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Despite modern chemistry's success in providing affordable fertilizers for feeding the population and supporting the ammonia industry, ineffective nitrogen management has led to pollution of water resources and air, contributing to climate change. Here, we report a multifunctional copper single-atom electrocatalyst-based aerogel (Cu SAA) that integrates the multiscale structure of coordinated single-atomic sites and 3D channel frameworks. The Cu SAA demonstrates an impressive faradaic efficiency of 87% for NH3 synthesis, as well as remarkable sensing performance with detection limits of 0.15 ppm for NO3- and 1.19 ppm for NH4+. These multifunctional features enable precise control and conversion of nitrate to ammonia in the catalytic process, facilitating accurate regulation of the ammonium and nitrate ratios in fertilizers. We thus designed the Cu SAA into a smart and sustainable fertilizing system (SSFS), a prototype device for on-site automatic recycling of nutrients with precisely controlled nitrate/ammonium concentrations. The SSFS represents a forward step toward sustainable nutrient/waste recycling, thus permitting efficient nitrogen utilization of crops and mitigating pollutant emissions. This contribution exemplifies how electrocatalysis and nanotechnology can be potentially leveraged to enable sustainable agriculture.
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The electrochemical nitrate reduction reaction (NO3RR) holds promise for converting nitrogenous pollutants to valuable ammonia products. However, conventional electrocatalysis faces challenges in effectively driving the complex eight-electron and nine-proton transfer process of the NO3RR while also competing with the hydrogen evolution reaction. In this study, we present the thermally enhanced electrocatalysis of nitrate-to-ammonia conversion over nickel-modified copper oxide single-atom alloy oxide nanowires. The catalyst demonstrates improved ammonia production performance with a Faradaic efficiency of approximately 80% and a yield rate of 9.7 mg h-1 cm-2 at +0.1 V versus a reversible hydrogen electrode at elevated cell temperatures. In addition, this thermally enhanced electrocatalysis system displays impressive stability, interference resistance, and favorable energy consumption and greenhouse gas emissions for the simulated industrial wastewater treatment. Complementary in situ analyses confirm that the significantly superior relay of active hydrogen species formed at Ni sites facilitates the thermal-field-coupled electrocatalysis of Cu surface-adsorbed *NOx hydrogenation. Theoretical calculations further support the thermodynamic and kinetic feasibility of the relay catalysis mechanism for the NO3RR over the Ni1Cu model catalyst. This study introduces a conceptual thermal-electrochemistry approach for the synergistic regulation of complex catalytic processes, highlighting the potential of multifield-coupled catalysis to advance sustainable-energy-powered chemical synthesis technologies.
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Strained carbon nanohoops exhibit attractive photophysical properties due to their unique π-conjugated structure. However, incorporation of such nanohoops into the pincer ligand of metal complexes has rarely been explored. Herein, a new family of highly strained cyclometalated platinum(II) nanohoops has been synthesized and characterized. Strain-promoted C-H bond activation has been observed during the metal coordination process, and Hückel-Möbius topology and random-columnar packing in the solid state are found. Transient absorption spectroscopy revealed the size-dependent excited state properties of the nanohoops. Moreover, the nanohoops have been successfully employed as active materials in the fabrication of solution-processable resistive memory devices, including the use of the smallest platinum(II) nanohoop for the fabrication of a binary memory, with low switching threshold voltages of ca. 1.5 V, high ON/OFF current ratios, and good stability. These results demonstrate that strain incorporation into the structure can be an effective strategy to fundamentally fine-tune the reactivity, optoelectronic, and resistive memory properties.
