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1.
Science ; 384(6691): 113-118, 2024 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-38574151

RESUMO

The synthesis of quaternary carbons often requires numerous steps and complex conditions or harsh reagents that act on heavily engineered substrates. This is largely a consequence of conventional polar-bond retrosynthetic disconnections that in turn require multiple functional group interconversions, redox manipulations, and protecting group chemistry. Here, we report a simple catalyst and reductant combination that converts two types of feedstock chemicals, carboxylic acids and olefins, into tetrasubstituted carbons through quaternization of radical intermediates. An iron porphyrin catalyst activates each substrate by electron transfer or hydrogen atom transfer, and then combines the fragments using a bimolecular homolytic substitution (SH2) reaction. This cross-coupling reduces the synthetic burden to procure numerous quaternary carbon---containing products from simple chemical feedstocks.

2.
ACS Nano ; 18(13): 9636-9644, 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38497667

RESUMO

A two-dimensional (2D) ferroelectric semiconductor, which is coupled with photosensitivity and room-temperature ferroelectricity, provides the possibility of coordinated conductance modulation by both electric field and light illumination and is promising for triggering the revolution of optoelectronics for monolithic multifunctional integration. Here, we report that semiconducting Sn2P2S6 crystals can be achieved in a 2D morphology using a chemical vapor transport approach with the assistant of space confinement and experimentally demonstrate the robust ferroelectricity in atomic-thin Sn2P2S6 nanosheet at room temperature. The intercorrelated programming of ferroelectric order along out-of-plane (OOP) and in-plane (IP) directions enables a tunable bulk photovoltaic (BPV) effect through multidirectional electrical control. By combining the capability of anisotropic in-plane optical absorption, a highly integrated Sn2P2S6 optoelectronic device vertically sandwiched with graphene electrodes yields the polarization-dependent open-circuit photovoltage with a dichroic ratio of 2.0 under 405 nm light illumination. The reintroduction of ferroelectric Sn2P2S6 to the 2D asymmetric semiconductor family provides possibilities to hardware implement of the self-powered polarization-sensitive photodetection and spotlights the promising applications for next-generation photovoltaic devices.

3.
BMC Infect Dis ; 24(1): 337, 2024 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-38515037

RESUMO

BACKGROUND: Genetic variation underly inter-individual variation in host immune responses to infectious diseases, and may affect susceptibility or the course of signs and symptoms. METHODS: We performed genome-wide association studies in a prospective cohort of 1138 patients with physician-confirmed Lyme borreliosis (LB), the most common tick-borne disease in the Northern hemisphere caused by the bacterium Borrelia burgdorferi sensu lato. Genome-wide variants in LB patients-divided into a discovery and validation cohort-were compared to two healthy cohorts. Additionally, ex vivo monocyte-derived cytokine responses of peripheral blood mononuclear cells to several stimuli including Borrelia burgdorferi were performed in both LB patient and healthy control samples, as were stimulation experiments using mechanistic/mammalian target of rapamycin (mTOR) inhibitors. In addition, for LB patients, anti-Borrelia antibody responses were measured. Finally, in a subset of LB patients, gene expression was analysed using RNA-sequencing data from the ex vivo stimulation experiments. RESULTS: We identified a previously unknown genetic variant, rs1061632, that was associated with enhanced LB susceptibility. This polymorphism was an eQTL for KCTD20 and ETV7 genes, and its major risk allele was associated with upregulation of the mTOR pathway and cytokine responses, and lower anti-Borrelia antibody production. In addition, we replicated the recently reported SCGB1D2 locus that was suggested to have a protective effect on B. burgdorferi infection, and associated this locus with higher Borrelia burgdorferi antibody indexes and lower IL-10 responses. CONCLUSIONS: Susceptibility for LB was associated with higher anti-inflammatory responses and reduced anti-Borrelia antibody production, which in turn may negatively impact bacterial clearance. These findings provide important insights into the immunogenetic susceptibility for LB and may guide future studies on development of preventive or therapeutic measures. TRIAL REGISTRATION: The LymeProspect study was registered with the International Clinical Trials Registry Platform (NTR4998, registration date 2015-02-13).


