Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 28
Filtrar
1.
J Exp Bot ; 75(8): 2351-2371, 2024 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-38205848

RESUMEN

Plant senescence, as a highly integrated developmental stage, involves functional degeneration and nutrient redistribution. NAM/ATAF1/CUC (NAC) transcription factors orchestrate various senescence-related signals and mediate the fine-tuning underlying plant senescence. Previous data revealed that knockout of either NtNAC028 or NtNAC080 leads to delayed leaf senescence in tobacco (Nicotiana tabacum), which implies that NtNAC028 and NtNAC080 play respective roles in the regulation of leaf senescence, although they share 91.87% identity with each other. However, the mechanism underlying NtNAC028- and NtNAC080-regulated leaf senescence remains obscure. Here, we determined that NtNAC028 and NtNAC080 activate a putative jasmonic acid (JA) biosynthetic gene, NtLOX3, and enhance the JA level in vivo. We found that NtNAC028 and NtNAC080 interact with each other and themselves through their NA-terminal region. Remarkably, only the dimerization between NtNAC028 and NtNAC080 stimulated the transcriptional activation activity, but not the DNA binding activity of this heterodimer on NtLOX3. Metabolome analysis indicated that overexpression of either NtNAC028 or NtNAC080 augments both biosynthesis and degradation of nicotine in the senescent stages. Thus, we conclude that NtNAC028 cooperates with NtNAC080 and forms a heterodimer to enhance NtLOX3 expression and JA biosynthesis to trigger the onset of leaf senescence and impact secondary metabolism in tobacco.


Asunto(s)
Ciclopentanos , Nicotiana , Oxilipinas , Factores de Transcripción , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Nicotiana/genética , Senescencia de la Planta , Hojas de la Planta/metabolismo , Regulación de la Expresión Génica de las Plantas
2.
Ecotoxicol Environ Saf ; 277: 116399, 2024 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-38677070

RESUMEN

Perfluoroalkyl and polyfluoroalkyl substances (PFASs), as pollutants, can cause palpable environmental and health impacts around the world, as endocrine disruptors, can disrupt endocrine homeostasis and increase the risk of diseases. Chlorinated polyfluoroalkyl ether sulfonate (F-53B), as a substitute for PFAS, was determined to have potential toxicity. Puberty is the stage when sexual organs develop and hormones change dramatically, and abnormal uterine development can increase the risk of uterine lesions and lead to infertility. This study was designed to explore the impact of F-53B on uterine development during puberty. Four-week-old female SD rats were exposed to 0.125 and 6.25 mg/L F-53B during puberty. The results showed that F-53B interfered with growth and sex hormone levels and bound to oestrogen-related receptors, which affected their function, contributed to the accumulation of reactive oxygen species, promoted cell apoptosis and inhibited cell proliferation, ultimately causing uterine dysplasia.


Asunto(s)
Alcanosulfonatos , Apoptosis , Disruptores Endocrinos , Especies Reactivas de Oxígeno , Maduración Sexual , Útero , Animales , Femenino , Ratas , Apoptosis/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Disruptores Endocrinos/toxicidad , Contaminantes Ambientales/toxicidad , Fluorocarburos/toxicidad , Ratas Sprague-Dawley , Especies Reactivas de Oxígeno/metabolismo , Receptores de Estrógenos/metabolismo , Maduración Sexual/efectos de los fármacos , Útero/efectos de los fármacos , Alcanosulfonatos/toxicidad
3.
Environ Toxicol ; 39(5): 2681-2691, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38234154

