nils-herrmann/clean_scirepeval huggingface dataset:
Neue Methoden der chemischen Modifizierung von Acetylcellulose

EINLEITUNG Die Acetylcellulose ist einer der wichtigsten Ester der Cellulose, der eine breite Verwendung gefunden hat. In den letzten Jahren hat man wichtige Ergebnisse in Richtung zur weiteren Verbesserung der Eigenschaften verschiedener Produkte, die aus Acetylcellulose hergestellt werden, erzielt. Das betrifft vor allem Acetatfasern, besonders Triacetatfasern und Triacetatfolien, sowie die Rationalisierung der Produktionsmethoden. Aber bis heute weisen die Acetatfasern erhebliche Nachteile auf, die die Steigerung der Herstellung und Anwendung dieser billigen und hochwertigen künstlichen Fasern hemmen. Zu diesen Nachteilen gehören: niedrige Festigkeit, erhebliche Schwierigkeiten beim Färben, niedrige Reibungsbeständigkeit und leichte Elektrisierbarkeit des Fertigproduktes. Auch ist es nötig, die Eigenschaften der Triacetatfolien zu verbessern. Das bezieht sich besonders auf die Erhöhung der Elastizität, Hydrofobizität, Verminderung der Schrumpfung, Erhöhung der Adhäsion zur Untershicht, was für die Herstellung von Kinofilmen wichtig ist. Einige dieser Nachteile können durch die sogenannte Strukturmodifizierung behoben werden. Durch Erhöhung des Molekulargewichts der Acetylcellulose und besonders durch Änderung der Spinnbedingungen kann eine erhebliche Steigerung der Festigkeit der Fasern sowie in bestimmtem Ausmasse auch der Elastizität der Folien erzielt werden. Aber diese interessanten Fragen der Strukturmodifizierung bilden nicht das Thema dieses Vortrags und werden deshalb im folgenden nicht besprochen. Die Anwendung der Methoden für die chemische Modifizierung der Acetylcellulose für die vorbestimmte Veränderung der chemischen Struktur und somit der Eigenschaften der Acetylcellulose können von grosser Bedeutung für die Beseitigung der oben erwähnten Nachteile und für die Herstellung von Fasern und Folien mit wichtigen technischen Eigenschaften se1n. Unter den verschiedenen Methoden der chemischen Modifizierung der Acetylcellulose sind folgende unser Meinung nach am interessantesten: (a) die Synthese von neuen Typen gemischter Celluloseester; (b) die Herstellung von Fasern und wahrscheinlich auch von Folien aus Lösungen der Mischungen der Acetylcellulose mit einigen synthetischen Polymeren; ( c) die Synthese von Pfropfcopolymeren der Acetylcellulose. Ein bestimmtes Interesse für die Erzielung einer echten Färbung der Acetylcellulose und aus ihr hergestellter Fertigwaren hat eine in der UdSSR

Field of study: Chemistry
Contact metamorphism of a basic igneous rock

In volumes 4 and 5 of the Final Report of the Geological and Natural History Survey of Minnesota, and in some of the annual reports of the same survey, mention is frequently made of certain peculiar crystalline rocks which occur along the northern edge of the great gabbro mass of northeastern Minnesota. The rocks in question furnish one of the most interesting cases of metamorphism of a series of rocks of varied lithology by the contact effect of a basic igneous mass. It is the object of this paper to present in outline an account of the phenomena here seen. Outline of local Geology The triangular area of Minnesota lying north of lake Superior is underlain by rocks of pre-Cambrian age. In general these are disposed in belts, which trend east-northeast and west-southwest. Those of greatest age are toward the north, so that in traversing this district from the . . .

Field of study: Geology
BRIEF COMMUNICATIONS: Dependences of the parameters of an optoacoustic signal on the radius of the excited region

Experimental and theoretical investigations were made of the dependence of the amplitude of an optoacoustic signal on the radius of a region excited by a focused beam. A linearized equation for the pressure was solved to show that the acoustic signal profile was governed primarily by the beam radius and that for r0 cτ it is proportional to r01/2. A series of experiments was carried out on the absorption in ozone and these experiments confirmed the r03/2 dependence for r0 < cτ.

