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Sample records for acrylonitrile potentiates hearing

  1. Synthesis and Thermal Properties of Acrylonitrile/Butyl Acrylate/Fumaronitrile and Acrylonitrile/Ethyl Hexyl Acrylate/Fumaronitrile Terpolymers as a Potential Precursor for Carbon Fiber

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    Siti Nurul Ain Md Jamil

    2014-09-01

    Full Text Available A synthesis of acrylonitrile (AN/butyl acrylate (BA/fumaronitrile (FN and AN/EHA (ethyl hexyl acrylate/FN terpolymers was carried out by redox polymerization using sodium bisulfite (SBS and potassium persulphate (KPS as initiator at 40 °C. The effect of comonomers, BA and EHA and termonomer, FN on the glass transition temperature (Tg and stabilization temperature was studied using Differential Scanning Calorimetry (DSC. The degradation behavior and char yield were obtained by Thermogravimetric Analysis. The conversions of AN, comonomers (BA and EHA and FN were 55%–71%, 85%–91% and 76%–79%, respectively. It was found that with the same comonomer feed (10%, the Tg of AN/EHA copolymer was lower at 63 °C compared to AN/BA copolymer (70 °C. AN/EHA/FN terpolymer also exhibited a lower Tg at 63 °C when compared to that of the AN/BA/FN terpolymer (67 °C. By incorporating BA and EHA into a PAN system, the char yield was reduced to ~38.0% compared to that of AN (~47.7%. It was found that FN reduced the initial cyclization temperature of AN/BA/FN and AN/EHA/FN terpolymers to 228 and 221 °C, respectively, in comparison to that of AN/BA and AN/EHA copolymers (~260 °C. In addition, FN reduced the heat liberation per unit time during the stabilization process that consequently reduced the emission of volatile group during this process. As a result, the char yields of AN/BA/FN and AN/EHA/FN terpolymers are higher at ~45.1% and ~43.9%, respectively, as compared to those of AN/BA copolymer (37.1% and AN/EHA copolymer (38.0%.

  2. Acrylonitrile-induced oxidative DNA damage in rat astrocytes.

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    Pu, Xinzhu; Kamendulis, Lisa M; Klaunig, James E

    2006-10-01

    Chronic administration of acrylonitrile results in a dose-related increase in astrocytomas in rat brain, but the mechanism of acrylonitrile carcinogenicity is not fully understood. The potential of acrylonitrile or its metabolites to induce direct DNA damage as a mechanism for acrylonitrile carcinogenicity has been questioned, and recent studies indicate that the mechanism involves the induction of oxidative stress in rat brain. The present study examined the ability of acrylonitrile to induce DNA damage in the DI TNC1 rat astrocyte cell line using the alkaline Comet assay. Oxidized DNA damage also was evaluated using formamidopyrimidine DNA glycosylase treatment in the modified Comet assay. No increase in direct DNA damage was seen in astrocytes exposed to sublethal concentrations of acrylonitrile (0-1.0 mM) for 24 hr. However, acrylonitrile treatment resulted in a concentration-related increase in oxidative DNA damage after 24 hr. Antioxidant supplementation in the culture media (alpha-tocopherol, (-)-epigallocathechin-3 gallate, or trolox) reduced acrylonitrile-induced oxidative DNA damage. Depletion of glutathione using 0.1 mM DL-buthionine-[S,R]-sulfoximine increased acrylonitrile-induced oxidative DNA damage (22-46%), while cotreatment of acrylonitrile with 2.5 mM L-2-oxothiazolidine-4-carboxylic acid, a precursor for glutathione biosynthesis, significantly reduced acrylonitrile-induced oxidative DNA damage (7-47%). Cotreatment of acrylonitrile with 0.5 mM 1-aminobenzotriazole, a suicidal inhibitor of cytochrome P450, prevented the oxidative DNA damage produced by acrylonitrile. Cyanide (0.1-0.5 mM) increased oxidative DNA damage (44-160%) in astrocytes. These studies demonstrate that while acrylonitrile does not directly damage astrocyte DNA, it does increase oxidative DNA damage. The oxidative DNA damage following acrylonitrile exposure appears to arise mainly through the P450 metabolic pathway; moreover, glutathione depletion may contribute to the

  3. Toxicologic profile of acrylonitrile.

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    Woutersen, R A

    1998-01-01

    Acrylonitrile is a monomer used extensively as a raw material in the manufacturing of acrylic fibers, plastics, synthetic rubbers, and acrylamide. It has been classified as a probable human carcinogen according to the results of numerous chronic rat bioassays. The present report summarizes the toxicity data on acrylonitrile and reviews available data concerning the mechanism (genetic versus epigenetic) by which acrylonitrile is carcinogenic in rats. From the evaluation of the relevant toxicity data, it can be concluded that acrylonitrile is indeed carcinogenic to rats after either oral or inhalational exposure. However, information on other mammalian species is lacking, and, moreover, the exact mechanism of the carcinogenic process is unclear. Therefore, it is recommended to conduct an additional long-term inhalation carcinogenicity study with acrylonitrile in mice, as well as studies into the mechanism by which acrylonitrile induces (brain) tumors in rats (genetic versus epigenetic).

  4. Mechanistic diversity of the van Leusen reaction applied to 6-ketomorphinans and synthetic potential of the resulting acrylonitrile substructures.

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    Schütz, Johannes; Windisch, Petra; Kristeva, Elka; Wurst, Klaus; Ongania, Karl-Hans; Horvath, Ulrike E I; Schottenberger, Herwig; Laus, Gerhard; Schmidhammer, Helmut

    2005-06-24

    Tosylmethyl isocyanide was used to convert 7,8-didehydro-6-ketomorphinans to 6,7-didehydromorphinan-6-carbonitriles with retainment of the 4,5-epoxy ring. However, ring opening occurred in the presence of NaH giving 5,6,7,8-tetradehydromorphinan-6-carbonitriles. Addition of nucleophiles such as Li diisopropylamide or Grignard reagents to the acrylonitrile substructure yielded ring-opened 5,6-didehydro products. Seven products were characterized by X-ray crystal structure analysis and revealed insight into the mechanistic diversity of the van Leusen reaction.

  5. Acrylonitrile: a suspected human carcinogen.

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    Koerselman, W; van der Graaf, M

    1984-01-01

    The literature on carcinogenicity of acrylonitrile (an important intermediate in the chemical industry) is reviewed. The three main conclusions are: (1) Acrylonitrile has genotoxic effects in various tests in microorganisms and in mammal cells. (2) Chronic exposure to acrylonitrile causes tumours in rats. (3) Results of epidemiological studies indicate that acrylonitrile may be a human carcinogen. From this it is clear that acrylonitrile is very probably carcinogenic to humans. Therefore the authors plead for a reduction of acrylonitrile standards to the lowest practicable limit.

  6. Vestibular evoked myogenic potential in sudden sensorineural hearing loss

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    Feroze Kancharu Khan

    2013-01-01

    Full Text Available Aim and Objective: To investigate saccular damage in patients with sudden sensorineural hearing loss (SSNHL with or without vertigo and to evaluate the saccular damage according to the hearing loss and presence or absence of vertigo. Materials and Methods: All tests done in this study were performed in the audio vestibular unit of ENT department from September 2009 to November 2010. Statistical Analysis Used: The association between the severity of hearing loss and changes in the vestibular evoked myogenic potential (VEMP recordings were assessed using descriptive statistics. The pattern of VEMP in different diseases and also the behavior of VEMP in presence or absence of vertigo were evaluated using SPSS 15. Results: Among 27 patients there were 11 cases of idiopathic SSNHL. Out of nine unaffected ears, 88% had normal and 12% had absent VEMP. Whereas out of 13 affected ears, only 53.9% had normal VEMP. Among all the 54 ears, 17 ears had normal hearing. In this group 76.47% had normal VEMP. The group with hearing loss > 90 dB had 61.53% absent VEMP. Conclusions: In patients with unilateral SSNHL, there was a tendency for the affected ear to have absent VEMP indicating the saccular involvement. The extent of saccular damage did not correspond to the amount of hearing loss or presence or absence of vertigo.

  7. Toxicologic profile of acrylonitrile

    NARCIS (Netherlands)

    Woutersen, R.A.

    1998-01-01

    Acrylonitrile is a monomer used extensively as a raw material in the manufacturing of acrylic fibers, plastics, synthetic rubbers, and acrylamide. It has been classified as a probable human carcinogen according to the results of numerous chronic rat bioassays. The present report summarizes the toxic

  8. The acrylonitrile dimer ion

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    Ervasti, Henri K.; Jobst, Karl J.; Burgers, Peter C.; Ruttink, Paul J. Ae; Terlouw, Johan K.

    2007-04-01

    Large energy barriers prohibit the rearrangement of solitary acrylonitrile ions, CH2CHCN+, into their more stable hydrogen-shift isomers CH2CCNH+ or CHCH-CNH+. This prompted us to examine if these isomerizations occur by self-catalysis in acrylonitrile dimer ions. Such ions, generated by chemical ionization experiments of acrylonitrile with an excess of carbon dioxide, undergo five dissociations in the [mu]s time frame, as witnessed by peaks at m/z 53, 54, 79, 80 and 105 in their metastable ion mass spectrum. Collision experiments on these product ions, deuterium labeling, and a detailed computational analysis using the CBS-QB3 model chemistry lead to the following conclusions: (i) the m/z 54 ions are ions CH2CHCNH+ generated by self-protonation in ion-dipole stabilized hydrogen-bridged dimer ions [CH2CHCN...H-C(CN)CH2]+ and [CH2CHCN...H-C(H)C(H)CN]+; the proton shifts in these ions are associated with a small reverse barrier; (ii) dissociation of the H-bridged ions into CH2CCNH+ or CHCH-CNH+ by self-catalysis is energetically feasible but kinetically improbable: experiment shows that the m/z 53 ions are CH2CHCN+ ions, generated by back dissociation; (iii) the peaks at m/z 79, 80 and 105 correspond with the losses of HCN, C2H2 and H, respectively. The calculations indicate that these ions are generated from dimer ions that have adopted the (much more stable) covalently bound "head-to-tail" structure [CH2CHCN-C(H2)C(H)CN]+; experiments indicate that the m/z 79 (C5H5N) and m/z 105 (C6H6N2) ions have linear structures but the m/z 80 (C4H4N2) ions consist of ionized pyrimidine in admixture with its stable pyrimidine-2-ylidene isomer. Acrylonitrile is a confirmed species in interstellar space and our study provides experimental and computational evidence that its dimer radical cation yields the ionized prebiotic pyrimidine molecule.

  9. Effect of acrylonitrile on the electrode processes ivolving copper cations

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    Viktor F. Vargalyuk

    2016-03-01

    Full Text Available Based on the results of cyclic voltammetry and study of deposits morphology, it has been shown that acrylonitrile does not have significant effect on the mechanism of Cu2+ + 2ē → Cu0 reaction. This distinguishes acrylonitrile from the unsaturated polyfunctional organic substances (acrylic acid, acrylamide which forms stable complexes with Cu2+ ions. Acrylonitrile just inhibits cathodic process by adsorbing on the surface of electrode thus blocking its active sites. But the presence of acrylonitrile significantly changes the mechanism of the anodic process. It has been found that acrylonitrile interacts with surface copper atoms thus forming thermodynamically stable [Cu π-AN]0 π‑complexes. Ionization potential of these π‑complexes is more negative if compare to copper atoms. As the result acceleration of anodic process takes place in the low polarization area. However, since the chemisorption is a slow process the presence of acrylonitrile mainly affects dissolution of the first surface layers of copper atoms. Further ionization of copper atoms runs out directly and requires higher polarization.

  10. Temporal resolution in the hearing system and auditory evoked potentials

    DEFF Research Database (Denmark)

    Miller, Lee; Beedholm, Kristian

    2008-01-01

    3pAB5. Temporal resolution in the hearing system and auditory evoked potentials. Kristian Beedholm Institute of Biology,University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark, beedholm@mail.dk, Lee A. Miller Institute of Biology,University of Southern Denmark, Campusvej 55, 5230...... Odense M, Denmark, lee@biology.sdu.dkA popular type of investigation with auditory evoked potentials AEP consists of mapping the dependency of the envelope followingresponse to the AM frequency. This results in what is called the modulation rate transfer function MRTF. The physiologicalinterpretation...... of the MRTF is not straight forward, but is often used as a measure of the ability of the auditory system to encodetemporal changes. It is, however, shown here that the MRTF must depend on the waveform of the click-evoked AEP ceAEP, whichdoes not relate directly to temporal resolution. The theoretical...

  11. Personal and social conditions potentially influencing women's hearing loss management.

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    Garstecki, D C; Erler, S F

    2001-12-01

    Little gender-specific data related to hearing loss and hearing loss management are available. The purpose of this investigation was to examine personal and social conditions affecting women at selected stages of the adult life course that may influence hearing loss management. In all, 191 women in three age groups, ranging from 35 to 85 years old, participated. None reported hearing problems. Participants completed a demographic data form and were given a standard audiometric evaluation to confirm age-normal hearing. Each completed assessments of speech understanding in quiet and noise, auditory signal duration discrimination, and binaural processing. Measures of hearing knowledge, behaviors, and attitudes; health-related locus of control; ego strength; and, social support were administered. Results revealed that although some variables deteriorate among subsequent age groups (i.e., hearing thresholds, central auditory processing, and ego strength), the reverse is true for others (i.e., social interaction and satisfaction with income). Age-specific sociodemographic burdens that may interfere with hearing loss management were noted. New psychosocial data are revealed against which women and men with impaired hearing may be compared.

  12. Theoretical and experimental investigations of the 2-(4-chlorophenyl)-3-{[5-(2-cyano-2-phenylethenyl)]furan-2-yl}acrylonitrile molecule as a potential acceptor in organic solar cells

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    Kazici, Mehmet; Bozar, Sinem; Aydin Yuksel, Sureyya; Ongul, Fatih; Gokce, Halil; Gunes, Serap; Yorur Goreci, Cigdem

    2016-06-01

    A novel soluble asymmetric acrylonitrile derivative, 2-(4-Chlorophenyl)-3-{[5-(2-cyano-2-phenylethenyl)]furan-2-yl}acrylonitrile (CPCPFA, 3) was synthesized in three steps by Knoevenagel condensation. The structure of the CPCPFA was characterized using UV-vis, FTIR, 1H NMR, 13C NMR, and LC-MS. CPCPFA was evaluated as an electron acceptor in bulk heterojunction organic solar cells. Its optical and electronic properties as well as photovoltaic performance were investigated.

  13. Characteristics of brain stem auditory evoked potentials in children with hearing impairment due to infectious diseases.

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    Ječmenica, Jovana Radovan; Opančina, Aleksandra Aleksandar Bajec

    2015-05-01

    Among objective audiologic tests, the most important were tests of brain stem auditory evoked potentials. The objective of the study was to test the configuration, degree of hearing loss, and response characteristics of auditory brain stem evoked potentials in children with hearing loss occurred due to infectious disease. A case control study design was used. The study group consisted of 54 patients referred for a hearing test because of infectious diseases caused by other agents or that occurred as congenital infection. Infectious agents have led to the emergence of various forms of sensorineural hearing loss. We have found deviations from the normal values of absolute and interwave latencies in some children in our group. We found that in the group of children who had the diseases such as purulent meningitis, or were born with rubella virus and cytomegalovirus infection, a retrocochlear damage was present in children with and without cochlear damage.

  14. Effects of potential neurotoxic pesticides on hearing loss: a review.

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    Gatto, M P; Fioretti, M; Fabrizi, G; Gherardi, M; Strafella, E; Santarelli, L

    2014-05-01

    Several pesticides are supposed to be neurotoxic for humans, consequently, they may also affect the auditory system. This review analyzes human and experimental animal studies testing the hypothesis that exposure to pesticides is associated with hearing loss. The literature on this topic is still sparse and methodological limitations of some papers evaluated are identified. As a whole, available data indicate a possible ototoxic action of pesticides, but alternative hypotheses could not be ruled out, also considering some confounders, such as the co-exposure to noise. Therefore, further studies are necessary in order to clarify the association between pesticides exposure and hearing loss. While awaiting more evidence, for precautionary action we recommend considering pesticides as possible ototoxic agents, in particular for vulnerable targets, such as pregnant women and children during early development.

  15. 0 to 5 year-old children hearing appraisal by encephalic trunk audition evoked potentials

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    Bustamante Mejía, César; Unidad de Otoneurología, Sección Otorrinolaringología, Hospital Central de la Fuerza Aérea del Perú, Lima, Perú

    2014-01-01

    OBJECTIVE: To analyze hearing development and maturation from 0 to 5 years of age by evaluating latency times with encephalic trunk audition evoked potentials (AEP). MATERIAL AND METHODS: Forty-four 0 to 5 year-old patients were grouped by age and AEP performed with identical parameters; all patients were sedated to avoid interference. RESULTS: Latency times decreased as age increased, denoting age/latency time (V wave) relation as indicator of hearing development and maturation. CONclusiOn: ...

  16. Hydrolyzed Poly(acrylonitrile) Electrospun Ion-Exchange Fibers

    OpenAIRE

    Jassal, Manisha; Bhowmick, Sankha; Sengupta, Sukalyan; Patra, Prabir K.; Walker, Douglas I.

    2014-01-01

    A potential ion-exchange material was developed from poly(acrylonitrile) fibers that were prepared by electrospinning followed by alkaline hydrolysis (to convert the nitrile group to the carboxylate functional group). Characterization studies performed on this material using X-ray photoelectron spectroscopy, scanning electron microscopy, Fourier-Transform infra-red spectroscopy, and ion chromatography confirmed the presence of ion-exchange functional group (carboxylate). Optimum hydrolysis co...

  17. Urinary excretion of the acrylonitrile metabolite 2-cyanoethylmercapturic acid is correlated with a variety of biomarkers of tobacco smoke exposure and consumption

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    Minet, Emmanuel; Cheung, Francis; Errington, Graham; Sterz, Katharina; Scherer, Gerhard

    2011-01-01

    Acrylonitrile is an IARC class 2B carcinogen present in cigarette smoke. Urinary 2-cyanoethylmercapturic acid (CEMA) is an acrylonitrile metabolite and a potential biomarker for acrylonitrile exposure. The objective of this work was to study the dose response of CEMA in urine of non-smokers and smokers of different ISO tar yield cigarettes. We observed that smokers excreted >100-fold higher amounts of urinary CEMA than non-smokers. The CEMA levels in smokers were significantly correlated with ISO tar yield, daily cigarette consumption, and urinary biomarkers of smoke exposure. In conclusion, urinary CEMA is a suitable biomarker for assessing smoking-related exposure to acrylonitrile. PMID:21108560

  18. Urinary excretion of the acrylonitrile metabolite 2-cyanoethylmercapturic acid is correlated with a variety of biomarkers of tobacco smoke exposure and consumption.

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    Minet, Emmanuel; Cheung, Francis; Errington, Graham; Sterz, Katharina; Scherer, Gerhard

    2011-02-01

    Acrylonitrile is an IARC class 2B carcinogen present in cigarette smoke. Urinary 2-cyanoethylmercapturic acid (CEMA) is an acrylonitrile metabolite and a potential biomarker for acrylonitrile exposure. The objective of this work was to study the dose response of CEMA in urine of non-smokers and smokers of different ISO tar yield cigarettes. We observed that smokers excreted >100-fold higher amounts of urinary CEMA than non-smokers. The CEMA levels in smokers were significantly correlated with ISO tar yield, daily cigarette consumption, and urinary biomarkers of smoke exposure. In conclusion, urinary CEMA is a suitable biomarker for assessing smoking-related exposure to acrylonitrile.

  19. Hearing outcomes after loss of brainstem auditory evoked potentials during microvascular decompression.

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    Thirumala, Parthasarathy D; Krishnaiah, Balaji; Habeych, Miguel E; Balzer, Jeffrey R; Crammond, Donald J

    2015-04-01

    The primary aim of this paper is to study the pre-operative characteristics, intra-operative changes and post-operative hearing outcomes in patients after complete loss of wave V of the brainstem auditory evoked potential. We retrospectively analyzed the brainstem auditory evoked potential data of 94 patients who underwent microvascular decompression for hemifacial spasm at our institute. Patients were divided into two groups - those with and those without loss of wave V. The differences between the two groups and outcomes were assessed using t-test and chi-squared tests. In our study 23 (24%) patients out of 94 had a complete loss of wave V, with 11 (48%) patients experiencing transient loss and 12 (52%) patients experiencing permanent loss. The incidence of hearing loss in patients with no loss of wave V was 5.7% and 26% in patients who did experience wave V loss. The incidence of hearing change in patients with no loss of wave V was 12.6% and 30.43% in patients who did experience wave V loss. Loss of wave V during the procedure or at the end of procedure significantly increases the odds of hearing loss. Hearing change is a significant under-reported clinical condition after microvascular decompression in patients who have loss of wave V.

  20. Biobased synthesis of acrylonitrile from glutamic acid

    NARCIS (Netherlands)

    Notre, le J.E.L.; Scott, E.L.; Franssen, M.C.R.; Sanders, J.P.M.

    2011-01-01

    Glutamic acid was transformed into acrylonitrile in a two step procedure involving an oxidative decarboxylation in water to 3-cyanopropanoic acid followed by a decarbonylation-elimination reaction using a palladium catalyst

  1. Evaluation of the Hearing Aid Rehabilitation Questionnaire in Dutch: examination of its psychometric properties and potential use as a screening instrument

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    Michelene N. Chenault

    2013-10-01

    Full Text Available Items pertaining to hearing and hearing aids from the Hearing Aid Rehabilitation Questionnaire were applied to a heterogeneous sample of Dutch patients aged 55 years and more to evaluate their potential use in hearing screening. Subjects aged 55+ were recruited from a large general practitioners practice to participate. Three groups were formed: a group of 63 persons with a hearing aid, a group of 64 without a hearing aid but with sufficient hearing impairment to qualify for hearing aid reimbursement, and a group of 85 non-hearing impaired persons. Factor and reliability analyses revealed a structure with two scales regarding hearing, namely functionality and social hearing and three scales pertaining to hearing aids, namely hearing aid stigma, pressure to be assessed and not wanting a hearing aid. Scale validity was assessed with pure tone averages over the frequencies 1, 2 and 4 kHz and with a visual analogue scale for subjective hearing. The derived scales can be applied reliably in audiological assessment in an adult hearing screen setting to detect experienced hearing problems as well as attitudes related to hearing and hearing aids.

  2. Hearing in the Juvenile Green Sea Turtle (Chelonia mydas): A Comparison of Underwater and Aerial Hearing Using Auditory Evoked Potentials.

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    Piniak, Wendy E D; Mann, David A; Harms, Craig A; Jones, T Todd; Eckert, Scott A

    2016-01-01

    Sea turtles spend much of their life in aquatic environments, but critical portions of their life cycle, such as nesting and hatching, occur in terrestrial environments, suggesting that it may be important for them to detect sounds in both air and water. In this study we compared underwater and aerial hearing sensitivities in five juvenile green sea turtles (Chelonia mydas) by measuring auditory evoked potential responses to tone pip stimuli. Green sea turtles detected acoustic stimuli in both media, responding to underwater stimuli between 50 and 1600 Hz and aerial stimuli between 50 and 800 Hz, with maximum sensitivity between 200 and 400 Hz underwater and 300 and 400 Hz in air. When underwater and aerial hearing sensitivities were compared in terms of pressure, green sea turtle aerial sound pressure thresholds were lower than underwater thresholds, however they detected a wider range of frequencies underwater. When thresholds were compared in terms of sound intensity, green sea turtle sound intensity level thresholds were 2-39 dB lower underwater particularly at frequencies below 400 Hz. Acoustic stimuli may provide important environmental cues for sea turtles. Further research is needed to determine how sea turtles behaviorally and physiologically respond to sounds in their environment.

  3. Hearing testing in the U.S. Department of Defense: Potential impact on Veterans Affairs hearing loss disability awards.

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    Nelson, J T; Swan, A A; Swiger, B; Packer, M; Pugh, M J

    2016-10-18

    Hearing loss is the second most common disability awarded by the U.S. Department of Veterans Affairs (VA) to former members of the U.S. uniformed services. Hearing readiness and conservation practices differ among the four largest uniformed military services (Air Force, Army, Marine Corps, and Navy). Utilizing a data set consisting of all hearing loss claims submitted to the VA from fiscal years 2003-2013, we examined characteristics of veterans submitting claims within one year of separation from military service. Our results indicate that having a hearing loss disability claim granted was significantly more likely for men, individuals over the age of 26 years at the time of the claim, individuals most recently serving in the U.S. Army, and those with at least one hearing loss diagnosis. Importantly, individuals with at least one test record in the Defense Occupational and Environmental Health Readiness System-Hearing Conservation (DOEHRS-HC) system were significantly less likely to have a hearing loss disability claim granted by the VA. Within the DOEHRS-HC cohort, those with at least one threshold shift or clinical hearing loss diagnosis while on active duty were more than two and three times more likely to have a hearing loss disability claim granted, respectively. These findings indicate that an established history of reduced hearing ability while on active duty was associated with a significantly increased likelihood of an approved hearing loss disability claim relative to VA claims without such a history. Further, our results show a persistent decreased rate of hearing loss disability awards overall. These findings support increased inclusion of personnel in DoD hearing readiness and conservation programs to reduce VA hearing loss disability awards.

  4. Mutagenicity, carcinogenicity, and teratogenicity of acrylonitrile.

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    Léonard, A; Gerber, G B; Stecca, C; Rueff, J; Borba, H; Farmer, P B; Sram, R J; Czeizel, A E; Kalina, I

    1999-05-01

    Acrylonitrile (AN) is an important intermediary for the synthesis of a variety of organic products, such as artificial fibres, household articles and resins. Although acute effects are the primary concern for an exposure to AN, potential genotoxic, carcinogenic and teratogenic risks of AN have to be taken seriously in view of the large number of workers employed in such industries and the world-wide population using products containing and possibly liberating AN. An understanding of the effect of acrylonitrile must be based on a characterization of its metabolism as well as of the resulting products and their genotoxic properties. Tests for mutagenicity in bacteria have in general been positive, those in plants and on unscheduled DNA synthesis doubtful, and those on chromosome aberrations in vivo negative. Wherever positive results had been obtained, metabolic activation of AN appeared to be a prerequisite. The extent to which such mutagenic effects are significant in man depends, however, also on the conditions of exposure. It appears from the limited data that the ultimate mutagenic factor(s), such as 2-cyanoethylene oxide, may have little opportunity to act under conditions where people are exposed because it is formed only in small amounts and is rapidly degraded. The carcinogenic action of AN has been evaluated by various agencies and ranged from 'reasonably be anticipated to be a human carcinogen' to 'cannot be excluded', the most recent evaluation being 'possibly carcinogenic to humans'. Animal data that confirm the carcinogenic potential of AN have certain limitations with respect to the choice of species, type of tumors and length of follow up. Epidemiological studies which sometimes, but not always, yielded positive results, encounter the usual difficulties of confounding factors in chemical industries. Exposure of workers to AN should continue to be carefully monitored, but AN would not have to be considered a cancer risk to the population provided

  5. Assessment of risk from exposure to acrylonitrile: the general approach used by a consultant.

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    Page, N P; Cook, B

    1990-12-15

    The concern from low-level exposure to acrylonitrile is primarily due to its potential for carcinogenicity. Several epidemiology studies provide suggestive evidence for an association of lung cancer in workers exposed to acrylonitrile; however, smoking may be a contributing factor and therefore the role of acrylonitrile as a causative factor is unclear. Seven animal bioassays, using three routes of exposure and two strains of rats, have provided consistent results. Tumors were induced in all studies, with the primary sites of tumor induction being the brain, ear canal, gastrointestinal tract and mammary glands. The linearized multistage model was used for extrapolation purposes. The risk based on brain tumors (astrocytomas) and stomach tumors following oral exposures ranged from 1 x 10(-1) to 4 x 10(-1)mg-1kg-1day-1. The risk of inhalation exposure is somewhat less, (2-3) x 10(-2). Support for carcinogenic potential is obtained from mutagenicity studies. Acrylonitrile has been found to be mutagenic and also binds with DNA. It has been speculated that acrylonitrile is metabolized to 2-cyanoethylene oxide, which is the proximate carcinogen.

  6. Biological monitoring of acrylonitrile exposure

    Energy Technology Data Exchange (ETDEWEB)

    Houthuijs, D.; Remijn, B.; Willems, H.; Boleij, J.; Biersteker, K.

    1982-01-01

    A study was made of the excretion pattern of acrylonitrile (AN) in urine of 15 AN-exposed workers. During a 7-day working period with the following 2 days off, the workers delivered all their urines separately. Exposure data, collected by personal monitoring, showed a mean 8-hour TWA value of 0.13 ppm. The excretion of AN in urine (AN(U) ) showed a typical pattern; concentrations peaked at the end or shortly after the end of the workday and decreased rapidly until the beginning of the next workday. A control group of 41 nonexposed workers of the same company showed a significant increase of AN(U) with increasing number of cigarettes smoked. The AN(U) concentrations of the exposed workers however were, despite the low exposure, much higher than those of the controls, both during the workdays and during the days off. Biological monitoring of AN-exposed workers by assessing AN(U) therefore seems a very sensitive exposure evaluation method, especially because it accounts for inhalation as well as skin penetration as routes for entering the body.

  7. 21 CFR 181.32 - Acrylonitrile copolymers and resins.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Acrylonitrile copolymers and resins. 181.32 Section... Ingredients § 181.32 Acrylonitrile copolymers and resins. (a) Acrylonitrile copolymers and resins listed in... of the vinyl chloride resin) resin—for use only in contact with oleomargarine. (iv)...

  8. Starch Modification by Graft Copolymerization of Acrylonitrile

    Institute of Scientific and Technical Information of China (English)

    刘瑞贤; 李莉; 茹宗玲; 张黎明; 高建平; 田汝川

    2003-01-01

    The graft copolymerization of acrylonitrile (AN) onto starch under the initiation of potassium permanganate was investigated. The effect of various reaction conditions on the graft copolymerization was studied. The relationships between the grafting rate and the initiator concentration of potassium permanganate, monomer acrylonitrile and backbone starch, as well as reaction temperature were established. The oxidation reaction of starch with manganic ions and valence changes of manganic ions during the graft copolymerization were discussed. The results show that manganic ion Mn7+ underwent a series of valence changes during the graft copolymerization: Mn(Ⅶ) → Mn(Ⅳ) → Mn(Ⅲ) → Mn(Ⅱ). The grafting rate of the graft copolymerization of acrylonitrile onto starch is also given.

  9. Assessment of potential effects of the electromagnetic fields of mobile phones on hearing

    Directory of Open Access Journals (Sweden)

    Gradauskiene Egle

    2005-04-01

    Full Text Available Abstract Background Mobile phones have become indispensable as communication tools; however, to date there is only a limited knowledge about interaction between electromagnetic fields (EMF emitted by mobile phones and auditory function. The aim of the study was to assess potential changes in hearing function as a consequence of exposure to low-intensity EMF's produced by mobile phones at frequencies of 900 and 1800 MHz. Methods The within-subject study was performed on thirty volunteers (age 18–30 years with normal hearing to assess possible acute effect of EMF. Participants attended two sessions: genuine and sham exposure of EMF. Hearing threshold levels (HTL on pure tone audiometry (PTA and transient evoked otoacoustic emissions (TEOAE's were recorded before and immediately after 10 min of genuine and/or sham exposure of mobile phone EMF. The administration of genuine or sham exposure was double blind and counterbalanced in order. Results Statistical analysis revealed no significant differences in the mean HTLs of PTA and mean shifts of TEOAE's before and after genuine and/or sham mobile phone EMF 10 min exposure. The data collected showed that average TEOAE levels (averaged across a frequency range changed less than 2.5 dB between pre- and post-, genuine and sham exposure. The greatest individual change was 10 dB, with a decrease in level from pre- to post- real exposure. Conclusion It could be concluded that a 10-min close exposure of EMFs emitted from a mobile phone had no immediate after-effect on measurements of HTL of PTA and TEOAEs in young human subjects and no measurable hearing deterioration was detected in our study.

  10. Cancer occurrence among workers exposed to acrylonitrile.

    Science.gov (United States)

    Rothman, K J

    1994-10-01

    A MEDLINE search identified 12 published epidemiologic studies that have reported incidence or mortality experience among workers exposed to acrylonitrile. Many of the studies contain scanty descriptions of subject ascertainment, and most do not have good information on exposure assessment. Many also may have suffered from incomplete follow-up, as evinced by an overall deficit in the number of deaths observed, compared with the number expected from general population mortality rates. Such problems are not unique to studies on acrylonitrile, and to some extent they reflect the difficulties of conducting retrospective cohort studies. Despite these drawbacks, a simplified meta-analysis of the mortality experience reported for these cohorts revealed little evidence for carcinogenicity. Approximately the same number of cancer deaths was observed as was expected according to general population mortality rates (standardized mortality ratio 1.03, 90% confidence interval 0.92-1.15). The combined information from these studies is insufficient to support confidence about a lack of carcinogenicity at all sites. Nevertheless, despite the flaws in some of the individual studies, the summarized findings offer reassurance that workers exposed to acrylonitrile face no striking increases in mortality for all cancers or for respiratory cancer.

  11. Characterisation of recycled acrylonitrile-butadiene-styrene and high-impact polystyrene from waste computer equipment in Brazil.

    Science.gov (United States)

    Hirayama, Denise; Saron, Clodoaldo

    2015-06-01

    Polymeric materials constitute a considerable fraction of waste computer equipment and polymers acrylonitrile-butadiene-styrene and high-impact polystyrene are the main thermoplastic polymeric components found in waste computer equipment. Identification, separation and characterisation of additives present in acrylonitrile-butadiene-styrene and high-impact polystyrene are fundamental procedures to mechanical recycling of these polymers. The aim of this study was to evaluate the methods for identification of acrylonitrile-butadiene-styrene and high-impact polystyrene from waste computer equipment in Brazil, as well as their potential for mechanical recycling. The imprecise utilisation of symbols for identification of the polymers and the presence of additives containing toxic elements in determinate computer devices are some of the difficulties found for recycling of acrylonitrile-butadiene-styrene and high-impact polystyrene from waste computer equipment. However, the considerable performance of mechanical properties of the recycled acrylonitrile-butadiene-styrene and high-impact polystyrene when compared with the virgin materials confirms the potential for mechanical recycling of these polymers.

  12. Hydrolyzed Poly(acrylonitrile) Electrospun Ion-Exchange Fibers.

    Science.gov (United States)

    Jassal, Manisha; Bhowmick, Sankha; Sengupta, Sukalyan; Patra, Prabir K; Walker, Douglas I

    2014-06-01

    A potential ion-exchange material was developed from poly(acrylonitrile) fibers that were prepared by electrospinning followed by alkaline hydrolysis (to convert the nitrile group to the carboxylate functional group). Characterization studies performed on this material using X-ray photoelectron spectroscopy, scanning electron microscopy, Fourier-Transform infra-red spectroscopy, and ion chromatography confirmed the presence of ion-exchange functional group (carboxylate). Optimum hydrolysis conditions resulted in an ion-exchange capacity of 2.39 meq/g. Ion-exchange fibers were used in a packed-bed column to selectively remove heavy-metal cation from the background of a benign, competing cation at a much higher concentration. The material can be efficiently regenerated and used for multiple cycles of exhaustion and regeneration.

  13. 21 CFR 177.1480 - Nitrile rubber modified acrylonitrile-methyl acrylate copolymers.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Nitrile rubber modified acrylonitrile-methyl... Nitrile rubber modified acrylonitrile-methyl acrylate copolymers. Nitrile rubber modified acrylonitrile... rubber modified acrylonitrile-methyl acrylate copolymers consist of basic copolymers produced by...

  14. Information draft on the development of air standards for acrylonitrile

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-01-01

    Acrylonitrile is a colourless liquid with a faintly sweet and pungent odour. It is widely used as a chemical intermediate in a variety of industrial and commercial products such as acrylic and modacrylic fibres, plastics, styrene-acrylonitrile, nitrile rubber resins, and acrylamide. Although not currently produced in Canada, acrylonitrile is used in the manufacture of industrial and commercial products. Acrylonitrile levels around end-use plants have been found to be significantly higher than at producing facilities. Almost all releases of acrylonitrile are to the atmosphere and one facility is responsible for all releases in Ontario. Human exposure is through air, water and food. Acrylonitrile is absorbed by inhalation, through the mouth and to some extent through the skin. Exposure at concentrations of 7 to 45 microgram/cubic meter for 20 to 45 minutes leads to irritation of the mucous membranes, nausea, headaches, and irritability. Low-grade anaemia, leukocytosis, kidney irritation and mild jaundice have also been observed. Children are more sensitive than adults. Acrylonitrile is classified as probable human carcinogen by the US Environmental Protection Agency. The current ambient air quality criterion (AAQC) in Ontario is 100 microgram/cubic metre and the half-hour interim point of impingement (POI) standard is 300 microgram/cubic meter. Review of world-wide literature showed the existence of standards in several American states. Cancer unit risks estimates have been made by the US Environmental Protection Agency as well as by the World Health Organization. 63 refs., 1 tab., appendix.

  15. Lipid profiles and obesity as potential risk factors of sudden sensorineural hearing loss.

    Directory of Open Access Journals (Sweden)

    Joong Seob Lee

    Full Text Available The objective of our study was to establish whether increased lipid profiles and obesity affect the prevalence and prognosis of sudden sensorineural hearing loss (SSNHL.This was a case-controlled study with a longitudinal design. According to our criteria, 324 patients with SSNHL were included in this study. To manage potential covariates, 972 subjects with normal hearing from the Korean National Health and Nutrition Examination Survey were matched as control group according to their propensity scores. Age, level of total cholesterol (TC, high density lipoprotein cholesterol (HDL-C, low-density lipoprotein cholesterol (LDL-C, triglycerides (TG, and body mass index (BMI were obtained from the clinical data. Multivariate logistic regression analysis was used to investigate the association between SSNHL and lipid profiles or obesity in the 1296 subjects. Multivariate Cox regression analysis was used to determine whether lipid profiles and obesity are prognostic factors in patients with SSNHL.Mean body weight, BMI, TC, and TG were significantly higher in patients with SSNHL compared with control subjects (p<0.05. However, LDL-C values did not differ significantly between the two groups. Subjects with elevated TC and TG levels had a 2.20- (95% CI 1.50-3.24 and 1.50-fold (95% CI 1.08-2.08 increased odds, respectively, of SSNHL compared with subjects with normal TC and TG levels. Subjects with grade III BMI had a 1.59-fold (95% CI 1.17-2.16 increased odds of SSNHL. Multivariate Cox regression analyses revealed that BMI was an independent risk factor of treatment outcome, as patients with BMI ≥27.5 were less likely to achieve complete recovery than those with BMI <27.5 (p<0.05.The results of this study revealed that elevated TC and TG levels and increased BMI are significantly associated with the prevalence of SSNHL and its prognosis, indicating that vascular compromise may play an important role in the pathogenesis of SSNHL.

  16. Uni- and multivariate models for investigating potential prognostic factors in idiopathic sudden sensorineural hearing loss.

    Science.gov (United States)

    Lionello, Marco; Staffieri, Claudia; Breda, Stefano; Turato, Chiara; Giacomelli, Luciano; Magnavita, Paola; de Filippis, Cosimo; Staffieri, Alberto; Marioni, Gino

    2015-08-01

    With a worldwide incidence estimated at 8-15 per 100,000 population a year, idiopathic sudden sensorineural hearing loss (ISSHL) is a common clinical finding for otologists. There is a shortage of information on the clinical factors capable of predicting hearing recovery and response to therapy. The aim of the present study was to retrospectively investigate the prognostic value of clinical variables in relation to hearing recovery, in a cohort of 117 consecutive patients with ISSHL. Clinical parameters (signs, symptoms, comorbidities and treatments) and audiometric data were analyzed with univariate and multivariate statistical approaches for prognostic purposes to identify any correlation with hearing recovery, also expressed according to the Wilson criteria. Univariate analysis showed that age and hypertension were significantly related to hearing outcome (p = 0.004 and p = 0.015, respectively). Elderly patients and those with hypertension were at higher risk of experiencing no hearing recovery (OR = 3.25 and OR = 2.89, respectively). Age was an independent prognostic factor on multivariate analysis (p = 0.007). Tinnitus as a presenting symptom showed a trend towards an association with hearing recovery (p = 0.07). The treatment regimen, the time elapsing between the onset of symptoms and the start of therapy (p = 0.34), and the duration of the treatment (p = 0.83) were unrelated to recovery on univariate analysis. Among the parameters considered, only age was significantly and independently related to hearing outcome. There is a need for well-designed, randomized clinical trials to enable an evidence-based protocol to be developed for the treatment of ISSHL.

  17. Hearing loss

    Science.gov (United States)

    Decreased hearing; Deafness; Loss of hearing; Conductive hearing loss; Sensorineural hearing loss; Presbycusis ... Symptoms of hearing loss may include: Certain sounds seeming too ... conversations when two or more people are talking Difficulty ...

  18. Hearing loss and PRPS1 mutations: Wide spectrum of phenotypes and potential therapy

    NARCIS (Netherlands)

    Liu, X.Z.; Xie, D.; Yuan, H.J.; Brouwer, A.P. de; Christodoulou, J.; Yan, D.

    2013-01-01

    OBJECTIVE: The purpose of this review was to evaluate the current literature on phosphoribosylpyrophosphate synthetase 1 (PRPS1)-related diseases and their consequences on hearing function. DESIGN: A literature search of peer-reviewed, published journal articles was conducted in online bibliographic

  19. NOISE INDUCED HEARING LOSS IN CHINA:A POTENTIALLY COSTLY PUB-LIC HEALTH LSSUE

    Institute of Scientific and Technical Information of China (English)

    Shi Yongbing; William Hal Martin

    2013-01-01

    Hearing loss and tinnitus are among the most common consequences of long term noise exposure and re-main an under-addressed heath issue in most developing nations including China. The rapid industrializa-tion and life style changes in China increase the concern over noise exposure and noise induced hearing loss (NIHL). Research on NIHL in China is limited. The current paper reviews studies published in English and Chinese language literatures regarding noise exposure and NIHL in China. Their implication on the Chi-nese population is discussed. The possible utility of a research model such as the Dangerous Decibels® as a means to increase understanding of the scope of NIHL among the Chinese population, to educate the gener-al public in China (especially the young) about NIHL and its prevention, and to study effects of language and cultural factors on international information dissemination and behavioral interventions is proposed.

  20. Survey of volatile substances in kitchen utensils made from acrylonitrile-butadiene-styrene and acrylonitrile-styrene resin in Japan.

    Science.gov (United States)

    Abe, Yutaka; Yamaguchi, Miku; Mutsuga, Motoh; Kawamura, Yoko; Akiyama, Hiroshi

    2014-05-01

    Residual levels of 14 volatile substances, including 1,3-butadiene, acrylonitrile, benzene, ethylbenzene, and styrene, in 30 kitchen utensils made from acrylonitrile-butadiene-styrene resin (ABS) and acrylonitrile-styrene resin (AS) such as slicers, picks, cups, and lunch boxes in Japan were simultaneously determined using headspace gas chromatography/mass spectroscopy (HS-GC/MS). The maximum residual levels in the ABS and AS samples were found to be 2000 and 2800 μg/g of styrene, respectively. The residual levels of 1,3-butadiene ranged from 0.06 to 1.7 μg/g in ABS, and three of 15 ABS samples exceeded the regulatory limit for this compound as established by the European Union (EU). The residual levels of acrylonitrile ranged from 0.15 to 20 μg/g in ABS and from 19 to 180 μg/g in AS. The levels of this substance in seven ABS and six AS samples exceeded the limit set by the U.S. Food and Drug Administration (FDA). Furthermore, the levels of acrylonitrile in three AS samples exceeded the voluntary standard established by Japanese industries. These results clearly indicate that the residual levels of some volatile compounds are still high in ABS and AS kitchen utensils and further observations are needed.

  1. Imaging Evaluation of Pediatric Sensorineural Hearing Loss in Potential Candidates for Cochlear Implantation

    OpenAIRE

    Jallu, Aleena Shafi; Jehangir, Majid; Ul Hamid, Waqar; Pampori, Rafiq Ahmad

    2015-01-01

    Computerized tomography (CT) and magnetic resonance (MR) are complementary in the imaging of the labyrinth, the internal auditory canal and the brain in children with sensorineural hearing loss who are being evaluated for cochlear implantation. An accurate anatomical description of the inner ear is essential in the preoperative work up. Computerized tomography visualizes the bony structures, whereas MR can discern soft-tissue components including intra labyrinthine fluid, cerebrospinal fluid ...

  2. Commercial Application of the XYA-5 Catalyst in Acrylonitrile Unit

    Institute of Scientific and Technical Information of China (English)

    Li Zhengguang

    2008-01-01

    The XYA-5 catalyst was first applied in commercial scale on an 80-kt/a acrylonitrile unit at the Daqing Refining and Chemical Company.Test results had shown that the once-through yield of acrylonitrile exceeded 80% with the unit consumption of propylene reaching 1032 kg on each ton of acryionitrile.The product quality could be easily put under control and the distribution of reaction products was reasonable with good cleaning performance and stability of the catalyst that was suitable for use on this commercial unit.

  3. Auditory Evoked Potentials for the Evaluation of Hearing Sensitivity in Navy Dolphins. Modification P00002: Assessment of Hearing Sensitivity in Adult Male Elephant Seals

    Science.gov (United States)

    2006-12-30

    investigation of Finneran, J. J., Schlundt, C. E., Carder, D. A., and Ridgway, S. H. (2002). hearing in the freshwater dolphin Inia geoffrensis ," Dokl. Biol. Sci...2006 Acoustical Society of America 3181 taliafluviatilis; Popov and Supin, 1990a), Amazon river dol- Computer -s- phins ( Inia geoffrensis ; Popov and...simultaneously gated pure tones," J. of hearing in fresh water dolphin Inia Geoffrensis ." Dokl. Biol. Sci. Acoust. Soc. Am., 94, 3215-3226. 313(1), 238-241

  4. Auditory Evoked Potentials for the Evaluation of Hearing Sensitivity in Navy Dolphins. Assessment of Hearing Sensitivity in Adult Male Elephant Seals

    Science.gov (United States)

    2006-12-01

    threshold were the same as that obtained when each tory sensitivity are augmented by presbycusis . Unlike WEN ear was considered independently. Differences...the ability of ( presbycusis ) and sex differences in the onset of hearing im- marine mammals to survive and exploit their environment. pairment have...behavioral approaches to audiometry require subjects causes of hearing loss are primarily attributed to noise expo- sure (33.7%), presbycusis (28%), and

  5. Adsorptive removal of acrylonitrile by commercial grade activated carbon: kinetics, equilibrium and thermodynamics.

    Science.gov (United States)

    Kumar, Arvind; Prasad, B; Mishra, I M

    2008-04-01

    The potential of activated carbons--powdered (PAC) and granular (GAC), for the adsorption of acrylonitrile (AN) at different initial AN concentrations (50PAC and GAC, respectively. Error analysis also confirmed the efficacy of the R-P isotherm to best fit the experimental data. The pseudo-second order kinetic model best represents the kinetics of the adsorption of AN onto PAC and GAC. Maximum adsorption capacity of PAC and GAC at optimum conditions of AN removal (adsorbent dose approximately 20 g/l of solution, and equilibrium time approximately 5 h) was found to be 51.72 and 46.63 mg/g, respectively.

  6. Radiation-induced graft copolymerization of binary monomer mixture containing acrylonitrile onto polyethylene films

    Science.gov (United States)

    Choi, Seong-Ho; Nho, Young Chang

    2000-04-01

    Graft copolymerization of acrylonitrile (AN)/acrylic acid (AA), acrylonitrile (AN)/methacrylic acid (MA), and acrylonitrile (AN)/glycidyl methacrylate (GMA) onto pre-irradiated polyethylene (PE) films were studied. The effect of reaction conditions such as solvents, additives, and monomer composition on the grafting yields was investigated. The extent of grafting was found to increase with increasing sulfuric acid concentration when sulfuric acid as an additive was added to the grafting solution. In AN/AA mixture, the proportion of acrylonitrile in the copolymer increased with an increasing AN component in feed monomers. On the other hand, in AN/MA mixture, acrylonitrile component in copolymer was very slight in spite of the increase AN component in feed monomers. In the AN/GMA mixture, the proportion of acrylonitrile in the copolymer increased with increasing acrylonitrile component in AN/GMA feed monomer.

  7. Exploring potentials of sense-making theory for understanding social processes in public hearing

    DEFF Research Database (Denmark)

    Lyhne, Ivar

    authorities and the public in such planning often characterised by conflict. A sense-making framework is developed based on Karl Weick's theory to investigate how participants at the meeting change their understanding aspects like other actors' opinions and the infrastructure project. Through interviews...... and observations it is shown that participants' senses do not change except from a few aspects. The participants at the meeting thus seem stuck in their positions without interest in being open for other interpretations or arguments. The investigation leads to considerations about the benefit and role...... of such a public meeting and the importance of trust and openness in the social processes in a public hearing....

  8. Potential barriers and facilitators for implementation of an integrated care pathway for hearing-impaired persons: an exploratory survey among patients and professionals

    Directory of Open Access Journals (Sweden)

    Verschuure Hans

    2007-04-01

    Full Text Available Abstract Background Because of the increasing costs and anticipated shortage of Ear Nose and Throat (ENT specialists in the care for hearing-impaired persons, an integrated care pathway that includes direct hearing aid provision was developed. While this direct pathway is still under investigation, in a survey we examined expectations and potential barriers and facilitators towards this direct pathway, of patients and professionals involved in the pathway. Methods Two study populations were assessed: members of the health professions involved in the care pathway for hearing-impaired persons (general practitioners (GPs, hearing aid dispensers, ENT-specialists and clinical audiologists and persons with hearing complaints. We developed a comprehensive semi-structured questionnaire for the professionals, regarding expectations, barriers, facilitators and conditions for implementation. We developed two questionnaires for persons with hearing complaints, both regarding evaluations and preferences, and administered them after they had experienced two key elements of the direct pathway: the triage and the hearing aid fitting. Results On average GPs and hearing aid dispensers had positive expectations towards the direct pathway, while ENT-specialists and clinical audiologists had negative expectations. Professionals stated both barriers and facilitators towards the direct pathway. Most professionals either supported implementation of the direct pathway, provided that a number of conditions were satisfied, or did not support implementation, unless roughly the same conditions were satisfied. Professionals generally agreed on which conditions need to be satisfied. Persons with hearing complaints evaluated the present referral pathway and the new direct pathway equally. Many, especially older, participants stated however that they would still visit the GP and ENT-specialist, even when this would not be necessary for reimbursement of the hearing aid, and

  9. Sensitivity of cortical auditory evoked potential detection for hearing-impaired infants in response to short speech sounds

    Directory of Open Access Journals (Sweden)

    Bram Van Dun

    2012-01-01

    Full Text Available

    Background: Cortical auditory evoked potentials (CAEPs are an emerging tool for hearing aid fitting evaluation in young children who cannot provide reliable behavioral feedback. It is therefore useful to determine the relationship between the sensation level of speech sounds and the detection sensitivity of CAEPs.

    Design and methods: Twenty-five sensorineurally hearing impaired infants with an age range of 8 to 30 months were tested once, 18 aided and 7 unaided. First, behavioral thresholds of speech stimuli /m/, /g/, and /t/ were determined using visual reinforcement orientation audiometry (VROA. Afterwards, the same speech stimuli were presented at 55, 65, and 75 dB SPL, and CAEP recordings were made. An automatic statistical detection paradigm was used for CAEP detection.

    Results: For sensation levels above 0, 10, and 20 dB respectively, detection sensitivities were equal to 72 ± 10, 75 ± 10, and 78 ± 12%. In 79% of the cases, automatic detection p-values became smaller when the sensation level was increased by 10 dB.

    Conclusions: The results of this study suggest that the presence or absence of CAEPs can provide some indication of the audibility of a speech sound for infants with sensorineural hearing loss. The detection of a CAEP provides confidence, to a degree commensurate with the detection probability, that the infant is detecting that sound at the level presented. When testing infants where the audibility of speech sounds has not been established behaviorally, the lack of a cortical response indicates the possibility, but by no means a certainty, that the sensation level is 10 dB or less.

  10. Comparison Acoustically Evoked Short Latency Negative Response with Vestibular Evoked Myogenic Potential in Adults with Profound Hearing Loss

    Directory of Open Access Journals (Sweden)

    Maryam Ramezani

    2012-03-01

    Full Text Available Background and Aim: A negative deflection with a 3-4 ms latency period has been reported to exist within the auditory brainstem response of some patients with profound hearing loss following a strong acoustic stimulus. This deflection, namingly the n3 or the acoustically evoked short latency negative response is assumed to be a vestibular-evoked potential, especially of saccular origin. Since the myogenic potential is also saccular in origin, the purpose of the present study was to investigate the relationship between these two tests in adults with profound hearing loss.Methods: The present cross sectional study was performed on 20 profoundly deaf volunteers(39 ears who aged between 18-40 years old, randomly selected from available deaf adults in Tehran. The auditory brainstem response of all subjects was recorded following a 1000 Hz tone burst in 70-100dB nHL. Subjects were also tested for vestibular evoked myogenic potential.Results: Only 34 of 39 ears recorded myogenic potential that negative response was recorded in 27 of 34 ears with normal p13 and n23. In seven ears with normal p13 and n23, the negative response was absent. In 3 ears with no p13 and n23, the negative response was observed, and two none.Conclusion: In view of the high prevalance of the negative response in profoundly deaf ears with normal p13 and n23, it could be concluded that the negative response can be used when for any reason, it is not possible to record myogenic potential and be considered as a new test in vestibular test battery.

  11. Polyacrylamide polymers derived from acrylonitrile without intermediate isolation

    Energy Technology Data Exchange (ETDEWEB)

    Norton, C.J.; Falk, D.O.

    1977-04-05

    Hydrolyzed and neutralized acrylonitrile is polymerized in solution without isolation to produce a high molecular weight polyacrylamide useful for mobility control in secondary recovery of petroleum. The polyacrylamide optionally may be hydrolyzed, methylolated, and sulfomethylated to further enhance its water-thickening properties. This procedure reduces the cost of making polyacrylamide. (5 claims)

  12. Comparison of Vestibular Evoked Myogenic Potential and Caloric Tests Findings in Noise Induced Hearing Loss-Affected and Healthy Individuals

    Directory of Open Access Journals (Sweden)

    Farinoosh Fakharnia

    2010-06-01

    Full Text Available Background and Aim: Balance disturbance is one of the non-auditory effects of noisy industrial environments that is usually neglected. The aim of the current study was to investigate the effect of occupational noise on vestibular system among workers with noise-induced hearing loss (NIHL, based on both vestibular evoked myogenic potentials (VEMP and caloric tests.Methods: Thirty male workers with noise-induced hearing loss and thirty male matched controls were examined by VEMP and caloric tests. Study parameters included unilateral weakness, p13 and n23 latencies, and p13-n23 amplitude. Caloric test was performed only for 20 patients.Results: No significant difference was observed in unilateral weakness between the two groups. On the other hand, the difference in mean latencies of p13 in the right ear (p=0.003 and left ear (p=0.01 was significant between the two groups. However, the difference in n23 latency was significant only in the right ear (p=0.03. There was no significant difference between groups in p13-n23 amplitude.Conclusion: It seems that pars inferior of vestibule is the susceptible part in individuals with NIHL. In general, abnormal findings in both VEMP and caloric tests were more common compared to functional symptoms such as vertigo, which may be due to central compensation and the symmetry of the disorder.

  13. Potential hazard of hearing damage to students in undergraduate popular music courses.

    Science.gov (United States)

    Barlow, Christopher

    2010-12-01

    In recent years, there has been a rapid growth in university courses related to popular and commercial music, with a commensurate increase in the number of students studying these courses. Students of popular music subjects are frequently involved in the use of electronically amplified sound for rehearsal and recording, in addition to the "normal" noise exposure commonly associated with young people. The combination of these two elements suggests a higher than average noise exposure hazard for these students. To date, the majority of noise studies on students have focused on exposure from personal music players and on classical, orchestral, and marching band musicians. One hundred students across a range of university popular music courses were surveyed using a 30-point questionnaire regarding their musical habits both within and external to their university courses. This was followed by noise dosimetry of studios/recording spaces and music venues popular with students. Questionnaire responses showed 76% of subjects reported having experienced symptoms associated with hearing loss, while only 18% reported using hearing protection devices. Rehearsals averaged 11.5 hrs/wk, with a mean duration 2 hrs 13 mins and mean level of 98 dB LAEQ. Ninety-four percent of subjects reported attending concerts or nightclubs at least once per week, and measured exposure in two of these venues ranged from 98 to 112 dB LAEQ with a mean of 98.9 dB LAEQ over a 4.5-hr period. Results suggested an extremely high hazard of excessive noise exposure among this group from both their social and study-based music activities.

  14. Hearing Aids

    Science.gov (United States)

    ... more in both quiet and noisy situations. Hearing aids help people who have hearing loss from damage ... your doctor. There are different kinds of hearing aids. They differ by size, their placement on or ...

  15. Hearing Loss

    Science.gov (United States)

    ... effects on your hearing — ringing in the ear (tinnitus) or hearing loss — can occur if you take ... adults with hearing loss, commonly reported problems include: Depression Anxiety An often false sense that others are ...

