Distributed feedback laser emitting at 1.3 µm for gigabit communication systems

A distributed feedback (DFB) laser emitting at 1.3 μm for gigabit lightwave communication systems has been developed. The distributed feedback structure has been introduced in a newly developed buried heterostructure and designs for stable single-mode operation, high speed modulation, and low noise have been done. Threshold current of 10-15 mA, differential efficiency of around 0.28 mW/mA, low noise, small signal modulation bandwidth of 13.9 GHz, and satisfactory modulation waveform at 5-Gbit/s NRZ modulation have been attained with high single-mode operation yield.     

Design and performance of an angled physical contact typemultifiber connector

An angled, physical contact type multifiber connector is developed on the basis of a structural design which enables direct fiber endface contact between multifiber arrays. The direct contact is achieved by utilizing the elastic nature of a ferrule material under compressive force. The fabricated connector provides a low insertion loss of 0.2 dB and a high return loss of 58.8 dB without index-matching. This connector is used in the successful development of push-on type and backpanel type 16-fiber connectors with a low insertion loss of 0.25 dB and a high return loss of 58.0 dB for future subscriber networks     

Quadriplegia caused by cervical hyperextension injury and intramedullary spinal cord tumour: a case report of autopsy

STUDY OBJECTIVE: To determine whether an association exists between individual anesthesiologists and nonpatient care time in the operating room (OR). DESIGN: Retrospective chart review. SETTING: Cardiac surgery operating theatre in a University Hospital. PATIENTS: 312 elective coronary artery bypass procedures over 2 years. MEASUREMENTS AND MAIN RESULTS: The time interval between cases, as defined by the time between the first patient out and the second patient in, was compared. Six anesthesiologists, labelled 1 to 6, were involved in the 156 data points analyzed. The mean (+/- SD) time interval between cases, in minutes, for anesthesiologists 1 to 6 were, respectively: 24 +/- 9, 25 +/- 8, 27 +/- 8, 29 +/- 5, 30 +/- 4, 31 +/- 7. The difference among the anesthesiologists' mean time interval between cases was significant (p < 0.01). The mean time interval between cases was significantly different between anesthesiologists 1 and 6 (p < 0.01) and between anesthesiologists 2 and 6 (p < 0.05). CONCLUSION: The impact of a shorter time interval between cases on OR efficiency remains unknown. Further education and investigation of this issue are warranted.     

Development of automatic fault point locating and sectional isolating system for power distribution line

This paper describes the development of the Automatic Fault Point Locating and Sectional Isolating System. This system locates a single-line-to-ground fault point at each pole by using ground-current sensors, and isolates the faulted section by controlling pole switches with no outage of unfaulted sections. The ground-current sensor is connected to the line between allied ground terminals of pole devices and grounded conductor. It detects a ground fault current of more than 0.64 amperes that is determined so as to avoid an unexpected operation by stray current, but to detect the fault current accurately, and sends out an emergency signal with time delay of 0.1 s. Sectional isolation starts when both the emergency signal from the sensor and relay operation signals from a substation are received and ends within a feeder circuit-breaker tripping time of 1.5 s.     

Prediction of membrane proteins based on classification of transmembrane segments

The number of transmembrane segments often corresponds to a structural or functional class of membrane proteins such as to seven-transmembrane receptors and six-transmembrane ion channels. We have developed a new prediction method to detect the membrane protein class that is defined by the number of transmembrane segments, as well as to locate the transmembrane segments in the amino acid sequence. Each membrane protein class is represented by a model of ordering different types of transmembrane segments. Specifically, we have classified the transmembrane segments in known membrane proteins into five groups (types) using the Mahalanobis distance with the average hydrophobicity and the periodicity of hydrophobicity as a measure of similarity. The discriminant functions derived for these groups were then used to detect transmembrane segments and to match with the models for one- to fourteen-spanning membrane proteins and for globular proteins. Using the test data set of 89 membrane proteins whose transmembrane positions are known by experimental evidence, 61.8% of the proteins and 85.1% of the transmembrane segments were correctly predicted. Because of the new feature to predict membrane protein classes, the method should be useful in the functional assignment of genomic sequences.     

