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1.
Spectrochim Acta A Mol Biomol Spectrosc ; 324: 124957, 2025 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-39154401

RESUMO

Hydrogen sulfide (H2S) has a comprehensive contribution to the normal operation and stability of organisms and is also present in environmental water samples and food deterioration. Thus, it is exceedingly promising and significant to develop a highly sensitive detection technique for tracing H2S. Inspired by this, we designed and synthesized a new fluorescent probe 2-[3-[2-[3-bromo-4-(2,4- dinitrobenzenesulfonate)] ethenyl]-5,5-dimethyl-2-cyclohexen-1-ylidene]propanedinitrile (SP-Br) for hydrosulfide ion detection by introducing bromine atom. Compared with reported H2S probes based on the same fluorescent parent, SP-Br has longer fluorescence emission (λem = 670 nm), shorter response time (3 min), lower detection limit (149 nM), and wider detection range (0-30 nM). SP-Br can emit weak yellow fluorescence, and the emission intensity at 670 nm is considerably enhanced in the presence of hydrosulfide ions. The identification mechanism of hydrosulfide ion by SP-Br was verified by high-resolution mass spectrometry, fluorescence, and UV-vis absorption spectroscopy. In addition, SP-Br has been successfully applied to the monitoring of actual water samples and beer samples and has certain development prospects and value in the fields of environmental pollution and food quality analysis.

2.
Artigo em Inglês | MEDLINE | ID: mdl-39363551

RESUMO

Optimizing the balance between thermodynamic interaction and kinetic diffusion is pivotal to obtaining high-performance gas chromatographic stationary phases. Here, three aluminum-based metal-organic frameworks featuring fym topology were chosen to achieve such balance by refined controlling the thermodynamic interactions toward analytes at angstrom level in a confined space. The CAU-10-H with the middle-sized channels (5.4 Å) provided weak interactions with xylenes because of the benzene ring around the channel, leading to the fastest diffusion. While the MIL-160 provided stronger interactions toward the analytes due to the abundance of O-heterocyclic sites of 2,5-furandicarboxylic acid ligands, resulting in slightly higher diffusion barriers. Thereby, although MIL-160 had a larger channel (5.9 Å) than CAU-10-H, the xylenes still diffused more slowly in MIL-160 than in CAU-10-H. The CAU-10-NH2 with the channel of 4.7 Å provided overstrong thermodynamic interactions and significant stereospecific blockade to the analytes because of the NH2 sites in the confined channels. These factors collectively contributed to achieving the lowest diffusion kinetics. The confined interactions were also proved by molecular dynamics simulation. Furthermore, the application indicated that MIL-160 exhibited the highest separation ability as a GC stationary phase among all reported materials. This strategy offers an approach for developing high-performance MOF stationary phases.

3.
Inorg Chem ; 2024 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-39373102

RESUMO

Electrochemical reduction of CO2 into high-value-added products is a potential approach to solving environmental problems but is limited by poor product selectivity and low efficiency. Metal-organic framework (MOF) materials have been considered one of the most promising catalysts, but their application is limited by complicated preparation processes, especially during the synthesis of organic ligands. In this work, a new three-dimensional Cu-MOF (JXUST-301) with high porosity was constructed based on the naphthalene diimide (NDI) ligand. Furthermore, JXUST-301 with ligand defects (JXUST-301D) originating from the missing NDI unit was synthesized via an in situ reaction. The presence of ligand defects endows JXUST-301D with a better CO2RR performance with a FEC2 of 56.7% and a jC2 of -162.4 mA cm-2. Mechanistic studies revealed that the hierarchical pore structure and amino sites are created from the absence of the NDI unit, which promotes the exposure of catalytically active sites and CO2 enrichment. Furthermore, the electronic structure of the Cu sites is modulated to upshift the d-band center, facilitating chemical adsorption and activation of key reaction intermediates. This work provides new insight into the in situ preparation of efficient Cu-MOF catalysts by introducing defects for the CO2RR.

