Determination of the probability of hearing loss in persons exposed to the noise of small arms

Aim to analyze the indicators of distortion-product otoacoustic emissions (DPOAE) in persons exposed to the noise of small arms and, on the basis of the most significant of them, to determine the probability of developing hearing loss. Material and methods. We examined 30 male volunteer shooters (60 ears) aged from 19 to 30 years. The shooters fired 30 shots from the AK74M in short bursts (2-3 shots in a burst) at targets when performing shooting exercises from three positions: from the knee, standing and lying down, in a free acoustic field without the use of personal protective equipment of the hearing organ. All participants were examined for distortion-product otoacoustic emissions (DPOAE) before and after firing from small arms. The method of binary logistic regression was used to develop a predictive model. Results. A mathematical model has been developed to assess the probability of developing hearing loss according to the indicators of DPOAE before exposure to the noise of small arms. This model, with a standard classification threshold of p = 0.5, has an accuracy of 83.3%, sensitivity of 79.0%, specificity of 88.0%. According to the results of the ROC analysis for the resulting model, the area under the characteristic curve was equal to 0.924 (0.834;1.0), which indicates the excellent quality of the mathematical model. Conclusion. The most significant were the signal/noise indicator (dB) at a frequency of 4.2 kHz on the left and the level of otoacoustic emission (dB) at a frequency of 4.2 kHz on the left before noise exposure. These indicators, as well as the age of the shooter, allow us to assess the probability of developing hearing loss

Evaluation of tinnitus severity in military personnel after exposure to high intensity noise

Aim to evaluate the severity of tinnitus before and after medical treatment in military personnel exposed to high-intensity noise. Material and methods. The study involved 14 soldiers with complaints of tinnitus who suffered hearing damage caused by gunshot noise (AK74 gun) during military training without hearing protectors. The tinnitus severity and its dynamics during the treatment by glucocorticosteroids was assessed using the Tinnitus Functional Index (TFI). The Tinnitus Handicap Inventory (THI) was used before the treatment, on the 3rd and 7th days after the treatment. Results. It was found that the greatest discomfort was caused by the intrusiveness of noise and inability to control it during the day, and the least discomfort was associated with sleep. The changes in the severity of noise on the THI and TFI scales on the third and seventh days after treatment were significantly different, if compared with the pre-treatment results, and had a positive trend. The therapy provided the significant decrease of noise intrusiveness and established the sense of noise control during the day, as well as minimized its effect on relaxation, hearing and quality of life, if compared to the data before treatment. Conclusion. The TFI and THI scales are recommended for assessing the severity of tinnitus and monitoring the treatment of patients exposed to high-intensity noise. Particular attention should be paid to the use of personal hearing protection equipment when working in conditions of increased level of noise

Radiation and the Risk of Chronic Lymphocytic and Other Leukemias among Chornobyl Cleanup Workers

Background: Risks of most types of leukemia from exposure to acute high doses of ionizing radiation are well known, but risks associated with protracted exposures, as well as associations between radiation and chronic lymphocytic leukemia (CLL), are not clear.
 Objectives: We estimated relative risks of CLL and non-CLL from protracted exposures to low-dose ionizing radiation.
 Methods: A nested case–control study was conducted in a cohort of 110,645 Ukrainian cleanup workers of the 1986 Chornobyl nuclear power plant accident. Cases of incident leukemia diagnosed in 1986–2006 were confirmed by a panel of expert hematologists/hematopathologists. Controls were matched to cases on place of residence and year of birth. We estimated individual bone marrow radiation doses by the Realistic Analytical Dose Reconstruction with Uncertainty Estimation (RADRUE) method. We then used a conditional logistic regression model to estimate excess relative risk of leukemia per gray (ERR/Gy) of radiation dose.
 Results: We found a significant linear dose response for all leukemia [137 cases, ERR/Gy = 1.26 (95% CI: 0.03, 3.58]. There were nonsignificant positive dose responses for both CLL and non-CLL (ERR/Gy = 0.76 and 1.87, respectively). In our primary analysis excluding 20 cases with direct in-person interviews less than 2 years from start of chemotherapy with an anomalous finding of ERR/Gy = –0.47 (95% CI: less than –0.47, 1.02), the ERR/Gy for the remaining 117 cases was 2.38 (95% CI: 0.49, 5.87). For CLL, the ERR/Gy was 2.58 (95% CI: 0.02, 8.43), and for non-CLL, ERR/Gy was 2.21 (95% CI: 0.05, 7.61). Altogether, 16% of leukemia cases (18% of CLL, 15% of non-CLL) were attributed to radiation exposure.
 Conclusions: Exposure to low doses and to low dose-rates of radiation from post-Chornobyl cleanup work was associated with a significant increase in risk of leukemia, which was statistically consistent with estimates for the Japanese atomic bomb survivors. Based on the primary analysis, we conclude that CLL and non-CLL are both radiosensitive.

