Fabrication of guided-mode resonance elements by nanoimprint lithography.

This paper addresses utilization of nanoimprint lithography for fabrication of nanopatterned resonant photonic elements. These compact periodic films resonate sharply when illuminated with light. The attendant spectral and angular signatures are useful in design of photonic devices for various applications. It is of interest to design and optimize resonant leaky-mode elements with prescribed filtering, polarization, and security attributes. Applying nanoimprint lithography techniques, we fabricate prototype devices using polymer materials produced by Dymax Corporation. The initial prototypes are designed for use in the near-IR and telecommunications spectral regions. We apply holographic surface-relief gratings as master templates. With these templates, we have formed submasters in PDMS (polydimethylsiloxane) to function as imprint stamps for the soft lithography steps. Using these submasters, we fabricate periodic surfaces in UV-curable polymers with resonant films deposited on the surface by sputtering. Several example devices possessing resonance efficiencies exceeding 90% are presented along with their spectral and angular characteristics.

Severity of obstructive sleep apnoea/hypopnoea syndrome and subsequent waking EEG spectral power.

It is well known that most patients with obstructive sleep apnoea/hypopnoea syndrome (OSAHS) suffer sleepiness, although the underlying mechanisms of this relationship remain unclear. The present study examined the relationship between nocturnal variables and the subsequent waking electroencephalogram (EEG), in order to determine if sleepiness was related to OSAHS severity and due to sleep fragmentation or to nocturnal hypoxaemia. In total, 12 moderate-to-severe OSAHS patients underwent a total sleep night followed by a 24-h period of sustained wakefulness where the waking EEG was measured every hour. The results showed that alpha (7.9-12.6 Hz) and beta (12.7-29.2 Hz) activities were strongly related to OSAHS severity, mainly reflected by the apnoea index. Moreover, spectral power in most of the waking EEG components was significantly correlated with nocturnal hypoxaemia indices, namely alpha and beta activity when hypoxaemia becomes severe. However, no correlation was found between the waking EEG and sleep fragmentation parameters. In conclusion, the present results suggest that the difficulty in maintaining an optimal level of alertness, reflected by a higher activity in awake alpha and beta bands (7.9-29.2 Hz) in obstructive sleep apnoea/hypopnoea syndrome, was better explained by: 1) the apnoea as opposed to the hypopnoea index; and 2) nocturnal hypoxaemia as opposed to sleep fragmentation.

Evaluation of the 10th External Quality Assessment Scheme results in clinical microbiology laboratories in Tehran and districts.

We evaluated the performance of microbiology laboratories in the 10th run of the external quality assessment scheme (EQAS) in Tehran and districts. Each laboratory was sent 2 species of bacteria for identification. Of the 487 laboratories that participated, 437 returned their findings. While 77.0% and 69.9% correctly identified Staphylococcus saprophyticus and Citrobacter freundii respectively, only 29.8% correctly identified Acinetobacter baumanii, 25.3% identified Enterococcus faecalis and 35.6% identified Enterobacter agglomerans. However 78.7% and 79.5% of the laboratories reported correct -results for susceptibility testing for S. saprophyticus and C. freundii respectively.

The first successful pregnancy following injection of testicular round spermatid in Iran.

The authors report the healthy delivery of the first successful round spermatid injection in Iran. The male was a 40-year-old with nonobstructive azoospermia whose previous testicular biopsy revealed only round spermatids. The wife was a 29-year-old healthy woman.