Assuntos
Grupo Borrelia Burgdorferi , Borrelia burgdorferi , Borrelia , Doença de Lyme , Humanos , Estudo de Associação Genômica Ampla , Estudos Prospectivos , Leucócitos Mononucleares , Suscetibilidade a Doenças , Doença de Lyme/genética , Doença de Lyme/diagnóstico , Borrelia burgdorferi/genética , Citocinas/genética , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/uso terapêutico , Grupo Borrelia Burgdorferi/genética , Secretoglobinas/genética
4.
Nat Commun ; 15(1): 1908, 2024 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-38459023

RESUMO

Liver injury is a core pathological process in the majority of liver diseases, yet the genetic factors predisposing individuals to its initiation and progression remain poorly understood. Here we show that asialoglycoprotein receptor 1 (ASGR1), a lectin specifically expressed in the liver, is downregulated in patients with liver fibrosis or cirrhosis and male mice with liver injury. ASGR1 deficiency exacerbates while its overexpression mitigates acetaminophen-induced acute and CCl4-induced chronic liver injuries in male mice. Mechanistically, ASGR1 binds to an endoplasmic reticulum stress mediator GP73 and facilitates its lysosomal degradation. ASGR1 depletion increases circulating GP73 levels and promotes the interaction between GP73 and BIP to activate endoplasmic reticulum stress, leading to liver injury. Neutralization of GP73 not only attenuates ASGR1 deficiency-induced liver injuries but also improves survival in mice received a lethal dose of acetaminophen. Collectively, these findings identify ASGR1 as a potential genetic determinant of susceptibility to liver injury and propose it as a therapeutic target for the treatment of liver injury.


Assuntos
Acetaminofen , Fígado , Animais , Humanos , Masculino , Camundongos , Acetaminofen/toxicidade , Receptor de Asialoglicoproteína/genética , Receptor de Asialoglicoproteína/metabolismo , Estresse do Retículo Endoplasmático , Fibrose , Fígado/metabolismo , Cirrose Hepática/patologia
5.
Adv Mater ; : e2314084, 2024 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-38446383

RESUMO

Although colorectal cancer diagnosed at an early stage shows high curability, methods simultaneously possessing point-of-care testing ability and high sensitivity are limited. Here, an orally deliverable biomarker-activatable probe (termed as HATS) for early detection of orthotopic tumors via remote urinalysis is presented. To enable its oral delivery to the colon, HATS is designed to have remarkable resistance to acidity and digestive enzymes in the stomach and small intestine and negligible intestinal absorption. Upon reaction with a cancer biomarker in the colon segment, HATS releases a small fragment of tetrazine that can transverse the intestinal barrier, enter blood circulation, and ultimately undergo renal clearance to urine. Subsequently, the urinary tetrazine fragment is detected by bioorthogonal reaction with trans-cyclooctene-caged resorufin (TCO-Reso) to afford a rapid and specific fluorescence enhancement of TCO-Reso. Such signal readout is correlated with the urinary tetrazine concentration and thus measures the level of cancer biomarkers in the colon. HATS-based optical urinalysis detects orthotopic colon tumors two weeks earlier than clinical serological tests and can be developed to a point-of-care paper test. Thereby, HATS-based urinalysis provides a non-invasive and sensitive approach to cancer screening at low-resource settings.

6.
Exp Ther Med ; 27(4): 157, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38476896

RESUMO

In humans, gut microbiota can determine the health status. The regulatory mechanisms of the gut microbiota in asthma must be elucidated. Although antibiotics (ABXs) can clear infections, they markedly alter the composition and abundance of gut microbiota. The present study used ABX-treated mice to examine the time-dependent effects of ABX administration on the gut microbiota and intestinal mucosal barrier. The mouse asthma model was established using ovalbumin (OVA) and gavaged with an ABX cocktail for different durations (1 or 2 weeks) and stacked sequences. The pathology of the model, model 2, OVA-ABX, OVA-ABX 2, ABX-OVA and ABX-OVA was severe when compared with the control group as evidenced by the following results: i) significantly increased pulmonary and colonic inflammatory cell infiltration; ii) enhanced pause values and iii) OVA-induced immunoglobulin E (IgE) and TGF-ß expression levels, and significantly downregulated Tight Junction Protein 1 (TJP1), claudin 1 and Occludin expression levels. Furthermore, the intestinal bacterial load in the OVA-ABX and OVA-ABX 2 groups was significantly lower than that in the ABX-OVA and ABX-OVA 2 groups, respectively. The predominant taxa were as follows: phyla, Firmicutes and Proteobacteria, genera, Escherichia-Shigella, Lactobacillus and Lachnospira. The abundances of Lachnospira and Escherichia-Shigella were correlated with the expression of OVA-induced IgE and TJPs. These findings indicated that ABX administration, which modifies microbiome diversity and bacterial abundance, can disrupt colonic integrity, downregulate TJ proteins, damage the intestinal barrier, enhance enterocyte permeability, and promote the release of inflammatory factors, adversely affecting asthma alleviation and long-term repair.

