Versatile Aerogels for Sensors Yang, Jing; Li, Yi; Zheng, Yuanyuan ...
Small (Weinheim an der Bergstrasse, Germany),
10/2019, Letnik:
15, Številka:
41
Journal Article
Recenzirano
Aerogels are unique solid‐state materials composed of interconnected 3D solid networks and a large number of air‐filled pores. They extend the structural characteristics as well as physicochemical ...properties of nanoscale building blocks to macroscale, and integrate typical characteristics of aerogels, such as high porosity, large surface area, and low density, with specific properties of the various constituents. These features endow aerogels with high sensitivity, high selectivity, and fast response and recovery for sensing materials in sensors such as gas sensors, biosensors and strain and pressure sensors, among others. Considerable research efforts in recent years have been devoted to the development of aerogel‐based sensors and encouraging accomplishments have been achieved. Herein, groundbreaking advances in the preparation, classification, and physicochemical properties of aerogels and their sensing applications are presented. Moreover, the current challenges and some perspectives for the development of high‐performance aerogel‐based sensors are summarized.
Aerogels have attracted tremendous attention as high‐performance sensing materials in gas sensors, biosensors, strain and pressure sensors, etc., due to their unique interconnected 3D highly porous network and the extension of physicochemical properties of nanoscale building blocks to macroscale. Here, considerable research efforts to develop aerogel and aerogel‐based sensors in recent years are reviewed.
Low‐cost, non‐noble‐metal electrocatalysts are required for direct methanol fuel cells, but their development has been hindered by limited activity, high onset potential, low conductivity, and poor ...durability. A surface electronic structure tuning strategy is presented, which involves doping of a foreign oxophilic post‐transition metal onto transition metal aerogels to achieve a non‐noble‐metal aerogel Ni97Bi3 with unprecedented electrocatalytic activity and durability in methanol oxidation. Trace amounts of Bi are atomically dispersed on the surface of the Ni97Bi3 aerogel, which leads to an optimum shift of the d‐band center of Ni, large compressive strain of Bi, and greatly increased conductivity of the aerogel. The electrocatalyst is endowed with abundant active sites, efficient electron and mass transfer, resistance to CO poisoning, and outstanding performance in methanol oxidation. This work sheds light on the design of high‐performance non‐noble‐metal electrocatalysts.
Bismuth doping reduces charge‐transfer resistance, creates a strained surface, and optimizes the d‐band center of porous NixBiy aerogels. The optimum benefits of the amorphous structure and abundant superficial oxygenated species are realized in a Ni97Bi3 aerogel, which demonstrates unprecedented electrocatalytic performance in methanol oxidation with both high activity and durability.
Plant architecture results from a balance of indeterminate and determinate cell fates. Cells with indeterminate fates are located in meristems, comprising groups of pluripotent cells that produce ...lateral organs. Meristematic cells are also found in intercalary stem tissue, which provides cells for internodes, and at leaf margins to contribute to leaf width. We identified a maize (Zea mays) mutant that has a defect in balancing determinacy and indeterminacy. The mutant has narrow leaves and short internodes, suggesting a reduction in indeterminate cells in the leaf and stem. In contrast, the mutants fail to control indeterminacy in shoot meristems. Inflorescence meristems are fasciated, and determinate axillary meristems become indeterminate. Positional cloning identified growth regulating factor-interacting factor1 (gif1) as the responsible gene. gif1 mRNA accumulates in distinct domains of shoot meristems, consistent with tissues affected by the mutation. We determined which GROWTH REGULATING FACTORs interact with GIF1 and performed RNA-seq analysis. Many genes known to play roles in inflorescence architecture were differentially expressed in gif1. Chromatin immunoprecipitation identified some differentially expressed genes as direct targets of GIF1. The interactions with these diverse direct and indirect targets help explain the paradoxical phenotypes of maize GIF1. These results provide insights into the biological functions of gif1.
