bluuebunny/crossref_metadata_2025 huggingface dataset:
Recovery of volatile fatty acids by reactive extraction using tri‐n‐octylamine and tri‐butyl phosphate in different solvents: Equilibrium studies, pH and temperature effect, and optimization using multivariate taguchi approach
Authors: Eda Sumalatha , Kumari Alka , Thella Prathap Kumar , Satyavathi Bankupalli , Rajarathinam Parthasarathy
Published: February 2017

Recovery of volatile fatty acids from fermentation broth has been investigated by adopting an intensified approach using extractants tri‐n‐octylamine and tri‐butyl phosphate dissolved in 1‐decanol and methyl isobutyl ketone. The effects on distribution coefficient (KD) and extraction efficiency (%E) were studied by varying the operating conditions like temperature (293.15–323.15) K, pH (2.5, 3.5, and 4.5), and compositions of extractant (10, 20, and 30 %). Taguchi (L36) orthogonal design with five factors, namely diluents, extractant type, composition, temperature, and pH, was employed for the multivariate optimization of reactive extraction of volatile fatty acids. In the Taguchi approach, a “larger is better” criterion was adopted to maximize and %E. The statistical analysis indicated that the degree of influence on by experimental variables follows the following trend: extractant type () > pH () > diluent type () > temperature () > extractant concentration (). The trend for %E observed is as follows: extractant type () > pH () > temperature () > extractant concentration () > diluent type (). The combination of optimum parameters were obtained as X1 = 1‐decanol, X2 = tri‐n‐octylamine, X3 = 20 %, X4 = 293.15 K, and X5 = 3.5. A confirmation run was conducted using these parameters and and %E values from this run were determined to be 8.65 and of 89.64 %, respectively, which were very close to the predicted values  10.36 and %E  = 91.26 %.
Qualifiers of atypia in the cytologic diagnosis of thyroid nodules are associated with different Afirma gene expression classifier results and clinical outcomes
Authors: Baca Sylvan C. , Wong Kristine S. , Strickland Kyle C. , Heller Howard T. , Kim Matthew I. , Barletta Justine A. , Cibas Edmund S. , Krane Jeffrey F. , Marqusee Ellen , Angell Trevor E.
Published: February 2017

BACKGROUND

Thyroid nodules with atypia of undetermined significance (AUS) on fine‐needle aspiration (FNA) have a low risk of malignancy that appears to vary based on specific features described in the AUS diagnosis. The Afirma gene expression classifier (GEC) is a molecular test designed to improve preoperative risk stratification of thyroid nodules, but its performance for different patterns of AUS has not been defined. The objective of this study was to assess GEC results and clinical outcomes in AUS nodules with architectural atypia (AUS‐A), cytologic atypia (AUS‐C) or both (AUS‐C/A).

METHODS

This was a retrospective review of all thyroid nodules with AUS cytopathology that underwent GEC testing at the authors' institution over a period of >4 years.

RESULTS

In 227 nodules that had AUS cytology results and Afirma GEC testing, the rate of benign GEC results was higher in AUS‐A nodules (70 of 107; 65%) than in AUS‐C/A nodules (25 of 65; 38%; P = .0008), and AUS‐C nodules exhibited an intermediate rate of benign results (27 of 55 nodules; 59%). The risk of cancer among patients who had GEC‐suspicious nodules, 86% of whom underwent resection, was 19% (6 of 25) for AUS‐A nodules compared with 57% (21 of 37) for AUS‐C/A nodules (P = .003) and 45% (10 of 22) for AUS‐C nodules (P = .07). In nodules that had an indeterminate repeat cytology result, no difference was observed in the rate of benign GEC results or in the malignancy rate compared with nodules that had a single cytology result.

CONCLUSIONS

The performance characteristics of Afirma GEC testing vary, depending on qualifiers of cytologic atypia. Recognition of these differences may enable clinicians to provide improved counseling and treatment recommendations to patients. Cancer Cytopathol 2017;125:313–322. © 2017 American Cancer Society.
Happy to breed in the city? Urban food resources limit reproductive output in Western Jackdaws
Authors: Meyrier Eva , Jenni Lukas , Bötsch Yves , Strebel Stephan , Erne Bruno , Tablado Zulima
Published: February 2017

Urban areas expand worldwide, transforming landscapes and creating new challenging habitats. Some bird species, mainly omnivorous feeding on human waste and cavity nesters, commonly breed in these habitats and are, therefore, regarded as urban‐adapted. Although urban areas may provide new nesting sites and abundant human waste, the low breeding success found in some of these species suggests that the poor protein content in human waste might limit breeding parameters. We investigated whether the breeding success of a cavity nester and omnivorous species commonly breeding in urban areas, the Western Jackdaw (Corvus monedula), depended on the availability of good‐quality non‐urban food. We approached the objective by combining a literature review and experiments in the field. With the literature review, we compared jackdaw populations in different habitats across Europe and found that clutch size and number of fledglings per pair decreased with distance to non‐urban foraging grounds, even after controlling for the effect of colony size, latitude, and climate. In two experiments, we tested whether the breeding success of urban pairs could be increased by supplementing high‐quality food, first only during egg formation and second also until chick fledging. Food supplementation during egg formation led to larger eggs and higher hatching success than in urban control nests, but this did not result in higher chick survival. However, when food supplementation was prolonged until fledging in the second experiment, we observed a significant increase of nestling survival. These findings highlight that research and management actions should not only focus on species displaced by urbanization, but also on “urban‐adapted” species, as they might be suffering from a mismatch between availability of nesting sites in buildings and adequate non‐urban food resources. In these cases, nest sites should be provided in or close to adequate food resources.
Invalidation of fMRI experiments secondary to neurovascular uncoupling in patients with cerebrovascular disease
Authors: Para Andrea E. , Sam Kevin , Poublanc Julien , Fisher Joseph A. , Crawley Adrian P. , Mikulis David J.
Published: February 2017

