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1.
Oncol Lett ; 27(6): 239, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38623571

RESUMO

[This retracts the article DOI: 10.3892/ol.2018.8797.].

2.
Ying Yong Sheng Tai Xue Bao ; 35(3): 678-686, 2024 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-38646755

RESUMO

Exploring the effects of ant nests on soil CH4 emissions in the secondary tropical forests is of great scientific significance to understand the contribution of soil faunal activities to greenhouse gas emissions. With static chamber-gas chromatography method, we measured the dry-wet seasonal dynamics of CH4 emissions from ant nests and control soils in the secondary forest of Syzygium oblatum communities in Xishuangbanna. We also examined the linkages of ant-mediated changes in functional microbial diversity and soil physicochemical properties with CH4 emissions. The results showed that: 1) Ant nests significantly accelerated soil CH4 emissions, with average CH4 emissions in the ant nests being 2.6-fold of that in the control soils. 2) The CH4 emissions had significant dry-wet seasonal variations, which was a carbon sink in the dry seasons (from -0.29±0.03 to -0.53±0.02 µg·m-2·h-1) and a carbon source in the wet seasons (from 0.098±0.02 to 0.041±0.009 µg·m-2·h-1). The CH4 emissions were significantly higher in ant nests than in control soils. The CH4 emissions from the ant nests had smaller dry-wet seasonal variation (from -0.38±0.01 to 0.12±0.02 µg·m-2·h-1) than those in the control soils (from -0.65±0.04 to 0.058±0.006 µg·m-2·h-1). 3) Ant nests significantly increased the values (6.2%-37.8%) of soil methanogen diversity (i.e., Ace and Shannon indices), temperature and humidity, carbon pools (i.e., total, easily oxidizable, and microbial carbon), and nitrogen pools (i.e., total, hydrolyzed, ammonium, and microbial biomass nitrogen), but decreased the diversity (i.e., Ace and Chao1 indices) of methane-oxidizing bacteria by 21.9%-23.8%. 4) Results of the structural equation modeling showed that CH4 emissions were promoted by soil methanogen diversity, temperature and humidity, and C and N pools, but inhibited by soil methane-oxidizing bacterial diversity. The explained extents of soil temperature, humidity, carbon pool, nitrogen pool, methanogen diversity, and methane-oxidizing bacterial diversity for the CH4 emission changes were 6.9%, 21.6%, 18.4%, 15.2%, 14.0%, and 10.8%, respectively. Therefore, ant nests regulated soil CH4 emission dynamics through altering soil functional bacterial diversities, micro-habitat, and carbon and nitrogen pools in the secondary tropical forests.


Assuntos
Formigas , Florestas , Metano , Solo , Clima Tropical , Metano/análise , Metano/metabolismo , Animais , Solo/química , China , Microbiologia do Solo , Estações do Ano
3.
Adv Mater ; : e2312566, 2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38630368

RESUMO

Transition metal oxides (TMOs) are widely studied for loading of various catalysts due to their low cost and high structure flexibility. However, the prevailing close-packed nature of most TMOs crystals has restricted the available loading sites to surface only, while their internal bulk lattice remains unactuated due to the inaccessible narrow space that blocks out most key reactants and/or particulate catalysts. Herein, using tunnel-structured MnO2, this study demonstrates how TMO's internal lattice space can be activated as extra loading sites for atomic Ag in addition to the conventional surface-only loading, via which a dual-form Ag catalyst within MnO2 skeleton is established. In this design, not only faceted Ag nanoparticles are confined onto MnO2 surface by coherent lattice-sharing, Ag atomic strings are also seeded deep into the sub-nanoscale MnO2 tunnel lattice, enriching the catalytically active sites. Tested for electrochemical CO2 reduction reaction (eCO2RR), such dual-form catalyst exhibits a high Faradaic efficiency (94%), yield (67.3 mol g-1 h-1) and durability (≈48 h) for CO production, exceeding commercial Ag nanoparticles and most Ag-based electrocatalysts. Theoretical calculations further reveal the concurrent effect of such dual-form catalyst featuring facet-dependent eCO2RR for Ag nanoparticles and lattice-confined eCO2RR for Ag atomic strings, inspiring the future design of catalyst-substrate configuration.