7.
Small ; : e2311204, 2024 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-38459801

RESUMO

Constructing a flexible and chemically stable multifunctional layer for the lithium (Li) metal anodes is a highly effective approach to improve the uneven deposition of Li+ and suppress the dendrite growth. Herein, an organic protecting layer of polythiophene is in situ polymerized on the Li metal via plasma polymerization. Compared with the chemically polymerized thiophene (C-PTh), the plasma polymerized thiophene layer (P-PTh), with a higher Young's modulus of 8.1 GPa, shows strong structural stability due to the chemical binding of the polythiophene and Li. Moreover, the nucleophilic C─S bond of polythiophene facilitates the decomposition of Li salts in the electrolytes, promoting the formation of LiF-rich solid electrolyte interface (SEI) layers. The synergetic effect of the rigid LiF as well as the flexible PTh-Li can effectively regulate the uniform Li deposition and suppress the growth of Li dendrites during the repeated stripping-plating, enabling the Li anodes with long-cycling lifespan over 8000 h (1 mA cm-2 , 1 mAh cm-2) and 2500 h (10 mA cm-2 , 10 mAh cm-2 ). Since the plasma polymerization is facile (5-20 min) and environmentally friendly (solvent-free), this work offers a novel and promising strategy for the construction of the forthcoming generation of high-energy-density batteries.

8.
Biomed Pharmacother ; 174: 116489, 2024 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-38513595

RESUMO

Maximakinin (MK), a homolog of bradykinin (BK), is extracted from skin venom of the Chinese toad Bombina maxima. Although MK has a good antihypertensive effect, its effect on myocardial cells is unclear. This study investigates the protective effect of MK on hydrogen peroxide (H2O2)-induced oxidative damage in rat cardiac H9c2 cells and explores its mechanism of action. A 3-(4,5-Dimethyl-2-Thiazolyl)-2,5-Diphenyl Tetrazolium Bromide (MTT) assay was selected to detect the effect of MK on H9c2 cell viability, while flow cytometry was used to investigate the influence of MK and H2O2 on intracellular reactive oxygen species (ROS) levels. Protein expression changes were detected by western blot. In addition, specific protein inhibitors were applied to confirm the induction of ROS-related signaling pathways by MK. MTT assay results show that MK significantly reversed H2O2-induced cell growth inhibition. Flow cytometry Dichlorodihydrofluorescein diacetate (DCFH-DA) staining shows that MK significantly reversed H2O2-induced increases in intracellular ROS production in H9c2 cells. Moreover, the addition of specific protein inhibitors suggests that MK reverses H2O2-induced oxidative damage by activating AMP-activated protein kinase (AMPK)/protein kinase B (Akt) and AMPK/extracellular-regulated kinase 1/2 (ERK1/2) pathways. Finally, an inhibitor of bradykinin B2 receptors (B2Rs), HOE-140, was applied to investigate potential targets of MK in H9c2 cells. HOE-140 significantly blocked induction of AMPK/Akt and AMPK/ERK1/2 pathways by MK, suggesting a potentially important role for B2Rs in MK reversing H2O2-induced oxidative damage. Above all, MK protects against oxidative damage by inhibiting H2O2-induced ROS production in H9c2 cells. The protective mechanism of MK may be achieved by activation of B2Rs to activate downstream AMPK/Akt and AMPK/ERK1/2 pathways.

