bluuebunny/crossref_metadata_2025_split huggingface dataset:
Serum prealbumin and its changes over time are associated with mortality in acute kidney injury
Authors: Wang Wenji , Pan Yu , Tang Xiao , Hao Guihua , Xie Yingxin , Ma Shuai , Luo Jianfeng , Guo Daqiao , Ding Feng 
Published: February 2017

AbstractSerum prealbumin is a clinically relevant indicator of nutritional status and inflammation in patients with acute kidney injury (AKI). This study aimed to determine whether serum prealbumin and its longitudinal changes over a week could improve the prediction of 90-day mortality in AKI patients. This prospective cohort study included 340 adults with AKI between 2014 and 2015. There were 94 (27.6%) patient deaths within 90 days. Serum prealbumin level <10 mg/dL at the time of AKI diagnosis was associated with a 155% increased death risk ratio (adjusted hazard ratio [HR], 2.55; 95% confidence interval [CI], 1.18 to 5.49; P = 0.02). Serum prealbumin fall >4 mg/dL was also associated with 90-day mortality in adjusted Cox regression models (HR, 1.79; 95% CI, 1.06 to 3.03; P = 0.03). Compared to serum albumin, mortality-predictability of serum prealbumin (P = 0.01) and its changes (P = 0.01) were both increased. Adding prealbumin and its changes on the conventional covariates improved the prediction of progression to 90-day mortality (NRI 0.29, P = 0.04; aIDI 0.08; P = 0.03). In conclusion, serum prealbumin, and its changes were independent predictors of worse prognosis in AKI, and could be potential surrogates to better predict 90-day mortality.
Identification of genomic regions for grain yield and yield stability and their epistatic interactions
Authors: Sehgal Deepmala , Autrique Enrique , Singh Ravi , Ellis Marc , Singh Sukhwinder , Dreisigacker Susanne 
Published: February 2017

AbstractThe task of identifying genomic regions conferring yield stability is challenging in any crop and requires large experimental data sets in conjunction with complex analytical approaches. We report findings of a first attempt to identify genomic regions with stable expression and their individual epistatic interactions for grain yield and yield stability in a large elite panel of wheat under multiple environments via a genome wide association mapping (GWAM) approach. Seven hundred and twenty lines were genotyped using genotyping-by-sequencing technology and phenotyped for grain yield and phenological traits. High gene diversity (0.250) and a moderate genetic structure (five groups) in the panel provided an excellent base for GWAM. The mixed linear model and multi-locus mixed model analyses identified key genomic regions on chromosomes 2B, 3A, 4A, 5B, 7A and 7B. Further, significant epistatic interactions were observed among loci with and without main effects that contributed to additional variation of up to 10%. Simple stepwise regression provided the most significant main effect and epistatic markers resulting in up to 20% variation for yield stability and up to 17% gain in yield with the best allelic combination.
Emergence of Persistent Infection due to Heterogeneity
Authors: Agrawal Vidit , Moitra Promit , Sinha Sudeshna 
Published: February 2017

AbstractWe explore the emergence of persistent infection in a closed region where the disease progression of the individuals is given by the SIRS model, with an individual becoming infected on contact with another infected individual. We investigate the persistence of contagion qualitatively and quantitatively, under increasing heterogeneity in the partitioning of the population into different disease compartments, as well as increasing heterogeneity in the phases of the disease among individuals within a compartment. We observe that when the initial population is uniform, consisting of individuals at the same stage of disease progression, infection arising from a contagious seed does not persist. However when the initial population consists of randomly distributed refractory and susceptible individuals, a single source of infection can lead to sustained infection in the population, as heterogeneity facilitates the de-synchronization of the phases in the disease cycle of the individuals. We also show how the average size of the window of persistence of infection depends on the degree of heterogeneity in the initial composition of the population. In particular, we show that the infection eventually dies out when the entire initial population is susceptible, while even a few susceptibles among an heterogeneous refractory population gives rise to a large persistent infected set.
New evidence of Yangtze delta recession after closing of the Three Gorges Dam
Authors: Luo X. X. , Yang S. L. , Wang R. S. , Zhang C. Y. , Li P. 
Published: February 2017

