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1.
EMBO J ; 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-39009676

RESUMO

Anthelmintics are drugs used for controlling pathogenic helminths in animals and plants. The natural compound betaine and the recently developed synthetic compound monepantel are both anthelmintics that target the acetylcholine receptor ACR-23 and its homologs in nematodes. Here, we present cryo-electron microscopy structures of ACR-23 in apo, betaine-bound, and betaine- and monepantel-bound states. We show that ACR-23 forms a homo-pentameric channel, similar to some other pentameric ligand-gated ion channels (pLGICs). While betaine molecules are bound to the classical neurotransmitter sites in the inter-subunit interfaces in the extracellular domain, monepantel molecules are bound to allosteric sites formed in the inter-subunit interfaces in the transmembrane domain of the receptor. Although the pore remains closed in betaine-bound state, monepantel binding results in an open channel by wedging into the cleft between the transmembrane domains of two neighboring subunits, which causes dilation of the ion conduction pore. By combining structural analyses with site-directed mutagenesis, electrophysiology and in vivo locomotion assays, we provide insights into the mechanism of action of the anthelmintics monepantel and betaine.

2.
Clin Microbiol Rev ; : e0002223, 2024 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-38899877

RESUMO

SUMMARYWithin weeks of the first report of acquired immunodeficiency syndrome (AIDS) in 1981, it was observed that these patients often had Kaposi sarcoma (KS), a hitherto rarely seen skin tumor in the USA. It soon became apparent that AIDS was also associated with an increased incidence of high-grade lymphomas caused by Epstein-Barr virus (EBV). The association of AIDS with KS remained a mystery for more than a decade until Kaposi sarcoma-associated herpesvirus (KSHV) was discovered and found to be the cause of KS. KSHV was subsequently found to cause several other diseases associated with AIDS and human immunodeficiency virus (HIV) infection. People living with HIV/AIDS continue to have an increased incidence of certain cancers, and many of these cancers are caused by EBV and/or KSHV. In this review, we discuss the epidemiology, virology, pathogenesis, clinical manifestations, and treatment of cancers caused by EBV and KSHV in persons living with HIV.

3.
Brain ; 147(7): 2552-2565, 2024 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-38366606

RESUMO

Chronic varicella zoster virus (VZV) infection induced neuroinflammatory condition is the critical pathology of post-herpetic neuralgia (PHN). The immune escape mechanism of VZV remains elusive. As to mice have no VZV infection receptor, herpes simplex virus type 1 (HSV-1) infection is a well established PHN mice model. Transcriptional expression analysis identified that the protein arginine methyltransferases 6 (Prmt6) was upregulated upon HSV-1 infection, which was further confirmed by immunofluorescence staining in spinal dorsal horn. Prmt6 deficiency decreased HSV-1-induced neuroinflammation and PHN by enhancing antiviral innate immunity and decreasing HSV-1 load in vivo and in vitro. Overexpression of Prmt6 in microglia dampened antiviral innate immunity and increased HSV-1 load. Mechanistically, Prmt6 methylated and inactivated STING, resulting in reduced phosphorylation of TANK binding kinase-1 (TBK1) and interferon regulatory factor 3 (IRF3), diminished production of type I interferon (IFN-I) and antiviral innate immunity. Furthermore, intrathecal or intraperitoneal administration of the Prmt6 inhibitor EPZ020411 decreased HSV-1-induced neuroinflammation and PHN by enhancing antiviral innate immunity and decreasing HSV-1 load. Our findings revealed that HSV-1 escapes antiviral innate immunity and results in PHN by upregulating Prmt6 expression and inhibiting the cGAS-STING pathway, providing novel insights and a potential therapeutic target for PHN.


