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1.
Bioorg Chem ; 147: 107405, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38696843

ABSTRACT

The prolonged intravitreal administration of anti-vascular endothelial growth factor (VEGF) drugs is prone to inducing aberrant retinal vascular development and causing damage to retinal neurons. Hence, we have taken an alternative approach by designing and synthesizing a series of cyclic peptides targeting CC motif chemokine receptor 3 (CCR3). Based on the binding mode of the N-terminal region in CCR3 protein to CCL11, we used computer-aided identification of key amino acid sequence, conformational restriction through different cyclization methods, designed and synthesized a series of target cyclic peptides, and screened the preferred compound IB-2 through affinity. IB-2 exhibits excellent anti-angiogenic activity in HRECs. The apoptosis level of 661W cells demonstrated a significant decrease with the escalating concentration of IB-2. This suggests that IB-2 may have a protective effect on photoreceptor cells. In vivo experiments have shown that IB-2 significantly reduces retinal vascular leakage and choroidal neovascularization (CNV) area in a laser-induced mouse model of CNV. These findings indicate the potential of IB-2 as a safe and effective therapeutic agent for AMD, warranting further development.


Subject(s)
Macular Degeneration , Peptides, Cyclic , Receptors, CCR3 , Animals , Peptides, Cyclic/chemistry , Peptides, Cyclic/pharmacology , Peptides, Cyclic/chemical synthesis , Macular Degeneration/drug therapy , Macular Degeneration/pathology , Mice , Receptors, CCR3/antagonists & inhibitors , Receptors, CCR3/metabolism , Humans , Angiogenesis Inhibitors/pharmacology , Angiogenesis Inhibitors/chemical synthesis , Angiogenesis Inhibitors/chemistry , Molecular Structure , Structure-Activity Relationship , Mice, Inbred C57BL , Dose-Response Relationship, Drug , Apoptosis/drug effects , Choroidal Neovascularization/drug therapy , Choroidal Neovascularization/pathology , Choroidal Neovascularization/metabolism , Photoreceptor Cells, Vertebrate/drug effects , Photoreceptor Cells, Vertebrate/pathology , Angiogenesis
2.
Front Psychiatry ; 15: 1404680, 2024.
Article in English | MEDLINE | ID: mdl-38807692

ABSTRACT

Introduction: Athletes, due to frequent physical interactions in competitive sports, are prone to impulsive behavior. Impulsive behavior is a prevalent psychological factor in sports, often leading to performance-affecting errors. This cross-sectional survey investigated the relationship between mindfulness and athletes' impulsive behavior. Methods: We sampled 403 athletes from youth training centers, universities, sports academies, and clubs in China using convenience and snowball sampling. Using AMOS v23, we analyzed the data with a structural equation model. Results: Our structural equation model confirmed that mindfulness and self-regulation inversely correlate with impulsive behavior, while social evaluation anxiety positively correlates with impulsive behavior. Furthermore, self-regulation and social evaluation anxiety serve as intermediaries in the link between mindfulness and impulsive behavior. Discussions: This research suggests introducing mindfulness meditation practices in competitive settings to improve athletes' social evaluation anxiety and enhance their self-regulation abilities, thereby boosting their psychological health and curbing impulsive behavior.

3.
Angew Chem Int Ed Engl ; 63(23): e202403415, 2024 Jun 03.
Article in English | MEDLINE | ID: mdl-38573437

ABSTRACT

Metal-backboned polymers (MBPs), with a unique backbone consisting of bonded metal atoms, are promising for optic, electric, magnetic, and thermoelectric fields. However, the application of MBP remains relatively understudied. Here, we develop a shear-induced orientation method to construct a flexible nickel-backboned polymer/carbon nanotube (NBP/CNT) thermoelectric composite fiber. It demonstrated a power factor of 719.48 µW ⋅m-1 K-2, which is ca. 3.5 times as high as the bare CNT fiber. Remarkably, with the regulation of carrier mobility and carrier concentration of NBP, the composite fiber further showed simultaneous increases in electrical conductivity and Seebeck coefficient in comparison to the bare CNT fiber. The NBP/CNT fiber can be integrated into fabrics to harvest thermal energy of human body to generate an output voltage of 3.09 mV at a temperature difference of 8 K. This research opens a new avenue for the development of MBPs in power supply.

