827 research outputs found
Asymmetric Information and R&D Disclosure: Evidence from Scientific Publications
Get PDFWe examine how asymmetric information in financial markets affects voluntary research and development (R&D) disclosure, considering scientific publications as a disclosure channel. Difference-in-differences regressions around brokerage house mergers and closures, which increase information asymmetry through reductions in analyst coverage, indicate a quick and sustained increase in scientific publications from treated firms relative to the number of publications from control firms. The treatment effects are concentrated among firms with higher information asymmetry and lower investor demand, firms with greater financial constraints, and firms with lower proprietary costs. We do not find evidence of changes in financial disclosure, nor do we find changes in patenting. Results from ordinary least squares regressions show that scientific publications by firms are positively associated with investor attention toward those firms. We complement these results with qualitative evidence from conference calls. Our results highlight the limitations and tradeoffs R&D firms face in their financial market disclosure policies
Infrared thermometers for small wires drawing
No full textThis work describes the design of two contactless thermometers based respectively on a
total radiance and two-color pyrometry scheme, developed to measure the temperature
of a small brass coated steel wire during wire drawing. In this critical condition, wire oscillation and relevant insertion errors do not allow using commercial contact or contactless
sensors. Thus, ad hoc pyrometers optical layouts have been designed in order to minimize
sensitivity to the wire oscillations and emissivity changes. Moreover, performances associated to different infrared detectors have been compared using as figure of merit the
achieved measurement uncertainty simulating typical disturbances, i.e. the background
temperature variation, the slope of the wire’s emissivity and the effect of the atmosphere
transmittance. Finally, the uncertainty budgets were drawn, evidencing the limitations of
the proposed methods and identifying the best configuration for both developed
instruments
Contactless temperature measurement of thin wires: methods comparison
No full textThis work describes the design of two contactless temperature measurement methods based on total radiance and two-colour pyrometry. The methods have been conceived to measure the temperature of a small brass coated steel wire during wire drawing. Usual contact sensors cannot be applied due to the wire movement and excessively large insertion errors in this critical condition. The pyrometers optical layouts have been analysed by means of numerical simulations in order to evidence their sensitivity to the wire oscillations. Performances of different infrared sensors have been compared on the basis of the achieved measurement uncertainty simulating background temperature variation, slope of the wire???s emissivity and the effect of the atmosphere absorption
3D bioprinting of cell-laden carbopol bioinks
Get PDFTraditional in vitro culture models are unable to fully reflect the organ microenvironment, due to differences in terms of cell morphology, protein expression, cell-cell and cell-matrix interactions, and drug response. In contrast, the flexibility of bioprinting modes allows for the deposition of cell-containing biomaterials in any free-form-inspired 3D structures on chip. The main purpose of this study was to design and optimize commercially available Carbopol-based 3D printing formulations, because of their many advantages, such as low-cost, the ability to produce clear and stable gels, and the water thickening. For this purpose, three different Carbopol gels (EDT 2020 NF, Ultrez 10 NF and NF-980) were tested in terms of printability and biocompatibility, with lung cancer epithelial (A549) and normal lung fibroblast (MRC-5) cells. This study demonstrates that Carbopol is a promising candidate for the 3D printing of cell-laden constructs, both in terms of rheology and printing performance
3D Cell Culture: Recent Development in Materials with Tunable Stiffness
Get PDFIt is widely accepted that three-dimensional cell culture systems simulate physiological conditions better than traditional 2D systems. Although extracellular matrix components strongly modulate cell behavior, several studies underlined the importance of mechanosensing in the control of different cell functions such as growth, proliferation, differentiation, and migration. Human tissues are characterized by different degrees of stiffness, and various pathologies (e.g., tumor or fibrosis) cause changes in the mechanical properties through the alteration of the extracellular matrix structure. Additionally, these modifications have an impact on disease progression and on therapy response. Hence, the development of platforms whose stiffness could be modulated may improve our knowledge of cell behavior under different mechanical stress stimuli. In this review, we have analyzed the mechanical diversity of healthy and diseased tissues, and we have summarized recently developed materials with a wide range of stiffness
