Bioinspired artificial haptic neuron system has received much attention in the booming artificial intelligence industry for its broad range of high‐impact applications such as personal healthcare ...monitoring, electronic skins, and human–machine interfaces. An artificial haptic neuron system is designed by integrating a piezoresistive sensor and a Nafion‐based memristor for the first time in this paper. The piezoresistive sensor serves as a sensory receptor to transform mechanical stimuli into electric signals, and the Nafion‐based memristor serves as the synapse to further process the information. The pyramid‐structured sensor exhibits excellent sensitivity (6.7 × 107 kPa−1 in 1–5 kPa and 3.8 × 105 kPa−1 in 5–50 kPa) and durability (>7000 cycles), while the memristor realizes fundamental synaptic functions under low power consumption (10–200 pJ) and remains stable for over 104 consecutive tests. The integrated system can detect tactile stimuli encoded with temporal information, such as the count, frequency, duration and speed of the external force. As a proof‐of‐concept, English characters recognition with high accuracy can be achieved on the system under a supervised learning method. This work shows promising potential in bioinspired sensing systems owing to the high performance, excellent durability, and simple fabrication procedure.
An artificial haptic neuron system is designed by integrating a piezoresistive sensor and a Nafion‐based memristor for the first time. The pyramid‐structured sensor exhibits excellent sensitivity and durability, while the memristor realizes fundamental synaptic functions under low power consumption and remains stable for over 104 consecutive tests. The integrated system can detect tactile stimuli encoded with temporal information.
TGF-β Signaling from Receptors to Smads Hata, Akiko; Chen, Ye-Guang
Cold Spring Harbor perspectives in biology,
2016-Sep-01, 2016-09-00, 20160901, Letnik:
8, Številka:
9
Journal Article
Recenzirano
Odprti dostop
Transforming growth factor β (TGF-β) and related growth factors are secreted pleiotropic factors that play critical roles in embryogenesis and adult tissue homeostasis by regulating cell ...proliferation, differentiation, death, and migration. The TGF-β family members signal via heteromeric complexes of type I and type II receptors, which activate members of the Smad family of signal transducers. The main attribute of the TGF-β signaling pathway is context-dependence. Depending on the concentration and type of ligand, target tissue, and developmental stage, TGF-β family members transmit distinct signals. Deregulation of TGF-β signaling contributes to developmental defects and human diseases. More than a decade of studies have revealed the framework by which TGF-βs encode a context-dependent signal, which includes various positive and negative modifiers of the principal elements of the signaling pathway, the receptors, and the Smad proteins. In this review, we first introduce some basic components of the TGF-β signaling pathways and their actions, and then discuss posttranslational modifications and modulatory partners that modify the outcome of the signaling and contribute to its context-dependence, including small noncoding RNAs.
Circular RNAs (circRNAs) are a novel class of RNAs generated from back-splicing and characterized by covalently closed continuous loops. Recently, circRNAs have recently shown large regulation on ...cardiovascular system, including atherosclerosis. The present study aims to investigate the circRNA expression profile and identify their roles on vascular endothelial cells induced by oxLDL. Human circRNA microarray analysis revealed that total 943 differently expressed circRNAs were screened with 2 fold change. Hsa_circ_0003575 was validated to be significantly up-regulated in oxLDL induced HUVECs. Loss-of-function experiments indicated that hsa_circ_0003575 silencing promoted the proliferation and angiogenesis ability of HUVECs. Bioinformatics online programs predicted the potential circRNA-miRNA-mRNA network for hsa_circ_0003575. In summary, circRNA microarray analysis reveals the expression profiles of HUVECs and verifies the role of hsa_circ_0003575 on HUVECs, providing a therapeutic strategy for vascular endothelial cell injury of atherosclerosis.
We propose a method for the fast generation of nonclassical ground states of the Rabi model in the ultrastrong and deep-strong coupling regimes via the shortcuts-to-adiabatic (STA) dynamics. The ...time-dependent quantum Rabi model is simulated by applying parametric amplification to the Jaynes-Cummings model. Using experimentally feasible parametric drive, this STA protocol can generate large-size Schrödinger cat states, through a process that is ∼10 times faster compared to adiabatic protocols. Such fast evolution increases the robustness of our protocol against dissipation. Our method enables one to freely design the parametric drive, so that the target state can be generated in the lab frame. A largely detuned light-matter coupling makes the protocol robust against imperfections of the operation times in experiments.
A transformation of fluxional into configurationally stable axially chiral N‐arylpyrroles was achieved with a highly atroposelective electrophilic aromatic substitution catalyzed by a chiral‐at‐metal ...rhodium Lewis acid. Specifically, N‐arylpyrroles were alkylated with N‐acryloyl‐1H‐pyrazole electrophiles in up to 93 % yield and with up to >99.5 % ee, and follow‐up conversions reveal the synthetic utility of this new method. DFT calculations elucidate the origins of the observed excellent atroposelectivity.
Freeze, don't move: A transformation of fluxional into configurationally stable axially chiral N‐arylpyrroles was achieved through a highly atroposelective electrophilic aromatic substitution catalyzed by a chiral‐at‐metal rhodium Lewis acid, with follow‐up transformations leading to structurally diverse axially chiral N‐arylpyrroles.