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Chemotherapy is an effective therapeutic modality; nevertheless, a significant proportion of patients diagnosed with lung adenocarcinoma (LUAD) demonstrate resistance to chemotherapy. Therefore, it is crucial to understand the potential regulatory mechanisms to develop novel treatment strategies. This study aims to understand how increased FAM83B expression impacts mitochondrial activity, cell apoptosis, and chemotherapy effectiveness in LUAD. Multiple assays, such as CCK8, wound healing, EdU, and transwell assays, were employed to confirm the augmented chemotherapy resistance, heightened cell proliferation, migration, and invasion caused by FAM83B overexpression in LUAD cells. Furthermore, MIMP, MTG, and ATP assays were utilized to quantify changes in mitochondrial metabolism. In vitro functional assays were performed to evaluate the influence of FAM83B overexpression on the malignant progression and resistance mechanisms to chemotherapy in LUAD. In the context of this study, it was determined that LUAD patients with increased FAM83B expression had shorter survival times, and tissue samples with FAM83B overexpression were more prone to metastasis compared to primary samples. As a result, FAM83B is identified as an adverse prognostic marker. The mechanistic analysis demonstrated that FAM83B impedes the translocation of calbindin 2 (CALB2) from the cytoplasm to the mitochondria, resulting in the inhibition of apoptosis and the promotion of mitochondrial activity. Consequently, this ultimately confers resistance to chemotherapy in LUAD. Furthermore, the administration of metformin, which blocks mitochondrial oxidative phosphorylation (OXPHOS), can restore sensitivity to drug resistance in LUAD. Taken together, these findings provide substantial evidence supporting the notion that FAM83B enhances chemotherapy resistance in LUAD through the upregulation of mitochondrial metabolism and the inhibition of apoptosis.
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Adenocarcinoma de Pulmão , Apoptose , Proliferação de Células , Neoplasias Pulmonares , Mitocôndrias , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adenocarcinoma de Pulmão/genética , Adenocarcinoma de Pulmão/metabolismo , Adenocarcinoma de Pulmão/patologia , Adenocarcinoma de Pulmão/tratamento farmacológico , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Apoptose/efeitos dos fármacos , Apoptose/genética , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/genética , Regulação Neoplásica da Expressão Gênica , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/tratamento farmacológico , Mitocôndrias/metabolismo , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/genética , Mitocôndrias/patologia , PrognósticoRESUMO
The management and comprehension of relapsed or refractory multiple myeloma (RRMM) continues to pose a significant challenge. By integrating single-cell RNA sequencing (scRNA-seq) data of 15 patients with plasma cell disorders (PCDs) and proteomic data obtained from mass spectrometry-based analysis of CD138+ plasma cells (PCs) from 144 PCDs patients, we identified a state of malignant PCs characterized by high stemness score and increased proliferation originating from RRMM. This state has been designated as proliferating stem-like plasma cells (PSPCs). NUCKS1 was identified as the gene marker representing the stemness of PSPCs. Comparison of differentially expressed genes among various PC states revealed a significant elevation in LGALS1 expression in PSPCs. Survival analysis on the MMRF CoMMpass dataset and GSE24080 dataset established LGALS1 as a gene associated with unfavourable prognostic implications for multiple myeloma. Ultimately, we discovered three specific ligand-receptor pairs within the midkine (MDK) signalling pathway network that play distinct roles in facilitating efficient cellular communication between PSPCs and the surrounding microenvironment cells. These insights have the potential to contribute to the understanding of molecular mechanism and the development of therapeutic strategies involving the application of stem-like cells in RRMM treatment.
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Single-atom catalysts (SACs), specifically iron single atoms dispersed on nitrogen-doped carbon (Fe-NC), have shown promising potential in the electrocatalytic reduction of nitrate to ammonia (NitRR), but there is a lack of understanding of their intrinsic activity. The conventional measurements often overlook the intrinsic performance of SACs, leading to significant underestimation. This study presents an in situ electrochemical probing protocol, using two poisoning molecules (SCN- and NO2-), to characterize the reactivity of Fe sites in Fe-NC SACs for NitRR. The technique aids in quantifying the yield rate of ammonia on Fe sites and the active site number. The findings reveal the intrinsic turnover frequency (TOF) based on the number and ammonia yield rate of Fe sites, challenging the current understanding of SACs' inherent performances. This unique approach holds considerable potential for determining the intrinsic activity of other SACs in complex reactions, opening new avenues for the exploration of electrocatalytic processes.
