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1.
J Asthma ; : 1-10, 2024 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-38696283

RESUMO

OBJECTIVE: Paclitaxel exhibits outstanding biological activities in inhibiting cell proliferation and inducing cell apoptosis. But the effects of paclitaxel on airway smooth muscle cells (ASMCs) have not been reported yet. The purpose of this study is to determine the effects of paclitaxel on the proliferation and apoptosis of ASMCs. METHODS: Rat primary ASMCs were isolated and used in all the experiments. Cell Counting Kit-8 (CCK-8) assay and Edu assay were used to analyse the cell viability and proliferation respectively. Flow cytometry was used to detect the cell cycle and apoptosis. Quantitative real-time PCR (qRT-PCR), western blotting, and immunostaining were used to detect the expression of Cyclin-dependent kinase 1 (Cdk1). RESULTS: Our study showed that paclitaxel inhibits the proliferation of ASMCs in a dose and time gradient dependent manner. Further study displayed that cell cycle is arrested at G2/M phase. And Cdk1 was dramatically down-regulated by paclitaxel treatment. Cell morphological analysis showed that ASMCs are elliptical with a larger surface area after paclitaxel treatment. Nucleus morphological analysis showed that the nuclei are in a diffuse state after paclitaxel treatment. But paclitaxel did not induce the apoptosis of ASMCs. CONCLUSIONS: Our study demonstrated that paclitaxel inhibits the proliferation of ASMCs at least partly by negatively regulating Cdk1-cell cycle axis.

2.
Transl Neurosci ; 15(1): 20220338, 2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-38623574

RESUMO

Background: The deposition of Aß42 has been regarded as one of the important pathological features of Alzheimer's disease (AD). However, drug development for Aß42 toxicity has been progressed slowly. Objective: Our aim was to introduce the effect and related mechanism of trehalose on an Aßarc (arctic mutant Aß42) Drosophila AD model. Methods: The human Aßarc was expressed in Drosophila to construct the AD model. Trehalose was added to the culture vial. The movement ability was determined by detecting climbing ability and flight ability. Enzyme-linked immunosorbent assay was used to detect the levels of Aßarc, ATP, and lactate. Electron microscopy assay, mitochondrial membrane potential assay, and mitochondrial respiration assay were used to assess the mitochondrial structure and function. Results: Trehalose strongly improved the movement ability of Aßarc Drosophila in a concentration gradient-dependent manner. Furthermore, trehalose increased the content of ATP and decreased the content of Aßarc and lactate both in the brain and thorax of Aßarc Drosophila. More importantly, the mitochondrial structure and function were greatly improved by trehalose treatment in Aßarc Drosophila. Conclusion: Trehalose improves movement ability at least partly by reducing the Aßarc level and restoring the mitochondrial structure and function in Aßarc Drosophila.

3.
Adv Sci (Weinh) ; : e2400967, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38626379

RESUMO

Recently, the altermagnetic materials with spin splitting effect (SSE), have drawn significant attention due to their potential to the flexible control of the spin polarization by the Néel vector. Here, the direct and inverse altermagnetic SSE (ASSE) in the (101)-oriented RuO2 film with the tilted Néel vector are reported. First, the spin torque along the x-, y-, and z-axis is detected from the spin torque-induced ferromagnetic resonance (ST-FMR), and the z-spin torque emerges when the electric current is along the [010] direction, showing the anisotropic spin splitting of RuO2. Further, the current-induced modulation of damping is used to quantify the damping-like torque efficiency (ξDL) in RuO2/Py, and an anisotropic ξDL is obtained and maximized for the current along the [010] direction, which increases with the reduction of the temperature, indicating the present of ASSE. Next, by way of spin pumping measurement, the inverse altermagnetic spin splitting effect (IASSE) is studied, which also shows a crystal direction-dependent anisotropic behavior and temperature-dependent behavior. This work gives a comprehensive study of the direct and inverse ASSE effects in the altermagnetic RuO2, inspiring future altermagnetic materials and devices with flexible control of spin polarization.

