Growth of highly strained GaInAs-GaAs quantum wells on patterned substrate and its application for multiple-wavelength vertical-cavity surface-emitting laser array

We carried out the growth of highly strained GaInAs-GaAs quantum wells (QWs) on a patterned substrate for extending emission wavelength on a GaAs substrate. We examined the shift of photoluminescence wavelength of the QWs and showed a large wavelength shift due to the spatial modulation in well thickness and indium composition. We demonstrated a single-mode multiple-wavelength vertical-cavity surface-emitting laser (VCSEL) array on a patterned GaAs substrate covering a new wavelength window of 1.1-1.2 /spl mu/m. By optimizing pattern shape, we achieved multiple-wavelength operation with widely and precisely controlled lasing wavelengths. The maximum lasing span is as large as 77 nm. We carried out a data transmission experiment through 5-km of single-mode fiber with a 2.5 Gb/s/channel. The total throughput reaches 10 Gb/s. The VCSEL-based wavelength-division-multiplexing (WDM) source would be a good candidate for WDM-LAN beyond 10 Gb/s.     

Self-assembly of nano-sized arrays on highly oriented thin films of poly(tetrafluoroethylene)

Self-assembly of nano-sized arrays by casting a dilute solution of a guest material on the friction-transferred poly(tetrafluoroethylene) (FT-PTFE) substrate was newly discovered. Long axis of the rod-like structures forming the arrays is aligned perpendicular to the chain direction of FT-PTFE, and accordingly, the arrays are highly anisotropic. This phenomenon was observed for aqueous or organic solutions of polymers or organic materials. Each rod-like structure forming the arrays is composed of small grains. The arrays in question are formed regardless to the crystallinity of the guest materials. The formation mechanism of the nano-sized arrays is still unclear. However, we guess that they are formed as a result of microscopic flow pattern at the edge of the solution film. The arrays in question may be a new type of dissipative structure.     

Stress effect for polarisation control of surface emitting lasers

To control the electric polarisation of output light in surface emitting (SE) lasers, the stress effect on the resonance model of SE lasers with an elliptical holed region is investigated. For the first time, polarisation switching by external stress has been observed and the relation between the polarisation characteristics and the structural dependence on stress clarified.<>     

Potential reprocessing improvements in the Advanced Fuel Recycle System

From the aspects of economical competitiveness, proliferation resistance, and minimizing waste problems, PNC has proposed an improved recycle concept for the FBR fuel cycle, termed Advanced Fuel Recycle System. Reprocessing in this system is based on the well-known PUREX flowsheet and features a “single cycle Pu/U co-extraction flowsheet” with lower decontamination factor (DF) than that in the conventional process. This feature is practical because of the FBR's low neutronic sensitivity to impurities.

Such a simplified extraction process without purification cycles should substantially reduce not only the number of process components but also the quantities of liquid to be treated in other related processes, so it will lead to the proportional reduction in waste processing, waste itself, and all other related equipments and facilities. This should improve overall economics. One method being examined to further reduce the liquid throughputs and simplify the process is to apply the crystallization technique to dissolver solution.

Overall, with this proposed concept, proliferation resistance will be significantly improved because plutonium is always recovered as a mixture with the uranium and DF of the plutonium product is low.

Reprocessing and fabrication processes are integrated into one fuel cycle plant in this system further contributing to these improvements.     

Smoke extract stimulates lung epithelial cells to release neutrophil and monocyte chemotactic activity

