Corpus Callosum Functional Activities in Children with Cerebral Palsy.

Background: Since cerebral palsy (CP) is a corollary to brain damage, persistent treatment should accompany an alteration in brain functional activity in line with clinical improvements. In this regard, the corpus callosum (CC), as a connecting bridge between the two hemispheres, plays an essential role. Objective: This study aimed to investigate the therapeutic effects of occupational therapy (OT) on CC functional activity and walking capacity in children with cerebral palsy. Material and Methods: In this clinical trial study, 4 children with CP (8.25±1.71 years) received 45 min OT sessions 3 times weekly for 8 weeks. Functional magnetic resonance imaging (fMRI) was acquired while conducting passive motor tasks to quantify CC activation. The pre-post activation changes in CC following therapy were quantified in terms of activated voxels. Walking capacity was evaluated using the timed-up-and-go (TUG), 6-minute walk test (6 MWT), and 10-meter walk test (10 MWT) in pre-and post-treatment. Results: The number of activated voxels in CC indicated significant improvement in participants. Post-treatment activated voxels substantially exceeded pre-treatment active voxels. Clinical measures, including TUG, 6 MWT, and 10 MWT are improved by 11.9%, 12.6%, and 25.4%, respectively. Conclusion: Passive task-based fMRI can detect the effects of OT on CC functional activity in children with CP. According to the results, OT improves CC functional activity in addition to gait and balance performance.

The Relationship between Structure of the Corticoreticular Tract and Walking Capacity in Children with Cerebral Palsy.

Background: Disruption in the descending pathways may lead to gait impairments in Cerebral Palsy (CP) children. Though, the mechanisms behind walking problems have not been completely understood. Objective: We aimed to define the relationship between the structure of the corticoreticular tract (CRT) and walking capacity in children with CP. Material and Methods: This is a retrospective, observational, and cross-sectional study. Twenty-six children with CP between 4 to 15 years old participated. Also, we used existed data of healthy children aged 4 to 15 years old. CRT structure was characterized using diffusion tensor imaging (DTI). The DTI parameters extracted to quantify CRT structure included: fractional anisotropy (FA), mean (MD), axial (AD), and radial (RD) diffusivity. Balance and walking capacity was evaluated using popular clinical measures, including the Berg balance scale (BBS), Timed-Up-and-Go (TUG; balance and mobility), six-minute walk test (6 MWT; gait endurance), and 10-meter walk Test (10 MWT; gait speed). Results: There are significant differences between MD, AD, and RD in CP and healthy groups. Brain injury leads to various patterns of the CRT structure in children with CP. In the CP group with abnormal CRT patterns, DTI parameters of the more affected CRT are significantly correlated with walking balance, speed, and endurance measures. Conclusion: Considering the high inter-subject variability, the variability of CRT patterns is vital for determining the nature of changes in CRT structure, their relationship with gait impairment, and understanding the underlying mechanisms of movement disorders. This information is also important for the development or prescription of an effective rehabilitation target for individualizing treatment.

Radiological landscape of natural resources and mining: Unveiling the environmental impact of naturally occurring radioactive materials in Ghana's mining areas.

This study provides a general observation of the status of naturally occurring radioactive materials (NORMs) distribution in mining and industrial areas of Ghana in order to establish regional and national data on NORMs. The study includes data on radioactivity concentrations of U-238, Th-232, and K-40 in soils and for water concentrations of Ra-226, Th-228, and K-40 from various mining, oil, and gas communities, as well as water sources used for crop farming and farmlands. The average activity concentrations of U-238, Th-232, and K-40 in the soil samples were found to be 59 ± 16 Bq/kg, 48 ± 15 Bq/kg, and 286 ± 57 Bq/kg, respectively. The average concentration of Ra-226, Th-228, and K-40 in the water samples were found to be 1.62 ± 0.33 Bq/L, 2.08 ± 0.53 Bq/L, and 22.36 ± 3.44 Bq/L, respectively. The estimated average annual effective doses from external and internal exposure pathways in soil and water samples were 0.09 mSv/y and 0.54 mSv/y, respectively. The total annual effective dose resulting from both exposure pathways was calculated to be 0.63 mSv/y, which is below the 1 mSv/y dose limit recommended by the International Commission on Radiological Protection (ICRP) for controlling public radiation exposure. Based on the radiological hazard indices, the majority of the soil samples were found to be suitable as building materials as their respective indices were below the limits except for two sample locations and the sludge and scale samples. The average Excess Lifetime Cancer Risk (ELCR) value of the water samples was 1.6 times greater than the recommended value of 1.16 × 10-3, presenting a relatively higher risk to the public of developing cancer. No significant regional differences in the levels of radioactive elements. The regression models demonstrate strong interrelationships between the studied elements, with high R-squared values suggesting a predictable nature of one element's concentration based on others.