RESUMEN

It is well known that polystyrene nanoplastics (PS-NaP) and nano-titanium dioxide (TiO2 NPs) are frequently co-appeared in daily life and can cause liver injury when they accumulate in the liver. Nonetheless, the combined toxicological impacts and potential molecular mechanisms of PS-NaP and TiO2 NPs in the hepatic system have not been revealed. Thus, we conducted experiments on C57BL/6 mice exposed to PS-NaP or/and TiO2 NPs for 4 weeks. The findings suggested that PS-NaP and TiO2 NPs co-exposed significantly altered the hepatic function parameters, levels of antioxidant-related enzymes and genes expression of Keap-1/Nrf2/ARE signaling pathway, as well as significantly increased the hepatic Ti contents, aggravated hepatic pathological and oxidative stress (OS) damage compared with individual exposure to PS-NaP or TiO2 NPs. Using N-Acetyl-L-cysteine (NAC), an OS inhibitor, we further demonstrated that OS played a pivotal role in coexposure-induced liver injury. NAC reduced the levels of OS in mice, which mitigated co-exposure-induced liver injury. Taken together, we proposed that PS-NaP and TiO2 NPs co-exposed activated the Keap-1, then inhibited the recognition of Nrf2 and ARE, consequently exacerbated liver injury. These findings shed light on the co-toxicity and potential mechanism of nanoplastics and nanoparticles, which informed the risk assessment of human exposure to environmental pollutants.


Asunto(s)
Enfermedad Hepática Crónica Inducida por Sustancias y Drogas , Nanopartículas , Animales , Ratones , Ratones Endogámicos C57BL , Microplásticos , Nanopartículas/toxicidad , Factor 2 Relacionado con NF-E2 , Estrés Oxidativo , Poliestirenos/toxicidad , Titanio/toxicidad
4.
Int Urogynecol J ; 34(7): 1369-1375, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-36001096

RESUMEN

INTRODUCTION AND HYPOTHESIS: International Consultation on Incontinence Questionnaire-Vaginal Symptoms (ICIQ-VS) is a simple and effective questionnaire for evaluating vaginal symptoms, sexual problems and the quality of life (QOL) in patients. This study was aimed at validating the simplified Chinese version of the ICIQ-VS. METHODS: A total of 120 women with pelvic organ prolapse (POP) stage <2, 124 with stage ≥ 2, and 51 patients who underwent POP surgery (POP stage ≥2) were included. Cronbach's alpha coefficient and intraclass correlation coefficient (ICC) were used for reliability analysis. We used the content validity index, Kruskal-Wallis H test, and Mann-Whitney U test to study validity. Paired sample t test, Wilcoxon signed-rank test, effect size and standardized response mean were used to assess sensitivity. RESULTS: The Cronbach's alpha coefficients of the vaginal symptoms score (VSS) and sexual matters score (SMS) were 0.787 and 0.861 respectively. The test-retest reliabilities of the VSS, SMS, and QOL score were 0.830, 0.894, and 0.948 respectively. The test-retest reliability was from good to excellent (ICC 0.669-0.948). The item-level content validity index was 0.60 to 1.00. The scale-level content validity index/universal agreement was 0.95, and the scale-level content validity index/average was 0.96. Significant score differences existed between the symptomatic and asymptomatic groups (p < 0.001). Criterion validity was significant (p < 0.001). VSS and QOL score had high sensitivity (p < 0.001, effect size and standardized response mean >0.8). CONCLUSIONS: The simplified Chinese version of the ICIQ-VS can objectively and reliably access vaginal symptoms, sexual matters, and QOL in Chinese women.


Asunto(s)
Calidad de Vida , Incontinencia Urinaria , Humanos , Femenino , Reproducibilidad de los Resultados , Incontinencia Urinaria/diagnóstico , Encuestas y Cuestionarios , Derivación y Consulta
5.
Appl Opt ; 62(33): 8804-8810, 2023 Nov 20.
Artículo en Inglés | MEDLINE | ID: mdl-38038027

RESUMEN

In this paper, the matrix difference method is used to calculate the photoelectron continuity equation and the outgoing electron flux density equation. The effects of the GaAsP/AlGaAsP recombination rate, electron diffusion coefficient, and activation layer thickness on the time-resolved characteristics and quantum efficiency of a GaAsP photocathode are systematically studied, and the accuracy of the theoretical calculation is verified by experiments. The response speed and quantum efficiency of the GaAsP photocathode can be greatly improved by adjusting the thickness of the GaAsP activation layer reasonably.