9.
Materials (Basel) ; 17(6)2024 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-38541451

RESUMO

The effect of extrusion on the microstructure, mechanical property, corrosion behavior, and in vitro biocompatibility of as-cast Mg-1.5Zn-1.2Y-0.1Sr (wt.%) alloy was investigated via tensile tests, electrochemical methods, immersion tests, methylthiazolyl diphenyltetrazolium bromide (MTT), and analytical techniques. Results showed that the as-cast and as-extruded Mg-1.5Zn-1.2Y-0.1Sr alloys comprised an α-Mg matrix and Mg3Y2Zn3 phase (W-phase). In the as-cast alloy, the W-phase was mainly distributed at the grain boundaries, with a small amount of W-phase in the grains. After hot extrusion, the W-phase was broken down into small particles that were dispersed in the alloy, and the grains were refined considerably. The as-extruded alloy exhibited appropriate mechanical properties that were attributed to refinement strengthening, dispersion strengthening, dislocation strengthening, and precipitation strengthening. The as-cast and as-extruded alloys exhibited galvanic corrosion between the W-phase and α-Mg matrix as the main corrosion mechanism. The coarse W-phase directly caused the poor corrosion resistance of the as-cast alloy. The as-extruded alloy obtained via hydrogen evolution and mass loss had corrosion rates of less than 0.5 mm/year. MTT, high-content screening (HCS) analysis, and cell adhesion tests revealed that the as-extruded alloy can improve L929 cell viability and has great potential in the field of biomedical biodegradable implant materials.

10.
Zhen Ci Yan Jiu ; 49(2): 164-170, 2024 Feb 25.
Artigo em Inglês, Chinês | MEDLINE | ID: mdl-38413037

RESUMO

OBJECTIVES: To observe the effects of the local stimulation with 3 acupuncture techniques, i.e. Canggui Tanxue (needle insertion method like dark tortoise detecting point) technique, electroacupuncture (EA) and warm needling (WN) with filiform needles on shoulder pain, shoulder joint function, quality of life, inflammatory indicators and recurrence rate in the patients with chronic scapulohumeral periarthritis (CSP), so as to explore the optimal needling method of acupuncture for the predominant symptoms of CSP during the attack stage in the patients. METHODS: A total of 108 patients with CSP were randomly divided into a manual acupuncture (MA) group (36 cases, one case dropped off), a WN group (36 cases, 3 cases dropped off) and an EA group (36 cases, 1 case dropped off). In the three groups, Jianqian (EX-UE12), Jianyu (LI15), Jianzhen (SI9), Ashi (Extra) and Yanglingquan (GB34) on the affected side were selected. Canggui Tanxue needling technique, WN technique and EA were delivered in the MA group, the WN group and the EA group, respectively, 30 min each time, 3 times weekly for 4 weeks. The Neer test scores were compared;the visual analogue scale (VAS) was used to assess the degree of shoulder joint pain;the daily life activity abilities was evaluated using the activities of daily living (ADL) scale;the serum prostaglandin E2 (PGE2) content was measured using ELISA before and after treatment. The effectiveness rate and recurrence rate were calculated, and the occurrences of adverse reactions were recorded. RESULTS: Compared with the scores before treatment, the scores of pain, joint function, and range of motion as well as the total score of Neer test were all increased after treatment in the three groups (P<0.05);the VAS score, ADL score and the content of serum PGE2 were decreased (P<0.05). After treatment, the pain score of Neer test in the EA group and the WN group were higher than those of the MA group (P<0.05), the joint function score of Neer test in the MA group and the WN group were higher than that of the EA group (P<0.05), and the range of motion score of Neer test in the MA group was higher when compared with the EA and WN groups (P<0.05). There was no statistical difference in the total score of Neer score among the three groups. VAS score in the EA group was lower than that of either the WN group or the MA group (P<0.05). ADL score in the MA group was lower compared with that of the WN group (P<0.05). PGE2 levels in both the WN group and the MA group were lower than that of the EA group (P<0.05). The total effective rate was 85.71% (30/35) in the MA group, 91.43% (32/35) in the EA group and 90.91% (30/33) in the WN group, there was no statistical differences among the three groups. At the end of the 6-month follow-up visit after treatment, there was no significant difference in the recurrence rate among three groups. No serious adverse reaction was found. CONCLUSIONS: In the treatment of CSP, the short-term effect is equivalent among EA, WN and MA. But, the analgesic effect is the best in the EA group, the treatment for anti-inflammation is the most effective in the MA and WN groups, and the needling technique of Canggui Tanxue in the MA group obtains the most favorable effect of releasing adhesion and recovering the range of motion in the shoulder joint.


