nils-herrmann/clean_scirepeval huggingface dataset:
Effect of Different Additives in Diets on Secondary Structure, Thermal and Mechanical Properties of Silkworm Silk

In this study, eight types of materials including nanoparticles (Cu and CaCO3), metallic ions (Ca2+ and Cu2+), and amino acid substances (serine, tyrosine, sericin amino acid, and fibroin amino acid) were used as additives in silkworm diets to obtain in-situ modified silk fiber composites. The results indicate that tyrosine and fibroin amino acids significantly increase potassium content in silk fibers and induce the transformation of α-helices and random coils to β-sheet structures, resulting in higher crystallinities and better mechanical properties. However, the other additives-modified silk fibers show a decrease in β-sheet contents and a slight increase or even decrease in tensile strengths. This finding provides a green and effective approach to produce mechanically enhanced silk fibers with high crystallinity on a large scale. Moreover, the modification mechanisms of these additives were discussed in this study, which could offer new insights into the design and regulation of modified fibers or composites with desirable properties and functions.

Field of study: Materials science
Maximum likelihood estimation of variance components in a completely random bib design

The purposes of this paper are to abstract from a number of articles variance component estimation procedures which can be used for completely random balanced incomplete block designs, to develop an iterated least squares (ITLS) computing algorithm for calculating maximum likelihood estimates, and to compare these procedures by use of simulated experiments. Based on the simulated experiments, the estimated mean square errors of the ITLS estimates are generally less than*those for previously proposed analysis of variance and symmetric sums estimators.

Field of study: Mathematics
Bayesian weighting for macromolecular crystallographic refinement.

A simple weighting scheme for atomic refinement is discussed. The approach, called 'Bayesian weighting', is designed to be robust with respect to the bias that arises from the incomplete nature of the atomic model, which in macromolecular crystallography is typically quite serious. Bayesian weights are based on the mean-squared residual errors over shells of resolution, with centric and acentric reflections considered separately and with allowances made for experimental uncertainties. Use of Bayesian weighting is shown in test cases typical for macromolecular crystallography to improve the accuracy of the refined coordinates when compared with schemes employing unit weights or experimental variances.

Field of study: Chemistry
Studies of the Lake Superior Pre-Cambrian by Accessory-Mineral Methods

Several hundred samples of pre-Cambrian rocks from the States bordering Lake Superior have been tested for heavy minerals and their ratios. Such ratios are believed to be of little value for correlation of masses of the same age or for distinction of those of different ages. Early pre-Huronian rocks on the south shore of Lake Superior and pre-Animikie intrusives north of the lake commonly have the “hyacinth” variety of accessory zircon, resembling the “purple” zircon described by Mackie from the pre-Cambrian of Scotland. Late pre-Huronian and Huronian rocks south of Lake Superior carry malacon alone, or more rarely malacon with some hyacinth that may be derived by incorporation of the older rocks. Intrusive rocks north of Lake Superior have not as yet yielded any abundant accessory malacon, and intrusives of the age of those bearing malacon in the southern areas may be rare north of the lake. Keweenawan igneous rocks on both sides of Lake Superior carry zircons that are characteristically euhedral simple crystals, colorless to pale yellow brown. These Keweenawan igneous rocks may, like the Huronian, have at places incorporated older rocks, but very few heavy separates have shown such contamination. The differences in those three types of zircons suggest very important correlations of certain granite masses, the age of which was not clearly settled by field relations. The dates of exposure of these igneous rocks are reflected in the sediments, showing the varieties of zircons derived from them. The detrital heavy mineral suites in all the Huronian and pre-Animikie sediments studied are so similar in the characters of the zircons and so irregular in the authigenic accessory minerals that individual Huronian formations cannot be distinguished by heavy mineral methods. Such methods, however, distinguish Huronian and older sediments from those of Keweenawan age and correlate certain formations of the Upper Keweenawan where the field observations left some uncertainty. In this respect the Keweenawan sediments resemble the Paleozoic and later sediments which have at places been correlated by heavy mineral work. Several generalizations as to igneous accessory minerals can be based on the data, especially those on the Keweenawan rocks: (1) The average relative percentages of accessory minerals is different for rocks of different composition even if the rocks are of the same age and appear to be genetically related; (2) The type of dominant zircon in Keweenawan rocks is remarkably constant regardless of rock composition—so long as zircon can be concentrated—and almost regardless of the texture and cooling history of the rock. The changes in heavy accessory minerals in weathering and sedimentation are striking, and the data in this region do not wholly agree with previous remarks as to which minerals are most rapidly attacked and which least by such processes. More work is needed.

