RESUMEN

The escalating threat of anthropogenic climate change has spurred an urgent quest for innovative CO2 capture and utilization (CCU) technologies. Metal-organic frameworks (MOFs) have emerged as prominent candidates in CO2 capture and conversion due to their large specific surface area, well-defined porous structure, and tunable chemical properties. This review unveils the latest advancements in MOF-based materials specifically designed for superior CO2 adsorption, precise separation, advanced photocatalytic and electrocatalytic CO2 reduction, progressive CO2 hydrogenation, and dual functionalities. We explore the strategies that enhance MOF efficiency and examine the challenges of and opportunities afforded by transitioning from laboratory research to industrial application. Looking ahead, this review offers a visionary perspective on harnessing MOFs for the sustainable capture and conversion of CO2.

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Fine particulate matter (PM2.5) is a major air pollutant affecting human survival, development and health. By predicting the spatial distribution concentration of PM2.5, pollutant sources can be better traced, allowing measures to protect human health to be implemented. Thus, the purpose of this study is to predict and analyze the PM2.5 concentration of stations based on the integrated deep learning of a convolutional neural network long short-term memory (CNN-LSTM) model. To solve the complexity and nonlinear characteristics of PM2.5 time series data problems, we adopted the CNN-LSTM deep learning model. We collected the PM2.5data of Qingdao in 2020 as well as meteorological factors such as temperature, wind speed and air pressure for pre-processing and characteristic analysis. Then, the CNN-LSTM deep learning model was integrated to capture the temporal and spatial features and trends in the data. The CNN layer was used to extract spatial features, while the LSTM layer was used to learn time dependencies. Through comparative experiments and model evaluation, we found that the CNN-LSTM model can achieve excellent PM2.5 prediction performance. The results show that the coefficient of determination (R2) is 0.91, and the root mean square error (RMSE) is 8.216 µg/m3. The CNN-LSTM model achieves better prediction accuracy and generalizability compared with those of the CNN and LSTM models (R2 values of 0.85 and 0.83, respectively, and RMSE values of 11.356 and 14.367, respectively). Finally, we analyzed and explained the predicted results. We also found that some meteorological factors (such as air temperature, pressure, and wind speed) have significant effects on the PM2.5 concentration at ground stations in Qingdao. In summary, by using deep learning methods, we obtained better prediction performance and revealed the association between PM2.5 concentration and meteorological factors. These findings are of great significance for improving the quality of the atmospheric environment and protecting public health.

Asunto(s)

Contaminantes Atmosféricos , Redes Neurales de la Computación , Material Particulado , Material Particulado/análisis , Material Particulado/efectos adversos , Contaminantes Atmosféricos/análisis , Contaminantes Atmosféricos/efectos adversos , Humanos , Monitoreo del Ambiente/métodos , Aprendizaje Profundo , China , Algoritmos , Contaminación del Aire/análisis

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Chondrocytes, known for their metabolic adaptability in response to varying stimuli, play a significant role in osteoarthritis (OA) progression. Glucose-6-phosphate dehydrogenase (G6PD), the rate-limiting enzyme of the pentose phosphate pathway, has recently been found to upregulate in OA chondrocyte. However, the exact role of G6PD in temporomandibular joint osteoarthritis (TMJOA) and its effect on chondrocyte function remains unclear. In present study, we induced OA-like conditions in the rat temporomandibular joint via occlusal disharmony (OD), noting a marked increase in G6PD expression in the condylar cartilage. Our data show that G6PD knockdown in mandibular condylar chondrocytes (MCCs) reduces the expression of catabolic enzymes (e.g., MMP3, MMP13) and inflammatory cytokines (e.g., IL6) induced by IL-1ß. G6PD knockdown also mitigates IL-1ß-induced upregulation of ERK, JNK, and p38 phosphorylation and reduces reactive oxygen species (ROS) levels by decreasing the nicotinamide adenine dinucleotide phosphate (NADPH) and NADPH oxidases 4 (NOX4) mRNA expression. In summary, G6PD appears to regulate the inflammatory state of condylar chondrocytes via the NOX-ROS-MAPK axis, highlighting its potential as a therapeutic target for TMJOA.

