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1.
Mol Cell Biochem ; 2023 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-37436654

RESUMO

Herein, we investigated the role of the m6A methylation enzyme METTL14 in regulating myocardial ischemia/reperfusion injury (IR/I) through the Akt/mTOR signaling pathway and related biological mechanisms. Enzyme-linked immunosorbent assay (ELISA) and fluorescence quantitative polymerase chain reaction (qPCR) were performed to detect the m6A mRNA and METTL3, METTL14, WTAP, and KIAA1429 levels in a mouse myocardial IR/I model. An oxygen-glucose deprivation/reperfusion (OGD/R) model was constructed by transfecting neonatal rat cardiomyocytes (NRCM) with METTL14-knockdown lentivirus. METTL14, Bax, and cleaved-caspase3 mRNA expression levels were detected using fluorescence qPCR. Apoptosis was detected using TUNEL staining. After the IR/I surgery following the adeno-associated virus injection, the METTL14 mRNA and apoptosis-related BAX/BCL2 protein expression was detected using fluorescence qPCR and western blotting, respectively. Degree of cell necrosis was detected using an LDH assay. The oxidative stress response of the myocardial tissue was detected, and IL-6 and IL-1ß serum levels were detected using ELISAs. The mice injected with METTL14-knockdown AAV9 adeno-associated virus underwent IR/I surgery after the injection of an Akt/mTOR pathway inhibitor (MK2206) into the myocardial layer. Elevated mRNA m6A modification and m6A methyltransferase METTL14 levels were observed in the IR/I-injured mouse heart tissues. METTL14 knockdown significantly inhibited the OGD/R- and IR/I-induced apoptosis and necrosis in cardiac myocytes, inhibited IR/I-induced oxidative stress and inflammatory factor secretion, and activated the Akt/ mTOR pathway in vitro and in vivo. Akt/mTOR pathway inhibition significantly attenuated the alleviating effect of METTL14 knockdown on myocardial IR/I injury-induced apoptosis. Knocking down m6A methylase METTL14 inhibits IR/I-induced myocardial apoptosis and necrosis, inhibits myocardial oxidative stress and secretion of inflammatory cytokines, and activates the Akt/mTOR signaling pathway. Hence, METTL14 regulated myocardial apoptosis and necrosis in mice with IR/I through the Akt/mTOR signaling pathway.

2.
Sleep Breath ; 25(1): 1-8, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-32333260

RESUMO

PURPOSE: It remains inconclusive whether continuous positive airway pressure (CPAP) therapy can significantly reduce subcutaneous adipose tissue (SAT) in patients with obstructive sleep apnea (OSA). This meta-analysis of randomized controlled trials (RCTs) aimed to evaluate the impact of CPAP treatment on SAT in patients with OSA. METHODS: We searched Pubmed, Cochrane, Web of Science, and Embase for RCTs, which investigated the effectiveness of CPAP treatment in reducing SAT among patients with OSA. Following the PRISMA guidelines, we extracted information on the study and patient characteristics, and pre- and post-CPAP measures of SAT. We then calculated the overall effects using the standardized mean difference (SMD) with a 95% confidence interval (CI). RESULTS: A total of 5 RCTs (comprising 153 patients) met inclusion criteria for the meta-analysis. We found that the SAT did not change before and after CPAP treatment in patients with OSA (SMD = - 0.02, 95% CI - 0.25 to 0.2, z = 0.19, p = 0.85). Subgroup analyses indicated that the outcome was not affected by age, CPAP therapy duration, baseline body mass index, and measure utilized. CONCLUSION: This meta-analysis of RCTs suggests that CPAP therapy does not significantly decrease the level of SAT among patients with OSA. Further large-scale, and high-quality randomized controlled trials are needed to better address this issue.


