nils-herrmann/clean_scirepeval huggingface dataset:
Enzymatic solubilization of fibre-bound and isolated birch xylans

Fibre-bound and isolated birch xylans from wood and from kraft pulp were characterized according to their chemical composition, macromolecular properties and solubilization in enzymatic hydrolysis. During kraft pulping, xylans are extensively modified. Xylan isolated from kraft pulp contained less substituents and had a lower molecular mass than native xylan isolated from wood. Reprecipitated xylan, which was a model of the xylan adsorbed on the fibre surfaces in the kraft process, was almost pure polyxylose. All isolated xylans were hydrolyzed efficiently by xylanolytic enzymes, although the solubilization decreased slighly as a function of chemical processing. The fibre-bound xylans were considerably less accessible to enzymes than the isolated xylans. Despite high enzyme loadings, the degree of hydrolysis of fibre-bound substrates did not exceed 20% of the theoretical value. Due to the low side-group content of pulp xylans, the side-group cleaving enzymes had only a moderate role in increasing their total solubilization. The results obtained strongly suggested that the observed low solubilization of fibre-bound xylans is mainly due to poor accessibility of enzymes to the fibrous material. The results are discussed in the light of new enzymatic applications in the pulp and paper industry.

Field of study: Biology, Engineering
A high di/dt 4H-SiC thyristor with ‘-shaped’ n-base

A high di/dt 4H-SiC thyristor with '-shaped' n-base is proposed and investigated by simulation. Unlike the conventional SiC thyristors, the proposed SiC thyristor features a lightly-highly-lightly doped ('-shaped') n-base. By modulating the concentration difference of the top p+-n emitter junction its injection efficiency increases. An extra electric field is induced by the existence of an abrupt high-low junction in n-base to force the transit of holes and therefore reduce the recombination. As a result, the turn-on time and turn-on di/dt of the new SiC thyristor are 145 ns and 948 A/cm2/μs, respectively, which are reduced by approximately 72% and increased by approximately 400% compared to conventional SiC thyristors (turn-on time is 514 ns and di/dt is 188 A/cm2/μs).

Field of study: Materials science
Study of Omethoate by Vibrational and Surface Enhanced Raman Spectroscopy

The vibrational structure of omethoate,and its changing features under different acid and base conditions were characterized by attenuated total reflection (ATR)-FTIR,FT-Raman spectroscopy,and the comprehensive information about omethoate structure vibrational characteristics was obtained. The surface enhanced Raman scattering (SERS) spectra of omethoate at different concentrations with different acid and base conditions,adsorbed on the substrate of core-shell Au/Ag nanoparticles,were also presented. The adsorption states of omethoate on the substrate′s surface and effects by the different acid,base conditions were investigated,with speculation of the SERS mechanism. From the results,νas(NH),νas(CH3),amide Ⅰ,ν(POC),ν(PO) ,ν(C-S) are the characteristic peaks inner omethoate structure′s vibrations; below 2.0×10-2 mol/L,omethoate had no obvious SERS at neutral condition,but there are still interactions between omethoate and the substrate in acidic and basic conditions even at 1.0×10-10mol/L,especially in acidic condition. Interactions of omethoate with the substrate′s surface are mainly through its phosphate ester′s structure,to which the effects from different hydrolysis courses at acidic and basic conditions were revealed. This could be a reference for the other organophosphorus pesticides′ transform characterization in environment.

Field of study: Chemistry
Regression and the Matching Fallacy in Quasi-Experimental Research

This self-cons ,.Pc'd end self-instructional unit is intended for use by evaluation aT:d acod'elopment personnel and. by studentt in introductory research ae.d evaluation courses. The unii. contains a discussion of the regression employing graphic illustrations with actual data. The uses: ic introduced to the regression.effect in the single group pretest-posttests design, after which he responds to mastery test instructional exercises. The second pa illustrates how the regression effect confounds the matched -'pair tyl)e of design and this, too, is followed by mastery test instructional exercises. The user should be familiar with the basic statistical concepts of mean, standard deviation, correlation, and z-scores.

