scholarly journals Smart Composite Hydrogels with pH-Responsiveness and Electrical Conductivity for Flexible Sensors and Logic Gates

Polymers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1564 ◽  
Author(s):  
Tong Wang ◽  
Xuan Zhang ◽  
Zichao Wang ◽  
Xiuzhong Zhu ◽  
Jie Liu ◽  
...  
Keyword(s):  
Environmental Changes ◽  
Logic Gates ◽  
Body Motion ◽  
Smart Composite ◽  
Stimuli Responsive ◽  
Ph Responsive ◽  
Flexible Sensors ◽  
Intelligent Analysis ◽  
Wide Range ◽  
Conductive Hydrogels

Stimuli-responsive conductive hydrogels have a wide range of applications due to their intelligent sensing of external environmental changes, which are important for smart switches, soft robotics, and flexible sensors. However, designing stimuli-responsive conductive hydrogels with logical operation, such as smart switches, remains a challenge. In this study, we synthesized pH-responsive conductive hydrogels, based on the copolymer network of acrylic acid and hydroxyethyl acrylate doped with graphene oxide. Using the good flexibility and conductivity of these hydrogels, we prepared a flexible sensor that can realize the intelligent analysis of human body motion signals. Moreover, the pH-responsive conductive hydrogels were integrated with temperature-responsive conductive hydrogels to develop logic gates with sensing, analysis, and driving functions, which realized the intellectualization of conductive hydrogels.

Highly sensitive gating in pH-responsive nanochannels as a result of ionic bridging and nanoconfinement

2018 ◽  
Author(s):  
Luis G. Lopez ◽  
Rikkert J. Nap
Keyword(s):  
Microphase Separation ◽  
Logic Gates ◽  
Ion Concentration ◽  
Molecular Organization ◽  
Bulk Solution ◽  
Dependent Manner ◽  
Stimuli Responsive ◽  
Ph Responsive ◽  
Concentration Dependent Manner ◽  
Ph Responsive Polymers

Sensitive switching between OFF and ON states is a desirable feature in stimuli-responsive nanopores and nanochannels. In this work, we show that nanogates modified with weak polyelectrolytes can be controlled by multivalent counterions and, more remarkably, can exhibit sensitive pH-gating due to an interplay between ionic bridging and nanoconfinement. We demonstrate these general features by systematically studying the effects of Ca2+ binding on the molecular organization and transport properties of poly(acrylic acid)-functionalized nanochannels. To this end, we extend and apply a molecular theory that has been successfully used in the past to describe and predict the behavior of pH-responsive polymers. Two main results emerge from the present study: First, the addition of Ca2+ to the bulk solution changes—in a concentration-dependent manner—both the ionization and structural state of the end-tethered polymers, affecting, respectively, the ionic conductivity and physical opening of the nanochannel. Second, in the presence of Ca2+ and under specific nanoconfinement conditions, the grafted channel can exhibit a sensitive response to pH in the transition between closed and open states. We attribute this sensitivity to bistability in the system. Our results also indicate that the polymer layer can undergo a microphase separation when the brush collapses on the nanochannel walls. Taken together, these findings suggest the possibility of designing nanogates that can respond to marginal changes in pH or multivalent ion concentration. Such nanodevices may be used as logic gates or for any application that requires a sensitive control over the ions, molecules, or nanoparticles flowing through them.

Highly sensitive gating in pH-responsive nanochannels as a result of ionic bridging and nanoconfinement

2018 ◽  
Author(s):  
Luis G. Lopez ◽  
Rikkert J. Nap
Keyword(s):  
Microphase Separation ◽  
Logic Gates ◽  
Ion Concentration ◽  
Molecular Organization ◽  
Bulk Solution ◽  
Dependent Manner ◽  
Stimuli Responsive ◽  
Ph Responsive ◽  
Concentration Dependent Manner ◽  
Ph Responsive Polymers

