Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 13 de 13
Filtrar
1.
Brain Behav Immun ; 119: 607-620, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38663772

RESUMEN

The vagus nerve, a pivotal link within the gut-brain axis, plays a critical role in maintaining homeostasis and mediating communication between the gastrointestinal tract and the brain. It has been reported that gastrointestinal infection by Salmonella typhimurium (S. typhimurium) triggers gut inflammation and manifests as anxiety-like behaviors, yet the mechanistic involvement of the vagus nerve remains to be elucidated. In this study, we demonstrated that unilateral cervical vagotomy markedly attenuated anxiety-like behaviors induced by S. typhimurium SL1344 infection in C57BL/6 mice, as evidenced by the open field test and marble burying experiment. Furthermore, vagotomy significantly diminished neuronal activation within the nucleus of the solitary tract and amygdala, alongside mitigating aberrant glial cell activation in the hippocampus and amygdala. Additionally, vagotomy notably decreases serum endotoxin levels, counters the increase in splenic Salmonella concentration, and modulates the expression of inflammatory cytokines-including IL-6, IL-1ß, and TNF-α-in both the gastrointestinal tract and brain, with a concurrent reduction in IL-22 and CXCL1 expression. This intervention also fostered the enrichment of beneficial gut microbiota, including Alistipes and Lactobacillus species, and augmented the production of gamma-aminobutyric acid (GABA) in the gut. Administration of GABA replicated the vagotomy's beneficial effects on reducing gut inflammation and anxiety-like behavior in infected mice. However, blockade of GABA receptors with picrotoxin abrogated the vagotomy's protective effects against gut inflammation, without influencing its impact on anxiety-like behaviors. Collectively, these findings suggest that vagotomy exerts a protective effect against infection by promoting GABA synthesis in the colon and alleviating anxiety-like behavior. This study underscores the critical role of the vagus nerve in relaying signals of gut infection to the brain and posits that targeting the gut-brain axis may offer a novel and efficacious approach to preventing gastrointestinal infections and associated behavioral abnormalities.


Asunto(s)
Ansiedad , Microbioma Gastrointestinal , Ratones Endogámicos C57BL , Vagotomía , Nervio Vago , Ácido gamma-Aminobutírico , Animales , Ansiedad/metabolismo , Ratones , Nervio Vago/metabolismo , Masculino , Ácido gamma-Aminobutírico/metabolismo , Salmonella typhimurium , Citocinas/metabolismo , Eje Cerebro-Intestino , Encéfalo/metabolismo , Infecciones por Salmonella/metabolismo , Conducta Animal , Hipocampo/metabolismo , Tracto Gastrointestinal/metabolismo , Tracto Gastrointestinal/microbiología , Inflamación/metabolismo , Amígdala del Cerebelo/metabolismo
2.
Sensors (Basel) ; 24(7)2024 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-38610467

RESUMEN

Lineament is a unique geological structure. The study of Lunar lineament structure has great significance on understanding its history and evolution of Lunar surface. However, the existing geographic feature extraction methods are not suitable for the extraction of Lunar lineament structure. In this paper, a new lineament extraction method is proposed based on improved-UNet++ and YOLOv5. Firstly, new lineament dataset is created containing lineaments structure based on CCD data from LROC. At same time the residual blocks are replaced with the VGG blocks in the down sample part of the UNet++ with adding the attention block between each layer. Secondly, the improved-UNet++ and YOLO networks are trained to execute the object detection and semantic segmentation of lineament structure respectively. Finally, a polygon-match strategy is proposed to combine the results of object detection and semantic segmentation. The experiment result indicate that this new method has relatively better and more stable performance compared with current mainstream networks and the original UNet++ network in the instance segmentation of lineament structure. Additionally, the polygon-match strategy is able to perform preciser edge detail in the instance segmentation of lineament structure result.