Characterization of environmental radiological parameters on dose coefficient - Realistic dosimetry compared with epidemiological dosimetry models.

Radiation exposure due to all-natural sources amounts to about 2.4 mSv per year. However, this amount might be changed to over 3 mSv y-1 according to the recently introduced ICRP radon dose coefficient factor. Previously, the radon contribution to the total dose from natural sources was about 1.2 mSv y-1. However, after the latest introduced dose conversion factor by ICRP, this value could technically be increased to around 2 mSv y-1. This paper attempts to address the following questions: (i) whether reducing radon concentration to the recommended level could address concerns about radiation exposure in underground workplaces, and (ii) the effects of the difference between the epidemiological dosimetry models and realistic dose estimation. The actual dose conversion factor (DCF) was calculated using measured annual average unattached and equilibrium factors, ranging from 16 ± 9 to 25 ± 10 mSv·WLM-1. Then, the estimated inhalation dose, both from self-calculated DCF and the value reported by ICRP-137, was compared: 5.6 ± 0.7-7.6 ± 0.9 mSv y-1 and 3.3 ± 0.4-3.6 ± 0.5 mSv y-1, respectively. It can be observed that exposure to a radon concentration lower than the recommended level does not guarantee a lower dose than the recommended value. The estimated dose was at least two times greater than the dose using pre-estimated values from epidemiological dosimetry models, specifically in this case study. Further experiments in different underground working environments, excluding caves, are needed for more precise observations. It might also be time to update the data regarding the dose contribution from natural radiation sources, as the radon contribution increased according to ICRP.

A Comparison Study of the Tehran Norms to the Reference Norms on Children Performance of the Bayley III.

Objectives: The Bayley Scales of Infant and Toddler Development (3rd ed.; Bayley III) are widely used to assess cognitive, language, and motor development of children aged 1-42 months. It is unclear whether or not the reference norms of the Bayley III are acceptable for use in other populations or lead to over- or underestimating the developmental status of target children. This study aimed to compare the Tehran norms to the reference norms. Materials & Methods: We used Bayley III norms to assess cognitive, language, and motor development of 1,674 healthy children from health care centers in Tehran. Differences between the scaled scores were calculated based on the Tehran and reference norms. A one-sample multivariate analysis of variance (MANOVA) was used to control the mean difference scores over all subtests. When MANOVA showed significant differences between the scaled scores based on the Tehran and reference norms, we used univariate analysis to see which subtest and age group led to these significant differences. Finally, the proportions of children with low scores (scaled scores <7 or -1 SD and <4 or -2 SD) based on 2 norms were compared using the McNemar test to determine the over- or underestimation of developmental delay. Results: The scaled scores based on the Tehran norms varied across values based on the reference norms in all subtests. The mean differences were significant in all 5 subtests (p < .05) with large effect sizes for receptive and expressive communication, fine and gross motor subtests of .20, .23, .14, and .25, respectively, as well as with a small effect size for the cognition subtest of .02. Large effect sizes for all age groups were found for cognition, expressive communication, and fine motor subtests. More children scored below 1 and 2 SD using the Tehran norms. Using the reference norms resulted in underestimation of developmental delay regarding cognitive, receptive and expressive communication, and fine and gross motor skills. Conclusion: Population-specific norms should be used to identify children with low scores for referral and intervention. The Tehran norms differed from the reference norms for all subtests, and these differences were clinically significant.