Sensitive switching between OFF and ON states is a desirable feature in stimuli-responsive nanopores and nanochannels. In this work, we show that nanogates modified with weak polyelectrolytes can be controlled by multivalent counterions and, more remarkably, can exhibit sensitive pH-gating due to an interplay between ionic bridging and nanoconfinement. We demonstrate these general features by systematically studying the effects of Ca2+ binding on the molecular organization and transport properties of poly(acrylic acid)-functionalized nanochannels. To this end, we extend and apply a molecular theory that has been successfully used in the past to describe and predict the behavior of pH-responsive polymers. Two main results emerge from the present study: First, the addition of Ca2+ to the bulk solution changes—in a concentration-dependent manner—both the ionization and structural state of the end-tethered polymers, affecting, respectively, the ionic conductivity and physical opening of the nanochannel. Second, in the presence of Ca2+ and under specific nanoconfinement conditions, the grafted channel can exhibit a sensitive response to pH in the transition between closed and open states. We attribute this sensitivity to bistability in the system. Our results also indicate that the polymer layer can undergo a microphase separation when the brush collapses on the nanochannel walls. Taken together, these findings suggest the possibility of designing nanogates that can respond to marginal changes in pH or multivalent ion concentration. Such nanodevices may be used as logic gates or for any application that requires a sensitive control over the ions, molecules, or nanoparticles flowing through them.

scholarly journals Using green emitting pH-responsive nanogels to report environmental changes within hydrogels: a nanoprobe for versatile sensing

Nanoscale ◽  
2019 ◽  
Vol 11 (24) ◽  
pp. 11484-11495 ◽  
Author(s):  
Mingning Zhu ◽  
Dongdong Lu ◽  
Shanglin Wu ◽  
Qing Lian ◽  
Wenkai Wang ◽  
...  
Keyword(s):  
Stem Cells ◽  
Tensile Strain ◽  
Environmental Changes ◽  
Stimuli Responsive ◽  
Ph Responsive ◽  
Low Concentrations ◽  
Green Fluorescent

Low concentrations of new stimuli-responsive blue-green-fluorescent nanogel probes within four different gels and stem cells reversibly report five different stimuli: cations, degradation, pH, temperature and tensile strain.

scholarly journals Thermo- and Photoresponsive Behaviors of Dual-Stimuli-Responsive Organogels Consisting of Homopolymers of Coumarin-Containing Methacrylate

Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 329
Author(s):  
Seidai Okada ◽  
Eriko Sato
Keyword(s):  
Functional Group ◽  
Solution Temperature ◽  
Stimuli Responsive ◽  
Critical Solution Temperature ◽  
Equilibrium Degree ◽  
Stimuli Responsive Polymers ◽  
Responsive Polymers ◽  
Dual Functional ◽  
Wide Range ◽  
Increasing Temperature

Coumarin-containing vinyl homopolymers, such as poly(7-methacryloyloxycoumarin) (P1a) and poly(7-(2′-methacryloyloxyethoxy)coumarin) (P1b), show a lower critical solution temperature (LCST) in chloroform, which can be controlled by the [2 + 2] photochemical cycloaddition of the coumarin moiety, and they are recognized as monofunctional dual-stimuli-responsive polymers. A single functional group of monofunctional dual-stimuli-responsive polymers responds to dual stimuli and can be introduced more uniformly and densely than those of dual-functional dual-stimuli-responsive polymers. In this study, considering a wide range of applications, organogels consisting of P1a and P1b, i.e., P1a-gel and P1b-gel, respectively, were synthesized, and their thermo- and photoresponsive behaviors in chloroform were investigated in detail. P1a-gel and P1b-gel in a swollen state (transparent) exhibited phase separation (turbid) through a temperature jump and reached a shrunken state (transparent), i.e., an equilibrium state, over time. Moreover, the equilibrium degree of swelling decreased non-linearly with increasing temperature. Furthermore, different thermoresponsive sites were photopatterned on the organogel through the photodimerization of the coumarin unit. The organogels consisting of homopolymers of coumarin-containing methacrylate exhibited unique thermo- and photoresponsivities and behaved as monofunctional dual-stimuli-responsive organogels.