Field of study: Engineering, Physics
Onshore disposition of offshore oil and gas platforms: Western politics and international standards

Onshore-only disposition of retired offshore oil and gas platforms has become a core strategic objective for ocean/environmental advocates and policy makers. Although international oil companies oppose an onshore-only requirement, its rejection is no longer a high priority for them. The ascendancy of onshore-only disposition reflects a rational and predictable response to political attitudes, values, and expectations in Western Europe by both governmental policy makers and petroleum industry strategists. Repercussions from the fight over the disposition of the obsolete Brent Spar offshore oil storage and transfer facility are the proximate cause of the shift. Onshore disposition has been least expensive option for most platforms, but as platforms move further from shore toward deeper waters onshore disposition is more frequently inferior to other disposition alternatives — from both an environmental and economic point of view. If onshore-only disposition were to become an international standard, either de facto or de jure, some offshore producing areas would incur significantly higher disposition costs and lose opportunities to better utilize and protect their marine resources.

Field of study: Environmental science
Integer powers of real odd order skew-persymmetric anti-tridiagonal matrices with constant anti-diagonals (antitridiagn (a, c, -a), a ∈ R∖{0}, c ∈ R)

In this paper we give the eigenvalue decomposition for real odd order skew-persymmetric anti-tridiagonal matrices with constant anti-diagonals and derive the general expression for integer powers of such matrices.

Field of study: Mathematics
Genotype analysis for measles vaccine strain and wild-type viruses of H1 genotype by RT-PCR-RFLP

To establish RT-PCR-RFLP method for studying the genotype of wild mea-sles virus strains isolated from Tianjin area from 2002 to 2008.  Isolations of measles virus were carried out by tissue culture method from urine and throat swab specimens collected from suspected cases. RNA were extracted from the virus specimens. The 594 bp fragment of C terminal of the N (nucleoprotein) gene was amplified by one-step RT-PCR, then the PCR products were digested with Bcn I , separated on agarose gel electrophoresis and then analyzed by the method of RFLP (restriction fragment length polymor-phism). In addition, above results were compared with DNA sequencing. Phylogenetic tree was plotted based on the results for the genetic relationship and distance analysis.  Sixty-nine measles virus strains were isolated from 189 specimens from 2002 to 2008, of which the C terminals of N gene were all de-tected positive. Among the 69 strains of measles virus isolates, 98.55% (68/69) belonged to Hla sub-geno-type which was the predominant sub-genotype, and only one strain (1.45%) belonged to H1b sub-genotype by RFLP analysis which was in accordance with the results by DNA sequencing method. Phylogenetic tree analysis indicated the H1a sub-genotype measles virus strains should be further divided into 2 clades, and the variation fluctuated between 0.2% and 3.8%. There were transmission chains caused by different virus strains co-cireulation.  A genotype, H1a and H1b sub-genotype can be identified by RT-PCR-RFLP assay specically based on the restriction enzyme Bcn I .The RT-PCR-RFLP assay can be a rapid, simple, accurate and efficient method for large-scale surveillance of measles virus strains in China. 
 
 
Measles virus;  Reverse transeription-polymerase chain reaction(RT-PCR) ;  Restric-tion fragment length polymorphism (RFLP) ;  Genotype;  Sequence analysis

Field of study: Biology
Investigation into the Effectiveness of Staff Appraissal in the Job Perfomance in Secondary Schools in Kenya

Performance appraisal has become a major human resource management tool in secondary schools as it enhances performance and productivity of employees. More often than not, the school management ignores this major activity and later experiences decreased productivity resulting from lack of recognition and appreciation. The purpose of this study was to investigate the effectiveness of appraisal programs adopted by secondary schools. The study adopted a descriptive research design by way of survey. Data was collected from across section of schools by use of questionnaires and interview guides. Data was statistically analyzed and the results discussed in a  narrative way. The study found out that very few school managers conducted performance appraisal of their employees. The main fear being tedious procedures involved. It was also realized that most appraisals done in schools were informal. The study concludes that performance appraisal is an important tool which improves the school chances of attaining key operational goals.  The study recommends that proper appraisal techniques be adopted. This will assist the appraisee to appreciate their performance and improve in order to achieve organizational goals and objectives  Staff appraisal, Employee performance, Motivation, Appraisal ratings, Feedback process,

Field of study: Education
Involvement of CCR-2 chemokine receptor activation in ischemic preconditioning and postconditioning of brain in mice.