4.
Head Neck ; 46(6): E61-E66, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38469981

RESUMO

BACKGROUND: Extrathyroid implantation or dissemination of thyroid tissue secondary to a thyroid procedure is rare. Most of these belonged to thyroid carcinoma with metastatic potential and uncommon for benign pathologies. METHODS: We report the case of a 31-year-old female who was identified to have multiple subcutaneous implantation of thyroid tissue 5 years after transoral endoscopic thyroidectomy vestibular approach. A comprehensive literature search on implantation of thyroid tissue secondary to thyroid procedures was performed. RESULTS: Accidental tearing of the capsule during previous surgery may lead to the subcutaneous implantation. Through literature review, a total 29 articles with 47 patients were identified. 33.3% were benign lesions, and implantation was mostly secondary to fine needle aspiration biopsy (46.5%). CONCLUSIONS: Subcutaneous or port site implantation after endoscopic thyroid surgery may occur in benign thyroid pathologies and therefore, oncologic principles must be strictly followed during surgery regardless of its histopathological nature.


Assuntos
Bócio Nodular , Tireoidectomia , Humanos , Feminino , Tireoidectomia/métodos , Tireoidectomia/efeitos adversos , Adulto , Bócio Nodular/cirurgia , Bócio Nodular/patologia , Cirurgia Endoscópica por Orifício Natural/métodos , Cirurgia Endoscópica por Orifício Natural/efeitos adversos , Endoscopia/métodos
5.
Nat Commun ; 15(1): 1888, 2024 Feb 29.
Artigo em Inglês | MEDLINE | ID: mdl-38424092

RESUMO

Stacking order plays a crucial role in determining the crystal symmetry and has significant impacts on electronic, optical, magnetic, and topological properties. Electron-phonon coupling, which is central to a wide range of intriguing quantum phenomena, is expected to be intricately connected with stacking order. Understanding the stacking order-dependent electron-phonon coupling is essential for understanding peculiar physical phenomena associated with electron-phonon coupling, such as superconductivity and charge density waves. In this study, we investigate the effect of stacking order on electron-infrared phonon coupling in graphene trilayers. By using gate-tunable Raman spectroscopy and excitation frequency-dependent near-field infrared nanoscopy, we show that rhombohedral ABC-stacked trilayer graphene has a significant electron-infrared phonon coupling strength. Our findings provide novel insights into the superconductivity and other fundamental physical properties of rhombohedral ABC-stacked trilayer graphene, and can enable nondestructive and high-throughput imaging of trilayer graphene stacking order using Raman scattering.

6.
Nat Commun ; 15(1): 1825, 2024 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-38418816

RESUMO

Monolayer molybdenum disulfide (MoS2), an emergent two-dimensional (2D) semiconductor, holds great promise for transcending the fundamental limits of silicon electronics and continue the downscaling of field-effect transistors. To realize its full potential and high-end applications, controlled synthesis of wafer-scale monolayer MoS2 single crystals on general commercial substrates is highly desired yet challenging. Here, we demonstrate the successful epitaxial growth of 2-inch single-crystal MoS2 monolayers on industry-compatible substrates of c-plane sapphire by engineering the formation of a specific interfacial reconstructed layer through the S/MoO3 precursor ratio control. The unidirectional alignment and seamless stitching of MoS2 domains across the entire wafer are demonstrated through cross-dimensional characterizations ranging from atomic- to centimeter-scale. The epitaxial monolayer MoS2 single crystal shows good wafer-scale uniformity and state-of-the-art quality, as evidenced from the ~100% phonon circular dichroism, exciton valley polarization of ~70%, room-temperature mobility of ~140 cm2v-1s-1, and on/off ratio of ~109. Our work provides a simple strategy to produce wafer-scale single-crystal 2D semiconductors on commercial insulator substrates, paving the way towards the further extension of Moore's law and industrial applications of 2D electronic circuits.

