查找使用阿拉丁产品的科研文献

α-ketoglutarate ameliorates spinal motor neuron ferroptosis after sacral plexus transection via enhancing PINK1 O‑GlcNAcylation and mitophagy

Hui Han,Sheng Wang,Jiajia Lu,Jing Li,Jinlong Zheng,Yongchuan Li,Hongtao Lu,Aimin Chen

Sacral plexus transection (SPT), mostly caused by high‑energy trauma, induces secondary death of spinal motor neurons in the lumbosacral segments and contributes to poor clinical outcomes after nerve repair. This study aimed to investigate the protective effect of α‑ketoglutarate (AKG) against ferroptosis in spinal motor neurons following SPT and the underlying molecular mechanism. Our results showed that endogenous AKG levels were significantly decreased in the spinal cord of SPT rats and in oxidative stress‑injured motor neurons, accompanied by abnormal expression of core ferroptosis‑related proteins, including downregulated glutathione peroxidase 4 and solute carrier family 7 member 11, upregulated acyl-CoA synthetase long-chain family member 4, as well as Fe2+ overload, malondialdehyde accumulation, and glutathione depletion. Exogenous AKG supplementation markedly reversed these anomalies, suppressed ferroptosis, and improved neuronal survival. Mechanistically, AKG specifically enhanced O-GlcNAcylation at the Thr177 site of PTEN‑induced kinase 1 (PINK1) and suppressed its ubiquitin-mediated degradation, which in turn selectively activated PINK1-PRKN-dependent mitophagy to eliminate damaged mitochondria and sustain mitochondrial homeostasis. Furthermore, downregulation of isocitrate dehydrogenase 1 (IDH1) after SPT was identified as a critical upstream event leading to endogenous AKG depletion. This study systematically elucidates the key role of the IDH1‑AKG‑PINK1 O‑GlcNAcylation ‑mitophagy axis in regulating SPT‑induced ferroptosis in spinal motor neurons, providing novel targets and experimental evidence for neuroprotective therapy of sacral plexus injury.

Synthesis of compressible and reusable chitin/O-gCN sponges for efficient removal of phthalate esters in water environments

Cuizhu Sun,Zhenggang Wang,Hao Zheng,Shasha Zhao,Xianxiang Luo,Chenguang Li,Lingyun Chen,Fengmin Li

Phthalate esters (PAEs) widely used as plasticizers in industrial products are a major threat to human health and water ecological security. In this work, chitin-based sponges doped with oxygen-modified graphitic carbon nitride (O- g CN) (ChCN) demonstrated adsorption-photocatalytic synergistic ability for the efficient removal of two typical PAEs, diethyl phthalate (DEP) and dibutyl phthalate (DBP). The addition of O- g CN increased the sponge mechanical strength from 0.629 to 1.39 MPa, enabling materials with interconnected pores, excellent compressibility, and mechanical durability. The saturated adsorption capacities of DEP and DBP reached 37.41–42.93 mg g −1 for ChCN sponges, wherein the driving forces were hydrophobic interactions, hydrogen bonding, and π-π interactions. Notably, O- g CN significantly improved PAE removal by simultaneously enhancing the adsorption and photocatalytic effect of ChCN sponges due to its high catalytic activity, leading to 100% removal of DEP and DBP within 2 h. The degradation pathway of DEP was confirmed to be de-esterification. Finally, filtration columns assembled with ChCN sponges showed 87.8–90.9% PAE removal from water under natural light, and the removal efficiency did not significantly change even after three reuses, indicating stable removal performance and good reusability with potential for practical applications. The sponges also possessed good biocompatibility and biodegradability, as demonstrated through algal toxicity experiments and biodegradation tests. Therefore, this research presents a convenient method for preparation of compressible and reusable sponge materials from renewable biomass for efficient PAE removal from aqueous environments and has revealed the underlying mechanisms of such removal by the adsorption-photocatalysis synergistic effect.