AbstractMany deltas are likely undergoing net erosion because of rapid decreases in riverine sediment supply and rising global sea levels. However, detecting erosion in subaqueous deltas is usually difficult because of the lack of bathymetric data. In this study, by comparing bathymetric data between 1981 and 2012 and surficial sediment grain sizes from the Yangtze subaqueous delta front over the last three decades, we found severe erosion and significant sediment coarsening in recent years since the construction of Three Gorges Dam (TGD), the largest dam in the world. We attributed these morphological and sedimentary variations mainly to the human-induced drastic decline of river sediment discharge. Combined with previous studies based on bathymetric data from different areas of the same delta, we theorize that the Yangtze subaqueous delta is experiencing overall (net) erosion, although local accumulation was also noted. We expect that the Yangtze sediment discharge will further decrease in the near future because of construction of new dams and delta recession will continue to occur.
Where are the solar magnetic poles?
Authors: Pastor Yabar A. , Martínez González M. J. , Collados M. 
Published: February 2017

Abstract
Regardless of the physical origin of stellar magnetic fields – fossil or dynamo induced - an inclination angle between the magnetic and rotation axes is very often observed. Absence of observational evidence in this direction in the solar case has led to generally assume that its global magnetic field and rotation axes are well aligned. We present the detection of a monthly periodic signal of the photospheric solar magnetic field at all latitudes, and especially near the poles, revealing that the main axis of the Sun's magnetic field is not aligned with the surface rotation axis. This result reinforces the view of our Sun as a common intermediate-mass star. Furthermore, this detection challenges and imposes a strong observational constraint to modern solar dynamo theories.
A New Solid State Beta Dosemeter
Authors: Jones A.R. , Sanders J.M. 
Published: February 2017

Abstract
The use of a metal oxide silicon field effect transistor (MOSFET) as a gamma and X ray dosemeter has been previously reported. This paper reports measurements on the performance of MOSFETS for beta dosimetry. The sensitive area of the sensor is less than 7 mg.cm-2 below the surface of the MOSFET and hence, with the appropriate window thickness, the MOSFET should be energy independent for beta rays. The sensitivity of MOSFETS to beta rays of different energies has been measured for various thicknesses in order to establish the optimum thickness for energy independence. Using a polycarbonate cover, the optimum thickness was about 5.4 mg.cm-2. With this cover the energy dependence was less than ±10% for beta ray spectra with end point energies from 0.23 to 2.2 MeV. The dependence upon direction was less than 20% for angles of incidence up to 45o. The results of these experiments and other dosimetric parameters are presented. The application of MOSFETS to beta dosimetry is discussed in terms of the values of the dosimetric parameters obtained.
The Angular Response of Lithium Fluoride for Several Beta Emitters
Authors: King C.W. 
Published: February 2017

Abstract
The angular dependence of the response of thermoluminescent lithium fluoride (TLD-100) solid detectors has been investigated. The angle of incidence was varied from perpendicular to parallel for 147Pm, 204Tl and 90Sr-90Y beta particles. The test dose was 1 mGy (in air) in all cases. The TL detector response is also determined for thin Teflon encapsulation and for attenuating absorber thicknesses from 0 to 75 mg.cm-2. Experimental results are presented in mGy and also in arbitrary units normalised to the perpendicular TL detector response.
A Comparison of Two Methods of Rapidly Heating Thick TLDs
Authors: Jones A.R. 
Published: February 2017

Abstract
To heat a TLD quickly, the process should be limited only by the thermal characteristics of the TLD itself. One method is to bring the TLD into thermal contact with a metal mass, or anvil at a constant temperature which is approached asymptotically by that of the TLD. An alternative is to supply radiant heat to the TLD, for example from a CO2 laser. If this is done quickly, to minimise heat losses, the TLD temperature will rise linearly with time. Measurements have been made with experimental heaters of both types with the following parameters needed for their comparison: the time needed to heat the TLDs and its reproducibility, and the reproducibility of TLD readings when exposed and unexposed to radiation. With a 5 W CO2 laser, the heating time for a 0.9 mm thick TLD was about 10 s compared with about 6 s for the anvil heater. The heating rate for the laser heater was more consistent than for the anvil heater, but the latter provided more reproducibility in dosemeter readings. The use of the laser reduced the residual signal below a detectable level. The performance of both methods was shown to depend upon the methods of mounting the phosphor and the data analysis.
Dosimetric Characteristics of Different TL Phosphors
Authors: Ranogjec-Komor M. , Osvay M. 
Published: February 2017