7.
New Phytol ; 241(4): 1605-1620, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38179647

RESUMO

Dynamic DNA methylation regulatory networks are involved in many biological processes. However, how DNA methylation patterns change during flower senescence and their relevance with gene expression and related molecular mechanism remain largely unknown. Here, we used whole genome bisulfite sequencing to reveal a significant increase of DNA methylation in the promoter region of genes during natural and ethylene-induced flower senescence in carnation (Dianthus caryophyllus L.), which was correlated with decreased expression of DNA demethylase gene DcROS1. Silencing of DcROS1 accelerated while overexpression of DcROS1 delayed carnation flower senescence. Moreover, among the hypermethylated differentially expressed genes during flower senescence, we identified two amino acid biosynthesis genes, DcCARA and DcDHAD, with increased DNA methylation and reduced expression in DcROS1 silenced petals, and decreased DNA methylation and increased expression in DcROS1 overexpression petals, accompanied by decreased or increased amino acids content. Silencing of DcCARA and DcDHAD accelerates carnation flower senescence. We further showed that adding corresponding amino acids could largely rescue the senescence phenotype of DcROS1, DcCARA and DcDHAD silenced plants. Our study not only demonstrates an essential role of DcROS1-mediated remodeling of DNA methylation in flower senescence but also unravels a novel epigenetic regulatory mechanism underlying DNA methylation and amino acid biosynthesis during flower senescence.


Assuntos
Dianthus , Syzygium , Dianthus/genética , Syzygium/metabolismo , Senescência Vegetal , Metilação de DNA/genética , Aminoácidos/metabolismo , Flores/genética , Flores/metabolismo
8.
Sci Adv ; 9(44): eadg9819, 2023 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-37910619

RESUMO

Spin-orbit torque (SOT) is a promising strategy to deterministically switch the perpendicular magnetization, but usually requires an in-plane magnetic field for breaking the mirror symmetry, which is not suitable for most advanced industrial applications. Van der Waals (vdW) materials with low crystalline symmetry and topological band structures, e.g., Weyl semimetals (WSMs), potentially serve as an outstanding system that may simultaneously realize field-free switching and high energy efficiency. Yet, the demonstration of these superiorities at room temperature has not been realized. Here, we achieve a field-free switching of perpendicular magnetization by using a layered type II WSM, TaIrTe4, in a TaIrTe4/Ti/CoFeB system at room temperature with the critical switching current density ~2.4 × 106 A cm-2. The field-free switching is ascribed to the out-of-plane SOT allowed by the low crystal symmetry. Our work suggests that using low-symmetry materials to generate SOT is a promising route for the manipulation of perpendicular magnetization at room temperature.

9.
BMC Gastroenterol ; 23(1): 404, 2023 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-37986047

RESUMO

BACKGROUND: Very early-onset inflammatory bowel disease (VEOIBD) with interleukin-10 (IL10R) signaling deficiency usually requires enterostomy in patients who are refractory to traditional treatment. This study aimed to evaluate long-term outcomes after enterostomy for VEOIBD patients with IL10R signaling deficiency. METHODS: The medical records of all patients undergoing enterostomy for signaling deficiency were retrospectively assessed during 2012.1-2022.7 in a tertiary teaching hospital, Children's Hospital of Fudan University, Shanghai, China. Data on disease history, diagnosis and details of enterostomy and stoma closure and follow-up were collected. Univariate and multivariate logistic regression analyses were used to evaluate the risk factors associated with the long-term outcome of delayed stoma closure. RESULTS: A total of 46 patients underwent an enterostomy, 19 who required emergency enterostomy and 27 with selective enterostomy. After ten years of follow-up, 35 patients underwent hematopoietic stem cell transplantation (HSCT), and 25 patients were alive after HSCT. The median timeframe between HSCT and stoma closure was 19.6 [15.9,26.2] months. Nineteen patients underwent stoma closure and had an average age of 3.9 ± 1.5 years; 6 patients were waiting for stoma closure. Based on a univariate logistic model, risk factors significantly associated with late stoma closure were age at enterostomy and age at HSCT. However, multivariate logistic regression showed no statistically significant factor associated with late stoma closure. There was no significant difference between the stoma closure group and delay closure group in the z scores of weight for age at follow up. CONCLUSIONS: This study determined the long-term outcomes after enterostomy for VEOIBD with interleukin-10 signaling deficiency. The appropriate time point of enterostomy and HSCT may improve quality of life in the long term.


