bluuebunny/crossref_metadata_2025 huggingface dataset:
No evidence that medicinal honey reduces bacterial skin colonisation at a peripheral catheter insertion site in dogs
Authors: Royaux E. , Polis I. , Boyen F. , Van Ham L. , de Rooster H.
Published: July 2016

Objectives

To determine whether topical exit‐site application of medicinal honey at the catheter insertion place reduces bacterial skin colonisation.

Measurements and Results

Dogs were selected at random and divided into the honey or the control group. When the catheter was removed, an area of approximately 3×3 cm of the skin at the insertion site was sampled with a sterile cotton swab. The catheter stayed in place for a median of 84 hours. Out of 46 patients, 6 patients in the honey group and 5 out of 54 patients in the control group had a positive skin culture at the time of catheter removal (P=0·547). Infection was clinically suspected in 1 of those 11 dogs; catheter‐associated complications were observed in 8 additional dogs that did not have a positive skin culture.

Clinical Significance

Few catheter‐associated complications were observed. Extra attention to hygiene by working with a standardised catheter placement and handling protocol might have resulted in this low incidence. In this study topical application of a medicinal honey did not reduce bacterial skin colonisation at the insertion site of peripheral catheters in dogs.
Antimicrobial‐resistant Escherichia coli in hospitalised companion animals and their hospital environment
Authors: Tuerena I. , Williams N. J. , Nuttall T. , Pinchbeck G.
Published: July 2016

Introduction

Antimicrobial resistance is a growing concern with implications for animal health. This study investigated the prevalence of antimicrobial resistance among commensal and environmental Escherichia coli isolated from animals sampled in referral hospitals in the UK.

Materials and Methods

Resistant Escherichia coli isolated from animal faeces and practice environments were tested for susceptibility to antimicrobial agents. PCR and sequencing techniques were used to identify extended spectrum beta‐lactamase and AmpC‐producer genotypes.

Results

In total, 333 faecal and 257 environmental samples were collected. Multi‐drug resistant Escherichia coli were found in 13·1% of faecal and 8·9% of environmental samples. Extended spectrum beta‐lactamase and AmpC genes were identified 14% and 7·7% of faecal samples and 8·6% and 8·6% of environmental samples, respectively. The most common extended spectrum beta‐lactamase gene type detected was blaCTX‐M −15, although blaTEM‐158 was detected in faecal and environmental samples from one practice.

Clinical Significance

Escherichia coli resistant to key antimicrobials were isolated from hospitalised animals and the practice environment. We identified the emergence of the inhibitor resistant and extended spectrum beta‐lactamase blaTEM‐158 in companion animals. Further investigation to determine risk factors for colonisation with antimicrobial‐resistant bacteria is needed to provide evidence for antimicrobial stewardship and infection control programmes.
Is Belief in God Related to Differences in Adolescents’ Psychological Functioning?
Authors: Huuskes Lee M. , Heaven Patrick C. L. , Ciarrochi Joseph , Parker Philip , Caltabiano Nerina
Published: July 2016

Many studies have documented links between positive psychological functioning and religiousness during the adolescent years, but very few have contrasted religious and nonreligious youth. The purpose of the present study was to examine differences in psychological functioning among adolescent atheists, agnostics, and believers using a profile analysis approach. The authors conducted a survey of Grade 8 students (N = 1,925) enrolled in Catholic schools in two Australian states. The survey included 10 measures of psychological functioning, broadly divided into three categories (positive adjustment, social well‐being, and negative outcomes). Results indicated that belief in God was related to distinct profiles of psychological adjustment. The implications of these findings for understanding how differing value systems are related to particular developmental stages are discussed.
Cyclic di‐AMP targets the cystathionine beta‐synthase domain of the osmolyte transporter OpuC
Authors: Huynh TuAnh Ngoc , Choi Philip H. , Sureka Kamakshi , Ledvina Hannah E. , Campillo Julian , Tong Liang , Woodward Joshua J.
Published: July 2016

Cellular turgor is of fundamental importance to bacterial growth and survival. Changes in external osmolarity as a consequence of fluctuating environmental conditions and colonization of diverse environments can significantly impact cytoplasmic water content, resulting in cellular lysis or plasmolysis. To ensure maintenance of appropriate cellular turgor, bacteria import ions and small organic osmolytes, deemed compatible solutes, to equilibrate cytoplasmic osmolarity with the extracellular environment. Here, we show that elevated levels of c‐di‐AMP, a ubiquitous second messenger among bacteria, result in significant susceptibility to elevated osmotic stress in the bacterial pathogen Listeria monocytogenes. We found that levels of import of the compatible solute carnitine show an inverse correlation with intracellular c‐di‐AMP content and that c‐di‐AMP directly binds to the CBS domain of the ATPase subunit of the carnitine importer OpuC. Biochemical and structural studies identify conserved residues required for this interaction and transport activity in bacterial cells. Overall, these studies reveal a role for c‐di‐AMP mediated regulation of compatible solute import and provide new insight into the molecular mechanisms by which this essential second messenger impacts bacterial physiology and adaptation to changing environmental conditions.
Can acaricide‐impregnated leg bands fitted to female red grouse reduce sheep tick parasitization of chicks and increase chick survival?
Authors: BAINES D. , TAYLOR L.
Published: July 2016

