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1.
Proc Natl Acad Sci U S A ; 120(15): e2214558120, 2023 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-37011203

RESUMO

The modern pattern of the Asian monsoon is thought to have formed around the Oligocene/Miocene transition and is generally attributed to Himalaya-Tibetan Plateau (H-TP) uplift. However, the timing of the ancient Asian monsoon over the TP and its response to astronomical forcing and TP uplift remains poorly known because of the paucity of well-dated high-resolution geological records from the TP interior. Here, we present a precession-scale cyclostratigraphic sedimentary section of 27.32 to 23.24 million years ago (Ma) during the late Oligocene epoch from the Nima Basin to show that the South Asian monsoon (SAM) had already advanced to the central TP (32°N) at least by 27.3 Ma, which is indicated by cyclic arid-humid fluctuations based on environmental magnetism proxies. A shift of lithology and astronomically orbital periods and amplified amplitude of proxy measurements as well as a hydroclimate transition around 25.8 Ma suggest that the SAM intensified at ~25.8 Ma and that the TP reached a paleoelevation threshold for enhancing the coupling between the uplifted plateau and the SAM. Orbital short eccentricity-paced precipitation variability is argued to be mainly driven by orbital eccentricity-modulated low-latitude summer insolation rather than glacial-interglacial Antarctic ice sheet fluctuations. The monsoon data from the TP interior provide key evidence to link the greatly enhanced tropical SAM at 25.8 Ma with TP uplift rather than global climate change and suggest that SAM's northward expansion to the boreal subtropics was dominated by a combination of tectonic and astronomical forcing at multiple timescales in the late Oligocene epoch.

2.
Opt Express ; 32(2): 1451-1464, 2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-38297696

RESUMO

An interleaved coding Janus metasurface is proposed, which can generate bidirectional functionalities with full phase control of the reflected and transmitted waves. By introducing rotation and geometric parameter changes into the meta-atoms, the reflection and transmission channels with required energy distribution and foci are realized. More remarkably, our approach is based on a single metasurface design that arranges two types of unidirectional propagating unit structures with simultaneous desired reflection and transmission properties into a checkerboard configuration to obtain four different holograms. The results verify the excellent performances of the multifunctional metasurface, laying a foundation for manipulation of EM waves with more degree of freedom, and promoting its applications in the entire frequency spectrum.

3.
J Cell Mol Med ; 27(10): 1341-1352, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-37029501

RESUMO

Impaired mitochondrial function and dysregulated energy metabolism have been shown to be involved in the pathological progression of kidney diseases such as acute kidney injury (AKI) and diabetic nephropathy. Hence, improving mitochondrial function is a promising strategy for treating renal dysfunction. NADH: ubiquinone oxidoreductase core subunit V1 (NDUFV1) is an important subunit of mitochondrial complex I. In the present study, we found that NDUFV1 was reduced in kidneys of renal ischemia/reperfusion (I/R) mice. Meanwhile, renal I/R induced kidney dysfunction as evidenced by increases in BUN and serum creatinine, severe injury of proximal renal tubules, oxidative stress, and cell apoptosis. All these detrimental outcomes were attenuated by increased expression of NDUFV1 in kidneys. Moreover, knockdown of Ndufv1 aggravated cell insults induced by H2 O2 in TCMK-1 cells, which further confirmed the renoprotective roles of NDUFV1. Mechanistically, NDUFV1 improved the integrity and function of mitochondria, leading to reduced oxidative stress and cell apoptosis. Overall, our data indicate that NDUFV1 has an ability to maintain mitochondrial homeostasis in AKI, suggesting therapies by targeting mitochondria are useful approaches for dealing with mitochondrial dysfunction associated renal diseases such as AKI.