Characterization of key aroma compounds in Chinese smoked duck by SAFE-GC-O-MS and aroma-recombination experiments

Huan Liu,Jingyu Li,Nazimah Hamid,Junke Li,Xuemei Sun,Fang Wang,Dengyong Liu,Qianli Ma,Shuyang Sun,Hansheng Gong

Smoked duck is a popular meat product in China. The aroma profile and key aroma compounds in smoked ducks were elucidated using solvent-assisted flavor evaporation-gas chromatography–olfactometry-mass spectrometry (SAFE-GC-O-MS), odor activity values (OAVs), aroma recombination and omission experiments, and sensory evaluation. The results indicated that the predominant aroma profiles of rice-, tea oil- and sugarcane-smoked ducks all contained strong smoky, roasty, fatty, meaty, and grassy aromas. A total of 31 aroma compounds were identified as important odorants by OAVs, including 8 aldehydes, 6 pyrazines, 5 phenols, and 2 sulfur compounds. The aroma recombination and omission experiments confirmed that 13 odorants were key aroma compounds in smoked ducks. Of these odorants, 2-methoxyphenol, 4-methylphenol, 5-ethyl-2,3-dimethylpyrazine, methional, 2-methyl-3-furanthiol, ( E, E )-2,4-decadienal, 1-octen-3-ol, and anethole significantly contributed to the aroma profile of smoked duck flavor ( p  < 0.01).

Toluidine blue O photosensitizer combined with caffeic acid improves antibacterial performance by increasing the permeability of cell membrane

Xiaoxiao Gu,Haoyang Yuan,Cailing Li,Lixian Xu,Shuang Li,Dinghua Yu

Photodynamic therapy has always been an antibacterial tool for solving multi-drug resistant bacteria problem, but the side effects and the low efficiency due to the high aggregation and low solubility of photosensitizers limit its application. Due to the anti-inflammatory effect of caffeic acid , two novel photosensitizers (CA-1-TBO, CA-TBO) were synthesized by conjugating caffeic acid with toluidine blue O (TBO). The structures have been characterized by 1 HNMR and high-resolution mass spectrometry . The UV–vis absorption, fluorescence spectra and the octanol-water partition coefficient of two photosensitizers were measured to evaluate their photophysical properties and hydrophilic/hydrophobic properties. Compared with parent TBO, the two modified photosensitizers have shown a higher quantum yield and kinetics constants of singlet oxygen, which has been supported by the simulation results of density functional theory . As drug-resistant representatives of gram-positive and gram-negative bacteria, respectively, S. aureus and P. aeruginosa have been used for in vitro antibacterial experiments. The sterilization efficiencies of the two modified photosensitizers far exceed that of parent TBO. The results of the octanol-water partition coefficient and fluorescence quantification showed that modified photosensitizers CA-1-TBO and CA-TBO could be more accumulated than parent TBO. Based on scanning electron microscopy images, protein gel electrophoresis , and the conductivity of the bacterial solution, the possible mechanism of improved antibacterial photodynamic efficiencies could be induced by membrane permeability due to the caffeic acid effect. The findings demonstrate the significant potential of natural phenolic compounds in the development of photosensitizer molecules with characteristics such as more efficient, biocompatible and less side effects.

O-GlcNAcylation Inhibition Upregulates Connexin43 Expression in the Endothelium to Protect the Tight Junction Barrier in Diabetic Retinopathy

Guodong Liu,Le Feng,Xiaoqiang Liu,Peng Gao,Fang Wang

Purpose:This study aimed to investigate the effects of O-linked N-acetylglucosamine modification (O-GlcNAcylation) on connexin43 (Cx43) expression and its subsequent effects on tight junction properties in diabetic retinopathy (DR).Methods:O-GlcNAcylation levels in primary human retinal vascular endothelial cells (HRVECs) and retinas from rats with diabetes were regulated by treatment with Thiamet G or alloxan. Immunoprecipitation was used to examine the relationship between O-GlcNAcylation and Cx43 expression. Stable overexpression and knockdown of Cx43 in HRVECs were achieved using lentivirus constructs; further, their effects on occludin and zonula occluden-1 (ZO-1) expression and tight junction barrier function were determined.Results:O-GlcNAcylation level increased significantly, whereas Cx43 expression decreased in retinas from rats with diabetes and HRVECs cultured under high-glucose conditions. Immunoprecipitation revealed that Cx43 was modified by O-GlcNAcylation and phosphorylation simultaneously. O-GlcNAcylation inhibition negatively regulated both total Cx43 and phosphorylated Cx43 expression, subsequently disrupting tight junction properties. Conversely, Cx43 overexpression reversed the disruption of tight junction properties and downregulated vascular endothelial growth factor expression. Consistently, Cx43 overexpression increased transendothelial electrical resistance values in HRVEC layers.Conclusions:O-GlcNAcylation negatively regulated Cx43 expression, contributing to the disruption of the blood retinal barrier. However, O-GlcNAcylation inhibition and Cx43 overexpression could reverse the tight junction disruption. Therefore, O-GlcNAcylation inhibition is a potential target for avoiding tight junction disruption through the Cx43 pathway in DR.

