WorldWideScience

Sample records for evaluating low-level exposure

  1. Mixed low-level waste form evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Pohl, P.I.; Cheng, Wu-Ching; Wheeler, T.; Waters, R.D.

    1997-03-01

    A scoping level evaluation of polyethylene encapsulation and vitreous waste forms for safe storage of mixed low-level waste was performed. Maximum permissible radionuclide concentrations were estimated for 15 indicator radionuclides disposed of at the Hanford and Savannah River sites with respect to protection of the groundwater and inadvertent intruder pathways. Nominal performance improvements of polyethylene and glass waste forms relative to grout are reported. These improvements in maximum permissible radionuclide concentrations depend strongly on the radionuclide of concern and pathway. Recommendations for future research include improving the current understanding of the performance of polymer waste forms, particularly macroencapsulation. To provide context to these estimates, the concentrations of radionuclides in treated DOE waste should be compared with the results of this study to determine required performance.

  2. Reflections on the process of using systematic review techniques to evaluate the literature regarding the neurotoxicity of low level exposure to organophosphate pesticides.

    Science.gov (United States)

    Mackenzie Ross, Sarah; McManus, Chris; Harrison, Virginia; Mason, Oliver

    2016-01-01

    We undertook a systematic review (incorporating meta-analysis) of the literature concerning the neurotoxicity of cumulative low level occupational exposure to organophosphate pesticides, which was published online by the journal Critical Reviews in Toxicology in 2012. As far as we are aware, we were the first research team to attempt quantitative evaluation of study findings on this topic, using meta-analysis. We wish to encourage others to apply systematic review techniques in chemical risk assessment to reduce bias, increase transparency and better inform public policy. We thought it would be useful to share our experience of undertaking a systematic review in the hope of dispelling misconceptions about the complexity, time and resource issues involved along with the view that meta-analysis is meaningless when studies are not homogeneous. In this commentary paper we reflect on aspects of the process which were relatively straightforward; aspects which were more challenging; the advantages of using systematic review techniques; and the advantages and limitations of using statistical techniques such as meta-analysis in this context. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Effect of Low Level Cadmium Exposure on Superoxide Dismutase ...

    African Journals Online (AJOL)

    Purpose: To investigate the effect of low level cadmium (Cd) exposure on the activity of superoxide dismutase (SOD) in rat. Methods: Thirty-two male albino rats were divided into four groups of eight animals each. Group one received distilled water and served as control. The other three groups were exposed to 100, 200 ...

  4. Hormesis [Biological Effects of Low Level Exposures (Belle)] and Dermatology

    OpenAIRE

    Thong, Haw-Yueh; Maibach, Howard I

    2008-01-01

    Hormesis, or biological effects of low level exposures (BELLE), is characterized by nonmonotonic dose response which is biphasic, displaying opposite effects at low and high dose. Its occurrence has been documented across a broad range of biological models and diverse type of exposure. Since hormesis appears to be a relatively common phenomenon in many areas, the objective of this review is to explore its occurrence related to dermatology and its public health and risk assessment implication....

  5. Low-level prenatal lead exposure and infant sensory function.

    Science.gov (United States)

    Silver, Monica K; Li, Xiaoqing; Liu, Yuhe; Li, Ming; Mai, Xiaoqin; Kaciroti, Niko; Kileny, Paul; Tardif, Twila; Meeker, John D; Lozoff, Betsy

    2016-06-07

    Lead is a pervasive neurotoxicant that has been associated with poorer cognitive, behavioral, and motor outcomes in children. The effects of lead on sensory function have not been well characterized. The aim of this study was to assess the effects of prenatal lead exposure on infant sensory function, as measured by auditory brainstem response (ABR) and grating visual acuity (VA). Lead was measured in maternal blood in mid- and late-pregnancy (mean gestational age = 15.5 and 39.0 weeks, respectively) and umbilical cord blood in a cohort of full-term infants in rural northeastern China. ABR latencies (peaks I, III, V) were measured in newborns during unsedated sleep (n = 315). The ABR central-to-peripheral (C-P) ratio was calculated as the ratio between the III-V and I-III interpeak intervals. VA was measured in 6-week-olds using Teller Acuity Cards (n = 1019) and assigned as the narrowest grid the infant fixated on. Multivariate linear regression was used to evaluate relationships between tertiles of mid-pregnancy, late-pregnancy, or cord lead and newborn ABR or 6-week VA. Higher late-pregnancy lead levels were associated with higher ABR C-P ratios and lower VA. In covariate-adjusted analyses, mean C-P ratios were 4.6 and 3.2 % higher in infants whose mothers had lead > 3.8 μg/dL and lead = 2-3.8 μg/dL, respectively, than for infants whose mothers had lead lead > 3.8 μg/dL and lead = 2-3.8 μg/dL, respectively, compared to lead lead exposure during late-pregnancy, even at relatively low levels. Both systems start myelinating in late gestation and mature rapidly in infancy. Higher ABR C-P ratio and lower grating VA scores suggest effects of low-level lead exposure on sensory system myelination.

  6. Effects of high vs low-level radiation exposure

    Energy Technology Data Exchange (ETDEWEB)

    Bond, V.P.

    1983-01-01

    In order to appreciate adequately the various possible effects of radiation, particularly from high-level vs low-level radiation exposure (HLRE, vs LLRE), it is necessary to understand the substantial differences between (a) exposure as used in exposure-incidence curves, which are always initially linear and without threshold, and (b) dose as used in dose-response curves, which always have a threshold, above which the function is curvilinear with increasing slope. The differences are discussed first in terms of generally familiar nonradiation situations involving dose vs exposure, and then specifically in terms of exposure to radiation, vs a dose of radiation. Examples are given of relevant biomedical findings illustrating that, while dose can be used with HLRE, it is inappropriate and misleading the LLRE where exposure is the conceptually correct measure of the amount of radiation involved.

  7. Evaluation of miosis, behavior and cholinesterase inhibition from low-level, whole-body vapor exposure to soman in African green monkeys (Chlorocebus sabeus).

    Science.gov (United States)

    Genovese, Raymond F; Benton, Bernard J; Oubre, John L; Fleming, Patrick J; Jakubowski, E Michael; Mioduszewski, Robert J

    2010-10-01

    Relatively little is known about the effects of very low-level exposures to nerve agents where few signs or symptoms are present. African green monkeys (Chlorocebus sabeus) (n = 8) were exposed for 10 min, whole-body, to a single concentration of soman (0.028-0.891 mg/m³). EC₅₀ values for miosis were determined to be 0.055 mg/m³ and 0.132 mg/m³ when defined as a 50 percent reduction in pupil area and diameter, respectively. In general, performance on a serial probe recognition task remained unchanged at lower concentrations, but responding was suppressed at the largest concentration tested. Soman produced concentration-dependent inhibition of acetylcholinesterase activity and, to a lesser extent, butyrylcholinesterase activity. These results characterize threshold soman exposure concentrations that produce miosis in the absence of other overt signs of toxicity and extend previous studies indicating that miosis is a valuable early indicator for the detection of soman vapor exposure. Published 2010. This article is a US Government work and is in the public domain in the USA.

  8. Hormesis [biological effects of low level exposures (BELLE)] and dermatology.

    Science.gov (United States)

    Thong, Haw-Yueh; Maibach, Howard I

    2008-02-01

    Hormesis, or biological effects of low level exposures (BELLE), is characterized by nonmonotonic dose response which is biphasic, displaying opposite effects at low and high dose. Its occurrence has been documented across a broad range of biological models and diverse type of exposure. Since hormesis appears to be a relatively common phenomenon in many areas, the objective of this review is to explore its occurrence related to dermatology and its public health and risk assessment implication. Hormesis appears to be a common phenomenon in in-vitro skin biology. However, in vivo data are lacking and the clinical relevance of hormesis has yet to be determined. Better understanding of this phenomenon will likely lead to different strategies for risk assessment process employed in the fields of dermatologic toxicology and pharmacology. We believe that hormesis is a common phenomenon and should be given detailed consideration to its concept and its risk assessment implications, and how these may be incorporated into the experimental and regulatory processes in dermatology. The skin, with its unique characteristics, its accessibility, and the availability of non-invasive bioengineering and DNA microarray technology, will be a good candidate to extend the biology of hormesis.

  9. Human IgG response to a salivary peptide, gSG6-P1, as a new immuno-epidemiological tool for evaluating low-level exposure to Anopheles bites

    Directory of Open Access Journals (Sweden)

    Simondon François

    2009-08-01

    Full Text Available Abstract Background Human populations exposed to low malaria transmission present particular severe risks of malaria morbidity and mortality. In addition, in a context of low-level exposure to Anopheles vector, conventional entomological methods used for sampling Anopheles populations are insufficiently sensitive and probably under-estimate the real risk of malaria transmission. The evaluation of antibody (Ab responses to arthropod salivary proteins constitutes a novel tool for estimating exposure level to insect bites. In the case of malaria, a recent study has shown that human IgG responses to the gSG6-P1 peptide represented a specific biomarker of exposure to Anopheles gambiae bites. The objective of this study was to investigate if this biomarker can be used to estimate low-level exposure of individuals to Anopheles vector. Methods The IgG Ab level to gSG6-P1 was evaluated at the peak and at the end of the An. gambiae exposure season in children living in Senegalese villages, where the Anopheles density was estimated to be very low by classical entomological trapping but where malaria transmission occurred during the studied season. Results Specific IgG responses to gSG6-P1 were observed in children exposed to very low-level of Anopheles bites. In addition, a significant increase in the specific IgG Ab level was observed during the Anopheles exposure season whereas classical entomological data have reported very few or no Anopheles during the studied period. Furthermore, this biomarker may also be applicable to evaluate the heterogeneity of individual exposure. Conclusion The results strengthen the hypothesis that the evaluation of IgG responses to gSG6-P1 during the season of exposure could reflect the real human contact with anthropophilic Anopheles and suggest that this biomarker of low exposure could be used at the individual level. This promising immuno-epidemiological marker could represent a useful tool to assess the risk to very low

  10. Human IgG response to a salivary peptide, gSG6-P1, as a new immuno-epidemiological tool for evaluating low-level exposure to Anopheles bites.

    Science.gov (United States)

    Poinsignon, Anne; Cornelie, Sylvie; Ba, Fatou; Boulanger, Denis; Sow, Cheikh; Rossignol, Marie; Sokhna, Cheikh; Cisse, Badara; Simondon, François; Remoue, Franck

    2009-08-13

    Human populations exposed to low malaria transmission present particular severe risks of malaria morbidity and mortality. In addition, in a context of low-level exposure to Anopheles vector, conventional entomological methods used for sampling Anopheles populations are insufficiently sensitive and probably under-estimate the real risk of malaria transmission. The evaluation of antibody (Ab) responses to arthropod salivary proteins constitutes a novel tool for estimating exposure level to insect bites. In the case of malaria, a recent study has shown that human IgG responses to the gSG6-P1 peptide represented a specific biomarker of exposure to Anopheles gambiae bites. The objective of this study was to investigate if this biomarker can be used to estimate low-level exposure of individuals to Anopheles vector. The IgG Ab level to gSG6-P1 was evaluated at the peak and at the end of the An. gambiae exposure season in children living in Senegalese villages, where the Anopheles density was estimated to be very low by classical entomological trapping but where malaria transmission occurred during the studied season. Specific IgG responses to gSG6-P1 were observed in children exposed to very low-level of Anopheles bites. In addition, a significant increase in the specific IgG Ab level was observed during the Anopheles exposure season whereas classical entomological data have reported very few or no Anopheles during the studied period. Furthermore, this biomarker may also be applicable to evaluate the heterogeneity of individual exposure. The results strengthen the hypothesis that the evaluation of IgG responses to gSG6-P1 during the season of exposure could reflect the real human contact with anthropophilic Anopheles and suggest that this biomarker of low exposure could be used at the individual level. This promising immuno-epidemiological marker could represent a useful tool to assess the risk to very low exposure to malaria vectors as observed in seasonal, urban

  11. Extremely low-level microwaves attenuate immune imbalance induced by inhalation exposure to low-level toluene in mice.

    Science.gov (United States)

    Novoselova, Elena G; Glushkova, Olga V; Khrenov, Maxim O; Novoselova, Tatyana V; Lunin, Sergey M; Fesenko, Eugeny E

    2017-05-01

    To clarify whether extremely low-level microwaves (MW) alone or in combination with p38 inhibitor affect immune cell responses to inhalation exposure of mice to low-level toluene. The cytokine profile, heat shock proteins expression, and the activity of several signal cascades, namely, NF-κB, SAPK/JNK, IRF-3, p38 MAPK, and TLR4 were measured in spleen lymphocytes of mice treated to air-delivered toluene (0.6 mg/m 3 ) or extremely low-level microwaves (8.15-18 GHz, 1μW/cm 2 , 1 Hz swinging frequency) or combined action of these two factors. A single exposure to air-delivered low-level toluene induced activation of NF-κB, SAPK/JNK, IFR-3, p38 MAPK and TLR4 pathways. Furthermore, air toluene induced the expression of Hsp72 and enhanced IL-1, IL-6, and TNF-α in blood plasma, which is indicative of a pro-inflammatory response. Exposure to MW alone also resulted in the enhancement of the plasma cytokine values (e.g. IL-6, TNF-α, and IFN-γ) and activation of the NF-κB, MAPK p38, and especially the TLR4 pathways in splenic lymphocytes. Paradoxically, pre-exposure to MW partially recovered or normalized the lymphocyte parameters in the toluene-exposed mice, while the p38 inhibitor XI additionally increased protective activity of microwaves by down regulating MAPKs (JNK and p38), IKK, as well as expression of TLR4 and Hsp90-α. The results suggest that exposure to low-intensity MW at specific conditions may recover immune parameters in mice undergoing inhalation exposure to low-level toluene via mechanisms involving cellular signaling.

  12. Low level methylmercury exposure affects neuropsychological function in adults

    Directory of Open Access Journals (Sweden)

    Platt Illeane

    2003-06-01

    Full Text Available Abstract Background The neurotoxic effects of methylmercury (MeHg have been demonstrated in both human and animal studies. Both adult and fetal brains are susceptible to the effects of MeHg toxicity. However, the specific effects of adult exposures have been less well-documented than those of children with prenatal exposures. This is largely because few studies of MeHg exposures in adults have used sensitive neurological endpoints. The present study reports on the results of neuropsychological testing and hair mercury concentrations in adults (>17 yrs living in fishing communities of Baixada Cuiabana (Mato Grosso in the Pantanal region of Brazil. Methods A cross-sectional study was conducted in six villages on the Cuiaba River. Participants included 129 men and women older than 17 years of age. They were randomly selected in proportion to the age range and number of inhabitants in each village. Questionnaire information was collected on demographic variables, including education, occupation, and residence history. Mercury exposure was determined by analysis of hair using flameless atomic absorption spectrophotometry. The neurocognitive screening battery included tests from the Wechsler Memory Scale and the Wechsler Adult Intelligence Scale, Concentrated Attention Test of the Toulouse-Pierron Factorial Battery, the Manual Ability Subtests of the Tests of Mechanical Ability, and the Profile of Mood States. Results Mercury exposures in this population were associated with fish consumption. The hair mercury concentration in the 129 subjects ranged from 0.56 to 13.6 μg/g; the mean concentration was 4.2 ± 2.4 micrograms/g and the median was 3.7 μg/g. Hair mercury levels were associated with detectable alterations in performance on tests of fine motor speed and dexterity, and concentration. Some aspects of verbal learning and memory were also disrupted by mercury exposure. The magnitude of the effects increased with hair mercury concentration

  13. Low-level arsenic exposure via drinking water consumption and female fecundity - A preliminary investigation.

    Science.gov (United States)

    Susko, Michele L; Bloom, Michael S; Neamtiu, Iulia A; Appleton, Allison A; Surdu, Simona; Pop, Cristian; Fitzgerald, Edward F; Anastasiu, Doru; Gurzau, Eugen S

    2017-04-01

    High level arsenic exposure is associated with reproductive toxicity in experimental and observational studies; however, few data exist to assess risks at low levels. Even less data are available to evaluate the impact of low level arsenic exposure on human fecundity. Our aim in this pilot study was a preliminary evaluation of associations between low level drinking water arsenic contamination and female fecundity. This retrospective study was conducted among women previously recruited to a hospital-based case-control study of spontaneous pregnancy loss in Timiṣ County, Romania. Women (n=94) with planned pregnancies of 5-20 weeks gestation completed a comprehensive physician-administered study questionnaire and reported the number of menstrual cycles attempting to conceive as the time to pregnancy (TTP). Drinking water samples were collected from residential drinking water sources and we determined arsenic levels using hydride generation-atomic absorption spectrometry (HG-AAS). Multivariable Cox-proportional hazards regression with Efron approximation was employed to evaluate TTP as a function of drinking water arsenic concentrations among planned pregnancies, adjusted for covariates. There was no main effect for drinking water arsenic exposure, yet the conditional probability for pregnancy was modestly lower among arsenic exposed women with longer TTPs, relative to women with shorter TTPs, and relative to unexposed women. For example, 1µg/L average drinking water arsenic conferred 5%, 8%, and 10% lower likelihoods for pregnancy in the 6th, 9th, and 12th cycles, respectively (P=0.01). While preliminary, our results suggest that low level arsenic contamination in residential drinking water sources may further impair fecundity among women with longer waiting times; however, this hypothesis requires confirmation by a future, more definitive study. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. The effects of repeated low-level blast exposure on hearing in marines.

    Science.gov (United States)

    Kubli, Lina R; Pinto, Robin L; Burrows, Holly L; Littlefield, Philip D; Brungart, Douglas S

    2017-01-01

    The study evaluates a group of Military Service Members specialized in blast explosive training called "Breachers" who are routinely exposed to multiple low-level blasts while teaching breaching at the U.S. Marine Corps in Quantico Virginia. The objective of this study was to determine if there are any acute or long-term auditory changes due to repeated low-level blast exposures used in training. The performance of the instructor group "Breachers" was compared to a control group, "Engineers". A total of 11 Breachers and four engineers were evaluated in the study. The participants received comprehensive auditory tests, including pure-tone testing, speech-in-noise (SIN) measures, and central auditory behavioral and objective tests using early and late (P300) auditory evoked potentials over a period of 17 months. They also received shorter assessments immediately following the blast-exposure onsite at Quantico. No acute or longitudinal effects were identified. However, there were some interesting baseline effects found in both groups. Contrary to the expected, the onsite hearing thresholds and distortion product otoacoustic emissions were slightly better at a few frequencies immediately after blast-exposure than measurements obtained with the same equipment weeks to months after each blast-exposure. To date, the current study is the most comprehensive study that evaluates the long-term effects of blast-exposure on hearing. Despite extensive testing to assess changes, the findings of this study suggest that the levels of current exposures used in this military training environment do not seem to have an obvious deleterious effect on hearing.

  15. The effects of repeated low-level blast exposure on hearing in marines

    Directory of Open Access Journals (Sweden)

    Lina R Kubli

    2017-01-01

    Full Text Available Background: The study evaluates a group of Military Service Members specialized in blast explosive training called “Breachers” who are routinely exposed to multiple low-level blasts while teaching breaching at the U.S. Marine Corps in Quantico Virginia. The objective of this study was to determine if there are any acute or long-term auditory changes due to repeated low-level blast exposures used in training. The performance of the instructor group “Breachers” was compared to a control group, “Engineers”. Methods: A total of 11 Breachers and four engineers were evaluated in the study. The participants received comprehensive auditory tests, including pure-tone testing, speech-in-noise (SIN measures, and central auditory behavioral and objective tests using early and late (P300 auditory evoked potentials over a period of 17 months. They also received shorter assessments immediately following the blast-exposure onsite at Quantico. Results: No acute or longitudinal effects were identified. However, there were some interesting baseline effects found in both groups. Contrary to the expected, the onsite hearing thresholds and distortion product otoacoustic emissions were slightly better at a few frequencies immediately after blast-exposure than measurements obtained with the same equipment weeks to months after each blast-exposure. Conclusions: To date, the current study is the most comprehensive study that evaluates the long-term effects of blast-exposure on hearing. Despite extensive testing to assess changes, the findings of this study suggest that the levels of current exposures used in this military training environment do not seem to have an obvious deleterious effect on hearing.

  16. A preliminary evaluation of alternatives for treatment of INEL Low-Level Waste and low-level mixed waste

    Energy Technology Data Exchange (ETDEWEB)

    Smith, T.H.; Roesener, W.S.; Jorgensen-Waters, M.J.; Edinborough, C.R.

    1992-06-01

    The Mixed and Low-Level Waste Treatment Facility (MLLWTF) project was established in 1991 by the US Department of Energy Idaho Field Office to provide treatment capabilities for Idaho National Engineering Laboratory (INEL) low-level mixed waste and low-level waste. This report identifies and evaluates the alternatives for treating that waste. Twelve treatment alternatives, ranging from ``no-action`` to constructing and operating the MLLWTF, are identified and evaluated. Evaluations include facility performance, environmental, safety, institutional, schedule, and rough order-of-magnitude cost comparisons. The performance of each alternative is evaluated against lists of ``musts`` and ``wants.`` Also included is a discussion of other key considerations for decision making. Analysis of results indicated further study is necessary to obtain the best estimate of future waste volumes and characteristics from the expanded INEL Decontamination and Decommissioning Program. It is also recommended that conceptual design begin as scheduled on the MLLWTF, maximum treatment alternative while re-evaluating the waste volume projections.

  17. Low level exposure to sulfur mustard: Development of an SOP for analysis of albumin adducts

    NARCIS (Netherlands)

    Noort, D.; Fidder, A.; Kant, S. de; Hulst, A.G.

    2004-01-01

    The need for retrospective detection procedures for exposure to low levels of chemical warfare agents has been urgently illustrated by the conflicts in the Gulf Area. Furthermore, in the case of a terrorist attack with CWA, rapid and reliable diagnosis of the exposure is essential. The present

  18. Respiratory health effects of exposure to low levels of airborne endotoxin - a systematic review.

    Science.gov (United States)

    Farokhi, Azadèh; Heederik, Dick; Smit, Lidwien A M

    2018-02-08

    Elevated endotoxin levels have been measured in ambient air around livestock farms, which is a cause of concern for neighbouring residents. There is clear evidence that occupational exposure to high concentrations of airborne endotoxin causes respiratory inflammation, respiratory symptoms and lung function decline. However, health effects of exposure to low levels of endotoxin are less well described. The aim of this systematic review is to summarize published associations between exposure to relatively low levels of airborne endotoxin and respiratory health endpoints. Studies investigating respiratory effects of measured or modelled exposure to low levels of airborne endotoxin (average respiratory symptoms and lung function. However, considerable heterogeneity existed in the outcomes of the included studies and no overall estimate could be provided by meta-analysis to quantify the possible relationship. Instead, a best evidence synthesis was performed among studies examining the exposure-response relationship between endotoxin and respiratory outcomes. Significant exposure-response relationships between endotoxin and symptoms and FEV1 were shown in several studies, with no conflicting findings in the studies included in the best evidence synthesis. Significantly different effects of endotoxin exposure were also seen in vulnerable subgroups (atopics and patients with broncho-obstructive disease) and smokers. Respiratory health effects of exposure to low levels of airborne endotoxin (respiratory health effects, especially in vulnerable subgroups of the population.

  19. Current practices for maintaining occupational exposures ALARA at low-level waste disposal sites

    Energy Technology Data Exchange (ETDEWEB)

    Hadlock, D.E.; Herrington, W.N.; Hooker, C.D.; Murphy, D.W.; Gilchrist, R.L.

    1983-12-01

    The United States Nuclear Regulatory Commission contracted with Pacific Northwest Laboratory (PNL) to provide technical assistance in establishing operational guidelines, with respect to radiation control programs and methods of minimizing occupational radiation exposure, at Low-Level Waste (LLW) disposal sites. The PNL, through site visits, evaluated operations at LLW disposal sites to determine the adequacy of current practices in maintaining occupational exposures as low as is reasonably achievable (ALARA). The data sought included the specifics of: ALARA programs, training programs, external exposure control, internal exposure control, respiratory protection, surveillance, radioactive waste management, facilities and equipment, and external dose analysis. The results of the study indicated the following: The Radiation Protection and ALARA programs at the three commercial LLW disposal sites were observed to be adequate in scope and content compared to similar programs at other types of nuclear facilities. However, it should be noted that there were many areas that could be improved upon to help ensure the health and safety of occupationally exposed individuals.

  20. Assessing risks from occupational exposure to low-level radiation: The statistician's role

    Energy Technology Data Exchange (ETDEWEB)

    Gilbert, E.S.

    1989-06-01

    Currently, several epidemiological studies of workers who have been exposed occupationally to radiation are being conducted. These include workers in the United States, Great Britain, and Canada, involved in the production of both defense materials and nuclear power. A major reason for conducting these studies is to evaluate possible adverse health effects that may have resulted because of the radiation exposure received. The general subject of health effects resulting from low levels of radiation, including these worker studies, has attracted the attention of various news media, and has been the subject of considerable controversy. These studies provide a good illustration of certain other aspects of the statistician's role; namely, communication and adequate subject matter knowledge. A competent technical job is not sufficient if these other aspects are not fulfilled.

  1. Low-level inorganic arsenic exposure and neuropsychological functioning in American Indian elders.

    Science.gov (United States)

    Carroll, Clint R; Noonan, Carolyn; Garroutte, Eva M; Navas-Acien, Ana; Verney, Steven P; Buchwald, Dedra

    2017-07-01

    Inorganic arsenic at high and prolonged doses is highly neurotoxic. Few studies have evaluated whether long-term, low-level arsenic exposure is associated with neuropsychological functioning in adults. To investigate the association between long-term, low-level inorganic arsenic exposure and neuropsychological functioning among American Indians aged 64-95. We assessed 928 participants in the Strong Heart Study by using data on arsenic species in urine samples collected at baseline (1989-1991) and results of standardized tests of global cognition, executive functioning, verbal learning and memory, fine motor functioning, and speed of mental processing administered during comprehensive follow-up evaluations in 2009-2013. We calculated the difference in neuropsychological functioning for a 10% increase in urinary arsenic with adjustment for sex, age, education, and study site. The sum of inorganic and methylated arsenic species (∑As) in urine was associated with limited fine motor functioning and processing speed. A 10% increase in ∑As was associated with a .10 (95% CI -.20, -.01) decrease on the Finger Tapping Test for the dominant hand and a .13 decrease (95% CI -.21, -.04) for the non-dominant hand. Similarly, a 10% increase in ∑As was associated with a .15 (95% CI -.29, .00) decrease on the Wechsler Adult Intelligence Scale-Fourth Edition Coding Subtest. ∑As was not associated with other neuropsychological functions. Findings indicate an adverse association between increased urinary arsenic fine motor functioning and processing speed, but not with other neuropsychological functioning, among elderly American Indians. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Low-level Mercury Exposure and Risk of Asthma in School-age Children.

    Science.gov (United States)

    Kim, Kyoung-Nam; Bae, Sanghyuk; Park, Hye Yin; Kwon, Ho-Jang; Hong, Yun-Chul

    2015-09-01

    Mercury (Hg) has been reported to have adverse effects on the immune system. However, the association between Hg exposure and asthma remains unclear. We hypothesized that blood Hg concentrations are associated with asthma and immune system blood profile changes in school-age children. Between 2005 and 2010, we evaluated 4,350 Korean children at 7-8 years of age with no previous asthma diagnosis. Follow-up surveys were conducted twice, each 2 years apart, until 11-12 years of age. For every survey, we evaluated asthma through a questionnaire and blood profile. We analyzed the association of Hg concentration with asthma by logistic and Cox regression models and the association with blood profile by generalized additive and linear mixed models. Blood Hg concentrations at 7-8 years of age were associated with an increased risk of asthma (odds ratio [OR] = 1.3; 95% confidence interval [CI] = 1.0, 1.6) at ages up to 11-12 years (n = 191). Hg concentration was also associated with wheezing (OR = 1.2; 95% CI = 1.0, 1.3), asthma medication use (OR = 1.4; 95% CI = 0.97, 2.0), and airway hyperresponsiveness (OR = 1.2; 95% CI = 1.0, 1.3). Further adjustment for fish consumption did not change the results appreciably. Low-level Hg exposure was associated with asthma and blood profile changes in school-age children.

  3. 78 FR 59729 - Final Comparative Environmental Evaluation of Alternatives for Handling Low-Level Radioactive...

    Science.gov (United States)

    2013-09-27

    ... off-normal conditions, environmental justice, geology and minerals, land use, socioeconomics, and... COMMISSION Final Comparative Environmental Evaluation of Alternatives for Handling Low-Level Radioactive... the Final Comparative Environmental Evaluation of Alternatives for Handling Low-Level Radioactive...

  4. HELLE: Health Effects of Low Level Exposures/ Gezondheidseffecten van lage blootstellingniveaus [International workshop: Influence of low level exposures to chemicals and radiation on human and ecological health

    Energy Technology Data Exchange (ETDEWEB)

    Schoten, Eert

    1998-11-26

    The Health Council is closely involved in establishing the scientific foundation of exposure limits for substances and radiation in order to protect public health. Through the years, the Council has contributed to the formulation of principles and procedures, both for carcinogenic and for noncarcinogenic agents. As a rule, the discussion with regard to the derivation of health-based recommended exposure limits centers around the appropriateness of extrapolation methods (What can be inferred from data on high exposure levels and on experimental animals?). Generally speaking, there is a lack of direct information on the health effects of low levels of exposure. Effects at these levels cannot usually be detected by means of traditional animal experiments or epidemiological research. The capacity of these analytical instruments to distinguish between ''signal'' and ''noise'' is inadequate in most cases. Annex B of this report contains a brief outline of the difficulties and the established methods for tackling this problem. In spite of this, the hope exists that the posited weak signals, if they are indeed present, can be detected by other means. The search will have to take place on a deeper level. In other words, effort must be made to discover what occurs at underlying levels of biological organization when organisms are exposed to low doses of radiation or substances. Molecular and cell biology provide various methods and techniques which give an insight into the processes within the cell. This results in an increase in the knowledge about the molecular and cellular effects of exposure to agents, or stated differently, the working mechanisms which form the basis of the health effects. Last year, the Health Council considered that the time was ripe to take stock of the state of knowledge in this field. To this end, an international working conference was held from 19 to 21 October 1997, entitled ''Health Effects of

  5. 77 FR 58416 - Comparative Environmental Evaluation of Alternatives for Handling Low-Level Radioactive Waste...

    Science.gov (United States)

    2012-09-20

    ... COMMISSION Comparative Environmental Evaluation of Alternatives for Handling Low-Level Radioactive Waste... Environmental Evaluation of Alternatives for Handling Low-Level Radioactive Waste Spent Ion Exchange Resins from... Comparative Environmental Evaluation of Alternatives for Handling Low-Level Radioactive Waste Spent Ion...

  6. Early life low-level cadmium exposure is positively associated with increased oxidative stress

    Energy Technology Data Exchange (ETDEWEB)

    Kippler, Maria [Institute of Environmental Medicine, Karolinska Institutet, Box 210, SE-171 77 Stockholm (Sweden); Bakhtiar Hossain, Mohammad [International Centre for Diarrhoeal Disease Research, Bangladesh (ICDDR,B), Dhaka 1212 (Bangladesh); Department of Laboratory Medicine, Section of Occupational and Environmental Medicine, Lund University, Lund (Sweden); Lindh, Christian [International Centre for Diarrhoeal Disease Research, Bangladesh (ICDDR,B), Dhaka 1212 (Bangladesh); Moore, Sophie E. [MRC Keneba, MRC Laboratories (Gambia); Kabir, Iqbal [Department of Laboratory Medicine, Section of Occupational and Environmental Medicine, Lund University, Lund (Sweden); Vahter, Marie [Institute of Environmental Medicine, Karolinska Institutet, Box 210, SE-171 77 Stockholm (Sweden); Broberg, Karin, E-mail: karin.broberg_palmgren@med.lu.se [International Centre for Diarrhoeal Disease Research, Bangladesh (ICDDR,B), Dhaka 1212 (Bangladesh)

    2012-01-15

    Environmental exposure to cadmium (Cd) is known to induce oxidative stress, a state of imbalance between the production of reactive oxygen species (ROS) and the ability to detoxify them, in adults. However, data are lacking on potential effects in early-life. We evaluated urinary concentrations of 8-oxo-7,8-dihydro-2 Prime -deoxyguanosine (8-oxodG), a recognized marker of oxidative DNA damage, in relation to Cd exposure in 96 predominantly breast-fed infants (11-17 weeks of age) in rural Bangladesh. Urinary 8-oxodG was measured using liquid chromatography tandem mass spectrometry and Cd in urine and breast milk by inductively coupled plasma mass spectrometry. Median concentration of 8-oxodG was 3.9 nmol/L, urinary Cd 0.30 {mu}g/L, and breast-milk Cd 0.13 {mu}g/L. In linear regression analyses, urinary 8-oxodG was positively associated with Cd in both urine (p=0.00067) and breast milk (p=0.0021), and negatively associated with body weight (kg; p=0.0041). Adjustment for age, body weight, socio-economic status, urinary arsenic, as well as magnesium, calcium, and copper in breast milk did not change the association between Cd exposure and urinary 8-oxodG. These findings suggest that early-life low-level exposure to Cd via breast milk induces oxidative stress. Further studies are warranted to elucidate whether this oxidative stress is associated with impaired child health and development.

  7. Low-level arsenic exposure from drinking water is associated with prostate cancer in Iowa.

    Science.gov (United States)

    Roh, Taehyun; Lynch, Charles F; Weyer, Peter; Wang, Kai; Kelly, Kevin M; Ludewig, Gabriele

    2017-11-01

    study shows a significant dose-dependent association between low-level arsenic exposure and prostate cancer, and if this result is replicated in future individual-level studies, may suggest that 10 ppb is not protective for human health. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Olfactory recognition memory is disrupted in young mice with chronic low-level lead exposure.

    Science.gov (United States)

    Flores-Montoya, Mayra Gisel; Alvarez, Juan Manuel; Sobin, Christina

    2015-07-02

    Chronic developmental lead exposure yielding very low blood lead burden is an unresolved child public health problem. Few studies have attempted to model neurobehavioral changes in young animals following very low level exposure, and studies are needed to identify tests that are sensitive to the neurobehavioral changes that may occur. Mechanisms of action are not yet known however results have suggested that hippocampus/dentate gyrus may be uniquely vulnerable to early chronic low-level lead exposure. This study examined the sensitivity of a novel odor recognition task to differences in pre-adolescent C57BL/6J mice chronically exposed from birth to PND 28, to 0 ppm (control), 30 ppm (low-dose), or 330 ppm (higher-dose) lead acetate (N=33). Blood lead levels (BLLs) determined by ICP-MS ranged from 0.02 to 20.31 μg/dL. Generalized linear mixed model analyses with litter as a random effect showed a significant interaction of BLL×sex. As BLLs increased olfactory recognition memory decreased in males. Among females, non-linear effects were observed at lower but not higher levels of lead exposure. The novel odor detection task is sensitive to effects associated with early chronic low-level lead exposure in young C57BL/6J mice. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  9. Effects of low-level blast exposure on the nervous system: Is there really a controversy?

    Directory of Open Access Journals (Sweden)

    Gregory A Elder

    2014-12-01

    Full Text Available High-pressure blast waves can cause extensive CNS injury in humans. However, in combat settings such as Iraq and Afghanistan, lower level exposures associated with mild TBI (mTBI or subclinical exposure have been much more common. Yet controversy exists concerning what traits can be attributed to low-level blast, in large part due to the difficulty of distinguishing blast-related mTBI from post-traumatic stress disorder (PTSD. We describe how TBI is defined in humans and the problems posed in using current definitions to recognize blast-related mTBI. We next consider the problem of applying definitions of human mTBI to animal models, in particular that TBI severity in humans is defined in relation to alteration of consciousness at the time of injury, which typically cannot be assessed in animals. However, based on outcome assessments a condition of low-level blast exposure can be defined in animals that likely approximates human mTBI or subclinical exposure. We review blast injury modeling in animals noting that inconsistencies in experimental approach have contributed to uncertainty over the effects of low-level blast. Yet animal studies show that low-level blast pressure waves are transmitted to the brain. In brain low-level blast exposures cause behavioral, biochemical, pathological and physiological effects on the nervous system including the induction of PTSD-related behavioral traits in the absence of a psychological stressor. We review the relationship of blast exposure to chronic neurodegenerative diseases noting the paradoxical lowering of Abeta by blast, which along with other observations suggest that blast-related TBI is pathophysiologically distinct from non-blast TBI. Human neuroimaging studies show that blast-related mTBI is associated with a variety of chronic effects that are unlikely to be explained by co-morbid PTSD. We conclude that abundant evidence supports low-level blast as having long-term effects on the nervous system.

  10. Perspectives on repeated low-level blast and the measurement of neurotrauma in humans as an occupational exposure risk

    Science.gov (United States)

    Carr, W.; Dell, K. C.; Yanagi, M. A.; Hassan, D. M.; LoPresti, M. L.

    2017-11-01

    A pressing question in military medical research is the nature and degree of effects on the human brain from occupational repeated exposure to low-level explosive blast, but reliable and effective means to objectively measure such effects remain elusive. In survey results, headache, difficulty sleeping, irritability, cognitive impairment, and a variety of other symptoms consistent with post-concussive syndrome have been reported by those exposed to blast and there was positive correlation between degree of blast exposure and degree of symptomology, but an important goal is to obtain more objective evidence of an effect than self-report alone. This review reflects recent efforts to measure and evaluate such hypothesized effects and current recommendations for ongoing study. Optimal measures are likely those with sensitivity and specificity to systemic effects in mild neurotrauma, that have minimal to no volitional component, and that can be sampled relatively quickly with minimal intrusion in prospective, observational field studies during routine training with explosives. An understanding of an association between parameters of exposure to repeated low-level blast and negative neurologic effects would support the evaluation of clinical implications and development of protective equipment and surveillance protocols where warranted. At present, low-level blast exposure surveillance measurements do not exist as a systematic record for any professional community.

  11. Perspectives on repeated low-level blast and the measurement of neurotrauma in humans as an occupational exposure risk

    Science.gov (United States)

    Carr, W.; Dell, K. C.; Yanagi, M. A.; Hassan, D. M.; LoPresti, M. L.

    2017-09-01

    A pressing question in military medical research is the nature and degree of effects on the human brain from occupational repeated exposure to low-level explosive blast, but reliable and effective means to objectively measure such effects remain elusive. In survey results, headache, difficulty sleeping, irritability, cognitive impairment, and a variety of other symptoms consistent with post-concussive syndrome have been reported by those exposed to blast and there was positive correlation between degree of blast exposure and degree of symptomology, but an important goal is to obtain more objective evidence of an effect than self-report alone. This review reflects recent efforts to measure and evaluate such hypothesized effects and current recommendations for ongoing study. Optimal measures are likely those with sensitivity and specificity to systemic effects in mild neurotrauma, that have minimal to no volitional component, and that can be sampled relatively quickly with minimal intrusion in prospective, observational field studies during routine training with explosives. An understanding of an association between parameters of exposure to repeated low-level blast and negative neurologic effects would support the evaluation of clinical implications and development of protective equipment and surveillance protocols where warranted. At present, low-level blast exposure surveillance measurements do not exist as a systematic record for any professional community.

  12. [Study on relationships between biomarkers in workers with low-level occupational lead exposure].

    Science.gov (United States)

    Yang, Hong; Zhang, Hengdong; Zhou, Qianqian; Gong, Wei; Zhu, Baoli; Li, Wenchao; Zhou, Yang

    2015-06-01

    To investigate the lead exposure, its effects, and the relationships between biomarkers of susceptibility in the workers with low-level occupational lead exposure, and to explore its sensitivity and practical value to evaluate the health hazard. The concentrations of lead fume and lead dust in workplaces of a lead acid storage battery enterprise in Jiangsu Province, China, were measured by occupational health monitoring method. The blood samples of 233 workers with occupational lead exposure and 76 non-occupational lead exposure were collected to measure the blood lead (Pb-B) level using graphite furnace atomic absorption spectrometry (GFAAS), the zinc Protoporphyrin (ZPP) level with blood fluorescence assay, and the delta-aminolevulinic acid dehydratase (ALAD) concentration by a spectrophotometer, and to determine the gene polymorphism of ALAD with TaqMan real-time polymerase chain reaction. At the same time, their urine samples were collected to measure urine lead (Pb-U) concentration with GFAAS and delta-aminolevulinic acid (ALA-U) concentration with a spectrophotometer. The correlations between the above indices were analyzed by multiple linear regression method. The concentration of lead fume in 18 testing sites and the concentration of lead dust in 30 testing sites were 0.002-0.019 mg/m3 and 0.004-0.013 mg/m3, respectively. Pb-B level was positively correlated with Pb-U concentration (r=0.62, Plead exposure. Among 233 workers, 218 (93.6%) had ≤70 µg/L Pb-U, and 15 (6.9%) had ≥400≥g/L Pb-B. Pb-B level was not correlated with ZPP level as Pb-B level was 0.05). And in 233 workers with occupational lead exposure, there were no significant differences in Pb-B level, ZPP level, and ALAD activity between the workers with ALAD1-2 genotype and the workers with ALAD1-1 genotype (P>0.05). In 76 workers with non-occupational lead exposure, there was no significant difference in Pb-B level between the workers with ALAD1-2 genotype and the workers with ALAD1

  13. A preliminary assessment of low level arsenic exposure and diabetes mellitus in Cyprus

    Directory of Open Access Journals (Sweden)

    Makris Konstantinos C

    2012-07-01

    Full Text Available Abstract Background A preliminary study was undertaken in a community of Cyprus where low-level arsenic (As concentrations were recently detected in the groundwater that was chronically used to satisfy potable needs of the community. The main objective of the study was to assess the degree of association between orally-ingested As and self-reported type-2 diabetes mellitus (DM in 317 adult (≥18 years old volunteers. Methods Cumulative lifetime As exposure (CLAEX (mg As was calculated using the median As concentrations in water, individual reported daily water consumption rates, and lifetime exposure duration. Logistic regression models were used to model the probability of self-reported DM and calculate odds ratios (OR in univariate and multivariate models. Results Significantly higher (p  0.02 CLAEX values were reported for the diabetics (median = 999 mg As versus non-diabetics (median = 573 mg As, suggesting that As exposure could perhaps be related to the prevalence of DM in the study area, which was 6.6%. The OR for DM, comparing participants in the 80th versus the 20th percentiles of low-level As CLAEX index values, was 5.0 (1.03, 24.17, but after adjusting for age, sex, smoking, education, and fish consumption, the As exposure effect on DM was not significant. Conclusions Further research is needed to improve As exposure assessment for the entire Cypriot population while assessing the exact relationship between low-level As exposure and DM.

  14. Development of a multimedia radionuclide exposure model for low-level waste management

    Energy Technology Data Exchange (ETDEWEB)

    Onishi, Y.; Whelan, G.; Skaggs, R.L.

    1982-03-01

    A method is being developed for assessing exposures of the air, water, and plants to low-level waste (LLW) as a part of an overall development effort of a LLW site evaluation methodology. The assessment methodology will predict LLW exposure levels in the environment by simulating dominant mechanisms of LLW migration and fate. The methodology consists of a series of physics-based models with proven histories of success; the models interact with each other to simulate LLW transport in the ecosystem. A scaled-down version of the methodology was developed first by combining the terrestrial ecological model, BIOTRAN; the overland transport model, ARM; the instream hydrodynamic model, DKWAV; and the instream sediment-contaminant transport model, TODAM (a one-dimensional version of SERATRA). The methodology was used to simulate the migration of /sup 239/Pu from a shallow-land disposal site (known as Area C) located near the head of South Mortandad Canyon on the LANL site in New Mexico. The scenario assumed that /sup 239/Pu would be deposited on the land surface through the natural processes of plant growth, LLW uptake, dryfall, and litter decomposition. Runoff events would then transport /sup 239/Pu to and in the canyon. The model provided sets of simulated LLW levels in soil, water and terrestrial plants in the region surrounding the site under a specified land-use and a waste management option. Over a 100-yr simulation period, only an extremely small quantity (6 x 10/sup -9/ times the original concentration) of buried /sup 239/Pu was taken up by plants and deposited on the land surface. Only a small fraction (approximately 1%) of that contamination was further removed by soil erosion from the site and carried to the canyon, where it remained. Hence, the study reveals that the environment around Area C has integrity high enough to curtail LLW migration under recreational land use.

  15. Short-term effects of subchronic low-level hydrogen sulfide exposure on oil field workers.

    Science.gov (United States)

    Mousa, Haider Abdul-Lateef

    2015-01-01

    To investigate the short-term effects of low-level hydrogen sulfide (H2S) exposure on oil field workers. Observational study included 34 patients who work at an oil field. All patients were males with age range of 22-60 years (mean 37 years). The data were collected by systematic questionnaire about symptoms. The inclusion criteria of patients were symptoms related to inhalation of H2S gas in the oil field. The complaints should be frequent and relapsed after each gas exposure and disappeared when there was no gas exposure. Exclusion criteria were the symptoms which experienced with or without H2S exposure. The presence of H2S gas was confirmed by valid gas detector devices. The most frequent presenting symptom was nasal bleeding. It was revealed in 18 patients (52.9%). This followed by pharyngeal bleeding, gum bleeding, and bloody saliva (mouth bleeding) which were encountered in five cases for each complaint (14.7%). Other less frequent presenting symptoms were tongue bleeding, bloody sputum, headache, abdominal colic, pharyngeal soreness, fatigue, and sleepiness. Nasal mucosa was the most vulnerable part to H2S effect. Inhalation of H2S produced upper respiratory tract epithelial damage that led to bleeding from nose, pharynx, gum, tongue, trachea, and bronchi. There were no complaints of asthmatic attack upon exposure to low level of H2S. Sunlight had a significant role in reduction of ambient air H2S level.

  16. Ubiquitin Carboxy-Terminal Hydrolase L1 as a serum neurotrauma biomarker for exposure to occupational low-level blast

    Directory of Open Access Journals (Sweden)

    Walter eCarr

    2015-03-01

    Full Text Available Repeated exposure to low-level blast is a characteristic of a few select occupations and there is concern that such occupational exposures present risk for traumatic brain injury. These occupations include specialized military and law enforcement units that employ controlled detonation of explosive charges for the purpose of tactical entry into secured structures. The concern for negative effects from blast exposure is based on rates of operator self-reported headache, sleep disturbance, working memory impairment, and other concussion-like symptoms. A challenge in research on this topic has been the need for improved assessment tools to empirically evaluate the risk associated with repeated exposure to blast overpressure levels commonly considered to be too low in magnitude to cause acute injury. Evaluation of serum-based neurotrauma biomarkers provides an objective measure that is logistically feasible for use in field training environments. Among candidate biomarkers, ubiquitin carboxy-terminal hydrolase L1 (UCH-L1 has some empirical support and was evaluated in this study.We used daily blood draws to examine acute change in UCH-L1 among 108 healthy military personnel who were exposed to repeated low-level blast across a 2-week period. These research volunteers also wore pressure sensors to record blast exposures, wrist actigraphs to monitor sleep patterns, and completed daily behavioral assessments of symptomology, postural stability, and neurocognitive function. UCH-L1 levels were elevated as a function of participating in the 2-week training with explosives, but the correlation of UCH-L1 elevation and blast magnitude was weak and inconsistent. Also, UCH-L1 elevations did not correlate with deficits in behavioral measures. These results provide some support for including UCH-L1 as a measure of central nervous system effects from exposure to low-level blast. However, the weak relation observed suggests that additional indicators of blast

  17. Silica exposure to excavation workers during the excavation of a low level radiological waste pit and tritium disposal shafts

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, K.M.

    1995-01-01

    This study evaluated the task-length average (TLA) respirable dust and respirable silica airborne concentrations to which construction workers excavating volcanic tuff at Los Alamos National Laboratory (LANL) were exposed. These workers were excavating a low level radiological waste disposal pit of final dimensions 720 feet long, 132 feet wide and 60 feet deep. The objectives of this study were as follows: (1) evaluate exposures; (2) determine if the type of machinery used affects the respirable dust concentration in the breathing zone of the worker; (3) evaluate the efficacy of wetting the pit to reduce the respirable dust exposure; and (4) determine if exposure increases with increasing depth of pit due to the walls of the pit blocking the cross wind ventilation.

  18. Low-level lead exposure in the prenatal and early preschool periods: Language development

    Energy Technology Data Exchange (ETDEWEB)

    Ernhart, C.B.; Greene, T. (Case Western Reserve Univ., Cleveland, OH (USA))

    1990-11-01

    Inconsistent results continue to be reported from studies linking low-level lead exposure and child development. This inconsistency is seen for both prenatal exposure and exposure in the preschool years. The primary outcome measures in most reports are indices of cognitive development, including IQ. Verbal skills may be particularly vulnerable to toxic insult. The fact that 2 y of age is both a time of peak exposure and also a time of rapid language development suggests that this may be a critical period for such an effect. The later prenatal and early infancy period, at which time the nervous system is developing rapidly, may also be critical exposure period. We examined the relationship of maternal and cord blood lead (PbB) at birth and venous PbB at 6 mo, 2 y, and 3 y with language measures at 1, 2, and 3 y of age. The sample consisted of disadvantaged urban children. Multivariate analyses revealed no statistically significant relationship of either prenatal PbB or early preschool PbB with language measures after control of cofactors. Supplementary partial correlations revealed a marginal relationship of cord PbB and mean length of utterance (MLU), which describes a child's ability to form meaningful word combinations. Because this analysis was one of a large number of analyses with both positive and negative regression coefficients, the possibility that this was a chance effect was considered. If there is an effect of low-level lead exposure on language development, that effect is not robust.

  19. Adverse effects of low level heavy metal exposure on male reproductive function.

    Science.gov (United States)

    Wirth, Julia J; Mijal, Renée S

    2010-04-01

    Lead, cadmium, mercury, and arsenic, often referred to as "heavy metals", are toxic for wildlife, experimental animals, and humans. While experimental animal and human occupational studies with high exposure levels generally support an adverse role for these metals in human reproductive outcomes, information on the effects of low, environmentally-realistic exposure levels of these metals on male reproductive outcomes is limited. We review the literature on effects of exposure to low levels of these metals on measures of male fertility (semen quality and reproductive hormone levels) and provide supporting evidence from experimental and occupational studies. Potentially modifying effects of genetic polymorphisms on these associations are discussed. A brief review of the literature on the effects of three trace metals, copper, manganese, and molybdenum, that are required for human health, yet may also cause adverse reproductive effects, follows. Overall, there were few studies examining the effects of exposure to low levels of these metals on male reproductive health. For all metals, there were several well-designed studies with sufficient populations appropriately adjusted for potential confounders and many of these reported harmful effects. However, many studies lacked sufficient numbers of participants to be able to detect differences in outcomes between exposed and non-exposed individuals, did not clearly identify the source and characteristics of the participants, and did not control for other exposures that could alter or contribute to the outcomes. The evidence for the effects of low exposure was strongest for cadmium, lead, and mercury and less certain for arsenic. The potential modifying effects of genetic polymorphisms has not been fully explored. Additional studies on the reproductive effects of these toxic ubiquitous metals on male reproduction are required to expand the knowledge base and to resolve inconsistencies.

  20. Long-Term Exposure to Low-Level Arsenic in Drinking Water and Diabetes Incidence

    DEFF Research Database (Denmark)

    Bräuner, Elvira V; Nordsborg, Rikke B; Andersen, Zorana Jovanovic

    2014-01-01

    , and 3,035 (5.8%) cases of diabetes based on a stricter definition. The adjusted incidence rate ratio's per 1 µg/L increment in arsenic levels in drinking water were (IRR = 1.03; 95% CI: 1.01, 1.06) and (IRR = 1.02; 95% CI: 0.99, 1.05) for all and strict diabetes cases, respectively. CONCLUSIONS: Long......BACKGROUND: Established causes of diabetes do not fully explain the epidemic. High level arsenic exposure has been implicated in diabetes risk but the effect of low-level arsenic exposure in drinking water remains unclear. OBJECTIVE: To determine if long-term exposure to low-level arsenic...... in drinking water in Denmark is associated with increased risk of diabetes using a large prospective cohort. METHODS: During 1993-1997 we recruited 57,053 persons. We followed each cohort member for diabetes occurrence from enrollment until 31 December 2006. We traced and geocoded residential addresses...

  1. Estimation of Nicotine Dose after Low Level Exposure Using Plasma and Urine Nicotine Metabolites

    Science.gov (United States)

    Benowitz, Neal L.; Dains, Katherine M.; Dempsey, Delia; Yu, Lisa; Jacob, Peyton

    2010-01-01

    Background We sought to determine the optimal plasma and urine nicotine metabolites, alone or in combination, to estimate the systemic dose of nicotine after low level exposure. Methods We dosed 36 nonsmokers with 100, 200 or 400 μg deuterium-labeled nicotine (doses similar to exposure to secondhand smoke, SHS) by mouth daily for 5 days and then measured plasma and urine nicotine metabolites at various intervals over 24 hours. Results The strongest correlations with nicotine dose were seen for the sum of four [cotinine + cotinine-glucuronide + trans-3′-hydroxycotinine + 3HC-glucuronide] or six [ including also nicotine + nicotine-glucuronide] of the major nicotine metabolites in 24 hour urine collection (r = 0.96), with lesser correlations for these metabolites using spot urines corrected for creatinine at various times of day (r = 0.72 – 0.80). Plasma [cotinine + trans 3′ hydroxycotine] was more highly correlated with nicotine dose than plasma cotinine alone (r = 0.82 vs 0.75). Conclusions Our results provide guidance for selection of biomarkers to estimate the dose of nicotine taken in low level (SHS) tobacco exposure. Impact This is probably relevant to active smoking as well. PMID:20447913

  2. Low-level exposure to lead, blood pressure, and hypertension in a population-based cohort.

    Science.gov (United States)

    Gambelunghe, Angela; Sallsten, Gerd; Borné, Yan; Forsgard, Niklas; Hedblad, Bo; Nilsson, Peter; Fagerberg, Björn; Engström, Gunnar; Barregard, Lars

    2016-08-01

    Environmental lead exposure is a possible causative factor for increased blood pressure and hypertension, but large studies at low-level exposure are scarce, and results inconsistent. We aimed to examine the effects of environmental exposure to lead in a large population-based sample. We assessed associations between blood lead and systolic/diastolic blood pressure and hypertension in 4452 individuals (46-67 years) living in Malmö, Sweden, in 1991-1994. Blood pressure was measured using a mercury sphygmomanometer after 10min supine rest. Hypertension was defined as high systolic (≥140mmHg) or diastolic (≥90mmHg) blood pressure and/or current use of antihypertensive medication. Blood lead was calculated from lead in erythrocytes and haematocrit. Multivariable associations between blood lead and blood pressure or hypertension were assessed by linear and logistic regression. Two-thirds of the cohort was re-examined 16 years later. At baseline, mean blood pressure was 141/87mmHg, 16% used antihypertensive medication, 63% had hypertension, and mean blood lead was 28µg/L. Blood lead in the fourth quartile was associated with significantly higher systolic and diastolic blood pressure (point estimates: 1-2mmHg) and increased prevalence of hypertension (odds ratio: 1.3, 95% confidence interval: 1.1-1.5) versus the other quartiles after adjustment for sex, age, smoking, alcohol, waist circumference, and education. Associations were also significant with blood lead as a continuous variable. Blood lead at baseline, having a half-life of about one month, was not associated with antihypertensive treatment at the 16-year follow-up. Low-level lead exposure increases blood pressure and may increase the risk of hypertension. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  3. Effect of low-level prenatal mercury exposure on neonate neurobehavioral development in China.

    Science.gov (United States)

    Wu, Jinhua; Ying, Tinger; Shen, Zhonghai; Wang, Haiyan

    2014-07-01

    This study aimed to assess the effects of low-level prenatal mercury exposure on neonate neurobehavioral development in China. In total, 418 mother-neonate pairs were included in the study. Maternal urine, hair, and blood samples and cord blood samples were used to document prenatal exposure to mercury. The Neonatal Behavioral Neurological Assessment was used to estimate neurobehavioral development in the neonates at 3 days of age. Total mercury level was significantly higher in cord blood than that in maternal blood. A strong correlation was found between total mercury levels in maternal blood and those in cord blood (r = 0.7431; P mercury levels (all P mercury levels among groups with different fish consumption frequencies (all P mercury level was significantly associated with total Neonatal Behavioral Neurological Assessment scores (β = 0.03; standard error = 0.01; P = 0.0409), passive muscle tone (odds ratio = 1.07; 95% confidence interval = 1.12-1.13; P = 0.0071), and active muscle tone (odds ratio = 1.06; 95% confidence interval = 1.01-1.11; P = 0.0170) scores after adjustment, respectively. Neonatal neurodevelopment was associated with prenatal exposure to mercury. Women with high mercury levels should avoid intake seafood excessively during pregnancy. Long-term effects of exposure to mercury on childhood development need to be further explored. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

  4. Effects of low-level sarin and cyclosarin exposure on hippocampal subfields in Gulf War Veterans.

    Science.gov (United States)

    Chao, Linda L; Kriger, Stephen; Buckley, Shannon; Ng, Peter; Mueller, Susanne G

    2014-09-01

    More than 100,000 US troops were potentially exposed to chemical warfare agents sarin (GB) and cyclosarin (GF) when an ammunition dump at Khamisiyah, Iraq was destroyed during the 1991 Gulf War (GW). We previously reported reduced hippocampal volume in GW veterans with suspected GB/GF exposure relative to matched, unexposed GW veterans estimated from 1.5T magnetic resonance images (MRI). Here we investigate, in a different cohort of GW veterans, whether low-level GB/GF exposure is associated with structural alterations in specific hippocampal subfields, estimated from 4T MRI. The Automatic Segmentation of Hippocampal Subfields (ASHS) technique was used to quantify CA1, CA2, CA3 and dentate gyrus (DG), and subiculum (SUB) subfields volumes from high-resolution T2-weighted images acquired on a 4T MR scanner in 56 GW veterans with suspected GB/GF exposure and 56 "matched" unexposed GW veterans (mean age 49±7 years). GB/GF exposed veterans had smaller CA2 (p=0.003) and CA3/DG (p=0.01) subfield volumes compared to matched, unexposed GW veterans. There were no group difference in total hippocampal volume, quantified with FreeSurfer, and no dose-response relationship between estimated levels of GB/GF exposure and total hippocampal or subfield volume. These findings extend our previous report of structural alterations in the hippocampi of GW veterans with suspected GB/GF exposure to volume changes in the CA2, CA3, and DG hippocampal subfields in a different cohort of GW veterans with suspected GB/GF exposure. Published by Elsevier B.V.

  5. Unmetabolized VOCs in urine as biomarkers of low level occupational exposure.

    Science.gov (United States)

    Janasik, Beata; Jakubowski, Marek; Wesołowski, Wiktor; Kucharska, Małgorzata

    2010-01-01

    To compare the usefulness of determining unchanged forms of volatile organic compounds (VOCs), namely toluene (TOL), ethylbenzene (EB) and xylene (XYL), in urine with the effectiveness of the already used biomarkers of occupational exposure. Surveys were conducted in two workplaces (paint factory and footwear factory). In total, 65 subjects participated in the study. Air samples were collected using individual samplers during work shift. Urine and blood samples were collected at the end of work shift. Urine samples were analyzed for unchanged compounds and selected metabolites, while blood samples were tested for unchanged compounds. VOCs in blood and urine were determined by solid phase microextraction gas chromatography (SPME-GC-MS). In the paint factory, the geometric mean (GM) concentrations of VOCs in the air ranged as follows: 0.2-4.7 mg/m(3) for TOL, 0.4-40.9 mg/m(3) for EB and 0.1-122.6 mg/m(3) for XYL. In the footwear factory, the GM concentration of TOL in the air amounted to 105.4 mg/m(3). A significant correlation (p factory workers showed that TOL-U and TOL-B were better biomarkers of exposure (r = 0.72 and r = 0.81) than benzoic acid (r = 0.12) or o-cresol (r = 0.55). The findings of the study point out that the concentration of unchanged VOCs in urine can be a reliable biological indicator of low level occupational exposure to these compounds.

  6. Low-level environmental arsenic exposure correlates with unexplained male infertility risk.

    Science.gov (United States)

    Wang, Xiaofei; Zhang, Jie; Xu, Weipan; Huang, Qingyu; Liu, Liangpo; Tian, Meiping; Xia, Yankai; Zhang, Weibing; Shen, Heqing

    2016-11-15

    Humans are exposed to arsenic via drinking water, dietary intake and inhaled particulates. Endemic chronic arsenic exposure related reproductive toxicity is well documented, but the effect of low-level general environmental arsenic exposure on unexplained male infertility (UMI) remains unclear. In this case-control study, we aimed to investigate the relationship between non-geogenic environmental arsenic exposure and UMI risk. One hundred and one infertile men with normal semen as cases and sixty one fertile men as controls were recruited. Five urinary arsenic species: pentavalent arsenate (Asi(V)), trivalent arsenite (Asi(III)), methylated to monomethylarsonic acid (MMA(V)), dimethylarsinic acid (DMA(V)), arsenobetaine (AsB) were quantitatively measured by liquid chromatography-inductively coupled plasma-mass spectrometry (LC-ICP-MS). To assess the semen quality, semen volume, sperm concentration, total motility, and progressive motility were measured. The nonparametric Mann-Whitney U test was used to compare the differences of arsenic species and index between the case and the control group; we observed that concentrations of Asi(V), AsB, MMA(V), DMA(V), total inorganic As and total As were significantly higher in the cases than the controls. The urine Asi(V) level increased more than twenty folds in case group. Moreover, higher redox index (Asi(V)/Asi(III)) and lower primary arsenic methylation index (PMI=MMA(V)/Asi) were observed for case group. Furthermore, through the logistic regression analysis, we observed that the urine Asi(V) level and PMI were most significantly associated with UMI risk among the observations. Specifically, in comparison to the first quartile, the subjects with higher Asi(V) levels were more likely to exhibit UMI with increasing adjusted odds ratios (AORs) (adjusted by age, body mass index, drinking status and smoking status) of 8.39 [95% confidence interval (CI), 2.59-27.17], 13.12 (95% CI, 3.44-50.12) and 36.51 (95% CI, 8

  7. Low level exposure to manganese from drinking water and cognition in school-age children.

    Science.gov (United States)

    Bouchard, Maryse F; Surette, Céline; Cormier, Pierre; Foucher, Delphine

    2018-01-01

    and cognitive development in this sample of school-age children although the data suggest there might be sex-specific associations. Given the low levels of exposure and sex-specific associations, a larger sample size would have been required to increase the statistical power and better characterize the relations. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Pulmonary effects of intermittent subacute exposure to low-level nitrogen dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Gregory, R.E.; Pickrell, J.A.; Hahn, F.F.; Hobbs, C.H.

    1983-01-01

    The pulmonary biochemical and morphological changes resulting from the inhalation of relatively low levels of NO/sub 2/ for up to 15 weeks were investigated. Specific pathogen-free Fischer 344 rats were exposed to 0, 1, or 5 ppm NO/sub 2/ or to 1 ppm with two spikes to 5 ppm NO/sub 2/ for 7 h/d, 5 d/wk for up to 15 weeks. These exposures produced a mild, concentration-related pulmonary injury, with the 5-ppm group sustaining the most damage. The other NO/sub 2/-exposed animals showed similar types of damage, although the extent was less than that observed in the 5-ppm-exposed group. After 15 weeks of exposure, histopathological examination revealed focal areas of hyperinflation and alveolar macrophage accumulation in some of the 5-ppm- and 1-5-ppm-exposed animals. These changes were preceded by a series of biochemical changes in the bronchoalveolar fluid. 19 references, 1 figure, 2 tables.

  9. Low Level Laser Therapy Reduces the Development of Lung Inflammation Induced by Formaldehyde Exposure.

    Directory of Open Access Journals (Sweden)

    Cristiane Miranda da Silva

    Full Text Available Lung diseases constitute an important public health problem and its growing level of concern has led to efforts for the development of new therapies, particularly for the control of lung inflammation. Low Level Laser Therapy (LLLT has been highlighted as a non-invasive therapy with few side effects, but its mechanisms need to be better understood and explored. Considering that pollution causes several harmful effects on human health, including lung inflammation, in this study, we have used formaldehyde (FA, an environmental and occupational pollutant, for the induction of neutrophilic lung inflammation. Our objective was to investigate the local and systemic effects of LLLT after FA exposure. Male Wistar rats were exposed to FA (1% or vehicle (distillated water during 3 consecutive days and treated or not with LLLT (1 and 5 hours after each FA exposure. Non-manipulated rats were used as control. 24 h after the last FA exposure, we analyzed the local and systemic effects of LLLT. The treatment with LLLT reduced the development of neutrophilic lung inflammation induced by FA, as observed by the reduced number of leukocytes, mast cells degranulated, and a decreased myeloperoxidase activity in the lung. Moreover, LLLT also reduced the microvascular lung permeability in the parenchyma and the intrapulmonary bronchi. Alterations on the profile of inflammatory cytokines were evidenced by the reduced levels of IL-6 and TNF-α and the elevated levels of IL-10 in the lung. Together, our results showed that LLLT abolishes FA-induced neutrophilic lung inflammation by a reduction of the inflammatory cytokines and mast cell degranulation. This study may provide important information about the mechanisms of LLLT in lung inflammation induced by a pollutant.

  10. Association of hypothyroidism with low-level arsenic exposure in rural West Texas

    Energy Technology Data Exchange (ETDEWEB)

    Gong, Gordon, E-mail: gordon.gong@ttuhsc.edu [F. Marie Hall Institute for Rural and Community Health, Texas Tech University Health Sciences Center, Lubbock, TX (United States); Basom, Janet [F. Marie Hall Institute for Rural and Community Health, Texas Tech University Health Sciences Center, Lubbock, TX (United States); Department of Family and Community Medicine, Texas Tech University Health Sciences Center, Lubbock, TX (United States); Mattevada, Sravan [Department of Internal Medicine, University of North Texas Health Science Center, Fort Worth, TX (United States); Onger, Frederick [Department of Family and Community Medicine, Texas Tech University Health Sciences Center, Lubbock, TX (United States)

    2015-04-15

    It has been reported recently that a higher airborne arsenic level was correlated with higher urinary arsenic concentration and lower serum thyroxin level among urban policemen and rural highway workmen in Italy. The current study was to determine whether exposure to low-level arsenic groundwater (2–22 µg/L) is associated with hypothyroidism among 723 participants (118 male and 267 female Hispanics; 108 male and 230 female non-Hispanic whites, NHW) living in rural West Texas counties. Arsenic and iodine levels in their groundwater used for drinking and or cooking were estimated by the inverse distance weighted (IDW) interpolation technique. Groundwater arsenic was ≥8 µg/L in 36% of the subjects' wells while iodine concentration was <1 µg/L in 91% of their wells. Logistic regression analysis showed that arsenic in groundwater ≥8 µg/L and cumulative arsenic exposure (groundwater arsenic concentration multiplied by the number of years living in the current address) but not groundwater iodine concentration were significant predictors for hypothyroidism among Hispanics (p<0.05) but not NHW after adjusting for covariates such as age, gender, annual household income and health insurance coverage. The ethnic difference may be due to a marginally higher percentage of Hispanics (p=0.0622) who lived in areas with groundwater arsenic ≥8 µg/L compared with NHW. The prevalence of hypothyroidism was significantly higher in Hispanics or NHW of this rural cohort than the national prevalence. Measures should be taken to reduce arsenic in drinking water in order to prevent hypothyroidism in rural areas. - Highlights: • We determined if arsenic exposure is associated with hypothyroidism in rural Texas. • Groundwater arsenic level is associated with hypothyroidism among Hispanics only. • The rate of hypothyroidism in rural Texas was higher than the US general population.

  11. Health effects associated with occupational exposure to low levels of mercury vapors by employees of a chloralkali plant

    Directory of Open Access Journals (Sweden)

    M.A. Norozi

    2010-04-01

    Full Text Available Background and aims   The present study carried out to evaluate health effects associated with chronic occupational exposure to low levels of mercury vapors.     Methods   The study population consisted of 46 male workers occupationally exposed to  mercury vapors and 65 healthy unexposed employees. Subjects were administered a questionnaire on symptoms experienced and underwent clinical examinations as well routine biochemical tests.   Additionally, using standard methods, atmospheric and urinary concentrations of mercury were measured.     Results   Environmental and urinary concentrations of mercury were estimated to be 3/97±6/28  μg/m 2 and 34/30±26/77 μg/lit, respectively. While these values were blow the recommended TLV and BEI for this substance, exposed subjects had significantly higher concentrations of urinary mercury levels than their unexposed counterparts. No significant differences were noted between CBC, BUN, serum creatinine or serum activity of liver enzymes of both groups. Conversely, analysis of the data revealed that symptoms such as somatic and mental fatigue, anorexia, loss off  memory and personality change were significantly more common among exposed individuals.  Likewise, painful spasm of the extremities, irritability, vague fears and insomnia were more frequent among exposed population, although the differences were not statistically significant.     Conclusion Theses observations indicate that occupational exposure to mercury vapors, even at low levels, is likely to be associated with neurological and psychological symptoms.  

  12. Biological effects of low levels of radiation exposure. [Radiation hazards to man from radioactive consumer products

    Energy Technology Data Exchange (ETDEWEB)

    Casarett, G.W.

    1977-01-01

    Some general perspective is provided concerning the orders of radiation dose equivalent levels associated with exposure of human populations to ionizing radiations from consumer products. This is followed by considerations of the biological effects and risks of low levels of radiation exposure. Some consumer products emit low-LET (i.e., low linear energy transfer) radiations beyond their confines and these penetrating radiations can result virtually in whole-body irradiation, while in the case of other products the radiation to tissue consists mainly of the high-LET alpha particles which penetrate tissue only shallowly and close to the products. There are some radiation-emitting consumer products which are in such widespread use in the United States that large numbers of people are irradiated by them. Some of these products may irradiate on the order of 10/sup 6/ to 10/sup 8/ people to average annual whole-body or gonadal dose equivalents varying over a range on the order of 1 to 10 millirem (mrem). These include television receivers, time pieces with radium-containing dials, gas and aerosol detectors, and building and road construction materials. On the order of 10/sup 4/ people may be irradiated by vacuum high voltage switches to 30 mrem or from electron microscopes to 300 mrem average annual whole-body or gonadal dose equivalent. Smaller annual whole-body or gonadal dose equivalents, of the order of less than 1 microrem (..mu..rem) to 1 mrem, may be received by many people from cold cathode gas discharge tubes, airport x-ray inspection systems, time pieces with dials containing tritium or /sup 147/Pm, and other sources. Possible health hazards are discussed.

  13. Low level occupational exposure to styrene: its effects on DNA damage and DNA repair.

    Science.gov (United States)

    Wongvijitsuk, Sirilak; Navasumrit, Panida; Vattanasit, Udomratana; Parnlob, Varabhorn; Ruchirawat, Mathuros

    2011-03-01

    The present study aimed to evaluate the effects of styrene exposure at levels below the recommended standards of the Threshold Limit Value (TLV-TWA(8)) of 20 ppm (ACGIH, 2004) in reinforced-fiberglass plastics workers. Study subjects comprised 50 exposed workers and 40 control subjects. The exposed workers were stratified by styrene exposure levels, i.e. group I (20 ppm, >84.40 mg/m(3)). The mean styrene exposure levels of exposed workers were significantly higher than those of the control workers. Biomarkers of exposure to styrene, including blood styrene and the urinary metabolites, mandelic acid (MA) and phenylglyoxylic acid (PGA), were significantly increased with increasing levels of styrene exposure, but were not detected in the control group. DNA damage, such as DNA strand breaks, 8-hydroxydeoxyguanosine (8-OHdG), and DNA repair capacity, were used as biomarkers of early biological effects. DNA strand breaks and 8-OHdG/10(5)dG levels in peripheral leukocytes of exposed groups were significantly higher compared to the control group (Prisk from occupational styrene exposure, even at levels below the recommended TLV-TWA(8) of 20 ppm. Copyright © 2010 Elsevier GmbH. All rights reserved.

  14. Rice consumption contributes to low level methylmercury exposure in southern China.

    Science.gov (United States)

    Li, Ping; Feng, Xinbin; Yuan, Xiaobo; Chan, Hing Man; Qiu, Guangle; Sun, Guo-Xin; Zhu, Yong-Guan

    2012-11-15

    Fish consumption is considered as the primary pathway of human methylmercury (MeHg) exposure. However, recent studies highlighted that, rice, rather than fish, is the main route of human MeHg exposure in Guizhou, inland China. China is considered as the largest anthropogenic source of mercury (Hg) emission in the world, which has led to serious environmental Hg pollution. But there are no comprehensive studies regarding this environmental health problem to evaluate human Hg exposure and associated health effects. This study aimed to estimate daily MeHg intake and health risk in 7 provinces in southern China, and to assess the relative contribution from rice and fish consumption. The average levels of total mercury (THg) and MeHg in rice samples were generally low at 10.1 ng·g⁻¹ and 2.47 ng·g⁻¹, respectively. But a total of 36 rice samples (12.7%) had THg concentration exceeding the national limit (20 ng·g⁻¹). Generally, rural population had significantly higher Probable Daily Intakes (PDIs) of MeHg than urban population from rice consumption and its relative contribution to MeHg exposure increased significantly from coastal to inland area. The averages of PDIs of MeHg were 0.020 μg·kg⁻¹·d⁻¹ and 0.028 μg·kg⁻¹·d⁻¹ for urban and rural population in southern China, respectively. Despite the serious environmental Hg pollutions in China, the general population in southern China had low risk of MeHg exposure. But rice is an important route of human MeHg exposure in southern China, especially for the rural population in inland area. The findings indicate that rice consumption should be considered when evaluating MeHg exposure in rice eating population in southern China. Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. Relationship between the prenatal exposure to low-level of mercury and the size of a newborn's cerebellum.

