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1.
Food Funct ; 2024 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-38738702

RESUMO

Background: Chronic obstructive pulmonary disease (COPD) is a common respiratory disease, and its development and prognosis are influenced by many nutrients. However, the relationship between polyunsaturated fatty acids (PUFAs) and COPD remains unclear. Methods: This study searched all literature reports on PUFAs and COPD based on electronic databases from their inception up to October 2023. Meta-analysis was conducted to evaluate the differences in PUFAs between COPD patients and controls, the risk of COPD in subjects with different levels of PUFA concentrations, and the effect of PUFA supplementation on COPD. Results: A total of nineteen studies met our inclusion criteria, which included 155 636 subjects. Our meta-analysis results showed that the daily dietary intake of PUFAs was lower in COPD patients than in controls (SMD = -0.80 g, 95% CI: -1.28, -0.31 g, I2 = 98.6%, P < 0.001). Meanwhile, the lower n-3 PUFA levels and higher n-6 PUFA levels were associated with an increased risk of COPD (effect size n-3 = 0.87, 95% CI: 0.77, 0.98, I2 = 52.2%, P = 0.018; effect size n-6 = 1.23, 95% CI: 1.05, 1.43, I2 = 75.2%, P < 0.001). Furthermore, the content of low-density lipoprotein cholesterol in the PUFA supplementation group was higher than that in the control group (SMD = 0.63 mg dL-1, 95% CI: 0.15, 1.12 mg dL-1, I2 = 0.0%, P = 0.697). Conclusions: Our meta-analysis indicated a potential relationship between PUFAs and COPD. More large-scale prospective cohort studies and clinical trials are necessary to validate this relationship.

2.
Dev Comp Immunol ; 157: 105196, 2024 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-38762097

RESUMO

The thymus-derived lymphocytes of jawed vertebrates have four T-cell receptor (TCR) chains that play a significant role in immunity. As chickens have commercial value, their immune systems require a great deal of attention. Local chicken breeds are an essential part of poultry genetic resources in China. Here, we used high-throughput sequencing to analyze the TCRα and TCRß repertoires and their relative expression levels in the native chicken breeds Baier Buff, Longyou Partridge, Xiaoshan, and Xianju. We found that TCR Vα and TCR Vß were expressed and included 17, 19, 17, and six segments of the Vα2, Vα3, Vß1, and Vß2 subgroups, respectively. V-J pairing was biased; Jα11 was utilized by nearly all Vα segments and was the most commonly used. Breed-specific V segments and V-J pairings were detected as well. The results of the principal coordinate analysis (PCoA) as well as the V-J pairing and CDR3 diversity analyses suggested that the four local chicken breeds did not significantly differ in terms of TCR diversity. Hence, they expressed not significant differentiation, and they are rich genetic resources for the development and utilization of immune-related poultry breeding.

3.
Front Genet ; 15: 1339683, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38680426

RESUMO

Introduction: The CapG gene, which is an actin-binding protein, is prevalent in eukaryotic cells and is abundantly present in various pathways associated with plateau hypoxia adaptation. Tibetan pigs, which have inhabited high altitudes for extended periods, provide an excellent research population for investigating plateau hypoxia adaptation. Results: This study focused on Tibetan pigs and Yorkshire pigs residing in Nyingchi, Tibet. The blood physiological data of Tibetan pigs were found to be significantly higher than those of Yorkshire pigs, including RBC, HGB, HCT, MCH, and MCHC. The SNP analysis of the CapG gene identified six sites with mutations only present in Tibetan pigs. Notably, the transcription factors at sites C-489T, C-274T, and A-212G were found to be altered, and these sites are known to be associated with hypoxia adaptation and blood oxygen transportation. The mRNA expression of the CapG gene exhibited highly significant differences in several tissues, with the target proteins predominantly higher in the Yorkshire pig compared to the Tibetan pig. Specifically, a notable difference was observed in the lung tissues. Immunohistochemistry analysis revealed high expression levels of CapG proteins in the lung tissues of both Tibetan and Yorkshire pigs, primarily localized in the cytoplasm and cell membrane. Conclusion: The CapG gene plays a significant role in regulating hypoxia adaptation in Tibetan pigs. This study provides a theoretical basis for the conservation and utilization of Tibetan pig resources, the breeding of highland breeds, epidemic prevention and control, and holds great importance for the development of the highland livestock economy.