3.
Int J Mol Sci ; 23(21)2022 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-36362097

RESUMEN

Chlorine dioxide is widely used for pulp bleaching because of its high delignification selectivity. However, efficient and clean chlorine dioxide bleaching is limited by the complexity of the lignin structure. Herein, the oxidation reactions of phenolic (vanillyl alcohol) and non-phenolic (veratryl alcohol) lignin model species were modulated using chlorine dioxide. The effects of chlorine dioxide concentration, reaction temperature, and reaction time on the consumption rate of the model species were also investigated. The optimal consumption rate for the phenolic species was obtained at a chlorine dioxide concentration of 30 mmol·L-1, a reaction temperature of 40 °C, and a reaction time of 10 min, resulting in the consumption of 96.3% of vanillyl alcohol. Its consumption remained essentially unchanged compared with that of traditional chlorine dioxide oxidation. However, the consumption rate of veratryl alcohol was significantly reduced from 78.0% to 17.3%. Additionally, the production of chlorobenzene via the chlorine dioxide oxidation of veratryl alcohol was inhibited. The structural changes in lignin before and after different treatments were analyzed. The overall structure of lignin remained stable during the optimization of the chlorine dioxide oxidation treatment. The signal intensities of several phenolic units were reduced. The effects of the selective oxidation of lignin by chlorine dioxide on the pulp properties were analyzed. Pulp viscosity significantly increased owing to the preferential oxidation of phenolic lignin by chlorine dioxide. The pollution load of bleached effluent was considerably reduced at similar pulp brightness levels. This study provides a new approach to chlorine dioxide bleaching. An efficient and clean bleaching process of the pulp was developed.


Asunto(s)
Compuestos de Cloro , Lignina , Lignina/química , Compuestos de Cloro/farmacología , Compuestos de Cloro/química , Fenoles/farmacología , Ácido Hipocloroso , Cloro/química , Papel
4.
Appl Opt ; 60(7): 1903-1915, 2021 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-33690280

RESUMEN

Debye series expansion (DSE) is developed for electromagnetic (light) scattering by a charged sphere. By comparing our results with Mie theory (for a charged sphere) and with DSE (for a neutral sphere), we verify our theory numerically. DSE is employed for calculation of far-field intensity, and absorption and extinction efficiencies of charged spherical particles illuminated by a plane wave. The influences of various parameters (including surface charge, refractive index, size parameters, Debye mode, etc.) are studied. The rainbow produced by charged particles is analyzed. These results are of great significance in many fields including particle sizing, optical tweezers, etc.

5.
Int J Biol Macromol ; 279(Pt 1): 135172, 2024 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-39208526

RESUMEN

Demethylation modification of lignin is an effective strategy to overcome the barrier to its high-value conversion. The purpose of this study focuses on the new proton-based ionic liquid (PIL) 1, 2-propanediamine/glycolic acid (PD/GA) as a catalyst and solvent to achieve the targeted oxidation of lignin. The PD/GA solvents have higher selectivity and efficiency. Optimal phenolic hydroxyl (PH)-increment was achieved, demonstrating enhanced demethylating effect on lignin by modulating the acid-base molar ratio, reaction temperature, and reaction time. Compared to ethanolamine/acetic acid (CE/AC) treatment, the PD/GA treatment at molar ratio 1.25, temperature 60 °C, and 3 h increased the PH-content from 37.74 to 59.91 %. Additionally, the lignin treated with PD/GA exhibited excellent recyclability, featuring a larger Brunauer-Emmett-Teller surface area (1.45 m2.g-1), total pore volume (9.51*10-3 cm3.g-1), and mesoporous size (26.15 nm). The treated lignin yielded maximum ultraviolet resistance and antioxidant activity. These results present new avenues for the development of green and efficient lignin demethylation methods.