The second family affected with a PRDM8-related disease.

INTRODUCTION: Lafora disease (LD) is a severe form of progressive myoclonus epilepsy characterized by generalized seizures, myoclonus, intellectual decline, ataxia, spasticity, dysarthria, visual loss, and in later stages, psychosis and dementia. To date, mutations in the EPM2A and EPM2B/NHLRC1 genes have been identified as the common causes of LD. However, a mutation in PRDM8 has been reported only once in a Pakistani family affected with early-onset Lafora disease. In the present study, we report the second family with a PRDM8 mutation. METHODS: Two affected individuals of an Iranian family initially diagnosed as complicated hereditary spastic paraplegia (HSP) underwent careful neurologic examination. Homozygosity mapping and whole-exome sequencing were performed. Based on the results of genetic analysis to detection of Lafora bodies, a skin biopsy was done. RESULTS: The clinical features of the patients were described. Linkage to chromosome 4 and a mutation in the PRDM8 gene were identified, suggesting the patients may be affected with early-onset LD. However, like the Pakistani family, the search for Lafora bodies in their skin biopsies was negative. Their electroencephalograms showed generalized epileptiform discharges in the absence of clinical seizures. CONCLUSIONS: The current study increases the number of PRDM8-related cases and expands the phenotypic spectrum of mutations in the PRDM8 gene. Both reported PRDM8-related families presented intra and inter-familial heterogeneity and they have originated from the Middle East. Thus, it seems the PRDM8 mutations should be considered not only in LD but also in other neurodegenerative disorders such as a complicated HSP-like phenotype, especially in this region.

Contribution of altered corticospinal microstructure to gait impairment in children with cerebral palsy.

OBJECTIVE: Corticospinal tract (CST) injury may lead to motor disorders in children with Cerebral Palsy (CP). However, the precise underlying mechanisms are still ambiguous. We aimed to characterize the CST structure and function in children with CP and determine their contributions to balance and gait impairments. METHOD: Twenty-six children with spastic CP participated. Transcranial magnetic stimulation (TMS) and diffusion tensor imaging (DTI) were utilized to characterize CST structure and function. Common clinical measures were used to assess gait speed, endurance and balance, and mobility. RESULTS: CST structure and function were significantly altered in children with CP. Different abnormal patterns of CST structure were identified as either abnormal appearance of brain hemispheres (Group-1) or semi-normal CST appearance (Group-2). We found significant correlations between the DTI parameters of the more affected CST and gait features only in Group-1. CONCLUSION: CST structure and function are abnormal in children with CP and these abnormalities may contribute to balance and gait impairment in some children with CP. SIGNIFICANCE: Our findings may lead to the development of further investigations on the mechanisms underlying gait impairment in children with CP and on decision-making for more effective rehabilitation.

Natural radioactivity and radiological risks of common building materials used in Semnan Province dwellings, Iran.

Impact assessment of building materials is a focused topic in the field of radioecology. A radiological survey has conducted to monitor radioactivity of most common building materials in Semnan Province, Iran, and assess the radiation risk. Activity concentrations of 226Ra, 232Th, and 40K were measured in 29 samples including nine commonly used building materials that were collected from local suppliers and manufacturers, using a high purity germanium gamma-ray detector. The activity concentrations of 226Ra, 232Th, and 40K varied from 6.7±1 to 43.6±9, 5.9±1 to 60±11, and 28.5±3 to 1085±113 Bq kg-1 with averages of 26.8±5, 22.7±4, and 322.4±4 Bq kg-1, respectively. By applying multivariate statistical approach (Pearson correlation, cluster, and principal component analyses (PCA)), the radiological health hazard parameters were analyzed to obtain similarities and correlations between the various samples. The Pearson correlation showed that the 226Ra distribution in the samples is controlled by changing the 232Th concentration. The variance of 95.58% obtained from PCA resulted that the main radiological health hazard parameters exist due to the concentration of 226Ra and 232Th. The resulting dendrogram of cluster analysis also shows a well coincidence with the correlation analysis.

Multivariate statistical approach on distribution of natural and anthropogenic radionuclides and associated radiation indices along the north-western coastline of Aegean Sea, Greece.

