A linear single-molecule magnet based on [Ru(III)(CN)6]3-

We report the synthesis, structure and magnetic properties of the first molecular cluster and single-molecule magnet to incorporate [Ru(III)(CN)(6)](3-). Frequency-domain Fourier-transform THz-EPR (FDFT THz-EPR) and magnetic susceptibility measurements indicate strongly anisotropic Mn-Ru exchange interactions.     

Pretreatment of Chicken Feather Waste for Improved Biogas Production

This study deals with the utilization of chicken feather waste as a substrate for anaerobic digestion and improving biogas production by degradation of the compact structure of the feather keratin. In order to increase the digestibility of the feather, different pretreatments were investigated, including thermal pretreatment at 120 °C for 10 min, enzymatic hydrolysis with an alkaline endopeptidase [0.53–2.66 mL/g volatile solids (VS) feathers] for 0, 2, or 24 h at 55 °C, as well as a combination of these pretreatments. The effects of the treatments were then evaluated by anaerobic batch digestion assays at 55 °C. The enzymatic pretreatment increased the methane yield to 0.40 Nm³/kg VS_added, which is 122 % improvement compared to the yield of the untreated feathers. The other treatment conditions were less effective, increasing the methane yield by 11–50 %. The long-term effects of anaerobic digestion of feathers were examined by co-digestion of the feather with organic fraction of municipal solid waste performed with and without the addition of enzyme. When enzyme was added together with the feed, CH₄ yield of 0.485 Nm³/kg VS^?1 d^?1 was achieved together with a stable reactor performance, while in the control reactor, a decrease in methane production, together with accumulation of undegraded feather, was observed.     

Rapid synthesis of SBA-15 rods with variable lengths, widths, and tunable large pores

Dispersed SBA-15 rods have been synthesized with varying lengths, widths, and pore sizes in a low-temperature synthesis in the presence of heptane and NH(4)F. The pore size of the material can systematically be varied between 11 and 17 nm using different hydrothermal treatment times and/or temperatures. The particle length (400-600 nm) and width (100-400 nm) were tuned by varying the HCl concentration. All the synthesized materials possess a large surface area of 400-600 m(2)/g and a pore volume of 1.05-1.30 cm(3). A mechanism for the effect of the HCl concentration on the particle morphology is suggested. Furthermore, it is shown that the reaction time can be decreased to 1 h, with well-retained pore size and morphology. This work has resulted in SBA-15 rods with the largest pore size reported for this morphology.     

Infrared (810 nm) low-level laser therapy in rat achilles tendinitis: a consistent alternative to drugs

Nonsteroidal anti-inflammatory drugs (NSAIDs) are widely used and can reduce musculoskeletal pain in spite of the cost of adverse reactions like gastrointestinal ulcers or cardiovascular events. The current study investigates if a safer treatment such as low-level laser therapy (LLLT) could reduce tendinitis inflammation, and whether a possible pathway could be through inhibition of either of the two-cyclooxygenase (COX) isoforms in inflammation. Wistar rats (six animals per group) were injected with saline (control) or collagenase in their Achilles tendons. Then, we treated them with three different doses of IR LLLT (810 nm; 100 mW; 10 s, 30 s and 60 s; 3.57 W cm(-2); 1 J, 3 J, 6 J) at the sites of the injections, or intramuscular diclofenac, a nonselective COX inhibitor/NSAID. We found that LLLT dose of 3 J significantly reduced inflammation through less COX-2-derived gene expression and PGE(2) production, and less edema formation compared to nonirradiated controls. Diclofenac controls exhibited significantly lower PGE(2) cytokine levels at 6 h than collagenase control, but COX isoform 1-derived gene expression and cytokine PGE(2) levels were not affected by treatments. As LLLT seems to act on inflammation through a selective inhibition of the COX-2 isoform in collagenase-induced tendinitis, LLLT may have potential to become a new and safer nondrug alternative to coxibs.     

Über freie Faktorgruppen und freie Untergruppen gegebener Gruppen

Ohne ZusammenfassungPh. Furtwängler zum 70. Geburtstag.     

