74 research outputs found

    A systematic review of maggot debridement therapy for chronically infected wounds and ulcers

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    SummaryObjectiveThis study aimed to systematically evaluate maggot debridement therapy (MDT) in the treatment of chronically infected wounds and ulcers.MethodsWe performed a meta-analysis referring to the PRISMA statement (Preferred Reporting Items for Systematic Reviews and Meta-Analyses). We searched for published articles in the following databases: PubMed, Web of Science, Embase, Wanfang (Chinese), and the China National Knowledge Infrastructure (CNKI). The latest search was updated on March 14, 2014. For dichotomous outcomes, the effects of MDT were expressed as the relative risk (RR) and 95% confidence interval (CI). For continuous outcomes with different measurement scales, we calculated the standardized mean difference (SMD). The pooled effects were estimated using a fixed effect model or random effect model based on the heterogeneity test. Subgroup analyses were performed according to the types of wounds or ulcers.ResultsMDT had a significantly increased positive effect on wound healing compared with conventional therapies, with a pooled RR of 1.80 (95% CI 1.24–2.60). The subgroup analysis revealed that the combined RRs were 1.79 (95% CI 0.95–3.38) for patients with diabetic foot ulcers (DFU) and 1.70 (95% CI 1.28–2.27) for patients with other types of ulcers. The time to healing of the ulcers was significantly shorter among patients treated with MDT, with a pooled SMD of −0.95 (95% CI −1.24, −0.65). For patients with DFU, the SMD was −0.79 (95% CI −1.18, −0.41), and for patients with other types of ulcers, the SMD was −1.16 (95% CI −1.63, −0.69).ConclusionMDT not only shortened the healing time but also improved the healing rate of chronic ulcers. Therefore, MDT may be a feasible alternative in the treatment of chronic ulcers

    Crystal structure, thermal analyses, and acetate binding properties in Zinc(II) complex of a urea-functionalized pyridyl ligand

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    1302-1310A zinc(II) acetate complex with a urea-functionalized pyridyl ligand, [ZnL2(OAc)2]·2H2O (1) (L = N-(4-chlorophenyl)-N'-(4-pyridyl)urea), has been synthesized by the reaction of L with Zn(OAc)2·2H2O under water-containing condition. X-ray single-crystal diffraction analyses reveal that 2-D sheetlike network structure has been formed by the urea N−H×××Npyridyl interactions and C–H···O interactions in the free ligand L. Complex 1 features 3-D hydrogen bonded network formed by intermolecular N−H···O hydrogen bonds and O−H×××O hydrogen bonds involving urea groups, acetate anions and bridged water molecules. The hydrogen bonds play an important role in stabilizing the supramolecular structures. Thermal gravity analyses have been used to investigate the thermal stabilities of L and 1, and the apparent activation energy (Ea) of the decompositions have also been calculated, and the results indicate that the main decomposition of L needs higher apparent activation energy values Ea than that of 1. The acetate binding properties of L in solution have also been evaluated by Ultraviolet-Visible (UV-Vis) spectroscopy. CCDC: 1506202, L; 1506203, 1

    Enhanced photocatalytic reduction of Cr(VI) by ZnO–TiO2–CNTs composites synthesized via microwave-assisted reaction

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    ZnO–TiO2–carbon nanotubes (CNTs) composites are successfully synthesized using microwave-assisted reaction of ZnO precursor in TiO2 and CNTs suspension using a microwave synthesis system and they are used as photocatalysts for photocatalytic reduction of Cr(VI). The results show that the CNTs addition could enhance the photocatalytic performance of ZnO–TiO2 composites. The ZnO–TiO2 composites achieve a maximum reduction rate of 90% at 240 min under UV light irradiation, much higher than those for the pure ZnO (58%) and the ZnO–TiO2 (69%). The improvement is ascribed to the increased light absorption intensity and range as well as the reduction of electron–hole pair recombination with the introduction of CNTs

    Visible light photocatalytic degradation of dyes by bismuth oxide-reduced graphene oxide composites prepared via microwave-assisted method

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    Bi2O3-reduced graphene oxide (RGO) composites were successfully synthesized via microwave-assisted reduction of graphite oxide in Bi2O3 precursor solution using a microwave system. Their morphologies, structures, and photocatalytic performance in the degradation of methylene blue (MB) and methyl orange (MO) were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction spectroscopy, UV–vis absorption spectroscopy, and electrochemical impedance spectroscopy, respectively. The results show that the RGO addition can enhance the photocatalytic performance of Bi2O3–RGO composites. Bi2O3–RGO composite with 2 wt.% RGO achieves maximum MO and MB degradation rates of 93% and 96% at 240 min under visible light irradiation, respectively, much higher than those for the pure Bi2O3 (78% and 76%). The enhanced photocatalytic performance is ascribed to the increased light adsorption and the reduction in electron–hole pair recombination in Bi2O3 with the introduction of RGO