    Science.gov (United States)

    Cace, I Bilic; Milardovic, A; Prpic, I; Krajina, R; Petrovic, O; Vukelic, P; Spiric, Z; Horvat, M; Mazej, D; Snoj, J

    2011-04-01

    Exposure to methylmercury at any stage of central nervous system development could induce alterations and result in severe congenital abnormalities. Total mercury level in maternal hair during pregnancy correlates well with blood levels of methylmercury and with total mercury levels in fetal brain. A prospective study has been conducted and a total of 137 childbearing women living at the coastal region with term, normal pregnancies were included and their newborns evaluated by ultrasonography. Mothers and their newborns are divided in two groups according to their hair mercury levels; examined group with high body levels of mercury (≥ 1 μg/g) and control group with low body levels of mercury (mercury levels lower than 1 μg/g (N = 107). Mean value was 0.88 μg/g (SD 1.24), ranging from 0.02 to 8.71 μg/g. There was no significant difference between the two groups when it comes to the width of cerebellum (Mann-Whitney test: Z = 1471; p = 0.141). However, comparison related to the length of cerebellum shows statistically significant smaller cerebellum in newborns whose mother had hair mercury levels higher than 1 μg/g (Mann-Whitney test: Z = 2329; p = 0.019). Our results lead to a conclusion that prenatal exposure to, what we consider to be, low-levels of methylmercury does influence fetal brain development detected as decreased size of newborn's cerebellum. From a clinical point of view, a question related to the influence of prenatal low-level methylmercury exposure on fetal neurodevelopment remains open. Our further objectives are to direct the research towards performing detailed neuropshychological tests on children at the age of 18 months. Such tests could indicate the presence of subtle neurological or neuropsychological deficits. Copyright © 2010 Elsevier Ltd. All rights reserved.

  16. The association between low level exposures to ambient air pollution and term low birth weight: a retrospective cohort study

    Directory of Open Access Journals (Sweden)

    Stieb David

    2006-02-01

    Full Text Available Abstract Background Studies in areas with relatively high levels of air pollution have found some positive associations between exposures to ambient levels of air pollution and several birth outcomes including low birth weight (LBW. The purpose of this study was to examine the association between LBW among term infants and ambient air pollution, by trimester of exposure, in a region of lower level exposures. Methods The relationship between LBW and ambient levels of particulate matter up to 10 um in diameter (PM10, sulfur dioxide (SO2 and ground-level ozone (O3 was evaluated using the Nova Scotia Atlee Perinatal Database and ambient air monitoring data from the Environment Canada National Air Pollution Surveillance Network and the Nova Scotia Department of Environment. The cohort consisted of live singleton births (≥37 weeks of gestation between January1,1988 and December31,2000. Maternal exposures to air pollution were assigned to women living within 25 km of a monitoring station at the time of birth. Air pollution was evaluated as a continuous and categorical variable (using quartile exposures for each trimester and relative risks were estimated from logistic regression, adjusted for confounding variables. Results There were 74,284 women with a term, singleton birth during the study period and with exposure data. In the analyses unadjusted for year of birth, first trimester exposures in the highest quartile for SO2 and PM10suggested an increased risk of delivering a LBW infant (relative risk = 1.36, 95% confidence interval = 1.04 to 1.78 for SO2 exposure and relative risk = 1.33, 95% confidence interval = 1.02 to 1.74 for PM10. After adjustment for birth year, the relative risks were attenuated somewhat and not statistically significant. A dose-response relationship for SO2 was noted with increasing levels of exposure. No statistically significant effects were noted for ozone. Conclusion Our results suggest that exposure during the first

  17. Reduced exercise time in competitive simulations consequent to low level ozone exposure

    Energy Technology Data Exchange (ETDEWEB)

    Schelegle, E.S.; Adams, W.C.

    1986-08-01

    Ten highly trained endurance athletes were studied to determine the effects of exposure to low ozone (O/sub 3/) concentrations on simulated competitive endurance performance and associated physiological and subjective symptom responses. Each subject was randomly exposed to filtered air (FA), and to 0.12, 0.18, and 0.24 ppm O/sub 3/ while performing a 1 h competitive simulation protocol on a bicycle ergometer. Endurance performance was evaluated by the number of subjects unable to complete rides (last 30 min at an intense work load of approximately 86% VO/sub 2/max). All subjects completed the FA exposure, whereas one, five, and seven subjects did not complete the 0.12, 0.18, and 0.24 ppm O/sub 3/ exposures, respectively. Statistical analysis indicated a significant (P less than 0.05) increase in the inability of subjects to complete the competitive simulations with increasing O/sub 3/ concentration, including a significant difference between the 0.24 ppm O/sub 3/ and FA exposure. Significant decreases (P less than 0.05) were also observed following the 0.18 and 0.24 ppm O/sub 3/ exposures, respectively, in forced vital capacity (-7.8 and -9.9%), and forced expiratory volume in 1 s (-5.8 and -10.5%). No significant O/sub 3/ effect was observed for exercise respiratory metabolism or ventilatory pattern responses. However, the number of reported subjective symptoms increased significantly following the 0.18 and 0.24 ppm O/sub 3/ protocols. These data demonstrate significant decrements in simulated competitive endurance performance and in pulmonary function, with accompanying enhanced subjective symptoms, following exposure to low O/sub 3/ levels commonly observed in numerous metropolitan environments during the summer months.

  18. Assessment of saliva, hair and toenails as biomarkers of low level exposure to manganese from drinking water in children.

    Science.gov (United States)

    Ntihabose, Ruth; Surette, Céline; Foucher, Delphine; Clarisse, Olivier; Bouchard, Maryse F

    2017-09-01

    We evaluated hair, toenails, and saliva (whole and supernatant) as biomarkers of exposure to manganese (Mn) in 274 school age children (6-13 years) consuming well water in southeastern New Brunswick, Canada. Mn concentrations in tap water ranged from <0.03 to 1046μgL-1 (geometric mean 5.96μgL-1). The geometric mean of Mn intake resulting from the consumption of water was 0.25 (0-34.95) μg kg-1day-1. Both Mn concentration in water and Mn intake were significantly correlated with Mn in hair (r=0.60 and r=0.53, respectively), Mn in toenail (r=0.29 and r=0.37 respectively) and to a lesser extent with Mn in saliva supernatant (r=0.14 and r=0.18, respectively). Mn in whole saliva did not correlate with Mn in water or Mn intake. Both Mn in hair and Mn in toenail allowed to discriminate the most exposed group from the least exposed group, based on Mn in water and Mn intake from water. In this group of children with low level Mn exposure, Mn concentrations in hair, and toenails reflected reasonably well Mn exposure from drinking water, whereas Mn content in saliva correlated less strongly. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Low-Level Toxic Metal Exposure in Healthy Weaning-Age Infants: Association with Growth, Dietary Intake, and Iron Deficiency.

    Science.gov (United States)

    Choi, Jungil; Chang, Ju Young; Hong, Jeana; Shin, Sue; Park, Jeong Su; Oh, Sohee

    2017-04-06

    Even low levels of toxic metal exposure (As, Cd, Hg, and Pb) in infancy might be harmful to children's development. This study investigated toxic metal exposure on healthy weaning-age infants and its relationship with growth, diet, and iron/anemia status. The weight, height, head circumference, whole blood levels of four toxic metals, hemoglobin, and serum ferritin of healthy infants was measured. Among 210 infants with a median age of 11.4 months (interquartile range: 10.5-12.0), the median levels of As, Cd, Hg, and Pb were 1.2 μg/L, 0.05 μg/L, 0.8 μg/L, and 0.83 μg/dL, respectively. In adjusted linear regression models, post-birth weight gain (Pb) and current head circumference (As, Pb) were negatively associated with toxic metal levels. In multiple linear regression or logistic regression analysis, the duration of breastfeeding (all four metals), perceived adequacy of rice-based food intake (As), regular fish intake (As, Hg), and iron deficiency with/without anemia (Cd, Pb) were associated with increased toxic metal levels. Although levels of toxic metals may not usually be high in this population, individual exposure risk may need to be assessed after considering the type of feeding or intake of complementary foods and the iron/anemia status while evaluating growth status during late infancy.

  20. Impact of exposure to low levels of mercury on the health of dental workers

    Directory of Open Access Journals (Sweden)

    Leda Freitas Jesus

    2016-09-01

    Full Text Available This work evaluated the impact of exposure to mercury on the health of workers comparing dentists and dental assistants exposed to mercury by handling amalgam in a public dental clinic with a reference group which, in private offices, did not make use of the metal in their professional routine. Data collection included mercury levels in urine and air samples determined by cold vapor atomic absorption spectrometry, questionnaires and direct observation. The difference between urine and air samples in both groups was statistically significant while mercury levels in air and urine showed positive associations. Mercury concentration in urine correlated with gender, practice time, and age of workers. Half of those exposed had complaints compatible with mercury contamination. Among the exposed, the most common complaints were cognitive and neurocognitive symptoms. Correlations between symptoms and exposure time and also number of amalgam fillings placed per week were positive. Amalgam handling resulted in environmental and biological contamination by mercury.

  1. Assessment of hemato-biochemical parameters on exposure to low level of deltamethrin in mouse model

    Directory of Open Access Journals (Sweden)

    Anita Tewari

    2014-03-01

    Full Text Available Aim: In this study, sub-acute toxicity of deltamethrin on hematological and biochemical blood parameters of male albino Swiss mice was evaluated. Materials and Methods: Generally, the maximum permissible residue level (MRL of deltamethrin for food products lies between 0.01 to 0.5 mg/kg body weight. So the mice were exposed orally with two doses of pesticide i.e. 0.1 and 0.5 mg/kg body weight. The doses were given on a daily basis for a period of 15 days and 30 days respectively. Ground nut oil was used as control treatment. Samples of blood were collected at the end of the treatment. Hepatotoxicity was evaluated by quantitative analysis of the serum enzymes alanine transaminase (ALT, aspartate transaminase (AST, alkaline phosphatase (ALKP, total bilirubin (TBIL and serum urea. Alterations of hematological parameters were analysed by total leukocyte, differential leukocyte count and hemoglobin levels. Results: Significant increase in the levels of hepatic enzymes (ALT, AST, ALKP were observed for both doses, but no considerable differences were found by histological analysis. The hematological parameters showed significant alterations for 0.5 mg/kg body weight dose which is indicated by leukocytosis, lymphocytosis and neutropenia in long duration study. Conclusions: The results indicated that even very low dose of deltamethrin can promote hematological and hepatic alterations. Thus it is imperative to do further studies on the detrimental effect of the low levels of pyrethroid commonly present in our food, which further necessitate the reduction of maximum permissible levels of residual synthetic pyrethroid levels in foods and feed.

  2. Chronic low-level exposure to the common seafood toxin domoic acid causes cognitive deficits in mice.

    Science.gov (United States)

    Lefebvre, Kathi A; Kendrick, Preston S; Ladiges, Warren; Hiolski, Emma M; Ferriss, Bridget E; Smith, Donald R; Marcinek, David J

    2017-04-01

    The consumption of one meal of seafood containing domoic acid (DA) at levels high enough to induce seizures can cause gross histopathological lesions in hippocampal regions of the brain and permanent memory loss in humans and marine mammals. Seafood regulatory limits have been set at 20mgDA/kg shellfish to protect human consumers from symptomatic acute exposure, but the effects of repetitive low-level asymptomatic exposure remain a critical knowledge gap. Recreational and Tribal-subsistence shellfish harvesters are known to regularly consume low levels of DA. The aim of this study was to determine if chronic low-level DA exposure, at doses below those that cause overt signs of neurotoxicity, has quantifiable impacts on cognitive function. To this end, female C57BL/6NJ mice were exposed to asymptomatic doses of DA (≈0.75mg/kg) or vehicle once a week for several months. Spatial learning and memory were tested in a radial water maze paradigm at one, six and 25 weeks of exposure, after a nine-week recovery period following cessation of exposure, and at three old age time points (18, 24 and 28 months old). Mice from select time points were also tested for activity levels in a novel cage environment using a photobeam activity system. Chronic low-level DA exposure caused significant spatial learning impairment and hyperactivity after 25 weeks of exposure in the absence of visible histopathological lesions in hippocampal regions of the brain. These cognitive effects were reversible after a nine-week recovery period with no toxin exposure and recovery was sustained into old age. These findings identify a new potential health risk of chronic low-level exposure in a mammalian model. Unlike the permanent cognitive impacts of acute exposure, the chronic low-level effects observed in this study were reversible suggesting that these deficits could potentially be managed through cessation of exposure if they also occur in human seafood consumers. Published by Elsevier B.V.

  3. The assessment of risks from exposure to low-levels of ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Gilbert, E.S.

    1992-06-01

    This report is concerned with risk assessments for human populations receiving low level radiation doses; workers routinely exposed to radiation, Japanese victims of nuclear bombs, and the general public are all considered. Topics covered include risk estimates for cancer, mortality rates, risk estimates for nuclear site workers, and dosimetry.

  4. Evaluation of low level laser therapy irradiation parameters on rat muscle inflammation through systemic blood cytokines

    Science.gov (United States)

    Mantineo, Matias; Pinheiro, João. P.; Morgado, António M.

    2014-02-01

    Low level laser therapy (LLLT) has been used for inflammation treatment. Here, we evaluate the effect of different doses, using continuous (830 and 980 nm) and pulsed illumination (830 nm), in the treatment of inflammation induced in the gastrocnemius muscle of Wistar rats, through cytokines concentration in systemic blood and histological analysis of muscle tissue. Animals were randomly divided into five groups per wavelength (5 animals per group: 10, 20, 30, 40 and 50 mW) plus a control group. LLLT was applied during five days, with constant exposure time and irradiated area (3 minutes; 0.5026 cm2). Blood was collected on days 0, 3 and 6. TNF-α, IL-1β, IL-2 and IL-6 cytokines were quantified by ELISA. Rats were killed on day 6. Muscle inflammatory cells were counted using optical microscopy. Treatment effects occurred for all applied doses (largest effect at 40 mW: 7.2 J, 14 J/cm2 per irradiation), with reduction of proinflammatory TNF-α, IL-1β and IL-6 cytokines and lower number of inflammatory cells. Results were better for 830 nm. Identical methodology was used with pulsed illumination. Average power (40 mW) and duty cycle were kept constant (80%) at five frequencies (5, 25, 50, 100 and 200 Hz). Treatment effects were observed at higher frequencies, with no significant differences between them. However, the treatment effect was lower than for continuous illumination. LLLT effect on inflammation treatment can be monitored by measuring systemic blood cytokines. A larger treatment effect was observed with continuous illumination, where results seem to be compatible with a biphasic dose response.

  5. Evaluation of low-level laser therapy in the treatment of masticatory muscles spasticity in children with cerebral palsy

    Science.gov (United States)

    Santos, Maria Teresa Botti Rodrigues; Diniz, Michele Baffi; Gouw-Soares, Sheila Cynthia; Lopes-Martins, Rodrigo Alvaro Brandão; Frigo, Lucio; Baeder, Fernando Martins

    2016-02-01

    Spasticity is a motor disorder frequently present in individuals with cerebral palsy (CP). This study aimed to evaluate the effect of low-level laser therapy (LLLT) on the spasticity of the masseter and anterior temporal muscle fibers in children with CP over three weeks of intermittent laser exposures. The bite force (BF) of the masticatory muscles and the amplitude of mouth opening were evaluated before and after laser irradiation in 30 children with CP. Both sides of the masseter and temporalis muscles were irradiated with low-intensity diode laser pulses of 808-nm wavelength six times over three consecutive weeks. During the subsequent three weeks of postlaser exposures, although no laser treatment was applied, the evaluation parameters were measured and recorded. A significant improvement in the amplitude of mouth opening and a decrease in the BF were observed in the weeks following LLLT (Pchildren with spastic CP over a time course of three weeks of intermittent laser applications.

  6. Evaluation of low-level laser therapy in the treatment of masticatory muscles spasticity in children with cerebral palsy.

    Science.gov (United States)

    Santos, Maria Teresa Botti Rodrigues; Diniz, Michele Baffi; Gouw-Soares, Sheila Cynthia; Lopes-Martins, Rodrigo Alvaro Brandão; Frigo, Lucio; Baeder, Fernando Martins

    2016-02-01

    Spasticity is a motor disorder frequently present in individuals with cerebral palsy (CP). This study aimed to evaluate the effect of low-level laser therapy (LLLT) on the spasticity of the masseter and anterior temporal muscle fibers in children with CP over three weeks of intermittent laser exposures. The bite force (BF) of the masticatory muscles and the amplitude of mouth opening were evaluated before and after laser irradiation in 30 children with CP. Both sides of the masseter and temporalis muscles were irradiated with low-intensity diode laser pulses of 808-nm wavelength six times over three consecutive weeks. During the subsequent three weeks of postlaser exposures, although no laser treatment was applied, the evaluation parameters were measured and recorded. A significant improvement in the amplitude of mouth opening and a decrease in the BF were observed in the weeks following LLLT (Pmuscle tonus of children with spastic CP over a time course of three weeks of intermittent laser applications.

  7. Acute low-level microwave exposure and central cholinergic activity: studies on irradiation parameters

    Energy Technology Data Exchange (ETDEWEB)

    Lai, H.; Horita, A.; Guy, A.W.

    1988-01-01

    Sodium-dependent high-affinity choline uptake was measured in the striatum, frontal cortex, hippocampus, and hypothalamus of rats after acute exposure (45 min) to pulsed (2 microseconds, 500 pps) or continuous-wave 2,450-MHz microwaves in cylindrical waveguides or miniature anechoic chambers. In all exposure conditions, the average whole-body specific absorption rate was at 0.6 W/kg. Decrease in choline uptake was observed in the frontal cortex after microwave exposure in all of the above irradiation conditions. Regardless of the exposure system used, hippocampal choline uptake was decreased after exposure to pulsed but not continuous-wave microwaves. Striatal choline uptake was decreased after exposure to either pulsed or continuous-wave microwaves in the miniature anechoic chamber. No significant change in hypothalamic choline uptake was observed under any of the exposure conditions studied. We conclude that depending on the parameters of the radiation, microwaves can elicit specific and generalized biological effects.

  8. Exposure to low levels of hydrogen sulfide : symptoms, sensory function, and cognitive performance

    Energy Technology Data Exchange (ETDEWEB)

    Fiedler, N.; Kipen, H.; Lioy, P.; Zhang, J.; Weisel, C. [Rutgers Univ., NJ (United States). Environmental and Occupational Health Sciences Inst.

    2003-07-01

    Petroleum refineries, kraft paper mills, and coke ovens are some of the sources of hydrogen sulfide exposure. In 1987, the World Health Organization (WHO) recommended an ambient exposure standard of .003 ppm for odor and .01 ppm for eye irritation. In communities with high exposure levels, health effects have been documented as being headaches, eye and nasal symptoms, coughs, breathlessness and decreased psychomotor performance. Refinery workers in some jurisdictions around the world have been subjected to higher exposure levels. This report presents results of clinical studies on the neurobehavioral effects in rats. The tasks of memory and learning in rats parallels those in humans. A pilot exposure study examined the health effects of controlled exposures to 3 concentrations of hydrogen sulfide (.05, .50, and 5 ppm). It was concluded that changes in neurobehavioral measurements can be directly associated with exposure and dose-response. 25 figs.

  9. Low-level gestational exposure to mercury and maternal fish consumption: Associations with neurobehavior in early infancy.

    Science.gov (United States)

    Xu, Yingying; Khoury, Jane C; Sucharew, Heidi; Dietrich, Kim; Yolton, Kimberly

    2016-01-01

    Studies examining the effects of low-level gestational methylmercury exposure from fish consumption on infant neurobehavioral outcomes in the offspring are limited and inconclusive. Our objective was to examine the effects of low-level gestational exposure to methylmercury on neurobehavioral outcomes in early infancy. We assessed neurobehavior of 344 infants at 5-weeks using the NICU Network Neurobehavioral Scale (NNNS). Gestational mercury exposure was measured as whole blood total mercury (WBTHg) in maternal and cord blood. We collected fish consumption information and estimated polyunsaturated fatty acid (PUFA) intake. We examined the association between gestational mercury exposure and NNNS scales using regression, adjusting for covariates. Geometric mean of maternal and cord WBTHg were 0.64 and 0.72 μg/L, respectively. Most mothers (84%) reported eating fish during pregnancy. Infants with higher prenatal mercury exposure showed increased asymmetric reflexes among girls (p=0.04 for maternal WBTHg and p=0.03 for cord WBTHg), less need for special handling during the assessment (p=0.03 for cord WBTHg) and a trend of better attention (p=0.054 for both maternal WBTHg and cord WBTHg). Similarly, infants born to mothers with higher fish consumption or estimated PUFA intake also had increased asymmetric reflexes and less need for special handling. In models simultaneously adjusted for WBTHg and fish consumption (or PUFA intake), the previously observed WBTHg effects were attenuated; and higher fish consumption (or PUFA intake) was significantly associated with less need for special handling. In a cohort with low level mercury exposure and reporting low fish consumption, we found minimal evidence of mercury associated detrimental effects on neurobehavioral outcomes during early infancy. Higher prenatal mercury exposure was associated with more frequent asymmetric reflexes in girls. In contrast, infants with higher prenatal mercury exposure and those whose mothers

  10. Low-level maternal methylmercury exposure through rice ingestion and potential implications for offspring health

    Energy Technology Data Exchange (ETDEWEB)

    Rothenberg, Sarah E., E-mail: rothenberg.sarah@gmail.com [State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, 46 Guanshui Lu, Guiyang 550002 (China); Feng Xinbin, E-mail: fengxinbin@vip.skleg.cn [State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, 46 Guanshui Lu, Guiyang 550002 (China); Li Ping [State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, 46 Guanshui Lu, Guiyang 550002 (China)

    2011-04-15

    Fish consumption is considered the primary pathway for MeHg (MeHg) exposure; however, MeHg exposure also occurs through rice ingestion. Rice is grown in an aquatic environment and although documented MeHg concentrations in rice are lower compared to fish tissue, human exposures exceed international guidelines in some regions where rice is a staple food and rice MeHg levels are elevated. Studies concerning human health exposure to MeHg should also include populations where maternal MeHg exposure occurs through ingestion of rice. Rice does not contain long-chain polyunsaturated fatty acids, which are associated with confounding developmental outcomes in offspring. Rice is also a staple food for more than half the world's population; therefore, it is critical to investigate the potential health risks of maternal ingestion of rice to the developing fetus, the most susceptible population to the deleterious effects of MeHg. Data concerning MeHg in rice are reviewed and micronutrients in rice are discussed. - Research highlights: > Maternal methylmercury exposure through rice may be important. > Rice does not contain the same micronutrients as fish, but may contain methylmercury. > Effects to offspring from methylmercury without beneficial micronutrients are unknown. - Studies concerning maternal methylmercury exposure and cognitive outcomes for offspring should include populations where rice ingestion is the primary methylmercury exposure pathway.

  11. Effect Of Chronic Exposure To Low Levels Of Lead On Renal ...

    African Journals Online (AJOL)

    Chronic exposure to lead is associated with adverse effects on renal function in laboratory animals and man. There is controversy concerning the direction of change of renal function parameters following chronic lead intoxication. The renal effects of low-dose lead exposure, as opposed to acute and pharmacological doses, ...

  12. Comparison of subjective symptoms associated with exposure to low levels of formaldehyde between students enrolled and not enrolled in a gross anatomy course.

    Science.gov (United States)

    Mori, Mihoko; Matsumoto, Yuuki; Kushino, Nanae; Morimatsu, Yoshitaka; Hoshiko, Michiko; Saga, Tsuyoshi; Yamaki, Koh-ichi; Ishitake, Tatsuya

    2016-01-01

    This study aimed to evaluate students' subjective symptoms associated with exposure to low levels of formaldehyde (FA) during a gross anatomy course and to survey how the risk of subjective symptoms was affected by exposure to FA. We conducted three questionnaire surveys of 125 students enrolled in an anatomy course (FA exposure group) and 124 students not enrolled in the course (FA nonexposure group) before, during, and 6 months after the course. The questionnaire included questions inquiring about subjective symptoms, sex, age, and allergies. We analyzed differences in the prevalence of subjective symptoms in distinct survey periods. Furthermore, we analyzed the relationship between the subjective symptoms and exposure to FA after adjusting for allergy, sex, and age using multiple logistic regression analysis. The prevalence of some of the ocular, nasal, and nonspecific symptoms in the FA exposure group was low before the course, increased during the course and decreased 6 months after the course. A significant positive relationship was observed between exposure to FA and some symptoms after adjusting for allergy, sex, and age. We identified some concrete symptoms associated with exposure to FA. We suggest that the exposure to low levels of FA influences students' subjective symptoms.

  13. Long-Term Low-Level Arsenic Exposure Is Associated with Poorer Neuropsychological Functioning: A Project FRONTIER Study

    Directory of Open Access Journals (Sweden)

    Robert Barber

    2011-03-01

    Full Text Available Exposure to elements in groundwater (toxic or beneficial is commonplace yet, outside of lead and mercury, little research has examined the impact of many commonly occurring environmental exposures on mental abilities during the aging process. Inorganic arsenic is a known neurotoxin that has both neurodevelopmental and neurocognitive consequences. The aim of this study was to examine the potential association between current and long-term arsenic exposure and detailed neuropsychological functioning in a sample of rural-dwelling adults and elders. Data were analyzed from 434 participants (133 men and 301 women of Project FRONTIER, a community-based participatory research study of the epidemiology of health issues of rural-dwelling adults and elders. The results of the study showed that GIS-based groundwater arsenic exposure (current and long-term was significantly related to poorer scores in language, visuospatial skills, and executive functioning. Additionally, long-term low-level exposure to arsenic was significantly correlated to poorer scores in global cognition, processing speed and immediate memory. The finding of a correlation between arsenic and the domains of executive functioning and memory is of critical importance as these are cognitive domains that reflect the earliest manifestations of Alzheimer’s disease. Additional work is warranted given the population health implications associated with long-term low-level arsenic exposure.

  14. Low-Level Prenatal and Postnatal Blood Lead Exposure and Adrenocortical Responses to Acute Stress in Children

    OpenAIRE

    Gump, Brooks B.; Stewart, Paul; Reihman, Jacki; Lonky, Ed; Darvill, Tom; Parsons, Patrick J.; Granger, Douglas A.

    2007-01-01

    Background A few recent studies have demonstrated heightened hypothalamic–pituitary–adrenal (HPA) axis reactivity to acute stress in animals exposed to heavy metal contaminants, particularly lead. However, Pb-induced dysregulation of the HPA axis has not yet been studied in humans. Objective In this study, we examined children’s cortisol response to acute stress (the glucocorticoid product of HPA activation) in relation to low-level prenatal and postnatal Pb exposure. Methods Children’s prena...

  15. Characterization of changes in gene expression and biochemical pathways at low levels of benzene exposure

    NARCIS (Netherlands)

    Thomas, Reuben; Hubbard, Alan E.; McHale, Cliona M.; Zhang, Luoping; Rappaport, Stephen M.; Lan, Qing; Rothman, Nathaniel; Vermeulen, Roel|info:eu-repo/dai/nl/216532620; Guyton, Kathryn Z.; Jinot, Jennifer; Sonawane, Babasaheb R.; Smith, Martyn T.

    2014-01-01

    Benzene, a ubiquitous environmental pollutant, causes acute myeloid leukemia (AML). Recently, through transcriptome profiling of peripheral blood mononuclear cells (PBMC), we reported dose-dependent effects of benzene exposure on gene expression and biochemical pathways in 83 workers exposed across

  16. Low-Level Toxic Metal Exposure in Healthy Weaning-Age Infants: Association with Growth, Dietary Intake, and Iron Deficiency

    OpenAIRE

    Jungil Choi; Ju Young Chang; Jeana Hong; Sue Shin; Jeong Su Park; Sohee Oh

    2017-01-01

    Even low levels of toxic metal exposure (As, Cd, Hg, and Pb) in infancy might be harmful to children?s development. This study investigated toxic metal exposure on healthy weaning-age infants and its relationship with growth, diet, and iron/anemia status. The weight, height, head circumference, whole blood levels of four toxic metals, hemoglobin, and serum ferritin of healthy infants was measured. Among 210 infants with a median age of 11.4 months (interquartile range: 10.5?12.0), the median ...

  17. No effect of low-level chronic neonicotinoid exposure on bumblebee learning and fecundity

    Directory of Open Access Journals (Sweden)

    Saija Piiroinen

    2016-03-01

    Full Text Available In recent years, many pollinators have declined in abundance and diversity worldwide, presenting a potential threat to agricultural productivity, biodiversity and the functioning of natural ecosystems. One of the most debated factors proposed to be contributing to pollinator declines is exposure to pesticides, particularly neonicotinoids, a widely used class of systemic insecticide. Also, newly emerging parasites and diseases, thought to be spread via contact with managed honeybees, may pose threats to other pollinators such as bumblebees. Compared to honeybees, bumblebees could be particularly vulnerable to the effects of stressors due to their smaller and more short-lived colonies. Here, we studied the effect of field-realistic, chronic clothianidin exposure and inoculation with the parasite Nosema ceranae on survival, fecundity, sugar water collection and learning using queenless Bombus terrestris audax microcolonies in the laboratory. Chronic exposure to 1 ppb clothianidin had no significant effects on the traits studied. Interestingly, pesticide exposure in combination with additional stress caused by harnessing bees for Proboscis Extension Response (PER learning assays, led to an increase in mortality. In contrast to previous findings, the bees did not become infected by N. ceranae after experimental inoculation with the parasite spores, suggesting variability in host resistance or parasite virulence. However, this treatment induced a slight, short-term reduction in sugar water collection, potentially through stimulation of the immune system of the bees. Our results suggest that chronic exposure to 1 ppb clothianidin does not have adverse effects on bumblebee fecundity or learning ability.

  18. How to evaluate PCR assays for the detection of low-level DNA

    DEFF Research Database (Denmark)

    Banch-Clausen, Frederik; Urhammer, Emil; Rieneck, Klaus

    2015-01-01

    are needed and how many of these should be positive or what amount of template should be used? We developed a mathematical model to obtain a simple tool for quick PCR assay evaluation before laboratory optimization and validation procedures. The model was based on the Poisson distribution and the Binomial...... distribution describing parameters for singleplex real-time PCR-based detection of low-level DNA. The model was tested against experimental data of diluted cell-free foetal DNA. Also, the model was compared with a simplified formula to enable easy predictions. The model predicted outcomes that were...

  19. Investigation of Hair Follicle and Plasma Biomarkers for Low-Level VX Vapor Exposure

    Science.gov (United States)

    2006-11-01

    become a popular method to determine exposure to drugs of abuse (e.g. cocaine, amphetamine, methamphetamine , heroin, marijuana, and steroids...inhibition levels of less than 20%. Secondly, due to the de novo synthesis of new AChE, this method cannot be used for retrospective determination

  20. Comments on results of a long-term low-level microwave exposure of rats

    NARCIS (Netherlands)

    Rongen, E. van; Rhoon, G.C. van; Aleman, A.; Kelfkens, G.; Kromhout, H.; Leeuwen, F.E. van; Savelkoul, H.F.J.; Wadman, W.J.; Weerdt, R.D.H.J. van de; Zwamborn, A.P.M.

    2011-01-01

    In a recent publication in this Transactions, Adang concluded that long-term exposure to RF electromagnetic fields may have effects on survival and on blood parameters in rats. The Electromagnetic Fields Committee of the Health Council of The Netherlands disputes this conclusion.

  1. Comments on "Results of a Long-Term Low-Level Microwave Exposure of Rats"

    NARCIS (Netherlands)

    van Rongen, Eric; van Rhoon, Gerard C.; Aleman, Andre; Kelfkens, Gert; Kromhout, Hans; van Leeuwen, Flora E.; Savelkoul, Huub F. J.; Wadman, Wytse J.; van de Weerdt, Rik D. H. J.; Zwamborn, A. Peter M.

    In a recent publication in this TRANSACTIONS, Adang et al. concluded that long-term exposure to RF electromagnetic fields may have effects on survival and on blood parameters in rats. The Electromagnetic Fields Committee of the Health Council of The Netherlands disputes this conclusion.

  2. Low-Level Effects of VX Vapor Exposure on Pupil Diameter and Cholinesterase Levels in Rats

    National Research Council Canada - National Science Library

    Benton, B. J; Crosier, R. B; Sommerville, D. R; Jakubowski, E. M., Jr; Anthony, J. S., Jr; Scotto, J; Hulet, S. W; Whalley, C. E; Crouse, C. L; Matson, K. L; Miller, D. B

    2004-01-01

    The median effective concentrations (EC sub 50's) for miosis in male and female rats exposed to VX vapor for 10, 60 and 240 min were estimated using whole body vapor exposures conducted in a 750 liter dynamic airflow inhalation chamber...

  3. Low-Level Effects of VX Vapor Exposure on Pupil Size and Cholinesterase Levels in Rats

    National Research Council Canada - National Science Library

    Matson, Kathy L; Crouse, Charles L; Miller, Dennis; Evans, Ronald A; McGuire, Jeffrey M; Jarvis, Jill; Benton, Bernard J; Sommerville, Douglas R; Scotto, Jacqueline; Burnett, David C

    2005-01-01

    The effective concentrations (EC(sub 50)'s,) for miosis in male and female rats exposed to VX vapor for 10, 60, and 240 min were estimated using whole body vapor exposures conducted in a 750 L dynamic airflow inhalation chamber...

  4. Metabolic response to low-level toxicant exposure in a novel renal tubule epithelial cell system

    NARCIS (Netherlands)

    Ellis, James Keith; Athersuch, Toby James; Cavill, Rachel; Radford, Robert; Slattery, Craig; Jennings, Paul; McMorrow, Tara; Ryan, Michael P; Ebbels, Timothy Mark David; Keun, Hector Charles

    Toxicity testing is vital to protect human health from exposure to toxic chemicals in the environment. Furthermore, combining novel cellular models with molecular profiling technologies, such as metabolomics can add new insight into the molecular basis of toxicity and provide a rich source of

  5. Characterization of Changes in Gene Expression and Biochemical Pathways at Low Levels of Benzene Exposure

    Science.gov (United States)

    Thomas, Reuben; Hubbard, Alan E.; McHale, Cliona M.; Zhang, Luoping; Rappaport, Stephen M.; Lan, Qing; Rothman, Nathaniel; Vermeulen, Roel; Guyton, Kathryn Z.; Jinot, Jennifer; Sonawane, Babasaheb R.; Smith, Martyn T.

    2014-01-01

    Benzene, a ubiquitous environmental pollutant, causes acute myeloid leukemia (AML). Recently, through transcriptome profiling of peripheral blood mononuclear cells (PBMC), we reported dose-dependent effects of benzene exposure on gene expression and biochemical pathways in 83 workers exposed across four airborne concentration ranges (from 10 ppm) compared with 42 subjects with non-workplace ambient exposure levels. Here, we further characterize these dose-dependent effects with continuous benzene exposure in all 125 study subjects. We estimated air benzene exposure levels in the 42 environmentally-exposed subjects from their unmetabolized urinary benzene levels. We used a novel non-parametric, data-adaptive model selection method to estimate the change with dose in the expression of each gene. We describe non-parametric approaches to model pathway responses and used these to estimate the dose responses of the AML pathway and 4 other pathways of interest. The response patterns of majority of genes as captured by mean estimates of the first and second principal components of the dose-response for the five pathways and the profiles of 6 AML pathway response-representative genes (identified by clustering) exhibited similar apparent supra-linear responses. Responses at or below 0.1 ppm benzene were observed for altered expression of AML pathway genes and CYP2E1. Together, these data show that benzene alters disease-relevant pathways and genes in a dose-dependent manner, with effects apparent at doses as low as 100 ppb in air. Studies with extensive exposure assessment of subjects exposed in the low-dose range between 10 ppb and 1 ppm are needed to confirm these findings. PMID:24786086

  6. Characterization of changes in gene expression and biochemical pathways at low levels of benzene exposure.

    Directory of Open Access Journals (Sweden)

    Reuben Thomas

    Full Text Available Benzene, a ubiquitous environmental pollutant, causes acute myeloid leukemia (AML. Recently, through transcriptome profiling of peripheral blood mononuclear cells (PBMC, we reported dose-dependent effects of benzene exposure on gene expression and biochemical pathways in 83 workers exposed across four airborne concentration ranges (from 10 ppm compared with 42 subjects with non-workplace ambient exposure levels. Here, we further characterize these dose-dependent effects with continuous benzene exposure in all 125 study subjects. We estimated air benzene exposure levels in the 42 environmentally-exposed subjects from their unmetabolized urinary benzene levels. We used a novel non-parametric, data-adaptive model selection method to estimate the change with dose in the expression of each gene. We describe non-parametric approaches to model pathway responses and used these to estimate the dose responses of the AML pathway and 4 other pathways of interest. The response patterns of majority of genes as captured by mean estimates of the first and second principal components of the dose-response for the five pathways and the profiles of 6 AML pathway response-representative genes (identified by clustering exhibited similar apparent supra-linear responses. Responses at or below 0.1 ppm benzene were observed for altered expression of AML pathway genes and CYP2E1. Together, these data show that benzene alters disease-relevant pathways and genes in a dose-dependent manner, with effects apparent at doses as low as 100 ppb in air. Studies with extensive exposure assessment of subjects exposed in the low-dose range between 10 ppb and 1 ppm are needed to confirm these findings.

  7. An acetylcholinesterase-independent mechanism for neurobehavioral impairments after chronic low level exposure to dichlorvos in rats.

    Science.gov (United States)

    Verma, Suresh Kumar; Kumar, Vijay; Gill, Kiran Dip

    2009-03-01

    The present study was designed to explore an alternate mechanism of action other than acetylcholinesterase inhibition for the chronic, low-level exposure to dichlorvos, an organophosphate, in vivo. Dichlorvos, at dose of 1.0 as well as 6.0 mg/kg b. wt. for 12 weeks to rats showed impairment in neurobehavioral indices viz. rota rod, passive avoidance and water maze tests. Though higher dose of dichlorvos had a detrimental effect on acetylcholinesterase activity, no significant inhibition was seen with lower dose of dichlorvos for the same period of exposure i.e. 12 weeks. Muscarinic acetylcholine receptor binding studies revealed a decrease in the number of binding sites (B(max)) in low as well as high dose groups but the dissociation constant (K(d)) value was unaffected with both doses of dichlorvos. Use of selective ligands against M(1), M(2) and M(3) receptor subtypes indicated that M(2) is the major receptor subtype being affected by chronic low-level exposure to dichlorvos. Western blot analysis and immunofluorescence studies also confirmed these biochemical findings. Thus, the present study suggests that M(2) receptors may play a major role in the development of neurobehavioral impairments after chronic exposure to dichlorvos.

  8. Prenatal low-level mercury exposure and infant neurodevelopment at 12 months in rural northern China.

    Science.gov (United States)

    Hu, Yi; Chen, Limei; Wang, Caifeng; Zhou, Yijun; Zhang, Yan; Wang, Yiwen; Shi, Rong; Gao, Yu; Tian, Ying

    2016-06-01

    Although MeHg is a confirmed neurotoxin at sufficiently high dosages, the effect of prenatal low-level Hg exposure on infant neurodevelopment is still unknown. Four hundred ten mother-infant pairs were recruited in rural northern China from September 2010 to September 2012. We investigated maternal diet during pregnancy, collected maternal and umbilical blood samples, and tested infant neurodevelopment using Gesell developmental schedules (GDS) at the age of 1 year old. The geometric means (GM) of Hg exposure in maternal and umbilical blood were 0.72 and 1.2 μg/L, respectively. Positive associations between Hg levels and the frequency of total fish consumption were found (Spearman's correlation, r = 0.09 for maternal Hg, r = 0.14 for umbilical Hg, p exposure and infant neurodevelopment. However, given the low-level Hg exposure and its predominant source, the potential positive associations in our study may be attributed to the beneficial nutrients of fish consumption.

  9. Low-level prenatal mercury exposure in north China: an exploratory study of anthropometric effects.

    Science.gov (United States)

    Ou, Langbo; Chen, Cen; Chen, Long; Wang, Huanhuan; Yang, Tianjun; Xie, Han; Tong, Yindong; Hu, Dan; Zhang, Wei; Wang, Xuejun

    2015-06-02

    In order to investigate anthropometric effects of mercury (Hg) exposure, we examined the status of human prenatal exposure to Hg species, including total mercury (THg), methylmercury (MeHg) and inorganic mercury (IHg), in North China, as well as their potential effects on fetal and infant growth. Hg concentrations in various bioindicators were measured from 50 Chinese women and newborns in 2011. The participants were followed for 12 months to collect anthropometric information. Linear and two-level regression analyses were performed to determine the associations between Hg levels and body growth. The geometric mean levels of THg in the placenta, cord blood, fetal hair, and maternal blood, hair, and urine were 25.88 μg/kg dry wt, 2.73 μg/L, 572.98 μg/kg, 2.29 μg/L, 576.54 μg/kg, and 0.58 μg/g creatinine, respectively. Nearly 100% of Hg presented as IHg in urine, and the percentage of IHg in other bioindicators was 14.86-48.73%. We observed significantly negative associations between Hg levels in some matrixes and anthropometry of neonates (weight and height) and infants (height) (p exposure could play a role in attenuating fetal and infant growth, and the effects of MeHg and IHg are different.

  10. The Influence of Chronic Exposure to Low Level Pulsed Microwave Radiation on Performance and Cognitive Behavior.

    Science.gov (United States)

    1983-05-15

    press levers) and a food reinforcement receptacle were located at one end of each exposure chamber. The arrangement of these operant components was such...that when actively engaged in bar-press, food retrieval and consumption the animal would be oriented 2 ° ° . . .° .° ° ° ° - N00014-79-C-0575 FINAL...behavioral components. At levels of irradiation that are significantly thermogenic (e.g., SAR of 6.8 mW/g) there ,- . . . . , N00014-79-C-0575 FINAL REPORT

  11. Decreased anxiety in juvenile rats following exposure to low levels of chlorpyrifos during development.

    Science.gov (United States)

    Carr, Russell L; Armstrong, Nathan H; Buchanan, Alenda T; Eells, Jeffrey B; Mohammed, Afzaal N; Ross, Matthew K; Nail, Carole A

    2017-03-01

    Exposure to chlorpyrifos (CPF) during the late preweanling period in rats inhibits the endocannabinoid metabolizing enzymes fatty acid hydrolase (FAAH) and monoacylglycerol lipase (MAGL), resulting in accumulation of their respective substrates anandamide (AEA) and 2-arachidonylglycerol (2-AG). This occurs at 1.0mg/kg, but at a lower dosage (0.5mg/kg) only FAAH and AEA are affected with no measurable inhibition of either cholinesterase (ChE) or MAGL. The endocannabinoid system plays a vital role in nervous system development and may be an important developmental target for CPF. The endocannabinoid system plays an important role in the regulation of anxiety and, at higher dosages, developmental exposure to CPF alters anxiety-like behavior. However, it is not clear whether exposure to low dosages of CPF that do not inhibit ChE will cause any persistent effects on anxiety-like behavior. To determine if this occurs, 10-day old rat pups were exposed daily for 7 days to either corn oil or 0.5, 0.75, or 1.0mg/kg CPF by oral gavage. At 12h following the last CPF administration, 1.0mg/kg resulted in significant inhibition of FAAH, MAGL, and ChE, whereas 0.5 and 0.75mg/kg resulted in significant inhibition of only FAAH. AEA levels were significantly elevated in all three treatment groups as were palmitoylethanolamide and oleoylethanolamide, which are also substrates for FAAH. 2-AG levels were significantly elevated by 0.75 and 1.0mg/kg but not 0.5mg/kg. On day 25, the latency to emerge from a dark container into a highly illuminated novel open field was measured as an indicator of anxiety. All three CPF treatment groups spent significantly less time in the dark container prior to emerging as compared to the control group, suggesting a decreased level of anxiety. This demonstrates that repeated preweanling exposure to dosages of CPF that do not inhibit brain ChE can induce a decline in the level of anxiety that is detectable during the early postweanling period. Copyright

  12. Determination of carboxyhaemoglobin in humans following low-level exposures to carbon monoxide.

    Science.gov (United States)

    Gosselin, Nathalie H; Brunet, Robert C; Carrier, Gaétan

    2009-11-01

    This study proposes to estimate carboxyhaemoglobin (COHb) levels in the blood of men and women of various ages exposed to common concentrations of carbon monoxide (CO) using a model with only one free parameter while integrating alveoli-blood and blood-tissue CO exchanges. The model retained is essentially that of Coburn et al. (1965) with two important additions: an alveoli compartment for the dynamics of CO exchanges between alveoli and blood, and a compartment for the significant amounts of CO bound to heme proteins in extravascular spaces. The model was validated by comparing its simulations with various published data sets for the COHb time profiles of volunteers exposed to known CO concentrations. Once the model was validated, it was used to simulate various situations of interest for their impact on public health. This approach yields reliable estimations of the time profiles of COHb levels resulting from different levels of CO exposure over various periods of time and under various conditions (resting, exercise, working, and smoking). The non-linear kinetics of CO, observed experimentally, were correctly reproduced by simulations with the model. Simulations were also carried out iteratively to determine the exposure times and CO concentrations in ambient air needed to reach the maximum levels of COHb recommended by Health Canada, the U.S. Environmental Protection Agency (EPA), and the World Health Organisation (WHO) for each age group of the general population. The lowest CO concentrations leading to maximum COHb levels of 1.5, 2, and 2.5% were determined.

  13. Proprioceptive evaluation in healthy women undergoing Infrared Low Level Laser Therapy

    Directory of Open Access Journals (Sweden)

    Grazieli da Silva

    2017-05-01

    Full Text Available Abstract Aim To evaluate if the application of infrared low-level laser therapy (LLLT alters proprioception in young women. Methods 26 female volunteers were evaluated statically and dynamically by means of electronic baropodometry in the variables: distance from the foot center, maximum and medium pressure, and surface. Proprioception was also functionally assessed by the Star Excursion Balance Test (SEBT. The intervention occurred in two distinct periods, separated by one week apart, as this was a crossover study, so volunteers were submitted to placebo or LLLT (830 nm, 8 J/cm2, on the muscles: gastrocnemius, soleus, tibialis previous and long and short fibular. Results the analysis of baropodometry for both dynamic and static found no significant differences for the intervention group and the control group. Similar results were observed for SEBT. Conclusion The application of the LLLT, in the proposed parameters, did not influence the proprioception in young women.

  14. Cancer risks related to low-level RF/MW exposures, including cell phones.

    Science.gov (United States)

    Szmigielski, Stanislaw

    2013-09-01

    For years, radiofrequency (RF) and microwave (MW) radiations have been applied in the modern world. The rapidly increasing use of cellular phones called recent attention to the possible health risks of RF/MW exposures. In 2011, a group of international experts organized by IARC (International Agency for Research on Cancer in Lyon) concluded that RF/MW radiations should be listed as a possible carcinogen (group 2B) for humans. Three meta-analyses of case-control studies have concluded that using cell phones for more than ten years was associated with an increase in the overall risk of developing a brain tumor. The Interphone Study, the largest health-related case-control international study of use of cell phones and head and neck tumors, showed no statistically significant increases in brain cancers related to higher amounts of cell phone use, but excess risk in a small subgroup of more heavily exposed users associated with latency and laterality was reported. So far, the published studies do not show that mobile phones could for sure increase the risk of cancer. This conclusion is based on the lack of a solid biological mechanism, and the fact that brain cancer rates are not going up significantly. However, all of the studies so far have weaknesses, which make it impossible to entirely rule out a risk. Mobile phones are still a new technology and there is little evidence about effects of long-term use. For this reason, bioelectromagnetic experts advise application of a precautionary resources. It suggests that if people want to use a cell phone, they can choose to minimize their exposure by keeping calls short and preferably using hand-held sets. It also advises discouraging children from making non essential calls as well as also keeping their calls short.

  15. Dose-to-risk conversion factors for low-level tritium exposures

    Energy Technology Data Exchange (ETDEWEB)

    Straume, T.

    1992-09-10

    During the past decade, a large number of radiobiological studies have become available for tritium-many of them focusing on the relative biological effectiveness (RBE) of tritium beta rays. These and previous studies indicate that tritium in body water produces the same spectrum of radiogenic effects, e.g., cancer, genetic effects, developmental abnormalities, and reproductive effects, observed following whole-body exposure to penetrating radiations such as gamma rays and x rays. The only significant difference in biological response between tritium beta-rays and the other common low linear-energy transfer (LET) radiations, such as gamma rays and x rays, appears to be the greater biological effectiveness of tritium beta rays. For example, tritium in the oxide form (HTO) is about 2 to 3 times more effective at low doses or low dose rates than gamma rays from [sup 137]Cs or [sup 60]CO (Straume, 1991). When tritium is bound to organic molecules, RBE values may be somewhat larger than those for HTO. It is now clear from the wealth of tritium data available that RBEs for tritium beta rays are higher than the quality factor of unity generally used in radiation protection.

  16. Evaluation of muscle regeneration in aged animals after treatment with low-level laser therapy

    Directory of Open Access Journals (Sweden)

    Adriana Pertille

    Full Text Available BACKGROUND: The aging process and its associated morphophysiological changes trigger a reduction in the regenerative ability of the satellite cells, a reduction of vascular tissue and an increase in the production of fibroblasts, developing a cellular environment unfavorable for muscle regeneration. OBJECTIVE: The aim of this study was to evaluate the effect of low-level laser therapy on the muscle regeneration of old experimental rat models after contusion. METHOD: A total of 25 old rats,18 months old, were divided into three groups: control group (CT without treatment; injury group (IN with muscle contusion and without treatment and laser group (LA with contusion and low-level laser therapy, 830 nm, 30 mW e 4 J/cm². The no invasive contusion was induced in the Tibialis Anterior muscle and the samples were collected after 7 and 21 treatment sessions. The muscle was evaluated by Light Microscopy and Immunoblotting. RESULTS: After 21 days of treatment there was a significant reduction in the areas of inflammation/regeneration of the LA 21 group compared to IN 21 group. The cross-sectional area of the fibers in regeneration was not statistically different between the groups. Molecular analysis showed that the content of MyoD was statistically reduced in the IN 21 group compared to the CT group. The Myogenin content was increased in the IN 21 group compared to the CT group. Ultimately, the content of TGF-β1 on the IN 21 group was higher when compared to the CT group. CONCLUSION: Considering the parameters used, the laser therapy demonstrated to be effective for muscle regeneration in old rats, however only through its anti-inflammatory effect.

  17. Oxidative Stress and Genotoxicity of Long-Term Occupational Exposure to Low Levels of BTEX in Gas Station Workers

    Directory of Open Access Journals (Sweden)

    Feng Xiong

    2016-12-01

    Full Text Available Atmospheric benzene, toluene, ethylbenzene, and xylenes (BTEX can lead to multiple health injuries. However, what remains uncertain is the effect of long-term exposure to low levels of BTEX. Thus, we determined the BTEX levels in the air from the refueling and office areas in gas stations. Then we collected workers’ (200 refueling vs. 52 office workers peripheral blood samples to analyze the serum total-superoxide dismutase (T-SOD, glutathione (GSH, malondialdehyde (MDA, and 8-hydroxydeoxyguanosine (8-OHdG levels. DNA damage was analyzed by the comet assay and micronucleus test in buccal epithelial cells. We found that the levels of BTEX in refueling areas were significantly higher than those in office areas (p < 0.001. The serum T-SOD and GSH of refueling workers were significantly lower than those in office workers (p < 0.001. By contrast, the serum MDA and 8-OHdG of refueling workers were significantly higher than those of office workers (p < 0.001, MDA; p = 0.025, 8-OHdG. Furthermore, tail and Olive tail moments in refueling workers were longer (p = 0.004, tail moment; p = 0.001, Olive tail moment, and the micronucleus rate was higher (p < 0.001 than those in office workers. Taken together, long-term exposure to low levels of BTEX may reduce the antioxidant ability and increase the risk of DNA damage in refueling workers of gas stations.

  18. Sub-acute occupational hypersensitivity pneumonitis due to low-level exposure to diisocyanates in a secretary.

    Science.gov (United States)

    Schreiber, J; Knolle, J; Sennekamp, J; Schulz, K T; Hahn, J U; Hering, K G; Raulf-Heimsoth, M; Merget, R

    2008-09-01

    There is virtually no information in the literature about the exposure levels needed to induce hypersensitivity pneumonitis (HP) by diisocyanates. The present study reports a case of occupational HP due to diisocyanates after low-level exposure. A 53-yr-old female never-smoker developed progressive shortness of breath on exertion, cough, fatigue and flu-like symptoms shortly after she began work as a secretary of a car body repair shop. A diagnosis of HP was made 2 yrs later, based on a restrictive ventilatory defect, a reticulonodular and discrete ground-glass pattern on high-resolution computed tomography, lymphocytosis in bronchoalveolar lavage and specific immunoglobulin G antibodies to diisocyanate human serum albumin conjugates in the patient's serum. The diagnosis was confirmed by recovery after exposure cessation and deterioration after re-exposure. Ambient monitoring revealed air concentrations of different diisocyanate monomers below the detection limit in both the patient's work station and in front of the paint spray booths, with the exception of one measurement that showed 4,4-methylenediphenyl diisocyanate concentrations of 3 microg x m(-3) in front of one booth (corresponding to a total reactive isocyanate group concentration of 1 microg x m(-3)). The present authors conclude that concentrations of diisocyanates far below current exposure limits may induce hypersensitivity pneumonitis in susceptible subjects.

  19. Reproductive and thyroid effects of low-level polychlorinated biphenyl (Aroclor 1254) exposure

    Energy Technology Data Exchange (ETDEWEB)

    Gray, L.E.; Ostby, J.; Marshall, R.; Andrews, J.

    1993-01-01

    The current study was conducted to evaluate the effects of subchronic administration of Aroclor 1254 on testicular gamete production and endocrine function. The thyroid hormone thyroxine (T4), which is critical for reproduction and development, was also measured because of the well-documented effects of PCBs on this hormone. Weanling (31-day-old) male Fischer rats were administered 0, 0.1, 1, 10, or 25 mg/kg/day Aroclor 1254 by gavage for 5, 10, or 15 weeks and necropsied. In the high-dose group, body, seminal vesicle, cauda epididymal, and pituitary weights were depressed at 10 and 15 weeks and cauda epididymal sperm numbers were reduced after 15 weeks of dosing. In contrast, testes weights, testicular sperm numbers, sperm motility, and serum and testicular testosterone levels were unaffected, even in the highest dose group (25 mg/kg/day). Aroclor 1254 administration produced histological alterations in the liver and kidney at doses of 1.0 mg/kg/day and above. These results indicate that the testis of the rat is not a specific target organ for Aroclor 1254.

  20. Up-regulation of neurotrophin-related gene expression in mouse hippocampus following low-level toluene exposure.

    Science.gov (United States)

    Win-Shwe, Tin-Tin; Tsukahara, Shinji; Yamamoto, Shoji; Fukushima, Atsushi; Kunugita, Naoki; Arashidani, Keiichi; Fujimaki, Hidekazu

    2010-01-01

    To investigate the role of strain differences in sensitivity to low-level toluene exposure on neurotrophins and their receptor levels in the mouse hippocampus, 8-week-old male C3H/HeN, BALB/c and C57BL/10 mice were exposed to 0, 5, 50, or 500 ppm toluene for 6h per day, 5 days per week for 6 weeks in an inhalation chamber. We examined the expressions of neurotrophin-related genes and receptors in the mouse hippocampus using real-time reverse transcription polymerase chain reaction (RT-PCR). The expression of nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), tyrosine kinase (Trk) A, and TrkB mRNAs in the C3H/HeN mice hippocampus was significantly higher in the mice exposed to 500 ppm toluene. Among the three strains of mice, the C3H/HeN mice seemed to be sensitive to toluene exposure. To examine the combined effect of toluene exposure and allergic challenge, the C3H/HeN mice stimulated with ovalbumin were exposed to toluene. The allergy group of C3H/HeN mice showed significantly elevated level of NGF mRNA in the hippocampus following exposure to 50 ppm toluene. Then, we also examined the expression of transcription factor, dopamine markers and oxidative stress marker in the hippocampus of sensitive strain C3H/HeN mice and found that the expression of CREB1 mRNA was significantly increased at 50 ppm toluene. In immunohistochemical analysis, the density of the NGF-immunoreactive signal was significantly stronger in the hippocampal CA3 region of the C3H/HeN mice exposed to 500 ppm toluene in non-allergy group and 50 ppm in allergy group. Our results indicate that low-level toluene exposure may induce up-regulation of neurotrophin-related gene expression in the mouse hippocampus depending on the mouse strain and an allergic stimulation in sensitive strain may decrease the threshold for sensitivity at lower exposure level. 2009 Elsevier Inc. All rights reserved.

  1. Evaluation of Activity Concentration Values and Doses due to the Transport of Low Level Radioactive Material

    Energy Technology Data Exchange (ETDEWEB)

    Rawl, Richard R [ORNL; Scofield, Patricia A [ORNL; Leggett, Richard Wayne [ORNL; Eckerman, Keith F [ORNL

    2010-04-01

    The International Atomic Energy Agency (IAEA) initiated an international Coordinated Research Project (CRP) to evaluate the safety of transport of naturally occurring radioactive material (NORM). This report presents the United States contribution to that IAEA research program. The focus of this report is on the analysis of the potential doses resulting from the transport of low level radioactive material. Specific areas of research included: (1) an examination of the technical approach used in the derivation of exempt activity concentration values and a comparison of the doses associated with the transport of materials included or not included in the provisions of Paragraph 107(e) of the IAEA Safety Standards, Regulations for the Safe Transport of Radioactive Material, Safety Requirements No. TS-R-1; (2) determination of the doses resulting from different treatment of progeny for exempt values versus the A{sub 1}/A{sub 2} values; and (3) evaluation of the dose justifications for the provisions applicable to exempt materials and low specific activity materials (LSA-I). It was found that the 'previous or intended use' (PIU) provision in Paragraph 107(e) is not risk informed since doses to the most highly exposed persons (e.g., truck drivers) are comparable regardless of intended use of the transported material. The PIU clause can also have important economic implications for co-mined ores and products that are not intended for the fuel cycle but that have uranium extracted as part of their industrial processing. In examination of the footnotes in Table 2 of TS-R-1, which identifies the progeny included in the exempt or A1/A2 values, there is no explanation of how the progeny were selected. It is recommended that the progeny for both the exemption and A{sub 1}/A{sub 2} values should be similar regardless of application, and that the same physical information should be used in deriving the limits. Based on the evaluation of doses due to the transport of low-level

  2. Evaluation of effect of low level laser therapy on pain during orthodontic tooth movement in human

    Directory of Open Access Journals (Sweden)

    Hosseini MH

    2010-06-01

    Full Text Available "nBackground and Aims: Lasers with different characteristics have been used to stimulate orthodontic tooth movements and to inhibit the pain during tooth movements. Considering the contradictory finding in this respect, the effect of low level laser therapy (LLLT was evaluated on the pain during orthodontic tooth movement. "nMaterials and Methods: In this randomized clinical trial study, 12 patients were included with extracted upper first premolars and required canine retraction into extraction site. While in both sides canines were retracted by Niti coil spring, one side was exposed to GaAlAs laser (890nm. LLLT was done on the buccal and palatal mucosa by slow movement of probe. The patients were asked about their pain on both sides 2 days after beginning of retraction. Pain measurement was evaluated with VAS. "nResults: Pain perception in LLLT side significantly decreased (P=0.007. "nConclusion: Based on the results, single irradiation of GaAlAs laser (12J energy per tooth can decrease pain perception.

  3. Effects of low-level sarin and cyclosarin exposure on white matter integrity in Gulf War Veterans.

    Science.gov (United States)

    Chao, Linda L; Zhang, Yu; Buckley, Shannon

    2015-05-01

    We previously found evidence of reduced gray and white matter volume in Gulf War (GW) veterans with predicted low-level exposure to sarin (GB) and cyclosarin (GF). Because loss of white matter tissue integrity has been linked to both gray and white matter atrophy, the current study sought to test the hypothesis that GW veterans with predicted GB/GF exposure have evidence of disrupted white matter microstructural integrity. Measures of fractional anisotropy and directional (i.e., axial and radial) diffusivity were assessed from the 4T diffusion tensor images (DTI) of 59 GW veterans with predicted GB/GF exposure and 59 "matched" unexposed GW veterans (mean age: 48 ± 7 years). The DTI data were analyzed using regions of interest (ROI) analyses that accounted for age, sex, total brain gray and white matter volume, trauma exposure, posttraumatic stress disorder, current major depression, and chronic multisymptom illness status. There were no significant group differences in fractional anisotropy or radial diffusivity. However, there was increased axial diffusivity in GW veterans with predicted GB/GF exposure compared to matched, unexposed veterans throughout the brain, including the temporal stem, corona radiata, superior and inferior (hippocampal) cingulum, inferior and superior fronto-occipital fasciculus, internal and external capsule, and superficial cortical white matter blades. Post hoc analysis revealed significant correlations between higher fractional anisotropy and lower radial diffusivity with better neurobehavioral performance in unexposed GW veterans. In contrast, only increased axial diffusivity in posterior limb of the internal capsule was associated with better psychomotor function in GW veterans with predicted GB/GF exposure. The finding that increased axial diffusivity in a region of the brain that contains descending corticospinal fibers was associated with better psychomotor function and the lack of significant neurobehavioral deficits in veterans

  4. Efficacy of low level laser therapy in myofascial pain syndrome: an algometric and thermographic evaluation.

    Science.gov (United States)

    Hakgüder, Aral; Birtane, Murat; Gürcan, Süleyman; Kokino, Siranuş; Turan, Fatma Nesrin

    2003-01-01

    The efficacy of low level laser therapy (LLLT) in myofascial pain syndrome (MPS) seems controversial. Our aim was to clarify the effect of LLLT in MPS by using algometry and thermography. Sixty-two patients with MPS having an active trigger point in the neck or upper back region were randomly divided into two equal groups according to therapy applied (group 1: LLLT + stretching exercises, group 2: stretching exercises alone). The outcome measures were pain measured with visual analogue scale (VAS), algometry on the trigger point, algometric difference, thermographic difference, and thermal asymmetry. Comparison was made within and between the groups pre- and post-therapeutically and 3 weeks after therapy. Mean pain values decreased more significantly in group 1 from baseline to 3 weeks follow up (7.54-3.06) while these values were 7.03-5.19 in group 2 (P < 0.05). Group comparisons revealed significant favorable differences in group 1 patients in terms of all other parameters at the first and the second evaluation post therapeutically (P < 0.05). LLLT seemed to be beneficial for pain in MPS by using algometry and thermography. Copyright 2003 Wiley-Liss, Inc.

  5. Low-level laser therapy on skeletal muscle inflammation: evaluation of irradiation parameters

    Science.gov (United States)

    Mantineo, Matías; Pinheiro, João P.; Morgado, António M.

    2014-09-01

    We evaluated the effect of different irradiation parameters in low-level laser therapy (LLLT) for treating inflammation induced in the gastrocnemius muscle of rats through cytokines concentration in systemic blood and analysis of muscle tissue. We used continuous (830 and 980 nm) and pulsed illuminations (830 nm). Animals were divided into five groups per wavelength (10, 20, 30, 40, and 50 mW), and a control group. LLLT was applied during 5 days with a constant irradiation time and area. TNF-α, IL-1β, IL-2, and IL-6 cytokines were quantified by ELISA. Inflammatory cells were counted using microscopy. Identical methodology was used with pulsed illumination. Average power (40 mW) and duty cycle were kept constant (80%) at five frequencies (5, 25, 50, 100, and 200 Hz). For continuous irradiation, treatment effects occurred for all doses, with a reduction of TNF-α, IL-1β, and IL-6 cytokines and inflammatory cells. Continuous irradiation at 830 nm was more effective, a result explained by the action spectrum of cytochrome c oxidase (CCO). Best results were obtained for 40 mW, with data suggesting a biphasic dose response. Pulsed wave irradiation was only effective for higher frequencies, a result that might be related to the rate constants of the CCO internal electron transfer process.

  6. Clinical evaluation of low level laser therapy in treatment of cutaneous leishmaniasis

    Directory of Open Access Journals (Sweden)

    Nafie A. Al-Muslet

    2012-07-01

    Full Text Available This study aimed to evaluate the effectiveness of Low Level Laser Therapy (LLLT, with specific laser parameters, in the treatment of Cutaneous Leishmaniasis (CL. Thirteen patients, clinically and by positive smear diagnosed as cases of CL, were referred from Khartoum Teaching Hospital and were considered as study population. The Treatment was done using diode laser probe with wavelength of 820 nm, followed by cluster probe (assembly of non-coherent and coherent diodes. The dose was: I. Diode laser probe with energy density of 48 J/cm2 for thirty seconds. II. Cluster probe with energy density of 9.6 J/cm2 for two minutes.The distance between the probe and the skin was less than 1cm. The frequency of treatment was three sessions weekly for total of ten sessions.The function of LLLT in this study was to reduce inflammation (anti-inflammatory effect and accelerate healing. The results showed that the response was excellent in the majority of treated patient (92.3 %. The complications were minimal and transient. The results proved that LLLT is a successful treatment method for Cutaneous Leishmaniasis and it is easy to perform.

  7. Source team evaluation for radioactive low-level waste disposal performance assessment

    Energy Technology Data Exchange (ETDEWEB)

    Cowgill, M.G.; Sullivan, T.M. [Brookhaven National Lab., Upton, NY (United States)

    1993-01-01

    Information compiled on the low-level radioactive waste disposed at the three currently operating commercial disposal sites during the period 1987--1989 have been reviewed and processed in order to determine the total activity distribution in terms of waste stream, waste classification and waste form. The review identified deficiencies in the information currently being recorded on shipping manifests and the development of a uniform manifest is recommended (the NRC is currently developing a rule to establish a uniform manifest). The data from waste disposed during 1989 at one of the sites (Richland, WA) were more detailed than the data available during other years and at other sites, and thus were amenable to a more in-depth treatment. This included determination of the distribution of activity for each radionuclide by waste form, and thus enabled these data to be evaluated in terms of the specific needs for improved modeling of releases from waste packages. From the results, preliminary lists have been prepared of the isotopes which might be the most significant from the aspect of the development of a source term model.

  8. Long-term, low-level exposure of guinea pigs and marmosets to sarin vapor in air: Lowest observable effect level

    NARCIS (Netherlands)

    Helden, H.P.M. van; Trap, H.C.; Oostdijk, J.P.; Kuijpers, W.C.; Langenberg, J.P.; Benschop, H.P.

    2003-01-01

    Realistic scenarios for low-level exposure to nerve agents will often involve exposures over several hours to extremely low doses of agent. In order to expose animals to the lowest controllable concentrations of agent and to increase exposure times until a lowest observable effect level (LOEL)

  9. Whole body exposure of marmoset monkeys to low levels of sarin: Lowest observable effect level in blood, and early effects on pupil size and EEG

    NARCIS (Netherlands)

    Helden, H.P.M. van; Trap, H.C.; Kuijpers, W.C.; Oostdijk, J.P.; Vanwersch, R.A.P.; Phillippens, I.H.C.H.M.; Benschop, H.P.

    2004-01-01

    Realistic scenarios for low-level exposure to nerve agents will often involve exposures over several hours to extremely low doses of agent. The purpose of this pilot study was to indicate for sarin: (i) the lowest observable effect level (LOEL), i.e., the C.t-value (t = 5 h) of exposure at which an

  10. Effect of Short-term 900 MHz low level electromagnetic radiation exposure on blood serotonin and glutamate levels.

    Science.gov (United States)

    Eris, A H; Kiziltan, H S; Meral, I; Genc, H; Trabzon, M; Seyithanoglu, H; Yagci, B; Uysal, O

    2015-01-01

    Long term exposure to low level electromagnetic radiation (LLER) by using cellular phones causes serious health problems. Ten male Wistar Albino rats were anesthetized 30 min before the LLER exposure, 0.5 ml blood was taken from the tail vein of rats in order to determine control values. Rats were grouped by three and placed on a plexi-glass flat. A fixed equivalent frequency emitter device was used. A sign to be an electromagnetic field 15.14 V/m (608 mW/m(2)) in strength in the head region with 100 kHz FM modulation at 900 MHz was applied to the animals. After calculating the ideal position for the device, electromagnetic LLER energy was applied for 45 minutes from a distance to be equal with energy transmitted by a mobile phone from a 0.5-1 cm distance to their head regions. After 1.5 hours and before the rats awoke, 0.5 ml of blood was taken from the tail veins in order to determine the treatment values. Plasma 5-HT and glutamate levels were measured by enzyme immunoassay (EIA) using commercial kits. It was found that a single 45 min of LLER exposure increased the blood 5-HT level significantly, but did not change the glutamate level of rats. It was concluded that even a single 45 min of LLER exposure may produce an increase in 5-HT level without changing the blood glutamate level. Increased 5-HT level may lead to a retarded learning and a deficit in spatial memory (Tab. 2, Fig. 2, Ref. 24).

  11. Evaluation of dental pulp repair using low level laser therapy (688 nm and 785 nm) morphologic study in capuchin monkeys

    Science.gov (United States)

    Pretel, H.; Oliveira, J. A.; Lizarelli, R. F. Z.; Ramalho, L. T. O.

    2009-02-01

    The aim of this study was to evaluate the hypothesis that low-level laser therapy (LLLT) 688 nm and 785 nm accelerate dentin barrier formation and repair process after traumatic pulp exposure. The sample consisted of 45 premolars of capuchin monkeys (Cebus apella) with pulp exposure Class V cavities. All premolars were treated with calcium hydroxide (Ca(OH)2), divided in groups of 15 teeth each, and analyzed on 7th, 25th, and 60th day. Group GI - only Ca(OH)2, GII - laser 688 nm, and GIII - laser 785 nm. Laser beam was used in single and punctual dose with the parameters: continuous, 688 nm and 785 nm wavelength, tip's area of 0.00785 cm2, power 50 mW, application time 20 s, dose 255 J/cm2, energy 2 J. Teeth were capped with Ca(OH)2, Ca(OH)2 cement and restored with amalgam. All groups presented pulp repair. On 25th day the thickness of the formed dentin barrier was different between the groups GI and GII (p < 0.05) and between groups GI and GIII (p < 0.01). On 60th day there was difference between GI and GIII (p < 0.01). It may be concluded that, LLLT 688 nm and 785 nm accelerated dentin barrier formation and consequently pulp repair process, with best results using infrared laser 785 nm.

  12. Evaluation of ultrafiltration membranes for treating low-level radioactive contaminated liquid waste

    Energy Technology Data Exchange (ETDEWEB)

    Koenst, J.W.; Roberts, R.C.

    1978-03-31

    A series of experiments were performed on Waste Disposal Facility (WD) influent using Romicon hollow fiber ultrafiltration modules with molecular weight cutoffs ranging from 2000 to 80,000. The rejection of conductivity was low in most cases. The rejection of radioactivity ranged from 90 to 98%, depending on the membrane type and on the feed concentration. Typical product activity ranged from 7 to 100 dis/min/ml of alpha radiation. Experiments were also performed on alpha-contaminated laundry wastewater. Results ranged from 98 to >99.8%, depending on the membrane type. This yielded a product concentration of less than 0.1 dis/min/ml of alpha radiation. Tests on PP-Building decontamination water yielded rejections of 85 to 88% alpha radiation depending on the membrane type. These experiments show that the ability to remove radioactivity by membrane is a function of the contents of the waste stream because the radioactivity in the wastewater is in various forms: ionic, polymeric, colloidal, and absorbed onto suspended solids. Although removal of suspended or colloidal material is very high, removal of ionic material is not as effective. Alpha-contaminated laundry wastewater proved to be the easiest to decontaminate, whereas the low-level PP-Building decontamination water proved to be the most difficult to decontaminate. Decontamination of the WD influent, a combined waste stream, varied considerably from day to day because of its constantly changing makeup. The WD influent was also treated with various substances, such as polyelectrolytes, complexing agents, and coagulants, to determine if these additives would aid in the removal of radioactive material from the various wastewaters by complexing the ionic species. At the present time, none of the additives evaluated has had much effect; but experiments are continuing.

  13. Evaluation of two protocols for low-level laser application in patients submitted to orthodontic treatment

    Directory of Open Access Journals (Sweden)

    Mariana Marquezan

    2013-02-01

    Full Text Available INTRODUCTION: Different low-level laser (LLL irradiation protocols have been tested to accelerate orthodontic tooth movement (OTM. Nevertheless, divergent results have been obtained. It was suggested that the stimulatory action of low level laser irradiation occurs during the proliferation and differentiation stages of bone cellular precursors, but not during later stages. OBJECTIVE: The purpose of this study was to determine the effect of two protocols of LLL irradiation on experimental tooth movement: One with daily irradiations and another with irradiations during the early stages. METHODS: Thirty-six rats were divided into control groups (CG1, CG2, CG3 and irradiated groups (IrG1, IrG2, IrG3 according to the presence of: experimental tooth movement, laser irradiation, type of laser irradiation protocol and date of euthanasia (3th or 8th day of experiment. At the end of experimental periods, a quantitative evaluation of the amount of OTM was made and the reactions of the periodontium were analyzed by describing cellular and tissue reactions and by counting blood vessels. RESULTS: The amount of OTM revealed no significant differences between groups in the same experimental period (p INTRODUÇÃO: diferentes protocolos de irradiação por laser de baixa potência (LBP têm sido testados para potencializar o movimento ortodôntico; entretanto, há resultados divergentes. Foi sugerido que seu efeito bioestimulador ocorre nas fases de proliferação e diferenciação celular, não agindo em estágios tardios. OBJETIVO: avaliar o efeito de dois protocolos de irradiação do LBP na movimentação ortodôntica: um com irradiações diárias e outro em que irradiações foram realizadas apenas nos períodos iniciais. MÉTODOS: trinta e seis ratos Wistar foram divididos em grupos controles (GC1, GC2 e GC3 e irradiados (GIr1, GIr2 e GIr3, de acordo com a presença de dispositivo ortodôntico, a presença de irradiação, o tipo de protocolo de irradia

  14. The non-linear association between low-level lead exposure and maternal stress among pregnant women.

    Science.gov (United States)

    Li, Shufang; Xu, Jian; Liu, Zhiwei; Yan, Chong-Huai

    2017-03-01

    Neuro-developmental impairments in the developing fetus due to exposure to low-level lead have been well documented. However, few studies have investigated the relation between maternal stress levels and low-level lead exposure among pregnant women. To investigate the relation between maternal blood lead and stress levels during index pregnancy. 1931 pregnant women (gestational week 28-36) were investigated using stratified-cluster-sampling in Shanghai in 2010. Maternal life event stress and emotional stress were assessed using "Life-Event-Stress-Scale-for-Pregnant-Women" (LESPW) and "Symptom-Checklist-90-Revised" (SCL-90-R), respectively. Maternal whole blood lead levels were determined, and other data on covariates were obtained from maternal interviews and medical records. Two piecewise linear regression models were applied to assess the relations between blood lead and stress levels using a data-driven approach according to spline smoothing fitting of the data. Maternal blood lead levels ranged from 0.80 to 14.84μg/dL, and the geometric mean was 3.97μg/dL. The P-values for the two piecewise linear models against the single linear regression models were 0.010, 0.003 and 0.017 for models predicting GSI, depression and anxiety symptom scores, respectively. When blood lead levels were below 2.57μg/dL, each unit increase in log10 transformed blood lead levels (μg/dL) was associated with about 18% increase in maternal GSI, depression and anxiety symptom scores (PGSI=0.013, Pdepression=0.002, Panxiety=0.019, respectively). However, no significant relation was found when blood lead levels were above 2.57μg/dL (all P-values>0.05). Our findings suggested a nonlinear relationship between blood lead and emotional stress levels among pregnant women. Emotional stress increased along with blood lead levels, and appeared to be plateaued when blood lead levels reached 2.57μg/dL. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Nuclear phenotype evaluation in skeletal muscle from Wistar rats exposed to low-level lasers

    Science.gov (United States)

    Almeida, L. G.; Sergio, L. P. S.; Vicentini, S. C.; Mencalha, A. L.; Paoli, F.; Fonseca, A. S.