Asunto(s)

Condrocitos , Glucosafosfato Deshidrogenasa , NADPH Oxidasa 4 , Osteoartritis , Especies Reactivas de Oxígeno , Animales , NADPH Oxidasa 4/metabolismo , NADPH Oxidasa 4/genética , Condrocitos/efectos de los fármacos , Condrocitos/metabolismo , Osteoartritis/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Glucosafosfato Deshidrogenasa/metabolismo , Glucosafosfato Deshidrogenasa/genética , Masculino , Ratas , Ratas Sprague-Dawley , Interleucina-1beta/metabolismo , Articulación Temporomandibular/patología , Articulación Temporomandibular/metabolismo , Células Cultivadas , Citocinas/metabolismo , Cartílago Articular/patología , Cartílago Articular/metabolismo , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Inflamación/metabolismo , Transducción de Señal , Modelos Animales de Enfermedad , Humanos

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Peroxymonosulfate (PMS) activation on efficient catalysts is a promising strategy to produce sulfate radical (SO4-) and singlet oxygen (1O2) for the degradation of refractory organic pollutants. It is a great challenge to selectively generate these two reactive oxygen species, and the regulation mechanism from non-radical to radical pathway and vice versa is not well established. Here, we report a strategy to regulate the activation mechanism of PMS for the selective generation of SO4- and 1O2 with 100 % efficiency by sulfur-doped cobalt cubic assembly catalysts that was derived from the Co-Co Prussian blue analog precursor. This catalyst showed superior catalytic performance in activating PMS with normalized reaction rate increased by 87 times that of the commercial Co3O4 nanoparticles and had much lower activation energy barrier for the degradation of organic pollutant (e.g., p-chlorophenol) (18.32 kJ⋅mol-1). Experimental and theoretical calculation results revealed that S doping can regulate the electronic structure of Co active centers, which alters the direction of electron transfer between catalyst and PMS. This catalyst showed a strong tolerance to common organic compounds and anions in water, wide environmental applicability, and performed well in different real-water systems. This study provides new opportunities for the development of metal catalyst with metal-organic frameworks structure and good self-regeneration ability geared specifically towards PMS-based advanced oxidation processes applied for water remediation.

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In years of research on classical pathways, the composition, information transmission mechanism, crosstalk with other pathways, and physiological and pathological effects of hedgehog (HH) pathway have been gradually clarified. HH also plays a critical role in tumor formation and development. According to the update of interpretation of tumor phenotypes, the latest relevant studies have been sorted out, to explore the specific mechanism of HH pathway in regulating different tumor phenotypes through gene mutation and signal regulation. The drugs and natural ingredients involved in regulating HH pathway were also reviewed; five approved drugs and drugs under research exert efficacy by blocking HH pathway, and at least 22 natural components have potential to treat tumors by HH pathway. Nevertheless, there is a deficiency of existing studies. The present review confirmed the great potential of HH pathway in future cancer treatment with factual basis.

Asunto(s)

Proteínas Hedgehog , Neoplasias , Transducción de Señal , Proteínas Hedgehog/metabolismo , Proteínas Hedgehog/genética , Humanos , Neoplasias/genética , Neoplasias/metabolismo , Neoplasias/tratamiento farmacológico , Neoplasias/patología , Transducción de Señal/efectos de los fármacos , Antineoplásicos/uso terapéutico , Antineoplásicos/farmacología , Animales , Mutación

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Advanced oxidation processes (AOPs) are the most efficient water cleaning technologies, but their applications face critical challenges in terms of mass/electron transfer limitations and catalyst loss/deactivation. Bipolar electrochemistry (BPE) is a wireless technique that is promising for energy and environmental applications. However, the synergy between AOPs and BPE has not been explored. In this study, by combining BPE with AOPs, we develop a general approach of using carbon nanotubes (CNTs) as electric-field-induced bipolar electrodes to control electron transfer for efficient water purification. This approach can be used for permanganate and peroxide activation, with superior performances in the degradation of refractory organic pollutants and excellent durability in recycling and scale-up experiments. Theoretical calculations, in situ measurements, and physical experiments showed that an electric field could substantially reduce the energy barrier of electron transfer over CNTs and induce them to produce bipolar electrodes via electrochemical polarization or to form monopolar electrodes through a single particle collision effect with feeding electrodes. This approach can continuously provide activated electrons from one pole of bipolar electrodes and simultaneously achieve "self-cleaning" of catalysts through CNT-mediated direct oxidation from another pole of bipolar electrodes. This study provides a fundamental scientific understanding of BPE, expands its scope in the environmental field, and offers a general methodology for water purification.

