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1.
Food Chem ; 452: 139544, 2024 May 04.
Article in English | MEDLINE | ID: mdl-38723571

ABSTRACT

This study investigated the effects of high hydrostatic pressure (HHP) on the binding interactions of cyanindin-3-O-glucoside (C3G) to bovine serum albumin, human serum albumin (HSA), bovine lactoferrin, and ovotransferrin. Fluorescence quenching revealed that HHP reduced C3G-binding affinity to HSA, while having a largely unaffected role for the other proteins. Notably, pretreating HSA at 500 MPa significantly increased its dissociation constant with C3G from 24.7 to 34.3 µM. Spectroscopic techniques suggested that HSA underwent relatively pronounced tertiary structural alterations after HHP treatments. The C3G-HSA binding mechanisms under pressure were further analyzed through molecular dynamics simulation. The localized structural changes in HSA under pressure might weaken its interaction with C3G, particularly polar interactions such as hydrogen bonds and electrostatic forces, consequently leading to a decreased binding affinity. Overall, the importance of pressure-induced structural alterations in proteins influencing their binding with anthocyanins was highlighted, contributing to optimizing HHP processing for anthocyanin-based products.

2.
Proc Natl Acad Sci U S A ; 121(23): e2322359121, 2024 Jun 04.
Article in English | MEDLINE | ID: mdl-38805286

ABSTRACT

Rearranged during transfection (RET) rearrangement oncoprotein-mediated Ras/MAPK signaling cascade is constitutively activated in cancers. Here, we demonstrate a unique signal niche. The niche is a ternary complex based on the chimeric RET liquid-liquid phase separation. The complex comprises the rearranged kinase (RET fusion); the adaptor (GRB2), and the effector (SHC1). Together, they orchestrate the Ras/MAPK signal cascade, which is dependent on tyrosine kinase. CCDC6-RET fusion undergoes LLPS requiring its kinase domain and its fusion partner. The CCDC6-RET fusion LLPS promotes the autophosphorylation of RET fusion, with enhanced kinase activity, which is necessary for the formation of the signaling niche. Within the signal niche, the interactions among the constituent components are reinforced, and the signal transduction efficiency is amplified. The specific RET fusion-related signal niche elucidates the mechanism of the constitutive activation of the Ras/MAPK signaling pathway. Beyond just focusing on RET fusion itself, exploration of the ternary complex potentially unveils a promising avenue for devising therapeutic strategies aimed at treating RET fusion-driven diseases.


Subject(s)
GRB2 Adaptor Protein , MAP Kinase Signaling System , Oncogene Proteins, Fusion , Proto-Oncogene Proteins c-ret , Src Homology 2 Domain-Containing, Transforming Protein 1 , ras Proteins , Src Homology 2 Domain-Containing, Transforming Protein 1/metabolism , Src Homology 2 Domain-Containing, Transforming Protein 1/genetics , Humans , GRB2 Adaptor Protein/metabolism , GRB2 Adaptor Protein/genetics , ras Proteins/metabolism , ras Proteins/genetics , Proto-Oncogene Proteins c-ret/metabolism , Proto-Oncogene Proteins c-ret/genetics , Oncogene Proteins, Fusion/metabolism , Oncogene Proteins, Fusion/genetics , Signal Transduction , Phosphorylation
4.
Bioorg Med Chem ; 107: 117750, 2024 May 17.
Article in English | MEDLINE | ID: mdl-38776567

ABSTRACT

Analgesia and blood sugar control are considered as two main unmet clinical needs for diabetes related neuropathic pain patients. Transient receptor potential vanilloid type-1 (TRPV1) channel is a highly validated target for pain perception, while no TRPV1 antagonists have been approved due to hyperthermia side effects. Herein, two series of new TRPV1 antagonists with flavonoid skeleton were designed by the structure-based drug design (SBDD) strategy. After comprehensive evaluation, compound CX-3 was identified as a promising TRPV1 antagonist. CX-3 exhibited equivalent TRPV1 antagonistic activity with classical TRPV1 antagonist BCTC in vitro, and exerted better analgesic activity in vivo than that of BCTC in the formalin induced inflammatory pain model without hyperthermia risk. Moreover, CX-3 exhibited robust glucose-lowering effects and showed high selectivity over other ion channels. Overall, these findings identified a first-in-class highly selective TRPV1 antagonist CX-3, which is a promising candidate to target the pathogenesis of diabetes related neuropathic pain.

