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BACKGROUND: Quercetin is a flavonol compound widely distributed in plants that possesses diverse biological properties, including antioxidative, anti-inflammatory, anticancer, neuroprotective and senescent cell-clearing activities. It has been shown to effectively alleviate neurodegenerative diseases and enhance cognitive functions in various models. The immune system has been implicated in the regulation of brain function and cognitive abilities. However, it remains unclear whether quercetin enhances cognitive functions by interacting with the immune system. RESULTS: In this study, middle-aged female mice were administered quercetin via tail vein injection. Quercetin increased the proportion of NK cells, without affecting T or B cells, and improved cognitive performance. Depletion of NK cells significantly reduces cognitive ability in mice. RNA-seq analysis revealed that quercetin modulated the RNA profile of hippocampal tissues in aging animals towards a more youthful state. In vitro, quercetin significantly inhibited the differentiation of Lin-CD117+ hematopoietic stem cells into NK cells. Furthermore, quercetin promoted the proportion and maturation of NK cells by binding to the MYH9 protein. CONCLUSIONS: In summary, our findings suggest that quercetin promotes the proportion and maturation of NK cells by binding to the MYH9 protein, thereby improving cognitive performance in middle-aged mice.
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Growth differentiation factor 11 (GDF11) is a putative systemic rejuvenation factor. In this study, we characterized the mechanism by which GDF11 reversed aging of mesenchymal stem cells (MSCs). In culture, aged MSCs proliferate slower and are positive for senescence markers senescence-associated ß-galactosidase and P16ink4a . They have shortened telomeres, decreased GDF11 expression, and reduced osteogenic potential. GDF11 can block MSC aging in vitro and reverse age-dependent bone loss in vivo. The antiaging effect of GDF11 is via activation of the Smad2/3-PI3K-AKT-mTOR pathway. Unexpectedly, GDF11 also upregulated a DNA demethylase Tet2, which served as a key mediator for GDF11 to autoregulate itself via demethylation of the GDF11 promoter. Mutation of Tet2 facilitates MSC aging by blocking GDF11 expression. Mutagenesis of Tet2-regulated CpG sites also blocks GDF11 expression, leading to MSC aging. Together, a novel mutual regulatory relationship between GDF11 and an epigenetic factor Tet2 unveiled their antiaging roles.
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Senescência Celular , Células-Tronco Mesenquimais , Senescência Celular/genética , Fatores de Diferenciação de Crescimento/genética , Fatores de Diferenciação de Crescimento/metabolismo , Células-Tronco Mesenquimais/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , HumanosRESUMO
BACKGROUND: Glycyrrhizic acid (GA), a saponin compound often used as a flavoring agent, can elicit anti-inflammatory and anti-tumor effects, and alleviate aging. However, the specific mechanism by which GA alters immune cell populations to produce these beneficial effects is currently unclear. RESULTS: In this study, we systematically analyzed single-cell sequencing data of peripheral blood mononuclear cells from young mice, aged mice, and GA-treated aged mice. Our in vivo results show that GA reduced senescence-induced increases in macrophages and neutrophils, and increased numbers of lymphoid lineage subpopulations specifically reduced by senescence. In vitro, GA significantly promoted differentiation of Lin-CD117+ hematopoietic stem cells toward lymphoid lineages, especially CD8+ T cells. Moreover, GA inhibited differentiation of CD4+ T cells and myeloid (CD11b+) cells by binding to S100 calcium-binding protein 8 (S100A8) protein. Overexpression of S100A8 in Lin- CD117+ hematopoietic stem cells enhanced cognition in aged mice and the immune reconstitution of severely immunodeficient B-NDG (NOD.CB17-Prkdcscid/l2rgtm1/Bcgen) mice. CONCLUSIONS: Collectively, GA exerts anti-aging effects by binding to S100A8 to remodel the immune system of aged mice.