How deep mantle processes affected plate interactions and the dynamics of deformation on both sides of the Paleo-Pacific has been a first order scientific challenge. The ubiquitous Early Cretaceous ...multiphase tectonic extensional structures in eastern Eurasia (EE) show marked contrasts to the episodic compressional structures in western North America (WNA), which provides convincing arguments linking deep and shallow tectonic processes.
Recent studies on Early Cretaceous tectonics in EE have shown that the continent is characterized by multiple phase of tectonic extension and weak compression, forming extensional structures in several major provinces in a vast area of ca. 3000 km × 3000 km. The peak tectonic extension occurred at 135–120 Ma, in addition to extensional episodes at pre- (160–145 Ma) and post-peak (120 Ma-) stages. Kinematic analysis reveals an identical NW-SE-oriented tectonic extension field for their formation. In addition, synextensional magmatism sourced from ancient and juvenile crust or lithospheric mantle was episodically active and peaked at ca. 160, 125 and 100–80 Ma, respectively. Particularly, a magmatic flare-up of extensional origin occurred at 125 ± 5 Ma in eastern China. In contrast, the WNA Cordillera displays a prolonged and episodic tectonic compression beginning ~170 Ma (Jurassic). Tectonic deformation involved the Nevadan, Sevier and Laramide orogenies from ca. 175 Ma, 125 Ma and 80 Ma, respectively, to form the Cordillera orogenic system. During the Nevadan orogeny intensive plate convergence from 154 to 150 Ma contributed to continental arc magmatism. The Sevier orogen is characterized by thin-skinned thrust sheets while the Laramide is dominated by shallow slab dip oceanic subduction and basement-core uplifts of Archean crust in the foreland. Significant sinistral strike-slip shearing at ~140–125 Ma is documented in the Early Cretaceous. Widespread crustal shortening and emplacement of major batholiths (magmatic flare-up) were contemporaneous with accretion of the high pressure-low temperature (blueschist) Franciscan Complex at ca. 125–100 Ma during the Sevier orogeny.
The EE extensional provinces constitute part of the retreating (Paleo-) Pacific-Eurasia subduction system, while crustal shortening along the WNA was resulted from the advancing Farallon-North America subduction system. Stratified mantle convection is needed, however, when taking the tectonic evolution of the continental margins and the mid-ocean range as an integral system of the evolving globe. Shallow-mantle convection contributed to subduction of oceanic plates, which resulted in Andean-type subduction zones on both sides of the Ocean at the early stage of subduction. Possibly from 160 Ma on, eastward deep mantle flow occurred, which induced migration of the shallow mantle convection systems. As a result, the west-dipping Paleo-Pacific slabs became steepened, stagnated and subsequently folded in the mantle transition zone, while the shallow part of the east-dipping Farallon slab became flattened, and its deep part subsequently penetrated the transition zone. The resultant eastward migration of shallow mantle convection systems continuously drove the retreating subduction of the Paleo-Pacific (or Izanagi) plate, advancing subduction of the Farallon plate and eastward migration of the Paleo-Pacific-Farallon mid-ocean ridge. As a consequence, multiple phases of tectonic extension dominated the deformation of the continental interior in EE and episodic compressional tectono-magmatic activities occurred along the continental margin of WNA.
•Early Cretaceous structures in eastern Eurasia (EE) by multiphase tectonic extension•Early Cretaceous episodic compressional structures in western North America (WNA)•EE extension related to retreating (Paleo-) Pacific-Eurasia subduction system•WNA crustal shortening from advancing Farallon-North America subduction system•Migration of the shallow mantle convection systems attributed to deep mantle convection
Wearable thermoelectric devices show promise to generate electricity in a ubiquitous, unintermittent and noiseless way for on-body applications. Three-dimensional thermoelectric textiles (TETs) ...outperform other types in smart textiles owing to their out-of-plane thermoelectric generation and good structural conformability with fabrics. Yet, there has been a lack of efficient strategies in scalable manufacture of TETs for sustainably powering electronics. Here, we fabricate organic spacer fabric shaped TETs by sewing carbon nanotube yarn based segmented thermoelectric textiles on a large scale. Combining finite element analysis with experimental evaluation, we elucidate that the fabric structure significantly influences the power generation. The optimally designed TET with good wearability and stability shows a high output power density of 51.5 mW m
−2
and a high specific power of 171.7 μW (g K)
−1
at Δ
T
= 47.5 K. The promising on-body application of the TET in directly and continuously powering electronics for healthcare and environmental monitoring is fully demonstrated. This work will broaden the research vision and provide new routines for developing high-performance and large-scale TETs toward practical applications.