4.
J Hazard Mater ; 471: 134282, 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38657509

RESUMO

Microplastics (MPs) pose a threat to farmland soil quality and crop safety. MPs exist widely in food legumes farmland soil due to the extensive use of agricultural film and organic fertilizer, but their distribution characteristics and their impact on soil environment have not been reported. The abundance and characteristics of MPs, soil physical and chemical properties, and bacterial community composition were investigated in 76 soil samples from five provinces in northern China. The results showed that the abundance of MPs ranged from 1600 to 36,200 items/kg. MPs in soil were mostly fibrous, less than 0.2 mm, and white. Rayon, polyester and polyethylene were the main types of MPs. The influences of MPs on soil physicochemical properties and bacterial communities mainly depended on the type of MPs. Notably, polyethylene significantly decreased the proportion of silt particles, and increased the nitrate nitrogen content as well as the abundance of MPs-degrading bacteria Paenibacillus (p < 0.05). Moreover, bacteria were more sensitive to polyesters in soil with low concentration of organic matter. This study indicated that MPs in food legumes farmland soil presented a higher-level. And, they partially altered soil physicochemical properties, and soil bacteria especially in soil with low organic matter.


Assuntos
Bactérias , Microplásticos , Microbiologia do Solo , Poluentes do Solo , Solo , China , Poluentes do Solo/análise , Solo/química , Microplásticos/análise , Bactérias/classificação , Fabaceae , Agricultura , Fazendas
5.
Pest Manag Sci ; 2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38629874

RESUMO

BACKGROUND: The pea leafminer, Liriomyza huidobrensis, is one of the most important insect pests on vegetables and ornamentals. The survival and egg-laying behavior of leafminers are markedly affected by the environment temperature. However, the mechanisms underlying the relationship between egg-laying and temperature are still largely unknown. RESULTS: Here, we find that leafminers have evolved an adaptive strategy to overcome the stress from high or low temperature by regulating oviposition-punching plasticity. We further show that this oviposition-punching plasticity is mediated by the expression of pyx in the ovipositor when subjected to disadvantageous temperature. Specifically, down-regulation of pyx expression in leafminers under low temperature stress led to a significant decrease in the swing numbers of ovipositor and puncture area of the egg spot, and consequently the lower amount of egg-laying compared to leafminers at ambient temperature. Conversely, activation of pyx expression under high temperature stress increased the swing numbers and puncture area, still resulting in a reduction of egg-laying amount. CONCLUSION: Thereby, leafminers are able to coordinate pyx channel expression level and accordingly depress the oviposition. Our study uncovers a molecular mechanism underlying the adaptive strategy in insects that can avoid disadvantageous temperature for reproducing offspring. © 2024 Society of Chemical Industry.

