Semiconductor laser diode optical amplifiers/gates in photonicpacket switching

In this paper, we will describe how semiconductor laser diode optical amplifiers/gates can be used in the photonic packet switching systems based on wavelength division multiplexed (WDM) techniques. First, we show that cross-gain modulation (XGM) can be suppressed when the device is used in the transparent condition of the waveguide material even when the input signal power exceeds +18 dBm. We then discuss an appropriate encoding for the optical signal. Experimental results show that high bit rate Manchester-encoding enables the use of semiconductor laser diode optical amplifiers/gates in the gain condition as well as the transparent condition. Finally, a new photonic packet receiver which utilizes a semiconductor laser diode optical amplifier as a packet power equalizer is proposed. This receiver accepts 17 dB power fluctuation at nanosecond speed for 10 Gb/s Manchester-encoded signal     

Interhemispheric asymmetry exists in female in the N100m source position of the auditory evoked magnetic fields

OBJECTIVE: To evaluate the affect of families' attitudes about the appropriateness of discussing psychosocial concerns on pediatric providers' identification of psychosocial problems. DESIGN: These data were collected as part of the Greater New Haven Child Health Study, New Haven, Conn. The study design was a prospective cohort. SETTING: Families were recruited from a stratified random sample of all primary care practices in the greater New Haven area. Nineteen of 23 invited practices agreed to participate including 2 prepaid practices, 2 neighborhood health centers, and 7 fee-for-service group and 8 fee-for-service solo practices. PARTICIPANTS: All families of children aged 4 to 8 years who attended these practices during 2 separate 3-week periods (1 in fall 1987 and 1 in spring 1988) were invited to participate in the study. Families were invited to participate only once, on the first contact with any eligible child, using approved procedures. Of 2006 eligible families, 1886 (94%) chose to participate. MAIN OUTCOME MEASURE: The outcome variable for these analyses is the identification of any behavioral, emotional, or developmental problem by the pediatrician on the 13-category checklist. Overall, pediatric clinicians identified 27.5% of children with 1 or more psychosocial problems. RESULTS: Our data suggest that there is a great deal of discrepancy between what parents report is appropriate to do when their children have psychosocial problems and what they actually do when they recognize such problems in their children. Most (81.1%) believed it was appropriate to discuss 4 or more of the 6 hypothetical situations with their children's physician, while only 40.9% actually did discuss any of these problems with a physician when a problem occurred. Given the correlates of parents who intended to discuss such problems (higher education, older age, Euro-American ethnicity, higher income, married, availability of medical insurance) the possibility that parents are providing socially acceptable responses to such questions seems likely. Further, our data indicate that parents' actual reports of discussions of psychosocial problems is unrelated to whether physicians identified those problems in children. CONCLUSIONS: Pediatricians'judgments about the presence of psychosocial problems in their young patients seem to be based on their own observations rather than on what parents report. Physician-parent communication about psychosocial problems will be increasingly important as primary care physicians assume their role as gatekeepers to more expensive services such as mental health interventions.     

New betaclamycin and aclarubicin analogs obtained by prolonged microbial conversion with an aclarubicin-negative mutant

Microbial conversion of beta-rhodomycinone and aklavinone using an aclarubicin-negative Streptomyces galilaeus mutant afforded new anthracycline antibiotics CG21-C and CG1-C which had a rednosyl-2-deoxyfucosyl-rhodosaminyl trisaccharide residue at C-7 of each added aglycone. They were produced only when a prolonged conversion culture took place. Because the usual conversion products containing a cinerulosyl-2-deoxyfucosyl-rhodosaminyl residue were at first accumulated and then decreased during further cultivation, it was evident that they occurred by the modification of terminal cinerulose. The isolation, purification, and structural determination are described, and cytotoxicity in vitro against cultured L1210 cells and the formation mechanism are discussed.     

Production and secretion of adrenomedullin from glial cell tumors and its effects on cAMP production

The expression of adrenomedullin (ADM) and its mRNA was studied in human glial cell tumors and cultured glioblastoma cell lines, T98G and A172. Northern blot analysis showed that ADM mRNA was expressed in all brain tumors examined (three anaplastic astrocytomas and two glioblastomas multiforme) and in the glioblastoma cell lines. Immunoreactive (IR-) ADM was detectable in these brain tumors by radioimmunoassay (0.31-2.0 pmol/g wet weight), except for one anaplastic astrocytoma. Reverse phase high performance liquid chromatography of the tumor extracts showed a single peak eluting in the position of ADM-(1-52). IR-ADM concentrations in the cultured media of T98G cells were 205.5 +/- 8.4 fmol/10(5) cells/24 h (mean +/- SEM, n = 5). Treatment of T98G cells with interferon gamma or interleukin 1 beta increased the expression levels of ADM mRNA and the IR-ADM concentrations in the cultured media, whereas tumor necrosis factor alpha decreased them in a dose-dependent manner. Treatment with synthetic ADM-(1-52) (10(-8) or 10(-7) mol/l) increased the cAMP concentrations in the cultured media of T98G cells. These findings suggest that ADM is secreted from glial cell tumors and is related to the pathophysiology of these tumors.     