Field of study: Geology
Vitrinite reflectances from Eocene rocks of southern British Columbia, a regional reconnaissance

Reflectances of Eocene vitrinite from a wide selection of sites in southern British Columbia show a concentration between 0.45 and ~1.0%. Localities with reflectances less than 0.45% may be less deeply buried (Kamloops at 0.25%) than most of the others, younger (Hat Creek), or perhaps associated with an abnormally low geothermal gradient (Princeton?). Localities with abnormally high reflectances (>1.0%) include sites with local heat sources, such as an intrusion (Afton mine near Kamloops), a coal fire (Hat Creek), or a hot, pyroclastic flow (south of Princeton). Other occurrences with high reflectances are those that may have been blanketed by an overthrust sheet (Big Bar), deposited on crustal rocks shortly after they had been tectonically stripped and while they were still warm (Enderby), or otherwise juxtaposed against such deep crustal rocks (White Lake area). Measurement of reflectance plays a useful role in calling attention to abnormal geothermal conditions once the regional pattern is determined.

Field of study: Environmental science
Characterization and application of a strain-specific monoclonal antibody against the rhizosphere bacterium Azospirillum brasilense Wa5.

A hybridoma cell line producing a rat monoclonal antibody (MAb Bo-33) directed against lipopolysaccharide of Azospirillum brasilense Wa5 has been established and characterized. Whole bacteria were used as immunogens. The number of antigens per cell was about 1500. The number of antigens per cell of reisolates from the rhizosphere of what was similar to the number of antigens of bacteria cultivated in rich medium. The sensitivity of detection using MAb Bo-33 was about 100 bacteria/ml. Therefore, the MAb was suitable for in situ immunofluorescence detection and a sensitive direct quantification of Azospirillum brasilense Wa5 in rhizosphere extracts.

Field of study: Biology
Effective moment of inertia in132Ce,134Nd and136Nd

The effective moment of inertiaIeff(2) of132Ce,134Nd and136Nd produced in40Ar induced reactions has been deduced from continuumγ-ray spectra measured by sum spectrometer methods. Results concerning the deformation of these nuclei are obtained by comparison of the experimental data and calculations in the frame of a cranking Nilsson — Strutinsky model.

Field of study: Physics
Uroguanylin Regulates Net Fluid Secretion via the NHE2 Isoform of the Na+/H+ Exchanger in an Intestinal Cellular Model

Uroguanylin (UGN) has been proposed as a key regulator of salt and water intestinal transport. Uroguanylin activates cell-surface guanylate cyclase C receptor (GC-C) and modulates cellular function via cyclic GMP (cGMP), thus increasing electrolyte and net water secretion. It has been suggested that the action of UGN could involve the Na+/H+ exchanger, but the actual contribution of this transporter still remains unclear. The objective of our study was to investigate the putative effects of UGN on some members of the Na+/H+ exchanger family (NHEs), as well as to clarify its consequences on transepithelial fluid flow in T84 cells. In order to do so, transepithelial fluid flow (Jv) was studied by optic techniques and intracellular pH (pHi) was measured with a fluorescence method. Results showed that NHE2 is found at the apical membrane and has a major role in Na+ absorption; NHE1 and NHE4 are localized at the basolateral membrane with a house-keeping role in steady state pHi. In the assayed conditions, cell exposure to apical UGN increases net secretory Jv, without changing short-circuit currents nor transepithelial resistance, and reduces NHE2 activity. Therefore, at physiological pH, the effect on net Jv was produced mainly by a reduction in normal Na+ absorption through NHE2, rather than by the stimulation of electrolyte secretion. Our study shows that the effect of UGN on pHi is GC-C/cGMP-mediated and enhanced by sildenafil, thus involving PDE5 enzyme. Additionally, cell exposure to apical UGN results in intracellular alkalinization, probably due to indirect effects on basolateral NHE1 and NHE4, which have a major role in pHi regulation.

