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Liquid phase exfoliation (LPE) of graphene is a potentially scalable method to produce conductive graphene inks for printed electronic applications. Among LPE methods, wet jet milling (WJM) is an emerging approach that uses high-speed, turbulent flow to exfoliate graphene nanoplatelets from graphite in a continuous flow manner. Unlike prior WJM work based on toxic, high-boiling-point solvents such as n-methyl-2-pyrollidone (NMP), this study uses the environmentally friendly solvent ethanol and the polymer stabilizer ethyl cellulose (EC). Bayesian optimization and iterative batch sampling are employed to guide the exploration of the experimental phase space (namely, concentrations of graphite and EC in ethanol) in order to identify the Pareto frontier that simultaneously optimizes three performance criteria (graphene yield, conversion rate, and film conductivity). This data-driven strategy identifies vastly different optimal WJM conditions compared to literature precedent, including an optimal loading of 15 wt% graphite in ethanol compared to 1 wt% graphite in NMP. These WJM conditions provide superlative graphene production rates of 3.2 g hr-1 with the resulting graphene nanoplatelets being suitable for screen-printed micro-supercapacitors. Finally, life cycle assessment reveals that ethanol-based WJM graphene exfoliation presents distinct environmental sustainability advantages for greenhouse gas emissions, fossil fuel consumption, and toxicity.
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This retrospective study at Beijing Children's Hospital (2020-2023) analyzed surgical procedures and complications in 24 pediatric hemophilia patients undergoing Totally Implantable Venous Access Port (TIVAP) insertion, primarily in the right jugular vein (RJV). We detailed the surgical process, including patient demographics and intraoperative imaging use. The choice of the RJV for TIVAP placement was influenced by its larger diameter and superficial anatomical position, potentially reducing risks like thrombosis and infection. Our findings support the RJV as a safer alternative for port placement in pediatric patients, aligning with current literature. Statistical analysis revealed no significant correlation between complications and baseline characteristics like weight and diagnosis type. However, the length of hospital stay and implant brand were significant risk factors for catheter or port displacement and removal. The limited patient number may introduce bias, suggesting a need for further studies with larger samples. Despite a 14.7 %-33 % complication rate and 5 port removals, the advantages of TIVAP, including reliable venous access, reduced discomfort, and treatment convenience, were evident. Most complications improved with symptomatic treatment, and there were no deaths due to port-related complications, underscoring the impact of TIVAP on improving pediatric hemophilia treatment.
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Hemofilia A , Humanos , Hemofilia A/complicações , Hemofilia A/tratamento farmacológico , Estudos Retrospectivos , Criança , Masculino , Pré-Escolar , Adolescente , Feminino , Cateterismo Venoso Central/efeitos adversos , Lactente , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/epidemiologia , Cateteres de Demora/efeitos adversos , Veias JugularesRESUMO
Single-atom catalysts (SACs) have attracted great attention for various chemical reactions because of their strong activity, high metal utilization ratio, and low cost. Here, by using the density functional theory (DFT) method, the stability of a single VIII-group metal atom (M = Ni, Pd, Pt) anchored on the defective hexagonal boron nitride (h-BN) sheet and its possible application in oxidative desulfurization (ODS) are investigated. Calculations show that the stability of the single M atom embedded in the h-BN surface with B and N vacancies is strikingly enhanced compared to that on the perfect h-BN surface. The catalytic activities of the defective h-BN-supported single metal atom are further studied by the activation of molecular oxygen and subsequent oxidation of dibenzothiophene (DBT). O2 is activated to the super-oxo state with large interaction energies on three M/VN surfaces. However, among the three M/VB surfaces, only Pt/VB performs efficient activation of O2. The oxidation of DBT proceeds in two steps; the rate-determining step is the initial step, in which activated O2 oxidizes DBT to produce sulfoxide. By comparing the energy barrier in the first reaction step, both Ni/VN and Pt/VB are revealed as promising candidates for the ODS reaction.