  16. Acoustically Induced Streaming Flows near a Model Cod Otolith and their Potential Implications for Fish Hearing

    Energy Technology Data Exchange (ETDEWEB)

    Kotas, Charlotte W [ORNL; Rogers, Peter [Georgia Institute of Technology; Yoda, Minami [Georgia Institute of Technology

    2011-01-01

    The ears of fishes are remarkable sensors for the small acoustic disturbances associated with underwater sound. For example, each ear of the Atlantic cod (Gadus morhua) has three dense bony bodies (otoliths) surrounded by fluid and tissue, and detects sounds at frequencies from 30 to 500 Hz. Atlantic cod have also been shown to localize sounds. However, how their ears perform these functions is not fully understood. Steady streaming, or time-independent, flows near a 350% scale model Atlantic cod otolith immersed in a viscous fluid were studied to determine if these fluid flows contain acoustically relevant information that could be detected by the ear s sensory hair cells. The otolith was oscillated sinusoidally at various orientations at frequencies of 8 24 Hz, corresponding to an actual frequency range of 280 830 Hz. Phaselocked particle pathline visualizations of the resulting flows give velocity, vorticity, and rate of strain fields over a single plane of this mainly two-dimensional flow. Although the streaming flows contain acoustically relevant information, the displacements due to these flows are likely too small to explain Atlantic cod hearing abilities near threshold. The results, however, may suggest a possible mechanism for detection of ultrasound in some fish species.

  17. A New Quenching Process and Tower to Improve the Recovery of Acrylonitrile

    Institute of Scientific and Technical Information of China (English)

    甘永胜; 顾军民; 方永成

    2004-01-01

    Quenching process and design of the quenching tower in acrylonitrile production in China were studied in order to decrease the polymerization loss of acrylonitrile in the quenching tower. Based on the research of acrylonitrile polymerization in the quenching tower, a new quenching process was proposed to avoid the disadvantages of the original process. Two kinds of internals were installed to improve the performance of the quenching tower. Through a series of air-flow and real-flow model experiments, the new quenching process and new design were showed to be successful in enhancing the mass and heat transfer in the vapor-liquid system and decreasing the loss of acrylonitrile.Industrial application showed satisfactory results of decrease of the acrylonitrile loss in the quenching tower by about 4.5% and increase of the acrylonitrile recovery of the whole plant by more than 4%.

  18. Thermal Stability of Poly (acrylonitrile-methyl acrylate) Copolymers

    Institute of Scientific and Technical Information of China (English)

    HAN Na; ZHANG Xing-xiang; WANG Xue-chen

    2008-01-01

    Poly (acrylonitrile-methyl acrylate) copolymer was synthesized by water depositing polymerization and has a typical feed ratio of 85/15. And then 1 - 3 wt% lauryl alcohol maleic anhydride (LAM) was adopted as stabilizer to mix with the acrylonitrile based copolymer. The mixtures were characterized by using Fourier Transform Infrared Spectroscopy (FTIR), Nuclear Magnetic Resonance (1H NMR ), Gel Permeation Chromatography ( GPC ), Differential Scanning Calorimetry (DSC), optic microscope and Ubbelohde viscosimetryr etc. The melting point (Tm) and glass transition temperature (Tg) of the 85/15 AN/MA copolymer mixed with LAM all decrease with the increase of stabilizer content. The lowest Tg and Tm were 116.1 ℃ and 209. 1℃ respectively at the heating rate of 100℃/min when the content of LAM is 2 wt%. The 85°/15 AN/MA copolymer mixed with 1 - 3 w t% LAM possess good thermal stability up to 30 min at 220 ℃.

  19. Radiation initiated copolymerization of allyl alcohol with acrylonitrile

    Energy Technology Data Exchange (ETDEWEB)

    Solpan, Dilek; Guven, Olgun [Hacettepe Univ., Ankara (Turkey). Dept. of Chemistry

    1996-07-01

    Copolymerization of allyl alcohol (AA) with acrylonitrile (AN) initiated by {gamma}-rays has been investigated to determine the respective reactivity ratios. Three different experimental techniques, namely Fourier Transform Infrared (FTIR), Ultraviolet (UV/vis) and elemental analysis (EA) have been used for the determination of copolymer compositions. Fineman-Ross (FR), Kelen-Tudos (KT), Non-Linear Least Square (NLLS) Analysis and Q-e methods have been applied to the three sets of experimental data. It has been concluded that data obtained from elemental analysis as applied to the Non-Linear Least Square approach gave the most reliable reactivity ratios as 2.09 and 0.40 for acrylonitrile and allyl alcohol, respectively. (Author).

  20. Radiation initiated copolymerization of allyl alcohol with acrylonitrile

    Science.gov (United States)

    Şolpan, Dilek; Güven, Olgun

    1996-07-01

    Copolymerization of allyl alcohol (AA) with acrylonitrile (AN) initiated by γ-rays has been investigated to determine the respective reactivity ratios. Three different experimental techniques, namely Fourier Transform Infrared (FTIR), Ultraviolet (UV/vis) and elemental analysis (EA) have been used for the determination of copolymer compositions. Fineman-Ross (FR), Kelen-Tüdös (KT), Non-Linear Least Square (NLLS) Analysis and Q-e methods have been applied to the three sets of experimental data. It has been concluded that data obtained from elemental analysis as applied to the Non-Linear Least Square approach gave the most reliable reactivity ratios as 2.09 and 0.40 for acrylonitrile and allyl alcohol, respectively.

  1. Hepatoprotective activity of quercetin against acrylonitrile-induced hepatotoxicity in rats.

    Science.gov (United States)

    Abo-Salem, Osama M; Abd-Ellah, Mohamed F; Ghonaim, Mabrouk M

    2011-01-01

    Acrylonitrile is a potent hepatotoxic, mutagen, and carcinogen. A role for free radical-mediated lipid peroxidation in the toxicity of acrylonitrile has been suggested. The present study was designed to assess the hepatoprotective effect of quercetin against acrylonitrile-induced hepatotoxicity in rats. Liver damage was induced by oral administration of acrylonitrile (50 mg/kg/day/5 weeks). Acrylonitrile produced a significant elevation of malondialdehyde (138.9%) with a marked decrease in reduced glutathione (72.4%), and enzymatic antioxidants; superoxide dismutase (81%), and glutathione peroxidase (53.2%) in the liver. Serum aspartate aminotransferase, alanine aminotransferases, direct bilirubin, and total bilirubin showed a significant increase in acrylonitrile alone treated rats (115.5%, 110.8%, 1006.8%, and 1000.8%, respectively). Pretreatment with quercetin (70 mg/kg/day/6 weeks) and its coadministration with acrylonitrile prevented acrylonitrile-induced alterations in hepatic lipid peroxides and enzymatic antioxidants as well as serum aminotransferases and bilirubin. Histopathological findings supported the biochemical results. We suggest that querectin possess hepatoprotective effect against acrylonitrile-induced hepatotoxicity through its antioxidant activity.

  2. 21 CFR 177.1020 - Acrylonitrile/butadiene/sty-rene co-polymer.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Acrylonitrile/butadiene/sty-rene co-polymer. 177... SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances.../butadiene/sty-rene co-polymer. Acrylonitrile/butadiene/styrene copolymer identified in this section may...

  3. 21 CFR 177.1030 - Acrylonitrile/butadiene/styrene/methyl methacrylate copolymer.

    Science.gov (United States)

    2010-04-01

    ... as determined by a method titled “Analysis of Cycopac Resin for Residual β-(2-Hydroxyethylmercapto... the range of 13.0 to 16.0 percent as determined by Micro-Kjeldahl analysis. (2) Residual acrylonitrile... a gas chromatographic method titled “Determination of Residual Acrylonitrile and Styrene...

  4. Carcinogenicity and other health effects of acrylonitrile with reference to occupational exposure limit.

    Science.gov (United States)

    Sakurai, H

    2000-04-01

    The occupational exposure limit for acrylonitrile (AN) has been set by many organizations on the basis of its carcinogenicity. However, recent epidemiological studies do not afford evidence supporting the hypothesis that AN is carcinogenic to humans. Review of the 18 published cohort studies revealed that, although there is not adequate evidence in humans for carcinogenicity of AN, the possibility of a causal association between high exposure to AN and lung cancer in humans cannot be excluded. It was pointed out that carcinogenic potential of AN may be weak, if any, to humans, and the current occupational exposure limit (OEL) for AN of 2 ppm was evaluated as appropriate in view of AN exposure levels reported by epidemiological studies. Based also on review of the literature on health effects other than carcinogenicity, it was concluded that the current OEL for AN is a reasonable value and there is no need for a revision at present.

  5. Kinetic and equilibrium studies of acrylonitrile binding to cytochrome c peroxidase and oxidation of acrylonitrile by cytochrome c peroxidase compound I

    Energy Technology Data Exchange (ETDEWEB)

    Chinchilla, Diana, E-mail: Diana_Chinchilla@yahoo.com; Kilheeney, Heather, E-mail: raindropszoo@yahoo.com; Vitello, Lidia B., E-mail: lvitello@niu.edu; Erman, James E., E-mail: jerman@niu.edu

    2014-01-03

    Highlights: •Cytochrome c peroxidase (CcP) binds acrylonitrile in a pH-independent fashion. •The spectrum of the CcP/acrylonitrile complex is that of a 6c–ls ferric heme. •The acrylonitrile/CcP complex has a K{sub D} value of 1.1 ± 0.2 M. •CcP compound I oxidizes acrylonitrile with a maximum turnover rate of 0.61 min{sup −1}. -- Abstract: Ferric heme proteins bind weakly basic ligands and the binding affinity is often pH dependent due to protonation of the ligand as well as the protein. In an effort to find a small, neutral ligand without significant acid/base properties to probe ligand binding reactions in ferric heme proteins we were led to consider the organonitriles. Although organonitriles are known to bind to transition metals, we have been unable to find any prior studies of nitrile binding to heme proteins. In this communication we report on the equilibrium and kinetic properties of acrylonitrile binding to cytochrome c peroxidase (CcP) as well as the oxidation of acrylonitrile by CcP compound I. Acrylonitrile binding to CcP is independent of pH between pH 4 and 8. The association and dissociation rate constants are 0.32 ± 0.16 M{sup −1} s{sup −1} and 0.34 ± 0.15 s{sup −1}, respectively, and the independently measured equilibrium dissociation constant for the complex is 1.1 ± 0.2 M. We have demonstrated for the first time that acrylonitrile can bind to a ferric heme protein. The binding mechanism appears to be a simple, one-step association of the ligand with the heme iron. We have also demonstrated that CcP can catalyze the oxidation of acrylonitrile, most likely to 2-cyanoethylene oxide in a “peroxygenase”-type reaction, with rates that are similar to rat liver microsomal cytochrome P450-catalyzed oxidation of acrylonitrile in the monooxygenase reaction. CcP compound I oxidizes acrylonitrile with a maximum turnover number of 0.61 min{sup −1} at pH 6.0.

  6. Ischemia as a potential etiologic factor in idiopathic unilateral sudden sensorineural hearing loss: Analysis of posterior circulation arteries.

    Science.gov (United States)

    Kim, Chulho; Sohn, Jong-Hee; Jang, Min Uk; Hong, Sung-Kwang; Lee, Joong-Seob; Kim, Hyung-Jong; Choi, Hui-Chul; Lee, Jun Ho

    2016-01-01

    The association between idiopathic sudden sensorineural hearing loss (ISSNHL) and the radiologic characteristics of the vertebrobasilar artery is unclear. We hypothesized that the degree and direction of vertebrobasilar artery curvature in the posterior circulation contribute to the occurrence of ISSNHL. We consecutively enrolled patients diagnosed with unilateral ISSNHL in two tertiary hospitals. Magnetic resonance images were performed in all patients to exclude specific causes of ISSNHL, such as vestibular schwannoma, chronic mastoiditis, and anterior inferior cerebellar artery infarct. We measured the following parameters of posterior circulation: vertebral and basilar artery diameter, the degree of basilar artery curvature (modified smoker criteria), and vertebral artery dominance. Pure tone audiometries were performed at admission and again 1 week and 3 months later. A total of 121 ISSNHL patients (mean age, 46.0 ± 17.3 years; 48.8% male) were included in these analyses. The proportion of patients with the left side hearing loss was larger than the proportion with the right side hearing loss (left, 57.9%; right, 42.1%). The majority of patients were characterized by a left dominant vertebral artery and right-sided basilar artery curvature. The direction of the basilar artery curvature was significantly associated with hearing loss lateralization (p = 0.036). Age and sex matched multivariable analyses revealed the absence of diabetes and right-sided basilar artery curvature as significant predictors for left sided hearing loss. There was no statistical difference between atherosclerotic cardiovascular risk score (high versus low) and hearing outcomes at 3 months. In ISSNHL, the laterality of hearing loss was inversely associated with the direction of basilar artery curvature. Our results, therefore, indicate the importance of vascular assessment when evaluating ISSNHL.

  7. Hearing loss and potential hazards of metallic middle-ear implants in NMR-magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Huettenbrink, K.B.

    1987-08-01

    Concurrent with the expanding clinical applications of nuclear magnetic resonance (NMR) imaging, patients with metallic middle-ear implants will certainly be exposed to this strong magnetic field in the future. To determine potential hazards, associated with movements of steel- or Platinium stapes-prostheses, several tests were performed in a 0.5 tesla NMR unit and the induced forces were calculated. Although the commonly used paramagnetic steel-wire or platinium-alloys will not dislodge in vivo, ferromagnetic prostheses may present a hazardous risk. Prior to exposure to the magnetic field, information about the implanted material should therefore be obtained. A side-effect of the induced current flow is the attenuation of the sound-vibrations of the stapes prosthesis. This, 5-10 dB impairment of transmission develops only at a certain position of the patient's head, when the prosthesis vibrates perpendicularly to the magnetic field's Z-axis. Patients with a metallic prosthesis should be informed about this purely physical, harmless phenomenon prior to entering the NMR-cylinder.

  8. Molecular biology of hearing [

    Directory of Open Access Journals (Sweden)

    Diensthuber, Marc

    2012-04-01

    Full Text Available [english] The inner ear is our most sensitive sensory organ and can be subdivided into three functional units: organ of Corti, stria vascularis and spiral ganglion. The appropriate stimulus for the organ of hearing is sound, which travels through the external auditory canal to the middle ear where it is transmitted to the inner ear. The inner ear houses the hair cells, the sensory cells of hearing. The inner hair cells are capable of mechanotransduction, the transformation of mechanical force into an electrical signal, which is the basic principle of hearing. The stria vascularis generates the endocochlear potential and maintains the ionic homeostasis of the endolymph. The dendrites of the spiral ganglion form synaptic contacts with the hair cells. The spiral ganglion is composed of neurons that transmit the electrical signals from the cochlea to the central nervous system. In recent years there has been significant progress in research on the molecular basis of hearing. An increasing number of genes and proteins related to hearing are being identified and characterized. The growing knowledge of these genes contributes not only to greater appreciation of the mechanism of hearing but also to a deeper understanding of the molecular basis of hereditary hearing loss. This basic research is a prerequisite for the development of molecular diagnostics and novel therapies for hearing loss.

  9. Perinatal Toxicity and Carcinogenicity Studies of Styrene –Acrylonitrile Trimer, A Ground Water Contaminant

    Science.gov (United States)

    Behl, Mamta; Elmore, Susan A.; Malarkey, David E.; Hejtmancik, Milton R.; Gerken, Diane K.; Chhabra, Rajendra S.

    2015-01-01

    Styrene Acrylonitrile (SAN) Trimer is a by-product in the production of acrylonitrile styrene plastics. Following a report of a childhood cancer cluster in the Toms River section of Dover Township, New Jersey, SAN Trimer was identified as one of the groundwater contaminants at Reich Farm Superfund site in the township. The contaminants from the Reich Farm site’s ground water plume impacted two wells at the Parkway well field. The National Toxicology Program (NTP) studied the toxicity and carcinogenicity of SAN Trimer in rats exposed during their perinatal developmental period and adulthood. The chronic toxicity and carcinogenicity studies in F344/N rats were preceded by 7- and 18-week perinatal toxicity studies to determine the exposure concentrations for the 2-year studies. Subsequently, Fisher 344 pregnant dams were exposed to SAN Trimer containing diet at 400, 800, or 1600 ppm concentrations during gestation, nursing and weaning periods of offspring followed by two year of adult exposures to both male and female pups. There was no statistically significant evidence of carcinogenic activity following SAN-Trimer exposure; however, rare neoplasms in the brain and spinal cord were observed in males and to lesser extent in female rats. These incidences were considered within the range of historical background in the animal model used in the current studies. Therefore, the presence of a few rarely occurring CNS tumors in the treated groups were not judged to be associated with the SAN Trimer exposure. The major finding was a dose-related peripheral neuropathy associated with the sciatic nerves in females and spinal nerve roots in males and females thereby suggesting that SAN trimer is potentially a nervous system toxicant. PMID:24060431

  10. Perinatal toxicity and carcinogenicity studies of styrene-acrylonitrile trimer, a ground water contaminant.

    Science.gov (United States)

    Behl, Mamta; Elmore, Susan A; Malarkey, David E; Hejtmancik, Milton R; Gerken, Diane K; Chhabra, Rajendra S

    2013-12-06

    Styrene acrylonitrile (SAN) trimer is a by-product in the production of acrylonitrile styrene plastics. Following a report of a childhood cancer cluster in the Toms River section of Dover Township, New Jersey, SAN Trimer was identified as one of the groundwater contaminants at Reich Farm Superfund site in the township. The contaminants from the Reich Farm site's ground water plume impacted two wells at the Parkway well field. The National Toxicology Program (NTP) studied the toxicity and carcinogenicity of SAN Trimer in rats exposed during their perinatal developmental period and adulthood. The chronic toxicity and carcinogenicity studies in F344/N rats were preceded by 7- and 18-week perinatal toxicity studies to determine the exposure concentrations for the 2-year studies. Subsequently, Fisher 344 pregnant dams were exposed to SAN Trimer containing diet at 400, 800, or 1600ppm concentrations during gestation, nursing and weaning periods of offspring followed by two year of adult exposures to both male and female pups. There was no statistically significant evidence of carcinogenic activity following SAN-Trimer exposure; however, rare neoplasms in the brain and spinal cord were observed in males and to lesser extent in female rats. These incidences were considered within the range of historical background in the animal model used in the current studies. Therefore, the presence of a few rarely occurring CNS tumors in the treated groups were not judged to be associated with the SAN Trimer exposure. The major finding was a dose-related peripheral neuropathy associated with the sciatic nerves in females and spinal nerve roots in males and females thereby suggesting that SAN Trimer is potentially a nervous system toxicant.

  11. Lungfish Hearing

    DEFF Research Database (Denmark)

    Christensen, Christian Bech; Madsen, Peter Teglberg; Christensen-Dalsgaard, Jakob

    and urodeles. Based on ABR and vibration measurements also on amphib - ians, lizards, snakes and alligators we can outline scenarios for the initial adaptations of the middle ear to non-tympanic hearing and assess the selection pressures later adapting the middle ear for tympanic hearing. Hearing by bone...

  12. Effect of noise pollution on hearing in auto-rickshaw drivers: A brainstem auditory-evoked potentials study

    Directory of Open Access Journals (Sweden)

    Bhupendra Marotrao Gathe

    2016-01-01

    Full Text Available Context: Auditory brainstem response is the most important tool in differential diagnosis and degree of hearing impairment. Many studies have been carried out to ascertain the effects of noise on human beings but very less on the transportation workers; hence, considering the need of time and use of brainstem auditory-evoked potentials (BAEP, this study was conducted to analyze the effect of noise pollution on auto-rickshaw drivers (ARDs. Aim: The aim of this study was to evaluate I, II, III, IV, and V wave latencies in ARDs and comparing it with control subjects in Central India. Settings and Design: This was a case-control study done on ARDs as participants and compared it with normal healthy individual BAEP pattern. Materials and Methods: We recorded BAEP from fifty healthy control subjects and fifty ARDs from the community of same sex and geographical setup. The absolute latencies were measured and compared. Recording was done using RMS EMG EP MARK II machine manufactured by RMS recorders and Medicare system, Chandigarh. Statistical Analysis Used: All the data related with subjects were filled in Excel sheet and analyzed with the help of EPI 6.0 info software with Student′s t-test. Results: There were prolongations of all absolute wave latencies of II, III, IV, and V in the ARDs as compared to control subjects. Conclusions: The prolongation of all absolute latencies of II, III, IV, and V suggests abnormality in brainstem auditory pathway mainly affecting the retrocochlear pathways in group of ARDs (noise exposure >10 years than other group who had exposed for <10 years and is more significant on the right ear than left.

  13. Characterization and development of new hydrogenated acrylonitrile-butadiene rubber blends

    Science.gov (United States)

    Severe, Geralda

    Characteristics were determined for hydrogenated acrylonitrile-butadiene rubber (HNBR), which is a copolymer of butadiene and acrylonitrile made from hydrogenation of the diene segment in acrylonitrile rubber. There was close attention given to the glass transition behavior of HNBR and its tendency to crystallize in the quiescent and in stretching state. The glass transition behavior in HNBR was similar to that of other ethylene copolymers such as for example ethylene vinyl-acetate etc. The crystallinity in HNBR at high acrylonitrile content was due to alternating sequence of acrylonitrile and hydrogenated trans-1,4 butadiene rubber. Furthermore, the structure of HNBR does not have any effect on it rheological properties at the temperature investigated. HNBR exhibits a zero shear viscosity. It is common knowledge that most polymers are immiscible. However, over the years scientists have found numerous miscible polymers. On that basis we investigated miscibility between HNBR with ethylenic copolymers, chlorinated polymers, diene polymers, and hydrogenated acrylonitrile-butadiene rubber. HNBR is miscible with high chlorine content chlorinated polymers like chlorinated polyethylene (42% Cl), chlorosulfonated polyethylene (43% Cl), PVC and CPVC. We have also developed dynamically vulcanized blends of HNBR with polychloroprene, epoxydized natural rubber, chlorobutyl, and carboxylated acrylonitrile-butadiene copolymer. Most of the blends at 75/25 composition have promising properties.

  14. Acrylonitrile is a multisite carcinogen in male and female B6C3F1 mice.

    Science.gov (United States)

    Ghanayem, Burhan I; Nyska, Abraham; Haseman, Joseph K; Bucher, John R

    2002-07-01

    Acrylonitrile is a heavily produced unsaturated nitrile, which is used in the production of synthetic fibers, plastics, resins, and rubber. Acrylonitrile is a multisite carcinogen in rats after exposure via gavage, drinking water, or inhalation. No carcinogenicity studies of acrylonitrile in a second animal species were available. The current studies were designed to assess the carcinogenicity of acrylonitrile in B6C3F1 mice of both sexes. Acrylonitrile was administered by gavage at 0, 2.5, 10, or 20 mg/kg/day, 5 days per week, for 2 years. Urinary thiocyanate and N-acetyl-S-(2-cyanoethyl)-L-cysteine were measured as markers of exposure to acrylonitrile. In general, there were dose-related increases in urinary thiocyanate and N-acetyl-S-(2-cyanoethyl)-L-cysteine concentrations in all dosed groups of mice and at all time points. Survival was significantly (p acrylonitrile-dosed groups. In female mice, the incidence of benign or malignant granulosa cell tumors (combined) in the ovary in the 10 mg/kg dose group was greater than that in the vehicle control group, but because of a lack of dose response, this was considered an equivocal finding. In addition, the incidences of atrophy and cysts in the ovary of the 10 and 20 mg/kg dose groups were significantly increased. The incidences of alveolar/bronchiolar adenoma or carcinoma (combined) were significantly increased in female mice treated with acrylonitrile at 10 mg/kg/day for 2 years. This was also considered an equivocal result. In conclusion, these studies demonstrated that acrylonitrile causes multiple carcinogenic effects after gavage administration to male and female B6C3F1 mice for 2 years.

  15. Acrylonitrile quenching of trp phosphorescence in proteins: a probe of the internal flexibility of the globular fold.

    Science.gov (United States)

    Strambini, Giovanni B; Gonnelli, Margherita

    2010-08-04

    Quenching of Trp phosphorescence in proteins by diffusion of solutes of various molecular sizes unveils the frequency-amplitude of structural fluctuations. To cover the sizes gap between O(2) and acrylamide, we examined the potential of acrylonitrile to probe conformational flexibility of proteins. The distance dependence of the through-space acrylonitrile quenching rate was determined in a glass at 77 K, with the indole analog 2-(3-indoyl) ethyl phenyl ketone. Intensity and decay kinetics data were fitted to a rate, k(r) =k(0) exp[-(r -r(0))/r(e)], with an attenuation length r(e) = 0.03 nm and a contact rate k(0) = 3.6 x 10(10) s(-1). At ambient temperature, the bimolecular quenching rate constant (kq) was determined for a series of proteins, appositely selected to test the importance of factors such as the degree of Trp burial and structural rigidity. Relative to kq = 1.9 x 10(9) M(-1)s(-1) for free Trp in water, in proteins kq ranged from 6.5 x 10(6) M(-1)s(-1) for superficial sites to 1.3 x 10(2) M(-1)s(-1) for deep cores. The short-range nature of the interaction and the direct correlation between kq and structural flexibility attest that in the microsecond-second timescale of phosphorescence acrylonitrile readily penetrates even compact protein cores and exhibits significant sensitivity to variations in dynamical structure of the globular fold.

  16. Synthesis, Characterization and Photophysical Properties of Pyridine-Carbazole Acrylonitrile Derivatives

    OpenAIRE

    Gabriel Ramos-Ortiz; Enrique Pérez-Gutiérrez; José Luis Maldonado; Chapela, Víctor M.; Margarita Cerón; M. Judith Percino

    2011-01-01

    We synthesized three novel highly fluorescent compounds, 2-(2’-pyridyl)-3-(N-ethyl-(3’-carbazolyl))acrylonitrile, 2-(3”-pyridyl)-3-(N-ethyl-(3’-carbazolyl))acrylonitrile, and 2-(4-pyridyl)-3-(N-ethyl-(3’-carbazolyl))acrylonitrile by Knoevenagel condensation. The first two were synthesized without solvent in the presence of piperidine as a catalyst; the third was synthesized without a catalyst and with N,N-dimethylformamide as a solvent. In solution, the molar absorption coefficients showed ab...

  17. In vivo comet assay of acrylonitrile, 9-aminoacridine hydrochloride monohydrate and ethanol in rats.

    Science.gov (United States)

    Nakagawa, Yuzuki; Toyoizumi, Tomoyasu; Sui, Hajime; Ohta, Ryo; Kumagai, Fumiaki; Usumi, Kenji; Saito, Yoshiaki; Yamakage, Kohji

    2015-07-01

    As part of the Japanese Center for the Validation of Alternative Methods (JaCVAM)-initiative international validation study of the in vivo rat alkaline comet assay, we examined the ability of acrylonitrile, 9-aminoacridine hydrochloride monohydrate (9-AA), and ethanol to induce DNA damage in the liver and glandular stomach of male rats. Acrylonitrile is a genotoxic carcinogen, 9-AA is a genotoxic non-carcinogen, and ethanol is a non-genotoxic carcinogen. Positive results were obtained in the liver cells of male rats treated with known genotoxic compounds, acrylonitrile and 9-AA.

  18. Compromised potassium recycling in the cochlea contributes to conservation of endocochlear potential in a mouse model of age-related hearing loss.

    Science.gov (United States)

    Yang, Haidi; Xiong, Hao; Huang, Qiuhong; Pang, Jiaqi; Zheng, Xuqing; Chen, Lian; Yu, Rongjun; Zheng, Yiqing

    2013-10-25

    The C57BL/6 strain is considered an excellent model to study age-related hearing loss (AHL). Aging C57BL/6 mice are characterized by profound hearing loss but conservation of the endocochlear potential (EP). Here we show 12-month-old C57BL/6 mice display a notable hearing loss at 4, 8, 16 and 32kHz while the EP is maintained at normal level. Morphological examination shows significant outer hair cells loss in the cochlear basal turn and atrophy of the stria vascularis (SV). Fluorescence immunohistochemical studies reveal that potassium channel KCNJ10 and KCNQ1 expression dramatically decreased in the SV. Concomitant with this, mRNA levels of KCNJ10 and KCNQ1 are also reduced. In addition, three other potassium transporters, including α1-Na,K-ATPase, α2-Na,K-ATPase and NKCC1, reduce their expression at mRNA levels as well. These observations suggest that conservation of the EP in aging C57BL/6 mice is attributable to the SV generating a new balance for potassium influx and efflux at a relatively lower level.

  19. Hydration of acrylonitrile to produce acrylamide using biocatalyst in a membrane dispersion microreactor.

    Science.gov (United States)

    Li, Jiahui; Chen, Jie; Wang, Yujun; Luo, Guangsheng; Yu, Huimin

    2014-10-01

    In this work, a membrane dispersion microreactor was utilized for the hydration of acrylonitrile to produce acrylamide. Through observation using a microscopy, it was found that the acrylonitrile was dispersed into the continuous phase (the aqueous phase contains nitrile hydratase (NHase)) as droplets with a diameter ranged from 25 to 35 μm, hence the mass transfer specific surface area was significantly increased, and the concentration of acrylamide reached 52.5 wt% within 50 min. By contrast, in stirred tanks, the concentration of acrylamide only got 39.5 wt% within 245 min. Moreover, only a few amounts of acrylonitrile were accumulated in this microreactor system. Through optimizing the flow rate, the concentration of acrylamide reached 45.8 wt% within 35 min, the short reaction time greatly weakened the inhibition of acrylonitrile and acrylamide on the enzyme activity, which is suitable for prolonging the life of free cell.

  20. BARRIER PROPERTY AND STRUCTURE OF ACRYLONITRILE/ACRYLIC COPOLYMERS

    Institute of Scientific and Technical Information of China (English)

    YANG Zhenghua; LI Yuesheng

    1997-01-01

    A series of acrylonitrile (AN) copolymers with methyl acrylate (MA) or ethyl acrylate (EA) as comonomer (5-23 wt%) was prepared by free-radical copolymerization. The permeability coefficients of the copolymers to oxygen and carbon dioxide were measured at 1.0 MPa and at 30 ℃, and those to water vapor also measured at 100% relative humidity and at 30 ℃. All the AN/acrylic copolymers are semicrystalline. As the acrylate content increase, the permeability coefficients of the copolymers to oxygen and carbon dioxide are increased progressively, but those to water vapor are decreased progressively. The gas permeability coefficients of the polymers were correlated with free-volume fractions or the ratio of free volume to cohesive energy.

  1. A risk assessment for acrylonitrile in consumer products.

    Science.gov (United States)

    Johnston, P K; Rock, A R

    1990-12-15

    A carcinogenic risk assessment for acrylonitrile in consumer products was prepared as part of the Second Workshop on Pragmatics of Risk Assessment, Bethesda, MD. Data from one inhalation and two oral rat bioassays served as input into several high-to-low-dose mathematical risk extrapolation models. The final unit risk estimates for humans were based on maximum likelihood estimates from the Global83 implementation of the multistage model after adjustments for surface area differences, continuous versus intermittent exposures, and the proportion of lifetime exposed. The unit risk estimates for lifetime exposure to 1 mg kg-1 day-1 by inhalation and ingestion were 0.0531 and 0.2385, respectively. These risks are equivalent to risks of 3.3 x 10(-8) for inhalation of 1 ppt in air and 3.4 x 10(-9) for ingestion of 1 ng day.-1

  2. KINETIC STUDIES ON THE POLYMERIZATION OF ACRYLONITRILE INITIATED BY METALLIC MAGNESIUM-NITRIC ACID SYSTEM

    Institute of Scientific and Technical Information of China (English)

    WU Chinyung

    1983-01-01

    This article reports the polymerization kinetics of acrylonitrile initiated by metallic magnesiumnitric acid system. The rate of polymerization is independent of the amount of magnesium used; when the concentration of nitric acid is higher than acrylonitrile, the equation of polymerization kinetics may be expressed as Rp=1.91 × 105e-15000/RT[Mg]0 [AN]2·2 [HNO3]0·46 The result of copolymerization of acyrlonitrile and methyl acrylate supports a free-radical mechanism.

  3. Perinatal Toxicity and Carcinogenicity Studies of Styrene –Acrylonitrile Trimer, A Ground Water Contaminant

    OpenAIRE

    Behl, Mamta; Elmore, Susan A.; Malarkey, David E.; Hejtmancik, Milton R.; Gerken, Diane K.; Chhabra, Rajendra S.

    2013-01-01

    Styrene Acrylonitrile (SAN) Trimer is a by-product in the production of acrylonitrile styrene plastics. Following a report of a childhood cancer cluster in the Toms River section of Dover Township, New Jersey, SAN Trimer was identified as one of the groundwater contaminants at Reich Farm Superfund site in the township. The contaminants from the Reich Farm site’s ground water plume impacted two wells at the Parkway well field. The National Toxicology Program (NTP) studied the toxicity and carc...

  4. EFFECTS OF SOLVENT POLARITY ON FREE RADICAL COPOLY MERIZATION OF 5-HEXENOIC ACID AND ACRYLONITRILE

    Institute of Scientific and Technical Information of China (English)

    WANG Bing; XIE Shishan; CAO Mengjiun

    1987-01-01

    The effects of solvent polarity on free radical copolymerization of 5-hexenoic acid and acrylonitrile at 60℃ were studied. It was observed that as the polarity of solvents enhanced, both the copolymerization rate and the reactivity ratios r1, r2 increased, while the alternating tendency of monomer units in copolymer chain decreased. It is believed that the solvent polarity raises the reactivities of acrylonitrile monomer and its growing chain radical, but causes no distinct variation in those of 5-hexenoic acid.

  5. Hearing Assistive Technology

    Science.gov (United States)

    ... for the Public / Hearing and Balance Hearing Assistive Technology Hearing Assistive Technology: FM Systems | Infrared Systems | Induction ... Assistive Technology Systems Solutions What are hearing assistive technology systems (HATS)? Hearing assistive technology systems (HATS) are ...

  6. Types of Hearing Aids

    Science.gov (United States)

    ... Devices Consumer Products Hearing Aids Types of Hearing Aids Share Tweet Linkedin Pin it More sharing options ... some features for hearing aids? What are hearing aids? Hearing aids are sound-amplifying devices designed to ...

  7. Grafting of acrylonitrile onto cellulosic material derived from bamboo (Dendrocalamus strictus

    Directory of Open Access Journals (Sweden)

    2008-01-01

    Full Text Available Bamboo, a lignocellulosic biopolymer material, is of interest as feedstock for production of cellulose derivatives by chemical functionalization. Optimization of grafting of acrylonitrile onto cellulosic material (average Degree of Polymerization 816, isolated from bamboo (Dendrocalamus stictus was performed by varying the process parameters such as duration of soaking of cellulosic material in ceric ammonium nitrate solution, ceric ammonium nitrate concentration, polymerization time, temperature of reaction and acrylonitrile concentration to study their influence on percent grafting and grafting efficiency. Graft copolymerization of acrylonitrile onto cellulosic material derived from bamboo (Dendrocalamus strictus in heterogenous medium can be initiated effectively with ceric ammonium nitrate. The optimum reaction conditions obtained for grafting of acrylonitrile onto cellulosic material were: duration of dipping cellulosic material in ceric ammonium nitrate solution 1 hr, ceric ammonium nitrate concentration 0.02 M, acrylonitrile concentration 24.6 mol/anhydroglucose unit, temperature of reaction 40°C and polymerization time 4 hrs. The percent grafting for optimized samples is 210.3% and grafting efficiency is 97%. The characterization of the grafted products by means of FTIR and Scanning Electron Microscopy furnished the evidence of grafting of acrylonitrile onto the cellulosic material.

  8. The Formation and characteristics of Acrylonitrile/Urea Inclusion Compound

    CERN Document Server

    Zou, Jun-Ting; Pang, Wen-Min; Shi, Lei; Lu, Fei

    2012-01-01

    The formation process and composition of the acrylonitrile/urea inclusion compounds (AN/UIC) with different aging times and AN/urea molar feed ratios are studied by differential scanning calorimetry (DSC) and X-ray diffraction (XRD). It is suggested that DSC could be one of the helpful methods to determine the guest/host ratio and the heat of decomposition. Meanwhile, the guest/host ratio and heat of deformation are obtained, which are 1.17 and 5361.53 J/mol, respectively. It is found that the formation of AN/UIC depends on the aging time. The formation process ends after enough aging time and the composition of AN/UIC becomes stable. It is suggested AN molecules included in urea canal lattice may be packed flat against each other. XRD results reveal that once AN molecules enter urea lattice, AN/UIC are formed, which possess the final structure. When AN molecules are sufficient, the content of AN/UIC increased as aging time prolonging until urea tunnels are saturated by AN.

  9. Recycling of Chrome Tanned Leather Dust in Acrylonitrile Butadiene Rubber

    Science.gov (United States)

    El-Sabbagh, Salwa H.; Mohamed, Ola A.

    2010-06-01

    Concerns on environmental waste problem caused by chrome tanned leather wastes in huge amount have caused an increasing interest in developing this wastes in many composite formation. This leather dust was used as filler in acrylonitrile butadiene rubber (NBR) before treatment and after treatment with ammonia solution and sod. formate. Different formulations of NBR/ leather dust (untreated-treated with ammonia solution—treated with sod. formate) composites are prepared. The formed composite exhibit a considerable improvement in some of their properties such as rheometric characteristics especially with composites loaded with treated leather dust. Tensile strength, modulus at 100% elongation, hardness and youngs modulus were improved then by further loading start to be steady or decrease. Cross linking density in toluene were increased by incorporation of leather dust treated or untreated resulting in decreases in equilibrium swelling. Distinct increase in the ageing coefficient of both treated and untreated leather with drop in NBR vulcanizates without leather dust. Addition of leather dust treated or untreated exhibit better thermal stability.

  10. Lactoperoxidase catalyzes in vitro activation of acrylonitrile to cyanide.

    Science.gov (United States)

    Nasralla, Sherry N; Ghoneim, Asser I; Khalifa, Amani E; Gad, Mohamed Z; Abdel-Naim, Ashraf B

    2009-12-15

    Acrylonitrile (ACN) is a widely used industrial chemical. Although it is a well reported animal carcinogen, its current designation to humans is "possibly carcinogenic". The present study aimed at investigating the ability of LPO enzyme system to oxidize ACN to cyanide (CN(-)) in vitro. Detection of CN(-) served as a marker for the possible generation of free radical intermediates implicated in ACN induced toxicity in the activation process. Optimum conditions for the oxidation of ACN to CN(-) were characterized with respect to pH, temperature and time of incubation as well as ACN, LPO and H(2)O(2) concentrations in incubation mixtures. Maximum reaction velocity (V(max)) and Michaelis-Menten constant (K(m)) were assessed. Addition of nitrite (NO(2)(-)) salts to the reaction mixtures significantly enhanced the rate of the reaction. Free radical scavengers (quercetin and trolox C), LPO enzyme inhibitor (resorcinol) and competitors for LPO binding (sodium azide and indomethacin) were found to reduce the rate of CN(-) production. Inclusion of the sulfhydryl compounds glutathione (GSH), NAC (N-acetylcysteine), D-penicillamine or L-cysteine enhanced the rate of ACN oxidation. The present results demonstrate the ability of LPO enzyme system to oxidize ACN to CN(-) and provide insight for the elucidation of ACN chronic toxicity.

  11. Weight-of-the-evidence review of acrylonitrile reproductive and developmental toxicity studies.

    Science.gov (United States)

    Neal, Barbara H; Collins, James J; Strother, Dale E; Lamb, James C

    2009-01-01

    Risk assessment of acrylonitrile (AN) toxicity to humans has focused on potential carcinogenicity and acute toxicity. Epidemiological studies from China reported reproductive and developmental effects in AN workers, including infertility, birth defects, and spontaneous abortions. A weight-of-the-evidence (WoE) evaluation of the AN database assessed study strength, characterized toxicity, and identified no-observed-adverse-effect levels (NOAELs). The epidemiological studies do not demonstrate causality and are not sufficiently robust to be used for risk assessment. Rodent developmental studies showed fetotoxicity and malformations at maternally toxic levels; there was no unique developmental susceptibility. NOAELs for oral and inhalation exposures were 10 mg/kg/day and 12 ppm (6 h/day), respectively. Drinking-water and inhalation reproductive toxicity studies showed no clear effects on reproductive performance or fertility. Maternally toxic concentrations caused decreased pup growth. The drinking-water reproductive NOAEL was 100 ppm (moderate confidence due to study limitations). The inhalation exposure reproductive and neonatal toxicity high confidence NOAEL was 45 ppm (first generation 90 ppm) (6 h/day). The inhalation reproductive toxicity study provides the most robust data for risk assessment. Based on the WoE evaluation, AN is not expected to be a developmental or reproductive toxicant in the absence of significant maternal toxicity.

  12. Hearing Aids

    Science.gov (United States)

    ... slightly different from the ITC and is nearly hidden in the ear canal. Both canal hearing aids ... Privacy Policy & Terms of Use Visit the Nemours Web site. Note: All information on TeensHealth® is for ...

  13. Fish Hearing.

    Science.gov (United States)

    Blaxter, J. H. S.

    1980-01-01

    Provides related information about hearing in fish, including the sensory stimulus of sound in the underwater environment, mechanoreceptors in fish, pressure perception and the swimbladder, specializations in sound conduction peculiar to certain fish families. Includes numerous figures. (CS)

  14. Pre-irradiation induced emulsion graft polymerization of acrylonitrile onto polyethylene nonwoven fabric

    Science.gov (United States)

    Liu, Hanzhou; Yu, Ming; Deng, Bo; Li, Linfan; Jiang, Haiqing; Li, Jingye

    2012-01-01

    Acrylonitrile has been widely used in the modification of polymers by graft polymerization. In the present work, pre-irradiation induced emulsion graft polymerization method is used to introduce acrylonitrile onto PE nonwoven fabric instead of the traditional reaction in organic solvents system. The degree of grafting (DG) is measured by gravimetric method and the kinetics of the graft polymerization is studied. The existence of the graft chains is proven by Fourier transform infrared spectroscopy (FT-IR) analysis. Thermal stability of the grafted polymer is measured by Thermogravimetric analysis (TGA).

  15. Screening-level risk assessment for styrene-acrylonitrile (SAN) trimer detected in soil and groundwater.

    Science.gov (United States)

    Kirman, C R; Gargas, M L; Collins, J J; Rowlands, J C

    2012-01-01

    A screening-level risk assessment was conducted for styrene-acrylonitrile (SAN) Trimer detected at the Reich Farm Superfund site in Toms River, NJ. Consistent with a screening-level approach, on-site and off-site exposure scenarios were evaluated using assumptions that are expected to overestimate actual exposures and hazards at the site. Environmental sampling data collected for soil and groundwater were used to estimate exposure point concentrations. Several exposure scenarios were evaluated to assess potential on-site and off-site exposures, using parameter values for exposures to soil (oral, inhalation of particulates, and dermal contact) and groundwater (oral, dermal contact) to reflect central tendency exposure (CTE) and reasonable maximum exposure (RME) conditions. Three reference dose (RfD) values were derived for SAN Trimer for short-term, subchronic, and chronic exposures, based upon its effects on the liver in exposed rats. Benchmark (BMD) methods were used to assess the relationship between exposure and response, and to characterize appropriate points of departure (POD) for each RfD. An uncertainty factor of 300 was applied to each POD to yield RfD values of 0.1, 0.04, and 0.03 mg/kg-d for short-term, subchronic, and chronic exposures, respectively. Because a chronic cancer bioassay for SAN Trimer in rats (NTP 2011a) does not provide evidence of carcinogenicity, a cancer risk assessment is not appropriate for this chemical. Potential health hazards to human health were assessed using a hazard index (HI) approach, which considers the ratio of exposure dose (i.e., average daily dose, mg/kg-d) to toxicity dose (RfD, mg/kg-d) for each scenario. All CTE and RME HI values are well below 1 (where the average daily dose is equivalent to the RfD), indicating that there is no concern for potential noncancer effects in exposed populations even under the conservative assumptions of this screening-level assessment.

  16. KINETICS OF POLYMERIZATION OF ACRYLONITRILE INITIATED BY VANADIUM(V) - THIOUREA REDOX SYSTEM

    Institute of Scientific and Technical Information of China (English)

    WU Jinyuan; YANG Chaoxiong; WU Yuxian

    1990-01-01

    The kinetics of polymerization of acrylonitrile (AN) initiated by quinquevalent vanadium (V5+ )-thiourea (TU) redox system has been investigated in aqueous nitric acid in the temperature range from 30 to 50 ℃ . The polymerization rate (Rp) can be expressed as follows:Rp= 2.80×105e- 14,200/RT[AN] 2,2[V5+] 0~1/3[TU] 0~4/3[HNO3] 0.2. In the copolymerization of acrylonitrile with methyl acrylate (MA), the reactivity ratios were found to be 1.0 and 1.1, respectively. The experimental observations suggest that the initiating species is probably a complex consisting of a central ion of Lewis acid-VO+2 and the ligands of Lewis bases-acrylonitrile, thiourea, and nitrate anions, while the initiating system in lower concentration, the polymerization of acrylonitrile does not occur if the thiourea is acidified prior to its reaction with quinquevalent vanadium. This indicates that the primary radicals (or the monomeric radicals in the present article) are produced by associated thiourea rather than isothiourea.

  17. Arylation of Acrylamide and Acrylonitrile with Arenediazonium Salts Catalyzed by Palladium Acetate

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Arylation of acrylamide and acrylonitrile were carried out with various arenediazonium tetrafluoroborates in the presence of a catalytic amount of Pd(OAc)2 in ethanol and a variety of substituted (E)-cinnamamides and (E)-cinnamonitriles were obtained in high yields under mild reaction conditions.

  18. Uncertainty and variability in the exposure reconstruction of chemical incidents--the case of acrylonitrile.

    Science.gov (United States)

    Huizer, Daan; Ragas, Ad M J; Oldenkamp, Rik; van Rooij, Joost G M; Huijbregts, Mark A J

    2014-12-15

    The application of human physiologically based pharmacokinetic (PBPK) modeling combined with measured biomonitoring data, has a great potential to backtrack external exposure to chemicals during chemical incidents. So far, an important shortcoming of 'reversed dosimetry' is that uncertainty and variability in the model predictions are often neglected. The aim of this paper is to characterize the variation in predicted environmental air concentrations by means of reversed dosimetry as a result of uncertainty in chemical-specific input data and variability in physiological parameters. Human biomonitoring data (N-2-cyanoethylvaline in blood) from a chemical incident with acrylonitrile (ACN) combined with the BioNormtox PBPK model are used as a case to reconstruct the air concentration and uncertainty thereof at the time of the incident. The influence of uncertainty in chemical-specific properties and exposure duration, and interindividual variability in physiological parameters on the reconstructed air exposure concentrations were quantified via nested Monte Carlo simulation. The range in the reconstructed air concentrations of ACN during the incident was within a factor of 3. Uncertainty in the exact exposure duration directly after the chemical accident was found to have a dominant influence on the model outcomes. It was also shown that uncertainty can be further reduced by collecting human biomonitoring data as soon as possible after the incident. Finally, the collection of specific information about individual physiological parameters from the victims, such as body weight, may further reduce the variation by 5 to 20% in our case study. Future research should include the comparison of reversed dosimetry model outcomes with measured air and biological concentrations to further increase the confidence in the model approach and its implementation in practice.

  19. Vestibular Evoked Myogenic Potential Produced by Bone-Conducted Stimuli: A Study on its Basics and Clinical Applications in Patients With Conductive and Sensorineural Hearing Loss and a Group With Vestibular Schawannoma

    Directory of Open Access Journals (Sweden)

    Parvane Mahdi

    2013-06-01

    Full Text Available Introduction: Vestibular evoked myogenic potential (VEMP has recently been broadly studied in vestibular disorders. As it is evoked by loud sound stimulation, even mild conductive hearing loss may affect VEMP results. Bone-conducted (BC stimulus is an alternative stimulation for evoking this response. This study aims to assess the characteristics of BC-VEMP in different groups of patients.   Materials and Methods: We performed a cross sectional analysis on 20 healthy volunteers with normal pure-tone audiometry as a control group; and on a group of patients consisted of 20 participants with conductive hearing loss, five with bilateral sensorineural hearing loss and four with vestibular schawannoma. AC and BC-VEMP were performed in all participants.   Results: In control group the VEMP responses to both kinds of stimuli had an acceptable morphology and consisted of p13 and n23 waves. Latency value of these main components in each type of stimulus was not significantly different (P>0.05. However, the mean amplitude was larger in BC modality than AC stimulation (P=0.025. In the group with conductive hearing loss, the VEMP response was absent in fifteen (46.87% of the 32 ears using the AC method, whereas all (100% displayed positive elicitability of VEMP by BC method. Normal VEMP responses in both stimuli were evoked in all patients with sensorineural hearing loss. In patients with unilateral vestibular schwannomas (VS, 2 (50.00% had neither AC-VEMP nor BC-VEMP. Conclusion:  Auditory stimuli delivered by bone conduction can evoke VEMP response. These responses are of vestibular origin and can be used in vestibular evaluation of patients with conductive hearing loss.

  20. Hearing loss and cognition: the role of hearing AIDS, social isolation and depression.

    Directory of Open Access Journals (Sweden)

    Piers Dawes

    Full Text Available Hearing loss is associated with poor cognitive performance and incident dementia and may contribute to cognitive decline. Treating hearing loss with hearing aids may ameliorate cognitive decline. The purpose of this study was to test whether use of hearing aids was associated with better cognitive performance, and if this relationship was mediated via social isolation and/or depression. Structural equation modelling of associations between hearing loss, cognitive performance, social isolation, depression and hearing aid use was carried out with a subsample of the UK Biobank data set (n = 164,770 of UK adults aged 40 to 69 years who completed a hearing test. Age, sex, general health and socioeconomic status were controlled for as potential confounders. Hearing aid use was associated with better cognition, independently of social isolation and depression. This finding was consistent with the hypothesis that hearing aids may improve cognitive performance, although if hearing aids do have a positive effect on cognition it is not likely to be via reduction of the adverse effects of hearing loss on social isolation or depression. We suggest that any positive effects of hearing aid use on cognition may be via improvement in audibility or associated increases in self-efficacy. Alternatively, positive associations between hearing aid use and cognition may be accounted for by more cognitively able people seeking and using hearing aids. Further research is required to determine the direction of association, if there is any direct causal relationship between hearing aid use and better cognition, and whether hearing aid use results in reduction in rates of cognitive decline measured longitudinally.

  1. Measurements on Hearing

    DEFF Research Database (Denmark)

    Poulsen, Torben

    1996-01-01

    Background material for measurements of hearing for grammar school pupils. The note gives the necessary background for the exercise 'Measurement on Hearing'. The topics comprise sound and decibel, the ear, basic psychoacoustics, hearing threshold, audiometric measurement methods, speech and speech...

  2. Genotoxicity of Styrene–Acrylonitrile Trimer in Brain, Liver, and Blood Cells of Weanling F344 Rats

    OpenAIRE

    Hobbs, Cheryl A.; Chhabra, Rajendra S.; Recio, Leslie; Streicker, Michael; Witt, Kristine L.

    2012-01-01

    Styrene–acrylonitrile Trimer (SAN Trimer), a by-product in production of acrylonitrile styrene plastics, was identified at a Superfund site in Dover Township, NJ, where childhood cancer incidence rates were elevated for a period of several years. SAN Trimer was therefore tested by the National Toxicology Program in a 2-year perinatal carcinogenicity study in F344/N rats and a bacterial mutagenicity assay; both studies gave negative results. To further characterize its genotoxicity, SAN Trimer...

  3. Dimedone-catalyzed Addition of Amines into Cyano Group: Facile Synthesis of Thiazol-2-yl Substituted E-Acrylonitriles

    Institute of Scientific and Technical Information of China (English)

    朱伟军; 屠兴超; 冯惠; 屠蔓苏; 姜波; 吴飞跃; 屠树江

    2012-01-01

    An efficient dimedone-catalyzed synthesis of highly functionalized thiazol-2-yl substituted E-acrylonitrile derivatives has been established through two-step reaction of a-thiocyanate ketones with malononitrile and amines. The a-thiocyanate ketones were subjected with malononitrile to provide thiazol-2-ylidenemalononitrile derivatives, followed with various amines in the presence of dimedone to yield the final thiazol-2-yl substituted acrylonitrile derivatives.

  4. Significance of the Auditory Evoked Potential Test in the Medicolegal Identification of Hearing Loss%听觉诱发电位检查在听力下降法医学鉴定中的意义

    Institute of Scientific and Technical Information of China (English)

    刘瑾

    2012-01-01

    目的 研究听觉诱发电位检查在外伤性听力下降临床法医学鉴定中的意义.方法 通过对57例外伤后导致听力损伤的临床法医学鉴定案例进行分析,研究听觉诱发电位检查对临床法医学鉴定听力损伤程度的重要性,从而对听觉诱发电位检查结果 和听力下降程度的相关性进行统计学分析.结果 听觉诱发电位等客观检查结果 与被鉴定人的听力损伤下降程度相符;在听力受损伤后,听觉诱发电位检查结果 对比显示被鉴定人的听力损伤有不同程度的恢复;听力损伤程度与造成听力损害的损伤部位有密切关系.结论 应用ABR-click和40 Hz AERP-Tone-500 Hz,结合纯音测听、电测听、声导(阻)抗、耳声发射等可以客观公正的对听力障碍进行鉴定,并识别伪聋和明显夸大听力障碍者,在法医学鉴定中有重要意义.%Objective To study the significance of the auditory evoked potential test( AEPT )in the medicolegal identification of traumatic hearing loss. Methods 57 cases of traumatic hearing impairment in the clinical medicolegal identification were analyzed so as to study the importance of AEPT in the medicolegal identification of the severity of hearing impairment and conduct the statistical analysis on the correlation between AEPT results and hearing loss degree. Results The results of the objective items of AEPT were coincident with hearing loss degree for the persons to be identified. After hearing impairment, the comparison of AEPT results indicated that the hearing loss for the persons to be identified was recovered to different extents. The hearing loss degree was closely relevant with the injury location of hearing. Conclusion ABR -click and 40 Hz AERP - Tone - 500 Hz can objectively and righteously identify hearing impairment in association with pure tone audiometry, electric audiometry, acoustic resistance, otoacoustic emission and others and distinguish feigned deafness and

  5. Nitrilase-catalysed conversion of acrylonitrile by free and immobilized cells of Streptomyces sp.

    Indian Academy of Sciences (India)

    V K Nigam; A K Khandelwal; R K Gothwal; M K Mohan; B Choudhury; A S Vidyarthi; P Ghosh

    2009-03-01

    The biotransformation of acrylonitrile was investigated using thermophilic nitrilase produced from a new isolate Streptomyces sp. MTCC 7546 in both the free and immobilized state. Under optimal conditions, the enzyme converts nitriles to acids without the formation of amides. The whole cells of the isolate were immobilized in agar-agar and the beads so formed were evaluated for 25 cycles at 50°C. The enzyme showed a little loss of activity during reuse. Seventy-one per cent of 0.5 M acrylonitrile was converted to acid at 6 h of incubation at a very low density of immobilized cells, while 100% conversion was observed at 3 h by free cells.

  6. Detection of acrolein and acrylonitrile with a pulsed room temperature quantum cascade laser

    Science.gov (United States)

    Manne, J.; Jäger, W.; Tulip, J.

    2010-06-01

    We investigated the use of a pulsed, distributed feedback quantum cascade laser centered at 957 cm-1 in combination with an astigmatic Herriot cell with 250 m path length for the detection of acrolein and acrylonitrile. These molecules have been identified as hazardous air-pollutants because of their adverse health effects. The spectrometer utilizes the intra-pulse method, where a linear frequency down-chirp, that is induced when a top-hat current pulse is applied to the laser, is used for sweeping across the absorption line. Up to 450 ns long pulses were used for these measurements which resulted in a spectral window of ~2.2 cm-1. A room temperature mercury-cadmium-telluride detector was used, resulting in a completely cryogen free spectrometer. We demonstrated detection limits of ~3 ppb for acrylonitrile and ~6 ppb for acrolein with ~10 s averaging time. Laser characterization and optimization of the operational parameters for sensitivity improvement are discussed.

  7. Bioconversion of acrylonitrile to acrylamide using polyacrylamide entrapped cells of Rhodococcus rhodochrous PA-34.

    Science.gov (United States)

    Raj, J; Prasad, S; Sharma, N N; Bhalla, T C

    2010-09-01

    The nitrile hydratase (NHase) of Rhodococcus rhodochrous PA-34 catalyzed the conversion of acrylonitrile to acrylamide. The resting cells (having NHase activity) (8 %; 1 mL corresponds to 22 mg dry cell mass, DCM) were immobilized in polyacrylamide gel containing 12.5 % acrylamide, 0.6 % bisacrylamide, 0.2 % diammonium persulfate and 0.4 % TEMED. The polyacrylamide entrapped cells (1.12 mg DCM/mL) completely converted acrylonitrile in 3 h at 10 °C, using 0.1 mol/L potassium phosphate buffer. In a partitioned fed batch reactor, 432 g/L acrylamide was accumulated after 1 d. The polyacrylamide discs were recycled up to 3×; 405, 210 and 170 g/L acrylamide was produced in 1st, 2nd and 3rd recycling reactions. In four cycles, a total of 1217 g acrylamide was produced by recycling the same mass of entrapped cells.

  8. How do albino fish hear?

    Science.gov (United States)

    Lechner, W; Ladich, F

    2011-03-01

    Pigmentation disorders such as albinism are occasionally associated with hearing impairments in mammals. Therefore, we wanted to investigate whether such a phenomenon also exists in non-mammalian vertebrates. We measured the hearing abilities of normally pigmented and albinotic specimens of two catfish species, the European wels Silurus glanis (Siluridae) and the South American bronze catfish Corydoras aeneus (Callichthyidae). The non-invasive auditory evoked potential (AEP) recording technique was utilized to determine hearing thresholds at 10 frequencies from 0.05 to 5 kHz. Neither auditory sensitivity nor shape of AEP waveforms differed between normally pigmented and albinotic specimens at any frequency tested in both species. Silurus glanis and C. aeneus showed the best hearing between 0.3 and 1 kHz; the lowest thresholds were 78.4 dB at 0.5 kHz in S. glanis (pigmented), 75 dB at 1 kHz in S. glanis (albinotic), 77.6 dB at 0.5 kHz in C. aeneus (pigmented) and 76.9 dB at 1 kHz in C. aeneus (albinotic). This study indicates no association between albinism and hearing ability. Perhaps because of the lack of melanin in the fish inner ear, hearing in fishes is less likely to be affected by albinism than in mammals.

