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Acquired undescended testes were once considered a sporadic disease. In recent years, reports suggest that they are not uncommon, with an incidence rate about 3 times that of congenital undescended testes. The etiology of acquired undescended testes remains inconclusive, clinical diagnostic standards are unclear, and treatment approaches are still controversial. There is ongoing debate about the mechanism of testicular ascent. The prevailing view is that acquired undescended testes occur due to the partial absorption of the gubernaculum, which forms part of the parietal peritoneum. The residual gubernacular fibers continuously pull on the spermatic cord, preventing the spermatic cord from elongating proportionately to somatic growth, leading to a re-ascent of the testis. Acquired undescended testes may increase the risk of testicular cancer, but this is still debated. The preferred treatment method is also controversial. However, surgical fixation has an immediate effect; no studies have proven that early surgery improves fertility in patients. The etiology of acquired undescended testes is closely related to the continuous pull of the residual gubernacular fibers on the spermatic cord, which prevents the cord from extending proportionately to body growth. There are no clear diagnostic standards for acquired undescended testes yet, and spontaneous descent is possible, so testicular fixation surgery may not be the preferred treatment method.
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Criptorquidismo , Humanos , Masculino , Criptorquidismo/terapia , Criptorquidismo/diagnóstico , Criptorquidismo/etiologia , Testículo , OrquidopexiaRESUMO
Cuproptosis is characterized by the aggregation of lipoylated enzymes of the tricarboxylic acid cycle and subsequent loss of iron-sulfur cluster proteins as a unique copper-dependent form of regulated cell death. As dysregulation of copper homeostasis can induce cuproptosis, there is emerging interest in exploiting cuproptosis for cancer therapy. However, the molecular drivers of cancer cell evasion of cuproptosis were previously undefined. Here, we found that cuproptosis activates the Wnt/ß-catenin pathway. Mechanistically, copper binds PDK1 and promotes its interaction with AKT, resulting in activation of the Wnt/ß-catenin pathway and cancer stem cell (CSC) properties. Notably, aberrant activation of Wnt/ß-catenin signaling conferred resistance of CSCs to cuproptosis. Further studies showed the ß-catenin/TCF4 transcriptional complex directly binds the ATP7B promoter, inducing its expression. ATP7B effluxes copper ions, reducing intracellular copper and inhibiting cuproptosis. Knockdown of TCF4 or pharmacological Wnt/ß-catenin blockade increased the sensitivity of CSCs to elesclomol-Cu-induced cuproptosis. These findings reveal a link between copper homeostasis regulated by the Wnt/ß-catenin pathway and cuproptosis sensitivity, and suggest a precision medicine strategy for cancer treatment through selective cuproptosis induction.
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BACKGROUND: The incidence of osteochondral defects caused by trauma, arthritis or tumours is increasing annually, but progress has not been made in terms of treatment methods. Due to the heterogeneous structure and biological characteristics of cartilage and subchondral bone, the integration of osteochondral repair is still a challenge. RESULTS: In the present study, a novel bilayer hydrogel scaffold was designed based on anatomical characteristics to imitate superficial cartilage and subchondral bone. The scaffold showed favourable biocompatibility, and the addition of an antioxidant nanozyme (LiMn2O4) promoted reactive oxygen species (ROS) scavenging by upregulating antioxidant proteins. The cartilage layer effectively protects against chondrocyte degradation in the inflammatory microenvironment. Subchondral bionic hydrogel scaffolds promote osteogenic differentiation of rat bone marrow mesenchymal stem cells (BMSCs) by regulating the AMPK pathway in vitro. Finally, an in vivo rat preclinical osteochondral defect model confirmed that the bilayer hydrogel scaffold efficiently promoted cartilage and subchondral bone regeneration. CONCLUSIONS: In general, our biomimetic hydrogel scaffold with the ability to regulate the inflammatory microenvironment can effectively repair osteochondral defects. This strategy provides a promising method for regenerating tissues with heterogeneous structures and biological characteristics.