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BACKGROUND: NADPH oxidase (NOX), a primary source of endothelial reactive oxygen species (ROS), is considered a key event in disrupting the integrity of the blood-retinal barrier. Abnormalities in neurovascular-coupled immune signaling herald the loss of ganglion cells in glaucoma. Persistent microglia-driven inflammation and cellular innate immune system dysregulation often lead to deteriorating retinal degeneration. However, the crosstalk between NOX and the retinal immune environment remains unresolved. Here, we investigate the interaction between oxidative stress and neuroinflammation in glaucoma by genetic defects of NOX2 or its regulation via gp91ds-tat. METHODS: Ex vivo cultures of retinal explants from wildtype C57BL/6J and Nox2 -/- mice were subjected to normal and high hydrostatic pressure (Pressure 60 mmHg) for 24 h. In vivo, high intraocular pressure (H-IOP) was induced in C57BL/6J mice for two weeks. Both Pressure 60 mmHg retinas and H-IOP mice were treated with either gp91ds-tat (a NOX2-specific inhibitor). Proteomic analysis was performed on control, H-IOP, and treatment with gp91ds-tat retinas to identify differentially expressed proteins (DEPs). The study also evaluated various glaucoma phenotypes, including IOP, retinal ganglion cell (RGC) functionality, and optic nerve (ON) degeneration. The superoxide (O2-) levels assay, blood-retinal barrier degradation, gliosis, neuroinflammation, enzyme-linked immunosorbent assay (ELISA), western blotting, and quantitative PCR were performed in this study. RESULTS: We found that NOX2-specific deletion or activity inhibition effectively attenuated retinal oxidative stress, immune dysregulation, the internal blood-retinal barrier (iBRB) injury, neurovascular unit (NVU) dysfunction, RGC loss, and ON axonal degeneration following H-IOP. Mechanistically, we unveiled for the first time that NOX2-dependent ROS-driven pro-inflammatory signaling, where NOX2/ROS induces endothelium-derived endothelin-1 (ET-1) overexpression, which activates the ERK1/2 signaling pathway and mediates the shift of microglia activation to a pro-inflammatory M1 phenotype, thereby triggering a neuroinflammatory outburst. CONCLUSIONS: Collectively, we demonstrate for the first time that NOX2 deletion or gp91ds-tat inhibition attenuates iBRB injury and NVU dysfunction to rescue glaucomatous RGC loss and ON axon degeneration, which is associated with inhibition of the ET-1/ERK1/2-transduced shift of microglial cell activation toward a pro-inflammatory M1 phenotype, highlighting NOX2 as a potential target for novel neuroprotective therapies in glaucoma management.