4.
Nutrients ; 16(17)2024 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-39275195

RESUMO

The causal association of circulating metabolites with dementia remains uncertain. We assessed the causal association of circulating metabolites with dementia utilizing Mendelian randomization (MR) methods. We performed univariable MR analysis to evaluate the associations of 486 metabolites with dementia, Alzheimer's disease (AD), and vascular dementia (VaD) risk. For secondary validation, we replicated the analyses using an additional dataset with 123 metabolites. We observed 118 metabolites relevant to the risk of dementia, 59 of which were lipids, supporting the crucial role of lipids in dementia pathogenesis. After Bonferroni adjustment, we identified nine traits of HDL particles as potential causal mediators of dementia. Regarding dementia subtypes, protective effects were observed for epiandrosterone sulfate on AD (OR = 0.60, 95% CI: 0.48-0.75) and glycoproteins on VaD (OR = 0.89, 95% CI: 0.83-0.95). Bayesian model averaging MR (MR-BMA) analysis was further conducted to prioritize the predominant metabolites for dementia risk, which highlighted the mean diameter of HDL particles and the concentration of very large HDL particles as the predominant protective factors against dementia. Moreover, pathway analysis identified 17 significant and 2 shared metabolic pathways. These findings provide support for the identification of promising predictive biomarkers and therapeutic targets for dementia.


Assuntos
Doença de Alzheimer , Biomarcadores , Demência , Análise da Randomização Mendeliana , Humanos , Demência/sangue , Demência/genética , Doença de Alzheimer/sangue , Doença de Alzheimer/genética , Biomarcadores/sangue , Fatores de Risco , Teorema de Bayes , Demência Vascular/sangue , Demência Vascular/genética , Masculino , Feminino
5.
Angew Chem Int Ed Engl ; : e202414005, 2024 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-39290051

RESUMO

A desymmetrizing 1,2-addition of silicon nucleophiles to biaryl derivatives containing an 2,6-dicarbaldehyde-1-yl unit is reported. The reaction is catalyzed by copper with a triazolium-derived N-heterocyclic carbene as the chiral ligand and an Si-B reagent as the silicon pronucleophile. The practical methodology furnishes axially chiral aromatic carbaldehydes decorated with a centrally chiral α-hydroxysilane moiety in moderate to high yields and with high enantio- as well as excellent diastereoselectivities. The silicon nucleophile always attacks at either carbonyl group away from the ortho substituent on the phenyl ring at C1 of the 2,6-dicarbaldehyde-1-yl fragment. The resulting axially and centrally chiral products can be further converted into valuable biaryl compounds with hardly any erosion of the enantiomeric excess.

6.
Chem Sci ; 2024 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-39290589

RESUMO

Controllable ß-carbon elimination to extrude norbornene remains a long-standing challenge in palladium and norbornene chemistry. Herein, this manuscript describes a switchable synthesis of biologically active C4-ethylaminoindole and C7-aminoindoline scaffolds by controlling ß-carbon elimination, utilizing aziridine as a C-H ethylamination reagent through a C-N bond cleavage reaction. Furthermore, the protecting groups of the product can be easily removed, offering an unusual method for the synthesis of dopamine receptor agonists.

7.
Zhongguo Zhong Yao Za Zhi ; 49(16): 4313-4320, 2024 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-39307768

RESUMO

This study aims to investigate the mechanism of Xueshuantong Injection(XST) on pulmonary fibrosis induced by bleomycin(BLM) in rats based on the coagulation cascade pathway. Sixty SD rats were randomly divided into sham surgery group,model group, pirfenidone(PFD, 50 mg·kg~(-1)) group, and 27, 54, and 81 mg·kg~(-1) XST groups. The rat model of pulmonary fibrosis was established by intratracheal injection of BLM(5 mg·kg~(-1)). After 24 hours, the administration groups were given corresponding drugs, while the sham surgery group and model group were given equal volumes of saline. On the 28th day, samples were collected,and the imaging and collagen fiber changes in the lungs of rats were observed. Immunofluorescence(IF) method was used to detect the expression level of alpha-smooth muscle actin(α-SMA), collagen Ⅰ(Col-Ⅰ), E-cadherin(E-cad), and vimentin(Vim). Western blot was used to determine the protein expression of α-SMA, Col-Ⅰ, Vim, and E-cad. Enzyme-linked immunosorbent assay(ELISA)was used to detect the levels of prothrombin fragment(F1 + 2), thrombin-antithrombin complex(TAT), soluble fibrin monomer complex(SFMC), and rat fibrinogen degradation products(FDP) in rat lung tissue. Finally, the mRNA and protein levels of protease activated receptor 1(PAR-1) were detected by RT-qPCR, western blot, and IF. Compared with the model group, the scanning of the lungs of rats receiving XST treatment also exhibited patchy and non-homogeneous shadows, but these shadows were less dense than those in the model group. At the same time, there was a significant decrease in Col-Ⅰ fibers in the lungs of rats, and XST could inhibit epithelial-mesenchymal transition(EMT) and downregulate α-SMA and Col-Ⅰ protein expression. In the aspect of the coagulation system, administration of 81 mg·kg~(-1) XST significantly reduced the levels of SFMC and FDP. Meanwhile, 81 mg·kg~(-1) XST significantly downregulated the mRNA and protein levels of PAR-1. XST has an anti-pulmonary fibrosis effect in rats, and its mechanism may be related to the downregulation of PAR-1 to rebalance the coagulation cascade pathway.


