A case study of serial‐flow car disassembly: Ergonomics,productivity and potential system performance

A recent European Union (EU) directive increases demands on car recycling. Thus, present craft‐type disassembly systems need reconfiguration in order to be more efficient. A line‐based system tested in the Netherlands was investigated regarding system performance and ergonomics. The system had reduced performance compared to the design specifications due to such factors as system losses, operator inexperience, and teamwork deficiencies. Operators' peak low back loads were lower than in Swedish craft‐type systems. Direct, value‐adding work comprised 30% of the workday, compared to about 70% in the Swedish manufacturing industry. Alternative system configurations were simulated and discussed using a novel combination of flow and human simulations. For example, a smaller variation in cycle time implied higher output in number of cars per week and larger operator cumulative loading on the low back. In all models the cumulative load was high compared to the loads previously recorded in assembly work. © 2007 Wiley Periodicals, Inc. Hum Factors Man 17: 331–351, 2007.     

Activity of Selected Group of Monoterpenes in Alzheimer’s Disease Symptoms in Experimental Model Studies—A Non-Systematic Review

Alzheimer’s disease (AD) is the leading cause of dementia and cognitive function impairment. The multi-faced character of AD requires new drug solutions based on substances that incorporate a wide range of activities. Antioxidants, AChE/BChE inhibitors, BACE1, or anti-amyloid platelet aggregation substances are most desirable because they improve cognition with minimal side effects. Plant secondary metabolites, used in traditional medicine and pharmacy, are promising. Among these are the monoterpenes—low-molecular compounds with anti-inflammatory, antioxidant, enzyme inhibitory, analgesic, sedative, as well as other biological properties. The presented review focuses on the pathophysiology of AD and a selected group of anti-neurodegenerative monoterpenes and monoterpenoids for which possible mechanisms of action have been explained. The main body of the article focuses on monoterpenes that have shown improved memory and learning, anxiolytic and sleep-regulating effects as determined by in vitro and in silico tests—followed by validation in in vivo models.     

Cysteine-specific, covalent anchoring of transition organometallic complexes to the protein papain from Carica papaya

Site-directed and covalent introduction of various transition metal-organic entities to the active site of the cysteine endoproteinase, papain, was achieved by treatment of this enzyme with a series of organometallic maleimide derivatives specially designed for the purpose. Kinetic studies made it clear that time-dependent irreversible inactivation of papain occurred in the presence of these organometallic maleimides as a result of Michael addition of the sulfhydryl of Cys25. The rate and mechanism of inactivation were highly dependent on the structure of the organometallic entity attached to the maleimide group. Combined ESI-MS and IR analysis indicated that all the resulting papain adducts contained one organometallic moiety per protein molecule. This confirmed that chemospecific introduction of the metal complexes was indeed achieved. Thus, three novel reagents for heavy-atom derivatization of protein crystals, which include ruthenium, rhenium and tungsten, are now available for the introduction of electron-dense scatterers for phasing of X-ray crystallographic data.     

Localization of double bonds in wax esters by high-performance liquid chromatography/atmospheric pressure chemical ionization mass spectrometry utilizing the fragmentation of acetonitrile-related adducts

Unsaturated wax esters (WEs) provided molecular adducts with C(3)H(5)N ([M + 55](+?)) in APCI sources in the presence of acetonitrile. CID MS/MS of [M + 55](+?) yielded fragments allowing the localization of double bond(s) in the hydrocarbon chains of the WEs. These fragments were formed by a cleavage on each side of the double bond. In methylene-interrupted polyunsaturated WEs, diagnostic fragments related to each double bond were detected; the most abundant were those corresponding to the cleavage of the C-C bond next to the first and the last double bond. To differentiate between those fragments differing in their structure or origin, a simple nomenclature based on α and ω ions has been introduced. Fragmentation of the α-type ions (fragments containing an ester bond) provided information on the occurrence of a double bond in the acid or alcohol part of the WEs. While no significant differences between the spectra of the WEs differing by cis/trans isomerism were found, the isomers were separated chromatographically. A data-dependent HPLC/APCI-MS(2) method for the comprehensive characterization of WEs in their complex mixtures has been developed and applied to natural mixtures of WEs isolated from jojoba oil and beeswax. More than 50 WE molecular species were completely identified, including the information on the acid and alcohol chain length and the position of the double bonds.     