Assuntos
Pressão Positiva Contínua nas Vias Aéreas , Ensaios Clínicos Controlados Aleatórios como Assunto , Apneia Obstrutiva do Sono/metabolismo , Apneia Obstrutiva do Sono/terapia , Gordura Subcutânea/metabolismo , Humanos , Avaliação de Resultados em Cuidados de Saúde
3.
Sleep Breath ; 25(2): 555-562, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32857319

RESUMO

BACKGROUND: It is still controversial if the continuous positive airway pressure (CPAP) treatment for patients with obstructive sleep apnea (OSA) can markedly influence an effect on visceral adipose tissue (VAT). The current study aimed to assess the efficacy of CPAP interventions in reducing VAT in OSA patients. METHODS: The Web of Science, PubMed, Embase, and Cochrane Library (up to December, 2019) were searched for randomized trials that assessed the effect of CPAP therapy in decreasing VAT in OSA patients. Information on the study, pre- and post-CPAP treatment of VAT, and patient characteristics were extracted for analysis. The standardized mean difference (SMD) was applied to measure the summary estimates. The analysis was conducted with STATA 13.0 and RevMan v.5.3. RESULTS: Five studies (6 cohorts) that involved 169 patients were enrolled in the meta-analysis. There was no significant change of VAT in patients with OSA before and after CPAP treatment (SMD = - 0.00, 95% CI = - 0.21 to 0.21, z = 0.01, p = 0.99). Subgroup analyses further demonstrated that the results were not influenced by CPAP therapy duration, patient age, sample size, or baseline body mass index. CONCLUSIONS: Among the patients with OSA, our meta-analysis revealed that treatment with CPAP does not significantly lead to a reduction of VAT. High-quality randomized controlled trials may provide further clarifying information.


Assuntos
Pressão Positiva Contínua nas Vias Aéreas , Gordura Intra-Abdominal/metabolismo , Apneia Obstrutiva do Sono/terapia , Humanos , Ensaios Clínicos Controlados Aleatórios como Assunto , Resultado do Tratamento
4.
Nano Lett ; 20(11): 8053-8058, 2020 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-33112622

RESUMO

The modulation of optical harmonic generation in two-dimensional (2D) materials is of paramount importance in nanophotonic and nano-optoelectronic devices for their applications in optical switching and communication. However, an effective route with ultrafast modulation speed, ultrahigh modulation depth, and broad operation wavelength range is awaiting a full exploration. Here, we report that an optical pump can dynamically modulate the third harmonic generation (THG) of a graphene monolayer with a relative modulation depth above 90% at a time scale of 2.5 ps for a broad frequency ranging from near-infrared to ultraviolet. Our observation, together with the real-time, time-dependent density functional theory (TDDFT) simulations, reveals that this modulation process stems from nonlinear dynamics of the photoexcited carriers in graphene. The superior performance of the nonlinear all-optical modulator based on 2D materials paves the way for its potential applications including nanolasers and optical communication circuits.

5.
J Biol Chem ; 294(15): 6172-6187, 2019 04 12.
Artigo em Inglês | MEDLINE | ID: mdl-30718276

RESUMO

Yin Yang 1 (YY1) is a zinc-finger protein that plays critical roles in various biological processes by interacting with DNA and numerous protein partners. YY1 has been reported to play dual biological functions as either an oncogene or tumor suppressor in the development and progression of multiple cancers, but its role in human nasopharyngeal carcinoma (NPC) has not yet been revealed. In this study, we found that YY1 overexpression significantly inhibits cell proliferation and cell-cycle progression from G1 to S and promotes apoptosis in NPC cells. Moreover, we identified YY1 as a component of the c-Myc complex and observed that ectopic expression of YY1 inhibits c-Myc transcriptional activity, as well as the promoter activity and expression of the c-Myc target gene microRNA-141 (miR-141). Furthermore, restoring miR-141 expression could at least partially reverse the inhibitory effect of YY1 on cell proliferation and tumor growth and on the expression of some critical c-Myc targets, such as PTEN/AKT pathway components both in vitro and in vivo We also found that YY1 expression is reduced in NPC tissues, negatively correlates with miR-141 expression and clinical stages in NPC patients, and positively correlates with survival prognosis. Our results reveal a previously unappreciated mechanism in which the YY1/c-Myc/miR-141 axis plays a critical role in NPC progression and may provide some potential and valuable targets for the diagnosis and treatment of NPC.