In parts of northern England, North Wales and the Scottish Highlands, increasing numbers of sheep ticksIxodes ricinus(Ixodida: Ixodidae), and the louping ill virus they can carry, are considered to be important factors that reduce red grouseLagopus lagopus scoticaproductivity. The present study tested this hypothesis by fitting adult female grouse with leg bands impregnated with the acaricide cypermethrin to experimentally control ticks on their chicks on two managed grouse moors in northeast Scotland. The chicks of females fitted with acaricide leg bands showed reduced tick infestations and improved survival in one of the two study years, relative to chicks of control females. Acaricide leg bands constitute a potential management technique that may be adopted by grouse moor managers in circumstances of high tick infestations on grouse chicks.
Assertion: A Function First Account
Authors: Kelp Christoph
Published: July 2016

This paper aims to develop a novel account of the normativity of assertion. Its core thesis is that assertion has an etiological epistemic function, viz. to generate knowledge in hearers. In conjunction with a general account of etiological functions and their normative import, it is argued that an assertion is epistemically good if and only if it has the disposition to generate knowledge in hearers. In addition, reason is provided to believe that it makes sense to regulate the practice of assertion by a speaker rule—and, more specifically, by a knowledge rule—as so regulating assertion contributes to ensuring that assertion fulfils its etiological function reliably.
Transparency and the KK Principle
Authors: Das Nilanjan , Salow Bernhard
Published: July 2016

An important question in epistemology is whether the KK principle is true, i.e., whether an agent who knows that p is also thereby in a position to know that she knows that p. We explain how a “transparency” account of self‐knowledge, which maintains that we learn about our attitudes towards a proposition by reflecting not on ourselves but rather on that very proposition, supports an affirmative answer. In particular, we show that such an account allows us to reconcile a version of the KK principle with an “externalist” or “reliabilist” conception of knowledge commonly thought to make that principle particularly problematic.
Oxygen saturation/minute heart rate index: Simple lung function test for children
Authors: Ozdemir Ali , Dogruel Dilek , Yilmaz Ozlem
Published: July 2016

Background

The severity of airway obstruction can be accurately determined on spirometry in children with asthma. Other assessments may include peak expiratory flow and pulse oximetry. In the present study, we evaluated the validity and reliability of oxygen saturation/minute heart rate (SpO2/MHR) index in the prediction of degree of severe airway obstruction in children with asthma.

Methods

This was a retrospective study of children aged 7–17 followed for asthma at Mersin Women and Children's Hospital. The study compared SpO2/MHR ratio with forced expiratory volume in 1 s (FEV1) measured on spirometry, an important indicator of small airway obstruction. A total of 296 patients were included in the study, and classified either as having normal FEV1 (FEV1 > 80% of predicted, n = 178) or severely reduced FEV1 (FEV1 < 60% of predicted, n = 118). Positive and negative predictive values (PPV and NPV), sensitivity and specificity of SpO2/MHR index in predicting low FEV1 were calculated on receiver operating characteristics analysis.

Results

An SpO2/MHR ratio cut‐off <0.90 was associated with a PPV of 83.14%, NPV of 71.77%, sensitivity of 80.34% and specificity of 75.42% in predicting low FEV1.

Conclusions

SpO2/MHR ratio appears to be a highly useful index to assess airway obstruction in older children with asthma. Thus, it can be used as a marker of airway obstruction severity when spirometry is not available.
Outcomes in infants listed for liver transplantation: A retrospective cohort study using the United Network for Organ Sharing database
Authors: Jimenez‐Rivera Carolina , Nightingale Scott , Benchimol Eric I. , Mazariegos George V. , Ng Vicky L.
Published: July 2016

LT in neonates and young infants can be challenging due to a variety of factors. To describe the waitlist mortality rates and outcomes of patients listed and transplanted as infants identified from the UNOS database. Infants listed for LT between January 1985 and September 2010 were identified from the UNOS database. Mortality on the waitlist as well as outcomes post‐LT was compared between infants aged ≤60 days (Group 1), 61–179 days (Group 2), and 180–364 days (Group 3). Of 6763 infants listed for LT (Group 1 n = 496, Group 2 n = 2404, Group 3 n = 3863), mean age at listing was 196 ± 87 days (Group 1, 29 ± 16 days; Group 2, 132 ± 32 days; Group 3, 257 ± 52 days). Waitlist mortality was highest in Group 1 (Group 1 vs. 3 HR 3.01, 95% CI 2.19–4.15, Group 2 vs. Group 3 HR 0.82, 95% CI 0.66–1.03). One‐ and five‐yr graft survival was 59.6% and 42% (Group 1), 66% and 45% (Group 2), and 66.8% and 41% (Group 3) (one‐yr survival p = 0.20; five‐yr survival p = 0.19). Infants listed for LT at age ≤60 days had greater waitlist mortality risk than older infants. Infants undergoing LT at age ≤60 days had similar rates of patient and graft survival to older infants.
Understanding Multiple Behavioral Risk Factors for Cancer in Rural Women
Authors: Noonan Devon , Dardas Latefa , Bice‐Wigington Tiffany , Sloane Richard , Benjamin Rebecca , Choi Seung Hee , Simmons Leigh Ann
Published: July 2016

Objectives

To examine the demographic and health‐related factors associated with risk behaviors that have been linked to cancer including smoking, high BMI, and low physical activity.