6.
Phys Chem Chem Phys ; 19(28): 18273-18278, 2017 Jul 19.
Artículo en Inglés | MEDLINE | ID: mdl-28696469

RESUMEN

Doping (or substitution)-induced modification of the electronic structure to increase the electronic density of states (eDOS) near the Fermi level is considered as an effective strategy to enhance the Seebeck coefficient, and may consequently boost the thermoelectric performance. Through density-functional theory calculations of Mn-substituted TiFe2-xMnxSn compounds, we demonstrate that the d-states of the substituted Mn atoms induce a strong resonant level near the Fermi energy. Our experimental results are in good agreement with the calculations. They show that Mn substitution results in a large increase of the Seebeck coefficient, arising from an enhanced eDOS in Heusler compounds. The results prove that a proper substitution position and element selection can increase the eDOS, leading to a higher Seebeck coefficient and thermoelectric performance of ecofriendly materials.

7.
J Phys Chem Lett ; 15(27): 7055-7060, 2024 Jul 11.
Artículo en Inglés | MEDLINE | ID: mdl-38949914

RESUMEN

The low thermal conductivity of group IV-VI semiconductors is often attributed to the soft phonons and giant anharmonicity observed in these materials. However, there is still no broad consensus on the fundamental origin of this giant anharmonic effect. Utilizing first-principles calculations and group symmetry analysis, we find that the cation lone-pairs s electrons in IV-VI materials cause a significant coupling between occupied cation s orbitals and unoccupied cation p orbitals due to the symmetry reduction when atoms vibrate away from their equilibrium positions under heating. This leads to an electronic energy gain, consequently flattening the potential energy surface and causing soft phonons and strong anharmonic effects. Our findings provide an intrinsic understanding of the low thermal conductivity in IV-VI compounds by connecting the anharmonicity with the dynamical electronic structures, and can also be extended to a large family of hybrid systems with lone-pair electrons, for promising thermoelectric applications and predictive designs.

8.
J Multidiscip Healthc ; 16: 3737-3748, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38076591

RESUMEN

Purpose: To construct a training program for ICU nurses to manage artificial airway gasbags to prevent ventilator-associated pneumonia (VAP) and explore its application in ICU nurses. Methods: From January to March 2023, 17 experts were consulted using the Delphi method to construct the draft of the training program. 52 ICU nurses were selected from a third-level, first-class hospital in Henan Province. They received training using the program for 4 weeks. The training effects were evaluated by examining the theoretical knowledge, testing operation skills, and the ICU medical staff gasbag management knowledge-attitude-behavior questionnaire before and one week after the training in April 2023. Results: The coefficients of expert authority for the two round inquiries were 0.816 and 0.837, respectively. The coordination coefficient of expert opinions ranges from 0.2 to 0.3. The final training program for ICU nurses on managing artificial airway gasbags to prevent VAP was constructed and included 4 primary indicators, 25 secondary indicators, 47 tertiary indicators. After the training by the program, the scores of the ICU nurses' theoretical knowledge (before, 73.73 ± 8.54 VS after, 88.31 ± 6.29; t = 11.017, P<0.001) and technical operation (before, 75.29 ± 7.48 VS after, 86.92 ± 4.72; t = 8.986, P<0.001) were significantly increased. The total scores of the ICU nurses' knowledge-attitude-behavior on gasbag management (before, 76.67 ± 10.68 VS after, 109.04 ± 9.87; t = 19.916, P<0.001) were also significantly increased compared to the performance before training. Conclusion: The training program for ICU nurses on managing artificial airway gasbags to prevent VAP based on the Miller pyramid model is scientific and practical and can enhance the knowledge-attitude-behavior level of ICU nurses. This training program constructed in this study can be recommended and applied after further verification for the ICU nurses to manage the artificial airway gasbags in order to reducing the occurrence of the VAP in the clinical practice.

9.
Front Public Health ; 10: 797794, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35400043

RESUMEN

Global cancer statistics suggest that breast cancer (BC) is the most diagnosed cancer in women, with an estimated 2. 3 million new cases reported in 2020. Observational evidence shows a clear link between prevention and development of invasive BC and lifestyle-based interventions such as a healthy diet and physical activity. The recent findings reveal that even minimal amounts of daily exercise and a healthy diet reduced the risk of BC, mitigated the side effects of cancer treatment, and stopped the recurrence of cancer in the survivors. Despite the myriad benefits, the implementation of these lifestyle interventions in at-risk and survivor populations has been limited to date. Given the need to disseminate information about the role of physical activity and nutrition in BC reduction, the review aimed to present the recent scientific outreach and update on associations between the lifestyle interventions and BC outcomes to narrow the gap and strengthen the understanding more clearly. This review covers more direct, detailed, and updated scientific literature to respond to frequently asked questions related to the daily lifestyle-based interventions and their impact on BC risk and survivors. This review also highlights the importance of the oncology provider's job and how oncology education can reduce the BC burden.