Assuntos
MicroRNAs/biossíntese , Carcinoma Nasofaríngeo/metabolismo , Neoplasias Nasofaríngeas/metabolismo , Proteínas Proto-Oncogênicas c-myc/metabolismo , RNA Neoplásico/biossíntese , Transcrição Gênica , Proteínas Supressoras de Tumor/metabolismo , Fator de Transcrição YY1/metabolismo , Adulto , Linhagem Celular Tumoral , Feminino , Humanos , Masculino , MicroRNAs/genética , Pessoa de Meia-Idade , Carcinoma Nasofaríngeo/genética , Carcinoma Nasofaríngeo/patologia , Neoplasias Nasofaríngeas/genética , Neoplasias Nasofaríngeas/patologia , Proteínas Proto-Oncogênicas c-myc/genética , RNA Neoplásico/genética , Proteínas Supressoras de Tumor/genética , Fator de Transcrição YY1/genética
6.
Nano Lett ; 19(3): 2154-2161, 2019 03 13.
Artigo em Inglês | MEDLINE | ID: mdl-30789739

RESUMO

Two-dimensional (2D) magnetic materials provide an ideal platform for the application in spintronic devices due to their unique spin states in nanometer scale. However, recent research on the exfoliated monolayer magnetic materials suffers from the instability in ambient atmosphere, which needs extraordinary protection. Hence the controllable synthesis of 2D magnetic materials with good quality and stability should be addressed. Here we report for the first time the van der Waals (vdW) epitaxial growth of one-unit-cell-thick air-stable ferrimagnet Cr2S3 semiconductor via a facile chemical vapor deposition method. Single crystal Cr2S3 with the domain size reaching to 200 µm is achieved. Most importantly, we observe the as grown Cr2S3 with a Néel temperature ( TN) of up to 120 K and a maximum saturation magnetic momentum of up to 65 µemu. As the temperature decreases, the samples show a transition from soft magnet to hard magnet with the highest coercivity of 1000 Oe. The one-unit-cell-thick Cr2S3 devices show a p-type transfer behavior with an on/off ratio over 103. Our work highlights Cr2S3 monolayer as an ideal magnetic semiconductor for 2D spintronic devices. The vdW epitaxy of nonlayered magnets introduces a new route for realizing magnetism in 2D limit and provides more application potential in the 2D spintronics.

7.
J Am Chem Soc ; 140(44): 14952-14957, 2018 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-30353725

RESUMO

Photocarrier generation in a material, transportation to the material surface, and collection at the electrode interface are of paramount importance in any optoelectronic and photovoltaic device. In the last collection process, ideal performance comprises ultrafast charge collection to enhance current conversion efficiency and broadband collection to enhance energy conversion efficiency. Here, for the first time, we demonstrate ultrafast broadband charge collection achieved simultaneously at the clean graphene/organic-inorganic halide perovskite interface. The clean interface is realized by directly growing perovskite on graphene surface without polymer contamination. The tunable two-color pump-probe spectroscopy, time-resolved photoluminescence spectroscopy, and time-dependent density functional theory all reveal that the clean-interfacial graphene collects band-edge photocarriers of perovskite in an ultrashort time of ∼100 fs, with a current collection efficiency close to 99%. In addition, graphene can extract deep-band hot carriers of perovskite within only ∼50 fs, several orders faster than hot carrier relaxation and cooling in perovskite itself, due to the unique Dirac linear band structure of graphene, indicating a potential high energy conversion efficiency exceeding the Shockley-Queisser limit. Adding other graphene superiority of good transparency, high carrier mobility, and extreme flexibility, clean-interfacial graphene provides an ideal charge collection layer and electrode candidate for future optoelectronic and photovoltaic applications in two dimensions.