Field of study: Education
kA class resistive fault current limiting device development using QMG HTC bulk superconductor

kA class HTC bulk superconducting elements of devices for a resistive type fault current limiter for 6 kV distribution networks have been developed and tested. The YBCO devices made with the quench melt growth (QMG) method has 20000 30000 A/cm/sup 2/ critical current densities at 77 K and 1 T determined by the 1 /spl mu/V/cm criterion for the current flow parallel to the a-b plane. The QMG device has 5 /spl mu//spl Omega/-m normal state resistivity and an n-value of approximately 6 for the same direction of current flow. An element of the device with a 1.5/spl times/1.5 mm/sup 2/ cross-section with silver electrodes formed by sputtering could successfully carry exceeding 2200 A/sub peak/ AC transport current in self field at 77 K.

Field of study: Physics
Fluctuations of glaciers in the tropical Andes over the last millennium and palaeoclimatic implications: A review

The aim of this paper is to document the evolution of glaciers in the tropical Andes (between 10°N and 16°S) for the last millennium, based on moraines dated by lichenometry and radiocarbon, lake sediment records and historical documents. Viewed collectively, several glacial advances occurred synchronously. The first advance is dated around AD 1200–1350. The maximum glacial extent (MGE), defined as the furthest down-valley extent recorded synchronously by the majority of glaciers, occurred around 1630–1680 in Bolivia and Peru (the outer tropics ) and around AD 1730 in Ecuador, Colombia and Venezuela (the inner tropics ). Subsequently, during the 18th and 19th centuries, glaciers retreated continuously with only minor synchronous readvances. In the outer tropics, minor glacial advances occurred around 1730, 1760, 1800, 1850, and 1870. In the inner tropics, synchronous minor advances occurred around 1760, 1820 and 1880. Between the MGE and the early 20th century, glaciers lost about 30% of their total length. The retreat was slow between the 17th and 18th centuries but then became more marked. Use of the accumulation area ratio (AAR) method or historical observations in the different cordilleras revealed an increase in the equilibrium line altitude (ELA) of about 300 m from the MGE onward. Palaeoclimatic hypotheses, based on glaciological models run in different countries, suggest a cool and humid period in the 16–18th centuries followed by a colder and drier period in the 19th century. The reduction of glaciers observed from the middle of the 19th century is due to increasingly warmer conditions than before. Here, quantitative estimates are proposed to explain the evolution of the glaciers. In Venezuela, results indicate for the period 1250–1820 that mean air temperatures were 3.2 ± 1.4 °C cooler and precipitation was about 22% higher than at present. In Ecuador, temperatures of between 0.8° and 1.1 °C lower than today, and between 25% and 35% higher accumulation than today, appear to have occurred in the 18th century, followed by a short drier but colder period at the beginning of the 19th century. In Bolivia, the MGE could be a consequence of a decrease in temperature of 1.1 to 1.2 °C, and a 20 to 30% increase in accumulation or an increase in cloudiness of about 1–2/10. We discuss not only external climatic forcing but also the coincidence between glacier expansion and a decrease in solar irradiance. Dating uncertainties, however, have made the role of volcanism in glacier fluctuations impossible to determine. Finally, we discuss the relationships between ENSO and glacier fluctuations in recent centuries, which do not match directly with current knowledge of modern teleconnections between tropical Pacific SSTs and variations in glacier mass balance.

Field of study: Environmental science, Geography
Open-Access Knowledge and Economic Growth: An Economic Model

The intellectual property (IP) law has been forcefully challenged by scholars and multiple anti-IP movementshave been pushed by activists in recent years. The critiques from scholars mainly focused on the enclosure ofinformation and knowledge enforced by IP law. And the activists of anti-IP movements argued for the openaccess to knowledge to promote creation.This study proposes an endogenous economic growth model highlighting the role of open-access knowledge ineconomic growth. The solution of the model shows that the production efficiency of knowledge, the convertingefficiency from knowledge products into human capital, and the externality of knowledge products, will haveimpacts on the economic growth rate. The policy implication of this study is that government’s intervention,such as the subsidy to the knowledge production, investment in the open-access knowledge, and regulation onthe quality of knowledge products, will have positive effects on economic growth.