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Barreira Hematorretiniana , Pressão Intraocular , Camundongos Endogâmicos C57BL , NADPH Oxidase 2 , Doenças Neuroinflamatórias , Animais , NADPH Oxidase 2/metabolismo , NADPH Oxidase 2/genética , Camundongos , Barreira Hematorretiniana/patologia , Barreira Hematorretiniana/metabolismo , Pressão Intraocular/fisiologia , Doenças Neuroinflamatórias/metabolismo , Doenças Neuroinflamatórias/patologia , Camundongos Knockout , Proliferação de Células/fisiologia , Sistema de Sinalização das MAP Quinases/fisiologia , Neuroglia/metabolismo , Neuroglia/patologia , Hipertensão Ocular/patologia , Hipertensão Ocular/metabolismo , Glaucoma/patologia , Glaucoma/metabolismo , Estresse Oxidativo/fisiologiaRESUMO
MAIN CONCLUSION: ZmSUS1 improved drought tolerance of maize by regulating sucrose metabolism and increasing soluble sugar content, and endowing transgenic maize with higher relative water content and photosynthesis levels. Sucrose synthase (SUS), a key enzyme of sugar metabolism, plays an important role in the regulation of carbon partitioning in plant, and affects important agronomic traits and abiotic responses to adversity. However, the function of ZmSUS1 in plant drought tolerance is still unknown. In this study, the expression patterns of ZmSUS1 in different tissues and under drought stress were analyzed in maize (Zea mays L.). It was found that ZmSUS1 was highly expressed during kernel development but also in leaves and roots of maize, and ZmSUS1 was induced by drought stress. Homozygous transgenic maize lines overexpressing ZmSUS1 increased the content and activity of SUS under drought stress and exhibited higher relative water content, proline and abscisic acid content in leaves. Specifically, the net photosynthetic rate and the soluble sugar contents including sucrose, glucose, fructose and SUS decomposition products including UDP-glucose (UDP-G) and ADP-glucose (ADP-G) in transgenic plants were significantly improved after drought stress. RNA-seq analysis showed that overexpressing of ZmSUS1 mainly affected the expression level of carbon metabolism-related genes. Especially the expression level of sucrose metabolism-related genes including sucrose phosphatase gene (SPP), sucrose phosphate synthase gene (SPS) and invertase gene (INV) were significantly up-regulated in transgenic maize. Overall, these results suggested that ZmSUS1 improved drought tolerance by regulating sucrose metabolism and increasing the soluble sugar content, and endowing transgenic maize with higher relative water content and photosynthesis levels, which can serve as a new gene candidate for cultivating drought-resistant maize varieties.
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Resistência à Seca , Zea mays , Zea mays/metabolismo , Açúcares/metabolismo , Estresse Fisiológico , Secas , Sacarose/metabolismo , Água/metabolismo , Glucose/metabolismo , Carbono/metabolismo , Difosfato de Uridina/metabolismo , Regulação da Expressão Gênica de PlantasRESUMO
In the emerging field of high-capacity information encryption, multicolor, multitemporal, and multimodal luminescence inorganic materials are of great significance. However, conventional inorganic materials lack the flexibility to dynamically adjust the photon transition path, resulting in unicolor luminescence of the sample and reducing the reading and decoding levels. Herein, we elaborately designed the components for constructing dual-phase crystal fields for Eu2+ in phosphors based on a high temperature solid-state method. Specifically, SrAl2O4:Eu2+ crystal with a bright green afterglow and CaAl2O4:Eu2+ crystal with a blue afterglow were obtained in phosphors at the same time. As a result, a tunable afterglow behavior from blue to white was achieved due to the 4f65d1 â 4f7 transition of Eu2+ at different crystal field sites. Finally, the color tunable afterglow sample was used to explore the encryption and decryption processes of information, and the results showed that the prepared material has a good anti-counterfeiting performance, which is promising for the development of long persistent luminescent materials.
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The objective of this study is to examine the effectiveness and safety of zanubrutinib, rituximab, and lenalidomide (ZR2) in unfit patients with diffuse large B-cell lymphoma (DLBCL). Thrombosis or bleeding risk of ZR2 regimen, especially when antiplatelet agents were co-prescribed, was also evaluated. We retrospectively reviewed unfit newly diagnosed (ND) and refractory or relapsed (R/R) patients with DLBCL who were administered with ZR2 regimen in two medical centers between December 2019 and February 2022. Response rates, progression-free survival (PFS), overall survival (OS), bleeding adverse events (AEs), and thrombosis episodes were analyzed. Furthermore, we investigated the effects of zanubrutinib alone or in combination with lenalidomide on platelet functions in vitro and in vivo. A total of 30 unfit patients (13 ND DLBCL and 17 R/R DLBCL patients) who received ZR2 regimen were enrolled in the study (median age: 69.5 years). The ultimate ORRs for the ND DLBCL and R/R DLBCL were 77.0% and 50.1%, respectively. The median follow-up was 16.6 months. The median PFS and OS were not achieved during the follow-up time. Subcutaneous hemorrhage AEs occurred in four cases, three cases suffered severe bleeding events, and thrombosis events were observed in two patients. ZR2 regimen inhibited platelet functions (aggregation, clot retraction, spreading and activation) in vitro and in vivo function testing especially in response to collagen. ZR2 is an efficient treatment option for unfit patients with DLBCL and could be well tolerated. Notably, this regimen inhibited platelet functions. Antiplatelet agents should be used with caution in patients treated with this regimen.