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BACKGROUND: Frailty is a multifactorial syndrome; through this study, we aimed to investigate the physiological, psychological, and social factors associated with frailty and frailty worsening in community-dwelling older adults. METHODS: We conducted a cross-sectional and longitudinal study using data from the "Community Empowerment and Well-Being and Healthy Long-term Care: Evidence from a Cohort Study (CEC)," which focuses on community dwellers aged 65 and above in Japan. The sample of the cross-sectional study was drawn from a CEC study conducted in 2014 with a total of 673 participants. After excluding those who were frail during the baseline assessment (2014) and at the 3-year follow-up (2017), the study included 373 participants. Frailty assessment was extracted from the Kihon Checklist, while social relationships were assessed using the Social Interaction Index (ISI). Variable selection was performed using Least Absolute Shrinkage and Selection Operator (LASSO) regression and their predictive abilities were tested. Factors associated with frailty status and worsening were identified through the Maximum-min Hillclimb algorithm applied to Bayesian networks (BNs). RESULTS: At baseline, 14.1% (95 out of 673) participants were frail, and 24.1% (90 out of 373) participants experienced frailty worsening at the 3-years follow up. LASSO regression identified key variables for frailty. For frailty identification (cross-sectional), the LASSO model's AUC was 0.943 (95%CI 0.913-0.974), indicating good discrimination, with Hosmer-Lemeshow (H-L) test p = 0.395. For frailty worsening (longitudinal), the LASSO model's AUC was 0.722 (95%CI 0.656-0.788), indicating moderate discrimination, with H-L test p = 0.26. The BNs found that age, multimorbidity, function status, and social relationships were parent nodes directly related to frailty. It revealed an 85% probability of frailty in individuals aged 75 or older with physical dysfunction, polypharmacy, and low ISI scores; however, if their social relationships and polypharmacy status improve, the probability reduces to 50.0%. In the longitudinal-level frailty worsening model, a 75% probability of frailty worsening in individuals aged 75 or older with declined physical function and ISI scores was noted; however, if physical function and ISI improve, the probability decreases to 25.0%. CONCLUSION: Frailty and its progression are prevalent among community-dwelling older adults and are influenced by various factors, including age, physical function, and social relationships. BNs facilitate the identification of interrelationships among these variables, quantify the influence of key factors. However, further research is required to validate the proposed model.
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Teorema de Bayes , Idoso Fragilizado , Fragilidade , Vida Independente , Humanos , Estudos Transversais , Idoso , Masculino , Estudos Longitudinais , Feminino , Japão/epidemiologia , Fragilidade/epidemiologia , Idoso de 80 Anos ou mais , Idoso Fragilizado/estatística & dados numéricos , Idoso Fragilizado/psicologia , Avaliação Geriátrica/métodos , Fatores de Risco , População do Leste AsiáticoRESUMO
OBJECTIVES: This study aimed to explore the bidirectional association between frailty and social relationships in older adults while distinguishing between interpersonal and intrapersonal effects. METHODS: A prospective cohort study of community-dwelling older adults was conducted in Japan in three waves spanning six years with follow-ups in every three years. Random intercept cross-lagged panel model was used to explore temporal associations between frailty and social relationships. RESULTS: Data for 520 participants (mean age 73.02 [SD 6.38] years, 56.7% women) were analyzed. Across individuals, frailty was associated with social relationships (ß = -0.514, p < 0.001). At the interpersonal level, frailty was cross-sectionally associated with social relationships separately at T1(ß = -0.389, p < 0.01), T2 (ß = -0.343, p < 0.001) and T3 (ß = -0.273, p < 0.05). Moreover, social relationships were associated with subsequent increases in symptoms of frailty in all measurement waves (ß = -0.332, p < 0.001; ß = -0.169, p < 0.01) and vice versa (ß = -0.149, p < 0.05; ß = -0.292, p < 0.001). CONCLUSIONS: The results suggest that frailty was associated with lower levels of social relationships. Frailty improvement programs can be combined with interventions to enhance social relationships, which will be beneficial in preventing frailty. The results emphasize the importance of combining clinical treatments of frailty with interventions to improve social relationships.
