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1.
Org Biomol Chem ; 2024 Sep 25.
Article de Anglais | MEDLINE | ID: mdl-39318223

RÉSUMÉ

A convenient method for synthesizing ß-trifluoromethyl vinyl ethers and diethers through the base-mediated C-O coupling of (E)-1,2-dichloro-3,3,3-trifluoroprop-1-ene and phenols has been developed. Remarkably, the present process shows perfect regioselective and stereoselective yield of the Z/E isomers for ß-trifluoromethyl vinyl ethers with high efficiency. Additionally, ß-trifluoromethyl vinyl diethers with identical/diverse phenoxy groups were also obtained and the regulation of the product configuration was achieved. These reactions feature transition-metal-free conditions, wide substrate scope, and atom economy.

2.
Chaos ; 34(9)2024 Sep 01.
Article de Anglais | MEDLINE | ID: mdl-39312728

RÉSUMÉ

We perform the modulation instability analysis of the 2D and 3D nonlinear Klein-Gordon equation. The instability region depends on dispersion and wavenumbers of the plane wave. The N-breathers of the nonlinear Klein-Gordon equation are constructed directly from its 2N-solitons obtained in history. The regularity conditions of breathers are established. The dynamic behaviors of breathers of the 2D nonlinear Klein-Gordon equation are consistent with modulation instability analysis. Furthermore, by means of the bilinear method together with improved long-wave limit technique, we obtain general high order rogue waves of the 2D and 3D nonlinear Klein-Gordon equation. In particular, the first- and second-order rogue waves and lumps of the 2D nonlinear Klein-Gordon equation are investigated by using their explicit expressions. We find that their dynamic behaviors are similar to the nonlinear Schrödinger equation. Finally, the first-order rational solutions are illustrated for the 3D nonlinear Klein-Gordon equation. It is demonstrated that the rogue waves of the 2D and 3D nonlinear Klein-Gordon equation always exist by choosing dispersion and wavenumber of plane waves.

3.
Heliyon ; 10(16): e36039, 2024 Aug 30.
Article de Anglais | MEDLINE | ID: mdl-39247298

RÉSUMÉ

In order to adjust and detect micro-nano periodic structure optical surface accurately and efficiently, the problem of composite scattering between micro-ellipsoidal periodic structure optical surface and pore defects is studied use the multi-resolution time domain (MRTD) approach. A calculation model is established for the intensity distribution of composite scattering, which is modulated by the micro-ellipsoidal periodic structure optical surface and microdefects. Results are in good agreement with those obtained using CST Microwave Studio software and the finite-different time-domain (FDTD) approach, which demonstrates the effectiveness of the calculation model and method. By combining the field distribution of the micro-ellipsoidal periodic structure optical surface containing microdefects with the optical response at different wavelengths, it is necessary to study the influence of various parameters of the micro-ellipsoidal structure and microdefects on the optical system of metamaterials. The effects of the parameters such as roughness, structure of micro-ellipsoidal unit, defect sizes and buried depths on the composite scattering characteristics are analyzed numerically. The results provide technical support for the fields of functional surface design, ultrasensitive detection, scattering peak orientation and frequency selection.

4.
Angew Chem Int Ed Engl ; : e202414810, 2024 Sep 25.
Article de Anglais | MEDLINE | ID: mdl-39322938

RÉSUMÉ

Developing ionic copper-iodine clusters with multiple emitting is crucial for enriching lighting and display materials with various colors. However, the luminescent properties of traditional ionic copper-iodine clusters are often closely associated with low-energy cluster-centered triplet emission, which will redshift further as the Cu···Cu bond length decreases. This article utilizes a pressure-treated strategy to achieve an anomalous pressure-induced blue-shifted luminescence phenomenon in ionic Cu4I6(4-dimethylamino-1-ethylpyridinium)2 crystals for the first time, which is based on dominant through-space charge-transfer (TSCT). Herein, we reveal that the more advantageous through-space interactions in the competition between coprophilic interactions and through-space interactions can lead to a blue-shifted luminescence. High-pressure angle-dispersive X-ray diffraction and high-pressure infrared experiments show that the enhanced through-space interactions mainly originate from forming new intermolecular C-H···I hydrogen bonds and the enhancement of van der Waals interactions between organic cations and anionic clusters. Theoretical calculations and experimental studies of excited-state dynamics confirm that the blue-shifted emission is due to the increased energy gap between the excited triplet and ground states caused by the electron delocalization under stronger through-space interactions. This work deepens previous understanding and provides a new avenue to design and synthetic ionic copper-iodine clusters with high-energy TSCT emission.