4.
Mater Today Bio ; 26: 101053, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38654934

RESUMO

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

5.
J Sci Food Agric ; 104(5): 3069-3079, 2024 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-38072654

RESUMO

BACKGROUND: ε-polylysine hydrochloride (ε-PLH) is a naturally occurring antimicrobial peptide extensively utilized in the food and medical industries. However, its impact on animal husbandry remains to be further explored. Therefore, the present study aimed to determine the effect of ε-PLH on laying hens' health and laying performance. RESULTS: Dietary supplementation with ε-PLH to the diet significantly increased average egg weight during weeks 1-8. Meanwhile, compared with the control group, supplementation with ε-PLH decreased the feed egg ratio during weeks 9-12 and egg breakage rate during weeks 9-16 ,whereas it increased eggshell strength during weeks 1-4 and 13-16 . The ε-PLH 0.05% group increased yolk percentage during weeks 5-8 and yolk color during weeks 1-4 . Furthermore, ε-PLH supplementation significantly increased the concentrations of total protein, albumin, globulin and reproductive hormones estradiol, as well as decreased interleukin-1 beta and malondialdehyde in the serum. Compared with the control group, supplementation with 0.05% ε-PLH significantly increased the relative abundance of Cyanobacteria and Gastranaerophilales and decreased the abundance of Desulfovibrio and Streptococcus in the cecum microbiota. In addition, ε-PLH 0.1% supplementation also increased acetic acid content in the cecum. CONCLUSION: Dietary supplementation with ε-PLH has a positive impact on both productive performance and egg quality in laying hens. Furthermore, ε-PLH can also relieve inflammation by promoting the immunity and reducing oxidative damage during egg production. ε-PLH has been shown to improve intestinal morphology, gut microbial diversity and intestinal health. © 2023 Society of Chemical Industry.


Assuntos
Microbioma Gastrointestinal , Animais , Feminino , Polilisina/farmacologia , Galinhas/microbiologia , Suplementos Nutricionais/análise , Dieta/veterinária , Ácidos Graxos Voláteis , Ração Animal/análise
6.
Dalton Trans ; 52(48): 18206-18213, 2023 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-38010925

RESUMO

The design of magnetic molecular materials exhibiting multiple functions has garnered significant interest owing to their potential applications in molecular switches, sensors, and data storage devices. In this study, we synthesized a two-dimensional (2D) FeII-based Hofmann-type coordination polymer, namely {Fe(DPPE)2[Ag(CN)2]2}·2EtOH (1), using a luminescent ligand 1,1-diphenyl-2,2-di(4-pyridylbiphenyl)ethylene (DPPE). Single-crystal structural analyses and magnetic measurements revealed a thermally induced spin crossover (SCO) with the transition temperature T1/2 = 231 K. Variable-temperature fluorescence emission spectra indicated the coexistence of spin crossover and fluorescence properties. Moreover, a pronounced dielectric change (Δε' = 1.2 at 0.5 kHz) was observed during the SCO process, confirming the simultaneous magnetic and dielectric switching arising from the rearrangement of 3d electrons and deformation of the FeII-centered coordination sphere. This work provides an approach to explore the interplay between magnetic, dielectric, and fluorescence properties, and holds significance for developing multifunctional molecular materials.