Purpose

Blood oxygen level‐dependent (BOLD) functional magnetic resonance imaging (fMRI) is a technique used to infer neuronal activity from the observed changes in blood flow. Cerebrovascular reactivity (CVR) is the ability of arterioles to increase blood flow in response to vasodilatory stimulus. We hypothesize that in areas of disease where there is exhausted vascular reserve and impaired CVR there will be diminished blood flow response following neuronal activation, and that these areas would appear as false‐negative tests on BOLD fMRI.

Materials and Methods

Patients with steno‐occlusive disease and unilateral hemodynamic impairment received a standardized hypercapnic stimuli while being imaged with BOLD fMRI to generate CVR maps. These were compared to traditional BOLD fMRI maps of neuronal activation in the motor cortex in response to a motor task.

Results

Neuronal activation from the motor task was found to be linearly correlated with CVR (n = 11 patients, R = 0.82). Regions with positive (normal) CVR showed positive activation on BOLD fMRI, while regions with negative CVR had attenuated neuronal activation on BOLD fMRI.

Conclusion

In areas with cerebrovascular disease where CVR is impaired, there is uncoupling of neuronal activation and blood flow that confounds traditional BOLD fMRI. CVR mapping is a noninvasive MRI‐based imaging technique that can provide information about the vascular reactivity of the brain that is important to consider when interpreting traditional BOLD fMRI studies.

Level of Evidence: 2

Technical Efficacy: Stage 3

J. Magn. Reson. Imaging 2017;46:1448–1455.
Community delivery of semiautomated fractal analysis tool in cardiac mr for trabecular phenotyping
Authors: Captur Gabriella , Radenkovic Dina , Li Chunming , Liu Yu , Aung Nay , Zemrak Filip , Tobon‐Gomez Catalina , Gao Xuexin , Elliott Perry M. , Petersen Steffen E. , Bluemke David A. , Friedrich Matthias G. , Moon James C.
Published: February 2017

Purpose

To report the development of easy‐to‐use magnetic resonance imaging (MRI) fractal tools deployed on platforms accessible to all. The trabeculae of the left ventricle vary in health and disease but their measurement is difficult. Fractal analysis of cardiac MR images can measure trabecular complexity as a fractal dimension (FD).

Materials and Methods

This Health Insurance Portability and Accountability Act (HIPAA)‐compliant study was approved by the local Institutional Review Board. Participants provided written informed consent. The original MatLab implementation (region‐based level set segmentation and box‐counting algorithm) was recoded for two platforms (OsiriX and a clinical MR reporting platform [cvi42, Circle Cardiovascular Imaging, Calgary, Canada]). For validation, 100 subjects were scanned at 1.5T and 20 imaged twice for interstudy reproducibility. Cines were analyzed by the three tools and FD variability determined. Manual trabecular delineation by an expert reader (R1) provided ground truth contours for validation of segmentation accuracy by point‐to‐curve (P2C) distance estimates. Manual delineation was repeated by R1 and a second reader (R2) on 15 cases for intra/interobserver variability.

Results

FD by OsiriX and the clinical MR reporting platform showed high correlation with MatLab values (correlation coefficients: 0.96 [95% CI: 0.95–0.97] and 0.96 [0.95–0.96]) and high interstudy and intraplatform reproducibility. Semiautomated contours in OsiriX and the clinical MR reporting platform were highly correlated with ground truth contours evidenced by low P2C errors: 0.882 ± 0.76 mm and 0.709 ± 0.617 mm. Validity of ground truth contours was inferred from low P2C errors between readers (R1‐R1: 0.798 ± 0.718 mm; R1‐R2: 0.804 ± 0.649 mm).

Conclusion

This set of accessible fractal tools that measure trabeculation in the heart have been validated and released to the cardiac MR community (http://j.mp/29xOw3B) to encourage novel clinical applications of fractals in the cardiac imaging domain.

Level of Evidence: 3

Technical Efficacy: Stage 1

J. Magn. Reson. Imaging 2017;46:1082–1088.
Convective mixing and high littoral production established systematic errors in the diel oxygen curves of a shallow, eutrophic lake
Authors: Brothers Soren , Kazanjian Garabet , Köhler Jan , Scharfenberger Ulrike , Hilt Sabine
Published: February 2017

