74 Ge( n , γ ) cross section below 70 keV measured at n_TOF CERN.

Neutron capture reaction cross sections on 74 Ge are of importance to determine 74 Ge production during the astrophysical slow neutron capture process. We present new resonance data on 74 Ge( n , γ ) reactions below 70 keV neutron energy. We calculate Maxwellian averaged cross sections, combining our data below 70 keV with evaluated cross sections at higher neutron energies. Our stellar cross sections are in agreement with a previous activation measurement performed at Forschungszentrum Karlsruhe by Marganiec et al., once their data has been re-normalised to account for an update in the reference cross section used in that experiment.

Study of secondary neutron interactions with ²³²Th, ¹²9I, and ¹²7I nuclei with the uranium assembly "QUINTA" at 2, 4, and 8 GeV deuteron beams of the JINR Nuclotron accelerator.

The natural uranium assembly, "QUINTA", was irradiated with 2, 4, and 8GeV deuterons. The (232)Th, (127)I, and (129)I samples have been exposed to secondary neutrons produced in the assembly at a 20-cm radial distance from the deuteron beam axis. The spectra of gamma rays emitted by the activated (232)Th, (127)I, and (129)I samples have been analyzed and several tens of product nuclei have been identified. For each of those products, neutron-induced reaction rates have been determined. The transmutation power for the (129)I samples is estimated. Experimental results were compared to those calculated with well-known stochastic and deterministic codes.

[Impact of building and finishing materials and new furniture on the occurrence of respiratory diseases in children]. / Vliianie stroitel'no-otdelochnykh materialov i novoi mebeli na vozniknovenie respiratornykh zabolevanii u detei.

An epidemiological survey was made in 9 cities and towns of Russia to study the influence of emissions from building and finishing materials and new furniture on children's health. About 6,000 questionnaires containing the questions as to their apartment repairs and furniture changes were filled in. The questionnaire pays a particular attention to the types of used building materials, such as synthetic carpet covering, wood-particle boards, linoleum, paints, wall papers, and suspended ceilings. To study the children's health status, a number of questions of the questionnaire were devoted to the presence of some respiratory and allergic diseases (symptoms) reflecting the influence of unfavorable factors within the inhabited place. The logistic regression analysis was used to examine the relationship between the types of building materials used for repairs and the respiratory symptoms. There was a significant relationship of the chemical substances emitted from building materials and new furniture to the incidence of respiratory and allergic diseases in young schoolchildren.

[Influence of negative factors of the living environment on respiratory diseases in children]. / Vliianie negativnykh faktorov zhiloi sredy na respiratornye zabolevaniia u detei.

An epidemiological survey was made in 9 cities and towns of Russia to study the influence of negative characteristics of an inhabited place on respiratory diseases in children. About 6,000 questionnaires questioning the living conditions of young children were filled in. The questionnaire pays a particular attention to frequent leakages and mould in the flats. To study the children's health status, a number of questions of the questionnaire were devoted to the present of some respiratory and allergic diseases (symptoms) reflecting the influence of unfavorable factors within the inhabited place. The logistic regression analysis was used to examine the relationship between the characteristics of the inhabited place of schoolchildren and the presence of respiratory and allergic diseases. A significant relationship was established between the frequent leakages, the presence of mould in the rooms, and the risk for bronchial asthma, persistent productive cough, persistent stertorous respiration, respiratory infections and any manifestations of allergic reactions in children.

[Economic efficiency of sanitation measures at the JSC "Severstal" in the city of Cherepovets]. / Ekonomicheskaia éffektivnost' ozdorovitel'nykh meropriiatii na OAO "Severstal" (g. Cherepovets).

Using special dispersion dissemination model and software calculating average ground concentrations of air pollutants, the authors accomplished a demonstration project on determining priority measures in Federal program concerning sanitation of environment in Tcherepovets city. Based on cost-effectiveness ratio for reducing hazardous influence on public health in the city, the authors carried out evaluation and ranking of investment projects and therefore provided information to decide on priorities in realisation of investment projects at JSC "Severstal".

Schizophrenia subgroups differing in dichotic listening laterality also differ in neurometabolism and symptomatology.

Schizophrenia patients vary in right ear advantage (REA) on dichotic listening tests for assessing left hemispheric dominance for language processing. The authors examined if patients with low REA differed from other patients in symptoms and in resting brain metabolism. SPECT was conducted during visual fixation for 9 healthy control subjects and 16 schizophrenia patients: 8 with normal and 8 with diminished REA. REA-diminished patients had greater positive symptoms and lower mental status scores (all P<0.05) and had right middle temporal gyrus hypermetabolism. Both schizophrenia groups had decreased right frontal and increased medial temporal lobe metabolism vs. control subjects. REA-diminished patients had right temporal lobe hypermetabolism under a resting condition (eyes open, visual fixation). Results suggest reduced right ear (left hemisphere) advantage for dichotic word perception in schizophrenia is related to a predisposition to overactivate right temporal lobe regions and to positive symptoms. In contrast, the prefrontal-medial temporal imbalance present in both patient groups may typify the schizophrenia syndrome.

