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Among other improvements in chemical nomenclature used in the Chemical Registry System, Chemical Abstracts Service intends to standardize the fundamental principles for naming cyclic structures so that procedures for the derivation of ring names can become more amenable to computer generation and translation. (Author/NH)

Despite the many positive aspects of carbon fiber arising from its light-weighting potential, high cost and related environmental impact may inhibit even wider usage of the material in future. The ...

Most research on polymer composites has focused on adding discrete inorganic nanofillers to a polymer matrix to impart properties not found in polymers alone. However, properties such as ion conductivity and mechanical reinforcement would be greatly improved if the composite exhibited an interconnected network of inorganic and polymer phases. Here, we fabricate bicontinuous polymer-infiltrated scaffold metal (PrISM) composites by infiltrating polymer into nanoporous gold (NPG) films. Polystyrene (PS) and poly(2-vinylpyridine) (P2VP) films are infiltrated into the ∼43 nm diameter NPG pores via capillary forces during thermal annealing above the polymer glass transition temperature (Tg). The infiltration process is characterized in situ using spectroscopic ellipsometry. PS and P2VP, which have different affinities for the metal scaffold, exhibit slower segmental dynamics compared to their bulk counterparts when confined within the nanopores, as measured through Tg. The more attractive P2VP shows a 20 °C increase in Tg relative to its bulk, while PS only shows a 6 °C increase at a comparable molecular weight. The infiltrated polymer, in turn, stabilizes the gold nanopores against temporal coarsening. The broad tunability of these polymer/metal hybrids represents a unique template for designing functional network composite structures with applications ranging from flexible electronics to fuel cell membranes.

Background Although fructose as a source of excess calories increases uric acid, the effect of the food matrix is unclear. Objectives To assess the effects of fructose-containing sugars by food source at different levels of energy control on uric acid, we conducted a systematic review and meta-analysis of controlled trials. Methods MEDLINE, Embase, and the Cochrane Library were searched (through 11 January 2021) for trials ≥ 7 days. We prespecified 4 trial designs by energy control: substitution (energy-matched replacement of sugars in diets); addition (excess energy from sugars added to diets); subtraction (energy from sugars subtracted from diets); and ad libitum (energy from sugars freely replaced in diets) designs. Independent reviewers (≥2) extracted data and assessed the risk of bias. Grading of Recommendations, Assessment, Development, and Evaluation was used to assess the certainty of evidence. Results We included 47 trials (85 comparisons; N = 2763) assessing 9 food sources [sugar-sweetened beverages (SSBs), sweetened dairy, fruit drinks, 100% fruit juice, fruit, dried fruit, sweets and desserts, added nutritive sweetener, and mixed sources] across 4 energy control levels in predominantly healthy, mixed-weight adults. Total fructose-containing sugars increased uric acid levels in substitution trials (mean difference, 0.16 mg/dL; 95% CI: 0.06-0.27 mg/dL; P = 0.003), with no effect across the other energy control levels. There was evidence of an interaction by food source: SSBs and sweets and desserts increased uric acid levels in the substitution design, while SSBs increased and 100% fruit juice decreased uric acid levels in addition trials. The certainty of evidence was high for the increasing effect of SSBs in substitution and addition trials and the decreasing effect of 100% fruit juice in addition trials and was moderate to very low for all other comparisons. Conclusions Food source more than energy control appears to mediate the effects of fructose-containing sugars on uric acid. The available evidence provides reliable indications that SSBs increase and 100% fruit juice decreases uric acid levels. More high-quality trials of different food sources are needed. This trial was registered at clinicaltrials.gov as NCT02716870.

Self-cleaning fabrics can be developed based on introducing two mechanisms of superhydrophobicity and photocatalytic activity to conventional fabrics. However, there are some downsides such as inefficiency of superhydrophobic coatings against oily contaminants and low effectiveness of photocatalytic surface treatments under visible light which have restricted the widespread applications of these functional products. This research presents the development of self-cleaning cotton fabric with dual functionalities of superhydrophobicity and photocatalytic activity using microhierarchial TiO2-based particles. It is aimed to fabricate fluorine-free durable superhydrophobic coatings with simultaneous photocatalytic self-cleaning under simulated sunlight. Fluorine-free coating formulations composed of flower-like particles, either TiO2 or nitrogen-doped TiO2, and polydimethyl siloxane (PDMS) polymer were applied to cotton fabrics using a facile dip-coating method. The self-cleaning performance of fabrics was assessed based on their superhydrophobicity and effective removal of oil-based stains under simulated sunlight. Additionally, the impact of nitrogen doping on enhancing the photocatalytic activity of flower-like TiO2 particles was investigated. The obtained results demonstrated that the presence of both PDMS and hierarchical particles generated excellent superhydrophobicity on the cotton fabric with a water contact angle of 156.7° ± 1.9°. In addition, the coated fabric exhibited highly efficient photocatalytic activity, decomposing absorbed stains after 30 min of irradiation. Nitrogen doping process significantly boosted the photocatalytic activity of TiO2 particles in degrading food stains and Rhodamine B dye solution. The developed fabrics showed high robustness against chemical and physical durability tests.