Design and Sample

A secondary analysis was conducted using data from Rural Families Speak about Health, a multistate, epidemiologic study of rural American women and their families (N = 444).

Measures

Validated measures for various demographic and health‐related items including tobacco use, BMI, physical activity, and depression were used.

Results

Of the total sample with complete data (n = 399), the mean age was 32 years and the majority were White (64%), married (67%), had a high school education or higher (73%), and had an annual household income of less than $40,000 (90%). Regarding cancer risk behaviors, 36% of the sample were smokers, 39% reported low levels of physical activity, and 45% had a calculated BMI over 30. Thirty‐five percent of participants reported engaging in two or more risk behaviors. There were significant differences in income, perceived health status, and depression depending on the number of risk behaviors reported.

Conclusions

Understanding combinations of risk behaviors can assist nurses and other health professionals in tailoring multiple health behavior change interventions to prevent cancer among rural women.
Dead Sea ultraviolet climatotherapy for children with atopic dermatitis
Authors: Kudish Avraham , Marsakova Anna , Jahn Irmgard , Gkalpakiotis Spyridon , Arenberger Peter , Harari Marco
Published: July 2016

Background

Atopic dermatitis (AD) is a common, chronic, and relapsing inflammatory skin disorder. Moderate to severe cases represent an extremely disabling disease, for both children and their parents. Dead Sea climatotherapy (DSC), recognized as a natural treatment for patients with skin diseases, takes advantage of the selectively scattered ultraviolet irradiation (UV) present at the lowest terrestrial site on the earth.

Objectives

To investigate the impact on short‐term results of DSC in moderate to severe AD children from the Czech Republic treated 4 weeks at the Deutsches Medizinisches Zentrum (DMZ), Israel, and to correlate their results to the cumulative UVA and UVB irradiation doses received during treatment.

Patients and Methods

Seventy‐two patients aged <19 years were divided into three groups and treated in March 2014, October 2014, and March 2015 with gradually increasing sun exposure during 28 consecutive days. Daily and cumulative exposure doses of UVB and UVA were calculated through patients’ recorded sun exposure logs. The SCORing Atopic Dermatitis (SCORAD) index was recorded immediately after DSC and 3 months later by the same dermatologist.

Results

Good clinical results were observed in all groups, with overall improvement in SCORAD reaching 87.5 ± 13.4% and 71.3 ± 21.3% immediately after DSC and 3 months later, respectively. No side effects were observed during the treatments. Higher cumulative exposure times correlated with better results and enhanced remission.

Conclusion

Dead Sea climatotherapy represents a valuable option for the treatment of AD in children. Medically controlled and prescribed sun exposure seems to directly and positively influence the results obtained.
The Social Causes and Political Consequences of Group Empathy
Authors: Sirin Cigdem V. , Valentino Nicholas A. , Villalobos José D.
Published: July 2016

Recent scholarship has discovered significant racial/ethnic group variation in response to political threats such as immigration and terrorism. Surprisingly, minority groups often simultaneously perceive themselves to be at greater risk from such threats and yet still prefer more open immigration policies and civil liberties protections. We suggest a group‐level empathy process may explain this puzzle: Due to their higher levels of empathy for other disadvantaged groups, many minority group members support protections for others even when their own interests are threatened. Little is known, however, about the unique properties of group empathy or its role in policy opinion formation. In this study, we examine the reliability and validity of our new measure of group empathy, the Group Empathy Index (GEI), demonstrating that it is distinct from other social and political predispositions such as ethnocentrism, social dominance orientation, authoritarianism, ideology, and partisanship. We then propose a theory about the development of group empathy in reaction to life experiences based on one's race/ethnicity, gender, age, and education. Finally, we examine the power of group empathy to predict policy attitudes and political behavior.
Poplar plantations in coastal China: towards the identification of the best rotation age for optimal soil carbon sequestration
Authors: Wang G. B. , Deng F. F. , Xu W. H. , Chen H. Y. H. , Ruan H. H.
Published: July 2016

Poplar plantations are an important resource in China, which possess significant potential to offset carbon (C) emissions through the sequestration of atmospheric carbon dioxide (CO2) within biomass and soil. The traditional rotation age of poplar plantations is determined by maximizing the economic return from timber production. However, the optimal rotation age that results in the highest level of carbon sequestration within the soil remains unclear. In this study, we examined the total C, nitrogen (N) and microbial biomass (SMB) content of soils, as well as other properties in 0–10, 10–25 and 25–40 cm soil profiles along a 0‐ to 20‐yr chronosequence in a coastal region of Eastern China. Soil C stocks were determined for 1 m soil profiles, and the stand biomass in poplar plantations of different ages was investigated. We found that C concentrations within soils increased with plantation age, primarily in the topsoil layers. The periodic annual increment of C in soils peaked between stand ages of from 6 to 10 yr (0.71 t/ha/yr) and then decreased considerably at 17.5 yr, while the mean annual increment of C in soils was the highest at 15 yr (0.573 t/ha/yr). Soil C accumulation (i.e. soil C sequestration) was positively correlated with poplar biomass, soil N and SMB, and negatively correlated with soil potassium (K), calcium (Ca), magnesium (Mg) and sodium (Na), but not with sulphur (S) or phosphorus (P). Our results suggest that a rotation age of 15 yr is optimal for the sequestration of atmospheric CO2 in poplar plantations in the coastal region of Eastern China. The C sequestration capacity of soil was primarily controlled by poplar biomass, soil N and SMB.
Four new HLA class I alleles in Spaniards, HLA‐A*32:01:23, HLA‐B*18:01:24, HLA‐B*18:72:02 and HLA‐C*12:166
Authors: Balas A. , Pacho A. , Arrieta A. , García‐Sánchez F. , Vicario J. L.
Published: July 2016