6.
Environ Int ; 186: 108646, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38615543

RESUMEN

Environmental exposures during pregnancy have been associated with adverse obstetric outcomes. However, limited and inconsistent evidence exists regarding the association between air temperature exposure and the risk of preeclampsia (PE). This study aimed to evaluate the correlation between ambient temperature exposure during pregnancy and PE risk, as well as identify the specific time window of temperature exposure that increases PE risk. A population-based cohort study was conducted from January 2012 to April 2022 in Guangzhou, China. Pregnant women were recruited in early pregnancy and followed until delivery. A total of 3,314 PE patients and 114,201 normal pregnancies were included. Ambient temperature exposures at different gestational weeks were recorded for each participant. Logistic regression models were used to evaluate the correlation between ambient temperature exposure and PE risk. Stratified analyses were conducted based on maternal age and pre-pregnancy BMI. Distributed lag models were employed to identify the time window of temperature exposure related to PE. Exposure to extreme high temperature (aOR = 1.24, 95 % CI 1.12-1.38) and moderate high temperature (aOR = 1.22, 95 % CI 1.10-1.35) during early pregnancy was associated with an increased risk of PE. Furthermore, women with higher pre-pregnancy BMI had a higher risk of developing PE when exposed to high temperature during early pregnancy compared to normal-weight women. The time window of temperature exposure related to PE was identified as pregnancy weeks 1 to 8. This study provides evidence for the association of high temperature exposure during early pregnancy with the risk of PE, as well as identifies the specific time window of temperature exposure related to PE. These findings have implications for developing potential strategies to protect pregnant women, particularly those with higher pre-pregnancy BMI, from the adverse effects of extreme temperatures during early pregnancy.


Asunto(s)
Preeclampsia , Temperatura , Embarazo , Humanos , Femenino , Preeclampsia/epidemiología , China/epidemiología , Adulto , Exposición a Riesgos Ambientales/estadística & datos numéricos , Estudios de Cohortes , Factores de Riesgo , Adulto Joven , Exposición Materna/estadística & datos numéricos , Exposición Materna/efectos adversos
7.
Food Funct ; 15(1): 387-400, 2024 Jan 02.
Artículo en Inglés | MEDLINE | ID: mdl-38099485

RESUMEN

Autism Spectrum Disorder (ASD), a complex neurodevelopmental disorder marked by social communication deficits and repetitive behaviors, may see symptom amelioration through gut microbiota modulation. This study investigates the effects of a synbiotic - specifically a probiotic amplified by prebiotic supplementation - on ASD-like mouse model's social deficiencies. This model was established via valproic acid injection into pregnant females. Post-weaning, male progeny received daily synbiotic treatment, a combination of Lactobacillus reuteri (L. reuteri) and inulin, for four weeks. Results indicated that the synbiotic rectified social impairments and attenuated inflammatory cytokine expressions in the brain. Moreover, synbiotic intervention protected gut barrier integrity and altered the gut microbiota composition, enhancing the butyrate-producing Bifidobacterium abundance. The synbiotic elevated metabolites such as butyrate and 3-hydroxybutyric acid (3-HB), alongside upregulated genes associated with 3-HB synthesis in the colon and liver, and brain receptors. Conclusively, the synbiotic combination of L. reuteri and inulin mitigated ASD-related social impairments, partially via their regulatory effect on the gut-brain axis.


Asunto(s)
Trastorno del Espectro Autista , Limosilactobacillus reuteri , Simbióticos , Femenino , Masculino , Ratones , Animales , Inulina , Eje Cerebro-Intestino , Trastorno del Espectro Autista/terapia , Butiratos
8.
Brain Sci ; 14(8)2024 Aug 13.
Artículo en Inglés | MEDLINE | ID: mdl-39199501

RESUMEN

Brain networks based on functional magnetic resonance imaging (fMRI) provide a crucial perspective for diagnosing brain diseases. Representation learning has recently attracted tremendous attention due to its strong representation capability, which can be naturally applied to brain disease analysis. However, traditional representation learning only considers direct and local node interactions in original brain networks, posing challenges in constructing higher-order brain networks to represent indirect and extensive node interactions. To address this problem, we propose the Continuous Dictionary of Nodes model and Bilinear-Diffusion (CDON-BD) network for brain disease analysis. The CDON model is innovatively used to learn the original brain network, with its encoder weights directly regarded as latent features. To fully integrate latent features, we further utilize Bilinear Pooling to construct higher-order brain networks. The Diffusion Module is designed to capture extensive node interactions in higher-order brain networks. Compared to state-of-the-art methods, CDON-BD demonstrates competitive classification performance on two real datasets. Moreover, the higher-order representations learned by our method reveal brain regions relevant to the diseases, contributing to a better understanding of the pathology of brain diseases.