scholarly journals Identification of Putative Virulence Genes by DNA Methylation Studies in the Cereal Pathogen Fusarium graminearum

Cells ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1192
Author(s):  
Francesco Tini ◽  
Giovanni Beccari ◽  
Gianpiero Marconi ◽  
Andrea Porceddu ◽  
Micheal Sulyok ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Fusarium Graminearum ◽  
Environmental Changes ◽  
Virulent Strain ◽  
Fungal Virulence ◽  
Wheat Seedlings ◽  
Wide Range ◽  
Conidia Production ◽  
Natural Hosts

DNA methylation mediates organisms’ adaptations to environmental changes in a wide range of species. We investigated if a such a strategy is also adopted by Fusarium graminearum in regulating virulence toward its natural hosts. A virulent strain of this fungus was consecutively sub-cultured for 50 times (once a week) on potato dextrose agar. To assess the effect of subculturing on virulence, wheat seedlings and heads (cv. A416) were inoculated with subcultures (SC) 1, 23, and 50. SC50 was also used to re-infect (three times) wheat heads (SC50×3) to restore virulence. In vitro conidia production, colonies growth and secondary metabolites production were also determined for SC1, SC23, SC50, and SC50×3. Seedling stem base and head assays revealed a virulence decline of all subcultures, whereas virulence was restored in SC50×3. The same trend was observed in conidia production. The DNA isolated from SC50 and SC50×3 was subject to a methylation content-sensitive enzyme and double-digest, restriction-site-associated DNA technique (ddRAD-MCSeEd). DNA methylation analysis indicated 1024 genes, whose methylation levels changed in response to the inoculation on a healthy host after subculturing. Several of these genes are already known to be involved in virulence by functional analysis. These results demonstrate that the physiological shifts following sub-culturing have an impact on genomic DNA methylation levels and suggest that the ddRAD-MCSeEd approach can be an important tool for detecting genes potentially related to fungal virulence.

scholarly journals Microglial Pruning: Relevance for Synaptic Dysfunction in Multiple Sclerosis and Related Experimental Models

Cells ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 686
Author(s):  
Maria Concetta Geloso ◽  
Nadia D’Ambrosi
Keyword(s):  
Multiple Sclerosis ◽  
Neuronal Death ◽  
Environmental Changes ◽  
Experimental Models ◽  
Synaptic Dysfunction ◽  
Synapse Elimination ◽  
Neurodegenerative Process ◽  
Immune Mediated ◽  
Wide Range ◽  
Demyelinating Lesions

Microglia, besides being able to react rapidly to a wide range of environmental changes, are also involved in shaping neuronal wiring. Indeed, they actively participate in the modulation of neuronal function by regulating the elimination (or “pruning”) of weaker synapses in both physiologic and pathologic processes. Mounting evidence supports their crucial role in early synaptic loss, which is emerging as a hallmark of several neurodegenerative diseases, including multiple sclerosis (MS) and its preclinical models. MS is an inflammatory, immune-mediated pathology of the white matter in which demyelinating lesions may cause secondary neuronal death. Nevertheless, primitive grey matter (GM) damage is emerging as an important contributor to patients’ long-term disability, since it has been associated with early and progressive cognitive decline (CD), which seriously worsens the quality of life of MS patients. Widespread synapse loss even in the absence of demyelination, axon degeneration and neuronal death has been demonstrated in different GM structures, thus raising the possibility that synaptic dysfunction could be an early and possibly independent event in the neurodegenerative process associated with MS. This review provides an overview of microglial-dependent synapse elimination in the neuroinflammatory process that underlies MS and its experimental models.

