nils-herrmann/clean_scirepeval huggingface dataset:
D-3-hydroxybutyrate dehydrogenase from Rhodopseudomonas spheroides. Kinetics of radioisotope redistribution at chemical equilibrium catalysed by the enzyme in solutions.

1. The reversible NAD(+)-linked oxidation of d-3-hydroxybutyrate to acetoacetate in 0.1m-sodium pyrophosphate buffer, pH8.5, at 25.0 degrees C, catalysed by d-3-hydroxybutyrate dehydrogenase (d-3-hydroxybutyrate-NAD(+) oxidoreductase, EC 1.1.1.30), was studied kinetically at chemical equilibrium by monitoring radioisotope redistribution with sodium dl-hydroxy[3-(14)C]butyrate and [4-(3)H]NAD(+)(labelled in the nicotinamide ring). 2. When all substrates are maintained at concentrations approaching saturation (approx. 3-50 times the K(m) values) the first-order rate constant for the enzyme-catalysed interconversion of NAD(+) and NADH is much smaller than that for the enzyme-catalysed interconversion of d-3-hydroxybutyrate and acetoacetate. 3. The rate of interconversion of NAD(+) and NADH increases initially with increasing concentrations of d-3-hydroxybutyrate and acetoacetate (ratio of concentrations maintained constant), passes through a maximum and approaches closely to zero at saturating concentrations of the latter substrates. 4. The rates of interconversion of NAD(+) and NADH and of d-3-hydroxybutyrate and acetoacetate increase with increasing concentration of NAD(+) (up to 66 times its K(m) value) and NADH (up to 180 times its K(m) value) (ratio of the concentrations of the nicotinamide nucleotides maintained constant). 5. These findings support the description of this catalysis as an ordered Bi Bi mechanism with no detectable alternative pathway, in which the interconversion of the central ternary complexes is not rate-limiting, and provide no evidence for the formation of dead-end complexes. 6. The solubility of 2,4-dinitrophenylhydrazine in HCl exhibits an acidity optimum, the maximum solubility at 25.0 degrees C (3.8mg/ml, 19mm) occurring at 2.29m-HCl; in solutions of this acidity acetone 2,4-dinitrophenylhydrazone is relatively insoluble (0.098mg/ml, 0.413mm).

Field of study: Biology, Computer science
The History of Crop Cultivation in West Africa: a Bibliographical Guide

T is only in the last few years that the study of African agricultural history has spread from a few specialists to a much wider public as part of the surge of interest in the African past connected with the independence of the new African nations. Nor is it only historians who are concerned, since the intensified study of the theory of economic growth and its application to underdeveloped countries has led economists and political scientists to turn to the historical record for enlightenment and guidance. Nevertheless it is somewhat surprising that the study of African agricultural history-at any rate insofar as it relates to West Africa-should have been relatively neglected in Britain since West African agricultural products have been entering this country in considerable quantities since the i 890's. We have long been familiar with cocoa, coffee, bananas, ginger, and other obviously tropical products, but it is not always realized what large quantities of palm-oil, palm-kernel oil, and groundnut oil go into our soap and margarine; although farmers are well aware of their dependence on groundnuts to provide the protein content of their cattle cake. It is, however, extremely doubtful whether many people appreciate the close link between their daily pint of milk and the northern Nigerian peasant wielding his hoe under the scorching sun. The basic figures for West African crop exports have been summarized in Tables I, 2, and 3.2 In i960 Africa produced 9i per cent of the world's total supply of palm-kernel oil, amounting to 825,ooo metric tons, and of this total, 663,000 metric tons or 8o per cent were produced in West Africa-the great bulk (429,000 metric tons) coming from Nigeria. In palm-oil Africa was not quite so dominant, producing 67 per cent of the world's supply, of which West Africa provided just under half; but Nigeria, though it had slipped behind the Congo, was still a major producer exporting I 92,000 metric tons. In cocoa production West Africa's dominance of the world market is well known. Of 840,000 metric tons of cocoa which entered into world trade in I 960, Africa produced 76 per cent, nearly all of which came from three West African countries-Ghana (formerly Gold Coast) 308,ooo metric tons, Nigeria I95,000 metric tons, and Ivory Coast go,ooo metric tons. Finally, in groundnut production, although Africa's share of the world's total was only 29 per cent in i960,

Field of study: Economics, History
Inhibitory effect of 1-(2, 6-dimethylphenoxy)-2-(3, 4-dimethoxyphenyl-ethylamino) propane hydrochloride on inward rectifier and delayed rectifier K+ currents in guinea pig ventricular myocytes.