Assuntos
Bleomicina , Medicamentos de Ervas Chinesas , Fibrose Pulmonar , Ratos Sprague-Dawley , Animais , Fibrose Pulmonar/induzido quimicamente , Fibrose Pulmonar/metabolismo , Fibrose Pulmonar/tratamento farmacológico , Fibrose Pulmonar/genética , Bleomicina/efeitos adversos , Ratos , Medicamentos de Ervas Chinesas/administração & dosagem , Medicamentos de Ervas Chinesas/farmacologia , Masculino , Coagulação Sanguínea/efeitos dos fármacos , Pulmão/efeitos dos fármacos , Pulmão/metabolismo , Humanos , Actinas/metabolismo , Actinas/genética , Caderinas/genética , Caderinas/metabolismo , Colágeno Tipo I/metabolismo , Colágeno Tipo I/genética , Vimentina/metabolismo , Vimentina/genética , Injeções
8.
J Am Chem Soc ; 146(38): 26233-26242, 2024 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-39269922

RESUMO

The efficient synthesis of chiral macrocycles with highly enantioselective recognition remains a challenge. We have addressed this issue by synthesizing a pair of chiral macrocycles, namely, R/S-BINOL[2], achieving total isolated yields of up to 62% through a two-step reaction sequence. These macrocycles are readily purified by column chromatography over silica gel without the need for chiral separation, thus streamlining the overall synthesis. R/S-BINOL[2] demonstrated enantioselective recognition toward chiral ammonium salts, with enantioselectivity (KS/KR) values reaching up to 13.2, although less favorable separations were seen for other substrates. R/S-BINOL[2] also displays blue circularly polarized luminescence with a |glum| value of up to 2.2 × 10-3. The R/S-BINOL[2] macrocycles of this study are attractive as chiral hosts in that they both display enantioselective guest recognition and benefit from a concise, high-yielding synthesis. As such, they may have a role to play in chiral separations.

9.
Clin Oral Investig ; 28(10): 549, 2024 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-39317736

RESUMO

OBJECTIVES: To provide an overview of the features of patients with medication-related osteonecrosis of the jaw (MRONJ) and explore recurrence-related factors after surgery. MATERIALS AND METHODS: All pathological records of patients diagnosed with osteonecrosis or osteomyelitis of the jaw were reviewed. Only patients who had a history of use of medication related to bone turnover were included. All demographic and clinical characteristics were collected during review. Univariate and logistic regression analyses were performed to evaluate the associations between risk factors and recurrence. A p value < 0.05 was considered to indicate statistical significance in all analyses. RESULTS: A total of 313 patients were ultimately included. Most patients (89.14%) underwent bone turnover-related treatment due to malignancy. The breast and prostate were the most common locations of primary tumors in females and males, respectively. Almost all MRONJ patients experienced inflammatory symptoms. Recurrence occurred in 55 patients at 60 locations. The total recurrence rate was 16.85%, with no significant differences between the maxilla and mandible. Extensive surgery and flap transfer were strongly related to a lower recurrence risk. Nearly 80% of patients had recurrence-related symptoms within 6 months. CONCLUSION: When MRONJ is treated with surgical methods, extensive resection and flap transfer can reduce recurrence risk. Six-month follow-up is needed to exclude recurrence after surgery. CLINICAL RELEVANCE: This study revealed the surgical-related risk factors, such as extensive surgery and flap transfer, when treating MRONJ patients, and 6-month follow-up is needed to detect recurrence. This could provide clinical guidance for head and neck surgeons.