    2017-03-01

    Low-level laser therapy includes devices emitting red and near-infrared radiation with output power below 100 mW. These devices are successfully used for the treatment of injuries and to improve exercise performance based on their biomodulatory effect. Despite the wide use of clinical protocols based on these lasers, the laser-induced effects on DNA are still disputed. Thus, the objective of this study was to investigate chromatin organization, ploidy degrees, and DNA fragmentation in skeletal muscle tissue from Wistar rats exposed to low-level red and infrared lasers. Wistar rats were exposed to low-level red and infrared lasers (25, 50, and 100 J cm-2, 100 mW, continuous-wave emission mode) and, after 24h, samples of this tissue were withdrawn for the analysis of chromatin organization, ploidy degrees, and DNA fragmentation by Feulgen reaction detection of micronucleus, and apoptosis by TUNEL assay. Data obtained show that low-level red and infrared lasers alter geometric and densitometric parameters as well ploidy degree in muscle nuclei from Wistar rats, but do not induce DNA fragmentation, chromatin loss, and apoptosis at fluences taken out from clinical protocols.

  16. Low-level arsenic exposure during pregnancy and its association with postpartum depression: A cohort study of women from Arica, Chile.

    Science.gov (United States)

    Valdés, M; Hanchey, A; Muñoz, M P; Baumert, B; Iglesias, V

    2017-11-01

    While the relationship between inorganic arsenic exposure and psychological impairment has been studied previously, the association between low-level arsenic exposure during pregnancy and postpartum depression has not yet been examined. The objective is to estimate the association between low-level arsenic exposure during pregnancy and the Edinburgh score. A sample of 223 women was collected from five public health services in Arica, Chile. Participation was voluntary and written consent was mandatory. Sociodemographic data related to arsenic exposure and urine samples for total inorganic arsenic assessments were collected during the second trimester. Postpartum depression symptoms were estimated by the Edinburgh Postpartum Depression scale. We examined descriptive statistics and ran multiple linear regressions. The modifying effect of age and depression history was evaluated separately. The median for total urinary inorganic arsenic was 14.6μg/L (range: 2-69.2μg/L), the median for postpartum depression score was 8 points (range: 0-27 points) and 20.6% of women were considered as postpartum depressed. For women older than 25years old without depression history, the adjusted coefficient for the total urinary natural logarithm of inorganic arsenic in multiple linear regressions was -2.51 (95% CI: -4.54, -0.48; P-value=0.02). For women older than 25years old with a depression history, this value was 2.09 (95% CI: -0.90, 5.08; P-value=0.16). In this cohort, the number of children, physical perception, depression history, stressful maternity, and age were associated with postpartum depression score. The Edinburgh score was associated with inorganic arsenic in women older than 25years without depression history. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  17. CYP2E1 epigenetic regulation in chronic, low-level toluene exposure: Relationship with oxidative stress and smoking habit

    Energy Technology Data Exchange (ETDEWEB)

    Jiménez-Garza, Octavio, E-mail: ojimenezgarza@ugto.mx [Health Sciences Division, University of Guanajuato Campus León, Blvd. Puente del Milenio 1001, Fracción del Predio San Carlos, C.P. 37670 León, Guanajuato (Mexico); Baccarelli, Andrea A.; Byun, Hyang-Min [Laboratory of Environmental Epigenetics, Department of Environmental Health, Harvard T.H. Chan School of Public Health, 677 Huntington Avenue, Boston, MA 02115 (United States); Márquez-Gamiño, Sergio [Health Sciences Division, University of Guanajuato Campus León, Blvd. Puente del Milenio 1001, Fracción del Predio San Carlos, C.P. 37670 León, Guanajuato (Mexico); Barrón-Vivanco, Briscia Socorro [Environmental Toxicology and Pollution Laboratory, Nayarit Autonomous University, Av. Ciudad de la Cultura s/n, “Amado Nervo”, Tepic, Nayarit C.P. 63155 (Mexico); Albores, Arnulfo [Department of Toxicology, CINVESTAV, Av. Instituto Politécnico Nacional 2508, Col. San Pedro Zacatenco, 07360 Mexico DF (Mexico)

    2015-08-01

    Background: CYP2E1 is a versatile phase I drug-metabolizing enzyme responsible for the biotransformation of most volatile organic compounds, including toluene. Human toluene exposure increases CYP2E1 mRNA and modifies its activity in leucocytes; however, epigenetic implications of this interaction have not been investigated. Goal: To determine promoter methylation of CYP2E1 and other genes known to be affected by toluene exposure. Methods: We obtained venous blood from 24 tannery workers exposed to toluene (mean levels: 10.86 +/− 7 mg/m{sup 3}) and 24 administrative workers (reference group, mean levels 0.21 +/− 0.02 mg/m{sup 3}) all of them from the city of León, Guanajuato, México. After DNA extraction and bisulfite treatment, we performed PCR-pyrosequencing in order to measure methylation levels at promoter region of 13 genes. Results: In exposed group we found significant correlations between toluene airborne levels and CYP2E1 promoter methylation (r = − .36, p < 0.05), as well as for IL6 promoter methylation levels (r = .44, p < 0.05). Moreover, CYP2E1 promoter methylation levels where higher in toluene-exposed smokers compared to nonsmokers (p = 0.009). We also observed significant correlations for CYP2E1 promoter methylation with GSTP1 and SOD1 promoter methylation levels (r = − .37, p < 0.05 and r = − .34, p < 0.05 respectively). Conclusion: These results highlight the importance of considering CYP2E1 epigenetic modifications, as well as its interactions with other genes, as key factors for unraveling the sub cellular mechanisms of toxicity exerted by oxidative stress, which can initiate disease process in chronic, low-level toluene exposure. People co-exposed to toluene and tobacco smoke are in higher risk due to a possible CYP2E1 repression. - Highlights: • We investigated gene-specific methylation in persons chronically exposed to toluene. • In a previous study, a reduced CYP2E1 activity was observed in these participants. • CYP2E1

  18. Evaluation of genotoxicity in workers exposed to low levels of formaldehyde in a furniture manufacturing facility.

    Science.gov (United States)

    Peteffi, Giovana Piva; da Silva, Luciano Basso; Antunes, Marina Venzon; Wilhelm, Camila; Valandro, Eduarda Trevizani; Glaeser, Jéssica; Kaefer, Djeine; Linden, Rafael

    2016-10-01

    Formaldehyde (FA) is a chemical widely used in the furniture industry and has been classified as a potential human carcinogen. The purpose of this study was to evaluate the occupational exposure of workers to FA at a furniture manufacturing facility and the relationship between environmental concentrations of FA, formic acid concentration in urine, and DNA damage. The sample consisted of 46 workers exposed to FA and a control group of 45 individuals with no history of occupational exposure. Environmental concentrations of FA were determined by high-performance liquid chromatography. Urinary formic acid concentrations were determined by gas chromatography with flame ionization detector. DNA damage was evaluated by the micronucleus (MN) test performed in exfoliated buccal cells and comet assay with venous blood. The 8-h time-weighted average of FA environmental concentration ranged from 0.03 ppm to 0.09 ppm at the plant, and the control group was exposed to a mean concentration of 0.012 ppm. Workers exposed to higher environmental FA concentrations had urinary formic acid concentrations significantly different from those of controls (31.85 mg L(-1) vs. 19.35 mg L(-), p ≤ 0.01 Mann-Whitney test). Significant differences were found between control and exposed groups for the following parameters: damage frequency and damage index in the comet assay, frequency of binucleated cells in the MN test, and formic acid concentration in urine. The frequency of micronuclei, nuclear buds, and karyorrhexis did not differ between groups. There was a positive correlation between environmental concentrations of FA and damage frequency (Spearman's rank correlation coefficient [r s] = 0.24), damage index (r s = 0.21), binucleated cells (r s = 0.34), and urinary formic acid concentration (r s = 0.63). The results indicate that, although workers in the furniture manufacturing facility were exposed to low environmental levels of FA, this agent contributes to the observed increase in

  19. Evaluation of the data available for estimating release rates from commercial low-level waste packages

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan, T.M.; Cowgill, M.G.

    1991-12-31

    In this paper, an overview of our findings concerning the distribution of activity within low-level radioactive wastes will be presented. This will begin in a general fashion and consider the distribution of the total activity by each of the following: waste class, waste stream, wasteform, and waste container. A radionuclide specific breakdown by waste class and wasteform follows. The findings are reviewed in terms of performance assessment modeling needs. Finally, we present our conclusions.

  20. An Evaluation of Long-Term Performance of Liner Systems for Low-Level Waste Disposal Facilities

    Energy Technology Data Exchange (ETDEWEB)

    Arthur S. Rood; Annette L. Schafer; A. Jeffrey Sondrup

    2011-03-01

    Traditional liner systems consisting of a geosynthetic membrane underlying a waste disposal facility coupled with a leachate collection system have been proposed as a means of containing releases of low-level radioactive waste within the confines of the disposal facility and thereby eliminating migration of radionuclides into the vadose zone and groundwater. However, this type of hydraulic containment liner system is only effective as long as the leachate collection system remains functional or an overlying cover limits the total infiltration to the volumetric pore space of the disposal system. If either the leachate collection system fails, or the overlying cover becomes less effective during the 1,000’s of years of facility lifetime, the liner may fill with water and release contaminated water in a preferential or focused manner. If the height of the liner extends above the waste, the waste will become submerged which could increase the release rate and concentration of the leachate. If the liner extends near land surface, there is the potential for contamination reaching land surface creating a direct exposure pathway. Alternative protective liner systems can be engineered that eliminate radionuclide releases to the vadose zone during operations and minimizing long term migration of radionuclides from the disposal facility into the vadose zone and aquifer. Non-traditional systems include waste containerization in steel or composite materials. This type of system would promote drainage of clean infiltrating water through the facility without contacting the waste. Other alternatives include geochemical barriers designed to transmit water while adsorbing radionuclides beneath the facility. Facility performance for a hypothetical disposal facility has been compared for the hydraulic and steel containerization liner alternatives. Results were compared in terms of meeting the DOE Order 435.1 low-level waste performance objective of 25 mrem/yr all-pathways dose

  1. Low-level exposure of guinea pigs and marmosets to sarin vapour in air: Lowest-observable-adverse-effect level (LOAEL) for miosis

    NARCIS (Netherlands)

    Helden, H.P.M. van; Trap, H.C.; Kuijpers, W.C.; Oostdijk, J.P.; Benschop, H.P.; Langenberg, J.P.

    2004-01-01

    The purpose of this pilot study was to indicate, for low-level exposure of conscious guinea pigs and marmoset monkeys to sarin vapour in air, the lowest-observable-adverse-effect level (LOAEL) of sarin for miosis. This is the concentration × time (C·t) value (t = 5 h) of exposure at which miosis

  2. Low level nose-only exposure to the nerve agent soman: Toxicokinetics of soman stereoisomers and cholinesterase inhibition in atropinized guinea pigs

    NARCIS (Netherlands)

    Benschop, H.P.; Trap, H.C.; Spruit, H.E.T.; Wiel, H.J. van der; Langenberg, J.P.; Jong, L.P.A. de

    1998-01-01

    In order to initiate a quantitative basis for the toxicology of low level exposure to nerve agents, the toxicokinetics of soman stereoisomers during nose-only exposure for 5 h to 20 ppb (160 μg/m3) of C(±)P(±)- soman in air were studied in restrained, anesthetized, and atropinized guinea pigs. The

  3. Development of methodology to evaluate microbially influenced degradation of cement-solidified low-level radioactive waste forms

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, R.D.; Hamilton, M.A.; Veeh, R.H.; McConnell, J.W. [Idaho National Engineering Lab., Idaho Falls, ID (United States)

    1994-12-31

    Because of its apparent structural integrity, cement has been widely used in the United States as a binder to solidify Class B and C low-level radioactive waste (LLW). However, the resulting cement preparations are susceptible to failure due to the actions of stress and environment. An environmentally mediated process that could affect cement stability is the action of naturally occurring microorganisms. The US Nuclear Regulatory Commission (NRC), recognizing this eventuality, stated that the effects of microbial action on waste form integrity must be addressed. This paper provides present results from an ongoing program that addresses the effects of microbially influenced degradation (MID) on cement-solidified LLW. Data are provided on the development of an evaluation method using acid-producing bacteria. Results are from work with one type of these bacteria, the sulfur-oxidizing Thiobacillus. This work involved the use of a system in which laboratory- and vendor-manufactured, simulated waste forms were exposed on an intermittent basis to media containing thiobacilli. Testing demonstrated that MID has the potential to severely compromise the structural integrity of ion-exchange resin and evaporator-bottoms waste that is solidified with cement. In addition, it was found that a significant percentage of calcium and other elements were leached from the treated waste forms. Also, the surface pH of the treated specimens decreased to below 2. These conditions apparently contributed to the physical deterioration of simulated waste forms after 60 days of exposure to the thiobacilli.

  4. Scoping evaluation of the technical capabilities of DOE sites for disposal of hazardous metals in mixed low-level waste

    Energy Technology Data Exchange (ETDEWEB)

    Gruebel, M.M.; Waters, R.D.; Langkopf, B.S.

    1997-05-01

    A team of analysts designed and conducted a scoping evaluation to estimate the technical capabilities of fifteen Department of Energy sites for disposal of the hazardous metals in mixed low-level waste (i.e., waste that contains both low-level radioactive materials and hazardous constituents). Eight hazardous metals were evaluated: arsenic, barium, cadmium, chromium, lead, mercury, selenium, and silver. The analysis considered transport only through the groundwater pathway. The results are reported as site-specific estimates of maximum concentrations of each hazardous metal in treated mixed low-level waste that do not exceed the performance measures established for the analysis. Also reported are site-specific estimates of travel times of each hazardous metal to the point of compliance.

  5. Clinical Evaluation of Low Level Diode Laser Application For Primary Teeth Pulpotomy.

    Science.gov (United States)

    Uloopi, K S; Vinay, C; Ratnaditya, A; Gopal, A Satya; Mrudula, K J N; Rao, R Chandrasekhar

    2016-01-01

    Inspite of latest advances in the materials and techniques practiced for the treatment of pulpally infected teeth with better reported success rate, still the question arises for safety and effectiveness of these medicaments. The objective of the present study was to compare the effectiveness of the Low Level Laser Therapy to Mineral Trioxide Aggregate (MTA) when used for pulpotomy in vital human primary molars. The sample consisted of 40 primary molars from 29 children aged four to seven years. The teeth were selected based on clinical, radiographic criteria and randomly allocated to two groups. All the 40 primary molars were subjected to standard pulpotomy procedure, where in 20 molars received MTA (Group I) and 20 molars received LLLT (Group II) pulpotomy. Children were recalled at 3, 6 and 12 months intervals and pulpotomised molars were examined clinically and radiographically. Data was analysed using chi-square test. MTA showed 94.7% success rate at all the three intervals, where as LLLT showed a success of 95% at three months, which decreased gradually to 85% at six months and 80% at 12 months. Intergroup comparisons were not significant. Low level laser therapy can be considered for primary teeth pulpotomy and its success is comparable to MTA pulpotomy technique.

  6. Evaluation of low level laser therapy in reducing diabetic polyneuropathy related pain and sensorimotor disorders.

    Science.gov (United States)

    Bashiri, Homayoon

    2013-09-09

    Over the past three decades physicians have used light level laser therapy (LLLT) for the management and the treatment of diabetic peripheral neuropathy and have obtained results that calls for further investigations. This study aimed to investigate the effectiveness of LLLT in treatment of pain symptoms in patients with diabetic polyneuropathy. In this study 60 patients with diabetic peripheral neuropathy were matched based on their sex, age, BMI, type of diabetes, duration of diabetes, and duration of pain, and randomized to case and control groups based on their established scores on the visual analog scale (VAS) and the Toronto clinical scoring system (TCSS). Cases received laser therapy with wavelength of 78 nm and 2.5 j/cm2 two times a week, each time for 5 min, for one month. During the same period, controls received sham laser therapy. Comparing the differences between the two groups' VAS and TCSS mean scores before the intervention with that of the 2 weeks and 4 weeks after the intervention we were able to see a statistically significant difference between the two groups (P<0.05). On the other hand, when we compared their VAS and TCSS mean scores 4 weeks and 2 weeks after the intervention we did not find any statistically significant difference between the two groups. We achieved the same results when we examined cases' and controls' pre and post VAS and TCSS scores independent from each other; no improvement in the assessment based on their 2 and 4 weeks comparisons tests. Laser therapy resulted in improved neuropathy outcomes in diabetic patients who received it relative to the group that received sham therapy, evaluating before and after LLLT assessments. Further studies are needed to test types of lasers, as well as different dosage and exposure levels required in different phase of neuropathic care, so as to obtain reproducible results.

  7. Evaluation of moisture effect on low-level CO2 adsorption by ion-exchanged zeolite.

    Science.gov (United States)

    Lee, Kyung-Mi; Lim, Yun-Hee; Jo, Young-Min

    2012-01-01

    To enhance the capture of low-level indoor CO2, a commercial zeolite (13X) was modified with alkali and alkaline earth metals using an ion-exchange method. Although the calcium-impregnated sorbent (zeo-Ca) showed the largest adsorption capacity, with a strong binding force for carbon dioxide, its regeneration by heat treatment was very difficult. Moisture in the gas flow caused significant decreases in CO2 adsorption capability as well as in the lifetime of the adsorbents. As for the regeneration gas, the test showed that nitrogen would hinder the CO2 adsorption more significantly than helium gas. Water vapour and nitrogen gas molecules are apt to competitively occupy the available sites of the adsorbent over the CO2 molecules.

  8. Evaluation of low-level laser therapy in patients with acute and chronic temporomandibular disorders.

    Science.gov (United States)

    Salmos-Brito, Janaina Andrade Lima; de Menezes, Rebeca Ferraz; Teixeira, Camila Epitácio Cravo; Gonzaga, Raphaella Karlla Machado; Rodrigues, Breno Henrique Mara; Braz, Rodivan; Bessa-Nogueira, Ricardo Viana; Gerbi, Marleny Elizabeth Márquez de Martínez

    2013-01-01

    The purpose of this study was to address the following question: among patients with acute or chronic temporomandibular disorders (TMD), does low-level laser therapy (LLLT) reduce pain intensity and improve maximal mouth opening? The sample comprised myogenic TMD patients (according Research Diagnostic Criteria for TMD). Inclusion criteria were: male/female, no age limit, orofacial pain, tender points, limited jaw movements and chewing difficulties. Patients with other TMD subtypes or associated musculoskeletal/rheumatologic disease, missing incisors teeth, LLLT contra-indication, and previous TMD treatment were excluded. According to disease duration, patients were allocated into two groups, acute (TMD (≥ 6 months). For each patient, 12 LLLT sessions were performed (gallium-aluminum-arsenide; λ = 830 nm, P = 40 mW, CW, ED = 8 J/cm(2)). Pain intensity was recorded using a 10-cm visual analog scale and maximal mouth opening using a digital ruler (both recorded before/after LLLT). The investigators were previously calibrated and blinded to the groups (double-blind study) and level of significance was 5% (p TMD), and 26 (chronic TMD). Both groups had a significant pain intensity reduction and maximal mouth opening improvement after LLLT (Wilcoxon test, p TMD patient had a more significant pain intensity reduction (Mann-Whitney test, p = 0.002) and a more significant maximal mouth opening improvement (Mann-Whitney test, p = 0.011). Low-level laser therapy can be considered as an alternative physical modality or supplementary approach for management of acute and chronic myogenic temporomandibular disorder; however, patients with acute disease are likely to have a better outcome.

  9. Low-level environmental lead exposure in childhood and adult intellectual function: a follow-up study

    Directory of Open Access Journals (Sweden)

    Gregas Matthew

    2011-03-01

    Full Text Available Abstract Background Early life lead exposure might be a risk factor for neurocognitive impairment in adulthood. Objectives We sought to assess the relationship between early life environmental lead exposure and intellectual function in adulthood. We also attempted to identify which time period blood-lead concentrations are most predictive of adult outcome. Methods We recruited adults in the Boston area who had participated as newborns and young children in a prospective cohort study that examined the relationship between lead exposure and childhood intellectual function. IQ was measured using the Wechsler Abbreviated Scale of Intelligence (WASI. The association between lead concentrations and IQ scores was examined using linear regression. Results Forty-three adults participated in neuropsychological testing. Childhood blood-lead concentration (mean of the blood-lead concentrations at ages 4 and 10 years had the strongest relationship with Full-Scale IQ (β = -1.89 ± 0.70, p = 0.01. Full-scale IQ was also significantly related to blood-lead concentration at age 6 months (β = -1.66 ± 0.75, p = 0.03, 4 years (β = -0.90 ± 0.41, p = 0.03 and 10 years (β = -1.95 ± 0.80, p = 0.02. Adjusting for maternal IQ altered the significance of the regression coefficient. Conclusions Our study suggests that lead exposure in childhood predicts intellectual functioning in young adulthood. Our results also suggest that school-age lead exposure may represent a period of increased susceptibility. Given the small sample size, however, the potentially confounding effects of maternal IQ cannot be excluded and should be evaluated in a larger study.

  10. Assessing Potential Exposure from Truck Transport of Low-level Radioactive Waste to the Nevada Test Site

    Energy Technology Data Exchange (ETDEWEB)

    J. Miller; D. Shafer; K. Gray; B. Church; S. Campbell; B. Holz

    2005-08-01

    Since 1980, over 651,558 m{sup 3} (23,000,000 ft{sup 3}) of low-level radioactive waste (LLW) have been disposed of at the Nevada Test Site (NTS) by shallow land burial. Since 1988, the majority of this waste has been generated at other United States (U.S.) Department of Energy (DOE) and Department of Defense (DoD) sites and facilities in the U.S. Between fiscal year (FY) 2002 and the publication date, the volumes of LLW being shipped by truck to the NTS increased sharply with the accelerated closure of DOE Environmental Management (EM) Program sites (DOE, 2002). The NTS is located 105 km (65 mi) northwest of Las Vegas, Nevada, in the U.S. There continue to be public concerns over the safety of LLW shipments to the NTS. They can be broadly divided into two categories: (1) the risk of accidents involving trucks traveling on public highways; and (2) whether residents along transportation routes receive cumulative exposure from individual LLW shipments that pose a long-term health risk. The DOE and U.S. Department of Transportation (DOT) regulations ensure that radiation exposure from truck shipments to members of the public is negligible. Nevertheless, particularly in rural communities along transportation routes in Utah and Nevada, there is a perceived risk from members of the public about cumulative exposure, particularly when ''Main Street'' and the routes being used by LLW trucks are one in the same. To provide an objective assessment of gamma radiation exposure to members of the public from LLW transport by truck, the Desert Research Institute (DRI) and the DOE, National Nuclear Security Administration Nevada Site Office (NNSA/NSO) established a stationary and automated array of four pressurized ion chambers (PICs) in a vehicle pullout for LLW trucks to pass through just outside the entrance to the NTS. The PICs were positioned at a distance of 1.0 m (3.3 ft) from the sides of the truck trailer and at a height of 1.5 m (5.0 ft) to simulate

  11. Assessing Potential Exposure from Truck Transport of Low-level Radioactive Waste to the Nevada Test Site

    Energy Technology Data Exchange (ETDEWEB)

    Miller, J; Shafer, D; Gray, K; Church, B; Campbell, S; Holtz, B.

    2005-08-15

    Since 1980, over 651,558 m{sup 3} (23,000,000 ft{sup 3}) of low-level radioactive waste (LLW) have been disposed of at the Nevada Test Site (NTS) by shallow land burial. Since 1988, the majority of this waste has been generated at other United States (U.S.) Department of Energy (DOE) and Department of Defense (DoD) sites and facilities in the U.S. Between fiscal year (FY) 2002 and the publication date, the volumes of LLW being shipped by truck to the NTS increased sharply with the accelerated closure of DOE Environmental Management (EM) Program sites (DOE, 2002). The NTS is located 105 km (65 mi) northwest of Las Vegas, Nevada, in the U.S. There continue to be public concerns over the safety of LLW shipments to the NTS. They can be broadly divided into two categories: (1) the risk of accidents involving trucks traveling on public highways; and (2) whether residents along transportation routes receive cumulative exposure from individual LLW shipments that pose a long-term health risk. The DOE and U.S. Department of Transportation (DOT) regulations ensure that radiation exposure from truck shipments to members of the public is negligible. Nevertheless, particularly in rural communities along transportation routes in Utah and Nevada, there is a perceived risk from members of the public about cumulative exposure, particularly when ''Main Street'' and the routes being used by LLW trucks are one in the same. To provide an objective assessment of gamma radiation exposure to members of the public from LLW transport by truck, the Desert Research Institute (DRI) and the DOE, National Nuclear Security Administration Nevada Site Office (NNSA/NSO) established a stationary and automated array of four pressurized ion chambers (PICs) in a vehicle pullout for LLW trucks to pass through just outside the entrance to the NTS. The PICs were positioned at a distance of 1.0 m (3.3 ft) from the sides of the truck trailer and at a height of 1.5 m (5.0 ft) to simulate

  12. Phytoextraction for clean-up of low-level uranium contaminated soil evaluated

    Energy Technology Data Exchange (ETDEWEB)

    Vandenhove, H. E-mail: hvandenh@sckcen.be; Hees, M. van

    2004-07-01

    Spills in the nuclear fuel cycle have led to soil contamination with uranium. In case of small contamination just above release levels, low-cost yet sufficiently efficient remedial measures are recommended. This study was executed to test if low-level U contaminated sandy soil from a nuclear fuel processing site could be phytoextracted in order to attain the required release limits. Two soils were tested: a control soil (317 Bq {sup 238}U kg{sup -1}) and the same soil washed with bicarbonate (69 Bq {sup 238}U kg{sup -1}). Ryegrass (Lolium perenne cv. Melvina) and Indian mustard (Brassica juncea cv. Vitasso) were used as test plants. The annual removal of soil activity by the biomass was less than 0.1%. The addition of citric acid (25 mmol kg{sup -1}) 1 week before the harvest increased U uptake up to 500-fold. With a ryegrass and mustard yield of 15,000 and 10,000 kg ha{sup -1}, respectively, up to 3.5% and 4.6% of the soil activity could be removed annually by the biomass. With a desired activity reduction level of 1.5 and 5 for the bicarbonate-washed and control soil, respectively, it would take 10-50 years to attain the release limit. However, citric acid addition resulted in a decreased dry weight production.

  13. Mathematical model for evaluating the suitability of a low-level radioactive waste site

    Energy Technology Data Exchange (ETDEWEB)

    Gureghian, A.B.; Sedlet, J.

    1982-02-01

    A mathematical model intended to study the one-dimensional transport of radionuclides in a non-homogeneous soil system under saturated-unsaturated and isothermal conditions is presented. The model is composed of two modules: the first to calculate the pressure distribution enabling one to compute velocities and soil moisture; the second to calculate the migration of species by considering the major processes associated with the transport phenomena of a dissolved substance in porous media, i.e., advection, mechanical dispersion, molecular diffusion, radioactive decay, and sorption, assuming a linear equilibrium isotherm. The numerical method of solving both flow and solute equations used here is the finite-element method based on the weighted residual technique. The flow equation is solved by the Bubnov-Galerkin method. The solute equation is solved by a Petrov-Galerkin type method. The model allows for a variety of boundary conditions; e.g., infiltration, drainage and/or evaporation. A test case involving the movement of a non-reacting ionic species is used to validate the model. Use of the model is illustrated by the analysis of the movement Sr-90 and Cs-137 and H-3 (as water) from a low-level solid-waste disposal trench subject to a steady rate of rainfall.

  14. Low level exposure to GB vapor in air: Diagnosis/dosimetry, lowest observable effect level (LOEL) and lowest observable adverse effect level (LOAEL)

    NARCIS (Netherlands)

    Trap, H.C.; Kuijpers, W.C.; Groen, B.; Oostdijk, J.P.; Vanwersch, R.A.P.; Phillippens, I.H.C.; Langenberg, J.P.; Benschop, H.P.; Helden, H.P.M. van

    2000-01-01

    The purpose of the present study was to establish for both saline-pretreated and pyridostigmine-pretreated conscious guinea pigs whole-body exposed to low levels of GB vapor: (i) The Lowest Observable Effect Level (LOEL) for GB, i.e., the C.t-value (t = 5-h) of exposure at which an internal dose

  15. Evaluation of the efficacy of low-level laser in improving the symptoms of burning mouth syndrome.

    Science.gov (United States)

    Arbabi-Kalati, Fateme; Bakhshani, Nour-Mohammad; Rasti, Maryam

    2015-10-01

    Burning mouth syndrome (BMS) is common conditions that affects menopause women, patients suffer from sever burning sensation. Up to now there is no definitive treatment for this disease. Present study was undertaken to evaluate the efficacy of low-level laser (LLL) in improving the symptoms of burning mouth syndrome. Twenty patients with BMS were enrolled in this study; they were divided in two groups randomly. In the laser group, in each patient, 10 areas on the oral mucosa were selected and underwent LLL irradiation at a wavelength of 630 nm, and a power of 30 mW for 10 seconds twice a week for 4 weeks. In the placebo group, silent/off laser therapy was carried out during the same period in the same areas. Burning sensation and quality of life were evaluated. Burning sensation severity and quality of life in the two groups after intervention were different significant statistically, (p= 0.004, p= 0.01 respectively) .Patients in laser group had better results. It can be concluded that low level laser might decrease the intensity of burning mouth syndrome. Pain, low-level laser, burning mouth syndrome, oral mucosa.

  16. End-stage renal disease and low level exposure to lead, cadmium and mercury; a population-based, prospective nested case-referent study in Sweden

    Science.gov (United States)

    2013-01-01

    Background Cadmium (Cd), lead (Pb), and mercury (Hg) cause toxicological renal effects, but the clinical relevance at low-level exposures in general populations is unclear. The objective of this study is to assess the risk of developing end-stage renal disease in relation to Cd, Pb, and Hg exposure. Methods A total of 118 cases who later in life developed end-stage renal disease, and 378 matched (sex, age, area, and time of blood sampling) referents were identified among participants in two population-based prospective cohorts (130,000 individuals). Cd, Pb, and Hg concentrations were determined in prospectively collected samples. Results Erythrocyte lead was associated with an increased risk of developing end-stage renal disease (mean in cases 76 μg/L; odds ratio (OR) 1.54 for an interquartile range increase, 95% confidence interval (CI) 1.18-2.00), while erythrocyte mercury was negatively associated (2.4 μg/L; OR 0.75 for an interquartile range increase, CI 0.56-0.99). For erythrocyte cadmium, the OR of developing end-stage renal disease was 1.15 for an interquartile range increase (CI 0.99-1.34; mean Ery-Cd among cases: 1.3 μg/L). The associations for erythrocyte lead and erythrocyte mercury, but not for erythrocyte cadmium, remained after adjusting for the other two metals, smoking, BMI, diabetes, and hypertension. Gender-specific analyses showed that men carried almost all of the erythrocyte lead and erythrocyte cadmium associated risks. Conclusions Erythrocyte lead is associated with end-stage renal disease but further studies are needed to evaluate causality. Gender-specific analyses suggest potential differences in susceptibility or in exposure biomarker reliability. PMID:23343055

  17. Evaluation of geologic materials to limit biological intrusion into low-level radioactive waste disposal sites

    Energy Technology Data Exchange (ETDEWEB)

    Hakonson, T.E.

    1986-02-01

    This report describes the results of a three-year research program to evaluate the performance of selected soil and rock trench cap designs in limiting biological intrusion into simulated waste. The report is divided into three sections including a discussion of background material on biological interactions with waste site trench caps, a presentation of experimental data from field studies conducted at several scales, and a final section on the interpretation and limitations of the data including implications for the user.

  18. Source term model evaluations for the low-level waste facility performance assessment

    Energy Technology Data Exchange (ETDEWEB)

    Yim, M.S.; Su, S.I. [North Carolina State Univ., Raleigh, NC (United States)

    1995-12-31

    The estimation of release of radionuclides from various waste forms to the bottom boundary of the waste disposal facility (source term) is one of the most important aspects of LLW facility performance assessment. In this work, several currently used source term models are comparatively evaluated for the release of carbon-14 based on a test case problem. The models compared include PRESTO-EPA-CPG, IMPACTS, DUST and NEFTRAN-II. Major differences in assumptions and approaches between the models are described and key parameters are identified through sensitivity analysis. The source term results from different models are compared and other concerns or suggestions are discussed.

  19. Low-Level Blast Exposure Increases Transient Receptor Potential Vanilloid 1 (TRPV1) Expression in the Rat Cornea

    OpenAIRE

    Por, Elaine D.; Choi, Jae-Hyek; Lund, Brian J.

    2016-01-01

    ABSTRACT Background: Blast-related ocular injuries sustained by military personnel have led to rigorous efforts to elucidate the effects of blast exposure on neurosensory function. Recent studies have provided some insight into cognitive and visual deficits sustained following blast exposure; however, limited data are available on the effects of blast on pain and inflammatory processes. Investigation of these secondary effects of blast exposure is necessary to fully comprehend the complex pat...

  20. Efficacy of multiple exposure with low level He-Ne laser dose on acute wound healing: a pre-clinical study

    Science.gov (United States)

    Prabhu, Vijendra; Rao, Bola Sadashiva S.; Mahato, Krishna Kishore

    2014-02-01

    Investigations on the use of Low Level Laser Therapy (LLLT) for wound healing especially with the red laser light have demonstrated its pro-healing potential on a variety of pre-clinical and surgical wounds. However, until now, in LLLT the effect of multiple exposure of low dose laser irradiation on acute wound healing on well-designed pre-clinical model is not much explored. The present study aimed to investigate the effect of multiple exposure of low dose Helium Neon laser on healing progression of full thickness excision wounds in Swiss albino mice. Further, the efficacy of the multiple exposure of low dose laser irradiation was compared with the single exposure of optimum dose. Full thickness excision wounds (circular) of 15 mm diameter were created, and subsequently illuminated with the multiple exposures (1, 2, 3, 4 and 5 exposure/ week until healing) of He-Ne (632.8 nm, 4.02 mWcm-2) laser at 0.5 Jcm-2 along with single exposure of optimum laser dose (2 J/cm-2) and un-illuminated controls. Classical biophysical parameters such as contraction kinetics, area under the curve and the mean healing time were documented as the assessment parameters to examine the efficacy of multiple exposures with low level laser dose. Experimental findings substantiated that either single or multiple exposures of 0.5 J/cm2 failed to produce any detectable alterations on wound contraction, area under the curve and mean healing time compared to single exposure of optimum dose (2 Jcm-2) and un-illuminated controls. Single exposure of optimum, laser dose was found to be ideal for acute wound healing.

  1. Energy evaluation of low-level control in UAVs powered by lithium polymer battery.

    Science.gov (United States)

    Gandolfo, Daniel C; Salinas, Lucio R; Serrano, Mario E; Toibero, Juan M

    2017-11-01

    Nowadays, the energetic cost of flying in electric-powered UAVs is one of the key challenges. The continuous evolution of electrical energy storage sources is overcome by the great amount of energy required by the propulsion system. Therefore, the on-board energy is a crucial factor that needs to be further analyzed. In this work, different control strategies applied to a generic UAV propulsion system are considered and a lithium polymer battery dynamic model is included as the propulsion system energy source. Several simulations are carried out for each control strategy, and a quantitative evaluation of the influence of each control law over the actual energy consumed by the propulsion system is reported. This energy, which is delivery by the battery, is next compared against a well-known control-effort-based index. The results and analysis suggest that conclusions regarding energy savings based on control effort signals should be drawn carefully, because they do not directly represent the actual consumed energy. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  2. Neurobehavioral function and low-level exposure to brominated flame retardants in adolescents: a cross-sectional study

    Directory of Open Access Journals (Sweden)

    Kiciński Michał

    2012-11-01

    Full Text Available Abstract Background Animal and in vitro studies demonstrated a neurotoxic potential of brominated flame retardants, a group of chemicals used in many household and commercial products to prevent fire. Although the first reports of detrimental neurobehavioral effects in rodents appeared more than ten years ago, human data are sparse. Methods As a part of a biomonitoring program for environmental health surveillance in Flanders, Belgium, we assessed the neurobehavioral function with the Neurobehavioral Evaluation System (NES-3, and collected blood samples in a group of high school students. Cross-sectional data on 515 adolescents (13.6-17 years of age was available for the analysis. Multiple regression models accounting for potential confounders were used to investigate the associations between biomarkers of internal exposure to brominated flame retardants [serum levels of polybrominated diphenyl ether (PBDE congeners 47, 99, 100, 153, 209, hexabromocyclododecane (HBCD, and tetrabromobisphenol A (TBBPA] and cognitive performance. In addition, we investigated the association between brominated flame retardants and serum levels of FT3, FT4, and TSH. Results A two-fold increase of the sum of serum PBDE’s was associated with a decrease of the number of taps with the preferred-hand in the Finger Tapping test by 5.31 (95% CI: 0.56 to 10.05, p = 0.029. The effects of the individual PBDE congeners on the motor speed were consistent. Serum levels above the level of quantification were associated with an average decrease of FT3 level by 0.18 pg/mL (95% CI: 0.03 to 0.34, p = 0.020 for PBDE-99 and by 0.15 pg/mL (95% CI: 0.004 to 0.29, p = 0.045 for PBDE-100, compared with concentrations below the level of quantification. PBDE-47 level above the level of quantification was associated with an average increase of TSH levels by 10.1% (95% CI: 0.8% to 20.2%, p = 0.033, compared with concentrations below the level of quantification. We did not

  3. Performance evaluation of the technical capabilities of DOE sites for disposal of mixed low-level waste: Volume 3, Site evaluations

    Energy Technology Data Exchange (ETDEWEB)

    Waters, R.D.; Gruebel, M.M. [eds.

    1996-03-01

    A team of analysts designed and conducted a performance evaluation to estimate the technical capabilities of fifteen Department of Energy sites for disposal of mixed low-level waste (i.e., waste that contains both low-level radioactive materials and hazardous constituents). Volume 1 summarizes the process for selecting the fifteen sites, the methodology used in the evaluation, and the conclusions derived from the evaluation. Volume 2 provides details about the site-selection process, the performance-evaluation methodology, and the overall results of the analysis. Volume 3 contains detailed evaluations of the fifteen sites and discussion of the results for each site.

  4. Field controlled experiments on the physiological responses of maize (Zea mays L.) leaves to low-level air and soil mercury exposures.

    Science.gov (United States)

    Niu, Zhenchuan; Zhang, Xiaoshan; Wang, Sen; Zeng, Ming; Wang, Zhangwei; Zhang, Yi; Ci, Zhijia

    2014-01-01

    Thousands of tons of mercury (Hg) are released from anthropogenic and natural sources to the atmosphere in a gaseous elemental form per year, yet little is known regarding the influence of airborne Hg on the physiological activities of plant leaves. In the present study, the effects of low-level air and soil Hg exposures on the gas exchange parameters of maize (Zea mays L.) leaves and their accumulation of Hg, proline, and malondialdehyde (MDA) were examined via field open-top chamber and Hg-enriched soil experiments, respectively. Low-level air Hg exposures ( 0.05). However, both the net photosynthesis rate and carboxylation efficiency of maize leaves exposed to 50 ng m(-3) air Hg were significantly lower than those exposed to 2 ng m(-3) air Hg in late morning (p plant leaves, inducing free proline accumulation and membrane lipid peroxidation. Due to minor translocation of soil Hg to the leaves, low-level soil Hg exposures ( 0.05). Compared to soil Hg, airborne Hg easily caused physiological stress to plant leaves. The effects of increasing atmospheric Hg concentration on plant physiology should be of concern.

  5. Size-dependent effects of low level cadmium and zinc exposure on the metabolome of the Asian clam, Corbicula fluminea

    Energy Technology Data Exchange (ETDEWEB)

    Spann, Nicole, E-mail: nicole.spann@web.de [Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ (United Kingdom); Aldridge, David C., E-mail: da113@cam.ac.uk [Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ (United Kingdom); Griffin, Julian L., E-mail: jlg40@mole.bio.cam.ac.uk [Sanger Building, Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 1GA (United Kingdom); Jones, Oliver A.H., E-mail: o.jones@gmail.com [Sanger Building, Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 1GA (United Kingdom)

    2011-10-15

    Highlights: Small and large Corbicula fluminea were exposed to cadmium and zinc spiked sediment. Metabolomic changes in the freshwater clams were determined by NMR and GC-MS. Metabolic perturbations were related to amino acid and energy related metabolism. Small and large clams were differentiated by their metabolic composition. Size classes showed opposite responses to metal stress. - Abstract: The toxic effects of low level metal contamination in sediments are currently poorly understood. We exposed different sized Asian clams, Corbicula fluminea, to sediment spiked with environmentally relevant concentrations of either zinc, cadmium or a zinc-cadmium mixture for one week. This freshwater bivalve is well suited for sediment toxicity tests as it lives partly buried in the sediment and utilises sediment particles as a food resource. After one week, the whole tissue composition of low molecular weight metabolites was analysed by nuclear magnetic resonance spectroscopy (NMR) and gas chromatography-mass spectrometry (GC-MS). The condition index (ratio of tissue dry weight to volume inside the shell valves) was also measured. Small and large clams were clearly differentiated by their metabolic composition and the two size classes showed opposite responses to the mixture spiked sediment. No effects of zinc alone on the metabolome were found and cadmium only influenced the smaller size class. The main perturbations were seen in amino acid and energy metabolism, with small clams using amino acids as an energy resource and larger clams primarily drawing on their larger storage reserves of carbohydrates. Our study demonstrates that metabolomics is a useful technique to test for low level toxicity which does not manifest in mortality or condition index changes. The differing effects between the two size classes stress that it is important to consider age/size when conducting metabolomic and ecotoxicology assessments, since testing for the effects on only one size class makes

  6. Size-dependent effects of low level cadmium and zinc exposure on the metabolome of the Asian clam, Corbicula fluminea.

    Science.gov (United States)

    Spann, Nicole; Aldridge, David C; Griffin, Julian L; Jones, Oliver A H

    2011-10-01

    The toxic effects of low level metal contamination in sediments are currently poorly understood. We exposed different sized Asian clams, Corbicula fluminea, to sediment spiked with environmentally relevant concentrations of either zinc, cadmium or a zinc-cadmium mixture for one week. This freshwater bivalve is well suited for sediment toxicity tests as it lives partly buried in the sediment and utilises sediment particles as a food resource. After one week, the whole tissue composition of low molecular weight metabolites was analysed by nuclear magnetic resonance spectroscopy (NMR) and gas chromatography-mass spectrometry (GC-MS). The condition index (ratio of tissue dry weight to volume inside the shell valves) was also measured. Small and large clams were clearly differentiated by their metabolic composition and the two size classes showed opposite responses to the mixture spiked sediment. No effects of zinc alone on the metabolome were found and cadmium only influenced the smaller size class. The main perturbations were seen in amino acid and energy metabolism, with small clams using amino acids as an energy resource and larger clams primarily drawing on their larger storage reserves of carbohydrates. Our study demonstrates that metabolomics is a useful technique to test for low level toxicity which does not manifest in mortality or condition index changes. The differing effects between the two size classes stress that it is important to consider age/size when conducting metabolomic and ecotoxicology assessments, since testing for the effects on only one size class makes it more difficult to extrapolate laboratory results to the natural environment. Copyright © 2011 Elsevier B.V. All rights reserved.

  7. CLINICAL EVALUATION OF THE HEALING PROCESS OF ORAL SOFT TISSUE SURGICAL WOUNDS STIMULATED BY LOW-LEVEL LASER THERAPY.

    Directory of Open Access Journals (Sweden)

    Hristina Lalabonova

    2013-03-01

    Full Text Available During the past decades laser therapy gained much popularity in clinical practice. Low-level lasers offer alternative solutions to numerous problems in oral surgery.Purpose: The purpose of the present study is to evaluate clinically the healing process of soft tissue surgical wounds in the oral cavity stimulated by low-level laser therapy (LLLT.Materials and methods: One hundred and twenty surgical wounds were assigned to three groups: Group I included 40 patients who underwent red spectrum LLLT with wavelength (λ of 658 nm;Group ІІ – 40 patients treated with infra-red LLLT with λ of 904 nm;Group ІІІ (control group - 40 patients without LLLT. In Group І and ІІ the LLLT procedures were applied 1 day before, in the day of and 1 day after the operation. Distant emission with a focused beam through an angled conical probe 3 mm in diameter (ø3mm was used. The irradiated area is 0,5 cm2. The area of impact is the surgical wound zone and the neighboring 0,5-1,0 cm of the adjacent oral mucosa.Results and discussion: The evaluation of the healing process included the following criteria: pain, edema, hyperemia, time for wound closure, postoperative complications.Conclusions: LLLT applied with the offered treatment modality accelerates the healing process of soft tissue surgical wounds in the oral cavity, reduces treatment time and restores patients’ comfort.

  8. Exposure to Low Levels of Lead in Utero and Umbilical Cord Blood DNA Methylation in Project Viva: An Epigenome-Wide Association Study.

    Science.gov (United States)

    Wu, Shaowei; Hivert, Marie-France; Cardenas, Andres; Zhong, Jia; Rifas-Shiman, Sheryl L; Agha, Golareh; Colicino, Elena; Just, Allan C; Amarasiriwardena, Chitra; Lin, Xihong; Litonjua, Augusto A; DeMeo, Dawn L; Gillman, Matthew W; Wright, Robert O; Oken, Emily; Baccarelli, Andrea A

    2017-08-25

    Early-life exposure to lead is associated with deficits in neurodevelopment and with hematopoietic system toxicity. DNA methylation may be one of the underlying mechanisms for the adverse effects of prenatal lead on the offspring, but epigenome-wide methylation data for low levels of prenatal lead exposure are lacking. We investigated the association between prenatal maternal lead exposure and epigenome-wide DNA methylation in umbilical cord blood nucleated cells in Project Viva, a prospective U.S.-based prebirth cohort with relatively low levels of lead exposure. Among 268 mother-infant pairs, we measured lead concentrations in red blood cells (RBC) from prenatal maternal blood samples, and using HumanMethylation450 Bead Chips, we measured genome-wide methylation levels at 482,397 CpG loci in umbilical cord blood and retained 394,460 loci after quality control. After adjustment for batch effects, cell types, and covariates, we used robust linear regression models to examine associations of prenatal lead exposure with DNA methylation in cord blood at epigenome-wide significance level [false discovery rate (FDR)lead level was 1.22 (0.63) μg/dL. CpG cg10773601 showed an epigenome-wide significant negative association with prenatal lead exposure (-1.4% per doubling increase in lead exposure; p=2.3×10-7) and was annotated to C-Type Lectin Domain Family 11, Member A (CLEC11A), which functions as a growth factor for primitive hematopoietic progenitor cells. In sex-specific analyses, we identified more CpGs with FDRlead exposure among female infants (-4.3% per doubling increase in lead exposure; p=1.1×10-06), was annotated to Dynein Heavy Chain Domain 1 gene (DNHD1) which is highly expressed in human brain. Interestingly, there were strong correlations between blood and brain methylation for CpG (cg24637308) based on another independent set of samples with a high proportion of female participants. Prenatal low-level lead exposure was associated with newborn DNA

  9. Total and Cause-Specific Mortality Risk Associated With Low-Level Exposure to Crystalline Silica: A 44-Year Cohort Study From China.

    Science.gov (United States)

    Liu, Yuewei; Zhou, Yun; Hnizdo, Eva; Shi, Tingming; Steenland, Kyle; He, Xinjian; Chen, Weihong

    2017-08-15

    The association between low-level crystalline silica (silica) exposure and mortality risk is not well understood. We investigated a cohort of 44,807 Chinese workers who had worked in metal mines or pottery factories for at least 1 year from January 1, 1960, to December 31, 1974, and were followed through 2003. Low-level silica exposure was defined as having a lifetime highest annual mean silica exposure at or under a permissible exposure limit (PEL). We considered 3 widely used PELs, including 0.05 mg/m3, 0.10 mg/m3, and 0.35 mg/m3. Cumulative silica exposure was estimated by linking a job exposure matrix with each participant's work history. For the 0.10-mg/m3 exposure level, Cox proportional hazards models showed significantly increased risk of mortality from all diseases (for each 1-ln mg/m3-years increase in logged cumulative silica exposure, hazard ratio (HR) = 1.05, 95% confidence interval (CI): 1.03, 1.07), malignant neoplasms (HR = 1.06, 95% CI: 1.03, 1.09), lung cancer (HR = 1.08, 95% CI: 1.02, 1.14), ischemic heart disease (HR = 1.09, 95% CI: 1.02, 1.16), pulmonary heart disease (HR = 1.08, 95% CI: 1.00, 1.16), and respiratory disease (HR = 1.20, 95% CI: 1.14, 1.26). The 0.05-mg/m3 and 0.35-mg/m3 exposure levels yielded similar associations. Long-term exposure to low levels (PELs ≤0.05 mg/m3, ≤0.10 mg/m3, or ≤0.35 mg/m3) of silica is associated with increased total and certain cause-specific mortality risk. Control of ambient silica levels and use of personal protective equipment should be emphasized in practice. © The Author(s) 2017. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  10. Effects of Long-Term Low-Level Radiofrequency Radiation Exposure on Rats. Volume 1. Design, Facilities, and Procedures.

    Science.gov (United States)

    1983-09-01

    8217* Power Generation and Distribution Each exposure room was equipped with two 2450-MHz pulsed microwave sources ( Epsco , model PG5KB, Trenton, NJ), each...METERS RS 232 COMMUNICATIONS WITH MASTER 4-DIGIT L ED DISPLAY FROM ALCOVE CONTROL SWITCHES TTL SYNC EPSCO 12-CHANNEL TEMP MONITOR OSCLLSCPE MICROWAVE

  11. Social and institutional evaluation report for Greater-Than-Class C Low-Level Radioactive Waste Disposal

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, T.L.; Lewis, B.E.; Turner, K.H.; Rozelle, M.A. [Dames and Moore, Denver, CO (United States)

    1993-10-01

    This report identifies and characterizes social and institutional issues that would be relevant to the siting, licensing, construction, closure, and postclosure of a Greater-Than-Class-C low-level radioactive waste (GTCC LLW) disposal facility. A historical perspective of high-level radioactive waste (HLW) and LLW disposal programs is provided as an overview of radioactive waste disposal and to support the recommendations and conclusions in the report. A characterization of each issue is provided to establish the basis for further evaluations. Where applicable, the regulatory requirements of 10 CFR 60 and 61 are incorporated in the issue characterizations. The issues are used to compare surface, intermediate depth, and deep geologic disposal alternatives. The evaluation establishes that social and institutional issues do not significantly discriminate among the disposal alternatives. Recommendations are provided for methods by which the issues could be considered throughout the lifecycle of a GTCC LLW disposal program.

  12. [Evaluation of low level laser and interferential current in the therapy of complex regional pain syndrome by infrared thermographic camera].

    Science.gov (United States)

    Kocić, Mirjana; Lazović, Milica; Dimitrijević, Irena; Mancić, Dragan; Stanković, Anita

    2010-09-01

    BACKGROUND/AIM; Complex regional pain syndrom type I (CRPS I) is characterised by continuous regional pain, disproportional according to duration and intensity and to the sort of trauma or other lesion it was caused by. The aim of the study was to evaluate and compare, by using thermovison, the effects of low level laser therapy and therapy with interferential current in treatment of CRPS I. The prospective randomized controlled clinical study included 45 patients with unilateral CRPS 1, after a fracture of the distal end of the radius, of the tibia and/or the fibula, treated in the Clinical Centre in Nis from 2004 to 2007. The group A consisted of 20 patients treated by low level laser therapy and kinesy-therapy, while the patients in the group B (n = 25) were treated by interferential current and kinesy-therapy. The regions of interest were filmed by a thermovision camera on both sides, before and after the 20 therapeutic procedures had been applied. Afterwards, the quantitative analysis and the comparing of thermograms taken before and after the applied therapy were performed. There was statistically significant decrease of the mean maximum temperature difference between the injured and the contralateral extremity after the therapy in comparison to the status before the therapy, with the patients of the group A (p infrared thermovision we showed that in the treatment of CRPS I both physical medicine methods were effective, but the effectiveness of laser therapy was statistically significantly higher compared to that of the interferential current therapy.

  13. Assessing Potential Exposure from Truck Transport of Low-level Radioactive Waste to the Nevada Test Site

    Energy Technology Data Exchange (ETDEWEB)

    J. Miller; D. Shafer; K. Gray; B. Church; S.Campbell; B. Holz

    2005-08-15

    This study has shown that, based upon measurements from industry standard radiation detection instruments, such as the RS model RSS-131 PICs in a controlled configuration, a person may be exposed to gamma radiation above background when in close proximity to some LLW trucks. However, in approximately half (47.7 percent) the population of trucks measured in this study, a person would receive no exposure above background at a distance of 1.0 m (3.3 ft) away from a LLW truck. An additional 206 trucks had net exposures greater than zero, but equal to or less than 1 {micro}R/h. Finally, nearly 80 percent of the population of trucks (802 of 1,012) had net exposures less than or equal to 10 {micro}R/h. Although there are no shipping or exposure standards at 1.0 m (3.3 ft) distance, one relevant point of comparison is the DOT shipping standard of 10 mrem/h at 2.0 m (6.6 ft) distance. Assuming a one-to-one correspondence between Roentgens and Rems, then 903 trucks (89.2 percent of the trucks measured) were no greater than one percent of the DOT standard at 1.0 m (3.3 ft). Had the distance at which the trucks been measured increased to 2.0 m (6.6 ft), the net exposure would be even less because of the increase in distance between the truck and the receptor. However, based on the empirical data from this study, the rate of decrease may be slower than for either a point or line source as was done for previous studies (Gertz, 2001; Davis et al., 2001). The highest net exposure value at 1.0 m (3.3 ft) distance, 11.9 mR/h, came from the only truck with a value greater than 10 mR/h at 1.0 m (3.3 ft) distance.

  14. Variability of high-dose melphalan exposure on oral mucositis in patients undergoing prophylactic low-level laser therapy.

    Science.gov (United States)

    Rodrigues, Gustavo Henrique; Jaguar, Graziella Chagas; Alves, Fabio Abreu; Guollo, Andre; Camandoni, Vanessa Oliveira; Damascena, Aline Santos; Lima, Vladmir Claudio Cordeiro

    2017-07-01

    The present study outlines the clinical impact and risk factors of oral mucositis in 79 patients with multiple myeloma following high-dose melphalan for autologous transplant. All patients underwent daily prophylactic low-level indium gallium aluminum phosphate diode laser therapy (660 nm, 15 mW, 3.75 J/cm2, 10 s per point) from the beginning of the conditioning regimen up to day +2. Oral mucositis assessments were made daily until hospital discharge. For analysis, oral mucositis was divided into two groups according to severity: group 1, patients with oral mucositis grade mucositis grade ≥III (n = 8). Univariate logistic models were used to determine the risk factors. Patients in group 1 were found to have statistically fewer days of oral pain than those in group 2 (3.94 and 6.25 days, respectively, p = 0.014). Morphine was required in 75% of patients in group 2, versus 42.25% in group 1 (p = 0.06). Risk of severe oral mucositis was associated with higher serum creatinine levels (OR = 6.10; 95% CI 1.25-31.60; p = 0.02) and older age (OR = 1.21; 95% CI 1.05-1.47; p = 0.027). Severe oral mucositis was associated with worse clinical outcomes. Older patients and those with renal dysfunction previous autologous transplant had the greatest risk for severe oral mucositis despite prophylactic laser treatment. Our results highlight the importance of further research to define the dose, application time, and number of prophylactic laser sessions in those patients with the greatest risk for severe oral mucositis.

  15. Low-level copper exposures increase visibility and vulnerability of juvenile coho salmon to cutthroat trout predators

    Science.gov (United States)

    McIntyre, Jenifer K.; Baldwin, David H.; Beauchamp, David A.; Scholz, Nathaniel L.

    2012-01-01

    Copper contamination in surface waters is common in watersheds with mining activities or agricultural, industrial, commercial, and residential human land uses. This widespread pollutant is neurotoxic to the chemosensory systems of fish and other aquatic species. Among Pacific salmonids (), copper-induced olfactory impairment has previously been shown to disrupt behaviors reliant on a functioning sense of smell. For juvenile coho salmon (O. kisutch), this includes predator avoidance behaviors triggered by a chemical alarm cue (conspecific skin extract). However, the survival consequences of this sublethal neurobehavioral toxicity have not been explored. In the present study juvenile coho were exposed to low levels of dissolved copper (5–20 μg/L for 3 h) and then presented with cues signaling the proximity of a predator. Unexposed coho showed a sharp reduction in swimming activity in response to both conspecific skin extract and the upstream presence of a cutthroat trout predator (O. clarki clarki) previously fed juvenile coho. This alarm response was absent in prey fish that were exposed to copper. Moreover, cutthroat trout were more effective predators on copper-exposed coho during predation trials, as measured by attack latency, survival time, and capture success rate. The shift in predator–prey dynamics was similar when predators and prey were co-exposed to copper. Overall, we show that copper-exposed coho are unresponsive to their chemosensory environment, unprepared to evade nearby predators, and significantly less likely to survive an attack sequence. Our findings contribute to a growing understanding of how common environmental contaminants alter the chemical ecology of aquatic communities.

  16. Health effects in the Flemish population in relation to low levels of mercury exposure: from organ to transcriptome level.

    Science.gov (United States)

    Croes, Kim; De Coster, Sam; De Galan, Sandra; Morrens, Bert; Loots, Ilse; Van de Mieroop, Els; Nelen, Vera; Sioen, Isabelle; Bruckers, Liesbeth; Nawrot, Tim; Colles, Ann; Den Hond, Elly; Schoeters, Greet; van Larebeke, Nicolas; Baeyens, Willy; Gao, Yue

    2014-03-01

    Due to possible health risks, quantification of mercury accumulation in humans was included in the Flemish biomonitoring programmes FLEHS I (2002-2006) and FLEHS II (2007-2011). The general objective of FLEHS I was to assess regional exposure levels in order to link possible differences in these internal exposure levels to different types of local environmental pressure. Therefore, Hg and MMHg (methylmercury) were only measured in pooled blood samples per region and per age class. In FLEHS II, mercury concentrations were measured in hair of each participant. About 200 adolescents and 250 mothers (reference group) and two times 200 adolescents (2 hotspots) were screened. The main objectives of the FLEHS II study were: (1) to determine reference levels of mercury in hair for Flanders; (2) to assess relations between mercury exposure and possible sources like fish consumption; (3) to assess dose-effect relations between mercury exposure and health effect markers. The results showed that mercury concentrations in the Flemish population were rather low compared to other studies. Mercury levels in the Flemish populations were strongly related to the age of the participants and consumption of fish. Significant negative associations were observed between mercury in hair and asthma, having received breast feeding as a newborn, age at menarche in girls, allergy for animals and free testosterone levels. Significant correlations were also observed between mercury in hair and genes JAK2, ARID4A, Hist1HA4L (boys) and HLAdrb5, PIAS2, MANN1B1, GIT and ABCA1 (girls). Copyright © 2013 Elsevier GmbH. All rights reserved.

  17. CYP2E1 epigenetic regulation in chronic, low-level toluene exposure: Relationship with oxidative stress and smoking habit.

    Science.gov (United States)

    Jiménez-Garza, Octavio; Baccarelli, Andrea A; Byun, Hyang-Min; Márquez-Gamiño, Sergio; Barrón-Vivanco, Briscia Socorro; Albores, Arnulfo

    2015-08-01

    CYP2E1 is a versatile phase I drug-metabolizing enzyme responsible for the biotransformation of most volatile organic compounds, including toluene. Human toluene exposure increases CYP2E1 mRNA and modifies its activity in leucocytes; however, epigenetic implications of this interaction have not been investigated. To determine promoter methylation of CYP2E1 and other genes known to be affected by toluene exposure. We obtained venous blood from 24 tannery workers exposed to toluene (mean levels: 10.86+/-7mg/m(3)) and 24 administrative workers (reference group, mean levels 0.21+/-0.02mg/m(3)) all of them from the city of León, Guanajuato, México. After DNA extraction and bisulfite treatment, we performed PCR-pyrosequencing in order to measure methylation levels at promoter region of 13 genes. In exposed group we found significant correlations between toluene airborne levels and CYP2E1 promoter methylation (r=-.36, ptoluene-exposed smokers compared to nonsmokers (p=0.009). We also observed significant correlations for CYP2E1 promoter methylation with GSTP1 and SOD1 promoter methylation levels (r=-.37, ptoluene exposure. People co-exposed to toluene and tobacco smoke are in higher risk due to a possible CYP2E1 repression. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Low-Level Lead Exposure Increases Systolic Arterial Pressure and Endothelium-Derived Vasodilator Factors in Rat Aortas

    Science.gov (United States)

    Fiorim, Jonaina; Ribeiro Júnior, Rogério F.; Silveira, Edna A.; Padilha, Alessandra S.; Vescovi, Marcos Vinícius A.; de Jesus, Honério C.; Stefanon, Ivanita; Salaices, Mercedes; Vassallo, Dalton V.

    2011-01-01

    Chronic lead exposure induces hypertension and alters endothelial function. However, treatment with low lead concentrations was not yet explored. We analyzed the effects of 7 day exposure to low lead concentrations on endothelium-dependent responses. Wistar rats were treated with lead (1st dose 4 µg/100 g, subsequent dose 0.05 µg/100 g, i.m. to cover daily loss) or vehicle; blood levels attained at the end of treatment were 9.98 µg/dL. Lead treatment had the following effects: increase in systolic blood pressure (SBP); reduction of contractile response to phenylephrine (1 nM–100 µM) of aortic rings; unaffected relaxation induced by acetylcholine (0.1 nM–300 µM) or sodium nitroprusside (0.01 nM–0.3 µM). Endothelium removal, NG-nitro-L-arginine methyl ester (100 µM) and tetraethylammonium (2 mM) increased the response to phenylephrine in treated rats more than in untreated rats. Aminoguanidine (50 µM) increased but losartan (10 µM) and enalapril (10 µM) reduced the response to phenylephrine in treated rats. Lead treatment also increased aortic Na+/K+-ATPase functional activity, plasma angiotensin-converting enzyme (ACE) activity, protein expression of the Na+/K+-ATPase alpha-1 subunit, phosphorylated endothelial nitric oxide synthase (p-eNOS), and inducible nitric oxide synthase (iNOS). Our results suggest that on initial stages of lead exposure, increased SBP is caused by the increase in plasma ACE activity. This effect is accompanied by increased p-eNOS, iNOS protein expression and Na+/K+-ATPase functional activity. These factors might be a compensatory mechanism to the increase in SBP. PMID:21364929

  19. Co-exposure to lead increases the renal response to low levels of cadmium in metallurgy workers.

    Science.gov (United States)

    Hambach, R; Lison, D; D'Haese, P C; Weyler, J; De Graef, E; De Schryver, A; Lamberts, L V; van Sprundel, M

    2013-10-24

    Research on the effect of co-exposure to Cd and Pb on the kidney is scarce. The objective of the present study was to assess the effect of co-exposure to these metals on biomarkers of early renal effect. Cd in blood (Cd-B), Cd in urine (Cd-U), Pb in blood (Pb-B) and urinary renal biomarkers, i.e., microalbumin (μ-Alb), beta-2-microglobulin (β₂-MG), retinol binding protein (RBP), N-acetyl-β-d-glucosaminidase (NAG), intestinal alkaline phosphatase (IAP) were measured in 122 metallurgic refinery workers examined in a cross-sectional survey. The median Cd-B, Cd-U, Pb-B were: 0.8 μg/l (IQR = 0.5, 1.2), 0.5 μg/g creatinine (IQR = 0.3, 0.8) and 158.5 μg/l (IQR = 111.0, 219.3), respectively. The impact of Cd-B on the urinary excretion of NAG and IAP was only evident among workers with Pb-B concentrations ≥ 75th percentile. The association between Cd-U and the renal markers NAG and RBP was also evidenced when Pb-B ≥ 75th percentile. No statistically significant interaction terms were observed for the associations between Cd-B or Cd-U and the other renal markers under study (i.e., μ-Alb and β2-MG). Our findings indicate that Pb increases the impact of Cd exposure on early renal biomarkers. Copyright © 2013 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

  20. Pathophysiology of blast-induced ocular trauma in rats after repeated exposure to low-level blast overpressure.

    Science.gov (United States)

    Choi, Jae Hyek; Greene, Whitney A; Johnson, Anthony J; Chavko, Mikulas; Cleland, Jeffery M; McCarron, Richard M; Wang, Heuy-Ching

    2015-04-01

    The incidence of blast-induced ocular injury has dramatically increased due to advances in weaponry and military tactics. A single exposure to blast overpressure (BOP) has been shown to cause damage to the eye in animal models; however, on the battlefield, military personnel are exposed to BOP multiple times. The effects of repeated exposures to BOP on ocular tissues have not been investigated. The purpose of this study is to characterize the effects of single or repeated exposure on ocular tissues. A compressed air shock tube was used to deliver 70 ± 7 KPa BOP to rats, once (single blast overpressure [SBOP]) or once daily for 5 days (repeated blast overpressure [RBOP]). Immunohistochemistry was performed to characterize the pathophysiology of ocular injuries induced by SBOP and RBOP. Apoptosis was determined by quantification activated caspase 3. Gliosis was examined by detection of glial fibrillary acidic protein (GFAP). Inflammation was examined by detection of CD68. Activated caspase 3 was detected in ocular tissues from all animals subjected to BOP, while those exposed to RBOP had more activated caspase 3 in the optic nerve than those exposed to SBOP. GFAP was detected in the retinas from all animals subjected to BOP. CD68 was detected in optic nerves from all animals exposed to BOP. SBOP and RBOP induced retinal damage. RBOP caused more apoptosis in the optic nerve than SBOP, suggesting that RBOP causes more severe optic neuropathy than SBOP. SBOP and RBOP caused gliosis in the retina and increased inflammation in the optic nerve. © 2014 Royal Australian and New Zealand College of Ophthalmologists.

  1. Morphological and metabolic alterations in duckweed (Spirodela polyrhiza) on long-term low-level chronic UV-B exposure.

    Science.gov (United States)

    Farooq, M; Shankar, U; Ray, R S; Misra, R B; Agrawal, N; Verma, K; Hans, R K

    2005-11-01

    Laboratory grown duckweed (Spirodela polyrhiza) plants were exposed to 0.72 and 1.44J of UV-B radiation daily for 7 days at 0.4mW/cm(2) intensity. Chlorosis and necrosis were observed along with depletion in protein, pigments (chlorophyll, pheophytin, carotenoids, phycoerythrin, phycocyanin, and flavoxanthin), biomass, root length, and frond size in UV-B-exposed plants. The study confirms morphological and metabolic alterations leading to reduction in the productivity of duckweed following long-term exposure to UV-B radiation.

  2. Evaluation of melter technologies for vitrification of Hanford site low-level tank waste - phase 1 testing summary report

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, C.N., Westinghouse Hanford

    1996-06-27

    Following negotiation of the fourth amendment to the Tri- Party Agreement for Hanford Site cleanup, commercially available melter technologies were tested during 1994 and 1995 for vitrification of the low-level waste (LLW) stream to be derived from retrieval and pretreatment of the radioactive defense wastes stored in 177 underground tanks. Seven vendors were selected for Phase 1 testing to demonstrate vitrification of a high-sodium content liquid LLW simulant. The tested melter technologies included four Joule-heated melters, a carbon electrode melter, a combustion melter, and a plasma melter. Various dry and slurry melter feed preparation processes also were tested. The technologies and Phase 1 testing results were evaluated and a preliminary technology down-selection completed. This report describes the Phase 1 LLW melter vendor testing and the tested technologies, and summarizes the testing results and the preliminary technology recommendations.

  3. Gene expression analysis reveals chronic low level exposure to the pesticide diazinon affects psychological disorders gene sets in the adult rat.

    Science.gov (United States)

    Savy, Claire Y; Fitchett, Ann E; Blain, Peter G; Morris, Christopher M; Judge, Sarah J

    2018-01-15

    Chronic low level exposure to organophosphate (OPs) pesticides in adulthood has been linked to adverse neurobehavioural deficits and psychological disorder symptoms, although this remains a contentious issue. The OP-induced biological changes that could underlie these effects are unclear. We assessed gene expression changes following chronic low level exposure to diazinon, a pesticide with a high dietary exposure risk. Adult male rats were orally exposed to diazinon (0, 1, 2mg/kg, 5days a week for 12 weeks). After 4 weeks, marble burying behaviour was lower in diazinon exposed rats than vehicle exposed rats; this difference persisted for 8 weeks. Chronic diazinon exposure did not significantly inhibit acetylcholinesterase activity, the primary mechanism of action of high level OPs. Affymetrix GeneChip ® HT RG-230 PM Arrays were used for gene profiling followed by Ingenuity Pathway analysis. In the hippocampus, the most significant gene expression changes caused by OP exposure were associated with Psychological Disorders, and Cell-To-Cell Signalling and Interaction functions. Genes encoding the AMPA 3 glutamate receptor, glutaminase, dopamine transporter and tyrosine hydroxylase were up-regulated, whereas the gene encoding the GABA B1 receptor was down-regulated. In the dorsal raphe nucleus, genes associated with development and the Psychological Disorders function were significantly affected, including the up-regulation of the gene encoding the α 1b -adrenoceptor, the major driver of serotoninergic (5-HT) neuronal activity. These data indicate that chronic exposure to diazinon in adulthood, below the threshold to inhibit acetylcholinesterase, stimulates glutamatergic, dopaminergic and serotonergic synaptic transmission which may underlie adverse neurological outcomes. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Excretion of N-mononitrosopiperazine after low level exposure to piperazine in air: effects of dietary nitrate and ascorbate

    Energy Technology Data Exchange (ETDEWEB)

    Bellander, T.; Osterdahl, B.G.; Hagmar, L.

    1988-04-01

    The secondary amine piperazine may be nitrosated in vivo, following oral intake or occupational exposure by inhalation. The suspected carcinogen N-mononitrosopiperazine could be formed in the human stomach, and in part excreted in the urine. In this study, 0.4 microgram N-mononitrosopiperazine, determined by gas chromatography-Thermal Energy Analysis, was observed in the urine in one of four volunteers, at an experimental exposure by inhalation of 0.3 mg piperazine/m3. The intake of spinach and beetroot caused an increased nitrosation of piperazine, and up to 1.7 microgram N-mononitrosopiperazine was excreted in the urine in the four individuals. This excretion indicates that about 5% of the absorbed piperazine dose was converted to N-mononitrosopiperazine. With the same nitrate-rich diet, but with the addition of citrus fruits and fresh vegetables, the highest excretion was 0.6 microgram N-mononitrosopiperazine. The excretion was significantly correlated with the ratio between the maximum level of nitrite in saliva and the ascorbate level in plasma. There was also a significant interindividual variation. N,N'-Dinitrosopiperazine was not found in any sample of urine.

  5. The Effect of Exposure to Low Levels of Chlorine Gas on the Pulmonary Function and Symptoms in a Chloralkali Unit.

    Science.gov (United States)

    Neghab, Masoud; Amiri, Fatemeh; Soleimani, Esmaeel; Hosseini, Seyed Younus

    2016-01-01

    The present study was undertaken to ascertain whether (or not) long term occupational exposure to low (sub-TLV levels) atmospheric concentrations of chlorine gas was associated with any significant decrements in the parameters of pulmonary function and/or  increased prevalence of respiratory symptoms. In this retrospective cohort study that was performed in 2012, 54 workers of a local chloralkali unit and 38 non-exposed office staff were enrolled and compared. Atmospheric concentrations of chlorine gas were measured by numerous sampling with gas detector tubes. Data on respiratory symptoms were gathered using a standard questionnaire. Furthermore, spirometry test was performed for subjects both prior to and at the end of shift. Mean atmospheric concentration of chlorine gas was 0.27 ±0.05 ppm that was lower than the existing TLV value for this toxic irritant gas. Symptoms of respiratory diseases were significantly more frequent among exposed subjects than in referent individuals. Additionally, mean values of most parameters of pulmonary function including FEV1 (P=0.031), FEV1/FVC ratio (P=0.003) and PEF (P=0.005) were significantly lower than their corresponding values for unexposed subjects. Additional cross shift decrements were also noted in some lung functional capacities, although changes were not statistically significant. Exposure to sub-TLV levels of chlorine gas is associated with statistically significant decrements in the parameters of pulmonary function as well as increased prevalence of respiratory symptoms.

  6. Neuropsychological assessment at school-age and prenatal low-level exposure to mercury through fish consumption in an Italian birth cohort living near a contaminated site.