The diel (24‐h) oxygen (O2) curves approach has become a popular method for analyzing gross primary production (GPP) and ecosystem respiration (ER) rates in aquatic systems. Despite the simplicity of this approach, there remain aspects of the calculation and interpretation of diel O2 curves which may skew results, with potentially large implications for estimates of metabolic rates. One common problem in lakes is the occurrence of unexpected changes in O2 concentrations (for instance, increasing overnight O2 concentrations). Such changes have typically been ascribed to the random mixing of pockets of O2. It has thus been suggested that negative GPP or positive ER values should be included in calculations, on the assumption that under‐ and overestimates should occur with equal frequency, and thus cancel each other out. Our data from a shallow, eutrophic lake provided a high share of negative GPP values. We argue that these may have been the result of elevated littoral productivity coupled with convective currents produced by consistent differences in the heating or cooling of littoral and offshore waters. Such phenomena might be common in small, sheltered lakes where the role of mixing by wind is diminished. We conclude that a failure to account for consistent metabolic gradients and periodic convective mixing may lead to a chronic underestimation of metabolic rates in lakes when using the diel O2 curves method.
Oligohydramnios compromises lung cells size and interferes with epithelial–endothelial development
Authors: Najrana Tanbir , Ramos Lauren M. , Abu Eid Rasha , Sanchez‐Esteban Juan
Published: February 2017

Background and Objective

Severe oligohydramnios can induce pulmonary hypoplasia. However, the mechanisms by which leaking of fluids cause lung hypoplasia are not well defined. The objective of this study was to characterize a mouse model of pulmonary hypoplasia induced by oligohydramnios.

Methods

Amniotic sacs were punctured on E14.5 of gestation. Untouched fetuses were used as control. Pregnancy was allowed to continue until E18.5 in which lung tissue was collected and evaluated for morphometry, proliferation, differentiation, apoptosis, and angiogenesis.

Results

Our results found that lung weight, lung to total body weight ratio, and lung water content were reduced in oligohydramnios when compared to controls. In contrast, oligohydramnios did not affect the DNA content. Morphometric studies confirmed that oligohydramnios fetuses had smaller air spaces than control. Interestingly, cells from oligohydramnios fetuses have smaller size and less regular shapes. Oligohydramnios decreased the differentiation of type I epithelial cells and compromised apoptosis and angiogenesis while proliferation was not affected.

Conclusions

Although, the smaller size of the lung could be explained by a decreased of lung fluids, our data suggest that increased of external compression secondary to severe oligohydramnios can compromise cell size and interfere with epithelial and endothelial development. Type I epithelial cells could have an unrecognized key role in the differentiation of the distal lung mediated by mechanical signals. Pediatr Pulmonol. 2017;52:746–756. © 2017 Wiley Periodicals, Inc.
INDIVIDUAL CONSCIENCE AND HOW IT SHOULD BE TREATED
Authors: Greenawalt Kent
Published: February 2017

This essay summarizes crucial ways that society—in particular, the United States—has treated claims by individuals to be free of generally required duties because their convictions tell them that performing the duties is deeply wrong. Among the topics I address are how the Supreme Court decisions involving constitutional rights and organizational claims relate to this treatment, but my main focus is on what I see as the critical issues and what I believe to be the wise choices for addressing such claims. Without attempting an extensive account of all that has been written on claims of exemptions, I refer to some relatively recent books that can help one to understand what is at stake and what can be said in favor of competing positions. I also provide references to recent and forthcoming work of my own that explores claims of exemptions in greater depth.
Training of residents and fellows: The Mayo Clinic experience
Authors: Driscoll David
Published: February 2017

“The oath of hippocrates states the following:To hold him who has taught me this art as equal to my parents and to live my life in partnership with him, and if he is in need of money to give him a share of mine, and to regard his offspring as equal to my brothers in male lineage and to teach them this art – if they desire to learn it – without fee and covenant; to give a share of precepts and oral instruction and all the other learning to my sons and to the sons of him who has instructed me and to pupils who have signed the covenant and have taken an oath according to the medical law, but no one else”.
What’s new in graduate medical education?
Authors: Hernandez Raquel G.
Published: February 2017

The development of new graduate medical education programmes provides both opportunities and challenges. Efforts to address physician workforce shortages as well as a realisation that curricula need to be updated to adjust to our rapidly changing healthcare environment have resulted in more educators considering the “how to” and “what’s new” of programme development. Understanding the Next Accreditation System, an accreditation system introduced by the Accreditation Council of Graduate Medical Education in 2012, is critical to the success of new as well as existing residency and fellowship programmes. Although many educators are aware of the general rational for the Next Accreditation System, an in-depth understanding of the meaning of Next Accreditation System is necessary from an experiential and theoretical perspective to be able to successfully launch new programmes and moves towards accreditation. A new paediatric categorical residency programme and a new paediatric surgical programme were developed at our institution immediately following the implementation of Next Accreditation System. We provide a series of insights and perspectives based on our experience relative to what priorities we saw outlined from both the programmatic and the institutional perspective to have our graduate medical education programmes reviewed for accreditation. During this discussion, the following objectives are outlined: to overview the Next Accreditation System as a framework and priorities, to discuss the opportunities and challenges that may exist in developing new programmes, and to discuss future directions in the evaluation of trainees and assessment of training competency. Although challenges are outlined, we hope to relay the continued excitement and opportunities that exist relative to enhancing training curricula for future graduate medical education programme builders.
Photo-activation of the delocalized lipophilic cation D112 potentiates cancer selective ROS production and apoptosis
Authors: Yang Ning , Weinfeld Michael , Lemieux Hélène , Montpetit Ben , Goping Ing Swie
Published: February 2017

