Enantiospecific Effect of Pulegone and Pulegone-Derived Lactones on Myzus persicae (Sulz.) Settling and Feeding

The effect of pulegone chiral center configuration on its antifeedant activity to Myzus persicae was examined. Biological consequences of structural modifications of (R)-(+)- and (S)-(−)-pulegone, the lactonization, iodolactonization, and incorporation of hydroxyl and carbonyl groups were studied, as well. The most active compounds were (R)-(+)-pulegone (1a) and δ-hydroxy-γ-spirolactones (5S,6R,8S)-(−)-6-hydroxy-4,4,8-trimethyl-1-oxaspiro[4.5]decan-2-one (5b) and (5R,6S,8S)-6-hydroxy-4,4,8-trimethyl-1-oxaspiro[4.5]decan-2-one (6b) derived from (S)-(−)-pulegone (1b). The compounds deterred aphid probing and feeding at preingestional, ingestional, and postingestional phases of feeding. The preingestional effect of (R)-(+)-pulegone (1a) was manifested as difficulty in finding and reaching the phloem (i.e., prolonged time preceding the first contact with phloem vessels), a high proportion of probes not reaching beyond the mesophyll layer before first phloem phase, and/or failure to find sieve elements by 20% of aphids during the 8-hr experiment. The ingestional activity of (R)-(+)-pulegone (1a) and hydroxylactones 5b and 6b resulted in a decrease in duration of phloem sap ingestion, a decrease in the proportion of aphids with sustained sap ingestion, and an increase in the proportion of aphid salivation in phloem. δ-Keto-γ-spirolactone (5R,8S)-(−)-4,4,8-trimethyl-1-oxaspiro[4.5]decan-2,6-dione (8b) produced a weak ingestional effect (shortened phloem phase). The postingestional deterrence of (R)-(+)-pulegone (1a) and δ-hydroxy-γ-spirolactones (5R,6S,8R)-(+)-6-hydroxy-4,4,8-trimethyl-1-oxaspiro[4.5]-decan-2-one (5a), 5b, (5S,6R,8R)-6-hydroxy-4,4,8-trimethyl-1-oxaspiro[4.5]decan-2-one (6a), 6b, and δ-keto-γ-spirolactone 8b prevented aphids from settling on treated leaves. The trans position of methyl group CH₃–8 and the bond C5–O1 in lactone 6b appeared to weaken the deterrent activity in relation to the cis diastereoisomer (5b).     

Multi-scale modelling of elastic moduli of trabecular bone

We model trabecular bone as a nanocomposite material with hierarchical structure and predict its elastic properties at different structural scales. The analysis involves a bottom-up multi-scale approach, starting with nanoscale (mineralized collagen fibril) and moving up the scales to sub-microscale (single lamella), microscale (single trabecula) and mesoscale (trabecular bone) levels. Continuum micromechanics methods, composite materials laminate theory and finite-element methods are used in the analysis. Good agreement is found between theoretical and experimental results.     

The model of maintenance planning and production scheduling for maximising robustness

The accuracy of prediction and detection capability have a strong influence over the efficiency of the bottleneck, all equipment and the production system. The function of predictive scheduling is to obtain stable and robust schedules for a shop floor. The first objective is to present an innovative maintenance planning and production scheduling method. The approach consists of four modules: a database to collect information about failure-free times, a prediction module of failure-free times, predictive scheduling and rescheduling module, a module for evaluating the accuracy of prediction and maintenance performance. The second objective is to apply the proposed methods for a job shop scheduling problem. Usually, researchers who are concerned about maintenance scheduling do not take unexpected disturbances into account. They assume that machines are always available for processing tasks during the future-planned production time. Moreover, researches use the criteria that are not effective to deal with the situation of unpredicted failures. In this paper, a method based on probability theory is proposed for maintenance scheduling. For unpredicted failures, a rescheduling method is also proposed. The evaluation module which gives information about the degradation of each performance measure and the stability of a schedule is proposed.     

