nils-herrmann/clean_scirepeval huggingface dataset:
Control of Phase in Tin Sulfide Thin Films Produced via RF-Sputtering of SnS2 Target with Post-deposition Annealing

Tin (II) Monosulfide (SnS) has become an interesting new material for thin film photovoltaics. SnS-based devices have achieved limited success in improved solar cell efficiency. While annealing is a typical post-deposition treatment used to improve thin film quality, sulfur volatility is an issue, despite strong Sn-S bonds in tin sulfide compounds. Annealing of sulfur-rich sputtered tin sulfide thin films in a vacuum environment has not been previously reported. In the present work, we investigated the optoelectronic properties, crystallographic phase, and morphology of annealed, sputtered tin sulfide thin films. Specifically, we studied the phase change and improvement in material quality as a result of post-deposition heat treatments. Tin sulfide thin films were sputtered with and without substrate heating. These samples were then annealed between 300°C and 500°C under moderate vacuum (<1 × 10−4 Pa) in the deposition chamber to find the optimal annealing process for producing α-SnS. Significantly improved crystallinity and morphology were seen in sulfur-rich thin films annealed at 400–500°C for 60 min. Annealed films had resistivity in the range of 30–300 Ω-cm. Experimental observations were confirmed by calculated phase diagrams, which show that annealing around 400°C at low pressure is optimal to obtain a phase-pure α-SnS film from an amorphous SnS2 film.

Field of study: Materials science
Effects of cyanide and dissolved oxygen concentration on biological Au recovery.

The number of discarded electric devices containing traces of Au is currently increasing. It is desirable to recover this Au because of its valuable physicochemical properties. Au is usually dissolved with relatively high concentrations of cyanide, which is associated with environmental risk. Chromobacterium violaceum is able to produce and detoxify small amounts of cyanide, and may thus be able to recover Au from discarded electric devices. This study investigated the effects of cyanide and dissolved oxygen concentration on biological Au recovery. Cyanide production by C. violaceum was sufficient to dissolve Au, while maintaining a high cyanide concentration did not enhance Au dissolution. Increased oxygen concentration enhanced Au dissolution from 0.04 to 0.16 mmol/l within the test period of 70 h. Electrochemical measurement clarified this phenomenon; the rest potential of Au in the cyanide solution produced by C. violaceum increased from -400 to -200 mV, while in the sterile cyanide solution, it was constant in cyanide concentrations ranging from 0 to 1.5 mmol/l and increased in dissolved oxygen concentrations ranging from 0 to 0.25 mmol/l. Therefore, it was clarified that dissolved oxygen concentration is the main factor affecting the efficiency of cyanide leaching of gold by using bacteria.

Field of study: Biology, Engineering
Understanding nanoscale structural distortions in Pb(Zr0.2Ti0.8)O3 by utilizing X-ray nanodiffraction and clustering algorithm analysis.

Hard X-ray nanodiffraction provides a unique nondestructive technique to quantify local strain and structural inhomogeneities at nanometer length scales. However, sample mosaicity and phase separation can result in a complex diffraction pattern that can make it challenging to quantify nanoscale structural distortions. In this work, a k-means clustering algorithm was utilized to identify local maxima of intensity by partitioning diffraction data in a three-dimensional feature space of detector coordinates and intensity. This technique has been applied to X-ray nanodiffraction measurements of a patterned ferroelectric PbZr0.2Ti0.8O3 sample. The analysis reveals the presence of two phases in the sample with different lattice parameters. A highly heterogeneous distribution of lattice parameters with a variation of 0.02 Å was also observed within one ferroelectric domain. This approach provides a nanoscale survey of subtle structural distortions as well as phase separation in ferroelectric domains in a patterned sample.

Field of study: Physics
Expression, refolding and purification of a human interleukin-17A variant.