Field of study: Biology, Chemistry
Semiparametric Accelerated Failure Time Modeling for Clustered Failure Times From Stratified Sampling

Clustered failure times often arise from studies with stratified sampling designs where it is desired to reduce both cost and sampling error. Semiparametric accelerated failure time (AFT) models have not been used as frequently as Cox relative risk models in such settings due to lack of efficient and reliable computing routines for inferences. The challenge roots in the nonsmoothness of the rank-based estimating functions, and for clustered data, the asymptotic properties of the estimator from the weighted version have not been available. The recently proposed induced smoothing approach, which provides fast and accurate rank-based inferences for AFT models, is generalized to incorporate weights to accommodate stratified sampling designs. The estimator from the induced smoothing weighted estimating equations are shown to be consistent and have the same asymptotic distribution as that from the nonsmooth version, which has not been developed before. The variance of the estimator is estimated by computationally efficient sandwich estimators aided by a multiplier bootstrap. The proposed method is assessed in extensive simulation studies where the estimators appear to provide valid and efficient inferences. A stratified case-cohort design with clustered times to tooth extraction in a dental study illustrates the usefulness of the method.

Field of study: Mathematics
Charge carrier transport in thermally oxidized metal/PS/p-Si and metal/PS/n-Si structures

Metal/PS/c-Si structures with porous silicon (PS) layers of 55?75% porosity were fabricated on moderately doped p- and n-type c-Si substrates and were thermally oxidized at 400?960 ?C. We studied the effect of oxidation on the charge carrier transport in these structures. It was demonstrated that trap-filled space charge limited current (SCLC) is the dominant transport mechanism at large forward bias. The analysis of the current?voltage characteristics in the SCLC region allowed us to determine the oxidation dependence of the effective thickness deff of the trap-rich tissue isthmuses, in which space charge is mostly accumulated. The exponential deff-dependence of the conductance in the ohmic region observed at low bias is explained by carrier tunnelling through potential barriers formed by SiOX isthmuses between silicon crystallites. The results can be used for fabrication of electronic devices based on oxidized PS and similar materials.

Field of study: Materials science
ARCJET ENGINE PERFORMANCE- EXPERIMENT AND THEORY

Analytical and experimental results are presented on the propulsion performance and the energy addition and loss mechandisms of a radiation-cooled arcjet engine having a constricted-arc configuration. A useful lifetime of one month was obtained with such an engine operated with hydrogen at 1000-sec specific impulse, 30-kw d-c power input, andd an electric to thrust power conversion efficiency of 40%. At 30-kw input power, reliable engine operation was obtained at up to 1000-sec specific impulse with ammonia and up to 1500-sec specific impulse with hydrogen. Specific impulses greater than 2000 sec were obtained using hydrogen in a radiation-cooled engine operated at 200-kw input power. Electric to thrust power conversion efficiencies were in the range from 35 to 45%. Visual examination of the arc discharge through a quartz constrictor indicated that there was a smooth, constant-diameter, luminous core extending from the cathode through the constrictor and terminating in the nozzle. Examination of experimental cool-off data and engine exterior surface temperature distributions indicated the existence of an energy transfer path from the hot engine walls to the cold incoming propellant. (auth)

Field of study: Physics
Production of ligninolytic activities when treating paper pulp effluents by Trametes versicolor

In this work, the ability of Trametes versicolor to decolorize the effluents from the alkaline cooking of cereal straw produced at a paper and paper pulp making plant is studied. Enzymatic activities related to the metabolism of lignin during fungal treatment have also been evaluated. The results that have been attained show the necessity of a carbon source for the progress of the decolorization process, which can reach color elimination values higher than 70%. The study of the enzymatic activities shows the production (starting from the first hours of treatment) of laccase activity much higher than that obtained under the same conditions in synthetic growth media. There is also a clear relationship between the effluent concentration in the medium and the laccase activity. In the decolorization media, manganese-dependent peroxidase activity has also been detected, when SO 4 Mn is added to those media. No LiP activity was detected in all the conditions assayed.

