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Quan Chen, Zhiling Zhu, Jun Wang, Analette I Lopez, Siheng Li, Amit Kumar, Fei Yu, Haoqing Chen, Chengzhi Cai, Lijuan Zhang
: Bacterial interference is an alternative strategy to fight against device-associated bacterial infections. Pursuing this strategy, a non-pathogenic bacterial biofilm is used as a live, protective barrier to fence off pathogen colonization. In this work, biofilms formed by probiotic Escherichia coli strain Nissle 1917 (EcN) are investigated for their potential for long-term bacterial interference against infections associated with silicone-based urinary catheters and indwelling catheters used in the digestive system, such as feeding tubes and voice prostheses...
January 6, 2017: Acta Biomaterialia
Michelle Schollert, Minna Kivimäenpää, Anders Michelsen, Daan Blok, Riikka Rinnan
BACKGROUND AND AIMS: Climate change in the Arctic is projected to increase temperature, precipitation and snowfall. This may alter leaf anatomy and gas exchange either directly or indirectly. Our aim was to assess whether increased snow depth and warming modify leaf anatomy and affect biogenic volatile organic compound (BVOC) emissions and CO2 exchange of the widespread arctic shrubs Betula nana and Empetrum nigrum ssp. hermaphroditum METHODS: Measurements were conducted in a full-factorial field experiment in Central West Greenland, with passive summer warming by open-top chambers and snow addition using snow fences...
January 7, 2017: Annals of Botany
Samiksha Tarun, Monika Arora, Tina Rawal, Sara E Benjamin Neelon
BACKGROUND: Increasing physical activity in children is an important public health goal in India. Schools may be a target for physical activity promotion, but little is known about outdoor school environments. The purpose of this study was to describe characteristics of the surrounding outdoor school environments that may promote children's physical activity in Delhi, India. METHODS: For this cross-sectional study, we conducted a structured observation of outdoor school environments in a random sample of 16 private schools in Delhi, India using the Sport, Physical activity and Eating behavior: Environmental Determinants in Young people (SPEEDY) audit tool...
January 5, 2017: BMC Public Health
Lijun Ye, Jipeng Guan, Zhixiang Li, Jingxin Zhao, Cuicui Ye, Jichun You, Yongjin Li
A facile and versatile strategy for fabricating superhydrophobic surfaces with controllable electrical conductivity and water-adhesion is reported. "Vine-on-fence" structured and cerebral cortex-like superhydrophobic surfaces are constructed by filtering a suspension of multi-walled carbon nanotubes (MWCNTs), using polyoxymethylene nonwovens as the filter paper. The nonwovens with micro- and nanoporous two-tier structures act as the skeleton, introducing a microscale structure. The MWCNTs act as nanoscale structures, creating hierarchical surface roughness...
January 4, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
T Teke
PURPOSE: To present and validate a set of quality control tests for trajectory treatment delivery using synchronized dynamic couch (translation and rotation), MLC and collimator motion. METHODS: The quality control tests are based on the Picket fence test, which consist of 5 narrow band 2mm width spaced at 2.5cm intervals, and adds progressively synchronized dynamic motions. The tests were exposed on GafChromic EBT3 films. The first test is a regular (no motion and MLC static while beam is on) Picket Fence test used as baseline...
June 2016: Medical Physics
L Wang, E Chin, A Lo
PURPOSE: This work reports the results of the physics evaluation of a newly released InCise™2 Multileaf Collimator (MLC) installed in our institution. METHODS: Beam property data was measured with unshielded diode and EBT2 films. The measurements included MLC leaf transmission, beam profiles, output factors and tissue-phantom ratios. MLC performance was evaluated for one month after commissioning. Weekly Garden Fence tests were performed for leaf / bank positioning in standard (A/P) and clinically relevant non-standard positions, before and after MLC driving exercises of 10+ minutes...