Assuntos
Enterostomia , Doenças Inflamatórias Intestinais , Criança , Humanos , Pré-Escolar , Qualidade de Vida , Interleucina-10 , Estudos Retrospectivos , China , Enterostomia/efeitos adversos , Doenças Inflamatórias Intestinais/cirurgia
10.
Nano Lett ; 23(16): 7561-7567, 2023 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-37530581

RESUMO

Chirality is an indispensable concept that pervades fundamental science and nature, manifesting itself in diverse forms, e.g., quasiparticles, and crystal structures. Of particular interest are Weyl phonons carrying specific Chern numbers and chiral phonons doing circular motions. Up to now, they have been studied independently and the interpretations of chirality seem to be different in these two concepts, impeding our understanding. Here, we demonstrate that they are entangled in chiral crystals. Employing a typical chiral crystal of elementary tellurium (Te) as a case study, we expound on the intrinsic relationship between Chern number of Weyl phonons and pseudoangular momentum (PAM, lph) of chiral phonons. We propose Raman scattering as a new technique to demonstrate the existence of Weyl phonons in Te, by detecting the chirality-induced energy splitting between the two constituent chiral phonon branches for Weyl phonons. Moreover, we also observe the obstructed phonon surface states for the first time.

11.
Science ; 379(6639): eadg0014, 2023 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-36996214

RESUMO

Moiré superlattices, the artificial quantum materials, have provided a wide range of possibilities for the exploration of completely new physics and device architectures. In this Review, we focus on the recent progress on emerging moiré photonics and optoelectronics, including but not limited to moiré excitons, trions, and polaritons; resonantly hybridized excitons; reconstructed collective excitations; strong mid- and far-infrared photoresponses; terahertz single-photon detection; and symmetry-breaking optoelectronics. We also discuss the future opportunities and research directions in this field, such as developing advanced techniques to probe the emergent photonics and optoelectronics in an individual moiré supercell; exploring new ferroelectric, magnetic, and multiferroic moiré systems; and using external degrees of freedom to engineer moiré properties for exciting physics and potential technological innovations.

12.
Plant J ; 114(3): 636-650, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36808165

RESUMO

Carnation (Dianthus caryophyllus L.) is a respiratory climacteric flower, comprising one of the most important cut flowers that is extremely sensitive to plant hormone ethylene. Ethylene signaling core transcription factor DcEIL3-1 plays a key role in ethylene induced petal senescence in carnation. However, how the dose of DcEIL3-1 is regulated in the carnation petal senescence process is still not clear. Here, we screened out two EBF (EIN3 Binding F-box) genes, DcEBF1 and DcEBF2, which showed quick elevation by ethylene treatment according to the ethylene induced carnation petal senescence transcriptome. Silencing of DcEBF1 and DcEBF2 accelerated, whereas overexpression of DcEBF1 and DcEBF2 delayed, ethylene induced petal senescence in carnation by influencing DcEIL3-1 downstream target genes but not DcEIL3-1 itself. Furthermore, DcEBF1 and DcEBF2 interact with DcEIL3-1 to degrade DcEIL3-1 via an ubiquitination pathway in vitro and in vivo. Finally, DcEIL3-1 binds to the promoter regions of DcEBF1 and DcEBF2 to activate their expression. In conclusion, the present study reveals the mutual regulation between DcEBF1/2 and DcEIL3-1 during ethylene induced petal senescence in carnation, which not only expands our understanding about ethylene signal regulation network in the carnation petal senescence process, but also provides potential targets with respect to breeding a cultivar of long-lived cut carnation.