5.
Micromachines (Basel) ; 15(8)2024 Aug 21.
Article de Anglais | MEDLINE | ID: mdl-39203703

RÉSUMÉ

Friction stir processing (FSP) manufacturing technology was used to fabricate medium Mn advanced high-strength steel in this study. The mechanical properties and microstructure of the steel fabricated using FSP were investigated. The steel obtained a total elongation of 35.1% and a tensile strength of 1034.6 MPa, which is about 59% higher than that of the steel without FSP. After FSP, a gradient structure occurs along the thickness direction. Specifically, across the thickness direction from the base material zone to the transition zone and finally to the stirring zone, both the grain size and austenite fraction decrease while the dislocation density increases, which results from the simultaneous effect of severe plastic deformation and recrystallization during FSP. Due to the gradient structure, an obvious difference in the strain across the thickness direction of the steel occurs during the deformation process, resulting in significant hetero-deformation-induced (HDI) strengthening. The deformation mechanism analysis reveals that HDI strengthening and dislocation strengthening are the main factors in the improvement in the strength-ductility balance. The obtained knowledge sheds light on the process of fabricating medium Mn steels with excellent properties using FSP manufacturing technology.

7.
BMC Cardiovasc Disord ; 24(1): 360, 2024 Jul 16.
Article de Anglais | MEDLINE | ID: mdl-39009987

RÉSUMÉ

BACKGROUND: The atherogenic index of plasma (AIP) is considered an independent risk factor for coronary artery disease (CAD). The present study investigated whether AIP correlates with the formation of coronary collateral circulation (CCC) in CAD patients with chronic total occlusion (CTO). METHODS: This retrospective study included 1093 CAD patients with CTO confirmed by coronary angiography from January 2020 to December 2020 at Beijing Anzhen Hospital. Based on the Rentrop scoring system, the patients were divided into the good CCC group and the poor CCC group. AIP was calculated by log (triglyceride/high-density lipoprotein cholesterol). Meanwhile, the study population was further divided into four groups according to the quartiles of AIP. RESULTS: Patients in the poor CCC group exhibited significantly higher AIP compared to those in the good CCC group (0.31 ± 0.27 vs. 0.14 ± 0.24, p < 0.001). Multivariate logistic regression analysis revealed an independent association between AIP and poor CCC, regardless of whether AIP was treated as a continuous or categorical variable (p < 0.001), after adjusting for confounding factors. Besides, this association remained consistent across most subgroups. The incorporation of AIP into the baseline model significantly enhanced the accuracy of identifying poor CCC [area under the curve (AUC): baseline model, 0.661 vs. baseline model + AIP, 0.721, p for comparison < 0.001]. CONCLUSIONS: Elevated AIP is independently associated with an increased risk of poor CCC in CAD patients with CTO, and AIP may improve the ability to identify poor CCC in clinical practice.