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The motion of Abrikosov vortices is the dominant origin of dissipation in type II superconductors subjected to a magnetic field, which leads to a finite electrical resistance. It is generally believed that the increase in the magnetic field results in the aggravation of energy dissipation through the increase in vortex density. Here, we show a distinctive re-entrance of the dissipationless state in quasi-one-dimensional superconducting Ta2PdS5 nanostrips. Utilizing magnetotransport measurements, we unveil a prominent magnetoresistance drop with the increase in the magnetic field below the superconducting transition temperature, manifesting itself as a giant re-entrance to the superconducting phase. Time-dependent Ginzburg-Landau calculations show that this is originated from the suppression of the vortex motion by the increased energy barrier on the edges. Interestingly, both our experiments and simulations demonstrate that this giant re-entrance of superconductivity occurs only in certain geometrical regimes because of the finite size of the vortex.
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Stimulated by novel properties in topological insulators, experimentally realizing quantum phases of matter and employing control over their properties have become a central goal in condensed matter physics. ß-silver telluride (Ag2Te) is predicted to be a new type narrow-gap topological insulator. While enormous efforts have been plunged into the topological nature in silver chalcogenides, sophisticated research on low-dimensional nanostructures remains unexplored. Here, we report the record-high bulk carrier mobility of 298â¯600 cm2/(V s) in high-quality Ag2Te nanoplates and the coexistence of the surface and bulk state from systematic Shubnikov-de Haas oscillations measurements. By tuning the correlation between the top and bottom surfaces, we can effectively enhance the contribution of the surface to the total conductance up to 87% at 130 V. These results are instrumental to the high-mobility physics study and even suitable to explore exotic topological phenomena in this material system.
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Transitional metal ditelluride WTe2 has been extensively studied owing to its intriguing physical properties like nonsaturating positive magnetoresistance and being possibly a type-II Weyl semimetal. While surging research activities were devoted to the understanding of its bulk properties, it remains a substantial challenge to explore the pristine physics in atomically thin WTe2. Here, we report a successful synthesis of mono- to few-layer WTe2 via chemical vapor deposition. Using atomically thin WTe2 nanosheets, we discover a previously inaccessible ambipolar behavior that enables the tunability of magnetoconductance of few-layer WTe2 from weak antilocalization to weak localization, revealing a strong electrical field modulation of the spin-orbit interaction under perpendicular magnetic field. These appealing physical properties unveiled in this study clearly identify WTe2 as a promising platform for exotic electronic and spintronic device applications.
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Hepatitis B virus (HBV) infection has been documented as a risk factor for non-Hodgkin lymphoma (NHL). However, there are few large cohort studies, and there is no report about the impact of HBV vaccination. We conducted this study to evaluate these issues. We used the nationwide cohort of the Taiwan National Health Insurance Research Database for 1997-2013. We compared the incidence and the risk of developing NHL and CD20+ aggressive lymphoma between HBV and non-HBV cohorts. The hazard ratios (HRs) were computed using Cox proportional hazards models. We matched these two large cohorts to reconfirm the data. We also compared the incidence of NHL between cohorts born before and after the inception of universal HBV vaccination. We found that HBV infection increased the risk for developing NHL and CD20+ aggressive lymphoma, with HRs of 4.14 and 5.52, with a higher incidence of 17.07 and 13.9 per 100 000 person-years, respectively, compared to the non-HBV cohort. The incidence of NHL in the cohort born in the era before universal HBV vaccination was higher with 1.85 per 100 000 person-years compared to 0.74 in the cohort born later aged younger than 20. Our study confirms that HBV confers a greater risk for developing NHL, especially CD20+ aggressive lymphoma. The impact of HBV vaccination is protective against lymphoma development in the teenagers in an endemic area, but longer follow-up is needed for older age.
