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1.
Huan Jing Ke Xue ; 45(5): 2622-2630, 2024 May 08.
Artigo em Chinês | MEDLINE | ID: mdl-38629526

RESUMO

A typical particulate matter pollution process occurred from October 9 to 17,2018,in Langfang,and 99 types of volatile organic compounds (VOCs) were monitored by using ZF-KU-1007. The characteristics of VOCs,formation potential of secondary organic aerosol (SOA),and source of VOCs were systematically analyzed. The results showed that the maximum concentration of PM2.5 was 198 µg·m-3 during the pollution process and was 2.64 times the National Ambient Air Quality Standard (GB 3095-2012). The average concentration of VOCs was 56.8×10-9,127.8×10-9,and 72.5×10-9 in the early,middle,and late stages of the pollution process,respectively,and the concentration of VOCs increased significantly in the middle stage. The formation potential of SOA was significantly positively correlated with PM2.5,and the contribution of aromatic hydrocarbon for SOA was larger and significantly correlated with the concentration of PM2.5. In the middle pollution stage,SOA increased,and the contribution ratio of aromatic hydrocarbon increased significantly. Conversely,the contribution of alkanes and olefin decreased significantly,which showed that aromatic hydrocarbons,namely benzene series,were the dominant species of SOA generation and had a great influence on the pollution process. Benzene,toluene,m-/p-xylene,o-xylene,and ethylbenzene and nonane,n-undecane,and methylcyclohexane were the priority control species in this pollution process. Solvent use source and motor vehicle emission source (gasoline and diesel vehicles) were the main sources affecting the concentration of VOCs during the autumn pollution process of Langfang,among which the contribution of gasoline vehicle emissions increased significantly in the middle pollution contribution and was the key control source.

2.
Artigo em Inglês | MEDLINE | ID: mdl-38565910

RESUMO

BACKGROUND: A growing number of studies have shown that in addition to adaptive immune cells such as CD8 + T cells and CD4 + T cells, various other cellular components within prostate cancer (PCa) tumor microenvironment (TME), mainly tumor-associated macrophages (TAMs), cancer-associated fibroblasts (CAFs) and myeloid-derived suppressor cells (MDSCs), have been increasingly recognized as important modulators of tumor progression and promising therapeutic targets. OBJECTIVE: In this review, we aim to delineate the mechanisms by which TAMs, CAFs and MDSCs interact with PCa cells in the TME, summarize the therapeutic advancements targeting these cells and discuss potential new therapeutic avenues. METHODS: We searched PubMed for relevant studies published through December 10 2023 on TAMs, CAFs and MDSCs in PCa. RESULTS: TAMs, CAFs and MDSCs play a critical role in the tumorigenesis, progression, and metastasis of PCa. Moreover, they substantially mediate therapeutic resistance against conventional treatments including anti-androgen therapy, chemotherapy, and immunotherapy. Therapeutic interventions targeting these cellular components have demonstrated promising effects in preclinical models and several clinical trials for PCa, when administrated alone, or combined with other anti-cancer therapies. However, the lack of reliable biomarkers for patient selection and incomplete understanding of the mechanisms underlying the interactions between these cellular components and PCa cells hinder their clinical translation and utility. CONCLUSION: New therapeutic strategies targeting TAMs, CAFs, and MDSCs in PCa hold promising prospects. Future research endeavors should focus on a more comprehensive exploration of the specific mechanisms by which these cells contribute to PCa, aiming to identify additional drug targets and conduct more clinical trials to validate the safety and efficacy of these treatment strategies.