June 2016: Medical Physics
J Kerns, D Yaldo
PURPOSE: Routine linac quality assurance (QA) tests have become complex enough to require automation of most test analyses. A new data analysis software library was built that allows physicists to automate routine linear accelerator quality assurance tests. The package is open source, code tested, and benchmarked. METHODS: Images and data were generated on a TrueBeam linac for the following routine QA tests: VMAT, starshot, CBCT, machine logs, Winston Lutz, and picket fence...
June 2016: Medical Physics
B Rusk, J Fontenot
PURPOSE: To report the results of a customer acceptance test (CAT) for VMAT treatments for two matched Elekta linear accelerators. METHODS: The CAT tests were performed on two clinically matched Elekta linear accelerators equipped with a 160-leaf MLC. Functional tests included performance checks of the control system during dynamic movements of the diaphragms, MLC, and gantry. Dosimetric tests included MLC picket fence tests at static and variable dose rates and a diaphragm alignment test, all performed using the on-board EPID...
June 2016: Medical Physics
H Yu, C Jenkins, S Yu, Y Yang, L Xing
PURPOSE: Routine quality assurance (QA) of linear accelerators represents a critical and costly element of a radiation oncology center. Recently, a system was developed to autonomously perform routine quality assurance on linear accelerators. The purpose of this work is to extend this system and contribute computer vision techniques for obtaining quantitative measurements for a monthly multi-leaf collimator (MLC) QA test specified by TG-142, namely leaf position accuracy, and demonstrate extensibility for additional routines...
June 2016: Medical Physics
R Underwood
PURPOSE: To determine the feasibility of using radiochromic and radiographic film with Pipspro software for quality assurance of linear accelerators with no on-board imaging. METHODS: The linear accelerator being used is a Varian Clinac 21EX. All IGRT is performed using the BrainLab ExacTrac system. Because of the lack of on board imaging, certain monthly and annual TG-142 quality assurance tests are more difficult to perform and analyze to a high degree of accuracy...
June 2016: Medical Physics
C Kalavagunta, X Yang, H Xu, B Zhang, S Mossahebi, A Sawant, B Yi
PURPOSE: Appropriate MLC QA is important to assure treatment accuracy. In addition to the TG-142 recommended picket fence test, our institution performs four MLC tests on a weekly basis. The purpose of this study was to evaluate the clinical necessity of our weekly MLC QA program after a two-year run. METHODS: Our Weekly MLC QA tests: 1) MLC positioning; 2) Interdigitation for testing hard MLC motion; 3) Picket fence at static gantry angle; 4) Leaf-end leakage and 5) dose match between a VMAT plan and the same plan with static-gantry-sliding window...
June 2016: Medical Physics
K Ding, T Ji, I Iordachita, E Velarde, J Hyatt, J Wong
PURPOSE: Monthly quality assurance (QA) is time consuming for external beam radiation therapy, taking as long as 6-8 hours for each machine. It is due to the use and setup of multiple devices for different QA procedures. We have developed a single system with rotational capability for the measurement of both optical light and radiation which significantly reduces the time spent on Monthly QA. METHODS: A single system using mirrors, a phosphor screen and a CCD camera is housed on a cylindrical motor so that it can rotate 360 degrees...
June 2016: Medical Physics
J DeMarco, J Moran, M Barnes, P Greer, G Kim, B Fraass, W Yang, E McKenzie Boehnke
PURPOSE: To assess the dosimetric performance of a new amorphous silicon flat-panel electronic portal imaging device (EPID) suitable for high-intensity, flattening-filter-free delivery mode. METHODS: An EPID-based QA suite was created with automation to periodically monitor photon central-axis output and two-dimensional beam profile constancy as a function of gantry angle and dose-rate. A Varian TrueBeamTM linear accelerator installed with Developer Mode was used to customize and deliver XML script routines for the QA suite using the dosimetry mode image acquisition for an aS1200 EPID...
June 2016: Medical Physics
X Li, M Studenski, F Yang, N Dogan, N Lamichhane, K Padgett
PURPOSE: MRI-guided-radiotherapy (MRIGRT) systems lack many features of traditional Linac based RT systems and specialized tests need to be developed to evaluate MLC performance. This work describes automatic tools for the analysis of positional accuracy of an MLC equipped MRIGRT system. METHODS: This MLC analysis tool was developed for the MRIdian™ RT system which has three Co-60 equipped treatment heads each with a double focused MLC containing 30 leaf pairs, leaf thickness is 1...