9.
Bioresour Technol ; 384: 129328, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37329991

RESUMEN

The efficiency of organic acid treatment in the conversion of lignocellulosic biomass fractions has been widely recognized. In this study, a novel green pyruvic acid (PA) treatment is proposed. The higher separation efficiency of eucalyptus hemicellulose was obtained at 4.0% PA and 150 °C. The hemicellulose separation yield was increased from 71.71 to 88.09% compared to glycolic acid (GA) treatment. In addition, the treatment time was significantly reduced from 180 to 40 min. The proportion of cellulose in the solid increased after PA treatment. However, the accompanying separation of lignin was not effectively controlled. Fortunately, a six-membered ring structure was formed on the diol structure of the lignin ß-O-4 side chain. Fewer lignin-condensed structures were observed. High-value lignin rich in phenol hydroxyl groups were obtained. It provides a green path for the simultaneous achievement of efficient hemicellulose separation and inhibition of lignin repolymerization using organic acid treatment.


Asunto(s)
Lignina , Ácido Pirúvico , Lignina/química , Polisacáridos/química , Celulosa/química , Biomasa
10.
Transl Pediatr ; 12(7): 1386-1395, 2023 Jul 31.
Artículo en Inglés | MEDLINE | ID: mdl-37575894

RESUMEN

Background: Reasonable personalized surgical design can achieve good treatment results for Helveston syndrome in one surgery, reducing the psychological and economic burden on patients. This article aims to explore the clinical characteristics of Helveston syndrome and the clinical effectiveness and feasibility of individualized surgical design. Methods: In this retrospective case series study, 28 patients who underwent strabismus correction for Helveston syndrome at the Affiliated Hospital of Yunnan University from June 2018 to December 2020 with complete follow-up data were enrolled. Preoperatively, all patients received standard assessment of vision, intraocular pressure, slit lamp, fundus and refractive status, excluding other eye diseases, as well as detailed special examination of strabismus. These patients were divided into two groups according to the surgical modality: the horizontal muscle surgery alone group and the horizontal muscle surgery combined with superior oblique muscle surgery (combined surgery) group. We used SPSS software for data analysis and compared the postoperative eye position, eye movement, success rate, and reoperation rate between these two groups. Clinical measurement data were compared and analyzed with Fisher's exact test for count data, the t-test for normally distributed measurement data, and the Mann-Whitney U test for non-normally distributed measurement data. P<0.05 was considered statistically significant. Results: This study included a total of 28 patients with Helveston syndrome, including 20 males and 8 females. The average age at the time of surgery is 12.04 ± 8.67 years (range, 4-43 years). The postoperative A-pattern degree was significantly greater in the group undergoing horizontal muscle surgery alone [6.23±1.31 prism diopters (PD); range, 0-10 PD] than in the group undergoing combined surgery (0.53±0.32 PD; range, 0-4 PD; P=0.002). Superior oblique muscle overactivity was significantly reduced in the combined surgery group (0.20±0.11+; range, 0-1+) compared to the horizontal muscle surgery alone group (1.31±0.26+; range, 0-2+; P=0.002). However, there was no significant difference in success rate or reoperation rate between the two groups. Additionally, after combining the recession of the superior rectus muscle with the horizontal muscle, the number of A-pattern degrees was greatly reduced. Conclusions: Helveston syndrome can be improved using a personalized surgical design according to the degree of external strabismus A-pattern, superior oblique muscle overaction, and dissociated vertical deviation (DVD) degree, which improves the success rate of single surgery.