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Vírus da Hepatite B/imunologia , Hepatite B/complicações , Hepatite B/imunologia , Linfoma não Hodgkin/epidemiologia , Linfoma não Hodgkin/etiologia , Adulto , Idoso , Comorbidade , Feminino , Hepatite B/prevenção & controle , Hepatite B/virologia , Humanos , Masculino , Pessoa de Meia-Idade , Risco , Fatores Socioeconômicos , Taiwan/epidemiologia , Vacinação , Adulto JovemRESUMO
In patients with haemophilia A, repeated occurrences of haemarthrosis and synovitis lead to limitations in range of motion (ROM) of major joints. However, the effect of limitations in joint ROM on health-related quality of life (HRQOL) in these patients has not been studied previously. The aim of this study was to assess the impact of ROM limitations of 10 major joints (bilateral shoulders, elbows, hips, knees and ankles), combined with other possibly influential factors, on HRQOL in patients with haemophilia A. The ROM limitations in 13 movements and pain intensity of the 10 major joints were measured. The socio-demographic and clinical data were recorded. Short-Form 36 was used as the HRQOL measurement. Eighteen patients (mean age: 36.9 years) were included. Hip ROM limitations, knee ROM limitations and hip pain intensity predicted physical functioning scale (P < 0.001; adjusted R2 = 0.553). Shoulder ROM limitations and age predicted role limitation were due to emotional problems scale (P < 0.001; adjusted R2 = 0.373). Elbow ROM limitations and haemophilia severity predicted mental health scale (P = 0.001; adjusted R2 = 0.320). Hip ROM limitations predicted social functioning scale (P = 0.041; adjusted R2 = 0.091). Educational level and elbow ROM limitations predicted vitality scale (P < 0.001; adjusted R2 = 0.416). The ROM limitations of hip, knee, shoulder and elbow could be predictors for HRQOL in patients with haemophilia A. Improving ROM of major joints could be an appropriate treatment strategy to enhance HRQOL in these patients.
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Hemartrose/diagnóstico , Hemartrose/etiologia , Hemofilia A/complicações , Qualidade de Vida , Amplitude de Movimento Articular , Sinovite/diagnóstico , Sinovite/etiologia , Adolescente , Adulto , Criança , Comorbidade , Hemartrose/epidemiologia , Hemofilia A/diagnóstico , Hemofilia A/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Medição da Dor , Estudos Prospectivos , Fatores de Risco , Índice de Gravidade de Doença , Sinovite/epidemiologia , Adulto JovemRESUMO
BACKGROUND: Mesenchymal stem cells (MSCs) hold a great promise for cell-based therapy in the field of regenerative medicine. In this study, we aimed to evaluate the safety and efficacy of intravenous infusion of human umbilical cord-derived MSCs (HUC-MSCs) in patients with aging frailty. METHODS: In this randomized, double-blind, placebo-controlled trial, participants diagnosed with aging frailty were randomly assigned to receive intravenous administrations of HUC-MSCs or placebo. All of serious adverse events and AEs were monitored to evaluate the safety of treatment during the 6-month follow-up. The primary efficacy endpoint was alteration of physical component scores (PCS) of SF-36 qualities of life at 6 months. The secondary outcomes including physical performance tests and pro-inflammatory cytokines, were also observed and compared at each follow-up visits. All evaluations were performed at 1 week, 1, 2, 3 and 6 months following the first intravenous infusion of HUC-MSCs. RESULTS: In the MSCs group, significant improvements in PCS of SF-36 were observed from first post-treatment visit and sustained throughout the follow-up period, with greater changes compared to the placebo group (p = 0.042). EQ-VAS scores of MSCs group improved significantly at 2 month (p = 0.023) and continued until the end of the 6-month visit (p = 0.002) in comparison to the placebo group. The timed up and go (TUG) physical performance test revealed significant group difference and showed continual enhancements over 6 months (p < 0.05). MSC transplantation improved the function of 4-m walking test (4MWT) compared with the placebo group with a decrease of 2.05 s at 6 months of follow-up (p = 0.21). The measurement of grip strength revealed group difference with MSCs group demonstrating better performance, particularly at 6 months (p = 0.002). Inflammatory cytokines (TNF-α, IL-17) exhibited declines in MSCs group at 6 months compared to the placebo group (p = 0.034 and 0.033, respectively). There was no difference of incidence of AEs between the two groups. CONCLUSION: Intravenous transplantation of HUC-MSCs is a safe and effective therapeutic approach on aging frailty. The positive outcomes observed in improving quality of life, physical performance, and reducing chronic inflammation, suggest that HUC-MSC therapy may be a promising potential treatment option for aging frailty. TRIAL REGISTRATION: Clinicaltrial.gov; NCT04314011; https://clinicaltrials.gov/ct2/show/NCT04314011 .