  9. Design and Testing of Digitally Manufactured Paraffin Acrylonitrile-Butadiene-Styrene Hybrid Rocket Motors

    OpenAIRE

    McCulley, Jonathan M.

    2013-01-01

    This research investigates the application of additive manufacturing techniques for fabricating hybrid rocket fuel grains composed of porous Acrylonitrile-butadiene-styrene impregnated with paraffin wax. The digitally manufactured ABS substrate provides mechanical support for the paraffin fuel material and serves as an additional fuel component. The embedded paraffin provides an enhanced fuel regression rate while having no detrimental effect on the thermodynamic burn properties of the fuel g...

  10. Innovative Application of Biopolymer Keratin as a Filler of Synthetic Acrylonitrile-Butadiene Rubber NBR

    OpenAIRE

    Mirosława Prochoń; Anita Przepiórkowska

    2013-01-01

    The current investigations show the influence of keratin, recovered from the tanning industry, on the thermal and mechanical properties of vulcanizates with synthetic rubber acrylonitrile-butadiene rubber NBR. The addition of waste protein to NBR vulcanizates influences the improvement of resistance at high temperatures and mechanical properties like tensile strength and hardness. The introduction of keratin to the mixes of rubber previously blended with zinc oxide (ZnO) before vulcanization ...

  11. Screening-Level Risk Assessment for Styrene-Acrylonitrile (SAN) Trimer Detected in Soil and Groundwater

    OpenAIRE

    Kirman, C. R.; Gargas, M L; Collins, J. J.; Rowlands, J. C.

    2012-01-01

    A screening-level risk assessment was conducted for styrene-acrylonitrile (SAN) Trimer detected at the Reich Farm Superfund site in Toms River, NJ. Consistent with a screening-level approach, on-site and off-site exposure scenarios were evaluated using assumptions that are expected to overestimate actual exposures and hazards at the site. Environmental sampling data collected for soil and groundwater were used to estimate exposure point concentrations. Several exposure scenarios were evaluate...

  12. Synthesis, Characterization and Photophysical Properties of Pyridine-Carbazole Acrylonitrile Derivatives

    OpenAIRE

    Pérez-Gutiérrez,Enrique; Percino, M. Judith; Chapela, Víctor M.; Cerón, Margarita; Maldonado, José Luis; Ramos-Ortiz, Gabriel

    2011-01-01

    in solid state, absorptions were at 398, 390, and 442 nm, respectively. The fluorescence emission was at 540, 540 and 604 nm, respectively, the 2-(4-pyridyl)-3-(N-ethyl-(3’-carbazolyl))acrylonitrile showed a red shift in the emission of 64 nm compared to the other two compounds. The fluorescence quantum yield for the compounds in powder form showed values of 0.05, 0.14, and 0.006, respectively

  13. STUDY ON THE EPOXY RESIN TOUGHENED BY HYDROXY-TERMINATED BUTADIENE-ACRYLONITRILE COPOLYMER

    Institute of Scientific and Technical Information of China (English)

    HAN Xiaozu; LI Shaoying; ZHANG Qingyu

    1990-01-01

    Toughened epoxy resin with excellent properties was obtained by adding organic acid anhydride curing agent and hydroxy-terminated butadiene-acrylonitrile copolymer (HTBN), which is cheaper than CTBN. The anhydride reacts with both epoxy groups on epoxy resin and hydroxyl groups on HTBN. As a result the soft long chains of HTBN and the rigid chain of epoxy resin form one network, giving the resin toughness. Two-phase structure of the toughened resin was observed by SEM and TEM.

  14. Sudden sensorineural hearing loss after heroin injection.

    Science.gov (United States)

    Schrock, Andreas; Jakob, Mark; Wirz, Stefan; Bootz, Friedrich

    2008-05-01

    Sudden sensorineural hearing loss is a symptom of cochlear injury. Potential aetiologies are vascular diseases, viral infections, allergic reactions, autoimmune disorders, and traumatic rupture of the intralabyrinthe membrane. Unlike in unilateral cases bilateral sensorineural hearing loss is often associated with specific disease entities. We report a case of sudden bilateral deafness after intravenous heroin abuse. The putative pathophysiological mechanisms are discussed.

  15. Sorption studies on Cr (VI) removal from aqueous solution using cellulose grafted with acrylonitrile monomer.

    Science.gov (United States)

    Hajeeth, T; Sudha, P N; Vijayalakshmi, K; Gomathi, T

    2014-05-01

    Graft copolymerization of acrylonitrile on to cellulosic material derived from sisal fiber can be initiated effectively with ceric ammonium nitrate. The grafting conditions were optimized by changing the concentration of initiator and monomer. The change in crystallinity of the grafted polymeric samples was concluded from the XRD patterns. The prepared cellulose grafted acrylonitrile copolymer was used as an adsorbent to remove Cr (VI) ions from aqueous solutions. The efficiency of the adsorbent was identified from the variation in the percentage of adsorption with contact time, adsorbent dose and pH. From the observed results it was evident that the adsorption of metal ions increases with the increase in contact time and metal ion concentration. An optimum pH was found to be 5.0 for the removal of Cr (VI) from the aqueous solution. The results of the Langmuir, Freundlich, and pseudo first- and second-order studies revealed that the adsorption was found to fit well with Freundlich isotherm and follows pseudo second-order kinetics. From the above results, it was concluded that the cellulose-g-acrylonitrile copolymer was found to be an efficient adsorbent for the removal of Cr (VI) from aqueous waste generated from industries.

  16. Electromechanical responses of poly(3-thiopheneacetic acid/acrylonitrile-butadiene rubbers

    Directory of Open Access Journals (Sweden)

    2008-12-01

    Full Text Available Acrylonitrile-butadiene rubber (NBR and blends of poly(3-thiopheneacetic acid/ acrylonitrile-butadiene rubber, P3TAA/NBR, were fabricated, and the electrorheological properties, dielectric, and electrical conductivities were investigated . The electrorheological properties were determined under an oscillatory shear mode in a frequency range of 0.1 to 100 rad/s at various electric field strengths, from 0 to 2 kV/mm, at a fixed 27°C to observe the effects of acrylonitrile content (ACN in the rubber systems and the conductive particle concentration in the blends. For the pure rubber systems, the storage modulus response (ΔG′ is linearly dependent on its dielectric constant (ε′, and increases with the ACN content. For the NBR/P3TAA blends, the storage modulus response varies nonlinearly with the dielectric constant. The bending responses of the rubbers and the blends were investigated in a vertical cantilever fixture. For the pure rubber system, the bending angle and the dielectrophoresis force vary linearly with electric field strength. For the blend system, the bending angle and the dielectrophoresis force vary nonlinearly with electric field strength.

  17. Adsorption of Acrylonitrile on Some Soils and Minerals from Aqueous Solutions

    Institute of Scientific and Technical Information of China (English)

    WUDE-YI; N.MATSUE; 等

    1993-01-01

    Equilibrium and kinetic studies have been made on the adsorption of acrylonitrile(CH2=CHCN) on three soils and four minerals from aqueous solutions.It was shown that the organic matter was the major factor affecting the adsorption process in the soils.The conformity of the equilibrium data to linear type(one soil) and Langmuir type(two soils) isotherms indicated that different mechanisms were involved in the adsorption.This behavior appears bo be related to the hydrophobicity of soil organic matter due to their composition and E4/E6 ratio of humic acids.The adsorption kinetics were also different among the soils,indicating the difference in porosity of organic matter among the soils,and the kinetics strongly affected the adsorption capacity of soils for acrylonitrile.Acrylonitrile was slightly adsorbed from aqueous solutions on pyrophyllite with electrically neutral and hydrophobic nature,and practically not on montmorillonite and kaolinite saturated with Ca.However,much higher adsorption occurred on the zeolitized coal ash,probably caused by high organic carbon content(107g/kg).

  18. Estimation of the Surface Properties of Styrene-Acrylonitrile Random Copolymers from Contact Angle Measurements.

    Science.gov (United States)

    Adão; Saramago; Fernandes

    1999-09-01

    The surface free energy per unit area of a solid, gamma(S), is a fundamental property of materials and determines their surface and interfacial behavior in processes like wetting and adhesion. In this study the gamma(S) of a series of styrene-acrylonitrile random copolymers is evaluated. Three different approaches are used to determine the components in which the surface free energy can be decomposed. Using the geometric and the harmonic mean approach, the dispersive, gamma(d), and polar, gamma(p), components of the solid surface free energy were determined and compared to the Lifshitz-van der Waals, gamma(LW), and acid-base, gamma(AB), components using the approach developed by C. J. van Oss et al. (1987, Adv. Colloid Interface Sci. 28, 35). The acid-base approach was also used to evaluate the work of adhesion of the test liquids: water, glycerol, and thiodiglycol. It was found that the contact angles of these liquids follow closely the predictions of Cassie equation. The evaluation of the surface free energy components on one hand and the relative magnitude of the work of adhesion components on the other hand, suggest that below 50% of acrylonitrile the polystyrene repeating units are preferentially at the surface. Above 50% of acrylonitrile the segregation of the low-energy homopolymer at the surface decreases. Copyright 1999 Academic Press.

  19. Stepwise mechanism of oxidative ammonolysis of propane to acrylonitrile over gallium-antimony oxide catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Osipova, Z.G.; Sokolovskii, V.D.

    1979-03-01

    The stepwise mechanism of oxidative ammonolysis of propane to acrylonitrile over gallium-antimony oxide catalysts GaSb/sub 19/O/sub x/, GaSb/sub 3/Ni/sub 1.5/0/sub x/, and GaSb/sub 2.5/Ni/sub 1.5/PW/sub 0//sub 0.25/O/sub x/ was studied at 450/sup 0/ and 550/sup 0/C by introducing alternating pulses of 0.5Vertical Bar3< propane/0.6Vertical Bar3< ammonia/helium (to reduce the steady-state catalytic surface) and 0.5Vertical Bar3< propane/0.6Vertical Bar3< ammonia/1.86Vertical Bar3< oxygen/helium mixtures into a fluidized-bed catalytic reactor. Over all the catalysts studied, the rates of acrylonitrile formation during the two types of pulses were very similar, but carbon dioxide was formed much faster during the reducing pulses, particularly at 450/sup 0/C. These findings suggested that acrylonitrile is formed by a stepwise redox mechanism involving consecutive interaction of propane and ammonia with the surface oxygen of the catalysts and oxidation of the reduced catalyst surface by gas-phase oxygen. The formation of carbon dioxide proceeds by both stepwise and associative mechanisms, the latter being more important at higher temperatures. The results are similar to published results for ammoxidation of propylene and olefins.

  20. STUDY ON POLYMERIC CATALYST—PALLADIUM COMPLEX WITH RADIATION GRAFTING ACRYLONITRILE ON INORGANIC COMPOUND

    Institute of Scientific and Technical Information of China (English)

    ZHANGWanxi; CHEJitai

    1993-01-01

    Polymer bound palladium (Pd) complex catalysts with grafting acrylonitrile on inorganic compound(MgO,Y-molecular sieve and SiO2) by pre-radiation method were studies.The palladium-grafting polymers have been investigated by X-ray photoelectron spectrscopy(XPS).It is indicated that peak width of C1s and O1s spectra of MgO-g-PAN-Pd(radiation-induced graft) is wider than that of MgO-PAN-Pd(chemical method) and Peak numbers of former are one more than later.According to the report in reference,this peak is attributed to -O-C group.Thus,the graft acrylonitrile on MgO may complete through oxygen atoms im MgO and β-carbon atoms in acrylonitrile.The polymer catalyst obtained by radiation grafting is a higher active hydrogenation catalyst for olefines and better antioxic than that of one obtained by chemical method,and it has selectivity for hydrogenation catalyst.

  1. Hearing Loss and Disability Exit: Measurement Issues and Coping Strategies

    DEFF Research Database (Denmark)

    T. Christensen, Vibeke; V. Rasmussen, Martin; Datta Gupta, Nabanita

    Using unique representative data containing self-reported functional and clinically measured hearing ability for the Danish population aged 50-64, we estimate the effect of hearing loss on receipt of disability benefits accounting for potential endogeneity of functional hearing. Our identification...

  2. Hard of Hearing?

    DEFF Research Database (Denmark)

    T Christensen, Vibeke

    This summary presents the results of a study of the impact of reduced hearing in relation to labour-market attachment and working life. Reduced hearing contributes to early retirement. Many people with impaired hearing are not aware of the impact of their hearing problems on their working life...

  3. Managing Hearing Loss

    Science.gov (United States)

    ... you can get help. See your doctor. Hearing aids, special training, certain medicines, and surgery are some of the choices that can help people with hearing problems, but they are not a cure. Read More "Hearing Loss" Articles Managing Hearing Loss / Symptoms, Devices, Prevention & Research / Screening ...

  4. CERN hearing day

    CERN Document Server

    2005-01-01

    1 in 10 people suffer from hearing loss ? do you? The Medical Service invites everyone working on the CERN site to participate in the NATIONAL HEARING DAY on: Thursday 10th March 2005 From 9am to 4pm The Infirmary, Blg. 57, Ground Floor We will be offering hearing tests (audiograms), as well as information and advice on hearing loss, tinnitus, etc. Deafness does not just affect the elderly: in Europe, 50% of the hearing-impaired are under the age of 55. Exposure to excessive noise is one of the main reasons for hearing problems but prevention is possible. For example, hearing protection devices can prevent 80% of tinnitus cases.

  5. CERN hearing day

    CERN Multimedia

    2005-01-01

    1 in 10 people suffer from hearing loss - do you? The Medical Service invites everyone working on the CERN site to participate in the NATIONAL HEARING DAY on: Thursday 10th March 2005 From 9am to 4pm The Infirmary, Blg. 57, Ground Floor We will be offering hearing tests (audiograms), as well as information and advice on hearing loss, tinnitus, etc. Deafness does not just affect the elderly: in Europe, 50% of the hearing-impaired are under the age of 55. Exposure to excessive noise is one of the main reasons for hearing problems but PREVENTION IS POSSIBLE. For example, hearing protection devices can prevent 80% of tinnitus cases.

  6. CERN hearing day

    CERN Document Server

    2005-01-01

    1 in 10 people suffer from hearing loss - do you? The Medical Service invites everyone working on CERN premises to participate in the National Hearing Day on: Thursday 10th March From 9am to 4pm The Infirmary, Blg. 57, Gr.Fl. We will be offering hearing tests (audiogram); information, advice on hearing loss, tinnitus and more. Deafness does not just affect the elderly: in Europe, 50% the hearing-impaired are under the age of 55. Exposure to excessive noise is one of the main reasons for hearing loss. But prevention is possible and effective: for example, Hearing protection devices could reduce tinnitus cases by 80%.

  7. CERN hearing day

    CERN Document Server

    2005-01-01

    1 in 10 people suffer from hearing loss - do you? The Medical Service invites everyone working on CERN premises to participate in the National Hearing Day on: Thursday 10th March From 9am to 4pm The Infirmary, Blg. 57, Gr.Fl. We will be offering hearing tests (audiogram); information, advice on hearing loss, tinnitus and more. Deafness does not just affect the elderly: in Europe, 50% the hearing-impaired are under the age of 55. Exposure to excessive noise is one of the main reasons for hearing loss. But PREVENTION IS POSSIBLE AND EFFECTIVE: for example, Hearing protection devices could reduce tinnitus cases by 80%.

  8. Melt-processable hydrophobic acrylonitrile-based copolymer systems with adjustable elastic properties designed for biomedical applications.

    Science.gov (United States)

    Cui, J; Trescher, K; Kratz, K; Jung, F; Hiebl, B; Lendlein, A

    2010-01-01

    Acrylonitrile-based polymer systems (PAN) are comprehensively explored as versatile biomaterials having various potential biomedical applications, such as membranes for extra corporal devices or matrixes for guided skin reconstruction. The surface properties (e.g. hydrophilicity or charges) of such materials can be tailored over a wide range by variation of molecular parameters such as different co-monomers or their sequence structure. Some of these materials show interesting biofunctionalities such as capability for selective cell cultivation. So far, the majority of AN-based copolymers, which were investigated in physiological environments, were processed from the solution (e.g. membranes), as these materials are thermo-sensitive and might degrade when heated. In this work we aimed at the synthesis of hydrophobic, melt-processable AN-based copolymers with adjustable elastic properties for preparation of model scaffolds with controlled pore geometry and size. For this purpose a series of copolymers from acrylonitrile and n-butyl acrylate (nBA) was synthesized via free radical copolymerisation technique. The content of nBA in the copolymer varied from 45 wt% to 70 wt%, which was confirmed by 1H-NMR spectroscopy. The glass transition temperatures (Tg) of the P(AN-co-nBA) copolymers determined by differential scanning calorimetry (DSC) decreased from 58 degrees C to 20 degrees C with increasing nBA-content, which was in excellent agreement with the prediction of the Gordon-Taylor equation based on the Tgs of the homopolymers. The Young's modulus obtained in tensile tests was found to decrease significantly with rising nBA-content from 1062 MPa to 1.2 MPa. All copolymers could be successfully processed from the melt with processing temperatures ranging from 50 degrees C to 170 degrees C, whereby thermally induced decomposition was only observed at temperatures higher than 320 degrees C in thermal gravimetric analysis (TGA). Finally, the melt processed P

  9. General Framework of Hearing Aid Fitting Management.

    Science.gov (United States)

    Oh, Soo Hee; Lee, Junghak

    2016-04-01

    Hearing aids are one of the most widely used treatment options for the hearing impaired and optimal outcomes of hearing aids are supported by comprehensive hearing aid fitting protocols. Currently, the term 'hearing aid fitting' is prevalently used among service and industry sectors with its comprehensive procedures not systematically explicated. In addition, a variety of non-normalized guidelines for hearing aid fitting has led to non-uniform care, outcome variability, and dissatisfaction of the use of hearing aids. The main purpose of the present study is to suggest a general framework of standardized practice for hearing aid fitting management including its pre- and post-fitting stages. The management framework centers on its fitting process with its prior steps of assessment as well as its posterior steps of follow-up, thereby eliminating diverging interpretations and non-uniform practices. Outcomes of this study are also expected to improve potential benefits such as quality of hearing aid fitting, user satisfaction, and cost effectiveness across relevant stakeholders.

  10. The Accuracy of IOS Device-based uHear as a Screening Tool for Hearing Loss: A Preliminary Study From the Middle East

    OpenAIRE

    Rashid Al-Abri; Mustafa Al-Balushi; Arif Kolethekkat; Deepa Bhargava; Amna Al-Alwi; Hana Al-Bahlani; Manal Al-Garadi

    2016-01-01

    Objectives: To determine and explore the potential use of uHear as a screening test for determining hearing disability by evaluating its accuracy in a clinical setting and a soundproof booth when compared to the gold standard conventional audiometry.   Methods: Seventy Sultan Qaboos University students above the age of 17 years who had normal hearing were recruited for the study. They underwent a hearing test using conventional audiometry in a soundproof room, a self-administered uHear ev...

  11. Factors affecting Thai workers' use of hearing protection.

    Science.gov (United States)

    Tantranont, Kunlayanee; Srisuphan, Wichit; Kaewthummanukul, Thanee; Suthakorn, Weeraporn; Jormsri, Pantip; Salazar, Mary K

    2009-11-01

    This study used an ecological model to examine Thai workers' beliefs and attitudes toward using occupational hearing protection. Data collection involved focus group sessions with 28 noise-exposed workers at four factories in Chiang Mai Province and an interview with a safety officer at each organization. Detailed content analysis resulted in the identification of three types of factors influencing the use of hearing protection: intrapersonal, including preventing impaired hearing, noise annoyance, personal discomfort, and interference with communication; interpersonal, including coworker modeling, supervisor support, and supervisor modeling; and organizational, including organizational rules and regulations, provision of hearing protection devices, dissemination of knowledge and information, noise monitoring, and hearing testing. Effective hearing protection programs depend on knowledge of all of these factors. Strategies to promote workers' use of hearing protection should include the complete range of factors having the potential to affect workers' hearing.

  12. Control of insects with fumigants at low temperatures: toxicity of mixtures of methyl bromide and acrylonitrile to three species of insects

    Energy Technology Data Exchange (ETDEWEB)

    Bond, E.J.; Buckland, C.T.

    1976-12-15

    Acrylonitrile can be mixed with methyl bromide to increase toxicity so that the quantity of methyl bromide required for control of Sitophilus granarius (L.), Tenebrio molitor L., and Tribolium confusum Jacquelin duval is reduced by one half. Mixtures of methyl bromide and acrylonitrile are considerably more effective at low temperatures than methyl bromide alone.

  13. Thermosensitive Poly(N-isopropylacrylamide-co-acrylonitrile) Hydrogels with Rapid Response%非离子型凝胶球在水中的溶胀行为

    Institute of Scientific and Technical Information of China (English)

    黄健; 黄志明; 包永忠; 翁志学

    2006-01-01

    Acrylonitrile (AN) was copolymerized with N-isopropylacrylamide (NIPA) to synthesize thermosensitive bydrogels, and the on-off switch behavior of poly(NIPA-co-AN) hydrogels with different fraction of hydrophobic component (AN) was investigated. It is found that the lower critical solution temperature (LCST), the swelling ratio at certain temperature and the reswelling rate of poly(NIPA-co-AN) hydrogels decreased as AN unit fraction in copolymers increased. In order to improve the responsive rate of poly(NIPA-co-AN) hydrogels, they were further treated by surface crosslinking using N, N'-methylene bisacrylamide (BIS) as a crosslinking agent. The swelling and deswelling behaviors of these copolymers were compared with those of the untreated hydrogels. The results indicated that the responsive rate of poly(NIPA-co-AN) hydrogel was improved by surface crosslinking. The resulting hydrogels bearing cyano groups with fast response have potential applications in the field of drug-controlled release and immobilization of biomolecules.

  14. NIOSH (National Institute for Occupational Safety and Health) testimony to DOL (Department of Labor) on occupational exposure to acrylonitrile, by R. Yodaiken, M. D. , March 3, 1978

    Energy Technology Data Exchange (ETDEWEB)

    1978-03-03

    Testimony was presented concerning the establishment of an occupational exposure standard for acrylonitrile (AN) to which an estimated 125,000 workers were potentially exposed. Two-year feeding and inhalation studies with animals indicated the chemical to be carcinogenic, producing tumors of the central nervous system (CNS), cerebral tumors, squamous cell neoplasms of the Zymbal gland, adenocarcinoma of the small intestine and large intestine, along with numerous benign tumors. Other findings included papillomata in the stomach, hemangioma of the kidney, fibroadenomas of the mammary gland, benign tumors of the uterus, and tumors of the ear canal. Teratogenicity studies indicated increased incidence of fetal malformation. Cases of AN as an allergen causing contact dermatitis and ulcers have been widely documented. It was recommended that drugs essential to the treatment of acute intoxication from AN be kept in the medical facility of all facilities using AN, and that employers institute a respiratory-protection program in accordance with requirements.

  15. Noise and Hearing Protection

    Science.gov (United States)

    ... ENTCareers Marketplace Find an ENT Doctor Near You Noise and Hearing Protection Noise and Hearing Protection Patient ... it is. How can I tell if a noise is dangerous? People differ in their sensitivity to ...

  16. Hearing Disorders and Deafness

    Science.gov (United States)

    ... impossible, to hear. They can often be helped. Deafness can keep you from hearing sound at all. ... certain medicines, and surgery. NIH: National Institute on Deafness and Other Communication Disorders

  17. Genetics of Hearing Loss

    Science.gov (United States)

    ... in Latin America Information For... Media Policy Makers Genetics of Hearing Loss Language: English Español (Spanish) Recommend ... of hearing loss in babies is due to genetic causes. There are also a number of things ...

  18. Devices for hearing loss

    Science.gov (United States)

    ... medlineplus.gov/ency/patientinstructions/000359.htm Devices for hearing loss To use the sharing features on this page, please enable JavaScript. If you are living with hearing loss , you know that it takes extra effort to ...

  19. Living with hearing loss

    Science.gov (United States)

    ... medlineplus.gov/ency/patientinstructions/000360.htm Living with hearing loss To use the sharing features on this page, please enable JavaScript. If you are living with hearing loss, you know that it takes extra effort to ...

  20. Hearing Loss: Screening Newborns

    Science.gov (United States)

    ... of this page please turn JavaScript on. Feature: Hearing Loss Screening Newborns Past Issues / Spring 2015 Table of ... of newborns in the U.S. are screened for hearing loss before they leave the hospital. Research improves the ...

  1. Help with Hearing

    Science.gov (United States)

    ... hand, a conductive hearing loss generally means that wax in the ear canal or fluid in the ... child seen by a team of medical, surgical, dental, speech, and hearing specialists to plan the appropriate ...

  2. STUDIES ON THE POLYMERIZATION OF ACRYLONITRILE INITIATED BY METAVANADATE- CONTAINING ANION EXCHANGER-THIOUREA REDOX SYSTEM

    Institute of Scientific and Technical Information of China (English)

    YANG Chaoxiong; WU Jinyuan; WU Yuxian

    1991-01-01

    The polymerization of acrylonitrile (AN) in aqueous nitric acid initiated by metavanadate-containing anion exchange resin (PV)-thiourea (TU) redox system at 20- 40 ℃. has been investigated. The overall rate of polymerization (Rp) is given by Rp= 1.92 × 104 e -6,860/RT [AN]1.2[PV]0.44[TU]1.0[HNO3]1.0 The kinetic parameters differed from those of V5+-TU system indicated that the generation of the primary radicals is mainly a difffusion-controlled reaction . The effect of macromolecular field arisen from the polymer matrix exerts a great influence on the polymerization process.

  3. DEPENDENCE OF ACRYLONITRILE POLYMERIZATION KINETICS ON THE COMPOSITION OF POLYAMID OXIME -THIOUREA SYSTEM

    Institute of Scientific and Technical Information of China (English)

    WU Jinyuan; YANG Chaoxiong; ZHANG Guangzhao

    1993-01-01

    The polymerization of acrylonitrile (AN) initiated by polypropylene based-polyamidoxime (PPAO)- thiourea (TU) system was investigated at [ TU]/[ PPAO] > 0.5 molar ratio. It shows that the variation of the concentrations of PPAO, thiourea and nitric acid does not exert an observable influence on the reaction rate. The overall rate of polymerization (Rp) is Rp = 2.07e - 7,800/RT[AN] 2.0The zero order dependence on PPAO and thiourea concentrations and the lowest value of the collision frequence factor were considered to be a feature of the primary radical termination.

  4. Mechanical properties of products of thermocatalytic and radiolytic styrene - acrylonitrile copolymerization

    Energy Technology Data Exchange (ETDEWEB)

    Gadalla, A.M.; Derini, M.A.E.

    1983-12-01

    The mechanical properties of styrene (S)-acrylonitrile (AN) mixtures, ranging from 20 to 80 wt % S, polymerized by thermocatalytic and radiolytic techniques were studied. Maximum compressive and tensile strength was obtained for the mixture containing 60 wt % styrene. The hardness increased with styrene concentration up to 40 wt % and then remained nearly constant. Radiolytic copolymerization gave stronger copolymers than thermal copolymerization since irradiation enhances crosslinking. For the same composition, as the dose increases, the strength increases to a maximum and then decreases due to competing rates of crosslinking and degradation. 5 figures.

  5. ION CONDUCTION IN COMPLEX OF ACRYLONITRILE-COPOLYMERIZED COMB POLYETHER WITH LITHIUM PERCHLORATE

    Institute of Scientific and Technical Information of China (English)

    XU Kang; DENG Zhenghua; WAN Guoxiang

    1991-01-01

    Poly ( oligoether methacrylate- co- acrylonitrile ) s, P ( MEOn- AN ), with oligoether pendants of different lengths were synthesized and the ion conduction property of their Li-salt complexes was studied as the function of polymer structure. At proper copolymer composition, lithium concentration and pendant length, the ion conductivity reaches 7.0×10-5S/cm at ambient temperature, together with improved mechanical strength. The ion transport in the polymer media is assisted by segmental relaxation ,which is confirmed both by the consistency between ion conductivity and Tg and by the study of TSC.

  6. Hearing and dementia

    OpenAIRE

    Hardy, Chris J. D.; Marshall, Charles R.; Golden, Hannah L.; Clark, Camilla N.; Mummery, Catherine J.; Griffiths, Timothy D.; Bamiou, Doris-Eva; Warren, Jason D.

    2016-01-01

    Hearing deficits associated with cognitive impairment have attracted much recent interest, motivated by emerging evidence that impaired hearing is a risk factor for cognitive decline. However, dementia and hearing impairment present immense challenges in their own right, and their intersection in the auditory brain remains poorly understood and difficult to assess. Here, we outline a clinically oriented, symptom-based approach to the assessment of hearing in dementias, informed by recent prog...

  7. Hearing Aids Communication

    DEFF Research Database (Denmark)

    Globally, hearing loss is the second most frequent disability. About 80% of the persons affected by hearing loss do not use hearing aids. The goal of this edited volume is to present a theoretically founded, interdisciplinary approach geared at understanding and improving social interaction impac...

  8. Hearing loss and music

    Science.gov (United States)

    Noise induced hearing loss - music; Sensory hearing loss - music ... turn up the volume to block out other noise. If you wear headphones, the volume is too loud if a person standing near you can hear the music through your headphones. Other tips about headphones are: ...

  9. Negotiating hearing disability and hearing disabled identities

    DEFF Research Database (Denmark)

    Lykke Hindhede, Anette

    2012-01-01

    . The discursively produced categorisation and subjectivity of senescence mean that rehabilitation technologies such as hearing aids identify a particular life-style (disabled) which determines their social significance. Thus wearing a hearing aid works against the contemporary attempt to create socially ideal...

  10. Unilateral sudden hearing loss due to otosyphilis

    Directory of Open Access Journals (Sweden)

    Maaike J. de Goffau

    2011-12-01

    Full Text Available The differential diagnosis of sudden hearing loss is very extensive. However, in most patients, no underlying pathology will be found and the patient is consequently diagnosed with idiopathic sudden hearing loss. Nevertheless, it is important that one stays alert in everyday routine practice to less common but potentially treatable pathology. We report a case of a 53- year old patient with sudden unilateral hearing loss and tinnitus caused by otosyphilis. Diagnosis, therapy and the incidence of (otosyphilis are discussed. Also, as ENT-surgeons, it is important to realise that syphilis is still with us, and that its prevalence might well increase in the near future.

  11. Theoretical study on the gas phase reaction of acrylonitrile with a hydroxyl radical.

    Science.gov (United States)

    Sun, Jingyu; Wang, Rongshun; Wang, Baoshan

    2011-10-01

    The mechanism and kinetics of the reaction of acrylonitrile (CH(2)=CHCN) with hydroxyl (OH) has been investigated theoretically. This reaction is revealed to be one of the most significant loss processes of acrylonitrile. BHandHLYP and M05-2X methods are employed to obtain initial geometries. The reaction mechanism conforms that OH addition to C[double bond, length as m-dash]C double bond or C atom of -CN group to form the chemically activated adducts, 1-IM1(HOCH(2)=CHCN), 2-IM1(CH(2)=HOCHCN), and 3-IM1(CH(2)=CHCOHN) via low barriers, and direct hydrogen abstraction paths may also occur. Temperature- and pressure-dependent rate constants have been evaluated using the Rice-Ramsperger-Kassel-Marcus theory. The calculated rate constants are in good agreement with the experimental data. At atmospheric pressure with N(2) as bath gas, 1-IM1(OHCH(2)=CHCN) formed by collisional stabilization is the major product in the temperature range of 200-1200 K. The production of CH(2)CCN and CHCHCN via hydrogen abstractions becomes dominant at high temperatures (1200-3000 K).

  12. Acrylonitrile-methyl Methacrylate Copolymer Films Containing Microencapsulated n-Octadecane

    Institute of Scientific and Technical Information of China (English)

    LI Jun; HAN Na; ZHANG Xing-xiang

    2006-01-01

    Acrylonitrile-methyl methacrylate copolymer was synthesized in aqueous solution by Redox. The copolymer was mixed with 10 - 40 wt% of microencapsulated n-octadecane (MicroPCMs) in water. Copolymer films containing MicroPCMs were cast at room temperature in N, N-Dimethylformamide solution. The copolymer of acrylonitrile-methyl methacrylate and the copolymer films containing MicroPCMs were characterized by using Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), Thermogravimetric Analyzer (TG), X-ray Diffrac tion (XRD) and Scanning Electron Microscopy (SEM), etc.The microcapsules in the films are evenly distributed in the copolymer matrix. The heat-absorbing temperatures and heat-evolving temperatures of the films are almost the same as that of the MicroPCMs, respectively, and fluctuate in a slight range. In addition, the enthalpy efficiency of MicroPCMs rises with the contents of MicroPCMs increasing.The crystallinity of the film increases with the contents of MicroPCMs increasing.

  13. Sensitive detection of acrolein and acrylonitrile with a pulsed quantum-cascade laser

    Science.gov (United States)

    Manne, J.; Lim, A.; Tulip, J.; Jäger, W.

    2012-05-01

    We report on spectroscopic measurements of acrolein and acrylonitrile at atmospheric pressure using a pulsed distributed feedback quantum-cascade laser in combination with intra- and inter-pulse techniques and compare the results. The measurements were done in the frequency region around 957 cm-1. In the inter-pulse technique, the laser is excited with short current pulses (5-10 ns), and the pulse amplitude is modulated with an external current ramp resulting in a ˜2.3 cm-1 frequency scan. In the intra-pulse technique, a linear frequency down-chirp during the pulse is used for sweeping across the absorption line. Long current pulses up to 500 ns were used for these measurements which resulted in a spectral window of ˜2.2 cm-1 during the down-chirp. These comparatively wide spectral windows facilitated the measurements of the relatively broad absorption lines (˜1 cm-1) of acrolein and acrylonitrile. The use of a room-temperature mercury-cadmium-telluride detector resulted in a completely cryogen-free spectrometer. We demonstrate ppb level detection limits within a data acquisition time of ˜10 s with these methodologies.

  14. The Effects of Different Bimodal Hearing Strategies on Event Related Potentials%不同策略的声电双模式助听对事件相关电位的影响

    Institute of Scientific and Technical Information of China (English)

    钟志茹; 郑亿庆; 段吉茸; 陶征; 张敏; 邹建华; 邱素梅

    2012-01-01

    目的 探讨听障儿童单侧耳植入人工耳蜗(cochlear implant,CI)后对侧耳联合使用助听器(hearing aid,HA)的双模式助听策略对事件相关电位P300的影响.方法 研究对象共52人,设实验组(人工耳蜗植入儿童)3组、听力正常对照组1组,每组13人,按实验设计步骤随机测试.按对侧耳配戴HA的不同将人工耳蜗植入儿童分为A(CI+模拟HA)、B(CI+数字HA,未优化)和C(CI+数字HA,优化)3组,评估实验对象术后左右耳的残余听力,分别设置和优化CI及HA的技术参数并在声场中评估其助听后的音频感知情况,测试并比较各组的P300潜伏期及振幅.结果 3组患者术后双耳均有残余听力,助听后组间比较无差别(P>0.05).P300潜伏期比较A组>B组>C组(P0.05);P300振幅A组和B组与对照组比较均无意义(P>0.05),C组P300振幅低于对照组(P<0.05).结论 大部分听障儿童一侧耳植入人工耳蜗后对侧耳仍有可利用的残余听力,可以联合配戴适合的全数字编程助听器,大脑听觉中枢可以整合声电双模式助听设备上传的听觉信息.%Objective To study the effects of bimodal hearing strategies on event related potentials P300 in patients with a cochlear implant(CI)in one ear and a hearing aid(HA)in the opposite ear.Methods Fifty-two Subjects were enrolled in this study.Including 13 normal-hearing people and 39 cochlear implant recipients.The cochlear implant recipients were randomly divided into 3 groups:Group A(CI&analog HA),Group B(CI&unoptimized digital HA)and Group C(CI &optimized digital HA).The subjects received the assessment on postope rative residual hearing in both ears.The technical parameters of CI and HA were optimized and the aided hearing of the patients was measured in the sound field.The latencies and amplitudes of P300 were also tested and compared among all the groups.Results The three groups of cochlear implant recipients had bilateral residual hearing after the operation and there was no

  15. Bacterial colonization and endotoxin content of a new renal dialysis water system composed of acrylonitrile butadiene styrene.

    Science.gov (United States)

    du Moulin, G C; Coleman, E C; Hedley-Whyte, J

    1987-06-01

    We measured endotoxin and bacterial levels in tap water, in water purified by reverse osmosis, and in dialysate samples over a 4-month period in a new 10-bed renal dialysis unit. Water treated by reverse osmosis is conducted to the 10 stations through 111 m of piping composed of acrylonitrile butadiene styrene (ABS). All determinations were made prior to the opening of the unit and after the system was purged for 35 h with all bedside station taps open. Formaldehyde disinfection of the piping system was attempted with a recommended protocol after 11 weeks by feeding 2.5 liters of 37% formaldehyde (0.85%, vol/vol) into the delivery system. Prior to water purging, 24 ng of endotoxin per ml was detected. This level decreased to 2.0 ng of endotoxin after the purging. Levels of endotoxin remained below 1.0 ng of endotoxin per ml throughout the duration of the study. In contrast, the level of viable microorganisms recovered from the treated water was approximately 3.5 X 10(4) CFU/100 ml. Even after disinfection of the system, there was no significant decrease in culturable bacteria from the water even though endotoxin levels were lower. Species isolated from the renal dialysis system were predominately pseudomonads, whereas species isolated from the tap water were Bacillus and Flavobacterium species. ABS provides a surface suitable for long-term colonization and growth of bacteria. Currently recommended decontamination protocols are ineffective in removing potentially pathogenic bacteria from ABS pipes and thus constitute an increased risk to patients undergoing dialysis.

  16. Music and hearing aids.

    Science.gov (United States)

    Madsen, Sara M K; Moore, Brian C J

    2014-10-31

    The signal processing and fitting methods used for hearing aids have mainly been designed to optimize the intelligibility of speech. Little attention has been paid to the effectiveness of hearing aids for listening to music. Perhaps as a consequence, many hearing-aid users complain that they are not satisfied with their hearing aids when listening to music. This issue inspired the Internet-based survey presented here. The survey was designed to identify the nature and prevalence of problems associated with listening to live and reproduced music with hearing aids. Responses from 523 hearing-aid users to 21 multiple-choice questions are presented and analyzed, and the relationships between responses to questions regarding music and questions concerned with information about the respondents, their hearing aids, and their hearing loss are described. Large proportions of the respondents reported that they found their hearing aids to be helpful for listening to both live and reproduced music, although less so for the former. The survey also identified problems such as distortion, acoustic feedback, insufficient or excessive gain, unbalanced frequency response, and reduced tone quality. The results indicate that the enjoyment of listening to music with hearing aids could be improved by an increase of the input and output dynamic range, extension of the low-frequency response, and improvement of feedback cancellation and automatic gain control systems.

  17. Use of Hearing Aids by Adults with Hearing Loss

    Science.gov (United States)

    ... Health Info » Statistics and Epidemiology Use of Hearing Aids by Adults with Hearing Loss [text version] Note: ... displays time trends in the use of hearing aids for adults (20–69 years) and older adults ( ...

  18. [Inner Ear Hearing Loss].

    Science.gov (United States)

    Hesse, G

    2016-06-01

    Hearing loss is one of the most dominant handicaps in modern societies, which additionally very often is not realized or not admitted. About one quarter of the general population suffers from inner ear hearing loss and is therefore restricted in communicational skills. Demographic factors like increasing age play an important role as well as environmental influences and an increasing sound and noise exposure especially in leisure activities. Thus borders between a "classical" presbyacusis - if it ever existed - and envirionmentally induced hearing loss disappear. Today restrictions in hearing ability develop earlier in age but at the same time they are detected and diagnosed earlier. This paper can eventually enlighten the wide field of inner ear hearing loss only fragmentarily; therefore mainly new research, findings and developments are reviewed. The first part discusses new aspects of diagnostics of inner ear hearing loss and different etiologies.

  19. Self-Fitting Hearing Aids

    Directory of Open Access Journals (Sweden)

    Gitte Keidser

    2016-04-01

    Full Text Available A self-contained, self-fitting hearing aid (SFHA is a device that enables the user to perform both threshold measurements leading to a prescribed hearing aid setting and fine-tuning, without the need for audiological support or access to other equipment. The SFHA has been proposed as a potential solution to address unmet hearing health care in developing countries and remote locations in the developed world and is considered a means to lower cost and increase uptake of hearing aids in developed countries. This article reviews the status of the SFHA and the evidence for its feasibility and challenges and predicts where it is heading. Devices that can be considered partly or fully self-fitting without audiological support were identified in the direct-to-consumer market. None of these devices are considered self-contained as they require access to other hardware such as a proprietary interface, computer, smartphone, or tablet for manipulation. While there is evidence that self-administered fitting processes can provide valid and reliable results, their success relies on user-friendly device designs and interfaces and easy-to-interpret instructions. Until these issues have been sufficiently addressed, optional assistance with the self-fitting process and on-going use of SFHAs is recommended. Affordability and a sustainable delivery system remain additional challenges for the SFHA in developing countries. Future predictions include a growth in self-fitting products, with most future SFHAs consisting of earpieces that connect wirelessly with a smartphone and providers offering assistance through a telehealth infrastructure, and the integration of SFHAs into the traditional hearing health-care model.

  20. Eldercare at Home: Hearing Problems

    Science.gov (United States)

    ... loss in itself is not an emergency. However, sudden hearing loss or hearing loss in combination with other symptoms ... to a serious infection, a tumor, or stroke. Sudden hearing loss in combination with nausea, vomiting, dizziness, or unsteadiness. ...

  1. Hearing Loss: Symptoms, Diagnosis & Treatment

    Science.gov (United States)

    ... 100dB or louder. Protect your hearing from loud music from personal music devices and concerts. Wear ear plugs or special ... mostly. The discovery offers a possible mechanism for interventions that could preserve hearing in people whose hearing ...

  2. Hearing Conservation Live #2430

    Energy Technology Data Exchange (ETDEWEB)

    Chochoms, Michael [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-08-09

    Occupational hearing loss is one of the most common work-related illnesses in the United States (US). From 22 to 30 million US workers are exposed to hazardous noise levels at work, and 25% of these workers will develop permanent hearing loss. Hearing loss from noise is slow and painless, and you can have a disability before you notice it. This course presents the hazards associated with workplace noise, the purpose and elements of the Los Alamos National Laboratory (LANL) Hearing Conservation Program (HCP), and controls that are available to reduce your exposure to hazardous levels of noise.

  3. Efficient polymerization of acrylonitrile catalyzed by diValent lanthanide complex/sodium phenolate systems

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Four divalent lanthanide complexes Sm(ArO)2(THF)4, Yb(ArO)2(THF)3, Eu(ArO)2(THF)3 (ArO = 2,6-ditert-butyl-4-methylphenolate) and (ButCp)2Sm(THF)2 were synthesized. Their catalytic activities on the polymerization of acrylonitrile were studied. The catalytic activities were influenced by the central metal ions involved. The catalytic activities of these divalent lanthanide complexes can be greatly increased by adding NaOC~H2-2,6-But2-4-Me,NaOC6H4-4-But, or NaOC10H6-2-Me. The amount of additive has apparent effect on the catalytic activity, but the additive has no effect on the tacticity of the resulting polyacrylonitrile

  4. Innovative Application of Biopolymer Keratin as a Filler of Synthetic Acrylonitrile-Butadiene Rubber NBR

    Directory of Open Access Journals (Sweden)

    Mirosława Prochoń

    2013-01-01

    Full Text Available The current investigations show the influence of keratin, recovered from the tanning industry, on the thermal and mechanical properties of vulcanizates with synthetic rubber acrylonitrile-butadiene rubber NBR. The addition of waste protein to NBR vulcanizates influences the improvement of resistance at high temperatures and mechanical properties like tensile strength and hardness. The introduction of keratin to the mixes of rubber previously blended with zinc oxide (ZnO before vulcanization process leads to an increase in the cross-linking density of vulcanizates. The polymer materials received including addition of proteins will undergo biodecomposition in natural conditions. After soil test, vulcanizates with keratin especially keratin with ZnO showed much more changes on the surface area than vulcanizates without protein. In that aerobic environment, microorganisms, bacteria, and fungus digested better polymer materials containing natural additives.

  5. Barrierity of hydrogenated butadiene-acrylonitrile rubber and butyl rubber after exposure to organic solvents.

    Science.gov (United States)

    Krzemińska, Sylwia; Rzymski, Władysław M

    2011-01-01

    Resistance of antichemical clothing primarily depends on the type of material it is made from, in particular on the type of polymer used for coating the fabric carrier. This paper reports on systematic investigations on the influence of the cross-linking density of an elastomer and the composition of a cross-linked elastomer on its resistance to permeation of selected organic solvents. Tests of barrier material samples made from nonpolar butyl rubber (IIR) and polar hydrogenated butadiene-acrylonitrile rubber (HNBR) showed that (a) in rubber-solvent systems with medium thermodynamic affinity, cross-linking density influenced resistance to permeation and (b) the polarity of the system had a significant influence on barrierity.

  6. Improved procedure for determination of acrylonitrile in foods and its application to meat.

    Science.gov (United States)

    Page, B D; Charbonneau, C F

    1985-01-01

    The previously described headspace-gas chromatographic procedure for the determination of acrylonitrile (AN) in several foods, with N/P selective detection, has been modified to include packaged luncheon meats. The loss of AN during equilibration at 100 degrees C in meat samples as well as the previously described loss in cold pack cheese and peanut butter has been studied. The loss of AN could be prevented by the addition of 10% phosphoric acid, which increases the acidity of the food-acid-salt slurry to pH 1.2-1.5. This acidification permits detection of AN at 2 ppb (5% FSD at 16 X 10(-2) amp/mV) in all foods studied. AN was not detected in 10 samples of luncheon meat packaged in AN-based plastic which contained up to 2.6 ppm AN.

  7. Thermo-Physical Properties of Kenaf-Filled Acrylonitrile Butadiene Styrene Composites

    Directory of Open Access Journals (Sweden)

    Nikmatin Siti

    2017-01-01

    Full Text Available Studies on advantageous of natural fillers incorporated into polymer composites on thermo-physical and mechanical properties are still intensively investigated. Several evidences suggest that the natural fillers with small contents combined with polymer increase their composite properties. We thus investigate thermo-physical properties of kenaf-filled acrylonitrile butadiene styrene (ABS composites. ABS with 5% kenaf microparticle size (ABS/K5, ABS with 5% kenaf short fiber (ABS/KSF5, and recycled ABS with 5% kenaf microparticle size (RABS/K5 were manufactured. Granular composites were manufactured by the twin screw extruder. Composite properties in terms of X-ray diffractions, surface morphologies, and thermal behaviors were investigated. The present work found that ABS/KSF5 has the highest degree of crystallinity compared to others. No significant difference was found in terms of thermal properties of the composites.

  8. Comparison of cancer risks projected from animal bioassays to epidemiologic studies of acrylonitrile-exposed workers.

    Science.gov (United States)

    Ward, C E; Starr, T B

    1993-10-01

    Bioassay findings have demonstrated that acrylonitrile (ACN) is a rodent carcinogen, but the available epidemiologic evidence provides little support for the human carcinogenicity of ACN. This discordance between laboratory animal and human study findings is explored by determining post hoc the statistical power of 11 epidemiologic studies of ACN-exposed workers to detect the all-site and brain cancer excesses that are projected from rodent drinking water bioassay data. At reasonable estimates of the level and duration of exposures among the occupational cohorts, a majority of the human studies had sufficient power (> 80%) to detect the projected excesses, yet such responses were consistently absent. We conclude, subject to certain caveats, that the upper bound estimate of ACN's inhalation cancer potency of 1.5 x 10(-4) per ppm is too high to be consistent with the human ACN experience.

  9. Flame Retardant Effects of Nano-Clinoptilolite on AcrylonitrileButadiene-Styrene (ABS Nano-Composite

    Directory of Open Access Journals (Sweden)

    Aboulfazl Barati

    2012-01-01

    Full Text Available In recent years, intumescent technology has found a place in polymer science as a method of providing flame retardance to polymeric materials. On heating, fire-retardant intumescent material restricts the action of the heat flux or flame. The proposed mechanism is based on charred layer acting as physical barrier, which slows down heat and mass transfer between the gas and the condensed phases. In this paper, the flammability of intumescent fire-retardant acrylonitrile-butadiene-styrene (ABS matrix composites consisting of hydromagnesite (HMg as an acid source and blowing agent, pentaerythritol (PER as a carbonisation agent and natural zeolite (clinoptilolite rich, Kansar Shargh as a synergistic agent were examined. The flammability of composites was characterized by limiting oxygen index (LOI measurement and horizontal burning tests. A synergistic effect in flame retardancy was observed when natural zeolites were used in combination with HMg and PER.

  10. A flexible Li polymer primary cell with a novel gel electrolyte based on poly(acrylonitrile)

    Science.gov (United States)

    Akashi, Hiroyuki; Tanaka, Ko-ichi; Sekai, Koji

    The performance of a Li polymer primary cell with fire-retardant poly(acrylonitrile) (PAN)-based gel electrolytes is reported. By optimizing electrodes, electrolytes, the packaging material, and the structural design of the polymer cell, we succeeded in developing a "film-like" Li polymer primary cell with sufficient performance for practical use. The cell is flexible and less than 0.5 mm thick, which makes it suitable for a power source for some smart devices, such as an IC card. Fast cation conduction in the gel electrolyte minimizes the drop of the discharge capacity even at -20 °C. The high chemical stability of the gel electrolytes and the new packaging material allow the self-discharge rate to be limited to under 4.3%, which is equivalent to that of conventional coin-shaped or cylindrical Li-MnO 2 cells.

  11. Photoinitiated decomposition of substituted ethylenes: The photodissociation of vinyl chloride and acrylonitrile at 193 nm

    Energy Technology Data Exchange (ETDEWEB)

    Blank, D.A.; Suits, A.G.; Lee, Y.T. [Lawrence Berkeley National Lab., CA (United States)] [and others

    1997-04-01

    Ethylene and its substituted analogues (H{sub 2}CCHX) are important molecules in hydrogen combustion. As the simplest {pi}-bonded hydrocarbons these molecules serve as prototypical systems for understanding the decomposition of this important class of compounds. The authors have used the technique of photofragment translational spectroscopy at beamline 9.0.2.1 to investigate the dissociation of vinyl chloride (X=Cl) and acrylonitrile (X=CN) following absorption at 193 nm. The technique uses a molecular beam of the reactant seeded in helium which is crossed at 90 degrees with the output of an excimer laser operating on the ArF transition, 193.3 nm. The neutral photoproducts which recoil out of the molecular beam travel 15.1 cm where they are photoionized by the VUV undulator radiation, mass selected, and counted as a function of time. The molecular beam source is rotatable about the axis of the dissociation laser. The authors have directly observed all four of the following dissociation channels for both systems: (1) H{sub 2}CCHX {r_arrow} H + C{sub 2}H{sub 2}X; (2) H{sub 2}CCHX {r_arrow} X + C{sub 2}H{sub 3}; (3) H{sub 2}CCHX {r_arrow} H{sub 2} + C{sub 2}HX; and (4) H{sub 2}CCHX {r_arrow} HX + C{sub 2}H{sub 2}. They measured translational energy distributions for all of the observed channels and measured the photoionization onset for many of the photoproducts which provided information about their chemical identity and internal energy content. In the case of acrylonitrile, selective product photoionization provided the ability to discriminate between channels 2 and 4 which result in the same product mass combination.

  12. Immunoassay of haemoglobin-acrylonitrile adduct in rat as a biomarker of exposure.

    Science.gov (United States)

    L Wong Yu Ting Zheng Junyu Li Carlo H Tamburro Frederick W Benz, J

    1998-01-01

    Acrylonitrile (AN) is a rat carcinogen. Human exposure may come from chemical industries and smoking. A haemoglobin adduct of acrylonitrile (Hb-AN) has been used as a biomarker of exposure by means of gas chromatography-mass spectrometry (GC-MS) analysis. We have developed specific monoclonal antibodies (Mab) to human Hb-AN and wish to report evaluation of an immunoassay in rats using an Mab that cross-reacts with rat Hb-AN. A dose response study of LD 0, 10, 50, and 90 in Sprague-Dawley rats was undertaken, with each rat receiving \\[2,3-14C]AN at 50 Ci kg-1 sc, and Hb from an aliquot of blood was taken for covalent binding analysis by liquid scintillation spectrometry and fluorescence ELISA. The dose responses of rats at 0.25, 0.5, 1.0, and 2.0 h after AN doses of 20, 50, 80, 115 mg kg-1 were compared by both methods with Hb and globin samples. Regression analysis showed a linear relationship between immunoassay and 14C-AN binding. This indicates that an antigenic form of Hb-AN may be used as a surrogate of Hb-AN adduct. The sensitivity of ELISA was tested in rats exposed for 1 h to sub-toxic doses of AN (10-1.1 mg kg-1). Quantification of Hb-AN by immunoassay was achieved by calibration with a synthetic adduct HbAN4h, a reference adduct prepared by treating rat Hb with excess AN for 4 h. ELISA and GC-MS analysis of N-terminal valine-AN in the Hb-AN adduct were compared and similar detection levels were found. This rat study appears to have validated the new immunoassay method for biomonitoring of AN exposure.

  13. 提高丙烯腈回收率的一种新型急冷工艺和急冷塔%A new quenching process and tower to improve the recovery of acrylonitrile

    Institute of Scientific and Technical Information of China (English)

    甘永胜; 顾军民; 方永成

    2004-01-01

    Quenching process and design of the quenching tower in acrylonitrile production in China were studied in order to decrease the polymerization loss of acrylonitrile in the quenching tower.Based on the research of acrylonitrile polymerization in the quenching tower,a new quenching process was proposed to avoid the disadvantages of the original process.Two kinds of internals were installed to improve the performance of the quenching tower.Through a series of air-flow and real-flow model experiments,the new quenching process and new design were showed to be successful in enhancing the mass and heat transfer in the vapor-liquid system and decreasing the loss of acrylonitrile.Industrial application showed satisfactory results of decrease of the acrylonitrile loss in the quenching tower by about 4.5% and increase of the acrylonitrile recovery of the whole plant by more than 4%.

  14. Sudden sensorineural hearing loss after non-otologic surgery.

    Science.gov (United States)

    Page, Joshua Cody; Peters, Bob

    2015-01-01

    Sudden sensorineural hearing loss following non-otologic surgery is a rare event described in the medical literature. Cardiopulmonary bypass surgery is most commonly associated with this type of hearing loss. Our case report and review of the literature describe two cases with postoperative hearing loss - neither of which are cardiac surgeries - making them exceedingly rare in the medical literature. Regardless of the rarity of this unfortunate event, the possibility for permanent hearing loss is a potentially devastating unanticipated complication and one that all surgeons should be aware.

  15. Hereditary Hearing Loss.

    Science.gov (United States)

    Tran, LenhAnh P.; Grundfast, Kenneth M.

    1997-01-01

    This article discusses inheritance patterns in hearing loss, epidemiology, clues to genetic causes, locating genes that cause hereditary disorders, genes related to hearing loss disorders in individuals with Usher syndrome, Waardenburg syndrome, Treacher-Collins syndrome, Branchio-oto-renal and Pendred syndromes, and the significance of finding…

  16. Hearing poorly with skill

    DEFF Research Database (Denmark)

    Day, Dennis

    2012-01-01

    This paper offers an account of ongoing research into hearing. I offer a characterization of 'skil- led practitioners' from an Ethnomethodological perspective. The skilled practitioner in question is a generic 'hard of hearing' person. The ambition is that such a characterization, both in its...

  17. Magnetic Implants Aid Hearing

    Institute of Scientific and Technical Information of China (English)

    陈宏

    1995-01-01

    The next generation of hearing aids may use tiny magnets that fit inside the ear. Researchersat a California company and an engineer at the University of Virginia are both developing systems that rely on magnets to convey sounds. Conventional hearing aids have three components:a microphone, an amplifier, and a speaker. The microphone picks up sounds and sends them to the am-

  18. Hearing Aid Personalization

    DEFF Research Database (Denmark)

    Nielsen, Jens Brehm; Nielsen, Jakob; Jensen, Bjørn Sand

    2013-01-01

    Modern digital hearing aids require and offer a great level of personalization. Today, this personalization is not performed based directly on what the user actually perceives, but on a hearing-care professional’s interpretation of what the user explains about what is perceived. In this paper, an...

  19. Hearing Loss in Children

    Science.gov (United States)

    ... Español (Spanish) Recommend on Facebook Tweet Share Compartir Hearing loss can affect a child’s ability to develop communication, language, and social skills. The earlier children with hearing loss start getting services, the more likely they are ...

  20. [Hearing disorders with glaucoma].

    Science.gov (United States)

    Kremmer, S; Anastassiou, G; Selbach, J M

    2014-02-01

    One of the most common sensory impairments of elderly people is hearing loss. Glaucoma is one of the leading causes of blindness worldwide. Hearing and vision loss typically increase with older age. There is scientific evidence that the coincidence of hearing and vision loss is more frequent than expected by the prevalence of individual disorders. With regards to demographic changes and an aging population, in future, it is probable that the incidence of combined hearing and vision impairments will increase, representing a particular challenge not only for doctors and nurses but also a high burden for the private environment of the patients. Therefore, it is of particular importance to diagnose and to treat hearing and vision loss (dual sensory loss) as early as possible. The treatment of hearing disorders and glaucoma as well as possibly underlying systemic diseases such as circulatory disturbances is as important as responsible rehabilitation measures and the supply of hearing and low vision aids. During the last years, knowledge about the molecular biological background of hearing loss and glaucoma has continuously increased but it is currently still at the level of laboratory and animal experiments. Therefore, it remains to be seen whether and to what extent a real therapy for the underlying genetic, immunological and in particular mitochondrial disorders may be accessible in the future.