A comprehensive radiological survey using multivariate statistical analysis was carried out to evaluate the distribution of 40K, 232Th, 226Ra, 235U, and 137Cs, and associated radiation indices in beach sand samples of the coastal area of the Aegean Sea. The activity concentration of selected radionuclides was measured and no clue of recent migration of radiocaesium by not only precipitation but also through an indirect way, such as ocean runoff, was found. As part of radiological risk assessment, external radiation hazard index, radium equivalent activity, effective dose, and absorbed dose rate were estimated. Pearson correlation, cluster, and PCA analysis were used by processing observed radiological parameters to determine the correlation between the radiological parameters and locations. Pearson correlation shows a strong association between all parameters and activity of 226Ra and 232Th. A spatial distribution map was provided to a distinct visual representation of the distribution of radionuclide contents in the study area.

Radiological Assessment of Indoor Radon and Thoron Concentrations and Indoor Radon Map of Dwellings in Mashhad, Iran.

A comprehensive study was carried out to measure indoor radon/thoron concentrations in 78 dwellings and soil-gas radon in the city of Mashhad, Iran during two seasons, using two common radon monitoring devices (NRPB and RADUET). In the winter, indoor radon concentrations measured between 75 ± 11 to 376 ± 24 Bq·m-3 (mean: 150 ± 19 Bq m-3), whereas indoor thoron concentrations ranged from below the Lower Limit of Detection (LLD) to 166 ± 10 Bq·m-3 (mean: 66 ± 8 Bq m-3), while radon and thoron concentrations in summer fell between 50 ± 11 and 305 ± 24 Bq·m-3 (mean 115 ± 18 Bq m-3) and from below the LLD to 122 ± 10 Bq m-3 (mean 48 ± 6 Bq·m-3), respectively. The annual average effective dose was estimated to be 3.7 ± 0.5 mSv yr-1. The soil-gas radon concentrations fell within the range from 1.07 ± 0.28 to 8.02 ± 0.65 kBq·m-3 (mean 3.07 ± 1.09 kBq·m-3). Finally, indoor radon maps were generated by ArcGIS software over a grid of 1 × 1 km2 using three different interpolation techniques. In grid cells where no data was observed, the arithmetic mean was used to predict a mean indoor radon concentration. Accordingly, inverse distance weighting (IDW) was proven to be more suitable for predicting mean indoor radon concentrations due to the lower mean absolute error (MAE) and root mean square error (RMSE). Meanwhile, the radiation health risk due to the residential exposure to radon and indoor gamma radiation exposure was also assessed.

High level of natural ionizing radiation at a thermal bath in Dehloran, Iran.

It has been proven that more than half of the exposure to natural background radiation originates from radon isotopes and their decay products. The inhalation of radon and its decay products causes the irradiation of respiratory tracts, thus increasing the risk of lung cancer. In this study, the concentrations of radon and thoron in thermal baths at a spa in Dehloran (Iran) were investigated. The concentrations of dissolved 226Ra in samples of water from thermal baths were also measured. Additionally, the activity concentrations of abundant naturally occurring radionuclides in farmland soils irrigated with water from hot springs was measured and compared with other soil samples irrigated with water from other sources to estimate possible radioecological effects of natural radiation staff, patients and tourists at the spa are exposed to. In addition, the search for a link between the concentration of naturally occurring radionuclides in soil and the use of water from hot springs for irrigation was one of the main goals of the study. The activity concentrations of three major naturally occurring radionuclides in soil samples were measured; the ranges for 40K, 226Ra and 228Ra were 101 ± 8 to 240 ± 12, 276 ± 7 to 322 ± 12 and 20 ± 7 to 80 ± 10 Bq.kg-1, respectively. Higher activity concentrations of 226Ra and 228Ra were recorded in soil samples irrigated with hot spring water. The water from the same spring was used in all thermal baths so concentrations of dissolved 226Ra in water samples from different thermal baths were approximated to also be 0.42 ± 0.20 Bq.l-1. The indoor radon concentrations in the private thermal baths over a period of 45 days (including both occupied and vacant time) were measured to be between 1880 ± 410 and 2450 ± 530 Bq.m-3 and the radon concentrations in the spa galleries were measured to be between 790 ± 135 and 1050 ± 120 Bq.m-3, however, thoron concentrations were below the detection limit. The ventilation and centralized heating systems at the spa under investigation are inefficient so the radon concentrations in the therapy rooms and baths are high. The maximum radiation doses originating from the inhalation of radon for tourists and the staff were estimated to be 0.13 and 5.5 mSv.yr-1, respectively, which is slightly over the national limit in Iran (5 mSv.yr-1). The exposure duration was estimated 15 and 1468 h per year for visitors and workers, respectively.