4.
Bioorg Chem ; 147: 107371, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38643564

ABSTRACT

Due to the strong selectivity and permeability of tumor tissue, anti-cancer peptide-drug conjugates (PDCs) can accumulate high concentration of toxic payloads at the target, effectively killing tumor cells. This approach holds great promise for tumor-targeted treatment. In our previous study, we identified the optimal peptide P1 (NPNWGRSWYNQRFK) targeting HER2 from pertuzumab, a monoclonal antibody that blocks the HER2 signaling pathway. Here, a series of PDCs were constructed through connecting P1 and CPT with different linkers. Among these, Z8 emerged as the optimal compound, demonstrating good antitumor activity and targeting ability in biological activity tests. Z8 exhibited IC50 values of 1.04 ± 0.24 µM and 1.91 ± 0.71 µM against HER2-positive SK-BR-3 and NCI-N87 cells, respectively. Moreover, superior antitumor activity and higher biosafety of Z8 were observed compared to the positive control CPT in vivo, suggesting a novel idea for the construction of PDCs.


Subject(s)
Antineoplastic Agents , Camptothecin , Cell Proliferation , Drug Screening Assays, Antitumor , Peptides , Receptor, ErbB-2 , Humans , Receptor, ErbB-2/metabolism , Receptor, ErbB-2/antagonists & inhibitors , Antineoplastic Agents/pharmacology , Antineoplastic Agents/chemistry , Antineoplastic Agents/chemical synthesis , Camptothecin/pharmacology , Camptothecin/chemistry , Structure-Activity Relationship , Animals , Cell Proliferation/drug effects , Peptides/chemistry , Peptides/pharmacology , Peptides/chemical synthesis , Molecular Structure , Dose-Response Relationship, Drug , Mice , Drug Discovery , Cell Line, Tumor , Female , Mice, Inbred BALB C , Mice, Nude
5.
Stem Cell Res Ther ; 15(1): 87, 2024 Mar 22.
Article in English | MEDLINE | ID: mdl-38520027

ABSTRACT

BACKGROUND: The clinical application of human bone-marrow derived mesenchymal stem cells (MSCs) for the treatment of refractory diseases has achieved remarkable results. However, there is a need for a systematic evaluation of the quality and safety of MSCs sourced from donors. In this study, we sought to assess one potential factor that might impact quality, namely the age of the donor. METHODS: We downloaded two data sets from each of two Gene Expression Omnibus (GEO), GSE39035 and GSE97311 databases, namely samples form young (< 65 years of age) and old (> 65) donor groups. Through, bioinformatics analysis and experimental validation to these retrieved data, we found that MSCs derived from aged donors can lead to differential expression of gene profiles compared with those from young donors, and potentially affect the function of MSCs, and may even induce malignant tumors. RESULTS: We identified a total of 337 differentially expressed genes (DEGs), including two upregulated and eight downregulated genes from the databases of both GSE39035 and GSE97311. We further identified 13 hub genes. Six of them, TBX15, IGF1, GATA2, PITX2, SNAI1 and VCAN, were highly expressed in many human malignancies in Human Protein Atlas database. In the MSCs in vitro senescent cell model, qPCR analysis validated that all six hub genes were highly expressed in senescent MSCs. Our findings confirm that aged donors of MSCs have a significant effect on gene expression profiles. The MSCs from old donors have the potential to cause a variety of malignancies. These TBX15, IGF1, GATA2, PITX2, SNAI1, VCAN genes could be used as potential biomarkers to diagnosis aging state of donor MSCs, and evaluate whether MSCs derived from an aged donor could be used for therapy in the clinic. Our findings provide a diagnostic basis for the clinical use of MSCs to treat a variety of diseases. CONCLUSIONS: Therefore, our findings not only provide guidance for the safe and standardized use of MSCs in the clinic for the treatment of various diseases, but also provide insights into the use of cell regeneration approaches to reverse aging and support rejuvenation.