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Regeneração Óssea , Hidrogéis , Células-Tronco Mesenquimais , Osteogênese , Ratos Sprague-Dawley , Alicerces Teciduais , Animais , Hidrogéis/química , Hidrogéis/farmacologia , Alicerces Teciduais/química , Ratos , Células-Tronco Mesenquimais/efeitos dos fármacos , Regeneração Óssea/efeitos dos fármacos , Osteogênese/efeitos dos fármacos , Condrócitos/efeitos dos fármacos , Masculino , Diferenciação Celular/efeitos dos fármacos , Inflamação , Engenharia Tecidual/métodos , Espécies Reativas de Oxigênio/metabolismo , Condrogênese/efeitos dos fármacos , Cartilagem/efeitos dos fármacos , Cartilagem Articular/efeitos dos fármacos , Células CultivadasRESUMO
The judicious management of water and nitrogen (N) is pivotal for augmenting crop productivity and N use efficiency, while also mitigating environmental concerns. With the advent of the High-Farmland Construction Program in China, one-off irrigation has become feasible for most dryland fields, presenting a novel opportunity to explore the synergistic strategies of water and N management. This study delves into the impact of one-off alternate furrow irrigation (AFI) and topdressing N fertilizer (TN) on soil nitrate-N distribution, and N productivity-including plant N accumulation, translocation, and allocation, and grain yield, protein content, N use efficiency of winter wheat (Triticum aestivum L.) in 2018-2019 and 2019-2020. Experimental treatments administered at the jointing stage comprised of two irrigation methods-every (EFI) and alternative (AFI) furrow irrigation at 75 mm, and two topdressing N rates-0 (NTN) and 60 (TN) kg N ha-1. Additionally, a conventional local farmer practice featuring no irrigation and no topdressing N (NINTN) was served as control. Compared to NINTN, EFINTN substantially increased aboveground N accumulation, grain yield, and protein yield, albeit with a reduction in grain protein content by 8.1%-10.6%. AFI, in turn, led to higher nitrate-N accumulation in the 60-160 cm soil depth at booting and anthesis, but diminished levels at maturity, resulting in a significant surge in N accumulation from anthesis to maturity and its contribution to grain, N fertilizer partial factor productivity (PFPN), and N uptake efficiency (NUPE), thereby promoting grain yield by 9.9% and preserving grain protein content. Likewise, TN enhanced soil nitrate-N at key growth stages, reflected in marked improvements in N accumulation both from booting to anthesis and from anthesis to maturity, as well as in grain yield, protein content, and protein yield. The combination of AFI and TN (AFITN) yielded the highest grain yield, protein content, with PFPN, NUPE, and N internal efficiency outstripping those of EFINTN, but not AFINTN. In essence, one-off AFI coupled with TN at the jointing stage is a promising strategy for optimizing soil nitrate-N and enhancing wheat N productivity in dryland where one-off irrigation is assured.
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The aim of this study was to optimize the formation of sodium caseinate (CS) and gum arabic (GA) complexes through the Maillard reaction and to evaluate their effectiveness in improving the emulsification properties and stability of docosahexaenoic acid (DHA) nanoemulsions. First, the best target polysaccharides were selected, and the best modification conditions were determined using orthogonal experiments. Secondly, the response surface experiments were used to optimize the preparation process of the emulsion. The stability, in vitro digestion characteristics, and rheological characteristics of the emulsion prepared by means of CS-GA were compared with the emulsion prepared using a whey protein isolate (WPI). After the orthogonal test, the optimal modification conditions were determined to be a reaction time of 96 h, a CS-GA mass ratio of 1:2, a reaction temperature of 60 °C, and a degree of grafting of 44.91%. Changes in the infrared (IR), Raman, ultraviolet (UV), and endogenous fluorescence spectra also indicated that the complex structure was modified. The response surface test identified the optimal preparation process as follows: an emulsifier concentration of 5 g/L, an oil-phase concentration of 5 g/L, and a homogenization frequency of five, and the emulsion showed good stability. Therefore, the use of a nanoemulsion as a nanoscale DHA algal oil delivery system is very promising for extending the shelf life and improving the stability of food.
