49 research outputs found
Traditional Chinese medicine for smoking cessation: An umbrella review of systematic reviews and meta-analysis of randomized controlled trials.
Traditional Chinese medicine (TCM) may have special advantages in facilitating smoking cessation, but consensus on effectiveness is lacking. We aim to comprehensively review, update, and refine current evidence on TCM effectiveness and safety. Nine databases were searched from their inception up to 28 February 2023. Systematic reviews (SRs) and meta-analysis of TCM for smoking cessation were identified and retrieved. Additional databases and hand searches of RCTs from included SRs were performed for data pooling. Cochrane ROB tools and AMSTAR-2 were used to evaluate the methodological quality of RCTs and SRs, respectively. RCT data are presented as relative risks (RR) or mean differences (MD) with 95% confidence intervals (CI) using RevMan 5.4. Thirteen SRs involving 265 studies with 33081 participants were included. Among these 265 studies, 157 were duplicates (58.36%) and 52 were non-RCTs (19.62%). Combined with the remaining 56 RCTs identified through hand searches, 88 RCTs involving 12434 participants were finally included for data synthesis. All the SRs focused on acupoint stimulation, and the majority were of low or very low quality. The methodological quality of RCTs was either unclear or high risk. For continuous abstinence rate, TCM external interventions were better than placebo in 6 months to 1 year (RR=1.60; 95% CI: 1.14-2.25; I =27%; n=5533 participants). Compared with placebo, TCM external application was effective in reducing nicotine withdrawal symptoms, and the effect was gradually stable and obvious in the fourth week (MD= -4.46; 95% CI: -5.43 - -3.49; n=165 participants). Twelve RCTs reported adverse events as outcome indicators for safety evaluation, and no serious adverse events occurred. Despite the methodological limitations of the original studies, our review suggests that TCM intervention shows potential effectiveness on the continuous abstinence rate. Extending the intervention time can enhance the effect of TCM on nicotine withdrawal symptoms. Referred to adverse events, more data for safety evaluation are required. [Abstract copyright: © 2023 Lu CL. et al.
Liquid flame spray fabrication of polyimide-copper coatings for antifouling applications
Liquid flame sprayed polyimide-copper coatings were developed for marine antifouling applications. Mixture of polyimide precursor and copper particles was prepared as the starting feedstock for making the composite coatings. Synthesis of polyimide was achieved during the spraying and polyimide acts as binder to fix copper particles. Copper particles were enwrapped by polyimide matrix and distribute evenly in the coatings. Further electrochemical testing revealed excellent corrosion resistance of the coatings in artificial seawater. The coatings resist effectively colonization of E. coli and Bacillus sp. bacteria on their surfaces, suggesting their remarkable antifouling performances. The results shed light on construction of polymer-based antifouling layers for widespread marine applications. (C) 2017 Elsevier B.V. All rights reserved
Suspension Flame Spray Construction of Polyimide-Copper Layers for Marine Antifouling Applications
Individual capsule-like polyimide splats have been fabricated by suspension flame spray, and the polyimide splat exhibits hollow structure with an inner pore and a tiny hole on its top surface. Enwrapping of 200-1000-nm copper particles inside the splats is accomplished during the deposition for constrained release of copper for antifouling performances. Antifouling testing of the coatings by 24-h exposure to Escherichia coli-containing artificial seawater shows that the Cu-doped splat already prohibits effectively attachment of the bacteria. The prohibited adhesion of bacteria obviously impedes formation and further development of bacterial biofilm. This capsulated splat with releasing and loading of copper biocides results in dual-functional structures bearing both release-killing and contact-killing mechanisms. The suspension flame spray route and the encapsulated structure of the polyimide-Cu coatings would open a new window for designing and constructing marine antifouling layers for long-term applications
Construction of mechanically durable superhydrophobic surfaces by thermal spray deposition and further surface modification
Here we report a simple and cost-effective technical route for constructing superhydrophobic surfaces with excellent abrasion resistance on various substrates. Rough surface structures were fabricated by thermal spray deposition of a variety of inorganic materials, and further surface modification was made by applying a thin layer of polytetrafluoroethylene. Results show that the Al, Cu, or NiCrBSi coatings with the surface roughness of up to 13.8 mu m offer rough surface profile to complement the topographical morphology in micro-/nano-scaled sizes, and the hydrophobic molecules facilitate the hydrophobicity. The contact angles of water droplets of 155 with a sliding angle of up to 3.5 degrees on the samples have been achieved. The newly constructed superhydrophobic coatings tolerate strong abrasion, giving clear insight into their long-term functional applications. (C) 2015 Elsevier B.V. All rights reserved
Enhanced Lubricant Property of Flame-Sprayed Aluminum Coatings Additivated by Reduced Graphene Oxide Nanosheets
Enhanced Lubricant Property of Flame-Sprayed Aluminum Coatings Additivated by Reduced Graphene Oxide Nanosheet
Heterogeneous cyclization of sorbitol to isosorbide catalyzed by a novel basic porous polymer-supported ionic liquid
