It is a great challenge to substantially improve the practical performance of flexible thermoelectric modules due to the absence of air-stable n-type thermoelectric materials with high-power factor. Here an excellent flexible n-type thermoelectric film is developed, which can be conveniently and rapidly prepared based on the as-grown carbon nanotube continuous networks with high conductivity. The optimum n-type film exhibits ultrahigh power factor of ∼1,500 μW m−1 K−2 and outstanding stability in air without encapsulation. Inspired by the findings, we design and successfully fabricate the compact-configuration flexible TE modules, which own great advantages compared with the conventional π-type configuration modules and well integrate the superior thermoelectric properties of p-type and n-type carbon nanotube films resulting in a markedly high performance. Moreover, the research results are highly scalable and also open opportunities for the large-scale production of flexible thermoelectric modules.
C1 inhibitor (C1INH) is beneficial in animal models of endotoxemia and sepsis. However, the mechanism(s) of C1INH protection remain(s) ill-defined. In this study, we demonstrated that both active C1INH and reactive center-cleaved, inactive C1INH protected mice from lethal Gram-negative endotoxemia. Both forms of C1INH blocked the LPS-binding protein-dependent binding of Salmonella typhimurium LPS to the murine macrophage cell line, RAW 264.7, and suppressed LPS-induced TNF-α mRNA expression. Inhibition of LPS binding to RAW 264.7 cells was reversed with anti-C1INH Ab and was more efficient when C1INH was incubated first with LPS rather than with the cells. C1INH also suppressed LPS-induced up-regulation of TNF-α mRNA in whole human blood. The interaction of C1INH with LPS was directly demonstrated both by ELISA and by nondenaturing PAGE, but deletion of the amino-terminal 97-aa residues abrogated this binding. Therefore, C1INH, in addition to its function as a serine protease inhibitor, has a novel anti-inflammatory function mediated via its heavily glycosylated amino-terminal non-serpin domain.
The class IIa histone deacetylases (HDACs) play important roles in the central nervous system during diverse biological processes such as synaptic plasticity, axon regeneration, cell apoptosis, and neural differentiation. Although it is known that HDAC5 regulates neuronal differentiation, neither the physiological function nor the regulation of HDAC5 in neuronal differentiation is clear. Here, we identify HDAC5 as an inhibitor of neurite elongation and show that HDAC5 is regulated by the brain enriched microRNA miR-124 and miR-9. We discover that HDAC5 inhibits neurite extension both in differentiated P19 cells and primary neurons. We also show that the neuronal membrane glycoprotein GPM6A (M6a) is a direct target gene of HDAC5 regulated transcriptional factor MEF2C. HDAC5 inhibits neurite elongation, acting at least partially via a MEF2C/M6a signaling pathway. We also confirmed the miR-124/miR-9 regulated HDAC5-MEF2C-M6a pathway regulates neurite development in primary neurons. Thus, HDAC5 emerges as a cellular conductor of MEF2C and M6a activity and is regulated by miR-124 and miR-9 to control neurite development.
An ingenious strategy is put forward to evaluate accurately the thermoelectric performance of carbon nanotube (CNT) thin films, including thermal conductivity, electrical conductivity, and Seebeck coefficient in the same direction. The results reveal that the as-prepared CNT interconnected films and CNT fibers possess enormous potential of thermoelectric applications because of their ultrahigh power factors.
UDP-GlcA 4-epimerase (UGlcAE) catalyzes the epimerization of UDP-α-d-glucuronic acid (UDP-GlcA) to UDP-α-d-galacturonic acid (UDP-GalA). UDP-GalA is a precursor for the synthesis of numerous cell-surface polysaccharides in bacteria and plants. Using a biochemical screen, a gene encoding AtUGlcAE1 in Arabidopsis (Arabidopsis thaliana) was identified and the recombinant enzyme biochemically characterized. The gene belongs to a small gene family composed of six isoforms. All members of the UGlcAE gene family encode a putative type-II membrane protein and have two domains: a variable N-terminal region approximately 120 amino acids long composed of a predicted cytosolic, transmembrane, and stem domain, followed by a large conserved C-terminal catalytic region approximately 300 amino acids long composed of a highly conserved catalytic domain found in a large protein family of epimerase/dehydratases. The recombinant epimerase has a predicted molecular mass of approximately 43 kD, although size-exclusion chromatography suggests that it may exist as a dimer (approximately 88 kD). AtUGlcAE1 forms UDP-GalA with an equilibrium constant value of approximately 1.9 and has an apparent Km value of 720 μm for UDP-GlcA. The enzyme has maximum activity at pH 7.5 and is active between 20°C and 55°C. Arabidopsis AtUGlcAE1 is not inhibited by UDP-Glc, UDP-Gal, or UMP. However, the enzyme is inhibited by UDP-Xyl and UDP-Ara, suggesting that these nucleotide sugars have a role in regulating the synthesis of pectin. The cloning of the AtUGlcAE1 gene will increase our ability to investigate the molecular factors that regulate pectin biosynthesis in plants. The availability of a functional recombinant UDP-GlcA 4-epimerase will be of considerable value for the facile generation of UDP-d-GalA in the amounts required for detailed studies of pectin biosynthesis.
