Patient preference for self-collected cultures for group B streptococcus in pregnancy

The purpose of this study was to examine the factors which affect the level of fatigue among patients participating in clinical trials in which this symptom had been assessed with the EORTC QLQ-C30. Data were assembled from 2390 patients in ten clinical trials in which the QLQ-C30 had been used to assess baseline and on-study quality of life. The relationship between the level of fatigue reported by the patients on the fatigue scale of this questionnaire and patient and disease characteristics was assessed in univariate and multivariate cross-sectional analyses. In addition, changes in fatigue scores were compared in a longitudinal analysis among patients on two arms of an anti-emetic trial whose emesis control was markedly different. Baseline fatigue levels differed substantially among patients taking part in the different trials. Factors associated with greater fatigue severity on univariate analysis included: female gender, presence of metastatic disease, and poorer performance status. In addition, on multivariate analyses the oldest patients were found to have less fatigue, as were patients with breast cancer, while patients with ovarian and lung cancer experienced greater fatigue. Patients on the arm of the anti-emetic trial in which emesis was better controlled showed significantly less increase in fatigue after receiving chemotherapy. The fatigue scale of the QLQ-C30 appears to provide a useful approach to assessing this important symptom. The relationships found between fatigue and patient and disease characteristics need further exploration as does the degree to which the QLQ-C30 fully captures this dimension of quality of life.     

Housing Tenure: Pacific Families in New Zealand

Home ownership has been associated with health, social and economic benefits. However, a decline in ownership has been observed over the past decade in New Zealand. Minority groups, including Pacific people, have been disadvantaged in the housing sector. This study investigated housing tenure and the relationship between tenure and health among mothers of a birth cohort of Pacific children in New Zealand. Findings showed that most families lived in state or private rental accommodation with few (15.4 per cent) owning their own homes. Homeowners were more likely to be older, partnered and have higher incomes. Better mental health was observed for homeowners compared to renters. Findings can inform housing and public health policy for Pacific families.     

p-ANCA target antigens in ulcerative colitis

Isolated hearts from two strains of rats bred for sensitivity or resistance to amygdala kindling that also exhibit, in vivo, differential sensitivity to the cardiotoxicity of cocaine were studied. The goal was to determine if the differential cardiotoxic sensitivity was due, at least in part, to intrinsic strain-dependent differences in the heart. The Langendorff preparation was used (n=8 per strain). Hearts were perfused with increasing concentrations of cocaine (5 x 10(-6), 1 x 10(-5), 5 x 10(-5), 1 x 10(-4), and 5 x 10(-4) M) for 5 min with a 5 min washout between exposure to successive concentrations. Consistent with in vivo observations, hearts from genetically slow amygdala kindling rats (Slow) required lower cocaine doses to develop cardiac arrhythmias and arrest as compared to the hearts from genetically fast amygdala kindling rats (Fast). At 5 x 10(-5) M cocaine arrhythmias occurred in 38% (3/8) Slow and 0% Fast hearts. Five of 8 Slow hearts and none of 8 Fast hearts were arrested by 10(-4) M cocaine. Arrest in Fast hearts occurred only with 5 x 10(-4) M cocaine. Cocaine constricted coronary arteries (no significant difference between strains). On the other hand, coronary arteries of Slow but not Fast hearts dilated during cocaine washout after perfusion with all but the highest concentration of cocaine. We conclude that factors intrinsic to the heart and coronary artery influence the sensitivity or response of these structures to cocaine.     

A new GaAs power MESFET structure for improved power capabilities

A GaAs microwave power MESFET structure is described that achieves a significant improvement of the gate mode attenuation by incorporating a suitably terminated transmission line parallel to the gate. The reduced attenuation allows a much wider single gate (a factor of 4 is possible) and a corresponding improvement of the total output power. It is shown that this approach leads to higher gain and cutoff frequency. An additional advantage of this MESFET structure is its higher input resistance relative to a device with equal total gate width but more gates in parallel. This results in simpler matching circuits of greater bandwidth. The single-gate structure can be connected in parallel to further increase the total output power. The results of an electrical characterization of the devices are presented, and its advantages and potential application are discussed     

High-power 980 nm quantum dot broad area lasers

High-power quantum dot broad area lasers emitting at 980 nm are presented. Continuous-wave output powers of 4.3 W from a 50 /spl mu/m stripe width laser and of 6.3 W from a 100 /spl mu/m stripe width laser were achieved at 15/spl deg/C     