Sujet(s)
Marqueurs biologiques , Circulation collatérale , Coronarographie , Circulation coronarienne , Occlusion coronarienne , Humains , Mâle , Occlusion coronarienne/physiopathologie , Occlusion coronarienne/imagerie diagnostique , Occlusion coronarienne/sang , Femelle , Études rétrospectives , Adulte d'âge moyen , Sujet âgé , Maladie chronique , Marqueurs biologiques/sang , Appréciation des risques , Maladie des artères coronaires/physiopathologie , Maladie des artères coronaires/imagerie diagnostique , Maladie des artères coronaires/sang , Maladie des artères coronaires/diagnostic , Valeur prédictive des tests , Triglycéride/sang , Cholestérol HDL/sang , Facteurs de risque , Pronostic
8.
Anal Bioanal Chem ; 416(22): 4873-4885, 2024 Sep.
Article de Anglais | MEDLINE | ID: mdl-38951148

RÉSUMÉ

Ferroptosis is a way of cell death mainly due to the imbalance between the production and degradation of lipid reactive oxygen species, which is closely associated with various diseases. Endogenous hypochlorous acid (HOCl) mainly produced in mitochondria is regarded as an important signal molecule of ferroptosis. Therefore, monitoring the fluctuation of endogenous HOCl is beneficial to better understand and treat ferroptosis-related diseases. Inspired by the promising aggregation-induced emission (AIE) properties of tetraphenylethene (TPE), herein, we rationally constructed a novel AIE-based fluorescent probe, namely QTrPEP, for HOCl with nice mitochondria-targeting ability and high sensitivity and selectivity. Probe QTrPEP consisted of phenylborate ester and the AIE fluorophore of quinoline-conjugated triphenylethylene (QTrPE). HOCl can brighten the strong fluorescence through a specific HOCl-triggered cleavage of the phenylborate ester bond and release of QTrPE, which has been demonstrated by MS, HPLC, and DLS experiments. In addition, combining QTrPE-doped test strips with a smartphone-based measurement demonstrated the excellent performance of the probe to sense HOCl. The obtained favorable optical properties and negligible cytotoxicity allowed the use of this probe for tracking of HOCl in three different cells. In particular, this work represents the first AIE-based mitochondria-targeting fluorescent probe for monitoring the fluctuation of HOCl in ferroptosis.


Sujet(s)
Ferroptose , Colorants fluorescents , Acide hypochloreux , Mitochondries , Acide hypochloreux/analyse , Acide hypochloreux/métabolisme , Colorants fluorescents/composition chimique , Mitochondries/métabolisme , Ferroptose/effets des médicaments et des substances chimiques , Humains , Spectrométrie de fluorescence/méthodes , Imagerie optique/méthodes
9.
Int J Med Sci ; 21(9): 1681-1688, 2024.
Article de Anglais | MEDLINE | ID: mdl-39006850

RÉSUMÉ

Hypertension affects a large number of individuals globally and is a common cause of nephropathy, stroke, ischaemic heart disease and other vascular diseases. While many anti-hypertensive medications are used safely and effectively in clinic practice, controlling hypertensive complications solely by reducing blood pressure (BP) can be challenging. α-Mangostin, a xanthone molecule extracted from the pericarp of Garcinia mangostana L., has shown various beneficial effects such as anti-tumor, anti-hyperuricemia, and anti-inflammatory properties. However, the effects of α-Mangostin on hypertension remain unknown. In this study, we observed that α-Mangostin significantly decreased systolic and diastolic blood pressure in spontaneously hypertensive rats (SHR), possibly through the down-regulation of angiotensin II (Ang II). We also identified early markers of hypertensive nephropathy, including urinary N-acetyl-ß-D-glucosaminidase (NAG) and ß2-microglobulin (ß2-MG), which were reduced by α-Mangostin treatment. Mechanistic studies suggested that α-Mangostin may inhibit renal tubular epithelial-to-mesenchymal transformation (EMT) by down-regulating the TGF-ß signaling pathway, thus potentially offering a new therapeutic approach for hypertension and hypertensive nephropathy.