Deep eutectic solvents (DESs) are tuneable solvents with attractive properties for numerous applications. Their structure–property relationships are still under investigation, especially at the solid–liquid interface. Moreover, the influence of water on interfacial nanostructure must be understood for process optimization. Here, we employ a combination of atomic force microscopy and molecular dynamics simulations to determine the lateral and surface-normal nanostructure of the DES choline chloride:glycerol at the mica interface with different concentrations of water. For the neat DES system, the lateral nanostructure is driven by polar interactions. The surface adsorbed layer forms a distinct rhomboidal symmetry, with a repeat spacing of ~0.9 nm, comprising all DES species. The adsorbed nanostructure remains largely unchanged in 75 mol-% DES compared with pure DES, but at 50 mol-%, the structure is broken and there is a compromise between the native DES and pure water structure. By 25 mol-% DES, the water species dominates the adsorbed liquid layer, leaving very few DES species aggregates at the interface. In contrast, the near-surface surface-normal nanostructure, over a depth of ~3 nm from the surface, remains relatively unchanged down to 25 mol-% DES where the liquid arrangement changed. These results demonstrate not only the significant influence that water has on liquid nanostructure, but also show that there is an asymmetric effect whereby water disrupts the nanostructure to a greater degree closer to the surface. This work provides insight into the complex interactions between DES and water and may enhance their optimization for surface-based applications.

We measure the center-of-mass diffusion of silica nanoparticles (NPs) in entangled poly(2-vinylpyridine) (P2VP) melts using Rutherford backscattering spectrometry. While these NPs are well within the size regime where enhanced, nonhydrodynamic NP transport is theoretically predicted and has been observed experimentally (2RNP/dtube ≈ 3, where 2RNP is the NP diameter and dtube is the tube diameter), we find that the diffusion of these NPs in P2VP is in fact well-described by the hydrodynamic Stokes–Einstein relation. The effective NP diameter 2Reff is significantly larger than 2RNP and strongly dependent on P2VP molecular weight, consistent with the presence of a bound polymer layer on the NP surface with thickness heff ≈ 1.1Rg. Our results show that the bound polymer layer significantly augments the NP hydrodynamic size in polymer melts with attractive polymer–NP interactions and effectively transitions the mechanism of NP diffusion from the nonhydrodynamic to hydrodynamic regime, particularly at high mole...

Polymer matrix composite materials have the capacity to aid the indirect transmission of viral diseases. Published research shows that respiratory viruses, including severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2 or COVID‐19), can attach to polymer substrata as a result of being contacted by airborne droplets resulting from infected people sneezing or coughing in close proximity. Polymer matrix composites are used to produce a wide range of products that are “high‐touch” surfaces, such as sporting goods, laptop computers and household fittings, and these surfaces can be readily contaminated by pathogens. This article reviews published research on the retention of SARS‐CoV‐2 and other virus types on plastics. The factors controlling the viral retention time on plastic surfaces are examined and the implications for viral retention on polymer composite materials are discussed. Potential strategies that can be used to impart antiviral properties to polymer composite surfaces are evaluated. These strategies include modification of the surface composition with biocidal agents (e.g., antiviral polymers and nanoparticles) and surface nanotexturing. The potential application of these surface modification strategies in the creation of antiviral polymer composite surfaces is discussed, which opens up an exciting new field of research for composite materials., Polymer matrix composites are used to produce a wide range of products that are “high‐touch” surfaces, such as sporting goods, laptop computers and household fittings, and these surfaces can be readily contaminated by pathogens. Factors controlling the viral retention time on plastic surfaces including SARS‐CoV‐2 (COVID‐19) are examined and the implications for viral retention on polymer composite materials are discussed. Potential strategies that can be used to impart antiviral properties to polymer composite surfaces are evaluated.

