Self-aligned chemically assisted ion-beam-etched GaAs/(Al,Ga)Asturning mirrors for photonic applications

It is shown that totally reflecting turning mirrors can be fabricated in GaAs/(Al,Ga)As graded-index separate-confinement-heterostructure single-quantum-well (GRIN-SCH SQW) material using Ti metal masking and Cl₂ chemically assisted ion-beam-etching (CAIBE). Combined with ridge waveguides, these techniques have been used to make turning-mirror cleaved-facet lasers that have acceptable external slope efficiencies with a modest estimated increase in threshold current. Scanning electron microscope examination of the mirrors indicates some residual roughness attributed to the edge definition of the deposited titanium film. The mirror loss is estimated to be 68% for these particular turning mirrors. These components, which continue to be developed and improved, are being applied to increasingly sophisticated and demanding photonic programs     

Excimer laser angioplasty versus balloon angioplasty in functional and total coronary occlusions

Registries of excimer laser coronary angioplasty have reported good results in the treatment of complex coronary artery disease, including total or subtotal coronary occlusions. One hundred three patients (103 lesions) with a functional or total coronary occlusion were included in a randomized trial (Amsterdam-Rotterdam [AMRO] trial, total of 308 patients), 49 patients were allocated to laser angioplasty and 54 patients to balloon angioplasty. The primary clinical end points were death, myocardial infarction, coronary bypass surgery, or repeated coronary angioplasty of the randomized segment during a 6-month follow-up period. The primary angiographic end point was the minimal lumen diameter at follow-up in relation to the baseline value (net gain), as determined by an automated contour-detection algorithm. Laser angioplasty was followed by balloon angioplasty in all procedures. The angiographic success rate was 65% in patients treated with excimer laser-assisted balloon angioplasty compared with 61% in patients treated with balloon angioplasty alone. No deaths occurred. There were no significant differences between the laser angioplasty group and the balloon angioplasty group in the incidence of myocardial infarctions (1 patient vs 3, respectively, p = 0.36), coronary bypass surgery (4 patients vs 2, respectively, p = 0.34), repeat angioplasty (10 patients vs 8, respectively, p = 0.46) or primary clinical end point (15 patients vs 12, respectively, p = 0.34). The net gain in minimal lumen diameter and restenosis rate (>50% diameter stenosis at follow-up) were 0.81 +/- 0.74 mm and 66.7%, respectively, in patients treated with laser angioplasty compared with 1.04 +/- 0.68 mm and 48.5%, respectively, in patients treated with balloon angioplasty (p = 0.59 and p = 0.15, respectively). Excimer laser-assisted balloon angioplasty demonstrated no benefit over balloon angioplasty with respect to initial and long-term clinical and angiographic outcome in the treatment of patients with functional or total coronary occlusions of >10 mm in length.     

Sarcomas of the stomach

Sarcomas of the gastric wall, other than lymphomas, are a heterogeneous group of stromal malignant neoplasms composed of round and spindle cells. Many are malignant forms of epithelioid leiomyoma. Small cell size, high cellular density, a high rate of mitotic activity, and cellular pleomorphism are helpful clues in distinguishing malignant from benign gastric stromal tumors. Sarcomas of the stomach are aggressive, rapidly growing neoplasms. Among 44 examples metastasis occurred in three-fourths of the patients, usually within the first year after diagnosis.     

Lead emissions from road transport in Europe: A revision of current estimates using various estimation methodologies

Large-scale use of leaded gasoline was an important source of the neurotoxin lead in the European environment. After a sequence of regulations on the allowed gasoline lead content and, eventually, a ban on the use of lead additives in gasoline, road transport was no longer considered a source of atmospheric lead. Currently a discrepancy exists between measured atmospheric lead concentrations and model-predicted concentrations, suggesting that lead emissions to the atmosphere may be underestimated. Recently it was suggested that lead emission from unleaded gasoline combustion is still an important source and may (partly) fill the gap between modelled and observed atmospheric lead concentrations. In this paper we assess the plausibility of the latter suggestion by following various emission estimation methodologies. The uncertainty of lead emissions from road transport is further reduced by chemical analysis of fuel samples. The result of our assessment is that lead from road transport fuel combustion is not the missing lead source needed to fill the gap between modelled and observed lead concentrations. Road transport is still a source of lead through brake wear and a small contribution from exhaust emissions but this contributes no more than 5–8% of the EU25 total emission.     

