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1.
J Colloid Interface Sci ; 677(Pt B): 1095-1106, 2025 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-39180844

RESUMO

Enhanced carriers separation on photocatalysts is crucial for improving photocatalytic activity. In this paper, the Co-doped BiVO4/ZnWO4 S-scheme heterojunctions were constructed to induce double internal electric fields (IEFs) for enhancing charges separation and transfer for efficient photocatalytic reduction of CO2. The photocatalytic CO2 reduction efficiencies of the heterojunctions were significantly enhanced as compared with the counterparts. The optimized Co-doped BiVO4/ZnWO4 exhibited the highest CO yield of 138.4 µmol·g-1·h-1, which were 86.5 and 1.4 folds of the BiVO4 and Co-doped BiVO4. Results of X-ray photoelectron spectroscopy (XPS), electron spin resonance (ESR), and work function demonstrated that charge transfer path of Co-doped BiVO4/ZnWO4 conformed to S-scheme heterojunction mechanism. The kelvin probe force microscopy (KPFM) and density functional theory (DFT) calculations of the differential charge distributions confirmed the existence of double IEFs, which accelerated carrier separation and improved CO2 adsorption and activation. In addition, in-situ Fourier transform infrared spectroscopy (ISFT-IR) revealed that HCOO- was the major intermediate during the CO2 reaction. This study provides a feasible means to develop composite photocatalysts with dual IEFs for effective photocatalytic CO2 reduction.

2.
Sci Total Environ ; 954: 176663, 2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-39362565

RESUMO

As the issue of global climate change becomes increasingly prominent, the grassland ecosystems in Central Asia are facing severe challenges posed by the impacts of climate change. However, the dominant factors, impact pathways, and cumulative and time-lagged effects of climate factors on various grassland indices remain to be explored. This study selected data from 1988 to 2019, including Fractional Vegetation Cover (FVC), Leaf Area Index (LAI), Net Primary Productivity (NPP), and Vegetation Optical Depth (VOD), to characterize grassland coverage, greenness, biomass accumulation, and water content features. Utilizing multiple linear regression, path analysis, and correlation analysis, this study investigated the dominant effects, direct impacts, indirect influences, and cumulative and time-lagged effects of climate factors on various grassland indices from spatial and climatic zone perspectives. The research findings indicate that over time, the grassland FVC and NPP exhibited increasing trends, while the LAI and VOD showed decreasing trends. Grassland indices are primarily influenced by precipitation and soil moisture (SM). The direct impact of SM on grassland indices was higher than precipitation. Vapour pressure deficit (VPD) has a direct negative impact on grassland indices. Grassland indices are subject to positive indirect effects from precipitation via SM and negative indirect effects from VPD via SM. Precipitation and SM mainly exhibited no cumulative and time-lagged effects on the impact of grassland VOD. VPD primarily demonstrated cumulative and time-lagged effects on grassland indices. The research findings offer valuable insights for conserving grassland ecosystems in Central Asia, as well as for shaping socioeconomic strategies and formulating climate policies.

3.
Int J Biol Macromol ; 281(Pt 2): 136306, 2024 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-39370061

RESUMO

Cellulose acetate (CA) is an important cellulose derivative with a wide range of applications. To adopt a more efficient and environmentally friendly method to synthesize cellulose acetate, a binary ionic liquid mixture of 1-butyl-3-methylimidazole chloride salt (BmimCl) and 1-butyl-3-methyldihydroimidazole phosphate (BmimH2PO4) was used. Compared to the conventional methods, this approach didn't require pre-activation of cellulose and the process of homogeneous acetylation proceeded without a catalyst. By simply adjusting the reaction conditions, cellulose acetate with a degree of substitution (DS) in the range of 0.83-3.0 was produced by one-step homogeneous acetylation without hydrolysis. Furthermore, the cellulose acetate film produced by solvent casting exhibited smooth surface characteristics, 95 % transparency, and 57.9 MPa tensile strength. Therefore, this study highlights the importance of using binary ionic liquid mixtures for facile synthesis of cellulose acetate. Due to their excellent transparency and mechanical properties, newly synthesized cellulose acetate films could replace commercial films.