6.
BMC Nurs ; 23(1): 197, 2024 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-38519927

RESUMO

BACKGROUND: Individuals with schizophrenia require prolonged antipsychotic medication treatment. But more than 50% of individuals with schizophrenia experience adverse medication experiences during their antipsychotic treatments. Such individuals often adjust or discontinue medication, leading to disease relapse and impaired social functioning. Psychiatric nurses should pay close attention to the medication experiences of individuals with schizophrenia. This research explore the relationship between medication burden and medication experience, as well as the mediating effect of medication belief in stable patients with schizophrenia. METHODS: A convenience sample of hospitalized stable patients with schizophrenia were selected from Daqing Third Hospital and Baiyupao Hospital from September 2023 to December 2023. A survey was conducted with them using a questionnaire consisting of general information questionnaire, The Subjective Well-being Under Neuroleptic Treatment Scale(SWN), The Living with Medicines Questionnaire(LMQ), Beliefs about Medicines Questionnaire-Specific (BMQ-Specific). Pearson correlation analysis was used to explore the correlation between LMQ, BMQ-Specific and SWN scores, and multiple linear regression analysis was used to explore the influencing factors of medication experience in patients with schizophrenia. AMOS 24.0 was used to construct the structural equation modeling(SEM), and the mediation effect of the SEM was tested using Bootstrap method. RESULTS: According to the sample size calculation requirements of structural equation model, a total of 300 samples were required in this study, and 400 effective questionnaires were actually collected in this study, which met the sample size requirements for constructing structural equation models. Bootstrap test showed that the mediation effect was significant. The total effect of medication burden on medication experience was significant (Z=-12.146, 95%CI (-0.577, -0.417), P < 0.001). The indirect effect of medication burden on medication experience, that is, the mediating effect of medication belief was significant (Z=-4.839, 95%CI (-0.217, -0.096), P < 0.001). The direct effect of medication burden on medication experience was significant (Z=-7.565, 95%CI (-0.437, -0.257), P < 0.001). This model belongs to partial mediation model. CONCLUSIONS: Psychiatric nurses can enhance the patients' medication experience by reducing medication burden and strengthening medication beliefs. Therefore, the results also provide theoretical references and decision-making foundations for psychiatric nursing professionals to develop appropriate management strategies for individuals with schizophrenia.

7.
Front Cardiovasc Med ; 11: 1346022, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38476375

RESUMO

This case report presents a 72-year-old male patient who presented with exertional dyspnea for over 10 years, which had progressively worsened over the past 4 months. Transthoracic echocardiography revealed severe aortic and mitral regurgitation, with a left ventricular ejection fraction of 37% and a left ventricular end-diastolic diameter of 64 mm. Despite receiving long-term optimal medical management, there was no improvement in symptoms or severity of valvular regurgitation. Given the relatively high surgical risk associated with double valve replacement in this elderly patient and his preference for minimally invasive procedures, a one-stage transapical aortic valve replacement and transcatheter mitral valve repair using the edge-to-edge technique were planned. The patient was discharged 8 days post-procedure without any complications. At 1-month follow-up, the patient's New York Heart Association (NYHA) functional class had improved to grade II.

8.
Ultrasonics ; 138: 107265, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38354524

RESUMO

This paper introduces a methodology to recover the morphology of a complex rough surface from ultrasonic pulse echo measurements with an array of equidistant sensors using the one dimensional convolution neural network (1DCNN). The neural network is trained by the datasets simulated from high-fidelity finite element simulations for surfaces with a range of roughness parameters and is tested on both numerical and real experimental data. To assess the performance of our proposed method, the rough surface reconstruction results from the deep learning approach are compared with those obtained from conventional ultrasonic array imaging methods. Unlike array imaging-based methods that require a large number of sensors (e.g., 128, 64 or 32), the deep learning-based method uses pulse echo signals and can achieve accurate results with much fewer sensors. The developed deep learning approach has the potential to enable low-cost, accurate, and real-time reconstruction of complex surface profiles.

9.
Angew Chem Int Ed Engl ; 63(18): e202401924, 2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38366134

RESUMO

Nitrate electroreduction reaction (eNO3 -RR) to ammonia (NH3) provides a promising strategy for nitrogen utilization, while achieving high selectivity and durability at an industrial scale has remained challenging. Herein, we demonstrated that the performance of eNO3 -RR could be significantly boosted by introducing two-dimensional Cu plates as electrocatalysts and eliminating the general carrier gas to construct a steady fluid field. The developed eNO3 -RR setup provided superior NH3 Faradaic efficiency (FE) of 99 %, exceptional long-term electrolysis for 120 h at 200 mA cm-2, and a record-high yield rate of 3.14 mmol cm-2 h-1. Furthermore, the proposed strategy was successfully extended to the Zn-nitrate battery system, providing a power density of 12.09 mW cm-2 and NH3 FE of 85.4 %, outperforming the state-of-the-art eNO3 -RR catalysts. Coupled with the COMSOL multiphysics simulations and in situ infrared spectroscopy, the main contributor for the high-efficiency NH3 production could be the steady fluid field to timely rejuvenate the electrocatalyst surface during the electrocatalysis.

