Application of cellulose nanocrystals in water treatment membranes: A review.

Nanomaterials have brought great changes to human society, and development has gradually shifted the focus to environmentally friendly applications. Cellulose nanocrystals (CNCs) are new one-dimensional nanomaterials that exhibit environmental friendliness and ensure the biological safety of water environment. CNCs have excellent physical and chemical properties, such as simple preparation process, nanoscale size, high specific surface area, high mechanical strength, good biocompatibility, high hydrophilicity and antifouling ability. Because of these characteristics, CNCs are widely used in ultrafiltration membranes, nanofiltration membranes and reverse osmosis membranes to solve the problems hindering development of membrane technology, such as insufficient interception and separation efficiency, low mechanical strength and poor antifouling performance. This review summarizes recent developments and uses of CNCs in water treatment membranes and discusses the challenges and development prospects of CNCs materials from the perspectives of ecological safety and human health by comparing them with traditional one-dimensional nanomaterials.

Comparison of the effect of fluticasone combined with salmeterol and fluticasone alone in the treatment of pediatric asthma.

INTRODUCTION: A systematic review and meta-analysis was performed to investigate the effect of fluticasone + salmeterol and fluticasone alone in the treatment of pediatric asthma. EVIDENCE ACQUISITION: Studies meeting specific selection criteria were selected from online databases, including Pubmed, Embase, and the Cochrane Library. The quality of randomized controlled trials was assessed using the Cochrane Library. Weighted mean difference (WMD) and 95% CI were used to evaluate the effect size of continuous variables, while rate ratio (RR) and 95% CI were used for dichotomous variables. EVIDENCE SYNTHESIS: A total of 11 studies, including 8272 pediatric asthma patients, were included in this meta-analysis. Among these, 4133 patients were in the salmeterol + fluticasone group. The changes in forced expiratory volume in 1 second in children with asthma in the salmeterol + fluticasone and fluticasone alone groups were significantly different (fixed effects model, WMD=3.26, 95% CI: 1.52-5.00, P=0.0002). Asthma exacerbation between two groups were significantly different (fixed effects model, RR=0.85, 95% CI: 0.73-0.98, Z=2.18, P=0.03). There was no difference in the incidence of adverse events between salmeterol + fluticasone and fluticasone alone in the treatment of pediatric asthma (P>0.05). When the control group was treated with double dose fluticasone, the difference of changes in FEV1 and asthma exacerbation in children with asthma between the two groups was not significant. CONCLUSIONS: The efficacy of salmeterol + fluticasone is better than fluticasone alone, and the efficacy of salmeterol + fluticasone is equal to doubling the dose of fluticasone in the treatment of pediatric asthma.