A human interleukin-17A (IL-17A) variant was overexpressed in Escherichia coli BL21 (DE3) under the control of a T(7) promoter. The resulting insoluble inclusion bodies were isolated and solubilized by homogenization with 6 M guanidine HCl. The denatured recombinant human IL-17A variant was refolded in 20 mM Tris-HCl, pH 9.0, 500 mM arginine, 500 mM guanidine HCl, 15% glycerol, 1 mM cystamine, and 5 mM cysteine at 2-8°C for 40 h. The refolded IL-17A variant was subsequently purified using a combination of cation-exchange, reversed-phase and fluoroapatite chromatography. The final purified product was a monodisperse and crystallizable homodimer with a molecular weight of 30,348.3 Da. The protein was active in both receptor binding competition assay and IL-17A-dependent biological activity assay using human dermal fibroblasts.

Field of study: Medicine
Predictive accuracy of risk scales following self-harm: multicentre, prospective cohort study†

Scales are widely used in psychiatric assessments following self-harm. Robust evidence for their diagnostic use is lacking.  To evaluate the performance of risk scales (Manchester Self-Harm Rule, ReACT Self-Harm Rule, SAD PERSONS scale, Modified SAD PERSONS scale, Barratt Impulsiveness Scale); and patient and clinician estimates of risk in identifying patients who repeat self-harm within 6 months.  A multisite prospective cohort study was conducted of adults aged 18 years and over referred to liaison psychiatry services following self-harm. Scale a priori cut-offs were evaluated using diagnostic accuracy statistics. The area under the curve (AUC) was used to determine optimal cut-offs and compare global accuracy.  In total, 483 episodes of self-harm were included in the study. The episode-based 6-month repetition rate was 30% (n = 145). Sensitivity ranged from 1% (95% CI 0–5) for the SAD PERSONS scale, to 97% (95% CI 93–99) for the Manchester Self-Harm Rule. Positive predictive values ranged from 13% (95% CI 2–47) for the Modified SAD PERSONS Scale to 47% (95% CI 41–53) for the clinician assessment of risk. The AUC ranged from 0.55 (95% CI 0.50–0.61) for the SAD PERSONS scale to 0.74 (95% CI 0.69–0.79) for the clinician global scale. The remaining scales performed significantly worse than clinician and patient estimates of risk (P < 0.001).  Risk scales following self-harm have limited clinical utility and may waste valuable resources. Most scales performed no better than clinician or patient ratings of risk. Some performed considerably worse. Positive predictive values were modest. In line with national guidelines, risk scales should not be used to determine patient management or predict self-harm.

Field of study: Medicine, Psychology
Direct sums of irreducible operators

It is known that every operator on a (separable) Hilbert space is the direct integral of irreducible operators, but not every one is the direct sum of irreducible ones. We show that an operator can have either finitely or uncountably many reducing subspaces, and the former holds if and only if the operator is the direct sum of finitely many irreducible operators no two of which are unitarily equivalent. We also characterize operators T which are direct sums of irreducible operators in terms of the C*-structure of the commutant of the von Neumann algebra generated by T .

Field of study: Mathematics
Neuroanatomical basis of maternal memory in postpartum rats: selective role for the nucleus accumbens.

The experience of interacting with pups causes long-term changes in mothers' brains that mediate long-term changes in maternal behavior. As little as 1 hr of pup experience postpartum results in enhanced maternal responses to pups 10 days later. This experiment investigated the effects of lesions in multiple neural sites that have been implicated either in the actual expression of maternal behavior or in learning and memory within other behavioral contexts on the initiation and the long-term experience-based retention of maternal behavior. Electrolytic lesions were performed either before or after a 1-hr or 24-hr maternal experience. Rats sustaining lesions of the nucleus accumbens (NACC), whether administered before parturition and experience or immediately after a brief experience, failed to show a maternal experience effect. NACC lesions sustained 24 hr after a maternal experience did not disrupt long-term retention of the maternal behavior.