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Linfoma Difuso de Grandes Células B , Piperidinas , Pirazóis , Pirimidinas , Trombose , Humanos , Idoso , Lenalidomida/efeitos adversos , Rituximab , Talidomida , Estudos Retrospectivos , Inibidores da Agregação Plaquetária/uso terapêutico , Linfoma Difuso de Grandes Células B/patologia , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Trombose/etiologiaRESUMO
AIMS: To devise effective preventive measures, a profound understanding of the evolving patterns and trends in atrial fibrillation (AF) and atrial flutter (AFL) burdens is pivotal. Our study was designed to quantify the burden and delineate the risk factors associated with AF and AFL across 204 countries and territories spanning 1990-2021. METHODS AND RESULTS: Data pertaining to AF and AFL were sourced from the Global Burden of Disease Study 2021. The burden of AF/AFL was evaluated using metrics such as incidence, disability-adjusted life years (DALYs), deaths, and their corresponding age-standardized rates (ASRs), stratified by age, sex, socio-demographic index (SDI), and human development index (HDI). The estimated annual percentage change was employed to quantify changes in ASRs. Population attributable fractions were calculated to determine the proportional contributions of major risk factors to age-standardized AF/AFL deaths. This analysis encompassed the period from 1990 to 2021. Globally, in 2021, there were 4.48 million incident cases [95% uncertainty interval (UI): 3.61-5.70], 8.36 million DALYs (95% UI: 6.97-10.13) and 0.34 million deaths (95% UI: 0.29-0.37) attributed to AF/AFL. The AF/AFL burden in 2021, as well as its trends from 1990 to 2021, displayed substantial variations based on gender, SDI quintiles, and geographical regions. High systolic blood pressure emerged as the leading contributor to age-standardized AF/AFL incidence, prevalence, death, and DALY rate globally among all potential risk factors, followed closely by high body mass index. CONCLUSION: Our study underscores the enduring significance of AF/AFL as a prominent public health concern worldwide, marked by profound regional and national variations. Despite the substantial potential for prevention and management of AF/AFL, there is a pressing imperative to adopt more cost-effective strategies and interventions to target modifiable risk factors, particularly in areas where the burden of AF/AFL is high or escalating.