The present study has been designed to investigate the potential role of CCR-2 chemokine receptor in ischemic preconditioning as well as postconditioning induced reversal of ischemia-reperfusion injury in mouse brain. Bilateral carotid artery occlusion of 17 min followed by reperfusion for 24h was employed in present study to produce ischemia and reperfusion induced cerebral injury in mice. Cerebral infarct size was measured using triphenyltetrazolium chloride staining. Memory was evaluated using elevated plus-maze test and Morris water maze test. Rota rod test was employed to assess motor incoordination. Bilateral carotid artery occlusion followed by reperfusion produced cerebral infarction and impaired memory and motor co-ordination. Three preceding episodes of bilateral carotid artery occlusion for 1 min and reperfusion of 1 min were employed to elicit ischemic preconditioning of brain, while three episodes of bilateral carotid artery occlusion for 10s and reperfusion of 10s immediately after the completion of were employed to elicit ischemic postconditioning of brain. Both prior ischemic preconditioning as well as ischemic postconditioning immediately after global cerebral ischemia prevented markedly ischemia-reperfusion-induced cerebral injury as measured in terms of infarct size, loss of memory and motor coordination. RS 102895, a selective CCR-2 chemokine receptor antagonist, attenuated the neuroprotective effect of both the ischemic preconditioning as well as postconditioning. It is concluded that the neuroprotective effect of both ischemic preconditioning as well as ischemic postconditioning may involve the activation of CCR-2 chemokine receptors.

Field of study: Medicine
Healthcare assistants in EU Member States: An overview.

With many European countries facing health workforce shortages, especially in nursing, and an increasing demand for healthcare, the importance of healthcare assistants (HCAs) in modern healthcare systems is expected to grow. Yet HCAs' knowledge, skills, competences and education are largely unexplored. The study 'Support for the definition of core competences for healthcare assistants' (CC4HCA, 2015-2016) aimed to further the knowledge on HCAs across Europe. This paper presents an overview of the position of healthcare assistants in 27 EU Member States (MSs) and reflects on the emerging country differences. It is shown that most learning outcomes for HCAs across Europe are defined in terms of knowledge and skills, often at a basic instead of more specialized level, and much less so in terms of competences. While there are many differences between MSs, there also appears to be a common, core set of knowledge and skills-related learning outcomes which almost all HCAs across Europe possess. Country differences can to a large extent be explained by the regulatory and educational frameworks in which HCAs operate, influencing their current and future position in the healthcare system. Further investments should be made to explore a common understanding of HCAs, in order to feed discussions at policy and organisational levels, while simultaneously investments in the development and implementation of context-specific HCA workforce policies are needed.

Field of study: Medicine, Political science
VERTICAL RESONANCE PHENOMENON OF SIMPLY SUPPORTED GIRDER BRIDGES ON HIGH-SPEED RAILWAY

The vertical resonance phenomenon which may take place for many kinds of different simply supported girder bridges on high-speed railway is studied with a vehicle-bridge interaction system model. The train's critical velocities are obtained when the vertical resonant vibration occurs. The influence of different spans upon the peak value of the vertical resonant vibration of the bridges is investigated. The precautions against the vertical resonance phenomenon of the bridges are addressed.

Field of study: Engineering
Cytokines and Langerhans cell mobilisation in mouse and man.