Assuntos
Injúria Renal Aguda , Traumatismo por Reperfusão , Animais , Camundongos , Injúria Renal Aguda/patologia , Apoptose/genética , Homeostase , Isquemia/patologia , Rim/patologia , Mitocôndrias/metabolismo , Oxirredutases/metabolismo , Traumatismo por Reperfusão/patologia
4.
Proc Natl Acad Sci U S A ; 116(31): 15368-15377, 2019 07 30.
Artigo em Inglês | MEDLINE | ID: mdl-31315983

RESUMO

Techniques for forming sophisticated, 3D mesostructures in advanced, functional materials are of rapidly growing interest, owing to their potential uses across a broad range of fundamental and applied areas of application. Recently developed approaches to 3D assembly that rely on controlled buckling mechanics serve as versatile routes to 3D mesostructures in a diverse range of high-quality materials and length scales of relevance for 3D microsystems with unusual function and/or enhanced performance. Nonlinear buckling and delamination behaviors in materials that combine both weak and strong interfaces are foundational to the assembly process, but they can be difficult to control, especially for complex geometries. This paper presents theoretical and experimental studies of the fundamental aspects of adhesion and delamination in this context. By quantifying the effects of various essential parameters on these processes, we establish general design diagrams for different material systems, taking into account 4 dominant delamination states (wrinkling, partial delamination of the weak interface, full delamination of the weak interface, and partial delamination of the strong interface). These diagrams provide guidelines for the selection of engineering parameters that avoid interface-related failure, as demonstrated by a series of examples in 3D helical mesostructures and mesostructures that are reconfigurable based on the control of loading-path trajectories. Three-dimensional micromechanical resonators with frequencies that can be selected between 2 distinct values serve as demonstrative examples.

5.
Am J Drug Alcohol Abuse ; 48(5): 548-561, 2022 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-35881880

RESUMO

Background: Methamphetamine use is associated with several negative consequences, including neurotoxicity and greater probability of exhibiting a substance use disorder. Sigma1 receptor is involved in the neurobiological basis of several drug use disorders. Cannabidiol has received attention in the treatment of drug use disorders and neurotoxicity.Objectives: To investigate the effects of cannabidiol on methamphetamine-induced conditioned place preference (CPP) and the viability of PC12 cells.Methods: Adult male rats (n = 70) underwent methamphetamine (2 mg/kg, IP) induced CPP, and were administered cannabidiol (10, 20, 40, or 80 mg/kg, IP) during the methamphetamine withdrawal period for five consecutive days. Methamphetamine (0.5 mg/kg) was then injected to reactivate CPP. Four brain regions (ventral tegmental area, nucleus accumbens, prefrontal cortex, and hippocampus) were extracted after the last test. PC12 cells were treated with cannabidiol, Sigma1R-siRNA, or BD1047 before methamphetamine exposure.Results: Administration of 20, 40, or 80 mg/kg cannabidiol facilitated CPP extinction (80 mg/kg, p < .001) and prevented CPP development (80 mg/kg, p < .0001). This was associated with changes in the expression of Sigma1R (ventral tegmental area, 80 mg/kg, p < .0001) in the four brain regions. Cannabidiol protected the PC12 cell's viability (10 µM, p = .0008) and inhibited the methamphetamine-induced activation of the AKT/GSK3ß/CREB signaling pathway by mediating Sigma1R (10 µM, p < .0001).Conclusions: Cannabidiol seems to inhibit the rewarding effects of methamphetamine and the effects of this drug on cell viability. Sigma1R should be given further consideration as a potential target for cannabidiol.