Abstract
The photon energy dependence of different TL phosphors LiF:Mg,Ti, MgB4O7:Dy, CaF2:Mn, Al2O3:Mg,Y was measured using X ray radiation (48-205 keV) and a 60Co source. The relative sensitivity, linearity, fading and UV light induced TL signal were investigated in the dose range from several mGy to several Gy.
Thermoluminescent Mechanisms in CaSO4:Dy Single Crystals
Authors: Morgan M.D. , Stoebe T.G. 
Published: February 2017

Abstract
ESR studies of gamma-irradiated CaSO4:Dy have shown, in addition to the usual intrinsic defects, four new paramagnetic centres. An analysis of the g values and the g tensors in conjunction with the anhydrite crystal structure indicate that these centres are related to sulphate ions, this structure being stabilised by a neighbouring Ca vacancy. Centre 3b is suggested as a hole associated with one sulphate ion, again stabilised by an adjacent Ca vacancy. Because of the two distinct crystallographic directions in the anhydrite structure, centre 3b was found to consist of two distinguishable defects with slightly differing decay temperatures. The fourth centre appears to be an electron trapping site with structure similar to centre 3b. Decay temperatures of these ESR defects are correlated with the observance of TL peaks in CaSO4:Dy. Thermoluminescence studies as a function of impurity content confirmed the presence of calcium vacancies, which are formed during crystal growth, and that they play an important role in the TL process. TL models are proposed to account for the observed properties of CaSO4:Dy.
The Variation with LET of the Responses of TLD-700 and TLD-600 at Temperatures up to 200 oC
Authors: Douglas J.A. , Perks C.A. , Cotterill D.A. 
Published: February 2017

Abstract
Previous research into the effects of temperature on the responses of the thermoluminescent (TL) material, TLD 700, has been extended to include: (i) the effect on the trap structure of heating before irradiation; (ii) increasing the temperature range to 200 oC; (iii) the influence of LET on the effects by utilising the 6Li(n,a)3H reaction in TLD-600. Slow ramp heating of phosphors which had been stored at temperatures of 120 oC and above before irradiation revealed an additional peak in the glow curve between peaks 3 and 4. The relative heights of peaks also change. The increase in sensitivity with irradiation temperature is less for high LET radiation; however, fading does not depend on LET. The fading of the 240 oC readout of TLD-700 agrees with the theory of Randall and Wilkins (1945) but TLD-600 does not. The changes in response are complex and studies are in progress to separate the effects on individual peaks.
Relationship Between Thermoluminescence and Thermally Stimulated Exoelectron Emission of BeO Thin Film Dosemeters
Authors: Lesz J. , Kriegseis W. , Scharmann A. 
Published: February 2017

Abstract
BeO thin films have been suggested as TSEE dosemeters. Apart from TSEE they also show thermoluminescence. Their TL properties are very similar to those of BeO ceramics with respect to temperature positions of the maxima, spectral distribution of the emitted light, optical fading and mass specific TL sensitivity. For both TSEE and TL optical fading is more pronounced at the low temperature glow peaks. However, TSEE and TL originate from different centres whose relationship to the corresponding centres in ceramic BeO is discussed. Previously emptied emission centres are refilled by phototransfer during UV irradiation. Thus dose reassessment is feasible. The TSEE signal can still be re-established after a dose readout heating cycle up to 600 oC, whereas TL is annealed completely already below 300 oC.
Study of Dose-Response Relationships for Late Somatic Effects of Low Neutron Doses
Authors: Coppola M. , Covelli V. , Di Majo V. , Rebessi S. 
Published: February 2017

