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1.
J Mater Chem B ; 2024 Jul 03.
Artículo en Inglés | MEDLINE | ID: mdl-38957936

RESUMEN

Paper-based analytical devices (PADs) are very convenient for determining biomarkers in point-of-care (POC) diagnosis while requiring sample pre-treatment or impurity separation. This study reports a novel hydrogel-coupled, paper-based analytical device (PAD) for separation-free H2O2 colorimetric detection in both aqueous solution and cell lysis with sample-to-answer analysis by directly loading into the sample test zone. By encapsulating an inorganic mimic enzyme and chromogenic substrate into the sodium alginate (SA) hydrogel, amplification of the color signal after catalyzing the substrate could be achieved. Taking advantage of the nanoscale porous structure of the hydrogel and the lateral flow channel of the PAD, large interference fragments or bio-macromolecules are prevented from diffusing into the chromogenic reaction, whereas the small target molecules enter the sensing region to trigger the catalytic reaction. This method demonstrated a rapid and accurate analysis with a limit of detection as low as 0.06 mM and detection selectivity. Our proposed device requires no enzyme and is separation-free, portable, easy-to-fabricate, and low-cost, and may offer a platform for quantitative or qualitative analysis of other analytes in body fluids for POC applications.

2.
J Hazard Mater ; 476: 135146, 2024 Jul 07.
Artículo en Inglés | MEDLINE | ID: mdl-38991643

RESUMEN

The pathway for pollutant degradation involving reactive oxygen species (ROS) in the rhizosphere is poorly understood. Herein, a rootchip system was developed to pinpoint the ROS hotspot along the root tip of Iris tectorum. Through mass balance analysis and quenching experiment, we revealed that ROS contributed significantly to rhizodegradation for beta-blockers, ranging from 22.18 % for betaxolol to 83.83 % for atenolol. The identification of degradation products implicated ROS as an important agent to degrade atenolol into less toxic transformation products during phytoremediation. Moreover, an active production of ROS in rhizosphere was identified by mesocosm experiment. Across three root-associated regions aquatic plants inhabiting the rhizosphere accumulated the highest •OH of ∼1200 nM after 3 consecutive days, followed by rhizoplane (∼230 nM) and bulk environment (∼60 nM). ROS production patterns were driven by rhizosphere chemistry (Fe and humic substances) and microbiome variations in different rhizocompartments. These findings not only deepen understanding of ROS production in aquatic plants rhizosphere but also shed light on advancing phytoremediation strategies.

3.
Neuroscience ; 2024 Jul 08.
Artículo en Inglés | MEDLINE | ID: mdl-38986737

RESUMEN

BACKGROUND: The classic renin-angiotensin system (RAS) induces organ damage, while the ACE2/Ang-(1-7)/MasR axis opposes it. However, the role of ACE2 in the brain is unclear. We studied ACE2's role in the brain. METHOD: We used male C57BL/6J (WT) mice, ACE2 knockout (KO) mice, and MPTP-induced mice. Behavioral tests confirmed successful modeling. We assessed the impact of ACE2 KO on the RAS axis and PD index, including ACE, ACE2, AT1, AT2, MasR, TH, α-syn, and Iba1. We investigated ACE2 and MasR's involvement in microglial activation via western blot and immunofluorescence. GSE10867 and GSE26532 datasets were used to analyze the effects of AT1 antagonists and in vitro PD models on microglia. RESULT: Behavioral tests revealed that MPTP mice displayed motor deficits, depression, anxiety, and increased inflammatory markers in the SN and CPU, with reduced antioxidant capacity. ACE2 KO worsened these symptoms and exacerbated inflammation and oxidative stress. LPS-induced ACE2/MasR activation in BV2 cells demonstrated anti-inflammatory and neuroprotective effects by modulating microglial polarization. Antagonists inhibited microglial activation via inflammation and ROS processes. CONCLUSION: The RAS axis regulates inflammation and oxidative stress to maintain CNS function, suggesting potential targets for neurologic disease treatment. Understanding microglial RAS activation can offer new therapeutic strategies.

