Self-Healing Mechanism and Conductivity of the Hydrogel Flexible Sensors: A Review

Sensors are devices that can capture changes in environmental parameters and convert them into electrical signals to output, which are widely used in all aspects of life. Flexible sensors, sensors made of flexible materials, not only overcome the limitations of the environment on detection devices but also expand the application of sensors in human health and biomedicine. Conductivity and flexibility are the most important parameters for flexible sensors, and hydrogels are currently considered to be an ideal matrix material due to their excellent flexibility and biocompatibility. In particular, compared with flexible sensors based on elastomers with a high modulus, the hydrogel sensor has better stretchability and can be tightly attached to the surface of objects. However, for hydrogel sensors, a poor mechanical lifetime is always an issue. To address this challenge, a self-healing hydrogel has been proposed. Currently, a large number of studies on the self-healing property have been performed, and numerous exciting results have been obtained, but there are few detailed reviews focusing on the self-healing mechanism and conductivity of hydrogel flexible sensors. This paper presents an overview of self-healing hydrogel flexible sensors, focusing on their self-healing mechanism and conductivity. Moreover, the advantages and disadvantages of different types of sensors have been summarized and discussed. Finally, the key issues and challenges for self-healing flexible sensors are also identified and discussed along with recommendations for the future.

Propolis-Based Nanofiber Patches to Repair Corneal Microbial Keratitis

In this research, polyvinyl-alcohol (PVA)/gelatin (GEL)/propolis (Ps) biocompatible nanofiber patches were fabricated via electrospinning technique. The controlled release of Propolis, surface wettability behaviors, antimicrobial activities against the S. aureus and P. aeruginosa, and biocompatibility properties with the mesenchymal stem cells (MSCs) were investigated in detail. By adding 0.5, 1, and 3 wt.% GEL into the 13 wt.% PVA, the morphological and mechanical results suggested that 13 wt.% PVA/0.5 wt.% GEL patch can be an ideal matrix for 3 and 5 wt.% propolis addition. Morphological results revealed that the diameters of the electrospun nanofiber patches were increased with GEL (from 290 nm to 400 nm) and Ps addition and crosslinking process cause the formation of thicker nanofibers. The tensile strength and elongation at break enhancement were also determined for 13 wt.% PVA/0.5 wt.% GEL/3 wt.% Ps patch. Propolis was released quickly in the first hour and arrived at a plateau. Cell culture and contact angle results confirmed that the 3 wt.% addition of propolis reinforced mesenchymal stem cell proliferation and wettability properties of the patches. The antimicrobial activity demonstrated that propolis loaded patches had antibacterial activity against the S. aureus, but for P. aeruginosa, more studies should be performed.

Emerging Role of Neutrophils in the Thrombosis of Chronic Myeloproliferative Neoplasms

Thrombosis is a major cause of morbimortality in patients with chronic Philadelphia chromosome-negative myeloproliferative neoplasms (MPN). In the last decade, multiple lines of evidence support the role of leukocytes in thrombosis of MPN patients. Besides the increase in the number of cells, neutrophils and monocytes of MPN patients show a pro-coagulant activated phenotype. Once activated, neutrophils release structures composed of DNA, histones, and granular proteins, called extracellular neutrophil traps (NETs), which in addition to killing pathogens, provide an ideal matrix for platelet activation and coagulation mechanisms. Herein, we review the published literature related to the involvement of NETs in the pathogenesis of thrombosis in the setting of MPN; the effect that cytoreductive therapies and JAK inhibitors can have on markers of NETosis, and, finally, the novel therapeutic strategies targeting NETs to reduce the thrombotic complications in these patients.

Application of Gold Silica Nanocomposites in Electrochemical Biosensors: A Review

Gold silica nanocomposite-based biosensors are performing well in sensor technology for biosensor development. Due to this biosensor has good selectivity, excellent conductivity, large surface area, efficient enhancement of electron transfer between enzymes and electrodes and good biocompatibility. Therefore, gold silica nanocomposite can be an ideal matrix for immobilization of biomolecules. This review describes the method of synthesizing gold silica nanocomposites and their characterization, interaction with biomolecules and application of gold silica nanocomposites in electrochemical biosensors.

Microbial, Physiochemical and Sensory Properties of Bael (Aegle marmelos) Incorporated Buffalo Milk Yoghurt Containing Lb. rhamnosus GG

Recently, there is a trend among food manufacturers in producing functional foods containing fruit and milk. On the other hand, there is an increasing demand for buffalo milk as an alternative to cow milk. Therefore, the aim of this study was to investigate the impact of adding bael fruit extract on microbial, physiochemical and sensory characteristics of buffalo yoghurt containing the EPS-producing probiotic Lactobacillus rhamnosus GG (LGG) during 21 days of refrigerated storage. Four formulations of buffalo yoghurt: a control yoghurt manufactured with conventional yoghurt culture (CON); a probiotic yoghurt containing Lb. rhamnosus GG plus yoghurt culture (PY); a probiotic yoghurt containing 5% (w/v) bael (PY5); and 10% (w/v) bael (PY10) were evaluated for changes in pH, syneresis, hardness, probiotic viability and sensory attributes during the storage. Control yoghurt experienced significant post acidification and a higher rate of syneresis. Addition of probiotics had a positive effect on post acidification and syneresis rate. Addition of bael did not affect post-acidification, but significantly decreased the level of syneresis. All probiotic formulations maintained LGG counts of >107 cfu/mL and the highest counts were observed in 5% (w/v) bael incorporated yoghurt. Results showed that buffalo yoghurt is an ideal matrix to deliver LGG and 5% bael incorporation would be ideal or symbiotic product development.