Subject(s)
Mesenchymal Stem Cells , Neoplasms , Humans , Aged , Aging/metabolism , Tissue Donors , Biomarkers/metabolism , Mesenchymal Stem Cells/metabolism , Neoplasms/metabolism , T-Box Domain Proteins/metabolism
6.
Front Psychol ; 15: 1304901, 2024.
Article in English | MEDLINE | ID: mdl-38283206

ABSTRACT

Introduction: In the highly competitive field of sports, impulsive behavior by athletes not only threatens personal and team harmony but also poses significant risks to their careers and public image. Despite these behaviors often becoming the focus of public attention, their underlying causes and prevention strategies remain relatively unknown. This study delves deep into the impact of mindfulness on athletes' impulsive behavior, revealing the mediating roles of self-reflection and coping effectiveness. Methods: Using a combination of snowball and convenience sampling, a sample of 403 athletes from high-level sports teams in the Central China region participated in a questionnaire survey. The data were analyzed using Amos v.23 software. Results: The findings indicate a positive correlation between mindfulness and coping effectiveness (standardized coefficient = 0.336, p < 0.001), as well as between self-reflection and coping effectiveness (standardized coefficient = 0.406, p < 0.001). There is a negative correlation between coping effectiveness and impulsive behavior (standardized coefficient = -0.476, p < 0.001). The positive impact of mindfulness on impulsive behavior (standardized coefficient = -0.371, p < 0.01) is mediated by self-reflection and coping effectiveness. The explanatory power of this study is R2 = 0.35. Discussion: Mindfulness reduces impulsive behavior by enhancing self-reflection capabilities and improving coping effectiveness. Based on these substantive research results, to mitigate impulsive behavior in athletes, it is recommended that the National Sports Administration and coaches actively implement mindfulness training. Additionally, targeted psychological intervention strategies should be developed to enhance athletes' mental health levels and optimize their sports performance.

7.
Int J Biol Macromol ; 260(Pt 2): 129527, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38246435

ABSTRACT

Oxidative stress-induced enteric neuropathy is an important factor in slow transit constipation (STC). Cistanche deserticola crude polysaccharides (CDCP) are natural antioxidants with various biological activities. We prepared CDCP through water-extract and alcohol-precipitation methods. The structural characteristics of CDCP were analyzed by infrared spectroscopy and methylation analysis. The results showed that CDCP was primarily composed of (1 â†’ 4)-linked glucans with minor amounts of pectic polysaccharides. Different doses of CDCP (100, 200, and 400 mg/kg) were administered to loperamide-induced STC mice to explore the therapeutic effects of CDCP. Compared with the untreated group, CDCP treatment significantly improved constipation symptoms, relevant gut-regulating peptides levels, colonic pathological damage, and colonic myenteric nerons injury. CDCP enhanced the antioxidant capacity by decreasing Malondialdehyde (MDA) content, increasing Superoxide Dismutase (SOD) activity and Reduced Glutathione (GSH) content. CDCP significantly reduced oxidative stress-induced injury by preserving mitochondrial function in the colonic myenteric plexus. Furthermore, the neuroprotective effects of CDCP might be associated with the Nrf2/Keap1 pathway. Thus, our findings first revealed the potential of CDCP to protect the colonic myenteric plexus against oxidative stress-induced damage in STC, establishing CDCP as promising candidates for natural medicine in the clinical management of STC.