Delocalized lipophilic cations (DLCs) selectively accumulate in cancer cell mitochondria and have long been explored for therapeutic applications. Although targeted effects to cancer cells are demonstrated in vitro, non-specific toxicities in vivo have hampered clinical development. Identifying the molecular mechanisms of action and enhancing selectivity are thus necessary next steps to improve these compounds and evaluate their suitability for further drug development. D112 is one such DLC with promising properties. We previously demonstrated that D112 selectively induced intrinsic apoptosis in transformed versus non-transformed cell lines. Here we show that D112 preferentially entered transformed cells where it interacted with, and damaged mitochondrial DNA, inhibited Complex I respiration and induced reactive oxygen species (ROS). ROS production was critical for Bax activation and subsequent apoptosis. Importantly, photo-activation of D112 potentiated selective ROS production and increased the window of toxicity towards cancer cells over non-transformed cells. Thus photodynamic therapy would be an exciting adjunct to D112 studies and may be generally applicable for other DLCs that are currently under therapeutic investigation.
Facile Synthesis of Nanoporous Pt-Y alloy with Enhanced Electrocatalytic Activity and Durability
Authors: Cui Rongjing , Mei Ling , Han Guangjie , Chen Jiyun , Zhang Genhua , Quan Ying , Gu Ning , Zhang Lei , Fang Yong , Qian Bin , Jiang Xuefan , Han Zhida
Published: February 2017

Recently, Pt-Y alloy has displayed an excellent electrocatalytic activity for oxygen reduction reaction (ORR), and is regarded as a promising cathode catalyst for fuel cells. However, the bulk production of nanoscaled Pt-Y alloy with outstanding catalytic performance remains a great challenge. Here, we address the challenge through a simple dealloying method to synthesize nanoporous Pt-Y alloy (NP-PtY) with a typical ligament size of ~5 nm. By combining the intrinsic superior electrocatalytic activity of Pt-Y alloy with the special nanoporous structure, the NP-PtY bimetallic catalyst presents higher activity for ORR and ethanol oxidation reaction, and better electrocatalytic stability than the commercial Pt/C catalyst and nanoporous Pt alloy. The as-made NP-PtY holds great application potential as a promising electrocatalyst in proton exchange membrane fuel cells due to the advantages of facile preparation and excellent catalytic performance.
Magnetic Fano resonances by design in symmetry broken THz meta-foils
Authors: Wu Jianfeng , Moser Herbert O. , Li Rujiang , Yang Yihao , Jing Liqiao , Chen Hongsheng , Breese Mark B. H.
Published: February 2017

Magnetic Fano resonances in there-dimensional symmetry broken meta-foils at THz frequencies are theoretically and experimentally studied. Sharp Fano resonances occur due to the interference between different resonances and can be designed by choosing geometric parameters of the meta-foil. At the Fano resonances, the meta-foil supports antisymmetric modes, whereas, at the main resonance, only a symmetric mode exists. The meta-foil is left-handed at the Fano resonances and shows sharp peaks of the real part of the refractive index in transmission with small effective losses opening a way to very sensitive high-speed sensing of dielectric changes in the surrounding media and of mechanical configuration.
Fabrication and characterization of electrospun feather keratin/poly(vinyl alcohol) composite nanofibers
Authors: He Ming , Zhang Buning , Dou Yao , Yin Guoqiang , Cui Yingde , Chen Xunjun
Published: February 2017

We have fabricated random and aligned feather keratin (FK)/PVA composite nanofibers through an electrospinning process. The morphology, molecular interactions, crystallization behavior, and tensile properties of the nanofibers were investigated.
Polylysine-grafted Au144nanoclusters: birth and growth of a healthy surface-plasmon-resonance-like band
Authors: Guryanov Ivan , Polo Federico , Ubyvovk Evgeniy V. , Korzhikova-Vlakh Evgenia , Tennikova Tatiana , Rad Armin T. , Nieh Mu-Ping , Maran Flavio
Published: February 2017

We describe a method for the preparation of polylysine-capped Au144clusters, which display a stable surface-plasmon-resonance-like band as if the clusters were four times larger.
Effect of oxidative surface treatments on charge storage at titanium nitride surfaces for supercapacitor applications
Authors: Gray Benjamin M. , Hector Andrew L. , Jura Marek , Owen John R. , Whittam Joshua
Published: February 2017

The effects of surface oxidation on the capacitance of titanium nitride electrode surfaces are examined. Electrochemical oxidation was effective in increasing capacitance.
Tin dioxide as a high-performance catalyst towards Ce(vi)/Ce(iii) redox reactions for redox flow battery applications
Authors: Na Zhaolin , Wang Xuxu , Yin Dongming , Wang Limin
Published: February 2017

SnO2/graphite felt composite electrodes exhibiting excellent electrocatalytic activity toward cerium redox reactions are developed for the first time.
Ferrihydrite deposited on cotton textiles as protection media against the chemical warfare agent surrogate (2-chloroethyl ethyl sulfide)
Authors: Wallace Rajiv , Giannakoudakis Dimitrios A. , Florent Marc , Karwacki Christopher J. , Bandosz Teresa
Published: February 2017

An active phase of ferrihydrite was deposited on cotton using a simple dip-and-dry process.
Novel Operation of Snapping Biceps Femoris Tendon
Authors: Flores Stephen , Hartigan David , Patel Karan , Roberts Justin , Chhabra Anikar
Published: February 2017