Characterization of four new human leukocyte antigen (HLA) class I alleles, A*32:01:23, B*18:01:24, B*18:72:02 and C*12:166.
A molecular dynamics study of the effect of glycosidic linkage type in the hemicellulose backbone on the molecular chain flexibility
Authors: Berglund Jennie , Angles d'Ortoli Thibault , Vilaplana Francisco , Widmalm Göran , Bergenstråhle‐Wohlert Malin , Lawoko Martin , Henriksson Gunnar , Lindström Mikael , Wohlert Jakob
Published: July 2016

The macromolecular conformation of the constituent polysaccharides in lignocellulosic biomass influences their supramolecular interactions, and therefore their function in plants and their performance in technical products. The flexibility of glycosidic linkages from the backbone of hemicelluloses was studied by evaluating the conformational freedom of the φ and ψ dihedral angles using molecular dynamic simulations, additionally selected molecules were correlated with experimental data by nuclear magnetic resonance spectroscopy. Three types of β‐(1→4) glycosidic linkages involving the monosaccharides (Glcp, Xylp and Manp) present in the backbone of hemicelluloses were defined. Different di‐ and tetrasaccharides with combinations of such sugar monomers from hemicelluloses were simulated, and free energy maps of the φ – ψ space and hydrogen‐bonding patterns were obtained. The glycosidic linkage between Glc‐Glc or Glc‐Man (C‐type) was the stiffest with mainly one probable conformation; the linkage from Man‐Man or Man‐Glc (M‐type) was similar but with an increased probability for an alternative conformation making it more flexible, and the linkage between two Xyl‐units (X‐type) was the most flexible with two almost equally populated conformations. Glycosidic linkages of the same type showed essentially the same conformational space in both disaccharides and in the central region of tetrasaccharides. Different probabilities of glycosidic linkage conformations in the backbone of hemicelluloses can be directly estimated from the free energy maps, which to a large degree affect the overall macromolecular conformations of these polymers. The information gained contributes to an increased understanding of the function of hemicelluloses both in the cell wall and in technical products.
IMAGING DIAGNOSIS—ECTOPIC SPLEEN MIMICKING HEPATIC TUMOR WITH INTRA‐ABDOMINAL METASTASES INVESTIGATED VIA TRIPLE‐PHASE HELICAL COMPUTED TOMOGRAPHY IN A DOG
Authors: Kutara Kenji , Konno Toshiaki , Kondo Hirotaka , Aoki Kotoyo , Yamazoe Hinako , Matsunaga Satoru
Published: July 2016

A 10‐year‐old castrated male miniature dachshund was presented with an abdominal mass. The dog had a history of splenectomy. Triple‐phase helical computed tomography was utilized, revealing a hepatic mass and multiple intra‐abdominal solid masses. In triple‐phase helical computed tomography the images, hepatic mass and two of four intra‐abdominal masses were heterogenous in all phases. Therefore, we diagnosed a malignant hepatic tumor and presumed intra‐abdominal metastases. The masses were surgically removed and were histologically composed of normal spleen tissues, findings which were consistent with ectopic spleen.
Analysis and Assessment of a Gas Turbine-Modular Helium Reactor for Nuclear Desalination
Authors: Khalid Farrukh , Dincer Ibrahim , Rosen Marc A.
Published: July 2016

A thermodynamic analysis of the coupling of a reverse osmosis (RO) process with the gas turbine-modular helium reactor (GT-MHR) is presented in which the waste heat is utilized for the generation of steam as it is expanded in a steam turbine. A comprehensive parametric study is carried out to reveal the effect of some parameters such as compression ratio, turbine inlet temperature, recovery ratio, and preheated feed seawater inlet temperature on the exergy efficiencies of the RO process, electricity generation process, electricity generation without steam turbine work output, and overall system. The analysis shows that the exergy efficiency of the electric generation process is increased by 10.3%, if the waste heat from the reactor is utilized. The exergy efficiencies of the RO process, electricity generation process, electricity generation without steam turbine work output, and overall system are found to be 89.0%, 40.0%, 29.7%, and 41.0%, respectively.
On Some Relevant Effects in the Simulation of Flow Stability With Fluids at Supercritical Pressure
Authors: Ambrosini Walter
Published: July 2016

