Over 1100 nm wavelength tuning in superstructure grating (SSG) DBR lasers

A broad range tuning of over 100 nm in tunable DBR lasers with superstructure grating (SSG) is reported. The SSG reflectors for 100 nm were designed and patterned by electron beam lithography. 1.55 mu m DBR lasers with SSG reflector operate in a single mode with a tuning range of 83 nm under CW conditions. With inclusion of the multimode operating region, the tuning range becomes as wide as 103 nm.<>     

Specific inhibition of Na+,K(+)-ATPase activity by atractylon, a major component of byaku-jutsu, by interaction with enzyme in the E2 state

Acute myocardial infarction (AMI) is known to be associated with a complex neuroendocrine activation, especially concerning sympathetic and renin-angiotensin systems, cortisol, atrial natriuretic peptide and endothelin. Results of our study show that the vasoactive intestinal peptide (VIP), also, is early involved in the neuroendocrine activation occurring in AMI. Plasma concentration of VIP, significantly increased in AMI patients within 6 hours after the onset of chest pain, soon decreased and remained below than normal along the first week. At the 14th day of the AMI, plasma levels of VIP returned into the normal range. A significant increase of VIP plasma concentration is detectable in the first hours of AMI in survived as compared with died patients. The phenomenon seems to be a suitable process to provide an endogenous support to the ischemic heart and to counteract the negative effects of other neuroendocrine activated factors.     

Reliability and degradation behavior of highly coherent 1.55 μmlong-cavity multiple quantum well (MQW) DFB lasers

Degradation behavior and reliability of 1.55 μm highly coherent MQW DFB laser with a long cavity are examined and clarified. The increase in spectral linewidth, due to the increase in 1/f noise and internal optical loss and the instability of the side mode, and the changes in FM response, especially the increase in FM efficiency, occur during degradation, e.g. increase in threshold current. In addition to these basic degradations, the degradation behavior of multisection DFB lasers is also clarified from the viewpoint of device characteristics, such as wavelength and tunability. By clarifying these changes in device characteristics, the possibility of long life for long-cavity MQW DFB lasers in optical coherent transmission systems is shown     

Phylogenetic analysis of 8 dermatophyte species using chitin synthase 1 gene sequences

Nucleotide sequences of chitin synthase 1 (CHS1) gene of eight species of dermatophytes, Arthroderma benhamiae, A. fulvum, A. grubyi, A. gypseum, A. incurvatum, A. otae, A. simii and A. vanbreuseghemii were obtained and analysed for their phylogenetic relationship. A 600-bp genomic DNA fragment of the CHS1 gene was amplified from these dermatophytes by polymerase chain reaction (PCR) and sequenced. The CHS1 nucleotide sequences of these eight dermatophyte species showed more than 85% similarity between the species. The phylogenetic analysis of their sequences revealed three clusters, the first cluster consisting of A. benhamiae, A. simii and A. vanbreuseghemii, the second cluster consisting of A. fulvum, A. gypseum and A. incurvatum, and the third cluster consisting of A. grubyi and A. otae. The phylogenetic analysis of CHS1 gene in this study will provide useful information for classification and understanding the evolution of these dermatophyte species.     

Electron temperature and density in the He-CdI2positive column used for and I+laser

Plasma parameters in the He-CdI2positive column used for an I+ laser were measured using a probe. The presence of iodine seems to partially cancel the influence on the electron temperature of the Penning process which is very dominant in the He-Cd positive column.     

Computer-aided diagnosis in chest radiography. Preliminary experience

RATIONALE AND OBJECTIVES: Computer-aided diagnosis (CAD) schemes for chest radiography are being developed with which to alert radiologists to possible lesions, and thus potentially improve diagnostic accuracy. However, CAD schemes have not been tested on a large number of clinical cases. The authors identify design parameters that would be required for development of an intelligent workstation. METHODS: Computer-aided diagnosis programs were applied for the automated detection of lung nodules, cardiomegaly, and interstitial infiltrates to 310 consecutive chest radiographs, and were analyzed for potential usefulness and limitations. Computer-aided diagnosis output was evaluated by radiologists and physicists for accuracy and technical problems, respectively. RESULTS: Approximately 70% of the results were judged to be potentially acceptable; however, the number of false-positive findings was relatively high. Technical problems included failure to detect subtle abnormalities and the occurrence of false-positive detections caused by normal anatomical structures. CONCLUSION: Computer-aided diagnosis has the potential to be a valuable aid to radiologists in clinical practice, if certain technical problems can be overcome and if optimal operating points can be defined for clinical use.     