Assuntos
Dianthus , Syzygium , Dianthus/genética , Syzygium/metabolismo , Melhoramento Vegetal , Etilenos/metabolismo , Flores/genética , Flores/metabolismo
13.
Nanomaterials (Basel) ; 13(2)2023 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-36678019

RESUMO

A semi-aromatic polybenzimidazole (DPBI) is synthesized via polycondensation of decanedioic acid (DCDA) and 3,3-diaminobenzidine (DAB) in a mixed phosphorus pentoxide/methanesulfonic acid (PPMA) solvent. Ascribing to in-situ macromolecular crosslinker of ploly((vinylbenzyl chloride) (PVBC), a robust crosslinked DPBI membrane (DPBI-xPVBC, x refers to the weight percentage of PVBC in the membrane) can be obtained. Comprehensive properties of the DPBI and DPBI-xPVBC membranes are investigated, including chemical structure, antioxidant stability, mechanical strength, PA uptake and electrochemical performances. Compared with pristine DPBI membrane, the PA doped DPBI-xPVBC membranes exhibit excellent antioxidative stability, high proton conductivity and enhanced mechanical strength. The PA doped DPBI-10PVBC membrane shows a proton conductivity of 49 mS cm-1 at 160 °C without humidification. Particularly, it reveals an enhanced H2/O2 single cell performance with the maximum peak power density of 405 mW cm-2, which is 29% higher than that of pristine DPBI membrane (314 mW cm-2). In addition, the cell is very stable in 50 h, indicating the in-situ crosslinked DPBI with a macromolecular crosslinker of PVBC is an efficient way to improve the overall performance of HT-PEMs for high performance HT-PEMFCs.

14.
J Sci Food Agric ; 103(8): 3850-3859, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36308756

RESUMO

BACKGROUND: Euryale ferox Salisb. is widely grown in China and Southeast Asia as a grain crop and medicinal plant. The composition, morphology, structure, physicochemical properties, thermal properties, and in vitro digestibility of North Euryale ferox seeds starch (NEFS), hybrid Euryale ferox seeds starch (HEFS), and South Euryale ferox seeds starch (SEFS) were studied. RESULT: Of the varieties that were studied, the amylose content of NEFS (23.03%) was the highest. Starch granules of each variety were smooth, sharp, small, and had an average diameter of 2 µm. All three varieties were A-type crystals with crystallinity ranging from 26.42% to 28.17%. The degree of double helix and the short-range order ranged from 1.9006 to 2.5324 and 1.4294 to 1.6006, respectively. The high proportion of C1 region in NEFS (17.74%) and HEFS (17.66%) were found. Thermodynamic properties in North Euryale ferox seeds included the highest onset temperature (To ) (71.43 °C), peak temperature (Tp ) (76.60 °C), conclusion temperature (Tc ) (82.77 °C), enthalpy of gelatinization (ΔH) (12.64 J g-1 ), and peak viscosity (1514 mPa·s). All three varieties maintained a low level of in vitro digestibility, with the highest resistant starch (RS) content (29.57%), the lowest rapidly digestible starch (RDS) content (27.07%), and the slowest hydrolysis kinetic constant (0.0303) in NEFS. CONCLUSION: The results revealed that the low digestibility of NEFS was attributable to compact granules, high crystallinity, high degree of order, and strong thermal stability. These digestive, physicochemical, and thermodynamic properties provide information for the future application of Euryale ferox seed starch in the food industry. © 2022 Society of Chemical Industry.


Assuntos
Nymphaeaceae , Amido , Amilose/análise , Nymphaeaceae/química , Sementes/química , Amido/química , Temperatura , Viscosidade , Fenômenos Químicos
15.
Phys Rev Lett ; 131(25): 256201, 2023 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-38181343