    Science.gov (United States)

    Deroma, L; Parpinel, M; Tognin, V; Channoufi, L; Tratnik, J; Horvat, M; Valent, F; Barbone, F

    2013-07-01

    The relative effects of prenatal and postnatal low-level mercury exposure and fish intake on child neurodevelopment are still controversial. Limited evidence is available from Mediterranean populations. In this prospective study, we measured the Verbal and Performance IQ in Italian children at school-age who were resident in an area declared as a National contaminated site because of mercury pollution, taking into account the possible beneficial effect of fish consumption and potential confounders. A mother-child cohort made up of 242 children was established at birth in Northeastern Italy in 2001. Their mothers were interviewed approximately 2 months after delivery to determine type, quantity, and origin of fish consumed during pregnancy and about a number of mother, child and family characteristics. Total mercury (THg) and methyl mercury (MeHg) were assessed in maternal hair and breast milk and in the child's hair. When children reached 7-9 years of age, 154 (63.6%) parents gave consent to participate in a follow-up evaluation. On that occasion, a child's hair sample was collected to determine the current concentration of THg, mothers were asked to complete a self-administered questionnaire, and children underwent neuropsychological testing. Verbal IQ, performance IQ and full scale IQ were measured by the Wechsler Intelligence Scale for Children (WISC III) administered by psychologists at school or local health centers. Demographic, socioeconomic and lifestyle information, medical information of the child's family and the child's dietary habits were collected using a questionnaire filled in by mothers. Multivariable linear regression models were used to evaluate the association between prenatal THg exposure through fish consumption of mothers in pregnancy and children's IQ after adjustment for possible confounders such as fish consumption of mothers in pregnancy, child's fish consumption at follow-up, child's birthweight, maternal cigarette smoking during

  7. Evaluation of low level laser and interferential current in the therapy of complex regional pain syndrome by infrared thermographic camera

    Directory of Open Access Journals (Sweden)

    Kocić Mirjana

    2010-01-01

    Full Text Available Background/Aim. Complex regional pain syndrome type I (CRPS I is characterized by continuous regional pain, disproportional according to duration and intensity and to the sort of trauma or other lesion it was caused by. The aim of the study was to evaluate and compare, by using thermovison, the effects of low level laser therapy and therapy with interferential current in treatment of CRPS I. Methods. The prospective randomized controlled clinical study included 45 patients with unilateral CRPS I, after a fracture of the distal end of the radius, of the tibia and/or the fibula, treated in the Clinical Centre in Nis from 2004 to 2007. The group A consisted of 20 patients treated by low level laser therapy and kinesy-therapy, while the patients in the group B (n = 25 were treated by interferential current and kinesy-therapy. The regions of interest were filmed by a thermovision camera on both sides, before and after the 20 therapeutic procedures had been applied. Afterwards, the quantitative analysis and the comparing of thermograms taken before and after the applied therapy were performed. Results. There was statistically significant decrease of the mean maximum temperature difference between the injured and the contralateral extremity after the therapy in comparison to the status before the therapy, with the patients of the group A (p < 0.001 as well as those of the group B (p < 0.001. The decrease was statistically significantly higher in the group A than in the group B (p < 0.05. Conclusions. By the use of the infrared thermovision we showed that in the treatment of CRPS I both physical medicine methods were effective, but the effectiveness of laser therapy was statistically significantly higher compared to that of the interferential current therapy.

  8. Estimating the risks of cancer mortality and genetic defects resulting from exposures to low levels of ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Buhl, T.E.; Hansen, W.R.

    1984-05-01

    Estimators for calculating the risk of cancer and genetic disorders induced by exposure to ionizing radiation have been recommended by the US National Academy of Sciences Committee on the Biological Effects of Ionizing Radiations, the UN Scientific Committee on the Effects of Atomic Radiation, and the International Committee on Radiological Protection. These groups have also considered the risks of somatic effects other than cancer. The US National Council on Radiation Protection and Measurements has discussed risk estimate procedures for radiation-induced health effects. The recommendations of these national and international advisory committees are summarized and compared in this report. Based on this review, two procedures for risk estimation are presented for use in radiological assessments performed by the US Department of Energy under the National Environmental Policy Act of 1969 (NEPA). In the first procedure, age- and sex-averaged risk estimators calculated with US average demographic statistics would be used with estimates of radiation dose to calculate the projected risk of cancer and genetic disorders that would result from the operation being reviewed under NEPA. If more site-specific risk estimators are needed, and the demographic information is available, a second procedure is described that would involve direct calculation of the risk estimators using recommended risk-rate factors. The computer program REPCAL has been written to perform this calculation and is described in this report. 25 references, 16 tables.

  9. Risk of death from cardiovascular disease associated with low-level arsenic exposure among long-term smokers in a US population-based study

    Energy Technology Data Exchange (ETDEWEB)

    Farzan, Shohreh F. [Department of Epidemiology, Geisel School of Medicine at Dartmouth, Lebanon, NH (United States); Departments of Population Health and Environmental Medicine, New York University School of Medicine, New York, NY (United States); Chen, Yu [Departments of Population Health and Environmental Medicine, New York University School of Medicine, New York, NY (United States); Rees, Judy R.; Zens, M. Scot [Department of Epidemiology, Geisel School of Medicine at Dartmouth, Lebanon, NH (United States); Karagas, Margaret R., E-mail: margaret.r.karagas@dartmouth.edu [Department of Epidemiology, Geisel School of Medicine at Dartmouth, Lebanon, NH (United States)

    2015-09-01

    High levels of arsenic exposure have been associated with increases in cardiovascular disease risk. However, studies of arsenic's effects at lower exposure levels are limited and few prospective studies exist in the United States using long-term arsenic exposure biomarkers. We conducted a prospective analysis of the association between toenail arsenic and cardiovascular disease mortality using longitudinal data collected on 3939 participants in the New Hampshire Skin Cancer Study. Using Cox proportional hazard models adjusted for potential confounders, we estimated hazard ratios and 95% confidence intervals associated with the risk of death from any cardiovascular disease, ischemic heart disease, and stroke, in relation to natural-log transformed toenail arsenic concentrations. In this US population, although we observed no overall association, arsenic exposure measured from toenail clipping samples was related to an increased risk of ischemic heart disease mortality among long-term smokers (as reported at baseline), with increased hazard ratios among individuals with ≥ 31 total smoking years (HR: 1.52, 95% CI: 1.02, 2.27), ≥ 30 pack-years (HR: 1.66, 95% CI: 1.12, 2.45), and among current smokers (HR: 1.69, 95% CI: 1.04, 2.75). These results are consistent with evidence from more highly exposed populations suggesting a synergistic relationship between arsenic exposure and smoking on health outcomes and support a role for lower-level arsenic exposure in ischemic heart disease mortality. - Highlights: • Arsenic (As) has been associated with increased cardiovascular disease (CVD) risk. • Little is known about CVD effects at lower levels of As exposure common in the US. • Few have investigated the joint effects of As and smoking on CVD in US adults. • We examine chronic low-level As exposure and smoking in relation to CVD mortality. • Arsenic exposure may increase ischemic heart disease mortality among smokers in US.

  10. Hydrologic evaluation methodology for estimating water movement through the unsaturated zone at commercial low-level radioactive waste disposal sites

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, P.D.; Rockhold, M.L.; Nichols, W.E.; Gee, G.W. [Pacific Northwest Lab., Richland, WA (United States)

    1996-01-01

    This report identifies key technical issues related to hydrologic assessment of water flow in the unsaturated zone at low-level radioactive waste (LLW) disposal facilities. In addition, a methodology for incorporating these issues in the performance assessment of proposed LLW disposal facilities is identified and evaluated. The issues discussed fall into four areas: estimating the water balance at a site (i.e., infiltration, runoff, water storage, evapotranspiration, and recharge); analyzing the hydrologic performance of engineered components of a facility; evaluating the application of models to the prediction of facility performance; and estimating the uncertainty in predicted facility performance. To illustrate the application of the methodology, two examples are presented. The first example is of a below ground vault located in a humid environment. The second example looks at a shallow land burial facility located in an arid environment. The examples utilize actual site-specific data and realistic facility designs. The two examples illustrate the issues unique to humid and arid sites as well as the issues common to all LLW sites. Strategies for addressing the analytical difficulties arising in any complex hydrologic evaluation of the unsaturated zone are demonstrated.

  11. Unreviewed Disposal Question Evaluation: Impact of New Information since 2008 PA on Current Low-Level Solid Waste Operations

    Energy Technology Data Exchange (ETDEWEB)

    Flach, G.; Smith, F.; Hamm, L.; Butcher, T.

    2014-10-06

    Solid low-level waste disposal operations are controlled in part by an E-Area Low-Level Waste Facility (ELLWF) Performance Assessment (PA) that was completed by the Savannah River National Laboratory (SRNL) in 2008 (WSRC 2008). Since this baseline analysis, new information pertinent to disposal operations has been identified as a natural outcome of ongoing PA maintenance activities and continuous improvement in model simulation techniques (Flach 2013). An Unreviewed Disposal Question (UDQ) Screening (Attachment 1) has been initiated regarding the continued ability of the ELLWF to meet Department of Energy (DOE) Order 435.1 performance objectives in light of new PA items and data identified since completion of the original UDQ Evaluation (UDQE). The present UDQE assesses the ability of Solid Waste (SW) to meet performance objectives by estimating the influence of new information items on a recent sum-of-fractions (SOF) snapshot for each currently active E-Area low-level waste disposal unit. A final SOF, as impacted by this new information, is projected based on the assumptions that the current disposal limits, Waste Information Tracking System (WITS) administrative controls, and waste stream composition remain unchanged through disposal unit operational closure (Year 2025). Revision 1 of this UDQE addresses the following new PA items and data identified since completion of the original UDQE report in 2013: New Kd values for iodine, radium and uranium; Elimination of cellulose degradation product (CDP) factors; Updated radionuclide data; Changes in transport behavior of mobile radionuclides; Potential delay in interim closure beyond 2025; and Component-in-grout (CIG) plume interaction correction. Consideration of new information relative to the 2008 PA baseline generally indicates greater confidence that PA performance objectives will be met than indicated by current SOF metrics. For SLIT9, the previous prohibition of non-crushable containers in revision 0

  12. Relation of cumulative low-level lead exposure to depressive and phobic anxiety symptom scores in middle-age and elderly women.

    Science.gov (United States)

    Eum, Ki-Do; Korrick, Susan A; Weuve, Jennifer; Okereke, Olivia; Kubzansky, Laura D; Hu, Howard; Weisskopf, Marc G

    2012-06-01

    Different lines of evidence suggest that low-level lead exposure could be a modifiable risk factor for adverse psychological symptoms, but little work has explored this relation. We assessed whether bone lead--a biomarker of cumulative lead exposure--is associated with depression and anxiety symptoms among middle-age and elderly women. Participants were 617 Nurses' Health Study participants with K-shell X-ray fluorescence bone lead measures and who had completed at last one Mental Health Index 5-item scale (MHI-5) and the phobic anxiety scale of the Crown-Crisp Index (CCI) assessment at mean ± SD age of 59 ± 9 years (range, 41-83 years). With exposure expressed as tertiles of bone lead, we analyzed MHI-5 scores as a continuous variable using linear regression and estimated the odds ratio (OR) of a CCI score ≥ 4 using generalized estimating equations. There were no significant associations between lead and either outcome in the full sample, but associations were found among premenopausal women and women who consistently took hormone replacement therapy (HRT) between menopause and bone lead measurement (n = 142). Compared with women in the lowest tertile of tibia lead, those in the highest scored 7.78 points worse [95% confidence interval (CI): -11.73, -3.83] on the MHI-5 (p-trend = 0.0001). The corresponding OR for CCI ≥ 4 was 2.79 (95% CI: 1.02, 7.59; p-trend = 0.05). No consistent associations were found with patella lead. These results provide support for an association of low-level cumulative lead exposure with increased depressive and phobic anxiety symptoms among older women who are premenopausal or who consistently take postmenopausal HRT.

  13. Repeated exposure to low-level extremely low frequency-modulated microwaves affects cortex-hypothalamus interplay in freely moving rats: EEG study.

    Science.gov (United States)

    Vorobyov, Vasily; Janać, Branka; Pesić, Vesna; Prolić, Zlatko

    2010-05-01

    To compare the effects of repeated exposure to extremely low frequency-modulated microwaves (ELF-MW) on cortical and hypothalamic electroencephalograms (EEG). In 10 freely moving rats with carbon electrodes implanted into the cortex and dorsomedial hypothalamus, averaged frequency spectra (0.5-30 Hz) of the EEG were studied for five consecutive days either under sham exposures (five rats) or under mixed sham/MW-exposures (five rats). The rats were exposed to ELF-MW (915 MHz, 20-ms pulse duration, approximately 0.3 mW/cm(2), 4 Hz) intermittently (1-min 'On', 1-min 'Off') for 10 min (specific absorption rate, SAR, approximately 0.7 mW/g on average) several times per day, with 10-min pre- and post-exposure periods. In baseline EEG, the activities of 3.2-6.0 Hz and 17.8-30.5 Hz dominated in the cortex and of 6.0-17.8 Hz in the hypothalamus. This cortical-hypothalamic imbalance was relatively stable at sham-exposures and insensitive to ELF-MW in all frequency ranges but one. ELF-MW increased the beta(2) (17.8-30.5 Hz) level in the hypothalamus to a greater extent than in the cortex, causing significant diminishing of the initial EEG bias between them. Moreover, a cumulative phenomenon under repeated exposures to ELF-MW was revealed. These results are in line with evidence that repeated low-level exposure to ELF-MW affects brain functioning and provide an additional approach when analysing underlying mechanisms.

  14. Results of the trials and light-delivery evaluation at low-level laser therapy of acute and chronic pain

    Science.gov (United States)

    Roeva, Tatiana; Petrov, Todor S.; Minkovski, Nikolai I.

    2004-06-01

    Although the low-level laser therapy (LLLT) is accepted in the clinical practice, its efficiency is still questionable because of the unclear mechanisms of LLLT action. This work presents the results of LLLT applied to volunteers who need recovery from trauma or suffer from rheumatic diseases, inflammatory disorders, etc. The control group we used for comparison consisted of patients being treated by conventional therapy that included massage and acupuncture needles. The effectiveness of the LLLT was graded under four categories. Short-term and long-term side effects as well as conditions responding only to LLLT were recorded. The successful treatments were up to 70%, which coincided with the result of the control group. The LLLT was performed with a GaAs laser system SIX LASER IR - Bulgaria provided with additional set of six light CW emitting diodes to scan a larger area of a tissue surface. To evaluate the light delivery inside the tissue, the spatial maps of the light spot at the laser output in different operating regimes were measured. On their basis, the absorbed dose was calculated both in the boundary layer under the tissue surface and in depth using a reduced variance Monte-Carlo code.

  15. Results of the trials and light delivery evaluation on low-level laser therapy of acute and chronic pain

    Science.gov (United States)

    Stoykova, Elena V.; Roeva, Tatiana; Petrova, Kremena S.; Petrov, Todor S.; Minkovski, Nikolai

    2003-11-01

    Although the low-level laser therapy (LLLT) has been accepted in the clinical practice, its efficiency is still questionable because of the unclear mechanisms of LLLT action. This work presents the results of LLLT applied to volunteers who need recovery from trauma or suffer from rheumatic diseases, inflammatory disorders, etc. The control group we used for comparison consisted of patients being treated by conventional therapy that included massage and acupuncture needles. The effectiveness of the LLLT was graded under four categories. Short-term and long-term side effects as well as conditions responding only to LLLT were recorded. The successful treatments were up to 70%, which coincided with the result of the control group. The LLLT was performed with a GaAs laser system provided with additional set of six light CW emitting diodes to scan a larger area of a tissue surface. To evaluate the light delivery inside the tissue, the spatial energy distribution within the laser beam was measured with a CCD camera. On its basis, the light dose absorbed in the tissue was calculated both in the boundary layer under the surface and in depth using a reduced variance Monte-Carlo code.

  16. Evaluation of uranium removal by Hydrilla verticillata (L.f.) Royle from low level nuclear waste under laboratory conditions.

    Science.gov (United States)

    Srivastava, Sudhakar; Bhainsa, K C

    2016-02-01

    The present study evaluated uranium (U) removal ability and tolerance to low level nuclear waste (LLNW) of an aquatic weed Hydrilla verticillata. Plants were screened for growth in 10%-50% waste treatments up to 3 d. Treatments of 20% and 50% waste imposed increasing toxicity with duration assessed in terms of change in fresh weight and in the levels of photosynthetic pigments and thiobarbituric acid-reactive substances. U concentration, however, did not show a progressive increase and was about 42 μg g(-1) dw from 20% to 50% waste at 3 d. This suggested that a saturation stage was reached with respect to U removal due to increasing toxicity. However, in another experiment with 10% waste and 10% waste+10 ppm U treatments, plants showed an increase in U concentration with the maximum level approaching 426 μg g(-1) dw at 3 d without showing any toxicity as compared to that at 20% and 50% waste treatments. Hence, plants possessed significant potential to take up U and toxicity of LLNW limited their U removal ability. This implies that the use of Hydrilla plants for U removal from LLNW is feasible at low concentrations and would require repeated harvesting at short intervals. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. A decision methodology for the evaluation of mixed low-level radioactive waste management options for DOE sites

    Energy Technology Data Exchange (ETDEWEB)

    Bassi, J. [Dept. of Energy, Washington, DC (United States); Abashian, M.S.; Chakraborti, S.; Devarakonda, M.; Djordjevic, S.M. [IT Corp., Albuquerque, NM (United States)

    1993-03-01

    Currently, many DOE sites are developing site-specific solutions to manage their mixed low-level wastes. These site-specific MLLW programs often result in duplication of efforts between the different sites, and consequently, inefficient use of DOE system resources. A nationally integrated program for MLLW eliminates unnecessary duplication of effort, but requires a comprehensive analysis of waste management options to ensure that all site issues are addressed. A methodology for comprehensive analysis of the complete DOE MLLW system is being developed by DOE-HQ to establish an integrated and standardized solution for managing MLLW. To be effective, the comprehensive systems analysis must consider all aspects of MLLW management from cradle-to-grave (i.e. from MLLW generation to disposal). The results of the analysis will include recommendations for alternative management options for the complete DOE MLLW system based on various components such as effectiveness, cost, health and safety risks, and the probability of regulatory acceptance for an option. Because of the diverse nature of these various components and the associated difficulties in comparing between them, a decision methodology is being developed that will integrate the above components into a single evaluation scheme for performing relative comparisons between different MLLW management options. The remainder of this paper provides an overview of the roles and responsibilities of the various participants of the DOE MLLW Program, and discusses in detail the components involved in the development of the decision methodology for a comprehensive systems analysis.

  18. Low level and sub-chronic exposure to methylmercury induces hypertension in rats: nitric oxide depletion and oxidative damage as possible mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Grotto, Denise; Barcelos, Gustavo R.M.; Barbosa, Fernando [Universidade de Sao Paulo, Departamento de Analises Clinicas, Toxicologicas e Bromatologicas, Faculdade de Ciencias Farmaceuticas de Ribeirao Preto, Ribeirao Preto, SP (Brazil); Castro, Michele M. de [Universidade de Sao Paulo, Departamento de Farmacologia, Faculdade de Medicina de Ribeirao Preto, Ribeirao Preto, SP (Brazil); Garcia, Solange C. [Universidade Federal de Santa Maria, Departamento de Analises Clinicas e Toxicologicas, Santa Maria, Rio Grande do Sul (Brazil)

    2009-07-15

    Increased risk of hypertension after methylmercury (MeHg) exposure has been suggested. However, the underlying mechanisms are not well explored. In this paper, we have analyzed whether sub-chronic exposure to MeHg increases systolic blood pressure even at very low levels. In addition, we analyzed if the methylmercury-induced hypertension is associated with a decreased plasmatic nitric oxide levels and with a dysregulation of the activities of the antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT), as well as the levels of MDA and glutathione. For this study, Wistar rats were treated with methylmercury chloride (100 {mu}g/kg per day) or vehicle. Total treatment time was 100 days. Malondialdehyde (MDA) and circulating NOx levels and superoxide dismutase (SOD) and catalase (CAT) activities were determined in plasma, whereas glutathione levels were determined in erythrocytes. Our results show that long-term treatment at a low level of MeHg affected systolic blood pressure, increasing and reducing the levels of plasmatic MDA and NOx, respectively. However, the activity of SOD did not decrease in the MeHg exposed group when compared to the control. We found a negative correlation between plasmatic nitrite/nitrate (NOx) levels and systolic blood pressure (r=-0.67; P=0.001), and a positive correlation between MDA and systolic blood pressure (r=0.61; P=0.03), thus suggesting increased inhibition of NO formation with the increase of hypertension. In conclusion, long-term exposure to a low dose of MeHg increases the systolic pressure and is associated, at least in part, with increased production of ROS as judged by increased production of malondialdehyde and depressed NO availability. (orig.)

  19. Conceptual Evaluation for the Installation of Treatment Capability for Mixed Low Level Waste at the Nevada National Security Site

    Energy Technology Data Exchange (ETDEWEB)

    NSTec Environmental Management

    2010-11-24

    National Security Technologies, LLC, initiated an evaluation of treatment technologies that they would manage and operate as part of the mixed low-level waste (MLLW) disposal facilities at the Nevada National Security Site (NNSS). The NNSS Disposal Facility has been receiving radioactive waste from the U.S. Department of Energy (DOE) complex since the 1960s, and since 2005 the NNSS Disposal Facility has been receiving radioactive and MLLW for disposal only. In accordance with the Resource Conservation and Recovery Act (RCRA), all mixed waste must meet land disposal restrictions (LDRs) prior to disposal. Compliance with LDRs is attained through treatment of the waste to mitigate the characteristics of the listed waste hazard. Presently, most generators utilize commercial capacity for waste treatment prior to shipment to the NNSS Disposal Facility. The objectives of this evaluation are to provide a conceptual study of waste treatment needs (i.e., demand), identify potential waste treatment technologies to meet demand, and analyze implementation considerations for initiating MLLW treatment capacity at the NNSS Disposal Facility. A review of DOE complex waste generation forecast data indicates that current and future Departmental demand for mixed waste treatment capacity will remain steady and strong. Analysis and screening of over 30 treatment technologies narrowed the field of treatment technologies to four: • Macroencapsulation • Stabilization/microencapsulation • Sort and segregation • Bench-scale mercury amalgamation The analysis of treatment technologies also considered existing permits, current the NNSS Disposal Facility infrastructure such as utilities and procedures, and past experiences such as green-light and red-light lessons learned. A schedule duration estimate has been developed for permitting, design, and construction of onsite treatment capability at the NNSS Disposal Facility. Treatment capability can be ready in 20 months.

  20. Effects of Low Level Lead Exposure on Associative Learning and Memory in the Rat: Influences of Sex and Developmental Timing Of Exposure

    Science.gov (United States)

    Anderson, D.W.; Mettil, W.; Schneider, J.S.

    2016-01-01

    Lead (Pb) exposure during development impairs a variety of cognitive, behavioral and neurochemical processes resulting in deficits in learning, memory, attention, impulsivity and executive function. Numerous studies have attempted to model this effect of Pb in rodents, with the majority of studies focusing on hippocampus-associated spatial learning and memory processes. Using a different paradigm, trace fear conditioning, a process requiring coordinated integration of both the medial prefrontal cortex and the hippocampus, we have assessed the effects of Pb exposure on associative learning and memory. The present study examined both female and male Long Evans rats exposed to three environmentally relevant levels of Pb (150 ppm, 375 ppm and 750 ppm) during different developmental periods: perinatal (PERI; gestation – postnatal day 21), early postnatal (EPN; postnatal days 1–21) and late postnatal (LPN; postnatal days 1–55). Testing began at postnatal day 55 and consisted of a single day of acquisition training, and three post training time points (1, 2 and 10 days) to assess memory consolidation and recall. All animals, regardless of sex, developmental window or level of Pb-exposure, successfully acquired conditioned-unconditioned stimulus association during training. However, there were significant effects of Pb-exposure on consolidation and memory recall at days 1–10 post training. In females, EPN and LPN exposure to 150 ppm Pb (but not PERI exposure) significantly impaired recall. In contrast, only PERI 150 ppm and 750 ppm-exposed males had significant recall deficits. These data suggest a complex interaction between sex, developmental window of exposure and Pb-exposure level on consolidation and recall of associative memories. PMID:26812500

  1. Low-level chronic exposure to cadmium enhances the risk of long bone fractures: a study on a female rat model of human lifetime exposure.

    Science.gov (United States)

    Brzóska, Malgorzata M

    2012-01-01

    In the present paper, the hypothesis that low chronic exposure to cadmium (Cd) enhances the risk of long bone fractures was investigated in a female rat model simulating human lifetime exposure in non-Cd-polluted areas. For this purpose, the femur and both tibias of control female rats and those exposed to Cd (1 mg Cd I(-1) in drinking water for 24 months since weaning) were assigned to geometric, densitometric (bone mineral content, BMC, and density, BMD), radiographic and biomechanical studies as well as assessing their chemical composition. The exposure to Cd disturbed mineralization (decreased BMD and minerals content, including calcium, magnesium, zinc, copper and iron) and weakened the biomechanical strength of the femur and tibia, enhancing their fragility. The Z-score values for the BMD revealed osteopenia of the femur and tibia in 20 and 30% of the Cd-exposed female rats, respectively, and osteoporosis in 80 and 70%, respectively. In 30% of the Cd-exposed animals, femoral neck fracture was evident in the radiographic picture. The findings seem to confirm the hypothesis that a low exposure to Cd during the lifetime may be an important risk factor for osteoporosis and fractures of long bones, and especially for femoral neck fracture in elderly women. The results indicate that greater attention should be paid to Cd as an environmental risk factor for the increasing rate of osteoporosis and bone fractures in old population. Copyright © 2011 John Wiley & Sons, Ltd.

  2. The Screening of Genes Sensitive to Long-Term, Low-Level Microwave Exposure and Bioinformatic Analysis of Potential Correlations to Learning and Memory.

    Science.gov (United States)

    Zhao, Ya Li; Li, Ying Xian; Ma, Hong Bo; Li, Dong; Li, Hai Liang; Jiang, Rui; Kan, Guang Han; Yang, Zhen Zhong; Huang, Zeng Xin

    2015-08-01

    To gain a better understanding of gene expression changes in the brain following microwave exposure in mice. This study hopes to reveal mechanisms contributing to microwave-induced learning and memory dysfunction. Mice were exposed to whole body 2100 MHz microwaves with specific absorption rates (SARs) of 0.45 W/kg, 1.8 W/kg, and 3.6 W/kg for 1 hour daily for 8 weeks. Differentially expressing genes in the brains were screened using high-density oligonucleotide arrays, with genes showing more significant differences further confirmed by RT-PCR. The gene chip results demonstrated that 41 genes (0.45 W/kg group), 29 genes (1.8 W/kg group), and 219 genes (3.6 W/kg group) were differentially expressed. GO analysis revealed that these differentially expressed genes were primarily involved in metabolic processes, cellular metabolic processes, regulation of biological processes, macromolecular metabolic processes, biosynthetic processes, cellular protein metabolic processes, transport, developmental processes, cellular component organization, etc. KEGG pathway analysis showed that these genes are mainly involved in pathways related to ribosome, Alzheimer's disease, Parkinson's disease, long-term potentiation, Huntington's disease, and Neurotrophin signaling. Construction of a protein interaction network identified several important regulatory genes including synbindin (sbdn), Crystallin (CryaB), PPP1CA, Ywhaq, Psap, Psmb1, Pcbp2, etc., which play important roles in the processes of learning and memorye. Long-term, low-level microwave exposure may inhibit learning and memory by affecting protein and energy metabolic processes and signaling pathways relating to neurological functions or diseases. Copyright © 2015 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

  3. Evaluation of Department of Energy-Held Potential Greater-Than-Class C Low-Level Radioactive Waste. Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-09-01

    A number of commercial facilities have generated potential greater-than-Class C low-level radioactive waste (GTCC LLW), and, through contractual arrangements with the US Department of Energy (DOE) or for health and safety reasons, DOE is storing the waste. This report presents the results of an assessment conducted by the GTCC LLW Management Program to consider specific circumstances under which DOE accepted the waste, and to determine whether disposal in a facility licensed by the US Nuclear Regulatory Commission, or by DOE in a nonlicensed facility, is appropriate. Input from EG&G Idaho, Inc., and DOE Idaho Operations Office legal departments concerning the disposal requirements of this waste were the basis for the decision process used in this report.

  4. Evaluation of a performance assessment methodology for low-level radioactive waste disposal facilities: Validation needs. Volume 2

    Energy Technology Data Exchange (ETDEWEB)

    Kozak, M.W.; Olague, N.E. [Sandia National Labs., Albuquerque, NM (United States)

    1995-02-01

    In this report, concepts on how validation fits into the scheme of developing confidence in performance assessments are introduced. A general framework for validation and confidence building in regulatory decision making is provided. It is found that traditional validation studies have a very limited role in developing site-specific confidence in performance assessments. Indeed, validation studies are shown to have a role only in the context that their results can narrow the scope of initial investigations that should be considered in a performance assessment. In addition, validation needs for performance assessment of low-level waste disposal facilities are discussed, and potential approaches to address those needs are suggested. These areas of topical research are ranked in order of importance based on relevance to a performance assessment and likelihood of success.

  5. Evaluation of the Effects of Intravenous and Percutaneous Low Level Laser Therapy in the Management of Shoulder Myofascial Pain Syndrome.

    Science.gov (United States)

    Momenzadeh, Sirous; Akhyani, Vahid; Razaghi, Zahra; Ebadifar, Asghar; Abbasi, Mohammadzaki

    2016-01-01

    Myofascial pain syndrome (MPS) treatment is challenging with a high recurrence rate and still lacks a clear treatment frame. Therefore research on new, more efficient and long lasting effect treatment modalities is necessary. This study looked at the effects of intravenous laser therapy (IVL) and percutaneous low level laser (PLLL) in the management of shoulder MPS. In this randomized controlled trial, 30 patients fulfilling inclusion criteria were randomly equally allocated to 3 groups, control, IVL and PLLL. Control group received 12 sessions of placebo low level laser, IVL group received 12 sessions of IVL therapy, and PLLL group received 12 sessions of PLLL therapy. All patients were trained for better body posture, body mechanics, gentle massage of trigger points, stretching exercises of affected muscle (trapezius), and received 10 mg of oral nortriptyline regimen every night for 3 months. Outcomes included pain severity, functional disability, and quality of life. Patients were assessed using Numeric Rating Scale (NRS), Pain Disability Index (PDI), and Short Form Health Survey (SF-12). Data collected were analyzed using analysis of variance (ANOVA), Mann-Whitney and t tests. The mean of PDI and maximum pain intensity during day and night significantly reduced in both PLLL and IVL groups compared to control group. Although pain severity and PDI reduction was more pronounced in IVL group compared to PLLL group, the differences were not statistically significant. Also, quality of life statistically significantly improved in both IVL and PLLL groups compared to control group was more, and although higher in IVL group, the difference was not statistically significant when compared to PLLL group. No side effects were observed in the intervention groups. Intravenous laser and PLLL therapy had a positive effect on pain severity and PDI reduction, and quality of life in this study. Also no adverse event was recorded. Thus, intravenous lasers and PLLL therapy seem to

  6. Repeat low-level blast exposure increases transient receptor potential vanilloid 1 (TRPV1 and endothelin-1 (ET-1 expression in the trigeminal ganglion.

    Directory of Open Access Journals (Sweden)

    Elaine D Por

    Full Text Available Blast-associated sensory and cognitive trauma sustained by military service members is an area of extensively studied research. Recent studies in our laboratory have revealed that low-level blast exposure increased expression of transient receptor potential vanilloid 1 (TRPV1 and endothelin-1 (ET-1, proteins well characterized for their role in mediating pain transmission, in the cornea. Determining the functional consequences of these alterations in protein expression is critical to understanding blast-related sensory trauma. Thus, the purpose of this study was to examine TRPV1 and ET-1 expression in ocular associated sensory tissues following primary and tertiary blast. A rodent model of blast injury was used in which anesthetized animals, unrestrained or restrained, received a single or repeat blast (73.8 ± 5.5 kPa from a compressed air shock tube once or daily for five consecutive days, respectively. Behavioral and functional analyses were conducted to assess blast effects on nocifensive behavior and TRPV1 activity. Immunohistochemistry and Western Blot were also performed with trigeminal ganglia (TG to determine TRPV1, ET-1 and glial fibrillary associated protein (GFAP expression following blast. Increased TRPV1, ET-1 and GFAP were detected in the TG of animals exposed to repeat blast. Increased nocifensive responses were also observed in animals exposed to repeat, tertiary blast as compared to single blast and control. Moreover, decreased TRPV1 desensitization was observed in TG neurons exposed to repeat blast. Repeat, tertiary blast resulted in increased TRPV1, ET-1 and GFAP expression in the TG, enhanced nociception and decreased TRPV1 desensitization.

  7. Effect of in vivo ozone exposure to Dorset sheep, an animal model with low levels of erythrocyte glucose-6-phosphate dehydrogenase activity

    Energy Technology Data Exchange (ETDEWEB)

    Moore, G.S.; Calabrese, E.J.; Schulz, E.

    1981-02-01

    Considerable interest has recently been directed to the possible extrapulmonary effects caused by exposure to ambient ozone. As a result of ozone induced in vivo alteration of red cell function within human subjects, it has been hypothesized that individuals with an erythrocyte glucose-6-phosphate dehydrogenase (G-6-PD) deficiency would be at increased hemolytic risk to elevated ambient ozone exposure. In order to evaluate such an hypothesis in an experimental setting it would be of great value to have an appropriate animal model with erythrocyte G-6-PD activity similar to the absolute activity range found in the human population. While no such unique animal model is presently known, the literature has revealed that Dorset sheep have an erythrocyte G-6-PD activity comparable in absolute units to a human G-6-PD deficient. Based on this information, we evaluated the mechanisms by which sheep and human G-6-PD deficient red cells handle oxidant stress. We evaluated the effects of in vivo ozone exposure in Dorset sheep over a broad range of concentrations.

  8. Evaluation of low-level laser therapy in rabbit oral mucosa after soft tissue graft application: A pilot study.

    Science.gov (United States)

    Kara, Cankat; Demir, Turgut; Ozbek, Elvan

    2013-12-01

    The aim of the present study was to assess the histopathological effects of low-level laser therapy (LLLT) on healing of the oral mucosa after soft tissue graft operations. The alterations at the end of healing in normal and LLLT-applied oral mucosa were studied in two healthy adult New Zealand white rabbits by taking specimens for light microscopic inspection. There was no adverse event reported in the study and no post-operative complications, such as swelling, bleeding, or edema, were observed in the rabbits. Complete wound healing was faster in the LLLT-applied rabbit. Compared to the normal rabbit oral mucosa, thickening of the stratum corneum (hyperkeratosis) was found in the epithelia of the rabbits. A significant increase in the epithelial thickness was found in the samples of rabbits, suggesting increased scar tissue following the wound repair. Additionally, many mitotic figures were present in the epithelia of the LLLT-applied rabbit, indicating epithelial cell hyperplasia. Long and irregular connective tissue protrusions projecting into the undersurface of the epithelium and mononuclear cell infiltrations were noted in the rabbits. The results suggest that LLLT used for soft tissue operations provides better and faster wound healing and that LLLT enhances epithelization.

  9. To evaluate the safety and efficiency of low level laser therapy (LLLT) in treating decubitus ulcers: a review

    Science.gov (United States)

    Ahmed, Ambereen

    2015-03-01

    Introduction: Pressure sores (decubitus ulcer) are a serious problem in health care management, especially for middleaged to older people who are bed-ridden. Although preventative measures are used, the condition remains common and development of novel, improved treatment methods are desirable. This article reviews the application of laser-based methods, previously shown to be effective in accelerating wound-healing in animal models and in the treatment of decubitus ulcers in humans. Methods: About 23 scientific articles on the effect of low level laser therapy (LLLT) on wound healing in animals and humans from 2000-2014 were reviewed. Additionally, results of several randomized controlled trials (RCTs) were reviewed, and compared with other treatment methods available. Results: Whilst carefully controlled, laboratory-based animal studies indicated that LLLT can reduce healing time for several types of injuries, however similar studies in humans failed to demonstrate consistent beneficial effects in the clinical setting. An acceleration of decubitus ulcer healing has been occasionally found, although limited to certain wavelengths and sometimes only in combination with other types of therapies. Indeed, some of the clinical articles indicated that certain laser wavelengths can have detrimental effects on time of healing. Conclusions: To date, there remains no convincing evidence that LLLT has consistent medical benefit in treating decubitus ulcers. Caution should be applied when considering LLLT since only certain wavelengths utilized have shown beneficial effects. It is concluded that, more RCTs are needed since, there is no clinical justification for LLLT, alone or in combination with other methods, in treating decubitus ulcers.

  10. Low-Level Environmental Lead Exposure and Dysglycemia in Adult Individuals: Results from the Canadian Health and Measure Survey 2007-2011.

    Science.gov (United States)

    Ngueta, Gerard; Kengne, André Pascal

    2017-02-01

    We aimed to evaluate the association of exposure to lead with glycated hemoglobin (HbA1c), fasting glucose levels (FGLs), and the likelihood for dysglycemia. We accessed data from Canada Health and Measures Survey. General linear models were used to estimate the association between blood lead concentrations (BPb) and both HbA1c and FGLs, while controlling for confounders. Multivariate logistic regression was used for assessing the relation between BPb and the likelihood for dysglycemia. FGLs in participants with moderate BPb (2.5-5.0 μg/dL) were 1.03 (95 % CI 1.00-1.06) times higher compared with participants with BPb Lead exposure was associated with the likelihood for neither FGLs ≥ 1.10 g/L nor HbA1c ≥ 5.7 %. The association between lead exposure and dysglycemia, if any, is likely to be very modest, at least at the population level.

  11. CHOLINERGIC AND NORADRENERGIC MODULATION OF LONG-TERM EXPLICIT MEMORY ARE ALTERED BY CHRONIC LOW-LEVEL LEAD EXPOSURE. (U915393)

    Science.gov (United States)

    Recent evidence suggests that septohippocampal cholinergic activity is suppressed in rats exposed to low levels of lead (Pb). As a result, noradrenergic activity may be elevated due to compensatory sympathetic sprouting. Therefore, the goals of this study were to (a) determine...

  12. Comparative evaluation of direct plating and most probable number for enumeration of low levels of Listeria monocytogenes in naturally contaminated ice cream products.

    Science.gov (United States)

    Chen, Yi; Pouillot, Régis; S Burall, Laurel; Strain, Errol A; Van Doren, Jane M; De Jesus, Antonio J; Laasri, Anna; Wang, Hua; Ali, Laila; Tatavarthy, Aparna; Zhang, Guodong; Hu, Lijun; Day, James; Sheth, Ishani; Kang, Jihun; Sahu, Surasri; Srinivasan, Devayani; Brown, Eric W; Parish, Mickey; Zink, Donald L; Datta, Atin R; Hammack, Thomas S; Macarisin, Dumitru

    2017-01-16

    A precise and accurate method for enumeration of low level of Listeria monocytogenes in foods is critical to a variety of studies. In this study, paired comparison of most probable number (MPN) and direct plating enumeration of L. monocytogenes was conducted on a total of 1730 outbreak-associated ice cream samples that were naturally contaminated with low level of L. monocytogenes. MPN was performed on all 1730 samples. Direct plating was performed on all samples using the RAPID'L.mono (RLM) agar (1600 samples) and agar Listeria Ottaviani and Agosti (ALOA; 130 samples). Probabilistic analysis with Bayesian inference model was used to compare paired direct plating and MPN estimates of L. monocytogenes in ice cream samples because assumptions implicit in ordinary least squares (OLS) linear regression analyses were not met for such a comparison. The probabilistic analysis revealed good agreement between the MPN and direct plating estimates, and this agreement showed that the MPN schemes and direct plating schemes using ALOA or RLM evaluated in the present study were suitable for enumerating low levels of L. monocytogenes in these ice cream samples. The statistical analysis further revealed that OLS linear regression analyses of direct plating and MPN data did introduce bias that incorrectly characterized systematic differences between estimates from the two methods. Published by Elsevier B.V.

  13. A systematic study of the disposition and metabolism of mercury species in mice after exposure to low levels of thimerosal (ethylmercury)

    Energy Technology Data Exchange (ETDEWEB)

    Carneiro, Maria Fernanda Hornos, E-mail: mafehoca@fcfrp.usp.br [Laboratório de Toxicologia e Essencialidade de Metais, Faculdade de Ciências Farmacêuticas de Ribeirão Preto – USP, Avenida do Café, s/n, Monte Alegre, CEP 14040-903 Ribeirão Preto, SP (Brazil); Oliveira Souza, Juliana Maria, E-mail: souza.jmo@gmail.com [Laboratório de Toxicologia e Essencialidade de Metais, Faculdade de Ciências Farmacêuticas de Ribeirão Preto – USP, Avenida do Café, s/n, Monte Alegre, CEP 14040-903 Ribeirão Preto, SP (Brazil); Grotto, Denise, E-mail: denise.grotto@prof.uniso.br [Laboratório de Toxicologia e Essencialidade de Metais, Faculdade de Ciências Farmacêuticas de Ribeirão Preto – USP, Avenida do Café, s/n, Monte Alegre, CEP 14040-903 Ribeirão Preto, SP (Brazil); Programa de Pós-Graduação em Ciências Farmacêuticas, Universidade de Sorocaba, Rodovia Raposo Tavares km 92.5, CEP 18023-000 Sorocaba, SP (Brazil); and others

    2014-10-15

    Thimerosal (TM) is an ethylmercury (etHg)-containing preservative used in some vaccines despite very limited knowledge on the kinetics and direct interaction/effects in mammals' tissues after exposure. Thus, this study aimed to evaluate the kinetics of Hg species in mice in a time course analysis after intramuscular injection of TM, by estimating Hg half-lives in blood and tissues. Mice were exposed to one single intramuscular dose of 20 µg of Hg as TM. Blood, brain, heart, kidney and liver were collected at 0.5 hour (h), 1 h, 8 h, 16 h, 144 h, 720 h and 1980 h after TM exposure (n=4). Hg species in animal tissues were identified and quantified by speciation analysis via liquid chromatography hyphenated with inductively coupled mass spectrometry (LC–ICP-MS). It was found that the transport of etHg from muscle to tissues and its conversion to inorganic Hg (inoHg) occur rapidly. Moreover, the conversion extent is modulated in part by the partitioning between EtHg in plasma and in whole blood, since etHg is rapidly converted in red cells but not in a plasma compartment. Furthermore, the dealkylation mechanism in red cells appears to be mediated by the Fenton reaction (hydroxyl radical formation). Interestingly, after 0.5 h of TM exposure, the highest levels of both etHg and inoHg were found in kidneys (accounting for more than 70% of the total Hg in the animal body), whereas the brain contributed least to the Hg body burden (accounts for <1.0% of total body Hg). Thirty days after TM exposure, most Hg had been excreted while the liver presented the majority of the remaining Hg. Estimated half-lives (in days) were 8.8 for blood, 10.7 for brain, 7.8 for heart, 7.7 for liver and 45.2 for kidney. Taken together, our findings demonstrated that TM (etHg) kinetics more closely approximates Hg{sup 2+} than methylmercury (meHg) while the kidney must be considered a potential target for etHg toxicity. - Highlights: • Ethylmercury is rapidly converted to inorganic

  14. TRACK--A new method for the evaluation of low-level extinction coefficient in optical films.

    Science.gov (United States)

    Vernhes, R; Martinu, L

    2015-11-02

    We develop a rigorous methodology named TRACK based on the collection of multi-angle spectrophotometric transmission and reflection data in order to assess the extinction coefficient of quasi-transparent optical films. The accuracy of extinction coefficient values obtained by this method is not affected by sample non-idealities (thickness non-uniformity, refractive index inhomogeneities, anisotropy, interfaces, etc.) and therefore a simple two-layer (substrate/film) optical model can be used. The method requires the acquisition of transmission and reflection data at two angles of incidence: 10° and 65° in p polarization. Data acquired at 10° provide information about the film thickness and the refractive index, while data collected at 65° are used for absorption evaluation and extinction coefficient computation. We test this method on three types of samples: (i) a CR-39 plastic substrate coated with a thick protective coating; (ii) the same substrate coated with a thin TiO(2) film; (iii) and a thick Si(3)N(4) film deposited on Gorilla glass that presents thickness non-uniformity and refractive index gradient non-idealities. We also compare absorption and extinction coefficient values obtained at 410 and 550 nm by both TRACK and Laser Induced Deflection techniques in the case of a 1 micron thick TiO(2) coating. Both methods display consistent extinction coefficient values in the 10(-4) and 10(-5) ranges at 410 and 550 nm, respectively, which proves the validity of the methodology and provides an estimate of its accuracy limit.

  15. Evaluation of Effectiveness of Photodynamic Therapy With Low-level Diode Laser in Nonsurgical Treatment of Peri-implantitis

    Science.gov (United States)

    Birang, Ehsan; Talebi Ardekani, Mohammad Reza; Rajabzadeh, Mahboobeh; Sarmadi, Gloria; Birang, Reza; Gutknecht, Norbert

    2017-01-01

    Introduction: Side effects related to antibiotic therapy for peri-implantitis are rare in laser therapy (LT); therefore, the aim of this study was to evaluate the effectiveness of LT and photodynamic therapy (PDT) on patients with primary peri-implantitis. Methods: In this randomized clinical trial, 40 implants presenting primary peri-implantitis in 20 patients with a mean age of 52.6 years old were included using the simple sampling technique. Periodontal treatment comprising scaling and root planing (SRP) was accomplished for the whole mouth while mechanical debridement with titanium curettes and air polishing with sodium bicarbonate powder was accomplished around the implants. The implants were randomly divided into two groups and treated with LT (control) and PDT (test). The clinical indices were measured at baseline, 6 weeks and 3 months after treatment. Real-time polymerase chain reaction (PCR) was used for analysis of microbial samples at baseline and 3-month follow-up. Data were analyzed with SPSS 20, using repeated-measures analysis of variance (ANOVA) and Friedman’s and Mann-Whitney tests (α = 0.05). Results: Both groups showed statistically significant improvements in terms of bleeding on probing (P 0.05). The number of Aggregatibacter actinomycetemcomitans (P = 0.022), Tannerella forsythia (P = 0.038) and Porphyromonas gingivalis (P = 0.05) in the test group and Porphyromonas gingivalis (P = 0.015) in the control group significantly decreased. Conclusion: The results suggested that LT and PDT have significant short-term benefits in the treatment of primary peri-implantitis. PMID:29123634

  16. Benzene metabolite levels in blood and bone marrow of B6C3F{sub 1} mice after low-level exposure

    Energy Technology Data Exchange (ETDEWEB)

    Bechtold, W.E.; Strunk, M.R.; Thornton-Manning, J.R. [and others

    1995-12-01

    Studies at the Inhalation Toxicology Research Institute (ITRI) have explored the species-specific uptake and metabolism of benzene. Results have shown that metabolism is dependent on both dose and route of administration. Of particular interest were shifts in the major metabolic pathways as a function of exposure concentration. In these studies, B6C3F{sub 1} mice were exposed to increasing levels of benzene by either gavage or inhalation. As benzene internal dose increased, the relative amounts of muconic acid and hydroquinone decreased. In contrast, the relative amount of catechol increased with increasing exposure. These results show that the relative levels of toxic metabolites are a function of exposure level. Based on these results and assuming a linear relationship between exposure concentration and levels of bone marrow metabolites, it would be difficult to detect an elevation of any phenolic metabolites above background after occupational exposures to the OSHA Permissible Exposure Limit of 1 ppm benzene.

  17. [A statistic approach to interpretation, results processing and hypo thesis testing in experiments on exposuring the human brain to perception of low level signals].

    Science.gov (United States)

    Chunovkina, A G; Li, A G

    1997-01-01

    There are shown the limitations of using the generally accepted approaches to statistic data processing at the perception of low level signals on Bernully scheme when specific nature on the phenomenon (the human ability to perception is not constant, uncontrolled and manifests itself for a short time) isn't taken into account. A new approach to the statistic processing of measurement results is also proposed. It is based on the sequence analysis of correct answers in a series, the use of sequential statistic procedures (criteria), maximally taking into account the perception specificity and the measurement features. The estimate of first kind error in proposed method has been carried out.

  18. Evaluation of a simplified modified Atkins diet for use by parents with low levels of literacy in children with refractory epilepsy: A randomized controlled trial.

    Science.gov (United States)

    Sharma, Suvasini; Goel, Shaiphali; Jain, Puneet; Agarwala, Anuja; Aneja, Satinder

    2016-11-01

    This study was planned to develop and evaluate a simple, easy-to-understand variation of the modified Atkins diet, for use by parents with low levels of literacy in children with refractory epilepsy. This study was conducted in two phases. In the first phase, a simplified version of the modified Atkins diet was developed. In the second phase this was evaluated in children aged 2-14 years who had daily seizures despite the appropriate use of at least two anticonvulsant drugs, in an open-label randomized-controlled-trial. Children were randomized to receive either the simplified modified Atkins diet or no dietary intervention for a period of 3 months with the ongoing anticonvulsant medications being continued unchanged in both the groups. Reduction in seizure frequency was the primary outcome-measure. Data was analyzed using intention to treat approach. Adverse effects were also studied. (Clinical trial identifier NCT0189989). Forty-one children were randomly assigned to the diet-group, and 40 were assigned to the control-group. Two patients discontinued the diet during the study period. The proportion of children with>50% seizure reduction was significantly higher in the diet group as compared to the control group (56.1% vs 7.5%, pAtkins diet was developed for use by parents with low levels literacy. This diet was found to be feasible, efficacious and well tolerated in children with refractory epilepsy. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Evaluation of the effects of the low-level laser therapy on swelling, pain, and trismus after removal of impacted lower third molar.

    Science.gov (United States)

    Alan, Hilal; Yolcu, Ümit; Koparal, Mahmut; Özgür, Cem; Öztürk, Seyit Ahmet; Malkoç, Sıddık

    2016-07-26

    In current study we aimed to examine the effect of a low-level laser therapy on the pain, mouth opening and swelling of patients whose impacted 3rd molar tooth was extracted in addition measurement volumetrically to the edema with 3dMD face system. It was surveyed 15 patients who had bilateral symmetric lower 3rd molars. Surgical sides of patients were randomly separated into two groups: the study group and the control group. It was applied extra oral low-level laser therapy (LLLT, 0.3 W, 40 s, 4 J/cm(2)) to the study group (n = 15) after the surgical operation and on the 2nd day. Only routine postoperative recommendation (ice application) was made in the control (n = 15) group. The maximum mouth opening, pain level and facial swelling evaluated. 3dMD Face® (3dMD, Atlanta, GA) Photogrammetric System was used to evaluate volumetric changes of the swelling. There was no statistically significant difference in the edema and interincisal opening between the groups and the pain level in the laser group was significantly lower than in the control group on the 7(th) postoperative day. Although there were decreasing trismus, swelling, and pain level, with this LLLT, there was significant difference only in the 7th day pain level in the laser group compared with the control group.

  20. A review of the data quality and comparability of case-control studies of low-level exposure to benzene in the petroleum industry.

    Science.gov (United States)

    Miller, B G; Fransman, W; Heederik, D; Hurley, J F; Kromhout, H; Fitzsimons, E

    2010-01-01

    Published case-control studies of risks of leukaemia following low exposures to benzene in the distribution of petroleum (gasoline) have not all identified the same level of risk, but the studies have had differences in cohort inclusion, case determination and availability of occupational and lifestyle data. We reviewed the quality and comparability of the data from three (of four) studies. Through site visits, discussions with the investigators and reading study reports, we reviewed and audited the methods used for selecting cases and controls, for estimating individual exposures and for analysing and interpreting the data. Case-control comparisons of exposures were examined using customized graphs. We found that there were no issues of subject selection, methods or general data quality that were likely to have distorted their internal comparisons; we could not check in detail whether the metric for exposure assessments was the same across the studies; the exposure assessments for the Australian study required the least backward estimation, and the Canadian, which also had fewest cases, the most; evidence of an increased risk at higher exposures in Australia was convincing. The findings are consistent with some effect of benzene at higher lifetime exposures. A proposed pooled analysis should improve quantification of any exposure-response relationship.

  1. Evaluation of low-level laser at auriculotherapy points to reduce postoperative pain in inferior third molar surgery: study protocol for a randomized controlled trial.

    Science.gov (United States)

    Sampaio-Filho, Hélio; Sotto-Ramos, Juliane; Pinto, Erika Horácio; Cabral, Marcia Regina; Longo, Priscila Larcher; Tortamano, Isabel Peixoto; Marcos, Rodrigo Labat; Silva, Daniela Fátima Teixeira; Pavani, Christine; Horliana, Anna Carolina Ratto Tempestini

    2016-09-02

    A comfortable postoperative return to daily activities has increased the need to control inflammation after third molar surgery. Anti-inflammatory drugs and analgesics are not exempt from adverse effects such as allergies and chronic gastritis, and they are not without cost. The association between low-level laser and auricular acupuncture can be an alternative when conventional drugs are contraindicated. Among its advantages, we can mention the low risk of side effects, low cost and simplicity of application. The objective of this study is to evaluate the efficiency of low-level laser at auriculotherapy points in reducing postoperative pain in lower third molar surgery. Ninety bilateral, symmetrical lower third molar surgeries will be performed in 45 healthy patients. Each patient will be their own control, through a split-mouth crossover study. One side of the mouth will be randomly chosen and, immediately after surgery, will be treated with low-level laser. After 21 days, the contralateral side will be operated on with low-level laser simulation used postoperatively. This regimen (laser application or not) will be repeated at 24 and 48 h after surgery. All patients will be requested to take analgesics (acetaminophen) if they have pain, i.e. in case of pain. Neither the surgeon nor the patients will know the assigned treatment. The primary variable will be postoperative pain assessed using a Visual Analog Scale, and the secondary variables will be trismus, edema, local temperature, dysphagia, presence of infection and painkiller ingestion. These variables will be assessed at baseline, 24 h, 48 h and 7 days after surgery. Blood samples for systemic inflammatory cytokine (TNF-α, IL-1, IL-6 and IL-8) analysis will be assessed at baseline and 24 h after surgery. Some authors believe that using a wavelength of 633 to 670 nm is a good option for laser therapy in the field of acupuncture. This wavelength can penetrate biological tissue to a depth of about 3 mm. However

  2. Ready-to-eat vegetables production with low-level water chlorination: an evaluation of water quality and of its impact on end products

    Directory of Open Access Journals (Sweden)

    Francesca D'Acunzo

    2012-06-01

    Full Text Available INTRODUCTION: We evaluated the microbiological impact of low-level chlorination (1 ppm free chlorine on the production of ready-to-eat (RTE vegetables by monitoring the microbiological quality of irrigation and processing water in two production plants over a 4-season period, as well as the microbiological quality of unprocessed vegetables and RTE product. Water samples were also characterized in terms of some chemical and physico-chemical parameters of relevance in chlorination management. MATERIALS AND METHODS: Both producers use water with maximum 1 ppm free chlorine for vegetables rinsing, while the two processes differ by the number of washing cycles. RESULTS AND CONCLUSIONS: Salmonella spp and Campylobacter spp were detected once in two different irrigation water samples out of nine from one producer. No pathogens were found in the vegetable samples. As expected, the procedure encompassing more washing cycles performed slightly better in terms of total mesophilic count (TCM when comparing unprocessed and RTE vegetables of the same batch. However, data suggest that low-level chlorination may be insufficient in preventing microbial build-up in the washing equipment and/or batch-to batch cross-contamination.

  3. A review of the data quality and comparability of case-control studies of low-level exposure to benzene in the petroleum industry

    NARCIS (Netherlands)

    Miller, B.G.; Fransman, W.; Heederik, D.; Hurley, J.F.; Kromhout, H.; Fitzsimons, E.

    2010-01-01

    Purpose Published case–control studies of risks of leukaemia following low exposures to benzene in the distribution of petroleum (gasoline) have not all identiWed the same level of risk, but the studies have had diVerences in cohort inclusion, case determination and availability of occupational and

  4. Estimating the risk of bladder and kidney cancer from exposure to low-levels of arsenic in drinking water, Nova Scotia, Canada.

    Science.gov (United States)

    Saint-Jacques, Nathalie; Brown, Patrick; Nauta, Laura; Boxall, James; Parker, Louise; Dummer, Trevor J B

    2017-10-28

    Arsenic in drinking water impacts health. Highest levels of arsenic have been historically observed in Taiwan and Bangladesh but the contaminant has been affecting the health of people globally. Strong associations have been confirmed between exposure to high-levels of arsenic in drinking water and a wide range of diseases, including cancer. However, at lower levels of exposure, especially near the current World Health Organization regulatory limit (10μg/L), this association is inconsistent as the effects are mostly extrapolated from high exposure studies. This ecological study used Bayesian inference to model the relative risk of bladder and kidney cancer at these lower concentrations-0-2μg/L; 2-5μg/L and; ≥5μg/L of arsenic-in 864 bladder and 525 kidney cancers diagnosed in the study area, Nova Scotia, Canada between 1998 and 2010. The model included proxy measures of lifestyle (e.g. smoking) and accounted for spatial dependencies. Overall, bladder cancer risk was 16% (2-5μg/L) and 18% (≥5μg/L) greater than that of the referent group (<2μg/L), with posterior probabilities of 88% and 93% for these risks being above 1. Effect sizes for kidney cancer were 5% (2-5μg/L) and 14% (≥5μg/L) above that of the referent group (<2μg/L), with probabilities of 61% and 84%. High-risk areas were common in southwestern areas, where higher arsenic-levels are associated with the local geology. The study suggests an increased bladder cancer, and potentially kidney cancer, risk from exposure to drinking water arsenic-levels within the current the World Health Organization maximum acceptable concentration. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Acute effects of low-level sulphur dioxide and nitrogen dioxide exposures on the respiratory tract of susceptible subjects in cold environments

    Energy Technology Data Exchange (ETDEWEB)

    Salonen, R.O.; Randell, J.T.; Haelinen, A.I.; Pennanen, A.S. [National Public Health Inst., Kuopio (Finland). Div. of Environmental Health; Kosma, V.M. [Kuopio Univ. (Finland). Dept. of Pathology; Pekkarinen, H. [Kuopio Univ. (Finland). Dept. of Physiology; Ruuskanen, J. [Kuopio Univ. (Finland). Dept. of Environmental Sciences; Tukiainen, H. [Kuopio Univ. (Finland). Dept. of Pulmonary Diseases

    1995-12-31

    Several recent epidemiological studies from Finland have suggested that sulphur dioxide (SO{sub 2}) and nitrogen dioxide (NO{sub 2}) cause adverse health effects in susceptible population groups, such as children and asthmatic patients, at much smaller concentrations than the present guideline values of the World Health Organization. One possible explanation of these findings is that the relatively long winter-time increases the sensitivity of the respiratory tract to irritant pollutants. This hypothesis is supported by experimental human and animal studies, which have shown obstruction and inflammatory changes in the conducting airways after ventilation of cold and dry air. Asthmatic patients are much more sensitive than healthy subjects to the irritating effects of cold and dry air and of air pollutants. The airways of many non-asthmatic a topic subjects are also sensitive to cold air, but these subjects are poorly defined as a potential susceptible population group to air pollutants. The aims of this project are: (1) to construct experimental human and animal facilities and protocols for short-term studies on SO{sub 2} and NO{sub 2} exposures at subfreezing temperatures, (2) to apply advanced lung function methodologies and symptom assessment for characterisation of short-term respiratory responses of asthmatic and a topic subjects to these exposures, (3) to apply well-established pulmonary physiological, cytological and morphological methods for characterisation of short-term responses to and mechanisms of these exposures in the guinea-pig lower airways. (author)

  6. Evaluation of passive avoidance learning and spatial memory in rats exposed to low levels of lead during specific periods of early brain development.

    Science.gov (United States)

    Rao Barkur, Rajashekar; Bairy, Laxminarayana K

    2015-01-01

    Widespread use of heavy metal lead (Pb) for various commercial purposes has resulted in the environmental contamination caused by this metal. The studies have shown a definite relationship between low level lead exposure during early brain development and deficit in children's cognitive functions. This study investigated the passive avoidance learning and spatial learning in male rat pups exposed to lead through their mothers during specific periods of early brain development. Experimental male rats were divided into 5 groups: i) the normal control group (NC) (N = 12) consisted of rat offspring born to mothers who were given normal drinking water throughout gestation and lactation, ii) the pre-gestation lead exposed group (PG) (N = 12) consisted of rat offspring, mothers of these rats had been exposed to 0.2% lead acetate in the drinking water for 1 month before conception, iii) the gestation lead exposed group (G) (N = 12) contained rat offspring born to mothers who had been exposed to 0.2% lead acetate in the drinking water throughout gestation, iv) the lactation lead exposed group (L) (N = 12) had rat offspring, mothers of these rats exposed to 0.2% lead acetate in the drinking water throughout lactation and v) the gestation and lactation lead exposed group (GL) (N = 12) contained rat offspring, mothers of these rats were exposed to 0.2% lead acetate throughout gestation and lactation. The study found deficit in passive avoidance learning in the G, L and GL groups of rats. Impairment in spatial learning was found in the PG, G, L and GL groups of rats. Interestingly, the study found that gestation period only and lactation period only lead exposure was sufficient to cause deficit in learning and memory in rats. The extent of memory impairment in the L group of rats was comparable with the GL group of rats. So it can be said that postnatal period of brain development is more sensitive to neurotoxicity compared to prenatal exposure. This work is available in Open

  7. Evaluation of passive avoidance learning and spatial memory in rats exposed to low levels of lead during specific periods of early brain development

    Directory of Open Access Journals (Sweden)

    Rajashekar Rao Barkur

    2015-06-01

    Full Text Available Objectives: Widespread use of heavy metal lead (Pb for various commercial purposes has resulted in the environmental contamination caused by this metal. The studies have shown a definite relationship between low level lead exposure during early brain development and deficit in children’s cognitive functions. This study investigated the passive avoidance learning and spatial learning in male rat pups exposed to lead through their mothers during specific periods of early brain development. Material and Methods: Experimental male rats were divided into 5 groups: i the normal control group (NC (N = 12 consisted of rat offspring born to mothers who were given normal drinking water throughout gestation and lactation, ii the pre-gestation lead exposed group (PG (N = 12 consisted of rat offspring, mothers of these rats had been exposed to 0.2% lead acetate in the drinking water for 1 month before conception, iii the gestation lead exposed group (G (N = 12 contained rat offspring born to mothers who had been exposed to 0.2% lead acetate in the drinking water throughout gestation, iv the lactation lead exposed group (L (N = 12 had rat offspring, mothers of these rats exposed to 0.2% lead acetate in the drinking water throughout lactation and v the gestation and lactation lead exposed group (GL (N = 12 contained rat offspring, mothers of these rats were exposed to 0.2% lead acetate throughout gestation and lactation. Results: The study found deficit in passive avoidance learning in the G, L and GL groups of rats. Impairment in spatial learning was found in the PG, G, L and GL groups of rats. Interestingly, the study found that gestation period only and lactation period only lead exposure was sufficient to cause deficit in learning and memory in rats. The extent of memory impairment in the L group of rats was comparable with the GL group of rats. Conclusions: So it can be said that postnatal period of brain development is more sensitive to neurotoxicity

  8. Influence of Low-Level Prenatal Exposure to PCDD/Fs and PCBs on Empathizing, Systemizing and Autistic Traits: Results from the Duisburg Birth Cohort Study.

    Directory of Open Access Journals (Sweden)

    Nikola Nowack

    Full Text Available Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs and polychlorinated biphenyls (PCBs are assumed to act as endocrine disruptor chemicals. Prenatal exposure to these pollutants might influence fetal steroid hormone levels, which are thought to be related to sex-typical development and autistic traits.We examined associations of prenatal levels of PCDD/Fs and PCBs with autism traits and sex-typical behaviour in childhood.We measured levels of PCDD/Fs and PCBs in maternal blood samples during pregnancy using gas chromatography/high-resolution mass spectrometry. Sex-typical behaviour was assessed at 9 years of age (n = 96 and autistic traits at 10 years of age using the Social Responsiveness Scale (SRS; n = 100. Multiple regression analyses were conducted to estimate the associations between prenatal exposure and outcome variables.Blood concentrations (WHO2005-TEq of ƩPCDD/Fs ranged from 2.93-46.45 pg/g lipid base (median = 12.91 pg/g lipid base and concentrations of ƩPCBs were in the range of 1.24-25.47 pg/g lipid base (median = 6.85 pg/g lipid base which is within the range of German background exposure. We found significant negative associations between PCDD/F levels in maternal blood and SRS scores in the whole group (β = -6.66, p < .05, in girls (β = -10.98, p < .05 and, in one SRS subscale, in boys (β = -6.86, p < .05. For PCB levels, associations with one SRS subscale were significant for the whole study group as were associations with two subscales in girls. We did not find significant associations between PCDD/F or PCB levels and sex-typical behaviour for either sex.In an earlier part of this study, prenatal exposure to PCDD/Fs and PCBs was found to be associated with lower testosterone levels, therefore, our findings are consistent with the idea that autism spectrum conditions are related to fetal androgen levels. Several possible mechanisms, through which PCDD/Fs and PCBs might influence autistic behaviour, are discussed.

  9. Low Level Exposure to Sulfur Mustard: Development of a SOP for Analysis of Albumin Adducts and of a System for Non-Invasive Diagnosis on Skin

    Science.gov (United States)

    2007-08-01

    Adrian had already prepared mass spec instrument (Sciex, API 4000), as described in “Retrospective detection of exposure to sulfur mustard: improvements...recorded at unit resolution on both Q1 and Q3 (i.e., with ion peaks between 0.60 and 0.80 m/z units wide at half-maximum height), at a declustering...only in the low µg/ml range, i.e., far less sensitive than mass spec analysis. Based on the positive results obtained for derivatization of the

  10. Significant changes in the amounts of neurotransmitter and related substances in rat brain induced by subacute exposure to low levels of toluene and xylene

    Energy Technology Data Exchange (ETDEWEB)

    Honma, T.; Sudo, A.; Miyagawa, M.; Sato, M.; Hasegawa, H.

    1983-01-01

    Rats were exposed to toluene and xylene at 200-800 ppm for 30 days. After exposure, changes in the dopamine, norepinephrine, serotonin, acetylcholine (ACh), cyclic AMP, cyclic GMP, GABA, glutamic acid, glutamine, aspartic acid, taurine, glycine and alanine content of different areas of the brain were investigated. ACh in the striatum and whole brain were reduced dose-dependently by toluene and xylene. The reduction at 800 ppm of the solvents was in the range of 10 to 20% of the ACh content of the control rats. Toluene and xylene caused different changes in monoamine content other than ACh, but the changes were not dose-dependent. Among the seven free amino acids that are the main amino acid components of the brain, the glutamine content was increased by toluene and xylene at 800 ppm. Decrease in ACh and increase in glutamine in the brain appear to be phenomena common to many kinds of organic solvents including toluene and xylene after acute and subacute exposure.

  11. INFLUENCE OF MORINGA OLEIFERA (DRUM-STICK FRUIT EXTRACT ON HAEMATOLOGICAL PROFILE FOLLOWING REPEATED EXPOSURE TO LOW LEVELS OF ARSENIC THROUGH FEED ON RATS

    Directory of Open Access Journals (Sweden)

    Vaibhav R. Pachade

    2012-01-01

    Full Text Available Effect of Moringa oleifera fruits hot methanolic extract (MFE, if any, in minimizing the adverse reactions of repeated exposure to arsenic trioxide (AT in feed was investigated in Wistar rats with reference to haematological profile. Three groups of rats each containing 10 (5male+5female were used. The group I served as negative control. Rats of group II were fed arsenic trioxide (AT alone @ 100 ppm in feed while those of group III simultaneously received AT (@100 ppm and MFE (50 mg/kg/day for 28 days. Blood samples were collected from retroorbital plexus for estimation of hematological parameters (haemoglobin, PCV, TEC, MCH, MCHC, MCV of different groups on 0 day, 15th day and 29th day respectively. Exposure to AT through feed in group II resulted in significant (P<0.05 decrease in haemoglobin, TEC and MCHC, accompanied by increased MCV, with no significant alteration of PCV or MCH of the rats. While rats of group III treated with AT (@100 ppm and MFE (50 mg/kg/day also resulted in same consequences as it was in group II but it was slightly less than that of group II suggesting of mild non significant protective effect.

  12. Process system evaluation-consolidated letters. Volume 1. Alternatives for the off-gas treatment system for the low-level waste vitrification process

    Energy Technology Data Exchange (ETDEWEB)

    Peurrung, L.M.; Deforest, T.J; Richards, J.R.

    1996-03-01

    This report provides an evaluation of alternatives for treating off-gas from the low-level waste (LLW) melter. The study used expertise obtained from the commercial nonradioactive off-gas treatment industry. It was assumed that contact maintenance is possible, although the subsequent risk to maintenance personnel was qualitatively considered in selecting equipment. Some adaptations to the alternatives described may be required, depending on the extent of contact maintenance that can be achieved. This evaluation identified key issues for the off-gas system design. To provide background information, technology reviews were assembled for various classifications of off-gas treatment equipment, including off-gas cooling, particulate control, acid gas control, mist elimination, NO{sub x} reduction, and SO{sub 2} removal. An order-of-magnitude cost estimate for one of the off-gas systems considered is provided using both the off-gas characteristics associated with the Joule-heated and combustion-fired melters. The key issues identified and a description of the preferred off-gas system options are provided below. Five candidate treatment systems were evaluated. All of the systems are appropriate for the different melting/feed preparations currently being considered. The lowest technical risk is achieved using option 1, which is similar to designs for high-level waste (HLW) vitrification in the Hanford Waste Vitrification Project (HWVP) and the West Valley. Demonstration Project. Option 1 uses a film cooler, submerged bed scrubber (SBS), and high-efficiency mist eliminator (HEME) prior to NO{sub x} reduction and high-efficiency particulate air (HEPA) filtration. However, several advantages were identified for option 2, which uses high-temperature filtration. Based on the evaluation, option 2 was identified as the preferred alternative. The characteristics of this option are described below.

  13. Reporting low-level analytical data

    African Journals Online (AJOL)

    Meyer

    at low level exposures, a linear extrapolation does not mimic the biological consequences of exponential dose-response curves ( 3). The extrapolation of a distribution function into the unmeasurable region (4) assumes the existence of a specific population of interest having certain measurable characteristics that can be ...

  14. Effects of corticopuncture (CP) and low-level laser therapy (LLLT) on the rate of tooth movement and root resorption in rats using micro-CT evaluation.

    Science.gov (United States)

    Suzuki, Selly Sayuri; Garcez, Aguinaldo Silva; Reese, Patricia Oblitas; Suzuki, Hideo; Ribeiro, Martha Simões; Moon, Won

    2017-12-27

    The aim of this study was to compare the rate of tooth displacement, quantity of root resorption, and alveolar bone changes in five groups: corticopuncture (CP), low-level laser therapy (LLLT), CP combined with LLLT (CP + LLLT), control (C), and negative control (NC). A total of 60 half-maxilla from 30 male Wistar rats (10 weeks old) were divided randomly into five groups: three (CP, LLLT, and CP + LLLT) test groups with different stimulation for accelerated-tooth-movement (ATM), one control (C) group, and one negative control (NC) group with no tooth movement. Nickel-titanium coil springs with 50 g of force were tied from the upper left and right first molars to micro-implants placed behind the maxillary incisors. For the CP and CP + LLLT groups, two perforations in the palate and one mesially to the molars were performed. For the LLLT and CP + LLLT groups, GaAlAs diode laser was applied every other day for 14 days (810 nm, 100 mW, 15 s). The tooth displacements were measured directly from the rat's mouth and indirectly from microcomputer (micro-CT) tomographic images. Bone responses at the tension and compression sites and root resorption were analyzed from micro-CT images. The resulting alveolar bone responses were evaluated by measuring bone mineral density (BMD), bone volume fraction (BV/TV), and trabecular thickness (TbTh). Root resorption crater volumes were measured on both compression and tension sides of mesial and distal buccal roots. The tooth displacement in the CP + LLLT group was the greatest when measured clinically, followed by the CP, LLLT, and control groups (C and NC), respectively (p CP and CP + LLLT groups compared to the LLLT and control groups. The BMD, BV/TV, and TbTh values were lower at the compression side and higher at the tension side for all three test groups compared to the control group. The root resorption crater volume of the distal buccal root was higher in the control group, followed by CP, LLLT

  15. Clinical Evaluation of High and Low-Level Laser Treatment (CO2vsInGaAlP Diode Laser) for Recurrent Aphthous Stomatitis.

    Science.gov (United States)

    Zeini Jahromi, Nasim; Ghapanchi, Janan; Pourshahidi, Sara; Zahed, Maryam; Ebrahimi, Hooman

    2017-03-01

    Recurrent aphthous stomatitis (RAS) is one of the most common lesions in the oral cavity. Due to its multifactorial nature, there is no definitive treatment for RAS. Laser therapy is one of the suggested treatments to reduce patient's discomfort. The purpose of the present clinical trial is to assess the effect of low and high level laser therapy on pain control and wound healing of RAS. Thirty six patients with minor RAS were divided into three groups. Group 1 (n=14) received CO2 laser, group 2 (n=12) were treated with InGaAlP Diode laser and group 3 (n=10) received sham laser as placebo. All patients were evaluated daily up to 15 days after receiving one session of laser therapy. Pain severity before and after treatment, wound healing, patient's satisfaction, and functional disturbance before and after treatment were recorded for each patient. According to statistical analysis, pain reduction after treatment in group 1 was 7.00±2.41, in group 2 was 2.08±2.31, and in group 3 was 1.40±1.77. In addition, a significant difference was observed in the reduction of functional complications in CO2 laser treated patients compared to the other two groups. High-level laser treatment showed analgesic effects on RAS, but no healing was observed. Low-level laser therapy demonstrated no positive effect on recurrent aphthous ulcers.

  16. Low-level malaria infections detected by a sensitive polymerase chain reaction assay and use of this technique in the evaluation of malaria vaccines in an endemic area.

    Science.gov (United States)

    Imoukhuede, Egeruan B; Andrews, Laura; Milligan, Paul; Berthoud, Tamara; Bojang, Kalifa; Nwakanma, Davis; Ismaili, Jamila; Buckee, Caroline; Njie, Fanta; Keita, Saikou; Sowe, Maimuna; Lang, Trudie; Gilbert, Sarah C; Greenwood, Brian M; Hill, Adrian V S

    2007-03-01

    The feasibility of using a sensitive polymerase chain reaction (PCR) to evaluate malaria vaccines in small group sizes was tested in 102 adult Gambian volunteers who received either the malaria vaccine regimen FP9 ME-TRAP/MVA ME-TRAP or rabies vaccine. All volunteers received the antimalarial drugs primaquine and Lapdap plus artesunate to eliminate malaria parasites. Volunteers in a further group received an additional single treatment with sulfadoxine-pyrimethamine (SP) to prevent new infections. There was substantially lower T-cell immunogenicity than in previous trials with this vaccine regimen and no protection against infection in the malaria vaccine group. Using the primary endpoint of 20 parasites per mL, no difference was found in the prevalence of low-level infections in volunteers who received SP compared with those who did not, indicating that SP did not reduce the incidence of very low-density infection. However, SP markedly reduced the incidence of higher density infections. These findings support the feasibility and potential of this approach to screen pre-erythrocytic vaccines for efficacy against infection in small numbers of vaccinees in endemic areas.