Field of study: Biology, Psychology
Construction of Full-length cDNA Library from Sugarcane Leaves and the Corresponding EST Analysis

In order to analyze gene expression pattern in the sugarcane(Saccharum Complex) leaves and set the basis for the cloning of some important functional genes, the functional leaves were taken as plant material from 3 development stage of sugarcane, and a full-length cDNA library was constructed by the method of Oligo-capping.After identification, the storage capacity of the library was 3.0×106 cfu, the recombinant rate was 89%, the full-length rate was 85%, and the average size of inserted fragment was about 1.0 kb.In total, two hundred and twenty-eight efficient ESTs(expressed sequence tags) of 5' end were obtained from this cDNA library.Bioinformatics analysis showed that these ESTs were assembled into 154 TUTs(tentative unique transcript).The homologous analysis of the 154 TUTs on NCBI showed that these 87 TUTs(including 117 ESTs) were determined to be the tags of gene with putative function, these genes were found to be involved in the biological process including cell development, signal transport, protein synthesis, transcription, stress tolerance response, energy metabolism and so on.

Field of study: Agricultural and Food sciences
Step-Wise Validation of Communication Protocols and Services

A highly automated approach is proposed for testing the consistency of distinct representations of identical system functionality. This approach is based on dynamic comparison and analysis of observable behaviors presented by system functionality representations given at different levels of abstraction. These representations are encoded in a relatively mechanical way as procedures in sequential PROLOG and thus provide the capability of generating and checking the system functionality they capture. The approach is extremely flexible, straightforward to use, and particularly appropriate to systems whose externally observable behavior can be modeled by finite state automata. The use of this approach is illustrated in the context of OSI communication protocol design and validation.

Field of study: Computer science
Chronology of a Kettle-Hole Peat Bog, Cherryfield, Maine

Parts of coastal and central Maine underwent marine submergence between approximately 13,500 and 12,500 yrs ago. An ice-contact marine delta near Cherryfield, Maine, was formed during this time. Ten radiocarbon dates of basal peat samples from a kettle hole on the delta ranged from 5,310 ± 100 yrs B.P. at a depth of 2.21 m to 9,170 ± 160 yrs B.P. at a depth of 5.28 m. Peat from depths of 5.55 m yielded dates within the statistical error of the oldest date. The radiocarbon dates indicate a time lag of approximately 2,000 yrs between the formation of the delta and the earliest deposition of organic matter in the kettle hole.

Field of study: Geology
Possible role of FDG-PET in the early prediction of therapy outcome in liver metastases of colorectal cancer.

Nonresectable colorectal cancer metastases in the liver respond to chemotherapy in 20-25% only. Early identification of nonresponders might allow the use of other regimens. In a limited feasibility study, it should be determined whether (a) a single high-dose chemotherapy application has an early effect on glucose-utilization, detectable and quantitatable by noninvasive positron emission tomography using [18F]-Fluoro-deoxyglucose (FDG-PET) and (b) assess its value as a predictor of the final therapeutic outcome. A total of 10 patients with documented nonresectable liver metastases of a colorectal cancer were studied by FDG-PET, prior and 72 h after a single infusion of 5-Fluorouracil and Folinic acid (5-FU/FA). Glucose utilization was quantitated by determination of standard-uptake values and correlated with final therapy outcome following completion of the anticipated therapy cycle. Patients were followed up for at least 6 months. All metastases responding to therapy (n = 6) exerted a statistically significant decrease of FDG uptake (-22+/-10%), metastases (n = 2) showing a short-term effect (duration of tumor reduction <3 months) had a slightly diminished, and progressing metastases (n = 3) an enhanced FDG uptake (13+/-17%). Our preliminary data indicate that acute changes of glucose utilization-as detected by FDG-PET-following a single application of chemotherapy, seems to be indicative for the final therapeutic outcome, at least in liver metastases of colorectal cancer.

Field of study: Biology
Contrasting patterns of cytokinins between years in senescing aspen leaves.