Simplified procedure for preparation of35S-labeled brain sulfatide

A simplified procedure for the preparation of³⁵S-labeled brain cerebroside sulfates has been developed. The labeled sulfatides are synthesized in vivo after intracerebral administration of inorganic³⁵S-sulfate in developing rats. The animals are sacrificed three days later and brain homogenates extracted with chloroform-methanol. The extract is subjected to mild alkaline treatment and washed with water. The organic phase is chromatographed on triethylaminoethyl-cellulose from which sulfatides are eluted with chloroform-methanol containing potassium acetate. Radioactive fractions are pooled, concentrated, and potassium acetate removed by dialysis against water. Alternatively, salts are removed by passing radioactive fractions through Sephadex G-25. After evaporating to near dryness, the radioactive cerebroside sulfates are dissolved in a small volume of chloroform-methanol and stored at −20 C. The³⁵S-sulfatides are essentially free of lipid contaminants, and 97% of the radio-activity corresponds with sulfatides on chromatographic analysis.     

Stimulation of alpha4beta2 nicotinic acetylcholine receptors inhibits beta-amyloid toxicity

We describe an immunocompetent 8-year-old boy with a serological profile indicating chronic infection by Epstein-Barr virus (EBV) who developed subcutaneous and pulmonary lesions related to a peripheral T-cell proliferation. No clonal rearrangement of T-cell receptor or immunoglobulin genes was seen. However, the finding of a t(3;17)(q21;q25) in 44 metaphases from one skin lesion demonstrated a clonal origin. We also showed that the proliferative T cells contained EBV genome leading to the diagnosis of EBV-associated peripheral T-cell lymphoma. Further cytogenetic and molecular studies are needed to identify genes implicated in the pathogenesis of this haematological malignancy.     

Improvement of exercise capacity by sarpogrelate as a result of augmented collateral circulation in patients with effort angina

OBJECTIVES: The purpose of this study was to evaluate whether a serotonin blocker, sarpogrelate, improves exercise capacity as a result of vasodilation of coronary collateral channels in patients with effort angina. BACKGROUND: Serotonin has been reported to decrease coronary collateral blood flow by collateral vasoconstriction in a canine model, suggesting that platelet activation in feeding coronary arteries of the collateral network has the potential to cause collateral vasoconstriction. METHODS: The subjects consisted of 22 patients with effort angina and reproducible ischemic threshold (group A, 11 patients with thrombolysis in myocardial infarction (TIMI) grade 2 or 3 flow of the ischemia-related coronary artery and Rentrop's collateral index 0 or 1; group B, 11 patients with TIMI grade 0 or 1 flow and Rentrop's collateral index 2 or 3). We repeated the symptom-limited treadmill exercise test using the Balke-Ware protocol and exercise tetrofosmin myocardial perfusion scintigraphy with and without pretreatment with 200 mg orally administered sarpogrelate. Each exercise test was performed at 9:00 a.m. on different days. The order of tests with and without sarpogrelate was randomized. RESULTS: In group A, sarpogrelate increased neither exercise time at 0.1 mV ST depression nor double product at 0.1 mV ST depression. In contrast, in group B sarpogrelate increased the exercise duration at 0.1 mV ST depression from 181+/-112 (SD) to 248+/-131 s (p < 0.05) and also increased the double product at 0.1 mV ST depression by 21% (p < 0.01). The severity score using myocardial perfusion scintigraphy at the same workload was significantly (p < 0.01) decreased by 37% in group B, but not in group A (11%), due to the sarpogrelate treatment. CONCLUSIONS: Sarpogrelate augments flow reserve of the collateral circulation and improves exercise capacity in anginal patients with well-developed collaterals. These findings indicate that a serotonin blocker, sarpogrelate, is useful not only as an antiplatelet drugs, but as an antianginal drug.     

Radiotherapy for post-operative inflammatory breast cancer

Two patients with inflammatory breast cancer treated with a combination of radical mastectomy, irradiation, and immunochemotherapy are reported. After radical mastectomy, both patients were given a dose of 4000 rad and 5000 rad to the chest wall and parasternal lymph nodes, and 5000 rad to the axillary and supraclavicular lymph nodes. However, both patients died of recurrence within the irradiated field of the chest wall and metastatic spread to the neighbouring skin. A discussion on the dose and field in radiation therapy for inflammatory breast cancer is presented.