Assuntos
Herpesvirus Humano 1 , Proteínas de Membrana , Neuralgia Pós-Herpética , Nucleotidiltransferases , Proteína-Arginina N-Metiltransferases , Regulação para Cima , Animais , Proteína-Arginina N-Metiltransferases/metabolismo , Proteína-Arginina N-Metiltransferases/genética , Proteína-Arginina N-Metiltransferases/antagonistas & inibidores , Camundongos , Proteínas de Membrana/metabolismo , Proteínas de Membrana/genética , Nucleotidiltransferases/metabolismo , Nucleotidiltransferases/genética , Neuralgia Pós-Herpética/metabolismo , Neuralgia Pós-Herpética/imunologia , Camundongos Endogâmicos C57BL , Imunidade Inata , Humanos , Camundongos Knockout , Masculino , Fator Regulador 3 de Interferon/metabolismo , Fator Regulador 3 de Interferon/genética , Herpes Simples/imunologia , Microglia/metabolismo , Microglia/imunologia , Proteínas Serina-Treonina Quinases
4.
Mol Ther ; 32(2): 503-526, 2024 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-38155568

RESUMO

Multiple myeloma (MM) is a rarely curable malignancy of plasma cells. MM expresses B cell maturation antigen (BCMA). We developed a fully human anti-BCMA chimeric antigen receptor (CAR) with a heavy-chain-only antigen-recognition domain, a 4-1BB domain, and a CD3ζ domain. The CAR was designated FHVH33-CD8BBZ. We conducted the first-in-humans clinical trial of T cells expressing FHVH33-CD8BBZ (FHVH-T). Twenty-five patients with relapsed MM were treated. The stringent complete response rate (sCR) was 52%. Median progression-free survival (PFS) was 78 weeks. Of 24 evaluable patients, 6 (25%) had a maximum cytokine-release syndrome (CRS) grade of 3; no patients had CRS of greater than grade 3. Most anti-MM activity occurred within 2-4 weeks of FHVH-T infusion as shown by decreases in the rapidly changing MM markers serum free light chains, urine light chains, and bone marrow plasma cells. Blood CAR+ cell levels peaked during the time that MM elimination was occurring, between 7 and 15 days after FHVH-T infusion. C-C chemokine receptor type 7 (CCR7) expression on infusion CD4+ FHVH-T correlated with peak blood FHVH-T levels. Single-cell RNA sequencing revealed a shift toward more differentiated FHVH-T after infusion. Anti-CAR antibody responses were detected in 4 of 12 patients assessed. FHVH-T has powerful, rapid, and durable anti-MM activity.


Assuntos
Mieloma Múltiplo , Receptores de Antígenos Quiméricos , Humanos , Mieloma Múltiplo/genética , Receptores de Antígenos Quiméricos/metabolismo , Linfócitos T , Imunoterapia Adotiva , Medula Óssea/metabolismo
5.
J Am Chem Soc ; 146(22): 15053-15060, 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38776531

RESUMO

Electrocatalysis is considered promising in renewable energy conversion and storage, yet numerous efforts rely on catalyst design to advance catalytic activity. Herein, a hydrodynamic single-particle electrocatalysis methodology is developed by integrating collision electrochemistry and microfluidics to improve the activity of an electrocatalysis system. As a proof-of-concept, hydrogen evolution reaction (HER) is electrocatalyzed by individual palladium nanoparticles (Pd NPs), with the development of microchannel-based ultramicroelectrodes. The controlled laminar flow enables the precise delivery of Pd NPs to the electrode-electrolyte interface one by one. Compared to the diffusion condition, hydrodynamic collision improves the number of active sites on a given electrode by 2 orders of magnitude. Furthermore, forced convection enables the enhancement of proton mass transport, thereby increasing the electrocatalytic activity of each single Pd NP. It turns out that the improvement in mass transport increases the reaction rate of HER at individual Pd NPs, thus a phase transition without requiring a high overpotential. This study provides new avenues for enhancing electrocatalytic activity by altering operating conditions, beyond material design limitations.

