A microwave resonator integrated on a polymer microfluidic chip.

We describe a novel stacked split-ring type microwave (MW) resonator that is integrated into a 10mm by 10mm sized microfluidic chip. A straightforward and scalable batch fabrication process renders the chip suitable for single-use applications. The resonator volume can be conveniently loaded with liquid sample via microfluidic channels patterned into the mid layer of the chip. The proposed MW resonator offers an alternative solution for compact in-field measurements, such as low-field magnetic resonance (MR) experiments requiring convenient sample exchange. A microstrip line was used to inductively couple MWs into the resonator. We characterised the proposed resonator topology by electromagnetic (EM) field simulations, a field perturbation method, as well as by return loss measurements. Electron paramagnetic resonance (EPR) spectra at X-band frequencies were recorded, revealing an electron-spin sensitivity of 3.7·10(11)spins·Hz(-1/2)G(-1) for a single EPR transition. Preliminary time-resolved EPR experiments on light-induced triplet states in pentacene were performed to estimate the MW conversion efficiency of the resonator.

[Characterisation of a Collective of Children with Early Language Delay, 'Late Talkers']. / Charakterisierung eines Kollektivs von Kindern mit früher Verzögerung im Spracherwerb "Late Talkers".

BACKGROUND: By considering their general development, 2-year-old children with delayed speech development (late -talkers, LT) were examined and described with respect to linguistic competence and hearing. METHODS: Initially, 50 monolingual German speaking LT (age: 23-28 months) were recruited. In addition to audiological tests (impedance testing, otoacoustic emissions, reaction audiometry), language development status test was performed (clinical impression during examination, expressive vocabulary: FRAKIS, receptive competence: SETK-2). RESULTS: After exclusion of 10 children with general retarded development (3 premature infants, 2 children with suspicion of autism and 2 children with infantile brain damage) 33 LTs with normal hearing were included. The expressive vocabulary (FRAKIS) of 82% of these 33 LTs were below the normal range. 39% showed deficits in language comprehension tests (SETK-2) although parental reports mentioned language comprehension problems in only 3 LT. No correlation was found between vocabulary (FRAKIS) and language comprehension (SETK-2). CONCLUSION: The clinical collective in this study showed severely affected children with a high percentage of other abnormalities and speech perception problems in many cases. Despite normal hearing, vocabulary and especially speech comprehension should also be tested. LT with language comprehension problems require early developmental psychological investigation in order to prevent language and general developmental limitations. Only in this way, remedial instruction adapted to the develop-mental level can be initiated.