5.
Anal Chem ; 2024 May 28.
Article in English | MEDLINE | ID: mdl-38805056

ABSTRACT

Over the years, a number of state-of-the-art data analysis tools have been developed to provide a comprehensive analysis of data collected from gas chromatography-mass spectrometry (GC-MS). Unfortunately, the time shift problem remains unsolved in these tools. Here, we developed a novel comprehensive data analysis strategy for GC-MS-based untargeted metabolomics (AntDAS-GCMS) to perform total ion chromatogram peak detection, peak resolution, time shift correction, component registration, statistical analysis, and compound identification. Time shift correction was specifically optimized in this work. The information on mass spectra and elution profiles of compounds was used to search for inherent landmarks within analyzed samples to resolve the time shift problem across samples efficiently and accurately. The performance of our AntDAS-GCMS was comprehensively investigated by using four complex GC-MS data sets with various types of time shift problems. Meanwhile, AntDAS-GCMS was compared with advanced GC-MS data analysis tools and classic time shift correction methods. Results indicated that AntDAS-GCMS could achieve the best performance compared to the other methods.

6.
Int J Biol Macromol ; : 132442, 2024 May 16.
Article in English | MEDLINE | ID: mdl-38761903

ABSTRACT

During the pathogenesis of rheumatoid arthritis, inflammatory cells usually infiltrate synovial tissues, notably, M1-type macrophages, whose redox imbalance leads to the degradation of joint structures and deterioration of function. Natural active products play a vital role in immune modulation and antioxidants. In this study, we constructed a ROS-responsive nanoparticle called FTL@SIN, which consists of fucoidan (Fuc) and luteolin (Lut) connected by a ROS-responsive bond, Thioketal (TK), and encapsulated with an anti-rheumatic drug, Sinomenine (SIN), for synergistic anti-inflammatory effects. The FTL@SIN is then dispersed in high molecular weight Fuc-fabricated dissolvable microneedles (FTL@SIN MNs) for local administration. Therapy of FTL@SIN MNs afforded a significant decrease in macrophage inflammation while decreasing key pro-inflammatory cytokines and repolarizing M1 type to M2 type, thereby ameliorating synovial inflammation, and promoting cartilage repair. Additionally, our investigations have revealed that Fucoidan (Fuc) demonstrates synergistic effects, exhibiting superior mechanical strength and enhanced physical stability when compared to microneedles formulated solely with hyaluronic acid. This study combines nanomedicine with traditional Chinese medicine, a novel drug delivery strategy that presents a promising avenue for therapeutic intervention in rheumatoid arthritis.

7.
Environ Pollut ; 352: 124022, 2024 Apr 26.
Article in English | MEDLINE | ID: mdl-38679130

ABSTRACT

The health risks associated with combined exposure to microplastics (MPs) and cyanobacteria toxins have gained increasing attention due to the large-scale prevalence of cyanobacterial blooms and accumulation of MPs in aquatic environments. Therefore, we explored the cardiovascular toxic effects of microcystin-LR (MC-LR, 1, 10, 100 µg/L) in the presence of 5 µm polystyrene microplastics (PS-MPs, 100 µg/L) and 80 nm polystyrene nanoplastics (PS-NPs, 100 µg/L) in zebrafish models. Embryos were exposed to certain PS-MPs and PS-NPs conditions in water between 3 h post-fertilization (hpf) and 168 hpf. Compared to MC-LR alone, a significant decrease in heart rate was observed as well as notable pericardial edema in the MC-LR + PS-MPs/NPs groups. At the same time, sinus venosus and bulbus arteriosus (SV-BA) distances were significantly increased. Furthermore, the addition of PS-MPs/NPs caused thrombosis in the caudal vein and more severe vascular damage in zebrafish larvae compared to MC-LR alone. Our findings revealed that combined exposure to PS-NPs and MC-LR could significantly decreased the expression of genes associated with cardiovascular development (myh6, nkx2.5, tnnt2a, and vegfaa), ATPase (atp1a3b, atp1b2b, atp2a1l, atp2b1a, and atp2b4), and the calcium channel (cacna1ab and ryr2a) compared to exposure to MC-LR alone. In addition, co-exposure with PS-MPs/NPs exacerbated the MC-LR-induced reactive oxygen species (ROS) production, as well as the ROS-stimulated apoptosis and heightened inflammation. We also discovered that astaxanthin (ASTA) treatment partially attenuated these cardiovascular toxic effects. Our findings confirm that exposure to MC-LR and PS-MPs/NPs affects cardiovascular development through calcium signaling interference and ROS-induced cardiovascular cell apoptosis. This study highlights the potential environmental risks of the co-existence of MC-LR and PS-MPs/NPs for fetal health, particularly cardiovascular development.