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Fibrilação Atrial , Flutter Atrial , Carga Global da Doença , Humanos , Fibrilação Atrial/epidemiologia , Fibrilação Atrial/mortalidade , Fibrilação Atrial/economia , Flutter Atrial/epidemiologia , Masculino , Feminino , Carga Global da Doença/tendências , Idoso , Incidência , Pessoa de Meia-Idade , Fatores de Risco , Idoso de 80 Anos ou mais , Adulto , Anos de Vida Ajustados por Deficiência/tendências , Medição de Risco , Distribuição por Idade , Saúde Global , Distribuição por Sexo , Adulto Jovem , Fatores de Tempo , AdolescenteRESUMO
Hydrogen energy with its advantages of high calorific value, renewable nature, and zero carbon emissions is considered an ideal candidate for clean energy in the future. The electrochemical decomposition of water, powered by renewable and clean energy sources, presents a sustainable and environmentally friendly approach to hydrogen production. However, the traditional electrochemical overall water-splitting reaction (OWSR) is limited by the anodic oxygen evolution reaction (OER) with sluggish kinetics. Although important advances have been made in efficient OER catalysts, the theoretical thermodynamic difficulty predetermines the inevitable large potential (1.23 V vs. RHE for the OER) and high energy consumption for the conventional water electrolysis to obtain H2. Besides, the generation of reactive oxygen species at high oxidation potentials can lead to equipment degradation and increase maintenance costs. Therefore, to address these challenges, thermodynamically favorable anodic oxidation reactions with lower oxidation potentials than the OER are used to couple with the cathodic hydrogen evolution reaction (HER) to construct new coupling hydrogen production systems. Meanwhile, a series of robust catalysts applied in these new coupled systems are exploited to improve the energy conversion efficiency of hydrogen production. Besides, the electrochemical neutralization energy (ENE) of the asymmetric electrolytes with a pH gradient can further promote the decrease in application voltage and energy consumption for hydrogen production. In this review, we aim to provide an overview of the advancements in electrochemical hydrogen production strategies with low energy consumption, including (1) the traditional electrochemical overall water splitting reaction (OWSR, HER-OER); (2) the small molecule sacrificial agent oxidation reaction (SAOR) and (3) the electrochemical oxidation synthesis reaction (EOSR) coupling with the HER (HER-SAOR, HER-EOSR), respectively; (4) regulating the pH gradient of the cathodic and anodic electrolytes. The operating principle, advantages, and the latest progress of these hydrogen production systems are analyzed in detail. In particular, the recent progress in the catalytic materials applied to these coupled systems and the corresponding catalytic mechanism are further discussed. Furthermore, we also provide a perspective on the potential challenges and future directions to foster advancements in electrocatalytic green sustainable hydrogen production.
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Purpose: To explore the clinical application value of indocyanine green (ICG)-rituximab in sentinel lymph node biopsy. Methods: This study included 156 patients with primary breast cancer: 50 patients were enrolled in dose-climbing test, and 106 patients were enrolled in verification test. This was to compare the consistency of ICG-rituximab and combined method in the detected lymph nodes. Results: According to the verification test, the imaging rate of ICG-rituximab was 97.3%. Compared with the combined method, the concordance rate of fluorescence method was 0.991 (28 + 78/107; p < 0.001). Conclusion: For ICG-rituximab as a fluorescent targeting tracer, the optimal imaging dose of ICG 93.75 µg/rituximab 375 µg can significantly reduce the imaging of secondary lymph nodes. Compared with the combined method, it has a higher concordance rate.
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Neoplasias da Mama , Linfonodo Sentinela , Humanos , Feminino , Biópsia de Linfonodo Sentinela/métodos , Neoplasias da Mama/patologia , Linfonodo Sentinela/patologia , Rituximab , Corantes , Verde de Indocianina , Linfonodos/patologia , Meios de ContrasteRESUMO
To conveniently implement the online detection of grain moisture in combined harvesters and the address the influence of the no-load measurement baseline, thereby enhancing detection accuracy and measurement continuity, this study developed a differential grain moisture detection device. For its convenient installation and integration on combined harvesters, a single-pole plate measurement element with a 1.6 mm thick epoxy resin coated with a 2-ounce copper film was designed, and a grain moisture detection device was constructed based on the STM32F103 microprocessor (STMicroelectronics International NV, Geneva, Switzerland). To enhance the device's interference resistance, a differential amplification measurement circuit integrated with high-frequency excitation was designed using a reference capacitance. To improve the resolution of the measurement circuit, Malab simulations were conducted at different excitation frequencies, ultimately selecting 30 kHz as the system's excitation signal frequency. To validate the effectiveness of the measurement circuit, validity tests were performed on the constructed sensor, which showed that the sensor's measurement voltage could effectively distinguish the moisture levels in grains, with a determination coefficient (R²) reaching 0.9978. To address the errors in moisture measurement caused by changes in grain temperature, an interaction experiment of the effect of moisture content and temperature on the measurement voltage was conducted using an integrated temperature sensor, resulting in the construction of a moisture content calculation model. Both the indoor static detection and field testing of the moisture detection device were conducted, indicating that the maximum average error in static measurements was 0.3%, with a maximum relative error of 0.47%, and the average relative error in field tests was ≤0.4%.