Snapping biceps femoris tendon (BFT) over the fibular head is an uncommon cause of lateral knee pain. This study reports a case of nontraumatic painful snapping of the BFT due to a prominent fibular head that was persistent intraoperatively after fibular head resection. We describe a novel surgical technique of release of the anterior arm of the biceps tendon followed by soft tissue tenodesis to the popliteofibular ligament, as opposed to the remaining fibular head, to prevent iatrogenic fracture.
Stellenwert neuer Untersuchungsmethoden des Tränenfilms in der Diagnostik des trockenen Auges: Tränenfilmosmolarität und Matrixmetalloproteinasen (MMP-9)
Authors: Schargus M. , Geerling G. , Joachim S.
Published: February 2017

Die Keratoconjunctivitis sicca ist eine der häufigsten Diagnosen in der Augenheilkunde. Eine Vielzahl von subjektiven und objektiven Testverfahren mit ungenauen Grenzbereichen und unterschiedlich hohen Sensitivitäten und Spezifitäten erschwert die Diagnostik. Gerade geringe bis moderate pathologische Befunde können so fehldiagnostiziert werden. In den letzten Jahren haben sich durch die Entwicklung neuer, klinisch einfach einsetzbarer Diagnostikgeräte bspw. für die Analyse der Tränenfilmosmolarität oder der Matrixmetalloproteinasen (MMP-9) neue Optionen ergeben. Der Stellenwert der Tränenfilmosmolarität und der Bestimmung der MMP-9-Werte in der Diagnostik des trockenen Auges und seiner Subformen wird diskutiert und anhand publizierter Studienergebnisse objektiv zu bewerten versucht.
A rubidium Mx-magnetometer for measurements on solid state spins
Authors: Arnold Daniel , Siegel Steven , Grisanti Emily , Wrachtrup Jörg , Gerhardt Ilja
Published: February 2017

The detection of environmental magnetic fields is well established by optically pumped atomic magnetometers. Another focus of magnetometry can be the research on magnetic or spin-active solid-state samples. Here we introduce a simple and compact design of a rubidium-based Mx magnetometer, which allows for hosting solid-state samples. The optical, mechanical, and electrical design is reported, as well as simple measurements which introduce the ground-state spin-relaxation time, the signal-to-noise ratio of a measurement, and subsequently the overall sensitivity of the magnetometer. The magnetometer is optimized for the most sensitive operation with respect to laser power and magnetic field excitation at the Larmor frequency.
Antihydrogen gives way to spectroscopic study
Authors: Miller Johanna L.
Published: February 2017

For the first time, researchers have probed the energy difference between two orbital states of an antimatter atom.
Optimal estimation of catch by the continuous underway fish egg sampler based on a model of the vertical distribution of American plaice (Hippoglossoides platessoides) eggs
Authors: Pepin P. , Curtis K. A. , Snelgrove P. V. R. , de Young B. , Helbig J. A.
Published: February 2017

Pepin, P., Curtis, K.A., Snelgrove, P.V.R., de Young, B., and Helbig, J.A. 2007. Optimal estimation of catch by the continous underway fish egg sampler based on a model of the vertical distribution of American plaice (Hippoglossoides platessoides) eggs – ICES Journal of Marine Science, 64, 18–30. We investigate how the vertical stratification of the water column (specifically density) affects predictions of the catch of American plaice eggs (Hipploglossoides platessoides) from a fixed-depth sampler [the continuous underway fish egg sampler (CUFES)] relative to the integrated abundance in the water column measured in bongo tows. A steady-state model of the vertical distribution of fish eggs coupled with a simple model of the vertical profile of eddy diffusivity (i.e. mixing) is applied. Key model parameters are estimated through optimization of a one-to-one relationship between predicted and observed catches fit, using a generalized linear model with a Poisson, negative binomial, or gamma error structure. The incorporation of data on the vertical structure of the water column significantly improved the ability to forecast CUFES catches when using Poisson or negative binomial error structure, but not using a gamma distribution. Optimal maximum likelihood parameter estimates for eddy diffusivity and egg buoyancy fell within the range of expected values. The degree of uncertainty in the parameterization of eddy diffusivity suggests, however, that greater understanding of the forces that determine the vertical profile of mixing is critical to achieving strong predictive capabilities. The inverse problem of predicting integrated abundance from CUFES catches did not benefit from the environmental-driven model because of the high uncertainty in the catches from the CUFES.
Type C Virus Expression in Lymphoma-Paralysis-Prone Wild Mice2
Authors: Gardner Murray B. , Klement Vaclav , Rongey Robert R. , McConahey Patricia , Estes John D. , Huebner Robert J.
Published: February 2017

Wild mice trapped near Lake Casitas (LC) in southern California showed a high prevalence of infectious type C virus in the liver, spleen, and thymus within the first few weeks of life. By young adulthood about 80% of LC mice (including their genital tissues) were infected. Virus isolates from these mice cause lymphoma and lower limb paralysis under both natural and experimental conditions. Mice destined to develop paralysis showed higher levels of serum gs antigen early in life, whereas mice destined to develop lymphoma or remain free of these diseases could not be distinguished by this test. The individual variation in virus expression suggested that differences in virus type or in the immune or other host defense mechanisms greatly influenced susceptibility or resistance to indigenous type C virus-caused disease in LC wild mice.
Fluxed and deposition rates of solutes in growing roots of Zea mays
Authors: Bret-Harte M. Syndonia , Silk Wendy K.
Published: February 2017