A critical event during the development of cutaneous immune responses, including those provoked by contact allergens, is the mobilisation of epidermal Langerhans cells (LC). These cells act as sentinels of the immune system in the skin, responding to a variety of local insults with migration and delivery of potentially foreign signals to draining lymph nodes. Experimental studies have revealed that the regulation of mobilisation and migration of LC display striking similarities in man and mouse. In both species it has been found that the successful induction of migration requires that LC receive (at least) 2 independent cytokine signals; provided by tumour necrosis factor-alpha (TNF-alpha) and interleukin 1beta. In addition, a similar heterogeneity in man and mouse is apparent with regard to the fraction of LC responding rapidly to mobilisation signals, with the same proportion of cells (20%-30%) being stimulated to migrate in each case. Other similarities exist between mice and humans with respect to LC function, including an age-related decrement in both LC frequency and responsiveness to TNF-alpha. Collectively these studies demonstrate that the mouse provides a valuable experimental surrogate for the human skin immune system, particularly with respect to LC biology, and suggest that it is possible to perform extrapolations between species with some confidence.

Field of study: Medicine
Understanding Consumers' Web-Mobile Shopping Extension Behavior: A Trust Transfer Perspective

This paper aims to identify factors that affect consumers' web-mobile shopping extension behaviors. Drawing on the trust transfer theory, the present study investigates the trust transfer process (including trust in source, trust in target, and relationship between source and target) and its effect on consumers' benefit-sacrifice evaluations and behaviors toward mobile shopping extension. The research model was empirically tested on the data collected from 309 web-shopping users of a famous business-to-consumer retailer in China. The SEM analysis results indicate that trust in web shopping services and perceived integration between web and mobile shopping services positively affect trust in mobile shopping services. The results also demonstrate that the trust transfer process positively affects behaviors toward mobile shopping extension directly and indirectly via a dual mechanism: by enhancing perceived benefit and by reducing perceived risk of mobile shopping services. Theoretical and practical implications of these findings are discussed.

Field of study: Computer science
MicroRNA-124 Functions as a Tumor Suppressor by Regulating CDH2 and Epithelial-Mesenchymal Transition in Non-Small Cell Lung Cancer

Abnormal expression of microRNA-124 (miR-124) was found in non-small cell lung cancer (NSCLC). However, the association between miR-124 and CDH2 has not been reported yet. This study aims to reveal the inhibiting effects of miR-124 on the expression of CDH2 in NSCLC.  Quantitative real-time polymerase chain reaction was used to evaluate the expression of miR-124 and CDH2 in NSCLC tissues. Cell viability, apoptosis and invasion assays were carried out in NSCLC cell lines after transfection. The regulation mechanism was confirmed by luciferase report assay and western blot (WB).  Significantly decreased expression of miR-124 was found in NSCLC specimens and cell lines. Overexpression of miR-124 apparently suppressed the proliferation and invasion of NSCLC cell lines in vitro. Luciferase report assay and WB revealed that CDH2 was a target gene of miR-124. Furthermore, results of WB showed that epithelial-mesenchymal transition (EMT) could be inhibited by up-regulation of miR-124.  Taken together, our findings present the first evidence that miR-124 could suppress the expression of CDH2 and regulate EMT, which might lead to a potential therapeutic strategy focusing on miR-124 and CDH2 for human lung cancer.

Field of study: Biology, Chemistry
Socioeconomic impacts of marine protected areas in the Mediterranean and Black Seas

The socioeconomic implications of Marine Protected Areas (MPAs) and perceptions of stakeholders on MPA impacts are important to consider when designing, implementing, and managing MPAs. However, the currently available knowledge about these areas and especially of stakeholder perceptions is scarce and limited to restricted geographic areas. The present study aims to address this gap by examining these factors in the Mediterranean and Black Seas using an extensive literature review and an online survey approach. We collated and examined a total of 208 published studies on socioeconomic impacts of MPAs and marine uses. We found that for fishing, the socioeconomic impacts of MPAs were generally perceived as negative for industrial fishing and positive for artisanal fishing. In the online survey, we collected ca. 100 responses and found that stakeholder perceptions on the impacts of MPAs differ across sectors and regions. Industrial fishing was perceived as being negatively impacted in the Black Sea, while most respondents from the Mediterranean Sea were neutral in their responses relating industrial fishing and MPAs. The impact of MPAs on artisanal and recreational fishing was generally viewed as neutral by respondents from the Black Sea, whereas most Mediterranean respondents indicated a positive impact of MPAs. We also found that perceptions of the major threats to MPAs differed across the Mediterranean and the Black Sea. Responses from the Black Sea were systematically shifted towards a more negative perception of threats to MPAs compared to those from the Mediterranean Sea. Illegal fishing and other illegal activities were considered to be the most relevant threats to MPAs by stakeholders in both regions. The mismatch found between evidence of MPA effectiveness and impacts from the scientific literature and the results of our survey suggests that within the framework of maritime spatial planning and ecosystem-based management, effective MPA planning should be informed by multiple sources across regions.