  1. Pharmacological reversal of endothelin-1 mediated constriction of the spiral modiolar artery: a potential new treatment for sudden sensorineural hearing loss

    Directory of Open Access Journals (Sweden)

    Arnold Wolfgang

    2005-11-01

    Full Text Available Abstract Background Vasospasm of the spiral modiolar artery (SMA may cause ischemic stroke of the inner ear. Endothelin-1 (ET-1 induces a strong, long-lasting constriction of the SMA by increasing contractile apparatus Ca2+ sensitivity via Rho-kinase. We therefore tested several Rho-kinase inhibitors and a cell-permeable analogue of cAMP (dbcAMP for their ability to reverse ET-1-induced constriction and Ca2+-sensitization. Methods The present study employed SMA isolated from gerbil temporal bones. Ca2+sensitivity was evaluated by correlating vascular diameter and smooth muscle cell [Ca2+]i, measured by fluo-4-microfluorometry and videomicroscopy. Results The Rho-kinase inhibitors Y-27632, fasudil, and hydroxy-fasudil reversed ET-1-induced vasoconstriction with an IC50 of 3, 15, and 111 μmol/L, respectively. DbcAMP stimulated a dose-dependent vasodilation (Ec50 = 1 mmol/L and a reduction of [Ca2+]i (EC50 = 0.3 μmol/L of ET-1-preconstricted vessels (1 nmol/L. Fasudil and dbcAMP both reversed the ET-1-induced increase in Ca2+ sensitivity. Conclusion Rho-kinase inhibition and dbcAMP reversed ET-1-induced vasoconstriction and Ca2+-sensitization. Therefore, Rho-kinase inhibitors or cAMP modulators could possess promise as pharmacological tools for the treatment of ET-1-induced constriction, ischemic stroke and sudden hearing loss.

  2. Medulloblastoma manifesting as sudden sensorineural hearing loss.

    Science.gov (United States)

    Terakawa, Yuzo; Tsuyuguchi, Naohiro; Takami, Toshihiro; Ohata, Kenji

    2011-07-01

    We present a rare case of medulloblastoma which presented with unilateral sudden sensorineural hearing loss as an initial symptom. A 19-year-old man was admitted to our hospital with a chief complaint of dizziness and facial numbness on the right side. His illness had begun two years previously with sudden hearing loss on the right side, for which he had been treated as an idiopathic sudden hearing loss. Magnetic resonance imaging demonstrated abnormal signals located mainly in the right middle cerebellar peduncle. We performed partial resection of the tumor by suboccipital craniotomy. The histopathological diagnosis was medulloblastoma. Intrinsic brain tumor is an extremely rare cause of sudden sensorineural hearing loss and is therefore easily overlooked as was in the present case. The present case highlights not only the need to evaluate patients with sudden sensorineural hearing loss by magnetic resonance imaging but also the importance of paying attention to intrinsic lesions involving the brainstem. Although this condition like the presented case might be rare, intrinsic brain tumor should be considered as a potential cause of sudden sensorineural hearing loss, as it may be easily missed leading to a delay in appropriate treatment.

  3. REDUCING NONSELECTIVE PROTEIN ADSORPTION AND CELL ADHESION ON POLYACRYLONITRILE FILMS BY COPOLYMERIZATION OF ACRYLONITRILE WITH α-ALLYL GLUCOSIDE

    Institute of Scientific and Technical Information of China (English)

    Rui-qiang Kou; Chao Qu; Zhi-kang Xu; You-yi Xu; Ke Yao

    2003-01-01

    In this work, the surface properties of novel sugar-containing polymers, α-allyl glucoside (AG)/acrylonitrile (AN)copolymers, were studied by contact angle, protein adsorption and cell adhesion measurements. It was found that the contact angle of the copolymer films decreased from 68° to 30° with the increase of AG content in the copolymer. The adsorption amount of bovine serum albumin (BSA) and the adhesive macrophage onto the film surface also decreased significantly with increasing α-allyl glucoside content from 0 to 42 wt% in the copolymer. These preliminary results reveal that both the hydrophilicity and the biocompatibility of polyacrylonitrile-based membranes could be improved by copolymerizing acrylonitrile with vinyl carbohydrates.

  4. Genotoxicity of styrene-acrylonitrile trimer in brain, liver, and blood cells of weanling F344 rats.

    Science.gov (United States)

    Hobbs, Cheryl A; Chhabra, Rajendra S; Recio, Leslie; Streicker, Michael; Witt, Kristine L

    2012-04-01

    Styrene-acrylonitrile Trimer (SAN Trimer), a by-product in production of acrylonitrile styrene plastics, was identified at a Superfund site in Dover Township, NJ, where childhood cancer incidence rates were elevated for a period of several years. SAN Trimer was therefore tested by the National Toxicology Program in a 2-year perinatal carcinogenicity study in F344/N rats and a bacterial mutagenicity assay; both studies gave negative results. To further characterize its genotoxicity, SAN Trimer was subsequently evaluated in a combined micronucleus (MN)/Comet assay in juvenile male and female F344 rats. SAN Trimer (37.5, 75, 150, or 300 mg/kg/day) was administered by gavage once daily for 4 days. Micronucleated reticulocyte (MN-RET) frequencies in blood were determined by flow cytometry, and DNA damage in blood, liver, and brain cells was assessed using the Comet assay. Highly significant dose-related increases (P exposure to SAN Trimer.

  5. Genotoxicity of Styrene–Acrylonitrile Trimer in Brain, Liver, and Blood Cells of Weanling F344 Rats

    Science.gov (United States)

    Hobbs, Cheryl A.; Chhabra, Rajendra S.; Recio, Leslie; Streicker, Michael; Witt, Kristine L.

    2012-01-01

    Styrene–acrylonitrile Trimer (SAN Trimer), a by-product in production of acrylonitrile styrene plastics, was identified at a Superfund site in Dover Township, NJ, where childhood cancer incidence rates were elevated for a period of several years. SAN Trimer was therefore tested by the National Toxicology Program in a 2-year perinatal carcinogenicity study in F344/N rats and a bacterial mutagenicity assay; both studies gave negative results. To further characterize its genotoxicity, SAN Trimer was subsequently evaluated in a combined micronucleus (MN)/Comet assay in juvenile male and female F344 rats. SAN Trimer (37.5, 75, 150, or 300 mg/kg/day) was administered by gavage once daily for 4 days. Micronucleated reticulocyte (MN-RET) frequencies in blood were determined by flow cytometry, and DNA damage in blood, liver, and brain cells was assessed using the Comet assay. Highly significant dose-related increases (P exposure to SAN Trimer. PMID:22351108

  6. Improved Method for Preparation of Amidoxime Modified Poly(acrylonitrile-co-acrylic acid: Characterizations and Adsorption Case Study

    Directory of Open Access Journals (Sweden)

    Nur Amirah Mohd Zahri

    2015-07-01

    Full Text Available Redox polymerization of poly(acrylonitrile-co-acrylic acid (poly(AN-co-AA is performed at 40 °C under N2 gas by varying the ratio of acrylonitrile (AN and acrylic acid (AA in the feed. The yield production of poly(acrylonitrile (PAN is 73% and poly(AN-co-AA with a feed ratio of 93:7 is the highest yield (72%. The PAN and poly(AN-co-AA are further chemically modify with hydroxylamine hydrochloride. The FTIR spectroscopy is used to confirm the copolymerization of poly(AN-co-AA and chemical modification of poly(AN-co-AA. Elemental microanalysis shows that the overall trend percentage of carbon, hydrogen, and nitrogen for all feed ratios are slightly decreasing as the feed ratio of AA is increasing except for poly(AN-co-AA 93:7. The SEM images shows that spherical diameter of poly(AN-co-AA is smaller compared to the PAN and amidoxime (AO modified poly(AN-co-AA. The TGA (thermogravimetric analysis analysis reveals that the poly(AN-co-AA degrades at lower temperatures compared to the PAN but higher than AO modified poly(AN-co-AA. The case study adsorption test showed that the AO modified poly(AN-co-AA 93:7 had the highest percentage removal of Cd2+ and Pb2+.

  7. International hearing protector standardization

    DEFF Research Database (Denmark)

    Poulsen, Torben

    2002-01-01

    Hearing protectors shall fulfill some minimum requirements to their performance. As hearing protector manufacturers sell the products all over the world, the testing and certification of hearing protectors has become an international issue. The ISO working group WG17 under the headlines Acoustics...... in impulse noise, protectors with active noise reduction). Furthermore, an overview of the present European standards (CEN) and the relation to American and Australian/New Zealand standards will be discussed.......Hearing protectors shall fulfill some minimum requirements to their performance. As hearing protector manufacturers sell the products all over the world, the testing and certification of hearing protectors has become an international issue. The ISO working group WG17 under the headlines Acoustics......, Noise, produce hearing protector standards to be used at an international level. The presentation will cover the ongoing work in WG17, including the revision of existing standards (ISO 4869-1, ISO 4869-3), upcoming new standards (ISO 4869-7) and the plans and status for future standards (performance...

  8. Treating hearing disorders with cell and gene therapy

    Science.gov (United States)

    Gillespie, Lisa N.; Richardson, Rachael T.; Nayagam, Bryony A.; Wise, Andrew K.

    2014-12-01

    Hearing loss is an increasing problem for a substantial number of people and, with an aging population, the incidence and severity of hearing loss will become more significant over time. There are very few therapies currently available to treat hearing loss, and so the development of new therapeutic strategies for hearing impaired individuals is of paramount importance to address this unmet clinical need. Most forms of hearing loss are progressive in nature and therefore an opportunity exists to develop novel therapeutic approaches to slow or halt hearing loss progression, or even repair or replace lost hearing function. Numerous emerging technologies have potential as therapeutic options. This paper details the potential of cell- and gene-based therapies to provide therapeutic agents to protect sensory and neural cells from various insults known to cause hearing loss; explores the potential of replacing lost sensory and nerve cells using gene and stem cell therapy; and describes the considerations for clinical translation and the challenges that need to be overcome.

  9. Nutrition Education in Medical Schools. Hearing Before the Subcommittee on Nutrition of the Committee on Agriculture, Nutrition, and Forestry, United States Senate. Ninety-Fifth Congress, Second Session on Current Status, Impediments, and Potential Solutions. September 20, 1978.

    Science.gov (United States)

    Congress of the U.S., Washington, DC. Senate Committee on Agriculture, Nutrition, and Forestry.

    Testimonies and articles, letters, and statements from a congressional hearing of the U.S. Senate concerning nutrition education in medical schools are presented. The hearing was held to ascertain the present status of nutrition instruction in U.S. medical schools, to determine the need for such instruction, and to identify problems with…

  10. Sudden sensorineural hearing loss.

    Science.gov (United States)

    Stew, B T; Fishpool, S J C; Williams, H

    2012-02-01

    Sudden onset sensorineural hearing loss is a medical emergency that continues to be poorly understood despite being recognized in the literature since 1944 (De Kleyn, 1944). A commonly used criterion to qualify for this diagnosis is a sensorineural hearing loss over three contiguous pure-tone frequencies of 30 dB or more that develops within 72 hours. The vast majority of cases are unilateral and the estimated annual incidence is 20 per 100 000 persons (Nosrati-Zarenoe et al, 2007). A cause for the hearing loss is only identified in up to 10% of cases but 50% of patients will improve spontaneously (Penido et al, 2009).

  11. Micromechanics of hearing

    Science.gov (United States)

    Hudspeth, A. J.

    2015-12-01

    The following summarizes the key points addressed during a tutorial session on the Micromechanics of Hearing that took place at the 12th International Workshop on the Mechanics of Hearing held at Cape Sounio, Greece, in June 2014. The tutorial was intended to present an overview of basic ideas and to address topics of current interest relevant to the Workshop. The session was recorded, and the audio file and accompanying visual content of the presentation can be found in the Mechanics of Hearing Digital Library (www.mechanicsofhearing.org).

  12. Age-related Hearing Impairment and the Triad of Acquired Hearing Loss

    Directory of Open Access Journals (Sweden)

    Chao-Hui eYang

    2015-07-01

    Full Text Available Understanding underlying pathological mechanisms is prerequisite for a sensible design of protective therapies against hearing loss. The triad of age-related, noise-generated, and drug-induced hearing loss ¬¬displays intriguing similarities in some cellular responses of cochlear sensory cells such as a potential involvement of reactive oxygen species and apoptotic and necrotic cell death. On the other hand, detailed studies have revealed that molecular pathways are considerably complex and, importantly, it has become clear that pharmacological protection successful against one form of hearing loss will not necessarily protect against another. This review will summarize pathological and pathophysiological features of age-related hearing impairment (ARHI in human and animal models and address selected aspects of the commonality (or lack thereof of cellular responses in ARHI to drugs and noise.

  13. Introduction to audiology: Some basics about hearing loss, hearing technologies and barriers to hearing aid use

    DEFF Research Database (Denmark)

    Mourtou, Eleni; Meis, Markus

    2012-01-01

    loss and their various effects on communication, (3) the different degrees of hearing loss as defined by different national and international organizations, (4) statistics on the preva- lence of hearing loss worldwide, (5) some technological aspects of hearing instruments, (6) sta- tistics on non......This chapter provides background information for researchers who wish to become familiar with some basic medical and audiological aspects of hearing loss and the technology of hearing aids. It introduces (1) the disciplines involved in research on hearing loss, (2) the medical categories of hearing...

  14. Buying a Hearing Aid

    Science.gov (United States)

    ... Contact Us Calendar ENTCareers Marketplace ENT Careers Marketplace Log in b Log in Toggle navigation b Join Now Donate Now ... using your hearing aids in quiet surroundings, gradually building up to noisier environments. Then eventually work up ...

  15. Hearing Conservation Team

    Data.gov (United States)

    Federal Laboratory Consortium — The Hearing Conservation Team focuses on ways to identify the early stages of noise-induced damage to the human ear. Our current research involves the evaluation of...

  16. What's Hearing Loss?

    Science.gov (United States)

    ... regular school, or be part of a regular classroom. Depending on how severe their hearing loss is, ... read along to follow the action. Technology is changing all the time, and you will probably see ...

  17. Experimental Investigations on Tribological Behaviour of Alumina Added Acrylonitrile Butadiene Styrene (ABS Composites

    Directory of Open Access Journals (Sweden)

    T. Panneerselvam

    2016-09-01

    Full Text Available Composite materials are multifunctional in nature, which can be custom-made based on the nature of the applications. The challenge of composite materials lie on complementing the properties of one another i.e. materials which go in the making of composites strengthen each other by inhibiting their weaknesses. Polymers are one of the widely used materials which serve a wide spectrum of engineering needs. In the present work, the tribological behaviour of a composite containing Acrylonitrile Butadiene Styrene (ABS and traces of Alumina is experimentally investigated. Alumina is added to ABS in various percentages such as 1%, and 3% by weight in order to improve the wear resistance of the polymer. Central Composite Design was used to design the experiments and a standard Pin-On-Disk apparatus was used to conduct the experiments. It is observed from the test results that the addition of alumina significantly enhances the wear behavior of the polymer. However, adding more percentage of alumina has led to adverse effect on wear resistance of polymer materials. Abrasive wear mechanism is found to be predominant in the case of alumina added composite materials. It is also found that 1% alumina added composite exhibits excellent wear properties compared to other materials.

  18. Barrier properties of hydrogenated acrylonitrile-butadiene rubber composites containing modified layered aluminosilicates

    Science.gov (United States)

    Krzemińska, S.; Rzymski, W. M.

    2011-12-01

    The resistance to permeation by the selected solvents of flat membranes made of cured hydrogenated acrylonitrile-butadiene rubber (HNBR) materials without any fillers and containing 5 phr of layered aluminosilicate nanofiller (bentonite), modified with various types of ammonium salts or N330 type carbon black, was investigated. The barrier properties were assessed on the basis of the breakthrough time of a liquid with low (cyclohexane) or average (butyl acetate) thermodynamic affinity to HNBR, determined according to EN 6529:2001, through a cured elastomer sample. The addition of bentonite, irrespectively of the method of modification of its particles, was found to increase the cured HNBR breakthrough time by 20 - 35 % in the case of slowly permeating non-polar cyclohexane, and by 50 - 130 % in the case of polar butyl acetate permeating more rapidly, in comparison with the barrier material containing no filler. The layered aluminosilicate nanofillers increased the breakthrough time of the material sample for both the tested solvents. In particular, the breakthrough time for polar butyl acetate was even longer than for conventional carbon black. Additionally, the increase of the breakthrough time was observed to depend on the modifier of bentonite particle surface.

  19. Design and testing of digitally manufactured paraffin Acrylonitrile-butadiene-styrene hybrid rocket motors

    Science.gov (United States)

    McCulley, Jonathan M.

    This research investigates the application of additive manufacturing techniques for fabricating hybrid rocket fuel grains composed of porous Acrylonitrile-butadiene-styrene impregnated with paraffin wax. The digitally manufactured ABS substrate provides mechanical support for the paraffin fuel material and serves as an additional fuel component. The embedded paraffin provides an enhanced fuel regression rate while having no detrimental effect on the thermodynamic burn properties of the fuel grain. Multiple fuel grains with various ABS-to-Paraffin mass ratios were fabricated and burned with nitrous oxide. Analytical predictions for end-to-end motor performance and fuel regression are compared against static test results. Baseline fuel grain regression calculations use an enthalpy balance energy analysis with the material and thermodynamic properties based on the mean paraffin/ABS mass fractions within the fuel grain. In support of these analytical comparisons, a novel method for propagating the fuel port burn surface was developed. In this modeling approach the fuel cross section grid is modeled as an image with white pixels representing the fuel and black pixels representing empty or burned grid cells.

  20. Covalent Immobilization of Lipase on Poly ( acrylonitrile-co-maleic acid) Ultrafiltration Hollow Fiber Membrane

    Institute of Scientific and Technical Information of China (English)

    YE Peng; XU Zhi-kang; WU Jian; DENG Hong-tao; SETA Patrick

    2005-01-01

    Lipase from Candida rugosa was covalently immobilized on the surface of an ultrafiltration hollow fiber membrane fabricated from poly (acrylonitrile-co-maleic acid) (PANCMA) in which the carboxyl groups were activated with 1-ethyl-3-(dimethylaminopropyl) carbodiimide hydrochloride (EDC) and dicyclohexyl carbodiimide (DCC)/N-hydroxyl succinimide(NHS), respectively. The properties of the immobilized lipase were assayed and compared with those of the free enzyme. The maximum activities were observed in a relatively broader pH value range at high temperatures for the immobilized lipase compared to the free one. It was also found that the thermal and pH stabilities of lipase were improved upon immobilization and at 50 ℃ the thermal inactivation rate constant values are 2.1×10-2 for the free lipase, 3.2×10-3 for the immobilized lipase on the EDC-activated PANCMA membrane and 3.5×10-3 for the immobilized lipase on the DCC/NHS-activated PANCMA membrane, respectively.

  1. THERMAL DECOMPOSITION AND FLAMMABILITY OF ACRYLONITRILE-BUTADIENE-STYRENE/MULTI-WALLED CARBON NANOTUBES COMPOSITES

    Institute of Scientific and Technical Information of China (English)

    Li-fang Tong; Hai-yun Ma; Zheng-ping Fang

    2008-01-01

    Thermal and flammability properties of acrylonitrile-butadiene-styrene copolymer (ABS) with the addition of multi-walled carbon nanotubes (MWNTs) were studied. ABS/MWNTs composites were prepared via melt blending with the MWNTs content varied from 0.2% to 4.0% by mass. Thermogravimetry results showed that the addition of MWNTs accelerated the degradation of ABS during the whole process under air atmosphere, and both onset and maximum degradation temperature were lower than those of pure ABS. The destabilization effect of MWNTs on the thermal stability of the composites became unobvious under nitrogen, and the addition of MWNTs could improve the maximum degradation temperature. The heat release rate and time of ignition (tign) for the composites reduced greatly with the addition of MWNTs especially when the concentration of nanotubes was higher than 1.0%. The accumulation of carbon nanotubes with a network structure was observed and the char layer became thicker with increasing nanotubes concentration. Results from Raman spectra showed a higher degree of graphitization for the residues of ABS/MWNTs composites.

  2. An investigation on chloroprene-compatibilized acrylonitrile butadiene rubber/high density polyethylene blends

    Directory of Open Access Journals (Sweden)

    Khalil Ahmed

    2015-11-01

    Full Text Available Blends of acrylonitrile butadiene rubber/high density polyethylene (NBR/HDPE compatibilized by Chloroprene rubber (CR were prepared. A fixed quantity of industrial waste such as marble waste (MW, 40 phr was also included. The effect of the blend ratio and CR on cure characteristics, mechanical and swelling properties of MW-filled NBR/HDPE blends was investigated. The results showed that the MW-filled NBR/HDPE blends revealed an increase in tensile strength, tear, modulus, hardness and cross-link density for increasing weight ratio of HDPE. The minimum torque (ML and maximum torque (MH of blends increased with increasing weight ratio of HDPE while scorch time (ts2 cure time (tc90, compression set and abrasion loss of blends decreased with increasing weight ratio of HDPE. The blends also showed a continuous reduction in elongation at break as well as swelling coefficient with increasing HDPE amount in blends. MW filled blends based on CR provided the most encouraging balance values of overall properties.

  3. Hg(II) adsorption using amidoximated porous acrylonitrile/itaconic copolymers prepared by suspended emulsion polymerization.

    Science.gov (United States)

    Ji, Chunnuan; Qu, Rongjun; Chen, Hou; Liu, Xiguang; Sun, Changmei; Ma, Caixia

    2016-01-01

    Initially, porous acrylonitrile/itaconic acid copolymers (AN/IA) were prepared by suspended emulsion polymerization. Successively, the cyano groups in AN/IA copolymers were converted to amidoxime (AO) groups by the reaction with hydroxylamine hydrochloride. The structures of the AN/IA and amidoximated AN/IA (AO AN/IA) were characterized by infrared spectroscopy, scanning electron microscopy, and porous structural analysis. The adsorption properties of AO AN/IA for Hg(II) were investigated. The results show that AO AN/IA has mesopores and macropores, and surface area of 11.71 m(2) g(-1). It was found that AO AN/IA has higher affinity for Hg(II), with the maximum adsorption capacity of 84.25 mg g(-1). The AO AN/IA also can effectively remove Hg(II) from different binary metal ion mixture systems. Furthermore, the adsorption kinetics and thermodynamics were studied in detail. The adsorption equilibrium can quickly be achieved in 4 h determined by an adsorption kinetics study. The adsorption process is found to belong to the second-order model, and can be described by the Freundlich model.

  4. Peroxydisulfate initiated synthesis of potato starch-graft-poly(acrylonitrile under microwave irradiation

    Directory of Open Access Journals (Sweden)

    2007-01-01

    Full Text Available Potato starch-graft-poly(acrylonitrile could be efficiently synthesized using small concentration of ammonium peroxydisulfate (0.0014M in aqueous medium under microwave irradiation. A representative microwave synthesized graft copolymer was characterized using Fourier Transform Infrared Spectroscopy, X-ray Diffraction, Scanning Electron Microscopy and Thermogravimetric Analysis. Under microwave conditions oxygen removal from the reaction vessel was not required and the graft copolymer was obtained in high yield using very small amount of ammonium peroxydisulfate, however using the same amount of ammonium peroxydisulfate (0.0014M on thermostatic water bath no grafting was observed up to 98°C (even in inert atmosphere. Raising the concentration of the initiator to 0.24 M resulted into 10% grafting at 50 °C but in inert atmosphere.The viscosity/shear stability of the grafted starch (aqueous solution and water/saline retention ability of the microwave synthesized graft copolymer were also studied and compared with that of the native potato starch.

  5. Effects of acrylonitrile on lymphocyte lipid rafts and RAS/RAF/MAPK/ERK signaling pathways.

    Science.gov (United States)

    Li, X J; Li, B; Huang, J S; Shi, J M; Wang, P; Fan, W; Zhou, Y L

    2014-09-26

    Acrylonitrile (ACN) is a widely used chemical in the production of plastics, resins, nitriles, acrylic fibers, and synthetic rubber. Previous epidemiological investigations and animal studies have confirmed that ACN affects the lymphocytes and spleen. However, the immune toxicity mechanism is unknown. Lipid rafts are cell membrane structures that are rich in cholesterol and involved in cell signal transduction. The B cell lymophoma-10 (Bcl10) protein is a joint protein that is important in lymphocyte development and signal pathways. This study was conducted to examine the in vitro effects of ACN. We separated lipid rafts, and analyzed Bcl10 protein and caveolin. Western blotting was used to detect mitogen-activated protein kinase (MAPK) and phosphorylated MAPK levels. The results indicated that with increasing ACN concentration, the total amount of Bcl10 remained stable, but was concentrated mainly in part 4 to part 11 in electrophoretic band district which is high density in gradient centrifugation. Caveolin-1 was evaluated as a lipid raft marker protein; caveolin-1 content and position were relatively unchanged. Western blotting showed that in a certain range, MAPK protein was secreted at a higher level. At some ACN exposure levels, MAPK protein secretion was significantly decreased compared to the control group (P lipid raft structures, causing Bcl10 protein and lipid raft separation and restraining Ras-Raf-MAPK-extracellular signal-regulated kinase signaling pathways.

  6. Regenerated thermosetting styrene-co-acrylonitrile sandwich composite panels reinforced by jute fibre: structures and properties

    Indian Academy of Sciences (India)

    Jinglong Li; Qin Peng; Anrong Zeng; Junlin Li; Xiaole Wu; Xiaofei Liu

    2016-02-01

    Jute fibres-reinforced sandwich regenerated composite panels were fabricated using industrial waste thermosetting styrene-co-acrylonitrile (SAN) foam scraps via compression moulding for the purpose of recycling waste SAN foam and obtaining high physical performance. The jute fibres were, respectively, treated by heat, sodium hydroxide (NaOH) solution (5.0 wt%), and N,N-dimethylacetamide (DMAc) in order to improve the mechanical properties of the composites. The structures and mechanical properties of the composites were studied. The SAN matrix got compact and some crystalline region formed in SAN matrix via compression moulding. The composite reinforced by DMAc-treated jute fibres performed optimum mechanical properties among the regenerated panels whose impact strength, flexural strength, and compressive strength were 19.9 kJ m−2, 41.7 MPa, and 61.0 MPa, respectively. Good interfacial bonding between DMAc-treated fibres and SAN matrix was verified by peel test and exhibited in SEM photographs. Besides, the water absorption of DMAc-treated fibres composite was lower than other SAN/jute fibre-reinforced sandwich composite panels.

  7. Study of the Effect of Grafted Antioxidant on the Acrylonitrile-Butadiene Copolymer Properties

    Directory of Open Access Journals (Sweden)

    Abdulaziz Ibrahim Al-Ghonamy

    2010-01-01

    Full Text Available The grafting of ADPEA onto natural rubber was executed with UV radiation. Benzoyl peroxide was used to initiate the free-radical grafting copolymerization. Natural rubber-graft-N-(4-aminodiphenylether acrylamide (NR-g-ADPEA was characterized with an IR technique. The paper aims interested to determine the crosslinking density by using the ultrasonic technique. The ultrasonic velocities of both longitudinal and shear waves were measured in thermoplastic discs of NBR vulcanizates as a function of aging time. Ultrasonic velocity measurements were taken at 2 MHz ultrasonic frequency using the pulse echo method. We studied the effect of aging on the mechanical properties, crosslinking density, and the swelling and extraction phenomena for acrylonitrile-butadiene copolymer (NBR vulcanizates, which contained the prepared NR-g-ADPEA and a commercial antioxidant, N-isopropyl-−-phenyl-p-phenylenediamine. The prepared antioxidant enhanced both the mechanical properties of the NBR vulcanizates and the permanence of the ingredients in these vulcanizates.

  8. Method for the separation of high impact polystyrene (HIPS) and acrylonitrile butadiene styrene (ABS) plastics

    Science.gov (United States)

    Jody, Bassam J.; Arman, Bayram; Karvelas, Dimitrios E.; Pomykala, Jr., Joseph A.; Daniels, Edward J.

    1997-01-01

    An improved method is provided for separating acrylonitrile butadiene styrene (ABS) and high impact polystyrene (HIPS) plastics from each other. The ABS and HIPS plastics are shredded to provide a selected particle size. The shredded particles of the ABS and HIPS plastics are applied to a solution having a solution density in a predefined range between 1.055 gm/cm.sup.3 and 1.07 gm/cm.sup.3, a predefined surface tension in a range between 22 dynes/cm to 40 dynes/cm and a pH in the range of 1.77 and 2.05. In accordance with a feature of the invention, the novel method is provided for separating ABS and HIPS, two solid thermoplastics which have similar densities by selectively modifying the effective density of the HIPS using a binary solution with the appropriate properties, such as pH, density and surface tension, such as a solution of acetic acid and water or a quaternary solution having the appropriate density, surface tension, and pH.

  9. Acrylonitrile Butadiene Styrene (ABS) plastic based low cost tissue equivalent phantom for verification dosimetry in IMRT.

    Science.gov (United States)

    Kumar, Rajesh; Sharma, S D; Deshpande, Sudesh; Ghadi, Yogesh; Shaiju, V S; Amols, H I; Mayya, Y S

    2009-12-17

    A novel IMRT phantom was designed and fabricated using Acrylonitrile Butadiene Styrene (ABS) plastic. Physical properties of ABS plastic related to radiation interaction and dosimetry were compared with commonly available phantom materials for dose measurements in radiotherapy. The ABS IMRT phantom has provisions to hold various types of detectors such as ion chambers, radiographic/radiochromic films, TLDs, MOSFETs, and gel dosimeters. The measurements related to pre-treatment dose verification in IMRT of carcinoma prostate were carried out using ABS and Scanditronics-Wellhoffer RW3 IMRT phantoms for five different cases. Point dose data were acquired using ionization chamber and TLD discs while Gafchromic EBT and radiographic EDR2 films were used for generating 2-D dose distributions. Treatment planning system (TPS) calculated and measured doses in ABS plastic and RW3 IMRT phantom were in agreement within +/-2%. The dose values at a point in a given patient acquired using ABS and RW3 phantoms were found comparable within 1%. Fluence maps and dose distributions of these patients generated by TPS and measured in ABS IMRT phantom were also found comparable both numerically and spatially. This study indicates that ABS plastic IMRT phantom is a tissue equivalent phantom and dosimetrically it is similar to solid/plastic water IMRT phantoms. Though this material is demonstrated for IMRT dose verification but it can be used as a tissue equivalent phantom material for other dosimetry purposes in radiotherapy.

  10. Induction of oxidative stress and oxidative damage in rat glial cells by acrylonitrile.

    Science.gov (United States)

    Kamendulis, L M; Jiang, J; Xu, Y; Klaunig, J E

    1999-08-01

    Chronic treatment of rats with acrylonitrile (ACN) resulted in a dose-related increase in glial cell tumors (astrocytomas). While the exact mechanism(s) for ACN-induced carcinogenicity remains unresolved, non-genotoxic and possibly tumor promotion modes of action appear to be involved in the induction of glial tumors. Recent studies have shown that ACN induced oxidative stress selectively in rat brain in a dose-responsive manner. The present study examined the ability of ACN to induce oxidative stress in a rat glial cell line, a target tissue, and in cultured rat hepatocytes, a non-target tissue of ACN carcinogenicity. Glial cells and hepatocytes were treated for 1, 4 and 24 h with sublethal concentrations of ACN. ACN induced an increase in oxidative DNA damage, as evidenced by increased production of 8-hydroxy-2'-deoxyguanosine (8-OH-dG) in glial cells but not in rat hepatocytes. Hydroxyl radical formation following ACN treatment was also selectively increased in glial cells. Following 1 and 4 h of ACN exposure, the levels of the non-enzymatic antioxidant glutathione, as well as the activities of the enzymatic antioxidants catalase and superoxide dismutase were significantly decreased in the rat glial cells. Lipid peroxidation and the activity of glutathione peroxidase were not affected by ACN treatment in rat glial cells. No changes in any of these biomarkers of oxidative stress were observed in hepatocytes treated with ACN. These data indicate that ACN selectively induced oxidative stress in rat glial cells.

  11. 2-Cyanoethylmercapturic acid (CEMA) in the urine as a possible indicator of exposure to acrylonitrile.

    Science.gov (United States)

    Jakubowski, M; Linhart, I; Pielas, G; Kopecký, J

    1987-12-01

    The aim of this study was to evaluate the efficiency of metabolism of acrylonitrile (ACN) to N-acetyl-S-(2-cyanoethyl)-L-cysteine (2-cyanoethylmercapturic acid (CEMA) in man, the kinetics of excretion of this metabolite, and the relation between the uptake of ACN and the excretion of CEMA in urine. Eleven experiments were performed on six male volunteers exposed for eight hours to ACN at concentrations of 5 or 10 mg/m3. The average respiratory retention of ACN was 52% and 21.8% of the retained ACN was excreted as CEMA in urine. Elimination approximated first order kinetics with half life of about eight hours. The best correlation between the uptake of ACN in the lungs and excretion of CEMA in urine was obtained when the concentration of CEMA in the urine fraction, collected between the sixth and eighth hours after the beginning of exposure, was adjusted to a specific gravity of 1.016 (y = 0.33x-13.3; r = 0.83). CEMA excretion, however, cannot be used as an individual index of exposure.

  12. High-Energy-Density Poly(styrene-co-acrylonitrile) Thin Films

    Science.gov (United States)

    Wen, Fei; Xu, Zhuo; Xia, Weimin; Ye, Hongjun; Wei, Xiaoyong; Zhang, Zhicheng

    2013-12-01

    The dielectric response of poly(styrene-co-acrylonitrile) (PSAN) thin films fabricated by a solution casting process was investigated in this work. Linear dielectric behavior was obtained in PSAN films under an electric field at frequencies from 100 Hz to 1 MHz and temperature of -50°C to 100°C. The polymer films exhibited an intermediate dielectric permittivity of 4 and low dielectric loss (tan δ) of 0.027. Under 400 MV/m, the energy density of the PSAN films was 6.8 J/cm3, which is three times higher than that of biaxially oriented polypropylene (BOPP) (about 1.6 J/cm3). However, their charge-discharge efficiency (about 90%) was rather close to that of BOPP. The calculated effective dielectric permittivity of the PSAN films under high electric field was as high as 9, which may be attributed to the improved displacement of the cyanide groups (-CN) polarized at high electric fields. These high-performance features make PSAN attractive for high-energy-density capacitor applications.

  13. Cobalt-Mediated Radical Polymerization of Vinyl Acetate and Acrylonitrile in Supercritical Carbon Dioxide.

    Science.gov (United States)

    Kermagoret, Anthony; Chau, Ngoc Do Quyen; Grignard, Bruno; Cordella, Daniela; Debuigne, Antoine; Jérôme, Christine; Detrembleur, Christophe

    2016-03-01

    Cobalt-mediated radical polymerization (CMRP) of vinyl acetate (VAc) is successfully achieved in supercritical carbon dioxide (scCO2). CMRP of VAc is conducted using an alkyl-cobalt(III) adduct that is soluble in scCO2. Kinetics studies coupled to visual observations of the polymerization medium highlight that the melt viscosity and PVAc molar mass (Mn) are key parameters that affect the CMRP in scCO2. It is noticed that CMRP is controlled for Mn up to 10 000 g mol(-1), but loss of control is progressively observed for higher molar masses when PVAc precipitates in the polymerization medium. Low molar mass PVAc macroinitiator, prepared by CMRP in scCO2, is then successfully used to initiate the acrylonitrile polymerization. PVAc-b-PAN block copolymer is collected as a free flowing powder at the end of the process although the dispersity of the copolymer increases with the reaction time. Although optimization is required to decrease the dispersity of the polymer formed, this CMRP process opens new perspectives for macromolecular engineering in scCO2 without the utilization of fluorinated comonomers or organic solvents.

  14. Nanostructured synthetic carbons obtained by pyrolysis of spherical acrylonitrile/divinylbenzene copolymers.

    Directory of Open Access Journals (Sweden)

    Danish J Malik

    Full Text Available Novel carbon materials have been prepared by the carbonization of acrylonitrile (AN/divinylbenzene (DVB suspension porous copolymers having nominal crosslinking degrees in the range of 30-70% and obtained in the presence of various amounts of porogens. The carbons were obtained by pre-oxidation of AN/DVB copolymers at 250-350°C in air followed by pyrolysis at 850°C in an N(2 atmosphere. Both processes were carried out in one furnace and the resulting material needed no further activation. Resulting materials were characterized by XPS and low temperature nitrogen adsorption/desorption. It was found that maximum pyrolysis yield was ca. 50% depending on the oxidation conditions but almost independent of the crosslinking degree of the polymers. Porous structure of the carbons was characterized for the presence of micropores and macropores, when obtained from highly crosslinked polymers or polymers oxidized at 350°C and meso- and macropores in all other cases. The latter pores are prevailing in the structure of carbons obtained from less porous AN/DVB resins. Specific surface area (BET of polymer derived carbons can vary between 440 m(2/g and 250 m(2/g depending on the amount of porogen used in the synthesis of the AN/DVB polymeric precursors.

  15. Microwave absorption properties of lightweight absorber based on Fe50Ni50-coated poly(acrylonitrile) microspheres and reduced graphene oxide composites

    Science.gov (United States)

    Zhang, Bin; Wang, Jun; Wang, Junpeng; Huo, Siqi; Zhang, Bin; Tang, Yushan

    2016-09-01

    In this paper, we proposed a facile method to obtain the lightweight composites consisting of surface modified Fe50Ni50-coated poly(acrylonitrile) microspheres (PANS@SMF), reduced graphene oxide (RGO) and epoxy resin. The as-prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), vibrating sample magnetometry (VSM) and vector network analyzer (VNA). Impedance matching condition and electromagnetic wave attenuation characteristic were used for the reflection loss (RL) performance of the composites. Compared with pure PANS@SMF and RGO composites, the -10 dB absorption bandwidth and the minimum RL of the hybrid composites were enhanced. The bandwidth less than -10 dB was almost 4.5 GHz in the range of 10 GHz to 14.5 GHz, with a matching thickness of 2.5 mm. The density of the hybrid composites was in the range of 0.25-0.34 g/cm3. Therefore, the hybrid composite can be considered as a potential lightweight microwave absorber.

  16. Your Baby's Hearing and Communicative Development Checklist

    Science.gov (United States)

    ... that make sounds YES NO Pays attention to music YES NO Babbles in a speech-like way ... Children Healthy Hearing 2020 How Do We Hear? Noise-Induced Hearing Loss Quick Statistics About Hearing Specific ...

  17. Genetics Home Reference: nonsyndromic hearing loss

    Science.gov (United States)

    ... Genetics Home Health Conditions nonsyndromic hearing loss nonsyndromic hearing loss Enable Javascript to view the expand/collapse boxes. Download PDF Open All Close All Description Nonsyndromic hearing loss is a partial or total loss of hearing ...

  18. Restaurant noise, hearing loss, and hearing aids.

    OpenAIRE

    Lebo, C P; M.F. Smith; Mosher, E R; Jelonek, S J; Schwind, D R; Decker, K E; Krusemark, H J; Kurz, P L

    1994-01-01

    Our multidisciplinary team obtained noise data in 27 San Francisco Bay Area restaurants. These data included typical minimum, peak, and average sound pressure levels; digital tape recordings; subjective noise ratings; and on-site unaided and aided speech discrimination tests. We report the details and implications of these noise measurements and provide basic information on selecting hearing aids and suggestions for coping with restaurant noise.

  19. Restaurant noise, hearing loss, and hearing aids.

    Science.gov (United States)

    Lebo, C P; Smith, M F; Mosher, E R; Jelonek, S J; Schwind, D R; Decker, K E; Krusemark, H J; Kurz, P L

    1994-07-01

    Our multidisciplinary team obtained noise data in 27 San Francisco Bay Area restaurants. These data included typical minimum, peak, and average sound pressure levels; digital tape recordings; subjective noise ratings; and on-site unaided and aided speech discrimination tests. We report the details and implications of these noise measurements and provide basic information on selecting hearing aids and suggestions for coping with restaurant noise.

  20. Perceptual consequences of "hidden" hearing loss.

    Science.gov (United States)

    Plack, Christopher J; Barker, Daphne; Prendergast, Garreth

    2014-09-09

    Dramatic results from recent animal experiments show that noise exposure can cause a selective loss of high-threshold auditory nerve fibers without affecting absolute sensitivity permanently. This cochlear neuropathy has been described as hidden hearing loss, as it is not thought to be detectable using standard measures of audiometric threshold. It is possible that hidden hearing loss is a common condition in humans and may underlie some of the perceptual deficits experienced by people with clinically normal hearing. There is some evidence that a history of noise exposure is associated with difficulties in speech discrimination and temporal processing, even in the absence of any audiometric loss. There is also evidence that the tinnitus experienced by listeners with clinically normal hearing is associated with cochlear neuropathy, as measured using Wave I of the auditory brainstem response. To date, however, there has been no direct link made between noise exposure, cochlear neuropathy, and perceptual difficulties. Animal experiments also reveal that the aging process itself, in the absence of significant noise exposure, is associated with loss of auditory nerve fibers. Evidence from human temporal bone studies and auditory brainstem response measures suggests that this form of hidden loss is common in humans and may have perceptual consequences, in particular, regarding the coding of the temporal aspects of sounds. Hidden hearing loss is potentially a major health issue, and investigations are ongoing to identify the causes and consequences of this troubling condition.

  1. Hearing Preservation in Acoustic Neuroma Surgery

    Institute of Scientific and Technical Information of China (English)

    HAN Dongyi; YU Limei; YANG Shiming; YU Liming

    2006-01-01

    Objective To report the authors' experiences in hearing preservation during acoustic neuroma (AN)resection procedures. Methods Two cases of AN removal via retrosigmoid approach were reviewed. Hearing preservation was attempted in the aid of endoscopic technique along with continuous monitoring of the compound action potential (CAP) and auditory brainstem response(ABR) during the surgery. Results The tumor in Case 1 was 1.5 cm in diameter. The average pure-tone hearing threshold was 30 dB HL and ABR was normal. Waves Ⅰ, Ⅲ and V of ABR were present following tumor removal. At 7th month follow-up, audiometric thresholds and ABR inter-peak intervals had recovered to pre-operative levels, with normal facial nerve function. The patient in Case 2 had bilateral AN. The tumors measured 4.0 cm (left) and 5.0 cm (right) on MRI scans. The AN on the right side was removed first, followed by removal of the left AN four months later. Intraoperative CAP monitoring was employed during removal of the left AN. While efforts to preserve the cochlear nerve were not successful, CAPs were still present after tumor removal. Conclusions Intraoperatively recorded CAPs are not reliable in predicting postoperative hearing outcomes. In contrast, ABRs are an indicator of function of the peripheral auditory pathway. Presence of waves Ⅰ, Ⅲ and V following tumor removal may represent preservation of useful hearing.

  2. Measuring Hearing in Wild Beluga Whales.

    Science.gov (United States)

    Mooney, T Aran; Castellote, Manuel; Quakenbush, Lori; Hobbs, Roderick; Goertz, Caroline; Gaglione, Eric

    2016-01-01

    We measured the hearing abilities of seven wild beluga whales (Delphinapterus leucas) during a collection-and-release experiment in Bristol Bay, AK. Here we summarize the methods and initial data from one animal and discuss the implications of this experiment. Audiograms were collected from 4 to 150 kHz. The animal with the lowest threshold heard best at 80 kHz and demonstrated overall good hearing from 22 to 110 kHz. The robustness of the methodology and data suggest that the auditory evoked potential audiograms can be incorporated into future collection-and-release health assessments. Such methods may provide high-quality results for multiple animals, facilitating population-level audiograms and hearing measures in new species.

  3. Hearing Loss in Children: Types of Hearing Loss

    Science.gov (United States)

    ... is different in each ear (asymmetrical). Progressive or Sudden Hearing loss worsens over time (progressive) or happens quickly (sudden). Fluctuating or Stable Hearing loss gets either better or worse over time (fluctuating) ...

  4. Analysis of acrylonitrile, 1,3-butadiene, and related compounds in acrylonitrile-butadiene-styrene copolymers for kitchen utensils and children's toys by headspace gas chromatography/mass spectrometry.

    Science.gov (United States)

    Ohno, Hiroyuki; Kawamura, Yoko

    2010-01-01

    A headspace gas chromatography/mass spectrometry method was developed for the simultaneous determination of the residual levels of acrylonitrile (AN), 1,3-butadiene (1,3-BD), and their related compounds containing propionitrile (PN) and 4-vinyl-1-cyclohexene (4-VC) in acrylonitrile-butadiene-styrene (ABS) copolymers for kitchen utensils and children's toys. A sample was cut into small pieces, then N,N-dimethylacetamide and an internal standard were added in a sealed headspace vial. The vial was incubated for 1 h at 90 degrees C and the headspace gas was analyzed by gas chromatography/mass spectrometry. The recovery rates of the analytes were 93.3-101.8% and the coefficients of variation were 0.3-6.5%. In ABS copolymers, the levels were 0.3-50.4 microg/g for AN, ND-4.5 microg/g for PN, 0.06-1.58 microg/g for 1,3-BD, and 1.1-295 microg/g for 4-VC. The highest level was found for 4-VC, which is a dimer of 1,3-BD, and the next highest was for AN, which is one of the monomers of the ABS copolymer. Furthermore, the method was also applied to acrylonitrile-styrene (AS) copolymers and polystyrenes (PS) for kitchen utensils, and nitrile-butadiene rubber (NBR) gloves. In AS copolymers, AN and PN were detected at 16.8-54.5 and 0.8-6.9 microg/g, respectively. On the other hand, the levels in PS and NBR samples were all low.

  5. Smartphone serious games for vision and hearing assessment.

    Science.gov (United States)

    Dias, Pedro; Aguiar, Bruno; Sousa, Filipe; Sousa, Augusto

    2015-01-01

    Falls are the second leading cause of accidental injury deaths worldwide. In this paper, it is intended to define methodologies that permit the evaluation of two potential factors which might have an impact on fall risk, these are: visual and hearing loss. The aim of the work developed is not to replace clinic visits, but to offer the user the means to continue the tracking of his vision and hearing at home, during the long time intervals between clinical tests. Tests conducted in a sample of our target users indicate a good ability to measure vision and hearing using an android smartphone and the proposed methodologies. While some tests require further validation, promising results were achieved in the most common tests for vision and hearing, presenting a good correlation between the system's results when compared to the traditional tests (for distance visual acuity) and the data gathered from the users (for hearing tests).

  6. Rate-Constrained Beamforming in Binaural Hearing Aids

    Science.gov (United States)

    Srinivasan, Sriram; den Brinker, Albertus C.

    2009-12-01

    Recently, hearing aid systems where the left and right ear devices collaborate with one another have received much attention. Apart from supporting natural binaural hearing, such systems hold great potential for improving the intelligibility of speech in the presence of noise through beamforming algorithms. Binaural beamforming for hearing aids requires an exchange of microphone signals between the two devices over a wireless link. This paper studies two problems: which signal to transmit from one ear to the other, and at what bit-rate. The first problem is relevant as modern hearing aids usually contain multiple microphones, and the optimal choice for the signal to be transmitted is not obvious. The second problem is relevant as the capacity of the wireless link is limited by stringent power consumption constraints imposed by the limited battery life of hearing aids.

  7. Rate-Constrained Beamforming in Binaural Hearing Aids

    Directory of Open Access Journals (Sweden)

    Sriram Srinivasan

    2009-01-01

    Full Text Available Recently, hearing aid systems where the left and right ear devices collaborate with one another have received much attention. Apart from supporting natural binaural hearing, such systems hold great potential for improving the intelligibility of speech in the presence of noise through beamforming algorithms. Binaural beamforming for hearing aids requires an exchange of microphone signals between the two devices over a wireless link. This paper studies two problems: which signal to transmit from one ear to the other, and at what bit-rate. The first problem is relevant as modern hearing aids usually contain multiple microphones, and the optimal choice for the signal to be transmitted is not obvious. The second problem is relevant as the capacity of the wireless link is limited by stringent power consumption constraints imposed by the limited battery life of hearing aids.

  8. Idiopathic Sudden Sensorineural Hearing Loss With Minimal Hearing Impairment

    OpenAIRE

    Lee, Ho Yun; Cho, Chin Saeng

    2015-01-01

    Objectives The aim of the study was to determine the characteristics of patients who did not match the audiometric criteria of idiopathic sudden sensorineural hearing loss (SSNHL) but complained of acute hearing loss. Methods By thorough medical chart reviews, historical cohort study was performed with consecutive data of 589 patients complaining of acute unilateral sensorineural hearing loss without identifiable causes between 2005 and 2013. Those patients demonstrating a hearing loss of at ...

  9. Noise-induced hearing loss and hearing aids requirement

    OpenAIRE

    Giordano, C; Garzaro, M; Nadalin, J; Pecorari, G; Boggero, R; Argentero, P.; Albera, R.

    2008-01-01

    Subjective disturbances, due to hearing loss, are auditory disability and handicap which can be evaluated with a questionnaire. The present study refers to a population of industrial workers affected by noise-induced hearing loss. Aim of the study is to identify the minimal level of hearing loss over which the patient felt changes in his quality of life, and the average auditory threshold at which the patient considered the application of a hearing aid useful or necessary. The sample comprise...

  10. Comparative analysis of endurance of not hearing and hearing students

    Directory of Open Access Journals (Sweden)

    Iwańska Dagmara

    2013-11-01

    Full Text Available Study aim: Sport participation is important for deaf children, as participants experience physical, psychological and social benefits [23]. This study is a summary of four year’s researches on the endurance level of deaf and well hearing girls and boys. The aim of this study was to compare endurance of not hearing and hearing students.

  11. Hearing Protection and Hearing Symptoms in Danish Symphony Orchestras

    DEFF Research Database (Denmark)

    Laitinen, Heli; Poulsen, Torben

    2006-01-01

    A study about hearing protectors, problems involving hearing protector usage, hearing problems and working surroundings of classical musicians was made in three Danish symphony orchestras. The questionnaire used in the study was based on a previous study, a study made in Sweden to rock musicians,...

  12. Underwater Hearing in Turtles.

    Science.gov (United States)

    Willis, Katie L

    2016-01-01

    The hearing of turtles is poorly understood compared with the other reptiles. Although the mechanism of transduction of sound into a neural signal via hair cells has been described in detail, the rest of the auditory system is largely a black box. What is known is that turtles have higher hearing thresholds than other reptiles, with best frequencies around 500 Hz. They also have lower underwater hearing thresholds than those in air, owing to resonance of the middle ear cavity. Further studies demonstrated that all families of turtles and tortoises share a common middle ear cavity morphology, with scaling best suited to underwater hearing. This supports an aquatic origin of the group. Because turtles hear best under water, it is important to examine their vulnerability to anthropogenic noise. However, the lack of basic data makes such experiments difficult because only a few species of turtles have published audiograms. There are also almost no behavioral data available (understandable due to training difficulties). Finally, few studies show what kinds of sounds are behaviorally relevant. One notable paper revealed that the Australian snake-necked turtle (Chelodina oblonga) has a vocal repertoire in air, at the interface, and under water. Findings like these suggest that there is more to the turtle aquatic auditory scene than previously thought.

  13. How to Get Hearing Aids

    Science.gov (United States)

    ... records from your hearing healthcare professional, and may purchase your hearing aid elsewhere (ex: by mail order, ... feeds Follow FDA on Twitter Follow FDA on Facebook View FDA videos on YouTube View FDA photos ...

  14. Could Anemia Cause Hearing Loss?

    Science.gov (United States)

    ... https://medlineplus.gov/news/fullstory_162793.html Could Anemia Cause Hearing Loss? Iron deficiency might keep ear ... Hearing loss may be linked to iron deficiency anemia -- a combination of low levels of iron and ...

  15. Noise and Hearing Loss Prevention

    Science.gov (United States)

    ... message, please visit this page: About CDC.gov . NOISE AND HEARING LOSS PREVENTION Recommend on Facebook Tweet ... when hazardous noise levels cannot be adequately reduced. Noise and Hearing Loss on the NIOSH Science Blog ...

  16. Different Styles of Hearing Aids

    Science.gov (United States)

    ... Careers Certification Publications Events Advocacy Continuing Education Practice Management Research Home / Information for the Public / Hearing and Balance Different Styles of Hearing Aids In-the-Canal (ITC) and ...

  17. [Hearing disorders and rock music].

    Science.gov (United States)

    Lindhardt, Bjarne Orskov

    2008-12-15

    Only few studies have investigated the frequency of hearing disorders in rock musicians. Performing rock music is apparently associated with a hearing loss in a fraction of musicians. Tinnitus and hyperacusis are more common among rock musicians than among the background population. It seems as if some sort of resistance against further hearing loss is developed over time. The use of ear protection devices have not been studied systematically but appears to be associated with diminished hearing loss.

  18. Pre-irradiation induced emulsion co-graft polymerization of acrylonitrile and acrylic acid onto a polyethylene nonwoven fabric

    Science.gov (United States)

    Liu, Hanzhou; Yu, Ming; Ma, Hongjuan; Wang, Ziqiang; Li, Linfan; Li, Jingye

    2014-01-01

    A pre-irradiation induced emulsion co-graft polymerization method was used to introduce acrylonitrile and acrylic acid onto a PE nonwoven fabric. The use of acrylic acid is meant to improve the hydrophilicity of the modified fabric. The kinetics of co-graft polymerization were studied. The existence of polyacrylonitrile (PAN) and poly(acrylic acid) (PAAc) graft chains was proven by Fourier transform infrared spectroscopy (FTIR) analysis. The existence of the nitrile groups in the graft chains indicates that they are ready for further amidoximation and adsorption of heavy metal ions.

  19. TERMINATION AND TRANSFER OF THE CHAIN RADICALS IN THE POLYMERIZATION OF ACRYLONITRILE INITIATED BY VANADIUM(V)-THIOUREA REDOX SYSTEM

    Institute of Scientific and Technical Information of China (English)

    WU Jinyuan; YANG Chaoxiong; WU Yuxian

    1990-01-01

    The dependence of the molecular weights on the concentration of reactants in the polymerization of acrylonitrile initiated by vanadium (V)-thiourea red ox system has been investigated. It was found that the molecular weights of the polymer change nonlinearly with increasing concentrations of nitric acid and thiourea. Probably, the composition of the complexes exert a great influence on the chain initiation and termination. The reaction of "complextermination " gives rise to the decrease of the molecular weights markedly while the concentrations of thiourea and vanadium (V)in the range from one to three molar ratios.

  20. SELECTIVE SEPARATION OF WATER—ETHANOL MIXTURE THROUGH COPOLYMERIC MEMBRANES.Ⅱ.ACRYLONITRILE AND MALEIC ANHYDRIDE COPOLYMERIC MEMBRANES

    Institute of Scientific and Technical Information of China (English)

    ZHangFuyao; ZhangYifeng; 等

    1993-01-01

    Acrylonitrile(AN) and maleic anhydride(MA) copolymer has been synthesized by radical polymerization using ammonium persulfate and sodium bisulfite as initiator.The pervaporation properties of the copolymeric membranes prepared have been investigated for the first time. The dependences of pervaporation characteristics on coplymer composition,feed concentration and operating temperature have been studied.In order to improve the separation properties of the copolymeric membranes,the membranes were hydrolyzed with 10 wt% soldium hydroxide or potassium hydroxide aqueous solution.The hydrolyzed membranes containing more than 0.069MA mol fraction showed higher tensile strength and separation properties than the original membranes.

  1. Hearing aid adjustment

    DEFF Research Database (Denmark)

    Heinemann, Trine; Matthews, Ben; Raudaskoski, Pirkko Liisa

    2012-01-01

    to the interaction during hearing aid fitting. This report of a Danish pilot study describes two such problems. The first problem arises from the requirement that the audiologist needs to ‘translate’ the patient’s subjective hearing description for making technological decisions. The second problem is the way......Conversation analytic research on clinical encounters shows that interactional conduct can be consequential for diagnosis, treatment and compliance. Problems reported for doctor-patient interaction can also be identified in Danish audiological encounters. There are, however, also specific aspects...

  2. Costs of workers' compensation claims for hearing loss.

    Science.gov (United States)

    Alleyne, B C; Dufresne, R M; Kanji, N; Reesal, M R

    1989-02-01

    Much has been written about the merits, needs, adequacy, and effectiveness of hearing conservation programs but very little about the cost of noise-induced hearing loss. Using claims for hearing loss submitted to a Canadian compensation board for a 5-years period (1979 to 1983), we estimated the current cost per claim to be $14,106. We observed an annual increase of 20.4% for noise-induced hearing loss claims and project that if 80% of the 450 claims submitted in 1987 are accepted, it will commit the Workers' Compensation Board in Alberta to a cost of $5,373,360--a considerable commitment for a disease that makes up only 0.3% of all claims. As a measure of morbidity we determined the years of potential hearing loss. The 207 workers between the ages of 18 and 70 years who were pensioned had a potential hearing loss value of 2529 years. Some authors have expressed the view that hearing loss is currently inadequately compensated and our review of the literature suggests that a fertile climate is emerging for increasing litigation. This tendency is likely to lead to further escalation of costs if prevention is not taken more seriously.

