Gas chromatography using a spin-coated stationary phase and a molded elastomer micro-channel.

Many different designs of microfabricated gas chromatography columns have recently been proposed and demonstrated. These designs either incorporate a stationary phase directly into the device which limits the versatility of the column as a separator, or require coating, which presents its own problems with determining the proper conditions for each different stationary phase a user may need. Here, we present a new approach: Uniformly spin coating a flat surface with the stationary phase and creating a column by pressing a lid, with micro-fabricated ridges, down onto the coated substrate. The lids are molded using commercially available epoxies so that when pressed onto a flat surface they create an airtight seal. The epoxy material is rendered inert by a thin layer of gold. We describe the fabrication and initial results from a standard, OV-1, stationary phase as proof of concept.

The effects of policy actions to improve population dietary patterns and prevent diet-related non-communicable diseases: scoping review.

Poor diet generates a bigger non-communicable disease (NCD) burden than tobacco, alcohol and physical inactivity combined. We reviewed the potential effectiveness of policy actions to improve healthy food consumption and thus prevent NCDs. This scoping review focused on systematic and non-systematic reviews and categorised data using a seven-part framework: price, promotion, provision, composition, labelling, supply chain, trade/investment and multi-component interventions. We screened 1805 candidate publications and included 58 systematic and non-systematic reviews. Multi-component and price interventions appeared consistently powerful in improving healthy eating. Reformulation to reduce industrial trans fat intake also seemed very effective. Evidence on food supply chain, trade and investment studies was limited and merits further research. Food labelling and restrictions on provision or marketing of unhealthy foods were generally less effective with uncertain sustainability. Increasingly strong evidence is highlighting potentially powerful policies to improve diet and thus prevent NCDs, notably multi-component interventions, taxes, subsidies, elimination and perhaps trade agreements. The implications for policy makers are becoming clearer.

Trace gas absorption spectroscopy using functionalized microring resonators.

We detect trace gases at parts-per-billion levels using evanescent-field absorption spectroscopy in silicon nitride microring resonators coated with a functionalized sorbent polymer. An analysis of the microring resonance line shapes enables a measurement of the differential absorption spectra for a number of vapor-phase analytes. The spectra are obtained at the near-infrared overtone of OH-stretch resonance, which provides information about the toxicity of the analyte vapor.

Cancer chemotherapy administered via hemodialysis fistulas.

End-stage renal failure (ESRF) patients can develop cancer before or after kidney disease occurs. Cancer chemotherapy often needs to be administered via the sort of central venous catheter that is normally avoided in ESRF care. Three cases are presented in which ESRF patients received chemotherapy for cancer via existing hemodialysis fistulas, and the consequences of central venous access in a fourth patient are discussed.

Statistical analysis of Salmonella test data and comparison to results of animal cancer tests.

A quantitative framework for the analysis of results of the Salmonella (Ames) test is presented, and the relationship between mutagenesis and carcinogenesis is examined. Color graphics are used for the Salmonella data to describe variability, and trends across multiple chemicals and test conditions. Positivity in the Salmonella test, using statistical criteria to classify results, is compared to positivity in carcinogenesis bioassays for 48 chemicals tested in NCI/NTP-sponsored programs. Sensitivity of the Salmonella test across 5 tester strains was 91% (21/23), while specificity was only 36% (9/25). Results were most concordant for TA100 Aroclor-induced rat S9: sensitivity was 87%, specificity 64%. The correlation of mutagenic potency and carcinogenic potency was 0.41 (p less than 0.001) for 80 chemicals, using results from both the general published literature and the NCI/NTP-sponsored programs. After removal of 3 extreme values, the correlation was 0.24 (p = 0.04).