Objective To evaluate how women with epithelial ovarian cancer (EOC), dichotomized by BRCA status, tolerate intravenous (IV) or intraperitoneal (IP) chemotherapy given with veliparib and bevacizumab (bev) on a GOG phase I study (GOG 9923, NCT00989651). Methods This is an unplanned, post hoc analysis of an IRB approved, multi-institutional, prospective study (GOG 9923). Clinical characteristics and toxicity data based on BRCA status were evaluated and descriptive statistics were used to summarize baseline patient characteristics and toxicities. The Kaplan Meier method was used to generate survival estimates. Results Four hundred twenty-four patients were evaluable. Patients were treated with IV carboplatin, paclitaxel, and bev every 21 days (regimen 1), weekly IV paclitaxel with carboplatin and bev (regimen 2) or IV paclitaxel and bev with IP cisplatin (regimen 3). Bev was continued as maintenance in all arms. Within each of these regimens, veliparib was given either twice daily for the entirety of each cycle (continuous) or on days −2 to 5 (intermittent). Ten percent of patients treated on regimen 1, 12% on regimen 2, and 19.8% on regimen 3 had BRCA-associated tumors. Patients with BRCA-associated tumors, when compared to wild type, experienced similar rates of anemia, febrile neutropenia (, abdominal pain, colonic perforation, nausea, vomiting, and peripheral sensory neuropathy. Median progression free survival (PFS) was not significantly different between BRCA-associated and wild type cancers (HR 0.96, CI 0.65–1.42), though this study's primary aim was not to evaluate outcomes. Conclusions Germline BRCA mutations positively affect chemosensitivity in EOC, but whether differences in toxicities among BRCA-associated and BRCA wild type tumors existed was previously not reported. In this population with newly diagnosed ovarian cancer no differences in reported toxicity between the two groups was observed.

Summary Background Although several randomized controlled trials (RCTs) have supported the beneficial effects of higher meal frequency (MF) on cardiometabolic risk factors, the putative effects of higher MF on health remain inconclusive. This study systematically reviewed the evidence from RCTs of the effect of higher compared with lower MF on the blood lipid profile, glucose homeostasis, and adipokines. Methods PubMed, Scopus, ISI Web of Science, and the Cochrane database were searched up to October 2020 to retrieve relevant RCTs. A DerSimonian and Laird random effects model was used to pool mean differences and 95% CI for each outcome. The quality of studies and evidence was assessed through standard methods. Results Twenty-one RCTs (686 participants) were included in this meta-analysis. Overall results showed a significant improvement in total cholesterol [weighted mean difference (WMD) = −6.08 mg/dl; 95% CI: −10.68, −1.48; P = 0.01; I2 = 88%], and low-density cholesterol (LDL-C) (WMD = −6.82 mg/dl; 95% CI: −10.97, −1.60; P = 0.009; I2 = 85.7%), while LDL-C to high-density cholesterol ratio (LDL-C: HDL-C) increased (WMD = 0.22; 95% CI: 0.07, 0.36; P = 0.003; I2 = 0.0%) in higher MF vs. lower MF. No significant effects were found on measures of glycemic control, apolipoproteins-A1 and B, or leptin. In subgroup analyses, higher MF significantly reduced serum triglyceride (TG), and increased HDL-C, compared with lower MF in interventions > 12 weeks, and decreased serum TC and LDL-C in healthy participants. A significant reduction in LDL-C also was observed in studies where the same foods given both arms, simply divided into different feeding occasions, and in feeding studies, following higher MF compared to lower MF. Conclusion Our meta-analysis found that higher, compared with lower MF may improve total cholesterol, and LDL-C. The intervention does not affect measures of glycemic control, apolipoproteins-A1 and B, or leptin. However, the GRADE ratings of low credibility of the currently available evidence highlights the need for more high-quality studies in order to reach a firm conclusion.

The polyketide synthase (PKS)‐like protein TerB, consisting of inactive dehydratase, inactive C‐methyltransferase, and functional ketoreductase domains collaborates with the iterative non reducing PKS TerA to produce 6‐hydroxymellein, a key pathway intermediate during the biosynthesis of various fungal natural products. The catalytically inactive dehydratase domain of TerB appears to mediate productive interactions with TerA, demonstrating a new mode of trans‐interaction between iterative PKS components., A new architecture for iterative Type I polyketide synthases (PKS) from fungi has been investigated. TerA is a canonical non‐reducing PKS which interacts with TerB, a fragment of a highly reducing PKS containing a functional ketoreductase. Interaction appears to be mediated between a non‐functional dehydratase domain of TerB and the TerA product template domain. Working together, TerAB synthesises 6‐hydroxymellein, a precursor of terrein and other fungal metabolites.