  17. A histological evaluation of a low-level laser therapy as an adjunct to periodontal therapy in patients with diabetes mellitus.

    Science.gov (United States)

    Obradović, Radmila; Kesić, Ljiljana; Mihailović, Dragan; Antić, Slobodan; Jovanović, Goran; Petrović, Aleksandar; Peševska, Snežana

    2013-01-01

    Diabetes mellitus (DM) and chronic periodontitis are common chronic diseases in adults in the world population. DM has a strong influence on the oral cavity and represents a risk factor for gingivitis and periodontitis. Low-level laser therapy (LLLT) has proven effective in the reduction of inflammation and swelling. The aim of the present study was to evaluate the efficacy of LLLT in diabetic periodontitis through histological analysis. A total of 300 diabetics with chronic periodontal disease and teeth indicated for extraction were assigned into six equal groups. In the groups 1 and 4, indicated teeth were extracted before treatment, and in the rest of the groups upon completion of the entire treatment. All patients received oral hygiene instructions and full-mouth conservative periodontal treatment. In groups 3 and 6, LLLT was applied (670 nm, 5 mW, 2 J/cm(2), 16 min, 5 days). Histologic findings of gingival tissue treated with LLLT showed expressed healing, as is evident by the absence of inflammatory cells. Tissue edema could not be seen, and the number of blood vessels was reduced. In the gingival lamina, propria pronounced collagenization and homogenization were present. It can be concluded that LLLT has shown efficacy in the treatment of periodontitis in diabetics. Because of more pronounced alterations of periodontium in diabetics, the use of LLLT is of particular importance.

  18. Evaluation of digital PCR for detecting low-level EGFR mutations in advanced lung adenocarcinoma patients: a cross-platform comparison study.

    Science.gov (United States)

    Gu, Jincui; Zang, Wanchun; Liu, Bing; Li, Lei; Huang, Lixia; Li, Shaoli; Rao, Guanhua; Yu, Yang; Zhou, Yanbin

    2017-09-15

    Emerging evidence has indicated that circulating tumor DNA (ctDNA) from plasma could be used to analyze EGFR mutation status for NSCLC patients; however, due to the low level of ctDNA in plasma, highly sensitive approaches are required to detect low frequency mutations. In addition, the cutoff for the mutation abundance that can be detected in tumor tissue but cannot be detected in matched ctDNA is still unknown. To assess a highly sensitive method, we evaluated the use of digital PCR in the detection of EGFR mutations in tumor tissue from 47 advanced lung adenocarcinoma patients through comparison with NGS and ARMS. We determined the degree of concordance between tumor tissue DNA and paired ctDNA and analyzed the mutation abundance relationship between them. Digital PCR and Proton had a high sensitivity (96.00% vs. 100%) compared with that of ARMS in the detection of mutations in tumor tissue. Digital PCR outperformed Proton in identifying more low abundance mutations. The ctDNA detection rate of digital PCR was 87.50% in paired tumor tissue with a mutation abundance above 5% and 7.59% in paired tumor tissue with a mutation abundance below 5%. When the DNA mutation abundance of tumor tissue was above 3.81%, it could identify mutations in paired ctDNA with a high sensitivity. Digital PCR will help identify alternative methods for detecting low abundance mutations in tumor tissue DNA and plasma ctDNA.

  19. Metabonomic analysis of the joint toxic action of long-term low-level exposure to a mixture of four organophosphate pesticides in rat plasma.

    Science.gov (United States)

    Du, Longfei; Li, Sifan; Qi, Lei; Hou, Yurong; Zeng, Yan; Xu, Wei; Wang, Hong; Zhao, Xiujuan; Sun, Changhao

    2014-05-01

    In previously published articles, we evaluated the toxicity of four organophosphate (OP) pesticides (dichlorvos, dimethoate, acephate, and phorate) in rats using metabonomic technology at their corresponding no observed adverse effect levels (NOAELs). The results show that a single pesticide did not elicit a toxic response. The joint toxic action of four pesticides (at their corresponding NOAELs) was evaluated by metabolomic analysis of rat plasma under experimental conditions similar to those of the four single OP pesticides. The pesticides were administered daily to rats through drinking water for 24 weeks. The mixture of four pesticides showed a joint toxic action at the NOAELs of each pesticide. The 19 metabolites were statistically significantly changed in all the treated groups compared with those in the control group (p mechanism of joint toxic action.

  20. The influence of low level pre- and perinatal exposure to PCDD/Fs, PCBs, and lead on attention performance and attention-related behavior among German school-aged children: results from the Duisburg Birth Cohort Study.

    Science.gov (United States)

    Neugebauer, Julia; Wittsiepe, Jürgen; Kasper-Sonnenberg, Monika; Schöneck, Nina; Schölmerich, Axel; Wilhelm, Michael

    2015-01-01

    Prenatal exposure to polychlorinated biphenyls (PCBs) and lead are thought to be risk factors for attention-deficit hyperactivity disorder (ADHD), whereas the prenatal influence of polychlorinated dibenzo-p-dioxins and -furans (PCDD/Fs) on attention performance has been less studied. Within the Duisburg Birth Cohort Study, we investigated low-level exposure to these compounds in relation to children's attention. We measured blood levels of PCDD/Fs, PCBs and lead from pregnant mothers (32(nd) week of pregnancy) and PCDD/Fs and PCBs in breast milk (2 weeks after delivery). The attention of school-aged children (N=117) was investigated with a computer-based test battery of attention performance (KITAP) and a parent rating questionnaire of behaviors related to ADHD (FBB-ADHS). Influences of the exposure on attention were analyzed by multiple regression analyses. Increasing prenatal PCDD/F and PCB concentrations were significantly (plead concentrations had few significant associations with attention performance (e.g., a 23% higher number of omission errors in the subtest Distractibility; 95%-CI: 1.00-1.51), whereas ADHD-related behavior (questionnaire based) was increased with increasing lead exposure (Overall-ADHD: 9%; 95%-CI: 1.01-1.17). ADHD-related behavior was negatively associated with prenatal PCDD/F or PCB exposures (e.g., for PCB exposure: -10%; 95%-CI: 0.82-0.99). Pre- and perinatal PCDD/F and PCB exposure may have subtle influences on attention performance in healthy children at low environmental levels, while behavior changes are negatively associated. Furthermore, we provide additional evidence for the impact of prenatal lead exposure on attention deficits. Copyright © 2014 Elsevier GmbH. All rights reserved.

  1. Low-Level Evidence Suggests that Perceived Ability to Evaluate and Trust Online Health Information is Associated with Low Health Literacy

    Directory of Open Access Journals (Sweden)

    Lindsay Alcock

    2016-04-01

    Full Text Available Objective – To review, based on research evidence, the correlation between low health literacy and four outcomes of interest: (1 the ability to evaluate online health information based on (2 perceived reliability and accuracy, (3 trust in the Internet as an information source, and (4 the application of established evaluation criteria. Design – Systematic review and narrative synthesis. Setting –MEDLINE, PsycInfo, Web of Science, CINAHL, and Communication and Mass-media Complete as well as articles discovered through the snowball method. Subjects – 38 studies identified through a systematic literature search. Methods – An exhaustive list of potential articles was gathered through searching five online databases and Google Scholar, and hand searching of references. Inclusion and exclusion criteria were applied in a two-phase screening process in which two researchers participated to address reliability. Data, including study characteristics and metadata, predictors, assessment methods, and outcomes, were extracted from relevant studies, and then synthesized narratively. Main Results – Following duplication removal 13,632 records were retrieved, 254 of which were identified for full-text assessment. Thirty-eight studies met the eligibility criteria. All studies were non-experimental and therefore graded as a low level of evidence; 35 were cross-sectional designs, 1 a focus group, and 2 were observational studies. Studies varied widely in population definition and sample size and were published between 2001 and 2013, primarily in North America. Overall, a positive association was identified between health literacy and outcomes related to the ability to evaluate or trust Internet health information, while findings were inconsistent related to perceived quality of information and the application of evaluative criteria. Four studies examined the impact of health literacy levels on one or more of the outcomes of interest. The most prevalent

  2. Evaluation effect of low level Helium-Neon laser and Iranian propolis extract on Collagen Type I gene expression by human gingival fibroblasts: anin vitrostudy.

    Science.gov (United States)

    Eslami, Hosein; Motahari, Paria; Safari, Ebrahim; Seyyedi, Maryam

    2017-06-30

    production of collagen by fibroblast cells is a key component in wound healing. Several studies have shown that low level laser therapy (LLLT) and propolis extract stimulate collagen Type I production. The aim of this study is to evaluation the combined effect of LLL helium neon (632.8 nm) and Iranian propolis extract on collagen Type I gene expression by human gingival fibroblasts (HGF3-PI 53). Human gingival fibroblasts after culturing divided into six experimental groups: G1-control group, which received no irradiation and propolis extract, G2-irradiated at1.5 J/cm 2 , G3-irradiated at 0.15 J/cm 2 , G4-recived extract of propolis, G5- combined extract of propolis and 1.5 J/cm 2 laser irradiation and G6- combined extract of propolis and 0.15 J/cm 2 laser irradiation. The experiments were conducted in triplicate. After 24 hour, the total RNA was extracted and cDNA synthesis was performed. Type I collagen mRNA expression was determined with real time PCR. The obtained results illustrated a statistically significant difference between G3 (0.15 J/cm 2 ) and G1 (control group) in levels of collagen Type I messenger RNA (mRNA) expression (pType I gene. Expression of this gene decreases in other groups that this difference was statistically significant. LLLT in different dosage and propolis extract may result in decreased or increased collagen type I gene expression. However this effect should be investigated in clinical studies.

  3. Evaluation of Groundwater Impacts to Support the National Environmental Policy Act Environmental Assessment for the INL Remote-Handled Low-Level Waste Disposal Project

    Energy Technology Data Exchange (ETDEWEB)

    Annette Schafer, Arthur S. Rood, A. Jeffrey Sondrup

    2011-12-23

    Groundwater impacts have been analyzed for the proposed remote-handled low-level waste disposal facility. The analysis was prepared to support the National Environmental Policy Act environmental assessment for the top two ranked sites for the proposed disposal facility. A four-phase screening and analysis approach was documented and applied. Phase I screening was site independent and applied a radionuclide half-life cut-off of 1 year. Phase II screening applied the National Council on Radiation Protection analysis approach and was site independent. Phase III screening used a simplified transport model and site-specific geologic and hydrologic parameters. Phase III neglected the infiltration-reducing engineered cover, the sorption influence of the vault system, dispersion in the vadose zone, vertical dispersion in the aquifer, and the release of radionuclides from specific waste forms. These conservatisms were relaxed in the Phase IV analysis which used a different model with more realistic parameters and assumptions. Phase I screening eliminated 143 of the 246 radionuclides in the inventory from further consideration because each had a half-life less than 1 year. An additional 13 were removed because there was no ingestion dose coefficient available. Of the 90 radionuclides carried forward from Phase I, 57 radionuclides had simulated Phase II screening doses exceeding 0.4 mrem/year. Phase III and IV screening compared the maximum predicted radionuclide concentration in the aquifer to maximum contaminant levels. Of the 57 radionuclides carried forward from Phase II, six radionuclides were identified in Phase III as having simulated future aquifer concentrations exceeding maximum contaminant limits. An additional seven radionuclides had simulated Phase III groundwater concentrations exceeding 1/100th of their respective maximum contaminant levels and were also retained for Phase IV analysis. The Phase IV analysis predicted that none of the thirteen remaining

  4. Acute exposure to low-level CW and GSM-modulated 900 MHz radiofrequency does not affect Ba 2+ currents through voltage-gated calcium channels in rat cortical neurons.

    Science.gov (United States)

    Platano, Daniela; Mesirca, Pietro; Paffi, Alessandra; Pellegrino, Monica; Liberti, Micaela; Apollonio, Francesca; Bersani, Ferdinando; Aicardi, Giorgio

    2007-12-01

    We have studied the non-thermal effects of radiofrequency (RF) electromagnetic fields (EMFs) on Ba(2+) currents (I Ba 2+) through voltage-gated calcium channels (VGCC), recorded in primary cultures of rat cortical neurons using the patch-clamp technique. To assess whether low-level acute RF field exposure could modify the amplitude and/or the voltage-dependence of I Ba 2+, Petri dishes containing cultured neurons were exposed for 1-3 periods of 90 s to 900 MHz RF-EMF continuous wave (CW) or amplitude-modulated according to global system mobile communication standard (GSM) during whole-cell recording. The specific absorption rates (SARs) were 2 W/kg for CW and 2 W/kg (time average value) for GSM-modulated signals, respectively. The results obtained indicate that single or multiple acute exposures to either CW or GSM-modulated 900 MHz RF-EMFs do not significantly alter the current amplitude or the current-voltage relationship of I Ba 2+, through VGCC. (c) 2007 Wiley-Liss, Inc.

  5. [Autoimmune processes after long-term low-level exposure to electromagnetic fields (the results of an experiment). Part 5. Impact of the blood serum from rats exposed to low-level electromagnetic fields on pregnancy, foetus and offspring development of intact female rats].

    Science.gov (United States)

    Liaginskaia, A M; Grigor'ev, Iu G; Osipov, V A; Grigor'ev, O A; Shafirkin, A V

    2010-01-01

    This study evaluated possible adverse effects of injection of blood serum from rats exposed to microwaves at a power density of 500 microW/cm2 on pregnancy and foetal and offspring development in intact female rats. The study was performed with 59 pregnant Wistar rats. In utero mortality, embryo and foetal body weights and placenta weight were used for the evaluation of embryo and foetal development. Generally accepted integral and specific parameters were used for the evaluation of postnatal development of offspring during the first 30 days of life. It was shown that intra peritoneal injection of blood serum from IMF exposed rats (chronic 30-day RF exposure at 500 microW/cm2) to intact rats on the 10th day of pregnancy resulted in adverse effects on foetal and offspring development. Total mortality (in utero + postnatal) as well as delay in offspring development was higher in this group.

  6. Evaluation of isotope migration: land burial. Water chemistry at commercially operated low-level radioactive waste disposal sites. Progress report No. 7, October--December 1977

    Energy Technology Data Exchange (ETDEWEB)

    Colombo, P.; Weiss, A. J.; Francis, A. J.

    1978-01-01

    Trench water samples from the commercial low-level radioactive waste disposal sites at Maxey Flats, Kentucky, and West Valley, New York, were collected, and the bacterial populations were enumerated. The range of bacterial populations in six trench water samples were 400 to 24,000 aerobic and 90 to 15,000 anaerobic bacteria/ml. Most of the bacteria isolated from the anaerobic culture plates were facultative anaerobes, although a few strict anaerobes were also present. Mixed bacterial populations isolated from the trench waters were able to grow anaerobically utilizing the carbon and nitrogen sources present in the trench waters. Trench waters supplemented with mineral salts supported only a modest increase in growth of these bacteria. The results of this study indicate that bacteria are active in the trenches, and the radioactivity and organic compounds present in the trenches are not toxic to these bacteria.

  7. Evaluation of effect of low-level laser therapy on adolescents with temporomandibular disorder: study protocol for a randomized controlled trial.

    Science.gov (United States)

    de Godoy, Camila Haddad Leal; Silva, Paula Fernanda da Costa; de Araujo, Deise Sales; Motta, Lara Jansiski; Biasotto-Gonzalez, Daniela Aparecida; Politti, Fabiano; Mesquita-Ferrari, Raquel Agnelli; Fernandes, Kristianne Porta Santos; Albertini, Regiane; Bussadori, Sandra Kalil

    2013-07-22

    A number of problems involving the temporomandibular joint (TMJ) and associated structures can lead to temporomandibular disorder (TMD). The aim of the proposed study is to assess the effect of low-level laser therapy on occlusal contacts, mandibular movements, electromyography activity in the muscles of mastication and pain in adolescents with TMD. A randomized, controlled, double-blind, clinical trial will be carried out involving 85 male and female adolescents between 15 and 18 years of age. The research diagnostic criteria for TMD will be used to assess all individuals who agree to participate. All participants will be submitted to a clinical examination and electromyographic analysis of the masseter muscles and anterior bundle of the temporal muscles bilaterally, to determine TMD. Based on the clinical findings, the participants will be classified as having or not having TMD. Those with TMD will be divided into four groups, three of which will receive low-level laser therapy and one of which will receive a placebo treatment. The treatments will involve the TMJ region alone, the masseter and temporal muscles alone, or both these regions together. The data will be submitted to descriptive statistical analysis. The chi-square test and Fisher's exact test will be used to determine associations among the categorical variables. The Student's t test and analysis of variance will be used for the comparison of mean electromyographic signals. Pearson's correlation coefficients will be calculated for the analysis of correlations among the continuous variables. The protocol for this study has been submitted to Clinical Trials - registration number NCT01846000.

  8. A Structured, Manual-Based Low-Level Intervention vs. Treatment as Usual Evaluated in a Randomized Controlled Trial for Adolescents with Extreme Obesity - the STEREO Trial

    Directory of Open Access Journals (Sweden)

    Yvonne Mühlig

    2017-08-01

    Full Text Available Background: To compare efficacy and safety of a manual-based low-level psychological intervention with treatment as usual (weight loss treatment. Methods: A two-armed randomized controlled trial without blinding and computer-based stratified block randomization included adolescents and young adults (14.0-24.9 years with a BMI ≥ 30 kg/m2 at five German university hospitals. Primary outcomes were adherence (participation rate ≥ 5/6 sessions and quality of life (DISABKIDS-37 6 months after randomization. Secondary outcomes included depression, self-esteem, and perceived stress scores. Results: Of 397 screened adolescents, 119 (mean BMI 40.4 ± 7.0 kg/m2, 49.6% female were randomized to the manual-based low-level intervention (n = 59 or treatment as usual (n = 60. We observed no group difference for adherence (absolute risk reduction 0.4%, 95% CI -14.7% to 15.5%; p = 1.0 or health-related quality of life (score difference 8.1, 95% CI -2.1 to 18.3; p = 0.11. Among all secondary outcomes, we detected explorative evidence for an effect on the DISABKIDS-37 ‘social exclusion' subscale (score difference 15.5; 95% CI 1.6-29.4; p = 0.03. 18/19 adverse events occurred in 26 participants, none were classified as serious. Conclusion: Adherence to a coping-oriented intervention was comparable to weight loss treatment, although it was weak in both interventions. Psychological interventions may help to overcome social isolation; further confirmation is required.

  9. A double-blind, placebo-controlled randomized trial evaluating the ability of low-level laser therapy to improve the appearance of cellulite.

    Science.gov (United States)

    Jackson, Robert F; Roche, Gregory C; Shanks, Steven C

    2013-03-01

    Cellulite is present in 90% of post-adolescent women. Several technologies have been developed for treating cellulite; however, they all involve some degree of massage or mechanical manipulation. The purpose of this study was to assess the effectiveness of a low-level laser light device employing green 532 nm diodes as a stand-alone procedure without massage or mechanical manipulation for improving the appearance of cellulite in the thighs and buttocks. This double-blind study randomized subjects to undergo treatment with the LLLT device (N = 34) or sham treatment (N = 34). During a 2-week treatment phase, each subject received three weekly treatment sessions 2-3 days apart. During each session, the front and back of the hips, thighs, and waist were exposed for 15 minutes (30 minutes total). Nineteen subjects in the LLLT group achieved a decrease of one or more stages on the Nurnberger-Muller grading scale (55.88%) versus three subjects (8.82%) in the sham-treated group (P cellulite (P cellulite they received versus 25.8% of sham-treated subjects. There were no reports of adverse events. Low-level laser therapy using green 532 nm diodes is safe and effective for improving the appearance of cellulite in the thighs and buttocks. In contrast with other technologies, LLLT is effective as a stand-alone procedure without requiring massage or mechanical manipulation. Future studies will assess the long-term benefits of LLLT for the treatment of cellulite. Copyright © 2013 Wiley Periodicals, Inc.

  10. Low level laser therapy on experimental myopathy

    Science.gov (United States)

    Dávila, Soledad; Vignola, María Belén; Cremonezzi, David; Simes, Juan C.; Soriano, Fernando; Campana, Vilma R.

    2011-01-01

    Purpose: The aim of the present work was to study the effect of Helium-Neon (HeNe) and Gallium Arsenide (GaAs) laser upon nitric oxide (NO) plasma levels, an inflammatory biomarker associated with oxidative stress, in rats with experimental myopathy. These were evaluated through histological assessment. Materials and Methods: The groups studied were: (A) control (intact rats that received LLLT sham exposures), (B) rats with myopathy and sacrificed at 24 h later, (C) rats with myopathy and sacrificed 8 days later, (D) rats with myopathy and treated with HeNe laser, (E) rats with myopathy and treated with GaAs laser, (F) intact rats treated with HeNe laser and (G) intact rats treated with GaAs laser. Myopathy was induced by injecting 50μl of 1% carrageenan λ (type IV) in the left gastrocnemius muscle. Low Level Laser Therapy (LLLT) was applied with 9.5 J.cm−2 daily for 10 consecutive days with each laser. The determination of the NO was made by spectrophotometry. The muscles were stained with Hematoxylin-Eosin and examined by optic microscopy. Quantitative variables were statistically analyzed by the Fisher test, and categorical by applying Pearson's Chi Squared test at p <0.05 for all cases. Results: In groups B and C, NO was significantly increased compared to groups A, D, E, F and G (p<0.05). In group C, the percentage of area with inflammatory infiltration was significantly increased compared to the other groups (p<0.001). Conclusions: LLLT decreased plasma levels of NO in rats with experimental myopathies and significant muscle recovery. PMID:24155539

  11. Evaluation of muscle activity, bite force and salivary cortisol in children with bruxism before and after low level laser applied to acupoints: study protocol for a randomised controlled trial.

    Science.gov (United States)

    Salgueiro, Mônica da Consolação Canuto; Bortoletto, Carolina Carvalho; Horliana, Anna Carolina RattoTempestini; Mota, Ana Carolina Costa; Motta, Lara Jansiski; Motta, Pamella de Barros; MesquitaFerrari, Raquel Agnelli; Fernandes, Kristianne Porta Santos; Bussadori, Sandra Kalil

    2017-08-08

    Bruxism is a repetitive activity that causes tooth wear, audible sounds, and discomfort. Preventive measures have been studied for conditions that can exert a negative influence on physiological development in children. Low-level laser therapy administered over acupoints is an effective, painless, low-cost treatment option that has achieved good results. Thus, the aim of the proposed study is to evaluate changes in muscle activity, bite force and salivary cortisol in children with bruxism after the application of low-level laser to accupoints. The children will be randomly allocated to four groups of 19 individuals: G1 - low-level laser; G2 - occlusal splint; G3 - placebo laser; and G4 - control (without bruxism). The BTS TMJOINT electromyography will be used to determine muscle activity and a digital gnathodynamometer will be used to measure bite force. Salivary cortisol will be analysed at baseline as well as one and six months after treatment. Two-way ANOVA will be employed and complemented by Tukey's test. Bruxism is a repetitive activity of the masticatory muscles that can have negative consequences if not treated, such as tooth wear, noises, discomfort and anxiety. Thus, control and treatment measures should be taken. Although low-level laser therapy over acupoints has been indicated for children, the effects of this treatment modality have not yet been studied. NCT02757261 on 8 April 2016. This study protocol received a grant from the Brazilian fostering agency São Paulo Research Foundation (FAPESP: #2015/24731-0).

  12. A pilot randomized trial evaluating low-level laser therapy as an alternative treatment to manual lymphatic drainage for breast cancer-related lymphedema.

    Science.gov (United States)

    Ridner, Sheila H; Poage-Hooper, Ellen; Kanar, Collin; Doersam, Jennifer K; Bond, Stewart M; Dietrich, Mary S

    2013-07-01

    To examine the impact of advanced practice nurse (APN)-administered low-level laser therapy (LLLT) as both a stand-alone and complementary treatment for arm volume, symptoms, and quality of life (QOL) in women with breast cancer-related lymphedema. A three-group, pilot, randomized clinical trial. A private rehabilitation practice in the southeastern United States. 46 breast cancer survivors with treatment-related lymphedema. Patients were screened for eligibility and then randomized to either manual lymphatic drainage (MLD) for 40 minutes, LLLT for 20 minutes, or 20 minutes of MLD followed by 20 minutes of LLLT. Compression bandaging was applied after each treatment. Data were collected pretreatment, daily, weekly, and at the end of treatment. Independent variables consisted of three types of APN-administered lymphedema treatment. Outcome variables included limb volume, extracellular fluid, psychological and physical symptoms, and QOL. No statistically significant between-group differences were found in volume reduction; however, all groups had clinically and statistically significant reduction in volume. No group differences were noted in psychological and physical symptoms or QOL; however, treatment-related improvements were noted in symptom burden within all groups. Skin improvement was noted in each group that received LLLT. LLLT with bandaging may offer a time-saving therapeutic option to conventional MLD. Alternatively, compression bandaging alone could account for the demonstrated volume reduction. APNs can effectively treat lymphedema. APNs in private healthcare practices can serve as valuable research collaborators. Lasers may provide effective, less burdensome treatment for lymphedema. APNs with lymphedema certification can effectively treat this patient population with the use of LLLT. In addition, bioelectrical impedance and tape measurements can be used to assess lymphedema.

  13. Evaluation of the capabilities of the Hanford Reservation and Envirocare of Utah for disposal of potentially problematic mixed low-level waste streams

    Energy Technology Data Exchange (ETDEWEB)

    Waters, R.D.; Pohl, P.I.; Cheng, W.C.; Gruebel, M.M.; Wheeler, T.A.; Langkopf, B.S.

    1998-03-01

    The US Department of Energy`s (DOE) Mixed Waste Focus Area is developing a program to address and resolve issues associated with final waste form performance in treating and disposing of DOE`s mixed low-level waste (MLLW) inventory. A key issue for the program is identifying MLLW streams that may be problematic for disposal. Previous reports have quantified and qualified the capabilities of fifteen DOE sites for MLLW disposal and provided volume and radionuclide concentration estimates for treated MLLW based on the DOE inventory. Scoping-level analyses indicated that 101 waste streams identified in this report (approximately 6,250 m{sup 3} of the estimated total treated MLLW) had radionuclide concentrations that may make their disposal problematic. The radionuclide concentrations of these waste streams were compared with the waste acceptance criteria (WAC) for a DOE disposal facility at Hanford and for Envirocare`s commercial disposal facility for MLLW in Utah. Of the treated MLLW volume identified as potentially problematic, about 100 m{sup 3} exceeds the WAC for disposal at Hanford, and about 4,500 m{sup 3} exceeds the WAC for disposal at Envirocare. Approximately 7% of DOE`s total MLLW inventory has not been sufficiently characterized to identify a treatment process for the waste and was not included in the analysis. In addition, of the total treated MLLW volume, about 30% was associated with waste streams that did not have radionuclide concentration data and could not be included in the determination of potentially problematic waste streams.

  14. Clinical and functional evaluation of patients with acute low back pain and radiculopathy treated with different energy doses of low level laser therapy

    Directory of Open Access Journals (Sweden)

    Jovičić Milica

    2012-01-01

    Full Text Available Background/Aim. The main clinical phenomena in acute low back pain (LBP with radiculopathy are pain and neurological disorders. Although some studies show that low level laser therapy (LLLT has the ability to modulate inflammatory processes and relieve acute pain condition, the laser therapy dose protocol has not been yet completely established. The aim of this study was to investigate the effects of three different energy doses of LLLT in patients with acute LBP and radiculopathy. Methods. The study included 66 patients with acute LBP and radiculopathy who had been randomly divided into three groups (22 patients each received three different doses of LLLT. The patients were treated 5 times weekly, for a total of 10 treatments, with the following parameters: wave length 904 nm, frequency 3,000 Hz, average diode power 25 mW; energy dose of 0.1 J per point in the first group, 1 J per point in the second and 4 J per point in the third group; daily treatment time and accumulated energy were 16 s and 0.4 J in the first group, 160 s and 4 J in the second group and 640 s and 16 J in the third group, respectively. The parameters of assessment before and after the therapy were: lumbar and leg pain measured by visual analogue scale (VAS, local and general functional changes (Schober test, manual muscle test, straight leg raise test and the modified North American Spine Society-Low Back Pain Outcome Instrument-NASS LBP. Results. Highly significant improvements (p < 0.01 were noted in all the groups after LLLT with respect to all the investigated parameters. The VAS scores were significantly lower in all the groups without a difference between the groups (p > 0,05. Functional improvements were better in the third group treated with the dose of 4 J per point than in other two groups (p < 0.05. Conclusions. Three different energy doses of LLLT were equally effective in alleviating lumbar and leg pain without side effects, but the dose of 4 J per point seemed

  15. Does the Low-level occupational exposure to volatile organic compounds alter the seasonal variation of selected markers of oxidative stress? A case-control study in nail technicians

    National Research Council Canada - National Science Library

    Grešner, Peter; Świercz, Radosław; Król, Magdalena Beata; Twardowska, Ewa; Gromadzińska, Jolanta; Wąsowicz, Wojciech

    2016-01-01

    In this study we tested whether the seasonal variations in levels of selected biomarkers of oxidative stress in female nail technicians occupationally exposed to low levels of volatile organic compounds (VOCs...

  16. Low-Level Evidence Suggests that Perceived Ability to Evaluate and Trust Online Health Information is Associated with Low Health Literacy

    OpenAIRE

    Lindsay Alcock

    2016-01-01

    Objective – To review, based on research evidence, the correlation between low health literacy and four outcomes of interest: (1) the ability to evaluate online health information based on (2) perceived reliability and accuracy, (3) trust in the Internet as an information source, and (4) the application of established evaluation criteria. Design – Systematic review and narrative synthesis. Setting –MEDLINE, PsycInfo, Web of Science, CINAHL, and Communication and Mass-media Complete a...

  17. Low level tank waste disposal study

    Energy Technology Data Exchange (ETDEWEB)

    Mullally, J.A.

    1994-09-29

    Westinghouse Hanford Company (WHC) contracted a team consisting of Los Alamos Technical Associates (LATA), British Nuclear Fuel Laboratories (BNFL), Southwest Research Institute (SwRI), and TRW through the Tank Waste Remediation System (TWRS) Technical Support Contract to conduct a study on several areas concerning vitrification and disposal of low-level-waste (LLW). The purpose of the study was to investigate how several parameters could be specified to achieve full compliance with regulations. The most restrictive regulation governing this disposal activity is the National Primary Drinking Water Act which sets the limits of exposure to 4 mrem per year for a person drinking two liters of ground water daily. To fully comply, this constraint would be met independently of the passage of time. In addition, another key factor in the investigation was the capability to retrieve the disposed waste during the first 50 years as specified in Department of Energy (DOE) Order 5820.2A. The objective of the project was to develop a strategy for effective long-term disposal of the low-level waste at the Hanford site.

  18. Application of ultraperformance liquid chromatography/mass spectrometry-based metabonomic techniques to analyze the joint toxic action of long-term low-level exposure to a mixture of organophosphate pesticides on rat urine profile.

    Science.gov (United States)

    Du, Longfei; Wang, Hong; Xu, Wei; Zeng, Yan; Hou, Yurong; Zhang, Yuqiu; Zhao, Xiujuan; Sun, Changhao

    2013-07-01

    In previously published articles, we evaluated the toxicity of four organophosphate (OP) pesticides (dichlorvos, dimethoate, acephate, and phorate) to rats using metabonomic technology at their corresponding no observed adverse effect level (NOAEL). Results show that a single pesticide elicits no toxic response. This study aimed to determine whether chronic exposure to a mixture of the above four pesticides (at their corresponding NOAEL) can lead to joint toxic action in rats using the same technology. Pesticides were administered daily to rats through drinking water for 24 weeks. The above mixture of the four pesticides showed joint toxic action at the NOAEL of each pesticide. The metabonomic profiles of rats urine were analyzed by ultraperformance liquid chromatography/mass spectrometry. The 16 metabolites statistically significantly changed in all treated groups compared with the control group. Dimethylphosphate and dimethyldithiophosphate exclusively detected in all treated groups can be used as early, sensitive biomarkers for exposure to a mixture of the OP pesticides. Moreover, exposure to the OP pesticides resulted in increased 7-methylguanine, ribothymidine, cholic acid, 4-pyridoxic acid, kynurenine, and indoxyl sulfate levels, as well as decreased hippuric acid, creatinine, uric acid, gentisic acid, C18-dihydrosphingosine, phytosphingosine, suberic acid, and citric acid. The results indicated that a mixture of OP pesticides induced DNA damage and oxidative stress, disturbed the metabolism of lipids, and interfered with the tricarboxylic acid cycle. Ensuring food safety requires not only the toxicology test data of each pesticide for the calculation of the acceptable daily intake but also the joint toxic action.

  19. Evaluation of quenching correction characteristics according to the standard source for calibration when analyzing the tritium using ultra-low-level liquid scintillation counter

    Energy Technology Data Exchange (ETDEWEB)

    Noh, Sung Jin; Kim, Hyo Jin; Kim, Hyun; Jeong, Dong Hyeok; Kang, Yeong Rok [Research Center, Dongnam Institute of Radiological and Medical Sciences, Busan (Korea, Republic of)

    2016-12-15

    The quenching is in general corrected during the process of calibrating equipment before analyzing the environmental sample. More specifically, the samples are counted for the number of prepared samples according to the mixing ratio of source, quencher and scintillator and then the quenching correction curve is created based on the results of counting. This study intends to evaluate the differences in the quenching correction curve using the standard sources for quenching with different vial properties and then, based on the results, evaluate the effect of the concentration of tritium among environmental samples. As introduced earlier, to correct the quenching using LSC, a series of samples with different degree of quenching but with consistent activity concentration are counted in sequence and the quenching correction curve is created using software. These results indicate that if the quenching is corrected under the same conditions (scintillation cocktail, vial, etc.) as the environmental samples to be counted and analyzed, it will minimize uncertainties, thereby enabling it to obtain more accurate results.

  20. SEROLOGIC EVALUATION OF HUMAN MICROCYSTIN EXPOSURE

    Science.gov (United States)

    Introduction Microcystins (MCYST) are among the most commonly detected toxins associated with cyanobacteria blooms worldwide. Biological evidence of human exposure is needed in order to evaluate potential MCYST-associated health effects. MCYST are detectable in free and bound fo...

  1. Packaged low-level waste verification system

    Energy Technology Data Exchange (ETDEWEB)

    Tuite, K.; Winberg, M.R.; McIsaac, C.V. [Idaho National Engineering Lab., Idaho Falls, ID (United States)

    1995-12-31

    The Department of Energy through the National Low-Level Waste Management Program and WMG Inc. have entered into a joint development effort to design, build, and demonstrate the Packaged Low-Level Waste Verification System. Currently, states and low-level radioactive waste disposal site operators have no method to independently verify the radionuclide content of packaged low-level waste that arrives at disposal sites for disposition. At this time, the disposal site relies on the low-level waste generator shipping manifests and accompanying records to ensure that low-level waste received meets the site`s waste acceptance criteria. The subject invention provides the equipment, software, and methods to enable the independent verification of low-level waste shipping records to ensure that the site`s waste acceptance criteria are being met. The objective of the prototype system is to demonstrate a mobile system capable of independently verifying the content of packaged low-level waste.

  2. Evaluation of low-level laser therapy in the prevention and treatment of radiation-induced mucositis: a double-blind randomized study in head and neck cancer patients.

    Science.gov (United States)

    Carvalho, P A G; Jaguar, G C; Pellizzon, A C; Prado, J D; Lopes, R N; Alves, F A

    2011-12-01

    The purpose of this prospective study was to determine the effect of the low-level laser in the prevention and treatment of mucositis in head and neck cancer patients. A total of 70 patients with malignant neoplasms in the oral cavity or oropharynx were evaluated. The patients were randomized into two low-level laser therapy groups: Group 1 (660nm/15mW/3.8J/cm(2)/spot size 4mm(2)) or Group 2 (660nm/5mW/1.3J/cm(2)/spot size 4mm(2)) starting on the first day of radiotherapy. Oral mucositis was assessed daily and weekly using the NCI and WHO scales. Oral pain was scored daily with a visual analogue scale before laser application. The patients in Group 1 had a mean time of 13.5days (range 6-26days) to present mucositis grade II, while the patients in Group 2 had a mean time of 9.8days (range 4-14days) (both WHO and NCI p=0.005). In addition, Group 2 also presented a higher mucositis grade than Group 1 with significant differences found in weeks 2 (p=0.019), 3 (p=0.005) and 4 (p=0.003) for WHO scale and weeks 2 (p=0.009) and 4 (p=0.013) for NCI scale. The patients in Group 1 reported lower pain levels (p=0.004). Low-level laser therapy during radiotherapy was found to be effective in controlling the intensity of mucositis and pain. Copyright © 2011 Elsevier Ltd. All rights reserved.

  3. Low-level red laser therapy alters effects of ultraviolet C radiation on Escherichia coli cells

    Directory of Open Access Journals (Sweden)

    K.S. Canuto

    2015-01-01

    Full Text Available Low-level lasers are used at low power densities and doses according to clinical protocols supplied with laser devices or based on professional practice. Although use of these lasers is increasing in many countries, the molecular mechanisms involved in effects of low-level lasers, mainly on DNA, are controversial. In this study, we evaluated the effects of low-level red lasers on survival, filamentation, and morphology of Escherichia coli cells that were exposed to ultraviolet C (UVC radiation. Exponential and stationary wild-type and uvrA-deficient E. coli cells were exposed to a low-level red laser and in sequence to UVC radiation. Bacterial survival was evaluated to determine the laser protection factor (ratio between the number of viable cells after exposure to the red laser and UVC and the number of viable cells after exposure to UVC. Bacterial filaments were counted to obtain the percentage of filamentation. Area-perimeter ratios were calculated for evaluation of cellular morphology. Experiments were carried out in duplicate and the results are reported as the means of three independent assays. Pre-exposure to a red laser protected wild-type and uvrA-deficient E. coli cells against the lethal effect of UVC radiation, and increased the percentage of filamentation and the area-perimeter ratio, depending on UVC fluence and physiological conditions in the cells. Therapeutic, low-level red laser radiation can induce DNA lesions at a sub-lethal level. Consequences to cells and tissues should be considered when clinical protocols based on this laser are carried out.

  4. Low-level red laser therapy alters effects of ultraviolet C radiation on Escherichia coli cells

    Energy Technology Data Exchange (ETDEWEB)

    Canuto, K.S.; Guimaraes, O.R.; Geller, M. [Centro Universitario Serra dos Orgaos, Teresopolis, RJ (Brazil). Centro de Ciencias da Saude; Sergio, L.P.S. [Instituto de Biologia Roberto Alcantara Gomes, Rio de Janeiro, RJ (Brazil). Departamento de Biofisica e Biometria; Paoli, F. [Universidade Federal de Juiz de Fora (UFJF), Juiz de Fora, MG (Brazil). Departamento de Morfologia; Fonseca, A.S., E-mail: adnfonseca@ig.com.br [Universidade Federal do Estado do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil). Departamento de Ciencias Fisiologicas

    2015-10-15

    Low-level lasers are used at low power densities and doses according to clinical protocols supplied with laser devices or based on professional practice. Although use of these lasers is increasing in many countries, the molecular mechanisms involved in effects of low-level lasers, mainly on DNA, are controversial. In this study, we evaluated the effects of low-level red lasers on survival, filamentation, and morphology of Escherichia coli cells that were exposed to ultraviolet C (UVC) radiation. Exponential and stationary wild-type and uvrA-deficient E. coli cells were exposed to a low-level red laser and in sequence to UVC radiation. Bacterial survival was evaluated to determine the laser protection factor (ratio between the number of viable cells after exposure to the red laser and UVC and the number of viable cells after exposure to UVC). Bacterial filaments were counted to obtain the percentage of filamentation. Area-perimeter ratios were calculated for evaluation of cellular morphology. Experiments were carried out in duplicate and the results are reported as the means of three independent assays. Pre-exposure to a red laser protected wild-type and uvrA-deficient E. coli cells against the lethal effect of UVC radiation, and increased the percentage of filamentation and the area-perimeter ratio, depending on UVC fluence and physiological conditions in the cells. Therapeutic, low-level red laser radiation can induce DNA lesions at a sub-lethal level. Consequences to cells and tissues should be considered when clinical protocols based on this laser are carried out. (author)

  5. Low-level laser effects on bacterial cultures submitted to heat stress

    Science.gov (United States)

    Gonçalves, E. M.; Guimarães, O. R.; Geller, M.; Paoli, F.; Fonseca, A. S.

    2016-06-01

    Low-level lasers have been used worldwide to treat a number of diseases, pain relief, and wound healing. Some studies demonstrated that low-level laser radiations induce effects depending on the physiological state and DNA repair mechanisms of cells. In this work we evaluated the effects of low-level red and infrared lasers on Escherichia coli cells deficient in SOS responses submitted to heat stress. Exponential and stationary E. coli cultures of wild type (AB1157), RecA deficient (AB2463) and LexA deficient (AB2494), both SOS response deficient, were exposed to low-level red and infrared lasers at different fluences and submitted to heat stress (42 °C, 20 min). After that, cell survival and morphology were evaluated. Previous exposure to red, but not infrared lasers, increases survival fractions and decreases the area ratios of E. coli AB1157 cells submitted to heat stress. Our research suggests that a low-level red laser increases cell viability and protects cells from morphological alteration in E. coli cultures submitted to heat stress depending on laser wavelength and SOS response.

  6. Information exposure, opportunity evaluation and entrepreneurial action

    DEFF Research Database (Denmark)

    Autio, E.; Dahlander, L.; Frederiksen, Lars

    2013-01-01

    We study how an individual's exposure to external information regulates the evaluation of entrepreneurial opportunities and entrepreneurial action. Combining data from interviews, a survey, and a comprehensive web log of an online user community spanning eight years, we find that technical...

  7. Low back pain and low level flying

    NARCIS (Netherlands)

    J.C.F.M. Aghina

    1989-01-01

    textabstractLow level flying is a very good tactical possibility to carry out a mission unseen by a hostile radarsystem. Nowadays, Western Europe in general and the Federal Republic of Germany in particular, decreased . the permissions to low level flying in assigned regions. That's why the

  8. Low-level waste forum meeting reports

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1992-12-31

    This report provides highlights from the 1992 fall meeting of the Low LEvel Radioactive Waste Forum. Topics included: disposal options after 1992; interregional agreements; management alternatives; policy; and storage.

  9. Low-level waste forum meeting reports

    Energy Technology Data Exchange (ETDEWEB)

    Sternwheeler, W.D.E.

    1992-12-31

    This paper provides highlights from the 1992 winter meeting of the Low Level Radioactive Wastes Forum. Topics of discussion included: legal information; state and compact reports; freedom of information requests; and storage.

  10. Polyethylene solidification of low-level wastes

    Energy Technology Data Exchange (ETDEWEB)

    Kalb, P.D.; Colombo, P.

    1985-02-01

    This topical report describes the results of an investigation on the solidification of low-level radioactive waste in polyethylene. Waste streams selected for this study included those which result from advanced volume reduction technologies (dry evaporator concentrate salts and incinerator ash) and those which remain problematic for solidification using contemporary agents (ion exchange resins). Four types of commercially available low-density polyethylenes were employed which encompass a range of processing and property characteristics. Process development studies were conducted to ascertain optimal process control parameters for successful solidification. Maximum waste loadings were determined for each waste and polyethylene type. Property evaluation testing was performed on laboratory-scale specimens to assess the potential behavior of actual waste forms in a disposal environment. Waste form property tests included water immersion, deformation under compressive load, thermal cycling and radionuclide leaching. Recommended waste loadings of 70 wt % sodium sulfate, 50 wt % boric acid, 40 wt % incinerator ash, and 30 wt % ion exchange resins, which are based on process control and waste form performance considerations are reported. 37 refs., 33 figs., 22 tabs.

  11. Which neuro-physiologic effects at low level 2.45 GHz RF exposure?; Quels effets neurophysiologiques pour un champ electromagnetique de faible puissance a 2,45 GHz?

    Energy Technology Data Exchange (ETDEWEB)

    Crouzier, D.; Perrin, A.; Debouzy, J.C. [Centre de Recherches du Service Sante des Armees, Unite BCM, 38 - La-Tronche (France); Testylier, G. [Centre de Recherches du Service Sante des Armees, Unite de Neuropharmacologie, 38 - La-Tronche (France)

    2007-06-15

    The LS electromagnetic band (1-4 GHz) is widely used both in domestic and industrial domains. Several studies suggested that the biological systems would exhibit a specific sensitivity to the 2.45 GHz microwaves (water resonance frequency). Potential human health hazards and especially a disruption of the cholinergic system have been reported, due to exposure to microwaves even at low power density. This work presents a multi-parametric study of freely moving rat where neuro-physiology was investigated during 70 hours using neurochemical (micro-dialysis technique), electrophysiological, behavioral (vigilance stages quantification) and thermo-physiological approaches. The rats were exposed 24 hours to a 2.45 GHz pulsed electromagnetic field at low power density. In this exposure conditions, no significant effect have been reported. (authors)

  12. Low-level waste forum meeting reports

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1992-12-31

    This paper provides highlights from the spring meeting of the Low Level Radioactive Waste Forum. Topics of discussion included: state and compact reports; New York`s challenge to the constitutionality of the Low-Level Radioactive Waste Amendments Act of 1985; DOE technical assistance for 1993; interregional import/export agreements; Department of Transportation requirements; superfund liability; nonfuel bearing components; NRC residual radioactivity criteria.

  13. Exposure to low level chronic radiation leads to adaptation to a subsequent acute X-ray dose and communication of modified acute X-ray induced bystander signals in medaka (Japanese rice fish, Oryzias latipes).

    Science.gov (United States)

    Smith, Richard W; Mothersill, Carmel; Hinton, Thomas; Seymour, Colin B

    2011-10-01

    To determine the effect of acute high dose X-rays on the direct and bystander response of chronically exposed medaka in vivo using the fish communication model. Medaka were obtained from the Low Dose Rate Irradiation Facility (LoDIF) located at the Savannah River Ecology Laboratory (SREL), University of Georgia, Aiken, South Carolina, USA where they had been exposed over 264 days to cumulative total doses of 0, 0.03, 0.66 and 5.88 Gy. They were exposed to the acute dose at McMaster University and then allowed to swim with unexposed medaka. All groups were sacrificed and fins were cultured as explants and assayed using an established technique and reporter assay. Directly irradiated medaka with no chronic exposure showed a classic in vivo bystander response. Chronic pre-exposure resulted in a chronic dose-dependent increase in reporter cell survival in directly exposed fish. A 'pro-survival' response was also seen in the bystander fish. The proteins bcl-2 (b cell lymphoma 2) and c-Myc (myelocytomatosis oncogene cellular) in tissue explants were good predictors of pro-life or pro-death signals. Environmentally relevant chronic exposure to medaka in vivo results in adaptive responses in fish subsequently irradiated with high acute doses and in communication of protective signals to fish swimming with exposed fish. The data have implications for interpretation of radiation effects in biota.

  14. Remote-Handled Low Level Waste Disposal Project Alternatives Analysis

    Energy Technology Data Exchange (ETDEWEB)

    David Duncan

    2010-10-01

    This report identifies, evaluates, and compares alternatives for meeting the U.S. Department of Energy’s mission need for management of remote-handled low-level waste generated by the Idaho National Laboratory and its tenants. Each alternative identified in the Mission Need Statement for the Remote-Handled Low-Level Waste Treatment Project is described and evaluated for capability to fulfill the mission need. Alternatives that could meet the mission need are further evaluated and compared using criteria of cost, risk, complexity, stakeholder values, and regulatory compliance. The alternative for disposal of remote-handled low-level waste that has the highest confidence of meeting the mission need and represents best value to the government is to build a new disposal facility at the Idaho National Laboratory Site.

  15. Evaluation of adjunctive effect of low-level laser Therapy on pain, swelling and trismus after surgical removal of impacted lower third molar: A double blind randomized clinical trial.

    Science.gov (United States)

    Farhadi, Farrokh; Eslami, Hosein; Majidi, Alireza; Fakhrzadeh, Vahid; Ghanizadeh, Milad; KhademNeghad, Sahar

    2017-09-30

    Wisdom teeth remains impacted in the jaw due to several reasons and surgery of impacted wisdom teeth is one of the most common surgeries in dental clinics. Pain, swelling and trismus are the common complications after this surgery which affect quality of life. In articles, various methods are introduced to control immediate inflammatory-response associated with third-molar surgery. The aim of this study is to evaluate the adjunctive effect of low-level laser Therapy on pain, swelling and trismus after surgical removal of impacted lower third molar. This double-blind randomized controlled trial (RCT) was conducted on two groups of 24 patients (age range of 18-35) that had referred to surgical ward of Faculty of Dentistry, Tabriz University of Medical Sciences for surgery of their mandibular third molar(2015-16). All the subjects were systemically healthy and had at least one impacted mandibular third molar. After surgery, in experimental group, the laser was applied intraorally (inside the tooth socket) and extraorally (at the insertion point of the masseter muscle) immediately after surgery in contact with the target area for 25 seconds each. The laser energy was 2.5 J per area with an energy density of 5 J/ cm2 at the surface of the probe (spot size= 0.5 cm2). In the other group, as the control group, it was pretended to radiate. Trismus, pain, and swelling were evaluated on the first and seventh days after surgery. The obtained data were evaluated using SPSS 16 software and independent samples T-test. In the group where LLLT had been used, P> 0.05 was calculated for pain, swelling, and trismus on days 1 and 7 after surgery that was not statistically significant. Under limitations of this study, using low-power laser with mentioned parameters, clinically reduces pain, swelling and trismus after surgical removal of impacted mandibular wisdom, but not statistically significant.

  16. Nucleotide excision repair genes are expressed at low levels and are not detectably inducible in Caenorhabditis elegans somatic tissues, but their function is required for normal adult life after UVC exposure

    Energy Technology Data Exchange (ETDEWEB)

    Boyd, Windy A. [Biomolecular Screening Branch, National Toxicology Program, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, NC (United States); Crocker, Tracey L. [Nicholas School of the Environment, Duke University, Durham, NC 27708 (United States); Rodriguez, Ana M. [Laboratory of Molecular Genetics, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, NC (United States); Leung, Maxwell C.K. [Nicholas School of the Environment, Duke University, Durham, NC 27708 (United States); Wade Lehmann, D. [Laboratory of Molecular Genetics, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, NC (United States); Freedman, Jonathan H. [Laboratory of Molecular Toxicology, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, NC (United States); Van Houten, Ben [Laboratory of Molecular Genetics, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, NC (United States); Meyer, Joel N., E-mail: joel.meyer@duke.edu [Nicholas School of the Environment, Duke University, Durham, NC 27708 (United States)

    2010-01-05

    We performed experiments to characterize the inducibility of nucleotide excision repair (NER) in Caenorhabditis elegans, and to examine global gene expression in NER-deficient and -proficient strains as well as germline vs. somatic tissues, with and without genotoxic stress. We also carried out experiments to elucidate the importance of NER in the adult life of C. elegans under genotoxin-stressed and control conditions. Adult lifespan was not detectably different between wild-type and NER-deficient xpa-1 nematodes under control conditions. However, exposure to 6 J/m{sup 2}/day of ultraviolet C radiation (UVC) decreased lifespan in xpa-1 nematodes more than a dose of 100 J/m{sup 2}/day in wild-type. Similar differential sensitivities were observed for adult size and feeding. Remarkably, global gene expression was nearly identical in young adult wild-type and xpa-1 nematodes, both in control conditions and 3 h after exposure to 50 J/m{sup 2} UVC. Neither NER genes nor repair activity were detectably inducible in young adults that lacked germ cells and developing embryos (glp-1 strain). However, expression levels of dozens of NER and other DNA damage response genes were much (5-30-fold) lower in adults lacking germ cells and developing embryos, suggesting that somatic and post-mitotic cells have a much lower DNA repair ability. Finally, we describe a refinement of our DNA damage assay that allows damage measurement in single nematodes.

  17. DNA damage in blood cells exposed to low-level lasers.

    Science.gov (United States)

    Sergio, Luiz Philippe da Silva; Silva, Ana Paula Almeida da; Amorim, Philipi Freitas; Campos, Vera Maria Araújo; Magalhães, Luis Alexandre Gonçalves; de Paoli, Flavia; de Souza da Fonseca, Adenilson

    2015-04-01

    In regenerative medicine, there are increasing applications of low-level lasers in therapeutic protocols for treatment of diseases in soft and in bone tissues. However, there are doubts about effects on DNA, and an adequate dosimetry could improve the safety of clinical applications of these lasers. This work aimed to evaluate DNA damage in peripheral blood cells of Wistar rats induced by low-level red and infrared lasers at different fluences, powers, and emission modes according to therapeutic protocols. Peripheral blood samples were exposed to lasers and DNA damage was accessed by comet assay. In other experiments, DNA damage was accessed in blood cells by modified comet assay using formamidopyrimidine DNA glycosylase (Fpg) and endonuclease III enzymes. Data show that exposure to low-level red and infrared lasers induce DNA damage depending on fluence, power and emission mode, which are targeted by Fpg and endonuclease III. Oxidative DNA damage should be considered for therapeutic efficacy and patient safety in clinical applications based on low-level red and infrared lasers. © 2015 Wiley Periodicals, Inc.

  18. Reasons for Low Levels of Interactivity

    DEFF Research Database (Denmark)

    Etter, Michael

    2013-01-01

    The interactivity levels of online CSR communication are typically low. This study explores the reasons for the low levels of interactivity in the popular social media tool Twitter. An analysis of 41,864 Twitter messages (tweets) from the thirty most central corporate accounts in a CSR Twitter...... network is conducted. Comparisons (t-test) between CSR tweets and general tweets and between specialized CSR Twitter accounts and general accounts reveal that the low levels of interactivity are due to a reactive interaction approach and a lack of specialization....

  19. Responses of Cell Renewal Systems to Long-term Low-Level Radiation Exposure: A Feasibility Study Applying Advanced Molecular Biology Techniques on Available Histological and Cytological Material of Exposed Animals and Men

    Energy Technology Data Exchange (ETDEWEB)

    Fliedner Theodor M.; Feinendegen Ludwig E.; Meineke Viktor; Fritz Thomas E.

    2005-02-28

    First results of this feasibility study showed that evaluation of the stored material of the chronically irradiated dogs with modern molecular biological techniques proved to be successful and extremely promising. Therefore an in deep analysis of at least part of the huge amount of remaining material is of outmost interest. The methods applied in this feasibility study were pathological evaluation with different staining methods, protein analysis by means of immunohistochemistry, strand break analysis with the TdT-assay, DNA- and RNA-analysis as well as genomic examination by gene array. Overall more than 50% of the investigated material could be used. In particular the results of an increased stimulation of the immune system within the dogs of the 3mSv group as both compared to the control and higher dose groups gives implications for the in depth study of the cellular events occurring in context with low dose radiation. Based on the findings of this study a further evaluation and statistically analysis of more material can help to identify promising biomarkers for low dose radiation. A systematic evaluation of a correlation of dose rates and strand breaks within the dog tissue might moreover help to explain mechanisms of tolerance to IR. One central problem is that most sequences for dog specific primers are not known yet. The discovery of the dog genome is still under progress. In this study the isolation of RNA within the dog tissue was successful. But up to now there are no gene arrays or gene chips commercially available, tested and adapted for canine tissue. The uncritical use of untested genomic test systems for canine tissue seems to be ineffective at the moment, time consuming and ineffective. Next steps in the investigation of genomic changes after IR within the stored dog tissue should be limited to quantitative RT-PCR of tested primer sequences for the dog. A collaboration with institutions working in the field of the discovery of the dog genome could

  20. Reporting low-level analytical data

    African Journals Online (AJOL)

    Meyer

    for the concept, including its uncertainty. This proposal is intended to help to standardize the method of reporting low-level analytical data, not to legitimize the data or any conclusions or actions resulting from their use or interpretation. 1. Introduction. The detection limit, determination limit, quantification limit, measurement ...

  1. Low-level waste forum meeting reports

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-31

    This paper provides highlights from the 1995 summer meeting of the Low Level radioactive Waste Forum. Topics included: new developments in state and compacts; federal waste management; DOE plans for Greater-Than-Class C waste management; mixed wastes; commercial mixed waste management; international export of rad wastes for disposal; scintillation cocktails; license termination; pending legislation; federal radiation protection standards.

  2. Infrared low-level wind shear work

    Science.gov (United States)

    Adamson, Pat

    1988-01-01

    Results of field experiments for the detection of clear air disturbance and low level wind shear utilizing an infrared airborne system are given in vugraph form. The hits, misses and nuisance alarms scores are given. Information is given on the infrared spatial resolution technique. The popular index of aircraft hazard (F= WX over g - VN over AS) is developed for a remote temperature sensor.

  3. Immobilized low-level waste disposal options configuration study

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, D.E.

    1995-02-01

    This report compiles information that supports the eventual conceptual and definitive design of a disposal facility for immobilized low-level waste. The report includes the results of a joint Westinghouse/Fluor Daniel Inc. evaluation of trade-offs for glass manufacturing and product (waste form) disposal. Though recommendations for the preferred manufacturing and disposal option for low-level waste are outside the scope of this document, relative ranking as applied to facility complexity, safety, remote operation concepts and ease of retrieval are addressed.

  4. IRMM low level underground laboratory in HADES

    Energy Technology Data Exchange (ETDEWEB)

    Mouchel, D. [CEC-JRC, Inst. for Reference Materials and Measurements (IRMM), Geel (Belgium); Wordel, R. [CEC-JRC, Inst. for Reference Materials and Measurements (IRMM), Geel (Belgium)

    1997-03-01

    The operation of low background HPGe detectors at a depth of 225 m, reduced the background by two orders of magnitude; a large amount of the remaining background is still attributable to the cosmic rays. The selection of radiopure materials, the characterization of reference matrices and the measurements of low radioactivities in environmental samples are performed. Coupling the low level spectrometry with additional techniques, e.g. neutron activation, will allow to measure extremely low radioactivities. (orig.)

  5. Low-level radioactive waste disposal facility closure

    Energy Technology Data Exchange (ETDEWEB)

    White, G.J.; Ferns, T.W.; Otis, M.D.; Marts, S.T.; DeHaan, M.S.; Schwaller, R.G.; White, G.J. (EG and G Idaho, Inc., Idaho Falls, ID (USA))

    1990-11-01

    Part I of this report describes and evaluates potential impacts associated with changes in environmental conditions on a low-level radioactive waste disposal site over a long period of time. Ecological processes are discussed and baselines are established consistent with their potential for causing a significant impact to low-level radioactive waste facility. A variety of factors that might disrupt or act on long-term predictions are evaluated including biological, chemical, and physical phenomena of both natural and anthropogenic origin. These factors are then applied to six existing, yet very different, low-level radioactive waste sites. A summary and recommendations for future site characterization and monitoring activities is given for application to potential and existing sites. Part II of this report contains guidance on the design and implementation of a performance monitoring program for low-level radioactive waste disposal facilities. A monitoring programs is described that will assess whether engineered barriers surrounding the waste are effectively isolating the waste and will continue to isolate the waste by remaining structurally stable. Monitoring techniques and instruments are discussed relative to their ability to measure (a) parameters directly related to water movement though engineered barriers, (b) parameters directly related to the structural stability of engineered barriers, and (c) parameters that characterize external or internal conditions that may cause physical changes leading to enhanced water movement or compromises in stability. Data interpretation leading to decisions concerning facility closure is discussed. 120 refs., 12 figs., 17 tabs.

  6. Evaluation of muscle regeneration in aged animals after treatment with low-level laser therapy Avaliação da regeneração muscular em animais idosos após tratamento com laser de baixa intensidade

    Directory of Open Access Journals (Sweden)

    Adriana Pertille

    2012-12-01

    Full Text Available BACKGROUND: The aging process and its associated morphophysiological changes trigger a reduction in the regenerative ability of the satellite cells, a reduction of vascular tissue and an increase in the production of fibroblasts, developing a cellular environment unfavorable for muscle regeneration. OBJECTIVE: The aim of this study was to evaluate the effect of low-level laser therapy on the muscle regeneration of old experimental rat models after contusion. METHOD: A total of 25 old rats,18 months old, were divided into three groups: control group (CT without treatment; injury group (IN with muscle contusion and without treatment and laser group (LA with contusion and low-level laser therapy, 830 nm, 30 mW e 4 J/cm². The no invasive contusion was induced in the Tibialis Anterior muscle and the samples were collected after 7 and 21 treatment sessions. The muscle was evaluated by Light Microscopy and Immunoblotting. RESULTS: After 21 days of treatment there was a significant reduction in the areas of inflammation/regeneration of the LA 21 group compared to IN 21 group. The cross-sectional area of the fibers in regeneration was not statistically different between the groups. Molecular analysis showed that the content of MyoD was statistically reduced in the IN 21 group compared to the CT group. The Myogenin content was increased in the IN 21 group compared to the CT group. Ultimately, the content of TGF-β1 on the IN 21 group was higher when compared to the CT group. CONCLUSION: Considering the parameters used, the laser therapy demonstrated to be effective for muscle regeneration in old rats, however only through its anti-inflammatory effect.CONTEXTUALIZAÇÃO: O processo de envelhecimento e suas consequentes alterações morfofisiológicas desencadeiam redução da habilidade regenerativa das células satélites, redução da vascularização tecidual e aumento da produção de fibroblastos, desenvolvendo-se um ambiente celular desfavor

  7. Evaluation of muscle regeneration in aged animals after treatment with low-level laser therapy Avaliação da regeneração muscular em animais idosos após tratamento com laser de baixa intensidade

    Directory of Open Access Journals (Sweden)

    Adriana Pertille

    2012-01-01

    Full Text Available BACKGROUND: The aging process and its associated morphophysiological changes trigger a reduction in the regenerative ability of the satellite cells, a reduction of vascular tissue and an increase in the production of fibroblasts, developing a cellular environment unfavorable for muscle regeneration. OBJECTIVE: The aim of this study was to evaluate the effect of low-level laser therapy on the muscle regeneration of old experimental rat models after contusion. METHOD: A total of 25 old rats,18 months old, were divided into three groups: control group (CT without treatment; injury group (IN with muscle contusion and without treatment and laser group (LA with contusion and low-level laser therapy, 830 nm, 30 mW e 4 J/cm². The no invasive contusion was induced in the Tibialis Anterior muscle and the samples were collected after 7 and 21 treatment sessions. The muscle was evaluated by Light Microscopy and Immunoblotting. RESULTS: After 21 days of treatment there was a significant reduction in the areas of inflammation/regeneration of the LA 21 group compared to IN 21 group. The cross-sectional area of the fibers in regeneration was not statistically different between the groups. Molecular analysis showed that the content of MyoD was statistically reduced in the IN 21 group compared to the CT group. The Myogenin content was increased in the IN 21 group compared to the CT group. Ultimately, the content of TGF-β1 on the IN 21 group was higher when compared to the CT group. CONCLUSION: Considering the parameters used, the laser therapy demonstrated to be effective for muscle regeneration in old rats, however only through its anti-inflammatory effect.CONTEXTUALIZAÇÃO: O processo de envelhecimento e suas consequentes alterações morfofisiológicas desencadeiam redução da habilidade regenerativa das células satélites, redução da vascularização tecidual e aumento da produção de fibroblastos, desenvolvendo-se um ambiente celular desfavor

  8. Effect of Low Level Cadmium Exposure on Superoxide Dismutase ...

    African Journals Online (AJOL)

    Cell and Tissue Culture Research Laboratory (Drug Discovery Unit), Department of Biochemistry, Lagos State University, Ojo,. PMB 0001, LASU Post Office, Lagos - Badagry Expressway, Lagos, Nigeria .... inhalation anesthesia. The blood was collected, centrifuge into plasma and erythrocyte while the brain and liver were ...

  9. Systematic evaluation of observational methods assessing biomechanical exposures at work

    National Research Council Canada - National Science Library

    Esa-Pekka Takala; Irmeli Pehkonen; Mikael Forsman; Gert-Åke Hansson; Svend Erik Mathiassen; W Patrick Neumann; Gisela Sjøgaard; Kaj Bo Veiersted; Rolf H Westgaard; Jørgen Winkel

    2010-01-01

    Objectives This systematic review aimed to identify published observational methods assessing biomechanical exposures in occupational settings and evaluate them with reference to the needs of different users...

  10. Russian low-level waste disposal program

    Energy Technology Data Exchange (ETDEWEB)

    Lehman, L. [L. Lehman and Associates, Inc., Burnsville, MN (United States)

    1993-03-01

    The strategy for disposal of low-level radioactive waste in Russia differs from that employed in the US. In Russia, there are separate authorities and facilities for wastes generated by nuclear power plants, defense wastes, and hospital/small generator/research wastes. The reactor wastes and the defense wastes are generally processed onsite and disposed of either onsite, or nearby. Treating these waste streams utilizes such volume reduction techniques as compaction and incineration. The Russians also employ methods such as bitumenization, cementation, and vitrification for waste treatment before burial. Shallow land trench burial is the most commonly used technique. Hospital and research waste is centrally regulated by the Moscow Council of Deputies. Plans are made in cooperation with the Ministry of Atomic Energy. Currently the former Soviet Union has a network of low-level disposal sites located near large cities. Fifteen disposal sites are located in the Federal Republic of Russia, six are in the Ukraine, and one is located in each of the remaining 13 republics. Like the US, each republic is in charge of management of the facilities within their borders. The sites are all similarly designed, being modeled after the RADON site near Moscow.

  11. User`s Manual for the SOURCE1 and SOURCE2 Computer Codes: Models for Evaluating Low-Level Radioactive Waste Disposal Facility Source Terms (Version 2.0)

    Energy Technology Data Exchange (ETDEWEB)

    Icenhour, A.S.; Tharp, M.L.

    1996-08-01

    The SOURCE1 and SOURCE2 computer codes calculate source terms (i.e. radionuclide release rates) for performance assessments of low-level radioactive waste (LLW) disposal facilities. SOURCE1 is used to simulate radionuclide releases from tumulus-type facilities. SOURCE2 is used to simulate releases from silo-, well-, well-in-silo-, and trench-type disposal facilities. The SOURCE codes (a) simulate the degradation of engineered barriers and (b) provide an estimate of the source term for LLW disposal facilities. This manual summarizes the major changes that have been effected since the codes were originally developed.

  12. Overview of resuspension model: application to low level waste management

    Energy Technology Data Exchange (ETDEWEB)

    Healy, J.W.

    1980-01-01

    Resuspension is one of the potential pathways to man for radioactive or chemical contaminants that are in the biosphere. In waste management, spills or other surface contamination can serve as a source for resuspension during the operational phase. After the low-level waste disposal area is closed, radioactive materials can be brought to the surface by animals or insects or, in the long term, the surface can be removed by erosion. Any of these methods expose the material to resuspension in the atmosphere. Intrusion into the waste mass can produce resuspension of potential hazard to the intruder. Removal of items from the waste mass by scavengers or archeologists can result in potential resuspension exposure to others handling or working with the object. The ways in which resuspension can occur are wind resuspension, mechanical resuspension and local resuspension. While methods of predicting exposure are not accurate, they include the use of the resuspension factor, the resuspension rate and mass loading of the air.

  13. Low level determinations of environmental cadmium

    Energy Technology Data Exchange (ETDEWEB)

    Rosman, K.J.R.; De Laeter, J.R.

    1976-06-24

    An isotope dilution technique has been developed to measure the concentration of cadmium in aqueous solutions with a sensitivity of 0.003 micrograms per liter. The concentrations of cadmium in two river systems in Western Australia has been measured to establish an accurate set of low level reference determinations in a region which is relatively free of sources of industrial pollution. The results of the study demonstrate that the cadmium content in the two major river systems in western Australia is about 100 times lower than the World Health Organization limits. The data indicate that the cadmium content tends to decrease upstream from the mouth of the river, and that in the reservoir areas the content is as low as 0.02 micrograms per liter. These values are substantially lower than waterways in other parts of the world. 13 references, 1 figure, 1 table.

  14. Low-level waste feed staging plan

    Energy Technology Data Exchange (ETDEWEB)

    Certa, P.J.; Grams, W.H.; McConville, C.M.; L. W. Shelton, L.W.; Slaathaug, E.J., Westinghouse Hanford

    1996-08-12

    The `Preliminary Low-Level Waste Feed Staging Plan` was updated to reflect the latest requirement in the Tank Waste Remediation Privatization Request for Proposals (RFP) and amendments. The updated plan develops the sequence and transfer schedule for retrieval of DST supernate by the management and integration contractor and delivery of the staged supernate to the private low-activity waste contractors for treatment. Two DSTs are allocated as intermediate staging tanks. A transfer system conflict analysis provides part of the basis for determining transfer system upgrade requirements to support both low-activity and high-level waste feed delivery. The intermediate staging tank architecture and retrieval system equipment are provided as a planning basis until design requirements documents are prepared. The actions needed to successfully implement the plan are identified. These include resolution of safety issues and changes to the feed envelope limits, minimum order quantities, and desired batch sizes.

  15. Polycomb Responds to Low Levels of Transcription

    Directory of Open Access Journals (Sweden)

    Georgina Berrozpe

    2017-07-01

    Full Text Available How is Polycomb (Pc, a eukaryotic negative regulator of transcription, targeted to specific mammalian genes? Our genome-wide analysis of the Pc mark H3K27me3 in murine cells revealed that Pc is preferentially associated with CpG island promoters of genes that are transcribed at a low level and less so with promoters of genes that are either silent or more highly expressed. Studies of the CpG island promoter of the Kit gene demonstrate that Pc is largely absent when the gene is silent in myeloid cells, as well as when the gene is highly expressed in mast cells. Manipulations that increase transcription in the former case, and reduce it in the latter, increase Pc occupancy. The average negative effect of Pc, we infer, is about 2-fold. We suggest possible biological roles for such negative effects and propose a mechanism by which Pc might be recruited to weakly transcribed genes.

  16. Low-level radioactive biomedical wastes

    Energy Technology Data Exchange (ETDEWEB)

    Casarett, G.W.

    A summary of the management and hazards of low-level radioactive biomedical wastes is presented. The volume, disposal methods, current problems, regulatory agencies, and possible solutions to disposal problems are discussed. The benefits derived from using radioactivity in medicine are briefly described. Potential health risks are discussed. The radioactivity in most of the radioactive biomedical waste is a small fraction of that contained naturally in the human body or in the natural environment. Benefit-risk-cost considerations are presented. The cost of managing these wastes is getting so high that a new perspective for comparison of radioactivity (facts, risks, costs, benefits and trade-offs) and alternate approaches to minimize the risk and cost and maximize the benefits is suggested. (DMC)

  17. Low-level therapy in ophthalmology

    Science.gov (United States)

    Pankov, O. P.

    1999-07-01

    Extremely slow introduction of low-level laser therapy into the practice of ophthalmologists is restricted by the lack of good methodological recommendation and modern equipment adopted to the needs of ophthalmology. The most perspective is considered to be further improvement of the methods and the elaboration of the medical equipment, working in several wave bands, combined with magnetotherapy and working with the use of various modes of the modulation of the intensity of the luminous flux. It may be asserted that unlike the mode of continuous radiation, in some cases, the effectiveness of the treatment increases when the modulated light with the frequency of one to a few tens HZ is used. Moreover, the methods are being elaborated, when the modulation frequency of laser light and the biorhythms of man physiologic parameters are synchronized. Very perspective seems the computerization of the treatment process with the simultaneous electrophysiological control of the condition of visual functions.

  18. Low level counting from meteorites to neutrinos

    Science.gov (United States)

    Heusser, Gerd

    2005-09-01

    The development in low level counting at Heidelberg with NaI(Tl) crystals, proportional counters and Germanium detectors is reviewed throughout the course of almost 40 years of experience. Research subjects changed from cosmogenic radionuclides in meteorites to solar neutrinos and double beta decay. Driven by screening measurements for these rare event experiments, the sensitivity in single gamma counting has gained almost 3 orders of magnitude. With Ge spectrometry the μBq/kg range is now accessible. It is discussed how further improvements can be realized. There is potential to reach a sensitivity at the level of 10 to 100 nBq/kg for cryogenic liquid type Gespectroscopy, a technique which the next generation 76Ge double beta decay experiment GERDA is based on.

  19. Draft low level waste technical summary

    Energy Technology Data Exchange (ETDEWEB)

    Powell, W.J.; Benar, C.J.; Certa, P.J.; Eiholzer, C.R.; Kruger, A.A.; Norman, E.C.; Mitchell, D.E.; Penwell, D.E.; Reidel, S.P.; Shade, J.W.

    1995-09-01

    The purpose of this document is to present an outline of the Hanford Site Low-Level Waste (LLW) disposal program, what it has accomplished, what is being done, and where the program is headed. This document may be used to provide background information to personnel new to the LLW management/disposal field and to those individuals needing more information or background on an area in LLW for which they are not familiar. This document should be appropriate for outside groups that may want to learn about the program without immediately becoming immersed in the details. This document is not a program or systems engineering baseline report, and personnel should refer to more current baseline documentation for critical information.

  20. Mechanisms of low level light therapy

    Science.gov (United States)

    Hamblin, Michael R.; Demidova, Tatiana N.