Asunto(s)

Electrodos , Nanotubos de Carbono , Oxidación-Reducción , Purificación del Agua , Nanotubos de Carbono/química , Purificación del Agua/métodos , Catálisis

RESUMEN

AIMS: The pharmacokinetic (PK) profiles of voriconazole in intensive care unit (ICU) patients differ from that in other patients. We aimed to develop a population pharmacokinetic (PopPK) model to evaluate the effects of using extracorporeal membrane oxygenation (ECMO) and continuous renal replacement therapy (CRRT) and those of various biological covariates on the voriconazole PK profile. METHODS: Modeling analyses of the PK parameters were conducted using the nonlinear mixed-effects modeling method (NONMEM) with a two-compartment model. Monte Carlo simulations (MCSs) were performed to observe the probability of target attainment (PTA) when receiving CRRT or not under different dosage regimens, different stratifications of quick C-reactive protein (qCRP), and different minimum inhibitory concentration (MIC) ranges. RESULTS: A total of 408 critically ill patients with 746 voriconazole concentration-time data points were included in this study. A two-compartment population PK model with qCRP, CRRT, creatinine clearance rate (CLCR), platelets (PLT), and prothrombin time (PT) as fixed effects was developed using the NONMEM. CONCLUSIONS: We found that qCRP, CRRT, CLCR, PLT, and PT affected the voriconazole clearance. The most commonly used clinical regimen of 200 mg q12h was sufficient for the most common sensitive pathogens (MIC ≤ 0.25 mg/L), regardless of whether CRRT was performed and the level of qCRP. When the MIC was 0.5 mg/L, 200 mg q12h was insufficient only when the qCRP was <40 mg/L and CRRT was performed. When the MIC was ≥2 mg/L, a dose of 300 mg q12h could not achieve ≥ 90% PTA, necessitating the evaluation of a higher dose.

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Germ cells (GCs) serve as indispensable carriers in both animals and plants, ensuring genetic continuity across generations. While it is generally acknowledged that the timing of germline segregation differs significantly between animals and plants, ongoing debates persist as new evidence continues to emerge. In this review, we delve into studies focusing on male germ cell specifications in plants, and we summarize the core gene regulatory circuits in germ cell specification, which show remarkable parallels to those governing meristem homeostasis. The similarity in germline establishment between animals and plants is also discussed.

Asunto(s)

Células Germinativas de las Plantas , Células Germinativas de las Plantas/crecimiento & desarrollo , Células Germinativas de las Plantas/metabolismo , Animales , Plantas/genética , Plantas/metabolismo , Diferenciación Celular/genética , Regulación de la Expresión Génica de las Plantas , Células Germinativas/citología , Células Germinativas/metabolismo , Meristema/crecimiento & desarrollo , Meristema/genética , Meristema/citología , Redes Reguladoras de Genes

RESUMEN

DNA, beyond its canonical B-form double helix, adopts various alternative conformations, among which the i-motif, emerging in cytosine-rich sequences under acidic conditions, holds significant biological implications in transcription modulation and telomere biology. Despite recognizing the crucial role of i-motifs, predictive software for i-motif forming sequences has been limited. Addressing this gap, we introduce 'iM-Seeker', an innovative computational platform designed for the prediction and evaluation of i-motifs. iM-Seeker exhibits the capability to identify potential i-motifs within DNA segments or entire genomes, calculating stability scores for each predicted i-motif based on parameters such as the cytosine tracts number, loop lengths, and sequence composition. Furthermore, the webserver leverages automated machine learning (AutoML) to effortlessly fine-tune the optimal i-motif scoring model, incorporating user-supplied experimental data and customised features. As an advanced, versatile approach, 'iM-Seeker' promises to advance genomic research, highlighting the potential of i-motifs in cell biology and therapeutic applications. The webserver is freely available at https://im-seeker.org.