A statistical filtering method for denoising of micro-force measurements

Precise measurement of mechanical forces is crucial to efficient micro-manufacturing. The quality of such measurements depends heavily on the properties of the noise inevitably accompanying every measurement process. In the micro-range, the signal-to-noise ratio tends to be very low, and the noise dynamic varies for different frequencies. In result, common denoising methods that assume white noise perform poorly in this setting. In this paper, a novel, easily implementable denoising method based on a local statistic of the measured data’s spectrum is proposed. By testing it on a representative dataset, it is shown that the proposed method is robust and stable. Particularly, it allows for an efficient retrieval of the force signal encountered in micro-milling processes.     

Cherry (Prunus cerasus cv Montmorency) extract with standardised antioxidant potential as preservative for refrigerated storage of ground pork

Antioxidants occurring naturally are much sought‐after for their safety of use for human nutrition and strong preservative properties. The study was performed to determine the antioxidant potential of sour cherry extract and its effect (equivalent of 20 mg and 40 mg GAE kg^?1) on the quality of ground pork patties during 8‐day storage. The patties were analysed for antioxidant capacity, oxidation, profile of fatty acids, flavour, colour, sensory properties and aerobic bacteria count. Patties with addition of cherry extract (40 mg GAE kg^?1) showed higher antioxidant capacity of 844 ± 149 μmol TE L^‐1 on the last day of the storage than the control group where the result was 480 ± 81 μmol TE L^‐1. The addition of extract caused lower overall increase in lipid oxidation and prevented loss of redness even on the last day of the storage. Flavour changes resulted from oxidation and decrease in the amount of desirable volatile compounds in storage. The application of the extract from Prunus cerasus combined with vacuum packaging inhibited both oxidation and quality deterioration of pork patties in cold storage.     

Studies of the Kinetics of Lithium Grease Microstructure Regeneration by Means of Dynamic Oscillatory Rheological Tests and FTIR–ATR Spectroscopy

As part of this research, the kinetics of soap grease thickener microstructure regeneration during 24-h relaxation after 1-h shearing were studied. A lubricating grease, based on mineral oil ORLEN OIL SN-400, containing associated molecules of lithium 12-hydroxystearate was subjected to analysis. Rheological dynamic oscillatory and FTIR–ATR (Fourier Transform Infrared Attenuated Total Reflectance) spectroscopy were used to study the kinetics of thickener microstructure regeneration. Changes in the values of storage modulus G′ and loss modulus G″ of the investigated grease during its relaxation in the linear viscoelastic range were examined. In addition, the mechanical stability of the thickener microstructure at a variable oscillation frequency was tested, and changes in the cohesive energy of the grease versus the latter’s relaxation time were assessed. FTIR–ATR spectroscopy was used to study the physicochemical interactions between the associated molecules of lithium 12-hydroxystearate. Infrared bands were assigned to the vibrations of the particular functional groups of the grease components, and the spectral parameters in the absorption spectra in the range of 700–3,700 cm^?1 were examined. The studies carried out using the two investigative methods have revealed that the intensity of thickener microstructure regeneration was the highest in the first hour of grease relaxation after shearing. In this time interval, the largest changes in the vibrations of the main functional groups of the grease components were observed. In the next hours, the kinetics of thickener microstructure regeneration were substantially lower.     

The Lipid A from the Lipopolysaccharide of the Phototrophic Bacterium Rhodomicrobium vannielii ATCC 17100 Revisited

The structure of lipid A from lipopolysaccharide (LPS) of Rhodomicrobium vannielii ATCC 17100 (Rv) a phototrophic, budding bacterium was re-investigated using high-resolution mass spectrometry, NMR, and chemical degradation protocols. It was found that the (GlcpN)-disaccharide lipid A backbone was substituted by a GalpA residue that was connected to C-1 of proximal GlcpN. Some of this GalpA residue was β-eliminated by alkaline de-acylation, which indicated the possibility of the presence of another so far unidentified substituent at C-4 in non-stoichiometric amounts. One Manp residue substituted C-4′ of distal GlcpN. The lipid A backbone was acylated by 16:0(3-OH) at C-2 of proximal GlcpN, and by 16:0(3-OH), i17:0(3-OH), or 18:0(3-OH) at C-2′ of distal GlcpN. Two acyloxy-acyl moieties that were mainly formed by 14:0(3-O-14:0) and 16:0(3-O-22:1) occupied the distal GlcpN of lipid A. Genes that were possibly involved in the modification of Rv lipid A were compared with bacterial genes of known function. The biological activity was tested at the model of human mononuclear cells (MNC), showing that Rv lipid A alone does not significantly stimulate MNC. At low concentrations of toxic Escherichia coli O111:B4 LPS, pre-incubation with Rv lipid A resulted in a substantial reduction of activity, but, when higher concentrations of E. coli LPS were used, the stimulatory effect was increased.     

