Hexachlorobenzene-negative ion formation in electron attachment experiments.

In this contribution, we report a comprehensive study on the formation of hexachlorobenzene (C6Cl6) negative ions probed by low-energy electron interactions from 0 up to 12 eV in a gas-phase crossed beam experiment. The anionic yields as a function of the electron energy reveal a rich fragmentation pattern of the dissociative electron attachment process, yet the most intense ion has been assigned to the non-dissociated parent anion that survives long enough within the detection time window. Other less intense fragment anions have been assigned as Cl-, Cl2-, C6Cl4-, and C6Cl5-. The experimental results are accompanied by quantum chemical calculations at various levels of accuracy, providing an insight into the electronic structure, thermochemical thresholds, electron affinities and structures of neutral and anionic molecular species. The electron attachment process induces a considerable geometry change in the temporary-negative ion relative to the neutral molecule, where the most intense fragment anion assigned to Cl- can be formed solely through a curve crossing involving a π*/σ* coupling. The yield of chlorine anions shows a signature of vibrational excitation reminiscent of a Jahn-Teller distortion.

Role of spirometry in detection of nasal obstruction.

BACKGROUND: A subjective feeling of nasal airflow obstruction is a common symptom. An objective method for quantitative measurement of nasal airflow has long been desired. Rhinomanometry and acoustic rhinometry have been developed for anatomical and physiological evaluation of nasal obstruction. This study was designed to determine the usefulness of a portable spirometer in assessing upper airway obstruction. METHODS: One hundred and ninety-six patients were assessed with nasal inspiratory spirometry to determine nasal airflow. All patients also underwent paranasal sinus computed tomography to determine anatomical abnormalities. Spirometry was performed on each nostril separately. RESULTS: Sensitivity and specificity levels were high. This portable and easy to use device may be useful in respiratory assessment. Correlation between anatomical obstructions and subjects' complaints was statistically significant (p < 0.001), but no definite correlation between septal deviation severity and spirometric values was found. CONCLUSION: Portable spirometry is an objective and useful method of evaluating nasal obstruction, but needs more investigation to establish a standardised test.

A novel missense mutation in exon 7 of the ECM1 gene in an Iranian lipoid proteinosis patient.

Lipoid proteinosis (LP) is a rare autosomal recessive disorder. Classical clinical features include warty skin infiltration, papules on the eyelids, skin scarring, as well as extracutaneous abnormalities such as hoarseness of the voice, epilepsy, and neuropsychiatric abnormalities. A defect in the ECM1 gene is responsible for this disease. A 21-year-old female patient from consanguineous parents (first cousins) was referred to our clinic with many symptoms of LP, such as hoarse voice from infancy, diffuse acneiform scars on her face, and hyperkeratosis on her knees and elbows. The entire ECM1 gene was screened using PCR and sequencing. A novel missense mutation was found in exon 7 of this patient. We report a novel missense mutation in exon 7 of the ECM1 gene found in an Iranian LP patient that causes a C269Y amino acid exchange.

Genetic diversity of the major histocompatibility complex region in commercial and noncommercial chicken flocks using the LEI0258 microsatellite marker.

Microsatellite marker LEI0258 was used as an indicator to examine the variability of the major histocompatibility complex (MHC) region in 2 commercial layer flocks, 1 experimental layer cross, and 5 noncommercial flocks (used for free-run and free-range meat and egg production). We hypothesized that the populations from noncommercial sources may have more diversity in MHC genes than that in the commercial-source populations. Two related parameters, heterozygosity and the number of alleles harbored by a population, were used to assess the genetic variability. The different combinations of the 22 alleles created 66 genotypes in the 8 chicken populations that were studied. The noncommercial populations, except for the Silkies (SK), harbored more alleles than those in the 2 commercial populations, Lohmann Brown and Lohmann White. The observed heterozygosity of the MHC region was high in all of the populations, except for SK. Considering the 2 parameters we have examined, we can generalize that the intensively selected commercial egg-layer varieties seem to have less genetic variability in their MHC regions compared with that of the noncommercial flocks, which are less intensively selected. The LEI0258 variants can be used as markers to detect most of the MHC haplotypes, but in the different populations the same allele size may not always be associated with the same serologically defined haplotype. The information obtained from this study will be useful for genetic resource conservation and the development of breeding stocks that are suitable for free-range production.

Peripheral neuropathy in type 2 diabetes mellitus in Isfahan, Iran: prevalence and risk factors.

BACKGROUND: To estimate the prevalence and risk factors of peripheral neuropathy (PN) in people with type 2 diabetes mellitus. METHODS: A total of 810 patients with type 2 diabetes (289 men and 521 women) from Isfahan Endocrinology and Metabolism Research Centre outpatient clinics, Iran, were examined. Part of examination included an assessment of neurological function including neuropathic symptoms and physical signs and nerve conduction velocity. RESULTS: The prevalence of PN was 75.1% (95% confidence interval 72.1, 78.0). PN was associated with age, proteinuria, and duration of diabetes, insulin-treatment, and presence of any retinopathy and ischaemic heart disease (IHD). The age-adjusted prevalence rate of PN was 78% higher among patients with IHD, 64% higher among patients with any retinopathy, 66% higher among insulin-treated type 2 diabetes, and it was greater with duration of diabetes. Using a stepwise binary logistic regression model, age, duration of diabetes and proteinuria were significant independent predictors of PN. CONCLUSION: Peripheral neuropathy is a common complication in this population of Iranian type 2 diabetic patients. It increases with age, duration of diabetes and proteinuria.