Soft stimuli-responsive grippers and machines with high load-to-weight ratios

2019 ◽  
Vol 6 (1) ◽  
pp. 160-168 ◽  
Author(s):  
Yajuan Sun ◽  
Linfeng Chen ◽  
Yan Jiang ◽  
Xuan Zhang ◽  
Xiukai Yao ◽  
...  
Keyword(s):  
General Class ◽  
High Load ◽  
Stimuli Responsive ◽  
Ph Responsive

A general class of stimuli-responsive grippers and actuators (e.g., temperature- and pH-responsive) with surprisingly high gripping strengths is introduced.

scholarly journals Enhancing the resilience of coupled human and natural systems of alpine rangelands on the Qinghai-Tibetan Plateau

2015 ◽  
Vol 37 (1) ◽  
pp. i ◽  
Author(s):  
Shikui Dong ◽  
Ruth Sherman
Keyword(s):  
Tibetan Plateau ◽  
Science Policy ◽  
Sustainable Management ◽  
Environmental Changes ◽  
Policy Design ◽  
Rangeland Management ◽  
Special Issue ◽  
Natural Systems ◽  
Wide Range ◽  
Science Policy Interface

This special issue covers a wide range of topics on the protection and sustainable management of alpine rangelands on the Qinghai-Tibetan Plateau (QTP), including Indigenous knowledge of sustainable rangeland management, science-policy interface for alpine rangeland biodiversity conservation, adaptations of local people to social and environmental changes and policy design for managing coupled human-natural systems of alpine rangelands.

The Research and Application of Artificial Intelligence in the Field of Intelligent Robot

2014 ◽  
Vol 898 ◽  
pp. 763-766
Author(s):  
Zhi Hao Li
Keyword(s):  
Artificial Intelligence ◽  
Environmental Changes ◽  
Vision System ◽  
Mineral Exploration ◽  
Intelligent Robot ◽  
Application Range ◽  
Intelligent Robots ◽  
External Data ◽  
Wide Range ◽  
Artificial Intelligence Application

The research and application of artificial intelligence has a very wide range in intelligent robot field. Intelligent robot can not only make use of artificial intelligence gain access to external data, information, (such as stereo vision system, face recognition and tracking, etc.), and then deal with it so as to exactly describe external environment, and complete a task independently, owing the ability of learning knowledge, but also have self-many kinds of artificial intelligence like judgment and decision making, processing capacity and so on. It can make corresponding decision according to environmental changes. Its application range is expanding. In deep sea exploration, star exploration, mineral exploration, heavy pollution, domestic service, entertainment clubs, health care and so on, the figure of intelligent robots artificial intelligence application can all be seen.

scholarly journals High strength and conductive hydrogel with fully interpenetrated structure from alginate and acrylamide

e-Polymers ◽  
2021 ◽  
Vol 21 (1) ◽  
pp. 391-397
Author(s):  
Tao Liu ◽  
Ripeng Zhang ◽  
Jianzhi Liu ◽  
Ling Zhao ◽  
Yueqin Yu
Keyword(s):  
Mechanical Performance ◽  
Three Dimensional ◽  
High Strength ◽  
Extreme Environment ◽  
Natural Polymers ◽  
Conductive Hydrogel ◽  
Wide Range ◽  
Interpenetrated Structure ◽  
Conductive Hydrogels ◽  
Conductive Properties

Abstract Highly stretched and conductive hydrogels, especially synthetized from natural polymers, are beneficial for highly stretched electronic equipment which is applied in extreme environment. We designed and prepared robust and tough alginate hydrogels (GMA-SA-PAM) using the ingenious strategy of fully interpenetrating cross-linking, in which the glycidyl methacrylate (GMA) was used to modify sodium alginate (SA) and then copolymerized with acrylamide (AM) and methylenebisacrylamide (BIS) as cross-linkers. The complete cross-linked structures can averagely dissipate energy and the polymer structures can maintain hydrogels that are three-dimensional to greatly improve the mechanical performance of hydrogels. The GMA-SA-PAM hydrogels display ultra-stretchable (strain up to ∼407% of tensile strain) and highly compressible (∼57% of compression strain) properties. In addition, soaking the GMA-SA-PAM hydrogel in 5 wt% NaCl solution also endows the conductivity of the hydrogel (this hydrogel was named as GSP-Na) with excellent conductive properties (5.26 S m−1). The GSP-Na hydrogel with high stability, durability, as well as wide range extent sensor is also demonstrated by researching the electrochemical signals and showing the potential for applications in wearable and quickly responded electronics.

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