Selective decontamination of the digestive tract: all questions answered?

Although many studies have shown beneficial effects of SDD on the incidence of respiratory tract infections, SDD did not become routine practice because mortality reduction was not demonstrated in individual trials, beneficial effects on duration of ventilation, ICU stay or hospital stay were not demonstrated, cost-efficacy had not been demonstrated, and selection of antibiotic resistance was considered a serious side-effect. A recent study has now shown improved patient survival and lower prevalence of antibiotic resistance in patients receiving SDD. Why could this study show mortality reduction, where all others studies had failed before? And do the microbiological data unequivocally prove protective effects of SDD on emergence of antibiotic resistance? Interestingly, the reported mortality reductions exceeds even the most optimistic predictions from previous meta-analyses, but a clear explanation is not yet evident. The data on antibiotic resistance, however, are rather superficial and do not allow to interpret the underlying epidemiological dynamics. Therefore, the recent findings are provocative and shed new light on the SDD issue, warranting studies confirming its beneficial effects but also addressing several important aspects related to study design

Triplet-Singlet Spin Relaxation via Nuclei in a Double Quantum Dot

The spin of a confined electron, when oriented originally in some direction, will lose memory of that orientation after some time. Physical mechanisms leading to this relaxation of spin memory typically involve either coupling of the electron spin to its orbital motion or to nuclear spins. Relaxation of confined electron spin has been previously measured only for Zeeman or exchange split spin states, where spin-orbit effects dominate relaxation, while spin flips due to nuclei have been observed in optical spectroscopy studies. Using an isolated GaAs double quantum dot defined by electrostatic gates and direct time domain measurements, we investigate in detail spin relaxation for arbitrary splitting of spin states. Results demonstrate that electron spin flips are dominated by nuclear interactions and are slowed by several orders of magnitude when a magnetic field of a few millitesla is applied. These results have significant implications for spin-based information processing

Comparison of Crocus sativus L. and imipramine in the treatment of mild to moderate depression: A pilot double-blind randomized trial [ISRCTN45683816]

BACKGROUND: The morbidity and mortality associated with depression are considerable and continue to increase. Depression currently ranks fourth among the major causes of disability worldwide, after lower respiratory infections, prenatal conditions, and HIV/AIDS. Crocus sativus L. is used to treat depression. Many medicinal plants textbooks refer to this indication whereas there is no evidence-based document. Our objective was to compare the efficacy of stigmas of Crocus sativus (saffron) with imipramine in the treatment of mild to moderate depression in a 6-week pilot double-blind randomized trial. METHODS: Thirty adult outpatients who met the Diagnostic and Statistical Manual of Mental Disorders, 4(th )edition for major depression based on the structured clinical interview for DSM IV participated in the trial. Patients have a baseline Hamilton Rating Scale for Depression score of at least 18. In this double-blind, single-center trial, patients were randomly assigned to receive capsule of saffron 30 mg/day (TDS) (Group 1) and capsule of imipramine 100 mg/day (TDS) (Group 2) for a 6-week study. RESULTS: Saffron at this dose was found to be effective similar to imipramine in the treatment of mild to moderate depression (F = 2.91, d.f. = 1, P = 0.09). In the imipramine group anticholinergic effects such as dry mouth and also sedation were observed more often that was predictable. CONCLUSION: The main overall finding from this study is that saffron may be of therapeutic benefit in the treatment of mild to moderate depression. To the best of our knowledge this is the first clinical trial that supports this indication for saffron. A large-scale trial with placebo control is warranted

The Escherichia coli transcriptome mostly consists of independently regulated modules

Underlying cellular responses is a transcriptional regulatory network (TRN) that modulates gene expression. A useful description of the TRN would decompose the transcriptome into targeted effects of individual transcriptional regulators. Here, we apply unsupervised machine learning to a diverse compendium of over 250 high-quality Escherichia coli RNA-seq datasets to identify 92 statistically independent signals that modulate the expression of specific gene sets. We show that 61 of these transcriptomic signals represent the effects of currently characterized transcriptional regulators. Condition-specific activation of signals is validated by exposure of E. coli to new environmental conditions. The resulting decomposition of the transcriptome provides: a mechanistic, systems-level, network-based explanation of responses to environmental and genetic perturbations; a guide to gene and regulator function discovery; and a basis for characterizing transcriptomic differences in multiple strains. Taken together, our results show that signal summation describes the composition of a model prokaryotic transcriptome