Field of study: Business
Prostaglandin E1 Inhibited Diabetes-Induced Phenotypic Switching of Vascular Smooth Muscle Cells Through Activating Autophagy

The phenotype switching of vascular smooth muscle cells (VSMCs) was associated with the onset or progression of the atherogenic process in type 2 diabetes mellitus (T2DM). Alprostadil (Prostaglandin E1, PGE1) as a bioactive drug had a protective effect on vascular function. However, it is unknown whether PGE1 inhibited the phenotype switching in VSMCs via autophagy, which played a protective role in the vascular complications of diabetes.  The phenotype switching was induced by high glucose (HG, 25mM) in VSMCs, the protein expression was measured by western blot analysis and immunofluorescent staining. In vivo study, vascular lesion and dysfunction were produced in the rats fed with high fat diet (HFD) combined with low dose streptozotocin (STZ) administration.  The decrease of α-SMA and the increase of vimentin, collagen I and proliferating cell nuclear antigen (PCNA) were found in HG-treated VSMCs. Along with more abundance of p62, autophagy markers LC3B and Beclin-1 significantly decreased in VSMCs exposed to HG. Such abnormal changes were significantly reversed by PGE1, which mimicked the role of autophagy activator rapamycin and was dramatically counteracted by 3-methyladenine, an autophagy inhibitor. Furthermore, PGE1 suppressed the phosphorylation of AKT and mTOR, which negatively regulated autophagy level in VSMCs. In vivo study, PGE1 remarkably improved the endothelium-independent contraction of thoracic aorta and restored the expression of α-SMA, osteopontin, LC3B, phosphorylated mTOR in the artery media of T2DM rats.  These results demonstrated that PGE1 maintained the phenotype of VSMCs via the AKT/mTOR-dependent autophagy, which prevented diabetes-induced vascular complications.

Field of study: Biology, Chemistry
Validação de critérios para controle de perdas de vitamina C em hortaliças preparadas em unidade de alimentação e nutrição hospitalar

This study aimed to validate laboratory tested criteria to preserve vitamin C (Ascorbic Acid (AA) and Dehydroascorbic Acid (DHA)) in collard and tomato prepared in a Hospital Food Service (HFS). The criteria were: 24 hour-storage under refrigeration (10 °C), cleansing for 15 minutes, and distribution right after preparation. The consume exposure times, frequently used by the HFS, were also analyzed. High Performance Liquid Chromatography (HPLC) was the analysis method employed, using as mobile phase sodium phosphate 1 mM, EDTA 1 mM, all diluted in ultra pure water, and pH 3.0 adjusted with phosphoric acid. ANOVA (a = 0.05) was used to data analysis. No significant differences were found as to the content of vitamin C after the steps of vegetables handling showing high vitamin stability with the adopted criteria. However, a reduction of AA retention was observed in collard after 60 minutes of exposure to consumption (retention: 46.94%) and in tomato after 120 minutes of exposure (retention: 71.81%). The criteria contributed to control vitamin C loss in vegetables; therefore, their implementation is suggested to be applied in other HFS.

Field of study: Agricultural and Food sciences
Familiarity of Stimulus-Words and Confidence in Responses on a Test of Verbal Meaning

The relationship between familiarity of stimulus-words and confidence in responses on a verbal meaning test was evaluated for 35 male and 53 female black undergraduate students. There were significant positive correlations (.72 for males, p < .01; .79 for females, p < .01) between familiarity and confidence. Partial correlations between confidence and test scores, when familiarity was partialled out, were .12 (p > .05) for the males and .22 (p > .05) for the females. About one-third of subjects' responses were guesses or outcome of being misled by familiarity.