Experimental study of new cerebral protective substances--functional recovery of severe, incomplete ischemic brain pretreated with mannitol and fluorocarbon emulsion-- (author's transl)

Using the "canine model of complete ischemic brain regulated with a perfusion method" in which it is possible to control the degree of blood flow to a cerebral hemisphere via a perfusion pump, the effects of mannitol (which acts as a free radical scavenger) and FC (which has 0.1 micrometer of average particle size and a high oxygen-carrying capacity) on cerebral ischemia were investigated. After pretreatment with the drugs, blood flow was reduced via the pump to 1/10 of the normal flow volume and 1 hr later, return to a normal flow was allowed. Subsequent changes in electrical activity were observed and the effects of the drugs evaluated. In the control group, no recovery of electrical activity was seen, but in the animals treated with either mannitol or FC, incomplete, yet distinct recovery was apparent. In the animals administered with mannitol together with FC, however, marked recovery was evident. These experimental results indicated that a combined administration of FC and mannitol is effective in protecting the brain from cerebral ischemia.     

Histomorphologic evaluation of Ti–13Nb–13Zr alloys processed via powder metallurgy. A study in rabbits

This study presents the in-vivo evaluation of Ti–13Nb–13Zr alloy implants obtained by the hydride route via powder metallurgy. The cylindrical implants were processed at different sintering and holding times. The implants' were characterized for density, microstructure (SEM), crystalline phases (XRD), and bulk (EDS) and surface composition (XPS). The implants were then sterilized and surgically placed in the central region of the rabbit's tibiae. Two double fluorescent markers were applied at 2 and 3 weeks, and 6 and 7 weeks after implantation. After an 8-week healing period, the implants were retrieved, non-decalcified section processed, and evaluated by electron, UV light (fluorescent labeling), and light microscopy (toluidine blue). BSE-SEM showed close contact between bone and implants. Fluorescent labeling assessment showed high bone activity levels at regions close to the implant surface. Toluidine blue staining revealed regions comprising osteoblasts at regions of newly forming/formed bone close to the implant surface. The results obtained in this study support biocompatible and osseoconductive properties of Ti–13Nb–13Zr processed through the hydride powder route.     

Optical properties of novel oxyfluoride glasses on the systems of LaF3–LaO3/2–NbO5/2 and LaF3–LaO3/2–NbO5/2–AlO3/2

Oxyfluoride glasses of xLaF₃–(60 − x)LaO_3/2–40NbO_5/2 (x = 0, 5, 10, 35) and xLaF₃–(60 − x)LaO_3/2–30NbO_5/2–10AlO_3/2 (x = 0, 10, 20, 30) were prepared using a levitation technique. Both the glass-transition temperature, T_g, and onset crystallization temperature, T_c, were lowered by substituting a part of the oxygen with fluorine in the glasses. An appropriate amount of fluorine maximized the difference between the temperatures, ΔT (= T_c − T_g), indicating the improvement in the glass-forming ability. The atomic packing densities of the glasses were approximately 60%, which gradually increased with the fluorine content. The absorption edge of the glasses shifted toward the shorter wavelength region in the ultraviolet spectra and toward the longer region in the infrared spectra by fluorine substitution. In addition, in one of the oxyfluoride glasses, a wide transparency from 307 nm to 9.2 µm was realized. Furthermore, the glass exhibited superior optical properties, with a combination of a high refractive index, n_d, of 2.020 and low wavelength dispersion, v_d, of 30.1. The effect of fluorine substitution on the n_d and its v_d was analyzed using the Lorentz–Lorenz dispersion formula.     

New Insight into the Structure–Activity Relationships of the Selective Excitatory Amino Acid Transporter Subtype 1 (EAAT1) Inhibitors UCPH‐101 and UCPH‐102

In the present study, we made further investigations on the structure–activity requirements of the selective excitatory amino acid transporter 1 (EAAT1) inhibitor, 2‐amino‐4‐(4‐methoxyphenyl)‐7‐(naphthalen‐1‐yl)‐5‐oxo‐5,6,7,8‐tetrahydro‐4H‐chromene‐3‐carbonitrile (UCPH‐101), by exploring 15 different substituents (R¹) at the 7‐position in combination with eight different substituents (R²) at the 4‐position. Among the 63 new analogues synthesized, we identified a number of compounds that unexpectedly displayed inhibitory activities at EAAT1 in light of understanding the structure–activity relationship (SAR) of this inhibitor class extracted from previous studies. Moreover, the nature of the R¹ and R² substituents were observed to contribute to the functional properties of the various analogues in additive and non‐additive ways. Finally, separation of the four stereoisomers of analogue 14 g (2‐amino‐4‐([1,1′‐biphenyl]‐4‐yl)‐3‐cyano‐7‐isopropyl‐5‐oxo‐5,6,7,8‐tetrahydro‐4H‐chromene) was carried out, and in agreement with a study of a related scaffold, the R configuration at C4 was found to be mandatory for inhibitory activity, while both the C7 diastereomers were found to be active as EAAT1 inhibitors. A study of the stereochemical stability of the four pure stereoisomers 14 g ‐ A – D showed that epimerization takes places at C7 via a ring‐opening, C?C bond rotation, ring‐closing mechanism.