8.
Appl Biochem Biotechnol ; 196(3): 1194-1210, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37378719

RESUMO

Myocardial ischemia/reperfusion (I/R) injury is a pathological damage secondary to myocardial ischemia that can further aggravate tissue and organ injuries. Therefore, there is an urgent need to develop an effective approach for alleviating myocardial I/R injury. Trehalose (TRE) is a natural bioactive substance that has been shown to have extensive physiological effects in various animals and plants. However, TRE's protective effects against myocardial I/R injury remain unclear. This study aimed to evaluate the protective effect of TRE pre-treatment in mice with acute myocardial I/R injury and to explore the role of pyroptosis in this process. Mice were pre-treated with trehalose (1 mg/g) or an equivalent amount of saline solution for 7 days. The left anterior descending coronary artery was ligated in mice from the I/R and I/R + TRE groups, followed by 2-h or 24-h reperfusion after 30 min. Transthoracic echocardiography was performed to assess cardiac function in mice. Serum and cardiac tissue samples were obtained to examine the relevant indicators. We established an oxygen-glucose deprivation and re-oxygenation model in neonatal mouse ventricular cardiomyocytes and validated the mechanism by which trehalose affects myocardial necrosis via overexpression or silencing of NLRP3. TRE pre-treatment significantly improved cardiac dysfunction and reduced the infarct size in mice after I/R, accompanied by a decrease in the I/R-induced levels of CK-MB, cTnT, LDH, reactive oxygen species, pro-IL-1ß, pro-IL-18, and TUNEL-positive cells. Furthermore, TRE intervention suppressed the expression of pyroptosis-related proteins following I/R. TRE attenuates myocardial I/R injury in mice by inhibiting NLRP3-mediated caspase-1-dependent pyroptosis in cardiomyocytes.


Assuntos
Traumatismo por Reperfusão Miocárdica , Camundongos , Animais , Traumatismo por Reperfusão Miocárdica/tratamento farmacológico , Traumatismo por Reperfusão Miocárdica/patologia , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Trealose/farmacologia , Trealose/uso terapêutico , Piroptose , Espécies Reativas de Oxigênio/metabolismo
9.
Coron Artery Dis ; 2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38767051

RESUMO

BACKGROUND: Previous reports have suggested that coronary computed tomography angiography (CCTA)-based radiomics analysis is a potentially helpful tool for assessing vulnerable plaques. We aimed to investigate whether coronary radiomic analysis of CCTA images could identify vulnerable plaques in patients with stable angina pectoris. METHODS: This retrospective study included patients initially diagnosed with stable angina pectoris. Patients were randomly divided into either the training or test dataset at an 8 : 2 ratio. Radiomics features were extracted from CCTA images. Radiomics models for predicting vulnerable plaques were developed using the support vector machine (SVM) algorithm. The model performance was assessed using the area under the curve (AUC); the accuracy, sensitivity, and specificity were calculated to compare the diagnostic performance using the two cohorts. RESULTS: A total of 158 patients were included in the analysis. The SVM radiomics model performed well in predicting vulnerable plaques, with AUC values of 0.977 and 0.875 for the training and test cohorts, respectively. With optimal cutoff values, the radiomics model showed accuracies of 0.91 and 0.882 in the training and test cohorts, respectively. CONCLUSION: Although further larger population studies are necessary, this novel CCTA radiomics model may identify vulnerable plaques in patients with stable angina pectoris.

10.
Cell Biochem Biophys ; 81(2): 349-358, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37129843

RESUMO

This study aimed to investigate the role of PPARγ and underlying mechanisms in myocardial ischemia/reperfusion injury (IRI). IRI was surgically induced in mice and neonatal rat cardiomyocytes (NRCM) were exposed to oxygen-glucose deprivation and reoxygenation (OGD/R). Quantitative genetic analysis and western blotting were performed to assess mRNA and protein levels, respectively, of PPARγ, as well as of different inflammatory, fibrosis, and apoptosis markers in cells and tissues. PPARγ was overexpressed in the heart of mice and NRCMs by viral transfection. Apoptosis and fibrosis were detected by TUNEL and Masson's trichrome staining, respectively. Enzyme-linked immunosorbent assay was performed to detect M1 and M2 macrophage-related inflammatory factors present in mouse sera. PPARγ overexpression significantly inhibited OGD/R- and IRI-induced cardiomyocyte apoptosis and fibrosis in vitro and in vivo. Moreover, PPARγ overexpression inhibited IRI-induced secretion of M1-related proinflammatory factors, whereas it supported the secretion of M2-related anti-inflammatory factors. Notably, these events were found to be mediated by the JAK/STAT pathway. In conclusion, PPARγ regulates macrophage polarization upon IRI via the JAK/STAT pathway, which will in turn prevent myocardial apoptosis and fibrosis. Hence, PPARγ may represent a valuable target for myocardial IRI treatment.