  3. Unilateral hearing during development: hemispheric specificity in plastic reorganizations

    Directory of Open Access Journals (Sweden)

    Andrej eKral

    2013-11-01

    Full Text Available The present study investigates the hemispheric contributions of neuronal reorganization following early single-sided hearing (unilateral deafness. The experiments were performed on ten cats from our colony of deaf white cats. Two were identified in early hearing screening as unilaterally congenitally deaf. The remaining eight were bilaterally congenitally deaf, unilaterally implanted at different ages with a cochlear implant. Implanted animals were chronically stimulated using a single-channel portable signal processor for two to five months. Microelectrode recordings were performed at the primary auditory cortex under stimulation at the hearing and deaf ear with bilateral cochlear implants. Local field potentials (LFPs were compared at the cortex ipsilateral and contralateral to the hearing ear. The focus of the study was on the morphology and the onset latency of the LFPs. The data revealed that effects of hearing experience were more pronounced when stimulating the hearing ear. With respect to morphology of LFPs, pronounced hemisphere-specific effects were observed. Morphology of amplitude-normalized LFPs for stimulation of the deaf and the hearing ear was similar for responses recorded at the same hemisphere. However, when comparisons were performed between the hemispheres, the morphology was more dissimilar even though the same ear was stimulated. This demonstrates hemispheric specificity of some cortical adaptations irrespective of the ear stimulated. The results suggest a specific adaptation process at the hemisphere ipsilateral to the hearing ear, involving specific (down-regulated inhibitory mechanisms not found in the contralateral hemisphere. Finally, onset latencies revealed that the sensitive period for the cortex ipsilateral to the hearing ear is shorter than that for the contralateral cortex. Unilateral hearing experience leads to a functionally-asymmetric brain with different neuronal reorganizations and different sensitive

  4. Disrupted functional brain connectome in unilateral sudden sensorineural hearing loss.

    Science.gov (United States)

    Xu, Haibo; Fan, Wenliang; Zhao, Xueyan; Li, Jing; Zhang, Wenjuan; Lei, Ping; Liu, Yuan; Wang, Haha; Cheng, Huamao; Shi, Hong

    2016-05-01

    Sudden sensorineural hearing loss (SSNHL) is generally defined as sensorineural hearing loss of 30 dB or greater over at least three contiguous audiometric frequencies and within a three-day period. This hearing loss is usually unilateral and can be associated with tinnitus and vertigo. The pathogenesis of unilateral sudden sensorineural hearing loss is still unknown, and the alterations in the functional connectivity are suspected to involve one possible pathogenesis. Despite scarce findings with respect to alterations in brain functional networks in unilateral sudden sensorineural hearing loss, the alterations of the whole brain functional connectome and whether these alterations were already in existence in the acute period remains unknown. The aim of this study was to investigate the alterations of brain functional connectome in two large samples of unilateral sudden sensorineural hearing loss patients and to investigate the correlation between unilateral sudden sensorineural hearing loss characteristics and changes in the functional network properties. Pure tone audiometry was performed to assess hearing ability. Abnormal changes in the peripheral auditory system were examined using conventional magnetic resonance imaging. The graph theoretical network analysis method was used to detect brain connectome alterations in unilateral sudden sensorineural hearing loss. Compared with the control groups, both groups of unilateral SSNHL patients exhibited a significantly increased clustering coefficient, global efficiency, and local efficiency but a significantly decreased characteristic path length. In addition, the primary increased nodal strength (e.g., nodal betweenness, hubs) was observed in several regions primarily, including the limbic and paralimbic systems, and in the auditory network brain areas. These findings suggest that the alteration of network organization already exists in unilateral sudden sensorineural hearing loss patients within the acute period

  5. EHDI Africa: advocating for infants with hearing loss in Africa.

    Science.gov (United States)

    Swanepoel, DeWet; Störbeck, Claudine

    2008-01-01

    Children with hearing loss who happen to reside in Africa deserve the chance to develop according to their potential as much as their peers living in more affluent regions. This leaves a moral obligation to pursue ways of initiating, developing,and growing early hearing detection and intervention services in Africa. For these reasons, the first EHDI Africa international conference was held in Johannesburg, South Africa, in 2007 (13-14 August). The theme was 'Building bridges in Africa: Early childhood development for children with hearing loss'. This special issue contains several reports from the EHDI Africa conference.

  6. Hearing Loss: Diagnosis and Evaluation.

    Science.gov (United States)

    Zazove, Philip; Atcherson, Samuel R; Moreland, Christopher; McKee, Michael M

    2015-07-01

    Hearing loss is a common disability in the United States, most frequent among men, elderly individuals, and veterans but is increasingly affecting other younger adults. Types of hearing loss include sensorineural, conductive, and mixed. Hearing loss in children often is related to infections, time spent in a neonatal intensive care unit, and genetic etiologies. Presbycusis (ie, age-related hearing loss) is the most common etiology in adults. Adverse effects of untreated hearing loss include isolation, depression, lower income, and higher unemployment. Hearing aid use reduces levels of disability, cognitive impairment, and psychosocial distress while improving quality of life. At least 75% of individuals with hearing loss are not receiving treatment for it. All infants should be screened for hearing loss, as should children and adults with risk factors. The Joint Commission on Infant Hearing Screening has a 1-3-6 goal for screening: identification by age 1 month, confirmation by age 3 months, and intervention by age 6 months. The presence of an ongoing physician-patient relationship increases the likelihood that a patient will admit to having a hearing loss. Adults can be screened using single-question or standardized instrument screens. All patients with suspected hearing loss should undergo audiometry by an audiology subspecialist.

  7. Fabrication of Acrylonitrile-Butadiene-Styrene Nanostructures with Anodic Alumina Oxide Templates, Characterization and Biofilm Development Test for Staphylococcus epidermidis.

    Directory of Open Access Journals (Sweden)

    Camille Desrousseaux

    Full Text Available Medical devices can be contaminated by microbial biofilm which causes nosocomial infections. One of the strategies for the prevention of such microbial adhesion is to modify the biomaterials by creating micro or nanofeatures on their surface. This study aimed (1 to nanostructure acrylonitrile-butadiene-styrene (ABS, a polymer composing connectors in perfusion devices, using Anodic Alumina Oxide templates, and to control the reproducibility of this process; (2 to characterize the physico-chemical properties of the nanostructured surfaces such as wettability using captive-bubble contact angle measurement technique; (3 to test the impact of nanostructures on Staphylococcus epidermidis biofilm development. Fabrication of Anodic Alumina Oxide molds was realized by double anodization in oxalic acid. This process was reproducible. The obtained molds present hexagonally arranged 50 nm diameter pores, with a 100 nm interpore distance and a length of 100 nm. Acrylonitrile-butadiene-styrene nanostructures were successfully prepared using a polymer solution and two melt wetting methods. For all methods, the nanopicots were obtained but inside each sample their length was different. One method was selected essentially for industrial purposes and for better reproducibility results. The flat ABS surface presents a slightly hydrophilic character, which remains roughly unchanged after nanostructuration, the increasing apparent wettability observed in that case being explained by roughness effects. Also, the nanostructuration of the polymer surface does not induce any significant effect on Staphylococcus epidermidis adhesion.

  8. Fire and Gas Barrier Properties of Poly(styrene-co-acrylonitrile Nanocomposites Using Polycaprolactone/Clay Nanohybrid Based-Masterbatch

    Directory of Open Access Journals (Sweden)

    S. Benali

    2008-01-01

    Full Text Available Exfoliated nanocomposites are prepared by dispersion of poly(ε-caprolactone (PCL grafted montmorillonite nanohybrids used as masterbatches in poly(styrene-co-acrylonitrile (SAN. The PCL-grafted clay nanohybrids with high inorganic content are synthesized by in situ intercalative ring-opening polymerization of ε-caprolactone between silicate layers organomodified by alkylammonium cations bearing two hydroxyl functions. The polymerization is initiated by tin alcoholate species derived from the exchange reaction of tin(II bis(2-ethylhexanoate with the hydroxyl groups borne by the ammonium cations that organomodified the clay. These highly filled PCL nanocomposites (25 wt% in inorganics are dispersed as masterbatches in commercial poly(styrene-co-acrylonitrile by melt blending. SAN-based nanocomposites containing 3 wt% of inorganics are accordingly prepared. The direct blend of SAN/organomodified clay is also prepared for sake of comparison. The clay dispersion is characterized by wide-angle X-ray diffraction (WAXD, atomic force microscopy (AFM, and solid state NMR spectroscopy measurements. The thermal properties are studied by thermogravimetric analysis. The flame retardancy and gas barrier resistance properties of nanocomposites are discussed both as a function of the clay dispersion and of the matrix/clay interaction.

  9. Sensorineural hearing loss in children.

    LENUS (Irish Health Repository)

    Wormald, R

    2010-02-01

    The objective of the study was to examine the aetiology of sensorineural hearing loss (SNHL) in a paediatric population presenting to the National Centre of Medical Genetics. A retrospective chart review from 1998 to 2006. One hundred and twenty nine children were investigated for SNHL. The average age of diagnosis of hearing loss was 36 months. The degree of hearing loss was mild in 8 children, moderate in 33 children, severe in 31 children and profound in 57 children. Eighty-five children (66%) were diagnosed with a hereditary hearing loss, 11 (8%) children had an acquired hearing loss and no cause found in 33 (26%) children. This is the first report of the causes of hearing loss in Irish children. The mean age of diagnosis in our cohort is high and emphasises the need for a neonatal screening programme. There remains a number of children for whom the cause of hearing loss remains unknown.

  10. OI Issues: Hearing Loss

    Science.gov (United States)

    Hearing Loss and Osteogenesis Imperfecta 804 W. Diamond Ave., Ste. 210 Gaithersburg, MD 20878 (800) 981-2663 (301) 947-0083 Fax: (301) 947-0456 ... www.oif.org Email: bonelink@oif.org The Osteogenesis Imperfecta Foundation, Inc. is the only voluntary national health ...

  11. Parent Hearing Aid Experiences

    Science.gov (United States)

    Munoz, Karen; Roberts, Mallory; Mullings, Day; Harward, Richard

    2012-01-01

    This study addresses parent experiences in obtaining and managing hearing aids for their young child. The purpose was to identify challenges parents encounter to determine what state agencies can do to improve parent access to amplification. Data were collected July through September of 2010; 40 parents of children ages birth to 3 years old…

  12. Occupational hearing loss

    Science.gov (United States)

    ... jobs. Causes Over time, repeated exposure to loud noise and music can cause hearing loss. Watch this video about: ... Airline ground maintenance Construction Farming Jobs involving loud music or machinery Military jobs that involve combat, aircraft noise, or other loud noise posts In the United ...

  13. Sudden Hearing Loss.

    Science.gov (United States)

    Vaughan, John C.

    1997-01-01

    Patients with a sudden dramatic decline in hearing usually require rapid diagnosis and treatment. Unfortunately, the treatment of this condition continues to be controversial and an exact etiology in most cases has been inconclusive. Nevertheless, physicians have reached a consensus regarding several broad principles, which are presented in this…

  14. NATIONAL HEARING DAY

    CERN Multimedia

    2003-01-01

    The 12th of June 2003 Is the French National Hearing Day. The Medical Service invites everyone working at CERN to come and have an ear test at the infirmary. Bld. 57, ground floor, between 9h00 and 16h00 Tel. 73802

  15. National hearing day

    CERN Multimedia

    2003-01-01

    The 12th of June 2003 Is the French National Hearing Day. The Medical Service invites everyone working at CERN to come and have an ear test at the infirmary. Bld. 57, ground floor, between 9h00 and 16h00 Tel. 73802

  16. Speech and Hearing Therapy.

    Science.gov (United States)

    Sakata, Reiko; Sakata, Robert

    1978-01-01

    In the public school, the speech and hearing therapist attempts to foster child growth and development through the provision of services basic to awareness of self and others, management of personal and social interactions, and development of strategies for coping with the handicap. (MM)

  17. Potencial evocado auditivo de longa latência para estímulo de fala apresentado com diferentes transdutores em crianças ouvintes Late auditory evoked potentials to speech stimuli presented with different transducers in hearing children

    Directory of Open Access Journals (Sweden)

    Raquel Sampaio Agostinho-Pesse

    2013-01-01

    Full Text Available OBJETIVO: analisar, de forma comparativa, a influência do transdutor no registro dos componentes P1, N1 e P2 eliciados por estímulo de fala, quanto à latência e à amplitude, em crianças ouvintes. MÉTODO: 30 crianças ouvintes de quatro a 12 anos de idade, de ambos os sexos. Os potenciais evocados auditivos de longa latência foram pesquisados por meio dos transdutores, fone de inserção e caixa acústica, eliciados por estímulo de fala /da/, sendo o intervalo interestímulos de 526ms, a intensidade de 70dBNA e a taxa de apresentação de 1,9 estímulos por segundo. Foram analisados os componentes P1, N1 e P2 quando presentes, quanto à latência e à amplitude. RESULTADOS: constatou-se um nível de concordância forte entre a pesquisadora e o juiz. Não houve diferença estatisticamente significante ao comparar os valores de latência e amplitude dos componentes P1, N1 e P2, ao considerar sexo e orelha, assim como para a latência dos componentes quando analisado os tipos de transdutores. Entretanto, houve diferença estatisticamente significante para a amplitude dos componentes P1 e N1, com maior amplitude para o transdutor caixa acústica. CONCLUSÃO: os valores de latência dos componentes P1, N1 e P2 e amplitude de P2 obtidos com fone de inserção podem ser utilizados como referência de normalidade independente do transdutor utilizado para a pesquisa dos potenciais evocados auditivos de longa latência.PURPOSE: to analyze, in a comparative manner, the influence of the transducer on the recordings of P1, N1 and P2components elicited through speech stimulus, as to the latency and amplitude in hearing children. METHOD: the sample was comprised of 30 hearing children aged 4-12 yrs, both genders. The long latency auditory evoked potentials were researched by means of transducers, insertion phone and speakers, elicited through speech stimulus /da/ presented with interstimuli interval of 526ms, the intensity of 70dBNA and presentation

  18. EFFECT OF AMPHIPHILIC POLY (STYRENE-B-ETHYLENE OXIDE) DIBLOCK COPOLYMER INTERCALATED LAYERED SILICATE AS FILLER ON ACRYLONITRILE-BUTADIENE-STYRENE RESIN

    Institute of Scientific and Technical Information of China (English)

    Guo Tianying; Zhang Jie; Hao Guangjie; Song Moudao; Zhang Banghua

    2003-01-01

    The diblock copolymers intercalated layered silicate was prepared via a melt dispersion technique. Then the effect of intercalated hybrid as filler on acrylonitrile- butadiene-styrene resin was characterized by X-ray diffraction, transmission electron microscopy, stress-strain measurements in elongation.

  19. A COMPARISON BETWEEN THE MORPHOLOGY OF SEMICRYSTALLINE POLYMER BLENDS OF POLY(EPSILON-CAPROLACTONE)/POLY(VINYL METHYL-ETHER) AND POLY(EPSILON-CAPROLACTONE)/(STYRENE-ACRYLONITRILE)

    NARCIS (Netherlands)

    OUDHUIS, AACM; THIEWES, HJ; VANHUTTEN, PF; TENBRINKE, G

    1994-01-01

    The morphology of polymer blends of poly(epsilon-caprolactone) (PCL) and poly(vinyl methyl ether) (PVME) is compared with that of PCL and a random copolymer of styrene and acrylonitrile (SAN). The main objective is to determine the influence of the glass transition temperature of the amorphous compo

  20. Oral steroid treatment for idiopathic sudden sensorineural hearing loss

    OpenAIRE

    Chen, Wei T.; Lee, Jui W.; Yuan, Chien H.; Chen, Rong F.

    2015-01-01

    Objectives: To describe the efficacy of long-term oral steroids in idiopathic sudden sensorineural hearing loss (ISSHL), and to explore potential prognosis factors, the relationship of hearing recovery outcome, and the recovery time-course in ISSHL. Methods: In this retrospective study, we analyzed 215 cases diagnosed with idiopathic unilateral sudden deafness between January 2003 and December 2012 at a regional hospital in southern Taiwan. All of them received oral steroid therapy and were f...

  1. A Taxonomy of Fatigue Concepts and Their Relation to Hearing Loss.

    Science.gov (United States)

    Hornsby, Benjamin W Y; Naylor, Graham; Bess, Fred H

    2016-01-01

    Fatigue is common in individuals with a variety of chronic health conditions and can have significant negative effects on quality of life. Although limited in scope, recent work suggests persons with hearing loss may be at increased risk for fatigue, in part due to effortful listening that is exacerbated by their hearing impairment. However, the mechanisms responsible for hearing loss-related fatigue, and the efficacy of audiologic interventions for reducing fatigue, remain unclear. To improve our understanding of hearing loss-related fatigue, as a field it is important to develop a common conceptual understanding of this construct. In this article, the broader fatigue literature is reviewed to identify and describe core constructs, consequences, and methods for assessing fatigue and related constructs. Finally, the current knowledge linking hearing loss and fatigue is described and may be summarized as follows: Hearing impairment may increase the risk of subjective fatigue and vigor deficits; adults with hearing loss require more time to recover from fatigue after work and have more work absences; sustained, effortful, listening can be fatiguing; optimal methods for eliciting and measuring fatigue in persons with hearing loss remain unclear and may vary with listening condition; and amplification may minimize decrements in cognitive processing speed during sustained effortful listening. Future research is needed to develop reliable measurement methods to quantify hearing loss-related fatigue, explore factors responsible for modulating fatigue in people with hearing loss, and identify and evaluate potential interventions for reducing hearing loss-related fatigue.

  2. Accurate quantification of the mercapturic acids of acrylonitrile and its genotoxic metabolite cyanoethylene-epoxide in human urine by isotope-dilution LC-ESI/MS/MS.

    Science.gov (United States)

    Schettgen, T; Bertram, J; Kraus, T

    2012-08-30

    Acrylonitrile is a highly important industrial chemical with a high production volume worldwide, especially in the plastics industry. It is classified as a possible human carcinogen by the International Agency for Research on Cancer (IARC group 2B). During metabolism of acrylonitrile, the genotoxic metabolite cyanoethylene-epoxide is formed. The urinary mercapturic acids of acrylonitrile, namely N-acetyl-S-(2-cyanoethyl)-L-cysteine (CEMA) and cyanoethylene-epoxide, namely N-acetyl-S-(1-cyano-2-hydroxyethyl)-L-cysteine (CHEMA) are specific biomarkers for the determination of individual internal exposure to acrylonitrile and its highly reactive metabolite. We have developed and validated a sensitive method for the accurate determination of CEMA and CHEMA in human urine with a multidimensional LC/MS/MS-method using deuterium-labelled analogues for both analytes as internal standards. Analytes were stripped from urinary matrix by online extraction on a restricted access material, transferred to the analytical column and determined by tandem mass spectrometry. The limit of quantification (LOQ) for CEMA and CHEMA was 1 μg/L urine and allowed to quantify the background exposure of the (smoking) general population. Precision within and between series for CHEMA ranged from 2.6 to 8.0% at four concentrations ranging from 8.3 to 86 μg/L urine, mean accuracy was between 94 and 100%. For CEMA, precision within and between series ranged from 2.4 to 14.5% at four concentrations ranging from 15.1 to 196 μg/L urine, mean accuracy was between 91 and 104%. We applied the method to spot urine samples of 83 subjects of the general population with no known occupational exposure to acrylonitrile. Median levels (range) for CEMA and CHEMA in urine samples of non-smokers (n=47) were 1.9 μg/L (<1-16.4 μg/L) and<1 μg/L (<1-3 μg/L), while in urine samples of smokers (n=36), median levels were 184 μg/L (2-907 μg/L) and 29.3 μg/L (<1-147 μg/L), respectively. Smokers showed a

  3. Pediatric Sudden Sensorineural Hearing Loss.

    Science.gov (United States)

    Kizilay, Ahmet; Koca, Çiğdem Firat

    2016-06-01

    Sudden sensorineural hearing loss is defined as sudden unilateral or bilateral sensorineural hearing loss with at least 30 dB decrease in threshold in 3 contiguous test frequencies occurring over 72 hours or less. It is rare among children. The mechanism of the process and prognosis of the disorder remains unclear. The current incidence of sudden sensorineural hearing loss among pediatric population is unknown. The authors carried out a retrospective chart analysis of patients under 15 years of age from 2004 to 2015, who consulted to the Otolaryngology Head and Neck Surgery Department of Inonu University Medical Faculty. Age, sex, number of affected ear and side, audiometric evaluations, medical follow-up, treatment method, duration of treatment recovery, associated complaints; tinnitus and/or vertigo, presence of mumps disease were recorded for each patient. A 4-frequency pure-tone average (500, 1000, 2000, and 4000 Hz) was calculated for each ear. Complete recovery, defined as some hearing level compared with the nonaffected ear, was observed in 3 patients (21.4 %) and there was no partial hearing recovery. The hearing loss of 11 patient remained unchanged after prednisolone treatment. Two of the 11 patients had bilaterally total sensorineural hearing loss and evaluated as appropriate for cochlear implantation. Sex of patient and laterality of hearing loss were not correlated with hearing recovery. Sensorineural hearing loss among pediatrics has been the issue of otolaryngologists. The incidence, etiology, and treatment methods should be more studied.

  4. Microwave absorption properties of lightweight absorber based on Fe{sub 50}Ni{sub 50}-coated poly(acrylonitrile) microspheres and reduced graphene oxide composites

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Bin [School of Material Science And Engineering, Wuhan University of Technology, Wuhan 430070 (China); Wang, Jun, E-mail: wgdfrp@whut.edu.cn [School of Material Science And Engineering, Wuhan University of Technology, Wuhan 430070 (China); Wang, Junpeng; Huo, Siqi [School of Material Science And Engineering, Wuhan University of Technology, Wuhan 430070 (China); Zhang, Bin [School of Science, Wuhan University of Technology, Wuhan 430070 (China); Tang, Yushan [School of Material Science And Engineering, Wuhan University of Technology, Wuhan 430070 (China)

    2016-09-01

    In this paper, we proposed a facile method to obtain the lightweight composites consisting of surface modified Fe{sub 50}Ni{sub 50}-coated poly(acrylonitrile) microspheres (PANS@SMF), reduced graphene oxide (RGO) and epoxy resin. The as-prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), vibrating sample magnetometry (VSM) and vector network analyzer (VNA). Impedance matching condition and electromagnetic wave attenuation characteristic were used for the reflection loss (RL) performance of the composites. Compared with pure PANS@SMF and RGO composites, the −10 dB absorption bandwidth and the minimum RL of the hybrid composites were enhanced. The bandwidth less than −10 dB was almost 4.5 GHz in the range of 10 GHz to 14.5 GHz, with a matching thickness of 2.5 mm. The density of the hybrid composites was in the range of 0.25–0.34 g/cm{sup 3}. Therefore, the hybrid composite can be considered as a potential lightweight microwave absorber. - Highlights: • PANS@SMF – RGO epoxy composite was fabricated by a facile method. • The absorption bandwidth less than −10 dB can reach up to 4.5 GHz with layer thickness of 2.5 mm. • The density of the composites is in the range of 0.25–0.34 g/cm{sup 3} and can be considered as a lightweight microwave absorber.

  5. Improvement in the etching performance of the acrylonitrile-butadiene-styrene resin by MnO2-H3PO4-H2SO4 colloid.

    Science.gov (United States)

    Zhao, Wenxia; Ding, Jie; Wang, Zenglin

    2013-05-21

    The present study aimed to evaluate the surface etching of the acrylonitrile-butadiene-styrene (ABS) resin in the MnO2-H3PO4-H2SO4 colloid. To enhance the soluble Mn(IV) ion concentration and improve the etching performance of ABS resin, H3PO4 was added as a complexing agent into the MnO2-H2SO4 etching system. The effects of the H2SO4 concentration and etching time on the surface topography, surface roughness, adhesion strength, and the surface chemistry of the ABS substrates were investigated. The optimal oxidation potentials of MnO2 in the colloids decreased from 1.426 to 1.369 V with the addition of H3PO4. Though the etching conditions changed from 70 °C for 20 min to 60 °C for 10 min, the adhesion strength between the ABS substrates and electroless copper film increased from 1.19 to 1.33 KN/m after etching treatment. This could be attributed to the significant increase of the soluble Mn(IV) ion concentration in the MnO2-H3PO4-H2SO4 colloid. The surface chemistry results demonstrated that the oxidation reaction of -C═C- bonds in the polybutadiene phase was accelerated in the etching process by the addition of H3PO4, and the abundant -COOH and -OH groups were formed rapidly on the ABS surface with the etching treatment. These results were in agreement with the results of surface scanning electron microscopic observations and adhesion strength measurement. The results suggested that the MnO2-H3PO4-H2SO4 colloid was an effective surface etching system for the ABS surface roughness.

  6. Single-sided deafness & directional hearing: contribution of spectral cues and high-frequency hearing loss in the hearing ear

    Directory of Open Access Journals (Sweden)

    Martijn Johannes Hermanus Agterberg

    2014-07-01

    Full Text Available Direction-specific interactions of sound waves with the head, torso and pinna provide unique spectral-shape cues that are used for the localization of sounds in the vertical plane, whereas horizontal sound localization is based primarily on the processing of binaural acoustic differences in arrival time (interaural time differences, or ITDs and sound level (interaural level differences, or ILDs. Because the binaural sound-localization cues are absent in listeners with total single-sided deafness (SSD, their ability to localize sound is heavily impaired. However, some studies have reported that SSD listeners are able, to some extent, to localize sound sources in azimuth, although the underlying mechanisms used for localization are unclear. To investigate whether SSD listeners rely on monaural pinna-induced spectral-shape cues of their hearing ear for directional hearing, we investigated localization performance for low-pass filtered (LP, 3 kHz and broadband (BB, 0.5 – 20 kHz noises in the two-dimensional frontal hemifield. We tested whether localization performance of SSD listeners further deteriorated when the pinna cavities of their hearing ear were filled with a mold that disrupted their spectral-shape cues. To remove the potential use of perceived sound level as an invalid azimuth cue, we randomly varied stimulus presentation levels over a broad range (45-65 dB SPL. Several listeners with SSD could localize HP and BB sound sources in the horizontal plane, but inter-subject variability was considerable. Localization performance of these listeners strongly reduced after diminishing of their spectral pinna-cues. We further show that inter-subject variability of SSD can be explained to a large extent by the severity of high-frequency hearing loss in their hearing ear.

  7. Diclofenac induced sudden sensorineural hearing loss

    Directory of Open Access Journals (Sweden)

    M Bhanukumar

    2015-07-01

    Full Text Available A few cases of mild to moderate, gradual and reversible sensorineural hearing loss (SNHL with prolonged doses of nonsteroidal anti-inflammatory drugs has been reported. We present a case of sudden irreversible SNHL in a 60-year-old female after taking a single dose of diclofenac. The patient was a known case of diabetes mellitus and hypertension and was on regular treatment. We postulate that the patient's hearing loss was the result of diclofenac's ototoxic effects which may have been potentiated as a result of her long standing diabetes, hypertension and old age. Accordingly, we recommend the cautious use of diclofenac in patients with underlying diseases where diclofenac induced ototoxicity could potentially result in adverse otologic consequences.

  8. The Accuracy of IOS Device-based uHear as a Screening Tool for Hearing Loss: A Preliminary Study From the Middle East

    Directory of Open Access Journals (Sweden)

    Rashid Al-Abri

    2016-03-01

    Full Text Available Objectives: To determine and explore the potential use of uHear as a screening test for determining hearing disability by evaluating its accuracy in a clinical setting and a soundproof booth when compared to the gold standard conventional audiometry.   Methods: Seventy Sultan Qaboos University students above the age of 17 years who had normal hearing were recruited for the study. They underwent a hearing test using conventional audiometry in a soundproof room, a self-administered uHear evaluation in a side room resembling a clinic setting, and a self-administered uHear test in a soundproof booth. The mean pure tone average (PTA of thresholds at 500, 1000, 2000 and 4000 Hz for all the three test modalities was calculated, compared, and analyzed statistically.   Results: There were 36 male and 34 female students in the study. The PTA with conventional audiometry ranged from 1 to 21 dB across left and right ears. The PTA using uHear in the side room for the same participants was 25 dB in the right ear and 28 dB in the left ear (3–54 dB across all ears. The PTA for uHear in the soundproof booth was 18 dB and 17 dB (1–43 dB in the right and left ears, respectively. Twenty-three percent of participants were reported to have a mild hearing impairment (PTA > 25 dB using the soundproof uHear test, and this number was 64% for the same test in the side room. For the same group, only 3% of participants were reported to have a moderate hearing impairment (PTA > 40 dB using the uHear test in a soundproof booth, and 13% in the side room.   Conclusion: uHear in any setting lacks specificity in the range of normal hearing and is highly unreliable in giving the exact hearing threshold in clinical settings. However, there is a potential for the use of uHear if it is used to rule out moderate hearing loss, even in a clinical setting, as exemplified by our study. This method needs standardization through further research.

  9. Risk factors for hearing impairment among adults with diabetes: The Hispanic Community Health Study/Study of Latinos (HCHS/SOL

    Directory of Open Access Journals (Sweden)

    Kathleen E. Bainbridge

    2016-12-01

    Conclusions: Current smoking, alcohol consumption, high triglycerides, and chronic kidney disease are potentially preventable correlates of hearing impairment for persons with diabetes. Low income is a marker of increased likelihood of hearing impairment.

  10. Hearing Loss in Patients with Shunt-Treated Hydrocephalus.

    Science.gov (United States)

    Panova, Margarita V; Geneva, Ina E; Madjarova, Kalina I; Bosheva, Miroslava N

    2015-01-01

    Hearing loss is a common manifestation of the long-term complications in patients with shunt treated hydrocephalus along with motor development disturbance, cognitive and visual impairment, epilepsy and endocrine disorders. The aim of the present study was to investigate the alterations of hearing in patients with shunt treated hydrocephalus of non-tumor etiology and at least one year after implantation of ventriculo-peritoneal shunt, as well as their impact on the quality of life of patients. The study included 70 patients (age range 1.25 years - 21.25 years) with shunted non-tumor hydrocephalus and at least one year after placement of the shunt system. Hearing alterations were proved by measuring the brainstem auditory evoked potentials (BAEP) for children up to 5 years of age and children with mental retardation; audiograms was used for children older than 5 years with normal neuro-psychological development (NPD). Of the 70 studied patients 17 (24%) had hearing loss (10 bilateral and 7-unilateral) and all of them had sensorineural hearing loss, which is associated with low weight at birth, posthemorrhagic hydrocephalus and brainstem symptoms at the time of diagnosis of hydrocephalus. Hearing pathology was found more often in shunt-treated patients with NPD retardation, poor functional status and low quality of life. Children with shunt-treated hydrocephalus have hearing loss of sensorineural type. Children with brain stem symptomatology at diagnosing hydrocephalus and children with post-hemorrhagic hydrocephalus show higher risk of hearing loss. Children with shunted hydrocephalus and hearing loss show lower NPD, lower quality of life and lower functional status.

  11. Cortical Electrophysiological Markers of Language Abilities in Children with Hearing Aids: A Pilot Study

    OpenAIRE

    2014-01-01

    Objective. To investigate cortical auditory evoked potentials (CAEPs) in pediatric hearing aid (HA) users, with and without language impairment. Design. CAEPs were measured in 11 pediatric HA users (age: 8–12 years) with moderate bilateral sensorineural hearing loss (HL); participants were classified according to language ability. CAEPs were also measured for a control group of 11 age-matched, normal-hearing (NH) children. Results. HL children without language impairment exhibited normal CAEP...

  12. Unilateral and Mild Bilateral Hearing Loss in Children: Past and Current Perspectives

    OpenAIRE

    2008-01-01

    Since the early 1980s, audiologists have become increasingly aware of the potential effect of even mild degrees of hearing loss on the psychoeducational and psychosocial outcomes of children. This review describes some of the key research findings during the past several decades that have led us to our current thinking about unilateral and mild bilateral hearing loss in children. The first section addresses unilateral hearing loss. This is followed by a review of the literature on mild bilate...

  13. Hereditary hearing loss: from human mutation to mechanism.

    Science.gov (United States)

    Lenz, Danielle R; Avraham, Karen B

    2011-11-01

    The genetic heterogeneity of hereditary hearing loss is thus far represented by hundreds of genes encoding a large variety of proteins. Mutations in these genes have been discovered for patients with different modes of inheritance and types of hearing loss, ranging from syndromic to non-syndromic and mild to profound. In many cases, the mechanisms whereby the mutations lead to hearing loss have been partly elucidated using cell culture systems and mouse and other animal models. The discovery of the genes has completely changed the practice of genetic counseling in this area, providing potential diagnosis in many cases that can be coupled with clinical phenotypes and offer predictive information for families. In this review we provide three examples of gene discovery in families with hereditary hearing loss, all associated with elucidation of some of the mechanisms leading to hair cell degeneration and pathology of deafness.

  14. Is Hearing Impairment Associated with Rheumatoid Arthritis?

    DEFF Research Database (Denmark)

    Emamifar, Amir; Bjoerndal, Kristine; Jensen Hansen, Inger Marie

    2016-01-01

    and ComDisDome to cover all relative reports. The following keywords were used: hearing loss, hearing difficulties, hearing disorders, hearing impairment, sensorineural hearing loss, conductive hearing loss, mixed hearing loss, autoimmune hearing loss, drug ototoxicity, drug-induced hearing loss, hearing......BACKGROUND: Rheumatoid arthritis (RA) is a systemic, inflammatory disease that affects 1% of the population. The auditory system may be involved during the course of disease; however the association of RA and hearing impairment has not been clearly defined. OBJECTIVE: The objective of this review...... is to evaluate published clinical reports related to hearing impairment in patients with RA. Furthermore, we discuss possible pathologies and associated factors as well as new treatment modalities. METHOD: A thorough literature search was performed using available databases including Pubmed, Embase, Cochrane...

  15. Hearing Loss in Children: Screening and Diagnosis

    Science.gov (United States)

    ... Form Controls NCBDDD Cancel Submit Search The CDC Hearing Loss in Children Note: Javascript is disabled or is ... message, please visit this page: About CDC.gov . Hearing Loss Homepage Facts Noise-Induced Hearing Loss Genetics of ...

  16. 7 CFR 273.15 - Fair hearings.

    Science.gov (United States)

    2010-01-01

    ..., notification of the hearing decision will be required within 70 days from the date of the request for a hearing... migrant farmworkers, that plan to move from the jurisdiction of the hearing official before the...

  17. Hearing Loss in Children: Data and Statistics

    Science.gov (United States)

    ... visit this page: About CDC.gov . Hearing Loss Homepage Facts Noise-Induced Hearing Loss Genetics of Hearing ... children CDC's Third National Health and Nutrition Examination Survey (NHANES III), 1988 - 1994 [ Read article ] 6-19 ...

  18. Long-term asymmetric hearing affects cochlear implantation outcomes differently in adults with pre- and postlingual hearing loss.

    Science.gov (United States)

    Boisvert, Isabelle; McMahon, Catherine M; Dowell, Richard C; Lyxell, Björn

    2015-01-01

    In many countries, a single cochlear implant is offered as a treatment for a bilateral hearing loss. In cases where there is asymmetry in the amount of sound deprivation between the ears, there is a dilemma in choosing which ear should be implanted. In many clinics, the choice of ear has been guided by an assumption that the reorganisation of the auditory pathways caused by longer duration of deafness in one ear is associated with poorer implantation outcomes for that ear. This assumption, however, is mainly derived from studies of early childhood deafness. This study compared outcomes following implantation of the better or poorer ear in cases of long-term hearing asymmetries. Audiological records of 146 adults with bilateral hearing loss using a single hearing aid were reviewed. The unaided ear had 15 to 72 years of unaided severe to profound hearing loss before unilateral cochlear implantation. 98 received the implant in their long-term sound-deprived ear. A multiple regression analysis was conducted to assess the relative contribution of potential predictors to speech recognition performance after implantation. Duration of bilateral significant hearing loss and the presence of a prelingual hearing loss explained the majority of variance in speech recognition performance following cochlear implantation. For participants with postlingual hearing loss, similar outcomes were obtained by implanting either ear. With prelingual hearing loss, poorer outcomes were obtained when implanting the long-term sound-deprived ear, but the duration of the sound deprivation in the implanted ear did not reliably predict outcomes. Contrary to an apparent clinical consensus, duration of sound deprivation in one ear has limited value in predicting speech recognition outcomes of cochlear implantation in that ear. Outcomes of cochlear implantation are more closely related to the period of time for which the brain is deprived of auditory stimulation from both ears.

  19. Hearing loss: diagnosis and management.

    Science.gov (United States)

    Lasak, John M; Allen, Patrick; McVay, Tim; Lewis, Douglas

    2014-03-01

    Hearing loss may affect all age groups from the newborn to the elderly, impacting speech and language development in children and causing social and vocational problems for adults. Hearing loss can arise from anywhere in the auditory circuit including the external auditory canal, sound conduction mechanism, cochlea, cochlear nerve, and central auditory pathways. Rehabilitation options exist for all types of hearing loss, regardless of cause or location within the auditory system. Awareness of symptoms, signs, and rehabilitative measures aids primary care physicians in early identification and treatment of hearing loss.

  20. Middle Ear Infection (Chronic Otitis Media) and Hearing Loss

    Science.gov (United States)

    ... You Middle Ear Infection (Chronic Otitis Media) and Hearing Loss Middle Ear Infection (Chronic Otitis Media) and Hearing ... learning important speech and language skills. Types of hearing loss Conductive hearing loss is a form of hearing ...

  1. The application of genome editing in studying hearing loss.

    Science.gov (United States)

    Zou, Bing; Mittal, Rahul; Grati, M'hamed; Lu, Zhongmin; Shu, Yilai; Tao, Yong; Feng, Youg; Xie, Dinghua; Kong, Weijia; Yang, Shiming; Chen, Zheng-Yi; Liu, Xuezhong

    2015-09-01

    Targeted genome editing mediated by clustered, regularly interspaced, short palindromic repeat (CRISPR)/CRISPR-associated nuclease 9 (Cas9) technology has emerged as one of the most powerful tools to study gene functions, and with potential to treat genetic disorders. Hearing loss is one of the most common sensory disorders, affecting approximately 1 in 500 newborns with no treatment. Mutations of inner ear genes contribute to the largest portion of genetic deafness. The simplicity and robustness of CRISPR/Cas9-directed genome editing in human cells and model organisms such as zebrafish, mice and primates make it a promising technology in hearing research. With CRISPR/Cas9 technology, functions of inner ear genes can be studied efficiently by the disruption of normal gene alleles through non-homologous-end-joining (NHEJ) mechanism. For genetic hearing loss, CRISPR/Cas9 has potential to repair gene mutations by homology-directed-repair (HDR) or to disrupt dominant mutations by NHEJ, which could restore hearing. Our recent work has shown CRISPR/Cas9-mediated genome editing can be efficiently performed in the mammalian inner ear in vivo. Thus, application of CRISPR/Cas9 in hearing research will open up new avenues for understanding the pathology of genetic hearing loss and provide new routes in the development of treatment to restore hearing. In this review, we describe major methodologies currently used for genome editing. We will highlight applications of these technologies in studies of genetic disorders and discuss issues pertaining to applications of CRISPR/Cas9 in auditory systems implicated in genetic hearing loss.

  2. Fittings of unplasticized polyvinyl chloride (PVC-U), chlorinated polyvinyl chloride (PVC-C) or acrylonitrile/butadiene/styrene (ABS) with plain sockets for pipes under pressure - Dimensions of sockets - Metric series

    CERN Document Server

    International Organization for Standardization. Geneva

    1985-01-01

    Fittings of unplasticized polyvinyl chloride (PVC-U), chlorinated polyvinyl chloride (PVC-C) or acrylonitrile/butadiene/styrene (ABS) with plain sockets for pipes under pressure - Dimensions of sockets - Metric series

  3. ON THE KINETICS AND MECHANISM OF THE COPOLYMERIZATION OF ACRYLONITRILE WITH STYRENE IN THE PRESENCE OF COPPER CHLORIDE

    Institute of Scientific and Technical Information of China (English)

    Hiroko Sato; Hiroshi Tsuji; Hitoshi Sasaki; Shinichi Ikemura; Yasuhito Gotoh; Junzo Ishikawa; Sei-ichi Nishimoto

    2003-01-01

    The copolymerization of styrene (St) and acrylonitrile (AN) complexed with CuCl2 monomer by a free radical mechanism was performed using benzoyl peroxide as an initiator at 65℃ under N2 atmosphere for 150 min. The rate of polymerization (Rp) was found to increase linearly with the concentration (in mol/L) of CuCl2, AN and St through scaling relations. The activation energy of the copolymerization process in the presence and absence of CuCl2 was found to be 46.5 kJ/mol and 102 kJ/mol, respectively. The viscosity average molecular weight of the copolymer and the kp2/kt ratio were determired to further assess the accelerating effect of CuCl2 on the copolymerization process. The copolymerization process in the presence of CuCl2 has a radical complex mechanism.

  4. STUDY ON THE GASEOUS PRODUCTS OF HIGH TEMPERATURE PYROLYSIS OF ACRYLONITRILE POLYMERS BY ON-LINE FTIR METHOD

    Institute of Scientific and Technical Information of China (English)

    ZHAO Genxiang; CHEN Bangjie

    1987-01-01

    The gaseous products of high temperature pyrolysis (300℃ to 960℃) of acrylonitrile polymers were measured continuously under nitrogen atnosphere by on-line Fourier Transform Infrared Spectroscopic method (FTIR). From the variations of characteristic peaks it was found that the nitrogen of macromolecules evolved were mainly in the form of hydrogen cyanide and ammonia. During the pyrolysis amorphous carbonaceous element was formed, and crosslinked to form network structure. Three kinds of samples were used for comparison. The experimental results show that the gaseous products of volatile small molecules were HCN, NH3, CH4, C2H6 and cyanide. CO and CO2 were also formed when copolymers of PAN were thermally pyrolyzed.

  5. Free radical induced grafting of acrylonitrile on pre-treated rice straw for enhancing its durability and flame retardancy.

    Science.gov (United States)

    Mukherjee, Aparna; Halder, Seema; Datta, Deepshikha; Anupam, Kumar; Hazra, Biren; Kanti Mandal, Mrinal; Halder, Gopinath

    2017-01-01

    The present investigation highlights the feasibility of a polymer grafting process to enhance the durability and flame retardancy of rice straw towards application as a low cost roofing material. The success of this grafting methodology was perceived to depend upon a bi-step pre-treatment process encompassing delignification and inorganic salts dispersion. Subsequently free radical polymer grafting of acrylonitrile onto rice straw was implemented by immersion mechanism initiated by oxalic acid-potassium permanganate initiator. The percentage of grafting, limiting oxygen index (LOI), biodegradability of the grafted rice straw and grafting yield percentage was estimated to be 57%, 27%, 0.02% and 136.67%, respectively. The weight loss of polymer grafted rice straw implied its less biodegradability over raw straw. Thus, the process of grafting contrived in the present analysis can be a promising and reliable technique for the efficient utilization of rice straw as an inexpensive roofing element through the augmentation of its durability and flame retardancy.

  6. Pressure induced graft-co-polymerization of acrylonitrile onto Saccharum cilliare fibre and evaluation of some properties of grafted fibre

    Indian Academy of Sciences (India)

    A S Singha; Anjali Shama; Vijay Kumar Thakur

    2008-02-01

    In the present work, graft co-polymerization of acrylonitrile (AN) onto Saccharum cilliare fibre has been carried out in the presence of potassium persulphate and ferrous ammonium sulphate (FAS–KPS) as redox initiator. The reactions were carried out under pressure in an autoclave. Various reaction parameters such as pressure, time, pH, concentrations of initiator and monomer were optimized to get maximum graft yield (35.59%). Grafted and ungrafted Saccharum cilliare fibres were then subjected to evaluation of some of their properties like swelling behaviour in different solvents, moisture absorbance under different humidity levels, water uptake and resistance towards chemicals such as hydrochloric acid and sodium hydroxide. The characterization of the graft copolymers were carried out by FTIR spectrophotometer, X-ray diffraction (XRD) and scanning electron microscopic (SEM) studies.

  7. Study on Exothermic Oxidation of Acrylonitrile-butadiene-styrene (ABS Resin Powder with Application to ABS Processing Safety

    Directory of Open Access Journals (Sweden)

    Jenq-Renn Chen

    2010-08-01

    Full Text Available Oxidative degradation of commercial grade ABS (Acrylonitrile-butadiene-styrene resin powders was studied by thermal analysis. The instabilities of ABS containing different polybutadiene (PB contents with respect to temperature were studied by Differential Scanning Calorimeter (DSC. Thermograms of isothermal test and dynamic scanning were performed. Three exothermic peaks were observed and related to auto-oxidation, degradation and oxidative decomposition, respectively. Onset temperature of the auto-oxidation was determined to be around 193 °C. However, threshold temperature of oxidation was found to be as low as 140 °C by DSC isothermal testing. Another scan of the powder after degeneration in air showed an onset temperature of 127 °C. Reactive hazards of ABS powders were verified to be the exothermic oxidation of unsaturated PB domains, not the SAN (poly(styrene-acrylonitrile matrix. Heat of oxidation was first determined to be 2,800 ± 40 J per gram of ABS or 4,720 ± 20 J per gram of PB. Thermal hazards of processing ABS powder are assessed by adiabatic temperature rise at process conditions. IR spectroscopy associated with heat of oxidation verified the oxidative mechanism, and these evidences excluded the heat source from the degradation of SAN. A specially prepared powder of ABS without adding anti-oxidant was analyzed by DSC for comparing the exothermic behaviors. Exothermic onset temperatures were determined to be 120 °C and 80 °C by dynamic scanning and isothermal test, respectively. The assessment successfully explained fires and explosions in an ABS powder dryer and an ABS extruder.

  8. Hearing loss at work? Hearing loss from leisure activities?

    CERN Multimedia

    2006-01-01

    The nurses of the Medical Service would like invite all persons working on the CERN site to take part in a: HEARING LOSS DETECTION WEEK From 28 August to 1st September 2006 At the Infirmary, Building 57 from 9 a.m. to 4 p.m. Hearing tests - advice - information - documentation - protective equipment

  9. Likely Age-Related Hearing Loss (Presbycusis) in a Stranded Indo-Pacific Humpback Dolphin (Sousa chinensis).

    Science.gov (United States)

    Li, Songhai; Wang, Ding; Wang, Kexiong; Hoffmann-Kuhnt, Matthias; Fernando, Nimal; Taylor, Elizabeth A; Lin, Wenzhi; Chen, Jialin; Ng, Timothy

    2016-01-01

    The hearing of a stranded Indo-Pacific humpback dolphin (Sousa chinensis) in Zhuhai, China, was measured. The age of this animal was estimated to be ~40 years. The animal's hearing was measured using a noninvasive auditory evoked potential (AEP) method. The results showed that the high-frequency hearing cutoff frequency of the studied dolphin was ~30-40 kHz lower than that of a conspecific younger individual ~13 year old. The lower high-frequency hearing range in the older dolphin was explained as a likely result of age-related hearing loss (presbycusis).

  10. Universal newborn hearing screening coming soon: "hear's" why.

    Science.gov (United States)

    Knott, C

    2001-12-01

    Screening the hearing of all newborns, both NICU and well nursery, is rapidly becoming the standard of care. The impetus for universal newborn hearing screening (UNHS) has come from outside the domain of nursing and the newborn nursery. Because nursing will be involved in nearly all aspects of UNHS, nurses need a thorough knowledge base about permanent childhood hearing loss (PCHL) and UNHS. Technology exisits today that can objectively and physiologically screen for this condition at a cost comparable to metabolic screening. PCHL occurs more than twice as often as all the hemoglobinopathies and inborn errors of metabolism combined. Undiagnosed hearing loss often leads to permanent developmental delays. The ultimate goal of early diagnosis and intervention for a congenital hearing loss is to enable the child to develop language and communication skills that correspond to his chronological age and innate cognitive abilities.

  11. Screening of the hearing of newborns - Update

    Directory of Open Access Journals (Sweden)

    von Voß, Hubertus

    2006-11-01

    Full Text Available Introduction: Permanent congenital bilateral hearing loss (CHL of moderate or greater degree (≥40 dB HL is a rare disease, with a prevalence of about 1 to 3 per 1000 births. However, it is one of the most frequent congenital diseases. Reliance on physician observation and parental recognition has not been successful in the past in detecting significant hearing loss in the first year of life. With this strategy significant hearing losses have been detected in the second year of life. With two objective technologies based on physiologic response to sound, otoacoustic emissions (OAE and auditory brainstem response (ABR hearing screening in the first days of life is made possible. Objectives: The objective of this health technology assessment report is to update the evaluation on clinical effectiveness and cost-effectiveness of newborn hearing screening programs. Universal newborn hearing screening (UHNS (i, selective screening of high risk newborns (ii, and the absence of a systematic screening program are compared for age at identification and age at hearing aid fitting of children with hearing loss. Secondly the potential benefits of early intervention are analysed. Costs and cost-effectiveness of newborn hearing screening programs are determined. This report is intended to make a contribution to the decision making whether and under which conditions a newborn hearing screening program should be reimbursed by the statutory sickness funds in Germany. Methods: This health technology assessment report updates a former health technology assessment (Kunze et al. 2004 [1]. A systematic review of the literature was conducted, based on a documented search and selection of the literature using predefined inclusion and exclusion criteria and a documented extraction and appraisal of the included studies. To assess the cost-effectiveness of the different screening strategies in Germany the decision analytic Markov state model which had been developed in

  12. Amplification Considerations for Children With Minimal or Mild Bilateral Hearing Loss and Unilateral Hearing Loss

    OpenAIRE

    2008-01-01

    Children with minimal or mild bilateral hearing loss and unilateral hearing loss are at higher risk for academic, speech-language, and social-emotional difficulties than their normal hearing peers. The choice to fit infants with moderate or greater degrees of bilateral hearing loss has been standard practice for most clinicians, but for those with minimal or mild bilateral hearing loss or unilateral hearing loss, the fitting of hearing technology must be based on limited data. Evidence does n...

  13. Wireless communication for hearing aid system

    DEFF Research Database (Denmark)

    Nour, Baqer

    This thesis focuses on the wireless coupling between hearing aids close to a human head. Hearing aids constitute devices withadvanced technology and the wireless communication enables the introduction of a range of completely new functionalities. Such devices are small and the available power...... the ear-to-ear wireless communication channel by understanding the mechanisms that control the propagations of the signals and the losses. The second objective isto investigate the properties of magneto-dielectric materials and their potential in antenna miniaturization. There are three approaches...... understanding of the ear-to-ear wireless communication channel. A circular patch antenna was used to study the properties of the magneto-dielectric materials. In the thesis, we focused on three properties; efficiency, quality factor and bandwidth of the antenna. An analytical method is used to calculatethe...

  14. Choosing which ear to implant in adult candidates with functional residual hearing.

    Science.gov (United States)

    Fielden, Claire A; Mehta, Rajnikant L; Kitterick, Pádraig T

    2016-04-01

    This study examined whether audiologists consider the potential benefits of contralateral hearing aid use following cochlear implantation when recommending which ear to implant in UK adult candidates with residual hearing. Thirty-four audiologists from providers of adult implantation services completed a decision-choice experiment. Clinicians were willing to consider recommending that the poorer ear be implanted, provided it had been aided continuously, suggesting that their decision making seeks to preserve access to residual hearing in the non-implanted ear where possible. Future approaches to determining candidacy should therefore consider that a sub-set of patients may obtain additional benefit from this residual hearing following implantation.

  15. A Hearing Aid Primer 1

    Science.gov (United States)

    Yetter, Carol J.

    2009-01-01

    This hearing aid primer is designed to define the differences among the three levels of hearing instrument technology: conventional analog circuit technology (most basic), digitally programmable/analog circuit technology (moderately advanced), and fully digital technology (most advanced). Both moderate and advanced technologies mean that hearing…

  16. Everyday trajectories of hearing correction

    DEFF Research Database (Denmark)

    Lykke Hindhede, Anette

    2010-01-01

    This paper reports on a qualitative study of the onset of acquired hearing impairment. The focus of attention is about why a person seeks treatment. The Danish welfare state serves the population ‘in need' such as those with an audiological need and gives them guidance on becoming hearing aid wea...

  17. Intellectual Disabilities and Hearing Loss

    Science.gov (United States)

    Herer, Gilbert R.

    2012-01-01

    Undetected/untreated hearing loss imposes significant limitations upon individuals with intellectual disabilities (ID). It can interfere with cognitive development, impede communicative and social interactions, and limit vocational aspirations. Over the past decade, the hearing of 9961 people with ID was evaluated at Special Olympics sports…

  18. The Stigma of Hearing Loss

    Science.gov (United States)

    Wallhagen, Margaret I.

    2010-01-01

    Purpose: To explore dimensions of stigma experienced by older adults with hearing loss and those with whom they frequently communicate to target interventions promoting engagement and positive aging. Design and Methods: This longitudinal qualitative study conducted interviews over 1 year with dyads where one partner had hearing loss. Participants…

  19. Hearing symptoms personal stereos

    Directory of Open Access Journals (Sweden)

    Tiara Santos da Luz1

    2012-01-01

    Full Text Available Introduction: Practical and portable the personal stereos if had become almost indispensable accessories in the day the day. Studies disclose that the portable players of music can cause auditory damages in the long run for who hear music in high volume for a drawn out time. Objective: to verify the prevalence of auditory symptoms in users of amplified players and to know its habits of use. Method: Observational prospective study of transversal cut carried through in three institutions of education of the city of Salvador BA, being two of public net and one of the private net. 400 students had answered to the questionnaire, of both the sex, between 14 and 30 years that had related the habit to use personal stereos. Results: The symptoms most prevalent had been hyperacusis (43.5%, auricular fullness (30.5% and humming (27.5, being that the humming is the symptom most present in the population youngest. How much to the daily habits: 62.3% frequent use, 57% in raised intensities, 34% in drawn out periods. An inverse relation between exposition time was verified and the band of age (p=0,000 and direct with the prevalence of the humming. Conclusion: Although to admit to have knowledge on the damages that the exposition the sound of high intensity can cause the hearing, the daily habits of the young evidence the inadequate use of the portable stereos characterized by long periods of exposition, raised intensities, frequent use and preference for the insertion phones. The high prevalence of symptoms after the use suggests a bigger risk for the hearing of these young.

  20. Hearing symptoms personal stereos

    Science.gov (United States)

    da Luz, Tiara Santos; Borja, Ana Lúcia Vieira de Freitas

    2012-01-01

    Summary Introduction: Practical and portable the personal stereos if had become almost indispensable accessories in the day the day. Studies disclose that the portable players of music can cause auditory damages in the long run for who hear music in high volume for a drawn out time. Objective: to verify the prevalence of auditory symptoms in users of amplified players and to know its habits of use Method: Observational prospective study of transversal cut carried through in three institutions of education of the city of Salvador BA, being two of public net and one of the private net. 400 students had answered to the questionnaire, of both the sex, between 14 and 30 years that had related the habit to use personal stereos. Results: The symptoms most prevalent had been hyperacusis (43.5%), auricular fullness (30.5%) and humming (27.5), being that the humming is the symptom most present in the population youngest. How much to the daily habits: 62.3% frequent use, 57% in raised intensities, 34% in drawn out periods. An inverse relation between exposition time was verified and the band of age (p = 0,000) and direct with the prevalence of the humming. Conclusion: Although to admit to have knowledge on the damages that the exposition the sound of high intensity can cause the hearing, the daily habits of the young evidence the inadequate use of the portable stereos characterized by long periods of exposition, raised intensities, frequent use and preference for the insertion phones. The high prevalence of symptoms after the use suggests a bigger risk for the hearing of these young. PMID:25991931

  1. HEARING LOSS IN DECOMPRESSION

    Science.gov (United States)

    hearing loss is often reported. Most of this can readily be attributed to the residual effects of repeated aerotitis media, and is not sudden. A review of the topic of sudden deafness reveals that every large hospital where such records have been published sees every month about 1-2 patients whose sudden deafness is not easily explained. Possible causes have been suggested: acute neuritis of the VIIIth nerve, virus infection, vascular accident, vasomotor neurosis, acoustic trauma at levels of noise not usually noxious, collagen disease, transient ischemia from violent

  2. Can You Hear Architecture

    DEFF Research Database (Denmark)

    Ryhl, Camilla

    2016-01-01

    Taking an off set in the understanding of architectural quality being based on multisensory architecture, the paper aims to discuss the current acoustic discourse in inclusive design and its implications to the integration of inclusive design in architectural discourse and practice as well...... design and architectural quality for people with a hearing disability and a newly conducted qualitative evaluation research in Denmark as well as architectural theories on multisensory aspects of architectural experiences, the paper uses examples of existing Nordic building cases to discuss the role...... of acoustics in both inclusive design and multisensory architecture....

  3. Hearing loss in stranded odontocete dolphins and whales.

    Directory of Open Access Journals (Sweden)

    David Mann

    Full Text Available The causes of dolphin and whale stranding can often be difficult to determine. Because toothed whales rely on echolocation for orientation and feeding, hearing deficits could lead to stranding. We report on the results of auditory evoked potential measurements from eight species of odontocete cetaceans that were found stranded or severely entangled in fishing gear during the period 2004 through 2009. Approximately 57% of the bottlenose dolphins and 36% of the rough-toothed dolphins had significant hearing deficits with a reduction in sensitivity equivalent to severe (70-90 dB or profound (>90 dB hearing loss in humans. The only stranded short-finned pilot whale examined had profound hearing loss. No impairments were detected in seven Risso's dolphins from three different stranding events, two pygmy killer whales, one Atlantic spotted dolphin, one spinner dolphin, or a juvenile Gervais' beaked whale. Hearing impairment could play a significant role in some cetacean stranding events, and the hearing of all cetaceans in rehabilitation should be tested.