In this study, heterogeneous cyclization of sorbitol to isosorbide under basic condition was realized for the first time with a novel porous polymer-supported ionic liquid as catalyst. These polymer-supported ILs were synthesized through the suspension polymerization of 4-vinylbenzyl chloride and divinylbenzene, followed by a quaternization reaction. As compared to those of non-porous, the porous polymers had high specific surface area and large number of active sites. Consequently, they exhibited excellent catalytic activity in the cyclization of sorbitol with dimethylcarbonate (DMC) to isosorbide. As a result, a high conversion of sorbitol (99%) was achieved with 83% yield of isosorbide under optimized conditions. Importantly, the catalysts could be easily separated by decantation and reused for five times without obvious loss of catalytic activity.</p
Colonization of Bacteria on the Surfaces of Cold-Sprayed Copper Coatings Alters Their Electrochemical Behaviors
Copper coatings were fabricated on stainless steel plates by cold spraying. Attachment and colonization of Bacillus sp. on their surfaces in artificial seawater were characterized, and their effects on anticorrosion performances of the coatings were examined. Attached bacteria were observed using field emission scanning electron microscopy. Electrochemical behaviors including potentiodynamic polarization and electrochemical impedance spectroscopy with/without bacterial attachment were evaluated using commercial electrochemical analysis station Modulab. Results show that Bacillus sp. opt to settle on low-lying spots of the coating surfaces in early stage, followed by recruitment and attachment of extracellular polymeric substances (EPS) secreted through metabolism of Bacillus sp. The bacteria survive with the protection of EPS. An attachment model is proposed to illustrate the bacterial behaviors on the surfaces of the coatings. Electrochemical data show that current density under Bacillus sp. environment decreases compared to that without the bacteria. Charge-transfer resistance increases markedly in bacteria-containing seawater, suggesting that corrosion resistance increases and corrosion rate decreases. The influencing mechanism of bacteria settlement on corrosion resistance of the cold-sprayed copper coatings was discussed and elucidated
SiCl4-catalyzed/PR3-mediated beta-C(sp(3))-H functionalization of nitrones to alpha,beta-unsaturated imines and aromatic heterocycles
A novel method of SiCl4-catalyzed/PR3-mediated beta-C(sp(3))-H functionalization of nitrones with aldehydes/ketones to alpha,beta-unsaturated imines was developed. The synthesis of 4-unsaturated imines mainly invovles deoxygenation and aldol condensation, each proceeding under a cooperation effect between Lewis acid and Lewis base. In addition, both the acidity and hydrolytic stability of the weak SiCl4 were supposed to be enhanced by coordination with phosphine oxide (R = Et) or phosphoric triamide (R = NMe2) that originated from deoxygenation of nitrones by PR3. In the case of 6-membered nitrone, a [1,3]-hydride shift within the resulted alpha,beta-unsaturated imines renders the aromatization leading to 3,5-dialkylpyridines. (C) 2018 Elsevier Ltd. All rights reserved.</p
Developing polyimide-copper antifouling coatings with capsule structures for sustainable release of copper
Polyimide-copper layers consisting of individual capsule-like splats were one-step fabricated by solution precursor flame spray through controlling the reaction between dianhydride and diamine dissolved in copper nanoparticles-containing dimethylformamide solvent. The polyimide splat exhibited hollow structure with an inner pore of 10-15 mu m and a tiny hole of 1-5 mu m on its top surface. Transversal cut by focused ion beam milling of the individual splats and scanning electron microscopy characterization further revealed unique dispersion of the copper nanoparticles inside the polyimide shell. After 1000 h exposure to the testing synthetic seawater, continuous release of copper from the coatings containing up to 30 wt% Cu kept remarkable. Antifouling performances of the constructed layers were assessed by examining colonization behaviors of typical bacteria Bacillus sp. and marine algae Phaeodactylum tricornutum and Chlorella on their surfaces. Distribution of the inorganic nanoparticles endows the polyimide coatings with special capsule structure and exciting hydrophobicity and antifouling performances. The liquid flame spray route and the encapsulated structure of the polyimide-Cu coatings would open a new window for designing and constructing environment-friendly marine antifouling layers for long-term applications.[GRAPHICS]
Developing titania-hydroxyapatite-reduced graphene oxide nanocomposite coatings by liquid flame spray deposition for photocatalytic applications
Nanostructured titania has been extensively investigated for photocatalytic applications. Persistent challenge yet is how to effectively promote adhesion of microorganisms on the material surface for consequent enhanced photocatalytic disinfection. Here we report fabrication and characterization of titania-based nanocomposite coatings with addition of hydroxyapatite-reduced graphene oxide (HA-rGO). The nano features of TiO2, HA, and rGO were well retained during liquid flame spray deposition. Photocatalytic activities of the coatings were examined by degradation of methylene blue and sterilization testing of Escherichia coli bacteria. Addition of HA-rGO effectively increased the specific surface area of the coatings and markedly enhanced adherence of the bacteria for subsequent extinguishment. The TiO2-10 wt.% (HA-rGO) coating showed the best photocatalytic performances and further overloading of HA-rGO resulted in enwrapping of TiO2 particles, resulting in deteriorated degradation activity. The results give clear insight into fabrication of novel photocatalytic nanocomposites by suspension thermal spray route for enhanced performances. (C) 2017 Elsevier Ltd. All rights reserved