Vibration produced by hand-held olive electrical harvesters

The paper reports the results of some laboratory and field tests aimed at assessing the acceleration levels transmitted to the hand-arm system by electric portable harvesters for olive. Four harvesting heads, different for shape and kinematic system, and five bars, different for diameter, length and material (aluminium and carbon fibre), were used in assembling eleven harvesters. The vibrations were measured in two points, next to the handgrips. The laboratory tests allowed the evaluation of the acceleration levels in standard controlled conditions, while the field tests allowed the assessing of the effects of the tree canopy with respect to the no load running. The laboratory tests showed that in reducing the vibration level plays a major role the kinematic system of the harvesting head and then the bar material. The classical flap-type harvester produced accelerations of around 20 m/s2, while by using a harvesting head with two parts in opposite movement, the accelerations were lowered to about 6 m/s2. The use of carbon fibres for the bars, besides the reduction in weight, produced also a reduction in acceleration (from 21 to 16 m/s2). The field tests proved that the tree canopy had a negative effect on the vibrations transmitted to the hand-arm system, especially when the aluminium bar of small diameter was used

Antimicrobial and Antibiofilm Activity of a Recombinant Fragment of β-Thymosin of Sea Urchin Paracentrotus lividus

With the aim to obtain new antimicrobials against important pathogens such as Staphylococcus aureus and Pseudomonas aeruginosa, we focused on antimicrobial peptides (AMPs) from Echinoderms. An example of such peptides is Paracentrin 1 (SP1), a chemically synthesised peptide fragment of a sea urchin thymosin. In the present paper, we report on the biological activity of a Paracentrin 1 derivative obtained by recombination. The recombinant paracentrin RP1, in comparison to the synthetic SP1, is 22 amino acids longer and it was considerably more active against the planktonic forms of S. aureus ATCC 25923 and P. aeruginosa ATCC 15442 at concentrations of 50 µg/mL. Moreover, it was able to inhibit biofilm formation of staphylococcal and P. aeruginosa strains at concentrations equal to 5.0 and 10.7 µg/mL, respectively. Molecular dynamics (MD) simulations allowed to rationalise the results of the experimental investigations, providing atomistic insights on the binding of RP1 toward models of mammalian and bacterial cell membranes. Overall, the results obtained point out that RP1 shows a remarkable preference for bacterial membranes, in excellent agreement with the antibacterial activity, highlighting the promising potential of using the tested peptide as a template for the development of novel antimicrobial agents

Synthesis, characterization, and in vitro antimicrobial activity of organotin(IV) complexes with triazolo-pyrimidine ligands containing exocyclic oxygen atoms.

Tri-organotin(IV) complexes of the triazolo-pyrimidine derivatives 4,5-dihydro-5-oxo-[1,2,4]triazolo-[1,5a]pyrimidine (5HtpO), 4,7-dihydro-5-methyl-7-oxo-[1,2,4]triazolo-[1,5a]pyrimidine (HmtpO), and 4,5,6,7-tetrahydro-5,7-dioxo-[1,2,4]triazolo-[1,5a]pyrimidine (H2tpO2), and the diorganotin derivative n-Bu2Sn(tpO2), were synthesized and characterized by means of infrared and 119Sn Mo¨ssbauer spectroscopy. In all the complexes obtained the triazolopyrimidines act as multidentate ligands producing polymeric structures. A trigonal bipyramidal arrangement of the ligands around the tin atom is proposed for triorganotin(IV) derivatives, with organic groups on the equatorial plane and bridging anionic ligands. DFT calculations were performed on the structure of H2tpO2 and on its mono- an di-anions, to investigate their harmonic vibrational modes. The observed trend of the experimental and calculated carbonyl stretching frequencies furnishes a support for the interpretation of the structure of the organotin(IV) complexes obtained with this ligand. The structure of n-Bu2Sn(tpO2) was elucidated by quantum chemical calculations, performed on a model system of the polymeric complex by a two layers ONIOM method. The combined experimental and theoretical results obtained support for a trans-n-Bu2 distorted octahedral geometry, with the tpO2 2 units acting as bis-chelate ligands bridging the diorganotin(IV) moieties, and with the N(1)O(7) and N(4)O(5) chelating groups in the equatorial plane showing a cis-O2, or cis-N2, coordination. In vitro antimicrobial tests were performed on n-Bu3Sn(HtpO2) and Ph3Sn(HtpO2), and a good antifungal and antibiofilm activity was observed, in particular for n-Bu3Sn(HtpO2)

Paracentrin 1, a synthetic antimicrobial peptide from the sea-urchin Paracentrotus lividus, interferes with staphylococcal and Pseudomonas aeruginosa biofilm formation