3.
Materials (Basel) ; 17(3)2024 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-38591456

RESUMO

In this work, 10 nm scandium-doped aluminum nitride (AlScN) capacitors are demonstrated for the construction of the selector-free memory array application. The 10 nm Al0.7Sc0.3N film deposited on an 8-inch silicon wafer with sputtering technology exhibits a large remnant polarization exceeding 100 µC/cm2 and a tight distribution of the coercive field, which is characterized by the positive-up-negative-down (PUND) method. As a result, the devices with lateral dimension of only 1.5 µm show a large memory window of over 250% and a low power consumption of ~40 pJ while maintaining a low disturbance rate of <2%. Additionally, the devices demonstrate stable multistate memory characteristics with a dedicated operation scheme. The back-end-of-line (BEOL)-compatible fabrication process, along with all these device performances, shows the potential of AlScN-based capacitors for the implementation of the high-density selector-free memory array.

6.
Langmuir ; 2024 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-38602229

RESUMO

In this work, a novel birnessite-type MnO2 modified corn husk sustainable biomass fiber (MnO2@CHF) adsorbent was fabricated for efficient cadmium (Cd) removal from aquatic environments. MnO2@CHF was designed from KMnO4 hydrothermally treated with corn husk fibers. Various characterization revealed that MnO2@CHF possessed the hierarchical structure nanosheets, large specific surface area, and multiple oxygen-containing functional groups. Batch adsorption experimental results indicated that the highest Cd (II) removal rate could be obtained at the optimal conditions of adsorbent amount of 0.200 g/L, adsorption time of 600 min, pH 6.00, and temperature of 40.0 °C. Adsorption isotherm and kinetics results showed that Cd (II) adsorption behavior on MnO2@CHF was a monolayer adsorption process and dominated by chemisorption and intraparticle diffusion. The optimum adsorption capacity (Langmuir model) of Cd (II) on MnO2@CHF was 23.0 mg/g, which was higher than those of other reported common biomass adsorbent materials. Further investigation indicated that the adsorption of Cd (II) on MnO2@CHF involved mainly ion exchange, surface complexation, redox reaction, and electrostatic attraction. Moreover, the maximum Cd (II) removal rate on MnO2@CHF from natural river samples (Xicheng Canal) could reach 59.2% during the first cycle test. This study showed that MnO2@CHF was an ideal candidate in Cd (II) practical application treatment, providing references for resource utilization of agricultural wastes for heavy metal removal.

7.
Artigo em Inglês | MEDLINE | ID: mdl-38635378

RESUMO

Thin-film piezoelectric micromachined ultrasound transducers (PMUTs) are an increasingly relevant and well-researched field, and their biomedical importance has been growing as the technology continues to mature. This review paper briefly discusses their history in biomedical use, provides a simple explanation of their principles for newer readers, and sheds light on the materials selection for these devices. Primarily, it discusses the significant applications of PMUTs in the biomedical industry and showcases recent progress that has been made in each application. The biomedical applications covered include common historical uses of ultrasound such as ultrasound imaging, ultrasound therapy, and fluid sensing, but additionally new and upcoming applications such as drug delivery, photoacoustic imaging, thermoacoustic imaging, biometrics, and intrabody communication. By including a device comparison chart for different applications, this review aims to assist MEMS designers that work with PMUTs by providing a benchmark for recent research works. Furthermore, it puts forth a discussion on the current challenges being faced by PMUTs in the biomedical field, current and likely future research trends, and opportunities for PMUT development areas, as well as sharing the opinions and predictions of the authors on the state of this technology as a whole. The review aims to be a comprehensive introduction to these topics without diving excessively deep into existing literature.