Ultrasound imaging-guided noninvasive ultrasound thrombolysis: preclinical results.

BACKGROUND: Catheter-based therapeutic ultrasound thrombolysis was recently shown to be effective and safe. The purpose of this work was to study the safety and efficacy of external high-intensity focused ultrasound thrombolysis guided by ultrasound imaging in experimental settings. METHODS AND RESULTS: A therapeutic transducer was constructed from an acoustic lens and integrated with an ultrasound imaging transducer. In vitro clots were inserted into bovine arterial segments and sonicated under real-time ultrasound imaging guidance in a water tank. With pulsed-wave (PW) ultrasound, the total sonication time correlated with thrombolysis efficiency (r(2)=0.7666). A thrombolysis efficiency of 91% was achieved with optimal PW parameters (1:25 duty cycle, 200-micros pulse length) at an intensity (I(spta)) of >35+/-5 W/cm(2). Ultrasound imaging during sonication showed the cavitation field as a spherical cloud of echo-dense material. Within <2 minutes, the vessel lumen evidenced neither residual clot nor damage to the arterial wall. On serial filtration, 93+/-1% of the lysed clot became subcapillary in size (<8 microm). In vitro safety studies, however, showed arterial damage when an I(spta) of 45 W/cm(2) was used for periods of >/=300 seconds. CONCLUSIONS: External high-intensity focused ultrasound thrombolysis using optimal PW parameters for periods of

SPECT study of visual fixation in schizophrenia and comparison subjects.

BACKGROUND: The consistent association of impaired eye movements and schizophrenia suggests a relationship between the neurobiology of the illness and visual pursuit systems. Visual fixation (VF), an eye "movement" task at zero velocity, is the simplest such abnormality in schizophrenia patients and their relatives. METHODS: We used a VF task for a functional imaging study. Six neuroleptic-free schizophrenia patients and eight gender and mean age matched comparison subjects had SPECT scans with 20 mCi of Tc99-HMPAO, during VF on a simple blue line intersection. MEDX data saved in ANALYZE format for SPM 95 was used to generate paired t-test statistical data for display in Talairach space, with rCBF changes given as Z-scores. RESULTS: Patients, compared to controls, had increased rCBF in both the parahippocampal gyrus (bilaterally) and in the right fusiform gyrus. They had decreased rCBF in the left frontal cortex, including medial and superior frontal gyri and anterior cingulate. Overall, compared to controls, patients had medial temporal lobe hyperperfusion along with left prefrontal hypoperfusion. CONCLUSIONS: These findings are consistent with the hypothesized imbalance between the medial temporal and frontal lobes that is postulated for schizophrenia. It was of interest that the relative rCBF differences between schizophrenia patients and controls in this small sample were observable with this cognitively non-demanding visual fixation task.

Evaluating noise induced hearing loss with distortion product otoacoustic emissions.

This study assessed the clinical efficacy of screening for noise induced hearing loss (NIHL) with distortion product otoacoustic emissions (DPOAE). DPOAEs were recorded from 76 military personnel (137 ears) aged between 17 and 41 years in response to equilevel 70 dB SPL primary stimulating tones. The 2f1-f2 DPOAE levels were correlated with audiometric thresholds at frequencies close to f2. Ears with normal audiograms, but with a history of military noise exposure, had DPOAEs that were significantly decreased in amplitude as compared to the ears of normal hearing non-exposed to noise subjects. These ears also had an increased absence of DPOAEs as compared with the ears of the normal hearing non-exposed to noise subjects. Although, in general, the DPOAE amplitudes and spectral frequency ranges reflected the audiometric NIHL configurations, in a number of cases DPOAEs were present for hearing losses up to 75 dB HL. As a consequence, DPOAEs correlated moderately and negatively with the audiometric thresholds. Applying test criteria designed to logically reflect NIHL, DPOAE sensitivity and specificity levels ranged between 0.51-0.90 and 0.63-0.25, respectively. These findings indicate that DPOAEs, recorded and analysed as described, are not sufficiently sensitive to serve as a single test to identify NIHL.

SPECT imaging of odor identification in schizophrenia.