The Abelson-helper integration site 1 (AHI1) gene encodes for a ciliary transition zone localizing protein that when mutated causes the human ciliopathy, Joubert syndrome. We prepared and examined neuronal cultures derived from male and female embryonicAhi1+/+andAhi1–/–mice (littermates) and found that the distribution of ciliary melanin-concentrating hormone receptor-1 (MchR1) was significantly reduced inAhi1–/–neurons; however, the total and surface expression of MchR1 onAhi1–/–neurons was similar to controls (Ahi1+/+). This indicates that a pathway for MchR1 trafficking to the surface plasma membrane is intact, but the process of targeting MchR1 into cilia is impaired in Ahi1-deficient mouse neurons, indicating a role for Ahi1 in localizing MchR1 to the cilium. MouseAhi1–/–neurons that fail to accumulate MchR1 in the ciliary membrane have significant decreases in two downstream MchR1 signaling pathways [cAMP and extracellular signal-regulated kinase (Erk)] on MCH stimulation. These results suggest that the ciliary localization of MchR1 is necessary and critical for MchR1 signaling, with Ahi1 participating in regulating MchR1 localization to cilia, and further supporting cilia as critical signaling centers in neurons.SIGNIFICANCE STATEMENTOur work here demonstrates that neuronal primary cilia are powerful and focused signaling centers for the G-protein-coupled receptor (GPCR), melanin-concentrating hormone receptor-1 (MCHR1), with a role for the ciliary transition zone protein, Abelson-helper integration site 1 (AHI1), in mediating ciliary trafficking of MCHR1. Moreover, our manuscript further expands the repertoire of cilia functions on neurons, a cell type that has not received significant attention in the cilia field. Lastly, our work demonstrates the significant influence of ciliary GPCR signaling in the overall signaling of neurons.

A standardized data workflow is described for large-scale serum metabolomic studies using multisegment injection-capillary electrophoresis-mass spectrometry. Multiplexed separations increase throughput ( 75%) from a multi-ethnic cohort of pregnant women (n = 1,004). We outline a validated protocol implemented in four batches over a 7-month period that includes details on preventive maintenance, sample workup, data preprocessing and metabolite authentication. We achieve stringent quality control (QC) and robust batch correction of long-term signal drift with good mutual agreement for a wide range of metabolites, including serum glucose as compared to a clinical chemistry analyzer (mean bias = 11%, n = 668). Control charts for a recovery standard (mean CV = 12%, n = 2,412) and serum metabolites in QC samples (median CV = 13%, n = 202) demonstrate acceptable intermediate precision with a median intraclass coefficient of 0.87. We also report reference intervals for 53 serum metabolites from a diverse population of women in their second trimester of pregnancy. A standardized protocol and data workflow for high-throughput analysis of the maternal serum metabolome is outlined. It uses multisegment injection–capillary electrophoresis–mass spectrometry and is applied to a multi-ethnic cohort of pregnant women.

Background: EP0057 (formerly CRLX101) is an investigational nanoparticle-drug conjugate (NDC) of a cyclodextrin-based polymer backbone plus camptothecin, a topoisomerase-1 inhibitor. Prior studies showed efficacy in recurrent or persistent, epithelial ovarian, fallopian tube or primary peritoneal cancer (EOC). Methods: This phase Ib/2 trial assessed safety and efficacy of EP0057 Q2W plus weekly paclitaxel in patients with EOC. The recommended phase 2 dose (RP2D) was identified using a 3+3 design. The single-arm phase 2 assessed overall response (ORR) per RECIST 1.1 in patients previously treated with bevacizumab. Secondary objectives included progression free survival (PFS) and duration of response. Results: The RP2D was established as 15 mg/m2 EP0057 Q2W plus 80 mg/m2 paclitaxel administered 3 weeks on/1 week off. Nine patients enrolled on phase 1b, with no DLTs; 21 additional patients enrolled on phase 2. All completed > 1 cycle. Median age was 62 (44-76) years, 57% ≥3 prior therapies. For the primary analysis, 6/19 patients with prior bevacizumab had confirmed responses (ORR=31.6% (95% CI: 15.4% to 54.0%)) including one complete response (CR). Median PFS was 5.4 months. Most common grade 3/4 adverse events attributed to treatment were decreased neutrophil count (13, 43%) and anemia (3, 10%). Conclusions: Although the observed ORR was not statistically better than the historical control rate, EP0057 remains an interesting option for treatment of recurrent EOC. EP0057 exhibits high plasma drug retention, slow clearance, and controlled slow release of CPT from the polymer when administered alone and with paclitaxel. (NCT02389985) 242 words