Assuntos
Traumatismo por Reperfusão Miocárdica , Traumatismo por Reperfusão , Ratos , Animais , Traumatismo por Reperfusão Miocárdica/metabolismo , PPAR gama/genética , PPAR gama/metabolismo , Janus Quinases/metabolismo , Transdução de Sinais , Fatores de Transcrição STAT/metabolismo , Macrófagos/metabolismo , Glucose/metabolismo , Fibrose , Apoptose/genética , Traumatismo por Reperfusão/prevenção & controle , Traumatismo por Reperfusão/metabolismo
11.
J Phys Chem Lett ; 14(24): 5573-5579, 2023 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-37306346

RESUMO

Raman spectroscopy, a nondestructive fingerprinting technique, is mainly utilized to identify molecular species and phonon modes of materials. However, direct Raman characterization of two-dimensional materials typically synthesized on catalytic metal substrates is extremely challenging because of the significant electric screening and interfacial electronic couplings. Here, we demonstrate that by covering as-grown graphene with boron nitride (BN) films, the Raman intensity of graphene can be enhanced by two orders of magnitude and is also several times stronger than that of suspended graphene. This great Raman enhancement originates from the optical field amplification by Fabry-Pérot cavity in BN films and the local field plasmon near copper steps. We further demonstrate the direct characterization of the local strain and doping level of as-grown graphene and in situ monitoring of the molecule reaction process by enhanced Raman spectroscopy. Our results will broaden the optical investigations of interfacial sciences on metals, including photoinduced charge transfer dynamics and photocatalysis at metal surfaces.

12.
Clin Cardiol ; 45(8): 821-830, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35758277

RESUMO

BACKGROUND AND HYPOTHESIS: The rehabilitation effect of circuit resistance training in coronary heart disease (CHD) patients remains unclear. We perform this review to examine the rehabilitation effect of circuit resistance training in CHD patients and to provide a basis for the formulation of reasonable individual exercise prescriptions for CHD patients. METHODS: Randomized controlled trials (RCTs) were searched on PubMed, Web of Science, The Cochrane Library, Embase, Clinical Trials, and CNKI. About 1232 studies were identified. Nine RCTs were finally used for the present meta-analysis to determine the rehabilitation effect of circuit resistance training in CHD patients, compared to aerobic training. Individuals enrolled for the studies were at a mean age of 60.5 years old and were all CHD patients. Following the PRISMA guidelines, we extracted basic information about the study and patient characteristics, as well as measurements (e.g., the peak oxygen uptake, the body mass index [BMI], the body fat percentage, the systolic blood pressure, the total cholesterol, and triglycerides). Subsequently, this meta-analysis determined the overall effect by using standardized mean difference (SMD) and 95% confidence interval (CI). RESULTS: Compared with aerobic training, circuit resistance training significantly decrease the BMI and the body fat percentage. CONCLUSIONS: As suggested from the present meta-analysis of RCTs, circuit resistance training is effective in improving the BMI and the body fat percentage in CHD patients and may help delay the progression of CHD. CRT has the advantage of lower load in most cases with a similar effect.