8.
Lab Chip ; 24(9): 2537-2550, 2024 Apr 30.
Article in English | MEDLINE | ID: mdl-38623757

ABSTRACT

The diverse commensal microbiome of the human intestine has been considered to play a central role in depression. However, no host-microbiota co-culture system has been developed for depression, which hinders the controlled study of the interaction between depression and gut microbiota. We designed and manufactured a microfluidic-based gut-on-a-chip model containing the gut microbiota of patients with depression (depression-on-gut-chip, DoGC), which enables the extended co-culture of viable aerobic human intestinal epithelial cells and anaerobic gut microbiota, and allows the direct study of interactions between human gut microbiota and depression. We introduced representative gut microbiota from individuals with depression into our constructed DoGC model, successfully recapitulating the gut microbiota structure of depressed patients. This further led to the manifestation of physiological characteristics resembling depression, such as reduced gut barrier function, chronic low-grade inflammatory responses and decreased neurotransmitter 5-HT levels. Metabolome analysis of substances in the DoGC revealed a significant increase in lipopolysaccharides and tyrosine, while hyodeoxycholic acid, L-proline and L-threonine were significantly reduced, indicating the occurrence of depression. The proposed DoGC can serve as an effective platform for studying the gut microbiota of patients with depression, providing important cues for their roles in the pathology of this condition and acting as a powerful tool for personalized medicine.


Subject(s)
Depression , Gastrointestinal Microbiome , Lab-On-A-Chip Devices , Humans , Depression/metabolism , Depression/microbiology , Coculture Techniques , Microfluidic Analytical Techniques/instrumentation , Caco-2 Cells , Models, Biological
9.
Plant Physiol Biochem ; 210: 108570, 2024 May.
Article in English | MEDLINE | ID: mdl-38560957

ABSTRACT

The WUSCHEL-related homeobox (WOX) gene family is vital for plant development and stress response. In this study, we conducted a comprehensive analysis of WOX genes in Cunninghamia lanceolata (C. lanceolata) and subsequently explored the potential roles of two ClWOX genes within the WUS clade. In total, six ClWOX genes were identified through a full-length transcriptome analysis. These genes, exhibiting conserved structural and functional motifs, were assigned to the ancient clade and Modern/WUS clade, respectively, through a phylogenetic analysis. Our expression analysis indicated that these ClWOX genes were highly expressed in the middle and late developmental stages of zygotic embryos in C. lanceolata. Moreover, only ClWOX5 and ClWOX6 within the Modern/WUS clade exhibited transcriptional activity, and their expressions were also induced in response to auxin and wounding. Overexpression of ClWOX5 and ClWOX6 in Arabidopsis caused a partially sterile phenotype, resulting in a very low seed setting rate. Transcriptomic analysis revealed that expressions of many embryo-defective (EMB) genes, phytohormone-related genes, and transcription factors (TFs) were dramatically altered in ClWOX5 and ClWOX6 transgenic plants, which suggested that ClWOX5 and ClWOX6 may play specific important roles in embryo development via complex gene networks. In addition, overexpression of ClWOX5 and ClWOX6 in leaf segments promoted shoot regeneration in tobacco, indicating that ClWOX5 and ClWOX6 can promote plant regeneration and could be used to improve genetic transformation. In conclusion, these results help to elucidate the function of the WOX gene and provide a valuable basis for future studies of the developmental regulation and applications of WOX genes in C. lanceolata.