6.
Cancer Immunol Immunother ; 73(8): 147, 2024 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-38833156

RESUMO

BACKGROUND: This study aimed to investigate the relationship between signal regulatory protein gamma (SIRPG) and tumor immune microenvironment phenotypes or T cell mediated-adaptive antitumor immunity, and its predictive value for response to PD-1 blockade in cancers. METHODS: Pan-cancer analysis of SIRPG expression and immune deconvolution was performed using transcriptomic data across 33 tumor types. Transcriptomic and clinical data from 157 patients with non-small-cell lung cancer (NSCLC) and melanoma received PD-1 blockade were analyzed. Expression characteristics of SIRPG were investigated using single-cell RNA sequencing (scRNA-seq) data of 103,599 cells. The effect of SIRPG expression was evaluated via SIRPG knockdown or overexpression in Jurkat T cells. RESULTS: The results showed that most cancers with high SIRPG expression had significantly higher abundance of T cells, B cells, NK cells, M1 macrophages and cytotoxic lymphocytes and increased expression level of immunomodulatory factors regulating immune cell recruitment, antigen presentation, T cell activation and cytotoxicity, but markedly lower abundance of neutrophils, M2 macrophages, and myeloid-derived suppressor cells. High SIRPG expression was associated with favorable response to PD-1 blockade in both NSCLC and melanoma. scRNA-seq data suggested SIRPG was mainly expressed in CD8+ exhausted T and CD4+ regulatory T cells, and positively associated with immune checkpoint expression including PDCD1 and CTLA4. In vitro test showed SIRPG expression in T cells could facilitate expression of PDCD1 and CTLA4. CONCLUSION: High SIRPG expression is associated with an inflamed immune phenotype in cancers and favorable response to PD-1 blockade, suggesting it would be a promising predictive biomarker for PD-1 blockade and novel immunotherapeutic target.


Assuntos
Inibidores de Checkpoint Imunológico , Receptor de Morte Celular Programada 1 , Microambiente Tumoral , Humanos , Microambiente Tumoral/imunologia , Inibidores de Checkpoint Imunológico/uso terapêutico , Inibidores de Checkpoint Imunológico/farmacologia , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Receptor de Morte Celular Programada 1/metabolismo , Carcinoma Pulmonar de Células não Pequenas/imunologia , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Carcinoma Pulmonar de Células não Pequenas/patologia , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Neoplasias Pulmonares/imunologia , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/genética , Biomarcadores Tumorais/metabolismo , Melanoma/imunologia , Melanoma/metabolismo , Melanoma/genética
9.
Brain Behav Immun ; 118: 101-114, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38402915

RESUMO

Microglia induced chronic inflammation is the critical pathology of Neuropathic pain (NP). Metabolic reprogramming of macrophage has been intensively reported in various chronic inflammation diseases. However, the metabolic reprogramming of microglia in chronic pain remains to be elusive. Here, we reported that immuno-metabolic markers (HIF-1α, PKM2, GLUT1 and lactate) were related with increased expression of PRMT6 in the ipsilateral spinal cord dorsal horn of the chronic construction injury (CCI) mice. PRMT6 deficiency or prophylactic and therapeutic intrathecal administration of PRMT6 inhibitor (EPZ020411) ameliorated CCI-induced NP, inflammation and glycolysis in the ipsilateral spinal cord dorsal horn. PRMT6 knockout or knockdown inhibited LPS-induced inflammation, proliferation and glycolysis in microglia cells. While PRMT6 overexpression exacerbated LPS-induced inflammation, proliferation and glycolysis in BV2 cells. Recent research revealed that PRMT6 could interact with and methylate HIF-1α, which increased HIF-1α protein stability. In sum, increased expression of PRMT6 exacerbates NP progress by increasing glycolysis and neuroinflammation through interacting with and stabilizing HIF-1α in a methyltransferase manner, which outlines novel pathological mechanism and drug target for NP.