Field of study: Psychology
Imperialism and the Origins of Mexican Culture by Colin MacLachlan (review)

Christine Hatzky’s book seeks to fill the void with a compelling story of the sacrifices of the Cubans in the struggle for sovereignty and independence. The subtitle of the book suggested that a materialist understanding of the world was at play in the SouthSouth cooperation. However, the real theoretical foundations of postmodernism and the stress on memory negated the evidence of the book of real international solidarity on the part of the Cuban peoples in Angola.

Field of study: History
Derivation, identification and validation of a computational model of a novel synthetic regulatory network in yeast

Systems biology aims at building computational models of biological pathways in order to study in silico their behaviour and to verify biological hypotheses. Modelling can become a new powerful method in molecular biology, if correctly used. Here we present step-by-step the derivation and identification of the dynamical model of a biological pathway using a novel synthetic network recently constructed in the yeast Saccharomyces cerevisiae for In-vivo Reverse-Engineering and Modelling Assessment. This network consists of five genes regulating each other transcription. Moreover, it includes one protein–protein interaction, and its genes can be switched on by addition of galactose to the medium. In order to describe the network dynamics, we adopted a deterministic modelling approach based on non-linear differential equations. We show how, through iteration between experiments and modelling, it is possible to derive a semi-quantitative prediction of network behaviour and to better understand the biology of the pathway of interest.

Field of study: Biology, Mathematics
Middle Viséan (Mississippian) coral biostrome in central Guizhou, southwestern China and its palaeoclimatological implications

A middle Visean (Mississippian) coral biostrome is reported for the first time from the Shangsi Formation in Yashui area, central Guizhou Province, southwestern China (palaeogeographically located in eastern Palaeotethys). The biostrome, which is about 500 m across and 2.5–3.9 m thick, is laterally variable and composed of rugose and tabulate corals with low taxonomic diversity comprising 4 rugose and 1 tabulate coral species belonging to 5 genera. Three growth stages of the biostrome are distinguished, based on different compositions of coral taxa. Average coral contents of the biostrome increase from 38.7% to 72.0% upward and the main builders are Siphonodendron pentalaxoidea, Syringopora sp. and Kueichouphyllum sinense. Associated fossils include abundant brachiopods, crinoids and common foraminifers together with rare calcareous algae, bryozoans, gastropods and ostracods. Relative sea-level changes are interpreted to have controlled growth and demise of the biostrome, which grew continuously during sea-level rise and decreasing water energy, as evident from the gradually increasing of micrite content and in situ coral colonies. However, the biostrome declined and died as the sea level fell and hydrodynamic energy strengthened, indicated by an increase of bioclasts and sparry calcite cement (indicating lack of micritic matrix due to higher energy) overlying the biostrome. This coral biostrome has similar biotic composition to middle to late Visean coral biostromes in Europe and North Africa (western Palaeotethys). The approximately coeval occurrence of coral biostromes in both eastern and western Palaeotethys suggests that a relatively global warm episode existed during the Visean Stage.

Field of study: Environmental science, Geography
Microscopic versus endoscopic approaches for craniopharyngiomas: choosing the optimal surgical corridor for maximizing extent of resection and complication avoidance using a personalized, tailored approach.

Resection remains the mainstay of treatment for craniopharyngiomas with the goal of radical resection, if safely possible, to minimize the rate of recurrence. Endoscopic endonasal and microscopic transcranial surgical approaches have both become standard methods for the treatment for craniopharyngiomas. However, the approach selection paradigm for craniopharyngiomas is still a point of discussion. Choosing the optimal surgical approach can play a significant role in maximizing the extent of resection and surgical outcome while minimizing the risks of potential complications. Craniopharyngiomas can present with a variety of different sizes, locations, and tumor consistencies, and each individual tumor has distinct features that favor one specific approach over another. The authors review standard cranial base techniques applied to craniopharyngioma surgery, using both the endoscopic endonasal approach and traditional open microsurgical approaches, and analyze factors involved in approach selection. They discuss their philosophy of approach selection based on the location and extent of the tumor on preoperative imaging as well as the advantages and limitations of each surgical corridor, and they describe the operative nuances of each technique, using a personalized, tailored approach to the individual patient with illustrative cases and videos.