Assuntos
Osteonecrose da Arcada Osseodentária Associada a Difosfonatos , Recidiva , Humanos , Masculino , Feminino , Estudos Retrospectivos , Fatores de Risco , Osteonecrose da Arcada Osseodentária Associada a Difosfonatos/cirurgia , Pessoa de Meia-Idade , Idoso , Adulto , Idoso de 80 Anos ou mais , Retalhos Cirúrgicos
10.
J Chromatogr A ; 1736: 465382, 2024 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-39341169

RESUMO

Accurate determination of nanoplastics (NPs) in aquatic ecosystems constitutes a challenge for which highly sensitive analytical methods are necessitated. Herein, a sample pretreatment based on self-made amino-functionalized activated carbon fibers (ACFs-NH2) dispersive solid-phase extraction (DSPE) allows for high-recovery, followed by high-sensitivity detection of NPs by pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). The developed methodology allowed low detection limits (20-100 µg/L) to be achieved quickly in a few steps. Under optimal conditions, ACFs-NH2 (12.5 mg) was able to recover ≥98.45 % of polystyrene (PS) nanoplastics at high concentration (100 mg/L) in 10 mL seawater. Based on the high adsorption performance of materials, the adsorption dynamics and isotherms were determined to infer the interaction mechanism of PSNPs on ACFs-NH2. After adsorption, the target on the surface of the adsorbent can be directly pyrolyzed, which can simplify the operation steps and avoid the elution of organic solvents, making the process more environmentally friendly. This strategy is feasible for the analysis of trace NPs in water systems.

11.
BMC Endocr Disord ; 24(1): 208, 2024 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-39350103

RESUMO

BACKGROUND: Parathyroid adenoma is the primary cause of primary hyperparathyroidism, commonly presenting with elevated parathyroid hormone (PTH) and blood calcium levels. Chronic primary hyperparathyroidism often results in bone destruction, resulting in the formation of brown tumors. The preferred clinical treatment for parathyroid adenoma is parathyroidectomy. Postoperative pancytopenia, although rare, is a critical complication that warrants further investigation into its mechanisms and management strategies. CASE PRESENTATION: We present a case of a 59-year-old female patient who was admitted due to nausea and vomiting. Positron emission tomography-computed tomography (PET-CT) revealed a mass posterior to the left thyroid lobe and multiple areas of fibrocystic osteitis throughout the body. Hematological tests showed elevated serum calcium and parathyroid hormone (PTH) levels. The patient subsequently underwent parathyroidectomy, and pathological examination confirmed the presence of a parathyroid adenoma. Postoperatively, the patient developed pancytopenia and received symptomatic treatment such as correction of anemia and elevation of white blood. At the two-month follow-up, all indicators had returned to normal. CONCLUSIONS: Pancytopenia is commonly seen in bone marrow diseases, infections and immune-related disorders, nutritional deficiencies, and metabolic diseases. This case confirms that pancytopenia can also occur postoperatively in patients with parathyroid adenoma. Therefore, Clinicians should be aware of the potential for postoperative pancytopenia following parathyroidectomy and the need for prompt management.


Assuntos
Adenoma , Pancitopenia , Neoplasias das Paratireoides , Paratireoidectomia , Complicações Pós-Operatórias , Humanos , Feminino , Pancitopenia/etiologia , Neoplasias das Paratireoides/cirurgia , Neoplasias das Paratireoides/complicações , Neoplasias das Paratireoides/patologia , Pessoa de Meia-Idade , Adenoma/cirurgia , Adenoma/complicações , Adenoma/patologia , Complicações Pós-Operatórias/etiologia , Hiperparatireoidismo Primário/cirurgia , Hiperparatireoidismo Primário/complicações , Hiperparatireoidismo Primário/etiologia , Osteíte Fibrosa Cística/etiologia
12.
Neuroscience ; 560: 167-180, 2024 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-39293730