Sujet(s)
Angiotensine-II , Pression sanguine , Transition épithélio-mésenchymateuse , Hypertension artérielle , Xanthones , Animaux , Humains , Mâle , Rats , Angiotensine-II/métabolisme , Antihypertenseurs/pharmacologie , Antihypertenseurs/usage thérapeutique , Pression sanguine/effets des médicaments et des substances chimiques , Lignée cellulaire , Transition épithélio-mésenchymateuse/effets des médicaments et des substances chimiques , Fibrose/traitement médicamenteux , Garcinia mangostana/composition chimique , Hypertension artérielle/traitement médicamenteux , Hypertension artérielle/anatomopathologie , Hypertension rénale/traitement médicamenteux , Hypertension rénale/anatomopathologie , Néphrite , Rats de lignée SHR , Transduction du signal/effets des médicaments et des substances chimiques , Xanthones/pharmacologie , Xanthones/usage thérapeutique
10.
J Pharm Sci ; 113(9): 2744-2755, 2024 Sep.
Article de Anglais | MEDLINE | ID: mdl-38901529

RÉSUMÉ

Honokiol (HNK) is one of the bioactive ingredients from the well-known Chinese herbal medicine Magnolia officinalis, and its research interests is rising for its extensive pharmacological activities, including novel therapeutic effect on ulcerative colitis (UC). However, further application of HNK is largely limited by its unique physicochemical properties, such as poor water solubility, low bioavailability, as well as unsatisfied targeting efficacy for inflammatory lesions. In this study, we constructed galactosylation modified PLGA nanoparticles delivery system for efficient target delivery of HNK to the colitic lesions, which could lay a research foundation for the deep development of HNK for the treatment of UC. D-galactose was grafted by chemical coupling reactions with PLGA to prepare Gal-PLGA, which was used as a carrier for HNK (Gal-PLGA@HNK nanoparticles (NPs)). To improve the colon targeting efficiency by oral administration of the NPs, Eudragit S100 was used for wrapping on the surface of Gal-PLGA@HNK NPs (E/Gal-PLGA@HNK NPs). Our results showed that the encapsulation efficiency and drug loading capacity of E/Gal-PLGA@HNK NPs were 90.72 ± 0.54% and 8.41 ± 0.02%, respectively. Its average particle size was 242.24 ± 8.42 nm, with a PDI value of 0.135 ± 0.06 and zeta-potential of -16.83 ± 1.89 mV. The release rate of HNK from E/Gal-PLGA@HNK NPs was significantly decreased when compared with that of free HNK in simulated gastric and intestinal fluids, which displayed a slow-releasing property. It was also found that the cellular uptake of E/Gal-PLGA@HNK NPs was significantly increased when compared with that of free HNK in RAW264.7 cells, which was facilitated by D-galactose grafting on the PLGA carrier. Additionally, our results showed that E/Gal-PLGA@HNK NPs significantly improved colonic atrophy, body weight loss, as well as reducing disease activity index (DAI) score and pro-inflammatory cytokine levels in UC mice induced by DSS. Besides, the retention time of E/Gal-PLGA@HNK NPs in the colon was significantly increased when compared with that of other preparations, suggesting that these NPs could prolong the interaction between HNK and the injured colon. Taken together, the efficiency for target delivery of HNK to the inflammatory lesions was significantly improved by galactosylation modification on the PLGA carrier, which provided great benefits for the alleviation of colonic inflammation and injury in mice.


Sujet(s)
Dérivés du biphényle , Rectocolite hémorragique , Galactose , Lignanes , Copolymère d'acide poly(lactique-co-glycolique) , Animaux , Rectocolite hémorragique/traitement médicamenteux , Lignanes/administration et posologie , Lignanes/pharmacocinétique , Lignanes/composition chimique , Lignanes/pharmacologie , Souris , Copolymère d'acide poly(lactique-co-glycolique)/composition chimique , Galactose/composition chimique , Dérivés du biphényle/administration et posologie , Dérivés du biphényle/composition chimique , Dérivés du biphényle/pharmacocinétique , Poly(acides méthacryliques)/composition chimique , Nanoparticules/composition chimique , Mâle , Vecteurs de médicaments/composition chimique , Côlon/métabolisme , Côlon/effets des médicaments et des substances chimiques , Côlon/anatomopathologie , Système d'administration de médicaments à base de nanoparticules/composition chimique , Systèmes de délivrance de médicaments/méthodes , Libération de médicament , Composés allyliques , Phénols
11.
Arch Gerontol Geriatr ; 126: 105536, 2024 11.
Article de Anglais | MEDLINE | ID: mdl-38941946

