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The shrinkage of metal oxide semiconductor field effect transistor (MOSFET) to the small size of the nanoscale results in changes in their channel current noise composition. This paper determines the channel current noise composition of 90 nm MOSFET through experiments, and according to the device material and noise characteristics analysis, the channel current noise of 90 nm and below is obtained, which not only contains thermal noise and suppressed channel shot noise, but also adds suppressed gate tunneling shot noise and cross-correlation noise. Then, Monte Carlo simulation of 10 nm MOSFET noise is further used to determine the channel current composition of small size nanoscale devices. Subsequently, based on the device structure and fundamental characteristics of channel current noise, the channel current noise model is established. Finally, this model is employed to analyze the relationship between thermal noise, suppressed shot noise, cross-correlation noise, and channel current noise in relation to bias parameters and device characteristics. The theoretical results are basically consistent with the experimental and the simulated results, and the channel noise increases with the increase of bias voltage. This achievement holds promise for enhancing the operational efficiency, reliability, and lifetime of nanoscale small-sized MOSFET devices.
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Layered lanthanum titanate (La2Ti2O7) perovskite is a good photocatalytic material owing to its high stability, strong redox ability, and non-toxicity. However, its inherent wide bandgap limits its application in photocatalytic hydrogen evolution. Therefore, combining La2Ti2O7 with two-dimensional (2D) narrow-bandgap semiconductors to form 2D/2D layered structures is the preferred strategy to improve its photocatalytic performance. In this study, a novel 2D/2D ZnIn2S4/La2Ti2O7 Z-scheme heterojunction was prepared through a solvothermal method. The experimental results show that when the molar ratio of La2Ti2O7 to ZnIn2S4 is 1 : 4, the hydrogen evolution rate of the composite under ultraviolet-visible light reaches 6.97 mmol g-1 h-1, which is 3.5 times higher than that of the pure ZnIn2S4. The results of the morphological characterization studies of the samples and the photoelectrochemical measurements show that channels for the rapid transfer of carriers are generated by the unique 2D/2D structure of these samples, and the separation and migration efficiency of the photogenerated carriers significantly improved due to the formation of the Z-scheme heterojunction. This study provides useful insights into the modulation of wide-bandgap semiconductors and research into solar energy conversion.
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This study introduces a new wide-bandgap graphene-like structure, denoted as C6BN, achieved by incorporating an eight-electron BN pair, substantially modifying its electronic properties. Utilizing extensive density functional calculations, we comprehensively analyzed the stability, electronic structure, mechanical properties, and optical-electrical characteristics of C6BN. Our investigations reveal the material's exceptional thermodynamic, mechanical, and dynamic stability. Notably, the calculated wide bandgap of 2.81 eV in C6BN, supported by analyses of energy levels, band structures, and density of states, positions it as a promising two-dimensional wide-bandgap semiconductor. Additionally, C6BN exhibits isotropic mechanical features, highlighting its inherent flexibility. Remarkably, our calculations indicate an ultra-low dielectric constant (k = 1.67) for C6BN, surpassing that of well-established third-generation semiconductors. Further exploration into the thermoelectric properties of C6BN demonstrates its promising performance, as evidenced by calculations of thermal conductivity (κ), power factor (P), and Seebeck coefficient (S). In summary, our findings underscore the significant potential of the proposed C6BN structure as a flexible two-dimensional material poised to drive future advancements in electronic and energy-related technologies.