Management of recurrent pilocytic astrocytoma with leptomeningeal dissemination in childhood

Neurofibromatoses are genetic disorders of the nervous system that primarily affect the development and growth of neural cell tissues. These disorders produce other abnormalities such as skin changes and bone deformities. Neurofibromatoses occur in both sexes and in all races and ethnic groups. Scientists have classified these disorders as neurofibromatosis type 1 (NF1) and neurofibromatosis type 2 (NF2). Other types of neurofibromatoses may exist, but are not yet identified. Nearly 50% of the cases shows a well definited familiarity for the disease, according to an autosomal dominant transmission, while the other 50% of patients shows a negative history of familiarity, according to a new chromosomal mutation interesting the same autosomal genes of the dominant transmission. Oral localization is more rare showing an incidence ranging from 4 to 7% in most series of different authors. The most frequent involvement site in oral neurofibromatosis is the tongue, followed by the oral mucosa and floor of the mouth; palate and maxillary-mandibular bones are a rare localization of the disease. In the present, the clinical, radiological, histopathological and therapeutical aspects of a clinical case of neurofibromatosis, presenting as mandibular tumor, are examined. The clinical case reported, a 37 year old man, was essentially characterized by a positive family history for the disease, a neurofibroma of the oral mucosa.     

Effects of glycosaminoglycans on the development of in vitro-matured and -fertilized porcine oocytes to the blastocyst stage in vitro

We examined the effects of four glycosaminoglycans (GAGs) on the development of in vitro-matured (IVM) and -fertilized (IVF) porcine oocytes to the blastocyst stage. IVM and IVF oocytes were cultured in Whitten's medium supplemented with hyaluronic acid, chondroitin sulfate A, dermatan sulfate, or heparin at 38.5 degrees C in an atmosphere of 5% CO2 in humidified air for up to 6 days. After 2 days in culture, 28-34% of the inseminated oocytes cleaved to the 2- to 8-cell stage, and the GAGs showed no significant effect on development. After 6 days in culture, blastocysts were observed in all groups. The percentage of blastocysts was significantly higher in hyaluronic acid-supplemented medium (14%) than in dermatan sulfate-supplemented (5%), heparin-supplemented (2%), or nonsupplemented (2%) media. In addition, the percentage of blastocysts was significantly higher in chondroitin sulfate A-supplemented medium (11%) than in heparin-supplemented and nonsupplemented media, although the number of blastocysts in chondroitin sulfate A was not significantly different from that in hyaluronic acid- and dermatan sulfate-supplemented media. There were no significant differences in the mean number of nuclei per blastocyst cultured in any group. The effects of hyaluronic acid and chondroitin sulfate A on development to the blastocyst stage was examined at various concentrations. After 6 days in culture, development of IVM and IVF oocytes to the blastocyst stage was best supported in 0.5 mg/ml hyaluronic acid-supplemented (17%) and in 0.1 or 0.5 mg/ml chondroitin sulfate A-supplemented (10% or 9%, respectively) media. It is concluded from these results that hyaluronic acid and chondroitin sulfate A supported the development of porcine oocytes matured and fertilized in vitro to the blastocyst stage.     

Modulation characteristics of 1.3 ?m buried-stripe InGaAsP laser up to 2 Gbit/s data rates

Modulation experimenting on a buried-stripe (b.s.) InGaAsP laser emitting at 1.3 ?m was carried out up to 2 Gbit/s. The b.s. laser is free from relaxation oscillation, which degrades modulated optical pube waveforms, especially at high data rates. The repeater gain of 1.6 Gbit/s transmission systems is improved by 9 dB compared with previously reported experiments. Modulation characteristics up to 2 Gbit/s are reported.