Воздействие высокой концентрации оксида азота на оксигенаторы аппаратов искусственного кровообращения (экспериментальное исследование)

The aim of the study. To study the effect of high nitric oxide concentrations on hollow polypropylene fibers of oxygenators.Materials and methods. The study was conducted in two stages. At the first stage, we evaluated the stability of oxygenator membrane made of hollow polypropylene fibers after six hours of exposure to air-oxygen mixture containing NO at 500 parts per million, or 500 pro pro mille (ppm) concentration, using mass spectrometry and infrared spectroscopy. At the second stage, an experiment with cardiopulmonary bypass (CPB) was conducted on 10 pigs. In the study group (n=5) animals sweep gas was supplied to the oxygenator as an air-oxygen mixture with NO at 100 ppm. In the control group animals (n=5) an air-oxygen mixture was used without NO. The CPB lasted for 4 hours, followed by observation for 12 hours. NO, NO2 (at the inlet and outlet of the oxygenator), and the dynamics of methemoglobin were evaluated. After weaning of animals from CPB, the oxygenators were tested for leakproofness, and scanning electron microscopy (SEM) was performed.Results. The oxygenator made of polypropylene hollow fibers retained its gas transfer parameters after six hours of exposure to air-oxygen mixture containing NO at 500 ppm. Based on IR-Fourier spectroscopy findings, NO did not affect structural integrity of polypropylene membranes. NO added to gas mixture at 100 ppm did not increase NO2 to toxic level of 2 ppm in 91% of control tests during 4 hours CPB in pigs; mean value was 1.58 ± 0.28 ppm. Methemoglobin concentration did not exceed the upper limit of permissible level (3%), and there were no statistically significant differences with the control group. All tested oxygenators have passed the leakproofness test. According to SEM findings, larger amounts of fibrin deposits were found in the control group oxygenators vs study group.Conclusion. There were no negative effects of NO at 500 ppm concentration on the oxygenator membrane made of hollow polypropylene fibers. NO at 100 ppm in a gas-mixture supplied to oxygenators did not lead to an exceedance of safe NO2 and methemoglobin concentrations in an animal model. Reduced fibrin deposits on hollow fibers of polypropylene oxygenator membranes were observed when with NO at a level of 100 ppm was added to a gas mixture.  Цель исследования. Изучить воздействие высоких концентраций оксида азота на полипропиленовые полые волокна оксигенаторов.Материалы и методы. Исследование провели в два этапа. На первом этапе с помощью масс-спектрометрии и инфракрасной спектроскопии выполнили оценку стабильности мембраны оксигенатора из полых волокон полипропилена после шестичасового воздействия воздушно-кислородной смеси, содержащей NO в концентрации 500 пропромилле, или 500 частей на миллион – parts per million (ppm). На втором этапе провели эксперимент на 10 свиньях с подключением аппарата искусственного кровообращения (ИК). Животным основной группы (n=5) в оксигенатор подавали воздушно-кислородную смесь, содержащую NO в концентрации 100 ppm. Животным контрольной группы (n=5) в оксигенатор подавали воздушно-кислородную смесь без NO. Процедура ИК длилась 4 часа, затем следовало наблюдение в течение 12 часов. Оценивали NO, NO2 (на входе и выходе из оксигенатора), динамику метгемоглобина. После отключения от ИК оксигенаторы тестировали на герметичность, а также выполняли сканирующую электронную микроскопию (СЭМ).Результаты. Оксигенатор из полипропиленовых полых волокон сохранял свои газотранспортные характеристики после шестичасового воздействия воздушно-кислородной смеси с добавлением NO в концентрации 500 ppm. По данным ИК-Фурье спектроскопии показали, что NO не влияет на структуру мембран из полипропилена. Добавление NO в дозировке 100 ppm во время 4 часов ИК у свиней не сопровождалось повышением концентрации NO2 до токсичного уровня 2 ppm в 91% измерений: среднее значение составило 1,58 ± 0,28 ppm. Концентрация метгемоглобина не превышала верхнего  предела  допустимых  значений  (3%),  не  обнаружили  каких-либо статистически значимых различий при сравнении с группой контроля. Все исследуемые оксигенаторы выдержали тестирование на герметичность. По результатам СЭМ оксигенаторы группы контроля характеризовались большим количеством отложений фибрина, чем оксигенаторы основной группы.Заключение. Негативного воздействия NO в концентрации 500 ppm на мембраны оксигенаторов из полых волокон полипропилена не обнаружили. Подача в оксигенатор NO в концентрации 100 ppm NO2 не приводила к превышению безопасного содержания NO2 и метгемоглобина в эксперименте на животных. Выявили снижение образования отложений фибрина на полых волокнах мембран оксигенаторов из полипропилена при подаче NO в концентрации 100 ppm