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Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais , Qualidade de Vida , Cordão Umbilical , Humanos , Feminino , Masculino , Método Duplo-Cego , Transplante de Células-Tronco Mesenquimais/métodos , Transplante de Células-Tronco Mesenquimais/efeitos adversos , Idoso , Células-Tronco Mesenquimais/citologia , Cordão Umbilical/citologia , Fragilidade/terapia , Pessoa de Meia-Idade , Envelhecimento/fisiologia , Idoso de 80 Anos ou mais , Resultado do TratamentoRESUMO
BACKGROUND: Metformin, a type 2 diabetes treatment, improves the cognitive function of aged mice; however, whether the protective effects of metformin on cognitive function in aged mice are associated with the gut microbiome is poorly understood. Although some studies suggest that the gut microbe composition influences cognitive function and that manipulating the gut microbiota might protect against age-related cognitive dysfunction, there is no direct evidence to validate that the gut microbiota mediates the effect of metformin on cognitive improvement. RESULTS: In this study, we show that the gut microbiota is altered by metformin, which is necessary for protection against ageing-associated cognitive function declines in aged mice. Mice treated with antibiotics did not exhibit metformin-mediated cognitive function protection. Moreover, treatment with Akkermansia muciniphila, which is enriched by metformin, improved cognitive function in aged mice. Mechanistically, A. muciniphila decreased pro-inflammatory-associated pathways, particularly that of the pro-inflammatory cytokine interleukin (IL)-6, in both the peripheral blood and hippocampal profiles, which was correlated with cognitive function improvement. An IL-6 antibody protected cognitive function, and an IL-6 recombinant protein abolished the protective effect of A. muciniphila on cognitive function in aged mice. CONCLUSION: This study reveals that A. muciniphila, which is mediated in the gut microbiota by metformin, modulates inflammation-related pathways in the host and improves cognitive function in aged mice by reducing the pro-inflammatory cytokine IL-6. Video Abstract.
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Diabetes Mellitus Tipo 2 , Microbioma Gastrointestinal , Interleucina-6 , Metformina , Animais , Camundongos , Cognição , Citocinas , Interleucina-6/metabolismo , Metformina/farmacologia , VerrucomicrobiaRESUMO
WHAT IS KNOWN AND OBJECTIVE: The beneficial effects of docetaxel plus cisplatin-based induction chemotherapy for patients with unresectable, advanced head and neck cancer (HNC) have been documented in Western countries. However, the efficacy of such treatment has not been confirmed in Asian patients. We aimed to determine whether incorporation of dose-modified docetaxel into a cisplatin-based induction regimen would be both effective and tolerable in our Asian population of patients. METHODS: Thirty-six patients with stage III or IV HNC who had undergone cisplatin-based induction chemotherapy were included in the current analysis. Fifty-three percentage of the patients had received induction chemotherapy with bolus cisplatin and continuous 5-fluorouracil (PF group), while the remaining 47% had additionally received dose-modified docetaxel (TPF group). We assessed the relative impact of the two treatments on clinical outcomes and treatment-related toxicities. RESULTS AND DISCUSSION: The disease control rate was higher in the TPF group (92·9% vs. 76·5%), although the difference did not reach statistical significance (P = 0·217). Addition of docetaxel increased the median progression-free survival to 435 days, which was 2·3 times longer than that (188 days) of patients not receiving docetaxel (P = 0·019). Non-haematological toxicity profile was similar and acceptable in both treatment groups. Higher incidence of grade 3/4 neutropenia and more episodes of neutropenic fever-related hospitalization occurred in the docetaxel-treated patients, but most of them were managed uneventfully. WHAT IS NEW AND CONCLUSION: Addition of dose-modified docetaxel to cisplatin-based induction chemotherapy was both efficacious and generally safe. Docetaxel addition significantly prolonged progression-free survival and had an acceptable safety profile in our Asian population of patients with locoregionally advanced HNC.
