Wavelength and pulse duration tunable ultrafast fiber laser mode-locked with carbon nanotubes.

Ultrafast lasers with tunable parameters in wavelength and time domains are the choice of light source for various applications such as spectroscopy and communication. Here, we report a wavelength and pulse-duration tunable mode-locked Erbium doped fiber laser with single wall carbon nanotube-based saturable absorber. An intra-cavity tunable filter is employed to continuously tune the output wavelength for 34 nm (from 1525 nm to 1559 nm) and pulse duration from 545 fs to 6.1 ps, respectively. Our results provide a novel light source for various applications requiring variable wavelength or pulse duration

Gut microbiota and cardiac arrhythmia

One of the most prevalent cardiac diseases is cardiac arrhythmia, however the underlying causes are not entirely understood. There is a lot of proof that gut microbiota (GM) and its metabolites have a significant impact on cardiovascular health. In recent decades, intricate impacts of GM on cardiac arrythmia have been identified as prospective approaches for its prevention, development, treatment, and prognosis. In this review, we discuss about how GM and its metabolites might impact cardiac arrhythmia through a variety of mechanisms. We proposed to explore the relationship between the metabolites produced by GM dysbiosis including short-chain fatty acids(SCFA), Indoxyl sulfate(IS), trimethylamine N-oxide(TMAO), lipopolysaccharides(LPS), phenylacetylglutamine(PAGln), bile acids(BA), and the currently recognized mechanisms of cardiac arrhythmias including structural remodeling, electrophysiological remodeling, abnormal nervous system regulation and other disease associated with cardiac arrythmia, detailing the processes involving immune regulation, inflammation, and different types of programmed cell death etc., which presents a key aspect of the microbial-host cross-talk. In addition, how GM and its metabolites differ and change in atrial arrhythmias and ventricular arrhythmias populations compared with healthy people are also summarized. Then we introduced potential therapeutic strategies including probiotics and prebiotics, fecal microbiota transplantation (FMT) and immunomodulator etc. In conclusion, the GM has a significant impact on cardiac arrhythmia through a variety of mechanisms, offering a wide range of possible treatment options. The discovery of therapeutic interventions that reduce the risk of cardiac arrhythmia by altering GM and metabolites is a real challenge that lies ahead

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Photoluminescence Investigation of Porous Anodic Alumina Films

International audienc

Sleep disorder, Mediterranean diet, and all-cause and cause-specific mortality: a prospective cohort study

Abstract Background There is a bidirectional effect between sleep disorders and Mediterranean diet (MED), but the joint effect of MED and sleep disorders on mortality is unclear. The aim of this study was to investigate whether there is a synergistic effect of adherence to MED and sleep disorders on all-cause and cause-specific mortality. Methods The study included 23,212 individuals in the National Health and Nutrition Examination Survey (NHANES) from 2005 to 2014. A 9-point evaluation score, alternative Mediterranean diet (aMED) index was used to assess adherence to MED. Sleep disorder and hours of sleep were assessed by structured questionnaires. Cox regression models were used to assess the relationship between sleep disorders, aMED and all-cause mortality, cause-specific mortality (cardiovascular-related death, cancer-related death). The interaction effect of sleep disorders with aMED on mortality was further assessed. Results Results showed that participants with lower aMED and presence of sleep disorders had significantly higher risk of all-cause mortality and cardiovascular-related mortality (HR, 2.16, 95% CI, 1.49–3.13, P < 0.0001; HR, 2.68, 95% CI, 1.58–4.54, P = 0.0003). A significant interaction effect was found between aMED and sleep disorders on cardiovascular mortality (p for interaction = 0.033). No significant interaction existed between aMED and sleep disorders on all-cause mortality (p for interaction = 0.184) and cancer-related mortality (p for interaction = 0.955). Conclusions Poorer adherence to MED and sleep disorders synergistically increased long-term all-cause mortality and cardiovascular mortality in NHANES population