To study the effects of 1-(2,6-dimethylphenoxy)-2-(3,4-dimethoxyphenyl-ethylamino) propane hydrochloride (DDPH) on action potential (AP), inward rectifier K+ current (IK1), and delayed rectifier K+ current (IK) in isolated guinea pig ventricular myocytes.



Whole cell patch-clamp recording techniques.



DDPH 0.1-100 mumol.L-1 decreased 50% duration of action potential (APD50) concentration-dependently. APD50 was shortened from (493 +/- 58) to (262 +/- 38) ms (n = 7 cells from 5 guinea pigs, P < 0.01) by DDPH 10 mumol.L-1. However, 90% duration of action potential (APD90) was increased by DDPH (> 1 mumol.L-1). At high concentration (> 10 mumol.L-1) DDPH decreased resting membrane potential (RP) and amplitude of action potential (APA). DDPH inhibited tail current of IK (IK.tail) concentration-dependently, 46% at 10 mumol.L-1 and 78% at 100 mumol.L-1. EC50 for DDPH inhibiting IK was 13.3 (11.6-16.7) mumol.L-1. DDPH also blocked IK1. DDPH at high concentration (> 10 mumol.L-1) shifted the reverse potential of IK1 positively. All the effects of DDPH were reversible after washout.



DDPH blocked both IK1 and IK current in guinea pig ventricular myocytes.

Field of study: Biology, Chemistry, Medicine
Spinodal in asymmetric nuclear matter

The phase diagram of nuclear matter is quite rich - it shows suchphenomena as phase-transitions, formation of condensates, clustering, etc.From the analysis of the spinodal instability, one can learn about the region ofliquid-gas coexistence in nuclear matter at low densitiesand finite isospin asymmetries. In a recent paper, we have shownthat asymmetric nuclear matter at sub-nuclear densities shouldundergo only one type of instability.The associated order parameter is dominated by the isoscalar density and sothe transition is of liquid-gas type. The instability goes in the directionof a restoration of the isospin symmetry leading to a fractionationphenomenon.

Field of study: Physics
Study of nonculturable Legionella pneumophila cells during multiple-nutrient starvation

The nonculturable form of Legionella pneumophila in multiple-nutrient starvation culture was studied. During extended starvation, the total direct counts (TDC) of L. pneumophila did not change significantly, but no colonies were detected on day 50. Quantitative PCR detection of L. pneumophila DNA demonstrated that nonculturable cells retained PCR-detectable DNA even after starvation for 300 days, and part of the nonculturable population possessed nonspecific esterase activity. However, resuscitation trials of nonculturable L. pneumophila on day 100 of starvation recovered no colony-forming units, and electrophoresis of nucleic acids extracted from nonculturable cells revealed rRNA subunit (23S, 16S and 5S) degradation. When legionellae have lost the ability to multiply, at least some DNA and enzyme functions may be retained for prolonged periods.

Field of study: Biology, Environmental science
Anisotropic flow generated by hard partons in medium

Hard partons which are produced copiously in nuclear collisions at the LHC, deposit most of their energy and momentum into the surrounding quark-gluon plasma. We show that this generates streams in the plasma and contributes importantly to flow anisotropies. With the help of event-by-event three-dimensional perfect hydrodynamic simulations we calculate the observable azimuthal anisotropies of hadronic distributions and show that the proposed mechanism is capable of generating non-negligible part of the observed signal. Hence, it must be taken into account in quantitative studies in which one tries to extract the values of viscosities from the comparison of simulated results with measured data.