Asunto(s)

ADN , Internet , Aprendizaje Automático , Motivos de Nucleótidos , Programas Informáticos , ADN/química , ADN/genética , Humanos , Análisis de Secuencia de ADN/métodos , Algoritmos

RESUMEN

Preeclampsia (PE) is considered as a disease of placental origin. However, the specific mechanism of placental abnormalities remains elusive. This study identified thrombospondin-1 (THBS1) is downregulated in preeclamptic placentae and negatively correlated with blood pressure. Functional studies show that THBS1 knockdown inhibits proliferation, migration, and invasion and increases the cycle arrest and apoptosis rate of HTR8/SVneo cells. Importantly, THBS1 silencing induces necroptosis in HTR8/SVneo cells, accompanied by the release of damage-associated molecular patterns (DAMPs). Necroptosis inhibitors necrostatin-1 and GSK'872 restore the trophoblast survival while pan-caspase inhibitor Z-VAD-FMK has no effect. Mechanistically, the results show that THBS1 interacts with transforming growth factor B-activated kinase 1 (TAK1), which is a central modulator of necroptosis quiescence and affects its stability. Moreover, THBS1 silencing up-regulates the expression of neuronal precursor cell-expressed developmentally down-regulated 4 (NEDD4), which acts as an E3 ligase of TAK1 and catalyzes K48-linked ubiquitination of TAK1 in HTR8/SVneo cells. Besides, THBS1 attenuates PE phenotypes and improves the placental necroptosis in vivo. Taken together, the down-regulation of THBS1 destabilizes TAK1 by activating NEDD4-mediated, K48-linked TAK1 ubiquitination and promotes necroptosis and DAMPs release in trophoblast cells, thus participating in the pathogenesis of PE.

Asunto(s)

Quinasas Quinasa Quinasa PAM , Necroptosis , Ubiquitina-Proteína Ligasas Nedd4 , Preeclampsia , Trombospondina 1 , Trofoblastos , Ubiquitinación , Humanos , Preeclampsia/metabolismo , Preeclampsia/genética , Femenino , Embarazo , Trofoblastos/metabolismo , Quinasas Quinasa Quinasa PAM/metabolismo , Quinasas Quinasa Quinasa PAM/genética , Necroptosis/genética , Ubiquitina-Proteína Ligasas Nedd4/metabolismo , Ubiquitina-Proteína Ligasas Nedd4/genética , Trombospondina 1/metabolismo , Trombospondina 1/genética , Adulto , Placenta/metabolismo

RESUMEN

Given the increasing use of bevacizumab in combinatorial drug therapy for a multitude of different cancer types, there is a need for therapeutic drug monitoring to analyze the possible correlation between drug trough concentration, and therapeutic effect and adverse reactions. An ultra-performance liquid chromatography tandem-mass spectrometry method was then developed and validated to determine bevacizumab levels in human plasma samples. Chromatographic separation was achieved on a Shimadzu InertSustainBio C18 HP column, whereas subsequent mass spectrometric analysis was performed using a Shimadzu 8050CL triple quadrupole mass spectrometer equipped with an electro-spray ionization source in the positive ion mode. In total, three multiple reaction monitoring transitions of each of the surrogate peptides were chosen with 'FTFSLDTSK' applied as the quantification peptide whereas 'VLIYFTSSLHSGVPSR' and 'STAYLQMNSLR' were designated as the verification peptides using the Skyline software. This analytical method was then fully validated, with specificity, linearity, lower limit of quantitation, accuracy, precision, stability, matrix effect and recovery calculated. The linearity of this method was developed to be within the concentration range 5-400 µg/ml for bevacizumab in human plasma. Subsequently, eight patients with non-small cell lung cancer (NSCLC) were recruited and injected with bevacizumab over three periods of treatment to analyze their steady-state trough concentration and differences. To conclude, the results of the present study suggest that bevacizumab can be monitored in a therapeutic setting in patients with NSCLC.