Do NICU developmental care improve cognitive and motor outcomes for preterm infants? A systematic review and meta-analysis.

BACKGROUND: The aim of this study was to review the effects of developmental care in neonatal intensive care unit (NICU) setting on mental and motor development of preterm infants. METHOD: We searched PubMed, EMBASE, CINAHL, Scopus, Web of Science and Cochrane library until October 8th 2017, and included randomized controlled trials that assessed effects of developmental care in NICU on mental and motor development of preterm infants at 12 and 24 months of age, using the Bayley scale of infant development in this systematic review. In addition, data were pooled by random effects model and Standardized Mean Difference (SMD) with 95% confidence intervals (CI), calculated for meta-analysis. RESULTS: Twenty one studies were eligible to be included in this systematic review; however, only thirteen studies had data suitable for meta-analysis. According to statistical analysis, developmental care in NICU improved mental developmental index (MDI) (standardized mean difference [SMD] 0.55, 95% confidence interval [CI] 0.23-0.87; p < 0.05), and psychomotor developmental index (PDI) (SMD 0.33, [CI] 95% CI 0.08-0.57; p < 0.05) of BSID at 12 months of age and PDI at 24 months of age (SMD 0.15, 95% CI -0.02-0.32; p < 0.1) of preterm infants. However, the benefit was not detected at 24 months of age on MDI (SMD 0.15, 95% CI -0.05-0.35; p = 0.15). CONCLUSION: Current evidence suggests that developmental care in only NICU setting could have significant effect on mental and motor development of preterm infants, especially at 12 months of age. However, because of clinical heterogeneity, more studies are needed to evaluate the effects of developmental NICU care in the development of preterm infants.

Therapeutic Effects of repetitive Transcranial Magnetic Stimulation on Corticospinal Tract Activities and Neuromuscular Properties in Children with Cerebral Palsy.

The objective of this research was to study the therapeutic effects of repetitive transcranial magnetic stimulation (rTMS) on corticospinal tract (CST) activities, reflex hyper-excitability, muscle stiffness, and the clinical status of children with spastic hemiplegic cerebral palsy (CP). Three children participated in this study. The treatment lasted for 6 weeks. Two of the patients, the experimental group, received rTMS therapy 4 days a week during the first 3 weeks, and then received typical occupational therapy (OT) after each rTMS session during the second 3 weeks. One patient, the control group, received the same treatment except that a sham coil was used. Each rTMS session lasted for 20 minutes and each OT session lasted for 45 minutes. We evaluated CST activities by transcranial magnetic stimulation (TMS), reflex hyperexcitability by H-reflex response, and muscle stiffness by sonoelastography images. The tests were taken before and after the treatment. Major TMS parameters (i.e., motor evoked potential (MEP) latency, MEP p-p amplitude, cortical silent period (cSP), and intensity of pulse) for experimental patients were improved in comparison with the control patient. H response latency and max H response on max M-wave (H/M) were improved for the experimental group compared to the control group. Two parameters of texture analysis of the sonoelastography images (i.e., entropy and contrast) were improved for the experimental group. Clinical evaluations such as 10 meter walk test (10MWT), timed up and go (TUG), and 6 minute walk test (6MWT) were performed before and after the course of treatment and were improved for the experimental group compared to the control group. These results indicated that rTMS therapy can improve CST activities, reflexes, muscle stiffness, and walking capacity of spastic hemiplegic CP. Therefore, it can be considered as an effective therapeutic tool for enhancing neuromuscular abnormalities resulting from CP.