5.
Plant Physiol Biochem ; 216: 109178, 2024 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-39388752

RESUMO

Cadmium (Cd), as a heavy metal pollutant, can seriously affect plant growth and development. Boron (B), as an indispensable nutrient element, plays an important role in plant growth and cell wall (CW) synthesis. However, the physiological effects of B and Cd on plant growth and the mechanism of Cd chelation by the CW remain unclear. Here, we investigate the effect of exogenous B on Cd accumulation in CW components of Cosmos bipinnatus roots and its mechanism of Cd mitigation. Under B deficiency and single Cd (30 µM) treatments, the growth of C. bipinnatus was significantly inhibited, but the addition of exogenous B significantly increased plant biomass, which increased the Cd content in the underground parts of C. bipinnatus by 20.18% and reduced the Cd translocation factor by 22.22%. Meanwhile, application of exogenous B affected the subcellular Cd content across various Cd forms and alleviated Cd-induced oxidative stress in C. bipinnatus. Additionally, exogenous B and Cd and their mixtures affected the functional groups of the root CW, the proportion of polysaccharide components, the Cd content of polysaccharides, and the polysaccharide uronic acid content of C. bipinnatus. However, B application increased 3-deoxy-oct-2-ulosonic acid content, pectin esterase activity, low esterified pectin content, and its Cd content by 149.52%, 55.69%, 206.38%, and 150.02%, respectively, compared to Cd treatment alone. Thus, our study showed that B mitigates the toxicity of Cd to plants, revealing the effect of B on the physiological aspects of Cd tolerance in plants.

6.
Food Chem ; 463(Pt 3): 141319, 2024 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-39326315

RESUMO

This study proposes a kill two birds with one stone strategy to improve the health and safety of pork with high internal phase Pickering emulsions (HIPPEs). HIPPEs improved the pseudoplasticity and viscosity (from 619.3 to 1712 Pa·s at 0.1 s-1) of the pork, favoring smooth extrusion and adhesion of the ink. Shear recovery of pork gel increased from 39.20 % to 77.78 % by addition of HIPPEs. HIPPEs enhanced the pork gel viscoelastic properties (K4 = 341.29, K5 = 453.11) and yield stress (268.55 Pa). HIPPEs-adjusted pork gel (HPG) has favorable 3D printing, pork aroma, safe swallowing (level 5 food), and high digestibility (80.40 %), demonstrating its potential as a dysphagia diet. HPG reduced the cooking loss of pork (from 30.8 % to 1.9 %), which is suitable for dysphagic patients with reduced salivation. HIPPEs adjusts the properties of pork gel by filling and winding gel networks. These results provide new ideas for the development of special formula foods.

7.
Foods ; 13(18)2024 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-39335808

RESUMO

Dry-aging is a postmortem process that can substantially enhance the texture and flavour of beef. This study entailed suspending Yanbian cattle M. gluteus medius in the aging cabinet, maintained at a temperature of 2-4 °C and a relative humidity of 85 ± 5% for 35 days. Throughout this period, samples were systematically collected every 7 days. The widely targeted metabolomic analysis has been used in this investigation to analyse the dynamic changes in Yanbian cattle metabolites during dry-aging. A total of 883 metabolites were identified, with amino acids and their metabolites representing the largest proportion. Multivariate statistical analysis showed that 373 metabolites were identified as differential metabolites that changed significantly during the dry-aging process, including metabolites of amino acids, glycerophospholipids, and nucleotides and their metabolites. Additionally, 308 metabolites exhibited various increasing trends with time in dry-aging. The analysis of KEGG pathway analysis showed that ABC transporters, glycerophospholipid, and arachidonic acid metabolism are the most important metabolic pathways during dry-aging. These findings can guide technological developments in the meat processing sector and provide valuable insights into the metabolic traits and pathways of Yanbian cattle during the dry-aging process.