Assuntos
Microglia , Neuralgia , Camundongos , Animais , Microglia/metabolismo , Lipopolissacarídeos/farmacologia , Lipopolissacarídeos/metabolismo , Inflamação/metabolismo , Neuralgia/metabolismo , Glicólise
10.
J Periodontal Res ; 2024 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-38594821

RESUMO

This image article presents a single patient receiving a reconstructed fibular bony peak (BP) for guided bone regeneration (GBR) with a customized titanium mesh. The patient was informed and understood the objectives and signed a written informed consent document before surgery.

11.
Phys Chem Chem Phys ; 26(28): 19543-19553, 2024 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-38979972

RESUMO

Rational design of γ-alumina-based catalysts relies on an extensive understanding of the distribution of hydroxyl groups on the surface of γ-alumina and their physicochemical properties, which remain unclear and challenging to determine experimentally due to the structural complexity. In this work, by means of DFT and thermodynamic calculations, various hydroxylation modes of γ-alumina (110) and (100) surfaces at different OH coverages were evaluated, based on which a thermodynamic model to reflect the relationship between temperature and the surface structure was established and the stable hydroxylation modes under experimental conditions were predicted. This enables us to identify the experimentally measured IR spectra. The effect of hydroxyl coverages on the surface Lewis acidity was then analyzed, showing that the presence of hydroxyl groups could promote the Lewis acidity of neighboring Al sites. This work provides fundamental insights into the molecular level understanding of the surface properties of γ-alumina and benefits the rational design of alumina-based catalysts.

12.
Environ Health ; 23(1): 36, 2024 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-38609898

RESUMO

BACKGROUND: Multifaceted SARS-CoV-2 interventions have modified exposure to air pollution and dynamics of respiratory diseases. Identifying the most vulnerable individuals requires effort to build a complete picture of the dynamic health effects of air pollution exposure, accounting for disparities across population subgroups. METHODS: We use generalized additive model to assess the likely changes in the hospitalisation and mortality rate as a result of exposure to PM2.5 and O3 over the course of COVID-19 pandemic. We further disaggregate the population into detailed age categories and illustrate a shifting age profile of high-risk population groups. Additionally, we apply multivariable logistic regression to integrate demographic, socioeconomic and climatic characteristics with the pollution-related excess risk. RESULTS: Overall, a total of 1,051,893 hospital admissions and 34,954 mortality for respiratory disease are recorded. The findings demonstrate a transition in the association between air pollutants and hospitalisation rates over time. For every 10 µg/m3 increase of PM2.5, the rate of hospital admission increased by 0.2% (95% CI: 0.1-0.7%) and 1.4% (1.0-1.7%) in the pre-pandemic and dynamic zero-COVID stage, respectively. Conversely, O3-related hospitalization rate would be increased by 0.7% (0.5-0.9%) in the pre-pandemic stage but lowered to 1.7% (1.5-1.9%) in the dynamic zero-COVID stage. Further assessment indicates a shift of high-risk people from children and young adolescents to the old, primarily the elevated hospitalization rates among the old people in Lianyungang (RR: 1.53, 95%CI: 1.46, 1.60) and Nantong (RR: 1.65, 95%CI: 1.57, 1.72) relative to those for children and young adolescents. Over the course of our study period, people with underlying diseases would have 26.5% (22.8-30.3%) and 12.7% (10.8-14.6%) higher odds of having longer hospitalisation and over 6 times higher odds of deaths after hospitalisation. CONCLUSIONS: Our estimates provide the first comprehensive evidence on the dynamic pollution-health associations throughout the pandemic. The results suggest that age and underlying diseases collectively determines the disparities of pollution-related health effect across population subgroups, underscoring the urgency to identifying the most vulnerable individuals to air pollution.