Are the Norms of Bayley Screening Test Appropriate for Persian Language Children?

OBJECTIVE: We aimed to assess the distribution of the Bayley screening test by age, and compare developmental risk category distributions between Persian language children and reference norms. MATERIALS & METHODS: A representative sample of 417 children, 1 to 42-months-old, by consecutive sampling from health -care centers were enrolled, during 2014 to 2015 in Tehran, Iran. The cognitive, language and motor development of children were evaluated using Bayley screening test. For determining cut-off point for the subtest scores, two cut-offs were determined for each age group, that classified children to the at risk, emerging, and competent categories. We estimated the agreement of the risk categories between the two samples using weighted kappa statistics. RESULTS: About 70%-80% of all tests operated to the participating children were classified as normal by both norms. Weighted kappa coefficients for the five subtests ranged from 0.56 to 0.89 suggesting moderate agreement between two classification norms. Expressive and receptive communication had the lowest kappa scores (0.56 and 0.59, respectively), and classification of gross motor revealed the highest level of agreement (0.89). CONCLUSION: Developmental disabilities are common disorders that impose important functional limitations on the affected children. Identifying infants at risk for developmental disorders by screening is a main step to minimize complications. Dependence on reference-based norms for the Bayley screening test in Persian language children results in misclassification of risk category.

Association of the Single Nucleotide Polymorphisms of the Genes Encoding IL-2 and IFN-γ With Febrile Seizure.

Inflammatory elements and genetics have major roles in febrile seizures (FS) pathogenesis. Seventy patients were enrolled and compared with 139 controls. The allele and genotype frequency of the IL-2 gene at -330 and +166 positions and the IFN-γ at +874 position were determined. A significant positive association with GG genotype at position -330 in the patient group was found (P=0.003). Further, a positive association was detected in simple and complex FS groups at the same position (P=0.03, P=0.004). IL-2 GT haplotype was significantly more common in the patients compared to controls (P=0.0008). Higher frequency of GT haplotype was detected in simple FS patients in comparison to controls (P=0.0003). Contrary, IL-2 TG haplotype frequency was lower in complex FS group (P=0.005). Overrepresentation of certain alleles, genotypes and haplotypes in IL-2 gene in FS patients could predispose individuals to this disease.

A Psychometric Study of the Bayley Scales of Infant and Toddler Development in Persian Language Children.

OBJECTIVE: Bayley Scales of infant & toddler development is a well-known diagnostic developmental assessment tool for children aged 1-42 months. Our aim was investigating the validity & reliability of this scale in Persian speaking children. MATERIALS & METHODS: The method was descriptive-analytic. Translation- back translation and cultural adaptation was done. Content & face validity of translated scale was determined by experts' opinions. Overall, 403 children aged 1 to 42 months were recruited from health centers of Tehran, during years of 2013-2014 for developmental assessment in cognitive, communicative (receptive & expressive) and motor (fine & gross) domains. Reliability of scale was calculated through three methods; internal consistency using Cronbach's alpha coefficient, test-retest and interrater methods. Construct validity was calculated using factor analysis and comparison of the mean scores methods. RESULTS: Cultural and linguistic changes were made in items of all domains especially on communication subscale. Content and face validity of the test were approved by experts' opinions. Cronbach's alpha coefficient was above 0.74 in all domains. Pearson correlation coefficient in various domains, were ≥ 0.982 in test retest method, and ≥0.993 in inter-rater method. Construct validity of the test was approved by factor analysis. Moreover, the mean scores for the different age groups were compared and statistically significant differences were observed between mean scores of different age groups, that confirms validity of the test. CONCLUSION: The Bayley Scales of Infant and Toddler Development is a valid and reliable tool for child developmental assessment in Persian language children.

Radon measurements and dose estimate of workers in a manganese ore mine.

