Broadband 2.4 µm superluminescent GaInAsSb/AlGaAsSb quantum well diodes for optical sensing of biomolecules.

High power, high radiance, broadband light sources emitting in the 2.0-2.5 µm wavelength range are important for optical sensing of biomolecules such as glucose in aqueous solutions. Here we demonstrate and analyze superluminescent diodes with output centered at 2.4 µm (range ~2.2-2.5 µm) from GaInAsSb/AlGaAsSb quantum wells in a separate confinement structure. Pulsed wave output of 1 mW (38 kW/cm2/sr) is achieved at room temperature for 40µm × 2mm devices. Superluminescence is evidenced in superlinear increase in emission, spectral narrowing, and angular narrowing of light output with increasing current injection. Optical output is analyzed and modeled with rate equations. Potential routes for future improvements are explored, such as additional Auger suppression and photonic mode engineering.

Hepatitis C virus infection increases hepatitis risk during anti-tuberculosis treatment.

OBJECTIVE: To study the impact of hepatitis B virus (HBV) and hepatitis C virus (HCV) co-infection on clinically significant transaminase elevation during short-course anti-tuberculosis treatment. DESIGN: Retrospective observation study. RESULTS: During standard anti-tuberculosis treatment of 295 patients with active pulmonary tuberculosis (TB) and normal baseline liver biochemical tests, 25 (8.5%) developed hepatitis and had a significantly higher mortality rate (32% vs. 7%, OR 6.22, 95%CI 2.0-17.6, P = 0.001). Multivariate analysis showed that HCV co-infected individuals were more likely to develop transaminase elevations (OR 3.43, 95%CI 1.14-10.35, P = 0.03) than those without HCV co-infection. They also had a longer duration of transaminase elevation than controls (43.3 +/- 40.4 vs. 13.5 +/- 8.6 days, P = 0.01). Co-infection with HBV was not associated with a higher rate of hepatitis but was associated with later onset (102 +/- 68.7 vs. 37.0 +/- 31.9 days, P = 0.01), higher peak alanine aminotransferase level and slower recovery (55.5 +/- 62.9 vs. 15.4 +/- 10.8 days, P = 0.01). CONCLUSION: Even with normal baseline liver biochemical tests, HCV co-infection had a higher incidence and longer exacerbations of hepatitis during anti-tuberculosis treatment. We suggest that screening for HCV infection before starting anti-tuberculosis treatment is helpful in planning the frequency of follow-up visits.

Non-tuberculous mycobacterial pleurisy: an 8-year single-centre experience in Taiwan.

OBJECTIVE: To investigate the clinical characteristics and outcomes of patients with pleurisy due to non-tuberculous mycobacteria (NTM), which are currently unclear. DESIGN: From 2000 to 2007, patients with NTM and Mycobacterium tuberculosis isolated from pleural effusion (PE) samples were identified and compared. RESULTS: Thirty-five NTM patients and 140 tuberculosis (TB) patients were reviewed. Patients with NTM pleurisy were less likely to have lung involvement and receive anti-mycobacterial treatment compared with those with tuberculous pleurisy. NTM pleurisy had a higher PE leukocyte count and a lower percentage of lymphocytes. M. avium complex (MAC) was the most common pathogen in NTM pleurisy. Patients with MAC pleurisy were younger and tended to have more extra-pleural involvement and immune dysfunction. One-year mortality in the NTM pleurisy group was 37%, and anti-NTM treatment was associated with better survival. Patients with additional diagnostic evidence were more likely to receive anti-NTM treatment. CONCLUSION: NTM pleurisy is common and has a high 1-year mortality rate. Anti-NTM treatment may provide better 1-year survival and should be considered once NTM pleurisy is diagnosed.

Use of quantitative models to design microbial transport experiments in a sandy aquifer.

A suite of numerical models was applied to the problem of designing field tracer and bacterial injection experiments in a sandy surficial aquifer near Oyster, Virginia. The models were constructed based on the integration of diverse characterization data including hydrologic, geophysical, geological, geochemical, and biological information. A one-dimensional particle-tracking model was used to analyze laboratory transport experiments conducted using intact core samples to prescribe transport parameters describing solute dispersion and bacterial fate. A geostatistical model of three-dimensional hydraulic conductivity variations was developed, conditioned on in situ measurements of hydraulic conductivity and interpretations of geophysical data, and used to generate alternative aquifer descriptions. A regional-scale, two-dimensional flow model was used to design pumping rates of a forced-gradient hydraulic control system. Information from these various models was then combined into a high-resolution, three-dimensional flow and transport model for the prediction of field-scale solute and bacterial transport. Model predictions were used in an iterative experimental design process to specify: (1) the locations of multilevel samplers for monitoring transport; (2) frequency and timing of sample collection during bromide tracer injection experiments; and (3) frequency and timing of sample collection during a bacterial injection experiment. At each stage of the design, information gained during the previous stage was used to refine the model and target subsequent experimentation.