RESUMO

Previous studies have demonstrated the roles of both microglia homeostasis and RNA editing in sepsis-associated encephalopathy (SAE), yet their relationship remains to be elucidated. In this study, we analyzed bulk and single-cell RNA-seq (scRNA) datasets containing 107 brain tissue and microglia samples of mice with microglial depletion and repopulation to explore canonical RNA editing associated with microglia homeostasis and to evaluate its role in SAE. Analysis of brain RNA-Seq of mice revealed hallmarks of microglial repopulation, including peak expressions of Apobec1 and Apobec3 at Day 5 and dramatically changed B2m RNA editing. Significant time-dependent changes in brain RNA editing during microglial depletion and repopulation were primarily observed in synaptic genes, such as Tbc1d24 and Slc1a2. ScRNA-Seq revealed heterogeneous RNA editing among microglia subpopulations and their distinct changes associated with microglia homeostasis. Moreover, repopulated microglia from LPS-induced septic mice exhibited intensified up-regulation of Apobec1 and Apobec3, with distinct RNA editing responses to LPS, mainly involved in immune-related pathways. The hippocampus from septic mice induced by peritoneal contamination and infection showed upregulated Apobec1 and Apobec3 expression, and altered RNA editing in immune-related genes, such as B2m and Mier1, and nervous-related lncRNA Meg3 and Snhg11, both of which were repressed by microglial depletion. Furthermore, the expression of complement-related genes, such as C4b and Cd47, was substantially correlated with RNA editing activity in microglia homeostasis and SAE. Our study demonstrates canonical RNA editing associated with microglia homeostasis and provides new insights into its potential role in SAE.

13.
Eur J Med Res ; 29(1): 416, 2024 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-39138539

RESUMO

OBJECTIVE: In this study, we evaluated the efficacy and safety of 1 µg/kg dexmedetomidine as an adjuvant treatment to ropivacaine in children undergoing upper limb surgeries under ultrasound-guided axillary brachial plexus blocks and general anesthesia. METHODS: We enrolled 90 children (aged 1-8 years; ASA I-II) undergoing closed reduction and internal fixation for upper extremity fractures at the Xiamen Children's Hospital and randomly assigned them to one of two groups: L (injection with 0.25% ropivacaine) or D (injection with 0.25% ropivacaine containing 1 µg/kg dexmedetomidine) using the random number table method. The main outcome indicators recorded were the facial expression, leg activity, position, crying, and Face, Legs, Activity, Cry, and Consolability (FLACC) scale scores of children after surgery and the duration of block and analgesia maintenance. The secondary outcome indicators were vital sign data at the time of ultrasound probe placement (T1), at the time of block completion (T2), prior to the beginning of surgery (T3), 5 min after the beginning of surgery (T4), and at the end of surgery (T5), as well as the time of postoperative recovery, the number of cases of remedial analgesia, and complications. RESULTS: There was no statistical difference between the two groups in terms of general data, block completion time, postoperative recovery time, and complications (P > 0.05). Compared to the L group, the D group had significantly lower FLACC scores at 6 h after surgery, as well as significantly lower systolic blood pressure, diastolic blood pressure, and heart rate values at T4 and T5, and significantly longer duration of postoperative analgesia maintenance (all P < 0.05). CONCLUSION: Dexmedetomidine (1 µg/kg) as a local anesthetic adjuvant to ropivacaine can alleviate pain at 6 h postoperatively, prolong analgesia maintenance, and reduce intraoperative blood pressure and heart rate in pediatric patients undergoing closed reduction and internal fixation for upper extremity fractures, with no obvious complications or delayed recovery. CLINICAL REGISTRY NUMBER: Registration website: www.chictr.org.cn, Registration number: ChiCTR2200065163, Registration date: October, 30, 2022.


