Heteroatom-Modulated Assembly of Hexalanthanoid-Containing Polyoxometalate-Based Coordination Networks.

Two series of lanthanoid (Ln)-containing polyoxometalates (POMs) {[Ln6(ampH)4(H2O)24-n(ampH2)n(PW11O39)2]·21H2O (Ln = Tb, n = 0 (1), Ln = Er, n = 1 (2)) and K2[Ln6(ampH)4(H2O)22(SiW11O39)2]·23H2O (Ln = Tb (3), Er (4)) (ampH2 = (aminomethyl) phosphonic acid)} have been synthesized with tri-lacunary Keggin-type POMs containing different types of heteroatoms. Compounds 1 and 2 display neutral organic-inorganic hybrid POM molecules containing {Ln6(ampH)4} ({Ln6}) cores sandwiched by two {PW11O39} units. By changing the heteroatoms from PV to SiIV, the extended 2D networks of 3 and 4 were successfully isolated where the adjacent {Ln6} clusters were connected by {SiW11O39} moieties. Luminescence performances and magnetic properties of 1-4 have been systematically surveyed. The solid-state fluorescence spectra of 1-4 display characteristic emissions of Ln components resulting from the 4f-4f transitions, and energy transfer from the POM segments to Ln3+ centers in 1 and 3 has been observed based on the lifetime decay behaviors. Furthermore, all compounds can be utilized as electrocatalysts toward reduction of nitrite with high stability.

pH-Controlled Assembly of Two Polynuclear Dy(III)-Containing Polytungstoarsenates with Magnetic and Luminescence Properties.

Two novel polynuclear dysprosium (Dy)-containing polytungstoarsenates, CsK7Na16[(AsW9O33)6Dy6W10O24(H2O)23]·40H2O (1) and Cs2K18Na18[(AsW9O33)7Dy7W8O21(H2O)17(µ3-OH)(OH)]·78H2O (2), have been synthesized via the reaction of the preformed polyoxometalate (POM) precursor [As2W19O67(H2O)]14- and Dy3+ ions through controlling pH. The polyanion of 1 can be described as a dimer of two similar trimers {(AsW9O33)3Dy2W5O12(H2O)6} that are linked by Dy cation and two µ2-oxo groups, and the Dy(III) ions in 1 are arranged in a linear fashion. Compound 2 presenting an interesting W-shaped structure, assembly composed of a dimeric {(AsW9O33)2W3Dy2O8(H2O)7}, a trimer {(AsW9O33)3W4Dy2O11(OH)(H2O)3}, and a particular sandwiched {(AsW9O33)2WDy3O4(µ3-OH)(H2O)7} segment concatenated by µ2-oxo groups. The solid-state luminescence performances and lifetime decay behaviors of 1 and 2 were systematically researched at ambient temperature, and time-resolved fluorescence spectra of 1 and 2 indicate energy transfer (ET) from the photoexcitation O → M ligand to the metal charge-transfer (LMCT) bands of the POM ligands to Dy3+ ions. Moreover, the dynamic magnetic measurement indicates that 1 and 2 exhibit slow relaxation of the magnetization.

RETRACTED: Preoperative chlorhexidine versus povidone-iodine antisepsis for preventing surgical site infection: A meta-analysis and trial sequential analysis of randomized controlled trials.

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the Editor of the Journal. The retraction has been made because the Editor has been informed that a similar article containing the same research was submitted to another journal by other authors. The authors have admitted errors in drafting and submitting the paper and apologise for the mistakes.

Mesh reinforcement for the prevention of incisional hernia formation: a systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: European Hernia Society guidelines suggested that the evidence of mesh augmentation for the prevention of incisional hernia (IH) was weak. In addition, previous systematic reviews seldom focused on quality of life and cost-effectiveness related to mesh placement. Therefore, an updated meta-analysis was performed to clarify quality of life, cost-effectiveness, the safety, and effectiveness of mesh reinforcement in preventing the incidence of IH. METHODS: Embase, Pubmed, and the Cochrane library were searched from the inception to May 2016 without language limitation for randomized controlled trials (RCTs) which explored mesh reinforcement for the prevention of IH in patients undergoing abdominal surgeries. RESULTS: Twelve RCTs totaling 1661 patients (958 in mesh, 703 in nonmesh) were included in our study. Compared with nonmesh, mesh reinforcement can effectively decrease the incidence of IH (relative risk: 0.19; 95% CI: 0.09-0.42). Besides, mesh placement was associated with improved quality of life, a higher rate of seroma (relative risk: 1.64; 95% CI: 1.13-2.37), and longer operating time (mean difference: 17.62; 95% CI: 1.44-33.80). No difference can be found between both groups in postoperative overall morbidity, systemic postoperative morbidity, wound-related morbidity, surgical site infection, hematoma, wound disruption, postoperative mortality, and length of hospital stay. CONCLUSIONS: Prophylactic mesh reinforcement may be effective and safe to prevent the formation of IH after abdominal surgery, without impairing quality of life. Thus, preventive mesh should be routinely recommended in high-risk patients.