Subject(s)
Cunninghamia , Gene Expression Regulation, Plant , Plant Proteins , Plant Proteins/genetics , Plant Proteins/metabolism , Cunninghamia/genetics , Multigene Family , Arabidopsis/genetics , Homeodomain Proteins/genetics , Homeodomain Proteins/metabolism , Seeds/genetics , Seeds/growth & development , Phylogeny , Plants, Genetically Modified/genetics , Genes, Plant
10.
Noncoding RNA Res ; 9(3): 913-920, 2024 Sep.
Article in English | MEDLINE | ID: mdl-38638146

ABSTRACT

Myeloid-derived suppressor cells (MDSCs) are closely related to the occurrence and development of many cancers, but the specific mechanism is not fully understood. It has been found that N6-methyladenosine (m6A) plays a key role in RNA metabolism, but its function in MDSCs has yet to be revealed. In this study, we found that MDSCs in mice with colorectal cancer (CRC) have significantly elevated levels of m6A, while ALKBH5 expression is decreased. Overexpression of ALKBH5 can reduce the immunosuppressive function of MDSCs in vivo and in vitro, and attenuates the protumorigenic ability of MDSCs. Mechanism study found that the overexpression of ALKBH5 in MDSCs reduced the m6A modification level of Arg-1 mRNA, and then weakened the stability of Arg-1 mRNA and protein expression. These data suggest that the decreased expression of ALKBH5 in CRC tumor mice may promote the expression of Arg-1, enhance the immunosuppressor function of MDSCs, and promote tumor growth. These findings highlight that ALKBH5 may regulate the function of MDSCs in tumor-bearing mice and may be a new target for immunotherapy. This research provides a new perspective for our understanding of the role of MDSCs in cancer development, and also brings new hope for cancer treatment.

11.
Small ; : e2400885, 2024 Apr 15.
Article in English | MEDLINE | ID: mdl-38616736

ABSTRACT

The development of pure-blue perovskite light-emitting diodes (PeLEDs) faces challenges of spectral stability and low external quantum efficiency (EQE) due to phase separation in mixed halide compositions. Perovskite quantum dots (QDs) with strong confinement effects are promising alternatives to achieve high-quality pure-blue PeLEDs, yet their performance is often hindered by the poor size distribution and high trap density. A strategy combining thermodynamic control with a polishing-driven ligand exchange process to produce high-quality QDs is developed. The strongly-confined pure-blue (≈470 nm) CsPbBr3 QDs exhibit narrow size distribution (12% dispersion) and are achieved in Br-rich ion environment based on growth thermodynamic control. Subsequent polishing-driven ligand exchange process removes imperfect surface sites and replaces initial long-chain organic ligands with short-chain benzene ligands. The resulting QDs exhibit high photoluminescence quantum yield (PLQY) to near-unity. The resulting PeLEDs exhibit a pure-blue electroluminescence (EL) emission at 472 nm with narrow full-width at half-maximum (FWHM) of 25 nm, achieving a maximum EQE of 10.7% and a bright maximum luminance of 7697 cd m-2. The pure-blue PeLEDs show ultrahigh spectral stability under high voltage, a low roll-off of EQE, and an operational half-lifetime (T50) of 127 min at an initial luminance of 103 cd m-2 under continuous operation.

12.
Eur J Med Chem ; 270: 116358, 2024 Apr 15.
Article in English | MEDLINE | ID: mdl-38574638

ABSTRACT

The fatty acid-binding protein 1 (FABP1) is a fatty acid transporter protein that is considered as an emerging target for metabolic diseases. Despite forceful evidence that the inhibition of FABP1 is essential for ameliorating NASH, pharmacological control and validation of FABP1 are hindered by a lack of relevant inhibitors as pharmacological tool. Therefore, the development of effective FABP1 inhibitors is a current focus of research. Herein, we firstly reported the comprehensive structure-activity relationship (SAR) study of novel FABP1 inhibitors derived from high throughput screening of our in-house library, which resulting in the identification of the optimal compound 44 (IC50 = 4.46 ± 0.54 µM). Molecular docking studies revealed that 44 forms stable hydrogen bonds with amino acids around the active pocket of FABP1. Moreover, 44 alleviated the typical histological features of fatty liver in NASH mice, including steatosis, lobular inflammation, ballooning and fibrosis. Additionally, 44 has been demonstrated to have lipid metabolism regulating, anti-oxidative stress and hepatoprotective properties. This study might be provided a promising insight into the field of NASH and inspiration for the development of FABP1 inhibitors.