Assuntos
Bloqueio do Plexo Braquial , Dexmedetomidina , Ropivacaina , Humanos , Dexmedetomidina/administração & dosagem , Ropivacaina/administração & dosagem , Bloqueio do Plexo Braquial/métodos , Masculino , Feminino , Pré-Escolar , Criança , Lactente , Anestésicos Locais/administração & dosagem , Ultrassonografia de Intervenção/métodos , Dor Pós-Operatória/tratamento farmacológico , Dor Pós-Operatória/prevenção & controle , Plexo Braquial/diagnóstico por imagem , Plexo Braquial/efeitos dos fármacos
14.
Zhonghua Nan Ke Xue ; 30(6): 483-492, 2024 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-39212356

RESUMO

OBJECTIVE: To investigate the effect of exosomes loaded with Lycium barbarum miRNA (Lb-miR2911) on spermatogenic function recovery in non-obstructive azoospermia (NOA) rats through cross-regulation of the Wnt/ß-catenin signaling pathways. METHODS: We established an NOA model in 30 four-week-old male SD rats by intraperitoneal injection of busulfan. At 5 weeks after modeling, we equally randomized the rats into a model control group (MC,untreated), an Lb-miR2911EXO group (Lb-miR2911EXO ,treated by intratesticular injection of Lb-miR2911-loaded exosomes), and a sham group (Shame,treated by intratesticular injection of exosomes-empty drug), with another 10 male SD rats taken as normal controls(NC). We observed the uptake and metabolic changes of Lb-miR2911 in the testis tissue of the rats by RNA FISH at 2 and 6 weeks after treatment, detected cell proliferation, spermatogenesis and gene expressions of the Wnt/ß-catenin signaling pathways in the testis tissue by Transcriptome sequencing analysis combined with Western blot and RT-PCR at 12 weeks, evaluated the recovery of the spermatogenic function based on the testis tissue morphology and sperm quality, and assessed the organ toxicity of Lb-miR2911 in the tissue and organs of the rats based on histomorphological analysis and the levels of serum TNF-α, IL-1ß, Aspartate aminotransferase (AST), Alanine aminotransferase (ALT) and other relevant indicators. RESULTS: After 12 weeks of treatment, histomorphological analysis showed regular arrangement of spermatogenic cells at all levels in the testis tissue, with a large number of mature sperm in the tubular lumen, and with significantly higher Johnsen scores, testis weight, testicular index, sperm concentration and sperm motility in the Lb-miR2911EXO than in the sham group (all P< 0.05). Compared with the model controls, the Lb-miR2911EXO group exhibited remarkably down-regulated gene expression of DACT3 (P< 0.05), up-regulated expressions of DVL2 and ß-catenin (P< 0.05), elevated levels of p-DVL2 and ß-catenin (nucleus) proteins (P< 0.05), increased expressions of cell proliferation-related genes CCND1, CCNE1 and CCNE2 (P< 0.05) and spermatogenesis-related genes DMC1, CCR6, JAM2 and KLC3 (P< 0.05). No pathological changes were observed in the lung, liver and kidney tissues of the rats, or in the levels of serum TNF-α, IL-1ß, AST, ALT, creatinine and urea nitrogen in the rats treated with Lb-miR2911EXO compared with the normal controls (P > 0.05). CONCLUSION: Lb-miR2911-loaded exosomes promote spermatogenic function recovery in NOA rats through cross-regulation of the DACT3, Wnt and ß-catenin signaling pathways.


Assuntos
Azoospermia , Exossomos , MicroRNAs , Ratos Sprague-Dawley , Espermatogênese , Testículo , Via de Sinalização Wnt , Animais , Masculino , Ratos , MicroRNAs/genética , Exossomos/metabolismo , Azoospermia/genética , Azoospermia/metabolismo , Testículo/metabolismo , beta Catenina/metabolismo , Modelos Animais de Doenças , Proliferação de Células
15.
Polymers (Basel) ; 16(16)2024 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-39204577

RESUMO

The insulation of high-voltage direct-current (HVDC) cables experiences a short period of voltage polarity reversal when the power flow is adjusted, leading to sever field distortion in this situation. Consequently, improving the insulation performance of the composite insulation structure in these cables has become an urgent challenge. In this paper, SiC-SR (silicone rubber) and TiO2-SR nanocomposites were chosen for fabricating HVDC cable accessories. These nanocomposites were prepared using the solution blending method, and an electro-acoustic pulse (PEA) space charge test platform was established to explore the electron transfer mechanism. The space charge characteristics and field strength distribution of a double-layer dielectric composed of cross-linked polyethylene (XLPE) and nano-composite SR at different concentrations were studied during voltage polarity reversal. Additionally, a self-built breakdown platform for flake samples was established to explore the effect of the nanoparticle doping concentration on the breakdown field strength of double-layer composite media under polarity reversal. Therefore, a correlation was established between the micro electron transfer process and the macro electrical properties of polymers (XLPE/SR). The results show that optimal concentrations of nano-SiC and TiO2 particles introduce deep traps in the SR matrix, significantly inhibiting charge accumulation and electric field distortion at the interface, thereby effectively improving the dielectric strength of the double-layer polymers (XLPE/SR).