Assuntos
Canabidiol , Metanfetamina , Animais , Canabidiol/farmacologia , Glicogênio Sintase Quinase 3 beta/metabolismo , Masculino , Metanfetamina/efeitos adversos , Células PC12 , Proteínas Proto-Oncogênicas c-akt/metabolismo , RNA Interferente Pequeno/metabolismo , Ratos , Transdução de Sinais/fisiologia
6.
Sensors (Basel) ; 22(21)2022 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-36365912

RESUMO

Railway damage detection is of great significance in ensuring railway safety. The cracks on the rail surface play a key role in studying the formation and development process of rail damage, predicting the occurrence of rail defects, and then improving the service life of the rail. However, due to the small shape of the cracks, the typical detection method is relatively complicated, and the speed is quite slow. Although traditional magnetic particle inspection technology is fairly accurate at detection, it is costly and inconvenient to carry and install, while also limiting the detection speed and affecting the system's operation. In this paper, a semantic segmentation detection method is developed by using various collected rail surface crack data and deep learning through a neural network. By comparing the inspection of the same rail surface with magnetic particle inspection technology, only inexpensive cameras are used and the inspection speed is increased while maintaining relatively high accuracy. In addition, the method can achieve fast detection speeds if it is extended to be combined with high-frequency cameras. It is an economical, efficient, and environmentally friendly method for future rail surface detection.


Assuntos
Fenômenos Magnéticos , Semântica , Fenômenos Físicos
7.
J Cell Mol Med ; 25(5): 2703-2713, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33605079

RESUMO

Acute kidney injury (AKI) is the main obstacle that limits the use of cisplatin in cancer treatment. Proton pump inhibitors (PPIs), the most commonly used class of medications for gastrointestinal complications in cancer patients, have been reported to cause adverse renal events. However, the effect of PPIs on cisplatin-induced AKI remains unclear. Herein, the effect and mechanism of lansoprazole (LPZ), one of the most frequently prescribed PPIs, on cisplatin-induced AKI were investigated in vivo and in vitro. C57BL/6 mice received a single intraperitoneal (i.p.) injection of cisplatin (18 mg/kg) to induce AKI, and LPZ (12.5 or 25 mg/kg) was administered 2 hours prior to cisplatin administration and then once daily for another 2 days via i.p. injection. The results showed that LPZ significantly aggravated the tubular damage and further increased the elevated levels of serum creatinine and blood urea nitrogen induced by cisplatin. However, LPZ did not enhance cisplatin-induced tubular apoptosis, as evidenced by a lack of significant change in mRNA and protein expression of Bax/Bcl-2 ratio and TUNEL staining. Notably, LPZ increased the number of necrotic renal tubular cells compared to that by cisplatin treatment alone, which was further confirmed by the elevated necroptosis-associated protein expression of RIPK1, p-RIPK3 and p-MLKL. Furthermore, LPZ deteriorated cisplatin-induced inflammation, as revealed by the increased mRNA expression of pro-inflammatory factors including, NLRP3, IL-1ß, TNF-α and caspase 1, as well as neutrophil infiltration. Consistently, in in vitro study, LPZ increased HK-2 cell death and enhanced inflammation, compared with cisplatin treatment alone. Collectively, our results demonstrate that LPZ aggravates cisplatin-induced AKI, and necroptosis may be involved in the exacerbation of kidney damage.


Assuntos
Antineoplásicos/efeitos adversos , Cisplatino/efeitos adversos , Necrose Tubular Aguda/etiologia , Necrose Tubular Aguda/metabolismo , Lansoprazol/efeitos adversos , Injúria Renal Aguda/etiologia , Injúria Renal Aguda/metabolismo , Injúria Renal Aguda/patologia , Animais , Apoptose/efeitos dos fármacos , Modelos Animais de Doenças , Sinergismo Farmacológico , Necrose Tubular Aguda/patologia , Camundongos
8.
Proc Natl Acad Sci U S A ; 115(36): 8913-8918, 2018 09 04.
Artigo em Inglês | MEDLINE | ID: mdl-30126998

RESUMO

Polarity reversals of the geomagnetic field have occurred through billions of years of Earth history and were first revealed in the early 20th century. Almost a century later, details of transitional field behavior during geomagnetic reversals and excursions remain poorly known. Here, we present a multidecadally resolved geomagnetic excursion record from a radioisotopically dated Chinese stalagmite at 107-91 thousand years before present with age precision of several decades. The duration of geomagnetic directional oscillations ranged from several centuries at 106-103 thousand years before present to millennia at 98-92 thousand years before present, with one abrupt reversal transition occurring in one to two centuries when the field was weakest. These features indicate prolonged geodynamo instability. Repeated asymmetrical interhemispheric polarity drifts associated with weak dipole fields likely originated in Earth's deep interior. If such rapid polarity changes occurred in future, they could severely affect satellites and human society.