Assuntos
Terapia por Acupuntura , Periartrite , Humanos , Periartrite/terapia , Atividades Cotidianas , Dinoprostona , Qualidade de Vida , Pontos de Acupuntura , Dor de Ombro/terapia , Resultado do Tratamento
12.
Adv Mater ; : e2400263, 2024 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-38412289

RESUMO

Low-cost and nontoxic deep eutectic liquid electrolytes (DELEs), such as [AlCl3 ]1.3 [Urea] (AU), are promising for rechargeable non-aqueous aluminum metal batteries (AMBs). However, their high viscosity and sluggish ion transport at room temperature lead to high cell polarization and low specific capacity, limiting their practical application. Herein, non-solvating 1,2-difluorobenzene (dFBn) is proposed as a co-solvent of DELEs using AU as model to construct a locally concentrated deep eutectic liquid electrolyte (LC-DELE). dFBn effectively improves the fluidity and ion transport without affecting the ionic dynamics in the electrolyte. Moreover, dFBn also modifies the solid electrolyte interphase growing on the aluminum metal anodes and reduces the interfacial resistance. As a result, the lifespan of Al/Al cells is improved from 210 to 2000 h, and the cell polarization is reduced from 0.36 to 0.14 V at 1.0 mA cm-2 . The rate performance of Al-graphite cells is greatly improved with a polarization reduction of 0.15 and 0.74 V at 0.1 and 1 A g-1 , respectively. The initial discharge capacity of Al-sulfur cells is improved from 94 to 1640 mAh g-1 . This work provides a feasible solution to the high polarization of AMBs employing DELEs and a new path to high-performance low-cost AMBs.

13.
Proc Natl Acad Sci U S A ; 121(8): e2316749121, 2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38349878

RESUMO

We investigate the moiré band structures and the strong correlation effects in twisted bilayer MoTe[Formula: see text] for a wide range of twist angles, employing a combination of various techniques. Using large-scale first-principles calculations, we pinpoint realistic continuum modeling parameters, subsequently deriving the maximally localized Wannier functions for the top three moiré bands. Simplifying our model with reasonable assumptions, we obtain a minimal two-band model, encompassing Coulomb repulsion, correlated hopping, and spin exchange. Our minimal interaction models pave the way for further exploration of the rich many-body physics in twisted MoTe[Formula: see text]. Furthermore, we explore the phase diagrams of the system through Hartree-Fock approximation and exact diagonalization (ED). Our two-band ED analysis underscores significant band-mixing effects in this system, which enlarge the optimal twist angle for fractional quantum anomalous Hall states.

14.
Food Chem ; 446: 138776, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-38417283

RESUMO

Chloropropanols are among the major food contaminants, and quantifying their content in food is a key food-safety issue. In response to the demand for highly sensitive and selective analysis, the scientific community is committed to continuous innovation and optimization of various analytical techniques. This paper comprehensively reviews the latest developments in chloropropanol analysis technologies and systematically compares and analyzes the working principles, application conditions, advantages, and challenges of these methods. Gas chromatography-mass spectrometry is the preferred choice for chloropropanol analysis in complex sample matrices owing to its high resolution, sensitivity, and accuracy. Electrochemical methods provide strong support for the real-time monitoring of chloropropanols because of their high selectivity and sensitivity towards electrochemically active molecules. Other techniques offer innovative solutions for the rapid and accurate analysis of chloropropanol at different levels. Finally, innovative directions for the development of chloropropanol analysis methods for food safety are highlighted.