Subject(s)
Cistanche , Neuroprotective Agents , Mice , Animals , Cistanche/chemistry , Neuroprotective Agents/pharmacology , Kelch-Like ECH-Associated Protein 1/metabolism , NF-E2-Related Factor 2/metabolism , Constipation/chemically induced , Constipation/drug therapy , Constipation/metabolism , Oxidative Stress , Antioxidants/pharmacology , Antioxidants/metabolism , Polysaccharides/pharmacology , Polysaccharides/chemistry
8.
Adv Mater ; 36(16): e2312590, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38227454

ABSTRACT

Fiber solar cells as promising wearable power supplies have attracted increasing attentions recently, while further breakthrough on their power conversion efficiency (PCE) and realization of multicolored appearances remain urgent needs particularly in real-world applications. Here, a fiber-dye-sensitized solar cell (FDSSC) integrated with a light diffusion layer composed of alumina/polyurethane film on the outmost encapsulating tube and a light conversion layer made from phosphors/TiO2/poly(vinylidene fluoride-co-hexafluoropropylene) film on the inner counter electrode is designed. The incident light is diffused to more surfaces of fiber electrodes, then converted on counter electrode and reflected to neighboring photoanode, so the FDSSC efficiently takes advantage of the fiber shape for remarkably enhanced light harvesting, producing a record PCE of 13.11%. These efficient FDSSCs also realize color-tunable appearances, improving their designability and compatibility with textiles. They are further integrated with fiber batteries as power systems, providing a power solution for wearables and emerging smart textiles.

9.
Adv Mater ; 36(11): e2304876, 2024 Mar.
Article in English | MEDLINE | ID: mdl-37543841

ABSTRACT

Photovoltaic devices represent an efficient electricity generation mode. Integrating them into textiles offers exciting opportunities for smart electronic textiles-with the ultimate goal of supplying power for wearable technology-which is poised to change how electronic devices are designed. Many human activities occur indoors, so realizing indoor photovoltaic fibers (IPVFs) that can be woven into textiles to power wearables is critical, although currently unavailable. Here, a dye-sensitized IPVF is constructed by incorporating titanium dioxide nanoparticles into aligned nanotubes to produce close contact and stable interfaces among active layers on a curved fiber substrate, thus presenting efficient charge transport and low charge recombination in the photoanode. With the combination of highly conductive core-sheath Ti/carbon nanotube fiber as a counter electrode, the IPVF shows a certified power conversion efficiency of 25.53% under 1500 lux illuminance. Its performance variation is below 5% after bending, twisting, or pressing for 1000 cycles. These IPVFs are further integrated with fiber batteries as self-charging power textiles, which are demonstrated to effectively supply electricity for wearables, solving the power supply problem in this important direction.

10.
Environ Sci Technol ; 58(1): 760-770, 2024 Jan 09.
Article in English | MEDLINE | ID: mdl-38149879

ABSTRACT

The photochemically generated oxidative organic radicals (POORs) in dissolved black carbon (DBC) was investigated and compared with that in dissolved organic matter (DOM). POORs generated in DBC solutions exhibited higher one-electron reduction potential values (1.38-1.56 V) than those in DOM solutions (1.22-1.38 V). We found that the photogeneration of POORs from DBC is enhanced with dissolved oxygen (DO) increasing, while the inhibition of POORs is observed in reference to DOM solution. The behavior of the one-electron reducing species (DBC•-/DOM•-) was employed to explain this phenomenon. The experimental results revealed that the DO concentration had a greater effect on DBC•- than on DOM•-. Low DO levels led to a substantial increase in the steady-state concentration of DBC•-, which quenched the POORs via back-electron reactions. Moreover, the contribution of POORs to the degradation of 19 emerging organic contaminants (EOCs) in sunlight-exposed DBC and DOM solutions was estimated. The findings indicate that POORs play an important role in the photodegradation of EOCs previously known to react with triplets, especially in DBC solutions. Compared to DOM solutions, POOR exhibits a lower but considerable contribution to EOC attenuation. This study enhances the understanding of pollutant fate in aquatic environments by highlighting the role of DBC in photochemical pollutant degradation and providing insights into pollutant transformation mechanisms involving POORs.


