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Nickel-catalyzed transannulation reactions triggered by the extrusion of small gaseous molecules have emerged as a powerful strategy for the efficient construction of heterocyclic compounds. However, their use in asymmetric synthesis remains challenging because of the difficulty in controlling stereo- and regioselectivity. Herein, we report the first nickel-catalyzed asymmetric synthesis of N-N atropisomers by the denitrogenative transannulation of benzotriazones with alkynes. A broad range of N-N atropisomers was obtained with excellent regio- and enantioselectivity under mild conditions. Moreover, density functional theory (DFT) calculations provided insights into the nickel-catalyzed reaction mechanism and enantioselectivity control.
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The recognition of human activity is crucial as the Internet of Things (IoT) progresses toward future smart homes. Wi-Fi-based motion-recognition stands out due to its non-contact nature and widespread applicability. However, the channel state information (CSI) related to human movement in indoor environments changes with the direction of movement, which poses challenges for existing Wi-Fi movement-recognition methods. These challenges include limited directions of movement that can be detected, short detection distances, and inaccurate feature extraction, all of which significantly constrain the wide-scale application of Wi-Fi action-recognition. To address this issue, we propose a direction-independent CSI fusion and sharing model named CSI-F, one which combines Convolutional Neural Networks (CNN) and Gated Recurrent Units (GRU). Specifically, we have introduced a series of signal-processing techniques that utilize antenna diversity to eliminate random phase shifts, thereby removing noise influences unrelated to motion information. Later, by amplifying the Doppler frequency shift effect through cyclic actions and generating a spectrogram, we further enhance the impact of actions on CSI. To demonstrate the effectiveness of this method, we conducted experiments on datasets collected in natural environments. We confirmed that the superposition of periodic actions on CSI can improve the accuracy of the process. CSI-F can achieve higher recognition accuracy compared with other methods and a monitoring coverage of up to 6 m.
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Internet das Coisas , Movimento , Humanos , Movimento (Física) , Efeito Doppler , Meio AmbienteRESUMO
In recent years, convolutional neural networks (CNNs) have played a dominant role in facial expression recognition. While CNN-based methods have achieved remarkable success, they are notorious for having an excessive number of parameters, and they rely on a large amount of manually annotated data. To address this challenge, we expand the number of training samples by learning expressions from a face recognition dataset to reduce the impact of a small number of samples on the network training. In the proposed deep joint learning framework, the deep features of the face recognition dataset are clustered, and simultaneously, the parameters of an efficient CNN are learned, thereby marking the data for network training automatically and efficiently. Specifically, first, we develop a new efficient CNN based on the proposed affinity convolution module with much lower computational overhead for deep feature learning and expression classification. Then, we develop an expression-guided deep facial clustering approach to cluster the deep features and generate abundant expression labels from the face recognition dataset. Finally, the AC-based CNN is fine-tuned using an updated training set and a combined loss function. Our framework is evaluated on several challenging facial expression recognition datasets as well as a self-collected dataset. In the context of facial expression recognition applied to the field of education, our proposed method achieved an impressive accuracy of 95.87% on the self-collected dataset, surpassing other existing methods.
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Reconhecimento Facial , Aprendizagem , Análise por Conglomerados , Face , Redes Neurais de ComputaçãoRESUMO
We report herein that copper(I) catalysis using a bis(phosphine) dioxide ligand can catalyze the desymmetric C-H arylation of prochiral bipyrroles. More than 50 nitrogen-nitrogen atropisomers were achieved in good to excellent yields with excellent enantioselectivities (≤97% yield, ≤98% ee). The reaction proceeds under mild conditions with good functional group compatibility on arenes and diaryliodonium salts. Moreover, this principle enables iterative arylation of the bipyrroles to enantioselectively arylate different positions during the catalysis of copper.
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Propofol offers important protective effects in ischemia/reperfusion-induced cardiomyocyte injury, but its specific mechanisms in doxorubicin (DOX)-induced cardiotoxicity have not been investigated. In this paper, we attempted to explore the effects of propofol on DOX-induced human cardiomyocyte injury and its related mechanisms. H9c2 cell viability was assessed by cell counting kit-8 and lactate dehydrogenase assay kit. Nuclear factor erythroid 2-related factor 2 (NRF2)/glutathione peroxidase 4 (GPx4) signaling pathway-related protein levels were measured by Western blot. Ferroptosis was evaluated by corresponding kits and Western blot and apoptosis was detected by CCK-8, terminal deoxynucleotidyl transferase dUTP nick-end labeling and Western blot. Oxidative stress was assessed by reactive oxygen species kit and the commercial kits, and inflammation response was analyzed by enzyme-linked immunosorbent assay and Western blot. The results showed that propofol attenuated DOX-induced cytotoxicity and activated Nrf2/GPx4 signaling pathways in H9c2 cells. In addition, propofol also alleviated DOX-induced ferroptosis, increased cell viability and inhibited apoptosis, oxidative stress and inflammatory responses in H9c2 cells through activation of Nrf2/GPx4 signaling pathways. In summary, propofol provides the protection against DOX-induced cardiomyocyte injury by activating Nrf2/GPx4 signaling, providing a new approach and theoretical basis for the repair of cardiomyocytes.