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Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Carcinoma de Células Escamosas/tratamento farmacológico , Cisplatino/administração & dosagem , Monitoramento de Medicamentos , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Quimioterapia de Indução , Taxoides/administração & dosagem , Adulto , Idoso , Antineoplásicos/administração & dosagem , Antineoplásicos/efeitos adversos , Antineoplásicos/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carcinoma de Células Escamosas/sangue , Carcinoma de Células Escamosas/etnologia , Carcinoma de Células Escamosas/patologia , Cisplatino/efeitos adversos , Cisplatino/uso terapêutico , Docetaxel , Febre/etiologia , Fluoruracila/administração & dosagem , Fluoruracila/efeitos adversos , Fluoruracila/uso terapêutico , Neoplasias de Cabeça e Pescoço/sangue , Neoplasias de Cabeça e Pescoço/etnologia , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Incidência , Quimioterapia de Indução/efeitos adversos , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Neutropenia/induzido quimicamente , Neutropenia/epidemiologia , Neutropenia/fisiopatologia , Neutropenia/terapia , Índice de Gravidade de Doença , Análise de Sobrevida , Taiwan/epidemiologia , Taxoides/efeitos adversos , Taxoides/uso terapêuticoRESUMO
Oral antibiotics remain the therapy of choice for severe bacterial infections; however, antibiotic use disrupts the intestinal microbiota, increasing the risk of colonization by intestinal pathogens. Currently, our understanding of antibiotic-mediated disturbances of the microbiota remains at the level of bacterial families or specific species, and little is known about the effect of antibiotics on potentially beneficial and pathogenic bacteria under the conditions of gut microbiota dysbiosis. Additionally, the question of whether the effects of antibiotics on the gut microbiota are temporary or permanent is controversial. In this study, we used 16S rRNA gene sequencing to evaluate the short- and long-term effects of ampicillin, vancomycin, metronidazole, and neomycin on the murine intestinal microbiota. We found that the changes in the intestinal microbiota reflected the antibiotics' mechanisms of action and that dysbiosis of the intestinal microbiota led to competition between different bacterial communities. In particular, an increase in Enterococcus, which accompanies a decrease in probiotics-related genera such as Lactobacillus, is commonly seen across antibiotic treatments. In addition, we found that these oral antibiotics had long-term negative effects on the intestinal microbiota and promoted the development of antibiotic-resistant bacterial strains. These results indicate that ampicillin, vancomycin, metronidazole, and neomycin have long-term negative effects and can cause irreversible changes in the diversity of the intestinal microbiota, thereby increasing the risk of host disease. IMPORTANCE The intestinal microbiota is a dynamic community of hundreds of millions of microorganisms that play important roles in human health. However, treatment with antibiotics can disrupt the delicate balance of this community, leading to deleterious effects on the host such as inflammation and enhanced susceptibility to infection. To date, most studies of the effects of antibiotic treatment on the microbiota have focused on specific intestinal pathogens and bacterial families. However, few studies have investigated the effects of antibiotic treatment on the relative abundance of probiotic bacteria, pathogenic bacteria, and opportunistic bacterial pathogens in the gut.
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Microbioma Gastrointestinal , Ampicilina/farmacologia , Animais , Antibacterianos/uso terapêutico , Bactérias/genética , Disbiose/microbiologia , Humanos , Metronidazol/farmacologia , Camundongos , Neomicina/farmacologia , RNA Ribossômico 16S/genética , Vancomicina/farmacologiaRESUMO
Traditional pathological diagnoses and clinical methods are insufficient to accurately predict the prognosis of lung adenocarcinoma (LUAD). Epithelial-mesenchymal transition (EMT) process is closely related to tumor cell migration. However, the prognostic value of EMT-related genes in LUAD is still unclear. In this study, we collected bulk RNA-sequencing (RNA-seq) and microarray data of LUAD patients from public databases and identified different expressed EMT-related genes in tumor and normal tissues. Then, we used the least absolute shrinkage and selection operator Cox regression model to develop a multigene signature in the cancer genome atlas (TCGA) cohort and validated the model in the OncoSG (Singapore Oncology Data Portal) cohort as well as other datasets. Finally, we constructed a 12-gene signature to divide LUAD patients into high-risk and low-risk groups of overall survival (OS), which has a better stability and accuracy in predicating the OS of patients compared with some other published signatures of LUAD. In addition, evaluation of the risk model using the time-related receiver operating characteristic (ROC) curve confirmed the predictive ability of the model. Functional analysis showed that these genes are related to immunity. CD8 T cell and CD4 T cell types were significantly negatively correlated with the risk score in the analysis of immune infiltration. In general, our model provides useful information that may help clinicians better predict the prognosis of LUAD patients and provides potential targets for immunotherapy of LUAD.