Subject(s)
Environmental Pollutants , Solar Energy , Photolysis , Oxygen , Soot , Dissolved Organic Matter , Carbon , Oxidative Stress
11.
Rev Sci Instrum ; 94(11)2023 Nov 01.
Article in English | MEDLINE | ID: mdl-37971322

ABSTRACT

The gas gap of a multi-gap gas switch can be classified as trigger and self-breakdown gaps based on the breakdown condition. A two-gap gas switch consisting of a trigger gap and a self-breakdown gap is developed to independently study the breakdown characteristics of these two types of switch gaps. Trigger experiments for the switch are conducted under various trigger voltage rise rates and different working coefficients. The experimental results indicate that the trigger gap has significantly more jitter than the self-breakdown gap, and the overall performance of the gas switch is determined primarily by the trigger gap. A novel pre-ionization structure with disks is implemented into the two-gap gas switch, considerably decreasing the breakdown delay of the trigger gap and reducing the jitter to a quarter or even less compared to that without pre-ionization. A calculation model of the breakdown time delay for the trigger gap is provided based on the foundational development of the avalanche. The probability distribution of the time required for the initial electron generation is derived in the absence of pre-ionization. The calculated breakdown time delay agrees well with the experimental results in cases with and without pre-ionization under most trigger settings. The method and principle of calculating the breakdown time delay can analyze the collapse of a gas gap with different electrode configurations (quasi-uniform or uniform electrical fields) and various gas media under a nanosecond pulse voltage.

12.
Food Res Int ; 173(Pt 1): 113327, 2023 11.
Article in English | MEDLINE | ID: mdl-37803637

ABSTRACT

The pH treatment significantly enhanced the functional properties of egg white protein (EWP), but little is known about the relationship between pH treatment and in vitro digestion of EWP. In this paper, we explored the effect of pH treatment (pH 2, pH 2-7, pH 12 and pH 12-7) on the digestibility of egg white protein and peptide profiling using the digestion kinetics and peptidomics methods, separately. The results implied that all pH treatment reduced the protein digestibility in gastric phase, while alkaline pH (pH 12 and pH 12-7) showed greater digestion level and more gastric peptides, and more importantly, produced a greater amount of potentially bioactive peptides than acid treated samples. Besides, the least number of potentially bioactive peptides was obtained at pH 2, but this could be improved by adjusting pH 2 back to 7. Notably, the unique bioactive peptides induced by pH were mainly relevant to DPP IV inhibitor. These differences of digestibility and peptide profiling might be attributed to the change of protein structure and the formation of molten sphere, altering cleavage sites of digestive enzymes. This work would give an enlightening insight into the digestive and nutritional characteristics of the pH-induced EWP to expand their application in the field of food and healthcare.


Subject(s)
Egg Proteins , Peptides , Proteolysis , Egg Proteins/chemistry , Peptides/chemistry , Hydrogen-Ion Concentration
13.
Adv Healthc Mater ; 12(31): e2301610, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37717208

ABSTRACT

Repairing high-load connective tissues, such as ligaments, by surgically implanting artificial grafts after injury is challenging because they lack biointegration with host bones for stable interfaces. Herein, a high-performance helical composite fiber (HCF) ligament by wrapping aligned carbon nanotube (CNT) sheets around polyester fibers is proposed. Anterior cruciate ligament (ACL) reconstruction surgery shows that HCF grafts could induce effective bone regeneration, thus allowing the narrowing of bone tunnel defects. Such repair of the bone tunnel is in strong contrast to the tunnel enlargement of more than 50% for commercial artificial ligaments made from bare polyester fibers. Rats reconstructed with this HCF ligament show normal jumping, walking, and running without limping. This work allows bone regeneration in vivo through a one-step surgery without seeding cells or transforming growth factors, thereby opening an avenue for high-performance artificial tissues.