RESUMEN

Background: The necessity of localization of pulmonary nodules lies in ensuring the ability to locate the nodule quickly and accurately during surgery, thereby improving the success rate of the operation. The accuracy and risk of preoperative localization of pulmonary nodules need further exploration. Therefore, the purpose of this study was to investigate the factors of accuracy and safety of computed tomography (CT)-guided localization of pulmonary nodules using a flexible wire hook positioner. Methods: In this retrospective cross-sectional analysis, 281 patients with a single pulmonary nodule underwent video-assisted thoracoscopic surgery (VATS) following localization with a soft hook-wire guided by CT scan from January 2021 to July 2022 at Nanjing Drum Tower Hospital. The patients underwent VATS to remove pulmonary nodules within 24 hours after localization. The demographic, pulmonary nodule, and technical factors were analyzed retrospectively. Univariate and multivariate analysis were used to analyze the identified factors that influence pulmonary nodule localization accuracy and complications. Results: Localization was successfully performed in 280 patients, with only 1 patient being excluded due to a displaced positioner and the hook wire failing to enter the lung parenchyma as a result of pneumothorax. Out of the total cases, 191 (68.2%) were accurately positioned in group G0, whereas 89 cases (31.7%) were inaccurately positioned in group G1. Hemorrhage and self-limited hemoptysis were observed in 64 patients (22.8%), whereas pneumothorax was observed in 84 patients (29.9%). There were no serious complications such as air embolism or death. The accuracy of localization was found to be influenced by both the depth of pulmonary nodules [odds ratio (OR) =22.610, 95% confidence interval (CI): 10.351-49.391, P=0.001] and the depth of the needle used (OR =0.322, 95% CI: 0.136-0.765, P=0.010). Additionally, postoperative hemorrhage was found to be affected by several important factors, including the diameter (P=0.036) and depth of the nodule (P=0.011), as well as the thickness of the chest wall (P=0.043) and the depth of the needle used (P=0.005). Conclusions: The CT-guided flexible wire hook positioner has been found to be a safe and effective device for locating pulmonary nodules. The depth of pulmonary nodules and needle penetration are key factors affecting the accuracy of lung nodule localization under CT guidance and are important factors affecting postoperative bleeding.

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The sodium-rich solid electrolyte, Na3SO4F (NSOF), holds promise for eco-friendly and resource-abundant energy storage. While the introduction of heterovalent dopants has the potential to enhance its suitability for battery applications by creating Na vacancies, the effect of vacancies and sodium concentrations on sodium conduction remains unclear. In this work, Mg2+ was introduced into Na+ sites in Na3SO4F, generating sodium vacancies with different contents by using solid-state synthesis method. Among the resulting materials, Na2.96Mg0.02SO4F exhibited an ionic conductivity that is two-order-of-magnitude higher than NSOF at 298 K. Notably, as the sodium concentration decreased, the ionic conductivity also declined, revealing an equilibrium between Na vacancies and concentrations. To further investigate the influence of sodium concentration, excess Na+ was introduced into NaMgSO4F, which inherently possesses a lower sodium content by using solid-state synthesis method. However, this adjustment only led to an approximately one-order-of-magnitude enhancement in optimal ionic conductivity at 298 K. Combined with an in situ X-ray diffraction analysis, our findings underscore the greater sensitivity of sodium conduction to variations in sodium vacancies. This study paves the way for the development of ultrafast sodium ion conductors, offering exciting prospects for advanced energy storage solutions.

RESUMEN

Zero-valent iron (ZVI) reduction represents a promising methodology for water remediation, but its broad application is limited by two critical challenges (i.e., aggregation and passivation). Here, we report a hybrid strategy of photochemical-promoted ZVI reduction with high efficiency and reduction capacity for removing coexisting refractory pollutants in water. A composite material with Pd/Fe bimetallic nanoparticles supported onto semiconducting metal oxide (Pd/Fe@WO3-GO) was prepared and subsequently used as the model catalyst. By using the developed strategy with visible light as light source, this catalyst showed a remarkable catalytic performance for simultaneously eliminating 4-chlorophenol (4-CP) and Cr(VI), with dehalogenation rate as high as 0.43 min-1, outperforming the reported ZVI-based catalysts. A synergistic interaction of photocatalysis and ZVI reduction occurred in this strategy, where the interfacial electron transfer on particles surface were greatly strengthened with light irradiation. The activation was attributed to the dual functions of semiconducting material as support to disperse Pd/Fe nanoparticles and as (photoexcited) electron donor to directly trigger reduction reactions and/or indirectly inhibit the formation of oxides passivation layer. Both direct electron transfer and H*-mediated indirect electron transfer mechanisms were confirmed to participate in the reduction of pollutants, while the later was quantitatively demonstrated as the predominant reaction route. Importantly, this strategy showed a wide pH applicability, long-term durability and excellent catalytic performance in different real-water systems. This work provides new insights into ZVI reduction and advances its applications for the removal of combined organic and inorganic pollutants. The developed photochemical-promoted ZVI reduction strategy holds a great potential for practical applications.