Over the past two decades, the designs of redox polymers have become critical to the field of mediated bioelectrocatalysis and are used in commercial glucose biosensors, as well as other bioelectrochemical applications (e.g., energy harvesting). These polymers are specifically used to immobilize redox mediators on electrode surfaces, allowing for self-exchange-based conduction of electrons from enzymes far from the electrode to the electrode surface. However, the synthesis of redox polymers is challenging and results in large batch-to-batch variability. Herein, we report a rapid entrapment of mediators for NAD+-dependent bioelectrocatalysis within reverse ionically condensed polyelectrolytes. A high ionic strength aqueous solution of oppositely charged polyelectrolytes, composed of cationic polyguanidinium (PG) chloride and anionic sodium hexametaphosphate (P6), undergoes phase inversion into a solid microporous polyelectrolyte complex (PEC) when introduced into a low ionic strength aqueous solution. The ionic strength-triggered phase inversion of PGP6 solutions was investigated as a means to entrap mediators on the surface of electrodes for mediated bioelectrocatalysis. Compared to the traditional cross-linked immobilizations using redox polymers, this phase inversion takes place within seconds and requires up to 60 min for complete stabilization. In this work, redox mediator phenazine ethosulfate (PES) was entrapped within PGP6 on electrode surfaces for nicotinamide adenine dinucleotide (NAD+)-dependent bioelectrocatalysis. In the bulk solution, NAD+-dependent dehydrogenase enzymes catalyze the oxidation of the substrate while reducing NAD to reduced nicotinamide adenine dinucleotide (NADH). The resulting NADH is reoxidized to NAD+ by the entrapped PES that gets reduced on the electrode, completing the NAD+-regeneration-based bioelectrocatalysis. To show the use of these new materials in an application, biofuel cells were evaluated using four different anodic enzyme systems (alcohol dehydrogenase, lactate hydrogenase, glycerol dehydrogenase, and glucose dehydrogenase).

Total biosynthesis in fungi is beginning to compete with traditional chemical total synthesis campaigns. Herein, the advantages, disadvantages and future opportunities are discussed within the scope of several recent examples.1 Introduction2 Synthetic Examples2.1 2-Pyridones2.2 Cytochalasans2.3 Sorbicillinoids2.4 Decalins: Solanapyrone2.5 α-Pyrone Polyenes: Citreoviridin and Aurovertin2.6 Anditomin and Related Meroterpenoids2.7 Tropolone Sesquiterpenoids3 Conclusion

The influence of increasing the waste loading of Ca- and Zn-containing MW high-level-waste glass, from 20 to 35 wt%, on the chemical durability was investigated using 112-day PCT-B tests at 90 °C in ultra-high-quality water. During the initial stage of dissolution, from 0 to 3 days, increased waste loadings corresponded to reduced boron dissolution rates. By 112 days, however, there was no difference in the normalised mass loss of boron as a function of waste loading, within experimental uncertainty. In comparison to literature values obtained for traditional MW high-level-waste glasses, containing no Ca and Zn, the boron dissolution rates of CaZn MW glasses in the residual stage of dissolution, > 28 days, were greater by at least an order of magnitude. Analysis of secondary phases, combined with geochemical modelling of the solutions, indicate that the dual formation of Mg- and Zn-smectite phyllosilicate clays, potentially saponite (Ca0.2Mg3(Si,Al)4O10(OH)2·4H2O) and sauconite (Na0.3Zn3(Si, Al)4O10(OH)2·nH2O), respectively, may be the cause of this enhanced dissolution.