10.
Sci Rep ; 14(1): 4800, 2024 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-38413719

RESUMO

Ultra-high-rise buildings require high concrete bearing capacity. Ordinary concrete often fails to meet the project requirements. Admixture of admixtures in concrete is a means of solution. Currently, studies on the incorporation of basalt fiber (BF) and fly ash (FA) in concrete are relatively mature. However, research on incorporating nano-Titanium Carbide (nano-TiC) in concrete is still relatively scarce, which has a lot of room for development. To further improve the mechanical properties of concrete, BF, and FA synergized with nano-TiC were incorporated into concrete to produce TBF concrete in this study. And Response Surface Methodology (RSM) was used to optimize the mechanical properties of concrete. The collapse and compressive deformation damage characteristics of concrete were analyzed. The microstructure of the cement matrix was analyzed by the SEM (Scanning Electron Microscope). An optimization model of the TBF concrete craving function was developed. Optimized ratios with compressive, split tensile, and flexural strengths as response objectives were obtained, and the accuracy of the optimized ratios was investigated using the same experimental conditions. The results of the study showed that FA increased the collapse of concrete, while nano-TiC and BF decreased the collapse of concrete. Under uniaxial compression, nano-TiC, FA, and BF together incorporated into concrete can improve its compressive damage state. Moderate amounts of nano-TiC, BF, and FA could improve the mechanical properties of concrete. Their optimal mixing ratio admixtures were 0.88%, 0.24%, and 5.49%, respectively. And the measured values under the same conditions were compared with the predicted values. The maximum difference in compressive strength was 6.09%. The maximum difference in split tensile strength was 7.14%. The maximum difference in flexural strength was 8.45%. This indicated that the accuracy of the RSM optimization model was good. A moderate amount of nano-TiC, FA, and BF could improve the densification of concrete.

11.
Artigo em Inglês | MEDLINE | ID: mdl-38379368

RESUMO

Marital concerns can trigger emotional stress, especially among long-term hospitalised individuals diagnosed with schizophrenia, significantly affecting their treatment and recovery. Unfortunately, rehabilitation programs tend to overlook the marital needs of individuals with diagnosed schizophrenia. This research aimed to investigate the content related to marital concerns of Chinese individuals diagnosed with schizophrenia who were undergoing extended hospitalisation. Fifteen participants diagnosed with schizophrenia were recruited through purposive sampling for face-to-face semi-structured interviews. The gathered data were analysed using Colaizzi's method, revealing three themes: (1) manifestations of marriage-related concerns, (2) effects of marriage on disease progression, and (3) the need for support from family and the hospital. This study offers new insights into marital concerns among long-term schizophrenia inpatients and underscores the significance of screening and intervention for such concerns. Healthcare professionals and family members should extend support to patients to foster confidence within their marital relationships.

12.
Small ; 20(11): e2306690, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37926792

RESUMO

Non-aqueous solvents, in particular N,N-dimethylaniline (NMP), are widely applied for electrode fabrication since most sodium layered oxide cathode materials are readily damaged by water molecules. However, the expensive price and poisonousness of NMP unquestionably increase the cost of preparation and post-processing. Therefore, developing an intrinsically stable cathode material that can implement the water-soluble binder to fabricate an electrode is urgent. Herein, a stable nanosheet-like Mn-based cathode material is synthesized as a prototype to verify its practical applicability in sodium-ion batteries (SIBs). The as-prepared material displays excellent electrochemical performance and remarkable water stability, and it still maintains a satisfactory performance of 79.6% capacity retention after 500 cycles even after water treatment. The in situ X-ray diffraction (XRD) demonstrates that the synthesized material shows an absolute solid-solution reaction mechanism and near-zero-strain. Moreover, the electrochemical performance of the electrode fabricated with a water-soluble binder shows excellent long-cycling stability (67.9% capacity retention after 500 cycles). This work may offer new insights into the rational design of marvelous water stability cathode materials for practical SIBs.