Cytokinins are plant hormones that typically block or delay leaf senescence. We profiled 34 different cytokinins/cytokinin metabolites (including precursors, conjugates and degradation products) in leaves of a free-growing mature aspen (Populus tremula) before and after the initiation of autumnal senescence over three consecutive years. The levels and profiles of individual cytokinin species, or classes/groups, varied greatly between years, despite the fact that the onset of autumn senescence was at the same time each year, and senescence was not associated with depletion of either active or total cytokinin levels. Levels of aromatic cytokinins (topolins) were low and changed little over the autumn period. Diurnal variations and weather-dependent variations in cytokinin content were relatively limited. We also followed the expression patterns of all aspen genes implicated as having roles in cytokinin metabolism or signalling, but neither the pattern of regulation of any group of genes nor the expression of any particular gene supported the notion that decreased cytokinin signalling could explain the onset of senescence. Based on the results from this tree, we therefore suggest that cytokinin depletion is unlikely to explain the onset of autumn leaf senescence in aspen.

Field of study: Environmental science
Research on arylhydrazones of substituted glyoxylic acids

Abstract3-Aryl-4-(arylhydrazonochloroformyl)-2-[(carbethoxy or carbarnoyl)cyanomethylene]-4-thiazolines were obtained by condensation of arylhydrazones of chloromethylglyoxylic chloride with arylamides of cyanomonothiomalonic acid ethyl ester or amide. The chlorine atom in these compounds is readily exchanged by a hydrazino group to give 3-aryl-4-(arylhydrazonohydrazinoformyl)-2-[(carbethoxy or carbamoyl)cyanomethylene]-4-thiazolines. 2-(Arylhydrazonocarbethoxyformyl)-4-(arylhydrazonochloroformyl)thiazoles were obtained by reaction of arylhydrazones of chloromethylglyoxylic chlorides with arylhydrazones of monothiomesoxalic acid ethyl ester amide. Arylhydrazones of ethyl 1H-tetrazolyl-5-glyoxylate were synthesized by condensation of arylhydrazones of ethyl cyanoglyoxylate with ammonium azide in dimethylformamide.

Field of study: Chemistry
Doubly Half-Injective PRGs for Incompressible White-Box Cryptography

White-box cryptography was originally introduced in the setting of digital rights management with the goal of preventing a user from illegally re-distributing their software decryption program. In recent years, mobile payment has become a popular new application for white-box cryptography. Here, white-box cryptography is used to increase the robustness against external adversaries (i.e., not the user) who aim to misuse/attack the cryptographic functionalities of the payment application. A necessary requirement for secure white-box cryptography is that an adversary cannot extract the embedded secret key from the implementation. However, a white-box implementation needs to fulfill further security properties in order to provide useful protection of an application. In this paper we focus on the popular property incompressibility that is a mitigation technique against code-lifting attacks. We provide an incompressible white-box encryption scheme based on the standard-assumption of one-way permutations whereas previous work used either public-key type assumptions or non-standard symmetric-type assumptions.

Field of study: Computer science, Mathematics
Parametric localization of distributed sources

Most array processing algorithms are based on the assumption that the signals are generated by point sources. This is a mathematical constraint that is not satisfied in many applications. In this paper, we consider situations where the sources are distributed in space with a parametric angular cross-correlation kernel. We propose an algorithm that estimates the parameters of this model using a generalization of the MUSIC algorithm. The method involves maximizing a cost function that depends on a matrix array manifold and the noise eigenvectors. We study two particular cases: coherent and incoherent spatial source distributions. The spatial correlation function for a uniformly distributed signal is derived. From this, we find the array gain and show that (in contrast to point sources) it does not increase linearly with the number of sources. We compare our method to the conventional (point source) MUSIC algorithm. The simulation studies show that the new method outperforms the MUSIC algorithm by reducing the estimation bias and the standard deviation for scenarios with distributed sources. It is also shown that the threshold signal-to-noise ratio required for resolving two closely spaced distributed sources is considerably smaller for the new method.

Field of study: Engineering
An Enhancement Method for Mine Underground Video Image Based on Curve Fitting

The images of underground monitoring system have the disadvantages of low contrast and poor details; this paper sets forth a contrast enhancement method based on curve fitting used by cubic spline interpolation. For different environments in the underground mine, the matched curve adapted to the environment is selected as a template, and nonlinear transformation is made for video image. In this case, the proposed method can effectively improve the image contrast, and stand out the image details.