Abstract
Complete observation of survival and late pathology was conducted on over 2000 female mice irradiated with single doses of 1.5 MeV neutrons (5, 10, 20, 40, 80, 160 mGy) and X rays (40, 80, 160, 320, 640, 1280, 2560 mGy). The results showed a statistically significant life shortening for neutron doses not lower then 80 mGy. Assuming linear non-threshold dose-effect relationships for both radiation qualities, a neutron RBE of 12.3 was obtained. Solid tumour induction was also significant from a neutron dose of 80 mGy and for X ray doses larger than 1 Gy. No sublinear dependence of the carcinogenic effect on low neutron doses was seen. Separate examination of ovarian tumour indication indicated that a threshold dose is likely to exist, especially for X rays. A trend analysis of the neoplasm incidence confirmed the above findings. Death rate analysis by the Weibull model showed agreement between the shift to earlier times and tumour induction.
Quality Factor: Conceptual Problems and Practical Solutions
Authors: Dennis (INVITED) J.A. 
Published: February 2017

Abstract
In the past ten years a growing divide has become apparent between the dosimetric concepts designed to provide measures of stochastic risks and those designed for the measurement and control of exposures to radiation. Those designed to provide estimates of risk, e.g. effective dose equivalent, might need to be further refined to incorporate the latest scientific beliefs and evidence about the dependence on radiation quality and dose rate as well as on age and sex. It may be anticipated that they will find increasing application in compensation schemes and in the evaluation of the health detriment from different applications of radiation, particularly in the medical field. Both animal and human evidence strongly supports a belief that different tissues and different types of neoplasm will have different dependencies on radiation quality and dose rate, although it is not at present possible to quantify this belief. For practical purposes of risk estimation it is necessary, therefore, to select the same values for all human neoplasms. There are reasons for using life shortening in animals as a basis for this purpose, but the data for the dependence on the whole range of radiation qualities is meagre. There is a resulting requirement for interpolation and extrapolation, and a variety of proposals for doing so. None of these proposals has any clear advantages. To provide some stability for the new concepts of measurement and calibration it may be better to accommodate changing perceptions on radiation risks by specifying different levels of exposure for different types of radiation without changing the current quality factors for the measurement quantities.
Individual Monitoring for Neutrons: Practical Measurements, ICRU Recommended Quantities and Limited Quantities
Authors: Wagner S.R. 
Published: February 2017

Abstract
The metrological properties of the new ICRU recommended quantities for individual monitoring are reviewed in the light of existing practice. Consequences for calibration procedures and for the relevance of monitoring results for radiation protection control are discussed. Response requirements for individual neutron monitors are stated and a formalisation for the direct entry of monitoring results into individual radiation exposure records is suggested. The expedience of the ICRU definition of the individual dose equivalent is thereby questioned.
Albedo Dosimetry System for Routine Personnel Monitoring
Authors: Piesch E. , Burgkhardt B. 
Published: February 2017

Abstract
The universal albedo neutron dosemeter used with automatic thermoluminescence readout systems manufactured by Alnor, Harshaw, Panasonic and Vinten, is a two component neutron dosemeter consisting of an albedo and an additional thermal neutron detector and may also incorporate a recoil etched track detector inside the boron-loaded plastic encapsulation. Within routine monitoring, the variety of neutron fields can be reduced to four: (N1) of reactors, low-energy linear accelerators, (N2) nuclear fuel processing, (N3) radioactive neutron sources, (N4) high energy accelerators. Within one area, the albedo neutron response does not vary by more than a factor of two. The albedo dosemeter system became the official neutron dosemeter in the Federal Republic of Germany, thereby replacing the neutron film dosemeter. The technique of dose estimation, the classification in stray neutron fields, the dosimetric properties, such as dose range, energy and angular response, uncertainties of neutron dose measurement and results of routine applications are all described.
Performance Characteristics of Neutron Personnel Dosemeters used in the Oak Ridge Intercomparison Studies
Authors: Swaja R.E. 
Published: February 2017

