Zosteric acid and salicylic acid bound to a low density polyethylene surface successfully control bacterial biofilm formation

The active moieties of the anti-biofilm natural compounds zosteric (ZA) and salicylic (SA) acids have been covalently immobilized on a low density polyethylene (LDPE) surface. The grafting procedure provided new non-toxic eco-friendly materials (LDPE-CA and LDPE-SA) with anti-biofilm properties superior to the conventional biocide-based approaches and with features suitable for applications in challenging fields where the use of antimicrobial agents is limited. Microbiological investigation proved that LDPE-CA and LDPE-SA: (1) reduced Escherichia coli biofilm biomass by up to 61% with a mechanism that did not affect bacterial viability; (2) significantly affected biofilm morphology, decreasing biofilm thickness, roughness, substratum coverage, cell and matrix polysaccharide bio-volumes by >80% and increasing the surface to bio-volume ratio; (3) made the biofilm more susceptible to ampicillin and ethanol. Since no molecules were leached from the surface, they remained constantly effective and below the lethal level; therefore, the risk of inducing resistance was minimized

Analysis and correction of the magnetic field effects in the Hybrid Photo-Detectors of the RICH2 Ring Imaging Cherenkov detector of LHCb

The Ring Imaging Cherenkov detectors of the LHCb experiment at the Large Hadron Collider at CERN are equipped with Hybrid Photo-Detectors. These vacuum photo-detectors are affected by the stray magnetic field of the LHCb magnet, which degrades their imaging properties. This effect increases the error on the Cherenkov angle measurement and would reduce the particle identification capabilities of LHCb. A system has been developed for the RICH2 Ring Imaging Cherenkov detector to perform a detailed characterisation of the magnetic distortion effects. It is described, along with the methods implemented to correct for these effects, restoring the optimal resolution.Comment: 16 pages, 11 figure

Effect of Carbon Support, Capping Agent Amount, and Pd NPs Size for Bio-Adipic Acid Production from Muconic Acid and Sodium Muconate

The effect of support, stabilizing agent, and Pd nanoparticles (NPs) size was studied for sodium muconate and t,t-muconic acid hydrogenation to bio-adipic acid. Three different activated carbons (AC) were used (Norit, KB, and G60) and carbon morphology did not affect the substrate conversion, but it greatly influenced the adipic acid yield. 1% Pd/KB Darco catalyst, which has the highest surface area and Pd surface exposure, and the smallest NPs size displayed the highest activity. Furthermore, the effect of the amount of the protective agent was studied varying metal/protective agent weight ratios in the range of 1/0.00-1/1.20, using KB as the chosen support. For sodium muconate reduction 1% Pd/KB_1.2 catalyst gave the best results in terms of activity (0.73 s-1), conversion, and adipic acid yield (94.8%), while for t,t-muconic acid hydrogenation the best activity result (0.85 s-1) was obtained with 1% Pd/KB_0.0 catalyst. Correlating the results obtained from XPS and TEM analyses with catalytic results, we found that the amount of PVA (polyvinyl alcohol) influences mean Pd NPs size, Pd(0)/Pd(II) ratio, and Pd surface exposure. Pd(0)/Pd(II) ratio and Pd NPs size affected adipic acid yield and activity during sodium muconate hydrogenation, respectively, while adipic acid yield was related by exposed Pd amount during t,t-muconic acid hydrogenation. The synthesized catalysts showed higher activity than commercial 5% Pd/AC

Green Synthesis, Molecular Characterization and Associative Behavior of Some Gemini Surfactants without a Spacer Group

A series of new gemini surfactants without a spacer group, disodium 2,3-dialkyl-1,2,3,4-butanetetracarboxylates, were synthesized in a green chemistry context minimizing the use of organic solvents and applying microwaves (MW) when activation energy was required. Once the desired architecture was confirmed by means of the nuclear magnetic resonance technique (1H-NMR, 1H-1H COSY) for all the studied surfactants, the critical micellization concentration was determined by conductance measurements. The diffusion coefficient of micelles formed by the four compounds was characterized using pulsed field gradient (PFG)-NMR. Diffusion coefficients were found to be dependent on the concentration and on the number of carbon atoms in the alkyl chain. The absence of the spacer group, peculiar to this new series of gemini surfactants, may confer relatively low flexibility to the molecules, with potential implications on the interfacial properties, namely on micellization. These gemini surfactants might have interesting applications in the preparation of composite materials, in nanotechnology, in gene transfection and mainly, due to the low CMCs, as new interesting ingredients of cosmetics and toiletries

Risk factors for benign ovarian teratomas.