RESUMEN

i-Motifs (iMs), are secondary structures formed in cytosine-rich DNA sequences and are involved in multiple functions in the genome. Although putative iM forming sequences are widely distributed in the human genome, the folding status and strength of putative iMs vary dramatically. Much previous research on iM has focused on assessing the iM folding properties using biophysical experiments. However, there are no dedicated computational tools for predicting the folding status and strength of iM structures. Here, we introduce a machine learning pipeline, iM-Seeker, to predict both folding status and structural stability of DNA iMs. The programme iM-Seeker incorporates a Balanced Random Forest classifier trained on genome-wide iMab antibody-based CUT&Tag sequencing data to predict the folding status and an Extreme Gradient Boosting regressor to estimate the folding strength according to both literature biophysical data and our in-house biophysical experiments. iM-Seeker predicts DNA iM folding status with a classification accuracy of 81% and estimates the folding strength with coefficient of determination (R2) of 0.642 on the test set. Model interpretation confirms that the nucleotide composition of the C-rich sequence significantly affects iM stability, with a positive correlation with sequences containing cytosine and thymine and a negative correlation with guanine and adenine.

Asunto(s)

ADN , Aprendizaje Automático , Motivos de Nucleótidos , Humanos , Secuencia de Bases , Citosina/química , ADN/química , ADN/genética

RESUMEN

BACKGROUND: Prenatal exposure to intrauterine inflammation (IUI) is a crucial event in preterm birth (PTB) pathophysiology, increasing the incidence of neurodevelopmental disorders. Gut microbiota and metabolite profile alterations have been reported to be involved in PTB pathophysiology. METHOD AND RESULTS: In this study, IUI-exposed PTB mouse model was established and verified by PTB rate and other perinatal adverse reactions; LPS-indued IUI significantly increased the rates of PTB, apoptosis and inflammation in placenta tissue samples. LPS-induced IUI caused no significant differences in species richness and evenness but significantly altered the species abundance distribution. Non-targeted metabolomics analysis indicated that the metabolite profile of the preterm mice was altered, and differential metabolites were associated with signaling pathways including pyruvate metabolism. Furthermore, a significant positive correlation between Parasutterella excrementihominis and S4572761 (Nb-p-coumaroyltryptamine) and Mreference-1264 (pyruvic acid), respectively, was observed. Lastly, pyruvic acid treatment partially improved LPS-induced IUI phenotypes and decreased PTB rates and decreased the apoptosis and inflammation in placenta tissue samples. CONCLUSION: This study revealed an association among gut microbiota dysbiosis, metabolite profile alterations, and LPS-induced IUI and PTB in mice models. Our investigation revealed the possible involvement of gut microbiota in the pathophysiology of LPS-induced IUI and PTB, which might be mediated by metabolites such as pyruvic acid. Future studies should be conducted to verify the findings through larger sample-sized animal studies and clinical investigations.

Asunto(s)

Microbioma Gastrointestinal , Nacimiento Prematuro , Recién Nacido , Embarazo , Humanos , Femenino , Animales , Ratones , Lipopolisacáridos/farmacología , Nacimiento Prematuro/etiología , Ácido Pirúvico/efectos adversos , Inflamación/metabolismo , Inseminación Artificial

RESUMEN

Switching from a linear mode of waste management to a circular loop by transforming plastic waste into carbon nanotubes (CNTs) is a promising approach to current plastic waste treatment. One of the many applications of CNTs is its use for electrocatalytic water splitting for hydrogen evolution. Existing methods of CNTs-based hydrogen evolution reaction (HER) electrode fabrication involve additives like polymeric binders and additional steps to improve CNT dispersion, which are detrimental to the CNT structure and properties. The in-situ fabrication approach can potentially be a one-pot solution to HER electrode synthesis. In this study, polyolefins pyrolysis gas and a Co:Ni:Mg catalyst were used to fabricate binder-free CNTs-based electrodes on different substrates for HER. The study assessed CNT quality on conductive carbon paper, semiconductive silicon, and dielectric glass substrates, evaluating their HER performance in 1 M KOH. A mixture of hollow-core, bamboo-like, and cup-stacked arrangement nanotubes were synthesized on the substrates, with CNTs on glass and carbon paper substrates possessing better graphitization than CNTs grown on silicon. This is in agreement with HER performance, whereby the as-prepared electrodes required overpotentials of 267 mV, 241 mV, and 216 mV for silicon, glass, and carbon paper, respectively, to achieve 10 mA/cm2. Despite being poorly conductive, the glass substrate electrode achieved a lower overpotential than the silicon electrode. Additionally, the as-prepared silicon electrode faced a delamination issue likely attributed to the lower surface energy of the silicon substrate surface, demonstrating the weaker adhesion between the CNTs and silicon surface. The proposed approach thus showed that the in-situ fabricated electrodes performed better than separately synthesized CNTs prepared into electrodes by 27.4% and 14.2% for carbon paper and glass substrates, respectively. The improved performance of the as-prepared, binder-free electrodes can be linked to the lower charge-transfer resistance and reduced contact resistance between the CNTs and substrate.