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Aim: This study aims to explore the psychological reactions of medical students during the pandemic. Design: A qualitative study. Methods: A purposive sampling technique was employed, and a qualitative approach was adopted. Semi-structured questionnaires were utilized, and online interviews were conducted. Forty medical students were selected as participants for the interviews. The interview data were analyzed using Colaizzi's seven-step analysis method. Results: The study identified five themes related to the psychological reactions of medical students during the pandemic. Firstly, COVID-19's influence on medical careers was characterized by increased interest and determination in pursuing medical professions, heightened admiration for frontline workers, reinforced commitment to a medical career due to the pandemic, and recognition of the significance of medical education. Secondly, challenges and concerns in medical career pursuit were identified, including negative sentiments towards medical careers during COVID-19 and hesitations and concerns about entering the medical field amidst the pandemic. Thirdly, the impact on mental well-being encompassed diverse anxieties expressed by participants regarding control, transmission, treatment, and intentional spreading of the virus. Participants experienced an emotional progression from calmness to fear and anxiety, with heightened anxiety when relatives or acquaintances contracted COVID-19. Academic delays also contributed to anxiety among medical students. Fourthly, changes in behaviors and mindset were observed, including altered behaviors and mindset in response to the pandemic, as well as increased attention to personal hygiene and disease prevention measures. Lastly, expectations of medical students from government, public, and parents were explored. Conclusion: Understanding the psychological reactions of medical students during public health emergencies is crucial for their well-being and professional development. The findings have implications for medical education and the development of strategies to enhance the psychological well-being of medical students during similar crises.
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Biotransformation of ursane-type triterpenoid ilexgenin A by endophytic fungi Lasiodiplodia sp. MQD-4 and Pestalotiopsis sp. ZZ-1, isolated from Ilex pubescences and Callicarpa kwangtungensis respectively, was investigated for the first time. Six previously undescribed metabolites (1-6) with 23-norursane triterpenoids skeleton were isolated and their structures were unambiguously established by the analysis of spectroscopic data and single-crystal X-ray crystallographic experiments. Decarboxylation, oxidation, and hydroxylation reactions were observed on the triterpenoid skeleton. Especially, the decarboxylation of C-23 provided definite evidence to understand the biogenetic process of 23-norursane triterpenoids. Moreover, the qualitative analysis of the extract of I. pubescences showed metabolites 1, 3, 4, and 6 could be detected in the originated plant, indicating biotransformation by endophytic fungi is a practical strategy for the isolation of novel natural products. Finally, all isolates were evaluated for the protective activities against H2O2-induced HUVECs dysfunction in vitro. Compound 5 could improve the viability of endothelial cells and decrease the level of intracellular ROS.
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Biotransformação , Endófitos , Células Endoteliais da Veia Umbilical Humana , Ilex , Triterpenos , Triterpenos/isolamento & purificação , Triterpenos/farmacologia , Triterpenos/metabolismo , Endófitos/química , Endófitos/metabolismo , Estrutura Molecular , Humanos , Ilex/microbiologia , Ascomicetos/química , Ascomicetos/metabolismo , ChinaRESUMO
Introduction: This study investigates the mechanisms linking students' perceived teacher support with math anxiety, focusing on the mediating roles of the teacher-student relationship and mathematics self-efficacy. Methods: The research was conducted with 401 fifth-grade students in China, utilizing scales for Students' Perceived Teacher Support, Teacher-Student Relationship, Math Self-Efficacy, and Math Anxiety. Results: Findings revealed that student-perceived math teacher support, teacher-student relationship, and math self-efficacy were all significantly negatively correlated with math anxiety. It was notably found that student-perceived math teacher support influenced math anxiety through the chain mediation of teacher-student relationship and math self-efficacy. Additionally, the effect of students' perceived emotional support from math teachers on math anxiety, mediated by teacher-student relationship intimacy, was significant only among male students. Discussion: These results underscore the importance of fostering positive teacher-student interactions and enhancing self-efficacy to reduce math anxiety among primary school students. The gender-specific findings regarding emotional support and relationship intimacy highlight the need for tailored strategies in addressing math anxiety.
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This study investigated the influence of yeast extract addition, carbon source, and photoperiod on the growth dynamics of Auxenochlorella pyrenoidosa FACHB-5. Employing response surface methodology, the culture strategy was optimized, resulting in the following optimal conditions: yeast extract addition at 0.75 g L-1, glucose concentration of 0.83 g L-1, and a photoperiod set at Light: Dark = 18 h: 6 h. Under these conditions, the biomass reached 1.76 g L-1 with a protein content of 750.00 g L-1, containing 40 % of essential amino acids, representing a 1.52-fold increase. Proteomic analysis revealed that the targeted cultivation strategy up-regulated genes involved in microalgal protein synthesis. The combined effect of yeast extract and glucose enhanced both the glutamine synthetase-glutamate synthetase mechanism and the free amino acid content.
