Preparation of progressive antibacterial LDPE surface via active biomolecule deposition approach

The use of polymers in all aspects of daily life is increasing considerably, so there is high demand for polymers with specific properties. Polymers with antibacterial properties are highly needed in the food and medical industries. Low-density polyethylene (LDPE) is widely used in various industries, especially in food packaging, because it has suitable mechanical and safety properties. Nevertheless, the hydrophobicity of its surface makes it vulnerable to microbial attack and culturing. To enhance antimicrobial activity, a progressive surface modification of LDPE using the antimicrobial agent grafting process was applied. LDPE was first exposed to nonthermal radio-frequency (RF) plasma treatment to activate its surface. This led to the creation of reactive species on the LDPE surface, resulting in the ability to graft antibacterial agents, such as ascorbic acid (ASA), commonly known as vitamin C. ASA is a well-known antioxidant that is used as a food preservative, is essential to biological systems, and is found to be reactive against a number of microorganisms and bacteria. The antimicrobial effect of grafted LDPE with ASA was tested against two strong kinds of bacteria, namely, Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli), with positive results. Surface analyses were performed thoroughly using contact angle measurements and peel tests to measure the wettability or surface free energy and adhesion properties after each modification step. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were used to analyze the surface morphology or topography changes of LDPE caused by plasma treatment and ASA grafting. Surface chemistry was studied by measuring the functional groups and elements introduced to the surface after plasma treatment and ASA grafting, using Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS). These results showed wettability, adhesion, and roughness changes in the LDPE surface after plasma treatment, as well as after ASA grafting. This is a positive indicator of the ability of ASA to be grafted onto polymeric materials using plasma pretreatment, resulting in enhanced antibacterial activity. - 2019 by the authors.Funding: This publication was made possible by Award JSREP07-022-3-010 and NPRP10-0205-170349 from the Qatar National Research Fund (a member of The Qatar Foundation). The statements made herein are solely the responsibility of the authors

Játékos kreativitás fejlesztés tapasztalatai egy szlovákiai óvodában

E tanulmány célja, hogy bemutassuk, hogyan lehet az OxIPO modell alapján kreativást fejlesztő játékokat megvalósítani már az óvodai nevelés keretein belül. Röviden meghatározzuk a kreativitás fogalmát, majd ismertetjük, hogy mennyire fontos az, hogy maga a pedagógus kreatívan álljon az óvodai foglalkozások tervezéséhez. Ismertetjük a kreatív pedagógus jellemzőit és személyiségjegyeit. Bemutatjuk az óvodáskorú gyerekek kreativitást támogató játékok megvalósításának tapasztalatait

Hiperaktív gyermek az osztályban

Az utóbbi évtizedben fokozott mértékben előtérbe került a hazai és külföldi pedagógiában egyaránt a tanulási és magatartászavarral küzdő gyerekek iskolai nevelésének problémája. A pedagógusok annak ellenére, hogy egyre gyakrabban tanítanak hiperaktív gyermeket, nincsenek rá kellőképpen felkészülve. Részükről a gond abban rejlik, hogy képzésük során nem ismerkedtek meg azokkal a módszerekkel, amelyek segítségével egyénileg fejleszthetőek a nehezen nevelhető, problematikus személyiségű tanulók. A hiperaktivitás felismerésére és megítélésére a bizonytalanság és a végletek jellemzőek, mert minden túlmozgásos és eleven gyermeket lassan hiperaktívnak titulálnak. A zavarok korai kiszűrése pedig lehetővé tenné, hogy a gyermekek időben, megfelelő segítésben részesüljenek. A következő tanulmány két fő részből, elméleti, illetve gyakorlati részből áll. A gyakorlati rész konkrét esettanulmányokat mutat be, segítve ezzel az időbeni felismerést. Három hiperaktív gyermek viselkedésformáit, a rájuk jellemző tüneteket fejtjük ki bővebben, figyelembe véve a családi és iskolai körülményeket. Felsorakoztatjuk a segítségnyújtás formáit az iskolában, konkrét ötletekkel, tanácsokkal látjuk el a pedagógusokat