Deficits in olfactory identification, despite normal odor perception, are found in some neuropsychiatric disorders, including schizophrenia. We examined if regional cerebral blood flow (rCBF) differed between schizophrenia patients and controls during odor identification, hypothesizing that these brain regions could be relevant to odor identification impairments. Eight schizophrenia and eight comparison subjects provided a baseline (picture identity matching) and activation (odor identification) SPECT scan, obtained using 99mTc-HMPAO in a low dose/high dose design. Six patients and seven controls had analyzable data. MEDX data saved in ANALYZE format for SPM 95 generated paired t-test statistical data for display in Talairach space, with rCBF changes given as Z-scores. There was no schizophrenia vs. control group difference in rCBF for the baseline picture-matching test. For odor identification, schizophrenia patients had a hypometabolic right-sided cortical region that included the frontal lobe Broca's area, superior temporal lobe, and supramarginal and angular gyri. Post hoc within-group contrasts of picture-matching vs. odor identification showed that the controls significantly increased rCBF in the right-sided inferior temporal fusiform gyrus, and bilateral hippocampi and visual association areas for the odor test. The schizophrenia group showed no rCBF differences for picture-matching compared to odor identification. Patients showed significant hypometabolism in right-sided cortical areas for odor identification. They also failed to show increased rCBF in the hippocampus and visual association area, as seen in controls for odor identification compared to picture-matching. These regions may be unique to schizophrenia or have broader implications for olfactory memory retrieval.

Event-related potentials in post-traumatic stress disorder of combat origin.

Visual event-related potentials (ERPs) of primary interest in this study of post-traumatic stress disorder (PTSD) were N1, N2, P2, and P3. Forty Israeli combat veterans consisting of 20 PTSD sufferers and 20 normal controls were evaluated. ERPs were recorded in response to three sets of computer-generated visual stimuli, presented in the form of a modified oddball paradigm. These stimuli included: domestic animal pictures (targets), emotionally neutral pictures of furnishings (nontargets), and combat-related pictures (nontarget probes). Subjects were required to discriminate between target and nontarget stimuli by pressing a button in response to target stimuli only. Subjects were instructed to ignore all nontarget stimuli. As expected, target stimuli evoked accentuated P3 amplitudes in both controls and PTSD patients. The nontarget combat-related pictures elicited enhanced P3 and N1 amplitudes in the PTSD patients only. N2 amplitudes were accentuated in PTSD patients for both targets and combat-related pictures. P3 latencies and reaction times to target stimuli were prolonged in PTSD patients. The same tendency was observed for N1 latencies. These results may indicate that an altered state of early and late cognitive selective attention processing exists in PTSD patients in addition to a vulnerability to traumatic reminiscences.

Impaired brain processing in noise-induced tinnitus patients as measured by auditory and visual event-related potentials.

OBJECTIVES: This study aimed to confirm that the brain processing of auditory stimuli in tinnitus patients is impaired (Attias, Urbach, Gold, & Shemesh, 1993). In addition, possible brain processing dysfunction in response to visual stimuli was assessed. DESIGN: Auditory and visual event-related potentials (ERPs) and reaction times were recorded in response to a standard oddball target detection paradigm. The subjects consisted of 21 noise-induced chronic tinnitus patients and 21 age- and hearing-matched control subjects without tinnitus. RESULTS: The tinnitus patients had significantly prolonged latencies for the auditory nontarget ERP components N1, N2, and P3 and for the auditory target ERP P3 component. The auditory P3 component was also significantly reduced in amplitude for both target and nontarget stimuli for the tinnitus patients. The visual P3 target and nontarget components were similarly significantly prolonged in latency for the tinnitus patients. Reaction times to both target and nontarget stimuli were significantly delayed for the tinnitus patients for both stimulus modalities. CONCLUSIONS: These findings point to a cortical information processing dysfunction in chronic tinnitus patients associated primarily with auditory stimuli. ERPs may provide an objective electrophysiologic tinnitus measure.

The influence of the efferent auditory system on otoacoustic emissions in noise induced tinnitus: clinical relevance.

This study demonstrates a clear relationship between noise induced tinnitus (NIT) and efferent neural auditory activity. The effect of contralateral white noise stimulation on click evoked otoacoustic emissions (CEOAEs) was studied in chronic tinnitus sufferers and controls, with and without a noise induced hearing loss (NIHL). For the non-tinnitus controls, increased contralateral white noise intensities resulted in decreased CEOAE amplitudes, irrespective of the hearing configuration. In contrast, the tinnitus patients responded with increased CEOAE amplitudes, particularly at lower contralateral noise intensities. While this was observed for both normal hearing and NIHL tinnitus patients, the effect was more pronounced amongst the normal hearing group. These findings were interpreted as reflecting a global efferent disorder in NIT patients, and are considered clinically relevant to the objective assessment of tinnitus.

Effect of repeated visual traumatic stimuli on the event related P3 brain potential in post-traumatic stress disorder.