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Fragilidade , Humanos , Feminino , Idoso , Masculino , Japão/epidemiologia , Fragilidade/epidemiologia , Estudos Prospectivos , Relações Interpessoais , NonoxinolRESUMO
BACKGROUND: This study aimed to evaluate whether a combination of platelet-rich plasma (PRP) and hyaluronic acid (HA) is more effective and safer than injection alone for treating KOA. MATERIALS AND METHODS: MEDLINE (PubMed), the Cochrane Library, EMBASE, and Web of Science databases were systematically searched for articles published until January 2024, and gray literature and bibliographic references were searched. All published randomized controlled trials (RCTs) compared pain, functional outcomes, and adverse events (AEs) associated with PRP + HA therapy vs. PRP or HA treatments. Two independent researchers extracted the pertinent data and evaluated the methodological quality following the PRISMA guidelines. The primary outcomes were pain, functional outcomes, and AEs. A fixed-effects model was used for data analysis in cases with low heterogeneity (P > 0.10 and I2 < 50%). Otherwise, a random effects model was used. RESULTS: Ten RCTs involving 943 patients were included in the analysis. The statistical findings did not differ between the treatment of PRP + HA and PRP alone, while a discernible enhancement in treatment efficacy was observed when compared to HA monotherapy: the visual analog scale scores at 1- (mean difference[MD], -1.00; 95% CI: -1.37 - -0.62; P < .001), 6- (MD, -1.87; 95% CI: -3.46 - -0.28; P = .02), 12-months (MD, -2.07; 95% CI: -3.77 - -0.38; P = .02), and the Western Ontario and McMaster Universities Arthritis Index total scores at 12-months (MD, -8.82; 95% CI: -14.48 - -3.16; P = .002). The incidence of adverse events was notably lower with PRP + HA than with HA alone (OR, 0.37; 95% CI: 0.19 - 0.69; P = .00) or PRP alone (OR, 0.51; 95% CI, 0.30 - 0.87; P = .01). CONCLUSIONS: PRP + HA therapy resulted in more pronounced pain and functional improvement in symptomatic KOA patients than HA treatments, and combination therapy may have higher clinical safety than PRP or HA monotherapy.
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KEY MESSAGE: A novel major adult-plant stripe rust resistance QTL derived from cultivated emmer wheat was mapped to a 123.6-kb region on wheat chromosome 2BL. Stripe rust, caused by the fungal pathogen Puccinia striiformis f. sp. tritici (Pst), is one of the most devastating diseases of wheat. Identification of new sources of resistance and their utilization in breeding programs is the effectively control strategy. The objective of this study was to identify and genetically characterize the stripe rust resistance derived from the cultivated emmer accession AS286. A recombinant inbred line population, developed from a cross between the susceptible durum wheat line langdon and AS286, was genotyped using the Wheat55K single nucleotide polymorphism array and evaluated in field conditions with a mixture of the prevalent Chinese Pst races (CYR32, CYR33, CYR34, Zhong4, and HY46) and in growth chamber with race CYR34. Three QTLs conferring resistance were mapped on chromosomes 1BS, 2BL, and 5BL, respectively. The QYrAS286-1BS and QYrAS286-2BL were stable with major effects, explaining 12.91% to 18.82% and 11.31% to 31.43% of phenotypic variation, respectively. QYrAS286-5BL was only detected based on growth chamber seedling data. RILs harboring both QYrAS286-1BS and QYrAS286-2BL showed high levels of stripe rust resistance equal to the parent AS286. The QYrAS286-2BL was only detected at the adult-plant stage, which is different from previously named Yr genes and inherited as a single gene. It was further mapped to a 123.6-kb region using KASP markers derived from SNPs identified by bulked segregant RNA sequencing (BSR-Seq). The identified loci enrich our stripe rust resistance gene pool, and the flanking markers developed here could be useful in marker-assisted selection for incorporating QYrAS286-2BL into wheat cultivars.