8.
Front Microbiol ; 15: 1452101, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39296299

RESUMO

Introduction: Gut microbiome plays a crucial role in the health of wild animals. Their structural and functional properties not only reflect the host's dietary habits and habitat conditions but also provide essential support for ecological adaptation in various environments. Methods: This study investigated the gut microbiome of Himalayan langurs (Semnopithecus schistaceus) and Xizang macaques (Macaca mulatta vestita) across different geographic regions using 16S rRNA gene and metagenomic sequencing. Results: Results showed distinct clustering patterns in gut microbiota based on geographic location. Soil had an insignificant impact on host gut microbiome. Himalayan langurs from mid-altitude regions exhibited higher levels of antibiotic resistance genes associated with multidrug resistance, while Xizang macaques from high-altitude regions showed a broader range of resistance genes. Variations in carbohydrate-active enzymes and KEGG pathways indicated unique metabolic adaptations to different environments. Discussion: These findings provide valuable insights into the health and conservation of these primates and the broader implications of microbial ecology and functional adaptations in extreme conditions.

9.
Front Nutr ; 11: 1424156, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39296507

RESUMO

Purpose: This study investigates the association between dietary Omega-3 fatty acid intake and accelerated phenotypic aging, referred to as PhenoAgeAccel. PhenoAgeAccel is defined as the difference between phenotypic biological age, calculated using blood biochemical markers, and chronological age. This study assesses the potential of Omega-3 intake to slow biological aging and its implications for public health. Methods: Utilizing data from the NHANES from 1999 to 2018, this cross-sectional study included 20,337 adult participants. Through a nationally representative sample combined with comprehensive phenotypic age calculation methods, a cross-sectional analysis of Omega-3 fatty acid intake and accelerated phenotypic aging was conducted. Weighted generalized linear regression models and restricted cubic spline analyses were applied to explore the potential non-linear relationships between them. Threshold effects were further clarified through piecewise regression models, and the impact of different demographic and health characteristics was evaluated through interaction effect tests. Results: After adjusting for various potential confounding factors, a significant negative correlation was found between Omega-3 fatty acid intake and PhenoAgeAccel (ß = -0.071; 95% CI: -0.119, -0.024; p = 0.004), indicating that an increase in Omega-3 intake is associated with a slowdown in PhenoAgeAccel. Specifically, for each unit increase in Omega-3 intake, the accelerated phenotypic aging decreased by an average of 0.071 units, revealing a significant linear negative correlation between Omega-3 intake and PhenoAgeAccel. Moreover, threshold effect analysis identified an Omega-3 fatty acid intake threshold (1.103 grams/day), beyond which the impact of Omega-3 intake on accelerated phenotypic aging tends to stabilize. Additionally, factors such as gender, age, race, and hypertension may influence the relationship between Omega-3 intake and PhenoAgeAccel, suggesting individual dietary guidance needs in different populations. Conclusion: This study highlights the potential role of dietary Omega-3 fatty acids in regulating PhenoAgeAccel and supports the strategy of delaying the aging process through dietary interventions to increase Omega-3 intake. The findings of this study contributes to the development of precise nutritional intervention strategies for different populations to optimize healthy longevity.

10.
Food Chem ; 463(Pt 1): 141055, 2024 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-39236382

RESUMO

Food safety is closely related to human health and has become a worldwide, pressing concern. Food safety analysis is essential for ensuring food safety. Sulfur quantum dots (SQDs), a new type of zero-dimensional metal-free nanomaterials, have recently become the focus of scientific research due to their good luminescence properties, dispersibility, biocompatibility, and inherent antibacterial properties. This review focuses on recent advances in SQDs, with emphasis on their practical applications in the food field. First, commonly used methods for the synthesis of SQDs are presented, including traditional and emerging strategies. The properties of SQDs are then analyzed in detail, particularly their luminescence properties, catalytic activities, and reducing properties. Next, the use of SQDs in food safety detection and antibacterial fields are elaborated. Finally, this review discusses the challenges associated with the use of SQDs in food safety detection and antimicrobial applications.