Mentolabial angle and aesthetics : a quantitative investigation of idealized and normative values

BACKGROUND: This study is a quantitative evaluation of the influence of the mentolabial angle on perceived attractiveness and threshold values of desire for surgery. METHODS: The mentolabial angle of an idealized silhouette male Caucasian profile image was altered incrementally between 84° and 162°. Images were rated on a Likert scale by pretreatment orthognathic patients (n = 75), lay people (n = 75) and clinicians (n = 35). RESULTS: A mentolabial angle of approximately 107° to 118° was deemed the most attractive, with a range of up to 140° deemed acceptable. Angles above or below this range were perceived as unattractive, and anything outside the range of below 98° or above 162° was deemed very unattractive. A deep mentolabial angle (84°) or an almost flat angle (162°) was deemed the least attractive. In terms of threshold values of desire for surgery, for all groups, a threshold value of ≥162° and ≤84° indicated a preference for surgery, although clinicians were least likely to suggest surgery. The clinician group was the most consistent, and for many of the images, there was some variation in agreement between clinicians and lay people as to whether surgery is required. There was even more variability in the assessments for the patient group. CONCLUSIONS: It is recommended that in orthognathic and genioplasty planning, the range of normal variability of the mentolabial angle, in terms of observer acceptance, is taken into account as well as threshold values of desire for surgery. The importance of using patients as observers in attractiveness research is stressed

Comparison between light scattering and gravimetric samplers for PM10 mass concentration in poultry and pig houses

The objective of this study was to compare co-located real-time light scattering devices and equivalent gravimetric samplers in poultry and pig houses for PM10 mass concentration, and to develop animal-specific calibration factors for light scattering samplers. These results will contribute to evaluate the comparability of different sampling instruments for PM10, concentrations. Paired DustTrak light scattering device (DustTrak aerosol monitor, TSI, U.S.) and PM10 gravimetric cyclone sampler were used for measuring PM10 mass concentrations during 24 h periods (from noon to noon) inside animal houses. Sampling was conducted in 32 animal houses in the Netherlands, including broilers, broiler breeders, layers in floor and in aviary system, turkeys, piglets, growing-finishing pigs in traditional and low emission housing with dry and liquid feed, and sows in individual and group housing. A total of 119 pairs of 24 h measurements (55 for poultry and 64 for pigs) were recorded and analyzed using linear regression analysis. Deviations between samplers were calculated and discussed. In poultry, cyclone sampler and DustTrak data fitted well to a linear regression, with a regression coefficient equal to 0.41, an intercept of 0.16 mg m(-3) and a correlation coefficient of 0.91 (excluding turkeys). Results in turkeys showed a regression coefficient equal to 1.1 (P = 0.49), an intercept of 0.06 mg m(-3) (P < 0.0001) and a correlation coefficient of 0.98. In pigs, we found a regression coefficient equal to 0.61, an intercept of 0.05 mg m(-3) and a correlation coefficient of 0.84. Measured PM10 concentrations using DustTraks were clearly underestimated (approx. by a factor 2) in both poultry and pig housing systems compared with cyclone pre-separators. Absolute, relative, and random deviations increased with concentration. DustTrak light scattering devices should be self-calibrated to investigate PM10 mass concentrations accurately in animal houses. We recommend linear regression equations as animal-specific calibration factors for DustTraks instead of manufacturer calibration factors, especially in heavily dusty environments such as animal houses. (C) 2015 Elsevier Ltd. All rights reserved.The study was financed by the Dutch Ministry of Economic affairs, Agriculture and Innovation. Authors wish to thank the Campus de Excelencia Internacional of the Universitat Politecnica de Valencia (Spain) for funding Dr. Cambra-Lopez's postdoc contract.Cambra López, M.; Winkel, A.; Mosquera, J.; Ogink, NW.; Aarnink, AJA. (2015). Comparison between light scattering and gravimetric samplers for PM10 mass concentration in poultry and pig houses. Atmospheric Environment. 111:20-27. doi:10.1016/j.atmosenv.2015.03.051S202711