Field of study: Physics
Versuche zur Frage nach einer Polarisation der Elektronenwelle

ZusammenfassungBei zweimaliger Reflexion eines Elektronenstrahles (120, 240, 380 Volt) an Einkristallfiächen von Kupfer zeigt die reflektierte Elektronenmenge keine selektiven Reflexionsmaxima in Abhängigkeit von einer Drehung des zweiten Reflektors um die Strahlachse. Elektronen, die durch ein äußeres Magnetfeld gerichtet sind, verhalten sich wie Elektronen im feldfreien Raum. Ob eine bei Reflexion eines Elektronenstrahles von 150 Volt Geschwindigkeit unter einem selektiven Beugungswinkel an der {111}-Fläche von Kupfer gefundene polarisationsähnliche Erscheinung reell ist, kann wegen experimenteller Schwierigkeiten nicht entschieden werden.

Field of study: Physics
Comparison of Gas Sensors Based on Oxygen Plasma-Treated Carbon Nanotube Network Films with Different Semiconducting Contents

We report on the effect of oxygen plasma treatment on the performance of single-wall carbon nanotube (SWCNT) NH3 gas sensors with different semiconducting contents (66% and 90% semiconducting SWCNTs). The performance of chemical sensors based on SWCNT networks depends on the concentration of semiconducting SWCNTs (s-SWCNTs), whose conductance can be significantly modulated by the absorbed molecules and the surface functionalization. After oxygen plasma treatment, the 66% s-SWCNT sample showed an increase in sensitivity from 0.0275%/ppm to 0.1525%/ppm (5.5 times), while the 90% s-SWCNT device demonstrated an increase in sensitivity from 0.1184%/ppm to 1.5707%/ppm (13 times). These results correspond to improvements in sensitivity of 57 times and 10 times compared with pristine and plasma-treated 66% s-SWCNT samples, respectively. In addition, the plasma-treated sensors exhibited much faster response and recovery times than the pristine one. The large improvement in performance was explained by the presence of oxygen-containing functional groups and the sp2–sp3 structure change of SWCNTs, which changes the binding energy while increasing the uptake of polar molecules such as NH3.

Field of study: Materials science
Comparison between Rosellinia necatrix isolates from soil and diseased roots in terms of hypovirulence.

The white root rot fungus, Rosellinia necatrix, is a devastating soil-borne pathogen of many plant species. Biocontrol with the hypovirulence factor is promising, but disease symptoms, signs or culture morphology of the pathogen cannot be reliably used as markers for hypovirulence in this fungus. We attempted to obtain hypovirulent isolates from soil rather than from diseased roots, based on the hypothesis that hypovirulent isolates were more likely to persist in soil as saprobes. Sixteen isolates, belonging to eight mycelial compatibility groups (MCGs), were obtained from soil in two active and one abandoned Japanese pear orchards. Comparison of these isolates based on clonality revealed that six MCGs were commonly recovered from both diseased roots and soil and two MCGs exclusively from soil. No MCG was found in more than one orchard. With two exceptions, isolates within the same MCG were similar in virulence, competitive saprophytic ability (CSA) and mycelial growth rate whether or not they carried dsRNA. The two exceptional isolates recovered from soil had multiple dsRNA segments that caused hypovirulence, weakened CSA and restricted mycelial growth on nutrient-rich media. They belonged to different MCGs, each including dsRNA-free isolates. Isolates from soil contained various dsRNAs (44%), including the hypovirulence factor, more frequently than isolates from diseased roots in the same fields (25%), which is much higher than the proportion of isolates with dsRNA from diseased roots (19%) in a total of 424 isolates from Japan examined so far. These results suggest that isolation of R. necatrix from soil is an effective method to obtain isolates with dsRNAs, including the hypovirulence factor.