Effect of geraniin extracted from sugar maple (Acer saccharum) leaves on the viability of the phytopathogen Xanthomonas campestris pv. vitians was evaluated with the SYTOX Green nucleic acid stain, penetrating only compromised membranes, and plate counts. In parallel, structural changes of treated bacteria were examined in transmission electron microscopy (TEM). Based on SYTOX Green and plate counts, geraniin at the minimum bactericidal concentration (3.125 mg/ml) increased mortality after 45 min by 37% and 62%, respectively, when compared with controls. According to observations in TEM, geraniin caused morphological alterations of these rod-shaped bacteria, including degradation of their envelopes, as also suggested by the incorporation of SYTOX. These alterations were often accompanied by cytoplasm leakage and the formation of more pronounced whitish areas in the cytoplasm similar to vacuolization. Moreover, multi-membranous and/or –wall systems were at times formed in the treated bacteria. The presence of some extracellular electron-dense material was frequently noted around the treated bacteria. The matrix surrounding control bacteria tended to disappear after geraniin treatment. This study highlights for the first time the effect of geraniin on bacterial ultrastructure, thus contributing to a better understanding of the mechanism by which this molecule exerts antibacterial activity.

Probing triplet transport in singlet fission materials can be challenging due to the presence of multiple diffusing species. We present a device-based method to measure the intrinsic triplet diffusion length (LD) in organic semiconductor thin films exhibiting singlet fission. Triplet states are optically injected into the singlet fission material of interest via energy transfer from an adjacent thin film characterized by strong spin-orbit coupling. Injected triplets migrate through the full thickness of the material before undergoing dissociation at a donor-acceptor interface. By modeling the ratio of injector and acceptor photocurrent as a function of layer thickness, the triplet LD is extracted separate from processes of unknown efficiency including singlet fission and diffusion. In considering three archetypical fission systems, a wide range is found for the triplet LD, ranging from 3.3 ± 0.4 nm for 5,12-bis((triisopropylsilyl)ethynyl)tetracene to 17.1 ± 1.3 nm for pentacene and 32.1 ± 2.6 nm for tetracene.

Transition metal complexes are often prodrugs which undergo activation by ligand exchange and redox reactions before they interact with target sites. It is therefore important to understand the roles of both the metal and the ligands in their activation, especially in cells. Here we use a combination of synchrotron nanoprobe X-ray fluorescence (XRF) from Os L3M5 and Br KL3 emissions and inductively coupled plasma-mass spectrometry (ICP-MS) detection of 189Os, 79Br, and 127I, to investigate the time-dependent accumulation and localization of osmium as well as the monodentate ligand and the chelated phenylazopyridine in A2780 human ovarian cancer cells treated with the potent anticancer complexes [Os(η6-p-cymene)(4-R2-phenyl-azopyridine-5-R1)X]PF6, with R2 = NMe2 or OH, R1 = H or Br, and X = Cl or I. The data confirm that the relatively inert iodido complexes are activated rapidly in cancer cells by release of the iodido ligand, probably initiated by attack by the intracellular tripeptide glutathione (γ-L-Glu-l-Cys-Gly) on the azo double bond. The bond between osmium and the azopyridine appears to remain stable in cells for ca. 24 h, although some release of the chelated ligand is observed. Interestingly, the complexes seem to be degraded more rapidly in normal human cells, perhaps providing a possible mechanism for selective cytotoxicity towards cancer cells.

The non-canonical fungal α-humulene synthase was investigated through isotopic labelling experiments for its stereochemical course regarding inversion or retention at C-1, the face selectivity at C-11, and the stereoselectivity of the final deprotonation. A new and convenient desymmetrisation strategy was developed to enable a full stereochemical analysis of the catalysed steps to the achiral α-humulene product from stereoselectively labelled farnesyl diphosphate.

The effect of static silica particles on the dynamics of quantum dot (QD) nanoparticles grafted with a poly(ethylene glycol) (PEG) brush in hydrogel nanocomposites is investigated using single particle tracking (SPT). At a low volume fraction of homogeneously dispersed silica (Φ = 0.005), two distinct populations of PEG-QDs are observed, localized and mobile, whereas almost all PEG-QDs are mobile in neat hydrogel (Φ = 0.0). Increasing the silica particle concentration (Φ = 0.01, 0.1) results in an apparent change in the network structure, confounding the impact of silica on PEG-QD dynamics. The localized behavior of PEG-QDs is attributed to pH-mediated attraction between the PEG brush on the probe and surface silanol groups of silica. Using quartz crystal microbalance with dissipation (QCM-D), the extent of this interaction is investigated as a function of pH. At pH 5.8, the PEG brush on the probe can hydrogen bond with the silanol groups on silica, leading to adsorption of PEG-QDs. In contrast, at pH 9.2, silanol groups are deprotonated and PEG-QD is unable to hydrogen bond with silica leading to negligible adsorption. To test the effect of pH, PEG-QD dynamics are further investigated in hydrogel nanocomposites at Φ = 0.005. SPT agrees with the QCM-D results; at pH 5.8, PEG-QDs are localized whereas at pH 9.2 the PEG-QDs are mobile. This study provides insight into controlling probe transport through hydrogel nanocomposites using pH-mediated interactions, with implications for tuning transport of nanoparticles underlying drug delivery and nanofiltration.