Field of study: Biology, Engineering
The Relationship between Social Work Skills and Value Idea

The Experimental View of social work holds that social work skill, similar with the technical level of other disciplines or activities, does not involve the social worker's subjective value, as is a misunderstanding of the social work skill. In social work practices, the application of social work skills has an inalienable relationship with its corresponding value idea and the focus of social work skills is the social worker's own value judgment or the corresponding value idea.

Field of study: Agricultural and Food sciences
HepaRG-Progenitor Cell Derived Hepatocytes Cultured in Bioartificial Livers Are Protected from Healthy- and Acute Liver Failure-Plasma Induced Toxicity

For applicability of cell-based therapies aimed at the treatment of liver failure, such as bioartificial livers (BALs) and hepatocyte transplantation, it is essential that the applied hepatocytes tolerate exposure to the patient plasma. However, plasma from both healthy donors and acute liver failure (ALF) patients is detrimental to hepatocytes and hepatic cell lines, such as HepaRG. We aimed to elucidate the underlying mechanisms of plasma-induced toxicity against HepaRG cells in order to ultimately develop methods to reduce this toxicity and render HepaRG-BAL treatment more effective.  Differentiated HepaRG cells cultured in monolayers and laboratory-scale BALs were exposed to culture medium, healthy human plasma, healthy porcine plasma and ALF porcine plasma. Healthy human plasma was fractionated based on size- and polarity, albumin depleted and heat treated to characterize the toxic fraction. The cells were assessed for viability by total protein content and trypan blue staining. Their hepatic differentiation was assessed on transcript level through qRT-PCR and microarray analysis, and on functional level for Cytochrome P450 3A4 activity and ammonia elimination. Mitochondrial damage was assessed by JC-1 staining and mitochondrial gene transcription.  Sixteen hours of healthy human plasma exposure did not affect viability, however, hepatic gene-transcript levels decreased dramatically and dose-dependently within four hours of exposure. These changes were associated with early NF-kB signaling and a shift from mitochondrial energy metabolism towards glycolysis. Healthy human plasma-toxicity was associated with the dose-dependent presence of heat-resistant, albumin-bound and (partly) hydrophobic toxic compound(s). HepaRG cells cultured in BALs were partially protected from plasma-toxicity, which was mainly attributable to medium perfusion and/or 3D configuration applied during BAL culturing. The detrimental human plasma effects were reversible in BAL-cultured cells. Porcine ALF-plasma elicited mitotoxicity additional to the basal detrimental effect of porcine healthy plasma, which were only partially reversible.  A specific fraction of human plasma reduces hepatic differentiation of HepaRG cultures, in association with early NF-κB activation. In addition, ALF-plasma elicits mitotoxic effects. These findings allow for a targeted approach in preventing plasma-induced cell damage.

Field of study: Biology, Chemistry
Bound states of a two-dimensional electron gas in inhomogeneous magnetic fields

We study the bound states of a two dimensional free electron gas (2DEG) subjected to a perpendicular inhomogeneous magnetic field. An analytical transfer matrix (ATM) based exact quantization formula is derived for magnetic fields that vary (arbitrarily) along one spatial direction. As illustrative examples, we consider (1) a class of symmetric power law magnetic fields confined within a strip, followed by the problem of a (2) 2DEG placed under a thin ferromagnetic film, which are hitherto unexplored. The exact Landau levels for either cases are obtained. Also, the role of the fringing magnetic field (present in the second example) on these levels is discussed.