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Biomassa , Aminoácidos/metabolismo , Proteômica/métodos , Glutamato-Amônia Ligase/metabolismo , Fotoperíodo , Glucose/metabolismo , Microalgas/metabolismo , Proteínas de Algas/metabolismo , Clorófitas/metabolismoRESUMO
Separation of lanthanide (Ln) and minor actinide (MA) elements and mutual separation between minor actinide elements (e.g. Am(III) and Cm(III)) represent a crucial undertaking. However, separating these elements poses a significant challenge owing to their highly similar physicochemical properties. Asymmetric N-heterocyclic ligands such as N-ethyl-6-(1H-pyrazol-3-yl)-N-(p-tolyl)picolinamide (Et-p-Tol-A-PzPy) and N-ethyl-N-(p-tolyl)-1,10-phenanthroline-2-carboxamide (ETPhenAm) have recently received considerable attention in the separation of MAs over Ln from acid solutions. By changing the central skeleton structures of these ligands and introducing substituents with different properties on the side chains, their complexation behavior with Am(III), Cm(III), and Eu(III) may be affected. In this work, we explore four different asymmetric N-containing heterocyclic ligands, namely Et-p-Tol-A-PzPy (L1), N-ethyl-6'-(1H-pyrazol-3-yl)-N-(p-tolyl)-[2,2'-bipyridine]-6-carboxamide (L2), N-ethyl-9-(1H-pyrazol-3-yl)-N-(p-tolyl)-1,10-phenanthroline-2-carboxamide (L3), and ETPhenAm (L4) using density functional theory (DFT). The calculated results demonstrate the potential of ligands L1-L4 for the extraction and separation of Am(III), Cm(III), and Eu(III). Ligand analysis shows that ligand L3 binds more easily to the central metal atom, in line with the stronger extraction capacity of L3. In spite of the higher covalence between the side chain and the central metal atom for complexes with L1-L3, the main chain seems to control the stability of the extraction complexes. The preorganized 1,10-phenanthroline backbone also further enhances the extraction performance of L3 and L4. The difference in coordination ability between the side chain donors of these ligands and metal ions may affect their separation efficiency. This work presents theoretical insights into synthesizing novel ligands for separating trivalent actinides by adjusting N-heterocyclic ligands.
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Objective: This study aims to investigate the phenomenon of sexual intercourse-related fear among women utilizing assisted reproductive technology due to dyspareunia. The primary objective is to offer insights that can inform the development of targeted nursing interventions. Methods: Employing a purposive sampling approach, a cohort of 23 female patients experiencing dyspareunia and undergoing treatment at the Reproductive Medicine Center of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, between July 2022 and December 2022, were selected as participants for this research. Semi-structured, in-depth interviews were conducted to gather qualitative data. The Colaizzi 7-step analysis method was subsequently applied to scrutinize the interview transcripts and identify emergent themes. Results: The analysis yielded five prominent themes: psychological disturbances, incongruent cognitive perceptions, anticipations regarding conception, insufficient adaptive responses, and sexual expectations. Conclusion: It is imperative for medical practitioners to demonstrate reverence for patients' sexual beliefs and conditions, attune to their apprehensions, and offer efficacious emotional support. Tailored and multifaceted sexual health knowledge should be dispensed based on patients' individual requirements and their envisioned sexual experiences, thereby fostering spousal and familial harmony. By prioritizing patients' sexual well-being, cultivating a compassionate medical milieu, and augmenting the quality of assisted reproductive services, comprehensive improvements can be achieved.
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Pancreatic ductal adenocarcinoma (PDAC) is a lethal malignant disease with a low 5-year overall survival rate. It is the third-leading cause of cancer-related deaths in the United States. The lack of robust therapeutics, absence of effective biomarkers for early detection, and aggressive nature of the tumor contribute to the high mortality rate of PDAC. Notably, the outcomes of recent immunotherapy and targeted therapy against PDAC remain unsatisfactory, indicating the need for novel therapeutic strategies. One of the newly described molecular features of PDAC is the altered expression of protein arginine methyltransferases (PRMTs). PRMTs are a group of enzymes known to methylate arginine residues in both histone and non-histone proteins, thereby mediating cellular homeostasis in biological systems. Some of the PRMT enzymes are known to be overexpressed in PDAC that promotes tumor progression and chemo-resistance via regulating gene transcription, cellular metabolic processes, RNA metabolism, and epithelial mesenchymal transition (EMT). Small-molecule inhibitors of PRMTs are currently under clinical trials and can potentially become a new generation of anti-cancer drugs. This review aims to provide an overview of the current understanding of PRMTs in PDAC, focusing on their pathological roles and their potential as new therapeutic targets.
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Carcinoma Ductal Pancreático , Neoplasias Pancreáticas , Humanos , Proteína-Arginina N-Metiltransferases/genética , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/genética , Carcinoma Ductal Pancreático/tratamento farmacológico , Carcinoma Ductal Pancreático/genética , Imunoterapia , ArgininaRESUMO
The aim of this study was to evaluate the role of angiotensin-converting enzyme 1 (ACE1) in H2O2-induced trophoblast cell injury and the potential molecular mechanisms. Oxidative stress was modeled by exposing HTR-8/SVneo cells to 200 µM H2O2. Western blot and real-time quantitative PCR methods were used to detect protein and mRNA expression level of ACE1 in chorionic villus tissue and trophoblast HTR-8/SVneo cell. Inhibition of ACE1 expression was achieved by transfection with small interfering RNA. Then flow cytometry, Cell Counting Kit-8, and Transwell assay was used to assess apoptosis, viability, and migration ability of the cells. Reactive oxygen species (ROS) were detected by fluorescent probes, and malondialdehyde (MDA), superoxide dismutase (SOD), and reduced glutathione (GSH) activities were determined by corresponding detection kits. Angiotensin-converting enzyme 1 expression was upregulated in chorionic villus tissue of patients with missed abortion (MA) compared with individuals with normal early pregnancy abortion. H2O2 induced elevated ACE1 expression in HTR-8/SVneo cells, promoted apoptosis, and inhibited cell viability and migration. Knockdown of ACE1 expression inhibited H2O2-induced effects to enhance cell viability and migration and suppress apoptosis. Additionally, H2O2 stimulation caused increased levels of ROS and MDA and decreased SOD and GSH activity in the cells, whereas knockdown of ACE1 expression led to opposite changes of these oxidative stress indicators. Moreover, knockdown of ACE1 attenuated the inhibitory effect of H2O2 on the Nrf2/HO-1 pathway. Angiotensin-converting enzyme 1 was associated with MA, and it promoted H2O2-induced injury of trophoblast cells through inhibiting the Nrf2 pathway. Therefore, ACE1 may serve as a potential therapeutic target for MA.
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Aborto Retido , Peróxido de Hidrogênio , Peptidil Dipeptidase A , Trofoblastos , Humanos , Trofoblastos/metabolismo , Trofoblastos/efeitos dos fármacos , Peróxido de Hidrogênio/farmacologia , Peptidil Dipeptidase A/genética , Peptidil Dipeptidase A/metabolismo , Feminino , Gravidez , Aborto Retido/genética , Aborto Retido/metabolismo , Apoptose/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Linhagem Celular , Espécies Reativas de Oxigênio/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Adulto , Movimento Celular/efeitos dos fármacosRESUMO
Genotoxic therapy triggers reactive oxygen species (ROS) production and oxidative tissue injury. S-nitrosylation is a selective and reversible posttranslational modification of protein thiols by nitric oxide (NO), and 5,6,7,8-tetrahydrobiopterin (BH4) is an essential cofactor for NO synthesis. However, the mechanism by which BH4 affects protein S-nitrosylation and ROS generation has not been determined. Here, we showed that ionizing radiation disrupted the structural integrity of BH4 and downregulated GTP cyclohydrolase I (GCH1), which is the rate-limiting enzyme in BH4 biosynthesis, resulting in deficiency in overall protein S-nitrosylation. GCH1-mediated BH4 synthesis significantly reduced radiation-induced ROS production and fueled the global protein S-nitrosylation that was disrupted by radiation. Likewise, GCH1 overexpression or the administration of exogenous BH4 protected against radiation-induced oxidative injury in vitro and in vivo. Conditional pulmonary Gch1 knockout in mice (Gch1fl/fl; Sftpa1-Cre+/- mice) aggravated lung injury following irradiation, whereas Gch1 knock-in mice (Gch1lsl/lsl; Sftpa1-Cre+/- mice) exhibited attenuated radiation-induced pulmonary toxicity. Mechanistically, lactate dehydrogenase (LDHA) mediated ROS generation downstream of the BH4/NO axis, as determined by iodoacetyl tandem mass tag (iodoTMT)-based protein quantification. Notably, S-nitrosylation of LDHA at Cys163 and Cys293 was regulated by BH4 availability and could restrict ROS generation. The loss of S-nitrosylation in LDHA after irradiation increased radiosensitivity. Overall, the results of the present study showed that GCH1-mediated BH4 biosynthesis played a key role in the ROS cascade and radiosensitivity through LDHA S-nitrosylation, identifying novel therapeutic strategies for the treatment of radiation-induced lung injury.
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Biopterinas , GTP Cicloidrolase , Lesão Pulmonar , Espécies Reativas de Oxigênio , Animais , Biopterinas/análogos & derivados , Biopterinas/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Camundongos , Lesão Pulmonar/metabolismo , Lesão Pulmonar/etiologia , GTP Cicloidrolase/metabolismo , GTP Cicloidrolase/genética , Humanos , Tolerância a Radiação/genética , Lactato Desidrogenase 5/metabolismo , Camundongos Knockout , Óxido Nítrico/metabolismo , L-Lactato Desidrogenase/metabolismo , L-Lactato Desidrogenase/genética , Processamento de Proteína Pós-Traducional , Radiação IonizanteRESUMO
In this study, a two-stage culture strategy was refined to concurrently enhance the growth and lipid accumulation of Tetradesmus obliquus. The results unveiled that, during the initial stage, the optimal conditions for biomass accumulation were achieved with 0.02 mg·L-1 Cu2+ concentration and red light. Under these conditions, biomass accumulation reached 0.628 g·L-1, marking a substantial 23.62 % increase compared to the control group. In the second stage, the optimal conditions for lipid accumulation were identified as 0.5 mg·L-1 Cu2+ concentration and red light, achieving 64.25 mg·g-1·d-1 and marking a 128.38 % increase over the control. Furthermore, the fatty acid analysis results revealed an 18.85 % increase in the saturated fatty acid content, indicating enhanced combustion performance of microalgae cultivated under the dual stress of red light and 0.5 mg·L-1 Cu2+. This study offers insights into the potential application of Tetradesmus obliquus in biofuel production.
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Biomassa , Cobre , Luz , Metabolismo dos Lipídeos , Microalgas , Microalgas/metabolismo , Microalgas/crescimento & desenvolvimento , Ácidos Graxos/metabolismo , Estresse Fisiológico , BiocombustíveisRESUMO
This study focuses on the recognition and isolation of fullerenes, which are crucial for further exploration of their physical and chemical properties. Our goal is to investigate the potential recognition of the D5h-C70 fullerene using crown-shaped metal compositions through density functional theory calculations. We assess the effectiveness of fullerene C70 recognition by studying the binding energy. Additionally, various analyses were conducted, including natural bond order charge analysis and reduced density gradient analysis, to understand the interaction mechanism between the host and guest molecules. These investigations provide valuable insights into the nature of the interaction and the stability of the host-guest system. To facilitate the release of the fullerene guest molecule, the vis-NIR spectra were simulated for the host-guest structures. This analysis offers guidance on the specific wavelengths that can be utilized to release the fullerene guest from the host-guest structures. Overall, this work proposes a new strategy for the effective recognition of various fullerene molecules and their subsequent release from host-guest systems. These findings could potentially be applied in assemblies involving fullerenes, advancing their practical applications.
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Objectives: Type 2 diabetes mellitus (T2DM) commonly complicates kidney stone disease (KSD). Our objective is to investigate the variations in the urinary microbiota between individuals with KSD alone and those with KSD plus T2DM. This exploration could have implications for disease diagnosis and treatment strategies. Methods: During lithotripsy, a ureterscope was employed, and 1 mL of urine was collected from the renal pelvis after bladder disinfection. Sequencing targeting the V3-V4 hypervariable region was performed using the 16S rRNA and Illumina Novaseq platform. Results: The Shannon index showed a significant decrease in the KSD plus T2DM group compared to the KSD-only group (false discovery rate = 0.041). Principal Coordinate Analysis (PCoA) demonstrated a distinct bacterial community in the KSD plus T2DM group compared to the KSD-only group (false discovery rate = 0.027). The abundance of Sphingomonas, Corynebacterium, and Lactobacillus was significantly higher in the KSD plus T2DM group than in the KSD-only group (false discovery rate < 0.05). Furthermore, Enhydrobacter, Chryseobacterium, and Allobaculum were positively correlated with fasting blood glucose and HbA1c values (P < 0.05). Conclusions: The urinary microbiota in the renal pelvis exhibits differences between patients with KSD plus T2DM and those with KSD alone. Further studies employing animal models are necessary to validate these distinctions, potentially paving the way for therapeutic developments based on the urinary microbiota.
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Diabetes Mellitus Tipo 2 , Cálculos Renais , Microbiota , Humanos , Diabetes Mellitus Tipo 2/complicações , RNA Ribossômico 16S/genética , Cálculos Renais/genética , BactériasRESUMO
The attributes of good solubility and the redox-neutral nature of molten salt fluxes enable them to be useful for the synthesis of novel crystalline actinide compounds. In this work, a flux growth method under an inert atmosphere is proposed to explore the valence diversity of uranium, and a series of five uranium silicate structures, [K3Cl][(UVIO2)(Si4O10)] (1), Cs3[(UVO2)(Si4O10)] (2), K2[UIV(Si2O7)] (3), K8[(UVIO2)(UVO2)2(Si8O22)] (4), and Cs6[UIV(UVO)2(Si12O32)] (5), were synthesized using different metal halide salt and feeding U/Si ratios. Crystal structure analysis reveals that the utilization of argon atmosphere that helps to avoid possible oxidation of low-valence uranium generates a variety of oxidation states of uranium including U(VI), U(V), U(IV), mixed-valence U(V) and U(VI), and mixed-valence U(IV) and U(V). Characterization of physicochemical properties of representative compounds shows that all these uranium silicate compounds have bandgaps among the range of 2.0-3.4 eV, and mixed-valence uranium silicate compounds have relatively narrower bandgaps. Density functional theory calculations on formation enthalpies, lattice energies, and bandgaps of all five compounds were also performed to provide more structural information about these uranium silicates. This work enriches the library of variable-valence uranium silicate compounds and provides a feasible way to produce novel actinide compounds with intriguing properties through the flux growth method that might show potential application in relevant fields such as storage media for nuclear waste.
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Toxic substances, like fluoride salts present in spent cathode carbon (SCC), have been a great risk to the environment and public health. Our approach involves alkali leaching to eliminate soluble fluoride, followed by microwave hydrothermal acid leaching to efficiently remove insoluble CaF2 from SCC. The optimized conditions, including a temperature of 353 K, a solid-liquid ratio of 1:20, and a 60-minute reaction time, resulted in an impressive 95.6 % removal of fluoride from SCC. Various characterization techniques were employed to analyze the composition, micro-morphology, and elemental content of the materials before and after the leaching process. Furthermore, critical process parameters on the leaching separation of insoluble CaF2 during microwave hydrothermal acid leaching were systematically investigated. The study removal mechanism revealed the transformation of insoluble CaF2 in the process of microwave oxidation insertion-hydrothermal acid leaching for SCC. The kinetic characteristics of the two-stage leaching process of CaF2 at different temperatures were analyzed according to the shrinkage kernel model. The results indicate that the two-stage leaching process of CaF2 is affected by mixing control and by diffusion control, severally. The expansion of the graphite flake layer of SCC through oxidative intercalation was identified as a critical process for the thorough removal of CaF2. Microwave hydrothermal acid leaching demonstrated a 17 % improvement over traditional hydrothermal acid leaching within the same reaction time, showcasing a noteworthy enhancement in fluoride removal. Consequently, the microwave oxidizing intercalation-hydrothermal acid leaching treatment of SCC, as explored in this study, offers an effective approach for achieving deep defluoridation of SCC.
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Alumínio , Fluoreto de Cálcio , Ácidos Sulfúricos , Carbono , Fluoretos , Micro-OndasRESUMO
BACKGROUND: Residual breast tumors may remain after vacuum-assisted excisional biopsy (VAEB). OBJECTIVE: To determine the incidence of residual breast tumors in patients after VAEB and the efficacy of magnetic resonance imaging (MRI) in detecting these tumors. METHODS: This retrospective analysis examined patients who received VAEB before a diagnosis of breast cancer (BC) at our hospital from 2015 to 2019. The incidence of residual tumors after VAEB was determined by MRI and pathological examination. The diagnostic value of MRI in detecting residual tumors was determined for all patients and different subgroups. Logistic regression analysis was used to identify factors associated with residual tumors. RESULTS: We examined 147 patients and obtained pathological samples from 146 patients, including 103 (70.5%) with residual tumors and 43 (29.5%) without residual tumors. The MRI examinations demonstrated the complete tumor resection rate was 48.9%. Compared to the pathological results, MRI had a positive predictive value of 77.8%, negative predictive value of 48.8%, specificity of 65.6%, and sensitivity of 60.7%. Further analysis indicated that MRI had moderate accuracies for patients with stage pT-1 (71.9%), stage pTNM-IA (73.1%), and luminal B subtype (78.3%). Binary logistic regression analysis showed that the risk of tumor residue correlated with the pathological stage. CONCLUSION: Tumor residue is common after VAEB, and MRI has limited accuracy in detecting these residual tumors. However, for small breast tumors and luminal B subtype BC, MRI had higher accuracy in the detection of residual tumors. The risk of tumor residue is closely associated with the pathological stage.
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Dilanthanide complexes with one-electron delocalization are important targets for understanding the specific 4f/5d-bonding feature in lanthanide chemistry. Here, we report an isolable azide-bridged dicerium complex 3 [{(TrapenTMS)Ce}2(µ-N3)]⢠[Trapen = tris (2-aminobenzyl)amine; TMS = SiMe3], which is synthesized by the reaction of tripodal ligand-supported (TrapenTMS)CeIVCl complex 2 with NaN3. The structure and bonding nature of 3 are fully characterized by X-ray crystal diffraction analysis, electron paramagnetic resonance (EPR), magnetic measurement, cyclic voltammetry, X-ray absorption spectroscopy, and quantum-theoretical studies. Complex 3 presents a trans-bent central Ce-N3-Ce unit with a single electron of two mixed-valent Ce atoms. The unique low-temperature (2 K) anisotropic EPR signals [g = 1.135, 2.003, and 3.034] of 3 indicate that its spin density is distributed on the central Ce-N3-Ce unit with marked electron delocalization. Quantum chemical analyses show strong 4f/5d orbital mixing in the singly occupied molecular orbital of 3, which allows for the unpaired electron to extend throughout the cerium-azide-cerium unit via a multicentered one-electron (Ce-N3-Ce) interaction. This work extends the family of mixed-valent dilanthanide complexes and provides a paradigm for understanding the bonding motif of ligand-bridged dilanthanide complexes.
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Mucormycosis is receiving much more attention because of its high morbidity and extremely high mortality rate in immunosuppressed populations. In this study, we isolated a Cunnignhamella bertholletiae Z2 strain from a skin lesion of a 14â¯year, 9â¯months old girl with acute lymphoblastic leukemia who die of infection from the Z2 strain. Genome sequencing was performed after isolation and amplification of the Z2 strain to reveal potential virulence factors and pathogenic mechanisms. The results showed that the genome size of the Z2 strain is 30.9â¯Mb with 9213 genes. Mucoral specific virulence factor genes found are ARF, CalN, and CoTH, while no gliotoxin biosynthesis gene cluster was found, which is a known virulence factor in Aspergillus fumigatus adapted to the environment. The Z2 strain was found to have 69 cytochrome P450 enzymes, which are potential drug resistant targets. Sensitivity testing of Z2 showed it was only inhibited by amphotericin B and posaconazole. Detailed genomic information of the C. bertholletiae Z2 strain may provide useful data for treatment.