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The formation of phytoene by condensing two geranylgeranyl diphosphate molecules catalyzed by phytoene synthase (PSY) is the first committed and rate-limiting step in carotenoid biosynthesis, which has been extensively investigated in bacteria, land plants and microalgae. However, this step in macroalgae remains unknown. In the present study, a gene encoding putative phytoene synthase was cloned from the economic red alga Pyropia yezoensis-a species that has long been used in food and pharmaceuticals. The conservative motifs/domains and the tertiary structure predicted using bioinformatic tools suggested that the cloned PyPSY should encode a phytoene synthase; this was empirically confirmed by pigment complementation in E. coli. This phytoene synthase was encoded by a single copy gene, whose expression was presumably regulated by many factors. The phylogenetic relationship of PSYs from different organisms suggested that red algae are probably the progeny of primary endosymbiosis and plastid donors of secondary endosymbiosis.
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Geranil-Geranildifosfato Geranil-Geraniltransferase , Filogenia , Rodófitas , Rodófitas/genética , Rodófitas/enzimologia , Geranil-Geranildifosfato Geranil-Geraniltransferase/genética , Geranil-Geranildifosfato Geranil-Geraniltransferase/metabolismo , Carotenoides/metabolismo , Escherichia coli/genética , Clonagem Molecular , Algas Comestíveis , PorphyraRESUMO
An Electroencephalography (EEG) dataset utilizing rich text stimuli can advance the understanding of how the brain encodes semantic information and contribute to semantic decoding in brain-computer interface (BCI). Addressing the scarcity of EEG datasets featuring Chinese linguistic stimuli, we present the ChineseEEG dataset, a high-density EEG dataset complemented by simultaneous eye-tracking recordings. This dataset was compiled while 10 participants silently read approximately 13 hours of Chinese text from two well-known novels. This dataset provides long-duration EEG recordings, along with pre-processed EEG sensor-level data and semantic embeddings of reading materials extracted by a pre-trained natural language processing (NLP) model. As a pilot EEG dataset derived from natural Chinese linguistic stimuli, ChineseEEG can significantly support research across neuroscience, NLP, and linguistics. It establishes a benchmark dataset for Chinese semantic decoding, aids in the development of BCIs, and facilitates the exploration of alignment between large language models and human cognitive processes. It can also aid research into the brain's mechanisms of language processing within the context of the Chinese natural language.
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Eletroencefalografia , Semântica , Humanos , Encéfalo/fisiologia , Interfaces Cérebro-Computador , China , Idioma , Linguística , Processamento de Linguagem Natural , LeituraRESUMO
Demetalation caused by the electrochemical dissolution of metallic Fe atoms is a major challenge for the practical application of FeâNâC catalysts. Herein, an efficient single metallic Mn active site is constructed to improve the strength of the FeâN bond, inhibiting the demetalation effect of FeâNâC. Mn acts as an electron donor inducing more delocalized electrons to reduce the oxidation state of Fe by increasing the electron density, thereby enhancing the FeâN bond and inhibiting the electrochemical dissolution of Fe. The oxygen reduction reaction pathway for the dissociation of FeâMn dual sites can overcome the high energy barriers to direct OâO bond dissociation and modulate the electronic states of FeâN4 sites. The resulting FeMnâNâC exhibits excellent ORR activity with a high half-wave potential of 0.92 V in alkaline electrolytes. FeMnâNâC as a cathode catalyst for Zn-air batteries has a cycle stability of 700 h at 25 °C and a long cycle stability of more than 210 h under extremely cold conditions at -40 °C. These findings contribute to the development of efficient and stable metal-nitrogen-carbon catalysts for various energy devices.