13.
Small Methods ; : e2301307, 2023 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-38088567

RESUMO

Despite that extensive efforts have been dedicated to the search for advanced catalysts to boost the electrocatalytic nitrobenzene reduction reaction (eNBRR), its progress is severely hampered by the limited understanding of the relationship between catalyst structure and its catalytic performance. Herein, this review aims to bridge such a gap by first analyzing the eNBRR pathway to present the main influential factors, such as electrolyte feature, applied potential, and catalyst structure. Then, the recent advancements in catalyst design for eNBRR are comprehensively summarized, particularly about the impacts of chemical composition, morphology, and crystal facets on regulating the local microenvironment, electron and mass transport for boosting catalytic performance. Finally, the future research of eNBRR is also proposed from the perspectives of performance enhancement, expansion of product scope, in-depth understanding of the reaction mechanism, and acceleration of the industrialization process through the integration of upstream and downstream technologies.

14.
BMC Psychol ; 11(1): 364, 2023 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-37908023

RESUMO

The Absorption-addiction model suggests that people worship celebrities to compensate for some personal or social defects, so poor mental state is related to celebrity worship. The current study aimed to explore the underlying mechanisms influencing celebrity worship. A total of 1,147 participants (aged 19-26 years) completed online questionnaires to assess social anxiety, mobile phone dependence, parental income and celebrity worship. Results showed that: (1) social anxiety, socioeconomic status (SES) and celebrity worship were positively correlated; (2) Social anxiety affected celebrity worship through mobile phone dependence; (3) SES played a moderating role in the mediation model. At higher levels of SES, individuals with high social anxiety showed reduced dependence on mobile phones. These findings highlight the importance of mobile phone dependence and family SES in celebrity worship. Additionally, the findings demonstrated that females are more likely to pay attention to celebrities, but the greater SES and reduced mobile phone dependence can mitigate their celebrity addiction.


Assuntos
Comportamento Aditivo , Telefone Celular , Pessoas Famosas , Feminino , Humanos , Inquéritos e Questionários , Ansiedade
15.
Adv Mater ; 35(52): e2310433, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37931017

RESUMO

The value-added chemicals, monoxide, methane, ethylene, ethanol, ethane, and so on, can be efficiently generated through the electrochemical CO2 reduction reaction (eCO2 RR) when equipped with suitable catalysts. Among them, ethylene is particularly important as a chemical feedstock for petrochemical manufacture. However, despite its high Faradaic efficiency achievable at relatively low current densities, the substantial enhancement of ethylene selectivity and stability at industrial current densities poses a formidable challenge. To facilitate the industrial implementation of eCO2 RR for ethylene production, it is imperative to identify key strategies and potential solutions through comprehending the recent advancements, remaining challenges, and future directions. Herein, the latest and innovative catalyst design strategies of eCO2 RR to ethylene are summarized and discussed, starting with the properties of catalysts such as morphology, crystalline, oxidation state, defect, composition, and surface engineering. The review subsequently outlines the related important state-of-the-art technologies that are essential in driving forward eCO2 RR to ethylene into practical applications, such as CO2 capture, product separation, and downstream reactions. Finally, a greenhouse model that integrates CO2 capture, conversion, storage, and utilization is proposed to present an ideal perspective direction of eCO2 RR to ethylene.