    2006-02-01

    The use of low levels of visible or near infrared light for reducing pain, inflammation and edema, promoting healing of wounds, deeper tissues and nerves, and preventing tissue damage has been known for almost forty years since the invention of lasers. Originally thought to be a peculiar property of laser light (soft or cold lasers), the subject has now broadened to include photobiomodulation and photobiostimulation using non-coherent light. Despite many reports of positive findings from experiments conducted in vitro, in animal models and in randomized controlled clinical trials, LLLT remains controversial. This likely is due to two main reasons; firstly the biochemical mechanisms underlying the positive effects are incompletely understood, and secondly the complexity of rationally choosing amongst a large number of illumination parameters such as wavelength, fluence, power density, pulse structure and treatment timing has led to the publication of a number of negative studies as well as many positive ones. In particular a biphasic dose response has been frequently observed where low levels of light have a much better effect than higher levels. This introductory review will cover some of the proposed cellular chromophores responsible for the effect of visible light on mammalian cells, including cytochrome c oxidase (with absorption peaks in the near infrared) and photoactive porphyrins. Mitochondria are thought to be a likely site for the initial effects of light, leading to increased ATP production, modulation of reactive oxygen species and induction of transcription factors. These effects in turn lead to increased cell proliferation and migration (particularly by fibroblasts), modulation in levels of cytokines, growth factors and inflammatory mediators, and increased tissue oxygenation. The results of these biochemical and cellular changes in animals and patients include such benefits as increased healing in chronic wounds, improvements in sports injuries and

  1. Low level CO2 effects on pulmonary function in humans

    Science.gov (United States)

    Sexton, J.; Mueller, K.; Elliott, A.; Gerzer, D.; Strohl, K. P.; West, J. B. (Principal Investigator)

    1998-01-01

    The purpose of the study was to determine whether chamber exposure to low levels of CO2 results in functional alterations in gas mixing and closing volume in humans. Four healthy volunteer subjects were exposed to 0.7% CO2 and to 1.2% CO2. Spirometry, lung volumes, single breath nitrogen washout, diffusing capacity for carbon monoxide (DLCO) by two methods, and cardiac output were measured in triplicate. Values were obtained over two non-consecutive days during the training period (control) and on days 2 or 3, 4, 6, 10, 13, and 23 of exposure to each CO2 level. Measurements were made during the same time of day. There was one day of testing after exposure, while still in the chamber but off carbon dioxide. The order of testing, up until measurements of DLCO and cardiac output, were randomized to avoid presentation effects. The consistent findings were a reduction in diffusing capacity for carbon monoxide and a fall in cardiac output, occurring to a similar degree with both exposures. For the group as a whole, there was no indication of major effects on spirometry, lung volumes, gas mixing or dead space. We conclude that small changes may occur in the function of distal gas exchanging units; however, these effects were not associated with any adverse health effects. The likelihood of pathophysiologic changes in lung function or structure with 0.7 or 1.2% CO2 exposure for this period of time, is therefore, low.

  2. Control of quality in spectrometry gamma of low level

    CERN Document Server

    Salazar, A

    1997-01-01

    Low level gamma spectrometry is a very precise technique to measure the concentration of nuclides present in different samples in Bq kg sup - sup 1. The quality control of the procedure and method used can be carried out by intercomparison exercises with world recognized institutions. During the last three years the Nuclear Physics Laboratory Of The University of Costa Rica (LAFNA) has been participating in the international quality assessment program (QAP) carried out by the Environmental Measurements Laboratory (EML), department of Energy, USA. The results show a very good agreement with the rest of the participant laboratories. This provides a very objective evaluation of the high precision of the methods used by LAFNA in low level spectroscopy measurements. (Author)

  3. BEIR-III report and the health effects of low-level radiation

    Energy Technology Data Exchange (ETDEWEB)

    Fabrikant, J.I.

    1980-01-01

    The present BEIR-III Committee has not highlighted any controversy over the health effects of low-level radiation. In its evaluation of the experimental data and epidemiological surveys, the Committee has carefully reviewed and assessed the value of all the available scientific evidence for estimating numerical risk coefficients for the health hazards to human populations exposed to low levels of ionizing radiation. Responsible public awareness of the possible health effects of ionizing radiations from medical and industrial radiation exposure, centers on three important matters of societal concern: (1) to place into perspective the extent of harm to the health of man and his descendants to be expected in the present and in the future from those societal activities involving ionizing radiation; (2) to develop quantitative indices of harm based on dose-effect relationships; such indices could then be used with prudent caution to introduce concepts of the regulation of population doses on the basis of somatic and genetic risks; and (3) to identify the magnitude and extent of radiation activities which could cause harm, to assess their relative significance, and to provide a framework for recommendations on how to reduce unnecessary radiation exposure to human populations. The main difference of the BEIR Committee Report is not so much from new data or new interpretations of existing data, but rather from a philosophical approach and appraisal of existing and future radiation protection resulting from an atmosphere of constantly changing societal conditions and public attitudes. (PCS)

  4. Expression of DNA repair genes in burned skin exposed to low-level red laser.

    Science.gov (United States)

    Trajano, Eduardo Tavares Lima; Mencalha, Andre Luiz; Monte-Alto-Costa, Andréa; Pôrto, Luís Cristóvão; de Souza da Fonseca, Adenilson

    2014-11-01

    Although red laser lights lie in the region of non-ionizing radiations in the electromagnetic spectrum, there are doubts whether absorption of these radiations causes lesions in the DNA molecule. Our aim was to investigate the expression of the genes involved with base excision and nucleotide excision repair pathways in skin tissue submitted to burn injury and exposed to low-level red laser. Wistar rats were divided as follows: control group-rats burned and not irradiated, laser group-rats burned and irradiated 1 day after injury for five consecutive days, and later laser group-rats injured and treated 4 days after injury for five consecutive days. Irradiation was performed according to a clinical protocol (20 J/cm(2), 100 mW, continuous wave emission mode). The animals were sacrificed on day 10, and scarred tissue samples were withdrawn for total RNA extraction, complementary DNA (cDNA) synthesis, and evaluation of gene expression by quantitative polymerase chain reaction. Low-level red laser exposure (1) reduces the expression of APE1 messenger (mRNA), (2) increases the expression of OGG1 mRNA, (3) reduces the expression of XPC mRNA, and (4) increases the expression of XPA mRNA both in laser and later laser groups. Red laser exposure at therapeutic fluences alters the expression of genes related to base excision and nucleotide excision pathways of DNA repair during wound healing of burned skin.

  5. Design issues for evaluating seedling exposure studies.

    Science.gov (United States)

    E. Charles Peterson; A. Robert. Mickler

    1993-01-01

    Tree seedling studies, covering a wide range of experimental conditions in pollutant treatment, species, facilities, and exposure regimes, have become commonplace in forestry research for assessing the actual and potential environmental effects of air pollutants on forest ecosystems. While assuring a wide breadth of scientific information, sufficient consideration has...

  6. Evaluation of the cloudy sky solar UVA radiation exposures.

    Science.gov (United States)

    Parisi, A V; Downs, N; Turner, J

    2014-09-05

    The influence of cloud on the solar UVA (320-400 nm) exposures over five minute periods on a horizontal plane has been investigated. The first approach used cloud modification factors that were evaluated using the influence of clouds on the global solar exposures (310-2800 nm) and a model developed to apply these to the clear sky UVA exposures to allow calculation of the five minute UVA exposures for any cloud conditions. The second approach established a relationship between the UVA and the global solar exposures. The models were developed using the first six months of data in 2012 for SZA less than or equal to 70° and were applied and evaluated for the exposures in the second half of 2012. This comparison of the modelled exposures for all cloud conditions to the measured data provided an R(2) of 0.8 for the cloud modification model, compared to an R(2) of 0.7 for the UVA/global model. The cloud modification model provided 73% of the five minute exposures within 20% of the measured UVA exposures. This was improved to 89% of the exposures within 20% of the measured UVA exposures for the cases of cloud with the sun not obscured. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. MESERAN Calibration for Low Level Organic Residues

    Energy Technology Data Exchange (ETDEWEB)

    Benkovich, M.G.

    2004-04-08

    Precision cleaning studies done at Honeywell Federal Manufacturing & Technologies (FM&T), the Kansas City Plant (KCP), and at other locations within the Department of Energy (DOE) Weapons complex over the last 30 years have depended upon results from MESERAN Evaporative Rate Analysis for detecting low levels of organic contamination. The characterization of the surface being analyzed is carried out by depositing a Carbon-14 tagged radiochemical onto the test surface and monitoring the rate at which the radiochemical disappears from the surface with a Geiger-Mueller counter. In the past, the total number of counts over a 2-minute span have been used to judge whether a surface is contaminated or not and semi-quantitatively to what extent. This technique is very sensitive but has not enjoyed the broad acceptance of a purely quantitative analysis. The work on this project developed calibrations of various organic contaminants typically encountered in KCP operations. In addition, a new analysis method was developed to enhance the ability of MESERAN Analyzers to detect organic contamination and yield quantitative data in the microgram and nanogram levels.

  8. Photomultiplier tubes for Low Level Cerenkov Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Strindehag, O.

    1965-03-15

    Tube backgrounds of several 2-inch photomultiplier types having S11, 'S' , S13 and S20 cathodes are compared by measuring signal and background pulse height distributions at pulse heights corresponding to a few photo-electrons. The reference signal is generated by means of a {beta}-source and a plexiglass radiator. It is found that comparatively good results are obtained with selected tubes of the EMI types 6097B and 9514B having equivalent dark current dc values down to 10{sup -12} input lumens. Special interest is devoted to the correlation between the measured tube backgrounds and the dark current dc values of the tubes, as a good correlation between these parameters simplifies the selection of photomultiplier tubes. The equivalent dark currents of the tested tubes extend over the range 10{sup -12} to 10{sup -9} input lumens. Although the investigation deals with photomultiplier tubes intended for use in low level Cerenkov detectors it is believed that the results could be valuable in other fields where photomultiplier tubes are utilized for the detection of weak light pulses.

  9. Low Level Infrared Irradiance Ocular Effects.

    Science.gov (United States)

    1978-11-01

    pupil. ANSI data are also expressed as maximum 4 0 a) Ln CC Nimons permissible exposure in J/cm2 for a 7-mm pupil. Such MPE data generally incorporate...900 50 45 13.27 No 900 50 45 13.27 No 900 60 54 15.92 No 900 70 63 18.58 No 900 70 63 18.58 No 900 115 104 30.68 Yes 900 140 126 37.17 No 900 150 135

  10. Even Low Levels of Alcohol during Pregnancy Can Affect Fetal Brain Development. Science Briefs

    Science.gov (United States)

    National Scientific Council on the Developing Child, 2008

    2008-01-01

    "Science Briefs" summarize the findings and implications of a recent study in basic science or clinical research. This brief reports on the study "Effects of Prenatal Alcohol Exposure on GABAergic Neurons" (V. C. Cuzone; P. W. L. Yeh; Y. Yanagawa; K. Obata; and H. H. Yeh). Study results indicate that even exposure to low levels of alcohol during…

  11. Effects of low-level laser therapy on wound healing

    Directory of Open Access Journals (Sweden)

    Fabiana do Socorro da Silva Dias Andrade

    Full Text Available OBJECTIVE: To gather and clarify the actual effects of low-level laser therapy on wound healing and its most effective ways of application in human and veterinary medicine.METHODS: We searched original articles published in journals between the years 2000 and 2011, in Spanish, English, French and Portuguese languages, belonging to the following databases: Lilacs, Medline, PubMed and Bireme; Tey should contain the methodological description of the experimental design and parameters used.RESULTS: doses ranging from 3 to 6 J/cm2 appear to be more effective and doses 10 above J/cm2 are associated with deleterious effects. The wavelengths ranging from 632.8 to 1000 nm remain as those that provide more satisfactory results in the wound healing process.CONCLUSION: Low-level laser can be safely applied to accelerate the resolution of cutaneous wounds, although this fact is closely related to the election of parameters such as dose, time of exposure and wavelength.

  12. Low-level light stimulates excisional wound healing in mice.

    Science.gov (United States)

    Demidova-Rice, Tatiana N; Salomatina, Elena V; Yaroslavsky, Anna N; Herman, Ira M; Hamblin, Michael R

    2007-10-01

    Low levels of laser or non-coherent light, termed low-level light therapy (LLLT) have been reported to accelerate some phases of wound healing, but its clinical use remains controversial. A full thickness dorsal excisional wound in mice was treated with a single exposure to light of various wavelengths and fluences 30 minutes after wounding. Wound areas were measured until complete healing and immunofluorescence staining of tissue samples was carried out. Wound healing was significantly stimulated in BALB/c and SKH1 hairless mice but not in C57BL/6 mice. Illuminated wounds started to contract while control wounds initially expanded for the first 24 hours. We found a biphasic dose-response curve for fluence of 635-nm light with a maximum positive effect at 2 J/cm(2). Eight hundred twenty nanometer was found to be the best wavelength tested compared to 635, 670, and 720 nm. We found no difference between non-coherent 635+/-15-nm light from a lamp and coherent 633-nm light from a He/Ne laser. LLLT increased the number of alpha-smooth muscle actin (SMA)-positive cells at the wound edge. LLLT stimulates wound contraction in susceptible mouse strains but the mechanism remains uncertain. 2007 Wiley-Liss, Inc

  13. Development and evaluation of an Exposure Control Efficacy Library (ECEL)

    NARCIS (Netherlands)

    Fransman, W.; Schinkel, J.; Meijster, T.; Hemmen, J. van; Tielemans, E.; Goede, H.

    2008-01-01

    Objectives: This paper describes the development and evaluation of an evidence database on the effectiveness of risk management measures (RMMs) to control inhalation exposure. This database is referred to as Exposure Control Efficacy Library (ECEL). Methods: A comprehensive review of scientific

  14. Exposure to violence in children referred for psychiatric evaluation ...

    African Journals Online (AJOL)

    One hundred consecutive patients referred to the Child Mental Health Section of Oranje Hospital in Bloemfontein for psychiatric evaluation were included in the study. Seventy-four per cent of children in the study reported exposure to some form of violence in the past: 32% reported exposure to domestic violence, 9% ...

  15. Exposure to violence in children referred for psychiatric evaluation

    African Journals Online (AJOL)

    One hundred consecutive patients referred to the Child. Mental Health Section of Oranje Hospital in Bloemfontein for psychiatric evaluation were included in the study. Seventy-four per cent of children in the study reported exposure to some form of violence in the past: 32% reported exposure to domestic violence, 9% ...

  16. Overview of UNSCEAR re-evaluation of public exposure

    Energy Technology Data Exchange (ETDEWEB)

    Rochedo, Elaine R.R. [Comissao Nacional de Energia Nuclear (CNEN-RJ), Rio de Janeiro, RJ (Brazil). Coordenacao de Instalacoes Nucleares], e-mail: erochedo@cnen.gov.br

    2009-07-01

    The United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) has re-evaluated the levels of public radiation exposure for four broad categories of sources: natural sources of radiation, enhanced exposure to naturally occurring radioactive material (NORM), man-made sources used for peaceful purposes and man-made sources used for military purposes. Regarding natural radiation sources, recent data confirmed former results from 2000 Report, but with a more wide range. Very few information is available for public exposure from NORM. Most works describes concentration levels but dose assessments are usually restricted to occupational exposures. The use of source and by-product materials may however lead to doses up to a few milisieverts to members of the public. The nuclear fuel cycle and electric energy generation have very small contributions to public exposure. Uranium mining contributes with the largest individual doses, mainly due to radon from tailings. Most relevant military use of nuclear energy were the atmospheric nuclear tests, interrupted in the 60's. Residual radioactivity deposited worldwide is now responsible for a very small contribution to worldwide exposures. However, they left a legacy of several contaminated sites. The use of depleted uranium in munitions in Kuwait, Kosovo, Serbia, Montenegro and Bosnia-Herzegovina, has led to great public concern, although not usually associated to any major consequence regarding public exposure. Some accidents resulted in environmental contamination and exposures of members of the public. Except for the Chernobyl accident, the areas affected were usually small and the exposure restricted to small number of persons, up to a few hundred, without any significant contribution to worldwide exposures. The exposure to natural sources of radiation is still the major component of worldwide exposure to ionizing radiation although for some highly developed countries, medical exposure has surpassed

  17. Low level laser therapy for sports injuries

    OpenAIRE

    Morimoto, Yusuke; Saito, Akiyoshi; Tokuhashi, Yasuaki

    2013-01-01

    Background and aims: Our hospital has used LLLT in the treatment of athletes since 1990. We had a good result about LLLT for sports injuries. However, few articles have attempted to evaluate the efficacy of LLLT for sports injuries. The aims of this study was to evaluate the efficacy of LLLT for sports injuries.

  18. Evaluation of medical radiation exposure in pediatric interventional radiology procedures

    Energy Technology Data Exchange (ETDEWEB)

    Navarro, Valeria Coelho Costa; Navarro, Marcus Vinicius Teixeira; Oliveira, Aline da Silva Pacheco, E-mail: vccnavarro@gmail.com [Instituto Federal de Educacao, Ciencia e Tecnologia da Bahia (IFBA), Salvador, BA (Brazil); Maia, Ana Figueiredo [Universidade Federal de Sergipe (UFS), Aracaju, SE (Brazil); Oliveira, Adriano Dias Dourado [Sociedade Brasileira de Hemodinamica e Cardiologia Intervencionista, Salvador, BA (Brazil)

    2012-07-15

    Objective: To evaluate pediatric radiation exposure in procedures of interventional radiology in two hospitals in the Bahia state, aiming at contributing to delineate the scenario at the state and national levels. The knowledge of exposure levels will allow an evaluation of the necessity of doses optimization, considering that peculiarities of radiology and pediatrics become even more significant in interventional radiology procedures which involve exposure to higher radiation doses. Materials and Methods: A total of 32 procedures were evaluated in four rooms of the two main hospitals performing pediatric interventional radiology procedures in the Bahia state. Air kerma rate and kerma-area product were evaluated in 27 interventional cardiac and 5 interventional brain procedures. Results: Maximum values for air kerma rate and kerma-area product and air kerma obtained in cardiac procedures were, respectively, 129.9 Gy.cm{sup 2} and 947.0 mGy; and, for brain procedures were 83.3 Gy.cm{sup 2} and 961.0 mGy. Conclusion: The present study results showed exposure values up to 14 times higher than those found in other foreign studies, and approximating those found for procedures in adults. Such results demonstrate excessive exposure to radiation, indicating the need for constant procedures optimization and evaluation of exposure rates. (author)

  19. Low level laser therapy for sports injuries.

    Science.gov (United States)

    Morimoto, Yusuke; Saito, Akiyoshi; Tokuhashi, Yasuaki

    2013-01-01

    Our hospital has used LLLT in the treatment of athletes since 1990. We had a good result about LLLT for sports injuries. However, few articles have attempted to evaluate the efficacy of LLLT for sports injuries. The aims of this study was to evaluate the efficacy of LLLT for sports injuries. Materials (Subjects) and Methods: Forty one patients underwent LLLT in our hospital. These patients included 22 men and 19 women with an average age of 38.9 years old. Patients were irradiated by diode laser at points of pain and/or acupuncture points. Patients underwent LLLT a maximum treatment of 10 times (mean 4.1 times). We evaluated the efficacy of LLLT using a Pain relief score (PRS). A score of 2 to 5 after treatment was regarded as very good, 6 to 8 as good, and 9 to 10 as poor. A PRS score of less than 5 was regarded as effective. The rate of effectiveness (PRS of 5 or less) after LLLT was 65.9% (27/41 patients). In this study, the resulting rate of effectiveness was 65.9% for all sports injuries. However, we have a high rate of effectiveness for Jumper's knee, tennis elbow and Achilles tendinitis and cases that were irradiated laser by a physician. LLLT is an effective treatment for sports injuries, particularly jumper's knee, tennis elbow and Achilles tendinitis.

  20. Treatment options for low-level radiologically contaminated ORNL filtercake

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hom-Ti [Oak Ridge Associated Universities, Inc., TN (United States); Bostick, W.D. [Oak Ridge K-25 Site, TN (United States)

    1996-04-01

    Water softening sludge (>4000 stored low level contaminated drums; 600 drums per year) generated by the ORNL Process Waste Treatment Plant must be treated, stabilized, and placed in safe storage/disposal. The sludge is primarily CaCO{sub 3} and is contaminated by low levels of {sup 90}Sr and {sup 137}Cs. In this study, microwave sintering and calcination were evaluated for treating the sludge. The microwave melting experiments showed promise: volume reductions were significant (3-5X), and the waste form was durable with glass additives (LiOH, fly ash). A commercial vendor using surrogate has demonstrated a melt mineralization process that yields a dense monolithic waste form with a volume reduction factor (VR) of 7.7. Calcination of the sludge at 850-900 C yielded a VR of 2.5. Compaction at 4500 psi increased the VR to 4.2, but the compressed form is not dimensionally stable. Addition of paraffin helped consolidate fines and yielded a VR of 3.5. In conclusion, microwave melting or another form of vitrification is likely to be the best method; however for immediate implementation, the calculation/compaction/waxing process is viable.

  1. Hyper-heuristics with low level parameter adaptation.

    Science.gov (United States)

    Ren, Zhilei; Jiang, He; Xuan, Jifeng; Luo, Zhongxuan

    2012-01-01

    Recent years have witnessed the great success of hyper-heuristics applying to numerous real-world applications. Hyper-heuristics raise the generality of search methodologies by manipulating a set of low level heuristics (LLHs) to solve problems, and aim to automate the algorithm design process. However, those LLHs are usually parameterized, which may contradict the domain independent motivation of hyper-heuristics. In this paper, we show how to automatically maintain low level parameters (LLPs) using a hyper-heuristic with LLP adaptation (AD-HH), and exemplify the feasibility of AD-HH by adaptively maintaining the LLPs for two hyper-heuristic models. Furthermore, aiming at tackling the search space expansion due to the LLP adaptation, we apply a heuristic space reduction (SAR) mechanism to improve the AD-HH framework. The integration of the LLP adaptation and the SAR mechanism is able to explore the heuristic space more effectively and efficiently. To evaluate the performance of the proposed algorithms, we choose the p-median problem as a case study. The empirical results show that with the adaptation of the LLPs and the SAR mechanism, the proposed algorithms are able to achieve competitive results over the three heterogeneous classes of benchmark instances.

  2. Evaluation of the noise exposure of symphonic orchestra musicians.

    Science.gov (United States)

    Rodrigues, Matilde Alexandra; Freitas, Marisa Alexandra; Neves, Maria Paula; Silva, Manuela Vieira

    2014-01-01

    For musicians, the impact of noise exposure is not yet fully characterized. Some inconsistencies can be found in the methodology used to evaluate noise exposure. This study aims to analyze the noise exposure of musicians in a symphonic orchestra to understand their risk for hearing loss, applying the methodology proposed by ISO 9612:2009. Noise levels were monitored among musicians during the rehearsal of eight different repertoires. Test subjects were selected according to their instrument and position in the orchestra. Participants wore noise dosimeters throughout the rehearsals. A sound meter was used to analyze the exposure of the conductor. The results showed that musicians are exposed to high noise levels that can damage hearing. Brass, woodwind and percussion and timpani musicians were exposed to noise levels in excess of the upper exposure action level of 85 dB (A), while the other instrumental groups had a lower exposure action level of 80 dB (A). Percussion musicians were exposed to high peak noise levels of 135 dB (C). Sound levels varied by instrument, repertoire and position. Octave frequency analyses showed differences among musicians. This study suggests that musicians are at risk for hearing loss. There is a need for more effective guidelines applicable to all countries, which should define standardized procedures for determining musician noise exposure and should allow exposure level normalization to the year, including different repertoires.

  3. Evaluation of workplace exposure to respirable crystalline silica in Italy.

    Science.gov (United States)

    Scarselli, Alberto; Corfiati, Marisa; Marzio, Davide Di; Iavicoli, Sergio

    2014-10-01

    Crystalline silica is a human carcinogen and its use is widespread among construction, mining, foundries, and other manufacturing industries. To evaluate occupational exposure to crystalline silica in Italy. Data were collected from exposure registries and descriptive statistics were calculated for exposure-related variables. The number of potentially exposed workers was estimated in a subset of industrial sectors. Linear mixed model analysis was performed to determine factors affecting the exposure level. We found 1387 cases of crystalline silica exposure between 1996 and 2012. Exposure was most common in construction work (AM = 0·057 mg/m(3), N = 505), and among miners and quarry workers (AM = 0·048 mg/m(3), N = 238). We estimated that 41 643 workers were at risk of exposure in the selected industrial sectors during the same period. This study identified high-risk sectors for occupational exposure to crystalline silica, which can help guide targeted dust control interventions and health promotion campaigns in the workplace.

  4. Low-level lasers and mRNA levels of reference genes used in Escherichia coli

    Science.gov (United States)

    Teixeira, A. F.; Machado, Y. L. R. C.; Fonseca, A. S.; Mencalha, A. L.

    2016-11-01

    Low-level lasers are widely used for the treatment of diseases and antimicrobial photodynamic therapy. Reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) is widely used to evaluate mRNA levels and output data from a target gene are commonly relative to a reference mRNA that cannot vary according to treatment. In this study, the level of reference genes from Escherichia coli exposed to red or infrared lasers at different fluences was evaluated. E. coli AB1157 cultures were exposed to red (660 nm) and infrared (808 nm) lasers, incubated (20 min, 37 °C), the total RNA was extracted, and cDNA synthesis was performed to evaluate mRNA levels from arcA, gyrA and rpoA genes by RT-qPCR. Melting curves and agarose gel electrophoresis were carried out to evaluate specific amplification. Data were analyzed by geNorm, NormFinder and BestKeeper. The melting curve and agarose gel electrophoresis showed specific amplification. Although mRNA levels from arcA, gyrA or rpoA genes presented no significant variations trough a traditional statistical analysis, Excel-based tools revealed that these reference genes are not suitable for E. coli cultures exposed to lasers. Our data showed that exposure to low-level red and infrared lasers at different fluences alter the mRNA levels from arcA, gyrA and rpoA in E. coli cells.

  5. Flight in low-level wind shear

    Science.gov (United States)

    Frost, W.

    1983-01-01

    Results of studies of wind shear hazard to aircraft operation are summarized. Existing wind shear profiles currently used in computer and flight simulator studies are reviewed. The governing equations of motion for an aircraft are derived incorporating the variable wind effects. Quantitative discussions of the effects of wind shear on aircraft performance are presented. These are followed by a review of mathematical solutions to both the linear and nonlinear forms of the governing equations. Solutions with and without control laws are presented. The application of detailed analysis to develop warning and detection systems based on Doppler radar measuring wind speed along the flight path is given. A number of flight path deterioration parameters are defined and evaluated. Comparison of computer-predicted flight paths with those measured in a manned flight simulator is made. Some proposed airborne and ground-based wind shear hazard warning and detection systems are reviewed. The advantages and disadvantages of both types of systems are discussed.

  6. Low-level lasers on microRNA and uncoupling protein 2 mRNA levels in human breast cancer cells

    Science.gov (United States)

    Canuto, K. S.; Teixeira, A. F.; Rodrigues, J. A.; Paoli, F.; Nogueira, E. M.; Mencalha, A. L.; Fonseca, A. S.

    2017-06-01

    MicroRNA is short non-coding RNA and is a mediator of post-transcriptional regulation of gene expression. In addition, uncoupling proteins (UCPs) regulate thermogenesis, metabolic and energy balance, and decrease reactive oxygen species production. Both microRNA and UCP2 expression can be altered in cancer cells. At low power, laser wavelength, frequency, fluence and emission mode deternube photobiological responses, which are the basis of low-level laser therapy. There are few studies on miRNA and UCP mRNA levels after low-level laser exposure on cancer cells. In this work, we evaluate the micrRNA (mir-106b and mir-15a) and UCP2 mRNA levels in human breast cancer cells exposed to low-level lasers. MDA-MB-231 human breast cancer cells were exposed to low-level red and infrared lasers, total RNA was extracted for cDNA synthesis and mRNA levels by real time quantitative polymerase chain reaction were evaluated. Data show that mir-106b and mir-15a relative levels are not altered, but UCP2 mRNA relative levels are increased in MDA-MB-231 human breast cancer cells exposed to low-level red and infrared lasers at fluences used in therapeutic protocols.

  7. [Development and verification of Chinese dietary exposure evaluation model software].

    Science.gov (United States)

    Liu, Pei; Li, Jing-xin; Sun, Jin-fang; Xue, Jianping; Chen, Bing-wei; Zhang, Hong; Yu, Xiao-jin; Wang, Can-nan; Yuan, Bao-jun; Ma, Yong-jian; Tian, Zi-hua

    2010-03-01

    To develop the dietary exposure evaluation model software accredited of Chinese intellectual property rights and to verify the rationality and accuracy of the results from the probabilistic model in Chinese dietary exposure evaluation model software according to international standards. The software of SAS was used to build various evaluation model based on the data from Chinese dietary survey and the chemical compound in food surveillance and to design an operation interface. The results from probabilistic dietary exposure model for children 2 - 7 years old were compared with that from duplicate portion study of 2-7 years children dietary exposure in Jinhu, Jiangsu province in order to analyze the rationality of model. The results from probabilistic model of dietary exposure were compared with the results from @Risk software to verify the correction of the probabilistic model by using the same data of randomly selected 10 000 study subjects from national dietary survey. While, the mean drift was used as an internal index to illustrate the accuracy of the computation. Chinese dietary exposure evaluation software was developed successfully. On the rationality, the results from probabilistic model were lower than that from the point estimation (e.g., cucumber: the result of point estimation of acephate was 4.78 microg x kg(-1) x d(-1), while the results of probabilistic model which was 0.39 microg x kg(-1) x d(-1)). Meanwhile the results from probabilistic model were higher than the results of duplicate portion study (on the P95, the result of probabilistic model of Pb exposure in children was 11.08 microg x kg(-1) x d(-1), while the results of duplicate portion study was 5.75 microg x kg(-1) x d(-1)). On accuracy, the results from @Risk and the probabilistic model were highly consistent (on the P95, the result of probabilistic assessment of acephate diet exposure was 4.27 microg x kg(-1) x d(-1), while the results of duplicate portion study was 4.24 microg x kg(-1

  8. Associations of low-level urine cadmium with kidney function in lead workers

    Science.gov (United States)

    Weaver, Virginia M.; Kim, Nam-Soo; Jaar, Bernard G.; Schwartz, Brian S.; Parsons, Patrick J.; Steuerwald, Amy J.; Todd, Andrew C.; Simon, David; Lee, Byung-Kook

    2010-01-01

    Objectives Low-level cadmium exposure, e.g., urinary cadmium < 2.0 μg/g creatinine, is widespread; recent data suggest nephrotoxicity even at these lower levels. Few studies have examined the impact of low-level cadmium exposure in workers who are occupationally exposed to other nephrotoxicants such as lead. Methods We evaluated associations of urine cadmium, a measure of cumulative dose, with four glomerular filtration measures and N-acetyl-β-D-glucosaminidase (NAG) in lead workers. Recent and cumulative lead dose was assessed via blood and tibia lead, respectively. Results In 712 lead workers, mean (SD) blood and tibia lead, urine cadmium, and estimated glomerular filtration rate (eGFR) using the Modification of Diet in Renal Disease equation were 23.1 (14.1) μg/dl, 26.6 (28.9) μg Pb/g bone mineral, 1.15 (0.66) μg/g creatinine, and 97.4 (19.2) ml/min/1.73m2, respectively. After adjustment for age, sex, body mass index, urine creatinine, smoking, alcohol, education, annual income, diastolic blood pressure, current or former lead worker job status, new or returning study participant, and blood and tibia lead, higher ln-urine cadmium was associated with higher calculated creatinine clearance, eGFR (β = 8.7 ml/min/1.73 m2; 95% CI = 5.4, 12.1) and ln-NAG but lower serum creatinine. Conclusions Potential explanations for these results include a normal physiologic response in which urine cadmium levels reflect renal filtration; the impact of adjustment for urine dilution with creatinine in models of kidney outcomes; and cadmium-related hyperfiltration. PMID:20974743

  9. The effects of low level laser therapy on both HIV-1 infected and uninfected TZM-bl cells

    CSIR Research Space (South Africa)

    Lugongolo, Masixole Y

    2017-01-01

    Full Text Available that would completely eradicate the virus in infected individuals, the quest for new therapies continues. Low level laser therapy (LLLT) involves the exposure of cells to low levels of red or infrared light. LLLT has been widely used in different medical...

  10. Occupational exposure assessment in a radioactive facility: a preliminary evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Alves, Alice dos Santos; Gerulis, Eduardo; Sanches, Matias P.; Carneiro, Janete C.G.G., E-mail: alicesante@hotmail.com [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    The risk that a worker has found on the job is a function of the hazards present and his exposure level to those hazards. Exposure and risk assessment is therefore the heart of all occupational health and industrial hygiene programs involving a continuous process of information gathering. The use of a systematic method to characterize workplace exposures to chemical, physical and biological risks is a fundamental part of this process. This study aims to carry out a preliminary evaluation in a radioactive facility, identifying potential exposures and consequently the existing occupational hazards (risk/agent) in the workplace which the employee is subject. The study is based on proposal to carry out a basic characterization of the facility, which could be the first step in the investigation of occupational exposure. For this study was essential to know the workplace, potential risks and agents; workforce profile including assignment of tasks, sources of exposure processes, and control measures. The main tool used in this study was based on references, records, standards, procedures, interviews with the workers and with management. Since the basic characterization of the facility has been carried out, consequently the potential exposure to the agents of risks to workers has been identified. The study provided an overview of the perception of risk founded at facility studied. It is expected to contribute with the occupational health program resources for welfare of the worker. (author)

  11. Low level laser therapy on injured rat muscle

    Science.gov (United States)

    Mantineo, M.; Pinheiro, J. P.; Morgado, A. M.

    2013-06-01

    Although studies show the clinical effectiveness of low level laser therapy (LLLT) in facilitating the muscle healing process, scientific evidence is still required to prove the effectiveness of LLLT and to clarify the cellular and molecular mechanisms triggered by irradiation. Here we evaluate the effect of different LLLT doses, using continuous illumination (830 nm), in the treatment of inflammation induced in the gastrocnemius muscle of Wistar rats, through the quantification of cytokines in systemic blood and histological analysis of muscle tissue. We verified that all applied doses produce an effect on reducing the number of inflammatory cells and the concentration of pro-inflammatory TNF-α and IL-1β cytokines. The best results were obtained for 40 mW. The results may suggest a biphasic dose response curve.

  12. Influence of Emotion on the Control of Low-Level Force Production

    Science.gov (United States)

    Naugle, Kelly M.; Coombes, Stephen A.; Cauraugh, James H.; Janelle, Christopher M.

    2012-01-01

    The accuracy and variability of a sustained low-level force contraction (2% of maximum voluntary contraction) was measured while participants viewed unpleasant, pleasant, and neutral images during a feedback occluded force control task. Exposure to pleasant and unpleasant images led to a relative increase in force production but did not alter the…

  13. Low levels of sarin affect the EEG in marmoset monkeys: A pilot study

    NARCIS (Netherlands)

    Helden, H.H.P.M. van; Vanwersch, R.A.P.; Kuijpers, W.C.; Trap, H.C.; Philippens, I.H.C.; Benschop, H.P.

    2004-01-01

    The main purpose of this pilot study was to estimate the lowest observable adverse effect level (LOAEL) for the electroencephalogram (EEG) upon long-term, low-level exposure of vehicle-pretreated and pyridostigmine-pretreated marmoset monkeys to sarin vapour. This is the C·t value (t = 5 h) of

  14. Low-Level Waste (LLW) forum meeting report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-31

    The Low-Level Radioactive Waste Forum (LLW Forum) is an association of state and compact representatives, appointed by governors and compact commissions, established to facilitate state and compact implementation of the Low-Level Radioactive Waste Policy Act of 1980 and the Low-Level Radioactive Waste Policy Amendments Act of 1985 and to promote the objectives of low-level radioactive waste regional compacts. The LLW Forum provides an opportunity for state and compact officials to share information with one another and to exchange views with officials of federal agencies and other interested parties.

  15. Biostimulation effect of low-level laser on healing process after third molar surgery, based on biochemical markers in saliva

    Science.gov (United States)

    Kroulikova, Veronika; Dostálová, Tatjana; Podzimek, Stepan

    2015-02-01

    Third molar extractions in general anesthesia have become a standard procedure in dentistry. There is an effort to shorten healing time and decrease the number of complications as well as increase comfort after the treatment. Low-level lasers are known for their analgesic, anti-inflammatory, and stimulatory effect. The aim of the study is to evaluate the effect of low-level laser after surgery in general anesthesia reducing the patient's discomfort, i.e. mainly pain, and also, to monitor the biostimulation process. Our study included 79 patients treated at the Department of Maxilofacial Surgery, diagnosed with third molar retention. Diode low-level laser radiation (wavelength 830 nm, output power 270 mW, probe aperture of 6.4 mm2) with dose ~ 3 mJ was applied. The control group was treated by using placebo - red light. The exposure time was 11 seconds immediately after the suture; the treatment was repeated every day for the following 3 days. To evaluate the effect of laser biostimulation, the objective markers for immunological determination of healing - sIgA and lysozyme in non-stimulated saliva of patients - were used. The sIgA decreases after laser application from 546.91 mg/l to 304. 91mg/l and in the control group from 602.25mg/l to 425.62 mg/l. The results were statistically significant. The level of lysozyme decreases from 54.27 mg/l to 2.45mg/l after laser biostimulation, from 304.371mg/l to 11.08mg/l after placebo effect. The study has confirmed a low-level laser healing effect not directly related to pain.

  16. Laboratory methods for evaluating the effect of low level laser ...

    African Journals Online (AJOL)

    The basic tenet of laser therapy is that laser radiation has a wavelength dependent capability to alter cellular behaviour in the absence of significant heating. Low intensity radiation can inhibit as well as stimulate cellular activity. Laser therapy typically involves the delivery of 1-4J/cm 2 to treatments sites with lasers having ...

  17. Laboratory methods for evaluating the effect of low level laser ...

    African Journals Online (AJOL)

    Low energy laser irradiation alters the cellular function by effecting protein synthesis, cell growth and differentiation, cell motility, membrane potential and binding affinities, neurotransmitter release, ATP synthesis and prostaglandin synthesis. Laboratory findings provide scientific rati onale of laser therapy and the effect of ...

  18. The Role of Low-Level Laser in Periodontal Surgeries

    Science.gov (United States)

    Sobouti, Farhad; Khatami, Maziar; Heydari, Mohaddase; Barati, Maryam

    2015-01-01

    Treatment protocols with low-level Laser (also called ‘soft laser therapy) have been used in health care systems for more than three decades. Bearing in mind the suitable sub-cellular absorption and the cellular-vascular impacts, low-level laser may be a treatment of choice for soft tissues. Low-level lasers have played crucial and colorful roles in performing periodontal surgeries. Their anti-inflammatory and painless effects have been variously reported in in-vitro studies. In this present review article, searches have been made in Pub Med, Google Scholar, and Science Direct, focusing on the studies which included low-level lasers, flap-periodontal surgeries, gingivectomy, and periodontal graft. The present study has sought to review the cellular impacts of low-level lasers and its role on reducing pain and inflammation following soft tissue surgical treatments. PMID:25987968

  19. Application of Low level Lasers in Dentistry (Endodontic)

    Science.gov (United States)

    Asnaashari, Mohammad; Safavi, Nassimeh

    2013-01-01

    Low level lasers, cold or soft lasers: These lasers do not produce thermal effects on tissues and induce photoreactions in cells through light stimulation which is called photobiostimulation. Power of these lasers is usually under 250mW. The main point differentiating low level lasers and high power ones is the activation of photochemical reactions without heat formation. The most important factor to achieve this light characteristic in lasers is not their power, but their power density for each surfa ceunit (i.e cm2). Density lower than 670mW/cm2, can induce the stimulatory effects of low level lasers without thermal effects. Low level lasers (therapeutic) used today as treatment adjunctive devices in medicine and dentistry. Numerous studies have been performed on the applications of low level lasers in patient pain reduction. Mechanisms of pain reduction with therapeutic lasers and their application are expressed, and the studies realized in this field are presented. PMID:25606308

  20. Application of Low level Lasers in Dentistry (Endodontic).

    Science.gov (United States)

    Asnaashari, Mohammad; Safavi, Nassimeh

    2013-01-01

    Low level lasers, cold or soft lasers: These lasers do not produce thermal effects on tissues and induce photoreactions in cells through light stimulation which is called photobiostimulation. Power of these lasers is usually under 250mW. The main point differentiating low level lasers and high power ones is the activation of photochemical reactions without heat formation. The most important factor to achieve this light characteristic in lasers is not their power, but their power density for each surfa ceunit (i.e cm(2)). Density lower than 670mW/cm(2), can induce the stimulatory effects of low level lasers without thermal effects. Low level lasers (therapeutic) used today as treatment adjunctive devices in medicine and dentistry. Numerous studies have been performed on the applications of low level lasers in patient pain reduction. Mechanisms of pain reduction with therapeutic lasers and their application are expressed, and the studies realized in this field are presented.

  1. Evaluation of cumulative PCB exposure estimated by a job exposure matrix versus PCB serum concentrations

    Science.gov (United States)

    Ruder, Avima M.; Succop, Paul; Waters, Martha A.

    2015-01-01

    Although polychlorinated biphenyls (PCBs) have been banned in many countries for more than three decades, exposures to PCBs continue to be of concern due to their long half-lives and carcinogenic effects. In National Institute for Occupational Safety and Health studies, we are using semiquantitative plant-specific job exposure matrices (JEMs) to estimate historical PCB exposures for workers (n=24,865) exposed to PCBs from 1938 to 1978 at three capacitor manufacturing plants. A subcohort of these workers (n=410) employed in two of these plants had serum PCB concentrations measured at up to four times between 1976 and 1989. Our objectives were to evaluate the strength of association between an individual worker’s measured serum PCB levels and the same worker’s cumulative exposure estimated through 1977 with the (1) JEM and (2) duration of employment, and to calculate the explained variance the JEM provides for serum PCB levels using (3) simple linear regression. Consistent strong and statistically significant associations were observed between the cumulative exposures estimated with the JEM and serum PCB concentrations for all years. The strength of association between duration of employment and serum PCBs was good for highly chlorinated (Aroclor 1254/HPCB) but not less chlorinated (Aroclor 1242/LPCB) PCBs. In the simple regression models, cumulative occupational exposure estimated using the JEMs explained 14–24 % of the variance of the Aroclor 1242/LPCB and 22–39 % for Aroclor 1254/HPCB serum concentrations. We regard the cumulative exposure estimated with the JEM as a better estimate of PCB body burdens than serum concentrations quantified as Aroclor 1242/LPCB and Aroclor 1254/HPCB. PMID:23475397

  2. A theoretical concept of low level/low LET radiation carcinogenic risk (LLCR) projection

    Energy Technology Data Exchange (ETDEWEB)

    Filyushkin, I.V. [Laboratory of Theoretical Radiobiology, Moscow (Russian Federation)

    1992-06-01

    Carcinogenic risk to humans resulting from low level/low LET radiation exposure (LLLCR) has not been observed directly because epidemiological observations have not yet provided statistically significant data on risk values. However, these values are of great interest for radiation health science and radiation protection practice under both normal conditions and emergency situations. This report presents a theoretical contribution to the validation of dose and dose rate efficiency factors (DDREF) transforming cocinogenic risk coefficients from those revealed in A-bomb survivors to factors appropriate for the projection of the risk resulting from very low levels of low LET radiation.

  3. Hanford low-level waste process chemistry testing data package

    Energy Technology Data Exchange (ETDEWEB)

    Smith, H.D.; Tracey, E.M.; Darab, J.G.; Smith, P.A.

    1996-03-01

    Recently, the Tri-Party Agreement (TPA) among the State of Washington Department of Ecology, U.S. Department of Energy (DOE) and the US Environmental Protection Agency (EPA) for the cleanup of the Hanford Site was renegotiated. The revised agreement specifies vitrification as the encapsulation technology for low level waste (LLW). A demonstration, testing, and evaluation program underway at Westinghouse Hanford Company to identify the best overall melter-system technology available for vitrification of Hanford Site LLW to meet the TPA milestones. Phase I is a {open_quotes}proof of principle{close_quotes} test to demonstrate that a melter system can process a simulated highly alkaline, high nitrate/nitrite content aqueous LLW feed into a glass product of consistent quality. Seven melter vendors were selected for the Phase I evaluation: joule-heated melters from GTS Duratek, Incorporated (GDI); Envitco, Incorporated (EVI); Penberthy Electomelt, Incorporated (PEI); and Vectra Technologies, Incorporated (VTI); a gas-fired cyclone burner from Babcock & Wilcox (BCW); a plasma torch-fired, cupola furnace from Westinghouse Science and Technology Center (WSTC); and an electric arc furnace with top-entering vertical carbon electrodes from the U.S. Bureau of Mines (USBM).

  4. Technical issues in licensing low-level radioactive waste facilities

    Energy Technology Data Exchange (ETDEWEB)

    Junkert, R. [California Dept. of Health Services, CA (United States)

    1993-03-01

    The California Department of Health Service spent two years in the review of an application for a low-level radioactive waste disposal facility in California. During this review period a variety of technical issues had to be evaluated and resolved. One of the first issues was the applicability and use of NRC guidance documents for the development of LLW disposal facilities. Other technical issues that required intensive evaluations included surface water hydrology, seismic investigation, field and numerical analysis of the unsaturated zone, including a water infiltration test. Source term verification became an issue because of one specific isotope that comprised more than 90% of the curies projected for disposal during the operational period. The use of trench liners and the proposed monitoring of the unsaturated zone were reviewed by a highly select panel of experts to provide guidance on the need for liners and to ensure that the monitoring system was capable of monitoring sufficient representative areas for radionuclides in the soil, soil gas, and soil moisture. Finally, concerns about the quality of the preoperational environmental monitoring program, including data, sample collection procedures, laboratory analysis, data review and interpretation and duration of monitoring caused a significant delay in completing the licensing review.

  5. [Factors associated with low levels of aerobic fitness among adolescents].

    Science.gov (United States)

    Gonçalves, Eliane Cristina de Andrade; Silva, Diego Augusto Santos

    2016-06-01

    To evaluate the prevalence of low aerobic fitness levels and to analyze the association with sociodemographic factors, lifestyle and excess body fatness among adolescents of southern Brazil. The study included 879 adolescents aged 14 to 19 years the city of São José/SC, Brazil. The aerobic fitness was assessed by Canadian modified test of aerobic fitness. Sociodemographic variables (skin color, age, sex, study turn, economic level), sexual maturation and lifestyle (eating habits, screen time, physical activity, consumption of alcohol and tobacco) were assessed by a self-administered questionnaire. Excess body fatness was evaluated by sum of skinfolds triceps and subscapular. We used logistic regression to estimate odds ratios and 95% confidence intervals. Prevalence of low aerobic fitness level was 87.5%. The girls who spent two hours or more in front screen, consumed less than one glass of milk by day, did not smoke and had an excess of body fatness had a higher chance of having lower levels of aerobic fitness. White boys with low physical activity had had a higher chance of having lower levels of aerobic fitness. Eight out of ten adolescents were with low fitness levels aerobic. Modifiable lifestyle factors were associated with low levels of aerobic fitness. Interventions that emphasize behavior change are needed. Copyright © 2015 Sociedade de Pediatria de São Paulo. Publicado por Elsevier Editora Ltda. All rights reserved.

  6. Mixed and Low-Level Treatment Facility Project

    Energy Technology Data Exchange (ETDEWEB)

    1992-04-01

    This appendix contains the mixed and low-level waste engineering design files (EDFS) documenting each low-level and mixed waste stream investigated during preengineering studies for Mixed and Low-Level Waste Treatment Facility Project. The EDFs provide background information on mixed and low-level waste generated at the Idaho National Engineering Laboratory. They identify, characterize, and provide treatment strategies for the waste streams. Mixed waste is waste containing both radioactive and hazardous components as defined by the Atomic Energy Act and the Resource Conservation and Recovery Act, respectively. Low-level waste is waste that contains radioactivity and is not classified as high-level waste, transuranic waste, spent nuclear fuel, or 11e(2) byproduct material as defined by DOE 5820.2A. Test specimens of fissionable material irradiated for research and development only, and not for the production of power or plutonium, may be classified as low-level waste, provided the concentration of transuranic is less than 100 nCi/g. This appendix is a tool that clarifies presentation format for the EDFS. The EDFs contain waste stream characterization data and potential treatment strategies that will facilitate system tradeoff studies and conceptual design development. A total of 43 mixed waste and 55 low-level waste EDFs are provided.

  7. Directions in low-level radioactive waste management: A brief history of commercial low-level radioactive waste disposal

    Energy Technology Data Exchange (ETDEWEB)

    1990-10-01

    This report presents a history of commercial low-level radioactive waste management in the United States, with emphasis on the history of six commercially operated low-level radioactive waste disposal facilities. The report includes a brief description of important steps that have been taken during the 1980s to ensure the safe disposal of low-level waste in the 1990s and beyond. These steps include the issuance of Title 10 Code of Federal Regulations Part 61, Licensing Requirements for the Land Disposal of Radioactive Waste, the Low-Level Radioactive Waste Policy Act of 1980, the Low-Level Radioactive Waste Policy Amendments Act of 1985, and steps taken by states and regional compacts to establish additional disposal sites. 42 refs., 13 figs., 1 tab.

  8. Wound healing stimulation in mice by low-level light

    Science.gov (United States)

    Demidova, Tatiana N.; Herman, Ira M.; Salomatina, Elena V.; Yaroslavsky, Anna N.; Hamblin, Michael R.

    2006-02-01

    It has been known for many years that low levels of laser or non-coherent light (LLLT) accelerate some phases of wound healing. LLLT can stimulate fibroblast and keratinocyte proliferation and migration. It is thought to work via light absorption by mitochondrial chromophores leading to an increase in ATP, reactive oxygen species and consequent gene transcription. However, despite many reports about the positive effects of LLLT on wound healing, its use remains controversial. Our laboratory has developed a model of a full thickness excisional wound in mice that allows quantitative and reproducible light dose healing response curves to be generated. We have found a biphasic dose response curve with a maximum positive effect at 2 J/cm2 of 635-nm light and successively lower beneficial effects from 3-25 J/cm2, the effect is diminished at doses below 2J/cm2 and gradually reaches control healing levels. At light doses above 25 J/cm2 healing is actually worse than controls. The two most effective wavelengths of light were found to be 635 and 820-nm. We found no difference between filtered 635+/-15-nm light from a lamp and 633-nm light from a HeNe laser. The strain and age of the mouse affected the magnitude of the effect. Light treated wounds start to contract after illumination while control wounds initially expand for the first 24 hours. Our hypothesis is that a single brief light exposure soon after wounding affects fibroblast cells in the margins of the wound. Cells may be induced to proliferate, migrate and assume a myofibroblast phenotype. Our future work will be focused on understanding the mechanisms underlying effects of light on wound healing processes.

  9. Low-level laser therapy and Calendula officinalis in repairing diabetic foot ulcers

    Directory of Open Access Journals (Sweden)

    Ana Flávia Machado de Carvalho

    Full Text Available Abstract OBJECTIVE To evaluate the effects of low-level laser therapy isolated and associated with Calendula officinalis oil in treating diabetic foot ulcers. METHOD An experimental, randomized, controlled, prospective, interventional clinical case study using a quantitative approach. The sample consisted of 32 diabetic patients of both genders. Participants were randomly divided into four groups. Doppler Ultrasound evaluation of the Ankle-Brachial Index, brief pain inventory and analog pain scale were performed at baseline and after 30 days. RESULTS Reduced pain was observed in the Low-level laser therapy and Low-level laser therapy associated with Essential Fatty Acids groups (p<0.01. Regarding the Ankle-Brachial Index and Doppler Ultrasound, all groups remained stable. By analyzing lesion area reduction, Low-level laser therapy associated with Essential fatty acids group showed a significance of p=0.0032, and the Low-level laser therapy group showed p=0.0428. CONCLUSION Low-level laser therapy, performed alone or associated with the Calendula officinalis oil was effective in relieving pain and accelerating the tissue repair process of diabetic foot.

  10. Performance assessment for the disposal of low-level waste in the 200 east area burial grounds

    Energy Technology Data Exchange (ETDEWEB)

    Wood, M.I., Westinghouse Hanford

    1996-08-15

    A performance assessment analysis was completed for the 200 East Area Low-Level Burial Grounds (LLBG) to satisfy compliance requirements in DOE Order 5820.2A. In the analysis, scenarios of radionuclide release from the 200 East Area Low-Level waste facility was evaluated. The analysis focused on two primary scenarios leading to exposure. The first was inadvertent intrusion. In this scenario, it was assumed that institutional control of the site and knowledge of the disposal facility has been lost. Waste is subsequently exhumed and dose from exposure is received. The second scenario was groundwater contamination.In this scenario, radionuclides are leached from the waste by infiltrating precipitation and transported through the soil column to the underlying unconfined aquifer. The contaminated water is pumped from a well 100 m downstream and consumed,causing dose. Estimates of potential contamination of the surrounding environment were developed and the associated doses to the maximum exposed individual were calculated. The doses were compared with performance objective dose limits, found primarily in the DOE order 5850.2A. In the 200 East Area LLBG,it was shown that projected doses are estimated to be well below the limits because of the combination of environmental, waste inventory, and disposal facility characteristics of the 200 East Area LLBG. Waste acceptance criteria were also derived to ensure that disposal of future waste inventories in the 200 East Area LLBG will not cause an unacceptable increase in estimated dose.

  11. Hanford low-level tank waste interim performance assessment

    Energy Technology Data Exchange (ETDEWEB)

    Mann, F.M.

    1996-09-16

    The Hanford Low-Level Tank Waste Interim Performance Assessment examines the long-term environmental and human health effects associated with the disposal of the low-level fraction of the Hanford single- and double-shell tank waste in the Hanford Site 200 East Area. This report was prepared as a good management practice to provide needed information about the relationship between the disposal system design and its performance as early as possible in the project cycle. The calculations in this performance assessment show that the disposal of the low-level fraction can meet environmental and health performance objectives.

  12. Hanford low-level tank waste interim performance assessment

    Energy Technology Data Exchange (ETDEWEB)

    Mann, F.M.

    1997-09-12

    The Hanford Low-Level Tank Waste Interim Performance Assessment examines the long-term environmental and human health effects associated with the disposal of the low-level fraction of the Hanford single and double-shell tank waste in the Hanford Site 200 East Area. This report was prepared as a good management practice to provide needed information about the relationship between the disposal system design and performance early in the disposal system project cycle. The calculations in this performance assessment show that the disposal of the low-level fraction can meet environmental and health performance objectives.

  13. Twelfth annual US DOE low-level waste management conference

    Energy Technology Data Exchange (ETDEWEB)

    1990-01-01

    The papers in this document comprise the proceedings of the Department of Energy's Twelfth Annual Low-Level Radioactive Waste Management Conference, which was held in Chicago, Illinois, on August 28 and 29, 1990. General subjects addressed during the conference included: mixed waste, low-level radioactive waste tracking and transportation, public involvement, performance assessment, waste stabilization, financial assurance, waste minimization, licensing and environmental documentation, below-regulatory-concern waste, low-level radioactive waste temporary storage, current challenges, and challenges beyond 1990.

  14. Development of a low-level radon reference chamber; Entwicklung einer Low-Level-Radon-Referenzkammer

    Energy Technology Data Exchange (ETDEWEB)

    Linzmaier, Diana

    2013-01-04

    The naturally occurring, radioactive noble gas radon-222 exists worldwide in different activity concentrations in the air. During the decay of radon-222, decay products are generated which are electrically charged and attach to aerosols in the air. Together with the aerosols, the radon is inhaled and exhaled by humans. While the radon is nearly completely exhaled, ca. 20 % of the inhaled aerosols remain in the lungs in one breath cycle. Due to ionizing radiation, in a chain of events, lung cancer might occur. Consequently, radon and its decay products are according to the current findings the second leading cause of lung cancer. At the workplace and in the home measurements of radon activity concentration are performed to determine the radiation exposition of humans. All measurement devices for the determination of radon activity concentration are calibrated above 1000 Bq/m{sup 3}, even though the mean value of the present investigation in Germany shows only 50 Bq/m{sup 3}. For the calibration of measurement devices in the range below 1000 Bq/m{sup 3} over a long time period, the generation of a stable reference atmosphere is presented in this work. Due to a long term calibration (t>5 days) of the measurement devices, smaller uncertainties result for the calibration factor. For the calibration procedure, a so-called low-level radon reference chamber was set up and started operation. The generation of a stable reference atmosphere is effected by means of emanation sources which consist of a radium-226 activity standard. On the basis of {gamma}-spectrometry, the effective emanation coefficient ofthe emanation sources is determined. The traceability of the activity concentration in the reference volume is realized via the activity ofthe radium-226, the emanation coefficient and the volume. With the emanation sources produced, stable reference atmospheres within the range of 150 Bq/m{sup 3} to 1900 Bq/m{sup 3} are achieved. For the realization, maintenance and

  15. Radioactive waste management complex low-level waste radiological composite analysis

    Energy Technology Data Exchange (ETDEWEB)

    McCarthy, J.M.; Becker, B.H.; Magnuson, S.O.; Keck, K.N.; Honeycutt, T.K.

    1998-05-01

    The composite analysis estimates the projected cumulative impacts to future members of the public from the disposal of low-level radioactive waste (LLW) at the Idaho National Engineering and Environmental Laboratory (INEEL) Radioactive Waste Management Complex (RWMC) and all other sources of radioactive contamination at the INEEL that could interact with the LLW disposal facility to affect the radiological dose. Based upon the composite analysis evaluation, waste buried in the Subsurface Disposal Area (SDA) at the RWMC is the only source at the INEEL that will significantly interact with the LLW facility. The source term used in the composite analysis consists of all historical SDA subsurface disposals of radionuclides as well as the authorized LLW subsurface disposal inventory and projected LLW subsurface disposal inventory. Exposure scenarios evaluated in the composite analysis include all the all-pathways and groundwater protection scenarios. The projected dose of 58 mrem/yr exceeds the composite analysis guidance dose constraint of 30 mrem/yr; therefore, an options analysis was conducted to determine the feasibility of reducing the projected annual dose. Three options for creating such a reduction were considered: (1) lowering infiltration of precipitation through the waste by providing a better cover, (2) maintaining control over the RWMC and portions of the INEEL indefinitely, and (3) extending the period of institutional control beyond the 100 years assumed in the composite analysis. Of the three options investigated, maintaining control over the RWMC and a small part of the present INEEL appears to be feasible and cost effective.

  16. Assessment of older driver performance under low level alcohol impairment.

    Science.gov (United States)

    2013-03-01

    This report summarizes the outcomes, to date, of the work undertaken to examine : the effects of low level alcohol impairment, especially for older drivers, based on : on-road driving studies. Some of the questions the project initially sought answer...

  17. Digital-to-analog converter operates from low level inputs

    Science.gov (United States)

    Winkelstein, R. A.

    1967-01-01

    Circuit controls a voltage controlled oscillator from computer output binary data representing a rate at which the oscillator is to change. It operates with low level output devices such as integrated circuit registers and devices with somewhat variable output levels.

  18. Steam reforming of low-level mixed waste. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-06-01

    ThermoChem has successfully designed, fabricated and operated a nominal 90 pound per hour Process Development Unit (PDU) on various low-level mixed waste surrogates. The design, construction, and testing of the PDU as well as performance and economic projections for a 300-lb/hr demonstration and commercial system are described. The overall system offers an environmentally safe, non-incinerating, cost-effective, and publicly acceptable method of processing LLMW. The steam-reforming technology was ranked the No. 1 non-incineration technology for destruction of hazardous organic wastes in a study commissioned by the Mixed Waste Focus Area and published in April 1997. The ThermoChem steam-reforming system has been developed over the last 13 years culminating in this successful test campaign on LLMW surrogates. Six surrogates were successfully tested including a 750-hour test on material simulating a PCB- and Uranium-contaminated solid waste found at the Portsmouth Gaseous Diffusion Plant. The test results indicated essentially total (> 99.9999%) destruction of RCRA and TSCA hazardous halogenated organics, significant levels of volume reduction (> 400 to 1), and retention of radionuclides in the volume-reduced solids. Economic evaluations have shown the steam-reforming system to be very cost competitive with more conventional and other emerging technologies.

  19. Mixed low-level waste minimization at Los Alamos

    Energy Technology Data Exchange (ETDEWEB)

    Starke, T.P.

    1998-12-01

    During the first six months of University of California 98 Fiscal Year (July--December) Los Alamos National Laboratory has achieved a 57% reduction in mixed low-level waste generation. This has been accomplished through a systems approach that identified and minimized the largest MLLW streams. These included surface-contaminated lead, lead-lined gloveboxes, printed circuit boards, and activated fluorescent lamps. Specific waste minimization projects have been initiated to address these streams. In addition, several chemical processing equipment upgrades are being implemented. Use of contaminated lead is planned for several high energy proton beam stop applications and stainless steel encapsulated lead is being evaluated for other radiological control area applications. INEEL is assisting Los Alamos with a complete systems analysis of analytical chemistry derived mixed wastes at the CMR building and with a minimum life-cycle cost standard glovebox design. Funding for waste minimization upgrades has come from several sources: generator programs, waste management, the generator set-aside program, and Defense Programs funding to INEEL.

  20. Effect of interstitial low level laser therapy on tibial defect

    Science.gov (United States)

    Lee, Sangyeob; Ha, Myungjin; Hwang, Donghyun; Yu, Sungkon; Jang, Seulki; Park, Jihoon; Radfar, Edalat; Kim, Hansung; Jung, Byungjo

    2016-03-01

    Tibial defect is very common musculoskeletal disorder which makes patient painful and uncomfortable. Many studies about bone regeneration tried to figure out fast bone healing on early phase. It is already known that low level laser therapy (LLLT) is very convenient and good for beginning of bone disorder. However, light scattering and absorption obstruct musculoskeletal therapy which need optimal photon energy delivery. This study has used an interstitial laser probe (ILP) to overcome the limitations of light penetration depth and scattering. Animals (mouse, C57BL/6) were divided into three groups: laser treated test group 1 (660 nm; power 10 mW; total energy 5 J) and test group 2 (660 nm; power 20 mW; total energy 10 J); and untreated control group. All animals were taken surgical operation to make tibial defect on right crest of tibia. The test groups were treated every 48 hours with ILP. Bone volume and X-ray attenuation coefficient were measured on 0, 14th and 28th day with u-CT after treatment and were used to evaluate effect of LLLT. Results show that bone volume of test groups has been improved more than control group. X-ray attenuation coefficients of each groups have slightly different. The results suggest that LLLT combined with ILP may affect on early phase of bone regeneration and may be used in various musculoskeletal disease in deep tissue layer.

  1. Support of low-level instrument background for HPGe detectors

    Energy Technology Data Exchange (ETDEWEB)

    Sokolov, A. D. [Baltic Scientific Instruments, Riga, LV-1005 (Latvia); Starostin, A. S. [Inst. of Theoretical and Experimental Physics, Moscow, 117218 (Russian Federation); Kuzmenko, V. I.; Rozite, A. R. [Baltic Scientific Instruments, Riga, LV-1005 (Latvia)

    2011-07-01

    The development results for the cryostats with the low-level of instrument background supported by special design, the reduction of mass of the materials surrounding detector and application of the materials with very low content of radiation impurities are presented. The development results for HPGe detector with ultra low-level of instrument background for gamma spectrometer under the GEMMA project for investigation of the neutrino magnetic moment are presented. (authors)

  2. Preliminary Safety Design Report for Remote Handled Low-Level Waste Disposal Facility

    Energy Technology Data Exchange (ETDEWEB)

    Timothy Solack; Carol Mason

    2012-03-01

    A new onsite, remote-handled low-level waste disposal facility has been identified as the highest ranked alternative for providing continued, uninterrupted remote-handled low-level waste disposal for remote-handled low-level waste from the Idaho National Laboratory and for nuclear fuel processing activities at the Naval Reactors Facility. Historically, this type of waste has been disposed of at the Radioactive Waste Management Complex. Disposal of remote-handled low-level waste in concrete disposal vaults at the Radioactive Waste Management Complex will continue until the facility is full or until it must be closed in preparation for final remediation of the Subsurface Disposal Area (approximately at the end of Fiscal Year 2017). This preliminary safety design report supports the design of a proposed onsite remote-handled low-level waste disposal facility by providing an initial nuclear facility hazard categorization, by discussing site characteristics that impact accident analysis, by providing the facility and process information necessary to support the hazard analysis, by identifying and evaluating potential hazards for processes associated with onsite handling and disposal of remote-handled low-level waste, and by discussing the need for safety features that will become part of the facility design.

  3. Remote-Handled Low-Level Waste Disposal Project Alternatives Analysis

    Energy Technology Data Exchange (ETDEWEB)

    David Duncan

    2011-04-01

    This report identifies, evaluates, and compares alternatives for meeting the U.S. Department of Energy’s mission need for management of remote-handled low-level waste generated by the Idaho National Laboratory and its tenants. Each alternative identified in the Mission Need Statement for the Remote-Handled Low-Level Waste Treatment Project is described and evaluated for capability to fulfill the mission need. Alternatives that could meet the mission need are further evaluated and compared using criteria of cost, risk, complexity, stakeholder values, and regulatory compliance. The alternative for disposal of remote-handled low-level waste that has the highest confidence of meeting the mission need and represents best value to the government is to build a new disposal facility at the Idaho National Laboratory Site.

  4. Remote-Handled Low-Level Waste Disposal Project Alternatives Analysis

    Energy Technology Data Exchange (ETDEWEB)

    David Duncan

    2011-03-01

    This report identifies, evaluates, and compares alternatives for meeting the U.S. Department of Energy’s mission need for management of remote-handled low-level waste generated by the Idaho National Laboratory and its tenants. Each alternative identified in the Mission Need Statement for the Remote-Handled Low-Level Waste Treatment Project is described and evaluated for capability to fulfill the mission need. Alternatives that could meet the mission need are further evaluated and compared using criteria of cost, risk, complexity, stakeholder values, and regulatory compliance. The alternative for disposal of remote-handled low-level waste that has the highest confidence of meeting the mission need and represents best value to the government is to build a new disposal facility at the Idaho National Laboratory Site.

  5. E AREA LOW LEVEL WASTE FACILITY DOE 435.1 PERFORMANCE ASSESSMENT

    Energy Technology Data Exchange (ETDEWEB)

    Wilhite, E

    2008-03-31

    , situated immediately north of the Mixed Waste Management Facility. The E-Area Low-Level Waste Facility is comprised of 200 acres for waste disposal and a surrounding buffer zone that extends out to the 100-m point of compliance. Disposal units within the footprint of the low-level waste facilities include the Slit Trenches, Engineered Trenches, Component-in-Grout Trenches, the Low-Activity Waste Vault, the Intermediate-Level Vault, and the Naval Reactor Component Disposal Area. Radiological waste disposal operations at the E-Area Low-Level Waste Facility began in 1994. E-Area Low-Level Waste Facility closure will be conducted in three phases: operational closure, interim closure, and final closure. Operational closure will be conducted during the 25-year operation period (30-year period for Slit and Engineered Trenches) as disposal units are filled; interim closure measures will be taken for some units. Interim closure will take place following the end of operations and will consist of an area-wide runoff cover along with additional grading over the trench units. Final closure of all disposal units in the E-Area Low-Level Waste Facility will take place at the end of the 100-year institutional control period and will consist of the installation of an integrated closure system designed to minimize moisture contact with the waste and to serve as a deterrent to intruders. Radiological dose to human receptors is analyzed in this PA in the all-pathways analysis, the inadvertent intruder analysis and the air pathway analysis, and the results are compared to the relevant performance measures. For the all-pathways analysis, the performance measure of relevance is a 25-mrem/yr EDE to representative members of the public, excluding dose from radon and its progeny in air. For the inadvertent intruder, the applicable performance measures are 100-mrem/yr EDE and 500 mrem/yr EDE for chronic and exposure scenarios, respectively. The relevant performance measure for the air pathway is 10

  6. In vitro transdentinal effect of low-level laser therapy

    Science.gov (United States)

    Oliveira, C. F.; Basso, F. G.; dos Reis, R. I.; Parreiras-e-Silva, L. T.; Lins, E. C.; Kurachi, C.; Hebling, J.; Bagnato, V. S.; de Souza Costa, C. A.

    2013-05-01

    Low-level laser therapy (LLLT) has been used for the treatment of dentinal hypersensitivity. However, the specific LLL dose and the response mechanisms of these cells to transdentinal irradiation have not yet been demonstrated. Therefore, this study evaluated the transdentinal effects of different LLL doses on stressed odontoblast-like pulp cells MDPC-23 seeded onto the pulpal side of dentin discs obtained from human third molars. The discs were placed in devices simulating in vitro pulp chambers and the whole set was placed in 24-well plates containing plain culture medium (DMEM). After 24 h incubation, the culture medium was replaced by fresh DMEM supplemented with either 5% (simulating a nutritional stress condition) or 10% fetal bovine serum (FBS). The cells were irradiated with doses of 15 and 25 J cm-2 every 24 h, totaling three applications over three consecutive days. The cells in the control groups were removed from the incubator for the same times as used in their respective experimental groups for irradiation, though without activating the laser source (sham irradiation). After 72 h of the last active or sham irradiation, the cells were evaluated with respect to succinic dehydrogenase (SDH) enzyme production (MTT assay), total protein (TP) expression, alkaline phosphatase (ALP) synthesis, reverse transcriptase polymerase chain reaction (RT-PCR) for collagen type 1 (Col-I) and ALP, and morphology (SEM). For both tests, significantly higher values were obtained for the 25 J cm-2 dose. Regarding SDH production, supplementation of the culture medium with 5% FBS provided better results. For TP and ALP expression, the 25 J cm-2 presented higher values, especially for the 5% FBS concentration (Mann-Whitney p < 0.05). Under the tested conditions, near infrared laser irradiation at 25 J cm-2 caused transdentinal biostimulation of odontoblast-like MDPC-23 cells.

  7. Evaluation of urinary biomarkers of exposure to benzene: correlation with blood benzene and influence of confounding factors.

    NARCIS (Netherlands)

    Hoet, P.; Smedt, E. De; Ferrari, M.; Imbriani, M.; Maestri, L.; Negri, S.; Wilde, P.C.M. de; Lison, D.; Haufroid, V.

    2009-01-01

    PURPOSE: trans,trans-Muconic acid (t,t-MA) is generally considered as a useful biomarker of exposure to benzene. However, because of its lack of specificity, concerns about its value at low level of exposure have recently been raised. The aim of this study was (a) to compare t,t-MA,

  8. Low-level lasers alter mRNA levels from traditional reference genes used in breast cancer cells

    Science.gov (United States)

    Teixeira, A. F.; Canuto, K. S.; Rodrigues, J. A.; Fonseca, A. S.; Mencalha, A. L.

    2017-07-01

    Cancer is among the leading causes of mortality worldwide, increasing the importance of treatment development. Low-level lasers are used in several diseases, but some concerns remains on cancers. Reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) is a technique used to understand cellular behavior through quantification of mRNA levels. Output data from target genes are commonly relative to a reference that cannot vary according to treatment. This study evaluated reference genes levels from MDA-MB-231 cells exposed to red or infrared lasers at different fluences. Cultures were exposed to red and infrared lasers, incubated (4 h, 37 °C), total RNA was extracted and cDNA synthesis was performed to evaluate mRNA levels from ACTB, GUSB and TRFC genes by RT-qPCR. Specific amplification was verified by melting curves and agarose gel electrophoresis. RefFinder enabled data analysis by geNorm, NormFinder and BestKeeper. Specific amplifications were obtained and, although mRNA levels from ACTB, GUSB or TRFC genes presented no significant variation through traditional statistical analysis, Excel-based tools revealed that the use of these reference genes are dependent of laser characteristics. Our data showed that exposure to low-level red and infrared lasers at different fluences alter the mRNA levels from ACTB, GUSB and TRFC in MDA-MB-231 cells.

  9. Health effects of low-level radiation in shipyard workers. Final report: [Draft

    Energy Technology Data Exchange (ETDEWEB)

    Matanoski, G.M.

    1991-06-01

    The Nuclear Shipyard Workers Study (NSWS) was designed to determine whether there is an excess risk of leukemia or other cancers associated with exposure to low levels of gamma radiation. The study compares the mortality experience of shipyard workers who qualified to work in radiation areas to the mortality of similar workers who hold the same types of jobs but who are not authorized to work in radiation areas. The population consists of workers from six government and two private shipyards.

  10. Low-level radioactive waste regulation: Science, politics and fear

    Energy Technology Data Exchange (ETDEWEB)

    Burns, M.E. (ed.)

    1988-01-01

    An inevitable consequence of the use of radioactive materials is the generation of radioactive wastes and the public policy debate over how they will be managed. In 1980, Congress shifted responsibility for the disposal of low-level radioactive wastes from the federal government to the states. This act represented a sharp departure from more than 30 years of virtually absolute federal control over radioactive materials. Though this plan had the enthusiastic support of the states in 1980, it now appears to have been at best a chimera. Radioactive waste management has become an increasingly complicated and controversial issue for society in recent years. This book discusses only low-level wastes, however, because Congress decided for political reasons to treat them differently than high-level wastes. The book is based in part on three symposia sponsored by the division of Chemistry and the Law of the American Chemical Society. Each chapter is derived in full or in part from presentations made at these meetings, and includes: (1) Low-level radioactive wastes in the nuclear power industry; (2) Low-level radiation cancer risk assessment and government regulation to protect public health; and (3) Low-level radioactive waste: can new disposal sites be found.

  11. The Dose That Works: Low Level Laser Treatment of Tendinopathy

    Science.gov (United States)

    Tumilty, Steve; Munn, Joanne; McDonough, Suzanne; Hurley, Deirdre A.; Basford, Jeffrey R.; David Baxter, G.

    2010-05-01

    Background: Low Level Laser Therapy (LLLT) is used in the treatment of tendon injuries. However, the clinical effectiveness of this modality remains controversial with limited agreement on the most efficacious dosage and parameter choices. Purpose: To assess the clinical effectiveness of LLLT in the treatment of tendinopathy and the validity of current dosage recommendations for treatment. Method: Medical databases were searched from inception to 1st August 2008. Controlled clinical trials evaluating LLLT as a primary intervention for any tendinopathy were included in the review. Methodological quality was classified using the PEDro scale. Appropriateness of treatment parameters were assessed using established guidelines. Results: Twenty five trials met the inclusion criteria. There was conflicting findings from multiple trials: 12 showed positive effects and 13 were inconclusive or showed no effect. Dosages used in the 12 positive studies support the existence of an effective dosage window that closely resembled current guidelines. Where pooling of data was possible, LLLT showed a positive effect size; in high quality studies of lateral epicondylitis, participants' grip strength was 9.59 Kg higher than the control group; for participants with Achilles tendinopathy, the effect was 13.6 mm less pain on a 100 mm visual analogue scale. Conclusion: This study found conflicting evidence as to the effectiveness of LLLT in the treatment of tendinopathy. However, an effective dosage window emerged showing benefit in the treatment of tendinopathy. Strong evidence exists from the 12 positive studies that positive outcomes are associated with the use of current dosage recommendations for the treatment of tendinopathy.

