ABSTRACT
Di-(2-ethylhexyl) phthalate (DEHP) might led to chronic and long-term effects on human organs due to its widespread use and bioaccumulation. Despite some cohorts reporting an association between DEHP exposure and BPH, its underlying mechanisms have not been investigated. Our findings indicate that exposure to DEHP or MEHP (main metabolites of DEHP in the human body) leads to increased prostate weights, elevated prostate index, and notable epithelial thickening in rats. It has been observed to promote BPH-1 cell proliferation with effects ranging from low to high concentrations. Transcriptome sequencing analysis of rat prostate tissues identified KIF11 as the key hub gene. KIF11 is highly expressed after DEHP/MEHP exposure, and knocking down of KIF11 inhibits the MEHP-induced promotion of cell proliferation. Exposure to MEHP has been observed to increase the expression of p-GSK-3ß and elevate the levels of ß-catenin, thereby activating the Wnt/ß-catenin signaling pathway. Knocking down of KIF11 significantly inhibits these effects. Histone H3 at Lysine 27 acetylation (H3K27ac) is implicated in the upregulation of KIF11 expression, as evidenced by the addition of the acetylation inhibitor C646. In summary, our findings established that DEHP exposure could promote BPH through H3K27ac regulated KIF11/Wnt/ß-catenin signaling pathway.
Subject(s)
Diethylhexyl Phthalate , Kinesins , Prostatic Hyperplasia , Wnt Signaling Pathway , Male , Animals , Diethylhexyl Phthalate/toxicity , Prostatic Hyperplasia/chemically induced , Prostatic Hyperplasia/pathology , Wnt Signaling Pathway/drug effects , Kinesins/genetics , Kinesins/metabolism , Rats , Cell Proliferation/drug effects , Rats, Sprague-Dawley , Humans , beta Catenin/metabolism , beta Catenin/genetics , Prostate/drug effects , Prostate/pathology , Prostate/metabolismABSTRACT
BACKGROUND: The effects of household air pollution on urinary incontinence (UI) symptoms and stress urinary incontinence (SUI) symptoms have not been studied. This study seeks to investigate the correlation between household air pollution and UI/SUI symptoms among middle-aged and elderly adults in India. METHODS: We employed data derived from individuals aged 45 years and older who participated in the inaugural wave (2017-2018) of the Longitudinal Aging Study in India (LASI). The assessment of household air pollution exposure and the occurrence of UI/SUI symptoms relied on self-reported data. The analytical approach adopted was cross-sectional in nature and encompassed a cohort of 64,398 participants. To explore relationships, we utilized multivariate logistic regression analysis, incorporating subgroup analysis and interaction tests. RESULTS: 1,671 (2.59%) participants reported UI symptoms and 4,862 (7.55%) participants reported SUI symptoms. Also, the prevalence of UI/SUI symptoms is much higher among middle-aged and elderly adults who use solid polluting fuels (UI: 51.23% vs. 48.77%; SUI: 54.50% vs. 45.50%). The results revealed a noteworthy correlation between household air pollution and the probability of experiencing UI/SUI symptoms, persisting even after adjusting for all conceivable confounding variables (UI: OR = 1.552, 95% CI: 1.377-1.749, p < 0.00001; SUI: OR: 1.459, 95% CI: 1.357-1.568, p < 0.00001). Moreover, significant interaction effects were discerned for age, education level, tobacco consumption, alcohol consumption, and physical activity (p for interaction < 0.05). CONCLUSIONS: The results of our study indicate that the utilization of solid fuels in the home increases the likelihood of developing urinary incontinence and stress urinary incontinence. As a result, we argue that there is an immediate need to reform the composition of cooking fuel and raise public awareness about the adverse effects of air pollution in the home.
