross-sectional transmission electron microscopy for single-crystal #alpha#-Al_2O_3 samples irradiated with triple ion beams (0.25 MeV H"+, 0.6 MeV He"+ and 2.4 MeV O"2"+; 'Triple (A)'), (0.33 MeV H"+, 0.45 MeV He"+ and 1.3 MeV O"+; 'Triple (B)') and three consecutive single ion beams (0.3 MeV H"+ ion followed by 0.6 MeV He"+ and then 0.8 MeV O"+ ions) at 650 C to doses in the range 0.1-8.4 dpa at the damage peak. In the specimen irradiated with Triple (A), having the same average projected range to a total peak dose of 3.7 dpa, cavities with an average diameter of 13 nm were formed between 1.2 and 1.75 #mu#m in depth causing a swelling of 0.1% at the peak, which is larger than those of the specimens irradiated with other conditions. The extent of the cavity-introduced region is some 40% smaller than observed in the damage region due to the He"+ and the O"+ ...

Energy Technology Data Exchange (ETDEWEB)

Detecting a camouflaged target in a visually noisy background depends on the ability of the observer to discriminate the target from the surrounding terrain. Visible laser irradiation at less than damage levels can act as a masking source by compromising or reducing the observer's ability to resolve differences in the visual scene. Previous research has examined this concept by investigating laser flash effects on: acuity (size discrimination); tracking (motion discrimination); visual sensitivity (color); and contrast sensitivity functions (luminance contrast). In all cases, flashes from continuous-wave (CW) sources have proven more effective visually than pulsed (Q-switched) sources, when compared on peak-energy criteria (i.e., MPE), even though Q-switched lasers induce damage at lower energy doses. Additionally, the inherent safety of ultra-short laser pulses has been questioned. Past animal research has shown ...

International Nuclear Information System (INIS)

In view of the anticipated increased use of atomic energy in industry, the possible long-term effects of chronic radiation exposure were studied in five generations of rats. Female rats (F_0) were given tritiated drinking water ("3HOH;3#mu#Ci/ml) from adolescence (60 days) until and throughout pregnancy. A separate study showed that the maximum radioactivity in the urine is reached in 30 days, and in the blood in 42 days. In the newborns, the highest specific activity was in the nucleic acid fraction, but total radioactivity was mainly due to the water (body fluids) compartment. No signs of radiation illness or increase in cataract formation in the mothers were observed. The food and water intake and body weight changes before pregnancy were normal. The course and the outcome of pregnancy were also normal. However, 60% of the newborns (F_1) exhibited hematomas, edemas, and subdural hemorrhages, which disappeared at 30 days of age. Bollod analysis of the F_1 offspring at various ages ...

International Nuclear Information System (INIS)

Olfactory tract has been demonstrated to be an important portal for inhaled solid nanoparticle transportation into the central nervous system (CNS). We have previously demonstrated that intranasally instilled Fe_2O_3 nanoparticles could transport into the CNS via olfactory pathway. In this study, we investigated the neurotoxicity and size effect of repeatedly low-dose (130 #mu#g) intranasal exposure of nano- and submicron-sized Fe_2O_3 particles (21 nm and 280 nm) to mice. The biomarkers of oxidative stress, activity of nitric oxide synthases and release of monoamine neurotransmitter in the brain were studied. Our results showed that significant oxidative stress was induced by the two sizes of Fe_2O_3 particles. The activities of GSH-Px, Cu,Zn-SOD, and cNOS significantly elevated and the total GSH and GSH/GSSG ratio significantly decreased in the olfactory bulb and hippocampus after the nano- and submicron-sized Fe_2O_3 particle treatment (p < 0.05). The ...

KoreaScience (Korea)

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International Nuclear Information System (INIS)

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.).

KoreaScience (Korea)

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KoreaScience (Korea)

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KoreaScience (Korea)

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Energy Technology Data Exchange (ETDEWEB)

Metal oxide semiconductor (MOS) integrated circuits, with the benefits of low power consumption, represent the state of the art technology for implantable medical devices. Three significant sources of radiation are classified as having the ability to damage or alter the behavior of implantable electronics; Secondary neutron cosmic radiation, alpha particle radiation from the device packaging and therapeutic doses(up to 70 G{gamma}) of high energy radiation used in radiation oncology. The effects of alpha particle radiation from the packaging may be eliminated by the use of polyimide or silicone rubber die coatings. The relatively low incidence of therapeutic radiation incident on an implantable device and the use of die coating leaves cosmic radiation induced secondary neutron single event upset (SEU) as the main pervasive ionising radiation threat to the reliability of implantable devices. A theoretical model which predicts the susceptibility ...