The paper collects and discusses findings emerging from the analysis of systems operating with fluids at supercritical pressure, with reference to flow stability. In particular, the influence of heating structures and numerical diffusion on the predicted dynamic behavior is highlighted, clarifying that results obtained paying little attention to the presence of these effects should be reconsidered for a better realistic prediction of stability characteristics. Examples of applications in which truncation error and the presence of heating structures play an important role are reported, in order to warn about a tendency to underestimate these effects on the basis of the knowledge of similar phenomena (e.g., in two-phase flow) or system configurations in which they might play a lesser role. The use of a computational fluid dynamics (CFD) code in the analysis of a simple single-tube stability problem shows that models more complex than the usual one-dimensional (1D) ones also show similar effects. The results obtained by 1D numerical tools developed for the analysis of natural circulation with supercritical pressure fluids, equipped with the capability to simulate linear and nonlinear stability with first- and second-order explicit schemes, are then reported. The discussion of the eigenvalues and the eigenvectors calculated for an existing natural circulation loop and a single channel highlight interesting aspects that can be helpful in understanding the results of stability analyses. The CFD code analysis adds additional aspects of interest for the discussion.
Paired Quasi-Linearization Analysis of Heat Transfer in Unsteady Mixed Convection Nanofluid Containing Both Nanoparticles and Gyrotactic Microorganisms Due to Impulsive Motion
Authors: Motsa S. S. , Animasaun I. L.
Published: July 2016

This paper presents the motion of unsteady gravity-induced nanofluid flow containing gyrotactic micro-organisms along downward vertical convectively heated surface subject to passively controlled nanofluid. Considering the influence of temperature on the dynamic viscosity during convection and nature of thermal conductivity during heat conduction processes, these thermophysical properties are treated as linear functions of temperature. The governing equations are nondimensionalized by using suitable similarity transformation. The dimensionless nonlinear coupled PDEs are solved using a new pseudo-spectral technique called paired quasi-linearization method (PQLM). Convergence tests and residual error analysis are also presented to validate the accuracy, solution error, and computational convergence. The proposed PQLM yields accurate results which are obtained after a very few iterations. Minimum coefficients of (ξ/xRex)Shx with Sc are obtained at final steady stage.
A Water-Lubricated Hybrid Thrust Bearing: Measurements and Predictions of Static Load Performance
Authors: San Andrés Luis , Phillips Stephen , Childs Dara
Published: July 2016

Process fluid-lubricated thrust bearings (TBs) in a turbomachine control rotor placement due to axial loads arising from pressure fields on the front shroud and back surface of impellers. To date, prediction of aerodynamic-induced thrust loads is still largely empirical. Thus, needs persist to design and operate proven TBs and to validate predictions of performance derived from often too restrictive computational tools. This paper describes a test rig for measurement of the load performance of water-lubricated hydrostatic/hydrodynamic TBs operating under conditions typical of cryogenic turbo pumps (TPs). The test rig comprises of a rigid rotor composed of a thick shaft and two end collars. A pair of flexure-pivot hydrostatic journal bearings (38 mm in diameter) supports the rotor and quill shaft connected to a drive motor. The test rig hosts two TBs (eight pockets with inner diameter equal to 41 mm and outer diameter equal to 76 mm); one is a test bearing and the other is a slave bearing, both facing the outer side of the thrust collars on the rotor. The slave TB is affixed rigidly to a bearing support. A load system delivers an axial load to the test TB through a nonrotating shaft floating on two aerostatic radial bearings. The test TB displaces to impose a load on the rotor thrust collar, and the slave TB reacts to the applied axial load. The paper presents measurements of the TB operating axial clearance, flow rate, and pocket pressure for conditions of increasing static load (max. 3600 N) and shaft speed to 17.5 krpm (tip speed 69.8 m/s) and for an increasing water supply pressure into the TBs, max. 17.2 bar (250 psig). Predictions from a bulk flow model that accounts for both fluid inertia and turbulence flow effects agree well with recorded bearing flow rates (supply and exiting through the inner diameter), pocket pressure, and ensuing film clearance due to the imposed external load. The measurements and predictions show a film clearance decreasing exponentially as the applied load increases. The bearing flow rate also decreases, and at the highest rotor speed and lowest supply pressure, the bearing is starved of lubricant on its inner diameter side, as predicted. The measured bearing flow rate and pocket pressure aid to the empirical estimation of the orifice discharge coefficient for use in the predictive tool. The test data and validation of a predictive tool give confidence to the integration of fluid film TBs in cryogenic TPs as well as in other more conventional (commercial) machinery. The USAF Upper Stage Engine Technology (USET) program funded the work during the first decade of the 21st century.
Experimental and Numerical Investigations of the Stribeck Curves for Lubricated Counterformal Contacts
Authors: He Tao , Zhu Dong , Wang Jiaxu , Jane Wang Q.
Published: July 2016

