The study of systems and methods for scientometric analysis of scientific publications

This paper provides an overview of the methods and systems that are applied for scientometric analysis of scientific publications. Methods to identify promising research directions are described. The results of an experimental study aimed at determining the directions of scientific research within the subject area of “regenerative medicine” by using various methods are presented. Conclusions are made about the prospects and shortcomings of the applied methods. Directions for further research are proposed.     

The use of economic classifiers for the indexing of scientific publications

The experience from the application of the OKVED 2 economic classifier for indexing scientific publications is considered. More than 9500 articles on the subject of “Automation. Computer Engineering” in authoritative Russian magazines were the material for the study. Some means for the comparative analysis of economic statistics and results of the classification of scientific publications are shown.     

Adolescents and Movie Ratings: Is Psychological Reactance a Theoretical Explanation for the Forbidden Fruit Effect?

Adolescents were recruited to participate in an experiment to assess whether psychological reactance can provide a theoretical explanation for the forbidden fruit effect in the context of movie rating restrictions. In addition to examining if movie ratings served as antecedents to freedom threat perceptions, we investigated the role authoritarian parents had on freedom threat perception and reactance arousal. Results indicated that a movie with an NC-17 rating was perceived as a stronger freedom threat than R and PG-13 rated movies. Interestingly, adolescents who perceived their parents to be authoritarian were less likely to view movie ratings as a freedom threat. As expected, freedom threat perceptions were positively associated with psychological reactance. Reactance, in turn, was positively associated with both first and third person attitudes. The results are discussed with an emphasis on the theoretical and practical implications of the findings.     

Gay On-Screen: The Relationship Between Exposure to Gay Characters on Television and Heterosexual Audiences' Endorsement of Gay Equality

The current study, grounded in the parasocial contact hypothesis, employed a survey of emerging adults to investigate the relationship between exposure to gay characters on television and heterosexuals' endorsement of gay equality. A positive relationship existed between exposure to on-screen gay characters and gay equality endorsement. The relationship was stronger for racial minority participants than for White participants, and for participants who had no or few interpersonal relationships with openly gay individuals than for participants who had more than three respective relationships. Results are discussed in terms of the parasocial contact hypothesis and television as an agent of social change.     

Shifting the Perspective of the Research Librarian: A CoResearch Paradigm

This article proposes the coresearch engagement model (CoRE), which addresses how the academic research librarian can become a coresearch partner with any patron. The CoRE model is an interpersonal process and is founded upon the concepts of mutual respect, collaboration, reciprocity, and empowerment. Grounded in Howard Gardner’s multiple intelligences theory, Malcolm Knowles’ andragogical model, and guidelines from the Reference and User Services Association, CoRE has the potential to result in engagement for the librarian and patron. The CoRE model can be utilized in many ways including self-awareness and development for those who need and want to expand their abilities as a research librarian. It provides a theoretical framework and a knowledge base, in addition to giving a context for further development by expanding, comparing the related theories for further research, and implementing various applications suggested by this article.     

Thermally multiplexed polymerase chain reaction

Amplification of multiple unique genetic targets using the polymerase chain reaction (PCR) is commonly required in molecular biology laboratories. Such reactions are typically performed either serially or by multiplex PCR. Serial reactions are time consuming, and multiplex PCR, while powerful and widely used, can be prone to amplification bias, PCR drift, and primer-primer interactions. We present a new thermocycling method, termed thermal multiplexing, in which a single heat source is uniformly distributed and selectively modulated for independent temperature control of an array of PCR reactions. Thermal multiplexing allows amplification of multiple targets simultaneously—each reaction segregated and performed at optimal conditions. We demonstrate the method using a microfluidic system consisting of an infrared laser thermocycler, a polymer microchip featuring 1 μl, oil-encapsulated reactions, and closed-loop pulse-width modulation control. Heat transfer modeling is used to characterize thermal performance limitations of the system. We validate the model and perform two reactions simultaneously with widely varying annealing temperatures (48 °C and 68 °C), demonstrating excellent amplification. In addition, to demonstrate microfluidic infrared PCR using clinical specimens, we successfully amplified and detected both influenza A and B from human nasopharyngeal swabs. Thermal multiplexing is scalable and applicable to challenges such as pathogen detection where patients presenting non-specific symptoms need to be efficiently screened across a viral or bacterial panel.     