4.
Oncol Lett ; 28(3): 407, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-38988445

RESUMEN

Despite significant improvements that have been made in terms of progression-free survival and overall survival rates brought about by targeted therapy in non-small cell lung cancer (NSCLC), the emergence of drug resistance remains a limiting factor. However, a previous study has shown promising results by combining local microwave ablation (MWA) with epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI) therapy for patients with oligometastatic NSCLC. The current study presented the case of a Chinese female patient who was identified as having lung adenocarcinoma (LADC) with EGFR exon 19 deletions (Del) in January 2014, and who experienced multiple instances of oligoprogression but showed a positive response to a combination of chemotherapy, MWA and a TKI drug. First, the patient was treated with four cycles of chemotherapy (120 mg docetaxel on day 1 and 40 mg cisplatin on days 1, 2 and 3; every three weeks as one cycle) and gefitinib (Iressa; 250 mg/day), maintaining a partial response for 17 months. In August 2015, a new solitary lesion was identified in the right lung and erlotinib (Tarceva; 150 mg/day) was administered for 3 months thereafter. In response, the patient underwent ablation of both the new right lung lesion and the primary left lung lesion in January 2016. Subsequently, a treatment course consisting of six cycles of chemotherapy (0.8 g pemetrexed on day 1 and 70 mg nedaplatin on days 1 and 2; every three weeks as one cycle) resulted in stable disease. In May 2016, the patient began treatment with osimertinib (AZD9291; 80 mg/day), resulting in a rapid shrinkage of the mediastinal lymph node after one month, which has been providing a benefit for the patient for 82 months and counting. Of note, the patient also developed metachronous colon cancer in January 2020, followed by the identification of right posterior liver metastases in February 2020 and lung metastases in May 2021 and in February 2022. To address this, the patient underwent radical resection of colon cancer and liver metastasectomy and received a combination of chemotherapy with bevacizumab, along with MWA for lung metastases. Remarkably, the patient has achieved long-term survival of 110 months. In conclusion, this case highlights the promising potential of combining MWA with systemic therapy for a patient with advanced LADC harboring EGFR exon 19 Del and metachronous lung and liver-metastasized colon adenocarcinoma. MWA effectively controlled both in situ oligoprogression and new oligoprogression, thereby enhancing the efficacy of systematic chemotherapy/TKI therapy. Furthermore, this case report emphasizes the importance of repeated histologic biopsies and genetic testing as reliable indicators for adjusting treatment regimens. Physicians should also remain vigilant regarding the occurrence of secondary primary carcinomas, and timely and accurate adjustments to treatment plans will be of significant benefit to patients in terms of treatment efficacy and overall quality of life.

5.
Chem Biodivers ; : e202401210, 2024 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-39007531

RESUMEN

Four novel Mesona chinensis Benth polysaccharides were isolated using aqueous alcohol precipitation. Their molecular weights were determined using high-performance gel permeation chromatography: MA1 (2.3 kDa), MA2 (80.5 kDa), MA3 (180.9 kDa), and MA4 (635.2 kDa), and their compositions were analyzed using GC-MS. The polysaccharides were mainly D-glucose, D-galactose, L-Rhamnose, D-arabinose, D-xylose, and D-mannose. The structural characteristics were further analyzed using infrared spectrophotometry and were identified as a type of pyrrhic sugar. An insulin-induced insulin resistance model of HepG2 cells and oleic acid-induced fat accumulation model of insulin were established to evaluate the hypolipidemic effects. Three Bacteroides spp. [Bacteroides thetaiotaomicron (BT), B. ovatus (BO), and B. cellulosilyticus (BC)] that were negatively correlated with lipid-lowering activity were used to evaluate the lipid-lowering activity of polysaccharides. The Bacteroides metabolites of MA1 and MA2 exhibited hypolipidemic effects and antioxidant activities and could potentially be used as lipid-lowering supplements.