The rise of antibiotic-resistance as well as the reduction of investments by pharmaceutical companies in the development of new antibiotics have stimulated the investigation for alternative strategies to conventional antibiotics. Many antimicrobial peptides show a high specificity for prokaryotes and a low toxicity for eukaryotic cells and, due to their mode of action the development of resistance is considered unlikely. We recently characterised an antimicrobial peptide that was called Paracentrin 1 from the 5-kDa peptide fraction from the coelomocyte cytosol of the Paracentrotus lividus. In this study, the chemically synthesised Paracentrin 1, was tested for its antimicrobial and antibiofilm properties against reference strains of Gram positive and Gram negative. The Paracentrin 1 was active against planktonic form of staphylococcal strains (reference and isolates) and Pseudomonas aeruginosa ATCC 15442 at concentrations ranging from 12.5 to 6.2 mg/ml. The Paracentrin 1 was able to inhibit biofilm formation of staphylococcal and Pseudomonas aeruginosa strains at concentrations ranging from 3.1 to 0.75 mg/ml. We consider the tested peptide as a good starting molecule for novel synthetic derivatives with improved pharmaceutical potentia

Investigation of hand forces applied to a pruning tool – pilot study

Introduction Winter pruning is a cultivation practice necessary for maintaining the balance between the vegetative and the productive activity of plants and requires many working days using hand scissors. This operation involves the subjects carrying out a series of gestures that are repeated with considerable frequency, which are all musculo-skeletal disorders risk factors (MSDs) for the hand-wrist area. Objective The aim of this study was to investigate the forces applied to pruning tools. Material and methods Using a sensor matrix, peak and average forces were measured which are exerted while cutting branches of 3 different diameters, from 5 wine-grape cultivars. Samples were tested on 8 participants using sensored scissors to record, in 6 hand areas, the forces necessary to cut. Results Results showed that while cutting, the factors which can impact the force employed (peak and average forces) by the subjects are branch diameter and percentage of branch humidity. Cut duration was inversely related to the size of the subject's hand. The middle finger area of the hand recorded the highest force average and peak levels, while the hand region least affected during the cuts was the farthest from the thumb. Conclusions The study enabled the highlighting of which factors influence the forces employed by the operator while cutting grape branches, and to identify the hand regions where muscle activation is at its most. These findings can be relevant in preventing MSDs. Further studies need to be conducted with a larger number of subjects

Lhermitte-Duclos disease presenting with positron emission tomography-magnetic resonance fusion imaging: a case report

<p>Abstract</p> <p>Introduction</p> <p>Lhermitte-Duclos disease or dysplastic gangliocytoma of the cerebellum is an extremely rare tumor. It is a slowly enlarging mass within the cerebellar cortex. The majority of cases are diagnosed in the third or fourth decade of life.</p> <p>Case presentation</p> <p>We report the case of a 37-year-old Caucasian woman who underwent positron emission tomography-computed tomography with fluorine-18-fluorodeoxyglucose for evaluation of a solitary lung node. No pathological uptake was detected in the solitary lung node but the positron emission tomography-computed tomography of her brain showed intense tracer uptake, suggestive of a malignant neoplasm, in a mass in her left cerebellar lobe. Our patient had experienced two years of occipital headache and movement disorder. Subsequently, magnetic resonance imaging was performed with contrast agent administration, showing a large subtentorial mass in her left cerebellar hemisphere, with compression and dislocation of the fourth ventricle. Metabolic data provided by positron emission tomography and morphological magnetic resonance imaging views were fused in post-processing, allowing a diagnosis of dysplastic gangliocytoma with increased glucose metabolism. Total resection of the tumor was performed and histological examination confirmed the diagnosis of Lhermitte-Duclos disease.</p> <p>Conclusions</p> <p>Our case indicates that increased uptake of fluorine-18-fluorodeoxyglucose may be misinterpreted as a neoplastic process in the evaluation of patients with Lhermitte-Duclos disease, but supports the usefulness of integrated positron emission tomography-magnetic resonance imaging in the exact pathophysiologic explanation of this disease and in making the correct diagnosis. However, an accurate physical examination and exact knowledge of clinical data is of the utmost importance.</p

A Novel Peptide with Antifungal Activity from Red Swamp Crayfish Procambarus clarkii

The defense system of freshwater crayfish Procambarus clarkii as a diversified source of bioactive molecules with antimicrobial properties was studied. Antimicrobial activity of two polypeptideenriched extracts obtained from hemocytes and hemolymph of P. clarkii were assessed against Gram positive (Staphylococcus aureus, Enterococcus faecalis) and Gram negative (Pseudomonas aeruginosa, Escherichia coli) bacteria and toward the yeast Candida albicans. The two peptide fractions showed interesting MIC values (ranging from 11 to 700 g/mL) against all tested pathogens. Polypeptideenriched extracts were further investigated using a high-resolution mass spectrometry and database search and 14 novel peptides were identified. Some peptides and their derivatives were chemically synthesized and tested in vitro against the bacterial and yeast pathogens. The analysis identified a synthetic derivative peptide, which showed an interesting antifungal (MIC and MFC equal to 31.2 g/mL and 62.5 g/mL, respectively) and antibiofilm (BIC50 equal to 23.2 g/mL) activities against Candida albicans and a low toxicity in human cells