Field of study: Biology, Environmental science
Research on Energy-saving Heating Process and Intelligent Control System for Asphalt Tank of Mixing Equipment

Based on heat balance analysis, the dynamic heating model of asphalt tank of mixture equipment was established, the heating time and using time nodes were determined, and the trapezoidal dynamic heating process of asphalt tank was also formed to realize the intelligent control and reduce energy consumption. After analyzing different schemes, the control scheme of the combination of feed-forward and feedback to realize intelligent control system for asphalt tank was adopted, which could ensure that the asphalt in the tank is in the operating temperature and the mixing equipment works continuously when the asphalt was used completely. In addition, a simulated analysis of calculation model, which was adopted by intelligent control system, was made in combination of entitative engineering. Results showed that compared with traditional process of heating asphalt, this intelligent heating control system could reduce the heat consumption by 15.8% under the condition of continuous construction.

Field of study: Engineering
Testing Hypotheses about an Identified Treatment when there are Multiple Endpoints

The problem of comparing an identified treatment with K other treatments is considered in a multivariate setting. Many formulations of composite alternative hypotheses are possible. For example, one might wish to examine whether the identified treatment is superior to the other treatments on all components of the response vector (i.e., is uniformly best) or whether the identified treatment is better than each treatment on at least one component (i.e., is admissible). For testing whether the identified treatment is uniformly best, the known optimality of the min test in the univariate case is extended to the multivariate case. If the distribution is multivariate normal, then the min test is shown to be a likelihood ratio test. For testing whether the identified treatment is admissible, a min test based on the Bonferroni inequality is suggested. For the multivariate normal with unknown covariance matrix, the likelihood ratio test is also a min test, but it has less stable power characteristics than...

Field of study: Mathematics
Chronic Subdural Hematoma Treated by Burr Holes and Closed Drainage System: A Review of 630 Cases

To study the clinical features and surgical results of patients with chronic subdural hematoma.  A retrospective study of the records of 630 patients treated surgically for chronic subdural hematoma using a burr hole and closed drainage system was conducted.  Six hundred and thirty patients (438 males and 192 females) ranging from 12 to 100 years with a mean age of 66.7 years were identified. Upon admission, 242 (38%) patients were in satisfactory condition (grades 0–1), 262 (42%) patients were at grade 2 and 126 (20%) were at grades 3 or 4. In 5.3% of the patients, surgical intervention was required to remove a recurring hematoma. In 77% of the patients, the results achieved could be graded as good (grades 0–1), with mortality being 2.5%. The only factor affecting the outcome was the grade at admission (p < 0.05).  A simple and routinely used burr hole procedure either under local or general anesthesia with a closed drainage system is a safe and effective procedure for the treatment of chronic subdural hematoma.

Field of study: Medicine
Effects of the liquid-gas phase transition and cluster formation on the symmetry energy

Various definitions of the symmetry energy are introduced for nuclei, dilute nuclear matter below saturation density and stellar matter, which is found in compact stars or core-collapse supernovae. The resulting differences are exemplified by calculations in a theoretical approach based on a generalized relativistic density functional for dense matter. It contains nucleonic clusters as explicit degrees of freedom with medium-dependent properties that are derived for light clusters from a quantum statistical approach. With such a model the dissolution of clusters at high densities can be described. The effects of the liquid-gas phase transition in nuclear matter and of cluster formation in stellar matter on the density dependence of the symmetry energy are studied for different temperatures. It is observed that correlations and the formation of inhomogeneous matter at low densities and temperatures causes an increase of the symmetry energy as compared to calculations assuming a uniform uncorrelated spatial distribution of constituent baryons and leptons.

Field of study: Physics
Efficacy of fixed filtration for rapid kVp-switching dual energy x-ray systems.

Dose efficiency of dual kVp imaging can be improved if the two beams are filtered to remove photons in the common part of their spectra, thereby increasing spectral separation. While there are a number of advantages to rapid kVp-switching for dual energy, it may not be feasible to have two different filters for the two spectra. Therefore, the authors are interested in whether a fixed added filter can improve the dose efficiency of kVp-switching dual energy x-ray systems.