Logic of visibility, perception, and knowledge and admissible inference rules

We investigate admissible inference rules for the multi-modal logic VSK+ extending the logic VSK – the logic of Visibility, Perception and Knowledge. The logic VSK has been introduced by M.Wooldridge and A. Lomuscio [21]. VSK was intended for reasoning about properties of computational agents situated in some environment. Admissible rules are important for modelling of logical consequence. We consider these rules for VSK+, the logic of a wise agent (one which knows anything visible). The main result of our paper is the construction of an algorithm which determines admissible inference rules in VSK+. The algorithm is based on the proof of existence of computable bounds on the size of special Kripke 3-frames refuting inadmissible rules

Impact of Uncertainties in Exposure Assessment on Thyroid Cancer Risk among Persons in Belarus Exposed as Children or Adolescents Due to the Chernobyl Accident.

The excess incidence of thyroid cancer in Ukraine and Belarus observed a few years after the Chernobyl accident is considered to be largely the result of 131I released from the reactor. Although the Belarus thyroid cancer prevalence data has been previously analyzed, no account was taken of dose measurement error.We examined dose-response patterns in a thyroid screening prevalence cohort of 11,732 persons aged under 18 at the time of the accident, diagnosed during 1996-2004, who had direct thyroid 131I activity measurement, and were resident in the most radio-actively contaminated regions of Belarus. Three methods of dose-error correction (regression calibration, Monte Carlo maximum likelihood, Bayesian Markov Chain Monte Carlo) were applied.There was a statistically significant (p<0.001) increasing dose-response for prevalent thyroid cancer, irrespective of regression-adjustment method used. Without adjustment for dose errors the excess odds ratio was 1.51 Gy- (95% CI 0.53, 3.86), which was reduced by 13% when regression-calibration adjustment was used, 1.31 Gy- (95% CI 0.47, 3.31). A Monte Carlo maximum likelihood method yielded an excess odds ratio of 1.48 Gy- (95% CI 0.53, 3.87), about 2% lower than the unadjusted analysis. The Bayesian method yielded a maximum posterior excess odds ratio of 1.16 Gy- (95% BCI 0.20, 4.32), 23% lower than the unadjusted analysis. There were borderline significant (p = 0.053-0.078) indications of downward curvature in the dose response, depending on the adjustment methods used. There were also borderline significant (p = 0.102) modifying effects of gender on the radiation dose trend, but no significant modifying effects of age at time of accident, or age at screening as modifiers of dose response (p>0.2).In summary, the relatively small contribution of unshared classical dose error in the current study results in comparatively modest effects on the regression parameters