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The effects of inorganic fertilizer addition method on the organic-inorganic co-composting process, especially the structure of humic acid and the mechanism of microbial nutrient restriction, are unclear. In this article, the effects of one-time and fractional addition of inorganic fertilizer on the structure of humic acid, extracellular enzyme activity, extracellular enzyme stoichiometry and the culturable growth-promoting bacteria during organic-inorganic co-composting were determined. The results showed that the addition of inorganic fertilizer promoted the humification degree of compost. Compared nitrogen with phosphorus, the fermentation microorganism behaved as N-restricted throughout the process. Compared one-time addition with fractional addition of inorganic treatments, the TOC, WSOC, NO3--N and humic acid content in the mature compost of the one-time addition treatment were higher. The contents of nitrogen, oxygen, the carboxyl functional groups, aromatic compounds, and the nitrogen/carbon atomic ratio in the humic acid structure increased as the composting process proceeded, while the contents of hydrogen, aliphatic substances, and the hydrogen/carbon atomic ratio decreased, and the elemental composition and structural changes of humic acids indicated that the humification degree of the one-time addition treatment was higher. The addition of inorganic fertilizer increased the relative abundances of Bacillus megaterium and Bacillus subtilis in the mature compost.
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Compostagem , Substâncias Húmicas , Substâncias Húmicas/análise , Solo , Fertilizantes/análise , Carbono , Hidrogênio , Nitrogênio/análise , EstercoRESUMO
The construction of chiral motifs containing nonadjacent stereocenters in an enantio- and diastereoselective manner has long been a challenging task in synthetic chemistry, especially with respect to their stereodivergent synthesis. Herein, we describe a protocol that enables the enantio- and diastereoselective construction of 1,5/1,7-nonadjacent tetrasubstituted stereocenters through a Pd/Cu-cocatalyzed Heck cascade reaction. Notably, a C=C bond relay strategy involving the shift of the π-allyl palladium intermediate was successfully applied in the asymmetric construction of 1,7-nonadjacent stereocenters. The current method allows for the efficient preparation of chiral molecules bearing two privileged scaffolds, oxindoles and non-natural α-amino acids, with good functional group tolerance. The full complement of the four stereoisomers of products bearing 1,5/1,7-nonadjacent stereocenters could be readily accessed by a simple combination of two chiral metal catalysts with different enantiomers.
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Atomically precise supported nanocluster catalysts (APSNCs), which feature exact atomic composition, well-defined structures, and unique catalytic properties, offer an exceptional platform for understanding the structure-performance relationship at the atomic level. However, fabricating APSNCs with precisely controlled and uniform metal atom numbers, as well as maintaining a stable structure, remains a significant challenge due to uncontrollable dispersion and easy aggregation during synthetic and catalytic processes. Herein, we developed an effective ligand engineering strategy to construct a Pt6 nanocluster catalyst stabilized on oxidized carbon nanotubes (Pt6/OCNT). The structural analysis revealed that Pt6 nanoclusters in Pt6/OCNT were fully exposed and exhibited a planar structure. Furthermore, the obtained Pt6/OCNT exhibited outstanding acidic HOR performances with a high mass activity of 18.37 A·mgpt-1 along with excellent stability during a 24 h constant operation and good CO tolerance, surpassing those of the commercial Pt/C. Density functional theory (DFT) calculations demonstrated that the unique geometric and electronic structures of Pt6 nanoclusters on OCNT altered the hydrogen adsorption energies on catalytic sites and thus lowered the HOR theoretical overpotential. This work presents a new prospect for designing and synthesizing advanced APSNCs for efficient energy electrocatalysis.