9.
Soft Matter ; 14(5): 693-703, 2018 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-29226930

RESUMO

Auxetic materials with negative Poisson's ratios have important applications across a broad range of engineering areas, such as biomedical devices, aerospace engineering and automotive engineering. A variety of design strategies have been developed to achieve artificial auxetic materials with controllable responses in the Poisson's ratio. The development of designs that can offer isotropic negative Poisson's ratios over large strains can open up new opportunities in emerging biomedical applications, which, however, remains a challenge. Here, we introduce deterministic routes to soft architected materials that can be tailored precisely to yield the values of Poisson's ratio in the range from -1 to 1, in an isotropic manner, with a tunable strain range from 0% to ∼90%. The designs rely on a network construction in a periodic lattice topology, which incorporates zigzag microstructures as building blocks to connect lattice nodes. Combined experimental and theoretical studies on broad classes of network topologies illustrate the wide-ranging utility of these concepts. Quantitative mechanics modeling under both infinitesimal and finite deformations allows the development of a rigorous design algorithm that determines the necessary network geometries to yield target Poisson ratios over desired strain ranges. Demonstrative examples in artificial skin with both the negative Poisson's ratio and the nonlinear stress-strain curve precisely matching those of the cat's skin and in unusual cylindrical structures with engineered Poisson effect and shape memory effect suggest potential applications of these network materials.

10.
Neurol Sci ; 36(4): 621-3, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25367407

RESUMO

In previous study, we have found the catechol-O-methyltransferase (COMT) Val158Met polymorphism may be associated with the risk of Parkinson's disease (PD) in Asians, especially Japanese population. In this study, we further evaluated the associations of PD wearing-off susceptibility with COMT polymorphisms. We carried out a retrieval of studies and included the relevant studies which met the criteria. After the data were extracted, the Stata software 11.0 was used to analyse the genotype frequencies. A total of five studies were included. The pooled result indicated that genotype AA was significantly associated with the wearing-off risk of PD (AA vs. others: OR = 2.52, 95 % CI 1.21-5.26, P = 0.013; AA vs. GA: OR = 2.51, 95 % CI 1.18-5.34, P = 0.017; AA vs. GG: OR = 2.17, 95 % CI 1.09-4.33, P = 0.027). The results also showed allele A was correlated with PD wearing-off risk (A vs. G: OR = 1.95, 95 % CI 1.18-3.22, P = 0.009). In conclusion, this study suggested that Val158Met polymorphisms in COMT may increase the risk of wearing-off. Further studies with larger sample sizes are needed to confirm our results.


Assuntos
Catecol O-Metiltransferase/genética , Predisposição Genética para Doença/genética , Doença de Parkinson/genética , Doença de Parkinson/fisiopatologia , Polimorfismo de Nucleotídeo Único/genética , Bases de Dados Bibliográficas , Feminino , Estudos de Associação Genética , Genótipo , Humanos , Japão , Masculino , Metionina/genética , Valina/genética
11.
Sensors (Basel) ; 14(5): 8513-27, 2014 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-24834907