RÉSUMÉ

BACKGROUND AND OBJECTIVE: A meta-analysis was conducted to evaluate the impact of resistance training on pro-inflammatory cytokines c-reactive protein (CRP), interleukin 6 (IL 6), and tumor necrosis factor- α (TNF- α) in middle-aged and elderly individuals. METHODS: The retrieval period for the Web of Science and other large electronic databases is set by default to March 2022. Both included and excluded researchers are independent examination literature on the impact of resistance exercise on markers of inflammation in the elderly. The physical medical care Evidence Database scale (Physical Therapy Evidence Database, PEDro) was used to evaluate the research quality, and Revmen 5.3 was used to end the index analysis. RESULTS: After a total of four rounds of elimination, 12 items were eventually included. The total sample size for the research was 388 persons. Resistance training substantially reduced CRP levels in middle-aged and older individuals, with SMD = -0.56 and 95 % confidence interval ([-0.78, -0.34], P < 0.00001, correspondingly. Resistance training can successfully lower IL6 concentrations in middle-aged and older adults, although the combined impact is not substantial. SMD = -0.25, 95 % CI [-0.54, 0.04]; P = 0.09. TNF- concentrations did not alter significantly following resistance exercise in middle-aged and older adults. The overall effect was SMD = -0.07, with a 95 % confidence interval [-0.37, 0.23], while P = 0.64. CONCLUSION: Resistance training reduces CRP, IL6, and TNF-α levels among middle-aged and elderly people. However, it has no significant anti-inflammatory effects on TNF-α. Resistance exercise at a moderate level for 3 times / week with a duration of 6-12 weeks or 16-32 weeks, significantly reduced CRP levels. This work contributing to exploring the resistance training program for the elderly to reduce inflammatory markers, and further, providing suggestions for the elderly to participate in resistance training and reduce the concentration of inflammatory markers.


Sujet(s)
Marqueurs biologiques , Protéine C-réactive , Inflammation , Interleukine-6 , Entraînement en résistance , Facteur de nécrose tumorale alpha , Sujet âgé , Humains , Adulte d'âge moyen , Marqueurs biologiques/sang , Marqueurs biologiques/métabolisme , Protéine C-réactive/analyse , Protéine C-réactive/métabolisme , Inflammation/sang , Inflammation/métabolisme , Inflammation/rééducation et réadaptation , Interleukine-6/sang , Interleukine-6/métabolisme , Entraînement en résistance/méthodes , Facteur de nécrose tumorale alpha/sang , Facteur de nécrose tumorale alpha/métabolisme
12.
Bioengineering (Basel) ; 11(6)2024 May 29.
Article de Anglais | MEDLINE | ID: mdl-38927786

RÉSUMÉ

Collision safety is an essential issue for dual-arm nursing-care robots. However, for coordinating operations, there is no suitable method to synchronously avoid collisions between two arms (self-collision) and collisions between an arm and the environment (environment-collision). Therefore, based on the self-motion characteristics of the dual-arm robot's redundant arms, an improved motion controlling algorithm is proposed. This study introduces several key improvements to existing methods. Firstly, the volume of the robotic arms was modeled using a capsule-enveloping method to more accurately reflect their actual structure. Secondly, the gradient projection method was applied in the kinematic analysis to calculate the shortest distances between the left arm, right arm, and the environment, ensuring effective avoidance of the self-collision and environment-collision. Additionally, distance thresholds were introduced to evaluate collision risks, and a velocity weight was used to control the smooth coordinating arm motion. After that, experiments of coordinating obstacle avoidance showed that when the redundant dual-arm robot is holding an object, the coordinating operation was completed while avoiding self-collision and environment-collision. The collision-avoidance method could provide potential benefits for various scenarios, such as medical robots and rehabilitating robots.