7.
Front Bioeng Biotechnol ; 11: 1224557, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37954016

RESUMO

There are still limitations in artificial bone materials used in clinical practice, such as difficulty in repairing large bone defects, the mismatch between the degradation rate and tissue growth, difficulty in vascularization, an inability to address bone defects of various shapes, and risk of infection. To solve these problems, our group designed stereolithography (SLA) 3D-printed calcium silicate artificial bone improved by a calcium sulfate-Cu2+ delivery system. SLA technology endows the scaffold with a three-dimensional tunnel structure to induce cell migration to the center of the bone defect. The calcium sulfate-Cu2+ delivery system was introduced to enhance the osteogenic activity of calcium silicate. Rapid degradation of calcium sulfate (CS) induces early osteogenesis in the three-dimensional tunnel structure. Calcium silicate (CSi) which degrades slowly provides mechanical support and promotes bone formation in bone defect sites for a long time. The gradient degradation of these two components is perfectly matched to the rate of repair in large bone defects. On the other hand, the calcium sulfate delivery system can regularly release Cu2+ in the temporal and spatial dimensions, exerting a long-lasting antimicrobial effect and promoting vascular growth. This powerful 3D-printed calcium silicate artificial bone which has rich osteogenic activity is a promising material for treating large bone defects and has excellent potential for clinical application.

8.
Aging (Albany NY) ; 15(20): 11412-11447, 2023 10 20.
Artigo em Inglês | MEDLINE | ID: mdl-37874682

RESUMO

Ferroptosis regulators have been found to affect tumor progression. However, studies focusing on ferroptosis and soft tissue sarcoma (STS) are rare. Somatic mutation, copy number variation, reverse transcription-quantitative polymerase chain reaction (RT-qPCR) analysis, consensus clustering, differentially expressed genes analysis (DEGs), principal component analysis (PCA) and gene set enrichment analysis (GSEA) were used to identify and explore different ferroptosis modifications in STS. A nomogram was constructed to predict the prognosis of STS. Moreover, three immunotherapy datasets were used to assess the Fescore. Western blotting, siRNA transfection, EdU assay and reactive oxygen species (ROS) measurement were performed. 16 prognostic ferroptosis regulators were screened and significant differences were observed in somatic mutation, copy number variation (CNV) and RT-qPCR among these ferroptosis regulators. 2 different ferroptosis modification patterns were found (Fe cluster A and B). Fe cluster A with higher Fescore was correlated with p53 pathway and had better prognosis of STS (p = 0.002) while Fe cluster B with lower Fescore was correlated with angiogenesis and MYC pathway and showed a poorer outcome. Besides, the nomogram effectively predicted the outcome of STS and the Fescore could also well predict the prognosis of other 16 tumors and immunotherapy response. Downregulation of LOX also inhibited growth and increased ROS production in sarcoma cells. The molecular characterization of ferroptosis regulators in STS was explored and an Fescore was constructed. The Fescore quantified ferroptosis modification in STS patients and effectively predicted the prognosis of a variety of tumors, providing novel insights for precision medicine.


Assuntos
Ferroptose , Sarcoma , Humanos , Prognóstico , Variações do Número de Cópias de DNA , Ferroptose/genética , Espécies Reativas de Oxigênio , Sarcoma/genética , Sarcoma/terapia , Biologia Computacional , Imunoterapia
9.
Environ Sci Pollut Res Int ; 30(52): 112462-112473, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37831237

RESUMO

Building Z-scheme heterojunctions with an electron bridge is a favored function for increasing photocatalytic activity. A facile approach for preparing g-C3N4/Ag@AgCl ternary heterojunctions by co-precipitation and photoreduction was established in this work. First, via co-precipitation, AgCl was modified on the surface of g-C3N4 to create a broad contact area between AgCl and g-C3N4. The AgCl is then reduced to Ag via an in-situ photoreduction technique, resulting in the formation of a ternary composite. The experimental results showed that when g-C3N4 modified 25% of the Ag@AgCl, that is, g-C3N4/Ag@AgCl-25 had the best photocatalytic performance, 94.9% of TC was degraded within 240 min, and the reaction rate to TC was 0.1214 min-1, which was 4.49 times and 8.12 times higher than that of g-C3N4 and Ag/AgCl, respectively. The excellent photocatalytic performance of g-C3N4/Ag@AgCl is attributed to the LSPR effect of Ag NPs and O-doping g-C3N4, which broadens the absorbance performance of g-C3N4, the establishment of Z-type heterojunctions between AgCl NPs and g-C3N4 NSs and Ag NPs as an electron transport bridge accelerate the photogenerated electrons transfer between AgCl and g-C3N4.