Über Automorphismen von Fundamentalgruppen berandeter Flächen

Ohne Zusammenfassung     

Catalysis enabled synthesis,structures, and reactivities of fluorinated S8-corona[n]arenes (n = 8–12)

Previously inaccessible large S₈-corona[n]arene macrocycles (n = 8–12) with alternating aryl and 1,4-C₆F₄ subunits are easily prepared on up to gram scales, without the need for chromatography (up to 45% yield, 10 different examples) through new high acceleration S_NAr substitution protocols (catalytic NR₄F in pyridine, R = H, Me, Bu). Macrocycle size and functionality are tunable by precursor and catalyst selection. Equivalent simple NR₄F catalysis allows facile late-stage S_NAr difunctionalisation of the ring C₆F₄ units with thiols (8 derivatives, typically 95+% yields) providing two-step access to highly functionalised fluoromacrocycle libraries. Macrocycle host binding supports fluoroaryl catalytic activation through contact ion pair binding of NR₄F and solvent inclusion. In the solid-state, solvent inclusion also intimately controls macrocycle conformation and fluorine–fluorine interactions leading to spontaneous self-assembly into infinite columns with honeycomb-like lattices.

NR₄F salts simultaneously catalyse and template the reaction of dithiols with C₆F₆ to generate the first fluorinated corona[n]arenes. Simple S_NAr functionalisation of the fluoraryl units easily afford diverse libraries of macrocyclic building blocks.     

Ability of Particulate Matter Index to describe sooting tendency of various gasoline formulations in a stratified-charge spark-ignition engine

This study investigates the ability of Particulate Matter Index (PMI) to describe the sooting behavior of various gasoline formulations in a stratified-charge (SC) spark-ignition engine. The engine was operated at 2000 rpm with an intake pressure of 130 kPa where soot formation is known to primarily occur in the bulk gases. Exhaust soot emissions were measured for nine test fuels at various exhaust gas recirculation levels. A comparison between measured soot levels and PMI shows that PMI is a relatively poor predictor of the sooting tendency of the tested fuels under lean SC combustion. Among the fuels, three fuels, namely the di-isobutylene blend, High Olefin, and E30 fuels exhibit measured soot behavior opposite of that predicted by PMI. Optical diagnostics were utilized to further investigate the in-cylinder phenomena for these three fuels. Analysis of natural luminosity and diffused back-illumination extinction imaging suggests that fuel-induced differences in the amount of soot formed are responsible for a majority of the discrepancy in measured versus predicted sooting tendency. Fuel-induced differences in soot oxidation and spray development seem to play minor roles. Because the combustion and air-fuel mixing processes for lean SC combustion are different from conventional stoichiometric operation it is hypothesized that the PMI correlation needs to be modified to account for differences in stoichiometric air-fuel ratio and level of oxygenation between fuels. Furthermore, the role of fuel volatility in PMI possibly needs to be de-emphasized for SC operation with fuel injection into compression-heated gases.     

Impact of Surface Defects on LaNiO3 Perovskite Electrocatalysts for the Oxygen Evolution Reaction

Perovskite oxides are regarded as promising electrocatalysts for water splitting due to their cost-effectiveness, high efficiency and durability in the oxygen evolution reaction (OER). Despite these advantages, a fundamental understanding of how critical structural parameters of perovskite electrocatalysts influence their activity and stability is lacking. Here, we investigate the impact of structural defects on OER performance for representative LaNiO₃ perovskite electrocatalysts. Hydrogen reduction of 700 °C calcined LaNiO₃ induces a high density of surface oxygen vacancies, and confers significantly enhanced OER activity and stability compared to unreduced LaNiO₃; the former exhibit a low onset overpotential of 380 mV at 10 mA cm⁻² and a small Tafel slope of 70.8 mV dec⁻¹. Oxygen vacancy formation is accompanied by mixed Ni²⁺/Ni³⁺ valence states, which quantum-chemical DFT calculations reveal modify the perovskite electronic structure. Further, it reveals that the formation of oxygen vacancies is thermodynamically more favourable on the surface than in the bulk; it increases the electronic conductivity of reduced LaNiO₃ in accordance with the enhanced OER activity that is observed.