RESUMO

A Highway Intelligent Space System (HISS) is proposed to study vehicle environment perception in this paper. The nature of HISS is that a space sensors system using laser, ultrasonic or radar sensors are installed in a highway environment and communication technology is used to realize the information exchange between the HISS server and vehicles, which provides vehicles with the surrounding road information. Considering the high-speed feature of vehicles on highways, when vehicles will be passing a road ahead that is prone to accidents, the vehicle driving state should be predicted to ensure drivers have road environment perception information in advance, thereby ensuring vehicle driving safety and stability. In order to verify the accuracy and feasibility of the HISS, a traditional vehicle-mounted sensor system for environment perception is used to obtain the relative driving state. Furthermore, an inter-vehicle dynamics model is built and model predictive control approach is used to predict the driving state in the following period. Finally, the simulation results shows that using the HISS for environment perception can arrive at the same results detected by a traditional vehicle-mounted sensors system. Meanwhile, we can further draw the conclusion that using HISS to realize vehicle environment perception can ensure system stability, thereby demonstrating the method's feasibility.


Assuntos
Redes de Comunicação de Computadores/instrumentação , Monitoramento Ambiental/instrumentação , Monitoramento Ambiental/métodos , Veículos Automotores , Processamento de Sinais Assistido por Computador/instrumentação , Transdutores , Tecnologia sem Fio/instrumentação , Simulação por Computador , Desenho de Equipamento , Análise de Falha de Equipamento , Armazenamento e Recuperação da Informação/métodos , Modelos Teóricos
12.
IEEE Trans Cybern ; 54(1): 123-135, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37099468

RESUMO

This article aims to solve a hierarchical multi-UAV Dubins traveling salesman problem (HMDTSP). Optimal hierarchical coverage and multi-UAV collaboration are achieved by the proposed approaches in a 3-D complex obstacle environment. A multi-UAV multilayer projection clustering (MMPC) algorithm is presented to reduce the cumulative distance from multilayer targets to corresponding cluster centers. A straight-line flight judgment (SFJ) was developed to reduce the calculation of obstacle avoidance. An improved adaptive window probabilistic roadmap (AWPRM) algorithm is addressed to plan obstacle-avoidance paths. The AWPRM improves the feasibility of finding the optimal sequence based on the proposed SFJ compared with a traditional probabilistic roadmap. To solve the solution to TSP with obstacles constraints, the proposed sequencing-bundling-bridging (SBB) framework combines the bundling ant colony system (BACS) and homotopic AWPRM. An obstacle-avoidance optimal curved path is constructed with a turning radius constraint based on the Dubins method and followed up by solving the TSP sequence. The results of simulation experiments indicated that the proposed strategies can provide a set of feasible solutions for HMDTSPs in a complex obstacle environment.

13.
ACS Nano ; 2024 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-38315123

RESUMO

Rapid advancements in human-machine interaction and voice biometrics impose desirability on soft mechanical sensors for sensing complex dynamic signals. However, existing soft mechanical sensors mainly concern quasi-static signals such as pressure and pulsation for health monitoring, limiting their applications in emerging wearable electronics. Here, we propose a hydrogel-based soft mechanical sensor that enables recording a wide range of dynamic signals relevant to humans by combining a preloading design strategy and iontronic sensing mechanism. The proposed sensor offers a two-orders-of-magnitude larger working bandwidth (up to 1000 Hz) than most of the reported soft mechanical sensors and meanwhile provides a high sensitivity (-23 dB) that surpasses the common commercial microphone. The amplitude-frequency characteristic of the proposed sensor can be precisely tuned to meet the desired requirement by adjusting the preloads and the parameters of the microstructured hydrogel. The sensor is capable of recording instrumental sounds with high fidelity from simple pure tones to melodic songs. Demonstration of a skin-mountable sensor used for human-voice-based remote control of a toy car shows great potential for applications in the voice user interface of human-machine interactions.