Subject(s)
Non-alcoholic Fatty Liver Disease , Mice , Animals , Non-alcoholic Fatty Liver Disease/drug therapy , Molecular Docking Simulation , Lipid Metabolism , Fibrosis , Fatty Acid-Binding Proteins/metabolism , Liver/metabolism
13.
Article in English | MEDLINE | ID: mdl-38442049

ABSTRACT

Accurate detection and segmentation of brain tumors is critical for medical diagnosis. However, current supervised learning methods require extensively annotated images and the state-of-the-art generative models used in unsupervised methods often have limitations in covering the whole data distribution. In this paper, we propose a novel framework Two-Stage Generative Model (TSGM) that combines Cycle Generative Adversarial Network (CycleGAN) and Variance Exploding stochastic differential equation using joint probability (VE-JP) to improve brain tumor detection and segmentation. The CycleGAN is trained on unpaired data to generate abnormal images from healthy images as data prior. Then VE-JP is implemented to reconstruct healthy images using synthetic paired abnormal images as a guide, which alters only pathological regions but not regions of healthy. Notably, our method directly learned the joint probability distribution for conditional generation. The residual between input and reconstructed images suggests the abnormalities and a thresholding method is subsequently applied to obtain segmentation results. Furthermore, the multimodal results are weighted with different weights to improve the segmentation accuracy further. We validated our method on three datasets, and compared with other unsupervised methods for anomaly detection and segmentation. The DSC score of 0.8590 in BraTs2020 dataset, 0.6226 in ITCS dataset and 0.7403 in In-house dataset show that our method achieves better segmentation performance and has better generalization.

14.
Article in English | MEDLINE | ID: mdl-38556538

ABSTRACT

Rheumatoid arthritis (RA) is a common immune disease characterized mainly by erosive arthritis with extensive clinical sequelae. Resveratrol (Res) has pharmacological effects in the treatment of RA, but it has not been widely used in the clinic due to its poor water solubility and low bioavailability. In this study, a drug delivery system (Res-NC MNs) of dissolved microneedles (MNs) loaded with Res nanocrystals (NC) was designed for the treatment of RA. Res-NC MNs can improve the drawbacks of long-term oral drug delivery with toxic side effects and low compliance associated with intra-articular drug delivery. In this study, Res-NC was prepared by media milling and loaded into soluble microneedles prepared from hyaluronic acid (HA) by vacuum casting for the treatment of RA. HA has high mechanical strength and can penetrate the cuticle layer of the skin for effective drug delivery. In in vivo pharmacodynamic experiments, Res-NC MNs achieved better therapeutic efficacy in the treatment of RA compared with oral Res. These findings suggest that Res-NC MNs may be an effective and promising drug delivery strategy for the treatment of RA.

15.
Carbohydr Res ; 538: 109071, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38471432

ABSTRACT

The ocean is the common home of a large number of marine organisms, including plants, animals, and microorganisms. Researchers can extract thousands of important bioactive components from the oceans and use them extensively to treat and prevent diseases. In contrast, marine polysaccharide macromolecules such as alginate, carrageenan, Laminarin, fucoidan, chitosan, and hyaluronic acid have excellent physicochemical properties, good biocompatibility, and high bioactivity, which ensures their wide applications and strong therapeutic potentials in drug delivery. Drug delivery systems (DDS) based on marine polysaccharides and modified marine polysaccharide molecules have emerged as an innovative technology for controlling drug distribution on temporal, spatial, and dosage scales. They can detect and respond to external stimuli such as pH, temperature, and electric fields. These properties have led to their wide application in the design of novel drug delivery systems such as hydrogels, polymeric micelles, liposomes, microneedles, microspheres, etc. In addition, marine polysaccharide-based DDS not only have smart response properties but also can combine with the unique biological properties of the marine polysaccharide base to exert synergistic therapeutic effects. The biological activities of marine polysaccharides and the design of marine polysaccharide-based DDS are reviewed. Marine polysaccharide-based responsive DDS are expected to provide new strategies and solutions for disease treatment.