  12. The effect of low level laser on anaplastic thyroid cancer

    Science.gov (United States)

    Rhee, Yun-Hee; Moon, Jeon-Hwan; Ahn, Jin-Chul; Chung, Phil-Sang

    2015-02-01

    Low-level laser therapy (LLLT) is a non-thermal phototherapy used in several medical applications, including wound healing, reduction of pain and amelioration of oral mucositis. Nevertheless, the effects of LLLT upon cancer or dysplastic cells have been so far poorly studied. Here we report that the effects of laser irradiation on anaplastic thyroid cancer cells leads to hyperplasia. 650nm of laser diode was performed with a different time interval (0, 15, 30, 60J/cm2 , 25mW) on anaplastic thyroid cancer cell line FRO in vivo. FRO was orthotopically injected into the thyroid gland of nude mice and the irradiation was performed with the same method described previously. After irradiation, the xenograft evaluation was followed for one month. The thyroid tissues from sacrificed mice were undergone to H&E staining and immunohistochemical staining with HIF-1α, Akt, TGF-β1. We found the aggressive proliferation of FRO on thyroid gland with dose dependent. In case of 60 J/ cm2 of energy density, the necrotic bodies were found in a center of the thyroid. The phosphorylation of HIF-1α and Akt was detected in the thyroid gland, which explained the survival signaling of anaplastic cancer cell was turned on the thyroid gland. Furthermore, TGF-β1 expression was decreased after irradiation. In this study, we demonstrated that insufficient energy density irradiation occurred the decreasing of TGF-β1 which corresponding to the phosphorylation of Akt/ HIF-1α. This aggressive proliferation resulted to the hypoxic condition of tissue for angiogenesis. We suggest that LLLT may influence to cancer aggressiveness associated with a decrease in TGF-β1 and increase in Akt/HIF-1α.

  13. Microbial degradation of low-level radioactive waste. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, R.D.; Hamilton, M.A.; Veeh, R.H.; McConnell, J.W. Jr

    1996-06-01

    The Nuclear Regulatory Commission stipulates in 10 CFR 61 that disposed low-level radioactive waste (LLW) be stabilized. To provide guidance to disposal vendors and nuclear station waste generators for implementing those requirements, the NRC developed the Technical Position on Waste Form, Revision 1. That document details a specified set of recommended testing procedures and criteria, including several tests for determining the biodegradation properties of waste forms. Information has been presented by a number of researchers, which indicated that those tests may be inappropriate for examining microbial degradation of cement-solidified LLW. Cement has been widely used to solidify LLW; however, the resulting waste forms are sometimes susceptible to failure due to the actions of waste constituents, stress, and environment. The purpose of this research program was to develop modified microbial degradation test procedures that would be more appropriate than the existing procedures for evaluation of the effects of microbiologically influenced chemical attack on cement-solidified LLW. The procedures that have been developed in this work are presented and discussed. Groups of microorganisms indigenous to LLW disposal sites were employed that can metabolically convert organic and inorganic substrates into organic and mineral acids. Such acids aggressively react with cement and can ultimately lead to structural failure. Results on the application of mechanisms inherent in microbially influenced degradation of cement-based material are the focus of this final report. Data-validated evidence of the potential for microbially influenced deterioration of cement-solidified LLW and subsequent release of radionuclides developed during this study are presented.

  14. Low level laser therapy in oral mucositis: a pilot study.

    Science.gov (United States)

    Cauwels, R G E C; Martens, L C

    2011-04-01

    The goal of this pilot study was to investigate the capacity of pain relief and wound healing of low level laser therapy (LLLT) in chemotherapy-induced oral mucositis (OM) in a paediatric oncology population group. 16 children (mean age 9.4 years) from the Gent University Hospital - Department Paediatric Oncology/haematology, suffering from chemotherapy-induced OM were selected. During clinical investigations, the OM grade was assessed using the WHO classification. All children were treated using a GaAlAs diode laser with 830 nm wavelength and a potency of 150 mW. The energy released was adapted according to the severity of the OM lesions. The same protocol was repeated every 48 hrs until healing of each lesion occurred. Subjective pain was monitored before and immediately after treatment by an appropriate pain scale and functional impairment was recorded. At each visit, related blood cell counts were recorded. After 12 mths, records were evaluated and information about treatment sequence, treatment sessions and frequencies related to the pain sensation and comfort were registered. Immediately after beaming the OM, pain relief was noticed. Depending on the severity of OM, on average, 2.5 treatments per lesion in a period of 1 week were sufficient to heal a mucositis lesion. LLLT, one of the most recent and promising treatment therapies, has been shown to reduce the severity and duration of mucositis and to relieve pain significantly. In the present study similar effects were obtained with the GaAlAs 830nm diode laser. It became clear that using the latter diode device, new guidelines could be developed as a function of the WHO-OM grades i.e. the lower the grade, the less energy needed. Immediate pain relief and improved wound healing resolved functional impairment that was obtained in all cases.

  15. Low Level Laser Therapy: A Panacea for oral maladies.

    Science.gov (United States)

    Kathuria, Vartika; Dhillon, Jatinder Kaur; Kalra, Gauri

    2015-10-02

    To review the applications of low level laser therapy on various soft and hard oral tissues. A variety of therapeutic effects of Low Level Laser Therapy have been reported on a broad range of disorders. It has been found amenably practical in dental applications including soft as well as hard tissues of the oral cavity. LLLT has been found to be efficient in acceleration of wound healing, enhanced remodelling and bone repair, regeneration of neural cells following injury, pain attenuation, endorphin release stimulation and modulation of immune system. The aforementioned biological processes induced by Low level lasers have been effectively applied in treating various pathological conditions in the oral cavity. With is article, we attempt to review the possible application of Low Laser Therapy in the field of dentistry.

  16. Perspectives of decision-making and estimation of risk in populations exposed to low levels of ionizing radiations

    Energy Technology Data Exchange (ETDEWEB)

    Fabrikant, J.I.

    1979-01-01

    The setting of any permissible radiation level or guide remains essentially an arbitrary procedure. Based on the radiation risk estimates derived, any lack of precision does not minimize either the need for setting public health policies nor the conclusion that such risks are extremely small when compared with those avialable of alternative options, and those normally accepted by society as the hazards of everyday life. When compared with the benefits that society has established as goals derived from the necessary activities of medical care and energy production, it is apparent that society must establish appropriate standards and seek appropriate controlling procedures which continue to assure that its needs are being met with the lowest possible risks. This implies continuing decision-making processes in which risk-benefit and cost-effectiveness assessments must be taken into account. Much of the practical information necessary for determination of radiation protection standards for public health policy is still lacking. It is now assumed that any exposure to radiaion at low levels of dose carries some risk of deleterious effects. However, how low this level may be, or the probability, or magnitude of the risk, still are not known. Radiation and the public health becomes a societal and political problem and not solely a scientific one. Our best scientific knowledge and our best scientific advice are essential for the protection of the public health, for the effective application of new technologies in medicine, and for guidance in the production of energy in industry. Unless man wishes to dispense with those activities which inevitably involve exposure to low levels of ionizing radiations, he must recognize that some degree of risk, however small, exists. In the evaluation of such risks from radiation, it is necessary to limit the radiation exposure to a level at which the risk is acceptable both to the individual and to society.

  17. GRABGAM Analysis of Ultra-Low-Level HPGe Gamma Spectra

    Energy Technology Data Exchange (ETDEWEB)

    Winn, W.G.

    1999-07-28

    The GRABGAM code has been used successfully for ultra-low level HPGe gamma spectrometry analysis since its development in 1985 at Savannah River Technology Center (SRTC). Although numerous gamma analysis codes existed at that time, reviews of institutional and commercial codes indicated that none addressed all features that were desired by SRTC. Furthermore, it was recognized that development of an in-house code would better facilitate future evolution of the code to address SRTC needs based on experience with low-level spectra. GRABGAM derives its name from Gamma Ray Analysis BASIC Generated At MCA/PC.

  18. Modeling and low-level waste management: an interagency workshop

    Energy Technology Data Exchange (ETDEWEB)

    Little, C.A.; Stratton, L.E. (comps.)

    1980-01-01

    The interagency workshop on Modeling and Low-Level Waste Management was held on December 1-4, 1980 in Denver, Colorado. Twenty papers were presented at this meeting which consisted of three sessions. First, each agency presented its point of view concerning modeling and the need for models in low-level radioactive waste applications. Second, a larger group of more technical papers was presented by persons actively involved in model development or applications. Last of all, four workshops were held to attempt to reach a consensus among participants regarding numerous waste modeling topics. Abstracts are provided for the papers presented at this workshop.

  19. Transportation and disposal configuration for DOE-managed low-level and mixed low-level waste

    Energy Technology Data Exchange (ETDEWEB)

    Johnsen, T.

    1993-06-01

    This report briefly examines the current U.S. Department of Energy complex-wide configuration for transportation and disposal of low-level and mixed low-level waste, and also retraces the historical sequence of events and rationale that has guided its development. The study determined that Nevada Test Site and the Hanford Site are the only two sites that currently provide substantial disposal services for offsite low-level waste generators. It was also determined that mixed low-level waste shipments are infrequent and are generally limited to shipments to offsite commercial treatment facilities or other Department of Energy sites for storage. The current alignment of generator to disposal site for low-level waste shipments is generally consistent with the programmatic mission of the generator; that is, defense-generated waste is shipped to the Nevada Test Site and research-generated waste is transported to the Hanford Site. The historical development of the current configuration was resurrected by retrieving Department of Energy documentation and interviewing both current and former department and contractor personnel. According to several accounts, the basic framework of the system was developed during the late 1970s, and was reportedly based on the ability of the disposal site to manage a given waste form. Documented evidence to support this reasoning, however, could not be uncovered.

  20. Relevance of biotic pathways to the long-term regulation of nuclear-waste disposal. Topical report on reference western arid low-level sites

    Energy Technology Data Exchange (ETDEWEB)

    McKenzie, D.H.; Cadwell, L.L.; Eberhardt, L.E.; Kennedy, W.E. Jr.; Peloquin, R.A.; Simmons, M.A.

    1982-10-01

    The purpose of the work reported here was to develop an order of magnitude estimate for the potential dose to man resulting from biotic transport mechanisms at a reference western arid low-level waste site. A description of the reference site is presented that includes the waste inventories, site characteristics and biological communities. Parameter values for biotic transport processes are based on data reported in current literature. Transport and exposure scenarios are developed for assessing biotic transport during 100 years following site closure. Calculations of radionuclide decay and waste container decomposition are made to estimate the quantities available for biotic transport. Dose to a man occupying the reference site following the 100 years of biotic transport are calculated. These dose estimates are compared to dose estimates for the intruder-agricultural scenario reported in the DEIS for 10 CFR 61 (NRC). Dose to man estimates as a result of biotic transport are estimated to be of the same order of magnitude as the dose resulting from the more commonly evaluated human intrusion scenario. The reported lack of potential importance of biotic transport at low-level waste sites in earlier assessment studies is not confirmed by the findings presented in this report. These results indicate that biotic transport has the potential to influence low-level waste site performance. Through biotic transport, radionuclides may be moved to locations where they can enter exposure pathways to man.

  1. The effects of discrepant events on the low-level paradigms of high school physics students

    Science.gov (United States)

    Weiner, Jerome I.

    1999-10-01

    Constructivist learning theory indicates that high school physics students do not enter their physics classrooms empty-headed. Students come with preconceptions that they constructed over time, which are based on their observations of the environment. One function of physics teachers is to facilitate students in altering their preconceptions if they are not in agreement with the currently accepted scientific view. Kuhn described a paradigm shift as a process that scientists undergo when they discard a currently accepted paradigm in favor of a more complete paradigm, because of the new paradigm's greater explanatory power. Physics students may undergo low level paradigm shifts when constructing, or reconstructing, their low level paradigms as they observe small parts of their world. This research was a multiple case study based on eight discrepant event exercises. Twenty-two self selected, untutored first year high school physics students individually performed these exercises. The students' written documents, student interviews, and the researcher's field notes were triangulated to describe the process that emerged as the students described their low level paradigms before and after performing the discrepant events exercises. The following research questions were addressed. Do students employ similar low level paradigms to explain the same physical phenomenon? Do the discrepant events observed by the students have a consequential effect upon their current low level paradigms? Are there specific discrepant events that affect students' low level paradigms to a greater degree compared to other discrepant events that are grounded in the same physical phenomenon? Do students apply scientific terminology, within its proper context, after their exposure to a discrepant event, compared to their utilization of scientific terminology prior to their exposure to the discrepant event? Can the students' low level paradigms be generalized to situations that are beyond the scope

  2. Low-Level Waste Disposal Alternatives Analysis Report

    Energy Technology Data Exchange (ETDEWEB)

    Timothy Carlson; Kay Adler-Flitton; Roy Grant; Joan Connolly; Peggy Hinman; Charles Marcinkiewicz

    2006-09-01

    This report identifies and compares on-site and off-site disposal options for the disposal of contract-handled and remote-handled low-level waste generated by the Idaho National Laboratory and its tenants. Potential disposal options are screened for viability by waste type resulting in a short list of options for further consideration. The most crediable option are selected after systematic consideration of cost, schedule constraints, and risk. In order to holistically address the approach for low-level waste disposal, options are compiled into comprehensive disposal schemes, that is, alternative scenarios. Each alternative scenario addresses the disposal path for all low-level waste types over the period of interest. The alternative scenarios are compared and ranked using cost, risk and complexity to arrive at the recommended approach. Schedule alignment with disposal needs is addressed to ensure that all waste types are managed appropriately. The recommended alternative scenario for the disposal of low-level waste based on this analysis is to build a disposal facility at the Idaho National Laboratory Site.

  3. Low-Level Violence: A Neglected Aspect of School Culture.

    Science.gov (United States)

    Dupper, David R.; Meyer-Adams, Nancy

    2002-01-01

    Examines the extent of low-level violence in public schools and its impact on school performance, asserting that the way to reduce such violence is to create a more positive school culture and climate. Guidelines for preventing or minimizing such violence at school are presented. (SM)

  4. Low level of Hepatitis B knowledge and awareness among pregnant ...

    African Journals Online (AJOL)

    Low level of Hepatitis B knowledge and awareness among pregnant women in the Kintampo North ... Journal Home > Vol 50, No 3 (2016) > ... The PDF file you selected should load here if your Web browser has a PDF reader plug-in installed ...

  5. A Climatology of Nocturnal Low-Level Jets at Cabauw

    NARCIS (Netherlands)

    Baas, P.; Bosveld, F.C.; Baltink, H.K.; Holtslag, A.A.M.

    2009-01-01

    A climatology of nocturnal low-level jets (LLJs) is presented for the topographically flat measurement site at Cabauw, the Netherlands. LLJ characteristics are derived from a 7-yr half-hourly database of wind speed profiles, obtained from the 200-m mast and a wind profiler. Many LLJs at Cabauw

  6. Low-level waste vitrification contact maintenance viability study

    Energy Technology Data Exchange (ETDEWEB)

    Leach, C.E., Westinghouse Hanford

    1996-07-12

    This study investigates the economic viability of contact maintenance in the Low-Level Waste Vitrification Facility, which is part of the Hanford Site Tank Waste Remediation System. This document was prepared by Flour Daniel, Inc., and transmitted to Westinghouse Hanford Company in September 1995.

  7. On Low-level Cognitive Components of Speech

    DEFF Research Database (Denmark)

    Feng, Ling; Hansen, Lars Kai

    2006-01-01

    In this paper we analyze speech for low-level cognitive features using linear component analysis. We demonstrate generalizable component ‘fingerprints’ stemming from both phonemes and speakers. Phonemes are fingerprints found at the basic analysis window time scale (20 msec), while speaker...

  8. On Low-level Cognitive Components of Speech

    DEFF Research Database (Denmark)

    Feng, Ling; Hansen, Lars Kai

    2005-01-01

    In this paper we analyze speech for low-level cognitive features using linear component analysis. We demonstrate generalizable component 'fingerprints' stemming from both phonemes and speaker. Phonemes are fingerprints found at the basic analysis window time scale (20 msec), while speaker...

  9. Low level cloud motion vectors from Kalpana-1 visible images

    Indian Academy of Sciences (India)

    The VIS channel provides better detection of low level clouds, which remain obscure in thermal IR images due to poor thermal contrast. The tracers are taken to be 15 × 15 pixel templates and hence each wind corresponds to about 120km × 120km at sub-satellite point. Multiplet based wind retrieval technique is followed for ...

  10. Reporting Low-level Analytical Data | Horwitz | South African Journal ...

    African Journals Online (AJOL)

    ... definitions and parameters for the concept, including its uncertainty. This proposal is intended to help to standardize the method of reporting low-level analytical data, not to legitimize the data or any conclusions or actions resulting from their use or interpretation. South African Journal of Chemistry Vol.53(3) 2000: 206-212 ...

  11. Developing and evaluating distributions for probabilistic human exposure assessments

    Energy Technology Data Exchange (ETDEWEB)

    Maddalena, Randy L.; McKone, Thomas E.

    2002-08-01

    This report describes research carried out at the Lawrence Berkeley National Laboratory (LBNL) to assist the U. S. Environmental Protection Agency (EPA) in developing a consistent yet flexible approach for evaluating the inputs to probabilistic risk assessments. The U.S. EPA Office of Emergency and Remedial Response (OERR) recently released Volume 3 Part A of Risk Assessment Guidance for Superfund (RAGS), as an update to the existing two-volume set of RAGS. The update provides policy and technical guidance on performing probabilistic risk assessment (PRA). Consequently, EPA risk managers and decision-makers need to review and evaluate the adequacy of PRAs for supporting regulatory decisions. A critical part of evaluating a PRA is the problem of evaluating or judging the adequacy of input distributions PRA. Although the overarching theme of this report is the need to improve the ease and consistency of the regulatory review process, the specific objectives are presented in two parts. The objective of Part 1 is to develop a consistent yet flexible process for evaluating distributions in a PRA by identifying the critical attributes of an exposure factor distribution and discussing how these attributes relate to the task-specific adequacy of the input. This objective is carried out with emphasis on the perspective of a risk manager or decision-maker. The proposed evaluation procedure provides consistency to the review process without a loss of flexibility. As a result, the approach described in Part 1 provides an opportunity to apply a single review framework for all EPA regions and yet provide the regional risk manager with the flexibility to deal with site- and case-specific issues in the PRA process. However, as the number of inputs to a PRA increases, so does the complexity of the process for calculating, communicating and managing risk. As a result, there is increasing effort required of both the risk professionals performing the analysis and the risk manager

  12. Effect of photon energy in collagen generation by interstitial low level laser stimulation

    Science.gov (United States)

    Jun, Eunkwon; Ha, Myungjin; Lee, Sangyeob; Radfar, Edalat; Park, Jihoon; Jung, Byungjo

    2015-03-01

    Although the mechanism of low level laser therapy (LLLT) is unclear, many studies demonstrated the positive clinical performance of LLLT for skin rejuvenation. An increase in dermal collagen plays an important role in skin rejuvenation and wound healing. This study aimed to investigate collagen generation after interstitial low level laser stimulation (ILLS). Rabbits were divided into two groups: surfacing irradiation and minimally invasive irradiation. 660nm diode laser of 20mW with 10J, 13J and 15J was applied to the backside of rabbits. Collagen formation was evaluated with ultrasound skin scanner every 12 hours. Results shows that ILLS groups have denser collagen density than surfacing groups.

  13. Low-level blast raises intracranial pressure and impairs cognitive function in rats: prophylaxis with processed cereal feed.

    Science.gov (United States)

    Säljö, Annette; Bolouri, Hayde; Mayorga, Maria; Svensson, Berndt; Hamberger, Anders

    2010-02-01

    There is increasing evidence that even low levels of blast cause brain injury, but little is known about their thresholds and mechanisms. Exposure of rats to 10-60 kPa blasts elevate intracranial pressure (ICP) in a dose-dependent manner and impair cognitive function. We have evaluated a prophylactic measure against these brain injuries in a rat animal model, consisting of feeding them processed cereal. This type of feed is known to ameliorate disturbances in secretion of body fluids and to have anti-inflammatory effects. In humans, intake of processed cereals is effective against intestinal diarrhea and also reduces the symptoms of Ménière's disease. Rats were given either standard laboratory feed or processed cereal feed for 2 weeks before exposure to blast in a shock tube. The ICP was monitored at different time points up to 1 week after exposure to a 60-kPa blast, and for up to 24 h after exposure to a 30-kPa blast. Maximal ICP elevation was reached at 10 h in both groups. In the group of rats on standard feed exposed to 60 kPa, an ICP increase of 145% was noted at 10 h, and the corresponding increase in the rats fed processed cereal feed was only 50%. In rats exposed to a 30-kPa blast, those fed standard feed and processed cereal feed demonstrated increases of ICP of 80% and 40%, respectively. Cognitive function as measured by the Morris water maze was assessed in other groups of rats at 2 days after exposure to 10- or 30-kPa blasts. Their performance was significantly impaired at both exposure levels in rats on standard feed, but no functional impairment was seen in rats fed processed cereal feed.

  14. The effects of low-level laser on muscle damage caused by Bothrops neuwiedi venom

    Energy Technology Data Exchange (ETDEWEB)

    Dourado, D.M.; Matias, R.; Almeida, M.F.; Paula, K.R. de; Carvalho, P.T.C. [University for the Development of the State and of the Region of Pantanal (UNIDERP), Campo Grande, MS (Brazil). Lab. of Experimental Histopathology]. E-mail: ccfi@uniderp.br; Vieira, R.P. [University of Sao Paulo (USP), SP (Brazil). School of Medicine. Dept. of Pathology and Physical Therapy; Oliveira, L.V.F. [Nove de Julho University (UNINOVE), Sao Paulo, SP (Brazil). Masters Program in Rehabilitation Sciences

    2008-07-01

    The present study aimed to assess the effects of low-level laser (660 nm) on myonecrosis caused by the insertion of Bothrops neuwiedi venom in the gastrocnemius muscle of rats. Male Wistar rats were divided into three groups (n = 24 each): Group S (0.9% saline solution); Group V (venom) and Group VLLL (venom plus low-level laser). These categories were subdivided into four additional groups (n = 6) based on the euthanasia timing (3 hours, 24 hours, 3 days and 7 days). The groups V and VLLL were inoculated with 100 {mu}L of concentrated venom (40 {mu}g/mL) in the gastrocnemius muscle. The muscle was irradiated using a gallium-aluminum-arsenide laser (GaAlAs) at 35 mW power and 4 J/cm{sup 2} energy density for 3 hours, 24 hours, 3 days or 7 days after venom inoculation. To evaluate the myotoxic activity of the venom, CK activity was measured and the muscle was histologically analyzed. The low-level laser reduced venom-induced CK activity in the groups euthanized at 3 hours, 24 hours and 3 days (p < 0.0001). Histological analysis revealed that low-level laser reduced neutrophilic inflammation as well as myofibrillar edema, hemorrhage and myonecrosis following B. neuwiedi envenomation. These results suggest that low-level laser can be useful as an adjunct therapy following B. neuwiedi envenomation. (author)

  15. The effects of low-level laser on muscle damage caused by Bothrops neuwiedi venom

    Directory of Open Access Journals (Sweden)

    DM Dourado

    2008-01-01

    Full Text Available The present study aimed to assess the effects of low-level laser (660 nm on myonecrosis caused by the insertion of Bothrops neuwiedi venom in the gastrocnemius muscle of rats. Male Wistar rats were divided into three groups (n = 24 each: Group S (0.9% saline solution; Group V (venom and Group VLLL (venom plus low-level laser. These categories were subdivided into four additional groups (n = 6 based on the euthanasia timing (3 hours, 24 hours, 3 days and 7 days. The groups V and VLLL were inoculated with 100 µL of concentrated venom (40 µg/mL in the gastrocnemius muscle. The muscle was irradiated using a gallium-aluminum-arsenide laser (GaAlAs at 35 mW power and 4 J/cm² energy density for 3 hours, 24 hours, 3 days or 7 days after venom inoculation. To evaluate the myotoxic activity of the venom, CK activity was measured and the muscle was histologically analyzed. The low-level laser reduced venom-induced CK activity in the groups euthanized at 3 hours, 24 hours and 3 days (p < 0.0001. Histological analysis revealed that low-level laser reduced neutrophilic inflammation as well as myofibrillar edema, hemorrhage and myonecrosis following B. neuwiedi envenomation. These results suggest that low-level laser can be useful as an adjunct therapy following B. neuwiedi envenomation.

  16. The effect of low-level laser therapy on human leukemic cells.

    Science.gov (United States)

    Dastanpour, Somayeh; Momen Beitollahi, Jalil; Saber, Kazem

    2015-01-01

    Laser phototherapy is used for the treatment of chemotherapy-induced oral mucositis in patients with leukemia, although there are limited data supporting the safety of this method. This study aimed to evaluate the effect of different doses of low-level laser on proliferation of acute myeloid leukemia (AML) cell line (KG-1a) in vitro. A plastic flask containing 5,000,000 KG-1a cultured cells was provided by Iran Pasteur Institute. KG-1a cell line has been produced from the bone marrow aspirate of a 59-year-old white male with acute myelogenous leukemia. Upon completion of the proliferation steps of KG-1a cell line, 7×10(4) cells were placed in 96-well tissue culture plates. All the surrounding wells were filled with Wright-Giemsa stain in order to prevent laser from scattering to the neighboring wells. In total, 28 plates were prepared using this method. After a forty-eight hours incubation period, irradiation was performed in continuous mode with an infrared laser of 810nm wavelength. After 24 hours, cells cultures were exposed to one, two, or three applications of laser irradiation. Irradiation exposures were performed at energy densities of 5, 10, and 20 J/cm(2) . Each experiment included 18 replicates for each application of laser and 6 replicates of negative/untreated controls. For experiments with two and three repeated exposures, the irradiation applications were separated by 48 hours. All the culture plates were incubated for seven days. Cell proliferation was evaluated using the MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay after seven days. Spectroscopy (620nm) was used to determine the optical density (OD) of both irradiated and control samples. Significant increase in cell proliferation was seen only after two exposures at energy density of 20J/cm2 (P=0.021). Although LLLT is commonly used to treat radiotherapy- or chemotherapy- induced mucositis, as long as further studies demonstrate that different wavelengths and doses of

  17. Occupational exposures and chronic obstructive pulmonary disease (COPD): comparison of a COPD-specific job exposure matrix and expert-evaluated occupational exposures.

    Science.gov (United States)

    Kurth, Laura; Doney, Brent; Weinmann, Sheila

    2017-03-01

    To compare the occupational exposure levels assigned by our National Institute for Occupational Safety and Health chronic obstructive pulmonary disease-specific job exposure matrix (NIOSH COPD JEM) and by expert evaluation of detailed occupational information for various jobs held by members of an integrated health plan in the Northwest USA. We analysed data from a prior study examining COPD and occupational exposures. Jobs were assigned exposure levels using 2 methods: (1) the COPD JEM and (2) expert evaluation. Agreement (Cohen's κ coefficients), sensitivity and specificity were calculated to compare exposure levels assigned by the 2 methods for 8 exposure categories. κ indicated slight to moderate agreement (0.19-0.51) between the 2 methods and was highest for organic dust and overall exposure. Sensitivity of the matrix ranged from 33.9% to 68.5% and was highest for sensitisers, diesel exhaust and overall exposure. Specificity ranged from 74.7% to 97.1% and was highest for fumes, organic dust and mineral dust. This COPD JEM was compared with exposures assigned by experts and offers a generalisable approach to assigning occupational exposure. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  18. Effect of low-level laser therapy on wound healing after depigmentation procedure: A clinical study

    Directory of Open Access Journals (Sweden)

    Kirti Chawla

    2016-01-01

    Full Text Available Aim: The aim of the present study is to evaluate and compare the effects of low-level laser therapy (LLLT on wound healing after depigmentation procedure. Materials and Methods: In this study, 12 patients with bilateral melanin hyperpigmentation were treated with surgical stripping using a blade. After completion of the surgical process and bleeding stasis, any of the symmetrical surgical sites was randomly assigned for LLLT (test site using a defocused diode laser at 1 mm distance for 5 min. After every laser exposure, the surgical site was coated with plaque disclosing solution (erythrosine on the 3rd, 7th, and 15th day. A photograph of the surgical site was taken using a Digital SLR Camera, which was placed at 30 cm distance at 55 mm zoom, 1/100 shutter speed, f 14 aperture size, and ISO 4000 with a ring flash. The area of the stained parts of the photographs was evaluated using image analysis software. Results: At day 3, test site showed 1.26 ± 0.23 mm2 and control site showed 1.45 ± 0.21 mm2 stain uptake by the tissue which was statistically significant. At day 7 and day 15, the test sites exhibited 1.24 ± 0.30 mm2 and 1.12 ± 0.25 mm2 stain uptake, whereas the control site showed 1.37 ± 25 mm2 and 1.29 ± 0.28 mm2 staining, respectively, which were not statistically significant. Conclusion: Within the limitations of this study, the findings revealed that LLLT promotes wound healing after depigmentation procedure until the 3rd day. On the 7th and 15th day, the difference in healing was not statistically significant.

  19. Is It Ethical to Condone Low Levels of Drinking in Pregnancy?

    DEFF Research Database (Denmark)

    Niclasen, Janni

    2016-01-01

    a scientific perspective it therefore cannot be concluded whether it is ethical to condone low levels of drinking in pregnancy. Some studies have reported that it is beneficial to the children that the mothers abstain from alco- hol during pregnancy. However, other studies report that it is, by contrast, ben...... of the human studies. Thereafter I will consider findings from animal studies and discuss the limita- tions of extrapolating such results to humans. Finally, I will return to discuss- ing whether it is ethical to condone low levels of drinking in pregnancy. My conclusion is that it is ‘better to be safe than...... a wide range of deleterious effects on children’s cognitive, behavioural and physical development. However, studies investigat- ing prenatal exposure to low doses of alcohol in relation to neurodevelopmental outcomes in childhood have been far less conclusive. Whereas some studies have reported negative...

  20. Mixed and low-level waste treatment facility project

    Energy Technology Data Exchange (ETDEWEB)

    1992-04-01

    The technology information provided in this report is only the first step toward the identification and selection of process systems that may be recommended for a proposed mixed and low-level waste treatment facility. More specific information on each technology will be required to conduct the system and equipment tradeoff studies that will follow these preengineering studies. For example, capacity, maintainability, reliability, cost, applicability to specific waste streams, and technology availability must be further defined. This report does not currently contain all needed information; however, all major technologies considered to be potentially applicable to the treatment of mixed and low-level waste are identified and described herein. Future reports will seek to improve the depth of information on technologies.

  1. Low level laser therapy in the treatment of aphthous ulcer.

    Science.gov (United States)

    Anand, Vishal; Gulati, Minkle; Govila, Vivek; Anand, Bhargavi

    2013-01-01

    Recurrent aphthous stomatitis (RAS) is one of the most common and painful ulcerative lesions of the oral cavity, but until now no cure has been recognized for it. Two patients diagnosed with minor RAS were treated in a single sitting with low level laser therapy using 940-nm diode laser. The lesions healed completely within 3-4 days and a follow-up for 1 showed no recurrence in these patients. According to the results of this study, low level laser therapy can decrease the healing time, pain intensity, size, and recurrence of the lesion in patients with minor RAS, and hence can be considered the most appropriate treatment modality for minor RAS, with greatest clinical effectiveness.

  2. Low level laser therapy in the treatment of aphthous ulcer

    Directory of Open Access Journals (Sweden)

    Vishal Anand

    2013-01-01

    Full Text Available Recurrent aphthous stomatitis (RAS is one of the most common and painful ulcerative lesions of the oral cavity, but until now no cure has been recognized for it. Two patients diagnosed with minor RAS were treated in a single sitting with low level laser therapy using 940-nm diode laser. The lesions healed completely within 3-4 days and a follow-up for 1 showed no recurrence in these patients. According to the results of this study, low level laser therapy can decrease the healing time, pain intensity, size, and recurrence of the lesion in patients with minor RAS, and hence can be considered the most appropriate treatment modality for minor RAS, with greatest clinical effectiveness.

  3. Low-level waste disposal in highly populated areas

    Energy Technology Data Exchange (ETDEWEB)

    Kowalski, E.; McCombie, C.; Issler, H. [NAGRA-Swiss National Cooperative for the Storage of Radioactive Waste, Baden (Switzerland)

    1989-11-01

    Nuclear-generated electricity supplies almost 40% of the demand in Switzerland (the rest being hydro-power). Allowing for a certain reserve and assuming an operational life-time of 40 years for each reactor, and taking into account wastes from decommissioning and from medicine, industry and research, the total amount of low-level radioactive waste to be disposed of is about 175,000 m{sup 3}. Since there are no unpopulated areas in Switzerland, and since Swiss Federal Law specifies that the safety of disposal may not depend upon supervision of the repository, no shallow-land burial has been foreseen, even for short-lived low-level waste. Instead, geological disposal in a mined cavern system with access through a horizontal tunnel was selected as the best way of meeting the requirements and ensuring the necessary public acceptance.

  4. A Multicounter System for Scanning Ultra-Low-Level Radiochromatograms

    DEFF Research Database (Denmark)

    Bøtter-Jensen, Lars; Hansen, Heinz Johs. Max; Theodorsson, P.

    1977-01-01

    A multicounter system consisting of an integrated array of flow counters for the scanning of ultra-low-level radioactivity on paper and thin-layer chromatograms was developed. Experience with routine measurements over a prolonged period has proved the advantages of this system over other systems,......, such as liquid scintillation counting. A description of the flow counter system is given together with an outline of an electronic data acquisition system, and results are presented to demonstrate its features....

  5. Commercial low-level radioactive waste disposal in the US

    Energy Technology Data Exchange (ETDEWEB)

    Smith, P.

    1995-10-01

    Why are 11 states attempting to develop new low-level radioactive waste disposal facilities? Why is only on disposal facility accepting waste nationally? What is the future of waste disposal? These questions are representative of those being asked throughout the country. This paper attempts to answer these questions in terms of where we are, how we got there, and where we might be going.

  6. Southern hemisphere low level wind circulation statisticsfrom the Seasat scatterometer

    OpenAIRE

    G. Levy

    1994-01-01

    Analyses of remotely sensed low-level wind vector data over the Southern Ocean are performed. Five-day averages and monthly means are created and the month-to-month variability during the winter (July-September) of 1978 is investigated. The remotely sensed winds are compared to the Australian Bureau of Meteorology (ABM) and the National Meteorological Center (NMC) surface analyses. In southern latitudes the remotely sensed winds are stronger than what the weather services' analyses sugge...

  7. Effect of Low-Level Laser Stimulation on EEG

    Directory of Open Access Journals (Sweden)

    Jih-Huah Wu

    2012-01-01

    Full Text Available Conventional laser stimulation at the acupoint can induce significant brain activation, and the activation is theoretically conveyed by the sensory afferents. Whether the insensible low-level Laser stimulation outside the acupoint could also evoke electroencephalographic (EEG changes is not known. We designed a low-level laser array stimulator (6 pcs laser diode, wavelength 830 nm, output power 7 mW, and operation frequency 10 Hz to deliver insensible laser stimulations to the palm. EEG activities before, during, and after the laser stimulation were collected. The amplitude powers of each EEG frequency band were analyzed. We found that the low-level laser stimulation was able to increase the power of alpha rhythms and theta waves, mainly in the posterior head regions. These effects lasted at least 15 minutes after cessation of the laser stimulation. The amplitude power of beta activities in the anterior head regions decreased after laser stimulation. We thought these EEG changes comparable to those in meditation.

  8. Low-level radioactive waste technology: a selected, annotated bibliography

    Energy Technology Data Exchange (ETDEWEB)

    Fore, C.S.; Vaughan, N.D.; Hyder, L.K.

    1980-10-01

    This annotated bibliography of 447 references contains scientific, technical, economic, and regulatory information relevant to low-level radioactive waste technology. The bibliography focuses on environmental transport, disposal site, and waste treatment studies. The publication covers both domestic and foreign literature for the period 1952 to 1979. Major chapters selected are Chemical and Physical Aspects; Container Design and Performance; Disposal Site; Environmental Transport; General Studies and Reviews; Geology, Hydrology and Site Resources; Regulatory and Economic Aspects; Transportation Technology; Waste Production; and Waste Treatment. Specialized data fields have been incorporated into the data file to improve the ease and accuracy of locating pertinent references. Specific radionuclides for which data are presented are listed in the Measured Radionuclides field, and specific parameters which affect the migration of these radionuclides are presented in the Measured Parameters field. In addition, each document referenced in this bibliography has been assigned a relevance number to facilitate sorting the documents according to their pertinence to low-level radioactive waste technology. The documents are rated 1, 2, 3, or 4, with 1 indicating direct applicability to low-level radioactive waste technology and 4 indicating that a considerable amount of interpretation is required for the information presented to be applied. The references within each chapter are arranged alphabetically by leading author, corporate affiliation, or title of the document. Indexes are provide for (1) author(s), (2) keywords, (3) subject category, (4) title, (5) geographic location, (6) measured parameters, (7) measured radionuclides, and (8) publication description.

  9. Multiple low-level antibiotic resistance in Aeromonas salmonicida.

    Science.gov (United States)

    Wood, S C; McCashion, R N; Lynch, W H

    1986-06-01

    Mutants with multiple low-level antibiotic resistance were isolated from virulent wild-type Aeromonas salmonicida strains exposed to a low concentration of any one of several low-molecular-mass (approximately 635 daltons or less) antibiotics. Multiple resistance was toward beta-lactam compounds (penicillin G, ampicillin, cloxacillin), quinolones (flumequine, oxolinic acid, nalidixic acid), tetracyclines, chloramphenicol, and novobiocin. Susceptibilities of the mutants toward several higher-molecular-mass (greater than 700 daltons) hydrophobic or polycationic antibiotics such as rifampin, erythromycin, polymyxin B, and streptomycin sulfate were not affected. The mutants were obtained at frequencies suggesting point mutations. Outer membrane protein profiles, examined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, revealed that all multiple low-level resistant mutants were deficient in a major protein of approximately 38.5 kilodaltons and contained a major protein of approximately 37 kilodaltons which was not present in significant amounts in the wild-type strains. In addition, these mutants lacked exoprotease activity. Furthermore, mutants isolated as deficient in exoprotease were found, with the exception of one avirulent strain, to exhibit multiple low-level antibiotic resistance and the outer membrane protein changes.

  10. Exposure Assessment Tools by Approaches - Indirect Estimation (Scenario Evaluation)

    Science.gov (United States)

    EPA ExpoBox is a toolbox for exposure assessors. Its purpose is to provide a compendium of exposure assessment and risk characterization tools that will present comprehensive step-by-step guidance and links to relevant exposure assessment data bases, mode

  11. Low-level laser therapy and Calendula officinalis in repairing diabetic foot ulcers

    OpenAIRE

    Carvalho, Ana Flávia Machado de; Feitosa, Maura Cristina Porto; Coelho, Nayana Pinheiro Machado de Freitas; Rebêlo, Veruska Cronemberger Nogueira; Castro, Juçara Gonçalves de; Sousa, Patrícia Regina Gomes de; Feitosa, Valrian Campos; Arisawa, Emilia Angela Lo Schiavo

    2016-01-01

    Abstract OBJECTIVE To evaluate the effects of low-level laser therapy isolated and associated with Calendula officinalis oil in treating diabetic foot ulcers. METHOD An experimental, randomized, controlled, prospective, interventional clinical case study using a quantitative approach. The sample consisted of 32 diabetic patients of both genders. Participants were randomly divided into four groups. Doppler Ultrasound evaluation of the Ankle-Brachial Index, brief pain inventory and analog pai...

  12. Correlation test to assess low-level processing of high-density oligonucleotide microarray data

    Directory of Open Access Journals (Sweden)

    Bergh Jonas

    2005-03-01

    Full Text Available Abstract Background There are currently a number of competing techniques for low-level processing of oligonucleotide array data. The choice of technique has a profound effect on subsequent statistical analyses, but there is no method to assess whether a particular technique is appropriate for a specific data set, without reference to external data. Results We analyzed coregulation between genes in order to detect insufficient normalization between arrays, where coregulation is measured in terms of statistical correlation. In a large collection of genes, a random pair of genes should have on average zero correlation, hence allowing a correlation test. For all data sets that we evaluated, and the three most commonly used low-level processing procedures including MAS5, RMA and MBEI, the housekeeping-gene normalization failed the test. For a real clinical data set, RMA and MBEI showed significant correlation for absent genes. We also found that a second round of normalization on the probe set level improved normalization significantly throughout. Conclusion Previous evaluation of low-level processing in the literature has been limited to artificial spike-in and mixture data sets. In the absence of a known gold-standard, the correlation criterion allows us to assess the appropriateness of low-level processing of a specific data set and the success of normalization for subsets of genes.

  13. Mixed and low-level waste treatment project: Appendix C, Health and safety criteria for the mixed and low-level waste treatment facility at the Idaho National Engineering Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Neupauer, R.M.; Thurmond, S.M.

    1992-09-01

    This report describes health and safety concerns associated with the Mixed and Low-level Waste Treatment Facility at the Idaho National Engineering Laboratory. Various hazards are described such as fire, electrical, explosions, reactivity, temperature, and radiation hazards, as well as the potential for accidental spills, exposure to toxic materials, and other general safety concerns.

  14. Mixed and low-level waste treatment project: Appendix C, Health and safety criteria for the mixed and low-level waste treatment facility at the Idaho National Engineering Laboratory. Part 1, Waste streams and treatment technologies

    Energy Technology Data Exchange (ETDEWEB)

    Neupauer, R.M.; Thurmond, S.M.

    1992-09-01

    This report describes health and safety concerns associated with the Mixed and Low-level Waste Treatment Facility at the Idaho National Engineering Laboratory. Various hazards are described such as fire, electrical, explosions, reactivity, temperature, and radiation hazards, as well as the potential for accidental spills, exposure to toxic materials, and other general safety concerns.

  15. WITHDRAWN: Low level laser therapy (Classes III) for treating osteoarthritis.

    Science.gov (United States)

    Brosseau, L; Robinson, V; Wells, G; Debie, R; Gam, A; Harman, K; Morin, M; Shea, B; Tugwell, P

    2007-07-18

    Osteoarthritis (OA) affects a large portion of the population. Low Level Laser Therapy (LLLT) is a light source that generates extremely pure light, of a single wavelength. The effect is not thermal, but rather related to photochemical reactions in the cells. LLLT was introduced as an alternative non-invasive treatment for OA about 30 years ago, but its effectiveness has to be examined more closely, especially in the treatment of OA. To assess the effectiveness of class III LLLT for osteoarthritis when irradiation is directed at the osteoarthritic joint capsule. Searches were conducted in the following databases: MEDLINE, EMBASE, the Cochrane Musculoskeletal registry, the Rehabilitation and Related Therapies field registry and the Cochrane Controlled Trials Register up to May, 2005. Following an a prior protocol, only controlled clinical trials of LLLT for the treatment of patients with a clinical diagnosis of OA were eligible. Abstracts lacking data were excluded unless further data could be obtained from the authors. Two reviewers independently selected trials and extracted data using predetermined forms. A fixed effects model was used throughout for continuous variables, except where heterogeneity existed; in which case, a random effects model was used. Results were analyzed as weighted mean differences (WMD) with 95% confidence intervals (CI), whereas the difference between the treatment and control groups was weighted by the inverse of the variance. Standardized mean differences (SMD) were calculated by dividing the difference between treatment and control by the baseline variance, and were used in the analysis of pain because different scales were used to measure it. Dichotomous outcomes were analyzed with relative risk (RR). Eight trials were included with 233 patients randomized to laser and 172 patients to placebo laser. Treatment duration ranged from two to six weeks. Pain was assessed in seven trials. When the results were pooled from different pain

  16. Status of low-level radioactive waste management in Korea

    Energy Technology Data Exchange (ETDEWEB)

    Lee, K.J. [Korea Advanced Inst. of Science and Technology, Taejon (Korea, Republic of). Dept. of Nuclear Engineering

    1993-03-01

    The Republic of Korea has accomplished dramatic economic growth over the past three decades; demand for electricity has rapidly grown more than 15% per year. Since the first nuclear power plant, Kori-1 [587 MWe, pressurized water reactor (PWR)], went into commercial operation in 1978, the nuclear power program has continuously expanded and played a key role in meeting the national electricity demand. Nowadays, Korea has nine nuclear power plants [eight PWRs and one Canadian natural uranium reactor (CANDU)] in operation with total generating capacity of 7,616 MWe. The nuclear share of total electrical capacity is about 36%; however, about 50% of actual electricity production is provided by these nine nuclear power plants. In addition, two PWRs are under construction, five units (three CANDUs and two PWRs) are under design, and three more CANDUs and eight more PWRs are planned to be completed by 2006. With this ambitious nuclear program, the total nuclear generating capacity will reach about 23,000 MWe and the nuclear share will be about 40% of the total generating capacity in the year 2006. In order to expand the nuclear power program this ambitiously, enormous amounts of work still have to be done. One major area is radioactive waste management. This paper reviews the status of low-level radioactive waste management in Korea. First, the current and future generation of low-level radioactive wastes are estimated. Also included are the status and plan for the construction of a repository for low-level radioactive wastes, which is one of the hot issues in Korea. Then, the nuclear regulatory system is briefly mentioned. Finally, the research and development activities for LLW management are briefly discussed.

  17. Could low level laser therapy and highly active antiretroviral therapy lead to complete eradication of HIV-1 in vitro?

    CSIR Research Space (South Africa)

    Lugongolo, Masixole Y

    2017-01-01

    Full Text Available used to treat different medical conditions such as diabetic wounds, sports injuries and others. The technique involves exposure of cells or tissue to low levels of red and near infrared laser light. Both HIV infected and uninfected cells were laser...

  18. The economic benefits to agriculture of a reduction of low-level ozone pollution in the Netherlands

    NARCIS (Netherlands)

    Kuik, O.J.; Helming, J.F.M.; Dorland, C.; Spaninks, F.A.

    2000-01-01

    Low-level ozone pollution affects crop yields adversely. Reduction of ozone pollution would therefore increase crop yields and provide economic benefits to producers and consumers of farm products. This paper assesses the potential magnitude of these benefits for the Netherlands. Exposure-response

  19. [Validity assessment of a low level phonological processing test material in preschool children].

    Science.gov (United States)

    Ptok, M; Altwein, F

    2012-07-01

    The BISC (Bielefelder Screening) is a German test to evaluate phonological skills believed to be a prerequisite for future reading and writing skills. BISC results may indicate an elevated risk for dyslexia. Our research group has put forward test material in order to specifically examine low-level phonological processing LLPP. In this study we analysed whether BISC and low-level phonological processing correlate. A retrospective correlation analysis was carried out on primary school children's test results of the BISC and the newly developed low-level phonological processing test material. Spearman's rho was 0.52 between total LLPP and total BISC. The subscales correlated with a rho below 0.5. Results indicate that a low level phonological processing and higher level phonological processing can be differentiated. Future studies will have to clarify whether these results can be used to construct specifically targeting therapy strategies and whether the LLPP test material can be used to assess the risk of subsequent dyslexia also. © Georg Thieme Verlag KG Stuttgart · New York.

  20. Low-level waste management alternatives and analysis in DOE`s programmatic environmental impact statement

    Energy Technology Data Exchange (ETDEWEB)

    Gerstein, J.S. [Dept. of Energy, Washington, DC (United States). Office of Environmental Restoration and Waste Management

    1993-03-01

    The Department of Energy is preparing a Programmatic Environmental Impact Statement (PEIS) for the Environmental Restoration and Waste Management Program. The PEIS has been divided into an Environmental Restoration section and a Waste Management section. Each section has a unique set of alternatives. This paper will focus on the waste management alternatives and analysis. The set of alternatives for waste management has been divided into waste categories. These categories are: high-level waste, transuranic waste, low-level waste, low-level mixed waste, greater-than-class C and low-level waste from commercial sources, hazardous waste, and spent nuclear fuel. This paper will discuss the alternatives and analytical approach that will be used to evaluate these alternatives for the low-level waste section. Although the same alternatives will be considered for all waste types, the analysis will be performed separately for each waste type. In the sections that follow, information will be provided on waste management configurations, the analysis of waste management alternatives, waste types and locations, facility and transportation activities, the facility and transportation impacts assessment, and the compilation of impacts.

  1. Public perceptions of low-level waste risks -- Lessons learned in Pennsylvania

    Energy Technology Data Exchange (ETDEWEB)

    Dornsife, W.; Serie, P.

    1989-11-01

    People in Pennsylvania are no different than citizens of other eastern states, other states, or any place in the world--they care most deeply about their health, the safety and security of their families, their investments, and their autonomy. How a particular risk is perceived depends on how it is believed to affect those valued possessions. The perception of risk from exposure to the radioactivity contained in low-level radioactive low-level waste disposal facility. The Commonwealth`s program, administered by the Department of Environmental Resources, places high priority on public dialogue on this issue. This paper discusses the Department`s program to develop and promulgate low-level waste regulations, provide a framework for selection of a qualified disposal facility operator, contract with the selected firm, and oversee its activities in siting, licensing, constructing, and operating the facility. This facility will meet the needs of the states of the Appalachian States Compact, including, in addition to Pennsylvania, West Virginia, Maryland, and Delaware. The focus of the paper is on the public information and outreach program accomplished to date, and the lessons learned regarding public perceptions of risk.

  2. Considerations for evaluating controlled exposure studies of tree seedlings.

    Science.gov (United States)

    E. Charles Peterson; A. Robert. Mickler

    1994-01-01

    Tree seedling exposure studies, covering a wide range of experimental conditions in pollutant treatments, species, facilities, and exposure regimes, have been conducted during the past several years to determine acute effects and relative sensitivity of tree species in response to simulated acid precipitation and gaseous pollutants. Because of tile difficulties...

  3. Steam Reforming of Low-Level Mixed Waste

    Energy Technology Data Exchange (ETDEWEB)

    None

    1998-01-01

    Under DOE Contract No. DE-AR21-95MC32091, Steam Reforming of Low-Level Mixed Waste, ThermoChem has successfully designed, fabricated and operated a nominal 90 pound per hour Process Development Unit (PDU) on various low-level mixed waste surrogates. The design construction, and testing of the PDU as well as performance and economic projections for a 500- lb/hr demonstration and commercial system are described. The overall system offers an environmentally safe, non-incinerating, cost-effective, and publicly acceptable method of processing LLMW. The steam-reforming technology was ranked the No. 1 non-incineration technology for destruction of hazardous organic wastes in a study commissioned by the Mixed Waste Focus Area published April 1997.1 The ThermoChem steam-reforming system has been developed over the last 13 years culminating in this successful test campaign on LLMW surrogates. Six surrogates were successfidly tested including a 750-hour test on material simulating a PCB- and Uranium- contaminated solid waste found at the Portsmouth Gaseous Diffusion Plant. The test results indicated essentially total (>99.9999oA) destruction of RCRA and TSCA hazardous halogenated organics, significant levels of volume reduction (> 400 to 1), and retention of radlonuclides in the volume-reduced solids. Cost studies have shown the steam-reforming system to be very cost competitive with more conventional and other emerging technologies.

  4. Is Low-Level Visual Experience Cognitively Penetrable?

    Directory of Open Access Journals (Sweden)

    Dávid Bitter

    2014-12-01

    Full Text Available Philosophers and psychologists alike have argued recently that relatively abstract beliefs or cognitive categories like those regarding race can influence the perceptual experience of relatively low-level visual features like color or lightness. Some of the proposed best empirical evidence for this claim comes from a series of experiments in which White faces were consistently judged as lighter than equiluminant Black faces, even for racially ambiguous faces that were labeled ‘White’ as opposed to ‘Black’ (Levin and Banaji 2006. The latter result is considered especially indicative of cognitive penetration, based on the reasoning that the relevant distortions were a function of lexical labeling, and hence the effect must have been mediated by categorization at the cognitive level. I argue that this reasoning is flawed, and that the assumptions on which it relies are questionable on both empirical and theoretical grounds. I propose an alternative, low-level explanation of the phenomena, which I argue is empirically more plausible and abductively preferable to the cognitive-penetration account. The upshot is that cognitively impenetrable perceptual systems may be psychologically more plastic and hence philosophically more significant than is nowadays commonly assumed.

  5. Southern hemisphere low level wind circulation statisticsfrom the Seasat scatterometer

    Directory of Open Access Journals (Sweden)

    G. Levy

    1994-01-01

    Full Text Available Analyses of remotely sensed low-level wind vector data over the Southern Ocean are performed. Five-day averages and monthly means are created and the month-to-month variability during the winter (July-September of 1978 is investigated. The remotely sensed winds are compared to the Australian Bureau of Meteorology (ABM and the National Meteorological Center (NMC surface analyses. In southern latitudes the remotely sensed winds are stronger than what the weather services' analyses suggest, indicating underestimation by ABM and NMC in these regions. The evolution of the low-level jet and the major stormtracks during the season are studied and different flow regimes are identified. The large-scale variability of the meridional flow is studied with the aid of empirical orthogonal function (EOF analysis. The dominance of quasi-stationary wave numbers 3, 4, and 5 in the winter flow is evident in both the EOF analysis and the mean flow. The signature of an exceptionally strong blocking situation is evident in July and the special conditions leading to it are discussed. A very large intraseasonal variability with different flow regimes at different months is documented.

  6. Southern hemisphere low level wind circulation statisticsfrom the Seasat scatterometer

    Directory of Open Access Journals (Sweden)

    Gad Levy

    Full Text Available Analyses of remotely sensed low-level wind vector data over the Southern Ocean are performed. Five-day averages and monthly means are created and the month-to-month variability during the winter (July-September of 1978 is investigated. The remotely sensed winds are compared to the Australian Bureau of Meteorology (ABM and the National Meteorological Center (NMC surface analyses. In southern latitudes the remotely sensed winds are stronger than what the weather services' analyses suggest, indicating underestimation by ABM and NMC in these regions. The evolution of the low-level jet and the major stormtracks during the season are studied and different flow regimes are identified. The large-scale variability of the meridional flow is studied with the aid of empirical orthogonal function (EOF analysis. The dominance of quasi-stationary wave numbers 3, 4, and 5 in the winter flow is evident in both the EOF analysis and the mean flow. The signature of an exceptionally strong blocking situation is evident in July and the special conditions leading to it are discussed. A very large intraseasonal variability with different flow regimes at different months is documented.

  7. Greater-than-Class C low-level waste characterization

    Energy Technology Data Exchange (ETDEWEB)

    Piscitella, R.R. [EG and G Idaho, Inc., Idaho Falls, ID (United States). Idaho National Engineering Lab.

    1991-12-31

    In 1985, Public Law 99-240 (Low-Level Radioactive Waste Policy Amendments Act of 1985) made the Department of Energy (DOE) responsible for the disposal of greater-than-Class C low-level radioactive waste (GTCC LLW). DOE strategies for storage and disposal of GTCC LLW required characterization of volumes, radionuclide activities, and waste forms. Data from existing literature, disposal records, and original research were used to estimate characteristics, project volumes, and determine radionuclide activities to the years 2035 and 2055. Twenty-year life extensions for 70% of the operating nuclear reactors were assumed to calculate the GTCC LLW available in 2055. The following categories of GTCC LLW were addressed: Nuclear Utilities Waste; Potential Sealed Sources GTCC LLW; DOE-Held Potential GTCC LLW; and Other Generator Waste. It was determined that the largest volume of these wastes, approximately 57%, is generated by nuclear utilities. The Other Generator Waste category contributes approximately 10% of the total GTCC LLW volume projected to the year 2035. DOE-Held Potential GTCC LLW accounts for nearly 33% of all waste projected to the year 2035. Potential Sealed Sources GTCC LLW is less than 0.2% of the total projected volume. The base case total projected volume of GTCC LLW for all categories was 3,250 cubic meters. This was substantially less than previous estimates.

  8. IGRIS for characterizing low-level radioactive waste

    Energy Technology Data Exchange (ETDEWEB)

    Peters, C.W. [Nuclear Diagnostic Systems, Springfield, VA (United States); Swanson, P.J. [Concord Associates, Knoxville, TN (United States)

    1993-03-01

    A recently developed neutron diagnostic probe system has the potential to noninvasively characterize low-level radioactive waste in bulk soil samples, containers such as 55-gallon barrels, and in pipes, valves, etc. The probe interrogates the target with a low-intensity beam of 14-MeV neutrons produced from the deuterium-tritium reaction in a specially designed sealed-tube neutron-generator (STNG) that incorporates an alpha detector to detect the alpha particle associated with each neutron. These neutrons interact with the nuclei in the target to produce inelastic-, capture-, and decay-gamma rays that are detected by gamma-ray detectors. Time-of-flight methods are used to separate the inelastic-gamma rays from other gamma rays and to determine the origin of each inelastic-gamma ray in three dimensions through Inelastic-Gamma Ray Imaging and Spectroscopy (IGRIS). The capture-gamma ray spectrum is measured simultaneously with the IGRIS measurements. The decay-gamma ray spectrum is measured with the STNG turned off. Laboratory proof-of-concept measurements were used to design prototype systems for Bulk Soil Assay, Barrel Inspection, and Decontamination and Decommissioning and to predict their minimum detectable levels for heavy toxic metals (As, Hg, Cr, Zn, Pb, Ni, and Cd), uranium and transuranics, gamma-ray emitters, and elements such as chlorine, which is found in PCBs and other pollutants. These systems are expected to be complementary and synergistic with other technologies used to characterize low-level radioactive waste.

  9. Changes in South American Low-level jet during summer

    Science.gov (United States)

    Jones, C.; Montini, T.; Carvalho, L. V.

    2016-12-01

    Climate variability and change in South America affect millions of people and impact water resources, agriculture, economic activity, human health, ecosystems and biodiversity. The South American Monsoon System (SAMS) is the most important climatic feature in the continent. South America has warmed significantly over the last several decades, and climate model projections from the Intergovernmental Panel on Climate Change confidently agree that warming will continue into the 21st century. The eastern Andes low-level winds can significantly intensify under certain synoptic and large-scale conditions forming the South America low-level jet (SALLJ). The SALLJ transports large amounts of moisture from the Amazon to the La Plata Basin and induces the formation of mesoscale convective systems that bring substantial amounts of precipitation. The Weather Research and Forecasting (WRF) model is used in this study to investigate regional warming in South America. WRF is configured with two nested grids with 45 km and 15 km horizontal grid sizes and 41 vertical levels. Climate Forecast System Reanalysis (CFSR) is used as initial and boundary conditions to develop dynamical downscaling over South America for the period 1 November - 31 March, 1980-2015. This presentation will discuss regional warming in South America in recent decades and the elevation dependency of such warming over the eastern slopes of the Central Andes. Potential changes in the SALLJ will also be discussed.

  10. Low Level and Transuranic Waste Segregation and Low Level Waste Characterization at the 200 Area of the Hanford Site - 12424

    Energy Technology Data Exchange (ETDEWEB)

    Donohoue, Tom; Martin, E. Ray; Mason, John A. [ANTECH Corporation 9050 Marshall Court, Westminster, CO, 80031 (United States); Blackford, Ty; Estes, Michael; Jasen, William [CH2M Hill Plateau Remediation Company, 2420 Stevens Drive, Richland, WA, 99352 (United States); Cahill, Michael [Fluor Federal Services, 1200 Jadwin Avenue, Richland, WA, 99352 (United States)

    2012-07-01

    This paper describes the waste measurement and waste characterization activities carried out by ANTECH Corporation (ANTECH) and CH2M Hill Plateau Remediation Company (CHPRC) at the 200 Area of the Hanford Site under Contracts No. 22394 and No. 40245 for the US Department of Energy (DOE). These include Low Level Waste (LLW) and Transuranic (TRU) Waste segregation and LLW characterization for both 55-gallon (200-litre) drums with gross weight up to 454 kg and 85-gallon over-pack drums. In order to achieve efficient and effective waste drum segregation and assay, ANTECH deployed an automated Gamma Mobile Assay Laboratory (G-MAL) at the trench face in both 200 Area West and East. The unit consists of a modified 40 foot ISO shipping container with an automatic flow through roller conveyor system with internal drum weigh scale, four measurement and drum rotation positions, and four high efficiency high purity Germanium (HPGe) detectors with both detector and shadow shields. The unit performs multiple far-field measurements and is able to segregate drums at levels well below 100 nCi/g. The system is sufficiently sensitive that drums, which are classified as LLW, are characterized at measurement levels that meet the Environmental Restoration Disposal Facility (ERDF) Waste Acceptance Criteria (WAC). With measurement times of between 20 and 30 minutes the unit can classify and characterize over 40 drums in an 8-hour shift. The system is well characterized with documented calibrations, lower limits of detection (LLD) and total measurement uncertainty. The calibrations are confirmed and verified using nationally traceable standards in keeping with the CHPRC measurement requirements. The performance of the system has been confirmed and validated throughout the measurement process by independent CHPRC personnel using traceable standards. All of the measurement and maintenance work has been conducted during the period under a Quality Assurance Plan (QAP) compliant with the

  11. Low-level laser therapy: Case-control study in dogs with sterile pyogranulomatous pododermatitis

    OpenAIRE

    Roberta Perego; Proverbio, D.; Zuccaro, A.; Spada, E.

    2016-01-01

    Aim: Low-level laser therapy (LLLT) is a therapeutic photobiostimulation with properties in reducing swelling, inflammation, and promoting tissue healing. The objective of this pilot study was to evaluate LLLT in sterile pyogranulomatous pododermatitis in five dogs. Materials and Methods: In each dog, one lesion was designated as the control (treated with a 0.0584% hydrocortisone aceponate spray), and one or more other lesions were treated with a gallium aluminum arsenide-laser, daily for ...

  12. MALE REPRODUCTIVE EFFECTS OF SOLVENT AND FUEL EXPOSURE DURING AIRCRAFT MAINTENANCE

    Science.gov (United States)

    Few studies have addressed the effects of mixed, low level exposures to complex mixtures on a man's reproductive potential. In this prospective study, each subject was evaluated prior to first exposure and at 15 and 30 weeks after exposures had begun. A total of 50 men working ...

  13. Role of complex organic arsenicals in food in aggregate exposure to arsenic

    Science.gov (United States)

    For much of the world’s population, food is the major source of exposure to arsenic. Exposure to this non-essential metalloid at relatively low levels has been linked to a wide range of adverse health effects. Thus, evaluating foods as sources of exposure to arsenic is important ...

  14. Low-level laser irradiation induces in vitro proliferation of mesenchymal stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Barboza, Carlos Augusto Galvão; Ginani, Fernanda [Universidade Federal do Rio Grande do Norte, Natal, RN (Brazil); Soares, Diego Moura [Universidade Federal de Pernambuco, Recife, PE (Brazil); Henriques, Águida Cristina Gomes; Freitas, Roseana de Almeida [Universidade Federal do Rio Grande do Norte, Natal, RN (Brazil)

    2014-07-01

    To evaluate the effect of low-level laser irradiation on the proliferation and possible nuclear morphological changes of mouse mesenchymal stem cells. Mesenchymal stem cells derived from bone marrow and adipose tissue were submitted to two applications (T0 and T48 hours) of low-level laser irradiation (660nm; doses of 0.5 and 1.0J/cm{sup 2}). The trypan blue assay was used to evaluate cell viability, and growth curves were used to analyze proliferation at zero, 24, 48, and 72 hours. Nuclear alterations were evaluated by staining with DAPI (4'-6-diamidino-2-phenylindole) at 72 hours. Bone marrow-derived mesenchymal stem cells responded to laser therapy in a dose-dependent manner. Higher cell growth was observed when the cells were irradiated with a dose of 1.0J/cm{sup 2}, especially after 24 hours (p<0.01). Adipose-derived mesenchymal stem cells responded better to a dose of 1.0J/cm{sup 2}, but higher cell proliferation was observed after 48 hours (p<0.05) and 72 hours (p<0.01). Neither nuclear alterations nor a significant change in cell viability was detected in the studied groups. Low-level laser irradiation stimulated the proliferation of mouse mesenchymal stem cells without causing nuclear alterations. The biostimulation of mesenchymal stem cells using laser therapy might be an important tool for regenerative therapy and tissue engineering.

  15. Identification of technical problems encountered in the shallow land burial of low-level radioactive wastes

    Energy Technology Data Exchange (ETDEWEB)

    Jacobs, D.G.; Epler, J.S.; Rose, R.R.

    1980-03-01

    A review of problems encountered in the shallow land burial of low-level radioactive wastes has been made in support of the technical aspects of the National Low-Level Waste (LLW) Management Research and Development Program being administered by the Low-Level Waste Management Program Office, Oak Ridge National Laboratory. The operating histories of burial sites at six major DOE and five commercial facilities in the US have been examined and several major problems identified. The problems experienced st the sites have been grouped into general categories dealing with site development, waste characterization, operation, and performance evaluation. Based on this grouping of the problem, a number of major technical issues have been identified which should be incorporated into program plans for further research and development. For each technical issue a discussion is presented relating the issue to a particular problem, identifying some recent or current related research, and suggesting further work necessary for resolving the issue. Major technical issues which have been identified include the need for improved water management, further understanding of the effect of chemical and physical parameters on radionuclide migration, more comprehensive waste records, improved programs for performance monitoring and evaluation, development of better predictive capabilities, evaluation of space utilization, and improved management control.

  16. The bioceramic implant: evaluation of implant exposures in 419 implants.

    Science.gov (United States)

    Jordan, David R; Klapper, Stephen R; Gilberg, Steven M; Dutton, Jonathan J; Wong, Amy; Mawn, Louise

    2010-01-01

    To compare the rate of exposure in the immediate 3-month postoperative follow-up period with the rate of exposure after the immediate postoperative period in 419 anophthalmic patients with a bioceramic (aluminum oxide) orbital implant. This is a retrospective, clinical case series of 419 patients who received a bioceramic orbital implant. All patients who presented to five oculofacial surgeons (D.J., S.G., J.D., S.K., L.M.) from January 1, 2000, to June 1, 2007, who received a bioceramic orbital implant and had a minimum of 3 months of follow-up were included in this study. The authors analyzed age, gender, type of surgery, implant size, peg system, follow-up duration, time of pegging, and problems encountered. The data from the patients with greater than 3 months of follow-up with exposure of the bioceramic implant are detailed in this report. There were 353 patients followed for 3 to 96 months with an average of 30 months of follow-up (median 23 months). Implant exposure occurred in 32/353 bioceramic implants (9.1%). Six of the 32 (19%) exposures occurred during the 90-day postoperative period (average 2.1 months). Twenty-six (81%) exposures occurred outside of the 90-day postoperative period (average 27.5 months, range 4-82 months). Implant exposures can occur anytime postimplant placement. This review discovered an implant exposure rate of 9.1%, with the majority of the exposures occurring after the postoperative follow-up period. Patients with porous orbital implants should be followed on a long-term basis to detect this complication.

  17. Evaluating exposure of pedestrians to airborne contaminants associated with non-potable water use for pavement cleaning.

    Science.gov (United States)

    Seidl, M; Da, G; Ausset, P; Haenn, S; Géhin, E; Moulin, L

    2016-04-01

    Climate change and increasing demography press local authorities to look after affordable water resources and replacement of drinking water for city necessities like street and pavement cleaning by more available raw water. Though, the substitution of drinking by non-drinking resources demands the evaluation of sanitary hazards. This article aims therefore to evaluate the contribution of cleaning water to the overall exposure of city dwellers in case of wet pavement cleaning using crossed physical, chemical and biological approaches. The result of tracer experiments with fluorescein show that liquid water content of the cleaning aerosol produced is about 0.24 g m(-3), rending possible a fast estimation of exposure levels. In situ analysis of the aerosol particles indicates a significant increase in particle number concentration and particle diameter, though without change in particle composition. The conventional bacterial analysis using total coliforms as tracer suggests that an important part of the contamination is issued from the pavement. The qPCR results show a more than 20-fold increase of background genome concentration for Escherichia coli and 10-fold increase for Enterococcus but a negligible contribution of the cleaning water. The fluorescence analysis of the cleaning aerosol confirms the above findings identifying pavement surface as the major contributor to aerosol organic load. The physical, chemical and microbiological approaches used make it possible to describe accurately the cleaning bioaerosol and to identify the existence of significantly higher levels of all parameters studied during the wet pavement cleaning. Though, the low level of contamination and the very short time of passage of pedestrian in the zone do not suggest a significant risk for the city dwellers. As the cleaning workers remain much longer in the impacted area, more attention should be paid to their chronic exposure.

  18. Experimental low-level jaw clenching inhibits temporal summation evoked by electrical stimulation in healthy human volunteers.

    Science.gov (United States)

    Tada, Hiroaki; Torisu, Tetsurou; Tanaka, Mihoko; Murata, Hiroshi; De Laat, Antoon; Svensson, Peter

    2015-05-01

    To examine the effect of low-level jaw clenching on temporal summation in healthy volunteers. In 18 healthy volunteers, the pain intensities evoked at the masseter muscle and the hand palm by the first and last stimuli in a train of repeated electrical stimuli (0.3 or 2.0 Hz) were rated using 0-100mm visual analogue scales (VAS), in order to evaluate temporal summation before and after three types of jaw-muscle tasks: low-level jaw clenching, repetitive gum chewing and mandibular rest position. A set of concentric surface electrodes with different diameters (small and large) was used for the electrical stimulation. The temporal summation evoked by the large diameter electrode with 2.0 Hz stimulation decreased significantly both on the masseter and the hand after low-level clenching (P ≤ 0.03), but did not show any significant change after the other tasks (P > 0.23). The VAS score of the first stimulation did not show any significant changes after low-level clenching (P > 0.57). Experimental low-level jaw clenching can inhibit pain sensitivity, especially temporal summation. Low-level jaw clenching can modify pain sensitivity, most likely through the central nervous system. The findings suggest that potential harmful low-level jaw clenching or tooth contacting could continue despite painful symptoms, e.g., temporomandibular disorders. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Low level gigabit Ethernet analysis for the LHCb computing farm

    CERN Document Server

    Walravens, Cedric

    2006-01-01

    This note presents the concept of Receive Descriptor Recycling to significantly reduce the performance drop associated with small packet Gigabit Ethernet traffic. High reliability of small-sized transmissions is crucial for correct calibration runs of the LHCb experiment, at the CERN LHC accelerator. Previous work applied to full link load Ethernet traffic, using UDP processes. This work covers more low-level details of the performance problem for small-sized traffic, using more lower-level Ethernet frames, and, with a deeper analysis at the PCI/PCI-X level. Measurements were performed at the LHCb online system, which is to a large extend made up of commodity equipment. Limits and trade-offs are inherent when optimising for small packet traffic. All important aspects in this context are covered. Results gathered show the Ethernet Controller's driver currently is the major bottleneck, preventing the system from reaching maximal Gigabit Ethernet performance. Receive Descriptor Recycling is implemented in the dr...

  20. SNS Low-Level RF Control System Design and Performance

    CERN Document Server

    Ma, Hengjie; Crofford, Mark; Doolittle, Lawrence; Kasemir, Kay-Uwe; Piller, Maurice; Ratti, Alessandro

    2005-01-01

    A full digital Low-Level RF controller has been developed for SNS LINAC. Its design is a good example of a modern digital implementation of the classic control theory. The digital hardware for all the control and DSP functionalities, including the final vector modulation, is implemented on a single high-density FPGA. Two models for the digital hardware have been written in VHDL and Verilog respectively, based on a very low latency control algorithm, and both have been being used for supporting the testing and commissioning the LINAC to the date. During the commissioning, the flexibility and ability for precise controls that only digital design on a larger FPGA can offer has proved to be a necessity for meeting the great challenge of a high-power pulsed SCL.

  1. Soil gas surveying at low-level radioactive waste sites

    Energy Technology Data Exchange (ETDEWEB)

    Crockett, A.B.; Moor, K.S.; Hull, L.C. [EG and G Idaho Inc., Idaho Falls, ID (United States). Idaho National Engineering Lab.

    1989-11-01

    Soil gas sampling is a useful screening technique for determining whether volatile organic compounds are present at low-level radioactive waste burial sites. The technique was used at several DOE sites during the DOE Environmental Survey to determine the presence and extent of volatile organic compound contamination. The advantages of the soil gas sampling are that near real time data can be obtained, no excavation is required, safety concerns are relatively minor, costs are relatively low, and large amounts of data can be obtained rapidly on the contaminants that may pose the greatest threat to groundwater resources. The disadvantages are that the data are difficult to interpret and relate to soil concentrations and environmental standards. This paper discusses the experiences of INEL sampling and analysis personnel, the advantages and disadvantages of the technique, and makes recommendations for improving the sampling and analytical procedures.

  2. Low level light therapy and tattoos: A case report.

    Science.gov (United States)

    Ingenito, Teresa

    2016-10-01

    Physical therapists (PTs) frequently provide neuromusculoskeletal treatment for patients who incidentally may have one or more tattoos. Low level light therapy (LLLT) is one of the modalities commonly used by physical therapists to decrease pain and facilitate healing. This case report describes a 22 year old man who was given LLLT to address his complaints of musculoskeletal pain. Blistering of the skin was documented over the LLLT application site, a black tattoo. The blisters, which formed after the LLLT treatment were most likely caused by the inadvertent and unexpected heating of the iron oxides and/or the metal salts in the tattoo's black pigment. PTs should exercise caution when applying LLLT in the presence of dark tattoos. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Oestrogen, ocular function and low-level vision: a review.

    Science.gov (United States)

    Hutchinson, Claire V; Walker, James A; Davidson, Colin

    2014-11-01

    Over the past 10 years, a literature has emerged concerning the sex steroid hormone oestrogen and its role in human vision. Herein, we review evidence that oestrogen (oestradiol) levels may significantly affect ocular function and low-level vision, particularly in older females. In doing so, we have examined a number of vision-related disorders including dry eye, cataract, increased intraocular pressure, glaucoma, age-related macular degeneration and Leber's hereditary optic neuropathy. In each case, we have found oestrogen, or lack thereof, to have a role. We have also included discussion of how oestrogen-related pharmacological treatments for menopause and breast cancer can impact the pathology of the eye and a number of psychophysical aspects of vision. Finally, we have reviewed oestrogen's pharmacology and suggest potential mechanisms underlying its beneficial effects, with particular emphasis on anti-apoptotic and vascular effects. © 2014 Society for Endocrinology.