Nasofacial angle and nasal prominence : a quantitative investigation of idealized and normative values

PURPOSE: A quantitative evaluation of the influence of the nasofacial angle on perceived attractiveness and threshold values of desire for rhinoplasty. MATERIAL AND METHODS: The nasofacial angle of an idealized silhouette male Caucasian/white profile image was altered incrementally between 21° and 48°. Images were rated on a Likert scale by pretreatment patients (n = 75), laypersons (n = 75), and clinicians (n = 35). RESULTS: A nasofacial angle of approximately 30° was deemed to be ideal, with a range of 27°-36° deemed acceptable. Angles above or below this range were perceived as unattractive. Angles outside the range of 21°-42° were deemed very unattractive. Excessive nasal prominence (nasofrontal angle of 48°) was deemed the least attractive. In terms of threshold values of desire for surgery, for all groups a threshold value of ≥39° and ≤24° indicated a preference for surgery, with clinicians least likely to suggest surgery. The patient group assessments demonstrated the greatest variability, stressing the importance of using patients as observers, as well as laypersons and clinicians, in facial attractiveness research. CONCLUSIONS: It is recommended that in rhinoplasty planning, the range of normal variability of the nasofrontal angle, in terms of observer acceptance, is taken into account, as well as threshold values of desire for surgery

PREPARING THE USAF CONTRACTING CAREER FIELD FOR THE NEXT HUMANITARIAN ASSISTANCE DISASTER RESPONSE WITHIN THE CONTINENTAL UNITED STATES

Includes Supplementary MaterialThis project’s focus is on the alignment of a U.S. Air Force (USAF) exercise design process with FEMA's challenges regarding humanitarian assistance and disaster response (HADR) events. The authors applied Joint Publication 4-10 and Yoder’s Three Tier Model approach to inform a disaster model that delineates roles and responsibilities for stakeholders. The authors also reviewed 104 after-action reports to identify trends within FEMA’s 15 emergency support functions and added three more categories to capture trends: finance, manpower, and training. This research resulted in six recommendations to the USAF contracting exercise designers: 1) ensure that exercise frameworks are aligned to the lead agency; 2) consolidate the many advance contracts throughout the federal agencies into one location such as Acquisition Gateway or GSA Advantage, or on a SharePoint site; 3) continue adopting category management practices within the disaster environment in order to effectively implement advance contracts; 4) further refine the career field education training plan with tiered development under a synthesized HADR framework; 5) consolidate the federal external stakeholders into a simplified location to improve the ability to research trends within the USAF contracting career field; and 6) ask other federal agencies for their approaches while de-conflicting procurement strategies.Captain, United States Air ForceCaptain, United States Air ForceApproved for public release. distribution is unlimite

Preparation of active antibacterial biomaterials based on sparfloxacin, enrofloxacin, and lomefloxacin deposited on polyethylene

Bacterial contamination is one of the biggest drawbacks of implanted biomaterials, which may cause nosocomial infection. Avoiding bacterial adhesion onto the biomaterial surface by preparing active antibacterial biomaterials is an accurate solution. In this study, three of the fluoroquinolones: sparfloxacin, enrofloxacin, and lomefloxacin were selected due to their broad bactericidal effect and immobilized onto low-density polyethylene surface at two different pH values (pH 3 and pH 6), after tailoring the surface by plasma treatment followed by grafting of polymer brush of N-allylmethylamine. Surface wettability test and morphological investigations were carried out by water contact angle measurement and scanning electron microscopy analysis, respectively. Chemical characterizations were carried out by Fourier transform infrared spectra and X-ray photoelectron spectroscopy. Antibacterial activity was checked against Staphylococcus aureus and Escherichia coli strains and results revealed that prepared surfaces were more effective against E. coli than S. aureus especially those prepared at pH 6. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46174. © 2017 Wiley Periodicals, Inc.17–05095S, GACR, Grantová Agentura České RepublikyCzech Science Foundation [17-05095S