8.
Res Sq ; 2024 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-38645058

RESUMO

Genome wide association studies (GWASs) have identified numerous risk loci associated with prostate cancer, yet unraveling their functional significance remains elusive. Leveraging our high-throughput SNPs-seq method, we pinpointed rs4519489 within the multi-ancestry GWAS-discovered 2p25 locus as a potential functional SNP due to its significant allelic differences in protein binding. Here, we conduct a comprehensive analysis of rs4519489 and its associated gene, NOL10, employing diverse cohort data and experimental models. Clinical findings reveal a synergistic effect between rs4519489 genotype and NOL10 expression on prostate cancer prognosis and severity. Through unbiased proteomics screening, we reveal that the risk allele A of rs4519489 exhibits enhanced binding to USF1, a novel oncogenic transcription factor (TF) implicated in prostate cancer progression and prognosis, resulting in elevated NOL10 expression. Furthermore, we elucidate that NOL10 regulates cell cycle pathways, fostering prostate cancer progression. The concurrent expression of NOL10 and USF1 correlates with aggressive prostate cancer characteristics and poorer prognosis. Collectively, our study offers a robust strategy for functional SNP screening and TF identification through high-throughput SNPs-seq and unbiased proteomics, highlighting the rs4519489-USF1- NOL10 regulatory axis as a promising biomarker or therapeutic target for clinical diagnosis and treatment of prostate cancer.

9.
ACS Omega ; 9(8): 9410-9423, 2024 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-38434893

RESUMO

The development of high energy gun propellants faces significant challenges in terms of erosion, partly due to the inadequate effectiveness of erosion inhibitors. In this paper, the influence of quite different flame temperature of five gun-propellants on erosion-reducing efficiency of four representative inhibitors materials (talc/TiO2/ PDMS/Paraffin) were studied in vented erosion vessel tester. From aspects of morphologies and element compositions of erode steel samples, as well as the pressure and heat generated by propellant burning, the relevant erosion-reducing processes and mechanisms were discussed. The results indicated that erosion inhibitors should be appropriately selected according to the type of gun propellant. The erosion of gun propellants having extremely high flame temperature of 3810 K were hardly reduced using talc, TiO2, and PDMS inhibitors, which can generate numerous solid particles aggravating the melt-wipe process. While paraffin exhibits a uniquely positive erosion-reducing efficiency for the gun propellant having a flame temperature of 3810 K, that was attributed to the mitigated melt-wipe process. The inference was further supported by the high-volume cooling gas, resulting from the higher burning pressure of propellants loading with paraffin and excellent heat absorption capacity of paraffin tested with propellants having higher propellant flame temperature. The obtained results indicated that the factors of flame temperature of gun propellants should be taken into the design and composition optimization of an effective inhibitor. This work could provide potential reference for the development of future novel inhibitors, which serves as high energy gun propellants.

10.
Ann Clin Lab Sci ; 54(1): 56-65, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38514068

RESUMO

OBJECTIVE: Multiple Myeloma (MM) is a malignant hematological disease. Heterogeneous nuclear ribonucleoprotein C1/C2 (HNRNPC) acts as an oncogene in a variety of cancers. However, the role of HNRNPC in MM has not been reported so far. METHODS: The mRNA and protein expressions of HNRN-PC and FOXM1 were detected by qRT-PCR and western blot. CCK8, EDU staining, flow cytometry and western blot were used to detect cell viability and cell cycle. The extracellular flux analyzer XF96 was used to detect the production of oxygen consumption rate (OCR) and extracellular acidification rate (ECAR). Lactic acid and glucose levels in culture medium were detected by lactic acid assay kits and glucose assay kits, respectively. Then, the binding ability of HNRNPC with FOXM1 was detected by RIP and the stability of FOXM1 mRNA was appraised with qRT-PCR. With the application of qRT-PCR and western blot, the transfection efficacy of si-HNRNPC and Oe-FOXM1 was examined. Western blot was applied for the estimation of GLUT1/LDHA signaling pathway-related proteins. RESULTS: The expression of HNRNPC in MM cell line was abnormally elevated. HNRNPC silence significantly inhibited the proliferation, facilitated the apoptosis, induced cycle arrest, and suppressed aerobic glycolysis in MM cells, which were all reversed by FOXM1 overexpression. It was also found that the regulatory effect of HNRNPC is realized by stabilizing FOXM1 mRNA and regulating GLUT1/LDHA pathway. CONCLUSION: HNRNPC regulated GLUT1/LDHA pathway by stabilizing FOXM1 mRNA to promote the progression and aerobic glycolysis of MM.


