Phospholipid studies of marine organisms: V1 new α-methoxy acids fromHigginsia tethyoides

The phospholipids of the demospongeHigginsia tethyoides are shown to have at least 16 long-chain α-methoxy acids, which represent a new class of fatty acids. Among them are the saturated α-methoxy acids containing 19–24 carbon atoms. The monounsaturated compounds are 2-OMe-Δ¹⁷-24:1, 2-OMe-Δ¹⁸-25:1, 2-OMeΔ¹⁹-26:1 and 2-OMe-Δ²¹-28:1. The major diunsatured ones were shown to be 2-OMe-Δ^{5, 19}-26:2 and 2-OMe-Δ^{7, 21}-28:2. Small amounts of 2-OMe-23∶1, 2-OMe-26∶3; 2-OMe-27∶1 and 2-OMe-28∶3 were also encountered. Structures of the minor monounsaturated compounds were tentatively assigned as 2-methoxy-16-tricosenoic acid and 2-methoxy-20-heptacosenoic acids. The double bonds of the fatty acids show all-cis configuration. Circular dichroism measurements indicate an R-configuration for the α-methoxy acids. The major component of the total phospholipid acid mixture is 5,9,23-triacontatrienoic acid. Possible biosynthetic routes to these unusual phospholipid acids are discussed. The major phospholipids were phosphatidylethanolamine, phosphatidylglycerol and phosphatidylserine. The distribution of fatty acids among the phospholipids was also investigated.     

Satisfying agent goals by executing different task semantics: HTN, OWL-S or plug one yourself

In this paper, we propose a plan execution architecture which supports different task semantics. This way, each goal that is identified during the deliberation cycle of an agent can be satisfied through tasks defined in different semantics. The capability of supporting different task semantics provides two main advantages. The first advantage is the reuse of legacy artifacts within agent plans. The second advantage is simplifying the adaptation of an agent architecture to different standards of a business organization. In order to integrate various task semantics within a plan execution architecture, we have used a smoothly revised version of a previously articulated workflow model into which different task semantics would be reduced before execution. We have integrated hierarchical task network and OWL-S semantics into our plan execution architecture to test the strength of it in terms of support for executing different task semantics in an agent architecture. We think that such a plan execution architecture will contribute to the industrialization of agent architectures.     

Therapeutic Potential of Antimicrobial Peptides in Polymicrobial Biofilm-Associated Infections

It is widely recognized that many chronic infections of the human body have a polymicrobial etiology. These include diabetic foot ulcer infections, lung infections in cystic fibrosis patients, periodontitis, otitis, urinary tract infections and even a proportion of systemic infections. The treatment of mixed infections poses serious challenges in the clinic. First, polymicrobial communities of microorganisms often organize themselves as biofilms that are notoriously recalcitrant to antimicrobial therapy and clearance by the host immune system. Secondly, a plethora of interactions among community members may affect the expression of virulence factors and the susceptibility to antimicrobials of individual species in the community. Therefore, new strategies able to target multiple pathogens in mixed populations need to be urgently developed and evaluated. In this regard, antimicrobial or host defense peptides (AMPs) deserve particular attention as they are endowed with many favorable features that may serve to this end. The aim of the present review is to offer a comprehensive and updated overview of studies addressing the therapeutic potential of AMPs in mixed infections, highlighting the opportunities offered by this class of antimicrobials in the fight against polymicrobial infections, but also the limits that may arise in their use for this type of application.     

Bond strength of repaired composite resins: surface treatments,adhesive systems,and composite type

The aim of the present study was to investigate the effects of three different surface treatments and two different adhesives on the microtensile bond strength (μTBS) of repaired composites using the same or different type of resin. Twenty-four nano-hybrid (Ceram X mono-C) and 24 nanofilled (Filtek Ultimate-F) composite discs were prepared. The specimens were aged with 5000 thermocycles and randomly divided into groups according to the surface treatment methods: (a) phosphoric acid (b) Er:YAG laser and (c) aluminum trioxide particle (air abrasion). Fresh composite resins (C and F) were added to the treated surfaces with two different adhesives (two-step and one-step self-etch adhesives). Then, the specimens were aged again. The stick-shaped specimens were prepared from the discs (n = 25) and the sticks were subjected to the μTBS test. Results indicated that significant differences were found in μTBS values among the surface treatment methods. In the C groups, the highest μTBS value (41.3 ± 8.3 MPa) was recorded in the air abrasion and one-step self-etch adhesive group, which were repaired with the same kind of composite. In the F groups, the highest μTBS value was observed in the air abrasion and one-step self-etch adhesive (37.6 ± 12.3 MPa) group. The treatment with air abrasion is more effective than the others, and it may be suggested for composite repair.     