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Anion exchange membrane (AEM) fuel cells (AEMFCs) and water electrolyzers (AEMWEs) suffer from insufficient performance and durability compared with commercialized energy conversion systems. Great efforts have been devoted to designing high-quality AEMs and catalysts. However, the significance of the stability of the catalyst layer has been largely disregarded. Here, an in situ cross-linking strategy was developed to promote the interactions within the catalyst layer and the interactions between catalyst layer and AEM. The adhesion strength of the catalyst layer after cross-linking was improved 7 times compared with the uncross-linked catalyst layer due to the formation of covalent bonds between the catalyst layer and AEM. The AEMFC can be operated under 0.6 A cm-2 for 1000 h with a voltage decay rate of 20 µV h-1. The related AEMWE achieved an unprecedented current density of 15.17 A cm-2 at 2.0 V and was operated at 0.5, 1.0, and 1.5 A cm-2 for 1000 h.
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To handle with the nonlinear external disturbances and unmodeled dynamics of self-balanced vehicle (SBV), a novel adaptive trajectory tracking controller based on asymptotic prescribed performance is proposed. First, a velocity planner based on kinematic is constructed to control the velocity signal to improve the motion stability of SBV. Second, the prescribed performance function (PPF) is designed to prescribe transient-state and steady-state performances (TSP). Afterwards, an optimization-based predictive control (OPC) is proposed for accurate trajectory tracking of SBV. Furthermore, a modified radial basis function neural network (RBFNN) approximator is developed to compensate the unmodeled dynamics and the nonlinear external disturbances of the SBV. The overall system stability is proved with the help of Lyapunov theorem. Finally, the tracking performance and anti-interference robustness of the proposed control method are verified by comparative numerical simulations.
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OBJECTIVE: This study aimed to elucidate brain areas mediated by oral anti-parkinsonian medicine that consistently show abnormal resting-state activation in PD and to reveal their functional connectivity profiles using meta-analytic approaches. METHODS: Searches of the PubMed, Web of Science databases identified 78 neuroimaging studies including PD OFF state (PD-OFF) versus (vs.) PD ON state (PD-ON) or PD-ON versus healthy controls (HCs) or PD-OFF versus HCs data. Coordinate-based meta-analysis and functional meta-analytic connectivity modeling (MACM) were performed using the activation likelihood estimation algorithm. RESULTS: Brain activation in PD-OFF vs. PD-ON was significantly changed in the right putamen and left inferior parietal lobule (IPL). Contrast analysis indicated that PD-OFF vs. HCs had more consistent activation in the right paracentral lobule, right middle frontal gyrus, right thalamus, left superior parietal lobule and right putamen, whereas PD-ON vs. HCs elicited more consistent activation in the bilateral middle temporal gyrus, left occipital gyrus, right inferior frontal gyrus and right caudate. MACM revealed coactivation of the right putamen in the direct contrast of PD-OFF vs. PD-ON. Subtraction analysis of significant coactivation clusters for PD-OFF vs. PD-ON with the medium of HCs showed effects in the sensorimotor, top-down control, and visual networks. By overlapping the MACM maps of the two analytical strategies, we demonstrated that the coactivated brain region focused on the right putamen. CONCLUSIONS: The convergence of local brain regions and co-activation neural networks are involved the putamen, suggesting its potential as a specific imaging biomarker to monitor treatment efficacy. SYSTEMATIC REVIEW REGISTRATION: [https://www.crd.york.ac.uk/PROSPERO/], identifier [CRD CRD42022304150].