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Fator 2 Relacionado a NF-E2 , Propofol , Apoptose , Doxorrubicina/toxicidade , Humanos , Miócitos Cardíacos/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Estresse Oxidativo , Fosfolipídeo Hidroperóxido Glutationa Peroxidase , Propofol/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Transdução de SinaisRESUMO
In cognitive neuroscience, there is an increasing interest in identifying and understanding the synchronization of distinct neural oscillations with different frequencies that might support dynamic communication within the brain. This study explored the cross-frequency phase-amplitude coupling brain network characteristics of resting-state electroencephalograms between 30 children with attention-deficit/hyperactivity disorder (ADHD) and 30 age-matched typically developing children. Compared with control group, children with ADHD show increased coupling intensity and altered distribution patterns of dominant paired channels, especially in the δ-γH, θ-γH, α-γH, ßL-γH, and ßH-γH coupling networks. Regarding graph theory properties, the characteristic path length, the mean clustering coefficient, the global efficiency, and the mean local efficiency significant difference in many cross-frequency coupling networks, especially in the δ-γH, θ-γH, α-γH, ßL-γH, and ßH-γH coupling networks. The area under the receiver operating characteristic curve (AUC) in low-frequency coupling with a high-gamma frequency was larger than that in coupling with low-gamma frequency (AUC values of δ-γL, θ-γL, α-γL, ßL-γL, ßH-γL, δ-γH, θ-γH, α-γH, ßL-γH, and ßH-γH were 0.794, 0.722, 0.666, 0.570, 0.881, 0.992, 0.998, 0.998, 0.989, and 0.974, respectively). These findings demonstrate altered coupling intensity and disrupted topological organization of coupling networks, support the altered brain network theory in children with ADHD. The coupling intensity and graph theory properties of low-frequency coupling with high-gamma frequency were promising resting-state electroencephalogram biomarkers of ADHD in children.
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Transtorno do Deficit de Atenção com Hiperatividade , Transtorno do Deficit de Atenção com Hiperatividade/diagnóstico , Encéfalo , Criança , Eletroencefalografia , Humanos , Curva ROCRESUMO
Altered functional networks in attention deficit/hyperactivity disorder (ADHD) have been frequently reported, but effective connectivity has hardly been studied. Especially the differences of effective connectivity in children with ADHD after receiving neurofeedback (NF) training have been merely reported. Therefore, this study aimed to explore the effective networks of ADHD and the positive influence of NF on the effective networks. Electroencephalogram (EEG) data were recorded from 22 children with ADHD (including data from children pretraining and posttraining) and 15 age-matched healthy controls during an eyes-closed resting state. Phase transfer entropy (PTE) was used to construct the effective connectivity. The topological properties of networks and flow gain were measured separately in four bands (delta, theta, alpha, and beta). Results revealed the following: pretraining children with ADHD manifested a higher clustering coefficient and lower characteristic path length in the delta band than healthy controls; weakened anterior-to-posterior flow gain in the delta band, strengthened posterior-to-anterior flow gain in the alpha band and strengthened anterior-to-posterior flow gain in the beta band were observed in pretraining children with ADHD; The topological properties and flow gain in posttraining children with ADHD were close to those of healthy controls. Moreover, parent's SWAN presented significant improvements of ADHD symptoms after NF. Our findings revealed that the effective connectivity of ADHD was altered and that NF could improve the brain function of ADHD. The present study provided the first evidence that children with ADHD differed from healthy children in phase-based effective connectivity and that NF could reduce the differences.
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Transtorno do Deficit de Atenção com Hiperatividade , Neurorretroalimentação , Transtorno do Deficit de Atenção com Hiperatividade/terapia , Criança , Eletroencefalografia , Humanos , DescansoRESUMO
BACKGROUND: Sedation with propofol injections is associated with a risk of addiction, but remimazolam benzenesulfonate is a comparable anesthetic with a short elimination half-life and independence from cell P450 enzyme metabolism. Compared to remimazolam, remimazolam benzenesulfonate has a faster effect, is more quickly metabolized, produces inactive metabolites and has weak drug interactions. Thus, remimazolam benzenesulfonate has good effectiveness and safety for diagnostic and operational sedation. AIM: To investigate the clinical value of remimazolam benzenesulfonate in cardiac surgery patients under general anesthesia. METHODS: A total of 80 patients who underwent surgery in the Department of Cardiothoracic Surgery from August 2020 to April 2021 were included in the study. Using a random number table, patients were divided into two anesthesia induction groups of 40 patients each: remimazolam (0.3 mg/kg remimazolam benzenesulfonate) and propofol (1.5 mg/kg propofol). Hemodynamic parameters, inflammatory stress response indices, respiratory function indices, perioperative indices and adverse reactions in the two groups were monitored over time for comparison. RESULTS: At pre-anesthesia induction, the remimazolam and propofol groups did not differ regarding heart rate, mean arterial pressure, cardiac index or volume per wave index. After endotracheal intubation and when the sternum was cut off, mean arterial pressure and volume per wave index were significantly higher in the remimazolam group than in the propofol group (P < 0.05). After endotracheal intubation, the oxygenation index and the respiratory index did not differ between the groups. After endotracheal intubation and when the sternum was cut off, the oxygenation index values were significantly higher in the remimazolam group than in the propofol group (P < 0.05). Serum interleukin-6 and tumor necrosis factor-α levels 12 h after surgery were significantly higher than before surgery in both groups (P < 0.05). The observation indices were re-examined 2 h after surgery, and the epinephrine, cortisol and blood glucose levels were significantly higher in the remimazolam group than in the propofol group (P < 0.05). The recovery and extubation times were significantly lower in the remimazolam group than in the propofol group (P < 0.05); there were significantly fewer adverse reactions in the remimazolam group (10.00%) than in the propofol group (30.00%; P < 0.05). CONCLUSION: Compared with propofol, remimazolam benzenesulfonate benefited cardiac surgery patients under general anesthesia by reducing hemodynamic fluctuations. Remimazolam benzenesulfonate influenced the surgical stress response and respiratory function, thereby reducing anesthesia-related adverse reactions.