6.
Carbohydr Res ; : 109177, 2024 Jun 06.
Artículo en Inglés | MEDLINE | ID: mdl-38880715

RESUMEN

Chitin oligosaccharides have garnered significant attention due to their biological activities, particularly their immunomodulatory properties. However, O-acetylation in chemically preparing chitin oligosaccharides seems inevitable and leads to some uncertainty on the bioactivity of chitin oligosaccharides. In this study, an O-acetyl-free chitin oligosaccharides and three different O-acetylated chitin oligosaccharides with degree of polymerization ranging from 2 to 6 were prepared using ammonia hydrolysis, and their structures and detailed components were further characterized with FTIR, NMR and MS. Subsequently, the effects of O-acetylation on the immunomodulatory activity of chitin oligosaccharides were investigated in vitro and in vivo. The results suggested that the chitin oligosaccharides with O-acetylation exhibited better inflammatory inhibition than pure chitin oligosaccharides, significantly reducing the expression of inflammatory factors, such as IL-6 and iNOS, in the LPS-induced RAW264.7 macrophage. The chitin oligosaccharides with a degree of O-acetylation of 93 % was found to effectively alleviate LPS-induced endotoxemia in mice, including serum inflammation indices reduction and damage repairment of the intestinal liver, and kidney tissues.

7.
J Hazard Mater ; 474: 134779, 2024 Aug 05.
Artículo en Inglés | MEDLINE | ID: mdl-38850935

RESUMEN

Bisphenol A (BPA), an endocrine disrupter with estrogen activity, can infiltrate animal and human bodies through the food chain. Enzymatic degradation of BPA holds promise as an environmentally friendly approach while it is limited due to lower stability and recycling challenges. In this study, laccase from Bacillus pumilus TCCC 11568 was expressed in Pichia pastoris (fLAC). The optimal catalytic conditions for fLAC were at pH 6.0 and 80 °C, with a half-life T1/2 of 120 min at 70 °C. fLAC achieved a 46 % degradation rate of BPA, and possible degradation pathways were proposed based on identified products and reported intermediates of BPA degradation. To improve its stability and degradation capacity, a whole-cell biocatalyst (WCB) was developed by displaying LAC (dLAC) on the surface of P. pastoris GS115. The functionally displayed LAC demonstrated enhanced thermostability and pH stability along with an improved BPA degradation ability, achieving a 91 % degradation rate. Additionally, dLAC maintained a degradation rate of over 50 % after the fourth successive cycles. This work provides a powerful catalyst for degrading BPA, which might decontaminate endocrine disruptor-contaminated water through nine possible pathways.


Asunto(s)
Bacillus pumilus , Compuestos de Bencidrilo , Biodegradación Ambiental , Disruptores Endocrinos , Lacasa , Fenoles , Compuestos de Bencidrilo/metabolismo , Lacasa/metabolismo , Lacasa/genética , Fenoles/metabolismo , Bacillus pumilus/enzimología , Bacillus pumilus/genética , Bacillus pumilus/metabolismo , Disruptores Endocrinos/metabolismo , Concentración de Iones de Hidrógeno , Saccharomycetales/metabolismo , Saccharomycetales/genética
8.
Gut ; 2024 Jun 21.
Artículo en Inglés | MEDLINE | ID: mdl-38906695