In the new European Basic Safety Standard (EU-BSS), a new reference level for indoor radon concentration in workplaces has recommended that the annual average activity concentration of indoor radon shall not be higher than 300Bqm-3. This paper describes the radon concentration level in an underground workplace (manganese ore mine) over long time intervals (4 years). Several common radon monitors devices - including NRPB and Raduet (as a passive method based on CR-39), AlphaGUARD PQ 2000Pro, SARAD EQF3220, TESLA and Pylon WLX (as active methods) - were used for continuous radon measurements. The output results were used, first, to comprised the result of each device, based on conditions present in underground mines; Second, to have comprehensive measurements about all factors that cause workers exposure to radiation (each monitoring device specified for a unique measurement). The results indicate that the mine's staff had successful efforts to reach the strict requirement of the new EU-BSS, and the average annual radon activity concentrations during the working hours were below 300Bqm-3 in the investigated period. The paper presents the effective dose calculations; applying different equilibrium factors suggested by the literature and calculated basing on our measurements at the site, concluding that the differences could be about threefold.

Determination of Po-210 content in cigarette smoke using a smoking machine: A case study of Iranian cigarettes.

The Po-210 content of tobacco has been known for a long time, however, different results can be found about the estimated amount of Po-210 that is inhaled by humans as a result of smoking cigarettes. Because of the unique properties of Po-210, the smoking machines available on the market are not suitable because of their failure to quantitatively collect Po-210 for measurement. Therefore, to estimate precisely the amount of Po-210 entering the lungs as a result of smoking, a smoking machine and sampling protocol based on relevant ISO standards - ISO-3308, ISO-3402 and ISO-4387 - was developed. A 5% HCl solution was found to be the best absorber of Po-210 from smoke. Seventeen different brands of cigarettes distributed in Iran were used to validate the new machine and sampling protocol. The Po-210 concentration was determined by alpha spectrometry; the cigarette smoke solution underwent combined acid treatment after adding a Po-209 tracer. The Po-210 activity concentration of cigarettes sold in Iran was between 9.7 ± 1.2 and 26.5 ± 4.6 mBq/cigarette and it was determined that there was no relationship between the Po-210 and nicotine contents of cigarette smoke. Additionally, it was found that 15 ± 10% of the cigarette Po-210 was transferred to the mainstream smoke.

Radon exhalation study of manganese clay residue and usability in brick production.

The reuse of by-products and residue streams is an important topic due to environmental and financial aspects. Manganese clay is a residue of manganese ore processing and is generated in huge amounts. This residue may contain some radionuclides with elevated concentrations. In this study, the radon emanation features and the massic exhalation rate of the heat-treated manganese clay were determined with regard to brick production. From the manganese mud depository, 20 samples were collected and after homogenization radon exhalation characteristics were determined as a function of firing temperatures from 100 to 750 °C. The major naturally occurring radionuclides 40K, 226Ra and 232Th concentrations were 607 ± 34, 52 ± 6 and 40 ± 5 Bq kg-1, respectively, comparable with normal clay samples. Similar to our previous studies a strong correlation was found between the internal structure and the radon emanation. The radon emanation coefficient decreased by ∼96% from 0.23 at 100 °C to 0.01 at 750 °C. The massic radon exhalation rate of samples fired at 750 °C reduced by 3% compared to samples fired at 100 °C. In light of the results, reusing of manganese clay as a brick additive is possible without any constraints.

The quality of life in boys with Duchenne muscular dystrophy.

We conducted a study to evaluate the quality of life in boys with Duchenne muscular dystrophy aged 8-18 years, compared with that in matched healthy controls. A total of 85 boys with Duchenne muscular dystrophy aged 8-18 years and 136 age, sex and living place matched healthy controls were included in this study. Patients and one of their parents separately completed the 27-item Persian version of KIDSCREEN questionnaire (child and adolescent version and parent version). From the children's perspective, the quality of life in patients was found to be lower in two subclasses: "physical activities and health" (p < 0.001) and "friends" (p = 0.005). Parental estimation of their sick child's quality of life was significantly lower than children's own assessment in two subclasses: "physical activities and health" (p < 0.001) and "general mood and feelings" (p < 0.001). Our results indicate that boys with Duchenne muscular dystrophy have quite a satisfactory quality of life. A happier and more hopeful life can be promoted through increasing social support and improving the parental knowledge regarding their child's more positive life perspective.