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Two-dimensional (2D) ferromagnetic materials have been discovered with tunable magnetism and orbital-driven nodal-line features. Controlling the 2D magnetism in exfoliated nanoflakes via electric/magnetic fields enables a boosted Curie temperature (T C) or phase transitions. One of the challenges, however, is the realization of high T C 2D magnets that are tunable, robust and suitable for large scale fabrication. Here, we report molecular-beam epitaxy growth of wafer-scale Fe3+XGeTe2 films with T C above room temperature. By controlling the Fe composition in Fe3+XGeTe2, a continuously modulated T C in a broad range of 185-320 K has been achieved. This widely tunable T C is attributed to the doped interlayer Fe that provides a 40% enhancement around the optimal composition X = 2. We further fabricated magnetic tunneling junction device arrays that exhibit clear tunneling signals. Our results show an effective and reliable approach, i.e. element doping, to producing robust and tunable ferromagnetism beyond room temperature in a large-scale 2D Fe3+XGeTe2 fashion.
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Aging frailty is a complex geriatric syndrome that becomes more prevalent with advancing age. It constitutes a major health problem due to frequent adverse outcomes. Frailty is characterized by disruption of physiological homeostasis and progressive decline of health status. Multiple factors contribute to development of frailty with advancing age, including genome instability, DNA damage, epigenetic alternations, stem cell exhaustion, among others. These interrelated factors comprehensively result in loss of tissue homeostasis and diminished reserve capacity in frailty. Therefore, the aged organism gradually represents symptoms of frailty with decline in physiological functions of organs. Notably, the brain, cardiovascular system, skeletal muscle, and endocrine system are intrinsically interrelated to frailty. The patients with frailty may display the diminished reserves capacity of organ systems. Due to the complex pathophysiology, no specific treatments have been approved for prevention of this syndrome. At such, effective strategies for intervening in pathogenic process to improve health status of frail patients are highly needed. Recent progress in cell-based therapy has greatly contributed to the amelioration of degenerative diseases related to age. Mesenchymal stem cells (MSCs) can exert regenerative effects and possess anti-inflammatory properties. Transplantation of MSCs represents as a promising therapeutic strategy to address the pathophysiologic problems of frail syndrome. Currently, MSC therapy have undergone the phase I and II trials in human subjects that have endorsed the safety and efficacy of MSCs for aging frailty. However, despite these positive results, caution is still needed with regard to potential to form tumors, and further large-scale studies are warranted to confirm the therapeutic efficacy of MSC therapy.
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Envelhecimento/fisiologia , Fragilidade/terapia , Células-Tronco Mesenquimais/citologia , Idoso , Animais , Idoso Fragilizado , Humanos , Transplante de Células-Tronco Mesenquimais/métodos , Medicina Regenerativa/métodos , SíndromeRESUMO
Plasmons in two-dimensional (2D) materials beyond graphene have recently gained much attention. However, the experimental investigation is limited due to the lack of suitable materials. Here, we experimentally demonstrate localized plasmons in a correlated 2D charge-density-wave (CDW) material: 2H-TaSe2. The plasmon resonance can cover a broad spectral range from the terahertz (40 µm) to the telecom (1.55 µm) region, which is further tunable by changing thickness and dielectric environments. The plasmon dispersion flattens at large wave vectors, resulted from the universal screening effect of interband transitions. More interestingly, anomalous temperature dependence of plasmon resonances associated with CDW excitations is observed. In the CDW phase, the plasmon peak close to the CDW excitation frequency becomes wider and asymmetric, mimicking two coupled oscillators. Our study not only reveals the universal role of the intrinsic screening on 2D plasmons, but also opens an avenue for tunable plasmons in 2D correlated materials.