  4. Deaf/Hearing Research Partnerships.

    Science.gov (United States)

    Wolsey, Ju-Lee A; Dunn, Kim Misener; Gentzke, Scott W; Joharchi, Hannah A; Clark, M Diane

    2017-01-01

    Deaf individuals typically are seen through the lens of the dominant hearing society's perception, i.e., that being deaf is an impairment. Today, a small but growing number of Deaf and hearing researchers are challenging this perception. The authors examined perceptions of what components are necessary for a successful Deaf/hearing research partnership, and propose that it is essential for Deaf and hearing researchers to embrace a Deaf epistemology. The authors found that a core category of equity is the key to effective teams. This equity is based in part on the mutual understanding that American Sign Language is the lingua franca of the team, as it provides full and easy access between Deaf and hearing team members. Additionally, a transformative paradigm, as a research frame, was found to be necessary to focus on leveling the playing field for Deaf researchers.

  5. 突发性耳聋患者眼肌前庭诱发肌源性电位特点%Characteristics of ocular vestibular evoked myogenic potentials in patients with sudden sensorineural hearing loss

    Institute of Scientific and Technical Information of China (English)

    舒博; 叶胜难; 林有辉; 林少莲; 胡婕; 林丁丁

    2016-01-01

    目的:观察突发性耳聋患者眼肌前庭诱发肌源性电位(oVEMP)的引出率和各参数指标,并探讨其临床诊断价值。方法选取2014年10月到2015年3月诊断为单侧突发性耳聋的患者36例,进行气导短纯音诱发的眼肌前庭诱发肌源性电位检测,分析对比oVEMP的引出率和各参数指标。分别以突聋对侧耳和25名年龄、性别匹配的健康人25例(50耳)为对照,分析前庭功能受损状况。结果突聋组患耳oVEMP引出率为44.4%(16/36),突聋组对侧健耳oVEMP引出率为52.7%(19/36);对照组oVEMP引出率为100%(50/50)。组间对比显示突聋组患耳和对侧耳与对照组oVEMP引出率比较,差异均有统计学意义(P值均0.05);突聋组患耳、对侧耳、对照组正常耳组间比较,oVEMP的N1潜伏期、Pl潜伏期、波间期、振幅等参数差异均无统计学意义(P值均>0.05)。结论突聋患者在耳蜗受损的同时可以伴有椭圆囊及前庭上神经传导功能障碍,这种功能障碍可以通过oVEMP检测进行客观评估。%Objective To report the response rate and characteristics of various parameters of ocular ves-tibular evoked myogenic potentials in patients with sudden sensorineural hearing loss (SSHL). Methods Thir-ty six cases of unilateral SSHL examined between October 2014 and March 2015 were included as the study group. Twenty five age-and gender-matched normal subjects were recruited as the control group. Both pa-tients and normal subjects underwent conventional air conduction ocular vestibular evoked myogenic poten-tial (oVEMP) tests in bilateral ears. The results were compared between the affected and contralateral ears and with the normal controls. Results oVEMPs were elicited in 16 affected ears (44.4%), 19 contralateral ears (52.7%) and 50 normal ears (100%) (P0.05). Conclusions The utricle and superior vestibular nerves may be damaged in SSHL patients. Such damages may be monitored objec-tively by o

  6. Touch and Emotional Availability in Hearing and Deaf or Hard of Hearing Toddlers and Their Hearing Mothers.

    Science.gov (United States)

    Pipp-Siegel, Sandra; Blair, Natalie L.; Deas, Ann M.; Pressman, Leah J.; Yoshinaga-Itano, Christine

    1999-01-01

    A study involving 48 hearing mothers and their 2-year-old children with and without hearing impairments found mothers with children with hearing impairments touched each other more and that, unlike hearing dyads, the presence of material hostility was related to a decrease in the number of maternal and child touches. (Contains references.)…

  7. Relationship between hearing complaint and hearing loss among older people

    Directory of Open Access Journals (Sweden)

    Teixeira, Adriane Ribeiro

    2009-03-01

    Full Text Available Introduction: Presbycusis is a public health problem. Despite its high prevalence, many elders do not have their hearing ability investigated periodically, because they do not have a specific complaint. Objective: To check whether there is a relationship between the complaint and the presence of hearing loss in elder people. Method: Transversal study in elders from a neighborhood in the city of Canoas, Rio Grande do Sul. After the definition of the neighborhood's geographic boundaries, all houses were visited, the older people's addresses were ascertained and the invitations to take part in the research were provided. A questionnaire survey was applied which had a question about hearing loss complaint and air-conducted hearing thresholds were obtained and studied. Out of the 72 identified elders 50 elders agreed to participate, 35 (70% women, and 15 (30% men. Results: It was confirmed that only 12 (24% elders showed a specific complaint of hearing loss, although 33 (66% elders showed slight, moderate, severe and profound hearing losses. Conclusion: Data analysis confirmed there was no relationship between the complaint and the presence of hearing loss in the assessed group, and demonstrated the need to forward the elders for audiological evaluation even without any specific complaint.

  8. 20 CFR 416.1415 - Disability hearing-disability hearing officers.

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Disability hearing-disability hearing... Reopening of Determinations and Decisions Reconsideration § 416.1415 Disability hearing—disability hearing officers. (a) General. Your disability hearing will be conducted by a disability hearing officer who...

  9. 21 CFR 874.3300 - Hearing Aid.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Hearing Aid. 874.3300 Section 874.3300 Food and... EAR, NOSE, AND THROAT DEVICES Prosthetic Devices § 874.3300 Hearing Aid. (a) Identification. A hearing aid is wearable sound-amplifying device that is intended to compensate for impaired hearing....

  10. 丙烯腈生殖毒理学研究概况%An Overview of the Study of Acrylonitrile on Reproductive Toxiocology

    Institute of Scientific and Technical Information of China (English)

    吴鑫; 金泰; 钟先玖

    2000-01-01

    @@ 丙烯腈(acrylonitrile,ACN)为有机合成工业中广泛应用的一种重要单体物质,可合成腈纶纤维,丁腈橡胶,ABS工程塑料及某些树脂.1994年全世界的ACN生产量超过30亿磅,1995年已达到100亿磅的生产能力[1].

  11. Early Hearing Detection and Intervention: Can Your Baby Hear?

    Centers for Disease Control (CDC) Podcasts

    2007-06-15

    This podcast discusses how important it is that every child receives a hearing screening as soon as possible after birth. It also gives specific ways that parents and health providers can find out if a child has a possible hearing loss and where to get further information. (Created 6/5/2007 by the Early Hearing Detection and Intervention Program, NCBDDD).  Created: 6/15/2007 by National Center on Birth Defects and Developmental Disabilities.   Date Released: 6/25/2007.

  12. IMPORTANT DESIGN POINTS FOR WASTE WATER INCINERATOR OF ACRYLONITRILE PLANT [39]%丙烯腈装置废水焚烧炉设计要点

    Institute of Scientific and Technical Information of China (English)

    丁天才

    2012-01-01

    Waste water incinerator of acryloni- trile plant treats the wastewater from the acrylo- nitrile plant to reach the environmental emission requirements and reclaims the waste heat. So it is the key equipment for the acrylonitrile plant. Taking a waste water incinerator of an acrylonitrile plant as an example, this article introduces and analyzes the process plan selection, refractory lining design and the Nox control of the waste water incinerator of acrylonitrile plant.%丙烯腈装置废水焚烧炉是丙烯腈装置的关键设备,处理来自丙烯腈装置的废水,使之达到环保的排放要求,同时回收废热,以某丙烯腈项目废水焚烧炉为例,介绍和分析了丙烯腈废水焚烧炉的工艺方案选择、耐火材料选择和NOx控制.

  13. Potencial evocado auditivo de tronco encefálico por via óssea em indivíduos com perda auditiva sensorioneural Brainstem auditory evoked potential in subjects with sensorineural hearing losses

    Directory of Open Access Journals (Sweden)

    Luciana Castelo Branco Camurça Fernandes

    2012-01-01

    Full Text Available OBJETIVO: caracterizar os resultados do PEATE por via óssea em indivíduos com perda auditiva sensorioneural leve, comparando esses dados com o grupo controle, formado por indivíduos audiologicamente normais. MÉTODO: a amostra foi constituída por 40 adultos, de ambos os sexos, com faixa etária de 18 a 55 anos, distribuídos em um grupo controle de 30 indivíduos com audição normal e um grupo estudo composto de 10 indivíduos com perda auditiva sensorioneural de grau leve. O PEATE foi realizado com equipamento EP15, da marca Interacoustics. O estímulo utilizado foi o clique com taxa de apresentação de 27,7/s, em um total de 2000 estímulos, com polaridade de rarefação por VA e alternada para VO e filtro passa-banda de 50Hz e 3000Hz. RESULTADOS: em indivíduos com perda sensorioneural de grau leve, não houve diferenças estatisticamente significantes entre o limiar do PEATE por via aérea e óssea, estando esses limiares equivalentes, com GAP aéreo-ósseo menor que 10dB. A latência da onda V no limiar eletrofisiológico e a 50 dBnNA foram menores que as referidas latências observadas em indivíduos com audição normal. CONCLUSÃO: foram encontrados limiares eletrofisiológicos por via óssea equivalente aos limiares obtidos por via aérea, com presença de GAP aéreo-ósseo menor que 10dBnNA. Assim a utilização do PEATE por VO fornece dados para uma caracterização mais detalhada do tipo da perda auditiva.PURPOSE: to characterize the results of ABR via bone in subjects with mild sensorineural hearing loss, comparing these data with the control group made up by subjects with normal hearing. METHOD: the sample consisted of 40 adults of both genders, 18 - 55 year old, divided into a control group of 30 subjects with normal hearing and a study group made up of 10 subjects with mild sensorineural hearing loss. ABR was carried out with Interacoustics brand EP15. The stimulus was the click presentation rate of 27.7 / s, for a total of

  14. Cellular and deafness mechanisms underlying connexin mutation induced hearing loss – A common hereditary deafness

    Directory of Open Access Journals (Sweden)

    Jeffrey C Wingard

    2015-05-01

    Full Text Available Hearing loss due to mutations in the connexin gene family which encodes gap junctional proteins is a common form of hereditary deafness. In particular, connexin 26 (Cx26, GJB2 mutations are responsible for ~50% of nonsyndromic hearing loss, which is the highest incidence of genetic disease. In the clinic, Cx26 mutations cause various auditory phenotypes ranging from profound congenital deafness at birth to mild, progressive hearing loss in late childhood. Recent experiments demonstrate that congenital deafness mainly results from cochlear developmental disorders rather than hair cell degeneration and endocochlear potential (EP reduction, while late-onset hearing loss results from reduction of active cochlear amplification, even though cochlear hair cells have no connexin expression. Moreover, new experiments further demonstrate that the hypothesized K+-recycling disruption is not a principal deafness mechanism for connexin deficiency induced hearing loss. Additionally, there is no clear relationship between specific changes in connexin (channel functions and the phenotypes of mutation-induced hearing loss. Cx30, Cx29, Cx31, and Cx43 mutations can also cause hearing loss with distinct pathological changes in the cochlea. These new studies provide invaluable information about deafness mechanisms underlying connexin mutation induced hearing loss and also provide important information for developing new protective and therapeutic strategies for this common deafness. However, the detailed cellular mechanisms underlying these pathological changes and pathogeneses of specific-mutation induced hearing loss remain unclear. Finally, little information is available for humans. Further studies to address these deficiencies are urgently required.

  15. Does Attempt at Hearing Preservation Microsurgery of Vestibular Schwannoma Affect Postoperative Tinnitus?

    Directory of Open Access Journals (Sweden)

    Martin Chovanec

    2015-01-01

    Full Text Available Background. The aim of this study was to analyze the effect of vestibular schwannoma microsurgery via the retrosigmoid-transmeatal approach with special reference to the postoperative tinnitus outcome. Material and Methods. A prospective study was performed in 89 consecutive patients with unilateral vestibular schwannoma indicated for microsurgery. Patient and tumor related parameters, pre- and postoperative hearing level, intraoperative findings, and hearing and tinnitus handicap inventory scores were analyzed. Results. Cochlear nerve integrity was achieved in 44% corresponding to preservation of preoperatively serviceable hearing in 47% and useful hearing in 21%. Main prognostic factors of hearing preservation were grade/size of tumor, preoperative hearing level, intraoperative neuromonitoring, tumor consistency, and adhesion to neurovascular structures. Microsurgery led to elimination of tinnitus in 66% but also new-onset of the symptom in 14% of cases. Preservation of useful hearing and neurectomy of the eighth cranial nerve were main prognostic factors of tinnitus elimination. Preservation of cochlear nerve but loss of preoperative hearing emerged as the main factor for tinnitus persistence and new onset tinnitus. Decrease of THI scores was observed postoperatively. Conclusions. Our results underscore the importance of proper pre- and intraoperative decision making about attempt at hearing preservation versus potential for tinnitus elimination/risk of new onset of tinnitus.

  16. Drug Induced Hearing Loss: Researchers Study Strategies to Preserve Hearing

    Science.gov (United States)

    ... of this page please turn JavaScript on. Feature: Drug-Induced Hearing Loss Researchers Study Strategies to Preserve ... brain there was a sound. What are ototoxic drugs and why are they important? Ototoxic drugs are ...

  17. The neuromechanics of hearing

    Science.gov (United States)

    Araya, Mussie K.; Brownell, William E.

    2015-12-01

    Hearing requires precise detection and coding of acoustic signals by the inner ear and equally precise communication of the information through the auditory brainstem. A membrane based motor in the outer hair cell lateral wall contributes to the transformation of sound into a precise neural code. Structural, molecular and energetic similarities between the outer hair cell and auditory brainstem neurons suggest that a similar membrane based motor may contribute to signal processing in the auditory CNS. Cooperative activation of voltage gated ion channels enhances neuronal temporal processing and increases the upper frequency limit for phase locking. We explore the possibility that membrane mechanics contribute to ion channel cooperativity as a consequence of the nearly instantaneous speed of electromechanical signaling and the fact that membrane composition and mechanics modulate ion channel function.

  18. Idiopathic sensorineural hearing loss in the only hearing ear.

    Science.gov (United States)

    Berrettini, S; De Vito, A; Bruschini, L; Fortunato, S; Forli, F

    2016-04-01

    A retrospective chart review was used for 31 patients with sudden, progressive or fluctuating sensorineural hearing loss (SHL) in the only hearing ear who had been consecutively evaluated at the ENT, Audiology and Phoniatrics Unit of the University of Pisa. The group of patients was evaluated with a complete history review, clinical evaluation, imaging exam (MRI, CT), audiologic tests (tone and speech audiometry, tympanometry, study of stapedial reflexes, ABR and otoacoustic emission) evaluation. In order to exclude genetic causes, patients were screened for CX 26 and CX30 mutations and for mitochondrial DNA mutation A1555G. Patients with sudden or rapidly progressive SHL in the only hearing ear were treated with osmotic diuretics and corticosteroids. In patients who did not respond to intravenous therapy we performed intratympanic injections of corticosteroid. Hearing aids were fitted when indicated and patients who developed severe to profound SHL were scheduled for cochlear implant surgery. The aim of this study is to report and discuss the epidemiology, aetiopathogenesis, therapy and clinical characteristic of patients affected by SHL in the only hearing hear and to discuss the issues related to the cochlear implant procedure in some of these patients, with regard to indications, choice of the ear to implant and results.

  19. Childhood Hearing Health: Educating for Prevention of Hearing Loss

    Directory of Open Access Journals (Sweden)

    Lacerda, Adriana Bender Moreira

    2014-09-01

    Full Text Available Introduction The presence of noise in our society has attracted the attention of health professionals, including speech-language pathologists, who have been charged along with educators with developing hearing conservation programs in schools. Objective To describe the results of three strategies for awareness and hearing preservation in first to fourth grades in public elementary schools. Methods The level of environmental noise in classrooms was assessed, and 638 elementary school students from first to fourth grades, 5 to 10 years of age, were audiologically evaluated. After the evaluations, educational activities were presented to children and educators. Results The noise level in the classroom ranged from 71.8 to 94.8 A-weighted decibels. The environment of the classroom was found to promote sound reverberation, which hinders communication. Thirty-two students (5.1% presented hearing alterations. Conclusion The application of strategies for a hearing conservation program at the school showed that noise is present in the room, and hearing loss, sometimes silent, affects schoolchildren. Students and teachers were aware that hearing problems can be prevented. Avoiding exposure to noise and improving the acoustics in classrooms are essential.

  20. Determination of Bound Acrylonitrile Content in Acrylonitrile-butadiene Rubber(NBR) by Infrared Spectroscopy Method%红外光谱法测定丁腈橡胶中的结合丙烯腈含量

    Institute of Scientific and Technical Information of China (English)

    高杜娟; 黄世英; 赵家琳; 刘俊保

    2015-01-01

    Infrared spectrometry in this article was used to determinate the bound acrylonitrile content in nitrile rubber( NBR). In the process of experimenting,the sample preparation conditions were determined and the stand-ard values of seven substitute standard sample were confirmed by Kjeldahl method,through which the quantitative calculation formula was get. And finally,the results were compared with the method of element analysis.%本文采用红外光谱法测定丁腈橡胶( NBR)中的结合丙烯腈含量,确定了样品前处理条件,通过凯氏定氮法确定7个代用标准胶中结合丙烯腈含量的标准值,得出了结合丙烯腈含量的定量计算公式,测试结果与元素分析法进行了对比。

  1. Purpose of Newborn Hearing Screening

    Science.gov (United States)

    ... that help with hearing loss and learning important communication skills. That is why the American Academy of Pediatrics ( ... for communicating with your baby including total communication, oral communication, cued speech, and American Sign Language. The Individuals ...

  2. Sudden hearing loss in children.

    Science.gov (United States)

    Ječmenica, Jovana; Bajec-Opančina, Aleksandra

    2014-08-01

    Sudden sensorineural hearing loss (SSHL) is defined as a unilateral or bilateral sensorineural hearing loss with at least 30 dB decrease in threshold in 3 contiguous test frequencies occurring over 72 hours or less. It is very rare in children. Sudden hearing loss is a symptom that suggests that there is a problem in the inner ear, surrounding structures, or the whole organism. The etiology and development of this disorder are still not fully understood. The literature contains numerous models of the pathogenesis of SSHL, with childhood SSHL having certain peculiarities. In practical terms, the multifactorial nature of SSHL is important in the choice of diagnostic methods and treatment methods. It is important to determine the cause and effect relationship between the underlying disease and hearing loss.

  3. Hearing Loss and Older Adults

    Science.gov (United States)

    ... embarrassed when you meet new people because you struggle to hear? YES NO Do you feel frustrated ... talk and for people to get used to speaking louder and more clearly. Be patient and continue ...

  4. How well can centenarians hear?

    Directory of Open Access Journals (Sweden)

    Zhongping Mao

    Full Text Available With advancements in modern medicine and significant improvements in life conditions in the past four decades, the elderly population is rapidly expanding. There is a growing number of those aged 100 years and older. While many changes in the human body occur with physiological aging, as many as 35% to 50% of the population aged 65 to 75 years have presbycusis. Presbycusis is a progressive sensorineural hearing loss that occurs as people get older. There are many studies of the prevalence of age-related hearing loss in the United States, Europe, and Asia. However, no audiological assessment of the population aged 100 years and older has been done. Therefore, it is not clear how well centenarians can hear. We measured middle ear impedance, pure-tone behavioral thresholds, and distortion-product otoacoustic emission from 74 centenarians living in the city of Shaoxing, China, to evaluate their middle and inner ear functions. We show that most centenarian listeners had an "As" type tympanogram, suggesting reduced static compliance of the tympanic membrane. Hearing threshold tests using pure-tone audiometry show that all centenarian subjects had varying degrees of hearing loss. More than 90% suffered from moderate to severe (41 to 80 dB hearing loss below 2,000 Hz, and profound (>81 dB hearing loss at 4,000 and 8,000 Hz. Otoacoustic emission, which is generated by the active process of cochlear outer hair cells, was undetectable in the majority of listeners. Our study shows the extent and severity of hearing loss in the centenarian population and represents the first audiological assessment of their middle and inner ear functions.

  5. Lower Hearing Threshold by Noise

    Institute of Scientific and Technical Information of China (English)

    龙长才; 邵峰; 张燕萍; 秦佑国

    2004-01-01

    We demonstrate that noise can be a benefit factor that enables us to hear weaker signals. We measured the hearing thresholds of subjects for pure tone in different noise levels. The results show that pure tone thresholds with noise of some levels are lower than that without noise. The largest down-shift of the threshold by noise among the examined subjects is 5. 7dB, and the smallest is 1.7dB.

  6. Protect Your Hearing at Work

    Centers for Disease Control (CDC) Podcasts

    2015-11-09

    Noise-induced hearing loss is one of the most common work-related illnesses. This podcast features information from CDC’s National Institute for Occupational Safety and Health on how to protect yourself from work-related noise-induced hearing loss.  Created: 11/9/2015 by National Institute for Occupational Safety and Health (NIOSH).   Date Released: 11/9/2015.

  7. TEMPERATURE AND pH RESPONSE, AND SWELLING BEHAVIOR OF POROUS ACRYLONITRILE-ACRYLIC ACID COPOLYMER HYDROGELS

    Institute of Scientific and Technical Information of China (English)

    Jian Huang; Zhi-ming Huang; Yong-zhong Bao; Zhi-xue Weng

    2006-01-01

    Macroporous acrylonitrile-acrylic acid (AN-AA) copolymer hydrogels were synthesized by free-radical solution polymerizations, using ammonium persulfate (APS)/N,N,N',N'-tetramethylethylenediamine (TEMED) redox initiator system and alcohols porogens. The morphology, temperature and pH sensitive swelling behavior, and swelling kinetics of the resulting hydrogels were investigated. It was found that alcohol type and concentration had great influences on the pore structure and porosity of hydrogels. The pore size of hydrogel increases with the moderate increase of the length of alcohol alkyl chain. However, a further increase of alkyl length would result in the formation of cauliflower-like structure and the decrease of pore size. The porosity of hydrogels increases with the increase of porogen concentration in the polymerization medium. The hydrogels with macroporous structure swell or shrink much faster in response to the change of pH in comparison with the conventional hydrogel without macroporous structure. Furthermore, the response rate is closely related to the porosity of the hydrogels, which could be easily controlled by modulating the concentration of the porogen in the medium. The circular swelling behavior of hydrogels indicated the formation of a relaxing three-dimensional network.

  8. Free radical induced grafting of acrylonitrile on pre-treated rice straw for enhancing its durability and flame retardancy

    Directory of Open Access Journals (Sweden)

    Aparna Mukherjee

    2017-01-01

    Full Text Available The present investigation highlights the feasibility of a polymer grafting process to enhance the durability and flame retardancy of rice straw towards application as a low cost roofing material. The success of this grafting methodology was perceived to depend upon a bi-step pre-treatment process encompassing delignification and inorganic salts dispersion. Subsequently free radical polymer grafting of acrylonitrile onto rice straw was implemented by immersion mechanism initiated by oxalic acid-potassium permanganate initiator. The percentage of grafting, limiting oxygen index (LOI, biodegradability of the grafted rice straw and grafting yield percentage was estimated to be 57%, 27%, 0.02% and 136.67%, respectively. The weight loss of polymer grafted rice straw implied its less biodegradability over raw straw. Thus, the process of grafting contrived in the present analysis can be a promising and reliable technique for the efficient utilization of rice straw as an inexpensive roofing element through the augmentation of its durability and flame retardancy.

  9. STUDY ON THE POLYMERIZATION OF ACRYLONITRILE INITIATED BY POLYPROPYLENE-BASED VANADYL POLYIMIDODIACETATE——THIOUREA REDOX SYSTEM

    Institute of Scientific and Technical Information of China (English)

    Yang Chaoxiong; Wu Jinyun; Liang Zhenming; Feng Zhouquan

    1989-01-01

    The present paper deals with the kinetics of polymerization of acrylonitrile ( AN ) initiated by the redox system of polypropylene-based vanadyl polyimidodiacetate (PV)-thiourea (TU)in aqueous sulfuric acid in the temperature range from 25 to 40 ℃ . The polymerization rate was measured by varying the concentrations of monomer, vanadyl polyimidodiacetate, thiourea and sulfuric acid. The overall rate of polymerization was summarized as RP =2.2 × 105e-6.860/RT[AN]1.0[PV]0.50[ TU]1.5[H2SO4]2.0 The molecular weight of polyacrylonitrile based on the experimental data was:(-M)n=k·1/T·[AN]/[PV]0.50[TU]1.5[H2SO4]2.0 These results indicated that the chain radicals are terminated by combination and/or disproportionation rather than chain transfer. The cooperation effect of carboxylic groups and the macromolecular field effect of polymer supporter are the characters of vanadyl polyimidodiacetate such as the case reported in early paper[ 1 ].

  10. Correlation Between Miscibility and Rheological Characteristics of the Polystyrene (PS) and Poly(styrene-co-acrylonitrile) (PSAN) Blends

    Science.gov (United States)

    Marwat, Zafrullah Khan; Baloch, Musa Kaleem

    2016-11-01

    Rheological measurement has been an effective technique to characterize the miscibility of polymer blends. This article investigates the viscoelastic behavior of poly(styrene) (PS) and poly(styrene-co-acrylonitrile) (PSAN) binary solutions in tetrahydrofuran (THF) relative to PS/PSAN/THF ternary solutions mainly reporting the findings of the authors involving the correlation between the miscibility and rheological behavior. Rheological properties, such as shear viscosity, and shear stress as a function of shear rate were investigated for different blend compositions. Moreover, complex viscosity, loss and storage moduli were also investigated as functions of both the frequency and blend composition. The criterion of miscibility based on the rule of mixture has been discussed. The present study revealed very small window of miscibility as only composition, 50/50 showed values close to the additivity rule or intermediate to those of the neat polymers, thereby indicating very weak interactions between the blend components. On the basis of various findings during the rheological investigation, the blend under study is classified almost immiscible. Moreover, the obtained results also suggested that the miscibility depends on the blend composition and frequency.

  11. Carboxyl-terminated butadiene-acrylonitrile-toughened epoxy/carboxyl-modified carbon nanotube nanocomposites: Thermal and mechanical properties

    Directory of Open Access Journals (Sweden)

    H. F. Xie

    2012-09-01

    Full Text Available Carboxyl-modified multi-walled carbon nanotubes (MWCNT–COOHs as nanofillers were incorporated into diglycidyl ether of bisphenol A (DGEBA toughened with carboxyl-terminated butadiene-acrylonitrile (CTBN. The carboxyl functional carbon nanotubes were characterized by Fourier-transform infrared spectroscopy and thermogravimetric analysis. Furthermore, cure kinetics, glass transition temperature (Tg, mechanical properties, thermal stability and morphology of DGEBA/CTBN/MWCNT–COOHs nanocomposites were investigated by differential scanning calorimetry (DSC, dynamic mechanical analysis (DMA, universal test machine, thermogravimetric analysis and scanning electron microscopy (SEM. DSC kinetic studies showed that the addition of MWCNT–COOHs accelerated the curing reaction of the rubber-toughened epoxy resin. DMA results revealed that Tg of rubber-toughened epoxy nanocomposites lowered with MWCNT–COOH contents. The tensile strength, elongation at break, flexural strength and flexural modulus of DGEBA/CTBN/MWCNT-COOHs nanocomposites were increased at lower MWCNT-COOH concentration. A homogenous dispersion of nanocomposites at lower MWCNT–COOH concentration was observed by SEM.

  12. Molecular mechanism of gelation upon the addition of water to a solution of poly(acrylonitrile) in dimethylsulfoxide

    Science.gov (United States)

    Vettegren, V. I.; Kulik, V. B.; Savitskii, A. V.; Fetisov, O. I.; Usov, V. V.

    2010-05-01

    The solidification of a solution of poly(acrylonitrile) (PAN) in dimethylsulfoxide (DMSO) upon introduction of water into the solution is studied by Raman spectroscopy. In the absence of water, DMSO molecules are found to produce dipole-dipole bonds with PAN molecules. Upon the introduction of water, DMSO molecules produce hydrogen bonds with it and bands at 1005 and 1015 cm-1 appear in the Raman spectrum, which are assigned to the valence vibrations of S=O bonds involved in the hydrogen bonds. Simultaneously, water molecules produce hydrogen bonds with PAN molecules: R-C≡N...H-O-H...N≡C-R, where R is the carbon skeleton of a PAN molecule. Accordingly, a band at 2250 cm-1 arises in the Raman spectrum, which is assigned to the valence vibrations of C≡N bonds producing hydrogen bonds with a water molecule. When the water content is low and the DMSO concentration is high, the length of the hydrogen bonds varies in wide limits and the band at 2250 cm-1 is wide. As the water content rises, DMSO molecules come out of PAN, the variation of the hydrogen bond length in it decreases (the band at 2250 cm-1 narrows), and a high-viscosity system (gel) arises that consists of PAN molecules bonded to water molecules via “equally strong” hydrogen bonds.

  13. Reclamation of post-consumer plastics for development of polycarbonate and acrylonitrile butadiene styrene based nanocomposites with nanoclay

    Science.gov (United States)

    Zicans, Janis; Meri, Remo Merijs; Ivanova, Tatjana; Berzina, Rita; Saldabola, Ruuta; Maksimov, Robert

    2016-05-01

    Suitability of recycled acrylonitrile-butadiene-styrene (R-ABS) and recycled polycarbonate (R-PC) for the development of polymer matrix nanocomposites with organically modified nanoclay (OMMT) is evaluated in comparison to virgin polymers (V-ABS and V-PC) based systems. The influence of OMMT content on the structure as well as calorimetric, mechanical and thermal properties of virgin and recycled polymers containing systems is revealed. Increase in stiffness and strength of virgin and recycled polymers based systems is observed along with rising nanoclay content. However, it is observed that reinforcing efficiency of clays on the R-ABS containing systems is reduced to certain extent in comparison to those, based on virgin polymers. It is shown, that in the presence of OMMT approximation of glass transition temperatures of both polymeric components is observed, which can testify about certain improvement of compatibility between PC and ABS. Increment of the modulus of elasticity and yield strength of the nanocomposites is associated with anisodiametric shape of OMMT, as well as with intercalation of polymer within the interlaminar space of the clay nanoparticles. It is also demonstrated that addition of nanoclay improves thermogravimetric behavior of the investigated compositions. Consequently, it is suggested that nanoclays can be used as promising functional additives and replace halogenated flame-retardants, without reducing mechanical properties of the composites.

  14. Effect of PAHM (Poly-acrylonitrile Hollow Microsphere) addition on the Lightweight and Firing Behavior of Whiteware

    Science.gov (United States)

    Choi, H. S.; Pee, J. H.; Kim, G. H.; Kim, J. Y.; Cho, W. S.; Kim, K. J.

    2011-10-01

    The pore generation technology using PAHM (Poly-acrylonitrile Hollow Microsphere) was studied in order to reduce the weights of tableware. In this study, we verify the property of modified slurry and plasticity of green body by adding PAHM. The modified slurry was prepared by adding 25~55vol% of PAHM to the slurry for whiteware. The viscosity of slurry was controlled to be low value (25~45vol%). However, the viscosity of modified slurry increased and the plasticity of modified green body decreased inside the 45~55vol% range. The formed specimen by slip casting was fired at 1225 °C, 1240°C. As the amount of PAHM content increased, the weight decreased and the addition of 45vol/% of PAHM resulted in a weight drop of 39%. However, when the PAHM content increased, the strength decreases over 50%. This is caused by the presence of a large volume of surface defects (pores) and defects from the agglomeration of PAHM.

  15. N-acetyl-S-(1-cyano-2-hydroxyethyl)-L-cysteine, a new urinary metabolite of acrylonitrile and oxiranecarbonitrile.

    Science.gov (United States)

    Linhart, I; Smejkal, J; Novák, J

    1988-01-01

    Two mercapturic acids, i.e., N-acetyl-S-(1-cyano-2-hydroxyethyl)-L-cysteine (CHEMA) and N-acetyl-S-(2-hydroxyethyl)-L-cysteine (HEMA), were isolated from the urine of rats dosed with four successive doses of oxiranecarbonitrile (glycidonitrile, GN), 5 mg/kg, a reactive metabolic intermediate of acrylonitrile (AN). GC-MS analysis of methylated urine extracts from both AN- and GN-dosed rats showed another mercapturate which was identified as N-acetyl-S-(1-cyanoethenyl)-L-cysteine (1-CEMA) methyl ester using an authentic reference sample. The mass spectrum of this compound was very similar to that of a methylated metabolite of AN tentatively identified by Langvardt et al. (1980) as N-acetyl-3-carboxy-5-cyanothiazane (ACCT). In contrast, no ACCT was found in rats dosed with either GN or AN. Hence, there is no evidence for the formation of ACCT or its isomers in rats dosed with AN or GN. The methyl ester of 1-CEMA is formed artificially by dehydration of CHEMA methyl ester in the injector of the gas chromatograph.

  16. Identification of alkylbenzene sulfonate surfactants leaching from an acrylonitrile butadiene rubber as novel inhibitors of calcineurin activity.

    Science.gov (United States)

    Ito, Noboru; Shibuguchi, Nao; Ishikawa, Ryoki; Tanaka, Susumu; Tokita, Yoshiharu; Nakajima-Shimada, Junko; Hosaka, Kohei

    2013-01-01

    Calcineurin (CN) is a Ca(2+)/calmodulin (CaM) dependent serine/threonine protein phosphatase and plays important role in several cellular functions in both higher and lower eukaryotes. Here we report inhibition of CN by linear alkylbenzene sulfonate. The clue to the finding was obtained while identifying the inhibitory material leaching from acrylonitrile butadiene rubber used for packing. Using standard dodecylbenzene sulfonate (C12-LAS), we obtained strong inhibition of CN with a half maximal inhibitory concentration of 9.3 µM, whereas analogs such as p-octylbenzene sulfonate and SDS hardly or only slightly affected CN activity. Three alkaline phosphatases, derived from shrimp, bacteria, and calf-intestine, which exhibit similar enzymatic activities to CN, were not inhibited by C12-LAS at concentrations of up to 100 µM. Furthermore, C12-LAS did not inhibit Ca(2+)/CaM-dependent myosin light chain kinase activity when tested at concentrations of up to 36 µM. The results indicate that C12-LAS is a potent selective inhibitor of CN activity.

  17. Evaluation of the detoxication efficiencies for acrylonitrile wastewater treated by a combined anaerobic oxic-aerobic biological fluidized tank (A/O-ABFT) process: Acute toxicity and zebrafish embryo toxicity.

    Science.gov (United States)

    Na, Chunhong; Zhang, Ying; Deng, Minjie; Quan, Xie; Chen, Shuo; Zhang, Yaobin

    2016-07-01

    Acrylonitrile (ACN) wastewater generated during ACN production has been reported to be toxic to many aquatic organisms. However, few studies have evaluated toxicity removal of ACN wastewater during and after the treatment process. In this study, the detoxication ability of an ACN wastewater treatment plant (WWTP) was evaluated using Daphnia magna, Danio rerio and zebrafish embryo. This ACN WWTP has a combined anaerobic oxic-aerobic biological fluidized tank (A/O-ABFT) process upgraded from the traditional anaerobic oxic (A/O) process. Moreover, the potential toxicants of the ACN wastewaters were identified by gas chromatography-mass spectrometry (GC-MS). The raw ACN wastewater showed high acute and embryo toxicity. 3-Cyanopyridine, succinonitrile and a series of nitriles were detected as the toxic contributors of ACN wastewater. The A/O process was effective for the acute and embryo toxicity removal, as well as the organic toxicants. However, the A/O effluent still showed acute and embryo toxicity which was attributed by the undegraded and the newly generated toxicants during the A/O process. The residual acute and embryo toxicity as well as the organic toxicants in the A/O effluent were further reduced after going through the downstream ABFT process system. The final effluent displayed no significant acute and embryo toxicity, and less organic toxicants were detected in the final effluent. The upgrade of this ACN WWTP results in the improved removal efficiencies for acute and embryo toxicity, as well as the organic toxicants.

  18. Chip-size-packaged silicon microphones [for hearing instruments

    DEFF Research Database (Denmark)

    Müllenborn, Matthias; Rombach, Pirmin; Klein, Udo;

    2001-01-01

    The first results of silicon microphones that are completely batch-packaged and integrated with signal conditioning circuitry in a chip stack are discussed. The chip stack is designed to be directly mounted into a system, such as a hearing instrument, without further single-chip handling or wire ...... consumption of about 50 μW in the near future, thereby living up to the tight specifications of microphones for hearing instruments. Other potential applications include mobile phones, headsets, and wearable computers, in which space is constrained....

  19. Psychosocial Aspects of Hearing Loss in Children.

    Science.gov (United States)

    Sorkin, Donna L; Gates-Ulanet, Patricia; Mellon, Nancy K

    2015-12-01

    Pediatric hearing loss changed more in the past two decades than it had in the prior 100 years with children now identified in the first weeks of life and fit early with amplification. Dramatic improvements in hearing technology allow children the opportunity to listen, speak and read on par with typically hearing peers. National laws mandate that public and private schools, workplaces, and anywhere people go must be accessible to individuals with disabilities. In 2015, most children with hearing loss attended mainstream schools with typically hearing peers. Psychosocial skills still present challenges for some children with hearing loss.

  20. Auditory-model based assessment of the effects of hearing loss and hearing-aid compression on spectral and temporal resolution

    DEFF Research Database (Denmark)

    Kowalewski, Borys; MacDonald, Ewen; Strelcyk, Olaf

    2016-01-01

    Most state-of-the-art hearing aids apply multi-channel dynamic-range compression (DRC). Such designs have the potential to emulate, at least to some degree, the processing that takes place in the healthy auditory system. One way to assess hearing-aid performance is to measure speech intelligibility....... However, due to the complexity of speech and its robustness to spectral and temporal alterations, the effects of DRC on speech perception have been mixed and controversial. The goal of the present study was to obtain a clearer understanding of the interplay between hearing loss and DRC by means...

  1. AFSC/NMML: Bristol Bay Beluga hearing sensitivity, August 2012 and 2014

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Hearing sensitivity data was collected on beluga whales in Bristol Bay with auditory evoked potential (AEP) methods for the frequencies 4, 8, 11.2, 16, 22.5, 32, 45,...

  2. Noise-induced hearing loss and symphony orchestra musicians: risk factors, effects, and management.

    Science.gov (United States)

    Teie, P U

    1998-01-01

    Although industrial and recreational noise have been recognized as potential causes of noise-induced hearing loss for quite some time, it is only recently that the sound levels within a symphony orchestra have been implicated as possible sources of harmful noise levels. Many studies have concluded that not only are dangerous levels of noise present within the symphony orchestra, but there is evidence of noise-induced hearing loss among symphony orchestra musicians. Although hearing protection designed for industrial use may not be appropriate for the special listening needs of professional musicians, recent advances in hearing protection design have made hearing protection practical for this population. Suggestions are made for monitoring and protecting the professional ear.

  3. Challenges and successes in recruiting firefighters for hearing loss prevention research.

    Science.gov (United States)

    Hong, OiSaeng; Fiola, Lauren Ann; Feld, Jamie

    2013-06-01

    Noise-induced hearing loss (NIHL) is a significant occupational health problem in the United States, affecting more than 1 million firefighters. Noise hazards include vehicles, sirens, and power tools. Additionally, firefighters are commonly exposed to ototoxic chemicals. Because the use of hearing protection is not universally required for firefighters, firefighters must be educated about NIHL to ensure they take personal responsibility for hearing loss prevention. This study discusses challenges associated with recruiting firefighters to participate in a randomized, controlled trial testing a web-based hearing protection training program. Successful recruitment strategies included collaboration with key stakeholders, a flexible and convenient computer-based intervention, expansion to multiple recruitment sites, and interactive outreach to potential participants. Future research should use quantitative methods to evaluate and compare the effectiveness of specific recruitment strategies to facilitate firefighter enrollment in research studies. Developing and testing effective hearing protection interventions for firefighters is a crucial first step toward preventing NIHL in this population.

  4. Cross-Modal Re-Organization in Clinical Populations with Hearing Loss

    Directory of Open Access Journals (Sweden)

    Anu Sharma

    2016-01-01

    Full Text Available We review evidence for cross-modal cortical re-organization in clinical populations with hearing loss. Cross-modal plasticity refers to the ability for an intact sensory modality (e.g., vision or somatosensation to recruit cortical brain regions from a deprived sensory modality (e.g., audition to carry out sensory processing. We describe evidence for cross-modal changes in hearing loss across the age-spectrum and across different degrees of hearing impairment, including children with profound, bilateral deafness with cochlear implants, single-sided deafness before and after cochlear implantation, and adults with early-stage, mild-moderate, age-related hearing loss. Understanding cross-modal plasticity in the context of auditory deprivation, and the potential for reversal of these changes following intervention, may be vital in directing intervention and rehabilitation options for clinical populations with hearing loss.

  5. Acoustics and Hearing

    CERN Document Server

    Damaske, Peter

    2008-01-01

    When one listens to music at home, one would like to have an acoustic impression close to that of being in the concert hall. Until recently this meant elaborate multi-channelled sound systems with 5 or more speakers. But head-related stereophony achieves the surround-sound effect in living rooms with only two loudspeakers. By virtue of their slight directivity as well as an electronic filter the limitations previously common to two-speaker systems can be overcome and this holds for any arbitrary two-channel recording. The book also investigates the question of how a wide and diffuse sound image can arise in concert halls and shows that the quality of concert halls decisively depends on diffuse sound images arising in the onset of reverberation. For this purpose a strong onset of reverberation is modified in an anechoic chamber by electroacoustic means. Acoustics and Hearing proposes ideas concerning signal processing in the auditory system that explain the measured results and the resultant sound effects plea...

  6. Mouse otocyst transuterine gene transfer restores hearing in mice with connexin 30 deletion-associated hearing loss.

    Science.gov (United States)

    Miwa, Toru; Minoda, Ryosei; Ise, Momoko; Yamada, Takao; Yumoto, Eiji

    2013-06-01

    Although numerous causative genes for hereditary hearing loss have been identified, there are no fundamental treatments for this condition. Herein, we describe a novel potential treatment for genetic hearing loss. Because mutations or deletions in the connexin (Cx) genes are common causes of profound congenital hearing loss in both humans and mice, we investigated whether gene supplementation therapy using the wild-type Cx gene could cure hearing loss. We first generated inner ear-specific connexin 30 (Cx30)-deficient mice via the transuterine transfer of Cx30-targeted short hairpin RNA (shRNA-Cx30) into otocysts. The inner ear-specific Cx30-deficient mice mimicked homozygous Cx30-deficient mice both histologically and physiologically. Subsequently, we cotransfected the shRNA-Cx30 and the wild-type Cx30 gene. The cotransfected mice exhibited Cx30 expression in the cochleae and displayed normal auditory functions. Next, we performed the transuterine transfer of the wild-type Cx30 gene into the otocysts of homozygous Cx30-deficient mice, thereby rescuing the lack of Cx30 expression in the cochleae and restoring auditory functioning. These results demonstrate that supplementation therapy with wild-type genes can restore postnatal auditory functioning. Moreover, this is the first report to show that Cx-related genetic hearing loss is treatable by in vivo gene therapy.

  7. Opportunistic hearing screening in elderly inpatients

    Directory of Open Access Journals (Sweden)

    Krishan Ramdoo

    2014-04-01

    Full Text Available Objective: To determine the prevalence of occult hearing loss in elderly inpatients, to evaluate feasibility of opportunistic hearing screening and to determine subsequent provision of hearing aids. Materials and methods: Subjects (>65 years were recruited from five elderly care wards. Hearing loss was detected by a ward-based hearing screen comprising patient-reported assessment of hearing disability and a whisper test. Subjects failing the whisper test or reporting hearing difficulties were offered formal audiological assessment. Results: Screening was performed on 51 patients aged between 70 and 95 years. Of the patients, 21 (41% reported hearing loss and 16 (31% failed the whisper test. A total of 37 patients (73% were referred for audiological assessment with 17 (33% found to have aidable hearing loss and 11 were fitted with hearing aids (22%. Discussion: This study highlights the high prevalence of occult hearing loss in elderly inpatients. Easy two-step screening can accurately identify patients with undiagnosed deafness resulting in significant proportions receiving hearing aids. Key sentences Approximately 14% of the elderly population use hearing aids despite a reported prevalence of deafness in up to 55%. The use of hearing aids is associated with an improvement in physical, emotional, mental and social well-being. An easy screening test for hearing loss consists of patient-reported hearing loss and a whisper test. Opportunistic screening of elderly inpatients resulted in referral of 73% of screened patients for formal audiology. Of the screened patients, 22% were provided with hearing aids.

  8. Dispensing Rates of Four Common Hearing Aid Product Features: Associations With Variations in Practice Among Audiologists

    OpenAIRE

    Johnson, Earl E.; Ricketts, Todd A.

    2010-01-01

    The purpose of the study was to develop and examine a list of potential variables that may account for variability in the dispensing rates of four common hearing aid features. A total of 29 potential variables were identified and placed into the following categories: (1) characteristics of the audiologist, (2) characteristics of the hearing aids dispensed by the audiologist, (3) characteristics of the audiologist's patient population, and (4) evidence-based practice grades of recommendation f...

  9. 17 CFR 204.38 - Pre-offset hearing.

    Science.gov (United States)

    2010-04-01

    ... 17 Commodity and Securities Exchanges 2 2010-04-01 2010-04-01 false Pre-offset hearing. 204.38... DEBT COLLECTION Salary Offset § 204.38 Pre-offset hearing. (a) The hearing official shall determine the... of the hearing official. (f) Pre-offset “paper” hearing. If a hearing is to be held only upon...

  10. Hearing Assessment in Zebrafish During the First Week Postfertilization.

    Science.gov (United States)

    Yao, Qi; DeSmidt, Alexandra A; Tekin, Mustafa; Liu, Xuezhong; Lu, Zhongmin

    2016-04-01

    The zebrafish (Danio rerio) is a valuable vertebrate model for human hearing disorders because of many advantages in genetics, embryology, and in vivo visualization. In this study, we investigated auditory function of zebrafish during the first week postfertilization using microphonic potential recording. Extracellular microphonic potentials were recorded from hair cells in the inner ear of wild-type AB and transgenic Et(krt4:GFP)(sqet4) zebrafish at 3, 5, and 7 days postfertilization in response to 20, 50, 100, 200, 300, and 400-Hz acoustic stimulation. We found that microphonic threshold significantly decreased with age in zebrafish. However, there was no significant difference of microphonic responses between wild-type and transgenic zebrafish, indicating that the transgenic zebrafish have normal hearing like wild-type zebrafish. In addition, we observed that microphonic threshold did not change with the recording electrode location. Furthermore, microphonic threshold increased significantly at all tested stimulus frequencies after displacement of the saccular otolith but only increased at low frequencies after displacement of the utricular otolith, showing that the saccule rather than the utricle plays the major role in larval zebrafish hearing. These results enhance our knowledge of early development of auditory function in zebrafish and the factors affecting hearing assessment with microphonic potential recording.

  11. Properties of hydrogenated butadiene-acrylonitrile rubber plasticized by hydroxyl terminated poly (butadiene-co-acrylonitrile)%端羟基液体丁腈橡胶增塑氢化丁腈橡胶的性能

    Institute of Scientific and Technical Information of China (English)

    李再峰; 董慧民; 刘晓丹; 李敏婷; 张成龙; 熊召举

    2011-01-01

    The hydrogenated butadiene-acrylonitrile( HNBR ) was plasticized by hydroxyl terminated poly ( butadiene-co-acrylonitrile ) ( HTBN ), the structure and properties of plasticized rubber were characterized with pulsed nuclear magnetic resonance, differential scanning calorimetry, thermogravimetric analysis and stress-strain test, and the plasticization effect of HTBN was compared with plasticizer TP-95,TP-90 B and TP-759. The results indicated that HTBN worked as the common plasticizer like TP-95, TP-90 B and TP-759, resulting in the decrease of HNBR Mooney viscosity, on the other hand, it worked as a reactive species, the free radical in the vulcanization system intiated the adjacent crosslinking reaction between HTBN double bond and HNBR macromolecular backbone , thus increasing the crosslinking density, tensile strength,modulus at 100% and Shore A hardness of vulcanizates, improving the heat resistance but the glass transition temperature ( no significant change ) .When HTBN was 3 phr, the tensile strength of HNBR vulcanizate reached 41. 7 MPa, the Mooney viscosity was lower and the heat aging property was better.%利用核磁共振仪、差示扫描量热仪、热重分析仪和材料拉伸试验机等研究了端羟基液体丁腈橡胶增塑氢化丁腈橡胶的结构与性能,并与增塑剂TP-95、TP-90 B及TP-759的增塑效果进行了对比.结果表明,端羟基液体丁腈橡胶增塑氢化丁腈橡胶后,一方面起到了与TP-95、TP-90 B和TP-759类似的增塑作用,如降低了混炼胶的门尼黏度;另一方面作为一种反应性增塑剂,在体系中自由基的引发下其结构双键与氢化丁腈橡胶分子主链发生了邻接交联反应,使硫化胶的交联密度、拉伸强度、100%定伸应力和硬度都增大,耐热性能提高,而玻璃化转变温度没有变化.端羟基液体丁腈橡胶用量为3份(质量)时其所增塑氢化丁腈橡胶的拉伸强度高达41.7 MPa,且具有较低的门尼黏度和较好的热老化性能.

  12. Cross-modal re-organization in adults with early stage hearing loss.

    Science.gov (United States)

    Campbell, Julia; Sharma, Anu

    2014-01-01

    Cortical cross-modal re-organization, or recruitment of auditory cortical areas for visual processing, has been well-documented in deafness. However, the degree of sensory deprivation necessary to induce such cortical plasticity remains unclear. We recorded visual evoked potentials (VEP) using high-density electroencephalography in nine persons with adult-onset mild-moderate hearing loss and eight normal hearing control subjects. Behavioral auditory performance was quantified using a clinical measure of speech perception-in-noise. Relative to normal hearing controls, adults with hearing loss showed significantly larger P1, N1, and P2 VEP amplitudes, decreased N1 latency, and a novel positive component (P2') following the P2 VEP. Current source density reconstruction of VEPs revealed a shift toward ventral stream processing including activation of auditory temporal cortex in hearing-impaired adults. The hearing loss group showed worse than normal speech perception performance in noise, which was strongly correlated with a decrease in the N1 VEP latency. Overall, our findings provide the first evidence that visual cross-modal re-organization not only begins in the early stages of hearing impairment, but may also be an important factor in determining behavioral outcomes for listeners with hearing loss, a finding which demands further investigation.

  13. Cross-modal re-organization in adults with early stage hearing loss.

    Directory of Open Access Journals (Sweden)

    Julia Campbell

    Full Text Available Cortical cross-modal re-organization, or recruitment of auditory cortical areas for visual processing, has been well-documented in deafness. However, the degree of sensory deprivation necessary to induce such cortical plasticity remains unclear. We recorded visual evoked potentials (VEP using high-density electroencephalography in nine persons with adult-onset mild-moderate hearing loss and eight normal hearing control subjects. Behavioral auditory performance was quantified using a clinical measure of speech perception-in-noise. Relative to normal hearing controls, adults with hearing loss showed significantly larger P1, N1, and P2 VEP amplitudes, decreased N1 latency, and a novel positive component (P2' following the P2 VEP. Current source density reconstruction of VEPs revealed a shift toward ventral stream processing including activation of auditory temporal cortex in hearing-impaired adults. The hearing loss group showed worse than normal speech perception performance in noise, which was strongly correlated with a decrease in the N1 VEP latency. Overall, our findings provide the first evidence that visual cross-modal re-organization not only begins in the early stages of hearing impairment, but may also be an important factor in determining behavioral outcomes for listeners with hearing loss, a finding which demands further investigation.

  14. Preference for Consonance over Dissonance by Hearing Newborns of Deaf Parents and of Hearing Parents

    Science.gov (United States)

    Masataka, Nobuo

    2006-01-01

    Behavioral preferences for consonance over dissonance were tested in hearing infants of deaf parents and in hearing infants of hearing parents when they were 2 days old. Using a modified visual-fixation-based, auditory-preference procedure, I found that both 2-day-old infants of deaf parents and those of hearing parents looked longer at a visual…

  15. Low empathy in deaf and hard of hearing (preadolescents compared to normal hearing controls.

    Directory of Open Access Journals (Sweden)

    Anouk P Netten

    Full Text Available The purpose of this study was to examine the level of empathy in deaf and hard of hearing (preadolescents compared to normal hearing controls and to define the influence of language and various hearing loss characteristics on the development of empathy.The study group (mean age 11.9 years consisted of 122 deaf and hard of hearing children (52 children with cochlear implants and 70 children with conventional hearing aids and 162 normal hearing children. The two groups were compared using self-reports, a parent-report and observation tasks to rate the children's level of empathy, their attendance to others' emotions, emotion recognition, and supportive behavior.Deaf and hard of hearing children reported lower levels of cognitive empathy and prosocial motivation than normal hearing children, regardless of their type of hearing device. The level of emotion recognition was equal in both groups. During observations, deaf and hard of hearing children showed more attention to the emotion evoking events but less supportive behavior compared to their normal hearing peers. Deaf and hard of hearing children attending mainstream education or using oral language show higher levels of cognitive empathy and prosocial motivation than deaf and hard of hearing children who use sign (supported language or attend special education. However, they are still outperformed by normal hearing children.Deaf and hard of hearing children, especially those in special education, show lower levels of empathy than normal hearing children, which can have consequences for initiating and maintaining relationships.

  16. Noise induced hearing loss and other hearing complaints among musicians of symphony orchestras

    NARCIS (Netherlands)

    Jansen, E.J.M.; Helleman, H.W.; Dreschler, W.A.; de Laat, J.A.P.M.

    2009-01-01

    OBJECTIVES: An investigation of the hearing status of musicians of professional symphony orchestras. Main questions are: (1) Should musicians be treated as a special group with regard to hearing, noise, and noise related hearing problems (2) Do patterns of hearing damage differ for different instrum

  17. 丁腈橡胶臭氧化制备羧基丁腈橡胶%Preparation of carboxylated acrylonitrile-butadiene rubber by ozonization of acrylonitrile-butadiene rubber

    Institute of Scientific and Technical Information of China (English)

    刘健; 程斌

    2011-01-01

    Carboxylated acrylnitrile-butadiene rubber(CNBR) was prepared via ozonization of acrylonitrile-butadiene rubber(NBR) in butyl acetate.Effects of reaction time, reaction temperature, the ozone flow rate and NBR concentration on intrinsic viscosity and acid value of CNBR were investigated.The results showed that higher reaction temperature,higher ozone flow rate and lower concentration of NBR could obviously increase the content of carboxylic group in CNBR and shorten the chain length of NBR. However, the factor of reaction time had a different performance. At the beginning, the intrinsic viscosity of CNBR rapidly dropped, but kept unchanged from some moment. And there was no influence of reaction time on acid value of CNBR.%以臭氧氧化丁腈橡胶合成了羧基丁腈橡胶,研究了反应时间、反应温度、臭氧通入量及丁腈橡胶胶液质量浓度对产物特性黏数和酸值的影响.结果表明,以丁腈橡胶臭氧化制备羧基丁腈橡胶,在实验范围内,反应温度升高、增大臭氧通入量和降低丁腈橡胶胶液质量浓度可以提高羧基丁腈橡胶的羧基含量,降低丁腈橡胶的相对分子质量.但是反应时间的影响较为复杂,开始时丁腈橡胶相对分子质量降低很快,到达某个时刻后保持不变.反应时间对羧基丁腈橡胶的酸值没有影响.

  18. Pragmatic Abilities of Children with Hearing Loss Using Cochlear Implants or Hearing Aids Compared to Hearing Children

    Science.gov (United States)

    Most, Tova; Shina-August, Ella; Meilijson, Sara

    2010-01-01

    This study characterized the profile of pragmatic abilities among 24 children with hearing loss (HL) aged 6.3-9.4 years, 13 using hearing aids (HAs) and 11 using cochlear implants (CIs), in comparison to those of 13 hearing children with similar chronological and language ages. All the children with HL used spoken language, attended regular…

  19. Hearing Disorders and Sensorineural Aging

    Directory of Open Access Journals (Sweden)

    Alessandra Fioretti

    2014-01-01

    Full Text Available The physiological age-related hearing loss is defined as presbycusis and it is characterized by reduced hearing sensitivity and problems in understanding spoken language especially in a noisy environment. In elderly the reduced speech recognition is generally caused by a reduction of the cochlear cells in the organ of Corti and degeneration of the central auditory pathways. In order to have a complete management strategy of central and peripheral presbycusis the diagnostic evaluation should include clinical ENT examination, standard audiological tests, and tests of central auditory function. Treatment should include not only the appropriate instruments for peripheral compensation but also auditory rehabilitative training and counseling to prevent social isolation and loss of autonomy. Other common hearing disorders in elderly are tinnitus and hyperacusis which are often undervalued. Tinnitus is characterized by the perception of a “phantom” sound due to abnormal auditory perception. Hyperacusis is defined as a reduced tolerance to ordinary environmental sounds. Furthermore auditory, visual, nociceptive, and proprioceptive systems may be involved together in a possible context of “sensorineural aging.” The aim of this review is to underline the presence of hearing disorders like tinnitus and hyperacusis which in many cases coexist with hearing loss in elderly.

  20. Hearing Loss Signals Need for Diagnosis

    Science.gov (United States)

    ... FDA strongly encourages a medical evaluation before the purchase of a hearing aid. Hearing aid sellers are ... feeds Follow FDA on Twitter Follow FDA on Facebook View FDA videos on YouTube View FDA photos ...

  1. Finally, Proof That Hearing Aids Help

    Science.gov (United States)

    ... news/fullstory_163889.html Finally, Proof That Hearing Aids Help High-quality digital devices provide 'significant benefit' ... but solid evidence about the value of hearing aids has been lacking -- until now. New research findings " ...