Field of study: Materials science
Pion production model - connection between dynamics and quark models

The authors discuss the difficulties in testing the hadron models by using the N{sup *} parameters extracted from the empirical amplitude analyses of the {pi}N and {gamma}N reaction data. As an alternative or perhaps a more advantageous approach, they present a Hamiltonian formulation that can relate the pion production dynamics and the constituent quark models of N{sup *} structure. The application of the approach in investigating the {Delta} and N{sup *}(S{sub 11}) excitations is reviewed. It is found that while the {Delta} excitation can be described satisfactory, the {pi}N scattering in S{sub 11} channel can not be described by the constituent quark models based on either the one-gluon-exchange or one-meson-exchange mechanisms. A phenomenological quark-quark potential has been constructed to reproduce the S{sub 11} amplitude.

Field of study: Physics
Self-Employment in the Russian Federation: Analysis of the Current Trends in the Activity of the Students Self-Employment

The independent employment phenomenon becomes more widespread every day in Russian Federation; the ambiguity of its consequences in political, economic and social spheres of public life defines the need to study it scientifically, as well as to seek ways of bringing this category of students . Room study results of the current phenomenon demonstrated the low pace of business legalizing in the pilot regions. Slow coming out of the shadow is due to the low expectations the students have for the new bill introduction. The analysis was carried out on the data of standard and legal base regulating this sphere of the legal relationship as well as by means of the secondary analysis of the self-employed who participated in the poll in 2018. The developing situation, according to authors, demands the implementation of educational actions; such actions have to rely on results of the sociological researches of self-employment conducted according to the recommendations developed by authors.

Field of study: Education, Sociology
On globally convergent multi-objective optimization

The multi-objective optimization problem is solved by using the compromise method which convert the multi-objective optimization problem to a single objective optimization problem, then a trust-region algorithm for solving the general nonlinear programming problem is used. In this algorithm, an active set strategy is used together with a reduced Hessian technique to covert the computation of the trial step to two easy trust-region subproblems and the conjugate-gradient method is used to compute the trial step.

Field of study: Mathematics
Attention-Deficit/Hyperactivity Disorder in African American Youth

This article examines attention-deficit/hyperactivity disorder (ADHD) in African American youth. Tackling the myths and misinformation surrounding ADHD in the African American community can be one of the most difficult issues in mental illness circles. There is a lot of conflicting information about how African Americans are diagnosed, examined, and treated. This article clarifies some of the misconceptions and offers some comprehensibility to the issue of ADHD in African American youth. The incidence of ADHD is probably similar in African Americans and Caucasians. However, fewer African Americans are diagnosed with and treated for ADHD. That reality flies in the face of some perceptions in many African American communities. Reasons for this disparity have not been fully clarified and are most likely complex and numerous. Some barriers to treatment are driven by the beliefs of patients and their families, while others are the result of limitations in the health care system. Patient-driven obstacles to care include inadequate knowledge of symptoms, treatment, and consequences of untreated ADHD and fear of overdiagnosis and misdiagnosis. System-driven limitations include a lack of culturally competent health care providers, stereotyping or biases, and failure of clinicians to evaluate the child in multiple settings before diagnosis.

Field of study: Medicine, Psychology
Conditioned reinstatement of drug-seeking behavior with a discrete compound stimulus classically conditioned with intravenous cocaine.

The present study investigated the ability of a light and tone (LT) compound stimulus paired with cocaine infusions to reinstate cocaine-seeking behavior. Rats were trained to self-administer cocaine in the presence or absence of the LT during daily 3-hr sessions (maintenance). During Maintenance Days 5 and 10, rats underwent classical conditioning, whereby passive cocaine infusions were paired with either short-delayed, random, or no presentations of an LT. After extinction sessions, rats underwent test sessions in which the LT was presented in a noncontingent or response-contingent manner to measure conditioned cocaine-seeking behavior. The results demonstrated that response-contingent LT presentations significantly increased cocaine-seeking behavior and that the LT trained in a classical conditioning format transferred to an operant secondary reinforcer.

Field of study: Biology, Psychology