16.
Front Neurosci ; 18: 1435185, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39156629

RESUMO

Introduction: The activation of cerebral endothelial cells (CECs) has recently been reported to be the earliest acute neuroinflammation event in the CNS during sepsis-associated encephalopathy (SAE). Importantly, adenosine-to-inosine (A-to-I) RNA editing mediated by ADARs has been associated with SAE, yet its role in acute neuroinflammation in SAE remains unclear. Methods: Our current study systematically analyzed A-to-I RNA editing in cerebral vessels, cerebral endothelial cells (CECs), and microglia sampled during acute neuroinflammation after treatment in a lipopolysaccharide (LPS)-induced SAE mouse model. Results: Our results showed dynamic A-to-I RNA editing activity changes in cerebral vessels during acute neuroinflammation. Differential A-to-I RNA editing (DRE) associated with acute neuroinflammation were identified in these tissue or cells, especially missense editing events such as S367G in antizyme inhibitor 1 (Azin1) and editing events in lincRNAs such as maternally expressed gene 3 (Meg3), AW112010, and macrophage M2 polarization regulator (Mm2pr). Importantly, geranylgeranyl diphosphate synthase 1 (Ggps1) and another three genes were differentially edited across cerebral vessels, CECs, and microglia. Notably, Spearman correlation analysis also revealed dramatic time-dependent DRE during acute neuroinflammation, especially in GTP cyclohydrolase1 (Gch1) and non-coding RNA activated by DNA damage (Norad), both with the editing level positively correlated with both post-LPS treatment time and edited gene expression in cerebral vessels and CECs. Discussion: The findings in our current study demonstrate substantial A-to-I RNA editing changes during acute neuroinflammation in SAE, underlining its potential role in the disease.

17.
Soft Matter ; 20(33): 6635-6647, 2024 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-39109438

RESUMO

Rapid adsorption of surfactants onto a freshly formed interface is vital for emulsification because emulsification is a competitive process occurring between the very short time span of interface formation and surfactant mass transport. The biosurfactant surfactin has been previously reported to reach adsorption equilibrium at the hydrophobic/hydrophilic interface within hundreds of milliseconds and rapidly reduce the interfacial tension compared to chemically synthesized surfactants. According to a prior study, surfactin is expected to exhibit good performance in stabilizing micro-droplets of oil within the aging time scale of milliseconds. Herein, the stabilities of micro-droplets of n-hexadecane in the presence of a biosurfactant, surfactin (C15-SFT), and a chemically synthesized surfactant, sodium cetyl benzene sulfonate (8-SCBS), were investigated using a microfluidic method. The coalescence frequency of micro-droplets, the evolution of micro-droplet size, and the coalescence time of micro-droplets were evaluated. The results indicated that C15-SFT exhibited superiority over 8-SCBS in stabilizing the micro-droplets of n-hexadecane. Biosurfactant C15-SFT effectively reduced the fusion probability between oil droplets and elongated the coalescence time compared to 8-SCBS, and these phenomena were obvious at a shorter aging time (150 ms) and lower surfactant concentration (0.1 × critical micelle concentration). The stabilities of micro-droplets increased with aging time and the bulk concentration of surfactants. Stable micro-droplets of n-hexadecane were formed in 1 × 10-4 mol L-1 C15-SFT solution at 600 ms aging time, and the bulk concentration was 1 × 10-3 mol L-1 in the case of 8-SCBS. The micro-droplets rarely coalesced in the presence of 1 × 10-4 mol L-1 C15-SFT after 600 ms aging time, but the micro-droplets in 1 × 10-4 mol L-1 8-SCBS coalesced frequently in the midstream and downstream of the coalescence chamber, and big droplets were dominant in the emulsion. The coalescence time of micro-droplets stabilized by C15-SFT was obviously longer than that of those stabilized by 8-SCBS under the same condition, indicating that the interfacial film formed by C15-SFT has much strength to resist coalescence during collisions. This work is helpful for understanding the activity of lipopeptides in the very short early stage of the emulsification process, laying the foundation for biosurfactant research in the fields of enhanced oil recovery, bioremediation of contaminated water or soil, etc.