Assuntos
Elétrons , Águas Residuárias , Luz , Catálise , Antibacterianos , Tetraciclina
10.
Environ Res ; 237(Pt 1): 116917, 2023 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-37611784

RESUMO

Due to poor management and the lack of environmental awareness, lots of masks (an emerging form of plastic pollution) are discarded into the environment during the COVID-19, thereby jeopardizing the health of humans and the environment. Our study introduces a novel perspective by examining the impact of physical damage on the microbial composition of masks in the water environment. We focus on the variations in biofilm formation on each layer of both damaged and undamaged masks, which allows us to understand more about the biofilm on each layer and the significant changes that occur when masks are physically damaged. Research has shown that the community structure of microorganisms on discarded masks can be altered in just ten days, showing an evolution from undifferentiated pioneer colonizing species ("non-picky") to adaptive dominant species ("picky"). Especially, considering that discarded masks were inevitably damaged, we found that the biomass on the damaged samples is 1.62-2.38 times higher than that of the undamaged samples, respectively. Moreover, the microbial community structure on it was also significantly different. Genes involved in biogeochemical cycles of nutrients are more enriched in damaged masks. When damaged, the colonization process and community structure in the middle layer significantly differ from those in the inner and outer layers and even enrich more pathogenic bacteria. Based on the above, it is evident that the environmental risk of masks cannot be assessed as a whole, and the middle layer carries a higher risk.

11.
Zhongguo Zhen Jiu ; 43(7): 739-42, 2023 Jul 12.
Artigo em Chinês | MEDLINE | ID: mdl-37429650

RESUMO

OBJECTIVE: To observe the effects of acupuncture on swallowing function and quality of life for patients with dysphagia in Parkinson's disease (PD). METHODS: A total of 60 patients of PD with dysphagia were randomly divided into an observation group (30 cases, 2 cases dropped off) and a control group (30 cases, 3 cases dropped off). The control group was given conventional medication therapy and rehabilitation training. On the basis of the treatment as the control group, the observation group was given acupuncture at Fengfu (GV 16), Baihui (GV 20), Shenting (GV 24), Yintang (GV 24+), Yansanzhen and bilateral Fengchi (GB 20), 30 min each time, once a day, 6 times a week for 4 weeks. Before and after treatment, the Kubota water swallowing test, standardized swallowing assessment (SSA) and swallowing quality of life (SWAL-QOL) were used to evaluate the swallowing function and quality of life of the two groups. RESULTS: After treatment, the Kubota water swallowing test grade, SSA scores in the two groups were decreased compared with those before treatment (P<0.05, P<0.001),the SWAL-QOL scores were increased compared with those before treatment (P<0.001); in the observation group,the Kubota water swallowing test grade and SSA score were lower than those in the control group (P<0.05),the SWAL-QOL score was higher than that in the control group (P<0.001). CONCLUSION: On the basis of conventional medication therapy and rehabilitation training,acupuncture could improve the swallowing function and quality of life for patients of PD with dysphagia.


Assuntos
Terapia por Acupuntura , Transtornos de Deglutição , Doença de Parkinson , Humanos , Transtornos de Deglutição/etiologia , Transtornos de Deglutição/terapia , Deglutição , Qualidade de Vida , Doença de Parkinson/complicações , Doença de Parkinson/terapia , Água
12.
Chemistry ; 29(45): e202301262, 2023 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-37272418