Assuntos
Poluição do Ar , Transtornos Respiratórios , Doenças Respiratórias , Adolescente , Criança , Humanos , Pandemias , Doenças Respiratórias/epidemiologia , Poluição do Ar/efeitos adversos , Material Particulado/efeitos adversos
13.
Demography ; 61(3): 797-827, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38814170

RESUMO

Despite rising numbers of only children in China, little is known about their family dynamics and well-being in adulthood-for example, how often they marry other only children and whether those in siblingless families have worse or better health than others. Theoretical expectations produce opposing predictions: siblings might provide social and emotional support and reduce parental caregiving pressures, but only children might receive more support from parents and grandparents. Using the 2010 China Family Panel Study, we examine marital sorting on Chinese adults' number of siblings and test whether sibling availability and sibling sorting are associated with subjective physical and mental health. Despite general perceptions that China has an exceedingly high prevalence of adults with no siblings that might produce very small families, results demonstrate a low prevalence of siblingless couples (i.e., both spouses are only children). Married adults with no siblings or siblings-in-law have better subjective physical health but similar levels of subjective mental health relative to their counterparts with siblings. The health advantages of siblingless marital unions are greater for rural and female adults. Declining sibling prevalence in China will shape future family demographic dynamics but appears less detrimental to population health than sometimes assumed.


Assuntos
Nível de Saúde , Saúde Mental , Irmãos , Humanos , Feminino , Masculino , China , Adulto , Pessoa de Meia-Idade , Características da Família , Fatores Socioeconômicos , Casamento/estatística & dados numéricos , Fatores Sexuais , Adulto Jovem , Fatores Sociodemográficos , População do Leste Asiático
14.
Angew Chem Int Ed Engl ; 63(32): e202404170, 2024 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-38781086

RESUMO

The key to rationally and rapidly designing high-performance materials is the monitoring and comprehension of dynamic processes within individual particles in real-time, particularly to gain insight into the anisotropy of nanoparticles. The intrinsic property of nanoparticles typically varies from one crystal facet to the next under realistic working conditions. Here, we introduce the operando collision electrochemistry to resolve the single silver nanoprisms (Ag NPs) anisotropy in photoelectrochemistry. We directly identify the effect of anisotropy on the plasmonic-assisted electrochemistry at the single NP/electrolyte interface. The statistical collision frequency shows that heterogeneous diffusion coefficients among crystal facets facilitate Ag NPs to undergo direction-dependent mass transfer toward the gold ultramicroelectrode. Subsequently, the current amplitudes of transient events indicate that the anisotropy enables variations in dynamic interfacial electron transfer behaviors during photothermal processes. The results presented here demonstrate that the measurement precision of collision electrochemistry can be extended to the sub-nanoparticle level, highlighting the potential for high-throughput material screening with comprehensive kinetics information at the nanoscale.

15.
Angew Chem Int Ed Engl ; : e202410835, 2024 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-39044707

RESUMO

Propane dehydrogenation (PDH) is crucial for propylene production, but commercially employed Pt-based catalysts face susceptibility to deactivation due to the Pt sintering during reaction and regeneration steps. Here, we report a SiO2 supported nanometric (MnCoCuZnPt) high-entropy PDH catalyst with high activity and stability. The catalyst exhibited a super high propane conversion of 56.6% with 94% selectivity of propylene at 600 °C. The propylene productivity reached 68.5 molC3H6·gPt-1·h-1, nearly three times that of Pt/SiO2 (23.5 molC3H6·gPt-1·h-1) under a weight hourly space velocity of 60 h-1. In a high-entropy nanoparticle, Pt atoms were atomically dispersed through coordination with other metals and exhibited a positive charge, thereby showcasing remarkable catalytic activity. The high-entropy effect contributes to the catalyst a superior stability with a low deactivation constant of 0.0004 h-1 during 200 hours of reaction under the industrial gas composition at 550 °C. Such high-entropy PDH catalyst is easy regenerated through simple air combustion of deposited coke. After the fourth consecutive regeneration cycle, satisfactory catalytic stability was observed, and the element distribution of spent catalysts almost returned to their initial state, with no detectable Pt sintering. This work provides new insights into designing active, stable, and regenerable novel PDH catalysts.