Post-Traumatic Stress Disorder (PTSD) patients are characterized by a hypersensitivity to traumatic stimuli which may be expressed as an automatic and involuntary cognitive response. Electrophysiologically this can be recorded as an augmented visual P3 (P300) event related potential (ERP). This study examined P3 changes in response to repeated traumatic pictorial stimuli presented in the form of a visual discrimination oddball paradigm to 40 Israeli combat veterans with and without PTSD. Subjects were asked to press a button when target stimuli (domestic animal pictures) appeared, and to ignore all non-target stimuli (irrelevant pictures of furnishings/flowers and traumatic combat related pictures). On average, P3 in response to combat related pictures was earlier and approximately 5 times greater in amplitude for the PTSD patients as compared to the controls. Repeated combat related pictures stimuli presentation resulted in a rapid and appreciable P3 amplitude reduction and latency prolongation. This effect was not observed for the target stimuli. These findings suggest that a gradually reduced amount of attentional resource is required and allocated to the processing of repeated CRP stimuli. This may occur as a consequence of the activation of an inhibitory mechanism related to the cognitive processing of traumatic stimuli.

Noise-induced otoacoustic emission loss with or without hearing loss.

The association between audiometric hearing thresholds and click-evoked otoacoustic emission (CEOAE) spectral properties was examined in 129 adult subjects with and without a noise-induced hearing loss (NIHL). Subjects were grouped according to their "beginning of hearing loss frequency" and their exposure to hazardous noise. Emissions were recorded with an ILO88 Otodynamic Analyzer (Version 2.9) used in the default mode. CEOAE levels decreased as the hearing threshold increased at each of the test frequencies (1,2,3, and 4 kHz). At frequencies where hearing thresholds were worse than 20 dB HL, CEOAEs could not be recorded. Thus as the "beginning of hearing loss frequency" decreased, the frequency range of the emissions became narrower. The hearing threshold for which emissions were not recorded varied significantly between subjects, such that even at frequencies where the hearing threshold was 0 dB HL emissions were not always observed. Noise-exposed, normal-hearing subjects had reduced overall CEOAE power with a narrow frequency range as compared with normal-hearing, nonexposed to noise subjects. For our test conditions, the presence of CEOAEs necessarily suggests hearing thresholds of 20 dB HL or less at the corresponding frequency. A lack of emissions does not necessarily indicate hearing thresholds beyond 20 dB HL.

Auditory event related potentials in simulated tinnitus.

It was previously demonstrated that noise induced tinnitus (NIT) patients have prolonged reaction times and event related potentials (ERPs) that are reduced in amplitude and prolonged in latency. This study considered whether these alterations occurred as a consequence of the competing auditory tinnitus sensation or as a result of a possible cognitive processing dysfunction in NIT patients. ERPs and reaction times (RTs) were recorded in response to a standard oddball auditory target detection paradigm, with and without simulated tinnitus. Tinnitus was simulated using a high tone narrow band noise presented at the forehead via a standard audiometric bone vibrator. The subjects consisted of 19 males suffering from noise induced hearing loss without tinnitus. The latencies and amplitudes of the ERP components N1, P2, N2, and P3, as recorded along the midline scalp sites (Fz, Cz, and Pz) and bilateral temporal sites (C3 and C4), did not differ significantly when recorded with and without simulated tinnitus. Similarly, the associated reaction times did not differ significantly. These findings suggest that the ERP alterations previously reported to exist for NIT patients cannot be explained simply as a consequence of increased task difficulty and cognitive loading due to the tinnitus sound.

Single P100 visual evoked potential analyses in man.

Standards evoked potential averaging leads to a loss of information inherent in the moment to moment variability of the amplitude and latency of single evoked potentials. In order to extract this information, attempts were made to develop procedures which would allow recording of single visual evoked potentials in at least a selected group of subjects. In 11 out of 25 non-selected subjects, 43% to 86% of all stimuli (reversal checkerboard pattern elicited single visual evoked potentials (VEP) which were recognized as such by a group of independent observers. The mean amplitude and latency obtained by directly measuring the peak to peak amplitudes and peak latencies of these single VEPs (arithmetic averaging) were compared to those obtained following conventional time-locked averaging of the same data. During long-term continuous stimulation, the arithmetic averaged VEPs increased in amplitude to a steady state while the time-locked averages of the same sets of responses decreased in amplitude. This reduction was found to be closely related to the latency jitter. It may provide a better understanding of the phenomenon of habituation. This finding was confirmed in model single VEPs obtained by summing on-going pre-stimulus EEG activity with a time-locked average VEP stationary wave form. The variability of the true single VEPs was found to be less than the variability of the model single VEPs. The latency and amplitude parameters of the true single VEPs were strongly correlated with each other while those of the model single VEPs were not. These findings show that single VEPs have an inherent variability which may reflect brain processing.