RESUMO

Cyano-bridged 4d-4f molecular nanomagnets have re-called increasing research interests in molecular magnetism since they offer more possibilities in achieving novel nanomagnets with versatile structures and magnetic interactions. In this work, four ß-diketone ligands bearing different substitution N-sites were designed and synthesized, namely 1-(2-pyridyl)-3-(3-pyridyl)-1,3-propanedione (HL1 ), 1,3-Bis (3-pyridyl)-1,3-propanedione (HL2 ), 1-(4-pyridyl)-3-(3-pyridyl)-1,3-propanedione (HL3 ), and 1,3-Bis (4-pyridyl)-1,3-propanedione (HL4 ), to tune the magnetic relaxation behaviors of cyano-bridged {DyIII MoV } systems. By reacting with DyCl3 ⋅ 6H2 O and K4 Mo(CN)8 ⋅ 2H2 O, four cyano-bridged complexes, namely {[Dy[MoV (CN)8 ](HL1 )2 (H2 O)3 ]} ⋅ 6H2 O (1), {[Dy[MoV (CN)8 ](HL2 )(H2 O)3 (CH3 OH)]}2 ⋅ 2CH3 OH ⋅ 3H2 O (2), {[Dy[MoV (CN)8 ](HL3 )(H2 O)2 (CH3 OH)] ⋅ H2 O}n (3), and {[Dy[MoV (CN)8 ](HL4 )2 (H2 O)3 ]} ⋅ 2H2 O⋅CH3 OH (4) were obtained. Structural analyses revealed that 1 and 4 are binuclear complexes, 2 has a tetragonal structure, and 3 exhibits a stair-like polymer chain structure. The DyIII ions in all complexes have eight-coordinated configurations with the coordination spheres DyO7 N1 for 1 and 4, DyO6 N2 for 2, and DyO5 N3 for 3. Magnetic measurements indicate that 1 is a zero-field single-molecule magnet (SMM) and complexes 2-4 are field-induced SMMs, with complex 4 featuring a two-step relaxation process. The magnetic characterizations and ab initio calculations revealed that changing the N-sites in the ß-diketone ligands can effectively alter the structures and magnetic properties of cyano-bridged 4d-4f nanomagnets by adjusting the coordination environments of the DyIII centers.

14.
Chem Sci ; 14(25): 6936-6942, 2023 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-37389243

RESUMO

Manipulating fluorescence by photo-switched spin-state conversions is an attractive prospect for applications in smart magneto-optical materials and devices. The challenge is how to modulate the energy transfer paths of the singlet excited state by light-induced spin-state conversions. In this work, a spin crossover (SCO) FeII-based fluorophore was embedded into a metal-organic framework (MOF) to tune the energy transfer paths. Compound 1 {Fe(TPA-diPy)[Ag(CN)2]2}·2EtOH (1) has an interpenetrated Hofmann-type structure, wherein the FeII ion is coordinated by a bidentate fluorophore ligand (TPA-diPy) and four cyanide nitrogen atoms and acts as the fluorescent-SCO unit. Magnetic susceptibility measurements revealed that 1 underwent an incomplete and gradual spin crossover with T1/2 = 161 K. Photomagnetic studies confirmed photo-induced spin state conversions between the low-spin (LS) and high-spin (HS) states, where the irradiation of 532 and 808 nm laser lights converted the LS and HS states to the HS and LS states, respectively. Variable-temperature fluorescence spectra study revealed an anomalous decrease in emission intensity upon the HS → LS transition, confirming the synergetic coupling between the fluorophore and SCO units. Alternating irradiation of 532 and 808 nm laser lights resulted in reversible fluorescence intensity changes, confirming spin state-controlled fluorescence in the SCO-MOF. Photo-monitored structural analyses and UV-vis spectroscopic studies demonstrated that the photo-induced spin state conversions changed energy transfer paths from the TPA fluorophore to the metal-centered charge transfer bands, ultimately leading to the switching of fluorescence intensities. This work represents a new prototype compound showing bidirectional photo-switched fluorescence by manipulating the spin states of iron(ii).

15.
Angew Chem Int Ed Engl ; 62(28): e202302815, 2023 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-37178444

RESUMO

Colossal and anisotropic thermal expansion is a key function for microscale or nanoscale actuators in material science. Herein, we present a hexanuclear compound of [(Tp*)FeIII (CN)3 ]4 [FeII (Ppmp)]2 ⋅2 CH3 OH (1, Tp*=hydrotris(3,5-dimethyl-pyrazol-1-yl)borate and Ppmp=2-[3-(2'-pyridyl)pyrazol-1-ylmethyl]pyridine), which has a rhombic core structure abbreviated as {FeIII 2 FeII 2 }. Magnetic susceptibility measurements and single-crystal X-ray diffraction analyses revealed that 1 underwent thermally-induced spin transition with the thermal hysteresis. The FeII site in 1 behaved as a spin crossover (SCO) unit, and significant deformation of its octahedron was observed during the spin transition process. Moreover, the distortion of the FeII centers actuated anisotropic deformation of the rhombic {FeIII 2 FeII 2 } core, which was spread over the whole crystal through the subsequent molecular rearrangements, leading to the colossal anisotropic thermal expansion. Our results provide a rational strategy for realizing the colossal anisotropic thermal expansion and shape memory effects by tuning the magnetic bistability.