Subject(s)
Air Pollution, Indoor , Humans , Male , Female , Middle Aged , Aged , Air Pollution, Indoor/adverse effects , India/epidemiology , Cross-Sectional Studies , Longitudinal Studies , Urinary Incontinence/epidemiology , Prevalence , Urinary Incontinence, Stress/epidemiology , Environmental Exposure/adverse effectsABSTRACT
Carbon:nitrogen:phosphorus (C:N:P) stoichiometry plays a vital role in regulating P transformation in agriculture ecosystems. However, the impact of balanced C:N:P stoichiometry in paddy soil, particularly regarding relative soil P transformation, remains unknown. This study explores the response of C:N:P stoichiometry to manure substitution and its regulatory role in soil P transformation, along with the associated release risk to the environment. Based on a 5-year field study, our findings reveal that replacing 30 % of chemical P fertilizer with pig manure (equal total NPK amounts with chemical P fertilizer treatment, named CFM) increased soil total C without altering soil total P, resulting in an elevated soil C:P ratio, despite the homeostasis of crop stoichiometry. This increase promoted microbial diversity and the accumulation of organic P in the soil. The Proteobacteria and Actinobacteria produced lower C:PEEA metabolism together, and enhanced in vivo turnover of P. Additionally, by integrating high-resolution dialysis (HR-Peeper), diffusive gradients in thin films (DGT), DGT-induced fluxes in the soil (DIFS), and sediment P release risk index (SPRRI) models, we observed that, in addition to organic P, CFM simultaneously increased soil Al-P, thereby weakening the diffusion and resupply capacity of P from soil solids to the solution. Consequently, this decrease in P release risk to the environment was demonstrated. Overall, this study establishes a connection between crop-soil-enzyme C:N:P stoichiometry, soil microorganisms, and soil P biogeochemical processes. The study further evaluates the P release risk to the environment, providing a novel perspective on both the direct and indirect effects of manure substitution on soil P cycling.
Subject(s)
Agriculture , Fertilizers , Manure , Nitrogen , Phosphorus , Soil Microbiology , Soil , Phosphorus/analysis , Soil/chemistry , Manure/analysis , Nitrogen/analysis , Fertilizers/analysis , Carbon/analysis , Crops, Agricultural , Soil Pollutants/analysisABSTRACT
Reactive oxygen species (ROS) constitute a spectrum of oxygenic metabolites crucial in modulating pathological organism functions. Disruptions in ROS equilibrium span various diseases, and current insights suggest a dual role for ROS in tumorigenesis and the immune response within cancer. This review rigorously examines ROS production and its role in normal cells, elucidating the subsequent regulatory network in inflammation and cancer. Comprehensive synthesis details the documented impacts of ROS on diverse immune cells. Exploring the intricate relationship between ROS and cancer immunity, we highlight its influence on existing immunotherapies, including immune checkpoint blockade, chimeric antigen receptors, and cancer vaccines. Additionally, we underscore the promising prospects of utilizing ROS and targeting ROS modulators as novel immunotherapeutic interventions for cancer. This review discusses the complex interplay between ROS, inflammation, and tumorigenesis, emphasizing the multifaceted functions of ROS in both physiological and pathological conditions. It also underscores the potential implications of ROS in cancer immunotherapy and suggests future research directions, including the development of targeted therapies and precision oncology approaches. In summary, this review emphasizes the significance of understanding ROS-mediated mechanisms for advancing cancer therapy and developing personalized treatments.
ABSTRACT
PURPOSE: This study aimed to develop and validate a nomogram for predicting the efficacy of transurethral surgery in benign prostatic hyperplasia (BPH) patients. METHODS: Patients with BPH who underwent transurethral surgery in the West China Hospital and West China Shang Jin Hospital were enrolled. Patients were retrospectively involved as the training group and were prospectively recruited as the validation group for the nomogram. Logistic regression analysis was utilized to generate nomogram for predicting the efficacy of transurethral surgery. The discrimination of the nomogram was assessed using the area under the receiver operating characteristic curve (AUC) and calibration plots were applied to evaluate the calibration of the nomogram. RESULTS: A total of 426 patients with BPH who underwent transurethral surgery were included in the study, and they were further divided into a training group (n = 245) and a validation group (n = 181). Age (OR 1.07, 95% CI 1.02-1.15, P < 0.01), the compliance of the bladder (OR 2.37, 95% CI 1.20-4.67, P < 0.01), the function of the detrusor (OR 5.92, 95% CI 2.10-16.6, P < 0.01), and the bladder outlet obstruction (OR 2.21, 95% CI 1.07-4.54, P < 0.01) were incorporated in the nomogram. The AUC of the nomogram was 0.825 in the training group, and 0.785 in the validation group, respectively. CONCLUSION: The nomogram we developed included age, the compliance of the bladder, the function of the detrusor, and the severity of bladder outlet obstruction. The discrimination and calibration of the nomogram were confirmed by internal and external validation.