13.
Food Chem ; 456: 140064, 2024 Oct 30.
Article de Anglais | MEDLINE | ID: mdl-38878548

RÉSUMÉ

Cysteine (Cys) not only plays an indispensable role in maintaining the redox balance in organisms, but is also an important nutrient in the food industry. Fluorescence-based detection systems have emerged as an effective method to track the locations and concentrations of different species. To achieve efficient monitoring of Cys in both food samples and biological systems, a novel lipid droplet (LD) targeted fluorescent probe (namely NIT-Cys) was constructed for the turn-on detection of Cys, characterized by a large Stokes shift (142 nm), a short response time (<8 min), and a low Cys detection limit (39 nM). Furthermore, the NIT-Cys probe has been successfully used not only to quantify the amounts of Cys in selected food samples, but also to enable the visualization of endogenous Cys in acetaminophen (APAP)-induced drug-induced liver injury cells, zebrafish larvae and mice models. Consequently, the work presented here provides an efficient tool for monitoring Cys.


Sujet(s)
Acétaminophène , Lésions hépatiques dues aux substances , Cystéine , Colorants fluorescents , Analyse d'aliment , Danio zébré , Colorants fluorescents/composition chimique , Animaux , Cystéine/analyse , Cystéine/métabolisme , Lésions hépatiques dues aux substances/diagnostic , Lésions hépatiques dues aux substances/métabolisme , Souris , Humains , Foie/composition chimique , Foie/métabolisme
14.
Molecules ; 29(11)2024 Jun 02.
Article de Anglais | MEDLINE | ID: mdl-38893497

RÉSUMÉ

Developing materials with dynamic room-temperature phosphorescence (RTP) properties is crucial for expanding the applications of organic light-emitting materials. In this study, we designed and synthesized two novel RTP molecules by combining functional units, incorporating the folded unit thianthrene into the classic luminescent cores thioxanthone or anthraquinone to construct TASO and TA2O. In this combination, the TA unit contributes to the enhancement of spin-orbit coupling (SOC), while the luminescent core governs the triplet energy level. After the strategic manipulation of SOC using the thianthrene unit, the target molecules exhibited a remarkable enhancement in RTP performance. This strategy led to the successful development of TASO and TA2O molecules with outstanding dynamic RTP properties when exposed to continuous ultraviolet irradiation, a result that can be ascribed to their efficient RTP, improved absorption ability, and oxygen-sensitive RTP properties. Leveraging the oxygen-mediated ultraviolet-radiation-induced RTP enhancement in TASO-doped polymer films, we developed a novel time-resolved detection technique for identifying phase separation in polymers with varying oxygen permeability. This research offers a promising approach for constructing materials with dynamic RTP properties.