18.
J Med Virol ; 96(8): e29882, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39185672

RESUMO

Establishing reliable noninvasive tools to precisely diagnose clinically significant liver fibrosis (SF, ≥F2) remains an unmet need. We aimed to build a combined radiomics-clinic (CoRC) model for triaging SF and explore the additive value of the CoRC model to transient elastography-based liver stiffness measurement (FibroScan, TE-LSM). This retrospective study recruited 595 patients with biopsy-proven liver fibrosis at two centers between January 2015 and December 2021. At Center 1, the patients before December 2018 were randomly split into training (276) and internal test (118) sets, the remaining were time-independent as a temporal test set (96). Another data set (105) from Center 2 was collected for external testing. Radiomics scores were built with selected features from Deep learning-based (ResUNet) automated whole liver segmentations on MRI (T2FS and delayed enhanced-T1WI). The CoRC model incorporated radiomics scores and relevant clinical variables with logistic regression, comparing routine approaches. Diagnostic performance was evaluated by the area under the receiver operating characteristic curve (AUC). The additive value of the CoRC model to TE-LSM was investigated, considering necroinflammation. The CoRC model achieved AUCs of 0.79 (0.70, 0.86), 0.82 (0.73, 0.89), and 0.81 (0.72-0.91), outperformed FIB-4, APRI (all p < 0.05) in the internal, temporal, and external test sets and maintained the discriminatory power in G0-1 subgroups (AUCs range, 0.85-0.86; all p < 0.05). The AUCs of joint CoRC-LSM model were 0.86 (0.79-0.94), and 0.81 (0.72-0.90) in the internal and temporal sets (p = 0.01). The CoRC model was useful for triaging SF, and may add value to TE-LSM.


Assuntos
Técnicas de Imagem por Elasticidade , Cirrose Hepática , Fígado , Imageamento por Ressonância Magnética , Humanos , Cirrose Hepática/diagnóstico por imagem , Cirrose Hepática/diagnóstico , Masculino , Feminino , Pessoa de Meia-Idade , Estudos Retrospectivos , Imageamento por Ressonância Magnética/métodos , Adulto , Técnicas de Imagem por Elasticidade/métodos , Fígado/patologia , Fígado/diagnóstico por imagem , Curva ROC , Aprendizado Profundo , Idoso , Triagem/métodos
19.
J Am Chem Soc ; 146(36): 25361-25370, 2024 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-39189853

RESUMO

Metal-halogen exchange reactions are fundamental processes in chemistry that transform organic halides into organometallic reagents. However, using these reactions to build intricate structures in a cascade manner, especially in a catalytic mode, has been a challenge. In this study, we introduce a homoleptic organolanthanum catalyst to initiate lanthanum-halogen exchange and intramolecular carbohalogenation. The catalytic pathway can be achieved through metal-halogen exchange and carbometalation, followed by the extraction of halogen atoms from starting materials. Our approach offers a flexible and sustainable way to create a variety of useful compounds, showcasing its potential in chemical synthesis.

20.
J Phys Chem Lett ; 15(35): 9010-9015, 2024 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-39186517

RESUMO

In recent years, J-aggregates, as supramolecular assembly structures, have increasingly attracted scientific interest. Currently, the prevailing consensus is that J-aggregates are formed through the interleaved stacking of monomers arranged in parallel. However, our findings suggest that the fundamental units constituting J-aggregates are not limited to monomers alone but also encompass molecular aggregates interconnected by noncovalent bonds, which we designate as aggregation units. We have synthesized three asymmetric pyrrolopyrrole cyanine (PPCy) dyes capable of forming hydrogen-bonded dimers and have verified that these hydrogen-bonded dimers can serve as aggregation units to generate J-aggregates. The detailed structural and optical properties revealed that the J-aggregates of these dyes exhibited a significantly red-shifted and narrowed emission in the near-infrared (NIR) fluorescence compared to the monomers.

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