Asunto(s)

Nanotubos de Carbono , Nanotubos de Carbono/química , Silicio , Hidrógeno , Electrodos

RESUMEN

TiOxNy is a solid solution of cubic TiN and cubic TiO, with the ability to adjust its physical and chemical properties by modifying the O/N ratio, thus making it suitable for various applications. However, the synthesis of TiOxNy remains a significant challenge for inorganic chemists. In this work, we have successfully synthesized TiOxNy nanoparticles using the layered oxide Cs0.68Ti1.83O4 as the precursor and urea as the nitrogen source. The synthesis process was conducted within a temperature range of 800 to 1200 °C, leading to the transformation of the nitrided products from a two-dimensional layered precursor structure to a three-dimensional structure as the temperature increased. By varying the reaction temperature, the O/N ratio can be controlled. The experimental findings demonstrate that the nitrogen content in TiOxNy nanoparticles increases with rising temperature, ranging from TiO0.8N0.2 at 800 °C to TiO0.25N0.75 at 1200 °C. This work highlights the potential of the solid-state method in tailoring the properties of TiOxNy nanoparticles and presents a novel approach for synthesizing oxynitrides.

RESUMEN

The severity of the volatile organic compounds (VOCs) issue calls for effective detection and management of VOC materials. Metal-organic frameworks (MOFs) are organic-inorganic hybrid crystals with promising prospects in luminescent sensing for VOC detection and identification. However, MOFs have limitations, including weak response signals and poor sensitivity towards VOCs, limiting their application to specific types of VOC gases. To address the issue of limited recognition and single luminosity for specific VOCs, we have introduced fluorescent guest molecules into MOFs as reference emission centers to enhance sensitivity. This composite material combines the gas adsorption ability of MOFs to effectively adsorb VOCs. We utilized (MIL-125/NH2-MIL-125) as the parent material for adsorbing fluorescent molecules and selected suitable solid fluorescent probes (FGFL-B1) through fluorescence enhancement using thioflavin T and MIL-125. FGFL-B1 exhibited a heightened fluorescence response to various VOCs through charge transfer between fluorescent guest molecules and ligands. The fluorescence enhancement effect of FGFL-B1 on tetrahydrofuran (THF) was particularly pronounced, accompanied by a color change from yellow to yellowish green in the presence of CCl4. FGFL-B1 demonstrated excellent adsorption properties for THF and CCl4, with saturated adsorption capacities of 655.4 mg g-1 and 811.2 mg g-1, respectively. Furthermore, FGFL-B1 displayed strong luminescence stability and reusability, making it an excellent sensing candidate. This study addresses the limitations of MOFs in VOC detection, opening avenues for industrial and environmental applications.

RESUMEN

Background: Due to media opacity, it is usually difficult to accurately evaluate the postoperative visual acuity in cataracts patients. As a small and portable tool, the critical flicker fusion frequency (CFF) device reflects the temporal resolution of visual function and has been widely used in clinical research. However, poor understanding of the technique and equipment limitations have restricted its clinical application in China. Main text: There was a decrease in the CFF value in various ophthalmic diseases, indicating that the CFF is sensitive to detect visual functional changes. A number of studies have shown that the CFF test can accurately distinguish patients with simple cataracts from those with cataracts combined with fundus disease, and, as a visual test, it can more accurately predict postoperative visual acuity without being affected by media opacity. This study comprehensive reviews the basic principles of CFF and its application in ophthalmology, especially in cataracts. Conclusions: As one of the tools for dynamic visual function detection, the CFF test could help doctors to assess the possible presence of fundus disease in cataracts patients, especially in eyes with dense cataracts, and more precisely provide a reasonable visual prognosis than other available visual tests.