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Doença de Parkinson , Putamen , Humanos , Putamen/diagnóstico por imagem , Putamen/metabolismo , Doença de Parkinson/diagnóstico por imagem , Doença de Parkinson/fisiopatologia , Doença de Parkinson/tratamento farmacológico , Dopamina/metabolismo , Neuroimagem/métodos , Imageamento por Ressonância Magnética/métodos , Descanso , Mapeamento Encefálico/métodosRESUMO
The low targeted drug delivery efficiency, including poor tumor accumulation and penetration and uncontrolled drug release, leads to the failure of cancer therapy. Herein, a multifunctional supramolecular nanoplatform loading triptolide (TPL/PBAETK@GA NPs) was fabricated via the host-guest interaction between glycyrrhetinic-acid-modified poly(ethylene glycol)-adamantanecarboxylic acid moiety and reactive oxygen species (ROS)/pH cascade-responsive copolymer poly(ß-amino esters)-thioketal (TK)-ß-cyclodextrin. TPL/PBAETK@GA NPs could accumulate in hepatocellular carcinoma (HCC) tissue effectively, mediated by nanoscale advantage and GA' recognition to specific receptors. The elevated concentration of ROS in tumor microenvironment (TME) quickly breaks the TK linkages, causing the detachment of shell (cyclodextrin) CD layer. Then, the accompanying negative-to-positive charge-reversal of NPs was realized via the PBAE moiety protonation under the slightly acidic TME, significantly enhancing the NPs' cellular internalization. Remarkably, the pH-responsive endo/lysosome escape of PBAE core triggered intracellular TPL burst release, promoting the cancer cell apoptosis, autophagy, and intracellular ROS generation, leading to the self-amplification of ROS in TME. Afterward, the ROS positive-feedback loop was generated to further promote size-shrinkage and charge-reversal of NPs. Both in vitro and in vivo tests verified that TPL/PBAETK@GA NPs produced a satisfactory anti-HCC therapy outcome. Collectively, this study offers a potential appealing paradigm to enhance TPL-based HCC therapy outcomes via multifunctionalized supramolecular nanodrugs.
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Carcinoma Hepatocelular , Neoplasias Hepáticas , Nanopartículas , Humanos , Carcinoma Hepatocelular/tratamento farmacológico , Espécies Reativas de Oxigênio , Microambiente Tumoral , Neoplasias Hepáticas/tratamento farmacológico , Concentração de Íons de Hidrogênio , Regeneração , Nanopartículas/química , Linhagem Celular TumoralRESUMO
During the freeze-thaw process, human spermatozoa are susceptible to oxidative stress, which may cause cryodamage and reduce sperm quality. As a novel mitochondria-targeted antioxidant, Mito-tempo has been used for sperm cryopreservation. However, it is currently unknown what role it will play in the process of sperm ultra-rapid freezing. The purpose of this study was to investigate whether Mito-tempo can improve sperm quality during ultra-rapid freezing. In this study, samples with the addition of Mito-tempo (0, 5, 10, 20, and 40 µM) to sperm freezing medium were selected to evaluate the changes in sperm quality, antioxidant capacity and ultrastructure after ultra-rapid freezing. After ultra-rapid freezing, the quality and antioxidant function of the spermatozoa were significantly reduced and the spermatozoa ultrastructure was destroyed. The addition of 10 µM Mito-tempo significantly increased post thaw sperm motility, viability, plasma membrane integrity and mitochondrial membrane potential (P < 0.05). Moreover, the DNA fragmentation index (DFI), ROS levels and MDA content were reduced, and the antioxidant enzyme (CAT and SOD) activities were enhanced in the 10 µM Mito-tempo group (P < 0.05). Moreover, Mito-tempo protected sperm ultrastructure from damage. In conclusion, Mito-tempo improved the quality and antioxidant function of sperm after ultra-rapid freezing while reducing freezing-induced ultrastructural damage.
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Antioxidantes , Preservação do Sêmen , Masculino , Humanos , Antioxidantes/farmacologia , Congelamento , Criopreservação/métodos , Motilidade dos Espermatozoides , Crioprotetores/farmacologia , Sêmen , Espermatozoides , MitocôndriasRESUMO
BACKGROUND: No study has yet demonstrated the effect of lower limb gait rehabilitation robot treatment combined with acupuncture on stroke patients. OBJECTIVE: To explore the effect of acupuncture combined with lower limb gait rehabilitation robot on walking function in patients with hemiplegia after stroke. METHODS: Fifty-six patients with hemiplegia after stroke were enrolled and randomly divided into two groups. The control group received regular rehabilitation training and acupuncture therapy; the intervention group was additionally trained by AiWalker-I lower limb gait robot. Both groups received 5 sessions a week for 4 weeks. Walking function parameters were assessed before and after the 4-week treatment. RESULTS: There was no significant difference in all parameters between the two groups in baseline (Pâ>â0.05). After 4 weeks of treatment, all parameters including the effectiveness of functional ambulation category (FAC), time up and go test (TUGT) time, Wisconsin gait scale (WGS) score, walking spatiotemporal parameters were all significantly improved in both groups with a significant better effect in the intervention group (Pâ<â0.05). CONCLUSION: Acupuncture combined with lower limb gait rehabilitation robot training has a positive effect on correction of abnormal gait and improvement of walking ability of hemiplegic patients after stroke.