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Anodal-transcranial pulsed current stimulation (a-tPCS) has been used in human studies to modulate cortical excitability or improve behavioral performance in recent years. Multiple studies show crucial roles of astrocytes in cortical plasticity. The calcium activity in astrocytes could regulate synaptic transmission and synaptic plasticity. Whether the astrocytic activity is involved in a-tPCS-induced cortical plasticity is presently unknown. The purpose of this study is to investigate the calcium responses in neurons and astrocytes evoked by a-tPCS with different current intensities, and thereby provides some indication of the mechanisms underlying a-tPCS-induced cortical plasticity. Two-photon calcium imaging was used to record the calcium responses of neurons and astrocytes in mouse somatosensory cortex. Local field potential (LFP) evoked by sensory stimulation was used to assess the effects of a-tPCS on plasticity. We found that long-duration a-tPCS with high-intensity current could evoke large-amplitude calcium responses in both neurons and astrocytes, whereas long-duration a-tPCS with low-intensity current evoked large-amplitude calcium responses only in astrocytes. The astrocytic Ca2+ elevations are driven by noradrenergic-dependent activation of the alpha-1 adrenergic receptors (A1ARs), while the intense Ca2+ responses of neurons are driven by action potentials. LFP recordings demonstrated that low-intensity a-tPCS led to enhancement of cortical excitability while high-intensity a-tPCS resulted in diminution of cortical excitability. The results provide some evidence that the enhancement of a-tPCS-induced cortical excitability might be partly associated with calcium elevation in astrocytes, whereas the diminution of a-tPCS-induced cortical excitability might be caused by excessive calcium activity in neurons. These findings indicate that the appropriate current intensity should be used in the application of a-tPCS.
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We herein present pioneering studies to reveal that excitation-wavelength-dependent photoluminescence properties of fluorescent silicon nanoparticles (SiNPs) can be realized by rationally designing surface ligands, i.e., several kinds of oxidized indole derivatives. The resultant ligand-decorated SiNPs exhibit strong fluorescence, with significant excitation-wavelength-dependent emissive shifting from â¼420 nm to â¼550 nm. Taking advantage of their unique optical merits, we further exploit the resultant ligand-decorated SiNPs as novel fluorescent labels for anti-counterfeiting and cell imaging.
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The phase I metabolizing enzyme and phase II metabolizing enzyme play vital roles in carcinogenesis, but little is known about the changes of their activities in patients with hepatocellular carcinoma (HCC) secondary to chronic hepatitis B virus (HBV) infection. In this study phenacetin, a probe drug (1 g for men and 0.85 g for women orally), was applied for the detection of sulfotransferase 1A1 (SULT1A1) and cytochrome P4501A2 (CYP1A2) activities in 82 healthy participants and 148 HCC, 106 cirrhosis, and 41 chronic hepatitis B patients. In addition, a prospective cohort study for susceptibility to HCC was performed in 205 patients with cirrhosis secondary to chronic HBV infection. Compared with the healthy participants, SLUT1A1 activity increased by 9.7-fold in the HCC patients (P < 0.01). CYP1A2 activity did not significantly differ between the healthy participants and HCC patients. CYP1A2 activity decreased by 91.2% (P < 0.01) and 67.7% (P < 0.05) in the patients with cirrhosis and chronic hepatitis B, respectively; SULT1A1 activity did not increase significantly. During an approximate 2-year follow up, three of the 46 cirrhosis patients with elevated SULT1A1 activity and normal CYP1A2 activity developed HCC, but none of the 159 cirrhosis patients used as parallel controls did (P = 0.012). These results indicate that SLUT1A1 activity is dramatically upregulated in patients with HCC secondary to chronic HBV infection. The upregulation of SULT1A1 activity is not caused by the tumor itself. The interaction between SULT1A1 and CYP1A2 can play an important role in hepatocarcinogenesis in the Chinese population.