Subject(s)
Prostatic Hyperplasia , Transurethral Resection of Prostate , Urinary Bladder Neck Obstruction , Male , Humans , Prostatic Hyperplasia/surgery , Nomograms , Retrospective Studies , Urinary Bladder Neck Obstruction/surgeryABSTRACT
Cancer is a major socioeconomic burden that seriously affects the life and spirit of patients. However, little is known about the role of environmental toxicant exposure in diseases, especially ubiquitous di-(2-ethylhexyl) phthalate (DEHP) which is one of the most widely used plasticizers. Hence, the objective of this study was to assess the potential association between cancer and DEHP. The data were collected using the 2011-2018 National Health and Nutrition Examination Survey (NHANES) data (n = 6147), and multiple logistic regression was conducted to evaluate the association. The concentrations of DEHP were calculated by each metabolite and split into quartiles for analysis. After adjusting for confounding factors, DEHP was significantly associated with an increased risk of cancer prevalence, and the metabolites of DEHP showed similar results (OR > 1.0, p < 0.05). Simultaneously, the association remained when the analyses were stratified by age and sex, and the risk of cancer appeared to be higher in male patients. In addition, further analysis suggested that DEHP exposure obviously increased the risk of female reproductive system cancer, male reproductive system cancer, and other cancers (OR > 1.0, p < 0.05) but not skin and soft tissue cancer. DEHP exposure is associated with the risk of cancer, especially female reproductive system cancer, male reproductive system cancer and other cancers.
Subject(s)
Diethylhexyl Phthalate , Neoplasms , Phthalic Acids , Humans , Male , Female , Diethylhexyl Phthalate/toxicity , Diethylhexyl Phthalate/analysis , Nutrition Surveys , Phthalic Acids/toxicity , Environmental Exposure/adverse effects , Environmental Exposure/analysis , Neoplasms/chemically induced , Neoplasms/epidemiologyABSTRACT
Two-dimensional (2D) Fe chalcogenides with their rich structures and properties are highly desirable for revealing the torturous transition mechanism of Fe chalcogenides and exploring their potential applications in spintronics and nanoelectronics. Hydrostatic pressure can effectively stimulate phase transitions between various ordered states, allowing one to successfully plot a phase diagram for a given material. Herein, the structural evolution and transport characteristics of 2D FeTe were systematically investigated under extreme conditions by comparing two distinct symmetries, i.e., tetragonal (t) and hexagonal (h) FeTe. We found that t-FeTe presented a pressure-induced transition from an antiferromagnetic state to a ferromagnetic state at â¼3 GPa, corresponding to the tetragonal collapse of the layered structure. Contrarily, the ferromagnetic order of h-FeTe was retained up to 15 GPa, which was evidently confirmed by electrical transport and Raman measurements. Furthermore, T-P phase diagrams for t-FeTe and h-FeTe were mapped under delicate critical conditions. Our results can provide a unique platform to elaborate the extraordinary properties of Fe chalcogenides and further develop their applications.
ABSTRACT
2D layered magnets, such as iron chalcogenides, have emerged these years as a new family of unconventional superconductors and provided the key insights to understand the phonon-electron interaction and pairing mechanism. Their mechanical properties are of strategic importance for the potential applications in spintronics and optoelectronics. However, there is still a lack of efficient approach to tune the elastic modulus despite the extensive studies. Herein, the modulated elastic modulus of 2D magnetic FeTe and its thickness-dependence is reported via phase engineering. The grown 2D FeTe by chemical vapor deposition can present various polymorphs, that is tetragonal FeTe (t-FeTe, antiferromagnetic) and hexagonal FeTe (h-FeTe, ferromagnetic). The measured Young's modulus of t-FeTe by nanoindentation method shows an obvious thickness-dependence, from 290.9 ± 9.2 to 113.0 ± 8.7 GPa when the thicknesses increased from 13.2 to 42.5 nm, respectively. In comparison, the elastic modulus of h-FeTe remains unchanged. These results can shed light on the efficient modulation of mechanical properties of 2D magnetic materials and pave the avenues for their practical applications in nanodevices.