International Nuclear Information System (INIS)

In this work the diffusion of ion-beam-injected self-interstitials (Is) and their interaction with impurities in crystalline Si are presented. In particular, the I penetration into a molecular beam epitaxy grown Si structure was studied by means of diffusion effects induced on B spikes, analyzed by a developed simulation code. Trapping effects at sample-surface and bulk are evidenced and modeled. The B marker approach was extended to the two-dimensional (2D) I-diffusion occurring as a consequence of ion implantation through a sub-micron dimension patterned oxide mask. I-source size effects on the I penetration have been found and modeled, quantitatively describing the 2D I-diffusion. The I-substitutional carbon interactions have been also studied, showing the C ability to effectively retain Is. The I-trapping mechanism was quantitatively studied by the simulation code, showing that one I is able to deactivate about two C traps by means of I-trapping and ...

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Peroxisome proliferating agents (PPAs) are a structurally diverse group of chemicals that include environmental chemical contaminants such as certain chlorinated herbicides, solvents and plasticizers. PPAs have previously been shown to induce anti-trout laruci acid hydroxylase immunoreactive proteins in bluegill and catfish. In this investigation, induction of lauric acid hydroxylase activity and immunoreactive proteins was confirmed, and the mass spectral analysis of specific hydroxylation products was performed in order to identify possible species-specific differences in fatty acid metabolism. Male bluegill (Lepomis macrochirus) and channel catfish (Ictalurus punctatus) were administered clofibrate or ciprofibrate 48 hr prior to hepatic or trunk kidney (catfish only) microsome preparation. While no significant differences were observed in male catfish, male bluegill had significant decreases in hematocrit and plasma protein indicating hemodilution due to ...

International Nuclear Information System (INIS)

The present study was designed to assess the radioprotective effects of amifostine on ovarian follicles. Three week-old female mice with or without pretreatment of amifostine were irradiated with 6.42 Gy of #gamma# -ray. Ovaries were collected 0 and 6h after irradiation. DNA fragmentation pattern and expression of genes and activity of proteins related with apoptosis were investigated by means of RT-PCR and Western blot. Proliferation of granulosa cells was reduced and incidence rate of follicular atresia was increased in ovarian follicles in #gamma# -ray irradiated mice compared to those in control or amifostine-treated group. DNA fragmentation was increased in time-dependent manner in granulosa cells of all irradiated groups. However, no difference between amifostine pre-treated group and irradiated groups was found and the expression of p53 as tumor suppressor gene and Bax as one of pro-apoptotic Bcl-2 family was increased in irradiated mice ovaries. PARP as DNA ...

Energy Technology Data Exchange (ETDEWEB)

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.

International Nuclear Information System (INIS)

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.).

Science.gov (United States)

Treatment Induced Hypertension

British Library Electronic Table of Contents (United Kingdom)

Integrative and firing properties are important characteristics of neuronal circuits and these responses are determined in large part by the repertoire of ion channels they express, which can vary considerably between cell types. Recently, a new mode of operation of voltage dependent sodium channels has been described that generates a so-called resurgent Na^+ current. Accumulating evidence suggests resurgent Na current participates in the generation of sub-threshold inward Na^+ current causing membrane depolarization which provides the necessary drive to fire high-frequency action potentials. Recent studies indicate that resurgent Na^+ current could be a more widespread feature than previously thought.

British Library Electronic Table of Contents (United Kingdom)

Summary Metabotropic GABAB receptors play a fundamental role in modulating the excitability of neurons and circuits throughout the brain. These receptors influence synaptic transmission by inhibiting presynaptic release or activating postsynaptic potassium channels. However, their ability to directly influence different types of postsynaptic glutamate receptors remains unresolved. Here we examine GABAB receptor modulation in layer 2/3 pyramidal neurons from the mouse prefrontal cortex. We use two-photon laser-scanning microscopy to study synaptic modulation at individual dendritic spines. Using two-photon optical quantal analysis, we first demonstrate robust presynaptic modulation of multivesicular release at single synapses. Using two-photon glutamate uncaging, we then reveal that GABAB r...