16.
J Glob Health ; 14: 04076, 2024 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-38574358

RESUMO

Background: Research on the health and economic costs due to insufficient sleep remains scant in developing countries. In this study we aimed to estimate the years of life lost (YLLs) due to short sleep and quantify its economic burden in China. Methods: We estimated both individual and aggregate YLLs due to short sleep (ie, ≤6 hours) among Chinese adults aged 20 years or older by sex and five-year age groups in 2010, 2014, and 2018. YLL estimates were derived from 1) the prevalence of short sleep using three survey waves of the China Family Panel Studies, 2) relative mortality risks from meta-analyses, and 3) life tables in China. YLL was the difference between the estimated life expectancy of an individual in the short sleep category vs in the recommended sleep category. We estimated the economic cost using the human capital approach. Results: The sample sizes of the three survey waves were 31 393, 31 207, and 28 618. Younger age groups and men had more YLLs due to short sleep compared to their counterparts. For individuals aged 20-24, men had an average YLL of nearly 0.95, in contrast to the approximate 0.75 in women across the observed years of 2010, 2014, and 2018. The trend in individual YLLs remained consistent over these years. In aggregate, China experienced a rise from 66.75 million YLLs in 2010 to 95.29 million YLLs in 2014, and to 115.05 million YLLs in 2018. Compared to 2010 (USD 191.83 billion), the associated economic cost in 2014 increased to USD 422.24 billion, and the cost in 2018 more than tripled (USD 628.15 billion). The percentage of cost to Chinese gross domestic product in corresponding years was 3.23, 4.09, and 4.62%. Conclusions: Insufficient sleep is associated with substantial YLLs in China, potentially impacting the population's overall life expectancy. The escalating economic toll attributed to short sleep underscores the urgent need for public health interventions to improve sleep health at the population level.


Assuntos
Estresse Financeiro , Privação do Sono , Adulto , Masculino , Humanos , Feminino , Expectativa de Vida , Prevalência , China/epidemiologia
17.
Heliyon ; 10(3): e25196, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38322845

RESUMO

A hybrid laser composed of infrared and blue laser is applied in fabricating TiB2/AlSi7Mg composites on AlSi7Mg substrate by LPBF. The effect on formability, molten pool morphology, molten pool size and microstructure under infrared, blue and hybrid laser were compared. It was confirmed that hybrid laser can make up for the unbalanced energy distribution of infrared laser and the low energy density of blue laser. The increased energy input improves the molten pool size and cellular dendrites size. Therefore, the hybrid laser can improve the formability and forming stability in the LPBF process of low absorption rate alloys.

18.
J Infect Dev Ctries ; 18(1): 44-52, 2024 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-38377093

RESUMO

INTRODUCTION: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant rapidly appeared in Shanghai, China in early March 2022. Although a few studies have analyzed the risk factors of the severe type, identifying risk factors for non-mild COVID-19 outcomes (general/severe/critical type) which occur with radiographic evidence of pneumonia is lacking. METHODOLOGY: The COVID-19 patients admitted to a district-level designated hospital from April 26 to May 21 were enrolled in this retrospective study. The clinical manifestations and laboratory examinations were analyzed. Logistic regression was employed to evaluate risk factors for non-mild outcomes. RESULTS: Of the 311 patients, 196 (63.0%) were mild and 115 (37.0%) were non-mild. Among them, 215 cases (69.1%) were unvaccinated. Male, ≥ 60 years age, and chronic kidney disease were risk factors of progressing to non-mild. Patients with more than two comorbidities were more likely to become non-mild, whereas two/booster doses vaccinated patients had a lower risk of developing to non-mild. The median negative conversion days (NCDs) were 12 days. Non-mild, > 2 comorbidities, delayed admission (> 3 days), and Paxlovid (Pfizer, Freiburg, Germany) treatment significantly lengthened the NCDs. CONCLUSIONS: Our results call for special concern for full and booster vaccination of the elderly, which will effectively protect from progression of COVID-19 to non-mild state. In the meantime, symptomatic COVID-19 patients should be treated as soon as possible.