ABSTRACT
BACKGROUND: There have been few investigations on the association between depression and benign prostatic hyperplasia (BPH). This study aims to explore the correlation between depression and BPH among middle-aged and older men in India. METHODS: We utilized data from male individuals aged 45 years and older who participated in the initial wave (2017-2018) of the Longitudinal Aging Study in India (LASI). The presence of BPH symptoms was based on self-reported information, while depressive symptoms were evaluated using CESD-10. The analysis was a cross-sectional study conducted on a final sample size of 30,108 male participants. To examine associations, we employed multivariate logistic regression analysis along with subgroup analysis and interaction tests. RESULTS: A total of 439 (1.46%) men reported BPH and had a higher depression score (10.18 ± 4.22 vs. 9.28 ± 4.00). The findings indicated a significant association between the depression score and the likelihood of developing BPH, even after accounting for all potential confounding variables (OR = 1.054, 95% CI: 1.030-1.078, p < 0.00001). The participants were then categorized into a depression group and a normal group based on their CESD-10 score, using a threshold of 10 to ascertain the existence or nonexistence of depression. After adjusting for all variables in model IV, the findings continued to exhibit statistical significance (OR = 1.611, CI: 1.327-1.955, p < 0.00001). Significant interaction effects of age, education level, caste or tribe, and alcohol consumption were observed (p for interaction < 0.05). CONCLUSION: Our research found that BPH was significantly linked to the presence of depressive symptoms among middle-aged and elderly Indian men. Additional prospective research is necessary to clarify this association and investigate potential mechanisms.
Subject(s)
Prostatic Hyperplasia , Aged , Middle Aged , Humans , Male , Female , Prostatic Hyperplasia/epidemiology , Depression/epidemiology , Prospective Studies , Cross-Sectional Studies , AgingABSTRACT
Anisotropic two-dimensional layered materials with low-symmetry lattices have attracted increasing attention due to their unique orientation-dependent mechanical properties. Black arsenic (b-As), with the puckered structure, exhibits extreme in-plane anisotropy in optical, electrical, and thermal properties. However, experimental research on mechanical properties of b-As is very rare, although theoretical calculations predicted the exotic elastic properties of b-As, such as the anisotropic Young's modulus and negative Poisson's ratio. Herein, experimental observations on highly anisotropic elastic properties of b-As were demonstrated using our developed in situ tensile straining setup based on the effective microelectromechanical system. The cyclic and repeatable load-displacement curves proved that Young's modulus along the zigzag direction was â¼1.6 times greater than that along the armchair direction, while the anisotropic ratio of ultimate strain reached â¼2.5, attributed to the hinge structure in the armchair direction. This study could provide significant insights into the design of novel anisotropic materials and explore their potential applications in nanomechanics and nanodevices.
ABSTRACT
Grafting is widely used to improve the stress tolerance and the fruit yield of horticultural crops. Ribonucleoprotein complexes formed by mRNAs and proteins play critical roles in the communication between scions and stocks of grafted plants. In Pyrus betulaefolia, ankyrin was identified previously to promote the long-distance movement of the ribonucleoprotein complex(PbWoxT1-PbPTB3) by facilitating callose degradation at plasmodesmata. However, the mechanism of the ankyrin-mediated callose degradation remains elusive. In this study, we discovered a ß-1,3-glucanase (EC 3.2.1.39, PbPDBG) using ankyrin as a bait from plasmodesmata by co-immunoprecipitation and mass spectrometry. Ankyrin was required for the plasmodesmata-localization of PbPDBG. The grafting and bombardment experiments indicated that overexpressing PbPDBG resulted in decreased callose content at plasmodesmata, and thereby promoting the long-distance transport of the ribonucleoprotein complex. Altogether, our findings revealed that PbPDBG was the key factor in ankyrin-mediated callose degradation at plasmodesmata.