The Stribeck curve is an important means to demonstrate the frictional behavior of a lubricated interface during the entire transition from boundary and mixed to full-film lubrication. In the present study, a new test apparatus has been built that can operate under rolling–sliding conditions at a continuously variable speed in an extremely wide range, approximately from 0.00006 to 60 m/s, covering six orders of magnitude. Hence, a complete Stribeck curve can be measured to reveal its basic characteristics for lubricated counterformal contacts. The measured curves are compared with numerical simulation results obtained from an available unified mixed elastohydrodynamic lubrication (EHL) model that is also capable of handling cases during the entire transition. A modified empirical model for the limiting shear stress of lubricant is obtained, and a good agreement between the measured and calculated Stribeck curves is achieved for the tested base oils in all the three lubrication regimes, which thus well validates the simulation methods employed. Both the experimental and numerical results indicate that the Stribeck curves for counterformal contact interfaces behave differently from those for conformal contacts. When the rolling speed increases at a fixed slide-to-roll ratio, the friction continuously decreases even in the full-film lubrication regime due to the reduction of the lubricant limiting shear stress caused mainly by the rise of the surface flash temperature. In addition, the test results indicate that the boundary additives in a commodity lubricant may have considerable influence on the boundary lubrication friction but that on the friction in the mixed and full-film lubrication appears to be limited.
Effect of Blowing Ratio on the Internal Heat Transfer of a Cooled Nozzle Guide Vane in a Linear Cascade
Authors: Kumar Pujari Arun , Prasad B. V. S. S. S. , Sitaram Nekkanti
Published: July 2016

Experimental and computational heat transfer investigations are reported on the interior side of a nozzle guide vane (NGV) subjected to combined impingement and film cooling. The domain of study is a two-dimensional five-vane cascade having a space chord ratio of 0.88. The vane internal surface is cooled by dry air, supplied through the two impingement inserts: the front and the aft. The blowing ratio (ρcVc/ρmVm) is varied systematically by varying the coolant mass flow through the impingement chamber and also by changing the mainstream Reynolds number, but by keeping a fixed spacing (H) to jet diameter (d) ratio of 1.2. The surface temperature distributions, at certain locations of the vane interior surface, are measured by pasting strips of liquid crystal sheets. The vane interior surface temperature distribution is also obtained by the computations carried out by using shear stress transport (SST) k–ω turbulence model in the flow solver ansys fluent-14. The computational data are in good agreement with the measured values of temperature. The internal heat transfer coefficients are thence determined from the computational data. The results show that, when the blowing ratio is increased by increasing the coolant flow rate, the average internal surface temperature decreases. However, when the blowing ratio is varied by increasing the mainstream Reynolds number, the internal surface temperature increases. Further, the temperature variations are different all along the internal surface from the leading edge to the trailing edge and are largely dependent on the coolant flow distributions on the internal as well as the external sides.
Influence of Injection Angle and Valve Opening Manner on Mixing Performance in a Large-Bore Port Fuel Injection Compressed Natural Gas-Fueled Engine
Authors: Wang Tianbo , Chang Siqin , Liu Liang
Published: July 2016

One new kind of gas injection devices (GIDs), with moving-coil electromagnetic linear actuator (MCELA) and mushroom-type poppet valve, was projected to inject sufficient compressed natural gas (CNG) to a large-bore port fuel injection (PFI) engine. It had larger mass flow rate and better controllability than conventional GID. And the transient computational fluid dynamics (CFD) engine model incorporating the GID's motion was established to analyze the effects of the GID injection angle and poppet valve opening manner on the mixing homogeneity in the intake port, and finally, the in-cylinder mixing performance and gas movement intensity were compared. The results indicate that with the increasing of injection angle, the mixing homogeneity in the near-field injection location of intake port will be better, and the time when fuel starts to get into cylinder will be later. At ignition time, the injection angles 60 deg, 90 deg, and 120 deg show better in-cylinder mixing performance, while 150 deg has the worst. The pull-open GID injects more momentum to the intake port than the push-open one, and the mixing degree both in the intake port and cylinder is higher.
Experimental Study on a Novel Foaming Formula for CO2 Foam Flooding
Authors: Xu X. , Saeedi A. , Liu K.
Published: July 2016

This research developed a viable and economical foaming formula (AOS/AVS/N70K-T) which is capable of creating ample and robust CO2 foams. Its foaming ability and displacement performance in a porous medium were investigated and compared with the two conventional formulations (AOS alone and AOS/HPAM). The results showed that the proposed formula could significantly improve the foam stability without greatly affecting the foaming ability, with a salinity level of 20,000 ppm and a temperature of 323 K. Furthermore, AOS/AVS/N70K-T foams exhibited thickening advantages over the other formulations, especially where the foam quality was located around the transition zone. This novel formulation also showed remarkable blocking ability in the resistance factor (RF) test, which was attributed to the pronounced synergy between AVS and N70K-T. Last but not the least, it was found that the tertiary oil recovery of the CO2 foams induced by AOS/AVS/N70K-T was 12.5% higher than that of AOS foams and 6.8% higher than that of AOS/HPAM foams at 323 K and 1500 psi, thus indicating its huge enhanced oil recovery (EOR) potential. Through systematic research, it is felt that the novel foaming formulation might be considered as a promising and practical candidate for CO2 foam flooding in the future.
Surface structure of in situ cleaved single crystal Bi2Se3 measured by low energy ion scattering
Authors: Zhou Weimin , Zhu Haoshan , Yarmoff Jory A.
Published: July 2016

Bismuth selenide is a two-dimensional topological insulator material composed of stacked quintuple layers (QL). The layers are held together by a weak van der Waals force that enables surface preparation by cleaving. Low energy ion scattering experiments show that Bi2Se3 cleaved under ultrahigh vacuum has a Se-terminated structure that is consistent with cleaving between QLs. Comparison of experimental data to molecular dynamics simulations confirms the Se-termination and provides an estimate of the surface relaxation.
SU‐A‐BRC‐00: AAPM Medical Physics Student Meeting: The Many Paths of Medical Physics
Authors: Roth Alison
Published: July 2016

This year's Annual Student Meeting consists of a panel of professionals who have pursued a traditional education in medical physics and have since pursued a variety of careers. These range from chief medical physicist, small business founder, FDA scientist, industry R&D scientist, and academic researcher. Each panelist will discuss their education, positions that they have held leading to their current one, and factors that influenced them to pursue their careers. Time will be left at the end of the talk to open the floor for questions from students and trainees. Discussion between the presenters and participants is encouraged.

