Udsenrios0882

Most of polyoxometallates (POMs) templated silver nanoclusters recorded so far are polyoxomolybdates and polyoxotungstates; however, as congeneric polyoxochromates, they are rarely observed in silver nanoclusters. Herein, a high-nuclearity polyoxochromate, (CrIII4CrVI8O36)12-, is uncovered in a novel silver nanocluster (SD/Ag56a) as an anion template. The mixed-valent (CrIII4CrVI8O36)12- consists of four edge-sharing CrIIIO6 octahedra and eight CrVIO4 tetrahedra, which are fused together by sharing one or two vertexes. The (CrIII4CrVI8O36)12- is the by far highest nuclearity polyoxochromate and is trapped by outer Ag56 bracelet-like shell coprotected by quaternary ligands including iPrS-, NapCOO- (2-naphthalenecarboxylate), CF3COO-, and CH3CN. The antiferromagnetic property and solution behavior of SD/Ag56a are discussed in detail.A novel Co-based metal-organic framework (MOF) with the formula of [Co3(BIBT)3(BTC)2(H2O)2]·solventsn (JXUST-2, where JXUST denotes Jiangxi University of Science and Technology, BIBT = 4,7-bi(1H-imidazol-1-yl)benzo-[2,1,3]thiadiazole, and H3BTC = 1,3,5-benzenetricarboxylic acid) has been solvothermally prepared, which takes 3D structure with a rare 3,4,6-c topology and contains intramolecular hydrogen bonds. Interestingly, the sensing investigations suggest that JXUST-2 could be considered as a multifunctional fluorescence sensor toward Fe3+, Cr3+, and Al3+ via a turn-on effect with good reusability and detection limits of 0.13, 0.10, and 0.10 μM, respectively. The turn-on effect of JXUST-2 could be ascribed to an absorbance caused enhancement (ACE) mechanism. Notably, JXUST-2 is the first turn-on MOF fluorescent sensor for Fe3+, Cr3+, and Al3+ simultaneously.The photochemical formation and decay rates of superoxide radical ions (O2•-) in irradiated dissolved organic matter (DOM) solutions were directly determined by the chemiluminescent method. Under irradiation, uncatalyzed and catalyzed O2•- dismutation account for ∼25% of the total O2•- degradation in air-saturated DOM solutions. Light-induced O2•- loss, which does not produce H2O2, was observed. Both the O2•- photochemical formation and light-induced loss rates are positively correlated with the electron-donating capacities of the DOM, suggesting that phenolic moieties play a dual role in the photochemical behavior of O2•-. In air-saturated conditions, the O2•- quantum yields of 12 DOM solutions varied in a narrow range, from 1.8 to 3.3‰, and the average was (2.4 ± 0.5)‰. find more The quantum yield of O2•- nonlinearly increased with increasing dissolved oxygen concentration. Therefore, the quantum yield of one-electron reducing intermediates, the precursor of O2•-, was calculated as (5.0 ± 0.4)‰. High-energy triplets (3DOM*, ET > 200 kJ mol-1) and 1O2 quenching experiments indicate that 3DOM* and 1O2 play minor roles in O2•- production. These results are useful for predicting the photochemical formation and decay of O2•- in sunlit surface waters.Bimetallic complexes are expected to offer unique catalytic property, by facilitating cooperative effects between proximate functional groups or adjacent active metal centers, and thus have attracted increasing attention in the chemical community. Treatment of Ln(CH2SiMe3)3(THF)2 or Ln(CH2C6H4NMe2-o)3 with 1,4-(C6H5NH)2C6H4 in a 21 molar ratio in tetrahydrofuran (THF) generated a series of bimetallic arylamide-ligated rare-earth metal alkyl complexes [1,4-(C6H5N)2C6H4][Ln(CH2SiMe3)2(THF)2]2 (Ln = Sc (1), Lu (2), Y (3)), and aminobenzyl complexes [1,4-(C6H5N)2C6H4][Ln(CH2C6H4NMe2-o)2(THF)x]2 (Ln = Sc (4), x = 0; Lu (5), Y (6), x = 1) in 65-73% isolated yields. To reveal the polymerization difference between bimetallic and monometallic rare-earth metal complexes, the monoarylamide-ligated scandium bis(aminobenzyl) complex [(C6H5)2N]Sc(CH2C6H4NMe2-o)2 (7) was prepared by the reaction of Sc(CH2C6H4NMe2-o)3 with 1 equiv of diphenylamine (C6H5)2NH. All these rare-earth metal complexes were characterized by elementatransfer mechanism. Preliminary results indicated that the bimetallic rare-earth metal complexes showed a higher polymerization activity than the corresponding monometallic species mostly resulting from the cooperative effect.While monoclonal antibodies are the fastest-growing class of therapeutic agents, we lack a method that can directly quantify the on- and off-target binding affinities of newly developed therapeutic antibodies in crude cell lysates. As a result, some therapeutic antibody candidates could have a moderate on-target binding affinity but a high off-target binding affinity, which not only gives a reduced efficacy but triggers unwanted side effects. Here, we report a single-molecule counting method that precisely quantifies antibody-bound receptors, free receptors, and unbound antibodies in crude cell lysates, termed digital receptor occupancy assay (DRO). Compared to the traditional flow cytometry-based binding assay, DRO assay enables direct and digital quantification of the three molecular species in solution without the additional antibodies for competitive binding. When characterizing the therapeutic antibody, cetuximab, using DRO assay, we found the on-target binding ratio to be 65% and the binding constant (Kd) to be 2.4 nM, while the off-target binding causes the binding constant to decrease by 0.3 nM. Other than cultured cells, the DRO assay can be performed on tumor mouse xenograft models. Thus, DRO is a simple and highly quantitative method for cell-based antibody binding analysis which can be broadly applied to screen and validate new therapeutic antibodies.In the United States, approximately 48 million people are served by private wells. Unlike public water systems, private well water quality is not monitored, and there are few studies on the extent and sources of contamination of private wells. We extensively investigated five private wells to understand the variability in microbial contamination, the role of septic systems as sources of contamination, and the effect of rainfall on well water quality. From 2016 to 2017, weekly or biweekly samples (n = 105) were collected from five private wells in rural Pennsylvania. Samples were tested for general water quality parameters, conventional and sewage-associated microbial indicators, and human pathogens. Total coliforms, human Bacteroides (HF183), and pepper mild mottle virus were detected at least once in all wells. Regression revealed significant relationships between HF183 and rainfall 8-14 days prior to sampling and between total coliforms and rainfall 8-14 or 0-14 days prior to sampling. Dye tracer studies at three wells confirmed the impact of household septic systems on well contamination.