Risk factors for benign ovarian teratomas have been analysed in a case-control study conducted in Milan. Cases were women aged less than 65 years with a histologically confirmed diagnosis of benign ovarian teratoma who were admitted to a network of Obstetrics and Gynecology Departments in Milan. A total of 77 women aged 16-64 years were interviewed. Controls were women admitted to hospital for acute, non-gynaecological, non-hormonal and non-neoplastic diseases; 231 controls were interviewed (age range 15-64 years). Cases tended to be more educated: in comparison with women with less than 7 years of education, the estimated relative risk (RR) of ovarian benign teratoma was 1.6 and 2.5 respectively in women with 7-11 and 12 or more years of schooling, the trend in risk being statistically significant (chi 2(1) trend 5.39, P < 0.01). Four of the 77 cases (5.2%) and two of the 231 controls (0.9%) reported a history of infertility, with a corresponding RR of 8.3 (95% confidence interval 1.3-54.0). There was no clear relation between parity and risk of ovarian benign teratomas: in comparison with nulliparae, the estimated RRs were 1.1 and 0.7 respectively in women reporting one or two or more births (chi 2(1) trend 0.53, P = not significant). No relation emerged between marital status, age at menarche, menstrual cycle pattern, menopausal status, abortions, age at first pregnancy, oral contraceptive use and risk of ovarian benign teratomas

Low density polyethylene functionalized with antibiofilm compounds inhibits Escherichia coli cell adhesion

The present work concerns an efficient strategy to obtain novel medical devices materials able to inhibit biofilm formation. The new materials were achieved by covalent grafting of p-aminocinnamic or p-aminosalicylic acids on low density polyethylene coupons. The polyethylene surface, previously activated by oxygen plasma treatment, was functionalized using 2-hydroxymethylmetacrylate as linker. The latter was reacted with succinic anhydride affording the carboxylic end useful for the immobilization of the antibiofilm molecules. The modified surface was characterized by scanning electron microscope, X-ray photoelectron spectroscopy, attenuated total reflectance Fourier transform infrared and fluorescence analyses. The antibiofilm activity of the modified materials were tested against Escherichia coli biofilm grown in the Center of Disease Control biofilm reactor. The results revealed that the grafted cinnamic and salicylic acid derivatives reduced biofilm biomass, in comparison with the control, by 73.7\u2009\ub1\u200910.7% and 63.4\u2009\ub1\u20097.1%, respectively

Spanish validation of the revised depression attitude questionnaire (R-daq)

Purpose: The aim of the study was to develop and validate a Spanish version of the Revised Depression Attitude Questionnaire (R-DAQ). Methods: The R-DAQ was used as a baseline for the study. It was translated and tested to ensure the instrument was appropriate for the target population. 537 Ecuadorian healthcare professionals completed the revised Spanish version of the R-DAQ (SR-DAQ). Statistical and exploratory factor analyses were performed to examine construct validity, internal consistency, readability and floor and ceiling effects. Results: Three factors were obtained: “Professional confidence in depression care”; “Therapeutic optimism about depression”; and “Generalist perspective about depression occurrence, recognition, and management”. The internal consistency of the SR-DAQ was determined by means of Cronbach’s α coefficient, with values ranging between 0.61–0.8. The correlations with the English version reflected adequate validity. The model explained 39% of the variance. Subsequent analysis with a sample restricted to those who had received training in depression produced a model that explained 42% of the variance. Conclusion: The SR-DAQ meets the psychometric requirements for measuring depression attitude in a Spanish-speaking population and shows adequate internal consistency and validity