16.
Food Funct ; 14(11): 5301-5310, 2023 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-37203349

RESUMO

Background: Precocious puberty, one of the common pediatric endocrine system diseases, has been related to reduced adult height, adverse psychological outcomes and long-term health consequences. Previous findings have found that low levels of vitamin D appear to be associated with the characteristics of precocious puberty such as early menarche. However, the effect of vitamin D on precocious puberty remains controversial. Methods: The published literature was searched from PubMed, Web of Science, Cochrane Library, MEDLINE, EMBASE, CNKI, Wan Fang and VIP databases up to October 2022. A randomized effect model was used to perform a meta-analysis to evaluate differences in vitamin D concentration between precocious puberty subjects and normal subjects, the risk of precocious puberty in subjects with low vitamin D levels, and the effect of supplementation of vitamin D on subjects with precocious puberty on medication. Results: Our study found that precocious puberty subjects had lower serum vitamin D levels than the normal population (standardized mean difference (SMD) = -1.16 ng ml-1 and 95% confidence interval (CI) = -1.41 and -0.91 ng ml-1). Meanwhile, the lower level of vitamin D was associated with the risk of precocious puberty (odd ratio (OR) = 2.25 and 95% CI = 1.66 and 3.04). Moreover, compared with gonadotropin-releasing hormone analogue (GnRHa) intervention alone, subjects receiving GnRHa + vitamin D intervention had significantly lower luteinizing hormone (LH), follicle-stimulating hormone (FSH), and estradiol levels and bone age, and higher predicted adult height (PAH). Conclusions: Vitamin D may have a potential role in precocious puberty and more data from large clinical trials are needed to confirm the findings.


Assuntos
Puberdade Precoce , Feminino , Adulto , Criança , Humanos , Puberdade Precoce/tratamento farmacológico , Hormônio Luteinizante , Vitamina D/uso terapêutico , Hormônio Foliculoestimulante/uso terapêutico , Vitaminas/uso terapêutico , Hormônio Liberador de Gonadotropina/uso terapêutico
17.
Materials (Basel) ; 16(6)2023 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-36984298

RESUMO

In order to study the mechanical properties of ultra-high performance engineered cementitious composites (UHP-ECC) used for cable channel repair, orthogonal tests were carried out with four influencing factors, water binder ratio, silica fume, fly ash and mortar ratio, to obtain the optimum mix ratio of the cement paste. On this basis, the effects of ethylene-vinyl acetate (EVA) polymer and polyvinyl alcohol (PVA) fiber on the fluidity, flexural strength and compressive strength of UHP-ECC were studied, and the micromechanism was analyzed with SEM. The results show that the fluidity of UHP-ECC material prepared was 170-200 mm, which meets the requirements of working performance. The average compressive strength at 28 days reached 85.3 MPa, and the average flexural strength at 28 days reached 22.3 MPa. EVA polymer has a fast film forming rate in an alkaline environment. The formed polymer film wraps the fiber, enhances the bridging role between the fiber and the matrix and increases the viscosity of the material. Therefore, the early flexural strength is significantly improved. The 1-d flexural strength of UHP-ECC material mixed with 9-mm fiber is increased by 18%, and the 1-d flexural strength of 3-mm fiber is increased by 15%. Due to PVA fiber's high elastic modulus and tensile strength, it improved the flexural and tensile properties of the material after incorporation, especially in the later stages; the 28-d flexural strength of UHP-ECC material mixed with 9-mm fiber increased by 12%, and the 28-d flexural strength of 3-mm fiber increased by 7%. It was concluded that the effect of 9-mm PVA fiber is better than that of 3 mm PVA fiber.

