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1.
Apoptosis ; 29(9-10): 1738-1756, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-38641760

RESUMEN

To investigate the protective role of immune response gene 1 (IRG1) and exogenous itaconate in autoimmune hepatitis (AIH) and elucidate the underlying mechanisms. Wild-type and IRG1-/- AIH mouse models were established, and samples of liver tissue and ocular blood were collected from each group of mice to assess the effects of IRG1/itaconate on the expression of pro- and anti-inflammatory cytokines. The levels of liver enzymes and related inflammatory factors were determined using enzyme-linked immunosorbent assay and real-time quantitative polymerase chain reaction (PCR). Liver histomorphology was detected through hematoxylin and eosin staining and then scored for liver injury, and the infiltration levels of tissue-resident memory T (TRM) cells and related molecules in the liver tissue were detected through immunofluorescence staining in vitro. RNA sequencing and gene enrichment analysis were conducted to identify the corresponding molecules and pathways, and lentiviral transfection was used to generate TRM cell lines with IRG1, Jak3, Stat3, and p53 knockdown. Real-time quantitative PCR and western blot were performed to detect the expression levels of relevant mRNAs and proteins in the liver tissue and cells. The percentage of apoptotic cells was determined using flow cytometry. IRG1/itaconate effectively reduced the release of pro-inflammatory cytokines and the pathological damage to liver tissue, thereby maintaining normal liver function. At the same time, IRG1/itaconate inhibited the JAK3/STAT3 signaling pathway, regulated the expression of related downstream proteins, and inhibited the proliferation and promoted the apoptosis of CD69+CD103+CD8+ TRM cells. For the first time, P53 was found to act as a downstream molecule of the JAK3/STAT3 pathway and was regulated by IRG1/itaconate to promote the apoptosis of CD8+ TRM cells. IRG1/itaconate can alleviate concanavalin A-induced autoimmune hepatitis in mice by inhibiting the proliferation and promoting the apoptosis of CD69+CD103+CD8+ TRM cells via the JAK3/STAT3/P53 pathway.


Asunto(s)
Antígenos de Diferenciación de Linfocitos T , Apoptosis , Linfocitos T CD8-positivos , Proliferación Celular , Hepatitis Autoinmune , Cadenas alfa de Integrinas , Janus Quinasa 3 , Factor de Transcripción STAT3 , Proteína p53 Supresora de Tumor , Animales , Ratones , Antígenos CD/genética , Antígenos CD/metabolismo , Antígenos de Diferenciación de Linfocitos T/genética , Antígenos de Diferenciación de Linfocitos T/metabolismo , Apoptosis/efectos de los fármacos , Linfocitos T CD8-positivos/inmunología , Linfocitos T CD8-positivos/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Modelos Animales de Enfermedad , Hepatitis Autoinmune/inmunología , Hepatitis Autoinmune/patología , Hepatitis Autoinmune/genética , Hepatitis Autoinmune/tratamiento farmacológico , Cadenas alfa de Integrinas/genética , Cadenas alfa de Integrinas/metabolismo , Janus Quinasa 3/genética , Janus Quinasa 3/metabolismo , Janus Quinasa 3/antagonistas & inhibidores , Lectinas Tipo C/genética , Lectinas Tipo C/metabolismo , Hígado/patología , Hígado/efectos de los fármacos , Hígado/metabolismo , Hígado/inmunología , Células T de Memoria/inmunología , Células T de Memoria/metabolismo , Células T de Memoria/efectos de los fármacos , Ratones Endogámicos C57BL , Ratones Noqueados , Transducción de Señal/efectos de los fármacos , Factor de Transcripción STAT3/metabolismo , Factor de Transcripción STAT3/genética , Proteína p53 Supresora de Tumor/metabolismo , Proteína p53 Supresora de Tumor/genética
2.
IUBMB Life ; 2024 Sep 02.
Artículo en Inglés | MEDLINE | ID: mdl-39223969