11.
Environ Res ; 262(Pt 2): 119898, 2024 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-39222727

RESUMO

In the context of global warming, vegetation changes exhibit various patterns, yet previous studies have focused primarily on monotonic changes, often overlooking the complexity and diversity of multiple change processes. Therefore, it is crucial to further explore vegetation dynamics and diverse change trajectories in this region under future climate scenarios to obtain a more comprehensive understanding of local ecosystem evolution. In this study, we established an integrated machine learning prediction framework and a vegetation change trajectory recognition framework to predict the dynamics of vegetation in Central Asia under future climate change scenarios and identify its change trajectories, thus revealing the potential impacts of future climate change on vegetation in the region. The findings suggest that various future climate scenarios will negatively affect most vegetation in Central Asia, with vegetation change intensity increasing with increasing emission trajectories. Analyses of different time scales and trend variations consistently revealed more pronounced downward trends. Vegetation change trajectory analysis revealed that most vegetation has undergone nonlinear and dramatic changes, with negative changes outnumbering positive changes and curve changes outnumbering abrupt changes. Under the highest emission scenario (SSP5-8.5), the abrupt vegetation changes and curve changes are 1.7 times and 1.3 times greater, respectively, than those under the SSP1-2.6 scenario. When transitioning from lower emission pathways (SSP1-2.6, SSP2-4.5) to higher emission pathways (SSP3-7.0, SSP5-8.5), the vegetation change trajectories shift from neutral and negative curve changes to abrupt negative changes. Across climate scenarios, the key climate factors influencing vegetation changes are mostly evapotranspiration and soil moisture, with temperature and relative humidity exerting relatively minor effects. Our study reveals the negative response of vegetation in Central Asia to climate change from the perspective of vegetation dynamics and change trajectories, providing a scientific basis for the development of effective ecological protection and climate adaptation strategies.

13.
J Biomater Sci Polym Ed ; : 1-22, 2024 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-39316729

RESUMO

Diabetic retinopathy (DR) is a common microvascular complication of diabetes necessitating early intervention to impede progression, despite current clinical treatments focusing on advanced stages. Essential oils from Fructus Alpiniae zerumbet (EOFAZ) have demonstrated efficacy in protecting against high glucose (HG)-induced Müller cell activation and DR development. This study introduced a reactive oxidative species (ROS)-responsive drug delivery system (NPSPHE@EOFAZ) targeting early DR stages and oxidative stress. Our engineered nanoparticles effectively deliver EOFAZ into HG-exposed Müller cells by detecting and responding to elevated oxidative stress levels. The NPSPHE@EOFAZ significantly inhibited abnormal cell growth, reduced oxidative stress, and alleviated inflammation in vitro. In vivo experiments on diabetic mice with DR revealed that NPSPHE@EOFAZ mitigated early pathological changes by reducing oxidative stress and inflammation while also alleviating organ damage in the heart, liver, spleen, lung, and kidney. These findings underscore the potential of NPSPHE@EOFAZ as a promising antioxidant for early intervention in DR pathogenesis.

14.
BMC Plant Biol ; 24(1): 807, 2024 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-39187785

RESUMO

Cadmium (Cd) is a biologically non-essential heavy metal, a major soil pollutant, and extremely harmful to plants. The phytohormone methyl jasmonate (MeJA) plays an important role in plant heavy-metal resistance. However, the understanding of the effects of MeJA supply level on alleviating Cd toxicity in plants is limited. Here, we investigated how MeJA regulated the development of physiological processes and cell wall modification in Cosmos bipinnatus. We found that low concentrations of MeJA increased the dry weight of seedlings under 120 µM Cd stress by reducing the transport of Cd from roots to shoots. Moreover, a threshold concentration of exogenous MeJA increased the activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) in plant roots, the concentration of Cd in the root cell wall, and the contents of pectin and hemicellulose 1 polysaccharides, through converting Cd into pectin-bound forms. These results suggested that MeJA mitigated Cd toxicity by modulating root cell wall polysaccharide and functional group composition, especially through pectin polysaccharides binding to Cd, with effects on Cd transport capacity, specific chemical forms of Cd, and homeostatic antioxidant systems in C. bipinnatus.


