H ypotHalamic hamartoma (HH) is a rare congenital abnormality, which presents with a hallmark feature of intractable gelastic seizures (GS). There is now strong evidence that HH involves intrinsic epileptogenesis, [7][8][9][10][11][12]14,17 and surgical treatment of HH itself is considered important for seizure control. Although various surgical treatments are available for epileptic patients with HH, the selection of treatment modalities depends on the type and size of the HH, as well as the surgeons' preference.3 Mittal et al. reported that no single neurosurgical approach is likely to treat all forms of HH, and that a multimodal or staged procedure must be used to treat the lesion. 16 Similarly, the Barrow group commonly use staged and multiple surgical approaches for HH treatment, including microsurgical resection, endoscopic disconnection, and stereotactic radiosurgery. 6,19,24 We previously developed a surgical procedure involving MRI-guided stereotactic radiofrequency thermocoagulation (SRT) of HH and reported an early series of cases in which this technique was used.9,12 In the present study, which was undertaken to determine the invasiveness abbreviatioNs DQ = developmental quotient; EEG = electroencephalography; EFP = emotional facial paresis; FIQ = full-scale IQ; GS = gelastic seizures; HH = hypothalamic hamartoma; SISCOM = subtraction ictal SPECT co-registered to MRI; SMA = supplementary motor area; SPECT = single-photon emission computed tomography; SRT = stereotactic radiofrequency thermocoagulation; WAIS = Wechsler Adult Intelligence Scale; WAIS-R = WAIS-Revised; WAIS-III = WAIS-Third Edition; WISC = Wechsler Intelligence Scale for Children; WISC-R = WISC-Revised; WISC-III = WISC-Third Edition. The median duration of follow-up was 3 years (range 1-17 years). Seventy cases involved pediatric patients. Ninety percent of patients also had other types of seizures (non-GS). The maximum diameter of the HHs ranged from 5 to 80 mm (median 15 mm), and 15 of the tumors were giant HHs with a diameter of 30 mm or more. Comorbidities included precocious puberty (33.0%), behavioral disorder (49.0%), and mental retardation (50.0%). results A total of 140 SRT procedures were performed. There was no adaptive restriction for the giant or the subtype of HH, regardless of any prior history of surgical treatment or comorbidities. Patients in this case series exhibited delayed precocious puberty (9.0%), pituitary dysfunction (2.0%), and weight gain (7.0%), besides the transient hypothalamic symptoms after SRT. Freedom from GS was achieved in 86.0% of patients, freedom from other types of seizures in 78.9%, and freedom from all seizures in 71.0%. Repeat surgeries were not effective for non-GS. Seizure freedom led to disappearance of behavioral disorders and to intellectual improvement. coNclusioNs The present SRT procedure is a minimally invasive and highly effective surgical procedure without adaptive limitations. SRT involves only a single surgical procedure appropriate for all forms of epileptogenic HH and should be...

Propagation of electromagnetic waves in several types of microplasmas has been examined experimentally in a frequency range 10-75 GHz. Firstly, the fundamental characteristics of the propagation were investigated using a planar geometry of microplasma assembly, and the electron density was derived by a comparison of the transmittance with the theoretical analyses using a Drude type model with collisional effects. Secondly, an extraordinary propagation phenomenon such as the focusing effect was observed in a two-dimensional periodical microplasma array. This kind of anomalous refraction cannot be interpreted only by predictions based on the dielectric property of bulk plasma, and it is suggested that a photonic-crystal-like periodical dielectric structure may play a significant role. Thirdly, it was demonstrated that the T-junction formed by a microplasma connected to a microstrip line can control the transmission of microwaves. An attenuation (or modulation) depth of about 35% was obtained with a series of two T-junctions connected to the strip line at the right-angled corners. All the above features come from (a) the relatively high electron density of the microplasmas near 10 13 cm −3 , (b) the complex dispersion relation with collisional effects and (c) the spatial arrangement with a characteristic scale of the same order of the wavelength of microwaves.

We present an experimental study of plasma enhanced chemical vapor deposition (PECVD) of SiO 2 films from tetraethoxysilane (TEOS) using a plasma jet based on capillary dielectric barrier discharge (CDBD) at atmospheric pressure. We tried three different configurations: (a) coaxial type, (b) a crossed type with a vertical plasma jet and a tilted TEOS supply, and (c) another crossed type with the reversed arrangement. The deposition rate of SiO 2 films increased with the driving frequency of the plasma jet in all configurations, and as the best record it reached up to 280 nm/s at a frequency of 15 kHz in the configuration (c) with the aid of O 3 supply, which was three times as fast as that measured in the configuration (a) without O 3 supply. #