Selected Natural Products in Neuroprotective Strategies for Alzheimer’s Disease—A Non-Systematic Review

Neurodegenerative disorders such as Alzheimer’s disease (AD) are distinguished by the irreversible degeneration of central nervous system function and structure. AD is characterized by several different neuropathologies—among others, it interferes with neuropsychiatrical controls and cognitive functions. This disease is the number one neurodegenerative disorder; however, its treatment options are few and, unfortunately, ineffective. In the new strategies devised for AD prevention and treatment, the application of plant-based natural products is especially popular due to lesser side effects associated with their taking. Moreover, their neuroprotective activities target different pathological mechanisms. The current review presents the anti-AD properties of several natural plant substances. The paper throws light on products under in vitro and in vivo trials and compiles information on their mechanism of actions. Knowledge of the properties of such plant compounds and their combinations will surely lead to discovering new potent medicines for the treatment of AD with lesser side effects than the currently available pharmacological proceedings.     

Influence of Electrostatic Interactions on Complexes with Short O···O Hydrogen Bonds in Basic Salts of Pyridine Betaines and Acid Salts of ω-Phenyloalkanocarboxylic Acids

The isostructural complexes [C₅H₅N⁺(CH₂)_nCOO]₂HX and [C₆H₅(CH₂)_nCOO]₂HK (n = 1–4), which differ in their counterions and charge on the ring, were synthesized, and their powder FT-IR spectra analyzed. All complexes containing a charged pyridine ring are of Hadži type iii, characterized by an intense broad (continuum) absorption below 1600 cm⁻¹ typical of a short-strong hydrogen bond (SSHB) with a delocalized proton and a single vC=O band. The positively charged nitrogen atoms interact electrostatically with the X⁻ ion and, additionally, with one of the oxygen atoms of the carboxylic group, producing a more or less symmetric environment of the H-bonded proton, and stabilizing the SSHB. The broad absorption of [C₆H₅CH₂COO]₂HK is very similar to that of other pyridine complexes. Upon addition of methylene groups the broad absorption moves to higher wavenumbers, the O···O distance is elongated, and the H-bonded proton becomes more localized. In the spectrum of [C₆H₅(CH₂)₄COO]₂HK the vC=O and v_asCOO bands were found at 1704 and 1641 cm⁻¹, respectively, which shows that the H-bonded proton is asymmetrically located. The observed variation of absorption with the number of CH₂ groups reflects changes of contacts between the K⁺ ion and COO⁻ groups.     

Recombination and Pol ζ Rescue Defective DNA Replication upon Impaired CMG Helicase—Pol ε Interaction

The CMG complex (Cdc45, Mcm2–7, GINS (Psf1, 2, 3, and Sld5)) is crucial for both DNA replication initiation and fork progression. The CMG helicase interaction with the leading strand DNA polymerase epsilon (Pol ε) is essential for the preferential loading of Pol ε onto the leading strand, the stimulation of the polymerase, and the modulation of helicase activity. Here, we analyze the consequences of impaired interaction between Pol ε and GINS in Saccharomyces cerevisiae cells with the psf1-100 mutation. This significantly affects DNA replication activity measured in vitro, while in vivo, the psf1-100 mutation reduces replication fidelity by increasing slippage of Pol ε, which manifests as an elevated number of frameshifts. It also increases the occurrence of single-stranded DNA (ssDNA) gaps and the demand for homologous recombination. The psf1-100 mutant shows elevated recombination rates and synthetic lethality with rad52Δ. Additionally, we observe increased participation of DNA polymerase zeta (Pol ζ) in DNA synthesis. We conclude that the impaired interaction between GINS and Pol ε requires enhanced involvement of error-prone Pol ζ, and increased participation of recombination as a rescue mechanism for recovery of impaired replication forks.