Assuntos
Inocuidade dos Alimentos , Alimentos , Cromatografia Gasosa-Espectrometria de Massas/métodos
15.
Mol Biotechnol ; 2024 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-38305844

RESUMO

Aptamers, as a kind of small-molecule nucleic acid, have attracted much attention since their discovery. Compared with biological reagents such as antibodies, aptamers have the advantages of small molecular weight, low immunogenicity, low cost, and easy modification. At present, aptamers are mainly used in disease biomarker discovery, disease diagnosis, treatment, and targeted drug delivery vectors. In the process of screening and optimizing aptamers, it is found that there are still many problems need to be solved such as the design of the library, optimization of screening conditions, the truncation of screened aptamer, and the stability and toxicity of the aptamer. In recent years, the incidence of liver-related diseases is increasing year by year and the treatment measures are relatively lacking, which has attracted the people's attention in the application of aptamers in liver diseases. This article mainly summarizes the research status of aptamers in disease diagnosis and treatment, especially focusing on the application of aptamers in liver diseases, showing the crucial significance of aptamers in the diagnosis and treatment of liver diseases, and the use of Discovery Studio software to find the binding target and sequence of aptamers, and explore their possible interaction sites.

16.
Environ Sci Atmos ; 4(2): 265-274, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38371605

RESUMO

Aerosols formed and grown by gas-to-particle processes are a major contributor to smog and haze in megacities, despite the competition between growth and loss rates. Rapid growth rates from ammonium nitrate formation have the potential to sustain particle number in typical urban polluted conditions. This process requires supersaturation of gas-phase ammonia and nitric acid with respect to ammonium nitrate saturation ratios. Urban environments are inhomogeneous. In the troposphere, vertical mixing is fast, and aerosols may experience rapidly changing temperatures. In areas close to sources of pollution, gas-phase concentrations can also be highly variable. In this work we present results from nucleation experiments at -10 °C and 5 °C in the CLOUD chamber at CERN. We verify, using a kinetic model, how long supersaturation is likely to be sustained under urban conditions with temperature and concentration inhomogeneities, and the impact it may have on the particle size distribution. We show that rapid and strong temperature changes of 1 °C min-1 are needed to cause rapid growth of nanoparticles through ammonium nitrate formation. Furthermore, inhomogeneous emissions of ammonia in cities may also cause rapid growth of particles.

17.
BMC Public Health ; 24(1): 491, 2024 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-38365682

RESUMO

BACKGROUND: This study examined the relationship between loneliness and bedtime procrastination among Chinese university students, the mediating effects of COVID-19 risk perception and self-regulatory fatigue, and connectedness to nature's protective role, post pandemic. METHODS: We recruited 855 students to complete the Loneliness, Perceived Risk of COVID-19 Pandemic, Self-Regulatory Fatigue, Bedtime Procrastination, and Connectedness to Nature Scales. Data for descriptive statistics, correlation analysis, and moderated chain mediation effects were analyzed using SPSS 24.0 and process 3.5 macros. RESULTS: Loneliness positively correlated with bedtime procrastination, COVID-19 risk perception mediated the impact of loneliness on bedtime procrastination, self-regulatory fatigue mediated the effect of loneliness on bedtime procrastination, and COVID-19 risk perception and self-regulatory fatigue mediated the effect between loneliness and bedtime procrastination. Furthermore, connectedness to nature mediated the impact of COVID-19 risk perception on self-regulatory fatigue. CONCLUSIONS: The results indicate the effects and potential mechanisms of loneliness on bedtime procrastination after the relaxation of the pandemic prevention and control policy in China from the perspective of self-regulatory resources and provide insights into improving university students' sleep routine and mental health post pandemic.


Assuntos
COVID-19 , Procrastinação , Humanos , Solidão , Pandemias , Universidades , COVID-19/epidemiologia , Fadiga , Estudantes
18.
Environ Int ; 184: 108477, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38340406

RESUMO

Nickel, a common environmental hazard, is a risk factor for craniosynostosis. However, the underlying biological mechanism remains unclear. Here, we found that early-life nickel exposure induced craniosynostosis in mice. In vitro, nickel promoted the osteogenic differentiation of human mesenchymal stem cells (hMSCs), and its osteogenic ability in vivo was confirmed by an ectopic osteogenesis model. Further mRNA sequencing showed that ERK1/2 signaling and FGFR2 were aberrantly activated. FGFR2 was identified as a key regulator of ERK1/2 signaling. By promoter methylation prediction and methylation-specific PCR (MSP) assays, we found that nickel induced hypomethylation in the promoter of FGFR2, which increased its binding affinity to the transcription factor Sp1. During pregnancy and postnatal stages, AZD4547 rescued nickel-induced craniosynostosis by inhibiting FGFR2 and ERK1/2. Compared with normal individuals, nickel levels were increased in the serum of individuals with craniosynostosis. Further logistic and RCS analyses showed that nickel was an independent risk factor for craniosynostosis with a nonlinear correlation. Mediated analysis showed that FGFR2 mediated 30.13% of the association between nickel and craniosynostosis risk. Collectively, we demonstrate that early-life nickel exposure triggers the hypomethylation of FGFR2 and its binding to Sp1, thereby promoting the osteogenic differentiation of hMSCs by ERK1/2 signaling, leading to craniosynostosis.