Subject(s)
Anterior Cruciate Ligament Reconstruction , Nanotubes, Carbon , Animals , Rats , Anterior Cruciate Ligament/transplantation , Polyesters
14.
Turk J Chem ; 47(2): 426-435, 2023.
Article in English | MEDLINE | ID: mdl-37528931

ABSTRACT

Based on the privileged fragment-based drug design strategy, a series of imatinib analogues bearing the moiety of 3-(2-amino-2-oxoacetyl)-1H-indole were designed and synthesized, and the in vitro antitumor activity of these compounds was detected by MTT method using K562 (human myeloid leukemia) and K562R (imatinib-resistant chronic myeloid leukemia) cell lines. Molecular docking was used to preliminarily explain the possible binding modes. The most potent compound I2 exhibited better antitumor activity than those of imatinib against K562 and K562R cancer cells with IC50 values of 0.8 µM and 0.7 µM.

15.
Water Res ; 243: 120395, 2023 Sep 01.
Article in English | MEDLINE | ID: mdl-37549448

ABSTRACT

Algal organic matter (AOM), a significant source of endogenous dissolved organic matter (DOM) is released in high concentrations during cyanobacterial blooms, along with cyanotoxins. Subsequent photobleaching of AOM is an important phenomenon to investigate. In this study, intracellular organic matter (IOM) and extracellular organic matter (EOM) were extracted from cultured cyanobacteria taken from Taihu Lake in China. The formation of photochemically produced reactive intermediates in different stages of IOM and EOM photobleaching was compared to Suwannee River DOM (SRDOM, reference standard DOM). Results revealed notable differences influenced by the pigment component among IOM, EOM, and SRDOM. The pigment in IOM contributed to a triplet state pool with strong energy-transfer but limited electron-transfer capabilities. Notably, IOM exhibited the highest triplets state quantum yield value in the visible region, suggesting its potential significance in pollutant degradation in deeper water layers. For EOM, one of the pools exhibits photolability and remarkable electron-transfer capability, indicating it as a high-energy triplet state component. Moreover, three cyanotoxins (MC-LR, ACA, and ATX-a) were detected in the extracted AOM, and their photodegradation was monitored during the AOM photobleaching process. This highlights the potential role of AOM as a photosensitizer in the natural self-cleaning mechanisms of water bodies, facilitating the degradation of organic pollutants through photochemical reactions. The findings of this study contribute to understanding the dynamic nature of AOM and its implications in environmental processes.


Subject(s)
Cyanobacteria , Photobleaching , Photolysis , Cyanobacteria Toxins , China
16.
Virol J ; 20(1): 193, 2023 08 28.
Article in English | MEDLINE | ID: mdl-37641134

ABSTRACT

Influenza A viruses cause severe respiratory illnesses in humans and animals. Overreaction of the innate immune response to influenza virus infection results in hypercytokinemia, which is responsible for mortality and morbidity. The influenza A virus surface glycoprotein neuraminidase (NA) plays a vital role in viral attachment, entry, and virion release from infected cells. NA acts as a sialidase, which cleaves sialic acids from cell surface proteins and carbohydrate side chains on nascent virions. Here, we review progress in understanding the role of NA in modulating host immune response to influenza virus infection. We also discuss recent exciting findings targeting NA protein to interrupt influenza-induced immune injury.


Subject(s)
Influenza A virus , Influenza, Human , Orthomyxoviridae Infections , Animals , Humans , Neuraminidase , Immunity, Innate
17.
Environ Sci Technol ; 57(30): 11144-11151, 2023 08 01.
Article in English | MEDLINE | ID: mdl-37462617

ABSTRACT

Photosensitized renoxification of HNO3 is found to produce HONO in an unexpectedly high yield, which has been considered an important source for atmospheric HONO. Conventionally, the production of HONO is ascribed to the secondary photolysis of the primarily formed NO2. In this study, by using humic acid (HA) as a model environmental photosensitizer, we provide evidence of the direct formation of NO2 in its electronic excited state (NO2*) as a key intermediate during the photosensitizing renoxification of HNO3. Moreover, the high HONO yield originates from the heterogeneous reaction of the primarily formed NO2* with the co-adsorbed water molecules on HA. Such a mechanism is supported by the increase of the product selectivity of HONO with relative humidity. Further luminescence measurements demonstrate clearly the occurrence of an electronic excited state (NO2*) from photolysis of adsorbed HNO3 on HA. This work deepens our understanding of the formation of atmospheric HONO and gives insight into the transformation of RNS.