Assuntos
Proteína Forkhead Box M1 , Ribonucleoproteínas Nucleares Heterogêneas Grupo C , Mieloma Múltiplo , Humanos , Linhagem Celular Tumoral , Proliferação de Células/genética , Proteína Forkhead Box M1/genética , Proteína Forkhead Box M1/metabolismo , Glucose/metabolismo , Transportador de Glucose Tipo 1/metabolismo , Glicólise/genética , Ribonucleoproteínas Nucleares Heterogêneas Grupo C/metabolismo , Ácido Láctico , Mieloma Múltiplo/genética , Mieloma Múltiplo/metabolismo , L-Lactato Desidrogenase/metabolismo
11.
Int J Pharm ; 655: 124015, 2024 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-38527565

RESUMO

Sonodynamic therapy (SDT) utilizes ultrasonic excitation of a sensitizer to generate reactive oxygen species (ROS) to destroy tumor. Two dimensional (2D) black phosphorus (BP) is an emerging sonosensitizer that can promote ROS production to be used in SDT but it alone lacks active targeting effect and showed low therapy efficiency. In this study, a stable dispersion of integrated micro-nanoplatform consisting of BP nanosheets loaded and Fe3O4 nanoparticles (NPs) connected microbubbles was introduced for ultrasound imaging guided and magnetic field directed precision SDT of breast cancer. The targeted ultrasound imaging at 18 MHz and efficient SDT effects at 1 MHz were demonstrated both in-vitro and in-vivo on the breast cancer. The magnetic microbubbles targeted deliver BP nanosheets to the tumor site under magnetic navigation and increased the uptake of BP nanosheets by inducing cavitation effect for increased cell membrane permeability via ultrasound targeted microbubble destruction (UTMD). The mechanism of SDT by magnetic black phosphorus microbubbles was proposed to be originated from the ROS triggered mitochondria mediated apoptosis by up-regulating the pro-apoptotic proteins while down-regulating the anti-apoptotic proteins. In conclusion, the ultrasound theranostic was realized via the magnetic black phosphorus microbubbles, which could realize targeting and catalytic sonodynamic therapy.


Assuntos
Neoplasias da Mama , Terapia por Ultrassom , Humanos , Feminino , Microbolhas , Espécies Reativas de Oxigênio/metabolismo , Linhagem Celular Tumoral , Ultrassonografia , Terapia por Ultrassom/métodos , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/terapia , Fósforo , Fenômenos Magnéticos
12.
Adv Sci (Weinh) ; : e2305724, 2024 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-38483933

RESUMO

Prostate cancer (PCa) is an extensive heterogeneous disease with a complex cellular ecosystem in the tumor microenvironment (TME). However, the manner in which heterogeneity is shaped by tumors and stromal cells, or vice versa, remains poorly understood. In this study, single-cell RNA sequencing, spatial transcriptomics, and bulk ATAC-sequence are integrated from a series of patients with PCa and healthy controls. A stemness subset of club cells marked with SOX9high ARlow expression is identified, which is markedly enriched after neoadjuvant androgen-deprivation therapy (ADT). Furthermore, a subset of CD8+ CXCR6+ T cells that function as effector T cells is markedly reduced in patients with malignant PCa. For spatial transcriptome analysis, machine learning and computational intelligence are comprehensively utilized to identify the cellular diversity of prostate cancer cells and cell-cell communication in situ. Macrophage and neutrophil state transitions along the trajectory of cancer progression are also examined. Finally, the immunosuppressive microenvironment in advanced PCa is found to be associated with the infiltration of regulatory T cells (Tregs), potentially induced by an FAP+ fibroblast subset. In summary, the cellular heterogeneity is delineated in the stage-specific PCa microenvironment at single-cell resolution, uncovering their reciprocal crosstalk with disease progression, which can be helpful in promoting PCa diagnosis and therapy.