Assuntos
Acetatos , Cádmio , Ciclopentanos , Oxilipinas , Reguladores de Crescimento de Plantas , Oxilipinas/metabolismo , Ciclopentanos/metabolismo , Acetatos/farmacologia , Cádmio/toxicidade , Reguladores de Crescimento de Plantas/metabolismo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Poluentes do Solo/toxicidade , Parede Celular/metabolismo , Parede Celular/efeitos dos fármacos , Plântula/efeitos dos fármacos , Plântula/crescimento & desenvolvimento , Plântula/metabolismo , Antioxidantes/metabolismo , Superóxido Dismutase/metabolismo
15.
J Affect Disord ; 365: 171-177, 2024 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-39147160

RESUMO

BACKGROUND: Rs768705 (TMEM161B) is one of the identified single nucleotide polymorphisms related to major depressive disorder (MDD). Paranoid personality traits are independently associated with the risk of MDD. This study aimed to investigate the interaction effect between rs768705 (TMEM161B) and paranoid personality traits on the new-onset risk of MDD in Chinese freshmen. METHODS: A longitudinal study was conducted among 7642 Chinese freshmen without lifetime MDD at baseline in 2018. 158 new-onset MDD cases were ascertained in 2019. DNA samples were extracted to detect the genotype of rs768705. The diagnostic and statistical manual of mental disorders-IV criteria were used to determine MDD and personality disorder traits. Multiplicative interaction was assessed by logistic regression models. Tomas Andersson's method for calculating biological interactions was used to estimate the additive interaction. RESULTS: Rs768705(AG) (OR = 1.88, 95 % CI: 1.24-2.83) and paranoid personality traits (OR = 3.68, 95 % CI: 2.57-5.26) were significantly associated with the risk of MDD. The multiplicative interaction model with the product term of rs768705 and paranoid personality trait traits had a significant interaction effect (OR = 4.20, 95 % CI:1.62-10.91). There was also a significant additive interaction effect (RR = 7.08, 95 % CI:4.31-11.65) for the incidence of MDD. Seventy seven percent patients among new MDD cases were attributed to the additive interaction effect between rs768705 and paranoid personality traits. CONCLUSIONS: Rs768705 (AG) may interact with paranoid personality traits to increase the incidence of MDD among Chinese college students. Schools and psychosocial health organizations should pay more attention to individuals with paranoid personality traits for MDD intervention and prevention.


Assuntos
Transtorno Depressivo Maior , Predisposição Genética para Doença , Proteínas de Membrana , Polimorfismo de Nucleotídeo Único , Adolescente , Adulto , Feminino , Humanos , Masculino , Adulto Jovem , China/epidemiologia , Transtorno Depressivo Maior/genética , Transtorno Depressivo Maior/epidemiologia , Genótipo , Estudos Longitudinais , Proteínas de Membrana/genética , Transtorno da Personalidade Paranoide/genética , Transtorno da Personalidade Paranoide/epidemiologia , População do Leste Asiático/genética
16.
Sci China Life Sci ; 2024 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-39153050