The water-binding reaction of the mercury-iodine thermochemical cycle ANL-4: precipitation of KHCO3 from a purely aqueous medium

Yields and compositions of the products of the reaction H₂O + NH₃ + CO₂ + KI → KHCO₃ + NH₄I in aqueous solution are reported for the temperature range from 300 to 354 K. The effects of using pure water as a solvent for the water-binding reaction of the mercury-iodine thermochemical cycle ANL-4 are discussed.     

All-optical switching technologies for protection applications

One of the key issues when designing an optical transport network is how to ensure survivability in the event of a network failure. With the increased penetration of dynamic DWDM networks the demand for new, reliable, and flexible protection schemes at the optical layer rises. Furthermore, over the last several years, enormous advances have been made in optical component technologies. As a result, all-optical components, such as the optical switch, now offer additional functionalities. This article examines the applicability of new and legacy all-optical switching technologies to serve as building blocks for different protection applications.     

Multimodality visualization of medical volume data

New developments in 3-D volume acquisitions are creating a rapidly increasing demand for integrating multimodality 3-D visualization. In order to accomplish routine clinical multimodality visualization, many issues have to be dealt with, such as techniques for accurate spatial registration, integrated representation, suitable graphical user interfaces, and obtaining adequate rendering speeds. The aim of this experience paper is 2-fold. First, it presents various results from our research on multimodality visualization/registration. Second, this paper explicitly addresses practical problems and findings related to software development and multimodality registration/visualization. We hope that this will give colleagues a better understanding in some of these issues based on our experience, including notably our mistakes.     

Immunolymphoscintigraphy in breast cancer: evaluation using 131I-labeled monoclonal antibody B72.3

Resistance to the organophosphates temephos and chlorpyrifos, the carbamate propoxur, the pyrethroid permethrin, and the organochloride DDT was investigated in Tunisian populations of Culex pipiens pipiens (L.) collected between 1990 and 1996. Resistance to temephos was uniformly low, reaching 10-fold in the most resistant population. In contrast, resistance to chlorpyrifos was highly variable, reaching the highest level (> 10,000-fold) recorded worldwide. The chlorpyrifos-resistant populations also were highly resistant to propoxur. Some populations also showed high resistance to permethrin (up to 5,000-fold) and moderate resistance to DDT (approximately 20-fold). Bioassays conducted in the presence of synergists showed that increased detoxification had only a minor role in resistance, although several over-produced esterases known to be involved in organophosphate resistance were detected. To better understand the factors influencing the distribution of resistance in Tunisia, the polymorphism of genes involved in organophosphate resistance (i.e., over-produced esterases and insensitive acetylcholinesterase) was investigated in relation to the genetic structure of populations studied by analyzing the electrophoretic polymorphism of "neutral" genes. Over the area studied, and despite a high level of gene flow, resistance genes showed a patchy distribution. Results are discussed in relation to the selection pressure caused by insecticide treatments.     

焦化废水与高炉排污水生化处理的中试和工业设计

艾莫伊登科拉斯带钢厂的几种废水的COD值和总凯氏氮（TKN）含量过高，难以符合政府法律和法规的要求，为此，废水在排放前必须进行生化处理。1972年以来，该厂用一套常规的活性污泥装置处理两个焦化厂的废水。80年代末，又增建了一套生物脱氮装置，但处理后废水中的TKN和TSS值居高不下。另外，来自炼铁厂废水中的COD和TKN值也相当高。