Assuntos
Exercícios em Circuitos , Doença das Coronárias , Treinamento Resistido , Doença das Coronárias/reabilitação , Terapia por Exercício , Humanos , Pessoa de Meia-Idade , Qualidade de Vida
13.
Front Nutr ; 9: 843076, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35369075

RESUMO

Objective: This study aimed to investigate the disparity of gut microbiota among elite athletes and young adults with different physical activity independent of dietary status. Methods: In Hangzhou, China, an age and sex matching study was conducted between April and May 2021. A total of 66 Chinese young adults were recruited in this study and divided into an elite athlete group, physically active group, and physically inactive group. Fecal samples were collected to assess gut microbiota composition. Dietary status was measured using a food-frequency questionnaire. Comparisons in gut microbiota and blood biomarkers among three groups were analyzed by using the analysis of covariance. Results: The findings depicted a tendency to form clusters for beta diversity among three groups, while no significant difference was observed in both alpha and beta diversity. In the multiple analysis model, by adjusting dietary status, a significantly higher abundance of Clostridiaceae (p = 0.029) and Megamonas_rupellensis (p = 0.087) was observed in elite athletes compared to that in general young adults. Furthermore, inflammation-related bacteria such as Bilophila (p = 0.011) and Faecalicoccus (p = 0.050) were enriched in physically inactive young adults compared to two other groups. Pearson's correlation analysis showed a positive association between Bilophila and circulating white body cell count (r = 0.332, p = 0.006) and its subtypes including neutrophils (r = 0.273, p = 0.027), and lymphocytes (r = 0.327, p = 0.007). Megamonas_rupellensis has been shown associated positively with serum lymphocytes levels (r = 0.268, p = 0.03). Although no significant differences were observed, the elite athletes tended to have lower levels of blood biomarkers of immunity within a normal range, which may reflect a better immune function. Conclusion: This matching study indicated that physically inactive young adults are more likely to have a lower immune function and a higher abundance of pro-inflammatory gut bacteria than elite athletes and physically active young adults. Dietary status should be considered as an important factor that may affect the association of physical activity with immune function and gut microbiota.

14.
J Diabetes Res ; 2021: 4542367, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34869777

RESUMO

The objective of the study is to analyze the association between early pregnancy body mass index (BMI), gestational weight gain (GWG), and maternal and neonatal outcomes. The retrospective cohort study was conducted at Quanzhou First Hospital Affiliated to Fujian Medical University from January 2018 to May 2021, with 552 women enrolled. Women were divided into the underweight group, normal weight group, overweight group, and obese group according to early pregnancy BMI. Univariate and multivariate logistic regression analyses were performed. The absolute risk of adverse maternal and neonatal outcomes in the early pregnancy BMI group was calculated to further analyze the association between GWG and adverse maternal and neonatal outcomes. Of the 552 women, 390 (70.65%) women had adverse maternal and neonatal outcomes. The result revealed that overweight was associated with increased risk of adverse maternal and neonatal outcomes (odds ratio (OR): 1.643, 95% confidence interval (CI): 1.006-2.684), maternal complications (OR: 1.937, 95% CI: 1.188-3.159), and large for gestational age (LGA) (OR: 1.905, 95% CI: 1.061-3.422). In the obese group, the risk of adverse maternal and neonatal outcomes (OR: 5.760, 95% CI: 1.997-16.786), maternal complications (OR: 3.112, 95% CI: 1.645-5.887), gestational diabetes mellitus (GDM) (OR: 2.943, 95% CI: 1.509-5.741), cesarean section (OR: 1.899, 95% CI: 1.002-3.599), and preterm delivery (OR: 4.752, 95% CI: 1.395-16.185) increased. Besides, there was an association between insufficient GWG and decreased risk of LGA (OR: 0.392, 95% CI: 0.187-0.826) and higher risk of preterm delivery (OR: 2.818, 95% CI: 1.171-6.784). This study demonstrates that BMI and GWG are related to maternal and neonatal outcomes. It is necessary to regularly monitor the weight of pregnant women during pregnancy. And regional guidelines for GWG also need to be explored.