RESUMEN

BACKGROUND AND AIMS: This study aimed to evaluate the efficacy and safety of vonoprazan and tetracycline (VT) dual therapy as first-line treatment for Helicobacter pylori infection in patients with penicillin allergy. METHODS: In this randomised controlled trial, treatment-naïve adults with H. pylori infection and penicillin allergy were randomised 1:1 to receive either open-label VT dual therapy (vonoprazan 20 mg two times per day+tetracycline 500 mg three times a day) or bismuth quadruple therapy (BQT; lansoprazole 30 mg two times per day+colloidal bismuth 150 mg three times a day+tetracycline 500 mg three times a day+metronidazole 400 mg three times a day) for 14 days. The primary outcome was non-inferiority in eradication rates in the VT dual group compared with the BQT group. Secondary outcomes included assessing adverse effects. RESULTS: 300 patients were randomised. The eradication rates in the VT group and the BQT group were: 92.0% (138/150, 95% CI 86.1% to 95.6%) and 89.3% (134/150, 95% CI 83.0% to 93.6%) in intention-to-treat analysis (difference 2.7%; 95% CI -4.6% to 10.0%; non-inferiority p=0.000); 94.5% (138/146, 95% CI 89.1% to 97.4%) and 93.1% (134/144, 95% CI 87.3% to 96.4%) in modified intention-to-treat analysis (difference 1.5%; 95% CI -4.9% to 8.0%; non-inferiority p=0.001); 95.1% (135/142, 95% CI 89.7% to 97.8%) and 97.7% (128/131, 95% CI 92.9% to 99.4%) in per-protocol analysis (difference 2.6%; 95% CI -2.9% to 8.3%; non-inferiority p=0.000). The treatment-emergent adverse events (TEAEs) were significantly lower in the VT group (14.0% vs 48.0%, p=0.000), with fewer treatment discontinuations due to TEAEs (2.0% vs 8.7%, p=0.010). CONCLUSIONS: VT dual therapy demonstrated efficacy and safety as a first-line treatment for H. pylori infection in the penicillin-allergic population, with comparable efficacy and a lower incidence of TEAEs compared with traditional BQT. TRIAL REGISTRATION NUMBER: ChiCTR2300074693.

9.
Polymers (Basel) ; 16(12)2024 Jun 13.
Artículo en Inglés | MEDLINE | ID: mdl-38932031

RESUMEN

With the rapid development of electronic information technology, higher requirements have been put forward for the dielectric properties and load-bearing capacity of materials. In continuous glass fiber-reinforced thermoplastic composites, polypropylene matrix is a non-polar polymer with a very low dielectric constant and dielectric loss, but polypropylene is extremely flammable which greatly limits its application. Aiming at the better application of flame retardant-modified continuous glass fiber-reinforced polypropylene composites (FR/GF/PP) in the field of electronic communication, the effects of four different kinds of flame retardants (Decabromodiphenyl ethane (DBDPE), halogen-free one-component flame retardant (MONO), halogen-free compound flame retardant (MULTI), and intumescent flame retardant (IFR)) on the properties of FR/GF/PP were compared, including the mechanical properties, dielectric properties and flame-retardant properties. The results showed that among the FR/GF/PP, IFR has the highest performance in mechanical properties, MULTI has better performance in LOI, DBDPE and IFR have better performance in flame retardant rating, and DBDPE and IFR have lower dielectric properties. Finally, gray relational analysis is applied to propose an approach for selecting the optimal combination (flame retardant type and flame-retardant content) of comprehensive performance. In the application exemplified in this paper, the performance of IFR-3-modified GF/PP is optimized.

10.
ACS Chem Neurosci ; 15(13): 2445-2453, 2024 Jul 03.
Artículo en Inglés | MEDLINE | ID: mdl-38905183

RESUMEN

Parkinson's disease (PD) is the second most common age-related neurodegenerative disease in the world, and synuclein is closely related to the onset and progression of PD. Synuclein is considered a therapeutic target for PD. Recent studies have found that abnormal aggregation of α-synuclein (α-Syn) in the brains of PD patients leads to mitochondrial dysfunction and neuroinflammation. Research in the field of neuroscience has confirmed that ß-synuclein (ß-Syn) also plays a role in Parkinson's disease. However, there has been little research on the role mechanisms and interactions between ß-Syn and α-Syn in PD. Therefore, the purpose of this study is to clarify the relationship between α-Syn, ß-Syn, and PD and to explore the roles and interactions of ß-Syn and α-Syn in PD.