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Terapia por Acupuntura , Robótica , Reabilitação do Acidente Vascular Cerebral , Acidente Vascular Cerebral , Humanos , Marcha , Hemiplegia/reabilitação , Extremidade Inferior , Equilíbrio Postural , Estudos de Tempo e Movimento , Resultado do Tratamento , CaminhadaRESUMO
Intervertebral disc degeneration (IDD) is a prevalent degenerative disorder that closely linked to aging. Numerous studies have indicated the crucial involvement of autophagy in the development of IDD. However, the non-selective nature of autophagy substrates poses great limitations on the application of autophagy-related medications. This study aims to enhance our comprehension of autophagy in the development of IDD and investigate a novel therapeutic approach from the perspective of selective autophagy receptor NBR1. Proteomics and immunoprecipitation and mass spectrometry analysis, combined with in vivo and in vitro experimental verification were performed. NBR1 is found to be reduced in IDD, and NBR1 retards cellular senescence and senescence-associated secretory phenotype (SASP) of nucleus pulposus cells (NPCs), primarily through its autophagy-dependent function. Mechanistically, NBR1 knockdown leads to the accumulation of S1 RNA-binding domain-containing protein 1 (SRBD1), which triggers cellular senescence via AKT1/p53 and RB/p16 pathways, and promotes SASP via NF-κß pathway in NPCs. Our findings reveal the function and mechanism of selective autophagy receptor NBR1 in regulating NPCs senescence and degeneration. Targeting NBR1 to facilitate the clearance of detrimental substances holds the potential to provide novel insights for IDD treatment.
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Degeneração do Disco Intervertebral , Núcleo Pulposo , Humanos , Núcleo Pulposo/metabolismo , Senescência Celular/genética , Envelhecimento , Degeneração do Disco Intervertebral/genética , Degeneração do Disco Intervertebral/metabolismo , Autofagia/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Proteínas de Ligação a RNA/metabolismoRESUMO
INTRODUCTION: We examined the association between physical activity (PA) and sedentary behavior (SEB) time with bone health and whether it changes depending on different patterns. MATERIALS AND METHODS: Cross-sectional data were derived from the baseline of the Physical Activity and Health in Older Women Study. PA and SEB were measured using Actigraph wGT3X-BT accelerometers. Bone mineral density (BMD) was derived from the SONOST-2000 ultrasound bone densitometer, with unhealthy bone defined as a BMD T-score of <2.5 standard deviation a young adult reference population's mean. A 10 min-bouted SEB was defined as an SEB duration of >10 min (allow 2 min 0 counts), similar to 30 min-bouted and 60 min-bouted SEBs. Sporadic and bouted PAs were defined by PA duration of <10 min or ≥ 10 min. Multivariate logistic regression analysis investigated the associations between PA and SEB patterns with bone health. RESULTS: Among 1111 female participants, 42.12 % had unhealthy bones. In a fully-adjusted model, increasing 30 min/day of SEB was associated with a higher odds ratio (OR) for an unhealthy bone (OR, 1.08; P = 0.005), similar to the 10 (OR, 1.06; P = 0.012), 30 (OR, 1.06; P = 0.043), and 60 min-bouted (OR 1.08, P = 0.032) SEBs. Total light PA (LPA) time (OR, 0.97; P = 0.005) had a lower OR for unhealthy bone. After adjusting for sporadic LPA time, bouted LPA (OR, 0.97; P = 0.005) retained this association. No association was observed between total moderate-to-vigorous PA (MVPA) and bone health, sporadic MVPA, and bouted MVPA. CONCLUSIONS: Performing bouted LPA and reducing 10 min-bouted SEB may maintain bone health.