Hybrid solar cells using PbS nanoparticles

Solution-processed bilayer heterojunction hybrid solar cells have been fabricated using size-quantized PbS nanoparticles and poly (3-hexylthiophene) (P3HT). PbS was used as an electron-transporting layer whereas P3HT was used for hole transport. A photovoltaic device consisting of PbS and P3HT exhibited 3% incident photon to current efficiencies (IPCE) under 550-nm monochromatic irradiation.     

Structural Characterization of EnpA D,L-Endopeptidase from Enterococcus faecalis Prophage Provides Insights into Substrate Specificity of M23 Peptidases

The best-characterized members of the M23 family are glycyl-glycine hydrolases, such as lysostaphin (Lss) from Staphylococcus simulans or LytM from Staphylococcus aureus. Recently, enzymes with broad specificities were reported, such as EnpA_CD from Enterococcus faecalis, that cleaves D,L peptide bond between the stem peptide and a cross-bridge. Previously, the activity of EnpA_CD was demonstrated only on isolated peptidoglycan fragments. Herein we report conditions in which EnpA_CD lyses bacterial cells live with very high efficiency demonstrating great bacteriolytic potential, though limited to a low ionic strength environment. We have solved the structure of the EnpA_CD H109A inactive variant and analyzed it in the context of related peptidoglycan hydrolases structures to reveal the bases for the specificity determination. All M23 structures share a very conserved β-sheet core which constitutes the rigid bottom of the substrate-binding groove and active site, while variable loops create the walls of the deep and narrow binding cleft. A detailed analysis of the binding groove architecture, specificity of M23 enzymes and D,L peptidases demonstrates that the substrate groove, which is particularly deep and narrow, is accessible preferably for peptides composed of amino acids with short side chains or subsequent L and D-isomers. As a result, the bottom of the groove is involved in interactions with the main chain of the substrate while the side chains are protruding in one plane towards the groove opening. We concluded that the selectivity of the substrates is based on their conformations allowed only for polyglycine chains and alternating chirality of the amino acids.     

Dyes derived from 1,4‐naphthoquinone as initiators for radical and cationic photopolymerisation

Several 2‐phenylamino‐1,4‐naphthoquinone‐based dyes and two related benzo[2,3‐b]–phenazines were synthesised and characterised by proton nuclear magnetic resonance spectroscopy and electron ionisation mass spectrometry. The electrochemical and spectral properties of these compounds were investigated. The synthesised dyes were found to be capable photosensitisers for radical (reducible/oxidisable) and cationic polymerisations, respectively. In radical polymerization, better results in the oxidisable process were achieved.     

Chemical biology techniques unlock the secrets of casein kinase 2 regulation by phosphorylation and glycosylation

The key to understanding: The application of expressed protein ligation and protein microarrays enabled an unparalleled insight into the complex interaction of phosphorylation and glycosylation on casein kinase 2 and its biological outcome.     

Towards osseointegration of bioinert ceramics: Introducing functional groups to alumina surface by tailored self assembled monolayer technique

The bioinert character of alumina implants does not promote bone bonding, thereby strongly limits possible applications for this material. Bone bonding to the implant surface is significantly dependent on its chemical composition. We hypothesized that a bioinert ceramic can be functionalized, introducing active groups onto the surface by self-assembled monolayer. The surface of alumina was coated with a silica layer using physical vapour deposition or flame pyrolysis. Subsequently SAM was attached by dint of octenyltrichlorosilane. Through further chemical treatments OH- and COOH-functional groups were created on the surface. The evidence of the functional groups was proven by X-ray photoelectron spectroscopy and contact angle measurements. Thereby for the first time functional groups were successfully coupled to an inert alumina surface using the method of SAM. In a next step of development, SAM technique could be used to couple biological agents to inert ceramic implant surfaces aiming the possible improvement of osseointegration.