Increased serum vascular endothelial growth factor levels and intrathyroidal vascular area in patients with Graves' disease and Hashimoto's thyroiditis

Vascular endothelial growth factor (VEGF) is one of the angiogenic factors. We examined both thyroid volume and intrathyroidal vascular area by color flow Doppler ultrasonography in patients with Graves' disease (GD), Hashimoto's thyroiditis (HT), and subacute thyroiditis. The serum concentrations of thyroid hormones, TSH, TSH receptor antibodies, and VEGF were also examined. There was a significant increase in serum VEGF levels in patients with untreated GD and goitrous HT compared with those in healthy subjects. The serum VEGF levels in untreated patients with subacute thyroiditis were significantly higher than those in patients with untreated GD or HT. There was a significant correlation between serum VEGF levels and the ratio of intrathyroidal vascular area and thyroid area in untreated patients with GD who had a goiter larger than or equal to 40 cm3. There was also a significant correlation between serum VEGF and TSH levels in patients with HT who were hypothyroid and had a goiter. Serum VEGF levels decreased significantly in these patients after treatment; this was accompanied by a significant decrease in intrathyroidal vascular area and thyroid volume. Our study demonstrates that VEGF appears to play an important role in intrathyroidal angiogenesis in patients with GD and goitrous HT.     

Tandem-crosspoint ATM switch with input and output buffers

This letter proposes a high-speed input and output buffering asynchronous transfer mode (ATM) switch, named the tandem-crosspoint (TDXP) switch, The TDXP switch consists of multiple crossbar switch planes, which are connected in tandem at every crosspoint. The TDXP switch does not increase the internal line speed in eliminating head-of-line (HOL) blocking. In addition, since the TDXP switch employs a simple cell reading algorithm at the input buffer in order to retain the cell sequence, the TDXP switch does not require the cell sequences to be rebuilt at output buffers using time stamps, as is required by a parallel switch. It is shown that the TDXP switch can eliminate the HOL blocking effectively and achieve high throughput     

Surgery for thoracic empyema concurrent with rupture of lung abscesses in a child

The authors report surgical treatment for thoracic empyema concurrent with rupture of lung abscesses and completely collapsed lung in a child. Right middle lobectomy for ruptured abscess, debridement and closure with interrupted sutures for another abscess in the lower lobe, and decortication were performed. Positive-pressure ventilation was needed to prevent reexpansion pulmonary edema because of long-term collapsed lobes. The patient is doing well with no recurrent empyema or thoracic deformity at 3 years postoperation.     

High-speed electroabsorption modulators buried with ruthenium-doped SI-InP

InGaAlAs-InAlAs electroabsorption modulators are successfully fabricated using ruthenium (Ru)-doped semi-insulating (SI)-InP burying technology. A comparison of measured and calculated microwave characteristics reveals that there is no additional microwave loss because zinc diffusion is inhibited by the use of Ru-doped SI-InP layers. A small-signal electrooptical response with a -3-dB electrical bandwidth of over 50 GHz is demonstrated.     

Monitoring of magnetic saturation level of a synchronous generatorunder load

This paper presents a new method to monitor magnetic saturation level of a synchronous generator operating in an electric power system. The proposed method makes use of air-gap permeance distributions, which can be derived from air-gap flux distributions measured by a search coil wound around a stator tooth of a generator. Tests were conducted on a laboratory-model power system to verify the validity of the proposed monitoring method. Test results under various operating conditions are presented to show a wide range of change in saturation level inside the generator. Its effects on generator performance in the power system and the benefits of the monitoring method are also discussed