14.
ACS Appl Mater Interfaces ; 16(25): 32411-32424, 2024 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-38865596

RESUMO

Introducing auxetic metamaterials into stretchable electronics shows promising prospects for enhancing the performance and innovating the functionalities of various devices, such as stretchable strain sensors. Nevertheless, most existing auxetics fail to meet the requirement of stretchable electronics, which typically include high mechanical flexibility and stable Poisson's ratio over large deformations. Moreover, despite being highly advantageous for application in diverse load-bearing conditions, achieving tunability of J-shaped stress-strain response independent of negative Poisson's ratio remains a significant challenge. This paper introduces a class of hybrid-microstructure-based soft network materials (HMSNMs) consisting of different types of microstructures along the loading and transverse directions. The J-shaped stress-strain curve and nonlinear Poisson's ratio for HMSNMs can be tuned independently of each other. The HMSNM provides much higher strength than the corresponding existing metamaterial while offering a nearly stable negative Poisson's ratio over large strains. Both mechanical properties under infinitesimal and large deformations can be well-tuned by geometric parameters. Fascinating functionalities such as shape programming and stress regulation are achieved by integrating a set of HMSNMs in series/parallel configurations. A stretchable LED-integrated display capable of displaying dynamic images without distortion under uniaxial stretching serves as a demonstrative application.

15.
IEEE Trans Cybern ; PP2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38358862

RESUMO

Multiple batteries in uninterruptible power supply (UPS)-microgrid systems based on multiagents composed of multiple electric vehicles (EVs) can encounter state of charge (SoC) consistency problems. To solve this differential expansion and controller saturation problem, an adaptive command filter sliding-mode control strategy based on virtual synchronous generators (VSGs) and considering the power allocation principle is proposed. First, based on directed graph theory, an SoC consistency algorithm and power allocation strategy for multiple EVs were proposed, forming a dc power system with a fixed communication topology. Second, the rotor motion equation of synchronous generator (SG) is introduced into the inverter control algorithm to form the mathematical model of VSG. Third, a low-pass filter (LFP) was introduced in the voltage control process to simulate the excitation attenuation characteristics of the SG. Based on the above, a backstepping control strategy, including a command filter and sliding mode controller is proposed, which improves the operating stability of the system based on the system errors of angle, frequency, and power output. Finally, the UPS-microgrid system based on multiagents is simulated to demonstrate the stability of the system and the effectiveness of the proposed control strategy.

16.
Stem Cells Int ; 2024: 5579228, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38550755

RESUMO

The immunoregulatory role of mesenchymal stem cells (MSCs) in inflammation is heterogeneous and can exhibit anti-inflammatory or proinflammatory properties depending on the microenvironment. We herein observed that the activation of Toll-like receptor 3 (TLR3) by polyinosinic : polycytidylic acid (poly(I : C)) stimulation facilitated the transformation of adipose-derived stem cells (ADSCs) into an anti-inflammatory phenotype. The enhanced anti-inflammatory properties were assessed in a taurocholate-induced pancreatitis model. The results demonstrated that poly(I : C) pretreated ADSCs exhibited enhanced anti-inflammatory properties than untreated ADSCs in taurocholate-induced pancreatitis. Mechanistically, poly(I : C)-treated ADSCs showed increased production and secretion of interleukin-10 (IL-10), which demonstrates a potent ability to alleviate inflammatory signaling cascades in acinar cells. Simultaneously, the heightened anti-inflammatory effects of poly(I : C)-treated ADSCs in pancreatitis were associated with the regulation of macrophage classical/alternative transformation, thereby mitigating inflammatory factor-mediated damage to the pancreatic acinar cell. We propose that TLR3 activation by poly(I : C) is an effective strategy to enhance the anti-inflammatory properties of MSCs, which offers a valuable consideration for improving the therapeutic efficacy of MSCs in inflammatory diseases.