Assuntos
Craniossinostoses , Sistema de Sinalização das MAP Quinases , Feminino , Gravidez , Camundongos , Humanos , Animais , Sistema de Sinalização das MAP Quinases/fisiologia , Níquel/toxicidade , Osteogênese , Craniossinostoses/genética , Transdução de Sinais , Receptor Tipo 2 de Fator de Crescimento de Fibroblastos
19.
Joint Bone Spine ; 91(3): 105698, 2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-38309518

RESUMO

OBJECTIVE: Hyperuricaemia is necessary for gout. High urate concentrations have been linked to inflammation in mononuclear cells. Here, we explore the role of the suppressor of cytokine signaling 3 (SOCS3) in urate-induced inflammation. METHODS: Peripheral blood mononuclear cells (PBMCs) from gout patients, hyperuricemic and normouricemic individuals were cultured for 24h with varying concentrations of soluble urate, followed by 24h restimulation with lipopolysaccharides (LPS)±monosodium urate (MSU) crystals. Transcriptomic profiling was performed using RNA-Sequencing. DNA methylation was assessed using Illumina Infinium® MethylationEPIC BeadChip system (EPIC array). Phosphorylation of signal transducer and activator of transcription 3 (STAT3) was determined by flow cytometry. Cytokine responses were also assessed in PBMCs from patients with JAK2 V617F tyrosine kinase mutation. RESULTS: PBMCs pre-treated with urate produced more interleukin-1beta (IL-1ß) and interleukin-6 (IL-6) and less interleukin-1 receptor anatagonist (IL-1Ra) after LPS simulation. In vitro, urate treatment enhanced SOCS3 expression in control monocytes but no DNA methylation changes were observed at the SOCS3 gene. A dose-dependent reduction in phosphorylated STAT3 concomitant with a decrease in IL-1Ra was observed with increasing concentrations of urate. PBMCs with constitutively activated STAT3 (JAK2 V617F mutation) could not be primed by urate. CONCLUSION: In vitro, urate exposure increased SOCS3 expression, while urate priming, and subsequent stimulation resulted in decreased STAT3 phosphorylation and IL-1Ra production. There was no evidence that DNA methylation constitutes a regulatory mechanism of SOCS3. Elevated SOCS3 and reduced pSTAT3 could play a role in urate-induced hyperinflammation since urate priming had no effect in PBMCs from patients with constitutively activated STAT3.

20.
Proc Inst Mech Eng H ; 238(2): 115-131, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38314788

RESUMO

Deep learning approaches for tooth segmentation employ convolutional neural networks (CNNs) or Transformers to derive tooth feature maps from extensive training datasets. Tooth segmentation serves as a critical prerequisite for clinical dental analysis and surgical procedures, enabling dentists to comprehensively assess oral conditions and subsequently diagnose pathologies. Over the past decade, deep learning has experienced significant advancements, with researchers introducing efficient models such as U-Net, Mask R-CNN, and Segmentation Transformer (SETR). Building upon these frameworks, scholars have proposed numerous enhancement and optimization modules to attain superior tooth segmentation performance. This paper discusses the deep learning methods of tooth segmentation on dental panoramic radiographs (DPRs), cone-beam computed tomography (CBCT) images, intro oral scan (IOS) models, and others. Finally, we outline performance-enhancing techniques and suggest potential avenues for ongoing research. Numerous challenges remain, including data annotation and model generalization limitations. This paper offers insights for future tooth segmentation studies, potentially facilitating broader clinical adoption.


Assuntos
Aprendizado Profundo , Dente , Dente/diagnóstico por imagem , Redes Neurais de Computação , Imageamento Tridimensional/métodos , Tomografia Computadorizada de Feixe Cônico , Processamento de Imagem Assistida por Computador/métodos
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