Assuntos
COVID-19 , Idoso , Humanos , Masculino , COVID-19/epidemiologia , SARS-CoV-2 , China/epidemiologia , Estudos Retrospectivos , Fatores de Risco
19.
Anal Methods ; 16(4): 537-550, 2024 01 25.
Artigo em Inglês | MEDLINE | ID: mdl-38180114

RESUMO

Hyaluronic acid (HA), a polysaccharide, is widely used for its essential physiological functions. Although the structures of low molecular weight HA produced by both acid and enzyme degradation methods are extremely similar, there are still differences due to the different degradation principles. There is currently no clear way to distinguish between HA prepared by acidolysis and enzymatic hydrolysis. Based on near-infrared (NIR) spectroscopy and aquaphotomics technology, a method for distinguishing HA raw materials and their mixtures from different sources was proposed, and HA with different mixed ratios was accurately quantified. First, NIR spectra of the HA samples were collected. The spectra were then preprocessed to improve the spectral resolution. Spectral information was extracted based on wavelet transform and principal component analysis, resulting in a final selection of 12 characteristic wavelengths containing classification information. The discriminative and quantitative models were then constructed using the 12 wavelengths. The discriminative model achieved a 100% identification rate for HA from different sources. The correlation coefficient of calibration (Rc), validation (Rp), external test (Rt), root mean square error of cross validation (RMSECV), calibration (RMSEC), validation (RMSEP), and external test (RMSET) of the mixed proportion quantitative model were 0.9876, 0.9876, 0.9898, 0.0546, 0.0433, 0.0440, and 0.0347, respectively. In this study, the problem of structural similarity and non-identifiability of HA produced by acidolysis and enzymatic hydrolysis was addressed, and quality monitoring of HA feedstock in HA circulating links was achieved. This is the first time to achieve accurate quantification of solid mixtures using the aquaphotomics method.


Assuntos
Ácido Hialurônico , Espectroscopia de Luz Próxima ao Infravermelho , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Análise de Componente Principal , Calibragem , Peso Molecular
20.
Materials (Basel) ; 17(9)2024 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-38730859

RESUMO

The wide size range and high tendency to agglomerate of in-situ TiB2 particles in reinforced Al matrix composites introduce great difficulties in their size characterization. In order to use a nanoparticle size analyzer (NSA) to obtain the precise size distribution of TiB2 particles, a controlled size characterization process has been explored. First, the extraction and drying processes for TiB2 particles were optimized. In the extraction process, alternated applications of magnetic stirring and normal ultrasound treatments were proven to accelerate the dissolution of the Al matrix in HCl solution. Furthermore, freeze-drying was found to minimize the agglomeration tendency among TiB2 particles, facilitating the acquisition of pure powders. Such powders were quantitatively made into an initial TiB2 suspension. Second, the chemical and physical dispersion technologies involved in initial TiB2 suspension were put into focus. Chemically, adding PEI (M.W. 10000) at a ratio of mPEI/mTiB2 = 1/30 into the initial suspension can greatly improve the degree of TiB2 dispersion. Physically, the optimum duration for high-energy ultrasound application to achieve TiB2 dispersion was 10 min. Overall, the corresponding underlying dispersion mechanisms were discussed in detail. With the combination of these chemical and physical dispersion specifications for TiB2 suspension, the bimodal size distribution of TiB2 was able to be characterized by NSA for the first time, and its number-average diameter was 111 ± 6 nm, which was reduced by 59.8% over the initial suspension. Indeed, the small-sized and large-sized peaks of the TiB2 particles characterized by NSA mostly match the results obtained from transmission electron microscopy and scanning electron microscopy, respectively.

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