  2. Hearing Loss Widespread, 'Progressive' in Older Americans

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_160985.html Hearing Loss Widespread, 'Progressive' in Older Americans Rates accelerate especially ... 2016 (HealthDay News) -- A new study finds widespread hearing loss among elderly Americans, with an especially high rate ...

  3. Drug Induced Hearing Loss: What Is Ototoxicity?

    Science.gov (United States)

    ... page please turn JavaScript on. Feature: Drug-Induced Hearing Loss What Is Ototoxicity? Past Issues / Spring 2016 Table ... of patients taking these drugs." "Antibiotics Caused My Hearing Loss..." Gulab Lalwani Photo Courtesy of: Gulab Lalwani When ...

  4. Talking to someone with hearing loss

    Science.gov (United States)

    ... ency/patientinstructions/000361.htm Talking to someone with hearing loss To use the sharing features on this page, ... It may be hard for a person with hearing loss to understand a conversation with another person. Being ...

  5. 10 Ways to Identify Hearing Loss

    Science.gov (United States)

    ... Current Issue Past Issues 10 Ways to Identify Hearing Loss Past Issues / Spring 2007 Table of Contents For ... exposure and other causes. 10 Ways to Identify Hearing Loss Take the following quiz to help determine if ...

  6. 34 CFR 300.512 - Hearing rights.

    Science.gov (United States)

    2010-07-01

    .... (c) Parental rights at hearings. Parents involved in hearings must be given the right to— (1) Have...)(5) of this section provided at no cost to parents. (Authority: 20 U.S.C. 1415(f)(2), 1415(h))...

  7. Hearing Evaluation in Children (For Parents)

    Science.gov (United States)

    ... of Audiology (F-AAA). Hearing Aids and Other Interventions While medical treatments and surgery can help people ... Loss? Going to a Speech Therapist Can Loud Music Hurt My Ears? Going to the Audiologist Hearing ...

  8. Case Factors Affecting Hearing Aid Recommendations by Hearing Care Professionals

    DEFF Research Database (Denmark)

    Gioia, Carmine; Ben-Akiva, Moshe; Jørgensen, Ole;

    2015-01-01

    Background: Professional recommendations to patients concerning hearing instrument (HI) technology levels are not currently evidence-based. Pre-fitting parameters have not been proven to be the primary indicators for optimal patient outcome with different HI technology levels. This results...... in subjective decision-making as regards the technology level recommendation made by professionals. Purpose: The objective of this study is to gain insight into the decision-making criteria utilized by professionals when recommending HI technology levels to hearing-impaired patients....

  9. Identifying Hearing Loss by Means of Iridology

    OpenAIRE

    Stearn, Natalie; Swanepoel, De Wet

    2006-01-01

    Isolated reports of hearing loss presenting as markings on the iris exist, but to date the effectiveness of iridology to identify hearing loss has not been investigated. This study therefore aimed to determine the efficacy of iridological analysis in the identification of moderate to profound sensorineural hearing loss in adolescents. A controlled trial was conducted with an iridologist, blind to the actual hearing status of participants, analyzing the irises of participants with and without ...

  10. Sensorineural hearing loss after magnetic resonance imaging

    DEFF Research Database (Denmark)

    Mollasadeghi, Abolfazl; Mehrparvar, Amir Houshang; Atighechi, Saeid

    2013-01-01

    Magnetic resonance imaging (MRI) devices produce noise, which may affect patient's or operators' hearing. Some cases of hearing impairment after MRI procedure have been reported with different patterns (temporary or permanent, unilateral or bilateral, with or without other symptoms like tinnitus......). In this report, a case of bilateral sensorineural hearing loss in an otherwise healthy patient underwent brain MRI was described. The patient's hearing loss was accompanied with tinnitus and was not improved after 3 months of followup....

  11. Preparation of acrylonitrile butadiene rubber by soap-free emulsion polymerization%无皂乳液聚合制备丁二烯-丙烯腈橡胶

    Institute of Scientific and Technical Information of China (English)

    桂强; 梁琨; 钟启林; 马朋高; 张元寿; 王真琴

    2011-01-01

    In this paper,soap-free acrylonitrile butadiene rubber was prepared using sulfate polymerisable emulsifier KD SE-10 by emulsion copolymerization at low temperature. The article studied the influence of the amount of polymerisable emulsifier on mooney viscosity, bound acrylonitrile content, the gel ratio, tensile strength and molecular weight. And the amount of KD SE-10 was determined as 2. 7%~3.0wt%. Acrylonitrile butadiene rubber prepared has the remarkable characteristics of high-strength,excellent oil resistance and narrow molecular weight distribution.%采用硫酸盐类可聚合乳化剂烯丙氧基壬基苯氧基丙醇聚氧乙烯醚硫酸铵(KD SE-10)通过低温乳液聚合法制备无皂丁腈橡胶.详细考察了可聚合乳化剂用量对门尼粘度、结合丙烯腈含量、凝胶量、拉伸强度、相对分子质量的影响情况,并确定了KD SE-10用量为2.7%~3.0%(质量分数).制得的无皂丁腈橡胶相比普通丁腈橡胶具有显著的高强度、更优良的耐油性、相对分子质量分布窄的特点.

  12. Online Personalization of Hearing Instruments

    Directory of Open Access Journals (Sweden)

    Ypma Alexander

    2008-01-01

    Full Text Available Online personalization of hearing instruments refers to learning preferred tuning parameter values from user feedback through a control wheel (or remote control, during normal operation of the hearing aid. We perform hearing aid parameter steering by applying a linear map from acoustic features to tuning parameters. We formulate personalization of the steering parameters as the maximization of an expected utility function. A sparse Bayesian approach is then investigated for its suitability to find efficient feature representations. The feasibility of our approach is demonstrated in an application to online personalization of a noise reduction algorithm. A patient trial indicates that the acoustic features chosen for learning noise control are meaningful, that environmental steering of noise reduction makes sense, and that our personalization algorithm learns proper values for tuning parameters.

  13. Hearing Aid Fitting & Electrophysiologic Procedure

    Directory of Open Access Journals (Sweden)

    Bahram Jalaei

    2001-05-01

    Full Text Available Rehabilitation of deaf individual is one of the important subjects that has attracted attention of many researchers during past centuries. Different opinions have been established in this direction. Electrophysiologic tests were established and developed parallel to developments in rehabilitation. Therefore, opinion of using electrophysiologic test for evaluation and fitting of hearing aid became gradually popular. Ultimately, the electrophysiologic tests are used in evaluation and fitting of hearing aid in two ways: 1-Direct way 2- Indirect way "nIn direct way aided ABR is obtained and special attention is paid to wave V. This technique has many difficulties. Inindirect way, electrophysiologic tests such, ECochG, OAE and ABR, AMLR, ALR and P300 and other objective tests are used, especially in infants and neonates for evaluating the state of hearing. Researches are continuing in this field. It is probable to have aided electrophysiologic responses with speech stimuli in near future.

  14. Online Personalization of Hearing Instruments

    Directory of Open Access Journals (Sweden)

    Bert de Vries

    2008-09-01

    Full Text Available Online personalization of hearing instruments refers to learning preferred tuning parameter values from user feedback through a control wheel (or remote control, during normal operation of the hearing aid. We perform hearing aid parameter steering by applying a linear map from acoustic features to tuning parameters. We formulate personalization of the steering parameters as the maximization of an expected utility function. A sparse Bayesian approach is then investigated for its suitability to find efficient feature representations. The feasibility of our approach is demonstrated in an application to online personalization of a noise reduction algorithm. A patient trial indicates that the acoustic features chosen for learning noise control are meaningful, that environmental steering of noise reduction makes sense, and that our personalization algorithm learns proper values for tuning parameters.

  15. Bringing Hearing to the Deaf

    Energy Technology Data Exchange (ETDEWEB)

    Shipsey, Ian (Purdue)

    2006-06-12

    In his talk, Shipsey will discuss the cochlear implant, the first device to successfully allow the profoundly deaf to regain some sense of hearing. A cochlear implant is a small electronic apparatus. Unlike a normal hearing aid, which amplifies sound, a cochlear implant is surgically implanted behind the ear where it converts sound waves into electrical impulses. These implants have instigated a popular but controversial revolution in the treatment of deafness, and they serve as a model for research in neuroscience and biomedical engineering. Shipsey will discuss the physiology of natural hearing from the perspective of a physicist. He will also touch on the function of cochlear implants in the context of historical treatments, electrical engineering, psychophysics, clinical evaluation of efficacy and personal experience. Finally, Shipsey will address the social implications of cochlear implantation and the future outlook for auditory prostheses.

  16. Hearing and music in dementia.

    Science.gov (United States)

    Johnson, Julene K; Chow, Maggie L

    2015-01-01

    Music is a complex acoustic signal that relies on a number of different brain and cognitive processes to create the sensation of hearing. Changes in hearing function are generally not a major focus of concern for persons with a majority of neurodegenerative diseases associated with dementia, such as Alzheimer disease (AD). However, changes in the processing of sounds may be an early, and possibly preclinical, feature of AD and other neurodegenerative diseases. The aim of this chapter is to review the current state of knowledge concerning hearing and music perception in persons who have a dementia as a result of a neurodegenerative disease. The review focuses on both peripheral and central auditory processing in common neurodegenerative diseases, with a particular focus on the processing of music and other non-verbal sounds. The chapter also reviews music interventions used for persons with neurodegenerative diseases.

  17. Hearing Loss due to Carbon Monoxide Poisoning

    DEFF Research Database (Denmark)

    Mehrparvar, Amir Houshang; Davari, Mohammad Hossein; Mollasadeghi, Abolfazl;

    2013-01-01

    Carbon monoxide poisoning is one of the rare causes of hearing loss which may cause reversible or irreversible, unilateral or bilateral hearing loss after acute or chronic exposure. In this report, we present a case of bilateral sensorineural hearing loss in a secondary smelting workshop worker...

  18. Noise and Hearing Loss: A Review

    Science.gov (United States)

    Daniel, Eileen

    2007-01-01

    Background: Noise-induced hearing loss is a major cause of deafness and hearing impairment in the United States. Though genetics and advanced age are major risk factors, temporary and permanent hearing impairments are becoming more common among young adults and children especially with the increased exposure to portable music players. Though…

  19. Hearing aid comprising an array of microphones

    NARCIS (Netherlands)

    Boone, M.M.; Berkhout, A.J.; Merks, I.L.D.M.

    1999-01-01

    Hearing aid for improving the hearing ability of the hard of hearing, comprising an array of microphones, the electrical output signals of which are fed to at least one transmission path belonging to an ear. Means are provided for deriving two array output signals from the output signals of the micr

  20. 22 CFR 216.8 - Public hearings.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Public hearings. 216.8 Section 216.8 Foreign Relations AGENCY FOR INTERNATIONAL DEVELOPMENT ENVIRONMENTAL PROCEDURES § 216.8 Public hearings. (a) In most... some cases the Administrator may wish to hold public hearings on draft Environmental Impact...

  1. Adult hearing screening: the Cyprus Pilot Program

    Directory of Open Access Journals (Sweden)

    C. Thodi

    2011-03-01

    Full Text Available Hearing loss is the third most common condition affecting adults over 65 (Cruickshanks et al., 1998. It can affect quality of life, limiting the ability to communicate efficiently, and leading to isolation, psychological strain, and functional decline (LaForge, Spector, Sternberg, 1992; Yueh, Shapiro, MacLean, Shekelle, 2003. Communication limitations impinge on the person directly, as well as the family, friends, and social circle. Reports on hearing loss among adults indicate that less than 25% of people who can benefit from amplification are actually using hearing aids, and that people diagnosed with a hearing loss delay seeking amplification by about seven years (Kochkin, 1997. Often, family members are the driving force behind a person with a hearing loss who decides to seek help. Adult hearing screening programs might have a positive effect on raising public awareness on hearing loss and its implications, and shortening delay time for intervention. There is no routine hearing screening for the adult population in Cyprus. The health system provides hearing tests for beneficiaries upon physician recommendation or self-referral. The Cyprus pilot adult hearing screening program (ΑΠΑΣ- EVERYONE- Greek acronym for Screening- Intervention-Hearing-Participation to Life screened hearing in retired adults.

  2. 22 CFR 401.29 - Hearings.

    Science.gov (United States)

    2010-04-01

    ... Relations INTERNATIONAL JOINT COMMISSION, UNITED STATES AND CANADA RULES OF PROCEDURE References § 401.29 Hearings. (a) A hearing or hearings may be held whenever in the opinion of the Commission such action would be helpful to the Commission in complying with the terms of a reference. Subject to any...

  3. Navigating Your Child's Hearing Loss Diagnosis

    Science.gov (United States)

    Trapp Petty, Melissa A.

    2011-01-01

    For hearing parents, receiving a hearing loss diagnosis for their child can be a shocking event. For some parents, the diagnosis is the fulfillment of a hunch; confirmation of the suspected, but still scary verdict. Recent research finds that the period directly after hearing loss diagnosis is the most stressful and burdensome for parents,…

  4. 42 CFR 431.222 - Group hearings.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 4 2010-10-01 2010-10-01 false Group hearings. 431.222 Section 431.222 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Recipients Right to Hearing § 431.222 Group hearings. The agency— (a) May respond to a series of...

  5. 11 CFR 7.28 - Hearing date.

    Science.gov (United States)

    2010-01-01

    ... 11 Federal Elections 1 2010-01-01 2010-01-01 false Hearing date. 7.28 Section 7.28 Federal... for Administrative Enforcement Proceedings § 7.28 Hearing date. (a) Setting of date by examiner. The examiner shall set the hearing at a reasonable time, date, and place. (b) Considerations....

  6. Role of cytochrome P450 2E1 in the metabolism of acrylamide and acrylonitrile in mice.

    Science.gov (United States)

    Sumner, S C; Fennell, T R; Moore, T A; Chanas, B; Gonzalez, F; Ghanayem, B I

    1999-11-01

    Acrylonitrile (AN) and acrylamide (AM) are commonly used in the synthesis of plastics and polymers. In rodents, AM and AN are metabolized to the epoxides glycidamide and cyanoethylene oxide, respectively. The aim of this study was to determine the role of cytochrome P450 in the metabolism of AM and AN in vivo. Wild-type (WT) mice, WT mice pretreated with aminobenzotriazole (ABT, 50 mg/kg ip, 2 h pre-exposure), and mice devoid of cytochrome P450 2E1 (P450 2E1-null) were treated with 50 mg/kg [(13)C]AM po. WT mice and P450 2E1-null mice were treated with 2.5 or 10 mg/kg [(13)C]AN po. Urine was collected for 24 h, and metabolites were characterized using (13)C NMR. WT mice excreted metabolites derived from the epoxides and from direct GSH conjugation with AM or AN. Only metabolites derived from direct GSH conjugation with AM or AN were observed in the urine from ABT-pretreated WT mice and P450 2E1-null mice. On the basis of evaluation of urinary metabolites at these doses, these data suggest that P450 2E1 is possibly the only cytochrome P450 enzyme involved in the metabolism of AM and AN in mice, that inhibiting total P450 activity does not result in new pathways of non-P450 metabolism of AM, and that mice devoid of P450 2E1 do not excrete metabolites of AM or AN that would be produced by oxidation by other cytochrome P450s. P450 2E1-null mice may be an appropriate model for the investigation of the role of oxidative metabolism in the toxicity or carcinogenicity of these compounds.

  7. Simultaneous quantitation of urinary cotinine and acrylonitrile-derived mercapturic acids with ultraperformance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Wu, Chia-Fang; Uang, Shi-Nian; Chiang, Su-Yin; Shih, Wei-Chung; Huang, Yu-Fang; Wu, Kuen-Yuh

    2012-02-01

    Acrylonitrile (AN), a widely used industrial chemical also found in tobacco smoke, has been classified as a possible human carcinogen (group 2B) by the International Agency for Research on Cancer. AN can be detoxified by glutathione S-transferase (GST) to form glutathione (GSH) conjugates in vivo. It can be metabolically activated by cytochrome P450 2E1 to form 2-cyanoethylene oxide, which can also be detoxified by GST to generate GSH conjugates. The GSH conjugates can be further metabolized to mercapturic acids (MAs), namely, N-acetyl-S-(2-cyanoethyl)cysteine (CEMA), N-acetyl-S-(2-hydroxyethyl)cysteine (HEMA), and N-acetyl-S-(1-cyano-2-hydroxyethyl)cysteine (CHEMA). This study developed an ultraperformance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS) method to quantitatively profile the major AN urinary metabolites (CEMA, HEMA, and CHEMA) to assess AN exposure, as well as analyze urinary cotinine (COT) as an indicator for tobacco smoke exposure. The limits of quantitation were 0.1, 0.1, 1.0, and 0.05 μg/L for HEMA, CEMA, CHEMA, and COT, respectively. This method was applied to analyze the three AN-derived MAs in 36 volunteers with no prior occupational AN exposure. Data analysis showed significant correlations between the level of COT and the levels of these MAs, suggesting them as biomarkers for exposure to low levels of AN. The results demonstrate that a highly specific and sensitive UPLC-MS/MS method has been successfully developed to quantitatively profile the major urinary metabolites of AN in humans to assess low AN exposure.

  8. Noise-induced hearing loss

    Directory of Open Access Journals (Sweden)

    Mariola Sliwinska-Kowalska

    2012-01-01

    Full Text Available Noise-induced hearing loss (NIHL still remains a problem in developed countries, despite reduced occupational noise exposure, strict standards for hearing protection and extensive public health awareness campaigns. Therefore NIHL continues to be the focus of noise research activities. This paper summarizes progress achieved recently in our knowledge of NIHL. It includes papers published between the years 2008-2011 (in English, which were identified by a literature search of accessible medical and other relevant databases. A substantial part of this research has been concerned with the risk of NIHL in the entertainment sector, particularly in professional, orchestral musicians. There are also constant concerns regarding noise exposure and hearing risk in "hard to control" occupations, such as farming and construction work. Although occupational noise has decreased since the early 1980s, the number of young people subject to social noise exposure has tripled. If the exposure limits from the Noise at Work Regulations are applied, discotheque music, rock concerts, as well as music from personal music players are associated with the risk of hearing loss in teenagers and young adults. Several recent research studies have increased the understanding of the pathomechanisms of acoustic trauma, the genetics of NIHL, as well as possible dietary and pharmacologic otoprotection in acoustic trauma. The results of these studies are very promising and offer grounds to expect that targeted therapies might help prevent the loss of sensory hair cells and protect the hearing of noise-exposed individuals. These studies emphasize the need to launch an improved noise exposure policy for hearing protection along with developing more efficient norms of NIHL risk assessment.

  9. Hearing aid fitting in older persons with hearing impairment: the influence of cognitive function, age, and hearing loss on hearing aid benefit

    Directory of Open Access Journals (Sweden)

    Meister H

    2015-02-01

    Full Text Available Hartmut Meister,1 Sebastian Rählmann,1 Martin Walger,2 Sabine Margolf-Hackl,3 Jürgen Kießling3 1Jean Uhrmacher Institute for Clinical ENT-Research, University of Cologne, Cologne, Germany; 2Department of Otorhinolaryngology, Head and Neck Surgery, University of Cologne, Cologne, Germany; 3Department of Othorhinolaryngology, Head and Neck Surgery, University of Giessen, Giessen, Germany Purpose: To examine the association of cognitive function, age, and hearing loss with clinically assessed hearing aid benefit in older hearing-impaired persons.Methods: Hearing aid benefit was assessed using objective measures regarding speech recognition in quiet and noisy environments as well as a subjective measure reflecting everyday situations captured using a standardized questionnaire. A broad range of general cognitive functions such as attention, memory, and intelligence were determined using different neuropsychological tests. Linear regression analyses were conducted with the outcome of the neuropsychological tests as well as age and hearing loss as independent variables and the benefit measures as dependent variables. Thirty experienced older hearing aid users with typical age-related hearing impairment participated.Results: Most of the benefit measures revealed that the participants obtained significant improvement with their hearing aids. Regression models showed a significant relationship between a fluid intelligence measure and objective hearing aid benefit. When individual hearing thresholds were considered as an additional independent variable, hearing loss was the only significant contributor to the benefit models. Lower cognitive capacity – as determined by the fluid intelligence measure – was significantly associated with greater hearing loss. Subjective benefit could not be predicted by any of the variables considered.Conclusion: The present study does not give evidence that hearing aid benefit is critically associated with cognitive

  10. Analgesic use and the risk of hearing loss in women.

    Science.gov (United States)

    Curhan, Sharon G; Shargorodsky, Josef; Eavey, Roland; Curhan, Gary C

    2012-09-15

    Use of analgesics is common and is associated with increased risk of hearing loss in men; however, the relation has not been examined prospectively in women. The authors prospectively examined the relation between frequency of aspirin, ibuprofen, and acetaminophen use and risk of hearing loss among 62,261 women aged 31-48 years at baseline (1995) in Nurses' Health Study II. The outcome was self-reported hearing loss (n = 10,012), and the follow-up period was 1995-2009. Cox proportional hazards regression was used to adjust for potential confounders. During 764,247 person-years of follow-up, ibuprofen use and acetaminophen use were independently associated with increased risk of hearing loss, but aspirin use was not. For ibuprofen, the multivariate-adjusted relative risk of hearing loss was 1.13 (95% confidence interval (CI): 1.06, 1.19) for use 2-3 days/week, 1.21 (95% CI: 1.11, 1.32) for use 4-5 days/week, and 1.24 (95% CI: 1.14, 1.35) for use ≥6 days/week (P-trend acetaminophen, the corresponding relative risks were 1.11 (95% CI: 1.02, 1.19), 1.21 (95% CI: 1.07, 1.37), and 1.08 (95% CI: 0.95, 1.22), respectively (P-trend = 0.0007). In this study, use of ibuprofen or acetaminophen (but not aspirin) 2 or more days per week was associated with an increased risk of hearing loss in women.

  11. Satisfaction with Hearing Aids Based on Technology and Style among Hearing Impaired Persons

    Science.gov (United States)

    Faraji- Khiavi, Farzad; Dashti, Rezvan; Sameni, Seyyed-Jalal; Bayat, Arash

    2016-01-01

    Introduction: Hearing loss is one of the most disabling impairments. Using a hearing aid as an attempt to improve the hearing problem can positively affect the quality of life for these people. This research was aimed to assess satisfaction of hearing impaired patients with their hearing aids regarding the employed technology and style. Materials and Methods: This descriptive-analytic cross-sectional research was conducted on 187 subjects with hearing loss who were using a hearing aid. The subjects were over 18 years of age and were using a hearing aid for at least 6 months. The Persian version of Satisfaction with Amplification in Daily Life (SADL) questionnaire was the instrument which was used for assessing satisfaction with the hearing aid. Cronbach’s alpha was calculated to be 0.80 for instrument reliability. Results: A significant difference was observed among satisfaction subscales’ mean scores with hearing aid technology. Also a significant difference was observed between the total satisfaction score and the hearing aid model. With respect to the analysis of satisfaction with the hearing aid and its style, cost and services was the only subscale which showed a significant difference (P=0.005). Conclusion: Respondents using hearing aids with different technology and style were estimated to be quite satisfied. Training audiologists in using more appropriate and fitting hearing aids in addition to using self-reporting questionnaires like SADL for estimating patients’ social condition and participation in their life can essentially change their disability condition and countervail their hearing loss. PMID:27738608

  12. A New Approach To Evaluating Metacognition in "Hearing Average-Achieving"; "Hearing Underachieving"; and "Deaf/Hard-of-Hearing" Elementary School Students.

    Science.gov (United States)

    Al-Hilawani, Yasser A.

    2000-01-01

    A study examined differences in metacognition among United Arab Emirates third-graders who were hearing average-achieving (N=58), had hearing impairments (N=25), and who were hearing underachieving (N=33). Students who were hearing average-achieving or had hearing impairments achieved significantly better on a metacognition evaluation than those…

  13. Hearing in Whales and Dolphins: Relevance and Limitations.

    Science.gov (United States)

    Pacini, Aude F; Nachtigall, Paul E

    2016-01-01

    Understanding the hearing of marine mammals has been a priority to quantify and mitigate the impact of anthropogenic sound on these apex predators. Yet our knowledge of cetacean hearing is still limited to a few dozen species, therefore compromising any attempt to design adaptive management strategies. The use of auditory evoked potentials allows scientists to rapidly and noninvasively obtain the hearing data of species rarely available in captivity. Unfortunately, many practical and ethical reasons still limit the availability of large whales, thus restricting the possibility to effectively ensure that anthropogenic sounds have minimum effects on these species. The example of a recent Blainville's beaked whale (Mesoplodon densirostris) audiogram collected after a stranding indicated, for instance, very specialized hearing between 40 and 50 kHz, which corresponded to the frequency-modulated upsweep signals used by this species during echolocation. The methods used during a stranding event are presented along with the major difficulties that have slowed down the scientific community in measuring the audition of large whales and the potential value in obtaining such results when successful.

  14. Plasma very long-chain n-3 polyunsaturated fatty acids and age-related hearing loss in older adults

    NARCIS (Netherlands)

    Dullemeijer, C.; Verhoef, P.; Brouwer, I.A.; Kok, F.J.; Brummer, R.J.; Durga, J.

    2010-01-01

    Objectives: Age-related hearing loss is a common social and health problem in the older adult population. Up until now, very little scientific attention has been given to the potential role of fatty acids in agerelated hearing loss. In this study we investigated whether plasma very long-chain n-3 po

  15. Analysis of audio-vestibular assessment in acute low-tone hearing loss.

    Science.gov (United States)

    Im, Gi Jung; Kim, Sung Kyun; Choi, June; Song, Jae Jun; Chae, Sung Won; Jung, Hak Hyun

    2016-07-01

    Conclusion This study demonstrated excellent hearing recovery following the combined treatment of diuretic and oral steroid, and electrocochleography (ECoG) was significantly higher than normal side. This study reports characteristics of acute low-tone hearing loss (ALHL) that show the greater low-tone hearing loss, the higher ECoG, and excellent recovery, even-though low-tone hearing loss is worse, which can be different compared with sudden deafness. Objective To analyze ALHL without vertigo, this study compared the ALHL group with all patients exhibiting low-tone hearing loss and ear fullness. Hearing changes and vestibular functions were analyzed. Materials and methods ALHL was defined as a mean hearing loss of ≥ 30 dB at 125, 250, and 500 Hz, and ≤ 20 dB at 2, 4, and 8 kHz. From 156 cases of low-tone hearing loss of more than 10 dB without vertigo, 31 met the ALHL criteria and were subjected to audio-vestibular assessments including PTA, ECoG, vestibular evoked myogenic potential (VEMP) testing, and caloric testing. Results In ALHL, low-tone hearing loss was 42.7 ± 9.5 dB, and 83.9% of ALHL significantly recovered by more than 10 dB. The ECoG in ALHL was 0.334 ± 0.11 (higher than 0.25 ± 0.08 on the normal side) and ECoG abnormality was 35.5% (the greater low-tone hearing loss, the higher ECoG value).

  16. Hearing in young adults. Part I: The effects of attitudes and beliefs toward noise, hearing loss, and hearing protector devices.

    Science.gov (United States)

    Keppler, Hannah; Dhooge, Ingeborg; Vinck, Bart

    2015-01-01

    There is great concern regarding the development of noise-induced hearing loss (NIHL) in youth caused by high sound levels during various leisure activities. Health-orientated behavior of young adults might be linked to the beliefs and attitudes toward noise, hearing loss, and hearing protector devices (HPDs). The objective of the current study was to evaluate the effects of attitudes and beliefs toward noise, hearing loss, and HPDs on young adults' hearing status. A questionnaire and an audiological test battery were completed by 163 subjects (aged 18-30 years). The questionnaire contained the Youth Attitude to Noise Scale (YANS) and Beliefs about Hearing Protection and Hearing Loss (BAHPHL). A more positive attitude or belief represented an attitude where noise or hearing loss is seen as unproblematic and attitudes and beliefs regarding HPDs is worse. Hearing was evaluated using (high frequency) pure tone audiometry (PTA), transient evoked and distortion product otoacoustic emissions. First, mean differences in hearing between the groups with different attitudes and beliefs were evaluated using one-way analysis of variance (ANOVA). Second, a χ² test was used to examine the usage of HPDs by the different groups with different attitudes and beliefs. Young adults with a positive attitude had significantly more deteriorated hearing and used HPDs less than the other subjects. Hearing conservation programs (HCPs) for young adults should provide information and knowledge regarding noise, hearing loss, and HPDs. Barriers wearing HPDs should especially be discussed. Further, those campaigns should focus on self-experienced hearing related symptoms that might serve as triggers for attitudinal and behavioral changes.

  17. Hearing in young adults. Part I: The effects of attitudes and beliefs toward noise, hearing loss, and hearing protector devices

    Directory of Open Access Journals (Sweden)

    Hannah Keppler

    2015-01-01

    Full Text Available There is great concern regarding the development of noise-induced hearing loss (NIHL in youth caused by high sound levels during various leisure activities. Health-orientated behavior of young adults might be linked to the beliefs and attitudes toward noise, hearing loss, and hearing protector devices (HPDs. The objective of the current study was to evaluate the effects of attitudes and beliefs toward noise, hearing loss, and HPDs on young adults′ hearing status. A questionnaire and an audiological test battery were completed by 163 subjects (aged 18-30 years. The questionnaire contained the Youth Attitude to Noise Scale (YANS and Beliefs about Hearing Protection and Hearing Loss (BAHPHL. A more positive attitude or belief represented an attitude where noise or hearing loss is seen as unproblematic and attitudes and beliefs regarding HPDs is worse. Hearing was evaluated using (high frequency pure tone audiometry (PTA, transient evoked and distortion product otoacoustic emissions. First, mean differences in hearing between the groups with different attitudes and beliefs were evaluated using one-way analysis of variance (ANOVA. Second, a χ2 test was used to examine the usage of HPDs by the different groups with different attitudes and beliefs. Young adults with a positive attitude had significantly more deteriorated hearing and used HPDs less than the other subjects. Hearing conservation programs (HCPs for young adults should provide information and knowledge regarding noise, hearing loss, and HPDs. Barriers wearing HPDs should especially be discussed. Further, those campaigns should focus on self-experienced hearing related symptoms that might serve as triggers for attitudinal and behavioral changes.

  18. Hazardous decibels: hearing health of firefighters.

    Science.gov (United States)

    Hong, OiSaeng; Samo, Daniel G

    2007-08-01

    Noise-induced hearing loss ranks among the most significant occupational health problems. In the United States, more than 1 million firefighters are at risk for noise-induced hearing loss due to exposure to hazardous levels of intermittent noise from sirens, air horns, and engines of emergency vehicles and fire trucks. Although irreversible, noise-induced hearing loss is entirely preventable through both engineering controls and personal protective equipment. This article describes occupational noise exposure, hearing loss, and strategies to prevent noise-induced hearing loss among firefighters.

  19. Update on the sudden hearing loss

    OpenAIRE

    Federica Bullo; Spyridon Tzamtzis; Giancarlo Tirelli

    2013-01-01

    Aims: Sudden hearing loss is defined as a sensory neural hearing deafness of at least 30 dB in three consecutive speech frequencies that as occurred within the 3 days. It is a medical emergency and the treatment should start as soon as possible; up to now therapies are empirically addressed to improve hearing. Materials and Methods: We have evaluated 558 patients with a diagnosis of sudden hearing loss. In our study, we have investigated possible prognostic factors of hearing loss and their i...

  20. Diabetes and Hearing Loss Among Underserved Populations.

    Science.gov (United States)

    Calvin, Donna; Watley, Sanreka R

    2015-09-01

    Type 2 diabetes (T2DM) disproportionately affects the underserved population, and has been identified as the major risk factor for many microvascular diseases. T2DM also affects the vasculature and neural system of the inner ear, often leading to hearing loss, a major risk factor for falls, depression, and other health problems. This article aims to: increase awareness of the association between T2DM and hearing loss; promote screening for hearing loss; discuss available resources and assistive devices for those with hearing loss; and encourage nurses to take an active role in advocating for assessment and treatment of hearing loss in T2DM patients.

  1. Pleiotropy in Coffin-Lowry syndrome: sensorineural hearing deficit and premature tooth loss as early manifestations.

    Science.gov (United States)

    Hartsfield, J K; Hall, B D; Grix, A W; Kousseff, B G; Salazar, J F; Haufe, S M

    1993-03-01

    We report on 7 patients (6 M, 1 F) with Coffin-Lowry syndrome who have a sensorineural hearing deficit in addition to developmental delay and characteristic facial changes. One of the patients also had a history of premature exfoliation of primary teeth. These are previously unappreciated clinical signs that may aid in the early diagnosis of Coffin-Lowry syndrome. Early diagnosis and recognition of a hearing deficit in the patient can lead to the use of hearing aids to help the patient achieve his or her full potential. These "new" clinical manifestations expand the phenotype of Coffin-Lowry syndrome and constitute an additional indication of pleiotropy.

  2. Studying VEMP in Sudden Sensorineural Hearing Loss

    Directory of Open Access Journals (Sweden)

    Mohsen Rajati

    2011-03-01

    Full Text Available Introduction: Sudden sensorineural hearing loss (SSNHL has a prevalence of 10 in 100,000. Viral infections, vascular obstruction and rupture of the intracochlear membranes are supposed to be its most common etiologies. About 40% of patients experience vertigo or imbalance. The VEMP (vestibular evoked myogenic potentials test is a known approach for detailed study of the labyrinth. The advantage of this test in comparison to other tests is the selected study of sacculus and sacculocochlear pathways. Materials and Methods:  In this cross sectional study all patients with SSNHL diagnosis were admitted and underwent routine standard treatments and diagnostic tests. Clinical symptoms and paraclinic findings were recorded in especially designed forms and VEMP test was performed on admission. Results: Among the 43 cases with sudden sensorineural hearing loss, 14 (32.6% had vertigo. Thirteen patients (39.2% out of 43 had a negative (abnormal VEMP, 6 of which (42.9% had vertigo, while in the 30 VEMP positive (normal cases, vertigo was detected in 8 (26.6%. Discussion: Saccular dysfunction seems to be an important finding in SSNHL. Although it is more prevalent in the patients with vertigo, it can be found in the non-dizzy cases. VEMP disturbance in SSNHL shows more extensive pathological involvement. Conclusion: In SSNHL the pathology isn’t limited to the cochlea and even in patients with no vestibular symptoms sacculus might be involved.

  3. Update on the sudden hearing loss

    Directory of Open Access Journals (Sweden)

    Federica Bullo

    2013-01-01

    Full Text Available Aims: Sudden hearing loss is defined as a sensory neural hearing deafness of at least 30 dB in three consecutive speech frequencies that as occurred within the 3 days. It is a medical emergency and the treatment should start as soon as possible; up to now therapies are empirically addressed to improve hearing. Materials and Methods: We have evaluated 558 patients with a diagnosis of sudden hearing loss. In our study, we have investigated possible prognostic factors of hearing loss and their influence on the recovery of the pathology. Results and Discussion: Sudden hearing loss requires an immediate therapeutic intervention. The corticosteroid therapy remains the most accredited one at which are reported the most satisfactory results. We have recognized as negative prognostic factors hearing loss on acute frequencies in the audiometric exam, the presence of a severe-deep hearing loss and a delay in starting therapy. Conclusion: The sudden hearing loss is an otologic emergency which requires an immediate therapeutic intervention. The most accredited therapy remains the corticosteroid therapy. Frequencies we have recognized as negative prognostic factors hearing loss on acute frequencies. The presence of a severe-deep hearing loss, and a delay in starting therapy.

  4. Noise-Induced Hearing Loss

    Science.gov (United States)

    ... eardrum. The eardrum vibrates from the incoming sound waves and sends these vibrations to three tiny bones in the middle ear. ... on which key hearing structures sit. Once the vibrations cause the fluid inside the cochlea to ripple, a traveling wave forms along the basilar membrane. Hair cells—sensory ...

  5. Age-Related Hearing Loss

    Science.gov (United States)

    ... eardrum. The eardrum vibrates from the incoming sound waves and sends these vibrations to three tiny bones in the middle ear. ... on which key hearing structures sit. Once the vibrations cause the fluid inside the cochlea to ripple, a traveling wave forms along the basilar membrane. Hair cells—sensory ...

  6. 77 FR 23319 - Public Hearing

    Science.gov (United States)

    2012-04-18

    ...%209-10-09.PDF . Opportunity to Appear and Comment: Interested parties may appear at the hearing to..., Schuylkill County, Pa. Application for groundwater withdrawal of up to 0.288 mgd (30-day average) from Well... County, Pa. Modification to increase total groundwater system withdrawal by an additional 0.499 mgd,...

  7. Moth hearing and sound communication

    DEFF Research Database (Denmark)

    Nakano, Ryo; Takanashi, Takuma; Surlykke, Annemarie

    2015-01-01

    Active echolocation enables bats to orient and hunt the night sky for insects. As a counter-measure against the severe predation pressure many nocturnal insects have evolved ears sensitive to ultrasonic bat calls. In moths bat-detection was the principal purpose of hearing, as evidenced by compar...

  8. Early detection of hearing loss

    Directory of Open Access Journals (Sweden)

    Schade, Götz

    2008-01-01

    Full Text Available The universal newborn hearing screening (UNHS is currently spreading in Germany, as well, even though there can be no talk of a comprehensive establishment. The introduction of UNHS in several federal states such as Hamburg, Hessen, and Schleswig-Holstein can be ascribed to the personal commitment of individual pediatric audiologists. Apart from the procurement of the screening equipment and the training of the staff responsible for the examination of the newborns, the tracking, i.e. the follow-up on children with conspicuous test results, is of utmost importance. This involves significant administration effort and work and is subject to data protection laws that can differ substantially between the various federal states. Among audiologists, there is consensus that within the first three months of a child’s life, a hearing loss must be diagnosed and that between the age of 3 and 6 months, the supply of a hearing aid must have been initiated. For this purpose, screening steps 1 (usually a TEOAE measurement and 2 (AABR testing need to be conducted in the maternity hospital. The follow-up of step 1 then comprises the repetition of the TEOAE- and AABR measurement for conspicuous children by a specialized physician. The follow-up of step 2 comprises the confirmatory diagnostics in a pediatric audiological center. This always implies BERA diagnostics during spontaneous sleep or under sedation. The subsequent early supply of a hearing aid should generally be conducted by a (pediatric acoustician specialized on children.

  9. Hearing Aid with Visual Indicator

    DEFF Research Database (Denmark)

    2004-01-01

    The invention comprises a hearing aid, which has a casing containing a signal receiving part for receiving an audio signal, an audio transducer for providing an audio signal to the user, a signal transmission path between the signal receiving part and the audio transducer, whereby a battery is pr...

  10. Boosting NAD to spare hearing.

    Science.gov (United States)

    Brenner, Charles

    2014-12-02

    Ex vivo experiments have strangely shown that inhibition or stimulation of NAD metabolism can be neuroprotective. In this issue of Cell Metabolism, Brown et al. (2014) demonstrate that cochlear NAD is diminished by deafening noise but protected by nicotinamide riboside or WldS mutation. Hearing protection by nicotinamide riboside depends on Sirt3.

  11. Hearing aids with no batteries

    DEFF Research Database (Denmark)

    Day, Dennis

    2011-01-01

    part of design practices concerning the development of hearing aids. Within design studies, the idea of a skilled practitioner has a host of brothers and sisters all prefaced with the family name 'skilled'- skilled users, skilled workers, skilled employees - but the basic idea is the same for all...

  12. Unilateral Hearing Loss in Children

    Science.gov (United States)

    ... as degree of hearing loss, chronic external or middle ear pathology, and maturity level. Any child under the age of 18 years requires medical ... him or her to the doctor. Has your child been diagnosed with large vestibular aqueduct syndrome (LVA)? This is a particular formation of the ...

  13. Fitting hearing aids with the Articulation Index: impact on hearing aid effectiveness.

    Science.gov (United States)

    Souza, P E; Yueh, B; Sarubbi, M; Loovis, C F

    2000-01-01

    Although most clinical tests focus on how much a particular hearing aid improves speech audibility under controlled conditions, it is unclear how these measures relate to hearing aid effectiveness, or the benefit perceived by the patient under everyday conditions. In this study, the relationship between audibility and hearing aid effectiveness was examined in a cohort of patients who obtained hearing aids through the Veteran's Administration. The measure of audibility was the Articulation Index, a common index of speech audibility. Measures of effectiveness included two hearing-specific surveys and self-reported ratings of global satisfaction and hearing aid use adherence. Results indicated that there were no systematic relationships between measurements of improved audibility and patient ratings of communication ability. Additionally, improved audibility was not related to overall satisfaction with the amplification characteristics of the hearing aid (fitting). However, improved audibility is related to hearing aid use adherence, with patients who achieve better audibility reporting that they use their hearing aids more frequently.

  14. Hearing screenings on children under three years at risk of hearing impairment.

    Directory of Open Access Journals (Sweden)

    Marcelino Lizano Rabelo

    2011-09-01

    Full Text Available This article presents the results of newborn hearing screenings on infants under three years at risk of hearing impairment at Paediatric Hospital of Sancti Spíritus¸on from 2008 to 2010. All children at risk of hearing impairment were tested by an auditory brainstem response (ABR for the positive diagnosis of hearing impairment. Results: Over the period, 398 infants were screened, among whom 36 (8,98% were diagnosed as deaf or hard of hearing. twenty seven children (6,8% had a sensorineural hearing impairment, The most important risk factors for sensorineural hearing loss were: severe birth asphyxia; mechanic ventilation, and antibiotics.Conclusion: Our hearing screening on infants at risk allowed 36 children diagnosed as hearing impairment, all of then received early management.

  15. Evidence and recommendation. What is the best technique for neonatal hearing screening?

    Directory of Open Access Journals (Sweden)

    José Ignacio BENITO-OREJAS

    2016-03-01

    Full Text Available Introduction and objective: Clinical question: The otoacoustic emissions (OAE and automated auditory evoked potentials brainstem response (ABR-A are acceptable and used in neonatal hearing screening. PICO question: In a newborn [patient], does technique ABR-A against AEE [compared], provide superior detection [result], for neonatal screening hearing loss [intervention]?. Material and Methods: Literature search in PubMed and Cochrane data meta-analysis, clinical trials and general articles, including descriptors "hearing loss", "neonatal screening", "infant, newborn," "evoked potentials, auditory", "otoacoustic emissions". Selected studies in Spanish or English directly comparing one technique over another. Results: The evidence is high for ABR-A because they are more effective (with higher levels of sensitivity and specificity than the OAE, especially in neonatal intensive care unit and in children at risk of auditory neuropathy. Conclusions: Recommendation: The recommendation is strongly in favor of using ABR-A versus OAS as an initial test in neonatal screening for hearing loss.

  16. Removal of As(V), Cr(III) and Cr(VI) from aqueous environments by poly(acrylonitril-co-acrylamidopropyl-trimethyl ammonium chloride)-based hydrogels.

    Science.gov (United States)

    Dudu, Tuba Ersen; Sahiner, Mehtap; Alpaslan, Duygu; Demirci, Sahin; Aktas, Nahit

    2015-09-15

    Cationic poly(Acrylonitril-co-Acrylamidopropyl-trimethyl Ammonium Chloride) (p(AN-co-APTMACl)) hydrogels in bulk were synthesized by using acrylonitrile (AN) and 3-acrylamidopropyl-trimethyl ammonium chloride (APTMACl) as monomers. The prepared hydrogels were exposed to amidoximation reaction to replace hydrophobic nitrile groups with hydrophilic amidoxime groups that have metal ion binding ability. Those replacements were increased the hydrogels absorption capacity for As(V) and Cr(VI). Langmuir and Freundlich isotherms equations were utilized to obtain the best-fitted isotherm model for the absorption of the ions at different metal ion concentrations. The absorption data of As(V) ion were fitted well to Freundlich isotherm while those of Cr(VI) and Cr(III) ions were fitted well to Langmuir isotherm. The maximum absorption of poly(3-acrylamidopropyl-trimethyl ammonium chloride (p(APTMACl)) and amid-p(AN-co-APTMACl) macro gels were 22.39 mg and 21.83 mg for As(V), and 30.65 mg and 18.16 mg for Cr(VI) ion per unit gram dried gel, respectively. Kinetically, the absorption behaviors of Cr(III) and Cr(VI) ions were fitted well to a pseudo 2nd-order kinetic model and those of As(V) ions were fitted well to a pseudo 1st order kinetic model.

  17. Spatial distribution of stabilizer-derived nitroxide radicals during thermal degradation of poly(acrylonitrile-butadiene-styrene) copolymers: a unified picture from pulsed ELDOR and ESR imaging.

    Science.gov (United States)

    Jeschke, Gunnar; Schlick, Shulamith

    2006-09-21

    Double Electron-Electron Resonance (DEER) provides information on the spatial distribution of radicals on the length scale of a few nanometres, while Electron Spin Resonance Imaging (ESRI) provides information on a length scale of millimetres with a resolution of about 100 micrometres. Despite the gap between these length scales, results from the two techniques are found to complement and support each other in the characterization of the identity and distribution of nitroxide radicals derived from the Hindered Amine Stabilizer (HAS) Tinuvin 770 in poly(acrylonitrile-butadiene-styrene) (ABS) copolymers. DEER measurements demonstrate that there is no significant formation of biradicals from the bifunctional HAS, and provide the distributions of local radical concentrations. These distributions are poorly resolved for model-free analysis of the DEER data by the Tikhonov regularization; the resolution was significantly improved by utilizing information obtained by ESRI. DEER data can be fitted with only one adjustable parameter, namely the average radical concentration, if 1D and 2D spectral--spatial ESRI results on both the spatial distribution of nitroxides and their distribution between the acrylonitrile--styrene-rich (SAN) and butadiene-rich (B) microphases are considered.

  18. Design of a Web services based system for remote hearing diagnosis.

    Science.gov (United States)

    Yao, Jianchu; Wan, Yongbo; Givens, Gregg

    2009-01-01

    This paper presents a web services based, distributed system that allows remote pure tone hearing tests. The system network follows browser-server architecture, which minimizes hardware and software requirements on the client computers and makes hearing test services more accessible to traditionally underserved population groups. Thanks to the three tier software design, the system functionality is easily scalable to include other audiological services. Since testing data are stored in a standard database, they can be potentially integrated into established electronic medical records.

  19. Otolithic organ function in patients with profound sensorineural hearing loss

    Institute of Scientific and Technical Information of China (English)

    Yujuan Zhou; Yongzhen Wu; Jing Wang

    2016-01-01

    Profound sensorineural hearing loss (PSHL) is not uncommonly encountered in otology. In clinics, there is a high incidence of otolithic damage in patients with PSHL, but relevant reports are few. Sharing a continuous membranous structure and similar receptor cell ultrastructures, the cochlea and vestibule may be susceptible to the same harmful factors. Disorders of the inner ear may result in a variety of manifestations, including vertigo, spatial disorientation, blurred vision, impaired articulation, and hearing impairment. Considering the diversity of clinical symptoms associated with PSHL with otolithic dysfunction, it may be frequently misdiagnosed, and objective means of testing the function of otolithic organs should be recommended for hearing-impaired patients. Vestibular-evoked myogenic potentials (VEMPs) via air-conducted sound are of great importance for the diagnosis of otolithic function. Hearing devices such as cochlear implants are commonly accepted treatments for PSHL, and early identification and treatment of vestibular disorders may increase the success rate of cochlear implantation. Therefore, it is necessary to increase awareness of otolithic functional states in patients with PSHL.

  20. Soybean β-Conglycinin Prevents Age-Related Hearing Impairment.

    Directory of Open Access Journals (Sweden)

    Tohru Tanigawa

    Full Text Available Obesity-related complications are associated with the development of age-related hearing impairment. β-Conglycinin (β-CG, one of the main storage proteins in soy, offers multiple health benefits, including anti-obesity and anti-atherosclerotic effects. Here, to elucidate the potential therapeutic application of β-CG, we investigated the effect of β-CG on age-related hearing impairment. Male wild-type mice (age 6 months were randomly divided into β-CG-fed and control groups. Six months later, the body weight was significantly lower in β-CG-fed mice than in the controls. Consumption of β-CG rescued the hearing impairment observed in control mice. Cochlear blood flow also increased in β-CG-fed mice, as did the expression of eNOS in the stria vascularis (SV, which protects vasculature. β-CG consumption also ameliorated oxidative status as assessed by 4-HNE staining. In the SV, lipofuscin granules of marginal cells and vacuolar degeneration of microvascular pericytes were decreased in β-CG-fed mice, as shown by transmission electron microscopy. β-CG consumption prevented loss of spiral ganglion cells and reduced the frequencies of lipofuscin granules, nuclear invaginations, and myelin vacuolation. Our observations indicate that β-CG ameliorates age-related hearing impairment by preserving cochlear blood flow and suppressing oxidative stress.

  1. Synthesis of novel well-defined poly(vinyl acetate)-b-poly(acrylonitrile) and derivatized water-soluble poly(vinyl alcohol)-b-poly(acrylic acid) block copolymers by cobalt-mediated radical polymerization

    NARCIS (Netherlands)

    Debuigne, A.; Warnant, J.; Jerome, R.; Voets, I.K.; Keizer, de A.; Cohen Stuart, M.A.; Detrembleur, C.

    2008-01-01

    Poly(vinyl acetate)¿Co(acac)2 macroinitiators, prepared by cobalt-mediated radical polymerization of vinyl acetate (VAc), were used to synthesize well-defined poly(vinyl acetate)-b-poly(acrylonitrile) (PVAc-b-PAN) block copolymers. Different solvents and temperatures were tested for the polymerizati

  2. Duration of Analgesic Use and Risk of Hearing Loss in Women.

    Science.gov (United States)

    Lin, Brian M; Curhan, Sharon G; Wang, Molin; Eavey, Roland; Stankovic, Konstantina M; Curhan, Gary C

    2017-01-01

    Aspirin, nonsteroidal antiinflammatory drugs (NSAID), and acetaminophen are commonly used. Frequent use of analgesics has been associated with a higher risk of hearing loss. However, the association between duration of analgesic use and the risk of hearing loss is unclear. We investigated the relationship between duration of analgesic use and self-reported hearing loss among 55,850 women in the Nurses' Health Study. Cox proportional hazards regression was used to adjust for potential confounders. During 873,376 person-years of follow-up (1990-2012), longer durations of NSAID use (for >6 years of use compared with acetaminophen use (for >6 years of use compared with hearing loss. Duration of aspirin use was not associated with hearing loss (for >6 years of use compared with acetaminophen use were associated with slightly higher risks of hearing loss, but duration of aspirin use was not. Considering the high prevalence of analgesic use, this may be an important modifiable contributor to hearing loss.

  3. The Importance of Saccular Function to Motor Development in Children with Hearing Impairments

    Directory of Open Access Journals (Sweden)

    Mary S. Shall

    2009-01-01

    Full Text Available Children with hearing deficits frequently have delayed motor development. The purpose of this study was to evaluate saccular function in children with hearing impairments using the Vestibular Evoked Myogenic Potential (VEMP. The impact of the saccular hypofunction on the timely maturation of normal balance strategies was examined using the Movement Assessment Battery for Children (Movement ABC. Thirty-three children with bilateral severe/profound hearing impairment between 4 and 7 years of age were recruited from a three-state area. Approximately half of the sample had one or bilateral cochlear implants, one used bilateral hearing aids, and the rest used no amplification. Parents reported whether the hearing impairment was diagnosed within the first year or after 2 years of age. No VEMP was evoked in two thirds of the hearing impaired (HI children in response to the bone-conducted stimulus. Children who were reportedly hearing impaired since birth had significantly poorer scores when tested with the Movement ABC.

  4. Self-Concept among Hearing Chinese Children of Deaf Parents.

    Science.gov (United States)

    Chan, Lik Man; Lui, Brian

    1990-01-01

    A questionnaire was administered to 42 Hong Kong Chinese deaf couples, their 70 hearing children, 41 hearing couples, and their 82 hearing children. No differences were found in the self-concepts of children of deaf parents compared to children of hearing parents, but deaf parents reported lower self-concepts than hearing parents. (Author/JDD)

  5. 20 CFR 702.441 - Claims for loss of hearing.

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Claims for loss of hearing. 702.441 Section... and Supervision Hearing Loss Claims § 702.441 Claims for loss of hearing. (a) Claims for hearing loss... regulations. (b) An audiogram shall be presumptive evidence of the amount of hearing loss on the...

  6. Identifying hearing loss by means of iridology.

    Science.gov (United States)

    Stearn, Natalie; Swanepoel, De Wet

    2006-11-13

    Isolated reports of hearing loss presenting as markings on the iris exist, but to date the effectiveness of iridology to identify hearing loss has not been investigated. This study therefore aimed to determine the efficacy of iridological analysis in the identification of moderate to profound sensorineural hearing loss in adolescents. A controlled trial was conducted with an iridologist, blind to the actual hearing status of participants, analyzing the irises of participants with and without hearing loss. Fifty hearing impaired and fifty normal hearing subjects, between the ages of 15 and 19 years, controlled for gender, participated in the study. An experienced iridologist analyzed the randomised set of participants' irises. A 70% correct identification of hearing status was obtained by iridological analyses with a false negative rate of 41% compared to a 19% false positive rate. The respective sensitivity and specificity rates therefore came to 59% and 81%. Iridological analysis of hearing status indicated a statistically significant relationship to actual hearing status (P iridology were not comparable to those of traditional audiological screening procedures.

  7. An economic model of adult hearing screening

    Directory of Open Access Journals (Sweden)

    A. Morris

    2011-03-01

    Full Text Available Populations are ageing and older adults make an increasing contribution to society, yet uncorrected hearing loss is common over the age of 50 years, increasing in prevalence and severity with age. The consequences of uncorrected hearing loss can be profound for hearing-impaired individuals and their communication partners but there is evidence that adults commonly delay 10-15 years before seeking help for hearing difficulty (Stephens et al., 1990; Davis et al., 2007 and the most common reason is the belief that their hearing is not bad enough (Ipsos-Mori/RNID survey, 2005. Hearing aids are currently the mainstay of intervention for hearing loss; evidence shows benefit to social functioning and quality of life even for mild hearing loss (Mulrow et al., 1990; Chisolm et al., 2007 and long term outcomes are better when they are obtained early (Davis et al., 2007. Screening adults for hearing loss would expedite intervention and reduce unmet need, leading to improved quality of life for many older adults. Previous work suggests adult hearing screening (AHS should target adults aged 50-65 years, old enough for prevalence to justify screening but young enough to gain from early intervention...

  8. Comparison of Reading Literacy in Hearing Impaired and Normal Hearing Students

    Directory of Open Access Journals (Sweden)

    Dr. Ali Asghar Kakojoibari

    2011-06-01

    Full Text Available Background and Aim: listening, speaking, reading and writing are considered the lingual skills. These skills are in direct relation with each other. Listening is the first skill learnt by the individual through development. If damaged by hearing impairment, listening can cause serious defect to lingual skills. The goal of our research was to study the effect of hearing loss on reading literacy in hearing impairment students in comparison with normal hearing students.Methods: Study was performed using the examination booklets of Progress in International Reading Literacy Study (PIRLS 2001. 119 hearing impairment students of 4th grade primary school, last year guidance school, and last year high school levels in schools providing exceptional student education were included. These individuals were compared to 46 normal hearing students of 4th grade primary school of ordinary schools. Comparative statistical analysis was performed using t-test.Results: Reading literacy and literal contents understanding was shown to have a significant difference between normal hearing and whole hearing impaired student (p<0.05, except the ones in high school level with moderate hearing loss. There was also seen a significant difference between normal hearing and hearing impairment students in understanding of information contents (p=0.03.Conclusion: Hearing loss has a negative effect on reading literacy. Consequently, curriculum change and evolution of educational programs in exceptional centers is needed, in order to promote reading literacy and to enhance rest hearing

  9. Timbre discrimination in normal-hearing and hearing-impaired listeners under different noise conditions.

    Science.gov (United States)

    Emiroglu, Suzan; Kollmeier, Birger

    2008-07-18

    In an attempt to quantify differences in object separation and timbre discrimination between normal-hearing and hearing-impaired listeners with a moderate sensorineural hearing loss of two different configurations, psychoacoustic measurements were performed with a total of 50 listeners. The experiments determined just noticeable differences (JND) of timbre in normal-hearing and hearing-impaired subjects along continua of "morphed" musical instruments and investigated the variance of JND in silence and different background noise conditions and on different sound levels. The results show that timbre JNDs of subjects with a steep hearing loss are significantly higher than of normal-hearing subjects, both in silence and noise, whereas timbre JNDs of flat/diagonal hearing-impaired subjects are similar to JNDs of normal-hearing subjects for signal levels above 55 dB (plus appropriate amplification for hearing-impaired). In noise (SNR=+10 dB) timbre JNDs of all subject groups are significantly higher than in silence. In the condition testing, transferability from silence to noise (i.e., the ability to imagine how the stimulus heard in silence would sound in noise), no significant JND differences across listener groups were found. The results can be explained by primary factors involved in sensorineural hearing loss and contradict the hypothesis that hearing-impaired people generally have more problems in object discrimination than normal-hearing people.

  10. The effect of hearing impairment on mathematical skill of hearing-impaired elementary-school students

    Directory of Open Access Journals (Sweden)

    Azam Sharifi

    2012-06-01

    Full Text Available Background and Aim: Hearing impairment can effect many educational abilities and will lead in a dealy in his growth. The objective of this research was to study the effect of hearing impairment on mathematical skill of hearing-impaired students of 4th grade of elementary in contrast with normal-hearing students.Methods: The project was cross-sectional and the tool used was the international standard booklet of mathematical questions. There has been 35 hearing-impaired students with range of moderately sever-profound hearing loss selected from the 4th grade of elementary from exceptional schools in Ray, Pakdasht and Varamina, Iran, and 35 normal-hearing students were randomly selected from ordinary schools next to exceptional schools.Results: By analyzing the outcomes, the normal-hearing students showed a better result in knowing, application, argument in aspects of cognitive in contrast with hearing-impaired students and there has been a meaningful difference (p<0.05. There was not a meaningful difference in mathematical skill between Ray, Pakdasht and Varamina, Iran in hearing-impaired and normal-hearing groups.Conclusion: The hearing impairment effects learing of mathematical skill. It is important for hearing-impaired students to presentation various methods in instruction in progress deductive thought and cognitive structure and also development in concepts understand in mathematical domain in rehabilitation services.