Asunto(s)
Neoplasias de la Mama , Dieta Saludable , Neoplasias de la Mama/terapia , Ejercicio Físico , Femenino , Humanos , Estilo de Vida , Sobrevivientes
10.
Front Nutr ; 9: 814095, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35284454

RESUMEN

In nutrition science, malnutrition is a state of imbalance between intake and the needs of the organism, leading to metabolic changes, impaired physiological functions, and weight loss. Regardless of the countless efforts being taken and researched for years, the burden of malnutrition is still alarming and considered a significant agent of mortality across the globe. Around 45% of 12 million children deaths (0-5 years old) annually are due to malnutrition, mostly from developing countries. Malnutrition develops associations with other infections and leads to substantial clinical outcomes, such as mortality, more visits to hospitals, poor quality of life and physical frailty, and socioeconomic issues. Here, in this review, we intend to provide an overview of the current burden, underlying risk factors, and co-existence of malnutrition and other infections, such as cancer. Following the rising concern of the vicious interplay of malnutrition and other medical illnesses, we believed that this narrative review would highlight the need to re-make and re-define the future strategies by giving comprehensive and sustainable programs to alleviate poverty and combat the rampant infectious diseases and those nutrition-related health problems. Furthermore, the study also raises the concern for hospitalized malnourished cancer patients as it is crucially important to knowledge the caregiver healthcare staff for early interventions of providing nutritional support to delay or prevent the onset of malnutrition.

11.
Foods ; 10(5)2021 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-33946424

RESUMEN

The hazard of titanium dioxide nanoparticles (TiO2 NPs) in diseased population should be given focus due to the huge number of these NPs in foods and medicine. This study aimed to evaluate the stronger biological adverse effect of oral exposure to TiO2 NPs in a fructose-induced metabolic syndrome mouse model. Compared to the normal mice, low-dose (2 mg/kg) TiO2 NPs did not cause severe hepatotoxicity. However, high-dose (20 mg/kg) TiO2 NPs induced aggravated hepatic inflammation, fibrosis, and apoptosis, with substantial alteration of related biochemical parameters in the mouse model. Moreover, significantly increased Ti and lipopolysaccharide burden were observed in metabolic syndrome murine liver and serum, which possibly worsened the portend intestinal leakage. The expression of tight junction-related protein showed that TiO2 NPs induced further increase in serious intestinal permeability. The intestinal inflammatory and oxidative stress response in the model were also assessed. Results showed that TiO2 NPs caused more severe intestinal inflammatory injury by intensifying the oxidative stress in metabolic syndrome mice and then induced further liver injury. This work provides information on the insights into the toxic effect of TiO2 NPs in sub-healthy population.

12.
Luminescence ; 25(5): 367-72, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-19757496

RESUMEN

An electrochemiluminescence (ECL) approach for methamphetamine determination was developed based on a glassy carbon electrode modified with a Ru(bpy)3 (2+)-doped silica nanoparticles/Nafion composite film. The monodispersed nanoparticles, which were about 50 nm in size, were synthesized using the water-in-oil microemulsion method. The ECL results revealed that Ru(bpy)3 (2+) doped in silica nanoparticles retained its original photo- and electrochemical properties. The ECL intensity was found to be proportional to methamphetamine concentration over the range from 1.0 × 10(-7) to 1.0 × 10(-5) mol L(-1), and the detection limit was found to be 2.6 × 10(-8) mol L(-1). The proposed ECL approach was used to analyze the methamphetamine content in drugs.