Subject(s)
Plasmodesmata , Pyrus , Plasmodesmata/metabolism , Pyrus/metabolism , Ankyrins/metabolism , Crops, Agricultural/metabolism , Ribonucleoproteins/genetics , Ribonucleoproteins/metabolismABSTRACT
Grafting is the main asexual propagation method for horticultural crops and can enhance their resistance to biotic or abiotic stress. Many mRNAs can be transported over long distances through the graft union, however, the function of mobile mRNAs remains poorly understood. Here, we exploited lists of candidate mobile mRNAs harboring potential 5-methylcytosine (m5C) modification in pear (Pyrus betulaefolia). dCAPS RT-PCR and RT-PCR were employed to demonstrate the mobility of the 3-hydroxy-3-methylglutaryl-coenzyme A reductase1 (PbHMGR1) mRNA in grafted plants of both pear and tobacco (Nicotiana tabacum). Overexpressing PbHMGR1 in tobacco plants enhanced salt tolerance during seed germination. In addition, both histochemical staining and GUS expression analysis showed that PbHMGR1 could directly respond to salt stress. Furthermore, it was found that the relative abundance of PbHMGR1 increased in heterografted scion, which avoided serious damage under salt stress. Collectively, these findings established that PbHMGR1 mRNA could act as a salt-responsive signal and move through the graft union to enhance salt tolerance of scion, which might be used as a new plant breeding technique to improve resistance of scion through a stress-tolerant rootstock.
Subject(s)
Pyrus , Pyrus/genetics , Pyrus/metabolism , Salt Tolerance/genetics , Phloem/genetics , Phloem/metabolism , RNA, Messenger/genetics , RNA, Messenger/metabolism , Plant BreedingABSTRACT
Numerous plant endogenous mRNAs move via phloem and thus affect the growth and development of long-distant organs. mRNAs are transported with RNA-binding proteins forming a ribonucleoprotein complex. However, it remains elusive how such RNP complex assembles and facilitates mRNA trafficking. Protease digestion and RNA immunoprecipitation were used to investigate the RNP assembly function of the complete Chaperonin Containing T-complex Polypeptide-1. In situ hybridization, hairy root transformation, microprojectile bombardment, and grafting experiments demonstrate the role of CCT complex in the transport of a PbWoxT1-PbPTB3 RNP complex in Pyrus betulaefolia. PbCCT5 silenced caused defective movement of GFP-PbPTB3 and GFP-PbWoxT1 from hairy roots to new leaves via the phloem. PbCCT5 is shown to interact with PbPTB3. PbCCT complex enhanced PbPTB3 stabilization and permitted assembly of PbWoxT1 and PbPTB3 into an RNP complex. Furthermore, silencing of individual CCT subunits inhibited the intercellular movement of GFP-PbPTB3 and long-distance trafficking of PbWoxT1 and PbPTB3 in grafted plants. Taken together, the CCT complex assembles PbPTB3 and PbWoxT1 into an RNP complex in the phloem in order to facilitate the long-distance trafficking of PbWoxT1 in P. betulaefolia. This study therefore provides important insights into the mechanism of RNP complex formation and transport.
Subject(s)
Pyrus , Chaperonin Containing TCP-1/metabolism , Plant Proteins/genetics , Plant Proteins/metabolism , Plants/metabolism , RNA, Messenger/genetics , RNA, Messenger/metabolism , RNA, Plant/genetics , RNA, Plant/metabolism , Ribonucleoproteins/metabolismABSTRACT
Smart tactile sensing materials have excellent development prospects, including wearable health-monitoring equipment and energy collection. Hydrogels have received extensive attention in tactile sensing owing to their transparency and high elasticity. In this study, highly crosslinked hydrogels are fabricated by chemically crosslinking polyacrylamide with lithium magnesium silicate and decorated with carbon quantum dots. Magnesium lithium silicate provides abundant covalent bonds and improves the mechanical properties of the hydrogels. The luminescent properties endowed by the carbon dots further broaden the application of hydrogels for realizing flexible electronics. The hydrogel-based strain sensor exhibits excellent sensitivity (gauge factor 2.6), a broad strain response range (0-2000%), good cyclicity, and durability (1250). Strain sensors can be used to detect human motions. More importantly, the hydrogel can also be used as a flexible self-supporting triboelectric electrode for effectively detecting pressure in the range of 1-25 N and delivering a short-circuit current (ISC ) of 2.6 µA, open-circuit voltage (VOC ) of 115 V, and short-circuit transfer charge (QSC ) of 29 nC. The results reveal new possibilities for human-computer interactions and electronic robot skins.