14.
BMC Pediatr ; 24(1): 172, 2024 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-38459440

RESUMO

BACKGROUND: Necrotizing enterocolitis (NEC) is a serious gastrointestinal disease, primarily affects preterm newborns and occurs after 7 days of life (late-onset NEC, LO-NEC). Unfortunately, over the past several decades, not much progress has been made in its treatment or prevention. This study aimed to analyze the risk factors for LO-NEC, and the impact of LO-NEC on short-term outcomes in very preterm infants (VPIs) with a focus on nutrition and different onset times. METHOD: Clinical data of VPIs were retrospectively collected from 28 hospitals in seven different regions of China from September 2019 to December 2020. A total of 2509 enrolled VPIs were divided into 2 groups: the LO-NEC group and non-LO-NEC group. The LO-NEC group was divided into 2 subgroups based on the onset time: LO-NEC occurring between 8 ~ 14d group and LO-NEC occurring after 14d group. Clinical characteristics, nutritional status, and the short-term clinical outcomes were analyzed and compared among these groups. RESULTS: Compared with the non-LO-NEC group, the LO-NEC group had a higher proportion of anemia, blood transfusion, and invasive mechanical ventilation (IMV) treatments before NEC; the LO-NEC group infants had a longer fasting time, required longer duration to achieve the target total caloric intake (110 kcal/kg) and regain birthweight, and showed slower weight growth velocity; the cumulative dose of the medium-chain and long-chain triglyceride (MCT/LCT) emulsion intake in the first week after birth was higher and breastfeeding rate was lower. Additionally, similar results including a higher proportion of IMV, lower breastfeeding rate, more MCT/LCT emulsion intake, slower growth velocity were also found in the LO-NEC group occurring between 8 ~ 14d when compared to the LO-NEC group occurring after 14 d (all (P < 0.05). After adjustment for the confounding factors, high proportion of breastfeeding were identified as protective factors and long fasting time before NEC were identified as risk factors for LO-NEC; early feeding were identified as protective factors and low gestational age, grade III ~ IV neonatal respiratory distress syndrome (NRDS), high accumulation of the MCT/LCT emulsion in the first week were identified as risk factors for LO-NEC occurring between 8 ~ 14d. Logistic regression analysis showed that LO-NEC was a risk factor for late-onset sepsis, parenteral nutrition-associated cholestasis, metabolic bone disease of prematurity, and extrauterine growth retardation. CONCLUSION: Actively preventing premature birth, standardizing the treatment of grade III ~ IV NRDS, and optimizing enteral and parenteral nutrition strategies may help reduce the risk of LO-NEC, especially those occurring between 8 ~ 14d, which may further ameliorate the short-term clinical outcome of VPIs. TRIAL REGISTRATION: ChiCTR1900023418 (26/05/2019).


Assuntos
Enterocolite Necrosante , Doenças do Prematuro , Síndrome do Desconforto Respiratório do Recém-Nascido , Feminino , Recém-Nascido , Humanos , Recém-Nascido Prematuro , Estado Nutricional , Enterocolite Necrosante/epidemiologia , Enterocolite Necrosante/etiologia , Enterocolite Necrosante/prevenção & controle , Emulsões , Estudos Retrospectivos , Doenças do Prematuro/epidemiologia , Doenças do Prematuro/etiologia , Doenças do Prematuro/prevenção & controle , Fatores de Risco
15.
Vet Microbiol ; 292: 110048, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38479301