RESUMO

Diabetic foot ulcers (DFUs) are a serious vascular disease. Currently, no effective methods are available for treating DFUs. Pro-protein convertase subtilisin/kexin type 9 (PCSK9) regulates lipid levels to promote atherosclerosis. However, the role of PCSK9 in DFUs remains unclear. In this study, we found that the expression of PCSK9 in endothelial cells (ECs) increased significantly under high glucose (HG) stimulation and in diabetic plasma and vessels. Specifically, PCSK9 promotes the E3 ubiquitin-protein ligase NEDD4 binding to vascular endothelial growth factor receptor 2 (VEGFR2), which led to the ubiquitination of VEGFR2, resulting in its degradation and downregulation in ECs. Furthermore, PCSK9 suppresses the expression and activation of AKT, endothelial nitric oxide synthase (eNOS), and ERK1/2, leading to decreased nitric oxide (NO) production and increased superoxide anion (O2._) generation, which impairs vascular endothelial function and angiogenesis. Importantly, using evolocumab to limit the increase in PCSK9 expression blocked the HG-induced inhibition of NO production and the increase in O2._ production, as well as inhibited the phosphorylation and expression of AKT, eNOS, and ERK1/2. Moreover, evolocumab improved vascular endothelial function and angiogenesis, and promoted wound healing in diabetes. Our findings suggest that targeting PCSK9 is a novel therapeutic approach for treating DFUs.

17.
J Sports Sci ; 42(14): 1313-1322, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-39133765

RESUMO

This review aims to investigate the dose-response relationship between walking speed and all-cause mortality. PubMed, Web of Science, Embase and Cochrane Library were searched to September, 2023 for cohort studies. A meta-analysis estimated the overall hazard ratio (HR) of mortality incidence and 95% Confidence Interval (CI) for individuals with the fastest walking speed compared to those with the slowest walking speed. Subgroup analyses were conducted based on sex, age and speed-measuring methods. Dose-response meta-analyses were examined by using "mvmeta" packages available in STATA. A total of 13 studies involving 530,841 participants were included. Of these, 11 studies provided data for dose-response meta-analyses. Individuals in the fastest walking-speed category had a 43% lower risk of all-cause mortality compared to those in the slowest walking-speed category (HR = 0.57, 95% CI 0.48-0.66). There was an inverse linear dose-response relationship between walking speed and all-cause mortality; for every 0.1 m/s increment in walking speed, the risk of mortality decreased by 6% (HR = 0.94; 0.92-0.96). There was an inverse nonlinear dose-response relationship between them when participants' age was larger than 65 years, but linear dose-response relationships were detected in both the timed walking speed test and self-reported walking speed measurements.


Assuntos
Mortalidade , Velocidade de Caminhada , Humanos , Velocidade de Caminhada/fisiologia , Fatores Etários , Causas de Morte , Modelos de Riscos Proporcionais , Fatores de Risco , Caminhada/fisiologia
18.
Anal Chim Acta ; 1321: 343039, 2024 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-39155104

RESUMO

BACKGROUND: In recent years, environmental pollution has attracted widespread global attention. Among them, environmental problems caused by heavy metal pollution pose a serious threat to human health and ecosystems. Mercury is a common heavy metal pollutant with high toxicity and wide distribution. Excessive intake of Hg2+ can cause permanent and severe damage to the nervous system, respiratory system, and kidneys in the human body. Therefore, developing both accurate and fast detection methods for Hg2+ is of great significance. RESULTS: A sensitive Hg2+ colorimetric sensor is designed based on PtNi nanowires (NWs) and Pt NWs with peroxidase-mimetic activity. PtNi NWs and Pt NWs catalyze the reaction of 3,3', 5,5'-tetramethylbenzidine (TMB) with hydrogen peroxide (H2O2) to produce blue oxidized TMB (oxTMB). The specific interaction of Pt-Hg significantly inhibits the peroxidase-mimetic activity of PtNi NW and Pt NW nanozymes, resulting in a lighter blue color. It is worth noting that compared with specific activity (SA) of Pt NWs (3.31 U/mg), PtNi NWs own superior SA (10.43 U/mg), which inevitably leads to a wider linear range of Hg2+ analysis (1 nM-200 µM) and a lower detection limit (0.6748 nM) for PtNi NWs-based colorimetric sensor, versus linear range (4 nM-5 µM) and LOD of 1.198 nM for Pt NWs-based colorimetric sensor, which are far below the Hg2+ threshold (10 nM) for drinking water set by the US Environmental Protection Agency. SIGNIFICANCE: The two nanozyme colorimetric sensors have been successfully used for the evaluation of Hg2+ in complex river water and tap water. Due to the advantages of simple operation, fast response, and high sensitivity, colorimetric sensors have broad application prospects in environmental monitoring.