Enhanced single-cell printing by acoustophoretic cell focusing

Recent years have witnessed a strong trend towards analysis of single-cells. To access and handle single-cells, many new tools are needed and have partly been developed. Here, we present an improved version of a single-cell printer which is able to deliver individual single cells and beads encapsulated in free-flying picoliter droplets at a single-bead efficiency of 96% and with a throughput of more than 10 beads per minute. By integration of acoustophoretic focusing, the cells could be focused in x and y direction. This way, the cells were lined-up in front of a 40 μm nozzle, where they were analyzed individually by an optical system prior to printing. In agreement with acoustic simulations, the focusing of 10 μm beads and Raji cells has been achieved with an efficiency of 99% (beads) and 86% (Raji cells) to a 40 μm wide center region in the 1 mm wide microfluidic channel. This enabled improved optical analysis and reduced bead losses. The loss of beads that ended up in the waste (because printing them as single beads arrangements could not be ensured) was reduced from 52% ± 6% to 28% ± 1%. The piezoelectric transducer employed for cell focusing could be positioned on an outer part of the device, which proves the acoustophoretic focusing to be versatile and adaptable.     

Disrupting the wall accumulation of human sperm cells by artificial corrugation

Many self-propelled microorganisms are attracted to surfaces. This makes their dynamics in restricted geometries very different from that observed in the bulk. Swimming along walls is beneficial for directing and sorting cells, but may be detrimental if homogeneous populations are desired, such as in counting microchambers. In this work, we characterize the motion of human sperm cells ∼60 μm long, strongly confined to ∼25 μm shallow chambers. We investigate the nature of the cell trajectories between the confining surfaces and their accumulation near the borders. Observed cell trajectories are composed of a succession of quasi-circular and quasi-linear segments. This suggests that the cells follow a path of intermittent trappings near the top and bottom surfaces separated by stretches of quasi-free motion in between the two surfaces, as confirmed by depth resolved confocal microscopy studies. We show that the introduction of artificial petal-shaped corrugation in the lateral boundaries removes the tendency of cells to accumulate near the borders, an effect which we hypothesize may be valuable for microfluidic applications in biomedicine.     

Microfluidic sampling system for tissue analytics

We have developed a microfluidics based sampling system for tissue analytics. The proof-of-concept of the sampling system was demonstrated by extracting lipid samples from tissue biopsies. The sample collection system consists of a disposable silicon based multiport microneedle integrated with polymer microfluidics. The polymethyl methacrylate polymer microfluidic chip has a 10 μl sample reservoir and actuation membranes for liquid pumping. A special automated robotic system was developed to control the positioning of the needle and the sampling procedure on preselected spots on the tissue. Real breast cancer tissue samples were used to test the feasibility of the sampling system. We successfully measured indicative cancer biomarkers from the tissue surface. Phosphatidylcholine and phosphoethanolamine were extracted from the tissue membrane with methyl tert-butyl ether solvent and detected by mass spectrometry. In the future, this tool could be used in characterization of preoperative biopsies and tumour tissues removed during surgery.     

Robust fluidic connections to freestanding microfluidic hydrogels

Biomimetic scaffolds approaching physiological scale, whose size and large cellular load far exceed the limits of diffusion, require incorporation of a fluidic means to achieve adequate nutrient/metabolite exchange. This need has driven the extension of microfluidic technologies into the area of biomaterials. While construction of perfusable scaffolds is essentially a problem of microfluidic device fabrication, functional implementation of free-standing, thick-tissue constructs depends upon successful integration of external pumping mechanisms through optimized connective assemblies. However, a critical analysis to identify optimal materials/assembly components for hydrogel substrates has received little focus to date. This investigation addresses this issue directly by evaluating the efficacy of a range of adhesive and mechanical fluidic connection methods to gelatin hydrogel constructs based upon both mechanical property analysis and cell compatibility. Results identify a novel bioadhesive, comprised of two enzymatically modified gelatin compounds, for connecting tubing to hydrogel constructs that is both structurally robust and non-cytotoxic. Furthermore, outcomes from this study provide clear evidence that fluidic interconnect success varies with substrate composition (specifically hydrogel versus polydimethylsiloxane), highlighting not only the importance of selecting the appropriately tailored components for fluidic hydrogel systems but also that of encouraging ongoing, targeted exploration of this issue. The optimization of such interconnect systems will ultimately promote exciting scientific and therapeutic developments provided by microfluidic, cell-laden scaffolds.