Synthesis of B,O,N-Doped Adamantanes and Diamantanes by Condensation of Oximes with Boronic Acids

Condensation of oximes with boronic acids RB­(OH)₂ or B­(OH)₃ affords remarkably stable 2,4,10-trioxa-1,5,7-triaza-3-boroadamantanes via an unprecedented multicomponent process. The mechanism involves the reversible generation of unstable oxime cyclotrimers, which are readily intercepted by boronic acids

Synthesis of B,O,N-Doped Adamantanes and Diamantanes by Condensation of Oximes with Boronic Acids

Condensation of oximes with boronic acids RB­(OH)₂ or B­(OH)₃ affords remarkably stable 2,4,10-trioxa-1,5,7-triaza-3-boroadamantanes via an unprecedented multicomponent process. The mechanism involves the reversible generation of unstable oxime cyclotrimers, which are readily intercepted by boronic acids

Risk of hematological malignancies among Chernobyl liquidators

International audienceA case-control study of hematological malignancies was conducted among Chernobyl liquidators (accident recovery workers) from Belarus, Russia and Baltic countries to assess the effect of low- to medium-dose protracted radiation exposures on the relative risk of these diseases. The study was nested within cohorts of liquidators who had worked around the Chernobyl plant in 1986-1987. A total of 117 cases [69 leukemia, 34 non-Hodgkin lymphoma (NHL) and 14 other malignancies of lymphoid and hematopoietic tissue] and 481 matched controls were included in the study. Individual dose to the bone marrow and uncertainties were estimated for each subject. The main analyses were restricted to 70 cases (40 leukemia, 20 NHL and 10 other) and their 287 matched controls with reliable information on work in the Chernobyl area. Most subjects received very low doses (median 13 mGy). For all diagnoses combined, a significantly elevated OR was seen at doses of 200 mGy and above. The excess relative risk (ERR) per 100 mGy was 0.60 [90% confidence interval (CI) _0.02, 2.35]. The corresponding estimate for leukemia excluding chronic lymphoid leukemia (CLL) was 0.50 (90% CI _0.38, 5.7). It is slightly higher than but statistically compatible with those estimated from A-bomb survivors and recent low-doserate studies. Although sensitivity analyses showed generally similar results, we cannot rule out the possibility that biases and uncertainties could have led to over- or underestimation of the risk in this study

Parameter estimates and 95% profile likelihood-based confidence intervals (95% CI) (or 95% Bayesian credible intervals (BCI)) for analysis of curvature in fits of excess odds ratio model (1) with or without adjustment for dose errors using regression calibration, for various sets of doses.

<p>^aunless otherwise stated all <i>p</i>-values refer to the improvement in fit of the current row in the Table with that of the model fitted in the row immediately above.</p><p>^b<i>p</i>-value of improvement in fit compared with a model with linear-exponential dose terms.</p><p>^c<i>p</i>-value of improvement in fit compared with a model with no dose terms.</p><p>^ddeviance information criterion [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0139826#pone.0139826.ref024" target="_blank">24</a>].</p><p>^eposterior distribution maximum probability estimate.</p><p>^f95% Bayesian credibility interval (BCI).</p><p>All models have underlying rates adjusted for age (treated categorically), gender and oblast.</p