Selective and Sustainable Production of Sub-terminal Hydroxy Fatty Acids by a Self-Sufficient CYP102 Enzyme from Bacillus Amyloliquefaciens

Enzymatic hydroxylation of fatty acids by Cytochrome P450s (CYPs) offers an eco-friendly route to hydroxy fatty acids (HFAs), high-value oleochemicals with various applications in materials industry and with potential as bioactive compounds. However, instability and poor regioselectivity of CYPs are their main drawbacks. A newly discovered self-sufficient CYP102 enzyme, BAMF0695 from Bacillus amyloliquefaciens DSM 7, exhibits preference for hydroxylation of sub-terminal positions (ω-1, ω-2, and ω-3) of fatty acids. Our studies show that BAMF0695 has a broad temperature optimum (over 70 % of maximal enzymatic activity retained between 20 to 50 °C) and is highly thermostable (T₅₀ >50 °C), affording excellent adaptive compatibility for bioprocesses. We further demonstrate that BAMF0695 can utilize renewable microalgae lipid as a substrate feedstock for HFA production. Moreover, through extensive site-directed and site-saturation mutagenesis, we isolated variants with high regioselectivity, a rare property for CYPs that usually generate complex regioisomer mixtures. BAMF0695 mutants were able to generate a single HFA regiosiomer (ω-1 or ω-2) with selectivities from 75 % up to 91 %, using C12 to C18 fatty acids. Overall, our results demonstrate the potential of a recent CYP and its variants for sustainable and green production of high-value HFAs.     

Selecting the suitable material handling equipment in the presence of vagueness

Selection of the suitable material handling equipment (MHE) is a very difficult task for the manufacturing companies because of the considerable capital investment required. There are many tangible and intangible factors for choosing the suitable MHE. Multiple criteria decision making (MCDM) has been found to be a useful approach to analyze these conflicting factors. The evaluation of MHE alternatives within the frame of various subjective criteria and the weights of the criteria are usually expressed in linguistic terms. This makes fuzzy logic a more natural approach to this kind of problems. This paper proposes a combined MCDM methodology for evaluation and selection of MHE types for a company in the steel construction industry in Istanbul, Turkey. Fuzzy analytic network process (FANP) is utilized for assigning weights of the criteria for MHE selection and fuzzy technique for order preference by similarity to ideal solution (TOPSIS) is used to determine the most proper system alternative using the criteria weights attained by FANP. The selection is based on the compatibility between MHE and production characteristics. Objective is to select the most efficient MHE considering also the cost efficiency. The study was followed by the sensitivity analyses of the results.     

A comparison of sintering techniques using different particle sized β-SiAlON powders

In the present study sintering behavior and mechanical properties of β-SiAlON ceramics were investigated using different sintering techniques (gas pressured sintering (GPS), pressureless sintering and spark plasma sintering (SPS)) and different particle sized powders (with D_BET 216 and 130 nm). After sintering of the microstructure and phase characterization were carried out using a scanning electron microscope (SEM) and the X-ray diffraction (XRD) method, respectively. All the samples, prepared using fine powder, were sintered at lower temperatures than samples prepared by conventional powder, by two sintering techniques (GPS and pressureless). Additionally, the results showed that cooling rates had an important effect on the formation and the amount of intermediate phase in the sample. As a result, it was shown that the particle size of starting raw materials, the amount of additive, the sintering temperature and the technique had a significant effect on the microstructure and mechanical properties of the SiAlON samples.     

Neural network-supported patient-adaptive fall prevention system

Neural Computing and Applications - Patient falls due to unattended bed-exits are costly to patients, healthcare personnel and hospitals. Numerous researches based on up to three predetermined...     

CuSCN Modified Back Contacts for High Performance CZTSSe Solar Cells

Optimization of the back contact interface is crucial for improving the performance of Cu₂ZnSnS₄ (CZTS) thin film solar cells. In this paper, self-depleted CuSCN is deployed as an intermediate layer at the Mo/CZTS interface to improve the quality of the back contact. This CuSCN layer, obtained via aqueous solution processing, reduces the thickness of Mo(S,Se)₂ and eliminates multi-layer crystallization of the absorber by suppressing the undesirable reaction between Mo and Se during the selenization process. By regulating the selenium infiltration into the CZTS precursor films during the selenization process, highly crystalline, single-layer Cu₂ZnSn(S,Se)₄ (CZTSSe) absorber layers are realized. The single-layer CZTSSe absorber exhibits reduced carrier recombination, enhanced carrier density and increased work function. The improved back contact and absorber layer enables 11.1% power-conversion-efficiency to be achieved.