Subject(s)
Drug Delivery Systems , Polysaccharides , Animals , Polysaccharides/pharmacology , Polysaccharides/chemistry , Carrageenan/chemistry , Alginates , Aquatic Organisms/chemistry
16.
Biomacromolecules ; 25(4): 2645-2655, 2024 Apr 08.
Article in English | MEDLINE | ID: mdl-38456398

ABSTRACT

Conventional techniques for the closure of wounds, such as sutures and staples, have significant drawbacks that can negatively impact wound healing. Tissue adhesives have emerged as promising alternatives, but poor adhesion, low mechanical properties, and toxicity have hindered their widespread clinical adoption. In this work, a dual modified, aldehyde and methacrylate hyaluronic acid (HA) biopolymer (HA-MA-CHO) has been synthesized through a simplified route for use as a double cross-linked network (DCN) hydrogel (HA-MA-CHO-DCN) adhesive for the effective closure and sealing of wounds. HA-MA-CHO-DCN cross-links in two stages: initial cross-linking of the aldehyde functionality (CHO) of HA-MA-CHO using a disulfide-containing cross-linker, 3,3'-dithiobis (propionic hydrazide) (DTPH), leading to the formation of a self-healing injectable gel, followed by further cross-linking via ultraviolet (UV) initiated polymerization of the methacrylate (MA) functionality. This hydrogel adhesive shows a stable swelling behavior and remarkable versatility as the storage modulus (G') has shown to be highly tunable (103-105 Pa) for application to many different wound environments. The new HA-MA-CHO-DCN hydrogel showed excellent adhesive properties by surpassing the burst pressure and lap-shear strength for the widely used bovine serum albumin-glutaraldehyde (BSAG) glue while maintaining excellent cell viability.


Subject(s)
Hyaluronic Acid , Hydrogels , Hydrogels/chemistry , Hyaluronic Acid/chemistry , Adhesives , Glutaral , Methacrylates
17.
Front Pharmacol ; 15: 1373582, 2024.
Article in English | MEDLINE | ID: mdl-38515854

ABSTRACT

Objective: The aim of this study is to assess the postoperative efficacy of the combined administration of dienogest (DNG) and gonadotropin-releasing hormone agonists (GnRH-a) in patients diagnosed with endometriosis (EMS), while acknowledging the extensive use of DNG in the extended therapeutic management of EMS. Methods: In this retrospective study, a cohort of 154 patients who underwent conservative surgical intervention for EMS were scrutinized. The cohort was stratified into two distinct groups based on their prescribed pharmacological regimens. Group A, 70 patients received postoperative oral administration of DNG at a dosage of 2 mg/day, whereas Group B, 84 patients underwent treatment involving 3 to 4 injections of GnRH-a post-surgery, followed by DNG therapy. Parameters assessed included pelvic pain visual analog scale (VAS) scores, quality of life metrics (EHP-5), and the incidence of adverse reactions within both groups. Results: Both groups exhibited sustained low VAS scores following the prescribed treatments. The predominant occurrence of adverse bleeding patterns manifested predominantly within the initial 6 months of the treatment. Notably, Group B demonstrated a significantly diminished of experiencing frequent and irregular bleeding in comparison to the DNG group (20.0% vs. 8.3%, 12.9% vs. 3.6%, p < 0.05). The administration of GnRH-a did not exacerbate the impact on bone health. Subsequent to health promotion interventions, the incidence of weight gain in both groups declined to 7.1% during the 6-month follow-up (p < 0.05). Group B exhibited a 100% satisfaction rate with the treatment, concomitant with a noteworthy reduction in EHP-5 scores (p < 0.05). Patients with deep infiltrating endometriosis (DIE) nodules displayed marginally higher postoperative VAS scores than their non-DIE counterparts (0.89 ± 0.96 vs. 0.49 ± 0.78). However, with sustained medication use, pain scores within the DIE group exhibited a continual decrease, maintaining a low level of 0.29 ± 0.67 at 12 months and beyond. Conclusion: The short-term adjunctive use of GnRH-a prior to DNG treatment postoperatively in patients with EMS proves efficacious in mitigating early adverse bleeding, enhancing patient adherence, and improving overall quality of life. Notably, this therapeutic approach demonstrates favorable safety profiles and is equally effective in patients with DIE.