The authors hypothesized that a K-edge filter would provide the energy selectivity needed to remove overlap of the spectra and hence increase the precision of material separation at constant dose. Preliminary simulations were done using calcium and water basis materials and 80 and 140 kVp x-ray spectra. Precision of the decomposition was evaluated based on the propagation of the Poisson noise through the decomposition function. Considering availability and cost, the authors chose a commercial Gd2O2S screen as the filter for their experimental validation. Experiments were conducted on a table-top system using a phantom with various thicknesses of acrylic and copper and 70 and 125 kVp x-ray spectra. The authors kept the phantom exposure roughly constant with and without filtration by adjusting the tube current. The filtered and unfiltered raw data of both low and high energy were decomposed into basis material and the variance of the decomposition for each thickness pair was calculated. To evaluate the filtration performance, the authors measured the ratio of material decomposition variance with and without filtration.



Simulation results show that the ideal filter material depends on the object composition and thickness, and ranges across the lanthanide series, with higher atomic number filters being preferred for more attenuating objects. Variance reduction increases with filter thickness, and substantial reductions (40%) can be achieved with a 2× loss in intensity. The authors' experimental results validate the simulations, yet were overall slightly worse than expectation. For large objects, conventional (non-K-edge) beam hardening filters perform well.



This study demonstrates the potential of fixed K-edge filtration to improve the dose efficiency and material decomposition precision for rapid kVp-switching dual energy systems.

Field of study: Medicine, Physics
Liquid Extracting from Cassava Leaves and Its Effects on Growth of Soft-shell Turtles

The liquid extracting from cassava leaves and its effects on turtles' growth are optimized in the study.Firstly,the optimal process of extracting liquid from cassava leaves is determined.The extracting conditions include ethanol density,solid-to-liquid ratio,extracting temperature and extracting time.Secondly,the effects of the liquid of cassava leaves on the growth of soft-shelled turtle by determining the survival rate,growth performance,feed conversion ratio,trophic component of turtles,blood biochemical and immunity indicators are analyzed.The result shows that the optimal process conditions are percent of ethanol density(50%),solid-to-liquid ratio(40:1),extracting temperature(70 ℃),extracting time(2 h).In conclusion,it indicates that the feed with the extracting liquid could improve the turtles' growth rate,decrease the feed coefficient,decrease the content of blood sugar,cholesterol and triglyceride of turtle and decrease MDA of turtle serum,so that the liquid could promote the glycometabolism,fat metabolism and immunity of turtle.Thus,this study not only firstly adds the liquid extracting from the cassava leaves into the turtles' feed,but also provides the theoretic reason for using the liquid as natural and low-toxic feed additive.

Field of study: Agricultural and Food sciences
Stochastic biperiodic oscillations in the electroreceptors of paddlefish.

We report that the electroreceptors in paddlefish possess the novel property of being biperiodic, that is, being composed of two intrinsic self-sustained noisy oscillators, one residing in the hair cells, and another in the terminals of primary afferent neurons. The two oscillators are coupled unidirectionally. Thus the receptor system as a whole undergoes stochastic biperiodic oscillations. We characterize the spontaneous activity of this system of coupled biological oscillators, and also discuss the impact of the biperiodic organization on the transduction of external sensory stimuli. In particular, we show that the existence of hair cell oscillations leads to additional variability of afferent spike trains.

Field of study: Physics
Analysis on influence of gathering and transportation technology on the effect of pour point depressant in high wax crude oil

The gathering and transportation technology of high-wax crude oil has a great influence on reducing the viscosity and pour point of oil.Jilin Munan crude oil is depressed by pour point depressant AE,and the influences of the dosage of pour point depressant,adding temperature,high-speed shearing of pump,repeated heating and cooling rate in gathering and transportation process on the effect of pour point depressant are researched.Experimental results show that the optimal conditions are as follows: additive dosage of pour point depressant is 0.7%,adding temperature is 70 ℃,the temperature of high-speed shearing is at least 10 ℃ higher than wax precipitation point,the repeated heating temperature should not be lower than 60 ℃,the cooling process should be slow down in the 55~40 ℃wax crystallization peak area.

Field of study: Chemistry, Environmental science