The equations and experimental methods are reviewed for calculating solute deposition rates and fluxes an growing parts of roots. Then the expression for the growth-sustaining sucrose flux in the meristem is presented and evaluated to show the sucrose flux required to produce the empirically observed biomass deposition rate in primary maize roots. Two independent methods (one based on dye transport measurements and the second based on Stokes radii) are used to estimate the symplasmic conductivity for diffusion. The concentration gradients required to drive a growth-sustaining symplasmic diffusion of sucrose are found to be physiologically unreasonable. Either our current understanding of plasmodesmatal ultrastructure is flawed, or alternative mechanisms must exist for sucrose transport to the meristem.
The Energy and Angle Dependence of Response to Photons of the NRPB Thermoluminescence Dosemeter in Terms of the New ICRU Quantities
Authors: Bartlett D.T. , Burgess P.H. , Francis T.M. , Dutt J.C. , Dimbylow P.J.
Published: February 2017

The ICRU has introduced the quantities ambient dose equivalent and directional dose equivalent for environmental monitoring; and individual dose equivalent, penetrating, and individual dose equivalent, superficial, for individual monitoring. The quantities are for use as secondary quantities within the framework of the system of dose limitation recommended by ICRP, which includes limits for effective dose equivalent for stochastic effects and for organ dose equivalent for non-stochastic effects. Measurements have been made of the energy dependence of the photon response of the NRPB thermoluminescence dosemeter mounted on a cuboid phantom, and of the energy and angle dependence of response of the dosemeter mounted on a 30 cm diameter spherical phantom. The phantom material was MS20, an epoxy resin based material designed to simulate muscle and found to be an acceptably close approximation to ICRU 4-element tissue. Values of exposures at the position of the dosemeter in the absence of dosemeter and phantom were converted to ICRU operational quantities using published conversion coefficients. Measurements were made for 137Cs and 60Co gamma radiation, the ISO narrow series of filtered X radiation (9 qualities, 33, 48, 65, 83, 100, 118, 161, 205 and 248 keV) and the ISO fluorescence series lower energy, 17.4 keV.
An Automated Laser Heated Thermoluminescence Dosimetry System
Authors: Braunlich P.F. , Tetzlaff W.
Published: February 2017

We describe a fully automated and computer controlled laser heated thermoluminescence dosimetry reader and a dosemeter which consists of eight thin-layer phosphor spots of thickness between 2 and 10 mg.cm-2. A CO2 laser delivers a heating beam of the same size as the dosemeter spots and has a uniform intensity profile. The heating power is 'time-shaped' by computer control to facilitate pre- and post-anneal treatment and to minimise background signals due to incandescence emission. The performance characteristics of this reader are demonstrated. Results obtained with beta exposures from 147Pm, 204Tl, and 90Sr sources, gamma radiation, and fast neutrons are presented.
Basic Data Necessary for Neutron Dosimetry
Authors: Caswell R.S. , Coyne J.J. , Gerstenberg H.M. , Axton (INVITED) E.J.
Published: February 2017

Among many developments in basic data for neutron dosimetry, four are highlighted: improvements in kerma factor data for carbon; the use of common data through unification of the European and American protocols for neutron radiation therapy dosimetry; the tabulation of a set of initial spectra of secondary particles produced in tissue and tissue-like materials; and proposed changes in the magnitude and definition of neutron quality factors, which, while not physical quantitites, are nevertheless basic to neutron dosimetry.
Implication of ICRU 39 for Radiation Protection Instrumentation
Authors: Portal (INVITED) G.
Published: February 2017

The implications for radiation protection instrumentation of the ICRU 39 proposals on new operational quantities for gamma and neutron ambient dose equivalent H* and individual dose equivalent, penetrating, Hp(10) measurements are considered. It is shown that the ICRU Working Committee has arranged for these quantities to be adaptable to existing instrumentation. The most important modification concerns the calibration procedure. It is essential to have at ones disposal transfer coefficients linking calibration and operational quantities.
Environmental Radiological Impact of Some Portuguese Uranium Mines
Authors: Galvão J.P. , de Bettencourt A.O. , Teixeira M.M.G.R. , Elias M.D.T.
Published: February 2017

An environmental radiological surveillance programme has been in progress around the most significant Portuguese uranium mines, from 1976 to 1983. A short description is given of the mines of Urgeirica (including uranium milling), Freixiosa, Pinhal de Souto and Bica. The results of the surveillance programme developed in the vicinity of these facilities are presented and the identified critical pathways are discussed. One of these pathways is the consumption of cabbage, which is an important component in the diet of the Portuguese population. The exposure of the critical groups, due to the intake of 226Ra through the diet, calculated from the results of this monitoring programme, range from 0.02 to 1.5 mSv.y-1, for the different mines under study.
Search for Buildings with High Radon Levels in Sweden: Measurements Carried out by Local Authorities in Both Older and Newly Built Homes
Authors: Swedjemark G.A.
Published: February 2017