18.
Nanoscale ; 15(11): 5300-5304, 2023 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-36810581

RESUMO

In recent years, spin defects in silicon carbide have become promising platforms for quantum sensing, quantum information processing and quantum networks. It has been shown that their spin coherence times can be dramatically extended with an external axial magnetic field. However, little is known about the effect of magnetic-angle-dependent coherence time, which is an essential complement to defect spin properties. Here, we investigate the optically detected magnetic resonance (ODMR) spectra of divacancy spins in silicon carbide with a magnetic field orientation. The ODMR contrast decreases as the off-axis magnetic field strength increases. We then study the coherence times of divacancy spins in two different samples with magnetic field angles, and both of the coherence times decrease with the angle. The experiments pave the way for all-optical magnetic field sensing and quantum information processing.

19.
Chemosphere ; 322: 138183, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36828110

RESUMO

Trivalent iron (Fe3+)-dependent anaerobic oxidation of methane (Fe-AOM), which is mediated by metal-reducing bacteria, is widely recognized as a major sink for the greenhouse gas methane (CH4), and is a key driver of the carbon (C) biogeochemical cycle. However, the effect of Fe3+ addition on AOM in the present investigation is still ambiguous, and the mechanism is vague. In this study, we investigated the mechanism of changes in AOM response to Fe3+ input at different wetlands by using laboratory incubation methods combined with molecular biology techniques. Results indicated that Fe3+ input did not always lead to promoted AOM rates, which may be mediated by complex environmental factors, while lower soil total nitrogen (TN) had a positive effect on the response of AOM subjected to Fe3+ input. Notably, the promoted response of AOM was regulated by higher soil microbial diversity, of which the Shannon index was a key indicator leading to variation in the AOM response. Additionally, several biomarkers, including Planctomycetota and Burkholderiaceae, were key microorganisms responsible for alterations in AOM response. Our results suggest that the capacity of Fe3+ cycling-mediated AOM may gradually decrease in light of increasing anthropogenic N and Fe inputs to global estuarine wetlands, while its reaction processes will become more complex and more strongly coupled with multiple environmental factors. This finding contributes to the enhanced understanding and prediction of the wetland CH4-related C with Fe cycles, as well as provides theoretical support for the underlying mechanisms.


Assuntos
Ferro , Áreas Alagadas , Metano/química , Solo , Nitrogênio , Anaerobiose , Oxirredução
20.
Artigo em Inglês | MEDLINE | ID: mdl-36673807

RESUMO

At present, collaborative industrial parks (CIPs) in the Yangtze River Delta Region (YRDR) have become an important spatial strategy for coordinating regional development. However, existing studies tend to focus on individualized micro-studies, ignoring the regional-scale production space reconstruction by the geographical expansion of CIPs. Based on this, this study takes the YRDR, where the development of CIPs is relatively mature, as an example and systematically analyzes their geographic expansion process and driving mechanism. The results found that CIPs in the YRDR have gone through three stages: the exploration period of CIP construction under the guidance of assistance policies; the blowout development period of CIPs under the demonstration effect; and the complete cluster formation period of CIPs. Regional central cities, such as Suzhou, Hangzhou, Nanjing, and underdeveloped cities, such as Tongling and Xuancheng, are core nodes, with Shanghai-Nantong; Shanghai-Anqing; Nanjing-Huainan; Wuxi-Xuzhou; Suzhou-Suqian; and Jiaxing-Lishui being important elements in the flow channel. The CIP network is basically formed. During this period, the degree of all nodes increased to 134, the network connection rate increased to 2.26, and the network complexity was more significant. Furthermore, CIPs are essentially a form of capital re-territorialization and space restoration organized and coordinated by the government (provincial government or central government). In the meantime, the market and the social environment, such as residents' living standards, urban development foundation, urban transportation, and urban investment, also have an important impact on the geographic expansion of CIPs. In the regression results, the coefficients of popu, finance, labor, and passenger are significantly negative, but the coefficients of wage, gdp, freight, and govrd are significantly positive.


Assuntos
Indústrias , Urbanização , China , Cidades , Rios , Desenvolvimento Econômico
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