Asunto(s)
Polímeros de Fluorocarbono/química , Membranas Artificiales , Metanfetamina/análisis , Nanopartículas/química , Compuestos Organometálicos/química , Dióxido de Silicio/química , Carbono/química , Electroquímica , Electrodos , Mediciones Luminiscentes , Propiedades de Superficie
13.
ACS Appl Mater Interfaces ; 12(10): 11852-11864, 2020 Mar 11.
Artículo en Inglés | MEDLINE | ID: mdl-32069390

RESUMEN

The high-throughput (HT) computational method is a useful tool to screen high-performance functional materials. In this work, using the deformation potential method under the single band model, we evaluate the carrier relaxation time and establish an electrical descriptor (χ) characterized by the carrier effective masses based on the simple rigid band approximation. The descriptor (χ) can be used to reasonably represent the maximum power factor without solving the electron Boltzmann transport equation. Additionally, the Grüneisen parameter (γ), a descriptor of the lattice anharmonicity and lattice thermal conductivity, is efficiently evaluated using the elastic properties, omitting the costly phonon calculations. Applying two descriptors (χ and γ) to binary chalcogenides, we HT compute 243 semiconductors and screen 50 promising thermoelectric materials. For these theoretically determined compounds, we successfully predict some previously experimentally and theoretically investigated promising thermoelectric materials. Additionally, 9 p-type and 14 n-type previously unreported binary chalcogenides are also predicted as promising thermoelectric materials. Our work provides not only new thermoelectric candidates with perfect crystalline structure for the future investigations but also reliable descriptors to HT screen high-performance thermoelectric materials.

14.
Anal Chem ; 81(2): 830-3, 2009 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-19067540

RESUMEN

A colorimetric electrochemiluminescence (ECL) sensor was fabricated for the first time, based on a dual-color system including a strong red Ru(bpy)(3)(2+) ECL and a green reference light from a light emitting diode. Traditional ECL intensity information can be easily transformed into a color variation with this sensor, and the color variation can be directly monitored using the naked eye or a commercial CCD camera. The sensor has been successfully used to determine the concentration of tripropylamine, proline (enhancing system), and dopamine (quenching system). The results indicated that the color variation obtained corresponded to the concentration of target analytes. This sensor has potential application in rapid and semiquantitative ECL analysis.

15.
Spectrochim Acta A Mol Biomol Spectrosc ; 207: 337-347, 2019 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-30267978

RESUMEN

In this work, we develop a simple and selective sensing method for the detection of mercury ions based on surface plasmon resonance (SPR) spectrum change of Au-Ag core-shell triangular nanoplates. When the concentration of mercury is increased, the etching-induced change of particle size and shape also leads to the decrease of the absorption peak at the fixed wavelength, until a spectrum dip takes place. This spectral change of "peak-to-dip" greatly enlarges the detection range of mercury ions, which could be fine tuned by changing the initial thickness of the Ag coating. Under optimal conditions, the decrease of the logarithmic absorption intensity has a good linear response with the concentration of mercury ions increasing from 10 to 1000 µM, and the limit of detection (LOD) is 0.88 µM. Interference studies and real samples test indicate that, this new sensing method has a good selection for mercury ions and can be practically used in lake water. This work shows the surface etching-induced SPR shift can also leads to the intensity change with "peak-to-dip" fashion, which greatly enlarge the concentration range of the detection and could be widely applied in the spectroscopy sensing based on SPR.