Local authorities in Sweden have made about 58,000 radon daughter measurements with the following aims: (1) to search for houses with high radon daughter levels, (2) to determine the level above which the house would be regarded as an insanitary dwelling, and (3) to check that the radon daughter concentrations in newly built houses are below the established limit. The sampling of dwellings is therefore not representative for Swedish homes. 5300 homes were found to have levels above the limit 400 Bq.m-3 EER. The highest level found was 28,000 Bq.m-3. In about one third of the homes found to have levels exceeding the limit, measures had been carried out to decrease the radon daughter concentration. About half of the homes in which the levels were decreased had levels below the limit for rebuilding, e.g. 200 Bq.m-3. Measurements in order to ascertain levels in newly built houses were made in about 1100 homes out of 200,000 built since 1981 which was the year in which requirements for newly built houses came into force. Of those built with radon-safe or radon-protective foundations, 94% had concentrations below the 70 Bq.m-3 EER limit, compared to 80% for traditional building techniques.
LET Dependence of Linear and Quadratic Terms in Dose-Response Relationships for Cellular Damage: Correlations with the Dimensions and Structures of Biological Targets
Authors: Barendsen G.W.
Published: February 2017

Dose-effect relationships and the dependence of RBE on LET can be analysed to derive insights about the amounts of deposited radiation energy required in critical structures and about the dimensions of targets involved in the induction of various cellular responses. Amounts of energy of several hundreds of eV and dimensions of the order of 10 nm have been derived as critical values associated with the induction of cell reproductive death and chromosome aberrations, while effective cross sections are of the order of tens of square micrometres. To apply information from microdosimetric studies and from cellular responses to the development and testing of hypotheses about mechanisms of radiation action, it is necessary to correlate these data with insights concerning dimensions and structures of cellular constituents and macromolecules. This approach is illustrated by the correlation of cross sections for inactivation with dimensions of the cell nucleus in dependence on the culture conditions and by the comparison of the derived dimensions of critical targets with DNA packing and chromatin structure in cells. A model is suggested in which lethal and potentially lethal damage induced in mammalian cells by single ionising particles involves the induction of two DNA double strand breaks in close proximity in a chromatin fibre, while accumulation of damage causing the contribution, which increases with the square of the dose, might be associated with interaction of single DSBs produced at larger distances.
Inactivation Cross Sections of Yeast and Bacteria Exposed to Heavy Ions of Low Energy (less than 600 keV/u)
Authors: Schneider E. , Kost M. , Schafer M.
Published: February 2017

A haploid yeast mutant of Saccharomyces cerevisiae and spores of Bacillus subtilis were exposed to heavy ions with energies of maximal 600 keV.u-1 down to energies associated with ranges which are just high enough to penetrate yeast cells and bacteria. The experiments were performed at the UNILAC at GSI (Darmstadt, FRG). The primary energy of 1.4 MeV.u-1 was reduced by a titanium window and by Hostaphan foils of different thickness. Generally the inactivation cross section decreases when the velocity of the primary particle is reduced due to the shrinking dimensions of the d electron penumbra. The results of the experiments with Kr, Pb and U ions demonstrate that the inactivation cross sections for yeast as well as for bacterial spores do not change significantly when the energy is reduced stepwise below 600 keV.u-1. Close to the end of the range of the ions, however, in all cases an increase of 10 to 30% in total is observed. These results indicate that at the very end of the range of the particles, i.e. at particle energies of around 100 keV.u-1, other interactions than electronic stopping may play a more important role.
Interpretation of Damage to Mammalian Cells, E.Coli and Bacteriophages by Incorporated Radionuclides for Prolonged Irradiation
Authors: Younis A.-R.S. , Watt D.E.
Published: February 2017

Previous analysis of published survival data for Auger electron and beta emitting nuclides incorporated into mammalian cells have been extended to include E. coli and bacteriophages. A unified scheme for the expression of damage is explored in terms of the localised secondary charged particle fluence of electrons, their average mean free path for ionisation and the number of DNA segments at risk in the target.
Thermoluminescent and Exoemission Properties of New High-Sensitivity TLD a-Al2O3:C Crystals
Authors: Akselrod M.S. , Kortov V.S.
Published: February 2017

To determine the mechanisms of the electron-hole processes in a-Al2O3:C crystals, characteristics of their thermo- and photo-stimulated exoelectron emission (TSEE, PSEE) and luminescence have been studied. It is shown that the emission of F+ centres takes place with the temperature shift relative to the emission of F centres, and the hole-induced TSEE takes place synchronously with the emission of F centres. The electron energy distribution parameters at PSEE do not depend on the energy of stimulating light photons, which testifies to thermalisation of the released holes before their recombination. Parameters determined for doped anion-deficient corundum crystals are considered within the framework of the two-stage Auger process model.
On the Application of Silicon for Fast Neutron Dosimetry
Authors: Iwanowski R.J. , Sienkiewicz A.
Published: February 2017

The defect structure of a neutron-damaged silicon as a function of irradiation dose has been investigated. Two types of defects had been detected in the neutron-irradiated n-Si (FZ) crystals studied: divacancies (V2), from the IR absorption (1.8 µm band), and four-vacancy clusters (P3) from EPR spectrum, their concentration increasing linearly with fast neutron dose, FN. In a recent paper both V2 and P3 centres had been simultaneously observed in neutron-irradiated Si. The production efficiency of P3 clusters was found equal to 1 per 20 divacancies, independently of FN. From our estimate, approximately two P3 centres per primary cascade were produced (irrespective of FN). This suggests that both the above defects are mainly associated with the displacement spike which terminates the cascade. Excellent agreement of our results with partial literature data indicates that the concentrations NV2 and NP3 depend only on FN,irrespective of the shape of the neutron spectrum. Therefore, the divacancy-related 1.8 µm absorption band of silicon can be used for simple determination of fast neutron dose, up to FN = 1018 cm-2. Proper high temperature annealing of radiation defects enables multiple use of Si crystal as a fast neutron dosemeter.
Fast Neutron Dosimetry by Thermoluminescence Detection of Knock-on Protons
Authors: Braunlich P. , Tetzlaff W.
Published: February 2017