Heart rate (HR) variability indicates health condition and mental stress. The development of non-contact HR monitoring techniques with Doppler radar is attracting great attention. However, the ...performance of heartbeat detection via radar signals easily degrades due to respiration and body motion. In this paper, first, a stochastic gradient approach is applied to reconstruct the high-resolution spectrum of heartbeat by proposing the zero-attracting sign least-mean-square (ZA-SLMS) algorithm. To correct the quantized gradient of cost function and penalize the sparse constraint on updating the spectrum, a more accurate heartbeat spectrum is reconstructed. Then, to better adapt to the noises of different strengths caused by subjects' movements, an adaptive regularization parameter is introduced in the ZA-SLMS algorithm as an improved variant, which can adaptively regulate the proportion between gradient correction and sparse penalty. Moreover, in view of the stability of the location of the spectral peak associated with the HR when the size of time window slightly changes, a time-window-variation (TWV) technique is further incorporated in the improved ZA-SLMS (IZA-SLMS) algorithm for more stable HR estimation. Through the experiments on five subjects, our proposal is demonstrated to bring a significant improvement in accuracy compared with existing detection methods. Specifically, the IZA-SLMS algorithm with TWV achieves the smallest average error of 3.79 beats per minute when subjects type on a laptop.
Recently, conductive metal−organic frameworks (MOFs) as the active material have provided broad prospects for electronic device application. The positioning technologies for MOFs enable the ...fabrication of novel microstructures, which can modulate the morphology of the material and tune the properties for the targeted application. Herein, a template‐method is used to synthesize the hierarchical structure of MOF hybrid array (MHA) on copper mesh (MHA@Mesh) for flexible sensor. Finite element method (FEM) results indicate that the 3D hierarchical MHA@Mesh can mimic the micro/nanoscale structure of human skin, which enables an interlocking contact. MHA@Mesh‐based flexible sensor presents rapid response rate (<1 ms) and high sensitivity (up to 307 kPa−1) which is 20 times higher than that of MHA@Foil‐based sensor (15 kPa−1). The flexible pressure device could be applied to monitor the finger motion and human pulses. Moreover, the music recognition can be performed by integrating the MOFs hardware sensors with machine learning algorithms. Overall, this design concept of 3D hierarchical microarray structures demonstrates potential in the fields of wearable technologies and human–machine interfaces.
A metal–organic framework hybrid array on a copper mesh with a hierarchical structure is synthesized and employed as the active layer of a resistive tactile sensor. Finite element method study reveals the mechanism of pressure‐dependent contact area modulation. The sensor can monitor biophysical signals and realize music recognition owing to the high sensitivity and stability.
The first phosphoric acid catalyzed direct arylation of 2‐naphthylamines with iminoquinones for the atroposelective synthesis of axially chiral biaryl amino alcohols has been developed. This reaction ...constitutes a highly functional‐group‐tolerant route for the rapid construction of enantioenriched axially chiral biaryl amino alcohols, and is a rare example of 2‐naphthylamines acting as nucleophiles in an organocatalytic enantioselective transformation. Furthermore, the products, which feature various halogen atoms, provide access to structurally diverse axially chiral amino alcohols through further transformations.
The phosphoric acid catalyzed direct arylation of 2‐naphthylamines with iminoquinones enables the atroposelective synthesis of axially chiral biaryl amino alcohols. Many functional groups are tolerated in this reaction, and it is a rare example of 2‐naphthylamines acting as nucleophiles in an organocatalytic enantioselective transformation.
N‐Boc‐protected α‐amino acids are synthesized in two steps from linear or branched carboxylic acid feedstocks. In the first step, the carboxylic acid is coupled with tert‐butyl aminocarbonate ...(BocNHOH) to generate azanyl ester (acyloxycarbamate) RCO2NHBoc. In the second step, this azanyl ester undergoes a stereocontrolled iron‐catalyzed 1,3‐nitrogen migration to generate the N‐Boc‐protected non‐racemic α‐amino acid. This straightforward protocol is applicable to the catalytic asymmetric synthesis of α‐monosubstituted α‐amino acids with aryl, alkenyl, and alkyl side chains. Furthermore, α,α‐disubstituted α‐amino acids are accessible in an enantioconvergent fashion from racemic carboxylic acids. The new method is also advantageous for the synthesis of α‐deuterated α‐amino acids. N‐Boc‐protected α‐amino acids synthesized using this two‐step protocol are ready‐to‐use building blocks.
A straightforward two‐step protocol was developed to convert linear or α‐branched carboxylic acids into non‐racemic N‐Boc‐protected α‐monosubstituted (asymmetric catalysis) or α,α‐disubstituted (enantioconvergent catalysis) α‐amino acids.
The intracellular multiprotein complex β‐catenin destruction complex plays a key role in Wnt/β‐catenin signaling. Wnt stimulation induces the assembly of the receptor‐associated signalosome and the ...inactivation of the destruction complex, leading to β‐catenin accumulation and transcriptional activation of the target genes. The core components of the destruction complex include Axin, APC, GSK3β, CK1α and other proteins. Recent studies demonstrated that Axin and APC undergo liquid–liquid phase separation (LLPS), which is critical for their function to regulate Wnt/β‐catenin signaling. Here, we discuss the possible roles of LLPS in Wnt/β‐catenin signaling and regulation of Axin LLPS by post‐translational modifications.
The formation of the destruction complex is driven by IDR1‐mediated Axin1 LLPS, which is promoted by APC LLPS. In addition, β‐catenin has been reported to undergo LLPS in the nucleus. It remains unclear whether Dvl go through LLPS and its effect on the destruction complex.
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