RESUMO

The optrA gene encodes an ABC-F protein which confers cross-resistance to oxazolidinones and phenicols. Insertion sequence ISVlu1, a novel ISL3-family member, was recently reported to be involved in the transmission of optrA in Vagococcus lutrae. However, the role of ISVlu1 in mobilizing resistance genes has not yet fully explored. In this study, two complete and three truncated copies of ISVlu1 were found on plasmid pBN62-optrA from Lactococcus garvieae. Analysis of the genetic context showed that both optrA and the phenicols resistance gene fexA were flanked by the complete or truncated ISVlu1 copies. Moreover, three different-sized ISVlu1-based translocatable units (TUs) carrying optrA and/or fexA, were detected from pBN62-optrA. Sequence analysis revealed that the TU-optrA was generated by homologous recombination while TU-fexA and TU-optrA+fexA were the products of illegitimate recombinations. Importantly, conjugation assays confirmed that pBN62-optrA was able to successfully transfer into the recipient Enterococcus faecalis JH2-2. To our knowledge, this is the first report about an optrA-carrying plasmid in L. garvieae which could horizontally transfer into other species. More importantly, the ISVlu1-flanked genetic structures containing optrA and/or fexA were also observed in bacteria of different species, which underlines that ISVlu1 is highly active and plays a vital role in the transfer of some important resistance genes, such as optrA and fexA.


Assuntos
Antibacterianos , Oxazolidinonas , Animais , Suínos , Antibacterianos/farmacologia , Farmacorresistência Bacteriana/genética , Lactococcus/genética , Enterococcus faecalis , Genes Bacterianos/genética , Testes de Sensibilidade Microbiana/veterinária
16.
Langmuir ; 40(9): 4927-4939, 2024 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-38377532

RESUMO

Serious water contamination induced by massive discharge of cadmium(II) ions is becoming an emergent environmental issue due to high toxicity and bioaccumulation; thus, it is extremely urgent to develop functional materials for effectively treating with Cd2+ from wastewater. Benefiting from abundant binding sites, simple preparation process, and adjustable structure, UiO-66-type metal-organic frameworks (MOFs) had emerged as promising candidates in heavy metal adsorption. Herein, monolithic UiO-66-(COOH)2-functionalized cellulose fiber (UCLF) adsorbents were simply fabricated by incorporating MOFs into cellulose membranes through physical blending and self-entanglement. A two-dimensional structure was facilely constructed by cellulose fibers from sustainable biomass agricultural waste, providing a support platform for the integration of eco-friendly UiO-66-(COOH)2 synthesized with lower temperature and toxicity solvent. Structure characterization and bath experiments were performed to determine operational conditions for the maximization of adsorption capacity, thereby bringing out an excellent adsorption capacity of 96.10 mg/g. UCLF adsorbent holding 10 wt % loadings of UiO-66-(COOH)2 (UCLF-2) exhibited higher adsorption capacity toward Cd2+ as compared to other related adsorbents. Based on kinetics, isotherms, and thermodynamics, the adsorption behavior was spontaneous, exothermic, as well as monolayer chemisorption. Coordination and electrostatic attraction were perhaps mechanisms involved in the adsorption process, deeply unveiled by the effects of adsorbate solution pH and X-ray photoelectron spectroscopy. Moreover, UCLF-2 adsorbent with good mechanical strength offered a structural guarantee for the successful implementation of practical applications. This study manifested the feasibility of UCLF adsorbents used for Cd2+ adsorption and unveiled a novel strategy to shape MOF materials for wastewater decontamination.

17.
Biomed Pharmacother ; 172: 116221, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38306843

RESUMO

The gene therapy attracted more and more attention for the tumor therapy. To obtain a safe gene therapy system, the new gene vectors beyond the virus were developed for a high gene therapy efficiency. The ultrasound mediated gene therapy was safer and the plasmid DNA could be delivered by the microbubbles and combined with the ultrasound to increase the gene transfection efficiency. In this work, the cationic microbubbles decorated with Cyclo(Cys-Arg-Gly-Asp-Lys-Gly-Pro-AspCys) (iRGD peptides) and magnetic Fe3O4 nanoparticles (MBiM) was designed for targeted ultrasound contrast imaging guided gene therapy of tumors. The ultrasound image intensity was dramatically enhanced at the tumor site that received MBiM with the magnet applied, compared to those administrated the non-targeted microbubbles (MBb) or the microbubbles with only one target material on the surface (MBM and MBbi). The pGPU6/GFP/Neo-shAKT2 was used as a sample gene, which down regulate the AKT2 protein expression for the cancer therapy. It illustrated that MBiM/AKT2 had the highest gene transfection efficiency in the studied microbubbles mediated by the ultrasound, leading to the AKT2 protein expression downregulation and the strongest tumor killing effect in vitro and in vivo. In summary, a novel and biocompatible gene delivery platform via MBiM with both the endogenous and external targeting effects for breast cancer theranostics was developed.


Assuntos
Neoplasias da Mama , Microbolhas , Humanos , Feminino , Ultrassonografia , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/genética , Neoplasias da Mama/terapia , Oncogenes , Fenômenos Magnéticos
18.
J Phys Condens Matter ; 36(20)2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38335547

RESUMO

In the search for high-temperature superconductivity in hydrides, a plethora of multi-hydrogen superconductors have been theoretically predicted, and some have been synthesized experimentally under ultrahigh pressures of several hundred GPa. However, the impracticality of these high-pressure methods has been a persistent issue. In response, we propose a new approach to achieve high-temperature superconductivity under ambient pressure by implanting hydrogen into lead to create a stable few-hydrogen binary perovskite, Pb4H. This approach diverges from the popular design methodology of multi-hydrogen covalent high critical temperature (Tc) superconductors under ultrahigh pressure. By solving the anisotropic Migdal-Eliashberg equations, we demonstrate that perovskite Pb4H presents a phonon-mediated superconductivity exceeding 46 K with inclusion of spin-orbit coupling, which is six times higher than that of bulk Pb (7.22 K) and comparable to that of MgB2, the highestTcachieved experimentally at ambient pressure under the Bardeen, Cooper, and Schrieffer framework. The highTccan be attributed to the strong electron-phonon coupling strength of 2.45, which arises from hydrogen implantation in lead that induces several high-frequency optical phonon modes with a relatively large phonon linewidth resulting from H atom vibration. The metallic-bonding in perovskite Pb4H not only improves the structural stability but also guarantees better ductility than the widely investigated multi-hydrogen, iron-based and cuprate superconductors. These results suggest that there is potential for the exploration of new high-temperature superconductors under ambient pressure and may reignite interest in their experimental synthesis in the near future.

19.
Opt Express ; 32(2): 1552-1561, 2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-38297704

RESUMO

What we believe to be a new hybrid-polarization diversity scheme which can eliminate the polarization state variation caused by wavelength tuning of laser in optical frequency domain reflectometry is proposed in the paper. In the scheme, a 45° polarizer is used to maintain the polarization of signals. It decreases the polarization angle fluctuation to 2.81° and realizes a -145 dB test sensitivity with a 32 dB Rayleigh scattering signal-to-noise ratio in a 10 m fiber single test. The polarization fading suppression is achieved for tests with a large wavelength tuning range from 1480 nm to 1640 nm. Meanwhile, a 6 µm spatial resolution is also achieved. The proposed scheme can be applied to the structure measurement of high-precision optical fiber devices with high spatial resolution and sensitivity.

20.
Materials (Basel) ; 17(2)2024 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-38255566

RESUMO

Ferroelectric scandium-doped aluminum nitride (Al1-xScxN) is of considerable research interest because of its superior ferroelectricity. Studies indicate that Al1-xScxN may suffer from a high leakage current, which can hinder further thickness scaling and long-term reliability. In this work, we systematically investigate the origin of the leakage current in Al0.7Sc0.3N films via experiments and theoretical calculations. The results reveal that the leakage may originate from the nitrogen vacancies with positively charged states and fits well with the trap-assisted Poole-Frenkel (P-F) emission. Moreover, we examine the cycling behavior of ferroelectric Al0.7Sc0.3N-based FeRAM devices. We observe that the leakage current substantially increases when the device undergoes bipolar cycling with a pulse amplitude larger than the coercive electric field. Our analysis shows that the increased leakage current in bipolar cycling is caused by the monotonously reduced trap energy level by monitoring the direct current (DC) leakage under different temperatures and the P-F emission fitting.

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