16.
Front Neurosci ; 13: 456, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31156363

RESUMEN

Importance: Accumulating evidence suggests that serum levels of S100B may play a role in epilepsy. Objective: We performed a meta-analysis to quantitatively summarize the serum S100B data available for patients with epilepsy. Data source: Two independent researchers conducted a systematic investigation of the Harvard Hollis+, Open Gray, Clinicaltrials, Wanfangdata, and CNKI databases through Dec 6, 2018, for all studies published in English and Chinese. The search terms included S100B and calcium-binding protein B in combination with epilepsy. Study selection: Original studies and reported data from these search terms are included. Studies where data overlapped with other studies were excluded. Data extraction and synthesis: investigators extracted, pooled and analyzed data from the included studies using a fixed-effects model in the Comprehensive Meta-Analysis3.3 and R software. Main outcomes and measures: Peripheral blood levels of S100B in patients with epilepsy compared with controls. Aberrations in peripheral blood levels of S100B were hypothesized to be related to epilepsy. Results: a fixed-effects meta-analysis of all 18 studies, including 1,057 unique participants, indicated that patients with epilepsy had significantly increased peripheral blood levels of S100B compared to controls (Hedges g = 1.568, 95% CI =1.431-1.706, P < 0.001). Sensitivity analysis showed that no single study significantly influenced the overall association of peripheral blood levels of S100B and epilepsy. Most of the subgroup analyses, including those of country, assay type and publication language, demonstrated a statistically significant association between peripheral blood levels of S100B and epilepsy. Meta-regression analyses indicated that gender (regression coefficient [SE], -0.2524 [0.0641]; 95%CI, -0.3781 to -0.1267; P = 0.0001) and mean age (regression coefficient [SE], -0.1224 [0.0426]; 95% CI, -0.2058 to -0.0390; P = 0.0040) might present serum S100B reductions, but sample size, years, assay type, publication language and country did not show moderating effects on the effect sizes. Furthermore, the trim-and-fill method used to adjust for funnel plot asymmetry in our meta-analysis confirmed that a positive outcome is unlikely to be due to publication bias. Conclusion and relevance: the results of this meta-analysis provide evidence for a significant increase in serum S100B levels in patients with epilepsy. Serum S100B is the most worthwhile biomarker of epilepsy, which is helpful for the clinical diagnosis and prognosis of epilepsy.

17.
J Hazard Mater ; 357: 355-362, 2018 09 05.
Artículo en Inglés | MEDLINE | ID: mdl-29909169

RESUMEN

The animal experiment was preformed to investigate the roles of PPAR-γ/PI3K/Akt pathway in apoptosis triggered by cadmium (Cd) and in the antagonistic effects of selenium (Se) on Cd in the pancreas of chicken. The current study showed that Cd treatment obviously increased the accumulation of Cd and directly led to lower activities of amylase, trypsin and lipase in chicken pancreas. The expression of PPAR-γ, PI3K, and Akt was declined, whereas the level of Bax, Cyt C and caspase-3 were increased in Cd group. In the result of TUNEL assay and the histological examination, typical apoptosis characteristics in the pancreas of Cd group were confirmed. Cd group also showed high levels of inducible nitric oxide synthase (iNOS) activity and nitric oxide (NO) content in pancreas. However, those Cd-induced changes were obviously alleviated in Cd + Se group. Our study revealed that Cd could impact the pancreas function and induce the activation of Bax and the overproduction of NO via PPAR-γ/PI3K/Akt pathway to promote apoptosis in chicken pancreas. However, Se could reduce Cd accumulation and antagonize Cd-triggered apoptosis in chicken pancreas.


Asunto(s)
Cadmio/toxicidad , Páncreas/efectos de los fármacos , Sustancias Protectoras/farmacología , Selenio/farmacología , Animales , Apoptosis/efectos de los fármacos , Pollos , Antagonismo de Drogas , Femenino , Microscopía Electrónica de Transmisión , Óxido Nítrico/metabolismo , Óxido Nítrico Sintasa de Tipo II/metabolismo , PPAR gamma/genética , PPAR gamma/metabolismo , Páncreas/metabolismo , Páncreas/ultraestructura , Fosfatidilinositol 3-Quinasas/genética , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Proto-Oncogénicas c-akt/genética , Proteínas Proto-Oncogénicas c-akt/metabolismo , Transducción de Señal/efectos de los fármacos
18.
Biol Trace Elem Res ; 184(1): 240-246, 2018 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-28994040