Asunto(s)
Enfermedad de Parkinson , alfa-Sinucleína , Sinucleína beta , Enfermedad de Parkinson/metabolismo , alfa-Sinucleína/metabolismo , Humanos , Sinucleína beta/metabolismo , Animales , Encéfalo/metabolismo
11.
Int J Mol Sci ; 25(11)2024 Jun 04.
Artículo en Inglés | MEDLINE | ID: mdl-38892361

RESUMEN

Sophora alopecuroides has important uses in medicine, wind breaking, and sand fixation. The CHY-zinc-finger and RING-finger (CHYR) proteins are crucial for plant growth, development, and environmental adaptation; however, genetic data regarding the CHYR family remain scarce. We aimed to investigate the CHYR gene family in S. alopecuroides and its response to abiotic stress, and identified 18 new SaCHYR genes from S. alopecuroides whole-genome data, categorized into 3 subclasses through a phylogenetic analysis. Gene structure, protein domains, and conserved motifs analyses revealed an exon-intron structure and conserved domain similarities. A chromosome localization analysis showed distribution across 12 chromosomes. A promoter analysis revealed abiotic stress-, light-, and hormone-responsive elements. An RNA-sequencing expression pattern analysis revealed positive responses of SaCHYR genes to salt, alkali, and drought stress. SaCHYR4 overexpression considerably enhanced alkali and drought tolerance in Arabidopsis thaliana. These findings shed light on SaCHYR's function and the resistance mechanisms of S. alopecuroides, presenting new genetic resources for crop resistance breeding.


Asunto(s)
Regulación de la Expresión Génica de las Plantas , Familia de Multigenes , Filogenia , Proteínas de Plantas , Sophora , Estrés Fisiológico , Estrés Fisiológico/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Sophora/genética , Arabidopsis/genética , Genoma de Planta , Sequías , Cromosomas de las Plantas/genética
12.
JMIR Mhealth Uhealth ; 12: e48777, 2024 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-38924786

RESUMEN

BACKGROUND: Early detection of cognitive impairment or dementia is essential to reduce the incidence of severe neurodegenerative diseases. However, currently available diagnostic tools for detecting mild cognitive impairment (MCI) or dementia are time-consuming, expensive, or not widely accessible. Hence, exploring more effective methods to assist clinicians in detecting MCI is necessary. OBJECTIVE: In this study, we aimed to explore the feasibility and efficiency of assessing MCI through movement kinetics under tablet-based "drawing and dragging" tasks. METHODS: We iteratively designed "drawing and dragging" tasks by conducting symposiums, programming, and interviews with stakeholders (neurologists, nurses, engineers, patients with MCI, healthy older adults, and caregivers). Subsequently, stroke patterns and movement kinetics were evaluated in healthy control and MCI groups by comparing 5 categories of features related to hand motor function (ie, time, stroke, frequency, score, and sequence). Finally, user experience with the overall cognitive screening system was investigated using structured questionnaires and unstructured interviews, and their suggestions were recorded. RESULTS: The "drawing and dragging" tasks can detect MCI effectively, with an average accuracy of 85% (SD 2%). Using statistical comparison of movement kinetics, we discovered that the time- and score-based features are the most effective among all the features. Specifically, compared with the healthy control group, the MCI group showed a significant increase in the time they took for the hand to switch from one stroke to the next, with longer drawing times, slow dragging, and lower scores. In addition, patients with MCI had poorer decision-making strategies and visual perception of drawing sequence features, as evidenced by adding auxiliary information and losing more local details in the drawing. Feedback from user experience indicates that our system is user-friendly and facilitates screening for deficits in self-perception. CONCLUSIONS: The tablet-based MCI detection system quantitatively assesses hand motor function in older adults and further elucidates the cognitive and behavioral decline phenomenon in patients with MCI. This innovative approach serves to identify and measure digital biomarkers associated with MCI or Alzheimer dementia, enabling the monitoring of changes in patients' executive function and visual perceptual abilities as the disease advances.