Hybrid hydro-responsive actuators are developed by infiltrating carbon nanotube yarns using poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate). These actuators demonstrate impressive rotation and contraction in response to water due to volumetric expansion of the helical arrangement of carbon nanotubes. The total torsional stroke is 3720 revolutions per m and the simultaneously generated contractive strain reaches 24% at a paddle-to-yarn mass ratio of 350. The contraction output can furthermore be significantly enhanced by constraining the rotational motion and it reaches 68% with an applied stress of 1 MPa. Additionally, hybrid yarns exhibit an approximately linear response to humidity changes and show extra capability of electrical actuation, which, combined with the excellent hydro-actuation performance, endow them with great potential for a variety of applications including artificial muscles, hydro-driven generators, moisture switches and microfluidic mixers.
Pressure sensors, which have the ability to detect the physical interaction between the external environment and the target, are essential for the control and sustainability of system in many fields such as healthcare, [1,2] robots, [3][4][5] intelligent terminals, [6] and aerospace crafts. [7,8] To match the requirements An all-carbon pressure sensor is designed and fabricated based on reduced graphene oxide (rGO) nanomaterials. By sandwiching one layer of superelastic rGO aerogel between two freestanding high-conductive rGO thin papers, the sensor works based on the contact resistance at the aerogel-paper interfaces, getting rid of the alien materials such as polymers and metals adopted in traditional sensors. Without the limitation of alien materials, the all-carbon sensors demonstrate an ultrawide detecting range (0.72 Pa-130 kPa), low energy consumption (≈0.58 µW), ultrahigh sensitivity (349-253 kPa −1 ) at low-pressure regime (<1.4 Pa), fast response time (8 ms at 1 kPa), high stability (10 000 unloading-loading cycles between 0 and 1 kPa), light weight (<10 mg), easily scalable fabrication process, and excellent chemical stability. These merits enable them to detect real-time human physiological signals and monitor the weights of various droplets of not only water but also hazardous chemical reagents including strong acid, strong alkali, and organic solvents. This shows their great potential applications in real-time health monitoring, sport performance detecting, harsh environmentrelated robotics and industry, and so forth.
Nucleotide-diphospho-sugars (NDP-sugars) are the building blocks of diverse polysaccharides and glycoconjugates in all organisms. In plants, 11 families of NDP-sugar interconversion enzymes (NSEs) have been identified, each of which interconverts one NDP-sugar to another. While the functions of these enzyme families have been characterized in various plants, very little is known about their evolution and origin. Our phylogenetic analyses indicate that all the 11 plant NSE families are distantly related and most of them originated from different progenitor genes, which have already diverged in ancient prokaryotes. For instance, all NSE families are found in the lower land plant mosses and most of them are also found in aquatic algae, implicating that they have already evolved to be capable of synthesizing all the 11 different NDP-sugars. Particularly interesting is that the evolution of RHM (UDP-L-rhamnose synthase) manifests the fusion of genes of three enzymatic activities in early eukaryotes in a rather intriguing manner. The plant NRS/ER (nucleotide-rhamnose synthase/epimerase-reductase), on the other hand, evolved much later from the ancient plant RHMs through losing the N-terminal domain. Based on these findings, an evolutionary model is proposed to explain the origin and evolution of different NSE families. For instance, the UGlcAE (UDP-D-glucuronic acid 4-epimerase) family is suggested to have evolved from some chlamydial bacteria. Our data also show considerably higher sequence diversity among NSE-like genes in modern prokaryotes, consistent with the higher sugar diversity found in prokaryotes. All the NSE families are widely found in plants and algae containing carbohydrate-rich cell walls, while sporadically found in animals, fungi and other eukaryotes, which do not have or have cell walls with distinct compositions. Results of this study were shown to be highly useful for identifying unknown genes for further experimental characterization to determine their functions in the synthesis of diverse glycosylated molecules.
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