  11. Assessment of hearing and hearing disorders in rock/jazz musicians.

    Science.gov (United States)

    Kähärit, Kim; Zachau, Gunilla; Eklöf, Mats; Sandsjö, Leif; Möller, Claes

    2003-07-01

    The aim of this study was to assess hearing and hearing disorders among rock/jazz musicians. One hundred and thirty-nine (43 women and 96 men) musicians participated. The results are based on pure-tone audiometry and questionnaire responses. According to our definition of hearing loss, tinnitus, hyperacusis, distortion and/or diplacusis as hearing disorders, we found disorders in 74%, of the rock/jazz musicians studied. Hearing loss, tinnitus and hyperacusis were most common, and the latter two were found significantly more frequently than in different reference populations. The women showed bilateral, significantly better hearing thresholds at 3-6 kHz than the men. Hyperacusis, and the combination of both hyperacusis and tinnitus, were found to be significantly more frequent among women than among men. Hearing loss and tinnitus were significantly more common among men than among women. It is important to evaluate all kinds of hearing problems (other than hearing loss) in musicians, since they represent an occupational group especially dependent on optimal, functional hearing. On the basis of our results, we suggest that hearing problems such as tinnitus, hyperacusis, distortion and/or diplacusis should, in addition to hearing loss, be defined as hearing disorders.

  12. Morphological correlates of hearing loss after cochlear implantation and electro-acoustic stimulation in a hearing-impaired Guinea pig model.

    Science.gov (United States)

    Reiss, Lina A J; Stark, Gemaine; Nguyen-Huynh, Anh T; Spear, Kayce A; Zhang, Hongzheng; Tanaka, Chiemi; Li, Hongzhe

    2015-09-01

    were not correlated with threshold shifts at any frequency. As in the previous study in a normal-hearing model, stria vascularis capillary changes were associated with immediate hearing loss after implantation, while little to no hair cell loss was observed even in cochlear regions with threshold shifts as large as 40-50 dB. These findings again support a role of lateral wall blood flow changes, rather than hair cell loss, in hearing loss after surgical trauma, and implicate the endocochlear potential as a factor in implantation-induced hearing loss. Further, the analysis of the hair cell ribbons and post-synaptic receptors suggest that delayed hearing loss may be linked to synapse or peripheral nerve loss due to stimulation excitotoxicity or inflammation. Further research is needed to separate these potential mechanisms of delayed hearing loss.

  13. Prevalence of Hearing Loss in Newborns Admitted to Neonatal Intensive Care Unit

    Directory of Open Access Journals (Sweden)

    Shahnaz Pourarian

    2012-03-01

    Full Text Available Introduction: Hearing is essential for humans to communicate with one another. Early diagnosis of hearing loss and intervention in neonates and infants can reduce developmental problems. The aim of the present study was to assess the prevalence of hearing impairment in newborns admitted to a neonatal intensive care unit (NICU and analyze the associated risk factors.   Materials and Methods: This cross-sectional study was conducted to assess the prevalence of hearing loss in neonates who were admitted to the NICU at Nemazee Hospital, Shiraz University of Medical Sciences between January 2006 and January 2007. Auditory function was examined using otoacoustic emission (OAE followed by auditory brainstem response (ABR tests. Relevant potential risk factors were considered and neonates with a family history of hearing loss and craniofacial abnormality were excluded. For statistical analysis logistic regression, the chi-squared test, and Fisher’s exact test were used.    Results: Among the 124 neonates included in the study, 17 (13.7% showed hearing loss in the short term. There was a significant statistical relationship between gestational age of less than 36 weeks (P=0.013, antibiotic therapy (P= 0.033, oxygen therapy (P=0.04, and hearing loss. On the contrary, there was no significant relationship between hearing loss and use of a ventilator, or the presence of sepsis, hyperbilirubinemia, congenial heart disease, transient tachypnea of newborn, congenital pneumonia, or respiratory distress syndrome.  Conclusion: Auditory function in neonates who are admitted to a NICU, especially those treated with oxygenor antibiotics and those born prematurely, should be assessed during their stay in hospital. The importance of early diagnosis of hearing loss and intervention in these neonates and avoidance of any unnecessary oxygenor antibiotic therapy needs to be further promoted.

  14. Connexin26 (GJB2) deficiency reduces active cochlear amplification leading to late-onset hearing loss.

    Science.gov (United States)

    Zhu, Y; Chen, J; Liang, C; Zong, L; Chen, J; Jones, R O; Zhao, H-B

    2015-01-22

    Connexin26 (Cx26, GJB2) mutations account for >50% of nonsyndromic hearing loss. The deafness is not always congenital. A large group of these patients (∼30%) demonstrate a late-onset hearing loss, starting in childhood. They have normal hearing early in life and are therefore good candidates for applying protective and therapeutic interventions. However, the underlying deafness mechanism is unclear. In this study, we used a time-controlled, inducible gene knockout technique to knockout Cx26 expression in the cochlea after birth. We found that deletion of Cx26 after postnatal day 5 (P5) in mice could lead to late-onset hearing loss. Similar to clinical observations, the mice demonstrated progressive, mild to moderate hearing loss. The hearing loss initiated at high frequencies and then extended to the middle- and low-frequency range. The cochlea showed normal development and had no apparent hair cell loss. However, distortion product otoacoustic emission (DPOAE) was reduced. The reduction was also progressive and large at high-frequencies. Consistent with DPOAE reduction, we found that outer hair cell electromotility-associated nonlinear capacitance was shifted to the right and the slope of voltage dependence was reduced. The endocochlear potential was reduced in Cx26 conditional knockout (cKO) mice but the reduction was not associated with progressive hearing loss. These data suggest that Cx26 deficiency may impair active cochlear amplification leading to late-onset hearing loss. Our study also helps develop newer protective and therapeutic interventions to this common nonsyndromic hearing loss.

  15. Methadone Induced Sensorineural Hearing Loss

    Directory of Open Access Journals (Sweden)

    Chadi Saifan

    2013-01-01

    Full Text Available Background. Sudden sensorineural hearing loss (SSHL caused by opiate abuse or overuse has been well documented in the medical literature. Most documented case reports have involved either heroin or hydrocodone/acetaminophen. Recently, case reposts of methadone induced SSHL have been published. Case Report. We present the case of a 31-year-old man who developed SSHL after a methadone overdose induced stupor. He was subsequently restarted on methadone at his regular dose. On follow-up audiometry exams, he displayed persistent moderately severe sensorineural hearing loss bilaterally. Discussion. This case is notable because unlike all but one previously reported case, the patient—who was restated on methadone—did not make a complete recovery. Conclusion. Methadone overuse in rare cases causes SSHL.

  16. Methadone induced sensorineural hearing loss.

    Science.gov (United States)

    Saifan, Chadi; Glass, Daniel; Barakat, Iskandar; El-Sayegh, Suzanne

    2013-01-01

    Background. Sudden sensorineural hearing loss (SSHL) caused by opiate abuse or overuse has been well documented in the medical literature. Most documented case reports have involved either heroin or hydrocodone/acetaminophen. Recently, case reposts of methadone induced SSHL have been published. Case Report. We present the case of a 31-year-old man who developed SSHL after a methadone overdose induced stupor. He was subsequently restarted on methadone at his regular dose. On follow-up audiometry exams, he displayed persistent moderately severe sensorineural hearing loss bilaterally. Discussion. This case is notable because unlike all but one previously reported case, the patient-who was restated on methadone-did not make a complete recovery. Conclusion. Methadone overuse in rare cases causes SSHL.

  17. Challenges in IC design for hearing aids

    DEFF Research Database (Denmark)

    Jørgensen, Ivan Harald Holger

    2012-01-01

    Designing modern hearing aids is a formidable challenge. The size of hearing aids is constantly decreasing, making them virtually invisible today. Still, as in all other modern electronics, more and more features are added to these devices driven by the development in modern IC technology....... The demands for performance and features at very low supply voltage and power consumption constantly prove a challenge to the physical design of hearing aids and not at least the design of the ICs for these. As a result of this all large hearing aid manufacturers use fully customized ASICs in their products....... The size of the amplifier is critical for the size of the final hearing aid and a study of the size of these for different manufactures will be presented. Designing the ICs for hearing aids poses many challenges and is a constant compromise between size, power consumption and performance of the individual...

  18. Efficient individualization of hearing aid processed sound

    DEFF Research Database (Denmark)

    Nielsen, Jens Brehm; Nielsen, Jakob

    2013-01-01

    Due to the large amount of options offered by the vast number of adjustable parameters in modern digital hearing aids, it is becoming increasingly daunting—even for a fine-tuning professional—to perform parameter fine tuning to satisfactorily meet the preference of the hearing aid user. In addition......, the communication between the fine-tuning professional and the hearing aid user might muddle the task. In the present paper, an interactive system is proposed to ease and speed up fine tuning of hearing aids to suit the preference of the individual user. The system simultaneously makes the user conscious of his own...... preferences while the system itself learns the user’s preference. Since the learning is based on probabilistic modeling concepts, the system handles inconsistent user feedback efficiently. Experiments with hearing impaired subjects show that the system quickly discovers individual preferred hearing-aid...

  19. Sudden bilateral hearing loss after organophosphate inhalation.

    Science.gov (United States)

    Dundar, Mehmet Akif; Derin, Serhan; Aricigil, Mitat; Eryilmaz, Mehmet Akif

    2016-12-01

    Sudden bilateral hearing loss are seen rarely and the toxic substance exposure constitutes a small part of etiology. A Fifty-eight-year-old woman admitted to our clinic with sudden bilateral hearing loss shortly after chlorpyrifos-ethyl exposure. Otolaryngologic examination findings were normal. The patient had 40 dB sensorineural hearing loss (SNHL) on the right ear and 48 dB SNHL on the left ear. Additional diagnostic tests were normal. The conventional treatment for sudden hearing loss was performed. On the second week following organophosphate (OP) exposure the patient's hearing loss almost completely resolved. OP's are heavily used in agriculture and should be taken into consideration as an etiologic factor in sudden hearing loss.

  20. Sensorineural hearing loss in hemorrhagic dengue?

    Directory of Open Access Journals (Sweden)

    Bruna Natália Freire Ribeiro

    2015-01-01

    Discussion and conclusion: This is the first case report that brings together DHF and sudden hearing loss. In the development of this case no other cause to sudden hearing loss was found and the correlation between dengue and hearing loss was questioned. In the literature review was found that some viruses, as mumps virus, varicella-zoster virus and HSV-1 and HSV-2 are related to sudden hearing loss, all of them fit in the viral theory. Besides the viral theory of sudden hearing loss, there is the vascular theory that is the occlusion of the end artery that supplies the cochlea. DHF has a vascular commitment, and the hypothesis of a vascular cause could be elicited in this case. Many studies in this area are needed and this article has the objective of elicit the discussion about the subject. Could dengue be associated with sensorineural hearing loss?

  1. Hearing loss and asymmetry in major depression.

    Science.gov (United States)

    Yovell, Y; Sackeim, H A; Epstein, D G; Prudic, J; Devanand, D P; McElhiney, M C; Settembrino, J M; Bruder, G E

    1995-01-01

    To assess patterns of hearing loss and asymmetry in major depressive disorder (MDD), pure-tone and brief-click audiometric thresholds were measured in 59 inpatients with MDD and 40 normal control subjects. For both tasks, patients had higher bilateral thresholds, with marked hearing loss for the highest pure-tone frequency. At lower frequencies, patients displayed significant asymmetry, with poorer hearing in the left ear. After ECT, patients maintained the bilateral hearing losses; however, the baseline asymmetry resolved. These findings suggest that bilateral hearing loss may be a stable characteristic in severe depression. Poorer left ear pure-tone hearing may be present during the depressed state. The baseline asymmetry in audiometric deficits suggests right-hemisphere dysfunction in severe MDD.

  2. Methadone Induced Sensorineural Hearing Loss

    OpenAIRE

    Chadi Saifan; Daniel Glass; Iskandar Barakat; Suzanne El-Sayegh

    2013-01-01

    Background. Sudden sensorineural hearing loss (SSHL) caused by opiate abuse or overuse has been well documented in the medical literature. Most documented case reports have involved either heroin or hydrocodone/acetaminophen. Recently, case reposts of methadone induced SSHL have been published. Case Report. We present the case of a 31-year-old man who developed SSHL after a methadone overdose induced stupor. He was subsequently restarted on methadone at his regular dose. On follow-up audiomet...

  3. Self-Fitting Hearing Aids: Status Quo and Future Predictions.

    Science.gov (United States)

    Keidser, Gitte; Convery, Elizabeth

    2016-04-12

    A self-contained, self-fitting hearing aid (SFHA) is a device that enables the user to perform both threshold measurements leading to a prescribed hearing aid setting and fine-tuning, without the need for audiological support or access to other equipment. The SFHA has been proposed as a potential solution to address unmet hearing health care in developing countries and remote locations in the developed world and is considered a means to lower cost and increase uptake of hearing aids in developed countries. This article reviews the status of the SFHA and the evidence for its feasibility and challenges and predicts where it is heading. Devices that can be considered partly or fully self-fitting without audiological support were identified in the direct-to-consumer market. None of these devices are considered self-contained as they require access to other hardware such as a proprietary interface, computer, smartphone, or tablet for manipulation. While there is evidence that self-administered fitting processes can provide valid and reliable results, their success relies on user-friendly device designs and interfaces and easy-to-interpret instructions. Until these issues have been sufficiently addressed, optional assistance with the self-fitting process and on-going use of SFHAs is recommended. Affordability and a sustainable delivery system remain additional challenges for the SFHA in developing countries. Future predictions include a growth in self-fitting products, with most future SFHAs consisting of earpieces that connect wirelessly with a smartphone and providers offering assistance through a telehealth infrastructure, and the integration of SFHAs into the traditional hearing health-care model.

  4. Parallel mechanisms suppress cochlear bone remodeling to protect hearing.

    Science.gov (United States)

    Jáuregui, Emmanuel J; Akil, Omar; Acevedo, Claire; Hall-Glenn, Faith; Tsai, Betty S; Bale, Hrishikesh A; Liebenberg, Ellen; Humphrey, Mary Beth; Ritchie, Robert O; Lustig, Lawrence R; Alliston, Tamara

    2016-08-01

    osteocytes, to protect hearing. Understanding the cellular and molecular mechanisms that confer site-specific control of bone remodeling has the potential to elucidate new pathways that are deregulated in skeletal disease.

  5. Sudden Sensorineural Hearing Loss in the Only Hearing Ear: Large Vestibular Aqueduct Syndrome

    OpenAIRE

    Bal, Kemal Koray; Ismi, Onur; Bucioglu, Helen; Vayısoğlu, Yusuf; Gorur, Kemal

    2016-01-01

    Sudden hearing loss in the only hearing ear cases are rarely published in the English literature; most of the cases are idiopathic. It is an otologic emergency needing urgent treatment. Delayed diagnosis can interfere with patient's social life with interrupting the verbal communication. In this case report we presented a 33-year-old female patient having sudden sensorineural hearing loss in the only hearing ear diagnosed as bilateral large vestibular aqueduct syndrome.

  6. Sudden Sensorineural Hearing Loss in the Only Hearing Ear: Large Vestibular Aqueduct Syndrome

    Directory of Open Access Journals (Sweden)

    Kemal Koray Bal

    2016-01-01

    Full Text Available Sudden hearing loss in the only hearing ear cases are rarely published in the English literature; most of the cases are idiopathic. It is an otologic emergency needing urgent treatment. Delayed diagnosis can interfere with patient’s social life with interrupting the verbal communication. In this case report we presented a 33-year-old female patient having sudden sensorineural hearing loss in the only hearing ear diagnosed as bilateral large vestibular aqueduct syndrome.

  7. Sudden Sensorineural Hearing Loss in the Only Hearing Ear: Large Vestibular Aqueduct Syndrome

    Science.gov (United States)

    Bal, Kemal Koray; Bucioglu, Helen; Vayısoğlu, Yusuf; Gorur, Kemal

    2016-01-01

    Sudden hearing loss in the only hearing ear cases are rarely published in the English literature; most of the cases are idiopathic. It is an otologic emergency needing urgent treatment. Delayed diagnosis can interfere with patient's social life with interrupting the verbal communication. In this case report we presented a 33-year-old female patient having sudden sensorineural hearing loss in the only hearing ear diagnosed as bilateral large vestibular aqueduct syndrome. PMID:28018692

  8. Hearing Preservation CI Surgery and Hybrid Hearing : From Anatomical Aspects to Patient Satisfaction

    OpenAIRE

    Erixon, Elsa

    2014-01-01

    A common cause of profound deafness is hair cell dysfunction in the cochlea. Cochlear implants (CI) bypass the hair cells via an electrode and stimulate the cochlear nerve directly. Nowadays, it is possible to preserve residual hair cell function and hearing through flexible electrodes and a-traumatic CI surgery techniques; called hearing preservation CI surgery. This may suit partially deaf patients who can use natural low frequency hearing in combination with electric high frequency hearing...

  9. Hearing aid effectiveness after aural rehabilitation - individual versus group (HEARING) trial: RCT design and baseline characteristics

    OpenAIRE

    Heagerty Patrick J; Liu Chuan-Fen; Souza Pamela E; Collins Margaret P; Amtmann Dagmar; Yueh Bevan

    2009-01-01

    Abstract Background Hearing impairment is the most common body system disability in veterans. In 2008, nearly 520,000 veterans had a disability for hearing loss through the Department of Veterans Affairs (VA). Changes in eligibility for hearing aid services, along with the aging population, contributed to a greater than 300% increase in the number of hearing aids dispensed from 1996 to 2006. In 2006, the VA committed to having no wait times for patient visits while providing quality clinicall...

  10. Numerical Estimation in Deaf and Hearing Adults

    OpenAIRE

    Bull, Rebecca; Marschark, Marc; Sapere, Patty; Davidson, Wendy A.; Murphy, Derek; Nordmann, Emily

    2011-01-01

    Deaf students often lag behind hearing peers in numerical and mathematical abilities. Studies of hearing children with mathematical difficulties highlight the importance of estimation skills as the foundation for formal mathematical abilities, but research with adults is limited. Deaf and hearing college students were assessed on the Number-to-Position task as a measure of estimation, and completed standardised assessments of arithmetical and mathematical reasoning. Deaf students performed si...

  11. Medulloblastoma Manifesting as Sudden Sensorineural Hearing Loss

    OpenAIRE

    Terakawa, Yuzo; Tsuyuguchi, Naohiro; Takami, Toshihiro; Ohata, Kenji

    2011-01-01

    We present a rare case of medulloblastoma which presented with unilateral sudden sensorineural hearing loss as an initial symptom. A 19-year-old man was admitted to our hospital with a chief complaint of dizziness and facial numbness on the right side. His illness had begun two years previously with sudden hearing loss on the right side, for which he had been treated as an idiopathic sudden hearing loss. Magnetic resonance imaging demonstrated abnormal signals located mainly in the right midd...

  12. Evaluation of Age-Related Hearing Loss

    OpenAIRE

    2013-01-01

    Age-related hearing loss (presbycusis) is characterized by an increased hearing threshold and poor speech understanding in a noisy environment, slowed central processing of acoustic information, and impaired localization of sound sources. Presbycusis seriously affects the older people's quality of life. Particularly, hearing loss in the elderly contributes to social isolation, depression, and loss of self-esteem. Current amplification methods related to auditory rehabilitation can provide imp...

  13. Laser application in otology for hearing restoration

    Science.gov (United States)

    Lombardo, Igino

    1994-09-01

    Prior to the development of the stapes replacement prosthesis in the early 1950s, loss of hearing due to otosclerosis remained an untreatable disease. Today, loss of hearing due to otosclerosis can be restored in the majority of cases to near normal levels. Since 1980 the laser has played a major and important role in otosclerosis surgery. This paper explores the use of lasers for hearing restoration and compares the results of laser surgery to non-laser surgery.

  14. [Incidence of normal hearing in acoustic neuroma].

    Science.gov (United States)

    De Donato, G; Russo, A; Taibah, A; Saleh, E; Sanna, M

    1995-04-01

    Unilateral or asymetrical sensorineural hearing loss, tinnitus and instability classically represent the main symptoms for the suspected diagnosis of acoustic neurinoma. In literature there are very few studies which refer about acoustic neurinoma in patients with normal hearing. In this article we report the results of a retrospective analysis of 155 acoustic neurinoma cases with normal hearing managed in our center in the last 7 years. These patients are classified in two groups: 1) with normal hearing at the time of diagnosis and 2) with at least a mild sensorineural hearing loss. Of this 155 cases, 21 (13.5%) had normal pure tone audiogram. An important characteristic of these patients, in comparison with the group with normal hearing, is the younger age. Tinnitus, instability, sudden hearing loss with complete recovery and vertigo are the most common symptoms. The mean pure tone threshold is 14.7 dB, speech audiometry is positive in very few cases, while a large number of cases show false negative. ABR are positive in 90.5% of cases, and demonstrate its high sensitivity for retrococlear pathology. The mean tumor size shows significant differences between the group with normal hearing and this with hearing loss. We believe that the presence of this symptoms in a young patient should necessitate complete neurotologic examination and in the patients with normal hearing a high level of suspicion represents the first step for early diagnosis of small tumors; the next step is the through evaluation of patient with pure tone audiogram, ABR, and imaging studies, preferably MRI with gadolinium, as this permits the diagnosis of small intracanalicular tumor. Thus, in cases of small tumors with good hearing we feel that will be possible to adopt hearing conservation surgical approach like FCM and retrosigmoid approach in more cases.

  15. Family perceptions of early hearing, detection, and intervention systems: listening to and learning from families.

    Science.gov (United States)

    DesGeorges, Janet

    2003-01-01

    As universal newborn hearing systems (screening, diagnosis, intervention) are being established around the world, the success of children who are identified to be deaf and hard of hearing is critically impacted by parent's reactions, acceptance, and advocacy for their child. It is imperative for professionals who are creating systems for Early Hearing, Detection, and Intervention to understand and learn from families' experiences in order to improve this process. This manuscript will identify the areas in which parents have spoken out about the professionals they have encountered through the system: what parents wish for in a healthy, productive relationship with professionals; and how parents can play a part in advocating for a system in which families needs are met so that infants identified to be deaf or hard of hearing can reach their full potential.

  16. Wilderness Study Report : Volume III : Public Hearing Transcripts

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document contains public hearing transcripts from the Kenai National Moose Range Wilderness Hearing. This hearing was held to obtain information relating to...

  17. 20 CFR 416.1417 - Disability hearing-disability hearing officer's reconsidered determination.

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Disability hearing-disability hearing officer... Review Process, and Reopening of Determinations and Decisions Reconsideration § 416.1417 Disability hearing—disability hearing officer's reconsidered determination. (a) General. The disability...

  18. 20 CFR 404.915 - Disability hearing-disability hearing officers.

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Disability hearing-disability hearing..., SURVIVORS AND DISABILITY INSURANCE (1950- ) Determinations, Administrative Review Process, and Reopening of Determinations and Decisions Reconsideration § 404.915 Disability hearing—disability hearing officers....

  19. How Hearing Loss Impacts Communication. Tipsheet: Serving Students Who Are Hard of Hearing

    Science.gov (United States)

    Atcherson, Samuel R.; Johnson, Marni I.

    2009-01-01

    Hearing, or auditory processing, involves the use of many hearing skills in a single or combined fashion. The sounds that humans hear can be characterized by their intensity (loudness), frequency (pitch), and timing. Impairment of any of the auditory structures from the visible ear to the central auditory nervous system within the brain can have a…

  20. Levels of Evidence: Universal Newborn Hearing Screening (UNHS) and Early Hearing Detection and Intervention Systems (EHDI)

    Science.gov (United States)

    Yoshinaga-Itano, Christine

    2004-01-01

    Levels of evidence differ according to the audience addressed. Implementation of universal newborn hearing screening requires responses to a complex myriad of diverse groups: the general public, families with children who are deaf or hard of hearing, the deaf and hard of hearing communities, hospital administrators, physicians (pediatricians,…

  1. Elderly With Different Types of Hearing Loss and Comorbidities: Satisfaction With Hearing Aids

    Directory of Open Access Journals (Sweden)

    Dashti

    2015-07-01

    Full Text Available Background Hearing loss is developing when age is rising. Initiation and progression rates of hearing loss vary among different individuals and groups. Objectives The current study aimed to determine satisfaction of the elderly with their hearing aids in different types of hearing loss and comorbidities. Patients and Methods The study was conducted on 40 elderly subjects suffering from hearing loss and using hearing aids. The data collection method included assessment of hearing loss in addition to using a questionnaire to estimate respondents' satisfaction with their hearing aids in daily life. The Persian version of the Satisfaction with Amplification in Daily Life (SADL questionnaire was administered. The data were analyzed using descriptive and inferential statistics by SPSS software version19. Results The mean satisfaction scores of the elderly were 4.83 ± 0.51 and 5.36 ± 0.30 in the sensorineural loss groups. There was no significant difference between different comorbidities. There was a significant difference between satisfaction level of cost and services subscales in the symmetrical styles of hearing loss (P value = 0.04. Conclusions The findings of the study indicated a high satisfaction of the elderly with their hearing aids, considering the type of hearing loss. Despite all the efforts to improve the audiologic services during verification process, the elderly should be consulted specifically in order to fit their hearing aid as well as their expectations from aid.

  2. Parenting Styles of Mothers with Deaf or Hard-of-Hearing Children and Hearing Siblings

    Science.gov (United States)

    Antonopoulou, Katerina; Hadjikakou, Kika; Stampoltzis, Aglaia; Nicolaou, Nicoletta

    2012-01-01

    The present study aims to determine whether rearing a deaf or hard-of-hearing (d/hh) child would differentiate the parenting and disciplinary preference of parents between the d/hh and the hearing child. The parenting styles of 30 hearing mothers from Cyprus were assessed using the Greek version of the Parenting Styles & Dimensions Questionnaire.…

  3. Bristol Bay Beluga hearing sensitivity data collected from 2012-09-02 to 2014-09-03 (NCEI Accession 0140481)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Hearing sensitivity data was collected on beluga whales in Bristol Bay with auditory evoked potential (AEP) methods for the frequencies 4, 8, 11.2, 16, 22.5, 32, 45,...

  4. Strategies for the prevention of MP3-induced hearing loss among adolescents : Expert opinions from a Delphi study

    NARCIS (Netherlands)

    Vogel, I.; Brug, J.; Ploeg, C.P.B. van der; Raat, H.

    2009-01-01

    OBJECTIVE. To identify parties involved in the prevention of MP3-induced hearing loss among adolescents and potentially effective prevention strategies and interventions. METHODS. Thirty experts in fields such as scientific research, medical practice, community health professions, education, youth w

  5. Satisfaction of Elderly Hearing Aid Users.

    Science.gov (United States)

    Kozlowski, Lorena; Ribas, Angela; Almeida, Gleide; Luz, Idalina

    2017-01-01

    Introduction The impact of auditory sensory deprivation in the life of an individual is enormous because it not only affects one's ability to properly understand auditory information, but also the way people relate to their environment and their culture. The monitoring of adult and elderly subjects with hearing loss is intended to minimize the difficulties and handicaps that occur as a consequence of this pathology. Objective To evaluate the level of user satisfaction with hearing aids. Methods A clinical and experimental study involving 91 elderly hearing aid users. We used the questionnaire Satisfaction with Amplification in Daily Life to determine the degree of the satisfaction provided by hearing aids. We evaluated mean global score, subscales, as well as the variables time to use, age, and degree of hearing loss. Results Mean global score was 4.73, the score for Positive Effects 5.45, Negative Factors 3.2, demonstrating that they were satisfied; Services and Costs 5.98: very satisfied ; 3.65 Personal Image: dissatisfied. We observed statistically significant difference for the time of hearing aid use, age, and degree of hearing loss. Conclusion The SADL is a tool, simple and easy to apply and in this study we can demonstrate the high degree of satisfaction with the hearing aids by the majority of the sample collected, increasing with time of use and a greater degree of hearing loss.

  6. Office of Hearings Case Tracking Data -

    Data.gov (United States)

    Department of Transportation — This data set contains information on hearings conducted for the Department of Transportation or its modal administrations by administrative law judges in accordance...

  7. Vibrant Soundbridge rehabilitation of sensorineural hearing loss.

    Science.gov (United States)

    Khan, Andleeb; Hillman, Todd; Chen, Douglas

    2014-12-01

    The Vibrant Soundbridge is a means to rehabilitate patients with sensorineural hearing loss. It differs from hearing aids in that it uses mechanical energy rather than acoustic sound to deliver better sound quality to the inner ear. The implant's crucial component is a floating mass transducer that is directly fixed to the incus to drive it, which is introduced into the middle ear through a facial recess approach. Although this is a newer technology, studies thus far have demonstrated better hearing results compared with hearing aids in terms of functional gain and speech intelligibility, and better outcomes on subjective assessments.

  8. Sudden bilateral hearing loss after organophosphate inhalation

    OpenAIRE

    Dundar, Mehmet Akif; Derin, Serhan; Aricigil, Mitat; Eryilmaz, Mehmet Akif

    2016-01-01

    Sudden bilateral hearing loss are seen rarely and the toxic substance exposure constitutes a small part of etiology. A Fifty-eight-year-old woman admitted to our clinic with sudden bilateral hearing loss shortly after chlorpyrifos-ethyl exposure. Otolaryngologic examination findings were normal. The patient had 40 dB sensorineural hearing loss (SNHL) on the right ear and 48 dB SNHL on the left ear. Additional diagnostic tests were normal. The conventional treatment for sudden hearing loss was...

  9. Sensorineural Hearing Loss after Magnetic Resonance Imaging

    Directory of Open Access Journals (Sweden)

    Abolfazl Mollasadeghi

    2013-01-01

    Full Text Available Magnetic resonance imaging (MRI devices produce noise, which may affect patient’s or operators’ hearing. Some cases of hearing impairment after MRI procedure have been reported with different patterns (temporary or permanent, unilateral or bilateral, with or without other symptoms like tinnitus. In this report, a case of bilateral sensorineural hearing loss in an otherwise healthy patient underwent brain MRI was described. The patient’s hearing loss was accompanied with tinnitus and was not improved after 3 months of followup.

  10. Hearing Conservation Self-Study #12350

    Energy Technology Data Exchange (ETDEWEB)

    Chochoms, Michael [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-08-09

    Occupational hearing loss is one of the most common work-related illnesses in the United States (US). From 22 to 30 million US workers are exposed to hazardous noise levels at work, and 25% of these workers will develop permanent hearing loss. Hearing loss from noise is slow and painless, and you can have a disability before you notice it. This course presents the hazards associated with workplace noise, the purpose and elements of the Los Alamos National Laboratory (LANL) Hearing Conservation Program (HCP), and controls that are available to reduce your exposure to hazardous levels of noise.

  11. Noise-induced hearing impairment and handicap

    Science.gov (United States)

    1984-01-01

    A permanent, noise-induced hearing loss has doubly harmful effect on speech communications. First, the elevation in the threshold of hearing means that many speech sounds are too weak to be heard, and second, very intense speech sounds may appear to be distorted. The whole question of the impact of noise-induced hearing loss upon the impairments and handicaps experienced by people with such hearing losses was somewhat controversial partly because of the economic aspects of related practical noise control and workmen's compensation.

  12. Hearing Preservation in Cochlear Implant Surgery

    Directory of Open Access Journals (Sweden)

    Priscila Carvalho Miranda

    2014-01-01

    Full Text Available In the past, it was thought that hearing loss patients with residual low-frequency hearing would not be good candidates for cochlear implantation since insertion was expected to induce inner ear trauma. Recent advances in electrode design and surgical techniques have made the preservation of residual low-frequency hearing achievable and desirable. The importance of preserving residual low-frequency hearing cannot be underestimated in light of the added benefit of hearing in noisy atmospheres and in music quality. The concept of electrical and acoustic stimulation involves electrically stimulating the nonfunctional, high-frequency region of the cochlea with a cochlear implant and applying a hearing aid in the low-frequency range. The principle of preserving low-frequency hearing by a “soft surgery” cochlear implantation could also be useful to the population of children who might profit from regenerative hair cell therapy in the future. Main aspects of low-frequency hearing preservation surgery are discussed in this review: its brief history, electrode design, principles and advantages of electric-acoustic stimulation, surgical technique, and further implications of this new treatment possibility for hearing impaired patients.

  13. Evidence-based practice: management of adult sensorineural hearing loss.

    Science.gov (United States)

    Chau, Justin K; Cho, John J W; Fritz, Dieter K

    2012-10-01

    Sensorineural hearing loss is a complex disease state influenced by genetics, age, noise, and many other factors. This article reviews our current knowledge regarding the causes of sensorineural hearing loss and reviews the more challenging clinical presentations of sensorineural hearing loss. We have reviewed the latest medical literature in an attempt to provide an evidence-based strategy for the assessment and management of sudden sensorineural hearing loss, rapidly progressive sensorineural hearing loss, and asymmetric/unilateral sensorineural hearing loss.

  14. Factors influencing the choice of prescribed hearing aid

    OpenAIRE

    Živić Ljubica; Živić Danijela

    2012-01-01

    In our paper we would like to emphasize the complexity of hearing aid prescription process. It is connected to a series of factors which impact the choice of hearing aid; type of hearing loss, degree of hearing loss according to the average hearing threshold expressed within the range from 500 Hz to 4000 Hz on a tonal audiogram, audiometric curve configuration, speech discrimination ability, patients’ age at which the hearing impairment occurred, time elapsed between the occurrence of h...

  15. Prevalence and Parental Awareness of Hearing Loss in Children with Down Syndrome

    Institute of Scientific and Technical Information of China (English)

    Wai-Ling Lau; Chun-Hung Ko; Wai-Wai Cheng

    2015-01-01

    Background:To establish the prevalence of hearing deficit in children with Down syndrome (DS) in Hong Kong as measured by brainstem auditory evoked potentials (BAEP).The secondary objective is to examine the agreement between BAEP and clinical questioning in detecting hearing deficit in DS.Methods:Consecutive DS patients attending the Down's Clinic in a regional pediatric referral center were recruited into this cross-sectional study.BAEP data performed within 12 months were retrieved.The care-taker was interviewed with a structured questionnaire to detect any symptom of hearing impairment.BAEP findings and clinical questionings were compared in an agreement analysis using quadratic weighted kappa statistics.Results:Fifty DS patients (35 male,15 female,mean age 11.70 years + 5.74 standard deviation) were recruited.Eighteen patients (36.0%) were identified having hearing deficit by BAEP.Among patients with hearing impairment,13 patients (72.2%) had a conductive deficit,and most have mild to moderate hearing loss.Five patients (27.8%) had sensorineural deficit and most have moderate to severe degree.Eight (44.4%) had bilateral hearing deficit.Care-takers of 13 patients (26.0%) reported symptoms of hearing impairment,with 9 (69.2%) having mild symptoms,3 (23.1%) had moderate symptoms and 1 (7.7%) had severe symptoms.The weighted kappa was 0.045 (95.0% confidence interval-0.138-0.229),indicating very poor strength of agreement between BAEP and clinical questioning.For patients with conductive hearing impairment,only 1 patients (7.7%) recalled history of otitis media.Conclusions:The estimated point prevalence of hearing impairment in Chinese DS children in Hong Kong is 36%.Our finding of poor strength of agreement between objective testing and symptom questioning reflects significant underestimation of hearing impairment by history taking alone.In view of the high prevalence and low parental awareness,continuous surveillance of hearing is mandatory

  16. Opening the Market for Lower Cost Hearing Aids: Regulatory Change Can Improve the Health of Older Americans.

    Science.gov (United States)

    Blustein, Jan; Weinstein, Barbara E

    2016-06-01

    Hearing loss is a leading cause of disability among older people. Yet only one in seven US adults who could benefit from a hearing aid uses one. This fraction has not increased over the past 30 years, nor have hearing aid prices dropped, despite trends of steady improvements and price reductions in the consumer electronics industry. The President's Council on Science and Technology has proposed changes in the regulation of hearing aids, including the creation of a "basic" low-cost over-the-counter category of devices. We discuss the potential to reduce disability as well as to improve public health, stakeholder responses to the president's council's proposal, and public health efforts to further mitigate the burden of disability stemming from age-related hearing loss.

  17. Changes in auditory perceptions and cortex resulting from hearing recovery after extended congenital unilateral hearing loss

    Directory of Open Access Journals (Sweden)

    Jill B Firszt

    2013-12-01

    Full Text Available Monaural hearing induces auditory system reorganization. Imbalanced input also degrades time-intensity cues for sound localization and signal segregation for listening in noise. While there have been studies of bilateral auditory deprivation and later hearing restoration (e.g. cochlear implants, less is known about unilateral auditory deprivation and subsequent hearing improvement. We investigated effects of long-term congenital unilateral hearing loss on localization, speech understanding, and cortical organization following hearing recovery. Hearing in the congenitally affected ear of a 41 year old female improved significantly after stapedotomy and reconstruction. Pre-operative hearing threshold levels showed unilateral, mixed, moderately-severe to profound hearing loss. The contralateral ear had hearing threshold levels within normal limits. Testing was completed prior to, and three and nine months after surgery. Measurements were of sound localization with intensity-roved stimuli and speech recognition in various noise conditions. We also evoked magnetic resonance signals with monaural stimulation to the unaffected ear. Activation magnitudes were determined in core, belt, and parabelt auditory cortex regions via an interrupted single event design. Hearing improvement following 40 years of congenital unilateral hearing loss resulted in substantially improved sound localization and speech recognition in noise. Auditory cortex also reorganized. Contralateral auditory cortex responses were increased after hearing recovery and the extent of activated cortex was bilateral, including a greater portion of the posterior superior temporal plane. Thus, prolonged predominant monaural stimulation did not prevent auditory system changes consequent to restored binaural hearing. Results support future research of unilateral auditory deprivation effects and plasticity, with consideration for length of deprivation, age at hearing correction, degree and type

  18. Effect of ultrasound in the free radical polymerization of acrylonitrile under a new multi-site phase-transfer catalyst - a kinetic study.

    Science.gov (United States)

    Selvaraj, Varathan; Sakthivel, Perumal; Rajendran, Venugopal

    2015-01-01

    The kinetics of polymerization of acrylonitrile (AN) was carried out under heterogeneous condition using a new multi-site phase-transfer catalyst (MPTC), viz., N,N'-dihexyl-4,4'-bipyridinium dibromide in the presence of water soluble initiator, potassium peroxydisulphate (PDS) under chlorobenzene/water two phase system assisted by ultrasound irradiation at constant temperature 60+1°C under nitrogen atmosphere. The rate of polymerization increases with an increasing the concentrations of AN, MPTC and PDS. The order with respect to [AN], [MPTC], and [PDS] were found to be 1.01, 1.03 and 0.52, respectively. Based on the observed results a suitable mechanism has been proposed to account for the experimental observations followed by a discussion on its significance.

  19. One-step Preparation and Antibacterial Property of Poly(N-iso- propyl-acrylamide) Grafted Poly(acrylonitrile/styrene) Micro- spheres Immobilized with Silver Nanoparticles

    Institute of Scientific and Technical Information of China (English)

    FENG,Jiao; FAN,Liheng; CHU,Hong; XIONG,Wanbin; JIANG,Jinqiang; CHEN,Mingqing

    2009-01-01

    Monodispersed silver nanoparticles were immobilized onto the surface of poly(N-isopropylacrylamide) grafted poly(acrylonitrile/styrene) (PNIPAAm-g-PAN/PSt) microspheres by a one-step method using AgNO3 as a silver source. This process was performed via the coordination interaction between Ag ions and amide groups on PNIPAAm-g-PAN/PSt microsphere surfaces with the reduction of the corresponding ions by ethanol taking place simultaneously. Fourier transform infrared (FTIR) spectroscopy and ultraviolet (UV)-visible spectra illustrated that the silver nanoparticles were successfully immobilized onto the PNIPAAm-g-PAN/PSt microspheres. The size and morphology of silvered microspheres were characterized by transmission electron microscopy (TEM). The weight percent of silver nanoparticles immobilized onto the microspheres was 12% based on the determination of thermogravimetric analysis (TGA). The antibacterial tests demonstrated that the as-prepared silvered microspheres showed activity against Gram-negative bacteria.

  20. FINITE ELEMENT SIMULATION FOR YIELD STRESS OF HARD POLY(VINYL CHLORIDE)/ACRYLONITRILE-BUTADIENE-STYRENE BLENDS AT DIFFERENT CROSSHEAD SPEEDS

    Institute of Scientific and Technical Information of China (English)

    Pei-hua Du; Jie Yu; Peng-fei Lin; Yi-hu Song; Qiang Zneng

    2011-01-01

    Hard poly(vinyl chloride) (PVC)/acrylonitrile-butadiene-styrene (ABS) blends were prepared using injectionmolding and influence of crosshead speed on mechanical properties was examined.Based on morphology parameters obtained from transmission electron microscopy photography and the material parameters from true stress-strain curves of neat PVC and ABS,yield stresses of the blends at different crosshead speeds were simulated employing a two-dimensional nine-particle model based on the finite element analysis (FEA).The FEA results were compared with the experimental yielding stress and the good agreement validated the simulation approach.The FEA approach allowed establishing a yielding criterion related to local yielding of the interstitial matrix between ABS particles.

  1. Studies on blends of cycloaliphatic epoxy resin with varying concentrations of carboxyl terminated butadiene acrylonitrile copolymer I: Thermal and morphological properties

    Indian Academy of Sciences (India)

    Garima Tripathi; Deepak Srivastava

    2009-04-01

    Differential scanning calorimetric (DSC), thermogravimetric analysis (TGA) and dynamic mechanical analysis (DMA) of the blends of cycloaliphatic epoxy (CAE) resin toughened with liquid elastomer such as carboxyl terminated butadiene acrylonitrile copolymer (CTBN) have been carried out. Exothermal heat of reaction due to cross linking of the resin in the presence of diamino diphenyl sulphone (DDS, an amine hardener) showed a decreasing trend with increasing rubber concentration. Enhancement of thermal stability as well as lower mass loss of the epoxy–rubber blends with increasing rubber concentration have been observed in thermogravimetric analysis (TGA). Dynamic mechanical properties reflected a monotonic decrease in the storage modulus (′) with increasing rubber concentration. The loss modulus (″) and the loss tangent (tan ) values, however, showed an increasing trend with rise of temperature up to a maximum (peak) followed by a gradual fall in both cases.

  2. Modification on liquid retention property of cassava starch by radiation grafting with acrylonitrile. I. Effect of γ-irradiation on grafting parameters

    Science.gov (United States)

    Kiatkamjornwong, S.; Chvajarernpun, J.; Nakason, C.

    1993-07-01

    Radiation modification on liquid retention properties of native cassava starch, gelatinized at 85°C, by graft copolymerization with acrylonitrile was carried out by mutual irradiation to gamma-rays. A thin aluminum foil was used to cover the inner wall of the reaction vessel, so that the homopolymer concentration was reduced to be less than 1.0% with a distilled water retention value of 665 g/g of the dry weight of the saponified grafted product. Confirmation of graft copolymerization and saponification reactions was made by the infrared spectrophotometric technique. The combined effect of radiation parameters in terms of an irradiation time and a dose rate to the total dose on the extent of the grafting reaction expressed in terms of grafting parameters which directly influenced liquid retention values was evaluated in conjunction with statistical analysis.

  3. SELECTIVE SEPARATION OF WATER-ETHANOL MIXTURES THROUGH COPOLYMERIC MEMBRANES:Ⅰ. ACRYLIC ACID AND ACRYLONITRILE COPOLYMER AND ITS IONIZED MEMBRANES

    Institute of Scientific and Technical Information of China (English)

    ZHANG Fuyao; ZHANG Yifeng; ZHAO Zhuomin; SHEN Zhiquan

    1993-01-01

    The copolymer of acrylic acid and acrylonitrile has been synthesized and pervaporation properties of the copolymeric membranes have been investigated. In order to elucidate the influence of membrane-permeate interaction on the pervaporation of water-ethanol mixtures and to prepare much improved membranes, the membranes have been treated with alkali metal, alkali earth metal and transition metal salt aqueous solutions. The treated membranes (ionized membranes)exhibited higher separation factors than the untreated membranes. The separation factors of various alkali metal cation membranes decreased in the following order: Li+>Na+>K+, and the permeation rates showed an opposite tendency. The dependence of pervaporation behavior on the copolymer composition ,feed concentration and operating temperature have been studied with both ionized and non-ionized membranes. The apparent activation energies of water and ethanol permeation were calculated.

  4. Objective Scaling of Sound Quality for Normal-Hearing and Hearing-Impaired Listeners

    DEFF Research Database (Denmark)

    Nielsen, Lars Bramsløw

    ) Subjective sound quality ratings of clean and distorted speech and music signals, by normal-hearing and hearing-impaired listeners, to provide reference data, 2) An auditory model of the ear, including the effects of hearing loss, based on existing psychoacoustic knowledge, coupled to 3) An artificial neural...... by both normal-hearing and hearing-impaired listeners. The scales were found not to be absolute, thus OSSQAR cannot predict the absolute sound quality, but it can be used to rank the sound quality. Using test data from the present subjective rating experiment, the prediction error of OSSQAR was found...

  5. Improving word recognition in noise among hearing-impaired subjects with a single-channel cochlear noise-reduction algorithm.

    Science.gov (United States)

    Fink, Nir; Furst, Miriam; Muchnik, Chava

    2012-09-01

    A common complaint of the hearing impaired is the inability to understand speech in noisy environments even with their hearing assistive devices. Only a few single-channel algorithms have significantly improved speech intelligibility in noise for hearing-impaired listeners. The current study introduces a cochlear noise reduction algorithm. It is based on a cochlear representation of acoustic signals and real-time derivation of a binary speech mask. The contribution of the algorithm for enhancing word recognition in noise was evaluated on a group of 42 normal-hearing subjects, 35 hearing-aid users, 8 cochlear implant recipients, and 14 participants with bimodal devices. Recognition scores of Hebrew monosyllabic words embedded in Gaussian noise at several signal-to-noise ratios (SNRs) were obtained with processed and unprocessed signals. The algorithm was not effective among the normal-hearing participants. However, it yielded a significant improvement in some of the hearing-impaired subjects under different listening conditions. Its most impressive benefit appeared among cochlear implant recipients. More than 20% improvement in recognition score of noisy words was obtained by 12, 16, and 26 hearing-impaired at SNR of 30, 24, and 18 dB, respectively. The algorithm has a potential to improve speech intelligibility in background noise, yet further research is required to improve its performances.

  6. Valproate-induced reversible sensorineural hearing loss: a case report with serial audiometry and pharmacokinetic modelling during a valproate rechallenge.

    Science.gov (United States)

    Yeap, Li-Ling; Lim, Kheng-Seang; Lo, Yoke-Lin; Bakar, Mohd Zukiflee Abu; Tan, Chong-Tin

    2014-09-01

    Hearing loss has been reported with valproic acid (VPA) use. However, this is the first case of VPA-induced hearing loss that was tested and confirmed with a VPA rechallenge, supported by serial audiometry and pharmacokinetic modelling. A 39-year-old truck driver with temporal lobe epilepsy was treated with VPA at 400 mg, twice daily, and developed hearing loss after each dose, but recovered within three hours. Hearing loss fully resolved after VPA discontinuation. Audiometry performed five hours after VPA rechallenge showed significant improvement in hearing thresholds. Pharmacokinetic modelling during the VPA rechallenge showed that hearing loss occurred at a level below the therapeutic range. Brainstem auditory evoked potential at three months after VPA discontinuation showed bilateral conduction defect between the cochlear and superior olivary nucleus, supporting a pre-existing auditory deficit. VPA may cause temporary hearing threshold shift. Pre-existing auditory defect may be a risk factor for VPA-induced hearing loss. Caution should be taken while prescribing VPA to patients with pre-existing auditory deficit.

  7. 光照射下丙烯腈活性自由基聚合的研究%Photo-induced Living Radical Polymerization of Acrylonitrile

    Institute of Scientific and Technical Information of China (English)

    何斌鸿

    2015-01-01

    Acrylonitrile as monomer, azobisisobutyronitrile as initiator, hexamethylenetetramine as ligand, copper chloride dihydrate as catalyst and Vitamin C as reducing agent, polyacrylonitrile was synthesized in N,N-dimethylformamide under the light irradiation. The effects of the amount of monomer, initiator, catalyst, hexamethylenetetramine and Vitamin C on the photo-induced polymerization of acrylonitrile have been invetigated. On the basis of experiments, it is concluded that the best polymerization conditions were that the amount of monomer is 0.2 mol and the usage of azobisisobutyronitrile, copper chloride dihydrate, hexamethylenetetramine and vitamin C was 1%, 0.75%, 1%, 4 % of the mole of monomer, respectively. The best reaction time is 11 h.%以丙烯腈作为单体,偶氮二异丁腈为引发剂,六次亚甲基四胺为配体,二水氯化铜为催化剂,维生素C为还原剂,在光的照射下,于溶剂 N,N-二甲基甲酰胺中采用自由基聚合的原理制得聚丙烯腈,并探究改变单一反应物的用量时对该聚合反应的影响,最后得出最佳的聚合条件为:在室温20℃下反应时,最佳单体用量为0.2mol,引发剂偶氮二异丁腈、催化剂二水氯化铜、配体六次亚甲基四胺、还原剂维生素C分别为单体摩尔总量的1%、0.75%、1%、4%,最佳反应时间为11 h.

  8. Hearing aid-related satisfaction based on type and degree of hearing loss in elderly

    Directory of Open Access Journals (Sweden)

    Farzad FarajiKhiavi

    2015-02-01

    Full Text Available Background and Aim: Hearing loss is one of the most prevalent chronic diseases in the elderly; using a hearing aid to alleviate auditory impairment can positively affect their quality of life. This research aimed to determine the level of satisfaction concerning hearing aids in elderly people with hearing impairment based on the type and degree of hearing loss.Methods: An analytic cross-sectional research design was used ; the sample included 40 elderly people who used hearing aids. According to the World Health Organization (WHO age classification, participants were divided into two age groups: 65-74 years (n=20 and 75-90 years (n=20. Satisfaction levels were assessed using a standard satisfaction with amplification in daily life (SADL questionnaire.Results: Satisfaction levels in the 65-74 age group were significantly higher than that in the 75-90 age group (p=0.02. Participants with mixed hearing loss revealed higher satisfaction levels than participants with sensorineural hearing loss (p=0.02. On the negative effects dimension, participants with severe hearing loss exhibited significantly higher satisfaction levels than participants with moderate or moderate to severe hearing loss (p=0.01.Conclusion: Total satisfaction mean scores were relatively high in the elderly participants . Negative features could be reduced via careful consultation regarding the aids’ amplifying capabilities and limitations in groups with moderate or moderate to severe hearing loss.

  9. Hearing loss in veterans and the need for hearing loss prevention programs.

    Science.gov (United States)

    Saunders, Gabrielle H; Griest, Susan E

    2009-01-01

    Currently, there are more than 445,000 veterans receiving compensation for hearing loss associated with military service, and 395,000 receiving compensation for service-related tinnitus. In addition to compensation payments, service-related hearing disorders cost the US Department of Veterans Affairs in terms of provision of hearing aids, hearing aid-related services, and clinical services at its 220 facilities nationwide. It is imperative that hearing conservation among military personnel and veterans be addressed. In this paper, we describe the rationale for and the development of a multimedia Hearing Loss Prevention Program aimed at preventing the progression of hearing loss among veterans associated with social, recreational, and nonmilitary occupational noise exposure. The program was developed based on the principles outlined in the Health Belief Model of Rosenstock (1966) and the Health Promotion Model of Pender et al. (2002).

  10. Viral causes of hearing loss: a review for hearing health professionals.

    Science.gov (United States)

    Cohen, Brandon E; Durstenfeld, Anne; Roehm, Pamela C

    2014-07-29

    A number of viral infections can cause hearing loss. Hearing loss induced by these viruses can be congenital or acquired, unilateral or bilateral. Certain viral infections can directly damage inner ear structures, others can induce inflammatory responses which then cause this damage, and still others can increase susceptibility or bacterial or fungal infection, leading to hearing loss. Typically, virus-induced hearing loss is sensorineural, although conductive and mixed hearing losses can be seen following infection with certain viruses. Occasionally, recovery of hearing after these infections can occur spontaneously. Most importantly, some of these viral infections can be prevented or treated. For many of these viruses, guidelines for their treatment or prevention have recently been revised. In this review, we outline many of the viruses that cause hearing loss, their epidemiology, course, prevention, and treatment.

  11. Genetic Effects on Sensorineural Hearing Loss and Evidence-based Treatment for Sensorineural Hearing Loss

    Institute of Scientific and Technical Information of China (English)

    Yong-qiang Yu; Huai-an Yang; Ming Xiao; Jing-wei Wang; Dong-yan Huang; Yagesh Bhambhani; Lyn Sonnenberg

    2015-01-01

    In this article, the mechanism of inheritance behind inherited hearing loss and genetic susceptibility in noise-induced hearing loss are reviewed. Conventional treatments for sensorineural hearing loss (SNHL), i.e. hearing aid and cochlear implant, are effective for some cases, but not without limitations. For example, they provide little benefit for patients of profound SNHL or neural hearing loss, especially when the hearing loss is in poor dynamic range and with low frequency resolution. We emphasize the most recent evidence-based treatment in this field, which includes gene therapy and allotransplantation of stem cells. Their promising results have shown that they might be options of treatment for profound SNHL and neural hearing loss. Although some treatments are still at the experimental stage, it is helpful to be aware of the novel therapies and endeavour to explore the feasibility of their clinical application.

  12. [Inner Ear Hearing Loss Part II: Sudden Sensorineural Hearing Loss, Therapeutic Options].

    Science.gov (United States)

    Hesse, Gerhard

    2016-07-01

    The great majority of hearing disorders generates from pathologies in the inner ear, mainly the outer hair cells, as mentioned in the first part of this review. Very often, however, hearing loss appears suddenly and even without external causes like noise exposure. This sudden hearing loss is mostly unilateral, recovers very often spontaneously and should be treated, if persisting. Only in this acute stage there are therapeutic options available. If the inner ear hearing loss is chronic there is no curative therapy, an effective management of the hearing disorder is only possible through rehabilitation. This is due to the fact, that hair cells of all mammals, incl. humans, have no regenerative capacity and neither pharmaceutic agents nor other means can induce regeneration and recovery of hair cells. Even a gen-therapy is not available yet. In the second part of this review the main focus lies in sudden hearing loss and general therapeutic options for inner ear hearing loss.

  13. 7 CFR 900.115 - Hearing.

    Science.gov (United States)

    2010-01-01

    ... Hearing. (a) The arbitrator shall have full discretion to conduct the hearing in such manner as will, in... material evidence may be presented. The arbitrator shall not be bound by the legal rules of evidence. (d) The arbitrator, in the presence of the parties, may require the production of books and records...

  14. 40 CFR 304.32 - Arbitral hearing.

    Science.gov (United States)

    2010-07-01

    ... consideration of evidence for reasons of business confidentiality as defined by 40 CFR 2.201(e) and as... CLAIMS Hearings Before the Arbitrator § 304.32 Arbitral hearing. (a) The Arbitrator may, in his sole... statement of disputed issues pursuant to § 304.31(g)(1) of this part. (b) The Arbitrator shall select...

  15. 29 CFR 4221.6 - Hearing.

    Science.gov (United States)

    2010-07-01

    ... the arbitrator shall, no later than 15 days after the written acceptance by the arbitrator is mailed...-day period, the arbitrator shall, within 10 additional days, choose a location and set a hearing date. The date set for the hearing may be no later than 50 days after the mailing date of the...

  16. Hearing Evaluation in Children (For Parents)

    Science.gov (United States)

    ... Lessons? Visit KidsHealth in the Classroom What Other Parents Are Reading Your Child's Development (Birth to 3 Years) Feeding Your 1- ... Year-Old Hearing Evaluation in Children KidsHealth > For Parents > Hearing Evaluation in Children A A A What's in this article? Causes ...

  17. 28 CFR 902.5 - Hearing procedures.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Hearing procedures. 902.5 Section 902.5 Judicial Administration NATIONAL CRIME PREVENTION AND PRIVACY COMPACT COUNCIL DISPUTE ADJUDICATION...)(1) of the Compact. (b) The Council Chairman or his/her designee shall preside over the hearing...

  18. 20 CFR 901.44 - Hearings.

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Hearings. 901.44 Section 901.44 Employees' Benefits JOINT BOARD FOR THE ENROLLMENT OF ACTUARIES REGULATIONS GOVERNING THE PERFORMANCE OF ACTUARIAL... complaint for the suspension or termination of an enrolled actuary. Hearings shall be...

  19. Aspects of Hearing Aid Fitting Procedures

    NARCIS (Netherlands)

    R.M. Metselaar (Mick)

    2010-01-01

    textabstractSensorineural hearing loss is a common and chronic disorder that affects almost ten percent of the world population. In the Netherlands, it is also the major disorder in the working population [NCvB, 2008]. Hearing loss leads to restriction in the interaction with others and withdrawal f

  20. 30 CFR 62.160 - Hearing protectors.

    Science.gov (United States)

    2010-07-01

    ... REGULATIONS OCCUPATIONAL NOISE EXPOSURE § 62.160 Hearing protectors. (a) A mine operator must provide a hearing protector to a miner whose noise exposure equals or exceeds the action level under § 62.120 of this part. In addition, the mine operator must: (1) Train the miner in accordance with § 62.180 of...