Calculation of photon and current fluctuations in traveling-wavesemiconductor laser amplifiers

The noise properties of semiconductor laser amplifiers are calculated using the Heisenberg equations of motion. Photon noise as well as the recombination current noise are calculated with this formalism, and agreement with previously published results was found for the photon noise. The formalism also gave the conventional current shot noise in the appropriate limits, e.g., when using the amplifier reverse-biased as a detector. The method gives reasonable agreement with reported experimental results and the results for the current noise could be given a consistent physical explanation. Some concluding remarks concerning the relationship with the Langevin approach and the possibilities of minimizing the noise are given     

Fabrication of Glass Matrix Composites by Tape Casting

A method has been developed to fabricate borosilicate glass matrix composites reinforced with monofilament SiC fibers by tape casting. Green matrix tapes are laminated with fiber mats of a uniform fiber spacing. The resulting laminate is sintered at 710°C to >98% relative density and HIP-consolidated to full density. The final specimens contain a high volume fraction of fibers (>35 vol%) in a uniform array. A variation of this technique can be used to mount "microcomposites" (i.e., coated fibers) in a glass matrix to facilitate fabrication of push-out test specimens.     

Pharmacokinetics of ceftiofur and metabolites after single intravenous and intramuscular administration and multiple intramuscular administrations of ceftiofur sodium to dairy goats

Twelve (12) lactating dairy goats (46-71 kg body wt at study initiation) were divided into four treatment groups and dosed with ceftiofur sodium at 1.1 mg ceftiofur free acid equivalents (CFAE)/kg or 2.2 CFAE/kg using a complete two route (intravenous, i.v.; intramuscular, i.m.), two-period crossover design, with a 2-week washout between injections. After another 2-week washout period, the goats were dosed with ceftiofur sodium i.m. for 5 consecutive days at either 1.1 or 2.2 mg CFAE/kg. The goats from the 2.2 mg/kg multiple dose group were dried off and the i.v. kinetic study repeated. After all injections, blood samples were obtained serially for determination of combined serum concentrations of ceftiofur and metabolites. After intravenous doses of 1.1 and 2.2 mg/kg, the harmonic means of the terminal phase half-lives were 171.8 and 233 min, respectively, for lactating does. The harmonic mean of the terminal phase half-life after an i.v. dose of 2.2 mg/kg in non-lactating does was 254 min. The AUC0-infinity was significantly less and the clearance significantly greater during lactation. After i.m. doses of 1.1 and 2.2 mg/kg, the harmonic mean terminal phase half-lives were 163 and 156 min, respectively. The i.m. bioavailability of ceftiofur sodium in goats was 100%, and the AUC0-infinity was dose-proportional from 1.1-2.2 mg CFAE/kg body weight. After five daily i.m. doses of ceftiofur sodium at either 1.1 or 2.2 mg CFAE, there was minimal accumulation of drug in serum as assessed by Cmax, and serum concentrations were dose-proportional after the multiple dosing regimen.     

Isolation, primary sequence determination, and disulfide bond structure of cyanovirin-N, an anti-HIV (human immunodeficiency virus) protein from the cyanobacterium Nostoc ellipsosporum

PURPOSE: To determine if portal setup films are an accurate representation of a patient's position throughout the course of fractionated tangential breast irradiation. METHODS AND MATERIALS: Thirteen patients undergoing external beam irradiation for T1-T2 infiltrating ductal carcinoma of the breast following excisional biopsy and axillary dissection were imaged using an on-line portal imaging device attached to a 6 MV linear accelerator. Medial and lateral tangential fields were imaged and a total of 139 fractions, 225 portal fields, and 4450 images were obtained. Interfractional and intrafractional variations for anatomical parameters including the central lung distance (CLD), central flash distance (CFD), and inferior central margin (ICM) were calculated from these images. A pooled estimate of the random error associated with a given treatment was determined by adding the interfractional and intrafractional standard deviations in quadrature. A 95% confidence level assigned a value of two standard deviations of the random error estimate. Central lung distance, CFD, and ICM distances were then measured for all portal setup films. Significant differences were defined as occurring when the simulation-setup difference was greater than the 95% confidence value. RESULTS: Differences between setup portal and simulation films were less than their 95% confidence values in 70 instances indicating that in 90% of the time these differences are a result of random differences in daily treatment positioning. CONCLUSIONS: In 90% of cases tested, initial portal setup films are an accurate representation of a patients daily treatment setup.     