Immobilization of open O-donor sites within a double-walled metal-organic framework for efficient C2H2/CO2 separation

Di-Ming Chen,Xue-Jing Zhang

Acetylene is an important industrial material for the production of acetaldehyde, acetic acid, benzene, synthetic rubber, synthetic fiber, etc., and its separation from the gas mixtures of C 2 H 2 /CO 2 is of great importance but a challenging task due to their similar physical properties and molecular sizes. In this study, taking the advantage of open-donor sites on the pore surface as the nano-traps for C 2 H 2 molecules, a new microporous metal-organic framework (MOF) formulated as {[C o 3 (OH) 2 (HCOO) 2 (CPT) 2 ](NMF) 2 (MeOH) 3 (H 2 O)} n ( 1 , NMF = N - methylformamide) has been prepared by virtue of a bifunctional organic ligand 4-(4H-1,2,4-triazol-4-yl)benzoic acid (HCPT), which showed discriminating sorption performance toward C 2 H 2 (113 cm 3 /g at 298 K and 1 bar) over CO 2 (33 cm 3 /g) under the same conditions. The different sorption behavior of {[C o 3 (OH) 2 (HCOO) 2 (CPT) 2 ]} n between C 2 H 2 and CO 2 results in a high uptake ration (3.4:1) and IAST selectivity (13) at 298 K and 1 bar. Furthermore, the force-field based grand canonical Monte Carlo (GCMC) simulation results demonstrate that the large electronegativity and polarizability of open O donor sites on the pore surface contribute to its high C 2 H 2 /CO 2 separation performance, leading to its more favorable C 2 H 2 uptakes than CO 2 .

Discovery of 7-O-1, 2, 3-triazole hesperetin derivatives as multi-target-directed ligands against Alzheimer's disease

Min Wang,Longji Fang,Tongtong Liu,Xuejie Chen,Yan Zheng,Yilong Zhang,Shiming Chen,Zeng Li

The development of multi-target-directed ligands (MTDLs) may improve complex central nervous system diseases such as Alzheimer's disease (AD). Here, a series of 7-O-1, 2, 3-triazole hesperetin derivatives was evaluated for their inhibition of cholinesterase , anti-neuroinflammatory, and neuroprotective activity. Among the hesperetin derivatives, compound a8 (7-O-((1-(3-chlorobenzyl)-1H-1,2,3-triazol-4-yl)methyl)hesperetin) possessed excellent anti-butyrylcholinesterase activity (IC 50  = 3.08 ± 0.29 μM) and exhibited good anti-neuroinflammatory activity (IC 50  = 2.91 ± 0.47 μM) against NO production through remarkably blocking the NF-κB signaling pathway and inhibiting the phosphorylation of P65. In addition, a8 showed a remarkable neuroprotective effect and lacked neurotoxicity up to 50 μM concentration. Furthermore, possessing significant self-mediated Aβ 1-42 aggregation inhibitory activity, chelated biometals and reduced ROS production were found in compound a8 . In the bi-directional transport assay, a8 exhibited a blood–brain barrier penetrating ability. In this study, the Morris water maze task showed that compound a8 significantly improved the learning and memory impairment of the scopolamine-induced AD mice model. Results highlighted the potential of compound a8 to be a potential MTDL for the development of anti-AD agents.

Degradation kinetics and isomerization of 5-O-caffeoylquinic acid under ultrasound: Influence of epigallocatechin gallate and vitamin C

Danli Wang,Jingjing Wang,Jiachen Sun,Shaoping Qiu,Bingquan Chu,Ruosi Fang,Ling Li,Jinyan Gong,Fuping Zheng

5- O -Caffeoylquinic acid (5-CQA), also known as chlorogenic acid, exhibits various biological activities. Hence the interest in its property change during processing and extraction has increased. The present work studied the influence of ultrasound on the stability of 5-CQA at different pH (pH 4.69, 7.09, 7.69 and 9.22) in water and 50% methanol-water system. Different parameters including solvent, ultrasonic power, time, temperature, duty cycle, and liquid height were investigated during the treatment. Results indicate that ultrasound accelerated the degradation of 5-CQA. Based on Weibull model, the degradation kinetics were described. The rate constant ( k ) of the degradation increased with the increasing pH, demonstrating the alkali sensitivity of 5-CQA. The isomerization of 5-CQA to 3- and 4- O -caffeoylquinic acid was found at neutral and alkaline conditions, which was further boosted by ultrasound. The stability of 5-CQA was improved by adding epigallocatechin gallate (EGCG) and vitamin C (VC) respectively.