16.
Angew Chem Int Ed Engl ; 62(44): e202313205, 2023 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-37721200

RESUMO

Enamides, functional derivatives of enamines, play a significant role as synthetic targets. However, the stereoselective synthesis of these molecules has posed a longstanding challenge in organic chemistry, particularly for acyclic enamides that are less thermodynamically stable. In this study, we present a general strategy for constructing ß-borylenamides by C-H borylation, which provides a versatile platform for generating the stereodefined enamides. Our approach involves the utilization of metalloid borenium cation, generated through the reaction of BBr3 and enamides in the presence of two different additives, avoiding any exogenous catalyst. Importantly, the stereoconvergent nature of this methodology allows for the use of starting materials with mixed E/Z configurations, thus highlighting the unique advantage of this chemistry. Mechanistic investigations have shed light on the pivotal roles played by the two additives, the reactive boron species, and the phenomenon of stereoconvergence.

17.
Sci Rep ; 13(1): 14876, 2023 09 08.
Artigo em Inglês | MEDLINE | ID: mdl-37684278

RESUMO

Intelligent recognition methods for classifying non-stationary and non-invasive epileptic diagnoses are essential tools in neurological research. Electroencephalogram (EEG) signals exhibit better temporal characteristics in the detection of epilepsy compared to radiation medical images like computed tomography (CT) and magnetic resonance imaging (MRI), as they provide real-time insights into the disease' condition. While classical machine learning methods have been used for epilepsy EEG classification, they still often require manual parameter adjustments. Previous studies primarily focused on binary epilepsy recognition (epilepsy vs. healthy subjects) rather than as ternary status recognition (continuous epilepsy vs. intermittent epilepsy vs. healthy subjects). In this study, we propose a novel deep learning method that combines a convolution neural network (CNN) with a long short-term memory (LSTM) network for multi-class classification including both binary and ternary tasks, using a publicly available benchmark database on epilepsy EEGs. The hybrid CNN-LSTM automatically acquires knowledge without the need for extra pre-processing or manual intervention. Besides, the joint network method benefits from memory function and stronger feature extraction ability. Our proposed hybrid CNN-LSTM achieves state-of-the-art performance in ternary classification, outperforming classical machine learning and the latest deep learning models. For the three-class classification, in the method achieves an accuracy, specificity, sensitivity, and ROC of 98%, 97.4, 98.3% and 96.8%, respectively. In binary classification, the method achieves better results, with ACC of 100%, 100%, and 99.8%, respectively. Our dual stream spatiotemporal hybrid network demonstrates superior performance compared to other methods. Notably, it eliminates the need for manual operations, making it more efficient for doctors to diagnose during the clinical process and alleviating the workload of neurologists.


Assuntos
Algoritmos , Epilepsia , Humanos , Redes Neurais de Computação , Memória de Longo Prazo , Eletroencefalografia , Epilepsia/diagnóstico por imagem
18.
PLoS One ; 18(8): e0289479, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37535586

RESUMO

Investigating the impact of different factors on soil and nutrient loss and suggesting viable control measures is currently a significant concern. This study aims to examine the variations in soil erosion, as well as nitrogen and phosphorus loss, in the core area of the typical hilly diffuse Blackland erosion control. To achieve this, runoff plots with slopes of 3° and 5° were set up in the Sunjiagou sub-basin, located in the upper reaches of the Feiketu River. These plots were subjected to various soil and water conservation measures, along with different levels of vegetation cover. This study aims to analyze the soil and nutrient loss patterns and characteristics in each runoff plot during the natural rainfall events occurring between 2020 and 2022. The results show that soil and nutrient losses are highly significantly and positively correlated with rainfall intensity. The RUSLE model demonstrates a better fit for both cross ridge tillage and bare ground. The loss of nitrogen was much more significant than that of phosphorus, and nitrate nitrogen is the main form of nitrogen loss. Nitrogen loss is mainly dominated by nitrate nitrogen (NN), which is easily soluble in water and constantly migrates with runoff due to the negatively charged NN (NN accounted for 45.2% ~ 81.8% of total nitrogen (TN)). In contrast, the positively charged ammonia nitrogen (AN) is more stable in combination with the soil; large losses only occur under severe sediment erosion. Phosphorus is easily attached to sediment, and the high sediment production leads to a more serious loss of total phosphorus (PP) in the particulate state (PP accounts for 72.7% ~ 96.2% of total phosphorus (TP)). Changing longitudinal ridge tillage to cross ridge tillage and planting vegetation with better water retention and sediment fixation as plant hedges can effectively prevent the loss of soil, runoff, nitrogen, and phosphorus.