15.
Plant Dis ; 2024 Jun 17.
Article de Anglais | MEDLINE | ID: mdl-38885029

RÉSUMÉ

Avocado (Persea americana), which is native to Latin America, is mostly planted in southwest China. In November 2021, leaf spot symptoms were observed in a nursery in Chongzuo (22.2019°N, 106.4723°E), Guangxi, China. Approximately 90% of avocado seedlings in the nursery were affected. Symptomatic plant fully expanded leaves showed small brown spots that ranged from 1 to 3 mm, with a yellow halo around (Fig.1). Lesions gradually expanded and became nearly round and dark brown. Finally, leaves withered or curled. For pathogen isolation, 15 symptomatic leaves were randomly sampled from different plants of the nursery, five leaves were selected and four samples size 4×4mm were taken from each leaf and were plated on potato glucose agar. Identical fungus colonies were observed in 80% of the samples, and no bacteria were isolated. Single conidial isolation was performed. After 4 days, the colony diameter reached 74.6 mm, colonies appeared gray, and developed aerial hyphae. Conidiophores were mostly solitary with a few clustered erect or slightly curved, knee shaped, and 3.89 to 5.24 µm wide. Conidia were 39.33 -96.88 × 9.96 - 15.59 µm, slightly curved, rarely straight, light brown to yellowish brown, fusoid or navicular, and truncated at the base with 4 to 10 septa. Based on morphological and cultural characteristics, the fungus was identified as Bipolaris sp. (Manamgoda et al. 2014). An isolate named MP211122 was grown on Sachs' ager at 27℃ under 12-h light/dark for 1 week and consistently with Adhikari et al. (2021) no sexual from was observed. To confirm the tentative identification, genomic DNA was extracted, ITS and GAPDH gene were amplified and sequenced using primers ITS1/ITS4 and GPD/GPD2, respectively (Tan et al. 2022). The ITS sequence (GenBank ON248469) shared 100% identity with B. setariae (MN215632.1), and the GAPDH sequence (ON642344) shared 99.82% identity with B. setariae (MF490833.1, MK144540.1) and B. yamadae (MK026428.1). A maximum likelihood phylogenetic analysis based on GAPDH and ITS sequences using MEGA 7.0 revealed that the isolate clustered with B. setariae with 100% bootstrap support(Fig. 2). Healthy 11-month old potted avocado seedlings from disease-free nursery were selected , the conidial suspension (1 × 105 conidia/mL) of MP211122 isolate was prepared by harvesting conidia from a 10-day-old culture on water agar. Conidia were sprayed onto young leaves of six potted plants. Three additional seedlings sprayed with sterile distilled water served as controls. All plants were covered with plastic bags for 3 days to maintain high humidity and then maintained in a greenhouse at 30℃ with a 12-h/12-h light/dark cycle. After 5 days, typical symptoms of small brown spots were observed on all inoculated leaves (Fig.3). All leaves on control plants remained asymptomatic. The reisolated fungus was morphologically identical to the original isolate used for inoculation, fulfilling Koch's postulates. This is the first report of B. setariae as a pathogen causing leaf spot on avocado in China. This information will facilitate further studies, monitoring and control of the disease as accurate identification of the causal agent is a primary requisite for designing management strategies.

16.
ACS Biomater Sci Eng ; 10(5): 2805-2826, 2024 05 13.
Article de Anglais | MEDLINE | ID: mdl-38621173

RÉSUMÉ

Tissue engineering involves implanting grafts into damaged tissue sites to guide and stimulate the formation of new tissue, which is an important strategy in the field of tissue defect treatment. Scaffolds prepared in vitro meet this requirement and are able to provide a biochemical microenvironment for cell growth, adhesion, and tissue formation. Scaffolds made of piezoelectric materials can apply electrical stimulation to the tissue without an external power source, speeding up the tissue repair process. Among piezoelectric polymers, poly(vinylidene fluoride) (PVDF) and its copolymers have the largest piezoelectric coefficients and are widely used in biomedical fields, including implanted sensors, drug delivery, and tissue repair. This paper provides a comprehensive overview of PVDF and its copolymers and fillers for manufacturing scaffolds as well as the roles in improving piezoelectric output, bioactivity, and mechanical properties. Then, common fabrication methods are outlined such as 3D printing, electrospinning, solvent casting, and phase separation. In addition, the applications and mechanisms of scaffold-based PVDF in tissue engineering are introduced, such as bone, nerve, muscle, skin, and blood vessel. Finally, challenges, perspectives, and strategies of scaffold-based PVDF and its copolymers in the future are discussed.


Sujet(s)
Polyvinyles , Ingénierie tissulaire , Structures d'échafaudage tissulaires , Polyvinyles/composition chimique , Structures d'échafaudage tissulaires/composition chimique , Ingénierie tissulaire/méthodes , Humains , Impression tridimensionnelle , Matériaux biocompatibles/composition chimique , Polymères/composition chimique , Animaux , Polymères de fluorocarbone
17.
Mater Today Bio ; 26: 101053, 2024 Jun.
Article de Anglais | MEDLINE | ID: mdl-38654934