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Densidade Óssea , Comportamento Sedentário , Adulto Jovem , Humanos , Feminino , Idoso , Estudos Transversais , Exercício Físico , China , AcelerometriaRESUMO
BACKGROUND: Self-related information is difficult to ignore and forget, which brings valuable implications for educational practice. Self-referential encoding techniques involve integrating self-referencing cues during the processing of learning material. However, the evidence base and effective implementation boundaries for these techniques in teaching and learning remain uncertain due to research variability. AIMS: The present meta-analysis aims to quantitatively synthesize the results from studies applying self-referential encoding techniques in education. METHODS: The analysis was based on data from 20 independent samples, including 1082 students from 13 primary studies identified through a systematic literature search. RESULTS: Results from random effect models show that incorporating self-referential encoding techniques improved learning (g = .40, 95% CI [.18, .62]). Subgroup analysis showed that the valence of learning material serves as a significant boundary condition for this strategy. The students' cohorts, types of learning materials, and research context did not moderate the effect sizes. CONCLUSIONS: Our results suggest that incorporating self-referential encoding techniques on negative materials shows an aversive effect. Overall, there is a universal benefit to using self-referential encoding techniques as an appropriate design guideline in educational contexts. Implications for teaching practice and future directions are discussed. Further studies are needed to investigate the effectiveness in more diverse educational and teaching situations.
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Aprendizagem , Estudantes , HumanosRESUMO
The rational design of the current anion exchange polyelectrolytes (AEPs) is challenging to meet the requirements of both high performance and durability in anion exchange membrane water electrolyzers (AEMWEs). Herein, highly-rigid-twisted spirobisindane monomer is incorporated in poly(aryl-co-aryl piperidinium) backbone to construct continuous ionic channels and to maintain dimensional stability as promising materials for AEPs. The morphologies, physical, and electrochemical properties of the AEPs are investigated based on experimental data and molecular dynamics simulations. The present AEPs possess high free volumes, excellent dimensional stability, hydroxide conductivity (208.1 mS cm-1 at 80 °C), and mechanical properties. The AEMWE of the present AEPs achieves a new current density record of 13.39 and 10.7 A cm-2 at 80 °C by applying IrO2 and nonprecious anode catalyst, respectively, along with outstanding in situ durability under 1 A cm-2 for 1000 h with a low voltage decay rate of 53 µV h-1 . Moreover, the AEPs can be applied in fuel cells and reach a power density of 2.02 W cm-2 at 80 °C under fully humidified conditions, and 1.65 W cm-2 at 100 °C, 30% relative humidity. This study provides insights into the design of high-performance AEPs for energy conversion devices.
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Alkaline polymer electrolytes (APEs) are essential materials for alkaline energy conversion devices such as anion exchange membrane fuel cells (AEMFCs) and water electrolyzers (AEMWEs). Here, we report a series of branched poly(aryl-co-aryl piperidinium) with different branching agents (triptycene: highly-rigid, three-dimensional structure; triphenylbenzene: planar, two-dimensional structure) for high-performance APEs. Among them, triptycene branched APEs showed excellent hydroxide conductivity (193.5â mS cm-1 @80 °C), alkaline stability, mechanical properties, and dimensional stability due to the formation of branched network structures, and increased free volume. AEMFCs based on triptycene-branched APEs reached promising peak power densities of 2.503 and 1.705â W cm-2 at 75/100 % and 30/30 % (anode/cathode) relative humidity, respectively. In addition, the fuel cells can run stably at a current density of 0.6â A cm-2 for 500â h with a low voltage decay rate of 46â µV h-1 . Importantly, the related AEMWE achieved unprecedented current densities of 16â A cm-2 and 14.17â A cm-2 (@2â V, 80 °C, 1â M NaOH) using precious and non-precious metal catalysts, respectively. Moreover, the AEMWE can be stably operated under 1.5â A cm-2 at 60 °C for 2000â h. The excellent results suggest that the triptycene-branched APEs are promising candidates for future AEMFC and AEMWE applications.