Science Quality and the Value of Inventions
Get PDFDespite decades of research, the relationship between the quality of science and the value of inventions has remained unclear. We present the result of a large-scale matching exercise between 4.8 million patent families and 43 million publication records. We find a strong positive relationship between quality of scientific contributions referenced in patents and the value of the respective inventions. We rank patents by the quality of the science they are linked to. Strikingly, high-rank patents are twice as valuable as low-rank patents, which in turn are about as valuable as patents without direct science link. We show this core result for various science quality and patent value measures. The effect of science quality on patent value remains relevant even when science is linked indirectly through other patents. Our findings imply that what is considered “excellent” within the science sector also leads to outstanding outcomes in the technological or commercial realm
Phosphorylation-dependent degradation of MEF2C contributes to regulate G2/M transition
No full textThe Myocyte Enhancer Factor 2C (MEF2C) transcription factor plays a critical role in skeletal muscle differentiation, promoting muscle-specific gene transcription. Here we report that in proliferating cells MEF2C is degraded in mitosis by the Anaphase Promoting Complex/Cyclosome (APC/C) and that this downregulation is necessary for an efficient progression of the cell cycle. We show that this mechanism of degradation requires the presence on MEF2C of a D-box (R-X-X-L) and 2 phospho-motifs, pSer98 and pSer110. Both the D-box and pSer110 motifs are encoded by the ubiquitous alternate α1 exon. These two domains mediate the interaction between MEF2C and CDC20, a co-activator of APC/C. We further report that in myoblasts, MEF2C regulates the expression of G2/M checkpoint genes (14-3-3γ, Gadd45b and p21) and the sub-cellular localization of CYCLIN B1. The importance of controlling MEF2C levels during the cell cycle is reinforced by the observation that modulation of its expression affects the proliferation rate of colon cancer cells. Our findings show that beside the well-established role as pro-myogenic transcription factor, MEF2C can also function as a regulator of cell proliferation
Phosphorylation-dependent degradation of MEF2C contributes to regulate G2/m transition
Get PDFThe Myocyte Enhancer Factor 2C (MEF2C) transcription factor plays a critical role in skeletal muscle differentiation, promoting muscle-specific gene transcription. Here we report that in proliferating cells MEF2C is degraded in mitosis by the Anaphase Promoting Complex/Cyclosome (APC/C) and that this downregulation is necessary for an efficient progression of the cell cycle. We show that this mechanism of degradation requires the presence on MEF2C of a D-box (R-X-X-L) and 2 phospho-motifs, pSer98 and pSer110. Both the D-box and pSer110 motifs are encoded by the ubiquitous alternate alpha 1 exon. These two domains mediate the interaction between MEF2C and CDC20, a co-activator of APC/C. We further report that in myoblasts, MEF2C regulates the expression of G2/M checkpoint genes (14-3-3 gamma, Gadd45b and p21) and the sub-cellular localization of CYCLIN B1. The importance of controlling MEF2C levels during the cell cycle is reinforced by the observation that modulation of its expression affects the proliferation rate of colon cancer cells. Our findings show that beside the well-established role as pro-myogenic transcription factor, MEF2C can also function as a regulator of cell proliferation
Visible light-induced crosslinking of unmodified gelatin with PEGDA for DLP-3D printable hydrogels
No full textThe possibility to 3D shape hydrogels is attracting an enormous interest in the biomedical field both for their application as scaffold or for the design of new medical hydrogels. Digital light processing (DLP) printing can create layer-by-layer models with high resolution and printing speed. Herein, a hybrid natural-synthetic hydrogel is propsed using cold-water fish gelatin as innovative co-initiating species of a camphorquinone photo-initiator instead of the traditional aliphatic or aromatic amines, for the crosslinking of PEGDA monomer. Such system allows to chemically bound gelatin to the PEGDA monomer without any previous modification and leads to the production of DLP-3D printable hydrogels. The real-time photorheological measurements showed that Gelatin behave as a binder during photopolymerization and ATR-FTIR spectroscopy proved that gelatin segments were chemically incorporated within PEGDA network. Mechanical and biological properties were improved by increasing gelatin content. Furthermore, the 3D digital light processing of this material leads to the creation of precise and rapidly printed structures that are biocompatible and able to support cell viability and proliferation. Considering those features, the proposed hydrogel may be a promising candidate in 3D-printed devices for cell culture
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