RESUMEN

Microglia, as immune cells in the central nervous system, possess the ability to adapt morphologically and functionally to their environment. Glymphatic system, the principal waste clearance system in the brain, exhibits circadian rhythms. However, the impact of microglia on the glymphatic system function remains unknown. In this study, we explored the intricate relationship between microglia and the glymphatic system. Examining diurnal patterns, we identified synchronized behaviors in glymphatic activity and microglial morphology, peaking during sleep and exhibiting distinct changes in branching complexity. Depleting microglia using PLX5622 or in P2Y12 knockout mice enhanced glymphatic function. Chemogenetic manipulation of microglia demonstrated that activating HM3D improved glymphatic function, while inhibiting HM4D unexpectedly increased microglial complexity. These findings highlight the dynamic influence of microglia on the glymphatic system.

3.
Langmuir ; 2024 Jul 16.
Artículo en Inglés | MEDLINE | ID: mdl-39012063

RESUMEN

A series of 1,2,4-triazolo-quinazolinones and 1,2-benzisothiazolone derivatives (S1-S12) were successfully synthesized as environmentally friendly alternatives to copper-based antifouling paints using N-alkylation, cyclocondensation, and one-pot three-component and amide coupling reactions. The monoclinic structure of single-crystal 1,2,4-triazolo-quinazolin-acetic acid (S8) was confirmed by single-crystal X-ray diffraction analysis. All the synthesized molecules were studied for their in silico molecular docking interactions with three target proteins, namely, RbmA, ToxR, and Bap. Following that, the antialgal activity was assessed against two types of marine algae: Chlorella sp. and Chaetoceros curvisetus. The minimal inhibitory concentration and zone of inhibition have been used to evaluate the antibacterial activities of S1-S12 against both marine Gram-positive (Staphylococcus aureus) and Gram-negative (Vibrio parahemolyticus and Vibrio vulnificus) bacteria. Additionally, antifouling studies have been done on all the compounds, and among them, 1,2,4-triazolo-quinazolinyl-acetate (S7), 1,2,4-triazolo-quinazolinyl-acetic acid (S8), 1,2,4-triazolo-quinazolinyl-oxobutanoate (S9), benzo[d]isothiazolyl butanoate (S10), benzo[d]isothiazolyl-acetic acid (S11), and 1,2,4-triazolo-quinazolinyl-acetyl-benzo[d]isothiazolone (S12) exhibited good antialgal, antibacterial, and antifouling activities.

4.
J Comput Assist Tomogr ; 48(2): 206-211, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38149651

RESUMEN

OBJECTIVE: To assess the performance of apparent diffusion coefficient (ADC; values or category) alone, Prostate Imaging Reporting and Data System version 2.1 (PI-RADS v2.1) scoring alone, and the two in combination, to diagnose transition zone prostate cancers (PCas). METHODS: This retrospective study included 222 patients who underwent multiparametric magnetic resonance imaging of the prostate between May 2020 and December 2022 and who had pathologically confirmed PCa or benign prostatic hyperplasia (BPH). Prostate Imaging Reporting and Data System version 2.1 and ADC (values or category) were used in the assessment of suspicious findings identified in the transition zone. The interobserver agreements for region-of-interest measurements were calculated by intraclass correlation coefficients. Logistic regression analyses were used to determine the performance of PI-RADS v2.1 alone and in combination with ADC (values or category) to diagnose PCa. Receiver operating characteristic curve and DeLong test were used to evaluate the diagnostic performance of the quantitative parameters. RESULTS: A total of 152 patients had BPH, and 70 patients had PCa. For BPH versus PCa, the ADC values of PCa (0.64 × 10 -3 ± 0.16 × 10 -3 mm 2 /s) were significantly lower than BPH (1.06 ± 0.18 × 10 -3 mm 2 /s; P < 0.001). The PI-RADS scores for PCa (5 [interquartile range, 5-5]) were significantly higher than BPH (2 [interquartile range, 2-3]; P < 0.001). For all patients who had PI-RADS 1-5, the combined use of ADC (values or category) together with PI-RADS v2.1 did not perform significantly better than the use of PI-RADS v2.1 alone. The receiver operating characteristic of ADC category in combination with PI-RADS v2.1 score, 0.756 (95% confidence interval, 0.646-0.846), was significantly higher than that for PI-RADS 2.1 alone, 0.631 (95% confidence interval, 0.514-0.738), in PI-RADS 3-4 lesions ( P = 0.047). CONCLUSION: The ADC category can help to improve the diagnostic performance of PI-RADS v2.1 category 3-4 lesions in diagnosing PCa.


Asunto(s)
Hiperplasia Prostática , Neoplasias de la Próstata , Masculino , Humanos , Neoplasias de la Próstata/diagnóstico por imagen , Neoplasias de la Próstata/patología , Imagen por Resonancia Magnética/métodos , Estudios Retrospectivos , Hiperplasia Prostática/diagnóstico por imagen , Imagen de Difusión por Resonancia Magnética/métodos
5.
Allergol Immunopathol (Madr) ; 52(5): 59-64, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39278852

RESUMEN

Acquired myasthenia (AM), a debilitating autoimmune disease, is typically characterized by skeletal muscle fatigue and weakness. Despite advances in myasthenia gravis treatment, current approaches remain unsatisfactory and many result in unexpected side effects. Traditional Chinese medicine has shown great potential in the treatment of myasthenia gravis, including relieving myasthenic symptoms, improving patients' quality of life, and reducing Western medicine side effects. This study investigates the protective effects and mechanism of BZYQD in mice with acquired myasthenia. BZYQD alleviates the reduced grip strength and increased expression of MAFbx and MuRF-1 in mice with acquired myasthenia. It also reduces levels of pro-inflammatory factors IL-1ß, IL-6, and TNF-α in the mouse serum. In addition, BZYQD reduces ROS accumulation and the mitochondrial ROS production rate, while increasing ATP levels and mitochondrial membrane potential in mice with acquired myasthenia. Moreover, BZYQD decreases the expression of p-JAK2, p-STAT3, and p-AKT in the skeletal muscle of mice with acquired myasthenia. In summary, BZYQD reduces inflammation, enhances mitochondrial function, and regulates the JAK2/STAT3/AKT signaling pathway to treat acquired myasthenia.


Asunto(s)
Medicamentos Herbarios Chinos , Janus Quinasa 2 , Mitocondrias , Proteínas Proto-Oncogénicas c-akt , Factor de Transcripción STAT3 , Transducción de Señal , Animales , Janus Quinasa 2/metabolismo , Factor de Transcripción STAT3/metabolismo , Medicamentos Herbarios Chinos/farmacología , Ratones , Transducción de Señal/efectos de los fármacos , Proteínas Proto-Oncogénicas c-akt/metabolismo , Mitocondrias/efectos de los fármacos , Mitocondrias/metabolismo , Miastenia Gravis/tratamiento farmacológico , Miastenia Gravis/inmunología , Femenino , Inflamación/tratamiento farmacológico , Inflamación/inmunología , Citocinas/metabolismo , Modelos Animales de Enfermedad , Humanos , Miastenia Gravis Autoinmune Experimental/tratamiento farmacológico , Miastenia Gravis Autoinmune Experimental/inmunología , Proteínas Ligasas SKP Cullina F-box/metabolismo , Proteínas de Motivos Tripartitos/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Proteínas Musculares/metabolismo , Ubiquitina-Proteína Ligasas/metabolismo
6.
Sensors (Basel) ; 24(5)2024 Feb 23.
Artículo en Inglés | MEDLINE | ID: mdl-38474975

RESUMEN

Because large oil-immersed transformers are enclosed by a metal shell, the on-site localization means it is difficult to achieve the accurate location of the patrol micro-robot inside a given transformer. To address this issue, a spatial ultrasonic localization method based on wavelet decomposition and PHAT-ß-γ generalized cross correlation is proposed in this paper. The method is carried out with a five-element stereo ultrasonic array for the location of a transformer patrol robot. Firstly, the localization signal is decomposed into wavelet coefficients of different scales, which would realize the adaptive decomposition of the frequency of the localization signal from low frequencies to high frequencies. Then, the wavelet coefficients are denoised and reconstructed by using the semi-soft threshold function. Second, a modified phase transform-beta-gamma (PHAT-ß-γ) method is used to calculate the exact time delay between different sensors by increasing the weights of the PHAT weighting function and introducing a correlation function. Finally, by using the proposed method, the accurate localization of the transformer patrol micro-robot is achieved with a five-element stereo ultrasonic array. The simulation and test results show that inside a transformer experimental oil tank (120 cm × 100 cm × 100 cm, L × W × H), the relative error of transformer patrol micro-robot spatial localization is within 4.1%, and the maximum localization error is less than 3 cm, which meets the requirement of engineering localization.

7.
Sensors (Basel) ; 24(13)2024 Jul 02.
Artículo en Inglés | MEDLINE | ID: mdl-39001089

RESUMEN

It is difficult to visually detect internal defects in a large transformer with a metal closure. For convenient internal inspection, a micro-robot was adopted, and an inspection method based on an image-enhancement algorithm and an improved deep-learning network was proposed in this paper. Considering the dim environment inside the transformer and the problems of irregular imaging distance and fluctuating supplementary light conditions during image acquisition with the internal-inspection robot, an improved MSRCR algorithm for image enhancement was proposed. It could analyze the local contrast of the image and enhance the details on multiple scales. At the same time, a white-balance algorithm was introduced to enhance the contrast and brightness and solve the problems of overexposure and color distortion. To improve the target recognition performance of complex carbon-trace defects, the SimAM mechanism was incorporated into the Backbone network of the YOLOv8 model to enhance the extraction of carbon-trace features. Meanwhile, the DyHead dynamic detection Head framework was constructed at the output of the YOLOv8 model to improve the perception of local carbon traces with different sizes. To improve the defect target recognition speed of the transformer-inspection robot, a pruning operation was carried out on the YOLOv8 model to remove redundant parameters, realize model lightness, and improve detection efficiency. To verify the effectiveness of the improved algorithm, the detection model was trained and validated with the carbon-trace dataset. The results showed that the MSH-YOLOv8 algorithm achieved an accuracy of 91.80%, which was 3.4 percentage points higher compared to the original YOLOv8 algorithm, and had a significant advantage over other mainstream target-detection algorithms. Meanwhile, the FPS of the proposed algorithm was up to 99.2, indicating that the model computation and model complexity were successfully reduced, which meets the requirements for engineering applications of the transformer internal-inspection robot.

8.
Sensors (Basel) ; 24(15)2024 Jul 30.
Artículo en Inglés | MEDLINE | ID: mdl-39123984

RESUMEN

In the detection process of the internal defects of large oil-immersed transformers, due to the huge size of large transformers and metal-enclosed structures, the positional localization of miniature inspection robots inside the transformer faces great difficulties. To address this problem, this paper proposes a three-dimensional positional localization method based on adaptive denoising and the SCOT weighting function with the addition of the exponent ß (SCOT-ß) generalized cross-correlation for L-type ultrasonic arrays of transformer internal inspection robots. Aiming at the strong noise interference in the field, the original signal is decomposed by an improved Empirical Mode Decomposition (EMD) method, and the optimal center frequency and bandwidth of each mode are adaptively searched. By extracting the modes in the frequency band of the positional localization signal, suppressing the modes in the noise frequency band, and reconstructing the Intrinsic Mode Function (IMF) of the independently selected superior modal components, a signal with a high signal-to-noise ratio is obtained. In addition, for the traditional mutual correlation algorithm with a large delay estimation error at a low signal-to-noise ratio, this paper adopts an improved generalized joint weighting function, SCOT-ß, which improves the anti-jamming ability of the generalized mutual correlation method at a low signal-to-noise ratio by adding an exponential function to the denominator term of the SCOT weighting function's generalized cross-correlation. Finally, the accurate positional localization of the transformer internal inspection robot is realized based on the quadratic L-array and search-based maximum likelihood estimation method. Simulation and experimental results show the following: the improved EMD denoising method better improves the signal-to-noise ratio of the positional localization signal with a lower distortion rate; in the transformer test tank, which is 120 cm in length, 100 cm in width, and 100 cm in height, based on the positional localization method in this paper, the average relative positional localization error of the transformer internal inspection robot in three-dimensional space is 2.27%, and the maximum positional localization error is less than 2 cm, which meets the requirements of engineering positional localization.

9.
Int J Mol Sci ; 25(5)2024 Feb 29.
Artículo en Inglés | MEDLINE | ID: mdl-38474064

RESUMEN

Our previous study has reported that metastasis-associated protein 2 (MTA2) plays essential roles in tumorigenesis and aggressiveness of gastric cancer (GC). However, the underlying molecular mechanisms of MTA2-mediated GC and its upstream regulation mechanism remain elusive. In this study, we identified a novel circular RNA (circRNA) generated from the MTA2 gene (circMTA2) as a crucial regulator in GC progression. CircMTA2 was highly expressed in GC tissues and cell lines, and circMTA2 promoted the proliferation, invasion, and metastasis of GC cells both in vitro and in vivo. Mechanistically, circMTA2 interacted with ubiquitin carboxyl-terminal hydrolase L3 (UCHL3) to restrain MTA2 ubiquitination and stabilize MTA2 protein expression, thereby facilitating tumor progression. Moreover, circMTA2 was mainly encapsulated and transported by exosomes to promote GC cell progression. Taken together, these findings uncover that circMTA2 suppresses MTA2 degradation by interacting with UCHL3, thereby promoting GC progression. In conclusion, we identified a cancer-promoting axis (circMTA2/UCHL3/MTA2) in GC progression, which paves the way for us to design and synthesize targeted inhibitors as well as combination therapies.


Asunto(s)
Neoplasias Gástricas , Humanos , Neoplasias Gástricas/patología , Proteínas Represoras/genética , Línea Celular Tumoral , Histona Desacetilasas/metabolismo , Proteolisis , Regulación Neoplásica de la Expresión Génica , Proliferación Celular/genética , Ubiquitina Tiolesterasa/metabolismo
10.
J Environ Manage ; 370: 122436, 2024 Sep 10.
Artículo en Inglés | MEDLINE | ID: mdl-39260289

RESUMEN

Soil aggregates organic matter (SAOM) is composed of free particulate organic matter (fPOM), intra-aggregate particulate organic matter (iPOM), and mineral-associated organic matter (mSOM), which are major antibiotic sorbents that play a significant role in the soil organic matter (SOM) turnover process. To date, the oxytetracycline (OTC) sorption and desorption behavior and mechanisms on SAOM have not been contrastively analyzed. SAOM organic components have been used to study scientific problems and to determine their influence on the fate and migration of OTC among the SOM turnover process. Results demonstrated that SAOM had great OTC sorption capacity ranging from approximately 12100-513,000 mg kg-1 and the desorption proportion was no more than 33.60%. The slow organic carbon pool (mSOM) had greater OTC accumulation capacity than the intermediate active pool (iPOM) and the active pool (fPOM), while OTC was more likely to reside in the active pool in wetlands (fPOM-w) and oil waste land (fPOM-o) than the organic carbon pool (mSOM-f) in farmland with human activity interference. The hysteresis was affected by SAOM's physical surface characteristics when the OTC initial equilibrium sorption concentration was higher than 200 mg L-1. When it was lower than that, it was affected by the organic carbon composition. Hydrogen bonds, electrostatic interactions, and π-π interactions dominated the SAOM-OTC interactions. The results of this study will be useful for evaluating the long-term behavior and migration of antibiotics in SOM turnover processes and could refine risk assessments of antibiotics contamination in soil environmental systems.

11.
J Environ Manage ; 368: 122203, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39153320

RESUMEN

Existing studies that assess the impact of cooking with dirty solid fuels on human beings tend to underestimate the adverse impact on welfare. This paper aims to address this research gap by examining the happiness benefits of transitioning from solid fuel to cleaner alternatives. Using an extensive panel dataset from China, which includes 150,248 observations collected from 43,251 survey respondents interviewed between 2010 and 2018, this study employs various complementary methodologies, such as the fixed-effect model, propensity score matching, and time-varying difference-in-differences, to overcome challenges related to treatment selection bias and unobserved time-invariant heterogeneity. Further, life satisfaction approach is used to evaluate the economic benefits of cooking energy transition. Our findings indicate that switching from firewood to LPG/natural gas/gas can significantly enhance individual subjective well-being (SWB). Although the improvement brought about by electricity is slightly lower than that of LPG/natural gas/gas, it remains substantial. Notably, the positive effect is more pronounced among specific demographic groups, including females, rural residents, and low-income families. Moreover, these well-being improvements can manifest quickly and persist many years before any noticeable enhancements in physical health. This effect further amplifies over time. However, biogas shows no significant effect on SWB. These findings underscore the importance of clean fuels that contribute to increased happiness, as they are more likely to be consistently adopted. Finally, we estimate that the economic benefits of the well-being improvements resulting from the use of LPG/natural gas/gas and electricity range between $5.15 and $5.44 per day.


Asunto(s)
Culinaria , Composición Familiar , Felicidad , Humanos , China , Gas Natural , Humo , Femenino
12.
Clin Psychol Psychother ; 31(3): e2981, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38687203

RESUMEN

OBJECTIVE: This study aimed to investigate whether attentional control serves as a mediator for mindfulness-based interventions for emotional distress, utilizing a randomized waitlist (WL)-controlled design. METHODS: A total of 498 participants with high emotional distress was recruited online and randomly assigned to a 49-day online Mindfulness Intervention for Emotional Distress (MIED) group (N = 249) or a WL control group (N = 249). Levels of attentional control, anxiety and depression were assessed at baseline (T0), Week 3 (T3), Week 5 (T5) and Week 7 (postintervention, T7). RESULTS: Linear mixed models revealed significant Group-by-Time interaction effects for attentional control (p < 0.001), anxiety (p < 0.001) and depression (p < 0.05). Latent growth curve analyses demonstrated a significant increase in attentional control and a decrease in anxiety and depression levels during the MIED programme. These changes becoming evident starting Week 3. Longitudinal mediation analyses revealed that the slope of attentional control significantly mediated the effects of the MIED programme on the slope of anxiety and depression levels. Further, attentional control level at Week 3 significantly mediates the effect of MIED programme on anxiety and depression levels at Weeks 5 and 7. Similarly, attentional control level at Week 5 significantly mediates the MIED programme's effects on anxiety and depression levels at Week 7. CONCLUSIONS: The present trial provides evidence suggesting that mindfulness interventions may alleviate emotional distress through the enhancement of attentional control. TRIAL REGISTRATION: Chinese Clinical Trial Registry number: ChiCTR2200064140.


Asunto(s)
Atención , Atención Plena , Humanos , Atención Plena/métodos , Femenino , Masculino , Adulto , Distrés Psicológico , Análisis de Mediación , Persona de Mediana Edad , Resultado del Tratamiento , Ansiedad/terapia , Ansiedad/psicología , Depresión/terapia , Depresión/psicología
13.
Small ; : e2308305, 2023 Dec 07.
Artículo en Inglés | MEDLINE | ID: mdl-38059736

RESUMEN

Li+ insertion-induced structure transformation in crystalline electrodes vitally influence the energy density and cycle life of secondary lithium-ion battery. However, the influence mechanism of structure transformation-induced Li+ migration on the electrochemical performance of micro-crystal materials is still unclear and the strategy to profit from such structure transformation remains exploited. Here, an interesting self-optimization of structure evolution during electrochemical cycling in Nb2 O5 micro-crystal with rich domain boundaries is demonstrated, which greatly improves the charge transfer property and mechanical strength. The lattice rearrangement activates the Li+ diffusion kinetics and hinders the particle crack, thus enabling a nearly zero-degeneration operation after 8000 cycles. Full cell paired with lithium cobalt oxides displays an exceptionally high capacity of 176 mA h g-1 at 8000 mA g-1 and excellent long-term durability at 6000 mA g-1 with 63% capacity retention over 2000 cycles. Interestingly, a unique fingerprint based on the intensity ratio of two X-ray diffraction peaks is successfully extracted as a measure of Nb2 O5 electrochemical performance. The structure self-optimization for fast charge transfer and high mechanical strength exemplifies a new battery electrode design concept and opens up a vast space of strategy to develop high-performance lithium-ion batteries with high energy density and ultra-long cycle life.

14.
Opt Express ; 31(23): 37516-37522, 2023 Nov 06.
Artículo en Inglés | MEDLINE | ID: mdl-38017879

RESUMEN

We report high-performance Al0.1Ga0.9N p-i-n ultraviolet (UV) avalanche photodiodes (APDs) based on sapphire substrates with stable breakdown voltages (VBR) around 113.4 V, low dark current densities (JBR) below 9 × 10-4 A/cm2 and a high avalanche gain over 2 × 106. A two-step deposition method was employed to reduce passivation-induced plasma damage while maintaining high dielectric film quality. Consistent JBR for various mesa sizes at the VBR are demonstrated, which reveals the suppression of the surface leakage current. Uniform electroluminescence (EL) distributions during the avalanche multiplication processes are displayed, which confirms the elimination of edge breakdown. Pure bulk leakage current distributions and uniform body avalanche breakdown behaviors are observed for the first time in AlGaN APDs. The emission spectra of the EL at various current levels are also presented.

15.
Opt Lett ; 48(2): 247-250, 2023 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-36638429

RESUMEN

The authors demonstrate the enhanced light output from 275-nm AlGaN-based deep ultraviolet (DUV) light-emitting diode (LED) structures via the in-plane modulation of shallow photonic crystal (PC) patterns that were fabricated on the p-AlGaN contact layer surface. The employed PC lattice constants are in the range of 270-780 nm, much larger than the fundamental Bragg order lattice constant (∼95 nm). As compared to the unpatterned sample, the intensity of the top (or bottom) emission can be enhanced by up to 331% (or 246%), attributed to the high-order coherent diffraction of the internal trapped light and also the Purcell enhancement of spontaneous emission. The findings in this Letter suggest an easier way for the realization of more energy-efficient DUV LEDs which offer the advantage of high emission for various applications in disinfection and sterilization.

16.
J Org Chem ; 88(13): 8400-8412, 2023 Jul 07.
Artículo en Inglés | MEDLINE | ID: mdl-37350730

RESUMEN

An unprecedented copper and in situ-generated triflic acid relay-promoted four-component cascade reaction of cyanamides, diaryliodonium triflates, propargylic amines, and H2O was established for rapid and concise construction of diverse five-membered cycloguanidines. Copper-catalyzed guanidination/intramolecular hydroamination and in situ-generated HOTf-accelerated hydration proceeded sequentially with high level of chemoselectivity and regioselectivity, and six new bonds were simultaneously built in high yields. Thus, diaryliodonium triflates served not only as an arylation reagent but also as an internal acid promoter, establishing an alternative strategy for highly efficient utilization of diaryliodonium trifates.

17.
J Phys Chem A ; 127(18): 3966-3975, 2023 May 11.
Artículo en Inglés | MEDLINE | ID: mdl-37116096

RESUMEN

Thermal decomposition of tetraethylsilane was investigated at temperatures up to 1330 K using flash pyrolysis vacuum ultraviolet photoionization mass spectrometry. Density functional theory and transition state theory calculations were performed to corroborate the experimental observations. Both experimental and theoretical evidence showed that the pyrolysis of tetraethylsilane was initiated by Si-C bond fission to the primary reaction products, triethylsilyl (SiEt3) and ethyl radicals. In the secondary reactions of the triethylsilyl radical, at lower temperatures, the ß-hydride elimination pathway (producing HSiEt2) was found to be more favored than its competing reaction channel, Si-C bond fission (producing :SiEt2); as the temperature further increased, the Si-C bond fission reaction became significant. Other important secondary reaction products, such as EtHSi═CH2 (m/z = 72), H2SiEt (m/z = 59), and SiH3 (m/z = 31) were identified, and their formation mechanisms were also proposed.

18.
J Phys Chem A ; 127(45): 9590-9600, 2023 Nov 16.
Artículo en Inglés | MEDLINE | ID: mdl-37933165

RESUMEN

The thermal decomposition mechanism of hydroxyacetone from 850 to 1390 K was examined by using flash pyrolysis vacuum ultraviolet photoionization time-of-flight mass spectrometry combined with density functional theory calculation. The results showed that keto-enol tautomerisms could occur prior to the thermal decomposition of hydroxyacetone. The decomposition pathways of hydroxyacetone and its isomer, 2-hydroxypropanal were characterized. The thermal decomposition reactions started at about 950 K. The homolysis reactions related to the cleavage of the CCO-CCOH bond of hydroxyacetone and 2-hydroxypropanal, as well as CH3 loss of hydroxyacetone, dominated the initial decomposition reactions. The subsequent decompositions of the radical intermediates generated by the initial homolysis decompositions were the major secondary decomposition reactions. The formation pathways of small molecules, such as H2, CH4, H2O, and HCHO, were proposed to proceed via molecular elimination reactions facilitated by the active α-H atoms. These elimination reactions were not negligible at high temperatures above 1230 K.

19.
J Phys Chem A ; 127(3): 781-788, 2023 Jan 26.
Artículo en Inglés | MEDLINE | ID: mdl-36649536

RESUMEN

Thermal-catalytic conversion and amination (TCC-A) of lignin and lignin derivates over zeolites is a promising and renewable method to produce aromatic amines, but suffers from product diversity. Currently, no unambiguous mechanism could fully describe the chemistry of this process. In this work, the TCC-A mechanism of guaiacol, a typical lignin model compound, with ammonia over HZSM-5 was investigated by online photoionization time-of-flight mass spectrometry combined with density functional theory. Various products including amines, pyrroles, and pyridines were identified. The formation of methylamine and aminophenol below 400 °C via nucleophilic substitutions is attributed to the strong adsorption of ammonia on the active site of HZSM-5. Aniline is the major product above 400 °C coproduced with pyrroles and pyridines. It is suggested that the reactions among radical intermediates (•CH3 and •NH2) and molecules (guaiacol and catechol) lead to poor aniline selectivity via transmethylation, amination, and partial deoxygenation reactions. Hydroamination is proposed as the main formation mechanism of pyrroles and pyridines. The maximum yield of aniline can be achieved at 650 °C owing to the enhancement of amination and deoxygenation and the suppression of transmethylation reactions.

20.
Molecules ; 28(10)2023 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-37241831

RESUMEN

Antibiotics are administered to livestock at subtherapeutic levels to promote growth, and their degradation in manure is slow. High antibiotic concentrations can inhibit bacterial activity. Livestock excretes antibiotics via feces and urine, leading to their accumulation in manure. This can result in the propagation of antibiotic-resistant bacteria and antibiotic resistance genes (ARGs). Anaerobic digestion (AD) manure treatment technologies are gaining popularity due to their ability to mitigate organic matter pollution and pathogens, and produce methane-rich biogas as renewable energy. AD is influenced by multiple factors, including temperature, pH, total solids (TS), substrate type, organic loading rate (OLR), hydraulic retention time (HRT), intermediate substrates, and pre-treatments. Temperature plays a critical role, and thermophilic AD has been found to be more effective in reducing ARGs in manure compared to mesophilic AD, as evidenced by numerous studies. This review paper investigates the fundamental principles of process parameters affecting the degradation of ARGs in anaerobic digestion. The management of waste to mitigate antibiotic resistance in microorganisms presents a significant challenge, highlighting the need for effective waste management technologies. As the prevalence of antibiotic resistance continues to rise, urgent implementation of effective treatment strategies is necessary.


Asunto(s)
Ganado , Estiércol , Animales , Estiércol/microbiología , Ganado/genética , Ganado/metabolismo , Anaerobiosis , Antibacterianos/farmacología , Antibacterianos/metabolismo , Bacterias/metabolismo , Genes Bacterianos
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