Assuntos
Índice de Massa Corporal , Ganho de Peso na Gestação/fisiologia , Resultado da Gravidez/epidemiologia , Adulto , China/epidemiologia , Estudos de Coortes , Feminino , Ganho de Peso na Gestação/etnologia , Humanos , Recém-Nascido , Gravidez , Estudos Retrospectivos
15.
Artigo em Inglês | MEDLINE | ID: mdl-34574565

RESUMO

Physical activity could improve the muscle fitness of youth, but the systematic analysis of physical activity elements and muscle fitness was limited. This systematic review and meta-analysis aim to explore the influence of physical activity elements on muscle fitness in children and adolescents. We analyzed literature in Embase, EBSCO, Web of Science, and PubMed databases from January 2000 to September 2020. Only randomized controlled studies with an active control group, which examined at least 1 muscle fitness evaluation index in individuals aged 5-18 years were included. Articles were evaluated using the Jaded scale. Weighted-mean standardized mean differences (SMDs) were calculated using random-effects models. Twenty-one studies and 2267 subjects were included. Physical activity had moderate effects on improving muscle fitness (SMD: 0.58-0.96, p < 0.05). Physical activity element subgroup analysis showed that high-intensity (SMD 0.68-0.99, p < 0.05) physical activity <3 times/week (SMD 0.68-0.99, p < 0.05), and <60 min/session (SMD 0.66-0.76, p < 0.01) effectively improved muscle fitness. Resistance training of ≥3 sets/session (SMD 0.93-2.90, p < 0.01) and <10 repetitions/set (SMD 0.93-1.29, p < 0.05) significantly improved muscle fitness. Low-frequency, high-intensity, and short-duration physical activity more effectively improves muscle fitness in children and adolescents. The major limitation of this meta-analysis was the low quality of included studies. The study was registered in PROSPERO with the registration number CRD42020206963 and was funded mainly by the Ministry of Education of Humanities and Social Science project, China.


Assuntos
Exercício Físico , Treinamento Resistido , Adolescente , Criança , Ciências Humanas , Humanos , Músculo Esquelético , Ensaios Clínicos Controlados Aleatórios como Assunto
16.
J Phys Chem Lett ; 12(11): 2886-2891, 2021 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-33724034

RESUMO

The capture of photoexcited deep-band hot carriers, excited by photons with energies far above the bandgap, is of significant importance for photovoltaic and photoelectronic applications because it is directly related to the quantum efficiency of photon-to-electron conversion. By employing time-resolved photoluminescence and state-of-the-art time-domain density functional theory, we reveal that photoexcited hot carriers in organic-inorganic hybrid perovskites prefer a zigzag interfacial charge-transfer pathway, i.e., the hot carriers transfer back and forth between CH3NH3PbI3 and graphene electrode, before they reach a charge-separated state. Driven by quantum coherence and interlayer vibrational modes, this pathway at the semiconductor-graphene interface takes about 400 fs, much faster than the relaxation process within CH3NH3PbI3 (several picoseconds). Our work provides new insight into the fundamental understanding and precise manipulation of hot carrier dynamics at the complex interfaces, paving the way for highly efficient photovoltaic and photoelectric device optimization.

17.
Adv Mater ; 33(5): e2004469, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33325574

RESUMO

The emergence of 2D polarized materials, including ferromagnetic, ferrovalley, and ferroelectric materials, has demonstrated unique quantum behaviors at atomic scales. These polarization behaviors are tightly bonded to the new degrees of freedom (DOFs) for next generation information storage and processing, which have been dramatically developed in the past few years. Here, the basic 2D polarized materials system and related devices' application in spintronics, valleytronics, and electronics are reviewed. Specifically, the underlying physical mechanism accompanied with symmetry broken theory and the modulation process through heterostructure engineering are highlighted. These summarized works focusing on the 2D polarization would continue to enrich the cognition of 2D quantum system and promising practical applications.