Learning Objectives:

The audience will learn about how to prepare for a career in medical physics.

The audience will be able to consider some of the widely different job opportunities open to medical physicists.

The audience will gain a better understanding of some future challenges facing medical physics graduates.

N. Childress, I am the owner of Mobius Medical Systems, LP.
SU‐A‐BRC‐01: Welcome and introduction to Student and Trainees Day
Authors: Roth A.
Published: July 2016

This year's Annual Student Meeting consists of a panel of professionals who have pursued a traditional education in medical physics and have since pursued a variety of careers. These range from chief medical physicist, small business founder, FDA scientist, industry R&D scientist, and academic researcher. Each panelist will discuss their education, positions that they have held leading to their current one, and factors that influenced them to pursue their careers. Time will be left at the end of the talk to open the floor for questions from students and trainees. Discussion between the presenters and participants is encouraged.

Learning Objectives:

The audience will learn about how to prepare for a career in medical physics.

The audience will be able to consider some of the widely different job opportunities open to medical physicists.

The audience will gain a better understanding of some future challenges facing medical physics graduates.

N. Childress, I am the owner of Mobius Medical Systems, LP.
SU‐A‐BRC‐04: The Path of a Research and Development Physicist
Authors: Ruchala K.
Published: July 2016

This year's Annual Student Meeting consists of a panel of professionals who have pursued a traditional education in medical physics and have since pursued a variety of careers. These range from chief medical physicist, small business founder, FDA scientist, industry R&D scientist, and academic researcher. Each panelist will discuss their education, positions that they have held leading to their current one, and factors that influenced them to pursue their careers. Time will be left at the end of the talk to open the floor for questions from students and trainees. Discussion between the presenters and participants is encouraged.

Learning Objectives:

The audience will learn about how to prepare for a career in medical physics.

The audience will be able to consider some of the widely different job opportunities open to medical physicists.

The audience will gain a better understanding of some future challenges facing medical physics graduates.

N. Childress, I am the owner of Mobius Medical Systems, LP.
SU‐A‐BRC‐05: The Path of a FDA Physicist
Authors: Ochs R.
Published: July 2016

This year's Annual Student Meeting consists of a panel of professionals who have pursued a traditional education in medical physics and have since pursued a variety of careers. These range from chief medical physicist, small business founder, FDA scientist, industry R&D scientist, and academic researcher. Each panelist will discuss their education, positions that they have held leading to their current one, and factors that influenced them to pursue their careers. Time will be left at the end of the talk to open the floor for questions from students and trainees. Discussion between the presenters and participants is encouraged.

Learning Objectives:

The audience will learn about how to prepare for a career in medical physics.

The audience will be able to consider some of the widely different job opportunities open to medical physicists.

The audience will gain a better understanding of some future challenges facing medical physics graduates.

N. Childress, I am the owner of Mobius Medical Systems, LP.
SU‐A‐BRC‐07: Q&A
Authors: Roth A.
Published: July 2016

This year's Annual Student Meeting consists of a panel of professionals who have pursued a traditional education in medical physics and have since pursued a variety of careers. These range from chief medical physicist, small business founder, FDA scientist, industry R&D scientist, and academic researcher. Each panelist will discuss their education, positions that they have held leading to their current one, and factors that influenced them to pursue their careers. Time will be left at the end of the talk to open the floor for questions from students and trainees. Discussion between the presenters and participants is encouraged.

Learning Objectives:

The audience will learn about how to prepare for a career in medical physics.

The audience will be able to consider some of the widely different job opportunities open to medical physicists.

The audience will gain a better understanding of some future challenges facing medical physics graduates.

N. Childress, I am the owner of Mobius Medical Systems, LP.
SU‐C‐204‐01: A Dosimetric Investigation Into the Effects of Yttrium‐90 Radioembolization On the GI Tract: In‐Vivo and Histological Analysis in An Animal Model
Authors: Pasciak A , Nodit L , Bourgeois A , Paxton B , Arepally A , Bradley Y
Published: July 2016

Purpose:

In Yttrium‐90 (90Y) radioembolization, non‐target embolization (NTE) to the stomach or small bowel can result in ulceration, a rare but difficult to manage clinical complication. However, dosimetric thresholds for toxicity to these tissues from radioembolization have never been evaluated in a controlled setting. We performed an analysis of the effect of 90Y radioembolization in a porcine model at different absorbed‐dose endpoints.

