An adaptive procedure for categorical loudness scaling

In this study, an adaptive procedure for categorical loudness scaling is introduced and evaluated. The procedure adjusts the presentation levels to the subject's individual auditory dynamic range without employing any premeasurement and presents levels in randomized order. The procedure has been named "Oldenburg-ACALOS" (Oldenburg-Adaptive CAtegorical LOudness Scaling). It was evaluated using repeated measurements with ten subjects with normal hearing and ten subjects with sensorineural hearing impairment. The results of this investigation revealed that the adaptive procedure provides greater reliability, while being more time efficient than a reference procedure that uses constant stimuli.     

Synthesis and determination of the absolute configuration of fugomycin and desoxyfugomycin: CD spectroscopy and fungicidal activity of butenolides

The dibromoalkenes (S)-3 and (R)- and (S)-4 are intermediates in the syntheses of the naturally occurring fungicidal butenolides fugomycin (1) and desoxyfugomycin (2), respectively. The stereoselective bromine-lithium exchange that leads to the carbenoid 12 and the vinyllithium reagent 17 a on the one hand, and palladium-catalyzed coupling reactions of the dibromoalkene 3 and the bromolactone 22 on the other are key steps en route to the butenolides 1 and 2. The chiral building blocks (S)-3, (R)-4, and (S)-4 are readily available from (R)-isopropylideneglyceraldehyde 5, isobutyl (R)-lactate 6 a, and ethyl (S)-lactate 6 b, respectively. The synthetic procedure adopted here permits the absolute configuration of the natural products fugomycin (1) and desoxyfugomycin (2) to be assigned by comparison of their chiroptical properties with those of the synthetic products. The CD spectra of the bromolactone 22, calculated by two different density functional methods (TDDFT, DFT/MRCI), are found to be in good agreement with the measured spectra. On the basis of these calculations, the two CD bands observed could be assigned to n-pi* and pi-pi* transitions, respectively. Fugomycin (1) and the synthetic butenolide 20 displayed high fungicidal activity against botrytis in greenhouse experiments, whereas the saturated lactone 21 was practically inactive.     

Self-assembly of an unpolar enantiomerically pure helicate-type metalla-cryptand

Chiral tetraketone ligands are obtained by Claisen-type condensation of 4-bromoacetophenone with the acetone ketal of L-tartraic acid diethylester and lead with gallium(III) or iron(III) ions in self-assembly processes to dinuclear helicate-type cryptands which are able to bind lithium cations.     

Iminoboronates as Dual-Purpose Linkers in Chemical Probe Development

Chemical probes that covalently modify proteins of interest are powerful tools for the research of biological processes. Important in the design of a probe is the choice of reactive group that forms the covalent bond, as it decides the success of a probe. However, choosing the right reactive group is not a simple feat and methodologies for expedient screening of different groups are needed. We herein report a modular approach that allows easy coupling of a reactive group to a ligand. α-Nucleophile ligands are combined with 2-formylphenylboronic acid derived reactive groups to form iminoboronate probes that selectively label their target proteins. A transimination reaction on the labeled proteins with an α-amino hydrazide provides further modification, for example to introduce a fluorophore.     

Triterpenes and Phenolic Compounds from the Fungus Fuscoporia torulosa: Isolation,Structure Determination and Biological Activity

Investigation of the methanol extract of the poroid fungus Fuscoporia torulosa resulted in the isolation of a novel triterpene, fuscoporic acid (1), together with inoscavin A and its previously undescribed Z isomer (2 and 3), 3,4-dihydroxy-benzaldehide (4), osmundacetone (5), senexdiolic acid (6), natalic acid (7), and ergosta-7,22-diene-3-one (8). The structures of fungal compounds were determined on the basis of NMR and MS spectroscopic analyses, as well as molecular modeling studies. Compounds 1, 6–8 were examined for their antibacterial properties on resistant clinical isolates, and cytotoxic activity on human colon adenocarcinoma cell lines. Compound 8 was effective against Colo 205 (IC₅₀ 11.65 ± 1.67 µM), Colo 320 (IC₅₀ 8.43 ± 1.1 µM) and MRC-5 (IC₅₀ 7.92 ± 1.42 µM) cell lines. Potentially synergistic relationship was investigated between 8 and doxorubicin, which revealed a synergism between the examined compounds with a combination index (CI) at the 50% growth inhibition dose (ED₅₀) of 0.521 ± 0.15. Several compounds (1 and 6–8) were tested for P-glycoprotein modulatory effect in Colo 320 resistant cancer cells, but none of the compounds proved to be effective in this assay. Fungal metabolites 2–5 were evaluated for their antioxidant activity using the oxygen radical absorbance capacity (ORAC) and DPPH assays. Compounds 4 and 5 were found to have a considerable antioxidant effect with EC₅₀ 0.25 ± 0.01 (DPPH) and 12.20 ± 0.92 mmol TE/g (ORAC). The current article provides valuable information on both the chemical and pharmacological profiles of Fuscoporia torulosa, paving the way for future studies with this species.     

Identification of energy consumption and nutritional stress by isotopic and elemental analysis of urine in bonobos (Pan paniscus)

A mounting body of evidence suggests that changes in energetic conditions like prolonged starvation can be monitored using stable isotope ratios of tissues such as bone, muscle, hair, and blood. However, it is unclear if urinary stable isotope ratios reflect a variation in energetic condition, especially if these changes in energetic condition are accompanied by shifts in dietary composition. In a feeding experiment conducted on captive bonobos (Pan paniscus), we monitored urinary δ(13)C, δ(15)N, total C (carbon), total N (nitrogen), and C/N ratios and compared these results with glucocorticoid levels under gradually changing energy availability and dietary composition. Measurements of daily collected urine samples over a period of 31 days showed that while shifts in urinary isotope signatures of δ(13)C and δ(15)N as well as total C were best explained by changes in energy consumption, urinary total N excretion as well as the C/N ratios matched the variation in dietary composition. Furthermore, when correcting for fluctuations in dietary composition, the isotope signatures of δ(13)C and δ(15)N as well as total C correlated with urinary glucocorticoid levels; however, the urinary total N and the C/N ratio did not. These results indicate for the first time that it is possible to non-invasively explore specific longitudinal records on animal energetic conditions and dietary compositions with urinary stable isotope ratios and elemental compositions, and this research provides a strong foundation for investigating how ecological factors and social dynamics affect feeding habits in wild animal populations such as primates.     

The Electrochemical Stability of Starch Carbon as an Important Property in the Construction of a Lithium-Ion Cell

This paper shows use of starch-based carbon (CSC) and graphene as the anode electrode for lithium-ion cell. To describe electrochemical stability of the half-cell system and kinetic parameters of charging process in different temperatures, electrochemical impedance spectroscopy (EIS) measurement was adopted. It has been shown that smaller resistances are observed for CSC. Additionally, Bode plots show high electrochemical stability at higher temperatures. The activation energy for the SEI (solid–electrolyte interface) layer, charge transfer, and electrolyte were in the ranges of 24.06–25.33, 68.18–118.55, and 13.84–15.22 kJ mol⁻¹, respectively. Moreover, the activation energy of most processes is smaller for CSC, which means that this electrode could serve as an eco-friendly biodegradable lithium-ion cell element.     

From Damage to Delamination

Delamination models are derived as the limits of models for partial isotropic volume damage via dimension reduction. (© 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)