A micromechanical biosensor with interdigitated capacitor readout

The growing demands of high-throughput, accurate and fast response biological or chemical sensors are driving the development of new detection technologies. This paper presents a micromechanical biosensor with capacitive read-out method. The proposed biosensor design consists of a fixed-fixed beam attached to an interdigitated capacitor. Implementation of the interdigitated capacitor design improves the sensitivity of the biosensor. The effects of the electrode thickness, length and the number of electrode fingers on the change of capacitance are investigated. The results show that the percentage change of capacitance is proportional to the number of the electrode fingers. Similarly, the increase in the length of the electrodes results in an increase in the percentage change of the capacitance. However, as the thickness of the electrode increases, the percentage change of the capacitance decreases.

N-Acetyl cysteine as a glutathione precursor for schizophrenia : a double blind, randomized, placebo-controlled trial

Background: Brain glutathione levels are decreased in schizophrenia, a disorder that often is chronic and refractory to treatment. N-acetyl cysteine (NAC) increases brain glutathione in rodents. This study was conducted to evaluate the safety and effectiveness of oral NAC (1 g orally twice daily [b.i.d.]) as an add-on to maintenance medication for the treatment of chronic schizophrenia over a 24-week period.

Methods: A randomized, multicenter, double-blind, placebo-controlled study. The primary readout was change from baseline on the Positive and Negative Symptoms Scale (PANSS) and its components. Secondary readouts included the Clinical Global Impression (CGI) Severity and Improvement scales, as well as general functioning and extrapyramidal rating scales. Changes following a 4-week treatment discontinuation were evaluated. One hundred forty people with chronic schizophrenia on maintenance antipsychotic medication were randomized; 84 completed treatment.

Results: Intent-to-treat analysis revealed that subjects treated with NAC improved more than placebo-treated subjects over the study period in PANSS total [5.97 (10.44, 1.51), p .009], PANSS negative [mean difference 1.83 (95% confidence interval: 3.33, .32), p .018], and PANSS general [2.79 (5.38, .20), p .035], CGI-Severity (CGI-S) [.26 (.44,.08), p .004], and CGI-Improvement (CGI-I) [.22 (.41, .03), p .025] scores. No significant change on the PANSS positive subscale was seen. N-acetyl cysteine treatment also was associated with an improvement in akathisia (p .022). Effect sizes at end point were consistent with moderate benefits.

Conclusions: These data suggest that adjunctive NAC has potential as a safe and moderately effective augmentation strategy for chronic schizophrenia.

Photochromic fabrics with improved durability and photochromic performance

Previously, we have reported a method for producing photochromic wool fabric by applying a thin layer of hybrid silica-photochromic dye onto the wool surface. While the photochromic coating showed a very fast optical response and had little influence on the fabric handle, its durability was poor. In this study, the durability of the photochromic coating layer was improved by introducing epoxy groups into the silica matrix via co-hydrolysis and co-condensation of an alkyl trialkoxysilane compound (ATAS) and 3-glycidoxypropyltrimethoxysilane (GPTMS). The presence of epoxy groups in the silica enhanced both washing and abrasion durability or fastness. In addition, the optical response speed was slightly increased as well. Effects of the type of alkyl silane and the GPTMS/alkyl silane ratio on the coating durability, fabric handle and optical response were examined.

Metabolite profiling reveals distinct changes in carbon and nitrogen metabolism in phosphate-deficient barley plants (Hordeum vulgare L.)

Plants modify metabolic processes for adaptation to low phosphate (P) conditions. Whilst transcriptomic analyses show that P deficiency changes hundreds of genes related to various metabolic processes, there is limited information available for global metabolite changes of P-deficient plants, especially for cereals. As changes in metabolites are the ultimate ‘readout’ of changes in gene expression, we profiled polar metabolites from both shoots and roots of P-deficient barley (Hordeum vulgare) using gas chromatography–mass spectrometry (GC-MS). The results showed that mildly P-deficient plants accumulated di- and trisaccharides (sucrose, maltose, raffinose and 6-kestose), especially in shoots. Severe P deficiency increased the levels of metabolites related to ammonium metabolism in addition to di- and trisaccharides, but reduced the levels of phosphorylated intermediates (glucose-6-P, fructose-6-P, inositol-1-P and glycerol-3-P) and organic acids (α-ketoglutarate, succinate, fumarate and malate). The results revealed that P-deficient plants modify carbohydrate metabolism initially to reduce P consumption, and salvage P from small P-containing metabolites when P deficiency is severe, which consequently reduced levels of organic acids in the tricarboxylic acid (TCA) cycle. The extent of the effect of severe P deficiency on ammonium metabolism was also revealed by liquid chromatography–mass spectrometry (LC-MS) quantitative analysis of free amino acids. A sharp increase in the concentrations of glutamine and asparagine was observed in both shoots and roots of severely P-deficient plants. Based on these data, a strategy for improving the ability of cereals to adapt to low P environments is proposed that involves alteration in partitioning of carbohydrates into organic acids and amino acids to enable more efficient utilization of carbon in P-deficient plants.