In this study, we investigated the feasibility of anaerobic sewage treatment at extremely low temperatures (4 °C) using two reactor setups: upflow anaerobic sludge blanket reactors (UASB) without and with (AnMBRUASB(UF)) a membrane. Both reactors were inoculated with seeds derived from sediments that were putatively acclimatized to low temperatures. A preliminary batch trial showed that treatment is feasible with the removal of carbon coupled to methane and sulphide production. The reactors operated for 180 days at a hydraulic retention time of 3 days. After 40 days acclimation, both systems met the EU chemical oxygen demand (COD) effluent standard (

Fusarochromene isolated from the plant pathogenic fungus, Fusarium sacchari is closely related to a group of mycotoxins including fusarochromanone previously isolated from various Fusaria spp. Despite their assumed polyketide biogenesis, incorporation studies with 13C-labelled acetate, glycerol and tryptophans show that fusarochromene is unexpectedly derived via oxidative cleavage of the aromatic amino acid tryptophan. A putative biosynthetic gene cluster has been identified.

The stable complex [bis(toluene-3,4-dithiolato)copper(iii)][NEt3H] has been synthesised and characterised as a square-planar Cu(iii) complex by X-ray photoelectron spectroscopy, cyclic voltammetry and DFT calculations. Intriguingly, when fragmented in FTICR-MS, an unusual [(toluene-3,4-dithiolate)Cu(iii)(peroxide)]- complex is formed by reaction with oxygen. Natural 1,2-dithiolenes known to bind molybdenum might stabilise Cu(iii) in vivo.

The microbial contamination of surfaces presents a significant challenge due to the adverse effects associated with biofilm formation, particularly on implantable devices. Here, the attachment and ...

Nanorod diffusion in polymer melts is faster than predicted by the continuum model (CM). Rutherford backscattering spectrometry is used to measure the concentration profile of titanium dioxide (TiO2) nanorods (L = 43 nm, d = 5 nm) in a polystyrene (PS) matrix having molecular weights (M) from 9 to 2000 kDa. In the entangled regime, the tracer diffusion coefficients (D) of TiO2 decrease as the M–1.4, whereas the CM predicts DCM ∼ M–3.0 using the measured zero-shear viscosity of TiO2(1 vol %): PS(M) blends. By plotting D/DCM versus M/Me, where Me is the entanglement molecular weight, diffusion is enhanced by a factor of 10–103 as M/Me increases. The faster diffusion is attributed to decoupling of nanorod diffusion from polymer relaxations in the surrounding matrix, which is facilitated by the nanorod dimensions (i.e., L greater than and d less than the entanglement mesh size, 8 nm).

Optical absorption due to surface plasmon resonances in ensembles of gold nanorods (Au NRs) depends strongly on the nanorod separation and orientation. Here, we study the dispersion of polystyrene-functionalized Au NRs in polystyrene (PS) thin films using UV-visible (UV-vis) spectroscopy and transmission electron microscopy (TEM) and find that Au NRs are dispersed for brush chain lengths that exceed the PS matrix chain length and are aggregated otherwise. Monte Carlo simulations using parameters from classical density functional theory (DFT) calculations indicate that this behavior is due to substantial depletion-attraction forces for brush chain lengths that are much smaller than the PS matrix chain length. Both UV-vis measurements and discrete dipole approximation (DDA) calculations confirm that optical absorption is a facile method to determine nanorod morphology in nanocomposite films (i.e., aggregation or dispersion). Futhermore, a dispersion map is constructed showing the conditions required for nanorod dispersion and, correspondingly, the optical absorption properties of Au NR:PS nanocomposites. Using this information, optically active materials with tunable morphologies can be fabricated and routinely characterized using optical spectroscopic methods.