  4. Low-level radioactive waste form qualification testing

    Energy Technology Data Exchange (ETDEWEB)

    Sohal, M.S.; Akers, D.W.

    1998-06-01

    This report summarizes activities that have already been completed as well as yet to be performed by the Idaho National Engineering and Environmental Laboratory (INEEL) to develop a plan to quantify the behavior of radioactive low-level waste forms. It briefly describes the status of various tasks, including DOE approval of the proposed work, several regulatory and environmental related documents, tests to qualify the waste form, preliminary schedule, and approximate cost. It is anticipated that INEEL and Brookhaven National Laboratory will perform the majority of the tests. For some tests, services of other testing organizations may be used. It should take approximately nine months to provide the final report on the results of tests on a waste form prepared for qualification. It is anticipated that the overall cost of the waste quantifying service is approximately $150,000. The following tests are planned: compression, thermal cycling, irradiation, biodegradation, leaching, immersion, free-standing liquid tests, and full-scale testing.

  5. Nocturnal low-level jets: sporadic turbulence on complex terrain

    Science.gov (United States)

    Jimenez, M. A.; Cuxart, J.

    2009-04-01

    Under weak pressure gradient conditions and clear-sky nights the development of locally generated circulations is favourished, specially in complex terrain. As night advances, the layer close to the ground cools down and stably stratified conditions prevail, with weak and usually sporadic or intermittent turbulence. In this work this phenomena is studied through high-resolution mesoscale simulations that are verified with data from weather stations and satellite information. The chosen domain is the island of Majorca, located in the western Mediterranean sea. A large variety of circulations is observed in the three main basins of the island, with drainage flows and organization at the basin scale. These low-level jet structures occasionaly cause turbulent bursts and very efficient mixing in the vertical, leading to significant changes of the atmospheric conditions close to the ground.

  6. Role of reactive oxygen species in low level light therapy

    Science.gov (United States)

    Chen, Aaron Chi-Hao; Huang, Ying-Ying; Arany, Praveen R.; Hamblin, Michael R.

    2009-02-01

    This review will focus on the role of reactive oxygen species in the cellular and tissue effects of low level light therapy (LLLT). Coincidentally with the increase in electron transport and in ATP, there has also been observed by intracellular fluorescent probes and electron spin resonance an increase in intracellular reactive oxygen species (ROS) such as superoxide, hydrogen peroxide, singlet oxygen and hydroxyl radical. ROS scavengers, antioxidants and ROS quenchers block many LLLT processes. It has been proposed that light between 400-500- nm may produce ROS by a photosensitization process involving flavins, while longer wavelengths may directly produce ROS from the mitochondria. Several redox-sensitive transcription factors are known such as NF-kB and AP1, that are able to initiate transcription of genes involved in protective responses to oxidative stress. It may be the case that LLLT can be pro-oxidant in the short-term, but anti-oxidant in the long-term.

  7. Summertime Low-Level Jets over the Great Plains

    Energy Technology Data Exchange (ETDEWEB)

    Stensrud, D.J. [NOAA/ERL/National Severe Storms Lab., Norman, OK (United States); Pfeifer, S. [Univ. of Oklahoma, Norman, OK (United States)

    1996-04-01

    The sky over the southern Great Plains Cloud and Atmospheric Radiation Testbed (CART) site of the Atmospheric Radiation Measurement (ARM) Program during the predawn and early morning hours often is partially obstructed by stratocumulus, stratus fractus, or cumulus fractus that are moving rapidly to the north, even through the surface winds are weak. This cloud movement is evidence of the low-level jet (LLJ), a wind speed maximum that occurs in the lowest few kilometers of the atmosphere. Owing to the wide spacing between upper-air sounding sites and the relatively infrequent sounding launches, LLJ evolution has been difficult to observe adequately, even though the effects of LLJs on moisture flux into North America are large. Model simulation of the LLJ is described.

  8. Low-level light therapy (LLLT) for cosmetics and dermatology

    Science.gov (United States)

    Sawhney, Mossum K.; Hamblin, Michael R.

    2014-02-01

    Over the last few years, low-level laser (light) therapy (LLLT) has been demonstrated to be beneficial to the field of aesthetic medicine, specifically aesthetic dermatology. LLLT encompasses a broad spectrum of procedures, primarily cosmetic, which provide treatment options for a myriad of dermatological conditions. Dermatological disorders involving inflammation, acne, scars, aging and pigmentation have been investigated with the assistance of animal models and clinical trials. The most commercially successful use of LLLT is for managing alopecia (hair loss) in both men and women. LLLT also seems to play an influential role in procedures such as lipoplasty and liposuction, allowing for noninvasive and nonthermal methods of subcutaneous fat reduction. LLLT offers a means to address such conditions with improved efficacy versatility and no known side-effects; however comprehensive literature reports covering the utility of LLLT are scarce and thus the need for coverage arises.

  9. Micronucleus, Nucleoplasmic Bridge, and Nuclear Budding in Peripheral Blood Cells of Workers Exposed to Low Level Benzene

    Directory of Open Access Journals (Sweden)

    I Jamebozorgi

    2016-10-01

    Full Text Available Background: Benzene is one of the important occupational pollutants. There are some reports about the leukemogenic effects related to low-level exposure to benzene. Objective: To study the frequency of micronucleus (MN, nucleoplasmic bridge (NB, and nuclear budding (NBUD in the peripheral blood lymphocytes of petrochemical workers with low level exposure to benzene. Methods: We enrolled 50 workers exposed to low-level benzene and 31 unexposed workers of a petrochemical industry. After exclusion of 3 samples, peripheral blood lymphocytes of the remaining 47 exposed and 31 unexposed workers were analyzed for the frequency of MN, NB, and NBUD by cytochalasin-blocked MN technique. Results: MN was present in 28 (60% exposed and 18 (58% unexposed workers. NB was observed in 6 (13%, and 2 (7% exposed and unexposed workers, respectively; the frequency for NBUD was 20 (43%, and 13 (42%, respectively. No significant difference was found in the observed frequencies of MN, NB, and NBUD in the peripheral blood lymphocytes between the exposed and unexposed group workers. Conclusion: Occupational exposure to low-level benzene does not increase the frequency of MN, NB, and NBUD in the peripheral blood lymphocytes, biomarkers for DNA damage.

  10. Noise exposure reconstruction and evaluation of exposure trends in two large automotive plants.

    Science.gov (United States)

    Brueck, Scott E; Prince Panaccio, Mary; Stancescu, Daniel; Woskie, Susan; Estill, Cheryl; Waters, Martha

    2013-11-01

    This study used a task-based approach to reconstruct employee noise exposures at two large automotive manufacturing plants for the period 1970-1989, utilizing historic noise measurement data, work history records, documented changes in plant operations, focus group discussions, structured interviews with long-tenure employees, and task-based job profiles. Task-based job noise exposure profiles were developed in the 1990s when the plants conducted task-based noise monitoring. Under the assumption that tasks and time-at-task profile within jobs did not change over time, these profiles were applied to historic jobs. By linking historic noise exposure measurements to job tasks, this approach allowed task-based reconstructed noise exposure profiles to capture variability of daily noise exposures. Reconstructed noise exposures, along with task-based noise exposure measurements collected at each plant during the 1990s, were analyzed to examine time trends in workplace noise levels and worker noise exposure. Our analysis of noise exposure trends revealed that noise levels for many jobs declined by ≥3 dBA from 1970 to 1998 as operational and equipment changes occurred in the plants and some noise control measures were implemented, but for some jobs, noise levels increased in the mid- to late 1990s, most likely because of an increase in production at that time. Overall, the percentage of workers exposed to noise levels >90 dBA decreased from 95% in 1970 to 54% in 1998 at one of the plants and decreased from 36% in 1970 to ~5% in 1999 at the other plant. These reductions indicate a degree of success for the hearing conservation program. However, the actual number of employees with noise exposure >90 dBA increased because of a substantial increase in the number of production employees, particularly in jobs with high noise levels, which shows a hearing conservation program challenge that companies face during periods of increased production. Future analysis of hearing levels

  11. Uranium internal exposure evaluation based on urine assay data

    Energy Technology Data Exchange (ETDEWEB)

    Lawrence, J.N.P.

    1984-09-01

    The difficulties in assessing internal exposures to uranium from urine assay data are described. A simplified application of the ICRP-30 and ICRP Lung Model concepts to the estimation of uranium intake is presented. A discussion follows on the development of a computer code utilizing the ICRP-30-based uranium elimination model with the existing urine assay information. The calculated uranium exposures from 1949 through 1983 are discussed. 13 references, 1 table.

  12. Low Level Laser Therapy for chronic knee joint pain patients.

    Science.gov (United States)

    Nakamura, Takashi; Ebihara, Satoru; Ohkuni, Ikuko; Izukura, Hideaki; Harada, Takashi; Ushigome, Nobuyuki; Ohshiro, Toshio; Musha, Yoshiro; Takahashi, Hiroshi; Tsuchiya, Kazuaki; Kubota, Ayako

    2014-12-27

    Chronic knee joint pain is one of the most frequent complaints which is seen in the outpatient clinic in our medical institute. In previous studies we have reported the benefits of low level laser therapy (LLLT) for chronic pain in the shoulder joints, elbow, hand, finger and the lower back. The present study is a report on the effects of LLLT for chronic knee joint pain. Over the past 5 years, 35 subjects visited the outpatient clinic with complaints of chronic knee joint pain caused by the knee osteoarthritis-induced degenerative meniscal tear. They received low level laser therapy. A 1000 mW semi-conductor laser device was used to deliver 20.1 J/cm(2) per point in continuous wave at 830nm, and four points were irradiated per session (1 treatment) twice a week for 4 weeks. A visual analogue scale (VAS) was used to determine the effects of LLLT for the chronic pain and after the end of the treatment regimen a significant improvement was observed (p<0.001). After treatment, no significant differences were observed in the knee joint range of motion. Discussions with the patients revealed that it was important for them to learn how to avoid postures that would cause them knee pain in everyday life in order to have continuous benefits from the treatment. The present study demonstrated that 830 nm LLLT was an effective form of treatment for chronic knee pain caused by knee osteoarthritis. Patients were advised to undertake training involving gentle flexion and extension of the knee.

  13. Low level cues and ultra-fast face detection

    Directory of Open Access Journals (Sweden)

    Sébastien M Crouzet

    2011-11-01

    Full Text Available Recent experimental work has demonstrated the existence of extremely rapid saccades towards faces in natural scenes that can be initiated only 100 ms after image onset (Crouzet, Kirchner, & Thorpe, 2010. These ultra-rapid saccades constitute a major challenge to current models of processing in the visual system because they do not seem to leave enough time for even a single feed-forward pass through the ventral stream. Here we explore the possibility that the information required to trigger these very fast saccades could be extracted very early on in visual processing using relatively low-level amplitude spectrum (AS information in the Fourier domain. Experiment 1 showed that AS normalization can significantly alter face detection performance. However, a decrease of performance following AS normalization does not alone prove that AS-based information is used (Gaspar & Rousselet, 2009. In Experiment 2, following the Gaspar and Rousselet paper, we used a swapping procedure to clarify the role of AS information in fast object detection. Our experiment is composed of 3 conditions: (i original images, (ii inverted, in which the face image has the AS of a vehicle, and the vehicle has the AS of a face, and (iii swapped, where the face has the AS of another face image, and the vehicle has the AS of another vehicle image. The results showed very similar levels of performance in the original and swapped conditions, and a clear drop in the inverted condition. This result demonstrates that, in the early temporal window offered by the saccadic choice task, the visual saccadic system does indeed rely on low-level AS information in order to rapidly detect faces. This sort of crude diagnostic information could potentially be derived very early on in the visual system, possibly as early as V1 and V2.

  14. Framework for DOE mixed low-level waste disposal: Site fact sheets

    Energy Technology Data Exchange (ETDEWEB)

    Gruebel, M.M.; Waters, R.D.; Hospelhorn, M.B.; Chu, M.S.Y. [eds.

    1994-11-01

    The Department of Energy (DOE) is required to prepare and submit Site Treatment Plans (STPS) pursuant to the Federal Facility Compliance Act (FFCAct). Although the FFCAct does not require that disposal be addressed in the STPS, the DOE and the States recognize that treatment of mixed low-level waste will result in residues that will require disposal in either low-level waste or mixed low-level waste disposal facilities. As a result, the DOE is working with the States to define and develop a process for evaluating disposal-site suitability in concert with the FFCAct and development of the STPS. Forty-nine potential disposal sites were screened; preliminary screening criteria reduced the number of sites for consideration to twenty-six. The DOE then prepared fact sheets for the remaining sites. These fact sheets provided additional site-specific information for understanding the strengths and weaknesses of the twenty-six sites as potential disposal sites. The information also provided the basis for discussion among affected States and the DOE in recommending sites for more detailed evaluation.

  15. Performance Assessment for the Idaho National Laboratory Remote-Handled Low-Level Waste Disposal Facility

    Energy Technology Data Exchange (ETDEWEB)

    Annette L. Schafer; A. Jeffrey Sondrup; Arthur S. Rood

    2012-05-01

    This performance assessment for the Remote-Handled Low-Level Radioactive Waste Disposal Facility at the Idaho National Laboratory documents the projected radiological dose impacts associated with the disposal of low-level radioactive waste at the facility. This assessment evaluates compliance with the applicable radiological criteria of the U.S. Department of Energy and the U.S. Environmental Protection Agency for protection of the public and the environment. The calculations involve modeling transport of radionuclides from buried waste to surface soil and subsurface media, and eventually to members of the public via air, groundwater, and food chain pathways. Projections of doses are calculated for both offsite receptors and individuals who inadvertently intrude into the waste after site closure. The results of the calculations are used to evaluate the future performance of the low-level radioactive waste disposal facility and to provide input for establishment of waste acceptance criteria. In addition, one-factor-at-a-time, Monte Carlo, and rank correlation analyses are included for sensitivity and uncertainty analysis. The comparison of the performance assessment results to the applicable performance objectives provides reasonable expectation that the performance objectives will be met

  16. Effect of low-level pulsed laser 890-nm on lumbar spondylolisthesis: a case report

    Science.gov (United States)

    Mortazavi, Seyed M. J.; Afsharpad, Mitra; Djavid, Gholam-reza E.

    2002-10-01

    Objective: Evaluating the effectiveness of low-level laser therapy (LLLT) in alleviating the symptoms of lumbar spondylolisthesis. Materials and Methods: Laser was irradiated for 2 mm at six symmetric points along the lumbosacral spine and 5 points along the referred point ofpain, six times a week for 2 weeks (890 nm; 8 J/cm2; pulsed at 1500 Hz). Perception of benefit, level of function was assessed by the Oswestry disability index, lumbar mobility range of motion and low back pain intensity. Results and Discussion: Results showed a complete reduction in pain and improvement in function in the patient. This case report suggests that low-level laser therapy (LLLT) could play a role in conservative management of low-grade lumbar spondylolisthesis.

  17. [Tuscany mesothelioma registry (1988-2000): evaluation of asbestos exposure].

    Science.gov (United States)

    Gorini, G; Silvestri, S; Merler, E; Chellini, E; Cacciarini, V; Seniori Costantini, A Seniori

    2002-01-01

    The Tuscany Mesothelioma Register (ARTMM) records pleural malignant mesothelioma cases of Tuscany residents, diagnosed by histological, cytological, or clinical (radiography or computerized tomography) examinations. The ARTMM began in 1988 and estimates mesothelioma incidence in Tuscany and collects information on past asbestos exposure of mesothelioma cases. The aim of this paper was to describe the incidence of pleural mesothelioma cases in Tuscany and to analyse their possible past asbestos exposures. We considered pleural mesothelioma cases recorded in ARTMM in the period 1988-2000 and interviews collected for these cases. In order to identify past asbestos exposure in the occupational and non-occupational history of patients, interviews were carried out using a standardised questionnaire. In the period 1988-2000, 494 pleural malignant mesothelioma cases were recorded in the ARTMM; 82% were males. In the periods 1988-1993, 1994-1997, 1998-2000 the incidence rates, standardised on the Italian population (per 100,000), were respectively 1.15, 1.57, 2.58 among males; 0.29; 0.27; 0.29 among females. Information on occupational history was collected for 418 mesothelioma patients (85% of recorded cases): 173 mesothelioma cases were directly interviewed; for 245 cases relatives or work colleagues were interviewed. Occupational asbestos exposure was ranked as certain, probable or possible in 72% of the interviewed cases (80% of males; 20% of females). Environmental and non-occupational asbestos exposure was identified in 1% of males, and 3% of females. In 24% of the interviewed cases (15% of males; 74% of females) no known asbestos exposure was identified. Occupational asbestos exposure occurred in maritime activities (shipyards, dock work, merchant and regular Navy), the building industry, railway carriage construction and maintenance, rail transport, textile industries (mainly rag sorting), electricity production, asbestos cement manufacture, chemical, iron and steel

  18. Use of Biomonitoring Data to Evaluate Methyl Eugenol Exposure

    Science.gov (United States)

    Robison, Steven H.; Barr, Dana B.

    2006-01-01

    Methyl eugenol is a naturally occurring material found in a variety of food sources, including spices, oils, and nutritionally important foods such as bananas and oranges. Given its natural occurrence, a broad cross-section of the population is likely exposed. The availability of biomonitoring and toxicology data offers an opportunity to examine how biomonitoring data can be integrated into risk assessment. Methyl eugenol has been used as a biomarker of exposure. An analytical method to detect methyl eugenol in human blood samples is well characterized but not readily available. Human studies indicate that methyl eugenol is short-lived in the body, and despite the high potential for exposure through the diet and environment, human blood levels are relatively low. The toxicology studies in animals demonstrate that relatively high-bolus doses administered orally result in hepatic neoplasms. However, an understanding is lacking regarding how this effect relates to the exposures that result when food containing methyl eugenol is consumed. Overall, the level of methyl eugenol detected in biomonitoring studies indicates that human exposure is several orders of magnitude lower than the lowest dose used in the bioassay. Furthermore, there are no known health effects in humans that result from typical dietary exposure to methyl eugenol. PMID:17107870

  19. Relevance of biotic pathways to the long-term regulation of nuclear waste disposal. Topical report on reference eastern humid low-level sites

    Energy Technology Data Exchange (ETDEWEB)

    McKenzie, D.H.; Cadwell, L.L.; Eberhardt, L.E.; Kennedy, W.E. Jr.; Peloquin, R.A.; Simmons, M.A.

    1983-01-01

    The purpose of the work reported here was to develop an order-of-magnitude estimate for the potential dose to man resulting from biotic transport mechanisms at a humid reference low-level waste site in the eastern US. A description of the reference site is presented that includes the waste inventories, site characteristics and biological communites. Parameter values for biotic transport processes are based on data reported in current literature. Transport and exposure scenarios are developed for assessing biotic transport during 500 years following site closure. Calculations of radionuclide decay and waste container decomposition are made to estimate the quantities available for biotic transport. Doses to man are calculated for the biological transport of radionucludes at the reference site after loss of institutional control. These dose estimates are compared to dose estimates we calculated for the intruder-agricultural scenarios reported in the DEIS for 10 CFR 61 (NRC). Dose to man estimates as a result of cumulative biotic transport are calculated to be of the same order-of-magnitude as the dose resulting from the more commonly evaluated human intrusion scenario. The reported lack of potential importance of biotic transport at low-level waste sites in earlier assessment studies is not confirmed by findings presented in this report. Through biotic transport, radionuclides can be moved to locations where they can enter exposure pathways to man.

  20. Low-level toxicity of chemicals: No acceptable levels?

    Directory of Open Access Journals (Sweden)

    Bruce P Lanphear

    2017-12-01

    Full Text Available Over the past 3 decades, in a series of studies on some of the most extensively studied toxic chemicals and pollutants, scientists have found that the amount of toxic chemical linked with the development of a disease or death-which is central to determining "safe" or "hazardous" levels-is proportionately greater at the lowest dose or levels of exposure. These results, which are contrary to the way the United States Environmental Protection Agency (EPA and other regulatory agencies assess the risk of chemicals, indicate that we have underestimated the impact of toxic chemicals on death and disease. If widely disseminated chemicals and pollutants-like radon, lead, airborne particles, asbestos, tobacco, and benzene-do not exhibit a threshold and are proportionately more toxic at the lowest levels of exposure, we will need to achieve near-zero exposures to protect public health.

  1. Ultra Low Level Environmental Neutron Measurements Using Superheated Droplet Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, A.C. [Centro de Ciencias e Tecnologias Nucleares, Instituto Superior Tecnico, Universidade Tecnica de Lisboa, Estrada Nacional 10 - km 139.7, 2695-066 Bobadela LRS (Portugal); Centro de Fisica Nuclear, Universidade de Lisboa. Av. Prof. Gama Pinto, 2, 1649- 003 Lisboa (Portugal); Felizardo, M.; Girard, T.A.; Kling, A.; Ramos, A.R. [Centro de Fisica Nuclear, Universidade de Lisboa. Av. Prof. Gama Pinto, 2, 1649- 003 Lisboa (Portugal); Marques, J.G.; Prudencio, M.I.; Marques, R.; Carvalho, F.P. [Centro de Ciencias e Tecnologias Nucleares, Instituto Superior Tecnico, Universidade Tecnica de Lisboa, Estrada Nacional 10 - km 139.7, 2695-066 Bobadela LRS (Portugal)

    2015-07-01

    Through the application of superheated droplet detectors (SDDs), the SIMPLE project for the direct search for dark matter (DM) reached the most restrictive limits on the spin-dependent sector to date. The experiment is based on the detection of recoils following WIMP-nuclei interaction, mimicking those from neutron scattering. The thermodynamic operation conditions yield the SDDs intrinsically insensitive to radiations with linear energy transfer below ∼150 keVμm{sup -1} such as photons, electrons, muons and neutrons with energies below ∼40 keV. Underground facilities are increasingly employed for measurements in a low-level radiation background (DM search, gamma-spectroscopy, intrinsic soft-error rate measurements, etc.), where the rock overburden shields against cosmic radiation. In this environment the SDDs are sensitive only to α-particles and neutrons naturally emitted from the surrounding materials. Recently developed signal analysis techniques allow discrimination between neutron and α-induced signals. SDDs are therefore a promising instrument for low-level neutron and α measurements, namely environmental neutron measurements and α-contamination assays. In this work neutron measurements performed in the challenging conditions of the latest SIMPLE experiment (1500 mwe depth with 50-75 cm water shield) are reported. The results are compared with those obtained by detailed Monte Carlo simulations of the neutron background induced by {sup 238}U and {sup 232}Th traces in the facility, shielding and detector materials. Calculations of the neutron energy distribution yield the following neutron fluence rates (in 10{sup -8} cm{sup -2}s{sup -1}): thermal (<0.5 eV): 2.5; epithermal (0.5 eV-100 keV): 2.2; fast (>1 MeV): 3.9. Signal rates were derived using standard cross sections and codes routinely employed in reactor dosimetry. The measured and calculated neutron count rates per unit of active mass were 0.15 ct/kgd and 0.33 ct/kg-d respectively. As the major

  2. Development of a Low-Level Ar-37 Calibration Standard

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Richard M.; Aalseth, Craig E.; Bowyer, Ted W.; Day, Anthony R.; Fuller, Erin S.; Haas, Derek A.; Hayes, James C.; Hoppe, Eric W.; Humble, Paul H.; Keillor, Martin E.; LaFerriere, Brian D.; Mace, Emily K.; McIntyre, Justin I.; Miley, Harry S.; Myers, Allan W.; Orrell, John L.; Overman, Cory T.; Panisko, Mark E.; Seifert, Allen

    2016-03-07

    Argon-37 is an important environmental signature of an underground nuclear explosion. Producing and quantifying low-level 37Ar standards is an important step in the development of sensitive field measurement instruments for use during an On-Site Inspection, a key provision of the Comprehensive Nuclear-Test-Ban Treaty. This paper describes progress at Pacific Northwest National Laboratory (PNNL) in the development of a process to generate and quantify low-level 37Ar standard material, which can then be used to calibrate sensitive field systems at activities consistent with soil background levels. The 37Ar used for our work was generated using a laboratory-scale, high-energy neutron source to irradiate powdered samples of calcium carbonate. Small aliquots of 37Ar were then extracted from the head space of the irradiated samples. The specific activity of the head space samples, mixed with P10 (90% stable argon:10% methane by mole fraction) count gas, is then derived using the accepted Length-Compensated Internal-Source Proportional Counting method. Due to the low activity of the samples, a set of three Ultra-Low Background Proportional-Counters designed and fabricated at PNNL from radio-pure electroformed copper was used to make the measurements in PNNL’s shallow underground counting laboratory. Very low background levels (<10 counts/day) have been observed in the spectral region near the 37Ar emission feature at 2.8 keV. Two separate samples from the same irradiation were measured. The first sample was counted for 12 days beginning 28 days after irradiation, the second sample was counted for 24 days beginning 70 days after irradiation (the half-life of 37Ar is 35.0 days). Both sets of measurements were analyzed and yielded very similar results for the starting activity (~0.1 Bq) and activity concentration (0.15 mBq/ccSTP argon) after P10 count gas was added. A detailed uncertainty model was developed based on the ISO Guide to the Expression of Uncertainty in

  3. [Effects of subliminal mere exposure to group members on intergroup evaluation: category evaluation measured in the Implicit Association Test (IAT)].

    Science.gov (United States)

    Kawakami, Naoaki; Yoshida, Fujio

    2010-10-01

    This study investigated the effects of subliminal mere exposure to ingroup or outgroup members on intergroup evaluation as measured in the Implicit Association Test (IAT). Participants first memorized the members of two groups. Then, they were assigned to either group by lot, and completed the IAT for intergroup evaluation (Time 1). In the next phase, half the participants were subliminally exposed to ingroup members and half to outgroup members. Upon completion of the exposure, the same IAT was administered at Time 2. The results showed that participants who were exposed to ingroup members evaluated the ingroup more positively at Time 2 than at Time 1. Participants who were exposed to outgroup members did not show an effect toward the outgroup. The finding that the mere exposure effect occurred only for the ingroup exposure condition suggests that unconscious awareness of the ingroup enhances the mere exposure effect.

  4. LOWRAD 96. Methods and applications of low-level radioactivity measurements. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Fietz, J. [ed.] [Forschungszentrum Rossendorf e.V. (FZR), Dresden (Germany)

    1997-03-01

    The newest developments in the field of low-level radioactivity measurements and new applications for existing and low-level measuring facilities are presented. The contributions mostly were devoted to basic physical aspects and applications of low-level counting. Papers on chemical separation and preparation techniques and on low-level radiation dose determinations were also presented. (DG)

  5. Evaluation of toxicological implications of ingestion exposure to ...

    African Journals Online (AJOL)

    Epidemiologic and experimental data suggest that exposure to petroleum hydrocarbon exert toxicities on variety of organs of living system such as the lungs, liver and kidney. Because increased LDL cholesterol, decreased HDL cholesterol and alteration in the level of total serum cholesterol have all been implicated as risk ...

  6. Towards Smart Homes Using Low Level Sensory Data

    Directory of Open Access Journals (Sweden)

    Young-Koo Lee

    2011-12-01

    Full Text Available Ubiquitous Life Care (u-Life care is receiving attention because it provides high quality and low cost care services. To provide spontaneous and robust healthcare services, knowledge of a patient’s real-time daily life activities is required. Context information with real-time daily life activities can help to provide better services and to improve healthcare delivery. The performance and accuracy of existing life care systems is not reliable, even with a limited number of services. This paper presents a Human Activity Recognition Engine (HARE that monitors human health as well as activities using heterogeneous sensor technology and processes these activities intelligently on a Cloud platform for providing improved care at low cost. We focus on activity recognition using video-based, wearable sensor-based, and location-based activity recognition engines and then use intelligent processing to analyze the context of the activities performed. The experimental results of all the components showed good accuracy against existing techniques. The system is deployed on Cloud for Alzheimer’s disease patients (as a case study with four activity recognition engines to identify low level activity from the raw data captured by sensors. These are then manipulated using ontology to infer higher level activities and make decisions about a patient’s activity using patient profile information and customized rules.

  7. Low level laser therapy for traumatic brain injury

    Science.gov (United States)

    Wu, Qiuhe; Huang, Ying-Ying; Dhital, Saphala; Sharma, Sulbha K.; Chen, Aaron C.-H.; Whalen, Michael J.; Hamblin, Michael R.

    2010-02-01

    Low level laser (or light) therapy (LLLT) has been clinically applied for many indications in medicine that require the following processes: protection from cell and tissue death, stimulation of healing and repair of injuries, and reduction of pain, swelling and inflammation. One area that is attracting growing interest is the use of transcranial LLLT to treat stroke and traumatic brain injury (TBI). The fact that near-infrared light can penetrate into the brain would allow non-invasive treatment to be carried out with a low likelihood of treatment-related adverse events. LLLT may have beneficial effects in the acute treatment of brain damage injury by increasing respiration in the mitochondria, causing activation of transcription factors, reducing key inflammatory mediators, and inhibiting apoptosis. We tested LLLT in a mouse model of TBI produced by a controlled weight drop onto the skull. Mice received a single treatment with 660-nm, 810-nm or 980-nm laser (36 J/cm2) four hours post-injury and were followed up by neurological performance testing for 4 weeks. Mice with moderate to severe TBI treated with 660- nm and 810-nm laser had a significant improvement in neurological score over the course of the follow-up and histological examination of the brains at sacrifice revealed less lesion area compared to untreated controls. Further studies are underway.

  8. Apparatus to measure low level helium for neutron dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Ozaki, Shuji; Takao, Yoshiyuki; Muramasu, Masatomo; Hida, Tomoya; Sou, Hirofumi; Nakashima, Hideki [Kyushu Univ., Fukuoka (Japan); Kanda, Yukinori

    1998-03-01

    An apparatus to measure low level helium in a solid sample for neutron dosimetry in the practical use such as area monitoring in the long-term and reactor surveillance was reported. In our previous work, the helium atoms measurement system (HAMS) was developed. A sample was evaporated in the furnace and the released gas from the sample was analyzed with the mass spectrometer of the system to determine the amount of helium contained in it. The system has been improved to advance the lower helium measurement limit in a solid sample for its application to an area monitoring system. The mass of a solid is up to 100mg. Two important points should be considered to advance the lower limit. One was to produce a high quality vacuum in the system chamber for suppressing background gases during the sample measurement. The other important point was to detect very small output from the mass spectrometer. A pulse counting system was used to get high sensitivity in the mass 4 analyzing. (author)

  9. Engineered sorbent barriers for low-level waste disposal.

    Energy Technology Data Exchange (ETDEWEB)

    Freeman, H.D.; Mitchell, S.J.; Buelt, J.L.

    1986-12-01

    The Engineered Sorbent Barriers Program at Pacific Northwest Laboratory is investigating sorbent materials to prevent the migration of soluble radio nuclides from low-level waste sites. These materials would allow water to pass, preventing the bathtub effect at humid sites. Laboratory studies identifield promising sorbent materials for three key radionuclides: for cesium, greensand; for cobalt, activated charcoal; and for strontium, synthetic zeolite or clinoptilolite. Mixtures of these sorbent materials were tested in 0.6-m-diameter columns using radioactive leachates. To simulate expected worst-case conditions, the leachate solution contained the radionuclides, competing cations, and a chelating agent and was adjusted to a pH of 5. A sorbent barrier comprised of greensand (1 wt%), activated charcoal (6 wt%), synthetic zeolite (20 wt%), and local soil (73 wt%) achieved the decontamination factors necessary to meet the regulatory performance requirements established for this study. Sorbent barriers can be applied to shallow-land burial, as backfill around the waste or engineered structures, or as backup to other liner systems. 7 refs., 14 figs., 12 tabs.

  10. Low Level Laser Therapy for Patients with Cervical Disk Hernia

    Science.gov (United States)

    Takahashi, Hiroshi; Okuni, Ikuko; Ushigome, Nobuyuki; Harada, Takashi; Tsuruoka, Hiroshi; Ohshiro, Toshio; Sekiguchi, Masayuki; Musya, Yoshiro

    2012-01-01

    Background and Aims: In previous studies we have reported the benefits of low level laser therapy (LLLT) for chronic shoulder joint pain, elbow, hand and finger pain, and low back pain. The present study is a report on the effects of LLLT for chronic neck pain. Materials and Methods: Over a 3 year period, 26 rehabilitation department outpatients with chronic neck pain, diagnosed as being caused by cervical disk hernia, underwent treatment applied to the painful area with a 1000 mW semi-conductor laser device delivering at 830 nm in continuous wave, 20.1 J/cm2/point, and three shots were given per session (1 treatment) with twice a week for 4 weeks. Results: 1. A visual analogue scale (VAS) was used to determine the effects of LLLT for chronic pain and after the end of the treatment regimen a significant improvement was observed (p<0.001). 2. After treatment, no significant differences in cervical spine range of motion were observed. 3. Discussions with the patients revealed that in order to receive continued benefits from treatment, it was important for them to be taught how to avoid postures that would cause them neck pain in everyday life. Conclusion: The present study demonstrates that LLLT was an effective form of treatment for neck and back pain caused by cervical disk hernia, reinforced by postural training. PMID:24511189

  11. Low-level light treatment ameliorates immune thrombocytopenia

    Science.gov (United States)

    Yang, Jingke; Zhang, Qi; Wu, Mei X.

    2017-02-01

    Immune thrombocytopenia (ITP) is an immune-mediated acquired bleeding disorder characterized by abnormally low platelet counts. We reported here the ability of low-level light treatment (LLLT) to alleviate ITP in mice. The treatment is based on noninvasive whole body illumination 30 min a day for a few consecutive days by near infrared light (830 nm) transmitted by an array of light-emitting diodes (LEDs). LLLT significantly lifted the nadir of platelet counts and restored tail bleeding time when applied to two passive ITP models induced by anti-CD41 antibody. The anti-platelet antibody hindered megakaryocyte differentiation from the progenitors, impaired proplatelet and platelet formation, and induced apoptosis of platelets. These adverse effects of anti-CD41 antibody were all mitigated by LLLT to varying degrees, owing to its ability to enhance mitochondrial biogenesis and activity in megakaryocytes and preserve mitochondrial functions in platelets in the presence of the antibody. The observations argue not only for contribution of mitochondrial stress to the pathology of ITP, but also clinical potentials of LLLT as a safe, simple, and cost-effective modality of ITP.

  12. Low-level laser therapy for Peyronie's disease

    Science.gov (United States)

    Johnson, Douglas E.; Bertini, John E. J.; Harris, James M.; Hawkins, Janet H.

    1995-05-01

    We are reporting the preliminary results of a nonrandomized trial using a low-level gallium- aluminum-arsenide (GaAlAs) laser at a wavelength of 830 nm (Microlight 830, Lasermedics, Inc., Stafford, TX) to treat patients with symptomatic Peyronie's disease. All patients entered into the study had disease consisting of a well-defined fibrous plaque causing pain and/or curvature of the penile shaft on erection that interfered with satisfactory sexual intercourse. Treatment has consisted of 30 mW administered over a duty cycle of 100 seconds (3 J) beginning at the base of the penis and extending to the coronal sulcus over the dorsum of the penis at 0.5 cm intervals. An additional duty cycle of 100 seconds was delivered to each 0.5 cm of palpable plaque. The ability of the therapy to reduce the size of the fibrous plaque, the severity of the penile curvature, and the severity of pain associated with penile erection and the treatment's effect on the patient's quality of life were assessed for each patient at completion of therapy and 6 weeks later.

  13. Selected radionuclides important to low-level radioactive waste management

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-11-01

    The purpose of this document is to provide information to state representatives and developers of low level radioactive waste (LLW) management facilities about the radiological, chemical, and physical characteristics of selected radionuclides and their behavior in the environment. Extensive surveys of available literature provided information for this report. Certain radionuclides may contribute significantly to the dose estimated during a radiological performance assessment analysis of an LLW disposal facility. Among these are the radionuclides listed in Title 10 of the Code of Federal Regulations Part 61.55, Tables 1 and 2 (including alpha emitting transuranics with half-lives greater than 5 years). This report discusses these radionuclides and other radionuclides that may be significant during a radiological performance assessment analysis of an LLW disposal facility. This report not only includes essential information on each radionuclide, but also incorporates waste and disposal information on the radionuclide, and behavior of the radionuclide in the environment and in the human body. Radionuclides addressed in this document include technetium-99, carbon-14, iodine-129, tritium, cesium-137, strontium-90, nickel-59, plutonium-241, nickel-63, niobium-94, cobalt-60, curium -42, americium-241, uranium-238, and neptunium-237.

  14. Graphics Processors in HEP Low-Level Trigger Systems

    Science.gov (United States)

    Ammendola, Roberto; Biagioni, Andrea; Chiozzi, Stefano; Cotta Ramusino, Angelo; Cretaro, Paolo; Di Lorenzo, Stefano; Fantechi, Riccardo; Fiorini, Massimiliano; Frezza, Ottorino; Lamanna, Gianluca; Lo Cicero, Francesca; Lonardo, Alessandro; Martinelli, Michele; Neri, Ilaria; Paolucci, Pier Stanislao; Pastorelli, Elena; Piandani, Roberto; Pontisso, Luca; Rossetti, Davide; Simula, Francesco; Sozzi, Marco; Vicini, Piero

    2016-11-01

    Usage of Graphics Processing Units (GPUs) in the so called general-purpose computing is emerging as an effective approach in several fields of science, although so far applications have been employing GPUs typically for offline computations. Taking into account the steady performance increase of GPU architectures in terms of computing power and I/O capacity, the real-time applications of these devices can thrive in high-energy physics data acquisition and trigger systems. We will examine the use of online parallel computing on GPUs for the synchronous low-level trigger, focusing on tests performed on the trigger system of the CERN NA62 experiment. To successfully integrate GPUs in such an online environment, latencies of all components need analysing, networking being the most critical. To keep it under control, we envisioned NaNet, an FPGA-based PCIe Network Interface Card (NIC) enabling GPUDirect connection. Furthermore, it is assessed how specific trigger algorithms can be parallelized and thus benefit from a GPU implementation, in terms of increased execution speed. Such improvements are particularly relevant for the foreseen Large Hadron Collider (LHC) luminosity upgrade where highly selective algorithms will be essential to maintain sustainable trigger rates with very high pileup.

  15. Treating cognitive impairment with transcranial low level laser therapy.

    Science.gov (United States)

    de la Torre, Jack C

    2017-03-01

    This report examines the potential of low level laser therapy (LLLT) to alter brain cell function and neurometabolic pathways using red or near infrared (NIR) wavelengths transcranially for the prevention and treatment of cognitive impairment. Although laser therapy on human tissue has been used for a number of medical conditions since the late 1960s, it is only recently that several clinical studies have shown its value in raising neurometabolic energy levels that can improve cerebral hemodynamics and cognitive abilities in humans. The rationale for this approach, as indicated in this report, is supported by growing evidence that neurodegenerative damage and cognitive impairment during advanced aging is accelerated or triggered by a neuronal energy crisis generated by brain hypoperfusion. We have previously proposed that chronic brain hypoperfusion in the elderly can worsen in the presence of one or more vascular risk factors, including hypertension, cardiac disease, atherosclerosis and diabetes type 2. Although many unanswered questions remain, boosting neurometabolic activity through non-invasive transcranial laser biostimulation of neuronal mitochondria may be a valuable tool in preventing or delaying age-related cognitive decline that can lead to dementia, including its two major subtypes, Alzheimer's and vascular dementia. The technology to achieve significant improvement of cognitive dysfunction using LLLT or variations of this technique is moving fast and may signal a new chapter in the treatment and prevention of neurocognitive disorders. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Low-level waste minimization at the Y-12 Plant

    Energy Technology Data Exchange (ETDEWEB)

    Koger, J. [Oak Ridge National Lab., TN (United States)

    1993-03-01

    The Y-12 Development Waste Minimization Program is used as a basis for defining new technologies and processes that produce minimum low-level wastes (hazardous, mixed, radioactive, and industrial) for the Y-12 Plant in the future and for Complex-21 and that aid in decontamination and decommissioning (D and D) efforts throughout the complex. In the past, the strategy at the Y-12 Plant was to treat the residues from the production processes using chemical treatment, incineration, compaction, and other technologies, which often generated copious quantities of additional wastes and, with the exception of highly valuable materials such as enriched uranium, incorporated very little recycle in the process. Recycle, in this context, is defined as material that is put back into the process before it enters a waste stream. Additionally, there are several new technology drivers that have recently emerged with the changing climate in the Nuclear Weapons Complex such as Complex 21 and D and D technologies and an increasing number of disassemblies. The hierarchies of concern in the waste minimization effort are source reduction, recycle capability, treatment simplicity, and final disposal difficulty with regard to Complex 21, disassembly efforts, D and D, and, to a lesser extent, weapons production. Source reduction can be achieved through substitution of hazardous substances for nonhazardous materials, and process changes that result in less generated waste.

  17. WRAP low level waste (LLW) glovebox operational test report

    Energy Technology Data Exchange (ETDEWEB)

    Kersten, J.K.

    1998-02-19

    The Low Level Waste (LLW) Process Gloveboxes are designed to: receive a 55 gallon drum in an 85 gallon overpack in the Entry glovebox (GBIOI); and open and sort the waste from the 55 gallon drum, place the waste back into drum and relid in the Sorting glovebox (GB 102). In addition, waste which requires further examination is transferred to the LLW RWM Glovebox via the Drath and Schraeder Bagiess Transfer Port (DO-07-201) or sent to the Sample Transfer Port (STC); crush the drum in the Supercompactor glovebox (GB 104); place the resulting puck (along with other pucks) into another 85 gallon overpack in the Exit glovebox (GB 105). The status of the waste items is tracked by the Data Management System (DMS) via the Plant Control System (PCS) barcode interface. As an item is moved from the entry glovebox to the exit glovebox, the Operator will track an items location using a barcode reader and enter any required data on the DMS console. The Operational Test Procedure (OTP) will perform evolution`s (described below) using the Plant Operating Procedures (POP) in order to verify that they are sufficient and accurate for controlled glovebox operation.

  18. Low-Level Laser Therapy for Treatment of Oral Mucositis

    Directory of Open Access Journals (Sweden)

    Ravina Naomi Tarigan

    2012-12-01

    Full Text Available Radiation and chemotherapy are the treatment options for head and neck cancer. Several side effects related to those treat-ment have been shown. Oral mucositis is a common side effect in patients undergoing those treatment. The presence of oral mucositis in these patients would influencing quality of life therefore compromising treatment outcome. The spec-trum of oral mucositis can be clinically seen as thinning of oral mucosa, oral discomfort to painful oral lesion causing mastication impairment with increasing risk of infection. The Multinational Association for Supportive Care in Cancer (MASCC/International Society for Oral Oncology (ISOO has recommended some means that have important role in the management oral mucositis. The low-level laser therapy (LLLT is a relatively new way of reducing the severity of oral mucositis, although the true mechanism of action is still under study. This review aimed in exploring update about the usage of LLLT for oral mucositis treatment.DOI: 10.14693/jdi.v17i3.42

  19. Body contouring using 635-nm low level laser therapy.

    Science.gov (United States)

    Nestor, Mark S; Newburger, Jessica; Zarraga, Matthew B

    2013-03-01

    Noninvasive body contouring has become one of the fastest-growing areas of esthetic medicine. Many patients appear to prefer nonsurgical less-invasive procedures owing to the benefits of fewer side effects and shorter recovery times. Increasingly, 635-nm low-level laser therapy (LLLT) has been used in the treatment of a variety of medical conditions and has been shown to improve wound healing, reduce edema, and relieve acute pain. Within the past decade, LLLT has also emerged as a new modality for noninvasive body contouring. Research has shown that LLLT is effective in reducing overall body circumference measurements of specifically treated regions, including the hips, waist, thighs, and upper arms, with recent studies demonstrating the long-term effectiveness of results. The treatment is painless, and there appears to be no adverse events associated with LLLT. The mechanism of action of LLLT in body contouring is believed to stem from photoactivation of cytochrome c oxidase within hypertrophic adipocytes, which, in turn, affects intracellular secondary cascades, resulting in the formation of transitory pores within the adipocytes' membrane. The secondary cascades involved may include, but are not limited to, activation of cytosolic lipase and nitric oxide. Newly formed pores release intracellular lipids, which are further metabolized. Future studies need to fully outline the cellular and systemic effects of LLLT as well as determine optimal treatment protocols.

  20. Development of a speech-discriminating electromyogram system for routine ambulatory recordings for the low-level masseter muscle activity.

    Science.gov (United States)

    Kumazaki, Y; Naito, M; Kawakami, S; Hirata, A; Oki, K; Minagi, S

    2014-04-01

    Previous work suggests a relationship between sustained low-level tooth clenching and the aetiology of myogenous temporomandibular disorder (TMD) pain. This study aimed to establish a reliable system with which to evaluate low-level electromyographic (EMG) activity related to low-level tooth clenching while discriminating speech activity, which is one of the most common facial muscle activities to be discriminated from low-level clenching. This device should facilitate the clinical evaluation of awake muscle activity in TMD patients. Eight female and eight male subjects (38.9 ± 11.3 years) participated in the study to evaluate the validity of estimation of speech duration. Actual speech duration was defined by one examiner by pointing out the timing of beginning and end point of each speech on wave-editing software. Speech duration, as detected by a voice sensor system, which was activated by a voice loudness of 54.71 ± 5.00 dB, was significantly correlated with the above actual speech duration (P speech, EMG activity during speech could be precisely discriminated. The results of this study demonstrate that the EMG system with voice sensor system would be an effective tool for the evaluation of low-level masticatory muscle activity. © 2014 John Wiley & Sons Ltd.

  1. Raptor responses to low-level jet aircraft and sonic booms

    Science.gov (United States)

    Ellis, David H.; Ellis, Catherine H.; Mindell, David P.

    1991-01-01

    We estimated effects of low-level military jet aircraft and mid- to high-altitude sonic booms (actual and simulated) on nesting peregrine falcons (Falco peregrinus) and seven other raptors by observing their responses to test stimuli, determining nesting success for the test year, and evaluating site reoccupancy rates for the year following the tests. Frequent and nearby jet aircraft passes: (1) sometimes noticeably alarmed birds, (2) occasionally caused birds to fly from perches or eyries, (3) most often evoked only minimal responses, and (4) were never associated with reproductive failure. Similarly, responses to real and simulated mid- to high-altitude sonic booms were often minimal and never appeared productivity limiting. Eighteen (95%) of 19 nest sites subjected to low-level jet flights and/or simulated sonic booms in 1980 fledged young during that year. Eighteen (95%) of 19 sites disturbed in 1980 were reoccupied by pairs or lone birds of the same species in 1981.We subjected four pairs of prairie falcons (Falco mexicanus) to low-level aircraft at ad libitum levels during the courtship and incubation phases when adults were most likely to abandon: all four eyries fledged young. From heart rate (HR) data taken via a telemetering egg at another prairie falcon eyrie, we determined that stimulus-induced HR alterations were comparable to rate changes for birds settling to incubate following flight.While encouraging, our findings cannot be taken as conclusive evidence that jet flights and/or sonic booms will have no long-term negative effects for other raptor species or for other areas. In addition, we did not experiment with totally naive wild adults, rotary-winged aircraft, or low-level sonic booms.

  2. Estimating costs of low-level radioactive waste disposal alternatives for the Commonwealth of Massachusetts

    Energy Technology Data Exchange (ETDEWEB)

    1994-02-01

    This report was prepared for the Commonwealth of Massachusetts by the Idaho National Engineering Laboratory, National Low-Level Waste Management Program. It presents planning life-cycle cost (PLCC) estimates for four sizes of in-state low-level radioactive waste (LLRW) disposal facilities. These PLCC estimates include preoperational and operational expenditures, all support facilities, materials, labor, closure costs, and long-term institutional care and monitoring costs. It is intended that this report bc used as a broad decision making tool for evaluating one of the several complex factors that must be examined when deciding between various LLRW management options -- relative costs. Because the underlying assumptions of these analyses will change as the Board decides how it will manage Massachusett`s waste and the specific characteristics any disposal facility will have, the results of this study are not absolute and should only be used to compare the relative costs of the options presented. The disposal technology selected for this analysis is aboveground earth-mounded vaults. These vaults are reinforced concrete structures where low-level waste is emplaced and later covered with a multi-layered earthen cap. The ``base case`` PLCC estimate was derived from a preliminary feasibility design developed for the Illinois Low-Level Radioactive Waste Disposal Facility. This PLCC report describes facility operations and details the procedure used to develop the base case PLCC estimate for each facility component and size. Sensitivity analyses were performed on the base case PLCC estimate by varying several factors to determine their influences upon the unit disposal costs. The report presents the results of the sensitivity analyses for the five most significant cost factors.

  3. The impact of multiple low-level BCR-ABL1 mutations on response to ponatinib

    Science.gov (United States)

    Yeung, David T. O.; Yeoman, Alexandra L.; Altamura, Haley K.; Jamison, Bronte A.; Field, Chani R.; Hodgson, J. Graeme; Lustgarten, Stephanie; Rivera, Victor M.; Hughes, Timothy P.; Branford, Susan

    2016-01-01

    The third-generation tyrosine kinase inhibitor (TKI) ponatinib shows activity against all common BCR-ABL1 single mutants, including the highly resistant BCR-ABL1-T315I mutant, improving outcome for patients with refractory chronic myeloid leukemia (CML). However, responses are variable, and causal baseline factors have not been well-studied. The type and number of low-level BCR-ABL1 mutations present after imatinib resistance has prognostic significance for subsequent treatment with nilotinib or dasatinib as second-line therapy. We therefore investigated the impact of low-level mutations detected by sensitive mass-spectrometry before ponatinib initiation (baseline) on treatment response in 363 TKI-resistant patients enrolled in the PONATINIB for Chronic Myeloid Leukemia Evaluation and Ph+ Acute Lymphoblastic Leukemia trial, including 231 patients in chronic phase (CP-CML). Low-level mutations were detected in 53 patients (15%, including low-level T315I in 14 patients); most, however, did not undergo clonal expansion during ponatinib treatment and, moreover, no specific individual mutations were associated with inferior outcome. We demonstrate however, that the number of mutations detectable by mass spectrometry after TKI resistance is associated with response to ponatinib treatment and could be used to refine the therapeutic approach. Although CP-CML patients with T315I (63/231, 27%) had superior responses overall, those with multiple mutations detectable by mass spectrometry (20, 32%) had substantially inferior responses compared with those with T315I as the sole mutation detected (43, 68%). In contrast, for CP-CML patients without T315I, the inferior responses previously observed with nilotinib/dasatinib therapy for imatinib-resistant patients with multiple mutations were not seen with ponatinib treatment, suggesting that ponatinib may prove to be particularly advantageous for patients with multiple mutations detectable by mass spectrometry after TKI resistance

  4. Complex-wide review of DOE`s management of low-level radioactive waste - progress to date

    Energy Technology Data Exchange (ETDEWEB)

    Letourneau, M.J.

    1995-12-31

    The Defense Nuclear Facilities Safety Board (DNFSB) Recommendation 94-2 includes a recommendation that the Department of Energy (DOE) conduct a comprehensive, complex-wide review of the low-level waste issue to establish the dimensions of the low-level waste problem and to identify necessary corrective actions to address the safe disposition of past, present, and future volumes. DOE`s Implementation Plan calls for the conduct of a complex-wide review of low-level radioactive waste treatment, storage, and disposal sites to identify environmental, safety, and health vulnerabilities. The complex-wide review focuses on low-level waste disposal facilities through a site evaluation survey, reviews of existing documentation, and onsite observations. Low-level waste treatment and storage facilities will be assessed for their ability to meet waste acceptance criteria for disposal. Results from the complex-wide review will be used to form the basis for an integrated and planned set of actions to correct the identified vulnerabilities and to prompt development of new requirements for managing low-level waste.

  5. Lessons from regadenoson and low-level treadmill/regadenoson myocardial perfusion imaging: initial clinical experience in 1263 patients.

    Science.gov (United States)

    Kwon, Deborah H; Cerqueira, Manuel D; Young, Ron; Houghtaling, Penny; Lieber, Elizabeth; Menon, Venu; Brunken, Richard C; Jaber, Wael A

    2010-10-01

    Regadenoson is a pharmacologic stress agent, which was recently approved for stress myocardial perfusion imaging (MPI). Aside from the initial protocol-driven studies, clinical experience with this stress agent is limited. Furthermore, low-level treadmill testing in a large population with regadenoson has not previously been evaluated. We describe our experience in the first 6 months of routine inpatient and outpatient clinical use. Between 7/1/08 and 12/04/08, 1263 patients underwent regadenoson stress testing (596 with low-level treadmill, 667 supine). Past medical history, clinical symptoms during stress, and changes in systolic blood pressure were prospectively recorded. Low-level treadmill testing was well tolerated in our patient population. Shortness of breath, dizziness, palpitations, transient heart block, and nausea were less frequent when patients were able to exercise. In our population, 51% experienced a drop in systolic blood pressure greater than 10 mmHg, with 9% experiencing a decrease in more than 30 mmHg. This decrease in blood pressure was more common in patients who underwent low-level treadmill testing vs those that were supine (56% vs 47%, P-value Regadenoson MPI was well tolerated. There were no procedural deaths. Regadenoson and Regadenoson combined with low level exercise MPI appear to be safe and well tolerated. An asymptomatic fall in systolic blood pressure seems to be more common in patients who undergo low-level treadmill testing.

  6. Evaluation of exposure to ionizing radiation among gamma camera operators

    OpenAIRE

    Agnieszka Anna Domańska; Małgorzata Bieńkiewicz; Jerzy Olszewski

    2013-01-01

    Background: Protection of nuclear medicine unit employees from hazards of the ionizing radiation is a crucial issue of radiation protection services. We aimed to assess the severity of the occupational radiation exposure of technicians performing scintigraphic examinations at the Nuclear Medicine Department, Central Teaching Hospital of Medical University in Łódź, where thousands of different diagnostic procedures are performed yearly. Materials and Methods: In 2013 the studied diagnostic uni...

  7. Low level laser therapy reduces inflammation in activated Achilles tendinitis

    Science.gov (United States)

    Bjordal, Jan M.; Iversen, Vegard; Lopes-Martins, Rodrigo Alvaro B.

    2006-02-01

    Objective: Low level laser therapy (LLLT) has been forwarded as therapy for osteoarthritis and tendinopathy. Results in animal and cell studies suggest that LLLT may act through a biological mechanism of inflammatory modulation. The current study was designed to investigate if LLLT has an anti-inflammatory effect on activated tendinitis of the Achilles tendon. Methods: Seven patients with bilateral Achilles tendonitis (14 tendons) who had aggravated symptoms by pain-inducing activity immediately prior to the study. LLLT (1.8 Joules for each of three points along the Achilles tendon with 904nm infrared laser) and placebo LLLT were administered to either Achilles tendons in a random order to which patients and therapist were blinded. Inflammation was examined by 1) mini-invasive microdialysis for measuring the concentration of inflammatory marker PGE II in the peritendinous tissue, 2) ultrasound with Doppler measurement of peri- and intratendinous blood flow, 3) pressure pain algometry and 4) single hop test. Results: PGE 2- levels were significantly reduced at 75, 90 and 105 minutes after active LLLT compared both to pre-treatment levels (p=0.026) and to placebo LLLT (p=0.009). Changes in pressure pain threshold (PPT) were significantly different (P=0.012) between groups. PPT increased by a mean value of 0.19 kg/cm2 [95%CI:0.04 to 0.34] after treatment in the active LLLT group, while pressure pain threshold was reduced by -0.20 kg/cm2 [95%CI:-0.45 to 0.05] after placebo LLLT. Conclusion: LLLT can be used to reduce inflammatory musculskeletal pain as it reduces inflammation and increases pressure pain threshold levels in activity-induced pain episodes of Achilles tendinopathy.

  8. The role of nitric oxide in low level light therapy

    Science.gov (United States)

    Hamblin, Michael R.

    2008-02-01

    The use of low levels of visible or near infrared light for reducing pain, inflammation and edema, promoting healing of wounds, deeper tissues and nerves, and preventing tissue damage by reducing cellular apoptosis has been known for almost forty years since the invention of lasers. Despite many reports of positive findings from experiments conducted in vitro, in animal models and in randomized controlled clinical trials, LLLT remains controversial. Firstly the biochemical mechanisms underlying the positive effects are incompletely understood, and secondly the complexity of choosing amongst a large number of illumination parameters has led to the publication of a number of negative studies as well as many positive ones. This review will focus on the role of nitric oxide in the cellular and tissue effects of LLLT. Red and near-IR light is primarily absorbed by cytochrome c oxidase (unit four in the mitochondrial respiratory chain). Nitric oxide produced in the mitochondria can inhibit respiration by binding to cytochrome c oxidase and competitively displacing oxygen, especially in stressed or hypoxic cells. If light absorption displaced the nitric oxide and thus allowed the cytochrome c oxidase to recover and cellular respiration to resume, this would explain many of the observations made in LLLT. Why the effect is only seen in hypoxic, stressed or damaged cells or tissues? How the effects can keep working for some time (hours or days) postillumination? Why increased NO concentrations are sometimes measured in cell culture or in animals? How blood flow can be increased? Why angiogenesis is sometimes increased after LLLT in vivo?

  9. Evaluation of exposure to ionizing radiation among gamma camera operators

    Directory of Open Access Journals (Sweden)

    Agnieszka Anna Domańska

    2013-08-01

    Full Text Available Background: Protection of nuclear medicine unit employees from hazards of the ionizing radiation is a crucial issue of radiation protection services. We aimed to assess the severity of the occupational radiation exposure of technicians performing scintigraphic examinations at the Nuclear Medicine Department, Central Teaching Hospital of Medical University in Łódź, where thousands of different diagnostic procedures are performed yearly. Materials and Methods: In 2013 the studied diagnostic unit has employed 10 technicians, whose exposure is permanently monitored by individual dosimetry. We analyzed retrospective data of quarterly doses in terms of Hp(10 dose equivalents over the years 2001-2010. Also annual and five-year doses were determined to relate the results to current regulations. Moreover, for a selected period of one year, we collected data on the total activity of radiopharmaceuticals used for diagnostics, to analyze potential relationship with doses recorded in technicians performing the examinations. Results: In a 10-year period under study, the highest annual dose recorded in a technician was 2 mSv, which represented 10% of the annual dose limit of 20 mSv. The highest total dose for a 5-year period was 7.1 mSv, less than 10% of a 5-year dose limit for occupational exposure. Positive linear correlation was observed between total activity of radiopharmaceuticals used for diagnostics in the period of three months and respective quarterly doses received by technicians performing examinations. Conclusions: Doses received by nuclear medicine technicians performing diagnostic procedures in compliance with principles of radiation protection are low, which is confirmed by recognizing the technicians of this unit as B category employees. Med Pr 2013;64(4:503–506

  10. [Evaluation of exposure to ionizing radiation among gamma camera operators].

    Science.gov (United States)

    Domańska, Agnieszka Anna; Bieńkiewicz, Malgorzata; Olszewski, Jerzy

    2013-01-01

    Protection of nuclear medicine unit employees from hazards of the ionizing radiation is a crucial issue of radiation protection services. We aimed to assess the severity of the occupational radiation exposure of technicians performing scintigraphic examinations at the Nuclear Medicine Department, Central Teaching Hospital of Medical University in Lódz, where thousands of different diagnostic procedures are performed yearly. In 2013 the studied diagnostic unit has employed 10 technicians, whose exposure is permanently monitored by individual dosimetry. We analyzed retrospective data of quarterly doses in terms of Hp(10) dose equivalents over the years 2001-2010. Also annual and five-year doses were determined to relate the results to current regulations. Moreover, for a selected period of one year, we collected data on the total activity of radiopharmaceuticals used for diagnostics, to analyze potential relationship with doses recorded in technicians performing the examinations. In a 10-year period under study, the highest annual dose recorded in a technician was 2 mSv, which represented 10% of the annual dose limit of 20 mSv. The highest total dose for a 5-year period was 7.1 mSv, less than 10% of a 5-year dose limit for occupational exposure. Positive linear correlation was observed between total activity of radiopharmaceuticals used for diagnostics in the period of three months and respective quarterly doses received by technicians performing examinations. Doses received by nuclear medicine technicians performing diagnostic procedures in compliance with principles of radiation protection are low, which is confirmed by recognizing the technicians of this unit as B category employees.

  11. Performance assessment for a hypothetical low-level waste disposal facility

    Energy Technology Data Exchange (ETDEWEB)

    Smith, C.S.; Rohe, M.J.; Ritter, P.D. [and others

    1997-01-01

    Disposing of low-level waste (LLW) is a concern for many states throughout the United States. A common disposal method is below-grade concrete vaults. Performance assessment analyses make predictions of contaminant release, transport, ingestion, inhalation, or other routes of exposure, and the resulting doses for various disposal methods such as the below-grade concrete vaults. Numerous assumptions are required to simplify the processes associated with the disposal facility to make predictions feasible. In general, these assumptions are made conservatively so as to underestimate the performance of the facility. The objective of this report is to describe the methodology used in conducting a performance assessment for a hypothetical waste facility located in the northeastern United States using real data as much as possible. This report consists of the following: (a) a description of the disposal facility and site, (b) methods used to analyze performance of the facility, (c) the results of the analysis, and (d) the conclusions of this study.

  12. Low level termination of external carotid artery and its clinical significance: A case report

    Directory of Open Access Journals (Sweden)

    Surekha Devadasa Shetty

    2015-09-01

    Full Text Available The external carotid arterial system is a complex vascular system providing nourishment to the territorial areas of the head and neck. The branches of the external carotid artery are the key landmarks for adequate exposure and appropriate placement of cross-clamps on the carotid arteries during carotid endarterectomy. Knowledge of anatomical variation of the external carotid artery is important in head and neck surgeries. Variations in the branching pattern of the external carotid artery are well known and documented. We report a rare case of low-level termination of the external carotid artery. It terminated by dividing into maxillary and superficial temporal arteries deep into the posterior belly of the digastric muscle, one inch below the angle of the mandible. The occipital and posterior auricular arteries arose from a common trunk given off by the external carotid artery. [Arch Clin Exp Surg 2015; 4(3.000: 160-163

  13. Uncertainty analysis for low-level radioactive waste disposal performance assessment at Oak Ridge National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Lee, D.W.; Yambert, M.W.; Kocher, D.C.

    1994-12-31

    A performance assessment of the operating Solid Waste Storage Area 6 (SWSA 6) facility for the disposal of low-level radioactive waste at the Oak Ridge National Laboratory has been prepared to provide the technical basis for demonstrating compliance with the performance objectives of DOE Order 5820.2A, Chapter 111.2 An analysis of the uncertainty incorporated into the assessment was performed which addressed the quantitative uncertainty in the data used by the models, the subjective uncertainty associated with the models used for assessing performance of the disposal facility and site, and the uncertainty in the models used for estimating dose and human exposure. The results of the uncertainty analysis were used to interpret results and to formulate conclusions about the performance assessment. This paper discusses the approach taken in analyzing the uncertainty in the performance assessment and the role of uncertainty in performance assessment.

  14. Closure Plan for Active Low Level Burial Grounds

    Energy Technology Data Exchange (ETDEWEB)

    SKELLY, W.A.

    2000-11-16

    This plan has been prepared in response to direction from the U.S. Department of Energy. The purpose of the plan is to define approaches that will be implemented to ensure protection of the public and the environment when active Low-Level Burial Grounds (LLBGs) at the Hanford Site are closed. Performance assessments for active burial grounds in the 200 East and West 200 Areas provide current estimates of potential environmental contamination and doses to the ''maximum exposed individual'' from burial ground operation and closure and compare dose estimates to performance objective dose limits for the facilities. This is an Operational Closure Plan. The intent of the guidance in DOE Order 435.1 is that this plan will be a living document, like the facility performance assessments, and will be revised periodically through the operational life of the LLBGs to reflect updated information on waste inventory. management practices, facility transition planning, schedule dates, assessments of post-closure performance, and environmental consequences. Out year dates identified in this plan are tentative. A Final Closure Plan will be prepared in the future when the timing and extent of closure-related activities for LLBGs can be established with greater certainty. After current operations at the LLBGs are concluded, this plan proposes transitioning of these facilities to the Environmental Restoration Program. This action will enable the Environmental Restoration Program to design and implement consistent and coordinated final remedial actions for active and inactive LLBGs. Active and inactive burial grounds in the 200 West and 200 East Areas are commingled. This plan describes approaches that will be implemented during Interim Closure, Final Closure, and Institutional Control Periods to prepare LLBGs for surface barriers, and the construction of barriers, as well as the scope of inspection, monitoring and maintenance practices that will be performed during

  15. Cellular chromophores and signaling in low level light therapy

    Science.gov (United States)

    Hamblin, Michael R.; Demidova-Rice, Tatiana N.

    2007-02-01

    The use of low levels of visible or near infrared light (LLLT) for reducing pain, inflammation and edema, promoting healing of wounds, deeper tissues and nerves, and preventing tissue damage by reducing cellular apoptosis has been known for almost forty years since the invention of lasers. Originally thought to be a peculiar property of laser light (soft or cold lasers), the subject has now broadened to include photobiomodulation and photobiostimulation using non-coherent light. Despite many reports of positive findings from experiments conducted in vitro, in animal models and in randomized controlled clinical trials, LLLT remains controversial. This likely is due to two main reasons; firstly the biochemical mechanisms underlying the positive effects are incompletely understood, and secondly the complexity of rationally choosing amongst a large number of illumination parameters such as wavelength, fluence, power density, pulse structure and treatment timing has led to the publication of a number of negative studies as well as many positive ones. In recent years major advances have been made in understanding the mechanisms that operate at the cellular and tissue levels during LLLT. Mitochondria are thought to be the main site for the initial effects of light and specifically cytochrome c oxidase that has absorption peaks in the red and near infrared regions of the electromagnetic spectrum matches the action spectra of LLLT effects. The discovery that cells employ nitric oxide (NO) synthesized in the mitochondria by neuronal nitric oxide synthase, to regulate respiration by competitive binding to the oxygen binding of cytochrome c oxidase, now suggests how LLLT can affect cell metabolism. If LLLT photodissociates inhibitory NO from cytochrome c oxidase, this would explain increased ATP production, modulation of reactive oxygen species, reduction and prevention of apoptosis, stimulation of angiogenesis, increase of blood flow and induction of transcription factors. In

  16. Low-level light therapy of the eye and brain

    Directory of Open Access Journals (Sweden)

    Rojas JC

    2011-10-01

    Full Text Available Julio C Rojas1,2, F Gonzalez-Lima1 1Departments of Psychology, Pharmacology and Toxicology, University of Texas at Austin, Austin, TX; 2Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX, USA Abstract: Low-level light therapy (LLLT using red to near-infrared light energy has gained attention in recent years as a new scientific approach with therapeutic applications in ophthalmology, neurology, and psychiatry. The ongoing therapeutic revolution spearheaded by LLLT is largely propelled by progress in the basic science fields of photobiology and bioenergetics. This paper describes the mechanisms of action of LLLT at the molecular, cellular, and nervous tissue levels. Photoneuromodulation of cytochrome oxidase activity is the most important primary mechanism of action of LLLT. Cytochrome oxidase is the primary photoacceptor of light in the red to near-infrared region of the electromagnetic spectrum. It is also a key mitochondrial enzyme for cellular bioenergetics, especially for nerve cells in the retina and the brain. Evidence shows that LLLT can secondarily enhance neural metabolism by regulating mitochondrial function, intraneuronal signaling systems, and redox states. Current knowledge about LLLT dosimetry relevant for its hormetic effects on nervous tissue, including noninvasive in vivo retinal and transcranial effects, is also presented. Recent research is reviewed that supports LLLT potential benefits in retinal disease, stroke, neurotrauma, neurodegeneration, and memory and mood disorders. Since mitochondrial dysfunction plays a key role in neurodegeneration, LLLT has potential significant applications against retinal and brain damage by counteracting the consequences of mitochondrial failure. Upon transcranial delivery in vivo, LLLT induces brain metabolic and antioxidant beneficial effects, as measured by increases in cytochrome oxidase and superoxide dismutase activities. Increases

  17. Galvanizing industry: evaluation of exposure levels using biomonitors

    Energy Technology Data Exchange (ETDEWEB)

    Menezes, Maria Angela de B.C.; Sabino, Claudia de V.S.; Amaral, Angela Maria [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN), Belo Horizonte, MG (Brazil); Mattos, Silvania V. de M. [FUNED, Belo Horizonte, MG (Brazil). Div. de Bromatologia e Toxicologia; S. Filho, Serafim [Secretaria Municipal de Saude de Belo Horizonte, MG (Brazil). Coordenacao de Saude do Trabalhador; Maia, Elene Cristina P. [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Dept. de Quimica

    1999-11-01

    In Brazil, statistical surveys concerning occupational diseases refer to accidents and damages. The surveys do not refer to the occupational diseases developed through long exposures to hazardous work conditions, involving physical risk and toxic chemical substances. The Program of Medical Control of Occupational Health determines the Maximum Biological Levels Allowed and the Values of Normality References. But concerning metal and toxic inorganic, values of only few elements are established. In Belo Horizonte and surroundings areas, which is an important industrial centre in the country, there are different industries distributed over various areas. There are about 80 galvanizing industries which are responsible for the majority of the metal contamination hospitalities. A preliminary sampling was performed in order to conduct a survey of the exposures to elements related to occupational diseases in galvanizing industry. The preliminary results for toxic and non-toxic elements obtained using hair and fingernails as biomonitors are shown. The K{sub 0} parametric neutron activation analysis method was applied and the elements determined were: Ag, Al, Au, Cl, Co, Cr, Cu, Fe, I, Mn, Na, Ti, V, Ta, and Zn. (author) 8 refs., 3 figs., 2 tabs.; e-mail: menezes at urano.cdtn.br

  18. Synergism between arsenite and proteasome inhibitor MG132 over cell death in myeloid leukaemic cells U937 and the induction of low levels of intracellular superoxide anion

    Energy Technology Data Exchange (ETDEWEB)

    Lombardo, Tomás [Laboratorio de Immunotoxicologia (LaITO), IDEHU-CONICET, Hospital de Clínicas, José de San Martín, Universidad de Buenos Aires (UBA), Buenos Aires (Argentina); Cavaliere, Victoria; Costantino, Susana N. [Laboratorio de Inmunología Tumoral (LIT), IDEHU-CONICET, Facultad de Farmacia y Bioquímica, UBA, Buenos Aires (Argentina); Kornblihtt, Laura [Servicio de Hematología, Hospital de Clínicas, José de San Martín (UBA), Buenos Aires (Argentina); Alvarez, Elida M. [Laboratorio de Inmunología Tumoral (LIT), IDEHU-CONICET, Facultad de Farmacia y Bioquímica, UBA, Buenos Aires (Argentina); Blanco, Guillermo A., E-mail: gblanco@ffyb.uba.ar [Laboratorio de Immunotoxicologia (LaITO), IDEHU-CONICET, Hospital de Clínicas, José de San Martín, Universidad de Buenos Aires (UBA), Buenos Aires (Argentina)

    2012-02-01

    Increased oxygen species production has often been cited as a mechanism determining synergism on cell death and growth inhibition effects of arsenic-combined drugs. However the net effect of drug combination may not be easily anticipated solely from available knowledge of drug-induced death mechanisms. We evaluated the combined effect of sodium arsenite with the proteasome inhibitor MG132, and the anti-leukaemic agent CAPE, on growth-inhibition and cell death effect in acute myeloid leukaemic cells U937 and Burkitt's lymphoma-derived Raji cells, by the Chou–Talalay method. In addition we explored the association of cytotoxic effect of drugs with changes in intracellular superoxide anion (O{sub 2}{sup −}) levels. Our results showed that combined arsenite + MG132 produced low levels of O{sub 2}{sup −} at 6 h and 24 h after exposure and were synergic on cell death induction in U937 cells over the whole dose range, although the combination was antagonistic on growth inhibition effect. Exposure to a constant non-cytotoxic dose of 80 μM hydrogen peroxide together with arsenite + MG132 changed synergism on cell death to antagonism at all effect levels while increasing O{sub 2}{sup −} levels. Arsenite + hydrogen peroxide also resulted in antagonism with increased O{sub 2}{sup −} levels in U937 cells. In Raji cells, arsenite + MG132 also produced low levels of O{sub 2}{sup −} at 6 h and 24 h but resulted in antagonism on cell death and growth inhibition. By contrast, the combination arsenite + CAPE showed high levels of O{sub 2}{sup −} production at 6 h and 24 h post exposure but resulted in antagonism over cell death and growth inhibition effects in U937 and Raji cells. We conclude that synergism between arsenite and MG132 in U937 cells is negatively associated to O{sub 2}{sup −} levels at early time points after exposure. -- Highlights: ► Arsenic combined cytotoxic and anti-proliferative effects by Chou–Talalay method. ► Cytotoxic effect

  19. New mechanisms in lead biodynamics at ultra-low levels.

    Science.gov (United States)

    Patterson, C; Settle, D

    1993-01-01

    It has been found that the mean concentration of 15 micrograms Pb/g bone ash in typical Americans today is 1000 times greater than the natural level of lead in Homo sapiens sapiens determined from analyses of ancient human bones. Since body burdens of lead only 3 to 5-fold greater than typical induce overtly poisonous effects, unrecognized dysfunctions caused by lead are probably widespread among Americans. Previous toxicological studies by others to delineate ill effects were made by comparisons of biological systems to which lead was added with systems to which no lead was added. It is now seen that such studies dealt entirely with unnatural mechanisms in lead biodynamics, and provided no knowledge of the operation of unperturbed natural mechanisms, because "non-leaded" controls were actually highly traumatized by unrecognized excessive lead exposures. New work should be carried out that would use an ultra-low lead diet to grow rats possessing "natural" lead levels which could be used as controls. Metabolisms of lead in these controls should be compared with metabolisms of lead in biological systems of rats traumatized by excessive lead exposures corresponding to typical levels within people today. Such comparisons would disclose previously unknown characteristics of intra-cellular processing of lead within osseous, neuronal, hepatic, renal and muscle tissues, and in red blood cells and sera, together with sizes and residence times of lead reservoirs in those tissues during fetal growth, maturation and adult aging in rats exposed to natural lead levels.(ABSTRACT TRUNCATED AT 250 WORDS)

  20. New mechanisms in lead biodynamics at ultra-low levels

    Energy Technology Data Exchange (ETDEWEB)