The viscosifying behavior of W/O emulsion and its underlying mechanisms: Considering the interfacial adsorption of heavy components

Changxiao Cao,Shaohua Gu,Zhaojie Song,Zehui Xie,Xuya Chang,Pingping Shen

Formation of water-in-oil (W/O) emulsion seriously limits heavy oil production, and the interfacial adsorption of heavy components of oil is the key to clarify the emulsification of crude oil and formation water. In this study, the viscosifying behavior of W/O emulsion was correlated with the interfacial adsorption of heavy components using two typical heavy oil samples, i.e., high-resins oil and high-asphaltenes oil. Results showed that the resins, instead of the asphaltenes , contributed to the pseudoplastic behavior of W/O emulsion. The interfacial adsorption of resins presented the lower interfacial tension (IFT), the higher interfacial viscosity and the stronger film stability. However, when more asphaltenes was adsorbed on the interface, the film of oil-water interface changed from viscous to brittle and breakable. According to the composition analysis, the interfacial activity of resins was much stronger than asphaltenes. Besides, the W/O emulsion formed using model oil with resins performed the better stability compared with that formed using model oil with asphaltenes. This study provided that the interfacial adsorption of resins enhanced the emulsifying ability of crude oil and the film stability of W/O emulsion, which heavily aggravated the viscosifying behavior.

Effect and regulation mechanism of oxidation degrees on the O–MoS2 structure and separation performance of nanofiltration membrane

Shishi Yang,Huali Tian,Matthew R. Hill,Kaisong Zhang

Oxidized molybdenum disulfide (O–MoS 2 ) as a two-dimensional (2D) functional nanosheets material, has been used to fabricate high separation performance nanofiltration (NF) membranes for water treatment. However, the effect and regulation mechanism of the degree of oxidation on structure and separation performance of O–MoS 2 modified NF membrane has not yet been fully understood. In this work, O–MoS 2 with different oxidation degrees was synthesized by adjusting the oxidation time and KMnO 4 oxidant content via Hummers’ method. The results demonstrated that the O–MoS 2 synthesized under with an oxidation time of 3 h and MoS 2 :KMnO 4 ratio of 1:2 had excellent stability under acidic, neutral and alkaline conditions. The pure water flux increased 2.5 times and the Na 2 SO 4 salt rejection increased to 97.6% with this O–MoS 2 incorporation compared to the control membrane. The influence of different oxidation degrees on the performance of O–MoS 2 is a breakthrough finding of this work to provide a theoretical basis for the application of O–MoS 2 in the field of membrane separations .

Study on the relationship between the tribological properties and oxidation degree of graphene derivatives in O/W emulsion

Yinglei Wu,Tao Sun,Zhongyi He,Xiangqiong Zeng,Tianhui Ren,Erik de Vries,Emile van der Heide

Graphene oxide (GO) underwent a single and double-side modification with octadecylamine (ODA) to MGO1 and MGO2 respectively. MGO1 and MGO2 were incorporated into the O/W base emulsion respectively to change the composition of the boundary layer and the oil phase. It was found that the tribological properties of MGO1-emulsion were better than that of MGO2-emulsion. Chemical composition analysis of the worn surfaces suggests that MGO1 nanosheets might adsorb more easily onto the surface and react better with the bearing steel to produce C–N–O–Fe-containing compounds than do MGO2 nanosheets, and that MGO1 nanosheets were more actively involved in the shear process that occurs in the contact area. SEM and nanoindentation indicated that there was a non-uniform softer MGO1-tribofilm on metal substrate.

Dielectric strength of glass fibre fabric reinforced epoxy by nano-Al2O3

Shuang Wang,Yu Chen,Jiale Mao,Cong Liu,Lei Zhang,Yonghong Cheng,Chaoyun Du,Toshikatsu Tanaka