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The interplay between quenched disorder and critical behavior in quantum phase transitions is conceptually fascinating and of fundamental importance for understanding phase transitions. However, it is still unclear whether or not the quenched disorder influences the universality class of quantum phase transitions. More crucially, the absence of superconducting-metal transitions under in-plane magnetic fields in 2D superconductors imposes constraints on the universality of quantum criticality. Here, we observe the thickness-tuned universality class of superconductor-metal transition by changing the disorder strength in ß-W films with varying thickness. The finite-size scaling uncovers the switch of universality class: quantum Griffiths singularity to multiple quantum criticality at a critical thickness of tcâ¥1~8nm and then from multiple quantum criticality to single criticality at tcâ¥2~16nm. Moreover, the superconducting-metal transition is observed for the first time under in-plane magnetic fields and the universality class is changed at tcâ~8nm. The observation of thickness-tuned universality class under both out-of-plane and in-plane magnetic fields provides broad information for the disorder effect on superconducting-metal transitions and quantum criticality.
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Glycyrrhizic acid (GA) is the substance with the highest content of triterpenoid saponins that can be extracted from licorice, and has anti-inflammatory, neuroprotective, and anticancer functions, among others. The aim of this study was to investigate the protective effect of GA on cognitive decline in middle-aged mice and explore its mechanisms. We injected GA by the tail vein of C57BL/6 mice and measured their cognitive levels using the Morris water maze. The Morris water maze results demonstrated that GA improved learning and memory abilities in middle-aged mice. Furthermore, the RNA-sequencing and flow cytometric analyses revealed that GA could increase T and B cells. We then confirmed the relationship between cognition and the immune system in the immune-deficient B-NDG mouse model. Our results suggest that GA improves cognition in aging mice by regulating T/B cell proliferation.
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WTe2, as a type-II Weyl semimetal, has 2D Fermi arcs on the (001) surface in the bulk and 1D helical edge states in its monolayer. These features have recently attracted wide attention in condensed matter physics. However, in the intermediate regime between the bulk and monolayer, the edge states have not been resolved owing to its closed band gap which makes the bulk states dominant. Here, we report the signatures of the edge superconductivity by superconducting quantum interference measurements in multilayer WTe2 Josephson junctions and we directly map the localized supercurrent. In thick WTe2 ([Formula: see text], the supercurrent is uniformly distributed by bulk states with symmetric Josephson effect ([Formula: see text]). In thin WTe2 (10 nm), however, the supercurrent becomes confined to the edge and its width reaches up to [Formula: see text]and exhibits non-symmetric behavior [Formula: see text]. The ability to tune the edge domination by changing thickness and the edge superconductivity establishes WTe2 as a promising topological system with exotic quantum phases and a rich physics.
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Metformin is a widely used drug for type 2 diabetes that is considered to have potential anti-aging effects. However, the beneficial effects of metformin in middle-aged normoglycemic mice are less explored. Here, we report that metformin treated by tail vein injection improved cognitive function of aged mice better than oral administration, which seem to show a dose-dependent manner. Correspondingly, long-term oral administration of metformin was associated with significant disability rates. Further, metformin restored cerebral blood flow and brain vascular density and promoted neurogenic potential of the subependymal zone/subventricular zone both in vivo and in vitro. RNA-Seq and q-PCR results indicated that metformin could enhance relative mRNA glycolysis expression in blood and hippocampal tissue, respectively. Mechanistically, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), a key enzyme in glycolysis pathway, may contribute to angiogenic and neurogenic potentials of NSCs. Interestingly, the relative GAPDH mRNA expression of peripheral blood mononuclear cell was gradually decreased with aging. Meanwhile its expression level positively correlated with cognitive levels. Our results indicated that metformin represents a candidate pharmacological approach for recruitment of NSCs in aged mouse brain by enhancing glycolysis and promoting neurovascular generation, a strategy that might be of therapeutic value for anti-aging in humans.