Asunto(s)
Disfunción Cognitiva , Humanos , Disfunción Cognitiva/diagnóstico , Disfunción Cognitiva/psicología , Masculino , Femenino , Anciano , Persona de Mediana Edad , Pruebas Neuropsicológicas/estadística & datos numéricos , Pruebas Neuropsicológicas/normas , Mano/fisiopatología , Anciano de 80 o más Años , Encuestas y Cuestionarios , Investigación Cualitativa
13.
Mikrochim Acta ; 191(6): 303, 2024 05 06.
Artículo en Inglés | MEDLINE | ID: mdl-38709340

RESUMEN

A platform was designed based on Fe3O4 and CsPbBr3@SiO2 for integrated magnetic enrichment-fluorescence detection of Salmonella typhimurium, which significantly simplifies the detection process and enhances the working efficiency. Fe3O4 served as a magnetic enrichment unit for the capture of S. typhimurium. CsPbBr3@SiO2 was employed as a fluorescence-sensing unit for quantitative signal output, where SiO2 was introduced to strengthen the stability of CsPbBr3, improve its biomodificability, and prevent lead leakage. More importantly, the SiO2 shell shows neglectable absorption or scattering towards fluorescence, making the CsPbBr3@SiO2 exhibit a high quantum yield of 74.4%. After magnetic enrichment, the decreasing rate of the fluorescence emission intensity of the CsPbBr3@SiO2 supernatant at 527 nm under excitation light at UV 365 nm showed a strong linear correlation with S. typhimurium concentration of 1 × 102~1 × 108 CFU∙mL-1, and the limit of detection (LOD) reached 12.72 CFU∙mL-1. This platform has demonstrated outstanding stability, reproducibility, and resistance to interference, which provides an alternative for convenient and quantitative detection of S. typhimurium.


Asunto(s)
Colorantes Fluorescentes , Límite de Detección , Salmonella typhimurium , Dióxido de Silicio , Salmonella typhimurium/aislamiento & purificación , Dióxido de Silicio/química , Colorantes Fluorescentes/química , Espectrometría de Fluorescencia/métodos , Plomo/química , Sistemas de Atención de Punto , Sulfuros/química , Nanopartículas de Magnetita/química , Humanos
14.
Biomolecules ; 14(5)2024 May 04.
Artículo en Inglés | MEDLINE | ID: mdl-38785961

RESUMEN

Osteoporosis (OP), a prevalent skeletal disorder characterized by compromised bone strength and increased susceptibility to fractures, poses a significant public health concern. This review aims to provide a comprehensive analysis of the current state of research in the field, focusing on the application of proteomic techniques to elucidate diagnostic markers and therapeutic targets for OP. The integration of cutting-edge proteomic technologies has enabled the identification and quantification of proteins associated with bone metabolism, leading to a deeper understanding of the molecular mechanisms underlying OP. In this review, we systematically examine recent advancements in proteomic studies related to OP, emphasizing the identification of potential biomarkers for OP diagnosis and the discovery of novel therapeutic targets. Additionally, we discuss the challenges and future directions in the field, highlighting the potential impact of proteomic research in transforming the landscape of OP diagnosis and treatment.


Asunto(s)
Biomarcadores , Osteoporosis , Proteómica , Humanos , Proteómica/métodos , Osteoporosis/diagnóstico , Osteoporosis/metabolismo , Osteoporosis/tratamiento farmacológico , Osteoporosis/terapia , Biomarcadores/metabolismo , Enfermedades Óseas Metabólicas/diagnóstico , Enfermedades Óseas Metabólicas/metabolismo , Animales , Huesos/metabolismo
15.
J Mol Graph Model ; 130: 108790, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38749235