A thermoluminescence equivalent to the etched track technique for fast neutron dosimetry is described. It is based on 'reading' thin thermoluminescent (TL) layers with a tightly focused, scanning CO2 laser beam. With a spatial resolution of 30 µm, it detects and counts areas of high TL emission that result from individual knock-on-protons generated in a polyethylene foil.
Fast Neutron Spectrometry Using CR-39 Track Detectors
Authors: Dajkó G.
Published: February 2017

Some years ago a fast neutron spectrometer method was developed based on the etched track density determinations of elastically scattered protons and using varying radiator thickness at fixed etching time and varying etching times at fixed radiator thicknesses. Some new results in this field are presented.
Ultra High Level Dosimetry by ESR Spectroscopy of Crystalline Quartz and Fused Silicate
Authors: Wieser A. , Regulla D.F.
Published: February 2017

At present there is a great interest in ultra-high-level dosimetry exceeding the 0.5 MGy which can still be detected more conventionally by the ESR spectroscopy of alanine. Recently, the E1' defect in SiO2 was discovered for dosimetry. The defect generated in crystalline quartz by gamma irradiation was found to be an excellent candidate for ultra-high-level dosimetry at ambient temperatures up to 300 oC. The E1' centre is observed in all pure forms of quartz and silicate, but its dosimetric properties are specific for each material. This provides the precondition for a wide range of applications in dosimetry. Here, the properties of the E1' centre are compared for fused silicates and crystalline quartz. For the first time, supralinearity was observed for the E1' centre and that in silicate glass. The experiments are designed to be used at the HAW project in the Asse salt mine, Braunschweig, FRG.
PTFE in High Dose ESR-NMR Gamma Dosimetry
Authors: Milman I. , Putyrsky V. , Naimark M. , Popov V.
Published: February 2017

ESR and NMR of the broad line of polytetrafluoroethylene (PTFE) have been studied in connection with the use of material in industrial high dose measurement. Interaction between radiation and PTFE results in free radical formation and change in the condition of resonance observed for 19F nuclei, which can be detected by ESR-NMR spectroscopy methods. It has been found that the intensity and form of lines of the ESR signal are unambiguously related to the value of absorbed dose. Processing of NMR signals had indicated an increase of width and second moment of absorption in the spectrum and decrease of the line form factor with increasing dose. Fading of radiation-induced ESR and NMR signals is no more than 2% after a year of storage under standard conditions. The results presented show the possibility of using PTFE in high precision high dose dosimetry.
Study of GR200F LiF:Mg,Cu,P Detectors for Extremity Dosimetry
Authors: Yuen P.S. , Richter W.F. , Aikens M.S.
Published: February 2017

The dosimetric properties of GR200F LiF;Mg,Cu,P detectors with 5 mg.cm-2 sensitive layers have been studied for applications in extremity dosimetry. These properties included batch homogeneity, minimum detectable dose, reproducibility, residual signals, fading characteristics, linearity of response, effect of light exposure, photon energy and angular response, and beta energy and angular response. It was found that they are acceptable for extremity dosimetry. In particular, if used in conjunction with an extremity dosemeter holder with a window thickness of approximately 4 mg.cm-2, this detector can measure accurately the tissue dose at 7 mg.cm-2 delivered by low energy beta emitters such as 147Pm.
Ultraviolet Radiation Measurement with Neutron Pre-Irradiated Thermoluminescence Dosemeters
Authors: Yeh S.-H. , Weng P.-S.
Published: February 2017

The characteristics of TL 6LiF:Mg,Ti (TLD-600) to be used as an ultraviolet (UV) radiation dosemeter based on the phototransfer thermoluminescence (PTTL) method are considered. Thermoluminescence dosemeters were pre-irradiated with D2O moderated 252Cf neutrons instead of gamma rays in order to increase the growth efficiency of residual thermoluminescence to be transferred by UV radiation. The optimal pre-annealing condition before UV irradiation was investigated. It depends on the pre-irradiation neutron fluence. Area variation of the glow curve was studied in detail and it is concluded that no new charge carriers were created in the PTTL process. The lower limit of detection for UV is dependent on the pre-irradiation neutron fluence and is about 10 to 103 J.m-2 for neutron fluences of 1013-1011 m-2. The upper limit may be at least 106 J.m-2.
Energy Loss Function for Biological Material: Poly (CSP)
Authors: Fung A.Y.C. , Zaider M.
Published: February 2017

In this paper calculated cross sections are presented for the interaction of electrons with poly(CSP), a single-stranded chain that contains one cytosine sugar phosphate unit in the elementary cell. To model a single strand of helical DNA (e.g. the base stacking), the Watson-Crick model for the geometry of poly(CSP) has been used. The use, for computational simplicity, of a single, rather than a double stranded polynucleotide may be justified on the basis of previous calculations indicating that - to a good approximation - the electronic structure (other than excitation states) of complementary base pairs may be described as a superposition of the corresponding structures of the individual components. The cross sections are obtained from the dielectric response function of the system, _(q,?), which is calculated with the aid of a semi-empirical Hamiltonian, the parameters of which have been adjusted to fit available optical and electron scattering data on DNA and related systems.