Subject(s)
Carbon , Wearable Electronic Devices , Humans , Hydrogels/chemistry , Lithium , Touch , Electric ConductivityABSTRACT
As global warming intensifies, heat stress has become a major environmental constraint threatening crop production and quality worldwide. Here, we characterize Heat-induced long intergenic noncoding RNA 1 (HILinc1), a cytoplasm-enriched lincRNA that plays a key role in thermotolerance regulation of pear (Pyrus spp.). HILinc1 Target 1 (PbHILT1) which is the target transcript of HILinc1, was stabilized via complementary base pairing to upregulate its expression. PbHILT1 could bind to Heat shock transcription factor A1b (PbHSFA1b) to enhance its transcriptional activity, leading to the upregulation of a major downstream transcriptional regulator, Multiprotein bridging factor 1c (PbMBF1c), during heat response. Transient overexpressing of either HILinc1 or PbHILT1 increases thermotolerance in pear, while transient silencing of HILinc1 or PbHILT1 makes pear plants more heat sensitive. These findings provide evidences for a new regulatory mechanism by which HILinc1 facilitates PbHSFA1b activity and enhances pear thermotolerance through stabilizing PbHILT1 transcripts.
Subject(s)
Pyrus , RNA, Long Noncoding , Thermotolerance , Pyrus/genetics , Pyrus/metabolism , Thermotolerance/genetics , Heat Shock Transcription Factors/metabolism , RNA, Long Noncoding/genetics , Base Pairing , Heat-Shock Proteins/metabolismABSTRACT
Basalt fiber and its resin composites have gradually supplanted traditional steel and glass fiber composites due to their superior strength, heat resistance, and corrosion resistance. However, basalt fiber still has significant flaws that restrict the functionality and use of its composites, such as less active functional groups and poor resin adherence. This study examines the effects of sizing agent on the characteristics of basalt fiber/epoxy resin composites. Epoxy resin emulsion and acrylate emulsion are employed as the primary auxiliary film-forming agents in this study. Polyurethane emulsion with various content levels is also used. The findings indicate that a 1% wt. of polyurethane emulsion concentration produces the greatest results, increasing the composite's flexural strength, flexural modulus, tensile strength, and interlaminar shear strength by 122%, 34.0%, 102%, and 10.2%, respectively. At the same time, the storage modulus and Tg of the material will decrease. In addition, the breakdown strength can be raised by 112%, and insulation parameters such as leakage current and dielectric loss factor can be decreased by 26.4% and 15.6%, respectively. The effect of sizing agent B is the best.
ABSTRACT
Basalt fiber (BF) has high mechanical strength, good insulation performance and low cost. It is suitable to be used as reinforcement material in the manufacture of electrical equipment. However, the large surface inertia of basalt fiber makes it difficult to combine with the matrix material, which seriously limits its service life and application scenarios. In addition, the serious vacancy in the research of insulation properties also limits its production and application in the electrical field. Therefore, in order to solve the problem of difficult bonding between basalt fiber and resin matrix and make up for the research blank of basalt fiber composites in insulation performance, this paper provides a basalt fiber modification method-SiO2 coating, and tests the insulation and mechanical properties of the modified composite. We used nano-SiO2 coating solution to modify basalt fiber, and manufactured BF/resin composite (BFRP) by hand lay-up and hot-pressing technology, and experimentally analyzed the influence of nano-SiO2 content on the mechanical and insulation properties of the modified composite. Fourier transform infrared spectrum and scanning electron microscope analysis showed that nano-SiO2 was successfully coated on basalt fibers. Through the microdroplet debonding test, it was found that the IFSS of fiber/resin was improved by 35.15%, 72.97 and 18.9%, respectively, after the modification of the coating solution with SiO2 concentration of 0.5%, 1% and 1.5%, showing better interface properties; the single fiber tensile test found that the tensile strength of the modified fiber increased slightly. Among all composites, 1 wt% SiO2 coating modified composites showed the best comprehensive properties. The surface flashover voltage and breakdown field strength reached 13.12 kV and 33 kV/mm, respectively, which were 34.6% and 83% higher than unmodified composite. The dielectric loss is reduced to 1.43%, which is 33.8% lower than the dielectric loss (2.16%) of the untreated composite, showing better insulation ability; the tensile strength, bending strength and interlaminar shear strength were increased to 618.22 MPa, 834.74 MPa and 16.29 MPa, respectively, which were increased by 53%, 42.4% and 59.7%, compared with untreated composites. DMA and glass transition temperature showed that the modified composite had better heat resistance. TGA experiments showed that the resin content of the modified composite increased, and the internal structure of the composite became denser.