RESUMEN

At present, the hydrogen evolution reaction (HER) of Ni-based electrode has an important influence on water electrolysis hydrogen production technology, involving complex electrochemical process of electrode. In this project, Materials Studio (MS) software was used to design and construct Ni-based electrode surface (NES) models with monatomic Mo, Co, Fe, Cr doping, and the NES models attached 1 H atom and 2H atoms were denoted as the NES-H models and NES-2H model, respectively. Then the first-principles calculation was carried out. The results showed that the doping of different atoms can effectively change the work function of the pure Ni. In the charge transfer process of the four NES-2H models, the distance between the two H atoms is most affected by Mo doping, and they leave the Ni electrode surface as a single H ion, respectively, while the effect on Co, Fe and Cr doping is relatively consistent, and they leave the Ni electrode surface with H2 molecules, respectively. The doping of four single atoms changes the distance of valence band (VB) top and conduction band (CB) bottom from Fermi level in NES, NES-H and NES-2H models, and affects the HER, in which Mo doping has the greatest effect. The TDOS of the above models is mainly derived from the PDOS of the d orbitals of the doped atoms and Ni atoms. The results will provide a theoretical basis for the research and development of Ni-based electrode materials in HER.


Asunto(s)
Electrodos , Hidrógeno , Níquel , Hidrógeno/química , Níquel/química , Propiedades de Superficie , Electrones , Modelos Moleculares
16.
Polymers (Basel) ; 16(10)2024 May 09.
Artículo en Inglés | MEDLINE | ID: mdl-38794533

RESUMEN

The application of continuous glass fiber-reinforced polypropylene thermoplastic composites (GF/PP) is limited due to the inadequate flame retardancy of the polypropylene (PP) matrix. Apart from altering the composition of the flame retardants, the distribution modes of flame retardants also impact material performance. In this study, an alternative approach involving non-uniform distribution is proposed, namely, dispersed distribution, in which non-flame-retardant-content layers (NFRLs) and/or low-flame-retardant-content layers (LFRLs) are dispersed among high-flame-retardant-content layers (HFRLs). The mechanical, flame retardant and dielectric properties of GF/PP with intumescent flame retardant (IFR/GF/PP) are investigated comparatively under uniform, gradient, and dispersed distributions of the flame retardants. The results demonstrate that non-uniform distribution exhibits superior flame retardant performance compared to uniform distribution. Dispersed distribution enables IFR/GF/PP to attain enhanced mechanical properties and reduced dielectric constants while maintaining excellent flame-retardant properties.

17.
bioRxiv ; 2024 May 12.
Artículo en Inglés | MEDLINE | ID: mdl-38766147

RESUMEN

Our understanding of how vision functions as primates actively navigate the real-world is remarkably sparse. As most data have been limited to chaired and typically head-restrained animals, the synergistic interactions of different motor actions/plans inherent to active sensing - e.g. eyes, head, posture, movement, etc. - on visual perception are largely unknown. To address this considerable gap in knowledge, we developed an innovative wireless head-mounted eye tracking system called CEREBRO for small mammals, such as marmoset monkeys. Our system performs Chair-free Eye-Recording using Backpack mounted micROcontrollers. Because eye illumination and environment lighting change continuously in natural contexts, we developed a segmentation artificial neural network to perform robust pupil tracking in these conditions. Leveraging this innovative system to investigate active vision, we demonstrate that although freely-moving marmosets exhibit frequent compensatory eye movements equivalent to other primates, including humans, the predictability of the visual system is enhanced when animals are freely-moving relative to when they are head-fixed. Moreover, despite increases in eye/head-motion during locomotion, gaze stabilization actually improved over periods when the monkeys were stationary. Rather than impair vision, the dynamics of gaze stabilization in freely-moving primates has been optimized over evolution to enable active sensing during natural exploration.