RESUMO

Moiré superlattices have emerged as an exciting condensed-matter quantum simulator for exploring the exotic physics of strong electronic correlations. Notable progress has been witnessed, but such correlated states are achievable usually at low temperatures. Here, we report evidence of possible room-temperature correlated electronic states and layer-hybridized SU(4) model simulator in AB-stacked MoS_{2} homobilayer moiré superlattices. Correlated insulating states at moiré band filling factors v=1, 2, 3 are unambiguously established in twisted bilayer MoS_{2}. Remarkably, the correlated electronic state at v=1 shows a giant correlated gap of ∼126 meV and may persist up to a record-high critical temperature over 285 K. The realization of a possible room-temperature correlated state with a large correlated gap in twisted bilayer MoS_{2} can be understood as the cooperation effects of the stacking-specific atomic reconstruction and the resonantly enhanced interlayer hybridization, which largely amplify the moiré superlattice effects on electronic correlations. Furthermore, extreme large nonlinear Hall responses up to room temperature are uncovered near correlated electronic states, demonstrating the quantum geometry of moiré flat conduction band.

16.
Head Neck ; 44(11): E38-E44, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36069506

RESUMO

BACKGROUND: Although the transoral endoscopic thyroidectomy vestibular approach (TOETVA) has been proven to be a safe procedure for select patients, as it is a novel approach, all associated complications require adequate attention. METHODS: We presented a 49-year old woman who underwent TOETVA developed delayed tracheal rupture 1 week after surgery. An extensive search of literature was carried out using PubMed, Embase, and Web of Science for studies reporting tracheal injury following endoscopic thyroidectomy. RESULTS: Thirteen cases of endoscopic thyroidectomy were analyzed, including eight cases of TOETVA. Tracheal injury occurred during various procedures, including accidental dissection, surgical needle puncture, Hegar dilation and trocar placement, and thermal injury by the energy device. CONCLUSIONS: Tracheal injury following TOETVA is an underreported complication that can be induced by various factors. Thermal injury to the trachea is more likely to cause a delayed rupture. Careful blunt dissection and standardized use of energy devices are suggested.


Assuntos
Cirurgia Endoscópica por Orifício Natural , Tireoidectomia , Dissecação , Feminino , Humanos , Pessoa de Meia-Idade , Cirurgia Endoscópica por Orifício Natural/efeitos adversos , Cirurgia Endoscópica por Orifício Natural/métodos , Ruptura/etiologia , Tireoidectomia/efeitos adversos , Tireoidectomia/métodos , Traqueia
17.
Front Plant Sci ; 13: 931063, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36160968

RESUMO

Euryale (Euryale ferox Salisb.) is an aquatic crop used as both food and drug in Asia, but its utilization is seriously limited due to low yield. Previously, we hypothesized that Euryale small auxin up RNAs (EuSAURs) regulate seed size, but the underlying biological functions and molecular mechanisms remain unclear. Here, we observed that the hybrid Euryale lines (HL) generate larger seeds with higher indole-3-acetic acid (IAA) concentrations than those in the North Gordon Euryale (WT). Histological analysis suggested that a larger ovary in HL is attributed to longer cells around. Overexpression of EuSAUR62 in rice (Oryza sativa L.) resulted in larger glumes and grains and increased the length of glume cells. Immunofluorescence and protein interaction assays revealed that EuSAUR62 modulates IAA accumulation around the rice ovary by interacting with the rice PIN-FORMED 9, an auxin efflux carrier protein. Euryale basic region/leucine zipper 55 (EubZIP55), which was highly expressed in HL, directly binds to the EuSAUR62 promoter and activated the expression of EuSAUR62. Constant light increased the expression of both EubZIP55 and EuSAUR62 with auxin-mediated hook curvature in HL seedlings. Overall, we proposed that EuSAUR62 is a molecular bridge between light and IAA and plays a crucial role in regulating the size of the Euryale seed.