Women's responses to young infants' cries.

Women's caregiving and perceptual responses to young infants' cries were assessed as a function of parity and cry cause. Ss cared for a crying infant manikin in a simulated baby-sitting situation. Mothers and nonmothers were quite similar in basic features of their caregiving behaviors, suggesting that the effects of parity may be to fine-tune skills that many women bring to the task of caring for young infants. The specific cause of the cry (hunger or pain) was associated with few differences in caregiving behavior, even though a subsequent perceptual task showed that Ss reliably discriminated the two cries. Further analyses of the perceptual data indicated that cry sounds communicate information about the general distress level of the infant better than information about specific causes. Thus, although the sound of the cry may inform caregivers about overall distress level, caregiving behaviors appear to be determined by additional factors. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

走向天堂

我们必须打理好自家花园,照顾好自己。 “走向天堂”是第11届威尼斯建筑双年展上展出的一个小园林,它激发人们的想象力,探寻家庭花园的维护方法。在理想世界里,人们需要智慧以及寻求智慧的欲望来照顾好自己的生活。法语“Jardin Secret”（花园秘密）是每个人私密和受保护的那部分灵魂。     

Comparison of microstructural and physical properties of two petroleum waxes

Microstructural and physical properties of two petroleum waxes, petrolatum and microcrystalline wax, were characterized in this work. Petroleum waxes are known to be hydrophobic and can be used in applications where a good moisture barrier is needed. In order to achieve a better understanding of different inherent properties of a wax, the two waxes in this work were characterized with infrared spectroscopy, confocal laser scanning microscopy, differential scanning calorimetry, rheology and X-ray diffraction. It was concluded from the results of infrared spectroscopy that the two waxes consisted only of saturated alkanes. Confocal laser scanning microscopy showed that the petrolatum sample had a more open microstructure with coarse crystals separated from each other than the microcrystalline wax, which appeared to have a more network-like crystalline structure consisting of somewhat finer crystals. Both waxes crystallized over a broad temperature range. Their crystallization characteristics were quite different, however, probably owing to a different oil content. According to modulated differential scanning calorimetry and rheological measurements the microcrystalline wax crystallized through a two-step process, whereas the petrolatum crystallized through only one step.     

A high-speed GaAs MESFET optical controller

Optical interconnects are being considered for control signal distribution in phased array antennas. A packaged hybrid GaAs optical controller with a 1:16 demultiplexed output that is suitable for this application is described. The controller, which was fabricated using enhancement/depletion mode MESFET technology, operates at demultiplexer-limited input data rates up to 305 Mb/s and requires less than 200 μW optical input power     

Evaluation of the thermodynamic properties of tungsten

A new evaluation of the thermodynamic properties of tungsten has been made. A set of parameters describing the Gibbs energy of each individual phase as a function of temperature and pressure is given. The experimental information on the P, T phase diagram and the thermodynamic data are compared with calculations made using the presented set of parameters.     

A Facile Cyclization Method Improves Peptide Serum Stability and Confers Intrinsic Fluorescence

Peptides are a growing class of macromolecules used in pharmaceutics. The path toward the clinical use of candidate peptides involves sequence optimization and cyclization for stability and affinity. For internalized peptides, tagging is also often required for intracellular trafficking studies, although fluorophore conjugation has an impact on peptide binding, permeability, and localization. Herein, a strategy based on cysteine arylation with tetrafluoroterephthalonitrile (4F‐2CN), which simultaneously cyclizes peptides and imparts fluorescence, is reported. The 4F‐2CN cyclization of an M2 macrophage‐targeting peptide yields, in a single step, a peptide with improved serum stability, intrinsic fluorescence, and increased binding affinity. In a murine breast cancer model, it is demonstrated that the intrinsic fluorescence from the cyclized peptide is sufficient for monitoring biodistribution by whole‐organ fluorescence imaging and cell internalization by flow cytometry.