We explore the fabric structural effect of thermoelectric textiles on power generation and achieve high power density for practical applications.
Regenerative medicine has become one of the hottest research topics in medical science that provides a promising way for repairing tissue defects in the human body. Due to their excellent ...physicochemical properties, the application of 2D nanomaterials in regenerative medicine has gradually developed and has been attracting a wide range of research interests in recent years. In particular, graphene and its derivatives, black phosphorus, and transition metal dichalcogenides are applied in all the aspects of tissue engineering to replace or restore tissues. This review focuses on the latest advances in the application of 2D‐nanomaterial‐based hydrogels, nanosheets, or scaffolds that are engineered to repair skin, bone, and cartilage tissues. Reviews on other applications, including cardiac muscle regeneration, skeletal muscle repair, nerve regeneration, brain disease treatment, and spinal cord healing are also provided. The challenges and prospects of applications of 2D nanomaterials in regenerative medicine are discussed.
2D nanomaterial‐based therapeutic strategies applied in tissue engineering and regenerative nanomedicines are discussed. Recent advances in the application of 2D nanomaterial‐based hydrogels, nanosheets, scaffolds, or drug delivery systems that engineered to repair skin, bone, cartilage, and other types of tissues are discussed along with the current challenges and future prospects.
Connexin 43 (Cx43)-associated gap junctions form electrical and mechanical conduits between adjacent ventricular cardiomyocytes, ensuring coordinate electrical excitation and synchronic contraction ...for each heartbeat. Cx43 dephosphorylation is a characteristic of ischemia, arrhythmia, and a failing and aging myocardium, but the exact phosphosite(s) triggering myocardial apoptosis and electrical disturbance and its underlying mechanisms are unclear. We previously found that Cx43-serine 282 phosphorylation (pS282) can regulate cardiomyocyte survival and electrical stability. Here, we investigated the hypothesis that S282 dephosphorylation occurs in and contributes to ischemia/reperfusion (
I
/
R
)-induced cardiac injury. We found enhanced Cx43-pS262 and Cx43-pS368 but decreased Cx43-pS282 in rat hearts subjected to
I
/
R
(30 min/2 h).
I
/
R
rats had ventricular arrhythmias and myocardial apoptosis with activation of the p38 mitogen-activated protein kinase (p38)/factor-associated suicide (Fas)/Fas-associating protein with a novel death domain (FADD) pathway. Similarly, S282 dephosphorylation, abnormal Ca
2+
transients, cell apoptosis and p38/Fas/FADD activation also occurred in neonatal rat ventricular myocytes exposed to anoxia/reoxygenation (12/6 h). To confirm the causative role of S282 dephosphorylation in cardiac injury, rat hearts were intramyocardially injected with a virus carrying the S282 mutant substituted with alanine (S282A), thus causing arrhythmias and reducing cardiac output and myocardial apoptosis with p38/Fas/FADD pathway activation. Moreover, Cx43-S282A
+/−
mice displayed arrhythmias and impaired cardiac output with global myocardial apoptosis. Our findings revealed that Cx43 dephosphorylation at S282 triggers arrhythmias and, at least partly, contributes to cardiomyocyte death upon
I
/
R
by activating the p38/Fas/FADD pathway, providing a novel molecular mechanism and potential target for protecting against cardiac
I
/
R
injury.
