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Background Microbial dysbiosis in critically ill patients is a leading cause of mortality and septic complications. Probiotics and synbiotics have emerged as novel therapy on gut microbiota to prevent septic complications. However, current evidence on their effects is conflicting. This work aims to systematically review the impact of probiotics or synbiotics in critically ill adult patients. Methods A comprehensive search of the PubMed, CBM, Embase, CENTRAL, ISI, and CNKI databases was performed to identify randomized controlled trials that evaluate probiotics or synbiotics in critically ill patients. The quality assessment was based on the modified Jadad's score scale and the Cochrane Handbook for Systematic Reviews of Interventions Version 5.0.1. The major outcome measure was mortality. Secondary outcomes included incidence of septic complications, sepsis incidence, length of intensive care unit (ICU) stay, incidence of non-septic complication, and ventilator day. Data synthesis was conduct by Review Manager 5.4. Results A total of 25 randomized controlled trials reporting on 5049 critically ill patients were included. In the intervention group, 2520 participants received probiotics or synbiotics, whereas 2529 participants received standard care or placebo. Pooling data from randomized controlled trials demonstrated a significant reduction in the incidence of ventilator-associated pneumonia (VAP) in the treatment group [(risk ratio (RR) 0.86; 95% confidence interval (CI): 0.78–0.95; p < 0.003, I2 = 85%)]. However, in the subgroup analysis, the reduction of incidence of VAP was only significant in patients receiving synbiotics (RR = 0.61, 95% CI: 0.47–0.80, p = 0.0004, I2 = 40%) and not significant in those receiving only probiotics (RR = 0.91, 95% CI: 0.82–1.01, p = 0.07, I2 = 65%). Moreover, sepsis incidence of critically ill patients was only significantly reduced by the addition of synbiotics (RR = 0.41; 95% CI: 0.22–0.72, p = 0.005, I2 = 0%). The incidence of ICU-acquired infections was significantly reduced by the synbiotics therapy (RR = 0.72; 95% CI: 0.58–0.89, p = 0.0007, I2 = 79%). There was no significant difference in mortality, diarrhea, or length of ICU stay between the treatment and control groups. Conclusions Synbiotics is an effective and safe nutrition therapy in reducing septic complications in critically ill patients. However, in such patients, administration of probiotics alone compared with placebo resulted in no difference in the septic complications.

In this article, the design, simulation, fabrication and measurement of an ultrathin and wide band radar metamaterial absorber (MMA) are introduced. The unit of the MMA consists of two different si...

In this paper, we reported on the preparation of porous materials via a reaction under Autogenic Pressure at Elevated Temperature (RAPET) at 700°Cusing natural product and alkoxides as precursors. The RAPET is a new simple efficient method to prepare inorganic materials. The porous carbon and its composite materials were prepared via the method of RAPET using natural products such as sweet potato, coriander, the absorbent cotton and viscose fiber doped by tetrabutyl titanate (TBOT) and tetraethoxysilane (TEOS). The reaction temperature of RAPET was 700°C. The carbon and its composites were studied with scanning electron microscopy (SEM), X-ray diffraction (XRD) and nitrogen adsorption-desorption measurements. The BET surface area of the materials are different from 4m2/g to 405m2/g. The XRD investigation indicates that the phases of the TiO2 in the carbon/TiO2 composites are anatase. The materials show a certain charge-discharge performance.

In this work, the influence of surfactant including the amount and the nature of the surfactant as well as alcohol solvents with different hydrocarbon chains including methanol, ethanol, 1-propanol and n-butanol on the formation of silica spheres were investigated. The morphologies and the composition of the prepared silica spheres were studied with scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR) techniques. The results revealed that the size and size distribution of the spheres can be modified by changing the concentration or the nature of the surfactant additives. The influence mechanisms of surfactants additives and the alcohol solvent on the formation of silica spheres were discussed based on nucleation and growing process of the spheres.

Carbon/TiO2 composites were prepared via the reaction under Autogenic Pressure at Elevated Temperature (RAPET) using alkoxides as precursor, and then porous TiO2 hollow spheres were derived after removing the carbon ingredient by calcination at 600°C. The influence of surfactant additives, including the addition ratio and the nature of the surfactants, on the morphology and the structures of the Carbon/TiO2 composites and the derived TiO2 were also studied with scanning electron microscopy (SEM), X-ray diffraction (XRD), UV-Vis diffuse reflectance spectrophotoscopy (DRS) and nitrogen adsorption-desorption measurements. The results revealed that the morphology of the products turned to spherical and then fusiform and the structures turned from hollow to solid with the increasing of surfactant additive. The BET surface area of the hollow TiO2 was modified from 12m2/g to 57m2/g after calcinations. The XRD investigation indicates that the phases of the TiO2 in both the carbon/TiO2 composites and the derived TiO2 hollow spheres are anatase.

The batch sorption methods were employed to investigate the sorption behavior of tetracycline (TC) on the activated sludge. It was shown that the mixed liquor suspended solids (MLSS) and the initial concentration of TC had great impacts on equilibrium time, adsorption capacity and adsorption rate. Compared with pseudo first-order model, pseudo second-order model showed the better agreement. At 10, 25 degrees C, the Langmuir model was the best isotherm to describe the experimental data for adsorption of TC on activated sludge, and the maximum adsorption capacities were 31.14, 70.95 mg x g(-1) respectively; at 40 degrees C, the linear isotherm confirmed the agreement. The data were also modeled by D-R isotherm to determine the type of adsorption. At 10 degrees C (E was 9.13 kJ x mol(-1)), the dominant type was physical, and at 40 degrees C (E was 7.07 kJ x mol(-1)), the dominant type was chemical. With the temperature increasing, the adsorption capacity increased. Ion exchange is one mechanism for adsorption of TC on activated sludge. When the initial concentrations of TC were 5, 10, 20 mg x L(-1), with the Na+ concentration increasing from 0 mol x L(-1) to 0.1 mol x L(-1), the adsorption capacities decreased by 15.32%, 15.00%, 20.12% respectively. The maximum adsorption capacity was got at pH 6 when pH varied from 5 to 10.