18.
ACS Nano ; 18(12): 8745-8753, 2024 Mar 26.
Article in English | MEDLINE | ID: mdl-38477519

ABSTRACT

We report a strategy for preparing cost-effective plasmonic square lattices with tunable unit structures of circles, crosses, and circle-cross pairs on a centimeter scale. The asymmetrical electromagnetic (EM) field distribution of the lattice enhances second harmonic generation (SHG) under oblique incidence. The SHG signals are progressively strengthened as the unit symmetry decreases from C∞v (circle) to C4v (cross) to C2v (circle-cross pair). The peak SHG signal is observed from the plasmonic lattice with a circle-cross pair, showcasing a conversion efficiency of 1.0 × 10-2, which is a 7.3-fold enhancement relative to the dielectric lattice comprised of circle units. This notably high conversion efficiency of SHG is on par with that of phase-matched bulk nanostructures under normal incidence, benefiting from the Bloch-surface plasmon polariton (Bloch-SPP) modes associated with the distribution of the photonic local density of states (LDOS). Furthermore, the SHG emission exhibits distinctive directional and polarization characteristics as the unit symmetry is reduced. This work offers valuable insights into a structural symmetry-dependent SHG in plasmonic lattices and the way forward for the design of functional nonlinear plasmonic devices.

19.
Front Pharmacol ; 15: 1267585, 2024.
Article in English | MEDLINE | ID: mdl-38414735

ABSTRACT

Myocardial infarction (MI) imposes a huge medical and economic burden on society, and cardiac repair after MI involves a complex series of processes. Understanding the key mechanisms (such as apoptosis, autophagy, inflammation, and fibrosis) will facilitate further drug development and patient treatment. Presently, a substantial body of evidence suggests that the regulation of epigenetic processes contributes to cardiac repair following MI, with DNA methylation being among the notable epigenetic factors involved. This article will review the research on the mechanism of DNA methylation regulation after MI to provide some insights for future research and development of related drugs.

20.
Materials (Basel) ; 17(4)2024 Feb 09.
Article in English | MEDLINE | ID: mdl-38399096

ABSTRACT

The growth of InGaAs quantum wells (QWs) epitaxially on InP substrates is of great interest due to their wide application in optoelectronic devices. However, conventional molecular beam epitaxy requires substrate temperatures between 400 and 500 °C, which can lead to disorder scattering, dopant diffusion, and interface roughening, adversely affecting device performance. Lower growth temperatures enable the fabrication of high-speed optoelectronic devices by increasing arsenic antisite defects and reducing carrier lifetimes. This work investigates the low-temperature epitaxial growth of InAs/GaAs short-period superlattices as an ordered replacement for InGaAs quantum wells, using migration-enhanced epitaxy (MEE) with low growth temperatures down to 200-250 °C. The InAs/GaAs multi-quantum wells with InAlAs barriers using MEE grown at 230 °C show good single crystals with sharp interfaces, without mismatch dislocations found. The Raman results reveal that the MEE mode enables the growth of (InAs)4(GaAs)3/InAlAs QWs with excellent periodicity, effectively reducing alloy scattering. The room temperature (RT) photoluminescence (PL) measurement shows the strong PL responses with narrow peaks, revealing the good quality of the MEE-grown QWs. The RT electron mobility of the sample grown in low-temperature MEE mode is as high as 2100 cm2/V∗s. In addition, the photoexcited band-edge carrier lifetime was about 3.3 ps at RT. The high-quality superlattices obtained confirm MEE's effectiveness for enabling advanced III-V device structures at reduced temperatures. This promises improved performance for applications in areas such as high-speed transistors, terahertz imaging, and optical communications.

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