Field of study: Environmental science
Reinforced Concrete Plates under Impact Load—Damage Quantification

A large number of impact experiments have been carried out at the Technische Universität Dresden in recent years in several research projects. The focus was on reinforced concrete plates on the one hand and on subsequently strengthened reinforced concrete plates on the other hand. Based on these investigations, two fundamental tasks arose: (1) finding an objective description of the damage of components made of steel reinforced concrete that had previously been subjected to an impact load and (2) quantification of the effect of a subsequently applied strengthening layer. In this paper we will focus on both. At first, the experimental conditions and program as well as the used drop tower facility at the Otto Mohr Laboratory of the Technische Universität Dresden are briefly explained. In the summary presentation of the main test results, the focus is on the observed component damage. Based on the observations, an approach for a damage description is presented. To define global damage, the stiffness of the investigated structural components before and after the impact event is used. At the end of the paper, the potential of the method, but also gaps in knowledge and research needs are discussed.

Field of study: Materials science
Effect of Electric Field on the Wetting Behavior of Eutectic Gallium–Indium Alloys in Aqueous Environment

Room-temperature liquid metals have many intriguing properties that have not previously been fully understood. Among them, surface tension behaviors of such metals are especially critical in a group of newly emerging areas such as printed electronics, functional materials and soft machines, etc. This study is dedicated to clarifying the wettability of liquid metals on various substrate surfaces with varied roughness immersed in solutions when subject to an electric field. The contact angles of Ga75.5In24.5 in several typical liquids were comprehensively measured and interpreted, and were revealed to be affected by the components and concentration of the environmental solution. Meanwhile, the roughness of the substrates is also revealed to be an important parameter dominating the process. The dynamic wetting behaviors of liquid metal in aqueous environment under an electric field were quantified. The contact angle values of eutectic gallium–indium alloys (eGaIn) on titanium substrates with different roughness would lead to better electrowetting performances on rougher surfaces. In particular, using an electrical field to control the wetting status of liquid metal with the matching substrate have been illustrated, which would offer a practical way to flexibly control liquid metal-based functional devices working in an aqueous environment. Furthermore, Lippmann–Young’s equation reveals the relationship between contact angle and applied voltage, explaining the excellent electrowetting property of eGaIn. The power law, R = αtβ, was adopted to characterize the two-stage wetting process of eGaIn under different voltages. In the initial process, β ≈ 1/2 represents the complete wetting law, while the later one, β ≈ 1/10, meets with Tanner’s law of a drop spontaneously spreading on a smooth surface.

Field of study: Materials science
CALCULATION OF SIZE-BASED TEMPERATURE RISE AT THE INTERFACE OF PARTICLES CAUSED BY FRICTION IN EXPLOSIVE CONSOLIDATION OF POWDERS

An oblique impaction model of two parallel plates is proposed to study the frictional effect between particles in explosive consolidation of powders. The change tendence of the friction between particles with the change of temperature is analyzed and the time for hole compaction is investigated using LS-DYNA program. The temperature rise at the interface of particles caused by the thermo-force coupled friction is calculated by integration. Size effect is considered during the calculation and the effective critical size is given. Results show that temperature rise increases as the particle size or shock pressure increases. For micron-scale to nanon-scale particles, temperature at the interfaces can reach the melting point only if the size and shock pressure are large enough.

Field of study: Engineering