Effects of chemical and plasma surface treatments on the O2-annealed Ni/Au contact to p-Gan

The effects of boiling Aqua Regia (AQ), N₂/Cl₂ plasma followed by AQ and O₂ plasma followed by AQ surface treatments prior to Ni/Au (20 nm/20 nm) metallization to p-GaN:Mg (∼ 3 × 10¹⁷ cm^− 3) have been investigated. N₂/Cl₂ plasma was employed in a bid to lower the Ga/N and O/Ga ratios of the GaN surface to improve the contact properties to p-GaN, while O₂ plasma was employed as an alternative to incorporate O into the Ni/Au system. Results show that a low Ga/N ratio does not necessarily correspond to a better contact. The positive effect of O₂ over N₂ anneal is observed only for the AQ-treated sample, although the mechanisms responsible for its positive effect: NiO formation and Ni/Au layer-reversal were observed for all O₂-annealed contacts. We conclude that the effect of O₂ anneal on the Ni/Au contact is dependant on the p-GaN surface prior to metallization.     

10W continuous-wave monolithically integrated master-oscillator power-amplifier

A semiconductor-based master-oscillator power-amplifier operating at 977 nm is demonstrated to emit more than 10 W continuous wave in a nearly diffraction limited beam with a narrow spectral bandwidth. The device consists of a distributed Bragg reflector laser and a flared amplifier monolithically integrated on a single chip     

Energy storage devices for future hybrid electric vehicles

Powertrain hybridization as well as electrical energy management are imposing new requirements on electrical storage systems in vehicles. This paper characterizes the associated vehicle attributes and, in particular, the various levels of hybrids. New requirements for the electrical storage system are derived, including: shallow-cycle life, high dynamic charge acceptance particularly for regenerative braking and robust service life in sustained partial-state-of-charge usage. Lead/acid, either with liquid or absorptive glass-fibre mat electrolyte, is expected to remain the predominant battery technology for 14 V systems, including micro-hybrids, and with a cost-effective battery monitoring system for demanding applications. Advanced AGM batteries may be considered for mild or even medium hybrids once they have proven robustness under real-world conditions, particularly with respect to cycle life at partial-states-of-charge and dynamic charge acceptance. For the foreseeable future, NiMH and Li-ion are the dominating current and potential battery technologies for higher-functionality HEVs. Li-ion, currently at development and demonstration stages, offers attractive opportunities for improvements in performance and cost. Supercapacitors may be considered for pulse power applications. Aside from cell technologies, attention to the issue of system integration of the battery into the powertrain and vehicle is growing. Opportunities and challenges for potential “battery pack” system suppliers are discussed.     

Apparent thermal conductivity of evacuated SiO2-aerogel tiles under variation of radiative boundary conditions

The apparent thermal conductivity λ of evacuated SiO₂-aerogel tiles was measured with our small guarded hot plate vacuum system LOLA II. In order to study the influence of the boundary emissivity on λ the plates (20 × 20 cm²) were either used with their plasma-sprayed surfaces ( ≈ 0.5) or with low-emissivity aluminum ( ≈ 0.05) foils as covers. The difference in the apparent conductivity already showed at room temperature and rose to about 50% for radiative temperatures T_r = 570 K. An important consequence is that superinsulating SiO₂-aerogel systems should always be provided with low-emissivity boundaries around the aerogel. The calorimetric results for λ are compared with radiative conductivity values derived from spectral i.r. transmission measurements.     

Carbon Aerogels as Electrode Material in Supercapacitors

Due to their large specific surface area and their high electrical conductivity carbon aerogels are promising materials for electrodes in electrochemical double-layer capacitors (supercapacitor). The carbon aerogels were made via pyrolysis of resorcinol formaldehyde aerogels. The latter were prepared by supercritical and subcritical drying as well. The important findings of our investigation were, that the highest capacities of 46 F/cm³ were measured for samples with a density of about 800 kg/m³ pyrolyzed at 800°C. Also it was shown that RF-gels with molar resorcinol/catalyst ratios 1000 or higher can be dried subcritically without cracking or significant shrinkage. Carbon aerogels derived from these RF-aerogels have a small mesopore surface area, however an especially large micropore area. They provide electrical capacities which are most suitable for their use in supercapacitors.