Field of study: Physics
Genome-Wide Linkage Scan in a Moroccan Family With Autosomal-Recessive Exstrophy of the Bladder Identifies a Novel Susceptibility Locus on Chromosome 3p25.3

Exstrophy of the bladder (EB) is part of the bladder exstrophy-epispadias complex (BEEC) representing a spectrum of urogenital anomalies in which part or all of the distal urinary tract fail to close and are exposed on the outer abdominal wall. Familial occurrence is rare and previous studies are suggestive of an underlying multifactorial mode of inheritance. However, no causally related genetic or non-genetic factor has been identified so far. In this study, we aim to identify potential risk/modifying loci that might contribute to EB.  A genome-wide linkage scan was performed in a consanguineous kindred of Moroccan origin where three affected males showed the same phenotype of classic EB.  Strongest evidence for linkage was obtained for chromosomal region 3p25.3 (parametric LOD score of 3.4). This region comprises at least seven genes listed in the current NCBI map (Build 36.1) and sequence analysis of all these genes has been initiated.  Our data provide a basis for the localization and identification of a causally related gene implicated in EB, most likely localized on 3p25.3.

Field of study: Medicine
Transport of a Bose gas in 1D disordered lattices at the fluid-insulator transition.

We investigate the momentum-dependent transport of 1D quasicondensates in quasiperiodic optical lattices. We observe a sharp crossover from a weakly dissipative regime to a strongly unstable one at a disorder-dependent critical momentum. In the limit of nondisordered lattices the observations suggest a contribution of quantum phase slips to the dissipation. We identify a set of critical disorder and interaction strengths for which such critical momentum vanishes, separating a fluid regime from an insulating one. We relate our observation to the predicted zero-temperature superfluid-Bose glass transition.

Field of study: Physics
Pollution Properties of Atmospheric HNO_2 and Its Effect on OH Radical Formation in the PRD Region in Autumn

Photolysis of HNO_2 in the atmosphere is an important source of OH radical, and plays a crucial role in the formation of photochemical pollution. Based on the online observation of gaseous HNO_2, NOx, O_3, HNO_2 photolysis rate constant, and solar radiation during October of 2013 at the atmospheric supersite in the Pearl River Delta(PRD) region, the variation pattern and pollution properties of HNO_2 were analyzed, and the production rate of OH radical through HNO_2 photolysis was evaluated. During the measurement period, the hourly concentrations of HNO_2 were 0.48 ~9.92 μg/m3, with average concentration of 3.02 μg/m3. The average values of OH radical production rate through HNO_2 photolysis was 1.53 ×107molecule/cm3 s. HNO_2 showed high concentrations at night and low ones during daytime, which was similar to the average diurnal variation of its precursor NOx. The positive relations between HNO_2 and NOxor surface area concentrations of particles were quite good, and the relation between HNO_2 and surface area concentrations of particles became significantly better with relative humidity over 60%. It indicated that heterogeneous reaction of NOxon the particle surface under conditions with high relative humidity contributed a lot in HNO_2 formation. HNO_2 photolysis rate constant was mainly affected by solar radiation,and showed similar average diurnal variation to the latter, with high values from 11:00 to 13:00. However, as the solar radiation became more and more intense, the increase rate of HNO_2 photolysis rate constant turned to be slower. In the average diurnal variation of OH radical production rate, a longer time period of high values were observed, from about 8:00until the high value period of O_3 in the afternoon. The daily maximum hourly average values of HNO_2 concentrations, OH radical production rate, and O_3 concentrations had positive relation, reflecting the important role of HNO_2 in the photochemical pollution.

Field of study: Environmental science
An Experimental Research on Executions of Land Expropriation Procedure in Anhui Province

After a preliminary analysis of the procedure, functions and flaws of land expropriation policies of Anhui Province, the paper discusses through many cases the land expropriation procedures in different stages such as preliminary stage, submission-for-approval stage and execution stage, and explores the land expropriation system and cost prestore system as well. The paper concludes with pointing out the flaws in the execution procedure of land expropriation in Anhui Province and putting forward some suggestions accordingly.

Field of study: Agricultural and Food sciences