    Sol–gel synthesis of Au/N–TiO2 composite for photocatalytic reduction of Cr(vi)

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    Au/N–TiO2 composites are successfully synthesized via a modified sol–gel method and their photocatalytic performance in reduction of Cr(VI) is investigated. Au/N–TiO2 composites exhibit an enhanced photocatalytic performance in the reduction of Cr(VI) with a maximum reduction rate of 90% under visible light irradiation as compared with pure TiO2 (34%) and N–TiO2 (80%) due to the increase of light absorption intensity and range as well as the reduction of electron–hole pair recombination in TiO2 with the incorporation of N and Au

    Microwave-assisted synthesis of ZnO for photocatalytic reduction of Cr(VI) in aqueous solution

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    ZnO sheets have been synthesized via microwave-assisted reaction of ZnO precursor in aqueous solution using a CEM microwave system. Their morphologies, crystal structures and photocatalytic performances in the reduction of Cr(VI) were characterized using scanning electron microscopy, transmission electron microscopy, X-ray diffraction spectroscopy and UV-vis absorption spectrophotometer, respectively. Results show that ZnO sheets synthesized in 5 min time scale exhibits a optimal photocatalytic performance in the reduction of Cr(VI) with removal efficiency of 81% under UV irradiation due to the maximal intensity of light absorption and the minimal probability of electron-hole pair recombination.Published versio

    (H, Li)Cl and LiOH hydration : surface tension, solution conductivity and viscosity, and exothermic dynamics

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    We systematically examined the effect of (H, Li)Cl and LiOH solvation on the O:H[sbnd]O bond network deformation, surface tension (contact angle), solution electrical conductivity, thermomics, and viscosity evolution aiming to clarifying the functionalities for ions, lone pairs, and protons acting in these solutions. Results confirmed that H + and electron lone pair ‘:’ introduction turns out the (H 3 O + , OH − )·4H 2 O motifs and that the Li + and Cl − form each a hydration volume through the screened electrostatic polarization. The (H 3 O + , OH − )·4H 2 O turns an O:H[sbnd]O bond into the H ↔ H anti–HB that disrupts the HCl solution network and its surface tension and into the O:⇔:O super–HB compressor that raises the LiOH solution surface tension and viscosity, as well as the solution temperature during solvation. The Li + /Cl − ion reserves/reduces its hydration volume because of the complete/incomplete screen shielding by the ordered hydrating H 2 O dipoles and the Cl − ↔ Cl − repulsion at higher concentrations. The invariant/variant Li + /Cl − hydration volume dictates, respectively, the linear/nonlinear concentration dependence of the Jones–Dole viscosity. Except for the HCl/H 2 O surface tension and LiOH/H 2 O viscosity, the conductivity, surface tension, and viscosity of these solutions follow the Jones–Dole notion that underscores the faction of bond transition from the mode of water to hydration.Accepted versio

    Discriminative ionic capabilities on hydrogen-bond transition from the mode of ordinary water to (Mg, Ca, Sr)(Cl, Br)₂ hydration

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    It has been a long pursuit to discriminate the ionic roles of mono- and di-valent salt solutions in modulating the hydrogen bonding network and solution properties. We attended this issue by examining the effect of concentrated YX 2 (Y[dbnd]Mg, Ca, Sr; X[dbnd]Cl, Br) solvation on O:H–O bonds transition from the mode of ordinary water to hydration in terms of the number fraction f YX2 (C) and the segmental O:H–O bond phonon stiffness shift Δω(C) with C being the solute concentration. The invariant df Y (C) / dC at C ≤ <0.05 suggests that the small Y 2+ forms a constantly-sized hydration droplet with weak responding to interference of other ions because its hydrating H 2 O dipoles screen mostly its electric field. However, the number inadequacy of the highly-ordered hydrating H 2 O dipoles partially screens the large X − . The X − ↔ X − electrostatic repulsion weakens its electric field. The concentration-trend consistency of the f YX2 (C), the solution conductivity σ YX2 (C), and surface stress (contact angle) θ YX2 (C) for YX 2 solutions clarifies their common origin of ionic polarization. However, the Jones–Dale notion disobedience of the viscosity η YX2 (C) suggests the dominance of the inter-ion repulsion.Submitted/Accepted versionFinancial support received from Natural Science Foundation of China (Nos. 11872052(YL); 21875024(CQ)), and the Science Challenge Project (No. TZ2016001) of China are acknowledged

    ZnO Meso-Mechano-Thermo physical chemistry

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