Assuntos
Monitoramento Ambiental , Solo , Nitratos , Fósforo/análise , Nitrogênio/análise , Nutrientes , Água , China , Movimentos da Água , Chuva
19.
Can J Cardiol ; 39(11): 1571-1580, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37516250

RESUMO

Calcific aortic valve disease (CAVD), which is involved in osteogenic reprogramming of valvular interstitial cells, is the most common form of valve disease. It still lacks effective pharmacologic intervention, as its cellular biological mechanisms remain unclear. Congenital abnormality (bicuspid valve) and older age are considered to be the most powerful risk factors for CAVD. Aortic valve sclerosis (AVS) and calcific aortic stenosis (CAS), 2 subclinical forms of CAVD, represent 2 distinct stages of aortic valve calcification. During the AVS stage, the disease is characterised by endothelial activation/damage, inflammatory response, and lipid infiltration accompanied by microcalcification. The CAS stage is dominated by calcification, resulting in valvular dysfunction and severe obstruction to cardiac outflow, which is life threatening if surgery is not performed in time. Endoplasmic reticulum (ER) stress, a state in which conditions disrupting ER homeostasis cause an accumulation of unfolded and misfolded proteins in the ER lumen, has been shown to promote osteogenic differentiation and aortic valve calcification. Therefore, identifying targets or drugs for suppressing ER stress may be a novel approach for CAVD treatment.


Assuntos
Estenose da Valva Aórtica , Calcinose , Humanos , Valva Aórtica , Estenose da Valva Aórtica/complicações , Osteogênese , Células Cultivadas , Calcinose/etiologia , Estresse do Retículo Endoplasmático
20.
Front Cardiovasc Med ; 10: 1170979, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37293280

RESUMO

Introduction: Transcatheter aortic valve replacement (TAVR) is the first-line treatment for patients with moderate-to-high surgical risk of severe aortic stenosis. Paravalvular leakage (PVL) is a serious complication of TAVR, and aortic valve calcification contributes to the occurrence of PVL. This study aimed to investigate the effect of location and quantity of calcification in the aortic valve complex (AVC) and left ventricular outflow tract (LVOT) on PVL after TAVR. Method: We performed a systematic review and meta-analysis to evaluate the effect of quantity and location of aortic valve calcification on PVL after TAVR using observational studies from PubMed and EMBASE databases from inception to February 16, 2022. Results: Twenty-four observational studies with 6,846 patients were included in the analysis. A high quantity of calcium was observed in 29.6% of the patients; they showed a higher risk of significant PVL. There was heterogeneity between studies (I2 = 15%). In the subgroup analysis, PVL after TAVR was associated with the quantity of aortic valve calcification, especially those located in the LVOT, valve leaflets, and the device landing zone. A high quantity of calcium was associated with PVL, regardless of expandable types or MDCT thresholds used. However, for valves with sealing skirt, the amount of calcium has no significant effect on the incidence of PVL. Conclusion: Our study elucidated the effect of aortic valve calcification on PVL and showed that the quantity and location of aortic valve calcification can help predict PVL. Furthermore, our results provide a reference for the selection of MDCT thresholds before TAVR. We also showed that balloon-expandable valves may not be effective in patients with high calcification, and valves with sealing skirts instead of those without sealing skirts should be applied more to prevent PVL from happening. Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=354630, identifier: CRD42022354630.

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