18.
Front Cell Dev Biol ; 9: 659392, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34109174

RESUMO

BRD7 functions as a crucial tumor suppressor in numerous malignancies. However, the effects of BRD7 on colorectal cancer (CRC) progression are still unknown. Here, based on the BRD7 knockout (BRD7-/-) and BRD7 flox/flox (BRD7+/+) mouse models constructed in our previous work, we established an azoxymethane/dextran sodium sulfate (AOM/DSS)-induced mouse model. BRD7+/+ mice were found to be highly susceptible to AOM/DSS-induced colitis-associated CRC, and BRD7 significantly promoted cell proliferation and cell cycle G1/S transition but showed no significant effect on cell apoptosis. Furthermore, BRD7 interacted with c-Myc and stabilized c-Myc by inhibiting its ubiquitin-proteasome-dependent degradation. Moreover, restoring the expression of c-Myc in BRD7-silenced CRC cells restored cell proliferation, cell cycle progression, and tumor growth in vitro and in vivo. In addition, BRD7 and c-Myc were both significantly upregulated in CRC patients, and high expression of these proteins was associated with clinical stage and poor prognosis in CRC patients. Collectively, BRD7 functions as an oncogene and promotes CRC progression by regulating the ubiquitin-proteasome-dependent stabilization of c-Myc protein. Targeting the BRD7/c-Myc axis could be a potential therapeutic strategy for CRC.

19.
Nat Nanotechnol ; 16(10): 1073-1078, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34385681

RESUMO

Non-invasive, high-throughput spectroscopic techniques can identify chiral indices (n,m) of carbon nanotubes down to the single-tube level1-6. Yet, for complete characterization and to unlock full functionality, the handedness, the structural property associated with mirror symmetry breaking, also needs to be identified accurately and efficiently7-14. So far, optical methods fail in the handedness characterization of single nanotubes because of the extremely weak chiroptical signals (roughly 10-7) compared with the excitation light15,16. Here we demonstrate the complete structure identification of single nanotubes in terms of both chiral indices and handedness by Rayleigh scattering circular dichroism. Our method is based on the background-free feature of Rayleigh scattering collected at an oblique angle, which enhances the nanotube's chiroptical signal by three to four orders of magnitude compared with conventional absorption circular dichroism. We measured a total of 30 single-walled carbon nanotubes including both semiconducting and metallic nanotubes and found that their absolute chiroptical signals show a distinct structure dependence, which can be qualitatively understood through tight-binding calculations. Our strategy enables the exploration of handedness-related functionality of single nanotubes and provides a facile platform for chiral discrimination and chiral device exploration at the level of individual nanomaterials.

20.
Psychol Res Behav Manag ; 13: 787-796, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33061694

RESUMO

PURPOSE: To investigate whether the physical activity at different intensities is correlated with depressive symptoms in college students. PATIENT AND METHODS: This cross-sectional study was a part of the Fitness Improvement Tactics in Youth Project, which was conducted in 2017. A total of 2,820 college freshmen aged 15-24 years were included in this study, of whom 699 (24.8%) were males and 2,121 (75.2%) were females. Depressive symptoms were measured using the Self-rating Depression Scale. Physical activity was assessed using the International Physical Activity Questionnaire-Short Form. Covariates included sociodemographic, lifestyle-related, and health-related factors. RESULTS: A total of 560 (19.9%) college students had depressive symptoms. Total physical activity levels (METs•hour/week) were positively associated with frequency of breakfast intake (p = 0.050) but no other participant characteristics. Logistic regression analysis showed that the prevalence of depressive symptoms in the highest quartile of physical activity was lower than in the lowest quartile when adjusted for sex, age, ethnicity, only child, smoking status, alcohol use, breakfast frequency, daily sleep duration, body mass index, grip strength, and the number of metabolic syndrome components (odds ratios [95% confidence intervals (CI)]: 0.75 [0.58, 0.98], p = 0.036). Furthermore, high physical activity levels of low-intensity tended to moderately correlate to lower prevalence of depressive symptoms (odds ratios [95% CI]: Q1, 0.71 [0.55, 0.91], Q2, 0.77 [0.59, 1.01], Q3, 0.75 [0.57, 0.98], p for trend = 0.037). Associations of moderate and vigorous physical activity with depressive symptoms were not found. For secondary outcomes, sex-stratified analysis showed that similar findings were only found in females, but not males. CONCLUSION: This study indicated that total physical activity and low-intensity physical activity were inversely associated with depressive symptoms in Chinese college students. All these observations showed gender differences.

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