June 2016: Medical Physics
Cristina Martínez-Garza, Julio Campo, Martin Ricker, Wolke Tobón
In restoration plantings in degraded pastures, initial soil nutrient status may lead to differential growth of tropical tree species with diverse life history attributes and capacity for N2 fixation. In 2006, we planted 1,440 seedlings of 15 native tree species in 16 fenced plots (30 × 30 m) in a 60-year-old pasture in Los Tuxtlas, Veracruz, Mexico, in two planting combinations. In the first year, we evaluated bulk density, pH, the concentration of organic carbon (C), total nitrogen (N), ammonia (NO3-), nitrate (NH4+), and total phosphorus (P) in the upper soil profile (0-20 cm in depth) of all plots...
December 2016: Ecology and Evolution
Abedin Saghafipour, Hassan Vatandoost, Ali Reza Zahraei-Ramazani, Mohammad Reza Yaghoobi-Ershadi, Yavar Rassi, Mohammad Reza Shirzadi, Amir Ahmad Akhavan
BACKGROUND & OBJECTIVES: Phlebotomus papatasi is the main vector of the zoonotic cutaneous leishmaniasis (ZCL) in Qom Province and many other provinces of Iran. Attractive toxic sugar baits (ATSB) treated barrier fence is one of the new methods for controlling the vectors such as sandflies. The present study was designed to evaluate the residual activity of ATSB-treated barrier fence that was used in control of P. papatasi. METHODS: Following the selection of villages in Markazi district of Qom Province, central Iran during 2015 for ATSB and ASB (bait containing no active ingredient) methods; barrier fences on the ground in front of the rodent's colony were installed...
October 2016: Journal of Vector Borne Diseases
Hongzhen Liu, Yanyan Lou, Siriporn Jungsuttiwong, Shuai Yuan, Yin Zhao, Zhuyi Wang, Liyi Shi, Hualan Zhou
Charge recombination and transfer at the TiO2/dye/electrolyte interface play a crucial role in dye-sensitized solar cells (DSSCs). Here, a fine-controlled gold nanoparticle (Au NP) via electrodeposition incorporated into a porous TiO2 photoanode and dodecanethiol molecules as an assembled monolayer capping on Au NPs was designed and prepared. The "fence-like" structure of gold thiol molecules at the TiO2/dye/electrolyte interface can not only insulate the electrolyte to suppress recombination but also make full use of the plasmon-enhanced light absorption of Au NPs...
January 11, 2017: ACS Applied Materials & Interfaces
Damin Si, John Marquess, Ellen Donnan, Bruce Harrower, Bradley McCall, Sonya Bennett, Stephen Lambert
BACKGROUND: Australian bat lyssavirus (ABLV) belongs to the genus Lyssavirus which also includes classic rabies virus and the European lyssaviruses. To date, the only three known human ABLV cases, all fatal, have been reported from Queensland, Australia. ABLV is widely distributed in Australian bats, and any bite or scratch from an Australian bat is considered a potential exposure to ABLV. METHODOLOGY/PRINCIPAL FINDINGS: Potential exposure to ABLV has been a notifiable condition in Queensland since 2005...
December 2016: PLoS Neglected Tropical Diseases
T M Brown-Brandl, C G Chitko-McKown, R A Eigenberg, J J Mayer, T H Welsh, J D Davis, J L Purswell
Heat stress has a significant impact on all livestock and poultry species causing economic losses and animal well-being concerns. Providing shade is one heat-abatement strategy that has been studied for years. Material selected to provide shade for animals greatly influences the overall stress reduction provided by shade. A study was conducted to quantify both the environment and animal response, when cattle had no shade access during summertime exposure or were given access to shade provided by three different materials...
December 23, 2016: Animal: An International Journal of Animal Bioscience
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