17.
Sci Adv ; 10(25): eadm8270, 2024 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-38896619

RESUMO

East Asian winter monsoon (EAWM) activity has had profound effects on environmental change throughout East Asia and the western Pacific. Much attention has been paid to Quaternary EAWM evolution, while long-term EAWM fluctuation characteristics and drivers remain unclear, particularly during the late Miocene when marked global climate and Asian paleogeographic changes occurred. To clarify understanding of late Miocene EAWM evolution, we developed a high-precision 9-million-year-long stacked EAWM record from Northwest Pacific Ocean abyssal sediments based on environmental magnetism, sedimentology, and geochemistry, which reveals a strengthened late Miocene EAWM. Our paleoclimate simulations also indicate that atmospheric CO2 decline played a vital role in this EAWM intensification over the Northwest Pacific Ocean compared to other factors, including central Asian orogenic belt and northeastern Tibetan Plateau uplift and Antarctic ice-sheet expansion. Our results expand understanding of EAWM evolution from inland areas to the open ocean and indicate the importance of atmospheric CO2 fluctuations on past EAWM variability over large spatial scales.

18.
Bioorg Med Chem Lett ; 23(3): 630-4, 2013 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-23290455

RESUMO

In our previous studies, geraniin was reported to have a preventive effect in the rat model of tretinoin-induced osteoporosis. However, whether geraniin exhibits an inhibitory effect on bone resorption or on MMP-9 expression is not yet known. We present here our novel findings from in vitro experiments that geraniin (a) decreases the number of mature osteoclasts and pre-osteoclast in cultures, (b) reduces the osteoclastic fusion index, and (c) inhibits the resorption areas and resorption pits. We also report that geraniin suppresses the mRNA and protein expression levels of MMP-9. These results demonstrate that geraniin has an inhibitory effect on the bone-absorption ability of osteoclasts in vitro, and the mechanisms may be closely associated with the downregulation of mRNA and protein expression of MMP-9.


Assuntos
Reabsorção Óssea , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Glucosídeos/farmacologia , Taninos Hidrolisáveis/farmacologia , Metaloproteinase 9 da Matriz/metabolismo , Osteoclastos/efeitos dos fármacos , Animais , Conservadores da Densidade Óssea/farmacologia , Linhagem Celular , Inibidores Enzimáticos/farmacologia , Glucosídeos/química , Taninos Hidrolisáveis/química , Metaloproteinase 9 da Matriz/genética , Estrutura Molecular , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos
19.
Adv Sci (Weinh) ; 10(8): e2206099, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36698297

RESUMO

Soft network materials (SNMs) represent one of the best candidates for the substrates and the encapsulation layers of stretchable inorganic electronics, because they are capable of precisely customizing the J-shaped stress-strain curves of biological tissues. Although a variety of microstructures and topologies have been exploited to adjust the nonlinear stress-strain responses of SNMs, the stretchability of most SNMs is hard to exceed 100%. Designing novel high-strength SNMs with much larger stretchability (e.g., >200%) than existing SNMs and conventional elastomers remains a challenge. This paper develops a class of hierarchical soft network materials (HSNMs) with developable lattice nodes, which can significantly improve the stretchability of SNMs without any loss of strength. The effects of geometric parameters, lattice topologies, and loading directions on the mechanical properties of HSNMs are systematically discussed by experiments and numerical simulations. The proposed node design strategy for SNMs is also proved to be widely applicable to different constituent materials, including polymers and metals.

20.
ISA Trans ; 138: 639-649, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36813663

RESUMO

This paper proposes a novel adaptive-gain generalized super twisting algorithm for permanent magnet synchronous motors. The stability of this algorithm is strict proof using the Lyapunov method. Both controllers of the speed-tracking loop and the current regulation loop are designed according to the proposed adaptive-gain generalized super twisting algorithm. Dynamically adjusted gains in the controllers can improve the transient performance and system's robustness while reducing chattering. A filtered high-gain observer is applied in the speed-tracking loop to estimate the lumped disturbances, including parameter uncertainties and external load torque disturbances. The estimates feeding forward to the controller further improve the robustness of the system. Meanwhile, the linear filtering subsystem reduces the sensitivity of the observer to the measurement noise. Finally, experiments are constructed using the adaptive gain generalized super twisting sliding mode algorithm and the fixed gain one, showing the effectiveness and advantages of the proposed control scheme.

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