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Electroreduction of nitrate to ammonia offers a promising pathway for nutrient recycling and recovery from wastewater with energy and environmental sustainability. There have been considerable efforts on the regulation of reaction pathways to facilitate nitrate-to-ammonia conversion over the competing hydrogen evolution reaction but only with limited success. Here, we report a Cu single-atom gel (Cu SAG) electrocatalyst that produces NH3 from both nitrate and nitrite under neutral conditions. Given the unique mechanism of NO2- activation on Cu SAGs with spatial confinement and strengthened kinetics, a pulse electrolysis strategy is presented to cascade the accumulation and conversion of NO2- intermediates during NO3- reduction with the prohibited competition from the hydrogen evolution reaction, thus substantially enhancing the Faradaic efficiency and the yield rate for ammonia production compared with constant potential electrolysis. This work underlines the cooperative approach of the pulse electrolysis and SAGs with three-dimensional (3D) framework structures for highly efficient nitrate-to-ammonia conversion enabled by tandem catalysis of unfavorable intermediates.
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Harvesting recyclable ammonia (NH3) from the electrocatalytic reduction of nitrate (NO3RR) offers a sustainable strategy to close the ecological nitrogen cycle from nitration contamination in an energy-efficient and environmentally friendly manner. The emerging intermetallic single-atom alloys (ISAAs) are recognized to achieve the highest site density of single atoms by isolating contiguous metal atoms into single sites stabilized by another metal within the intermetallic structure, which holds promise to couple the catalytic benefits from intermetallic nanocrystals and single-atom catalysts for promoting NO3RR. Herein, ISAA In-Pd bimetallene, in which the Pd single atoms are isolated by surrounding In atoms, is reported to boost neutral NO3RR with a NH3 Faradaic efficiency (FE) of 87.2%, a yield rate of 28.06 mg h-1 mgPd-1, and an exceptional electrocatalytic stability with increased activity/selectivity over 100 h and 20 cycles. The ISAA structure induces substantially diminished overlap of Pd d-orbitals and narrowed p-d hybridization of In-p and Pd-d states around the Fermi level, resulting in a stronger NO3- adsorption and a depressed energy barrier of the potential-determining step for NO3RR. Further integrating the NO3RR catalyst into a Zn-NO3- flow battery as the cathode delivers a power density of 12.64 mW cm-2 and a FE of 93.4% for NH3 production.
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BACKGROUND: The prognostic value of additional copies of chromosome 1q (1q gain/amplification [amp]) in multiple myeloma (MM) remains controversial. In the meantime, the kinetics of the response to MM therapy has long been an area of debate. Few studies have pointed out the relationship of response kinetics with cytogenetic abnormalities (CAs) in MM. METHODS: The authors retrospectively analyzed the data of 1068 real-world newly diagnosed MM patients from a Chinese national medical center. RESULTS: Overall, 405 (51.9%) patients had 1q gain/amp, with aggressive clinical characteristics and significant inferior survival. The variation in copy number (CN) of 1q (CN = 3 or CN >3) had no significant impact on the survival of MM patients with 1q abnormalities. No difference was found in the outcome of 1q gain/amp patients treated with doublet or triplet regimens. Upfront autologous stem cell transplantation could eliminate the adverse prognostic effect of 1q gain but not 1q amp. The duration from diagnosis to the first time achieving very good partial response (VGPR) or better was significantly shorter in patients with 1q gain/amp (77 days vs. 100 days, p = .001). Finally, multifactor regression analysis was performed to construct a new risk stratification model in MM patients with 1q gain/amp, which was validated in the Multiple Myeloma Research Foundation CoMMpass study cohort and worked better than the Revised International Staging System and Second Revision of the International Staging System (Harrell's concordance index: 0.631 vs. 0.598 and 0.537). CONCLUSIONS: In the setting of novel therapy, 1q gain/amp still acts as an independent adverse prognostic factor. Patients with 1q gain/amp achieved VGPR rapidly but had inferior survival.