Inflammatory cells accumulate within the lungs of cigarette smokers. Current concepts suggest that these cells can induce protease-antiprotease and/or oxidant-antioxidant imbalance(s), which may damage the normal lung alveolar and interstitial structures. Because type II pneumocytes line the alveolar space, and because the inflammatory cells migrate and reside at the alveolus, we postulated that the type II pneumocytes might release chemotactic activity for neutrophils and monocytes in response to smoke extract. To test this hypothesis, A549 cells were cultured and the supernatant fluids were evaluated for the neutrophil and monocyte chemotactic activity (NCA and MCA) by a blind-well chamber technique. A549 cells released NCA and MCA in response to smoke extract in a dose- and time-dependent manner (P < 0.05). Checkerboard analysis showed that the activity was chemotactic. Partial characterization of NCA and MCA revealed that the activity was partly heat labile, trypsin sensitive, and ethyl acetate extractable. Lipoxygenase inhibitors and cycloheximide inhibited the release of NCA and MCA. Molecular sieve column chromatography showed multiple peaks for both NCA and MCA. NCA was inhibited by anti-human-interleukin (IL)-8 antibody, granulocyte colony-stimulating factor (G-CSF) antibody, or leukotriene (LT)B4 receptor antagonist. Monocyte chemoattractant protein (MCP)-1 antibody or LTB4 receptor antagonist inhibited MCA. Immunoreactive IL-8, G-CSF, MCP-1, and LTB4 significantly increased in the supernatant fluids in response to smoke extract. These data suggest that the type II pneumocytes may release NCA and MCA and modulate the inflammatory cell recruitment into the lung.     

Immobilization-induced and crowded environment-induced stress delay barrier recovery in murine skin

To examine the effect of stress on skin homeostasis, cutaneous barrier recovery was measured in rate exposed to immobilization stress after tape stripping or sodium dodecyl sulphate treatment. The barrier function was evaluated by measuring transepidermal water loss. Barrier recovery was delayed in rats exposed to stress in comparison with untreated controls. This tendency was observed in both male and female animals. The delay in barrier recovery was blocked by application of the sedative drugs diazepam and chlorpromazine. The barrier recovery rate in mice which were kept at a high population density (10 animals per cage) for 2 weeks was slower than that in mice kept at lower population densities (five animals or one animal per cage). These animal models could be useful for objectively quantifying the influence of stress on the cutaneous function.     

Enhanced rectal absorption of amphotericin B lyophilized with glycyrrhizinate in rabbits

The influence of bases and additives in the formulation for rectal absorption of amphotericin B (AMB) lyophilized with dipotassium glycyrrhizinate (GLYK) was investigated using rabbits in relation to an in vitro release test. The release of AMB from the fatty base of Witepsol or a medium chain triglyceride (MCT) was markedly faster than that from the hydrophilic base of macrogol. The addition of polyoxyethylene (2) lauryl ether (POE(2)LE) into the fatty bases led to a marked increase in the release rate, whereas POE(9)LE or sodium lauryl sulfate resulted in a significantly lower release rate. Animals received rectally each of seven AMB formulations of Witepsol H-15, macrogol, MCT with surfactants and aqueous solution. The absorption of the AMB lyophilized mixture with GLYK at a 1:9 molar ratio from a MCT base was significantly superior to that from macrogol. The addition of POE(2)LE into the MCT base resulted in a marked increase in bioavailability, showing the highest bioavailability of 4.9%. High serum levels of over 100 ng/ml of serum were maintained for 24 h following administration. The lowest bioavailability was 0.32% for the macrogol suppository. There was a good correlation between the release rate of AMB from the formulations and bioavailability. These results suggest that an AMB rectal formulation may provide a promising therapeutic alternative to infusion, taking into account the serum level of AMB exceeding the minimal inhibitory concentration of the infecting organism.     

Acute respiratory distress syndrome due to methicillin-resistant Staphylococcus aureus sepsis in hyper-IgE syndrome

We report the case of a 34 year old woman with acute respiratory distress syndrome (ARDS) and disseminated intravascular coagulation (DIC) due to methicillin-resistant Staphylococcus aureus (MRSA) sepsis with hyperimmunoglobulin E syndrome (HIES). Although chemotactic activity of neutrophils was impaired in this patient, neutrophils accumulated in the lungs as assessed by bronchoalveolar lavage fluid (BALF) counts. In addition to antibiotics and oxygen therapy, the administration of recombinant human granulocyte colony-stimulating factor (rhG-CSF) resulted in a remarkable recovery.