18.
Adv Mater ; 34(52): e2200985, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35820163

RESUMO

The application of wearable devices is promoting the development toward digitization and intelligence in the field of health. However, the current smart devices centered on human health have disadvantages such as weak perception, high interference degree, and unfriendly interaction. Here, an intelligent health agent based on multifunctional fibers, with the characteristics of autonomy, activeness, intelligence, and perceptibility enabling health services, is proposed. According to the requirements for healthcare in the medical field and daily life, four major aspects driven by intelligent agents, including health monitoring, therapy, protection, and minimally invasive surgery, are summarized from the perspectives of materials science, medicine, and computer science. The function of intelligent health agents is realized through multifunctional fibers as sensing units and artificial intelligence technology as a cognitive engine. The structure, characteristics, and performance of fibers and analysis systems and algorithms are reviewed, while discussing future challenges and opportunities in healthcare and medicine. Finally, based on the above four aspects, future scenarios related to health protection of a person's life are presented. Intelligent health agents will have the potential to accelerate the realization of precision medicine and active health.


Assuntos
Inteligência Artificial , Dispositivos Eletrônicos Vestíveis , Humanos , Algoritmos , Inteligência
19.
ACS Appl Mater Interfaces ; 14(19): 22197-22205, 2022 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-35522974

RESUMO

The insufficient activation of a S/C cathode makes insufficient utilization of S in Li-S pouch cells, while the deep activation of a S/C cathode in a formation process is time-consuming and produces lithium polysulfides, which corrode a Li anode. Both situations lead to a low actual capacity of the Li-S pouch cells with a high S loading but are ignored for coin cells. In this work, electrochemical oscillation (EOS) formation employing hundreds of shallow discharge/charge cycles with high frequency was used to replace the resting and/or one deep discharge/charge cycle of traditional (TD) formation protocols. By controlling the discharge/charge capacity separately, symmetric oscillation (SOS) and asymmetric oscillation (ASOS) protocols were performed to facilitate the infiltration of electrolyte into the S cathode and restrict the formed lithium polysulfide in the cathode region. For SOS formation, the batteries were discharged/charged above 2.4 V with the same (symmetric) capacity with 2.78 × 10-3 Hz of oscillation frequency (∼1.4 mAh/g for SOS-500), in which the polysulfide dissolution was suppressed effectively. For ASOS formation, 100% discharge capacity (also ∼1.4 mAh/g for ASOS-500) and 92% charge capacity are set in each oscillation period, which leads to better activation effect but more shuttling polysulfides than SOS. Compared with SOS protocol, for ASOS protocol, more oxidative S (instead of polysulfides) inside original nonactivated cathode will be preferentially reduced in the next discharging process, but all the accumulated polysulfides during discharge of activation are oxidized into elemental S in the final charging process. These efficient formation protocols increase the practical capacity by up to 160% after 50 cycles without any change in pouch cell assembly.

20.
Nanomaterials (Basel) ; 12(5)2022 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-35269265

RESUMO

As a traditional high-temperature proton exchange membrane (HT-PEM), phosphoric acid (PA)-doped polybenzimidazole (PBI) is often subject to severe mechanical strength deterioration owing to the "plasticizing effect" of a large amount of PA. In order to address this issue, we fabricated the HT-PEMs with a crosslinked network of poly (arylene ether ketone) to confine polybenzimidazole in semi-interpenetration network using self-synthesized amino-terminated PBI (PBI-4NH2) as a crosslinker. Compared with the pristine linear poly [2,2'-(p-oxdiphenylene)-5,5'-benzimidazole] (OPBI) membrane, the designed HT-PEMs (semi-IPN/xPBI), in the semi-IPN means that the membranes with a semi-interpenetration structure and x represent the combined weight percentage of PBI-4NH2 and OPBI. In addition, they also demonstrate an enhanced anti-oxidative stability and superior mechanical properties without the sacrifice of conductivity. The semi-IPN/70PBI exhibits a higher proton conductivity than OPBI at temperatures ranging from 80 to 180 °C. The HT-PEMFC with semi-IPN/70PBI exhibits excellent H2/O2 single cell performance with a power density of 660 mW cm-2 at 160 °C with flow rates of 250 and 500 mL min-1 for dry H2 and O2 at a backpressure of 0.03 MPa, which is 18% higher than that of OPBI (561 mW cm-2) under the same test conditions. The results indicate that the introduction of PBI containing crosslinked networks is a promising approach to improve the comprehensive performance of HT-PEMs.

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