CERN Document Server

The Elman artificial neural network (ANN) (feedback connection) was used for seismic data filtering. The recurrent connection that characterizes this network offers the advantage of storing values from the previous time step to be used in the current time step. The proposed structure has the advantage of training simplicity by a back-propagation algorithm (steepest descent). Several trials were addressed on synthetic (with 10% and 50% of random and Gaussian noise) and real seismic data using respectively 10 to 30 neurons and a minimum of 60 neurons in the hidden layer. Both an iteration number up to 4000 and arrest criteria were used to obtain satisfactory performances. Application of such networks on real data shows that the filtered seismic section was efficient. Adequate cross-validation test is done to ensure the performance of network on new data sets.

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The ODS superalloys MA 6000 and MA 760 were investigated with regard to their behaviour under non-isothermal fatigue stress. For this purpose, strain-controlled thermomechanical and bithermal experiments with different phase relationships between strain and temperature were carried out on the one hand; on the other hand, the deformation behaviour under thermomechanical stress was modelled on the basis of isothermal cyclic creep data. The fatigue experiments show that a diamond-shaped cycle derived from the stress pattern of a turbine blade is clearly less critical than in-phase and out-of-phase cycles. The life of the diamond-shaped cycle is determined by oxidation-induced crack initiation and propagation and can be predicted easily with a suitable damage model. Important damage parameters required by the model can be obtained by the less complicated bithermal fatigue tests. Modelling of the TMF hystereses suggests that ...

Science.gov (United States)

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 ...

UK PubMed Central (United Kingdom)

mRNP granules at adult central synapses are postulated to regulate local mRNA translation and synapse plasticity. However, they are very poorly characterized in vivo. Here, in Drosophila...Full Text Available

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This paper deals with the control of an electromechanical valves engine. The control uses neural networks in order to build a non-linear model of engine filing which depends on the driven inlets. The aim is to build this real-time model and to integrate this model to a control system which performs an iterative inversion. (J.S.)

UK PubMed Central (United Kingdom)

We have identified another Drosophila GTP-binding protein (G protein) alpha subunit, dGq alpha-3. Transcripts encoding dGq alpha-3 are derived from alternative splicing of the dGq alpha locus previously...Full Text Available

International Nuclear Information System (INIS)

Computed tomographic findings in developmental brain anomalies are more easily classified when the system used is based on embryogenesis related to morphology. Analysis of computed tomographic findings in a series of 154 patients with brain anomalies (Chiari malformation not included) revealed that specific examples of abnormalities occurring in major stages of brain development may be recognized by computed tomography. This paper deals with a group of patients with abnormalities that reflect a disturbance in neuronal migration. (orig.).

Energy Technology Data Exchange (ETDEWEB)

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 ...

UK PubMed Central (United Kingdom)

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

Energy Technology Data Exchange (ETDEWEB)

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.

International Nuclear Information System (INIS)

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.).

International Nuclear Information System (INIS)

... 1343-3563 v. 57(1) SPECIFIC NUCLEAR REACTORS AND ASSOCIATED

KoreaScience (Korea)

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Science.gov (United States)

A sandwich construction, composed of hybrid carbon-glass fiber-reinforced plastic skins and a

Energy Technology Data Exchange (ETDEWEB)

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.

International Nuclear Information System (INIS)

(Dec 1973). United Kingdom Stevenson, AC Medical Research Council, Oxford

International Nuclear Information System (INIS)

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.).

Energy Technology Data Exchange (ETDEWEB)

The biomedical and ecological interest for the microwave impact on the Earth biosphere is continuously increased since the industrial, military and communication activities strongly contribute to the electromagnetic stress of living bodies. In the next the authors present some of the main results obtained regarding the microwave exposure of various types of biological material: bacteria, fungi, young plant seedlings, dry seeds, animal tissues. The electromagnetic exposure was carried out in open space in well controlled environmental conditions by using 10.75 GHz/1 m W cm{sup -2} microwaves. Biochemical assays and cytogenetic tests have been carried out to reveal the changes induced post irradiation. The response of some pathogen bacteria, have been emphasized by means of turbidimetric measurements - the stimulatory effect being noticed at the level of the microbial population density (the stimulation of the human body microbial flora seems to be one of the side ...

Energy Technology Data Exchange (ETDEWEB)

NO abstract prepared.