This paper investigates a method for precise mapping of human arm movements using sEMG signals. A multi-channel approach captures the sEMG signals, which, combined with the accurately calculated ...joint angles from an Inertial Measurement Unit, allows for action recognition and mapping through deep learning algorithms. Firstly, signal acquisition and processing were carried out, which involved acquiring data from various movements (hand gestures, single-degree-of-freedom joint movements, and continuous joint actions) and sensor placement. Then, interference signals were filtered out through filters, and the signals were preprocessed using normalization and moving averages to obtain sEMG signals with obvious features. Additionally, this paper constructs a hybrid network model, combining Convolutional Neural Networks and Artificial Neural Networks, and employs a multi-feature fusion algorithm to enhance the accuracy of gesture recognition. Furthermore, a nonlinear fitting between sEMG signals and joint angles was established based on a backpropagation neural network, incorporating momentum term and adaptive learning rate adjustments. Finally, based on the gesture recognition and joint angle prediction model, prosthetic arm control experiments were conducted, achieving highly accurate arm movement prediction and execution. This paper not only validates the potential application of sEMG signals in the precise control of robotic arms but also lays a solid foundation for the development of more intuitive and responsive prostheses and assistive devices.
Indolent T-lymphoblastic proliferation (iT-LBP) is the extrathymic proliferation of nonclonal TdT + T cells and is typically associated with lymphoid disorders. Although one study revealed that ...iT-LBP occurred in angioimmunoblastic T-cell lymphoma, no other lymphoma-related cases have been reported. Here, we report three cases of concurrent iT-LBP and benign or malignant lymphoid disorders. The first patient had bilateral cervical lymph node enlargement, and the resected lymph node showed polyclonal precursor T-cells distributed between benign hyperplastic lymphoid follicles. In the second case, iT-LBP occurred in peripheral T-cell lymphoma with a follicular growth pattern, showing that precursor T-cells were distributed between neoplastic follicles composed of CD4 + and CXCL13 + T-cells. In the third case, polyclonal precursor T-cells were distributed between the neoplastic follicles of follicular lymphoma. In summary, our results indicate an association between iT-LBP and reactive lymphoid hyperplasia (case 1) and lymphoma (cases 2 and 3).
Purpose
Systemic hypertension may induce adverse hypertrophy of the left cardiac ventricle. Pathological cardiac hypertrophy is a common cause of heart failure. We investigated the significance of ...ferroptosis repressor xCT in hypertrophic cardiomyopathy.
Methods
xCT expression in angiotensin II (Ang II)-treated mouse hearts and rat cardiomyocytes was determined using qRT-PCR and Western blotting. Cardiac hypertrophy was induced by Ang II infusion in xCT knockout mice and their wildtype counterparts. Blood pressure, cardiac pump function, and pathological changes of cardiac remodeling were analyzed in these mice. Cell death, oxidative stress, and xCT-mediated ferroptosis were examined in Ang II-treated rat cardiomyocytes.
Results
After Ang II infusion, xCT was downregulated at day 1 but upregulated at day 14 at both mRNA and protein levels. It was also decreased in Ang II-treated cardiomyocytes, but not in cardiofibroblasts. Inhibition of xCT exacerbated cardiomyocyte hypertrophy and boosted the levels of ferroptosis biomarkers Ptgs2, malondialdehyde, and reactive oxygen species induced by Ang II, while overexpression of xCT opposed these detrimental effects. Furthermore, knockout of xCT aggravated Ang II-mediated mouse cardiac fibrosis, hypertrophy, and dysfunction. Ferrostatin-1, a ferroptosis inhibitor, alleviated the exacerbation of cardiomyocyte hypertrophy caused by inhibiting xCT in cultured rat cells or ablating xCT in mice.
Conclusion
xCT acts as a suppressor in Ang II-mediated cardiac hypertrophy by blocking ferroptosis. Positive modulation of xCT may therefore represent a novel therapeutic approach against cardiac hypertrophic diseases.
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