11.
Bioresour Technol ; 382: 129154, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37172743

RESUMEN

The development of organic acid pretreatments from biological sources is essential to facilitate the progress of green and sustainable chemistry. In this study, the effectiveness of mandelic acid pretreatment (MAP) was analyzed for eucalyptus hemicellulose separation. 83.66% of xylose was separated under optimal conditions (temperature: 150 °C; concentration: 6.0 wt%; time: 80 min). The hemicellulose separation selectivity is higher than acetic acid pretreatment (AAP). The stable and effective separation efficiency (56.55%) is observed even after six reuses of the hydrolysate. Higher thermal stability, larger crystallinity index and optimized surface element distribution in the samples were demonstrated by MAP. Lignin condensation is effectively inhibited through MAP, as determined from the structural of different lignin. In particular, the demethoxylation of lignin by MA was found. These results open up a new way to construct a novel organic acid pretreatment for separating hemicellulose with high efficiency.


Asunto(s)
Lignina , Polisacáridos , Lignina/química , Polisacáridos/química , Ácidos/química , Compuestos Orgánicos , Hidrólisis , Biomasa
12.
Bioresour Technol ; 361: 127735, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-35934248

RESUMEN

The selectivity of alkali treatment (AT) for hemicellulose separation is reduced due to the alkali solubility of lignin. It was improved using freeze-thaw-assisted alkaline treatment (FT/AT). In this study, bamboo hemicellulose was separated via a one-step freeze-thaw-assisted alkali treatment (OFT/AT). The effects of freezing temperature, freezing time, alkali concentration, and treatment time on bamboo components were studied. The separation yield of hemicellulose was 73.26%, compared to 64.00% using conventional FT/AT. The separation of lignin and cellulose was inhibited as alkali concentration decreased from 7.0% to 5.0%. The extraction yield of hemicellulose increased from 46.35% to 56.12%. Structural analysis of extracted hemicellulose revealed the effective inhibition of the breakage of the xylose backbone and arabinose side chain of hemicellulose. This indicated that the molecular structure of extracted hemicellulose was relatively complete. It provides theoretical support for the efficient separation of hemicellulose by AT.


Asunto(s)
Álcalis , Lignina , Congelación , Lignina/química , Polisacáridos/química
13.
Front Psychol ; 12: 679538, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34594261

RESUMEN

Background: Home quarantine is an important strategy to contain the mass spread of the coronavirus disease 2019 (COVID-19) pandemic. However, there are a dearth of studies on the prevalence and risk factors of home quarantine strategy implementation among residents. This study aims to assess the state of home quarantine strategy implementation among Chinese residents, which could provide a reference for quarantine policymakers around the world during the pandemic. Method: We conducted a cross-sectional survey of 3,398 residents in China by adopting a convenience sampling strategy. We measured the prevalence and risk factors of home quarantine strategy implementation with the Center for Epidemiological Studies-Depression Scale (CES-D), 10-item Connor-Davidson Resilience Scale (CD-RISC 10), and Perceived Social Support Scale (PSSS). A multivariable model was used to determine the factors associated with home quarantine strategy implementation. Results: A total of 2,936 (86.4%) respondents carried out home quarantine. There were some factors significantly associated with home quarantine strategy implementation among Chinese residents during the COVID-19 outbreak. Respondents who were male, lived in western and central China, were aware of the primary symptoms of COVID-19, were willing to accept recommendations on relevant protective measures, understood local quarantine measures, had better resilience, and had better social support were more likely to engage in home quarantine. Respondents who were married, were employed, were healthy, and had high depression scores were more likely to refuse to follow home quarantine guidance. Conclusions: Gender, region, marital status, employment status, health status, awareness of the primary symptoms of COVID-19, willingness to accept recommendations on relevant protective measures, understanding of local quarantine measures, depression, psychological resilience, and perceived social support were the main factors affecting the implementation of residents' home quarantine strategy. Health service policymakers should adopt relevant measures to improve the prevalence of home quarantine strategy implementation among residents during the pandemic.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA