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1.
Proc Natl Acad Sci U S A ; 121(16): e2319119121, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38588435

RESUMO

The advancement of atomically precise dinuclear heterogeneous catalysts holds great potential in achieving efficient catalytic ozonation performance and contributes to the understanding of synergy mechanisms during reaction conditions. Herein, we demonstrate a "ship-in-a-bottle and pyrolysis" strategy that utilizes Fe2(CO)9 dinuclear-cluster to precisely construct Fe2 site, consisting of two Fe1-N3 units connected by Fe-Fe bonds and firmly bonded to N-doped carbon. Systematic characterizations and theoretical modeling reveal that the Fe-Fe coordination motif markedly reduced the devotion of the antibonding state in the Fe-O bond because of the strong orbital coupling interaction of dual Fe d-d orbitals. This facilitates O-O covalent bond cleavage of O3 and enhances binding strength with reaction intermediates (atomic oxygen species; *O and *OO), thus boosting catalytic ozonation performance. As a result, Fe dinuclear site catalyst exhibits 100% ozonation efficiency for CH3SH elimination, outperforming commercial MnO2 catalysts by 1,200-fold. This research provides insights into the atomic-level structure-activity relationship of ozonation catalysts and extends the use of dinuclear catalysts in catalytic ozonation and beyond.

2.
Nano Lett ; 24(25): 7593-7600, 2024 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-38869928

RESUMO

In traditional optical wireless communication (OWC) systems, the simultaneous use of multiple sets of light-emitting diodes (LEDs) and photodetectors (PDs) increases the system complexity and instability. Here we report bifunctional light-emitting photodetectors (LEPDs) fabricated with quasi-2D perovskite (F-PEA)2Cs4Pb5I11Br5 as light-emitting/detecting layers for efficient, miniaturized, and intelligent bidirectional OWC. By simply changing the solvent composition of the precursor solution and using antisolvent engineering, we manipulated the crystal orientation and phase distribution of (F-PEA)2Cs4Pb5I11Br5, realizing high irradiance (4.36 µW cm-2) and a -3 dB refresh rate (0.21 MHz) of electroluminescence in LED mode as well as low noise (below 1 pA Hz-1/2) and high responsivity (0.1 A W-1) in PD mode. The rapid and accurate OWC process was demonstrated through interaction of LEPDs. We also demonstrated the high-fidelity compression and digitization of high-resolution (256 × 256 pixels) color images using the four-step phase shift method to realize intelligent encrypted image OWC.

3.
Emerg Infect Dis ; 30(4): 826-828, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38526372

RESUMO

In 2022, we assessed avian influenza A virus subtype H5N6 seroprevalence among the general population in Guangdong Province, China, amid rising numbers of human infections. Among the tested samples, we found 1 to be seropositive, suggesting that the virus poses a low but present risk to the general population.


Assuntos
Influenza Aviária , Influenza Humana , Animais , Humanos , Influenza Aviária/epidemiologia , Estudos Soroepidemiológicos , Influenza Humana/epidemiologia , China/epidemiologia , Aves
4.
Am J Transplant ; 2024 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-38642712

RESUMO

Immune checkpoint inhibitors (ICIs) as a downstaging or bridging therapy for liver transplantation (LT) in hepatocellular carcinoma patients are rapidly increasing. However, the evidence about the feasibility and safety of pre-LT ICI therapy is limited and controversial. To this end, a multicenter, retrospective cohort study was conducted in 11 Chinese centers. The results showed that 83 recipients received pre-LT ICI therapy during the study period. The median post-LT follow-up was 8.1 (interquartile range 3.3-14.6) months. During the short follow-up, 23 (27.7%) recipients developed allograft rejection, and 7 of them (30.4%) were diagnosed by liver biopsy. Multivariate logistics regression analysis showed that the time interval between the last administration of ICI therapy and LT (TLAT) ≥ 30 days was an independent protective factor for allograft rejection (odds ratio = 0.096, 95% confidence interval 0.026-0.357; P < .001). Multivariate Cox analysis showed that allograft rejection was an independent risk factor for overall survival (hazard ratio = 9.960, 95% confidence interval 1.006-98.610; P = .043). We conclude that patients who receive a pre-LT ICI therapy with a TLAT shorter than 30 days have a much higher risk of allograft rejection than those with a TLAT longer than 30 days. The presence of rejection episodes might be associated with higher post-LT mortality.

5.
Small ; : e2404696, 2024 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-39155427

RESUMO

Graphitic carbon nitride (g-C3N4) is a prominent photocatalyst that has attracted substantial interest in the field of photocatalytic environmental remediation due to the low cost of fabrication, robust chemical structure, adaptable and tunable energy bandgaps, superior photoelectrochemical properties, cost-effective feedstocks, and distinctive framework. Nonetheless, the practical application of bulk g-C3N4 in the photocatalysis field is limited by the fast recombination of photogenerated e--h+ pairs, insufficient surface-active sites, and restricted redox capacity. Consequently, a great deal of research has been devoted to solving these scientific challenges for large-scale applications. This review concisely presents the latest advancements in g-C3N4-based photocatalyst modification strategies, and offers a comprehensive analysis of the benefits and preparation techniques for each strategy. It aims to articulate the complex relationship between theory, microstructure, and activities of g-C3N4-based photocatalysts for atmospheric protection. Finally, both the challenges and opportunities for the development of g-C3N4-based photocatalysts are highlighted. It is highly believed that this special review will provide new insight into the synthesis, modification, and broadening of g-C3N4-based photocatalysts for atmospheric protection.

6.
Small ; 20(31): e2311879, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38461527

RESUMO

Carbon-defect engineering in single-atom metal-nitrogen-carbon (M─N─C) catalysts by straightforward and robust strategy, enhancing their catalytic activity for volatile organic compounds, and uncovering the carbon vacancy-catalytic activity relationship are meaningful but challenging. In this study, an iron-nitrogen-carbon (Fe─N─C) catalyst is intentionally designed through a carbon-thermal-diffusion strategy, exposing extensively the carbon-defective Fe─N4 sites within a micro-mesoporous carbon matrix. The optimization of Fe─N4 sites results in exceptional catalytic ozonation efficiency, surpassing that of intact Fe─N4 sites and commercial MnO2 by 10 and 312 times, respectively. Theoretical calculations and experimental data demonstrated that carbon-defect engineering induces selective cleavage of C─N bond neighboring the Fe─N4 motif. This induces an increase in non-uniform charges and Fermi density, leading to elevated energy levels at the center of Fe d-band. Compared to the intact atomic configuration, carbon-defective Fe─N4 site is more activated to strengthen the interaction with O3 and weaken the O─O bond, thereby reducing the barriers for highly active surface atomic oxygen (*O/*OO), ultimately achieving efficient oxidation of CH3SH and its intermediates. This research not only offers a viable approach to enhance the catalytic ozonation activity of M─N─C but also advances the fundamental comprehension of how periphery carbon environment influences the characteristics and efficacy of M─N4 sites.

7.
Anesthesiology ; 140(1): 102-115, 2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-37812765

RESUMO

BACKGROUND: Multiple neural structures involved in maintaining wakefulness have been found to promote arousal from general anesthesia. The medial septum is a critical region that modulates arousal behavior. This study hypothesized that glutamatergic neurons in the medial septum play a crucial role in regulating states of consciousness during sevoflurane general anesthesia. METHODS: Adult male mice were used in this study. The effects of sevoflurane anesthesia on neuronal activity were determined by fiber photometry. Lesions and chemogenetic manipulations were used to study the effects of the altered activity of medial septal glutamatergic neurons on anesthesia induction, emergence, and sensitivity to sevoflurane. Optogenetic stimulation was used to observe the role of acute activation of medial septal glutamatergic neurons on cortical activity and behavioral changes during sevoflurane-induced continuous steady state of general anesthesia and burst suppression state. RESULTS: The authors found that medial septal glutamatergic neuronal activity decreased during sevoflurane anesthesia induction and recovered in the early period of emergence. Chemogenetic activation of medial septal glutamatergic neurons prolonged the induction time (mean ± SD, hM3Dq-clozapine N-oxide vs. hM3Dq-saline, 297.5 ± 60.1 s vs. 229.4 ± 29.9 s, P < 0.001, n = 11) and decreased the emergence time (53.2 ± 11.8 s vs. 77.5 ± 33.5 s, P = 0.025, n = 11). Lesions or chemogenetic inhibition of these neurons produced the opposite effects. During steady state of general anesthesia and deep anesthesia-induced burst suppression state, acute optogenetic activation of medial septal glutamatergic neurons induced cortical activation and behavioral emergence. CONCLUSIONS: The study findings reveal that activation of medial septal glutamatergic neurons has arousal-promoting effects during sevoflurane anesthesia in male mice. The activation of these neurons prolongs the induction and accelerates the emergence of anesthesia.


Assuntos
Estado de Consciência , Neurônios , Camundongos , Animais , Masculino , Sevoflurano/farmacologia , Vigília/fisiologia , Anestesia Geral
8.
Acta Pharmacol Sin ; 45(9): 1777-1792, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38671193

RESUMO

Despite the widespread prevalence and important medical impact of insomnia, effective agents with few side effects are lacking in clinics. This is most likely due to relatively poor understanding of the etiology and pathophysiology of insomnia, and the lack of appropriate animal models for screening new compounds. As the main homeostatic, circadian, and neurochemical modulations of sleep remain essentially similar between humans and rodents, rodent models are often used to elucidate the mechanisms of insomnia and to develop novel therapeutic targets. In this article, we focus on several rodent models of insomnia induced by stress, diseases, drugs, disruption of the circadian clock, and other means such as genetic manipulation of specific neuronal activity, respectively, which could be used to screen for novel hypnotics. Moreover, important advantages and constraints of some animal models are discussed. Finally, this review highlights that the rodent models of insomnia may play a crucial role in novel drug development to optimize the management of insomnia.


Assuntos
Modelos Animais de Doenças , Descoberta de Drogas , Distúrbios do Início e da Manutenção do Sono , Animais , Distúrbios do Início e da Manutenção do Sono/tratamento farmacológico , Humanos , Hipnóticos e Sedativos/uso terapêutico , Hipnóticos e Sedativos/farmacologia , Roedores
9.
Sensors (Basel) ; 24(14)2024 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-39065874

RESUMO

Synthetic Aperture Radar (SAR) is renowned for its all-weather and all-time imaging capabilities, making it invaluable for ship target recognition. Despite the advancements in deep learning models, the efficiency of Convolutional Neural Networks (CNNs) in the frequency domain is often constrained by memory limitations and the stringent real-time requirements of embedded systems. To surmount these obstacles, we introduce the Split_ Composite method, an innovative convolution acceleration technique grounded in Fast Fourier Transform (FFT). This method employs input block decomposition and a composite zero-padding approach to streamline memory bandwidth and computational complexity via optimized frequency-domain convolution and image reconstruction. By capitalizing on FFT's inherent periodicity to augment frequency resolution, Split_ Composite facilitates weight sharing, curtailing both memory access and computational demands. Our experiments, conducted using the OpenSARShip-4 dataset, confirm that the Split_ Composite method upholds high recognition precision while markedly enhancing inference velocity, especially in the realm of large-scale data processing, thereby exhibiting exceptional scalability and efficiency. When juxtaposed with state-of-the-art convolution optimization technologies such as Winograd and TensorRT, Split_ Composite has demonstrated a significant lead in inference speed without compromising the precision of recognition.

10.
Molecules ; 29(12)2024 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-38930930

RESUMO

Considering that heavy-metal contamination of seawater is getting worse, building a quick, accurate and portable device for detecting trace zinc in seawater in real time would be very beneficial. In this work, a microfluidic system was developed that includes a planar disc electrode, a micro-cavity for detection, an electrochemical workstation, a computer, a container for waste liquid reprocessing, an external pipeline and other components as well as a graphene/cerium oxide/nano-cerium oxide/Nafion composite membrane was used to modify the planar disc electrode (GR/CeO2/Nafion/Au) to investigate the electrochemical behaviour of Zn(II) using cyclic voltammetry, square-wave voltammetry and orthogonal test methods. Under optimal experimental conditions, the peak reaction current of Zn(II) showed a good linear relationship with the concentration of Zn(II) in the range of 1-900 µg/L with a correlation coefficient of 0.998, and the detection limit of the method was 0.87 µg/L. In addition, the microfluidic system had good stability, reproducibility and anti-interference. The system was used for determining zinc ions in real seawater samples, and the results were very similar to those of inductively coupled plasma-emission spectrometry, demonstrating the practicality of the system for the detection of trace zinc.

11.
Angew Chem Int Ed Engl ; 63(27): e202403463, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38661020

RESUMO

Metal sulfide (MS) is regarded as a promising candidate of the anode materials for sodium-ion battery (SIB) with ideal capacity and low cost, yet still suffers from the inferior cycling stability and voltage degradation. Herein, the coordination relationship between the discharge product Na2S with the Na+ (NaPF6) in the electrolyte, is revealed as the root cause for the cycling failure of MS. Na+-coordination effect assistants the dissolution of Na2S, further delocalizing Na2S from the reaction interface under the function of electric field, which leads to the solo oxidation of the discharge product element metal without the participation of Na2S. Besides, the higher highest occupied molecular orbital of Na2S suggest the facilitated Na2S solo oxidation to produce sodium polysulfides (NaPSs). Based on these, lowering the Na+ concentration of the electrolyte is proposed as a potential improvement strategy to change the coordination environment of Na2S, suppressing the side reactions of the solo-oxidation of element metal and Na2S. Consequently, the enhanced conversion reaction reversibility and prolonged cycle life are achieved. This work renders in-depth perception of failure mechanism and inspiration for realizing advanced conversion-type anode.

12.
Cardiovasc Pathol ; 71: 107648, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38649123

RESUMO

This case report presents a 20-year-old male patient initially diagnosed with infective endocarditis, later correctly identified as Behçet's syndrome. The patient's complex clinical presentation, including chest pain, aortic dilation, severe aortic regurgitation, and aortic root abscess, posed significant diagnostic and therapeutic challenges. Despite initial misdiagnosis and treatment difficulties, the patient's condition significantly improved with appropriate immunosuppressive therapy, underscoring the potential for successful management of this complex condition. This case serves as a valuable reminder of the diagnostic challenges posed by Behçet's syndrome and the importance of considering this condition in patients presenting with symptoms suggestive of infective endocarditis.


Assuntos
Síndrome de Behçet , Erros de Diagnóstico , Imunossupressores , Humanos , Síndrome de Behçet/diagnóstico , Síndrome de Behçet/tratamento farmacológico , Masculino , Adulto Jovem , Imunossupressores/uso terapêutico , Endocardite/diagnóstico , Endocardite/terapia , Endocardite/tratamento farmacológico , Resultado do Tratamento , Diagnóstico Diferencial , Insuficiência da Valva Aórtica/cirurgia , Insuficiência da Valva Aórtica/diagnóstico , Insuficiência da Valva Aórtica/etiologia , Valor Preditivo dos Testes
13.
Cardiovasc Pathol ; 71: 107651, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38679299

RESUMO

BACKGROUND: This study aimed to explore the clinical and pathological features of aortitis in China, which is a rare disease that is often overlooked preoperatively. METHODS: We reviewed the records of 2950 patients who underwent aortic surgery at Wuhan Asia General Hospital from 2016 to 2023. Clinical and pathological data were collected and compared across different groups. RESULTS: Out of 2950 patients, 15 had healed aortitis, 2 were healed Takayasu aortitis (TAK), and 13 were not further classified. Forty-two had active aortitis, including clinically isolated aortitis ([CIA], 42.9%), infectious aortitis ([IA], 26.2%), TAK (16.7%), and Behçet's syndrome ([BS], 14.3%), half of these cases were not recognized preoperatively. All patients who developed perivalvular leakage during follow-up had concurrent non-infectious valvulitis with mixed inflammatory pattern at the time of initial surgery. Seventeen out of 18 patients with CIA survived without complications, as did 8 out of 11 patients with IA, 6 out of 7 patients with TAK, and 2 out of 6 patients with BS. CONCLUSIONS: Half of the aortitis cases were initially diagnosed by pathologists. Noninfectious valvulitis with mixed inflammatory pattern is a risk factor for perivalvular leakage. BS is associated with a higher rate of complications. Patients with CIA have a good prognosis in China, which is different from the West.


Assuntos
Aortite , Arterite de Takayasu , Humanos , Masculino , Feminino , China/epidemiologia , Pessoa de Meia-Idade , Adulto , Aortite/patologia , Aortite/epidemiologia , Aortite/cirurgia , Arterite de Takayasu/epidemiologia , Arterite de Takayasu/patologia , Arterite de Takayasu/complicações , Estudos Retrospectivos , Idoso , Adulto Jovem , Síndrome de Behçet/complicações , Síndrome de Behçet/patologia , Síndrome de Behçet/epidemiologia , Síndrome de Behçet/diagnóstico , Fatores de Risco , Valor Preditivo dos Testes , Resultado do Tratamento , Aorta/patologia , Aorta/cirurgia , Adolescente , Prognóstico , População do Leste Asiático
14.
Front Genet ; 15: 1404515, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39144722

RESUMO

Background: Breast cancer recurrence and lymph node metastasis significantly impact patient outcomes. Understanding the molecular mechanisms behind these processes is crucial for developing effective treatments. CCN5 and E-cadherin are proteins involved in cell adhesion and epithelial-mesenchymal transition (EMT), playing roles in breast cancer progression. Objective: This study aimed to analyze the expression levels and clinical significance of CCN5 and E-cadherin in primary and recurrent breast cancer lesions. Methods: Immunohistochemical staining using the SP method was performed to detect CCN5 and E-cadherin expression levels in 28 normal breast tissue samples, 52 primary breast cancer lesions, and paired recurrent chest wall lesions. The expression levels of these proteins were compared across different tissue types and correlated with lymph node metastasis. Results: CCN5 and E-cadherin expression levels significantly differed among normal breast tissues, primary breast cancer lesions, and recurrent lesions (Χ2 = 18.934 and Χ2 = 14.516, p < 0.05). Primary breast cancer lesions exhibited higher CCN5 and E-cadherin expression levels compared with recurrent lesions and normal tissues, although these differences were not statistically significant. Patients without lymph node metastases exhibited significantly higher expression levels of CCN5 and E-cadherin compared with those with lymph node metastases (Χ2 = 9.775, Χ2 = 9.1479, p < 0.05). A positive correlation between CCN5 and E-cadherin expression levels was found in breast cancer tissues (r = 0.398, p < 0.001). Conclusion: CCN5 and E-cadherin were expressed at lower levels in recurrent breast cancer tissues and those with lymph node metastases, indicating their potential roles in breast cancer recurrence and metastasis. These findings suggest that CCN5 and E-cadherin might work synergistically to influence breast cancer progression.

15.
Appl Neuropsychol Adult ; : 1-10, 2024 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-38648268

RESUMO

PURPOSE: To evaluate the reliability and validity of a newly developed computerized Automated Battery of Cognitive Tests in healthy individuals without cognitive impairments or psychiatric disorders. METHODS: From April 20 to July 1, 2023, 142 healthy individuals in Beijing and Tangshan, China were assessed using the Automated Battery of Cognitive Tests. After a 3-week interval, 36 participants were randomly selected for retesting. The assessment also included administration of the Repeatable Battery for the Assessment of Neuropsychological Status and the Automated Battery of Cognitive Tests to 59 participants. RESULTS: The Automated Battery of Cognitive Tests consists of 16 subtests. Internal consistency reliability was 0.75. The test-retest reliability for each factor ranged from 0.337 to 0.850 (p < 0.05). The criterion-related validity, as measured by correlation with the total Repeatable Battery for the Assessment of Neuropsychological Status score, was 0.748 (p < 0.001). The cumulative variance contribution rate is 70.109%. The results of the confirmatory factor analysis indicated a good model fit. CONCLUSIONS: The computerized Automated Battery of Cognitive Tests is a cognitive self-assessment tool with good reliability and validity. It can evaluate multiple aspects of cognitive performance in healthy individuals and is suitable for self-administration through remote access via Internet.

16.
Med Phys ; 2024 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-38843522

RESUMO

BACKGROUND: Cirrhosis patients often exhibit clinical symptoms such as right liver atrophy, portal hypertension, spleen enlargement and increased blood supply, which exhibit considerable variation between the left and right liver sections. These differences are hypothesized to stem from disparities in blood flow within the left and right portal vein (PV) branches. However, rigorous quantitative evidence remains scarce. PURPOSE: We mainly aim at quantitatively revealing the relationship between the blood flow rates of two PV branches and liver volumes, and providing quantitative evidence and theoretical support for the diagnosis and treatment of cirrhosis from the perspective of hemodynamics. METHODS: Five cirrhotic patients and two healthy volunteers from Beijing Friendship Hospital are investigated. Their PV blood flow models are established based on computed tomography (CT) images and finite volume simulations. The volume of the left and right liver lobes are measured in 3-matic. The distributions of blood source in the PV branches are tracked by streamline analysis. The blood flow rates are quantitatively counted by integrating the blood source velocities. Linear analysis is performed to build the relationship between liver volumes and PV blood flow distributions. RESULTS: Streamline analysis reveals significant differences in blood distribution between the left and right PV branches. The majority of blood from the superior mesenteric vein (SMV) flowed into the right portal vein (RPV), while most blood from the splenic vein (SV) entered the left portal vein (LPV). The main PV pressure drop linearly increases with the SV blood velocity for all PV structures of patients and healthy volunteers. The flow rate ratio QRPV/QLPV demonstrates an increase in tandem with the volume ratio VR/VL, exhibiting a linear correlation with the Pearson correlation coefficient being 0.93. CONCLUSION: The differences in the blood distributions are consistent with the clinicians' knowledge and validate our simulations. We demonstrated a linear increase in PV pressure with elevated SV blood velocity. Additionally, the volumes of the left and right hepatic lobes exhibited a positive correlation with blood flow rates in the corresponding PV branches.

17.
Cardiovasc Pathol ; 71: 107637, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38552930

RESUMO

BACKGROUND: In patients with aortic dissection, the aortic wall is separated into two layers along a dissection plane. In this study, a survey was performed to investigate the distribution of the depth of dissection plane and its correlation with other clinical and pathological parameters to help understand and expand the current knowledge of aortic dissection. METHODS: Pathology information system were searched for patients with aortic dissection who had undergone aortic replacement between 2019 and 2022 in Wuhan Asia General Hospital. The depth of dissection plane and dissection depth index were measured in the area around the edge of dissection plane. Correlation between parameters was calculated using Spearman's rank correlation coefficient. RESULTS: 124 patients were included in this study. The depth of dissection plane ranged from 533 to 2335 microns, and the 5th percentile was 778 microns. The dissection depth index ranged from 0.320 to 0.972, and the 5th percentile was 0.503. The correlation coefficients were -0.305 (P=.0007), -0.259 (P=0.0111), 0.188 (P=0.0367), 0.189 (P=0.0359) respectively for male gender, the length of aortic dissection, atherosclerosis, and translamellar mucoid extracellular matrix accumulation. CONCLUSIONS: In 95% of patients with aortic dissection, the depth of dissection plane is larger than 778 microns, and the dissection depth index is greater than 0.503. In other words, aortic dissection rarely occurs in the inner 50.3% of the aortic media. The dissection depth index is negatively correlated with male gender and the length of aortic dissection, and positively correlated with atherosclerosis and translamellar mucoid extracellular matrix accumulation.


Assuntos
Aneurisma Aórtico , Dissecção Aórtica , Humanos , Dissecção Aórtica/patologia , Dissecção Aórtica/cirurgia , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Aneurisma Aórtico/patologia , Aneurisma Aórtico/cirurgia , Estudos Retrospectivos , Adulto , China/epidemiologia , Aorta/patologia , Aorta/cirurgia , Fatores de Risco , Implante de Prótese Vascular/efeitos adversos
18.
PLoS One ; 19(3): e0299044, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38427649

RESUMO

Scraper conveyor is the most important transportation equipment in the comprehensive mining equipment, and the chain drive system is its core subsystem, its dynamic characteristics will significantly affect the efficiency of coal transportation in the comprehensive mining face. In this paper, the dynamic characteristics of chain drive system when impacted by falling coal are investigated by means of test. The impact test bench of scraper conveyor was set up to analyze the effects of chain speed, impact height and impact load mass on the dynamic characteristics of the chain drive system of scraper conveyor under the working conditions of unloaded and loaded. The results show that the longitudinal vibration of the scraper conveyor is most obvious when it is impacted by the falling coal, and the chain speed, impact height and impact load mass of the scraper conveyor all play an excitation role on the vibration of the chain drive system, and the vibration of the chain ring is the most intense in the chain drive system, and the loaded coal pile conveyed on the scraper conveyor plays an inhibiting role on the vibration of the chain drive system. This study can help to identify the location where the scraper conveyor fails first in the impact condition, so as to provide a basis for its structural design and improvement, which is of great significance for the stable operation and structural optimization of the scraper conveyor.


Assuntos
Carvão Mineral , Mineração , Carvão Mineral/análise , Meios de Transporte , Vibração
19.
Chem Commun (Camb) ; 60(6): 710-713, 2024 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-38108242

RESUMO

The prepared PdCuB Ngs/C catalysts exhibited outstanding catalytic activity and stability in the formic acid oxidation reaction (FAOR). The improvement in electrocatalytic performance is due to the introduction of Cu and B atoms and the hollow nanocage structure, which changes the electronic structures of Pd, increases the reactive sites, and accelerates the reaction mass transfer rates.

20.
Science ; 384(6696): 670-676, 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38723074

RESUMO

Electrochemistry offers a sustainable synthesis route to value-added fine chemicals but is often constrained by competing electron transfer between the electrode and redox-sensitive functionalities distinct from the target site. Here, we describe an ion-shielding heterogeneous photoelectrocatalysis strategy to impose mass-transfer limitations that invert the thermodynamically determined order of electron transfer. This strategy is showcased to enable decarboxylative trifluoromethylation of sensitive (hetero)arenes by using trifluoroacetate, an inexpensive yet relatively inert trifluoromethyl group (CF3) source. An ion-shielding layer, formed by trifluoroacetate anions electrostatically adsorbed on a positive molybdenum-doped tungsten trioxide (WO3) photoanode, prevents undesired electron transfer between substrates and photogenerated holes. The practicality of the developed method was demonstrated with robust photoanode stability (approximately 380 hours), a good substrate scope, and scaling capability to achieve 100-gram synthesis by using photoelectrochemical flow cells.

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