Abstract
To provide an opportunity for dosimetrists to test and calibrate their neutron personnel monitoring systems, the staff of the Dosimetry Applications Research Facility at the Oak Ridge National Laboratory (ORNL) has conducted personnel dosimetry intercomparison studies (PDIS) periodically since 1974. During these studies, neutron dosemeters are mailed to ORNL, exposed to low level (less than 15 mSv) dose equivalents in a variety of mixed radiation fields produced using the Health Physics Research Reactor (HPRR), and then returned to the participants for evaluation. Beginning with the Seventh PDIS in 1981, interest and participation in the Oak Ridge intercomparisons increased significantly and consistent and documented methods for determining reference neutron dose equivalents for the HPRR were introduced. This paper presents a summary and analysis of about 3450 neutron dose equivalent measurements reported for PDIS 7 through 12 (1981-1986) with particular emphasis on low dose equivalent sensitivity, accuracy and precision, and performance relative to accreditation standards for the basic types of personnel dosimetry systems.
On the Calibration of Tissue-Equivalent Proportional Counters with Built-in Alpha Particle Sources
Authors: Schrewe U.J. , Brede H.J. , Pihet P. , Menzel H.G. 
Published: February 2017

Abstract
The calibration procedure for tissue-equivalent proportional counters (TEPC) with built-in collimated a sources was investigated. Pulse height spectra were measured for the a particle sources of several counters which were filled with propane based TE gas at various pressures in order to simulate a tissue layer thickness of 1 µm to 10 µm. The mean pulse height produced by unscattered a particles was determined relative to the maximum measured pulse height. These pulse height ratios were also calculated using tabulated stopping power data for a particles, the experimentally determined detector geometry and measured a source energies. The ratios obtained for various stopping power data are compared with the experimental values. Characteristic edges due to maximum energy losses of secondary protons and a particles over the finite cavity diameter also appear in neutron produced spectra. It is proposed to use the pulse heights related to maximum energy losses of charged particles in the detector cavity to examine the uncertainty of the conventional TEPC calibration techniques.
Determination of the Recombination Index of Quality for Neutrons and Charged Particles Employing High Pressure Ionisation Chambers
Authors: Golnik N. , Wilczynska-Kitowska T. , Zielczynski M. 
Published: February 2017

Abstract
The concept of the recombination index of quality (RIQ) is based on the degree of initial recombination and was introduced to provide a measurable quantity of radiation quality. The RIQR values can be determined employing a high pressure ionisation chamber operated under saturation conditions and at a suitable collecting potential, UR. Experiments were performed with various types of radiation including monoenergetic neutrons with energies of 0.9, 2.1, 5.5 and 14 MeV, polyenergetic neutrons (Pu-Be and 252Cf with different filters), high energy protons and alpha particles from natural uranium. To obtain RIQ values for neutrons alone, the photon component of the total absorbed dose was determined using the twin chamber technique and the photon component was subtracted from the total RIQ. It is shown that RIQ4 values can estimate with good accuracy the quality factor values (ICRP 1973). RIQ1 (or RIQ0.5/1 determined from measurements at saturation and two voltages) can be used for estimation of QF values recently proposed by ICRU. The expected independence of RIQ4 on filling gas pressure was confirmed experimentally for a Pu-Be source.
Measurement of the Neutron Spectrum inside the Containment of a PWR
Authors: Birch R. , Delafield H.J. , Parks C.A. 
Published: February 2017

Abstract
Neutron spectra inside the containment building of a PWR at Gosgen, Switzerland have been measured using a high resolution, transportable, neutron spectrometry system based on proportional counters. Small spherical proportional counters, filled with hydrogen to pressures of 100, 300 and 1000 kPa, were used to cover the energy range from 50 keV to 1.5 MeV. A larger cylindrical counter, filled with 600 kPa of 4He plus 400 kPa Ar was used to extend the measurement range up to 16 MeV. Compact electronics provided simultaneous data acquisition for up to four counters allowing spectrum measurements to be performed in dose equivalent rates down to ~50 µSv.h-1. Supporting measurements were made with a multisphere spectrometer to determine the fraction of neutrons below 50 keV. The neutron spectra measured at two positions show a steady rise in the neutron fluence as the neutron energy decreases, with very few neutrons having energies above 700 keV.