ABSTRACT
The dielectric constant of CCTO materials can be as high as 104, which makes it suitable for use in electronic devices but the high dielectric loss limits its application. In this paper, a series of Sr and Zr co-doped CCTO ceramics having the formula Ca0.8Sr0.2Cu3Ti4-xZrxO12 (x = 0.1, 0.2, 0.3, 0.4) were obtained via a solid-state reaction technique. We force the effect of the Zr content on the phase composition, microstructure, cationic valence states, impedance, and dielectric properties of the as-prepared ceramics to reduce dielectric loss. The results demonstrate that Sr and Zr co-doping increases dielectric constant and reduces dielectric loss simultaneously, and the maximum dielectric constant (1.87 × 105, 1 Hz) and minimum dielectric loss (0.43, 102 Hz) are obtained when x = 0.3. Mixed Cu+/Cu2+ and Ti3+/Ti4+ valence states are observed to coexist in the co-doped material lattices, which promote dipole polarization, and thereby increase the dielectric constant of the ceramics. The dielectric properties of the materials are analyzed according to the internal barrier layer capacitance model, which elucidates the contributions of the grains and grain boundaries to dielectric performance. The maximum grain boundary resistance (3.7 × 105 Ω) is obtained for x = 0.3, which contributes toward the minimum dielectric loss (0.43) obtained for this ceramic at a frequency less than 1 kHz. The average grain sizes of the samples decrease with increasing Zr content, which is the primary factor increasing the grain boundary resistance of the co-doped ceramics.
ABSTRACT
Basalt fiber (BF) has a high mechanical strength, excellent temperature resistance, good chemical stability, low energy consumption, and an environmentally friendly production process. In addition, BF-reinforced polymers (BFRPs) have good corrosion resistance and designability; thus, they meet the application requirements of electrical equipment, such as new conductors, insulating pull rods, and composite cross-arms. However, there are still a series of technical issues in the mass production of BF, and the stability of the products needs to be further improved. Therefore, the research on the production, modification, and application of BF is necessary. This paper discusses the chemical composition and production technology of BF, describes the morphology and properties of BF, summarizes the interface problems and modification methods of composites, and finally, introduces the application prospects of BF in the field of electrical materials, which is expected to provide a reference for the application and promotion of BFRP in the future.
ABSTRACT
Molecular light-harvesting capabilities and the production of low-temperature heat output are essential for flexible self-heated textiles. An effective strategy to achieve these characteristics is to introduce photoresponsive molecular interactions (photodynamic bonds) to increase the energy storage capacity and optimize the low-temperature photochromic kinetics. In this study, a series of sulfonic-grafted azobenzene-based polymers interacted with different metal ions (PAzo-M, M = Mg, Ca, Ni, Zn, Cu, and Fe) to optimize the energy level and isomerization kinetics of these polymers is designed and prepared. Photoinduced formation and dissociation of MO dynamic bonds enlarge the energy gap (∆E) between trans and cis isomers for high-energy storage and favor a high rate of isomerization for low-temperature heat release. The suitable binding energy and high ∆E enable PAzo-M to store and release isomerization energy and bond enthalpy even in a low-temperature (-5 °C) environment. PAzo-Mg possesses the highest energy storage density of 408.6 J g-1 (113.5 Wh kg-1 ). A flexible textile coated with PAzo-Mg can provide a high rise in temperature of 7.7-12.5 °C in a low-temperature (-5.0 to 5.0 °C) environment by selectively self-releasing heat indoors and outdoors. The flexible textile provides a new pathway for wearable thermal management devices.