18.
Sci Total Environ ; 934: 173204, 2024 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-38750735

RESUMEN

Climate change poses mounting threats to fragile alpine ecosystem worldwide. Quantifying changes in carbon stocks in response to the shifting climate was important for developing climate change mitigation and adaptation strategies. This study utilized a process-based land model (Community Land Model 5.0) to analyze spatiotemporal variations in vegetation carbon stock (VCS) and soil organic carbon stock (SOCS) across a typical permafrost area - Qinghai Province, China, from 2000 to 2018. Multiple potential factors influencing carbon stocks dynamics were analyzed, including climate, vegetation, soil hydrothermal status, and soil properties. The results indicated that provincial vegetation carbon storage was 0.22 PgC (0.32 kg/m2) and soil organic carbon pool was 9.12 PgC (13.03 kg/m2). VCS showed a mild increase while SOCS exhibited fluctuating uptrends during this period. Higher carbon stocks were observed in forest (21.74 kg/m2) and alpine meadow (18.08 kg/m2) compared to alpine steppes (9.63 kg/m2). Over 90 % of the carbon was stored in the 0-30 cm topsoil layer. The contribution rates of soil carbon in the 30-60 cm and 60-100 cm soil layers were significantly small, despite increasing stocks across all depths. Solar radiation, temperature, and NDVI emerged as primary influential factors for overall carbon stocks, exhibiting noticeable spatial variability. For SOCS at different depths, the normalized differential vegetation index (NDVI) was the foremost predictor of landscape-level carbon distributions, which explained 52.8 % of SOCS variability in shallow layers (0-30 cm) but dropped to just 12.97 % at the depth of 30-60 cm. However, the dominance of NDVI diminished along the soil depth gradients, superseded by radiation and precipitation. Additionally, with an increase in soil depth, the influence of inherent soil properties also increased. This simulation provided crucial insights for landscape-scale carbon responses to climate change, and offered valuable reference for other climate change-sensitive areas in terms of ecosystem carbon management.

19.
Sci Total Environ ; 938: 173495, 2024 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-38797410

RESUMEN

Zero-valent aluminum (ZVAl) is a potential activator for peroxodisulfate (PDS), yet the dense oxide film on its surface hampers electron transfer for the O-O bond cleavage of PDS. We synthesized zero-valent aluminum-biochar (BM-ZVAl@BC) composites through ball milling, which effectively disrupted the native oxide layer on BM-ZVAl@BC. Within the BM-ZVAl@BC/PDS system, biochar (BC) not only suppressed the rapid oxidation of BM-ZVAl@BC but also enhanced the dispersion and electron transfer rate of ZVAl, thereby improving the overall catalytic efficiency. Consequently, the phenol removal efficacy in the BM-ZVAl@BC/PDS system was notably improved. Optimal catalytic performance of the prepared BM-ZVAl@BC was achieved at a charcoal-to­aluminum mass ratio of 2:1, resulting in 95.7 % phenol removal after 180 min. Quenching experiments and electron paramagnetic resonance (EPR) analysis revealed that both free radicals (SO4•-, •OH, and O2•-) and non-radical species (1O2) contributed to phenol degradation, with SO4•- and •OH playing predominant roles. In summary, the BM-ZVAl@BC/PDS system represented an effective and promising technology for the remediation of phenolic water pollutants.

20.
bioRxiv ; 2024 Mar 17.
Artículo en Inglés | MEDLINE | ID: mdl-38559173

RESUMEN

Here we tested the respective contributions of primate premotor and prefrontal cortex to support vocal behavior. We applied a model-based GLM analysis that better accounts for the inherent variance in natural, continuous behaviors to characterize the activity of neurons throughout frontal cortex as freely-moving marmosets engaged in conversational exchanges. While analyses revealed functional clusters of neural activity related to the different processes involved in the vocal behavior, these clusters did not map to subfields of prefrontal or premotor cortex, as has been observed in more conventional task-based paradigms. Our results suggest a distributed functional organization for the myriad neural mechanisms underlying natural social interactions and has implications for our concepts of the role that frontal cortex plays in governing ethological behaviors in primates.

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