RESUMEN

Cadmium (Cd) is a highly toxic heavy metal that can affect human and animal health. Selenium (Se) is an essential microelement that can protect various organs against toxic heavy metals. Although many studies have investigated the adverse effect of Cd in rats and several other animals, little is known regarding the mechanisms of Cd-induced autophagy in the chicken pancreas and the antagonistic effect of Se on Cd. In the current study, we fed chickens Se, Cd, or Se and Cd supplements to establish the Se and Cd interaction model and to measure the concentrations of Se and Cd in the chicken pancreas. The ultrastructure changes of the chicken pancreas were also observed, and we detected oxidative stress indexes in each group. The expression levels of autophagy-related genes were also examined. We found that Cd exposure could increase the concentration of Cd, the activities of total superoxide dismutase (T-SOD), catalase (CAT), and glutathione peroxidase (GSH-Px); and the total antioxidant capacity (T-AOC) content in the chicken pancreas. The protein expression levels of dynein, Beclin1, LC3-1, LC3-2, and Atg5 were increased and that of TOR was decreased under Cd exposure conditions. However, the changes induced by Cd were significantly alleviated by Se. This study suggested that Cd could accumulate in the chicken pancreas and lead to oxidative stress and autophagy. Se was shown to antagonize Cd toxicity though reducing Cd accumulation, alleviating oxidative stress, and inhibiting autophagy. This study revealed a concrete mechanism for the Se antagonism of Cd and might provide a new clue for the detoxification of Cd poisoning.


Asunto(s)
Cadmio/toxicidad , Páncreas/efectos de los fármacos , Páncreas/metabolismo , Selenio/metabolismo , Selenio/farmacología , Animales , Antioxidantes/metabolismo , Apoptosis/efectos de los fármacos , Autofagia/efectos de los fármacos , Catalasa/metabolismo , Pollos , Femenino , Glutatión Peroxidasa/metabolismo , Peroxidación de Lípido/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Superóxido Dismutasa/metabolismo
19.
Sci Rep ; 6: 20971, 2016 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-26860967

RESUMEN

Based on the first-principles calculations, we have investigated in detail the bandgap opening of silicene nanomeshes. Different to the mechanism of bandgap opening induced by the sublattice equivalence breaking, the method of degenerate perturbation through breaking the bond symmetry could split the π-like bands in the inversion symmetry preserved silicene nanomeshes, resulting into the πa1 - πa2 and πz1 - πz2 band sets with sizable energy intervals. Besides the bandgap opening in the nanomeshes with Dirac point being folded to Γ point, the split energy intervals are however apart away from Fermi level to leave the semimetal nature unchanged for the other nanomeshes with Dirac points located at opposite sides of Γ point as opposite pseudo spin wave valleys. A mass bandgap could be then opened at the aid of uniaxial strain to transfer the nanomesh to be semiconducting, whose width could be continuously enlarged until reaching its maximum Emax. Moreover, the Emax could also be tuned by controlling the defect density in silicene nanomeshes. These studies could contribute to the understanding of the bandgap engineering of silicene-based nanomaterials to call for further investigations on both theory and experiment.

20.
PLoS One ; 11(2): e0148648, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26840532

RESUMEN

Music and exercise can both affect autonomic nervous system activity. However, the effects of the combination of music and exercise on autonomic activity are poorly understood. Additionally, it remains unknown whether music affects post-exercise orthostatic tolerance. The aim of this study was to evaluate the effects of music on autonomic nervous system activity in orthostatic tolerance after exercise. Twenty-six healthy graduate students participated in four sessions in a random order on four separate days: a sedentary session, a music session, a bicycling session, and a bicycling with music session. Participants were asked to listen to their favorite music and to exercise on a cycle ergometer. We evaluated autonomic nervous system activity before and after each session using frequency analysis of heart rate variability. High frequency power, an index of parasympathetic nervous system activity, was significantly increased in the music session. Heart rate was increased, and high frequency power was decreased, in the bicycling session. There was no significant difference in high frequency power before and after the bicycling with music session, although heart rate was significantly increased. Additionally, both music and exercise did not significantly affect heart rate, systolic blood pressure or also heart rate variability indices in the orthostatic test. These data suggest that music increased parasympathetic activity and attenuated the exercise-induced decrease in parasympathetic activity without altering the orthostatic tolerance after exercise. Therefore, music may be an effective approach for improving post-exercise parasympathetic reactivation, resulting in a faster recovery and a reduction in cardiac stress after exercise.


Asunto(s)
Presión Sanguínea/fisiología , Ejercicio Físico/fisiología , Frecuencia Cardíaca/fisiología , Música , Sistema Nervioso Parasimpático/fisiología , Adulto , Femenino , Humanos , Masculino
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA