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1.
JMIR Public Health Surveill ; 10: e58761, 2024 Jul 03.
Article in English | MEDLINE | ID: mdl-38967416

ABSTRACT

Background: Cycling is known to be beneficial for human health. Studies have suggested significant associations of physical activity with macroscale built environments and streetscapes. However, whether good streetscapes can amplify the benefits of a favorable built environment on physical activity remains unknown. Objective: This study examines whether streetscape perceptions can modify the associations between accessibility, land use mix, and bike-sharing use. Methods: This cross-sectional study used data from 18,019,266 bike-sharing orders during weekends in Shanghai, China. A 500 × 500 m grid was selected as the analysis unit to allocate data. Bike-sharing use was defined as the number of bike-sharing origins. Street view images and a human-machine adversarial scoring framework were combined to evaluate lively, safety, and wealthy perceptions. Negative binomial regression was developed to examine the independent effects of the three perceptual factors in both the univariate model and fully adjusted model, controlling for population density, average building height, distance to nearest transit, number of bus stations, number of points of interest, distance to the nearest park, and distance to the central business district. The moderation effect was then investigated through the interaction term between streetscape perception and accessibility and land use mix, based on the fully adjusted model. We also tested whether the findings of streetscape moderation effects are robust when examinations are performed at different geographic scales, using a small-sample statistics approach and different operationalizations of land use mix and accessibility. Results: High levels of lively, safety, and wealthy perceptions were correlated with more bike-sharing activities. There were negative effects for the interactions between the land use Herfindahl-Hirschman index with the lively perception (ß=-0.63; P=.01) and safety perception (ß=-0.52; P=.001). The interaction between the lively perception and road intersection density was positively associated with the number of bike-sharing uses (ß=0.43; P=.08). Among these, the lively perception showed the greatest independent effect (ß=1.29; P<.001), followed by the safety perception (ß=1.22; P=.001) and wealthy perception (ß=0.72; P=.001). The findings were robust in the three sensitivity analyses. Conclusions: A safer and livelier streetscape can enhance the benefits of land use mix in promoting bike-sharing use, with a safer streetscape also intensifying the effect of accessibility. Interventions focused on streetscape perceptions can encourage cycling behavior and enhance the benefits of accessibility and land use mix. This study also contributes to the literature on potential moderators of built environment healthy behavior associations from the perspective of microscale environmental perceptions.


Subject(s)
Bicycling , Humans , Cross-Sectional Studies , Bicycling/statistics & numerical data , Bicycling/psychology , China , Environment Design/statistics & numerical data , Built Environment/statistics & numerical data , Male , Female , Residence Characteristics/statistics & numerical data , Adult
2.
Macromol Rapid Commun ; : e2400245, 2024 Jul 16.
Article in English | MEDLINE | ID: mdl-39012277

ABSTRACT

Advancements in flexible electronic technology, especially the progress in foldable displays and under-display cameras (UDC), have created an urgent demand for high-performance colorless polyimide (CPI). However, current CPIs lack sufficient heat resistance for substrate applications. In this work, four kinds of rigid spirobifluorene diamines are designed, and the corresponding polyimides are prepared by their condensation with 5,5'-(perfluoropropane-2,2-diyl) bis(isobenzofuran-1,3-dione) (6FDA) or 9,9-bis(3,4-dicarboxyphenyl) fluorene dianhydride (BPAF). The rigid and conjugated spirobifluorene units endow the polyimides with higher glass transition temperature (Tg) ranging from 356 to 468 °C. Their optical properties are regulated by small side groups and spirobifluorene structure with a periodically twisted molecular conformation. Consequently, a series of CPIs with an average transmittance ranging from 75% to 88% and a yellowness index (YI) as low as 2.48 are obtained. Among these, 27SPFTFA-BPAF presents excellent comprehensive performance, with a Tg of 422 °C, a 5 wt.% loss temperature (Td5) of 562 °C, a YI of 3.53, and a tensile strength (δmax) of 140 MPa, respectively. The mechanism underlying the structure-property relationship is investigated by experimental comparison and theoretical calculation, and the proposed method provides a pathway for designing highly rigid conjugated CPIs with excellent thermal stability and transparency for photoelectric engineering.

3.
J Am Chem Soc ; 2024 Jul 08.
Article in English | MEDLINE | ID: mdl-38975938

ABSTRACT

An asymmetric intramolecular spiro-amination to high steric hindering α-C-H bond of 1,3-dicarbonyl via nitrene transfer using inactive aryl azides has been carried out by developing a novel Cp*Ir(III)-SPDO (spiro-pyrrolidine oxazoline) catalyst, thereby enabling the first successful construction of structurally rigid spiro-quaternary indolinone cores with moderate to high yields and excellent enantioselectivities. DFT computations support the presence of double bridging H-F bonds between [SbF6]- and both the ligand and substrate, which favors the plane-differentiation of the enol π-bond for nitrenoid attacking. These findings open up numerous opportunities for the development of new asymmetric nitrene transfer systems.

4.
MedComm (2020) ; 5(7): e625, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38919335

ABSTRACT

Overexposure to ultraviolet light (UV) has become a major dermatological problem since the intensity of ultraviolet radiation is increasing. As an adaption to outside environments, amphibians gained an excellent peptide-based defense system in their naked skin from secular evolution. Here, we first determined the adaptation and resistance of the dark-spotted frogs (Pelophylax nigromaculatus) to constant ultraviolet B (UVB) exposure. Subsequently, peptidomics of frog skin identified a series of novel peptides in response to UVB. These UV-induced frog skin peptides (UIFSPs) conferred significant protection against UVB-induced death and senescence in skin cells. Moreover, the protective effects of UIFSPs were boosted by coupling with the transcription trans-activating (TAT) protein transduction domain. In vivo, TAT-conjugated UIFSPs mitigated skin photodamage and accelerated wound healing. Transcriptomic profiling revealed that multiple pathways were modulated by TAT-conjugated UIFSPs, including small GTPase/Ras signaling and MAPK signaling. Importantly, pharmacological activation of MAPK kinases counteracted UIFSP-induced decrease in cell death after UVB exposure. Taken together, our findings provide evidence for the potential preventive and therapeutic significance of UIFSPs in UV-induced skin damage by antagonizing MAPK signaling pathways. In addition, these results suggest a practicable alternative in which potential therapeutic agents can be mined from organisms with a fascinating ability to adapt.

5.
Org Lett ; 26(27): 5657-5663, 2024 Jul 12.
Article in English | MEDLINE | ID: mdl-38941517

ABSTRACT

A protocol for the electrooxidative [3+2] annulation to generate indolo[2,3-b]indoles in an undivided cell is reported. It exhibits good yields with excellent regioselectivities and tolerates various functional groups without external chemical oxidants. Cyclic voltammetry and density functional theory calculations indicate that the [3+2] annulation is initiated by the simultaneous anodic oxidation of indole and aniline derivatives, and the step to determine the rate relies on the combination of radical cations.

6.
Inorg Chem ; 63(26): 12360-12369, 2024 Jul 01.
Article in English | MEDLINE | ID: mdl-38870427

ABSTRACT

The structural transformation of metal-organic frameworks (MOFs) has attracted increasing interests, which has not only produced various new structures but also served as a fantastic platform for MOF-based kinetic analysis. Multiple reaction conditions have been documented to cause structural transformation; nevertheless, central metal-induced topological alteration of MOFs is rare. Herein, we reported a structural transformation of a 2D layered Cd-MOF driven by Cd(II) ions. After being submerged in the aqueous solution of cadmium nitrate, the twofold interpenetrated 2D network of [Cd(hsb-2)(bdc)·5H2O]n [HSB-W10; bdc: 1,4-benzenedicarboxylate; hsb-2:1,2-bis(4'-pyridylmethylamino)-ethane] was converted into a novel noninterpenetrated 2D network [Cd1.5(hsb-2)(bdc)1.5(H2O)2·H2O]n (HSB-W16). This partial dissolution-recrystallization process was investigated by integrating controlled experiments, 1H NMR spectra, and photographic tracking analysis. Furthermore, a novel strategy combining in situ multicomponent dye encapsulation and central metal-triggered structural transformation was developed for the fabrication of MOF materials with white-light emission. By adopting this strategy, different dye guest molecules were concurrently introduced into the HSB-W16 host matrix, leading to a range of white-light-emitting MOF composites. This work will enable detailed studies of solid-state transformations and demonstrate a promising application prospect for structural transformation.

7.
Talanta ; 277: 126436, 2024 Jun 15.
Article in English | MEDLINE | ID: mdl-38901192

ABSTRACT

Cancer cells have a high abundance of hypochlorite compared to normal cells, which can be used as the biomarker for imaging cancer cells and tumor. Developing the tumor-targeting fluorescent probe suitable for imaging hypochlorite in vivo is urgently demanded. In this article, based on xanthene dye with a two-photon excited far-red to NIR emission, a tumor-targeting two-photon fluorescent probe (Biotin-HClO) for imaging basal hypochlorite in cancer cells and tumor was developed. For ClO-, Biotin-HClO (20.0 µM) has a linear response range from 15.0 × 10-8 to 1.1 × 10-5 M with a high selectivity and a high sensitivity, a good detection limit of 50 nM and a 550-fold fluorescence enhancement with high signal-to-noise ratio (20 mM PBS buffer solution with 50 % DMF; pH = 7.4; λex = 605 nm; λem = 635 nm). Morover, Biotin-HClO exhibited excellent performance in monitoring exogenous and endogenous ClO- in cells, and has an outstanding tumor-targeting ability. Subsequently, Biotin-HClO has been applied for imaging ClO- in 4T1 tumor tissue to distinguish from normal tissue. Furthermore, Biotin-HClO was successfully employed for high-contrast imaging 4T1 tumor in mouse based on its tumor-targeting ability. All these results proved that Biotin-HClO is a useful analytical tool to detect ClO- and image tumor in vivo.

8.
Cell Mol Immunol ; 2024 Jun 07.
Article in English | MEDLINE | ID: mdl-38849539

ABSTRACT

The key role of structural cells in immune modulation has been revealed with the advent of single-cell multiomics, but the underlying mechanism remains poorly understood. Here, we revealed that the transcriptional activation of interferon regulatory factor 1 (IRF1) in response to ionizing radiation, cytotoxic chemicals and SARS-CoV-2 viral infection determines the fate of structural cells and regulates communication between structural and immune cells. Radiation-induced leakage of mtDNA initiates the nuclear translocation of IRF1, enabling it to regulate the transcription of inflammation- and cell death-related genes. Novel posttranslational modification (PTM) sites in the nuclear localization sequence (NLS) of IRF1 were identified. Functional analysis revealed that mutation of the acetylation site and the phosphorylation sites in the NLS blocked the transcriptional activation of IRF1 and reduced cell death in response to ionizing radiation. Mechanistically, reciprocal regulation between the single-stranded DNA sensors SSBP1 and IRF1, which restrains radiation-induced and STING/p300-mediated PTMs of IRF1, was revealed. In addition, genetic deletion or pharmacological inhibition of IRF1 tempered radiation-induced inflammatory cell death, and radiation mitigators also suppressed SARS-CoV-2 NSP-10-mediated activation of IRF1. Thus, we revealed a novel cytoplasm-oriented mechanism of IRF1 activation in structural cells that promotes inflammation and highlighted the potential effectiveness of IRF1 inhibitors against immune disorders.

9.
Anal Methods ; 16(20): 3263-3270, 2024 May 23.
Article in English | MEDLINE | ID: mdl-38738477

ABSTRACT

To detect redox potential evolution during the initial stage of an acute wound, a redox-sensitive SERS-active optical fiber was fabricated by integrating redox-sensitive SERS probes in a hole of an optical fiber. The redox-sensitive SERS-active optical fibers carried redox-sensitive SERS probes into the inside of a wound to sense its redox potential. The laser was transmitted to the redox-sensitive SERS probes in the body by optical fibers, and the SERS signals of the redox-sensitive SERS probes were transferred out of the body by optical fibers to indicate the redox potentials in the wound. The redox-sensitive SERS probes dynamically sensed the redox potential in vivo, and their SERS signals were collected constantly to indicate the redox potentials. The assessments in vivo and in vitro proved the responsiveness of redox-sensitive SERS-active optical fibers. The redox potential evolution during the initial stage of an acute wound with the treatments of different concentrations of glucose was detected to verify the feasibility of redox-sensitive SERS-active optical fibers to dynamically detect redox potentials in vivo. The redox-sensitive SERS-active optical fiber would be a versatile tool to explore the roles of redox potentials in living organisms.


Subject(s)
Spectrum Analysis, Raman , Oxidation-Reduction , Spectrum Analysis, Raman/instrumentation , Spectrum Analysis, Raman/methods , Male , Animals , Rats , Rats, Sprague-Dawley , Acute Disease , Wounds and Injuries/diagnosis
10.
Chem Soc Rev ; 53(12): 6295-6321, 2024 Jun 17.
Article in English | MEDLINE | ID: mdl-38722208

ABSTRACT

In the electrocatalytic CO2 reduction reaction (CO2RR), metal catalysts with an oxidation state generally demonstrate more favorable catalytic activity and selectivity than their corresponding metallic counterparts. However, the persistence of oxidative metal sites under reductive potentials is challenging since the transition to metallic states inevitably leads to catalytic degradation. Herein, a thorough review of research on oxidation-state stabilization in the CO2RR is presented, starting from fundamental concepts and highlighting the importance of oxidation state stabilization while revealing the relevance of dynamic oxidation states in product distribution. Subsequently, the functional mechanisms of various oxidation-state protection strategies are explained in detail, and in situ detection techniques are discussed. Finally, the prevailing and prospective challenges associated with oxidation-state protection research are discussed, identifying innovative opportunities for mechanistic insights, technology upgrades, and industrial platforms to enable the commercialization of the CO2RR.

12.
Genes (Basel) ; 15(5)2024 05 15.
Article in English | MEDLINE | ID: mdl-38790255

ABSTRACT

Cordycepin is the primary active compound of Cordyceps militaris. However, the definitive genetic mechanism governing cordycepin synthesis in fruiting body growth and development remains elusive, necessitating further investigation. This study consists of 64 C. militaris strains collected from northeast China. The high-yielding cordycepin strain CMS19 was selected for the analysis of cordycepin production and the genetic basis of cordycepin anabolism. First, the whole-genome sequencing of CMS19 yielded a final size of 30.96 Mb with 8 contigs and 9781 protein-coding genes. The genome component revealed the presence of four additional secondary metabolite gene clusters compared with other published genomes, suggesting the potential for the production of new natural products. The analyses of evolutionary and genetic differentiation revealed a close relationship between C. militaris and Beauveria bassiana. The population of strains distributed in northeast China exhibited the significant genetic variation. Finally, functional genes associated with cordycepin synthesis were identified using a combination of genomic and transcriptomic analyses. A large number of functional genes associated with energy and purine metabolism were significantly enriched, facilitating the reconstruction of a hypothetical cordycepin metabolic pathway. Therefore, our speculation of the cordycepin metabolism pathway involved 24 genes initiating from the glycolysis and pentose phosphate pathways, progressing through purine metabolism, and culminating in the core region of cordycepin synthesis. These findings could offer fundamental support for scientific utilizations of C. militaris germplasm resources and standardized cultivation for cordycepin production.


Subject(s)
Cordyceps , Deoxyadenosines , Cordyceps/genetics , Cordyceps/metabolism , Cordyceps/growth & development , Deoxyadenosines/biosynthesis , Deoxyadenosines/metabolism , Transcriptome/genetics , Genome, Fungal , Gene Expression Profiling/methods , Genomics/methods , Multigene Family , Gene Expression Regulation, Fungal , Whole Genome Sequencing , Phylogeny
13.
Foods ; 13(10)2024 May 07.
Article in English | MEDLINE | ID: mdl-38790739

ABSTRACT

The quality of chrysanthemum tea has a great connection with its variety. Different types of chrysanthemum tea have very different efficacies and functions. Moreover, the discrimination of chrysanthemum tea varieties is a significant issue in the tea industry. Therefore, to correctly and non-destructively categorize chrysanthemum tea samples, this study attempted to design a novel feature extraction method based on the fuzzy set theory and improved direct linear discriminant analysis (IDLDA), called fuzzy IDLDA (FIDLDA), for extracting the discriminant features from the near-infrared (NIR) spectral data of chrysanthemum tea. To start with, a portable NIR spectrometer was used to collect NIR data for five varieties of chrysanthemum tea, totaling 400 samples. Secondly, the raw NIR spectra were processed by four different pretreatment methods to reduce noise and redundant data. Thirdly, NIR data dimensionality reduction was performed by principal component analysis (PCA). Fourthly, feature extraction from the NIR spectra was performed by linear discriminant analysis (LDA), IDLDA, and FIDLDA. Finally, the K-nearest neighbor (KNN) algorithm was applied to evaluate the classification accuracy of the discrimination system. The experimental results show that the discrimination accuracies of LDA, IDLDA, and FIDLDA could reach 87.2%, 94.4%, and 99.2%, respectively. Therefore, the combination of near-infrared spectroscopy and FIDLDA has great application potential and prospects in the field of nondestructive discrimination of chrysanthemum tea varieties.

14.
Adv Healthc Mater ; : e2301985, 2024 May 22.
Article in English | MEDLINE | ID: mdl-38776526

ABSTRACT

Infected diabetic wound (DW) presents a prolonged and challenging healing process within the field of regenerative medicine. The effectiveness of conventional drug therapies is hindered by their limited ability to reach deep tissues and promote adequate wound healing rates. Therefore, there is an imperative to develop drug delivery systems that can penetrate deep tissues while exhibiting multifunctional properties to expedite wound healing. In this study, w e devised a soluble microneedle (MN) patch made of γ-PGA, featuring multiple arrays, which w as loaded with core-shell structured nanoparticles (NPs) known as Ag@MSN@CeO2, to enhance the healing of infected DWs. The NP comprises a cerium dioxide (CeO2) core with anti-inflammatory and antioxidant properties, a mesoporous silica NP (MSN) shell with angiogenic characteristics, and an outermost layer doped with Ag to combat bacterial infections. W e demonstrated that the MN platform loaded with Ag@MSN@CeO2 successfully penetrated deep tissues for effective drug delivery. These MN tips induced the formation of multiple regenerative sites at various points, leading to antibacterial, reactive oxygen species-lowering, macrophage ecological niche-regulating, vascular regeneration-promoting, and collagen deposition-promoting effects, thus significantly expediting the healing process of infected DWs. Considering these findings, the multifunctional MN@Ag@MSN@CeO2 patch exhibits substantial potential for clinical applications in the treatment of infected DW.

15.
Nat Commun ; 15(1): 4591, 2024 May 30.
Article in English | MEDLINE | ID: mdl-38816373

ABSTRACT

Bridged chiral biaryls are axially chiral compounds with a medium-sized ring connecting the two arenes. Compared with plentiful methods for the enantioselective synthesis of biaryl compounds, synthetic approaches for this subclass of bridged atropisomers are limited. Here we show an atroposelective synthesis of 1,3-diaxial bridged eight-membered terphenyl atropisomers through an Co/SPDO (spirocyclic pyrrolidine oxazoline)-catalyzed aerobic oxidative coupling/desymmetrization reaction of prochiral phenols. This catalytic desymmetric process is enabled by combination of an earth-abundant Co(OAc)2 and a unique SPDO ligand in the presence of DABCO (1,4-diaza[2.2.2]bicyclooctane). An array of diaxial bridged terphenyls embedded in an azocane can be accessed in high yields (up to 99%) with excellent enantio- (>99% ee) and diastereoselectivities (>20:1 dr).

16.
Adv Sci (Weinh) ; 11(25): e2306253, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38582510

ABSTRACT

The extensive application of nuclear technology has increased the potential of uncontrolled radiation exposure to the public. Since skin is the largest organ, radiation-induced skin injury remains a serious medical concern. Organisms evolutionally develop distinct strategies to protect against environment insults and the related research may bring novel insights into therapeutics development. Here, 26 increased peptides are identified in skin tissues of frogs (Pelophylax nigromaculatus) exposed to electron beams, among which four promoted the wound healing of irradiated skin in rats. Specifically, radiation-induced frog skin peptide-2 (RIFSP-2), from histone proteolysis exerted membrane permeability property, maintained cellular homeostasis, and reduced pyroptosis of irradiated cells with decreased TBK1 phosphorylation. Subsequently, stearyl-CoA desaturase 1 (SCD1) is identified, a critical enzyme in biogenesis of monounsaturated fatty acids (MUFAs) as a direct target of RIFSP-2 based on streptavidin-biotin system. The lipidomic analysis further assured the restrain of MUFAs biogenesis by RIFSP-2 following radiation. Moreover, the decreased MUFA limited radiation-induced and STING-mediated inflammation response. In addition, genetic depletion or pharmacological inhibition of STING counteracted the decreased pyroptosis by RIFSP-2 and retarded tissue repair process. Altogether, RIFSP-2 restrains radiation-induced activation of SCD1-MUFA-STING axis. Thus, the stress-induced amphibian peptides can be a bountiful source of novel radiation mitigators.


Subject(s)
Inflammation , Skin , Animals , Skin/metabolism , Skin/radiation effects , Skin/drug effects , Rats , Inflammation/metabolism , Radiation-Protective Agents/pharmacology , Stearoyl-CoA Desaturase/metabolism , Stearoyl-CoA Desaturase/genetics , Peptides/pharmacology , Peptides/metabolism , Ranidae/metabolism , Disease Models, Animal , Wound Healing/drug effects , Anura/metabolism , Membrane Proteins/metabolism , Membrane Proteins/genetics
17.
Exp Mol Med ; 56(5): 1107-1122, 2024 May.
Article in English | MEDLINE | ID: mdl-38689083

ABSTRACT

Genotoxic therapy triggers reactive oxygen species (ROS) production and oxidative tissue injury. S-nitrosylation is a selective and reversible posttranslational modification of protein thiols by nitric oxide (NO), and 5,6,7,8-tetrahydrobiopterin (BH4) is an essential cofactor for NO synthesis. However, the mechanism by which BH4 affects protein S-nitrosylation and ROS generation has not been determined. Here, we showed that ionizing radiation disrupted the structural integrity of BH4 and downregulated GTP cyclohydrolase I (GCH1), which is the rate-limiting enzyme in BH4 biosynthesis, resulting in deficiency in overall protein S-nitrosylation. GCH1-mediated BH4 synthesis significantly reduced radiation-induced ROS production and fueled the global protein S-nitrosylation that was disrupted by radiation. Likewise, GCH1 overexpression or the administration of exogenous BH4 protected against radiation-induced oxidative injury in vitro and in vivo. Conditional pulmonary Gch1 knockout in mice (Gch1fl/fl; Sftpa1-Cre+/- mice) aggravated lung injury following irradiation, whereas Gch1 knock-in mice (Gch1lsl/lsl; Sftpa1-Cre+/- mice) exhibited attenuated radiation-induced pulmonary toxicity. Mechanistically, lactate dehydrogenase (LDHA) mediated ROS generation downstream of the BH4/NO axis, as determined by iodoacetyl tandem mass tag (iodoTMT)-based protein quantification. Notably, S-nitrosylation of LDHA at Cys163 and Cys293 was regulated by BH4 availability and could restrict ROS generation. The loss of S-nitrosylation in LDHA after irradiation increased radiosensitivity. Overall, the results of the present study showed that GCH1-mediated BH4 biosynthesis played a key role in the ROS cascade and radiosensitivity through LDHA S-nitrosylation, identifying novel therapeutic strategies for the treatment of radiation-induced lung injury.


Subject(s)
Biopterins , GTP Cyclohydrolase , Lung Injury , Reactive Oxygen Species , Animals , Biopterins/analogs & derivatives , Biopterins/metabolism , Reactive Oxygen Species/metabolism , Mice , Lung Injury/metabolism , Lung Injury/etiology , GTP Cyclohydrolase/metabolism , GTP Cyclohydrolase/genetics , Humans , Radiation Tolerance/genetics , Lactate Dehydrogenase 5/metabolism , Mice, Knockout , Nitric Oxide/metabolism , L-Lactate Dehydrogenase/metabolism , L-Lactate Dehydrogenase/genetics , Protein Processing, Post-Translational , Radiation, Ionizing
18.
Radiat Res ; 201(4): 294-303, 2024 Apr 01.
Article in English | MEDLINE | ID: mdl-38588381

ABSTRACT

Radiation-induced intestinal damage (RIID) is a common side effect of radiotherapy in patients with abdominopelvic malignancies. Gap junctions are special structures consisting of connexins (Cxs). This study aimed to investigate the expression and role of connexins in RIID and underlying mechanism. In this study, a calcein-AM fluorescence probe was used to detect changes in gap junctional intercellular communication in intestinal epithelial IEC-6 cells. Our results show that gap junctional intercellular communication of IEC-6 cells was reduced at 6, 12, 24, and 48 h after irradiation, with the most pronounced effect at 24 h. Western blotting and immunofluorescence results showed that the expression of Cx43, but not other connexins, was reduced in irradiated intestinal epithelial cells. Silencing of Cx43 reduced gap junctional intercellular communication between irradiated intestinal epithelial cells with increased ROS and intracellular Ca2+ levels. Furthermore, knockdown of Cx43 reduced the number of clonal clusters, decreased cell proliferation with increased cytotoxicity and apoptosis. Western blotting results showed that silencing of Cx43 resulted in changed γ-H2AX and PI3K/AKT pathway proteins in irradiated intestinal epithelial cells. Administration of the PI3K/AKT pathway inhibitor LY294002 inhibited the radioprotective effects in Cx43-overexpressing intestinal epithelial cells. Our study demonstrated that Cx43 expression is decreased by ionizing radiation, which facilitates the radioprotection of intestinal epithelial cells.


Subject(s)
Connexin 43 , Proto-Oncogene Proteins c-akt , Humans , Proto-Oncogene Proteins c-akt/metabolism , Phosphatidylinositol 3-Kinases/metabolism , Calcium/metabolism , Connexins/metabolism , Connexins/pharmacology , Signal Transduction , Gap Junctions , Cell Communication
19.
Chemosphere ; 357: 141951, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38626815

ABSTRACT

UV/Fe3+ and persulfate are two promising advanced oxidative degradation systems for in situ remediation of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS), yet a lack of comprehensive understanding of the degradation mechanisms. For the first time, we used density functional theory (DFT) to calculate the entire reaction pathways of the degradation of PFOA/PFOS in water by UV/Fe3+ and persulfate. In addition, we have deeply explored the different attack pathways driven by •OH and SO4-•, and found that SO4-• determines PFOA/PFOS to obtain PFOA/PFOS free radicals through single electron transfer to initiate the degradation reaction, while •OH determines the speed of PFOA/PFOS degradation reaction. Both degradation reactions were thermodynamically advantageous and kinetically feasible under calculated conditions. Based on the thermodynamic data, persulfate was found to be more favorable for the advanced oxidative degradation of Perfluorinated compounds (PFCs). Moreover, for SO4-• and •OH co-existing in the persulfate system, pH will affect the presence and concentration of these two types of free radicals, and low pH is not necessary for the degradation of PFOA/PFOS in the persulfate system. These results can considerably advance our understanding of the PFOA/PFOS degradation process in advanced oxidation processes (AOPs), which is driven by •OH and SO4-•. This study provides a DFT calculation process for the mechanism calculation of advanced oxidation degradation of other types of PFCs pollutants, hoping to elucidate the future development of PFCs removal. Further research should focus on determining the advanced oxidation degradation pathways of other types of PFCs, to support the development of computational studies on the advanced oxidation degradation of PFCs.


Subject(s)
Alkanesulfonic Acids , Caprylates , Fluorocarbons , Oxidation-Reduction , Water Pollutants, Chemical , Fluorocarbons/chemistry , Caprylates/chemistry , Kinetics , Water Pollutants, Chemical/chemistry , Alkanesulfonic Acids/chemistry , Ultraviolet Rays , Sulfates/chemistry , Density Functional Theory , Thermodynamics , Environmental Restoration and Remediation/methods , Iron/chemistry
20.
Org Lett ; 26(17): 3498-3502, 2024 May 03.
Article in English | MEDLINE | ID: mdl-38661476

ABSTRACT

A novel ion exchange strategy has been developed to enable the asymmetric construction of axially chiral sulfone-containing styrenes. This approach provides a practical synthesis pathway for various axially chiral sulfone-containing styrenes with good yields, exceptional enantioselectivities, and nearly complete E/Z selectivities. Additionally, the reaction mechanism is elucidated in detail through density functional theory (DFT) calculations.

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