Whole blood or plasma: what is the ideal matrix for pharmacokinetic-driven drug candidate selection?

In the present era of drug development, quantification of drug concentrations following pharmacokinetic studies has preferentially been performed using plasma as a matrix rather than whole blood. However, it is critical to realize the difference between measuring drug concentrations in blood versus plasma and the consequences thereof. Pharmacokinetics using plasma data may be misleading if concentrations differ between plasma and red blood cells (RBCs) because of differential binding in blood. In this review, factors modulating the partitioning of drugs into RBCs are discussed and the importance of determining RBC uptake of drugs for drug candidate selection is explored. In summary, the choice of matrix (plasma vs whole blood) is an important consideration to be factored in during drug discovery.

Cryoconite: an efficient accumulator of radioactive fallout in glacial environments

Cryoconite is rich in natural and artificial radioactivity, but a discussion about its ability to accumulate radionuclides is lacking. A characterization of cryoconite from two Alpine glaciers is presented here. Results confirm that cryoconite is significantly more radioactive than the matrices usually adopted for the environmental monitoring of radioactivity, such as lichens and mosses, with activity concentrations exceeding 10 000 Bq kg−1 for single radionuclides. This makes cryoconite an ideal matrix to investigate the deposition and occurrence of radioactive species in glacial environments. In addition, cryoconite can be used to track environmental radioactivity sources. We have exploited atomic and activity ratios of artificial radionuclides to identify the sources of the anthropogenic radioactivity accumulated in our samples. The signature of cryoconite from different Alpine glaciers is compatible with the stratospheric global fallout and Chernobyl accident products. Differences are found when considering other geographic contexts. A comparison with data from literature shows that Alpine cryoconite is strongly influenced by the Chernobyl fallout, while cryoconite from other regions is more impacted by events such as nuclear test explosions and satellite reentries. To explain the accumulation of radionuclides in cryoconite, the glacial environment as a whole must be considered, and particularly the interaction between ice, meltwater, cryoconite and atmospheric deposition. We hypothesize that the impurities originally preserved into ice and mobilized with meltwater during summer, including radionuclides, are accumulated in cryoconite because of their affinity for organic matter, which is abundant in cryoconite. In relation to these processes, we have explored the possibility of exploiting radioactivity to date cryoconite.

Interstícios Semióticos; o possível como um modo de ser: ferramentas para pesquisa em arte.

A prática da arte no contexto acadêmico e universitário requer a articulação de uma metodologia de pesquisa que possa dar conta de todos os aspectos do imaginário criativo. A partir de uma postura crítica sobre o modelo fundador de nossa epistemologia ocidental, este texto explora a ideia de que apenas a superação da dualidade razão / sensibilidade, em termos conceituais, permite a identificação de novos caminhos para a pesquisa em arte. E termina considerando a "semiose" de Charles Sanders Peirce como a matriz ideal para a abordagem cognitiva da criação artística.AbstractThe practice of art in the context of universities and academia requires the structuring of a research methodology that can encompass all aspects of imaginative creation. Starting with a critical position on the foundational model of our western epistemology, this text explores the idea that only overcoming the reason/sensibility duality in conceptual terms can we identify new avenues for research in art. It ends by considering Charles S. Peirce’s semiosis as an ideal matrix for a cognitive approach to artistic creation.

Atom-economical construction of carbon nanotube architectures for flexible supercapacitors with ultrahigh areal and volumetric capacities

Carbon nanotube nanoarrays were fabricated by a self-sustaining CVD method, which form an ideal matrix for supporting high mass-loading pseudocapacitance materials.

Phospholipid arrays on porous polymer coatings generated by micro-contact spotting

Nanoporous poly(2-hydroxyethyl methacrylate-co-ethylene dimethacrylate) (HEMA-EDMA) is used as a 3D mesh for spotting lipid arrays. Its porous structure is an ideal matrix for lipid ink to infiltrate, resulting in higher fluorescent signal intensity as compared to similar arrays on strictly 2D substrates like glass. The embedded lipid arrays show high stability against washing steps, while still being accessible for protein and antibody binding. To characterize binding to polymer-embedded lipids we have applied Streptavidin as well as biologically important biotinylated androgen receptor binding onto 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine-N-(cap biotinyl) (Biotinyl Cap PE) and anti-DNP IgE recognition of 2,4-dinitrophenyl[1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine-N-[6-[(2,4-dinitrophenyl)amino]hexanoyl] (DNP)] antigen. This approach adds lipid arrays to the range of HEMA polymer applications and makes this solid substrate a very attractive platform for a variety of bio-applications.