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International Nuclear Information System (INIS)

Classical beam line ion implantation is limited to low energies and cannot achieve P+/N junctions requested for <45nm ITRS node. RTA (rapid thermal annealing) needs to be improved for dopants activation and damage reductions. Spike annealing process also induces a large diffusion mainly due to TED (transient enhanced diffusion). Compared to conventional beam line ion implantation limited to a minimum energy implantation of 200eV, plasma immersion ion implantation (PIII) is an emerging technique to get ultimate shallow profiles (as-implanted) due to no lower limitation of energy and high dose rate. On the another hand, laser thermal processing (LTP) allows to obtain very shallow junction with no TED, abrupt profile and activated depth control. In this paper, we show the implementation of the BF_3 PIII associated with the LTP. Ions from BF_3"+ plasma have been implanted in 200mm n-type silicon wafers with energies from 100eV to 1keV and doses ...

International Nuclear Information System (INIS)

Transient enhanced diffusion (TED) from implantation of 5keVB_1_0H_1_4 and 0.5 keV B ions has been quantified and compared for nominal boron doses of 10"1"4 and 10"1"5cm"-"2. Boron diffusivity during annealing was extracted from secondary ion mass spectroscopy depth profiles of diffused marker layers in boron doping-superlattices and the actual implanted B dose was independently measured by nuclear reaction analysis. Comparable enhancements were observed from both ions. Transmission electron microscopy analysis revealed that both boron- and decaborane-implanted samples were amorphized at a nominal 10"1"5cm"-"2B dose. A comparison with data from low energy Si implants revealed a similar dependence of diffusivity enhancement on implant dose. These findings are consistent with the understanding that TED is caused by the interstitial supersaturation resulting from a number of excess interstitials approximately equal to the number of implanted atoms which can become substitutional in the ...

International Nuclear Information System (INIS)

Nitroaromatic radiosensitizers become metabolically bound preferentially to hypoxic cells and at least 10/sup 9/ adducts/cell can be tolerated as non-toxic. EMT-6 tumor cells have been incubated in hypoxia in the presence of /sup 3/H-Misonidazole and /sup 125/I-Azomycin Riboside for various times and the amount of /sup 3/H or /sup 125/I bound/cell was determined. Cells were stored as monolayers at 25"0C for up to 96 hr to accumulate radioactive decays and transferred at various times to 37"0C for colony-forming assays. No radiation inactivation was measured in cells which had incorporated at least 10/sup 6/ /sup 3/H or 10/sup 5/ /sup 125/I atoms. Previous studies had shown that -- 1% of MISO adducts to EMT-6 cells was associated with cellular DNA. These data indicate that the radiation-induced damage produced by these quantities of bound /sup 3/H or /sup 125/I causes little or not cell inactivation. The results of current studies to measure the ...

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In this experiments, we established long-termed culture methods of bone marrow stromal cells for proliferation and differentiation of stem cells. And we selected some extracts which support maximal proliferation of stromal cells with this method. We conformed the synergic effects of herval mixture extracts for stromal cell growth. The proliferation of stromal cells was increased rather by the addition of mixture extracts than by addition of single strain extract. In the previous and cooperative experiments, we selected complex extracts which increased the number of nonadherent mononuclear cells. Different cytokine expression patterns were observed stromal cells cultured in the presence or absence of mixture extracts which support differentiation of nonadherent cells. Stimulation of macrophage cell line with herval extracts with the treatments of recombinant interferon-{gamma} resulted in increased nitric oxide synthesis in a dose-dependent manners. In addition, these extracts ...

International Nuclear Information System (INIS)

Iron is one of the main constituents of stainless steel which is used as a structural material in nuclear reactors. In fast and conceptual fusion and fusion-fission hybrid systems the primary energy range of neutron interaction lies between 1 and 20 MeV which opens up several reaction channels. The reaction cross-sections in this energy range are important for dosimetry, radiation damage, neutronics and safety studies of nuclear reactors. Keeping this in view Nuclear Data Section of the International Atomic Energy Agency has sponsored a Research Co-ordination Programme on Methods for the Calculation of Fast Neutron Nuclear Data for Structural Elements. Under this programme we propose to study (n,n'), (n,2n), (n,3n), (n,p), (n,np), (n,pn), (n,#alpha#), (n,n#alpha#), (n,#alpha#n) and (n,#gamma#) reaction cross-sections. Besides these, total, elastic and discrete level inelastic scattering cross-sections, angular distributions of neutron production cross-sections, ...