Assuntos
Colorimetria , Mercúrio , Nanofios , Níquel , Platina , Mercúrio/análise , Platina/química , Nanofios/química , Níquel/química , Poluentes Químicos da Água/análise , Limite de Detecção , Benzidinas/química , Catálise , Peróxido de Hidrogênio/química , Peróxido de Hidrogênio/análise
19.
Front Neurosci ; 18: 1439443, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39148522

RESUMO

Background and objectives: The advent of new clinical subtyping systems for Parkinson's disease (PD) has led to the classification of patients into distinct groups: mild motor predominant (PD-MMP), intermediate (PD-IM), and diffuse malignant (PD-DM). Our goal was to evaluate the efficacy of diffusion tensor imaging (DTI) in the early diagnosis, assessment of clinical progression, and prediction of prognosis of these PD subtypes. Additionally, we attempted to understand the pathological mechanisms behind white matter damage using single-photon emission computed tomography (SPECT) and cerebrospinal fluid (CSF) analyses. Methods: We classified 135 de novo PD patients based on new clinical criteria and followed them up after 1 year, along with 45 healthy controls (HCs). We utilized tract-based spatial statistics to assess the microstructural changes of white matter at baseline and employed multiple linear regression to examine the associations between DTI metrics and clinical data at baseline and after follow-up. Results: Compared to HCs, patients with the PD-DM subtype demonstrated reduced fractional anisotropy (FA), increased axial diffusivity (AD), and elevated radial diffusivity (RD) at baseline. The FA and RD values correlated with the severity of motor symptoms, with RD also linked to cognitive performance. Changes in FA over time were found to be in sync with changes in motor scores and global composite outcome measures. Furthermore, baseline AD values and their rate of change were related to alterations in semantic verbal fluency. We also discovered the relationship between FA values and the levels of α-synuclein and ß-amyloid. Reduced dopamine transporter uptake in the left putamen correlated with RD values in superficial white matter, motor symptoms, and autonomic dysfunction at baseline as well as cognitive impairments after 1 year. Conclusions: The PD-DM subtype is characterized by severe clinical symptoms and a faster progression when compared to the other subtypes. DTI, a well-established technique, facilitates the early identification of white matter damage, elucidates the pathophysiological mechanisms of disease progression, and predicts cognitively related outcomes. The results of SPECT and CSF analyses can be used to explain the specific pattern of white matter damage in patients with the PD-DM subtype.

20.
Chem Sci ; 15(32): 12819-12826, 2024 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-39148780

RESUMO

Helicenes, featuring unique helical structures, have a long history as three-dimensional polycyclic aromatic hydrocarbons (PAHs). Incorporation of heteroatoms into helicenes may alter their electronic structures and achieve unexpected physical properties. Here, we disclose fusion of boron-doped π-systems onto helicenes as an efficient strategy to design boron-doped carbohelicenes. Two boron-doped double [6]carbohelicenes were synthesized, which possess the C58B2 and C86B2 polycyclic π-skeletons containing two [6]helicene subunits, respectively. The C86B2 molecule thus represents the largest-size helicene-based boron-doped PAH. A thorough investigation reveals that the helicene moieties and boron atoms endow the polycyclic π-systems with delocalized electronic structures, and well-tunable ground-state and excited-state photophysical properties. It is notable that the C58B2 molecule displays excited-state stimulated emission behavior and amplified spontaneous emission (ASE) properties in not only the blend films with various doped concentrations but also the pure film. To our knowledge, it is the first example of ASE-active [n]helicene (n ≥ 6), and moreover, such robust ASE performance has rarely been observed in PAHs, demonstrating the promising utility of boron-doped carbohelicenes for laser materials.

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