Field of study: Medicine
Dynamics Study on Two-Stage Constructed Wetland Treatment with Natural Reaeration to Treat Rural Sewage

Constructed wetland without natural reoxygenation is the reason of effluent quality deterioration. For the purpose of improving pollutants removing efficiency without oxygen increasing power,this study used a two-stage constructed wetland with an automatic increasing oxygen system to treat rural sewage,and used handy in-situ observation points to take water samples and observe the internal environment. Oxygen supply in the dropping flow process improved the removal efficiency of COD,TP,TN and NH3-N by 8.4%,4.1%,11.7% and 13.9% respectively. The pseudo-first order reaction analysis showed that COD,TP,TN and NH3-N all had a significant decline along the wetland. The aeration by dropping flow increased the decomposition rate of pollutants,but the shortcomings of the carbon source limited the nitrogen removal in the second wetland bed. Volume removal rate constant kv declined along with the decrease of temperature. Using Arrhenius equation to modify kv,the result showed that kv in the first land was bigger than that in the second land,with θ from 1.03 to 1.05 which can meet the correlational study.

Field of study: Environmental science
Expression of the orphan receptor steroidogenic factor-1 mRNA in the rat medial basal hypothalamus.

Steroidogenic factor-1 (SF-1), an orphan receptor of the nuclear hormone receptor family, binds to the AAGGTCA motif in the promoter elements of several diverse target genes, including some that mediate steroidogenesis and sexual differentiation. In addition, SF-1 is expressed in embryonic forebrain, suggesting that it plays a role in neural development. This study was undertaken to study the distribution and regulation of SF-1 mRNA expression in the rat brain. SF-1 mRNA levels were measured in tissue dissections by ribonuclease protection assay. A 452 nt 32P-labeled cRNA probe, complementary to the putative ligand-binding domain of the rat SF-1 mRNA, was synthesized from the rat SF-1 cDNA inserted into pBluescript II KS, using a Sty 1 fragment and T3 polymerase. The probe protected a single 390 nt transcript in the medial basal hypothalamus (MBH) and peripheral steroidogenic tissues of the male rat. The size of this protected band corresponded to that of the protected sense RNA standard (HindIII fragment of the SF-1 cDNA transcribed with T7 polymerase). No SF-1 mRNA was detected in the preoptic area, amygdala or cingulate cortex. The levels of SF-1 mRNA in MBH were not affected by gonadectomy or androgen treatment, nor was there a sex difference in its expression in adults. In situ hybridization histochemistry revealed that SF-1 was localized to the ventromedial nucleus of the adult hypothalamus. The levels of SF-1 mRNA were high on gestational day 18 after which they fell by approximately 30% and remained constant throughout gestation, the first week of neonatal life, and into adulthood. These results demonstrate that the gene encoding SF-1 is expressed in a discrete region of the rat hypothalamus and appears to be developmentally regulated, but not affected by gonadal hormones in adults.

Field of study: Biology
Differing Map Construction and Text Organization and Their Effects on Retention

On the basis of Kulhavy's (R. W. Kulhavy, J. B. Lee, & L. C. Caterino, 1985) conjoint retention model of text learning with organized spatial displays, the authors conducted 2 experiments to analyze the effects of different types of maps and a considerate text (i.e., a text that follows the scanning pattern of the map) or an inconsiderate text. In the 1st study, 158 participants viewed an intact or a segmented map and a considerate or a randomized text. Those participants who viewed the intact map and read the considerate text recalled significantly more information than those who viewed the intact map and read the randomized text. In the 2nd study, 179 participants viewed a flat map, a 1-point perspective map, or a 2-point perspective map, and a considerate text formulated on the basis of the predicted scanning pattern of the map. Those participants who viewed the flat map recalled significantly more information than those who viewed the perspective maps.

Field of study: Education