Methods:

Under approval of the University of Tennessee IACUC, 6 female pigs were included in this study. Animals underwent transfemoral angiography and infusion of calibrated dosages of 90Y resin microspheres into arteries supplying part of the gastric wall. A 99mTc‐MAA simulation study was performed first to determine perfused tissue volume for treatment planning along with contrast‐enhanced CT. The pigs were monitored for side effects for 9 weeks, after which time they were euthanized and their upper gastrointestinal tracts were harvested for analysis.

Results:

90Y radioembolization was infused resulting in average absorbed doses of between 35.5 and 91.9 Gy to the gastric wall. No animal exhibited any signs of pain or gastrointestinal distress through the duration of the study. Excised tissue showed 1–2 small (<3.0 cm2) healed or healing superficial gastric lesions in 5 out of 6 animals. Histologic analysis demonstrated that lesion location was superficial to areas of abnormally high microsphere deposition. An analysis of microsphere deposition patterns within the gastric wall indicated a high preference for submucosal deposition. Dosimetric evaluation at the luminal mucosa performed based on microsphere deposition patterns confirmed that 90Y dosimetry techniques conventionally used in hepatic dosimetry provide a reasonable estimate of absorbed dose.

Conclusion:

The upper gastrointestinal tract may be less sensitive to 90Y radioembolization than previously thought. Lack of charged‐particle equilibrium at the luminal mucosa may contribute to decreased toxicity of 90Y radioembolization compared to external‐beam radiation therapy in gastrointestinal tissue.

This project was supported by SIRTex Medical Ltd
SU‐C‐204‐02: Behavioral and Pathologic Differences in Mice Exposed to Proton Minibeam Arrays Versus Proton Broad Beams
Authors: Eley J , Wolfe T , Vichaya E , Quini C , Chadha A , Zhang C , Davis J , Sahoo N , Dilmanian F , Krishnan S
Published: July 2016

Purpose:

Minibeam therapy using protons or light‐ions offers a theoretical reduction of biologic damage to tissues upstream of a tumor compared to broad‐beam therapy while providing equal tumor control. The purpose of this study was to investigate behavioral and pathologic differences in mice after exposure of healthy brain to proton minibeam arrays versus proton broad beams.

Methods:

Twenty‐four C57BL/6J juvenile mice were divided into 5 study arms: sham irradiation (NoRT), broad‐beam 10 Gy (BB10), minibeam 10Gy (MB10), broad‐beam 30 Gy (BB30), and minibeam 30 Gy (MB30), approximate integral entrance doses. Circular beams of 100 MeV protons with 7‐mm diameter were delivered laterally through the brain, either as broad beams or as planar minibeam arrays having 300‐micron beam width and 1‐mm spacing on center. Mice were followed for 8 months using standard behavioral tests. Pathologic studies were carried out at 8 months after irradiation.

Results:

Peak entrance doses were 10.0, 23.8, 30.0, and 71.3 Gy for mice in BB10, MB10, BB30, and MB30, respectively. Despite the high single‐fraction doses, no animals showed signs of radiation sickness or neurophysical impairment over the 8‐month study duration. The Morris water maze alternate‐starting‐position trial showed significant evidence of better spatial learning for mice in MB10 versus BB10 (p=0.026), but other behavioral tests showed no significant differences. Glial fibrillary acidic protein stains showed gliosis in arms BB10, BB30, and MB30 but not in NoRT or MB10. A secondary finding was categorically higher epilation in broad‐beam arms compared with their minibeam dose counterparts.

Conclusion:

Our findings indicate trends that, despite the higher peak doses, proton minibeam therapy can reduce radiation side effects in shallow tissue and brain compared to proton broadbeam therapy. As the behavioral findings were mixed, confirmation studies are needed with larger numbers of animals.

AAPM Research Seed Funding Grant
SU‐B‐BRA‐00: The Medical Physicist Value Proposition for Tomorrow and Today
Authors: Sherouse G.
Published: July 2016

In the current rapidly changing Healthcare environment, many groups are competing for limited resources. How can medical physicists position themselves to be a relevant stakeholder in the discussion of how those resources are allocated Our value goes beyond what can be shown in a business plan and is heavily involved with safety and quality.

Three areas will be explored:

What is our value?

Who needs to receive that message?

How do we communicate that message?

To help frame the discussion in terms of how other stakeholders may view the value of medical physicists, a physician and an administrator will present their perspective.

Lastly, a multidisciplinary panel will present real life examples of strategies that can be utilized today to establish the value of medical physicists. The presentation of these examples will lead into an interactive question and answer time.

V. Willcut, I work for Elekta. There was no research associated with this talk.
SU‐B‐BRA‐02: The Medical Physics Value Proposition for Tomorrow and Today
Authors: White G.
Published: July 2016

In the current rapidly changing Healthcare environment, many groups are competing for limited resources. How can medical physicists position themselves to be a relevant stakeholder in the discussion of how those resources are allocated Our value goes beyond what can be shown in a business plan and is heavily involved with safety and quality.

Three areas will be explored:

What is our value?

Who needs to receive that message?

How do we communicate that message?

To help frame the discussion in terms of how other stakeholders may view the value of medical physicists, a physician and an administrator will present their perspective.

Lastly, a multidisciplinary panel will present real life examples of strategies that can be utilized today to establish the value of medical physicists. The presentation of these examples will lead into an interactive question and answer time.

V. Willcut, I work for Elekta. There was no research associated with this talk.