Subject(s)
Nitrogen Dioxide , Nitrous Acid , Humic Substances , Photolysis , Water
18.
Food Chem ; 426: 136575, 2023 Nov 15.
Article in English | MEDLINE | ID: mdl-37321120

ABSTRACT

This study aimed to form a novel emulsion gel (EG) through structured oil phase of natural component beeswax (BW), together with ovalbumin (OVA), and to investigate the mechanism of its formation and stabilization in terms of microstructure and processing properties. Confocal laser scanning microscopy (CLSM) demonstrated that the EG formed a continuous double network structure since the superior crystallinity of the oil phase was given by BW. Fourier transform infrared spectroscopy (FT-IR) illustrated that the acylation of the phenolic hydroxyl group in BW with an amide bond in OVA, increased the hydrogen bonding of EG. Furthermore, the immobilization of the oil phase results in better thermal and freeze-thaw stability of EG. Finally, EG was used as a curcumin delivery system, and the presence of BW significantly improved its adaptability to multiple environmental factors. In summary, our study would provide valuable ideas for developing the design of finely structured functional food.


Subject(s)
Waxes , Emulsions/chemistry , Ovalbumin/chemistry , Spectroscopy, Fourier Transform Infrared
19.
Rev Sci Instrum ; 94(5)2023 May 01.
Article in English | MEDLINE | ID: mdl-37133344

ABSTRACT

To improve the triggering characteristics of the gas switch used for linear transformer driver, a method of corona assisted triggering based on the pre-ionization in switch gaps is proposed and applied to a six-gap gas switch. The principle is demonstrated by electrostatic field analysis and verified by the experimental study on the discharge characteristics of the gas switch. The results indicate that when the gas pressure is 0.3 MPa, the self-breakdown voltage remains about ±80 kV, and its dispersivity is lower than 3%. The effect of corona assisted triggering on the triggering characteristics increases with the higher permittivity of the inner shield. The positive trigger voltage of the switch with the proposed method can be reduced from 110 to 30 kV at a charging voltage of ±80 kV when the jitter is equal to that of the original switch. There are no pre-fire or late-fire when the switch operates continuously for 2000 shots.

20.
Bioorg Med Chem Lett ; 88: 129265, 2023 05 15.
Article in English | MEDLINE | ID: mdl-37011767

ABSTRACT

Son of sevenless 1 (SOS1) is a vital guanine nucleotide exchange factor (GEFs) that activates rat sarcoma (Ras) protein in cells. SOS1 inhibitors can effectively inhibit the expression of downstream signaling pathways by blocking the interaction between SOS1 and Ras protein. Here, we designed and synthesized a series of quinazoline-based compounds, and conducted subsequent evaluations of their biological activities. Among them, the comparable compounds I-2 (IC50 = 20 nM, against SOS1) I-5 (IC50 = 18 nM, against SOS1) and I-10 (IC50 = 8.5 nM, against SOS1) have kinase activity equivalent to BAY-293 (IC50 = 6.6 nM, against SOS1), and I-10 also has cell activity equivalent to BAY-293, providing a theoretical reference for subsequent related researches on SOS1 inhibitors.


Subject(s)
Nuclear Family , Signal Transduction , Son of Sevenless Proteins , Guanine Nucleotide Exchange Factors/metabolism , Phosphorylation , Son of Sevenless Proteins/antagonists & inhibitors , Quinazolines/chemistry , Quinazolines/pharmacology
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