RÉSUMÉ

The complex genomics, immunosuppressive tumor microenvironment (TME), and chemotherapeutic resistance of osteosarcoma (OS) have resulted in limited therapeutic effects in the clinic. Ferroptosis is involved in tumor progression and is regulated mainly by glutathione peroxidase 4 (GPX4). Small interfering RNA (siRNA)-based RNA interference (RNAi) can precisely target any gene. However, achieving effective siRNA delivery is highly challenging. Here, we fabricated a TME-responsive metal-organic framework (MOF)-based biomimetic nanosystem (mFeP@si) with siGPX4 delivery and sonodynamic therapy (SDT) to treat OS by targeting ferroptosis. Under ultrasound (US) irradiation, mFeP@si achieves lysosomal escape via singlet oxygen (1O2)-mediated lysosomal membrane disruption and then accelerates ROS generation and glutathione (GSH) depletion. Meanwhile, siGPX4 silences GPX4 expression by binding to GPX4 mRNA and leads to the accumulation of toxic phospholipid hydroperoxides (PL-OOH), further magnifying the ROS storm and triggering ferroptosis. Notably, synergistic therapy remarkably enhances antitumor effects, improves the immunosuppressive TME by inducing potent immunogenic cell death (ICD), and increases the sensitivity of chemotherapy-resistant OS cells to cisplatin. Overall, this novel nanosystem, which targets ferroptosis by integrating RNAi and SDT, exhibits strong antitumor effects both in vitro and in vivo, providing new insights for treating OS.

18.
Front Pharmacol ; 15: 1364286, 2024.
Article de Anglais | MEDLINE | ID: mdl-38655182

RÉSUMÉ

Objective: This experiment aimed to obtain the relatively rare cis-crocetin isomer from natural plants, which predominantly exist in the more stable all-trans configuration. This was achieved through iodine-induced isomerization, followed by purification and structural identification. The study also aimed to compare the pharmacokinetic differences between cis- and trans-crocetin in vivo. Methods: Trans-crocetin of high purity was extracted by hydrolysis from gardenia yellow pigment. Cis-crocetin was then synthesized through an optimized electrophilic addition reaction induced by elemental iodine, and subsequently separated and purified via silica gel column chromatography. Structural identification of cis-crocetin was determined using IR, UV, and NMR techniques. In vivo pharmacokinetic studies were conducted for both cis- and trans-crocetin. In addition to this, we have conducted a comparative study on the in vivo anti-hypoxic activity of trans- and cis-crocetin. Results: Under the selected reaction conditions using DMF as the solvent, with a concentration of 2.5 mg/mL for both trans-crocetin and the iodine solution, and adjusting the illumination time according to the amount of trans-crocetin, the rate of iodine-induced isomerization was the fastest. Cis-crocetin was successfully obtained and, after purification, its structure was identified and found to be consistent with reported data. Cis-crocetin exhibited a faster absorption rate and higher bioavailability, and despite its shorter half-life, it could partially convert to trans-crocetin in the body, thereby extending the duration of the drug's action within the body to some extent. Conclusion: This study accomplished the successful preparation and structural identification of cis-crocetin. Additionally, through pharmacokinetic studies, it uncovered notable variations in bioavailability between cis- and trans-crocetin. These findings serve as a solid scientific foundation for future functional research and practical applications in this field.

20.
Opt Lett ; 49(5): 1221-1224, 2024 Mar 01.
Article de Anglais | MEDLINE | ID: mdl-38426978

RÉSUMÉ

This paper reports an optical strain sensor that integrates a self-powered mechanoluminescent (ML) elastic fiber with a flexible circuit. The inclusion of an alumina nanoparticle as the additive results in seven-fold enhancement of ML intensity while maintaining flexibility of 120% strain. The sensor facilitates the detection of strain and stretching speed. It attains a sensitivity of 0.0022 lx/(1% strain) and a resolution of 0.2% strain, respectively. We have successfully applied it to detect bending motions of the finger, wrist, and elbow. This wearable strain sensor holds promise for diverse applications in wearable technology.

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