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Basidiomycota , Triticum , Mapeamento Cromossômico , Triticum/genética , Triticum/microbiologia , Melhoramento Vegetal , Locos de Características Quantitativas , Genótipo , Resistência à Doença/genética , Doenças das Plantas/genética , Doenças das Plantas/microbiologiaRESUMO
Single-atom adsorbents (SAAs) featuring maximized atom utilization and uniform isolated adsorption sites have aroused extensive research interest in recent years as a novel class of adsorption materials research. Nevertheless, it is still challenging to gain a fundamental understanding of the complicated behaviors of SAAs for adsorbing thiophenic compounds (THs). Herein, this work systematically investigated the mechanisms of adsorption desulfurization (ADS) over a single group IIIA metal atom (Ga, In, and Tl) anchored on hexagonal boron nitride nanosheets (BNNSs) via density functional theory (DFT) calculations. First, all the possible doping sites have been considered and their stabilities have been evaluated by the doped energy. DFT calculations reveal that metal atoms prefer to substitute B atoms on BNNSs rather than N atoms. Additionally, SAAs all exhibit considerably enhanced adsorption capacity for THs primarily by the sulfur-metal (S-M) bond with π-π interactions maintained. Among them, In-atom-based SAAs would be adequate to provide the highest adsorption energy (In_cen_B, -40.1 kcal mol-1). Furthermore, from the perspective of adsorption energy, the SAAs show superior selectivity to THs than aromatic compounds due to the newly formed S-M bond. We hope that our work will manifest the design and application of SAAs in the field of ADS and shed light on a new strategy for fabricating SAAs based on BNNSs.
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The exploitation of highly efficient and cost-effective selective adsorbents for adsorptive desulfurization (ADS) remains a challenge. Fortunately, single-atom adsorbents (SAAs) characterized by maximized atom utilization and atomically dispersed adsorption sites have great potential to solve this problem as an emerging class of adsorption materials. Herein, aiming at improving the efficiency of ADS performance via the economical and feasible strategy, the desirable SAAs have been fabricated by uniformly anchoring aluminum (Al) atoms on hexagonal boron nitride nanofibers (BNNF) via an in situ pyrolysis method. Remarkably, Al-BN-1.0 exhibited a superior adsorption capacity of 46.1 mg S/g adsorbent for dibenzothiophene, with a 45% increase in adsorption capacity compared to the pristine BNNF. Additionally, it demonstrated excellent adsorption of other thiophene sulfides. Moreover, the ADS mechanisms have been investigated through special adsorption experiments combined with density functional theory (DFT) calculations. It was demonstrated that the superior ADS performance and selectivity of Al-BN-1.0 originate from the sulfur-aluminum (S-Al) and π-π interactions cooperating synergistically. This work would cast light on a novel fabrication strategy for the SAAs based on the two-dimensional material with a tunable metal site configurations and densities for varied selective adsorption and separation.
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Demand for graphite will grow with expanding use of lithium-ion batteries in the United States. Much graphite is imported, raising supply chain risks. It is therefore imperative to characterize graphite's sources and sinks. Accordingly, we present the first material flow analysis for natural and synthetic graphite in the U.S. The analysis (for 2018) begins with processed graphite trade and includes graphite production, graphite product trade, manufacturing of end products, end product use, and waste management. It considers 11 end-use applications for graphite, two waste management stages, and three recycling pathways. In 2018, 354 thousand tonnes (kt) of processed graphite were consumed in the U.S., including 60 kt natural graphite and 294 kt synthetic graphite. 145 kt of graphite were traded. Refractories and foundries consumed 56% of natural graphite; 42% of synthetic graphite went into making graphite electrodes. Batteries accounted for 10 and 5% of natural and synthetic graphite consumption, respectively; 78% of total graphite used dissipated into the environment; 22% reached the waste disposal stage of which 71% was landfilled and 29% was recycled; and 59 kt of graphite accumulated in in-use stocks. Recycling more graphite and producing graphite from lignin would favorably influence today's supply chain.
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Grafite , Eliminação de Resíduos , Gerenciamento de Resíduos , Estados Unidos , Lítio , Fontes de Energia Elétrica , ReciclagemRESUMO
Paranosema locustae is an entomopathogenic microsporidia with promising potential for controlling agricultural pests, including Locusta migratoria manilensis. However, it has the disadvantage of having a slow insecticidal rate, and how P. locustae infection impacts the host immune response is currently unknown. The present study investigated the effect of P. locustae on the natural immune response of L. migratoria and the activities of enzymes that protect against oxidative stress. Infection with P. locustae increased the hemocytes and nodulation number of L. migratoria at the initial stage of infection. The hemocyte-mediated modulation of immune response was also affected by a decrease in the number of hemocytes 12 days postinfection. Superoxide dismutase activity in locusts increased in the early stages of infection but decreased in the later stages, whereas the activities of peroxidase (POD) and catalase (CAT) showed opposite trends may be due to their different mechanisms of action. Furthermore, the transcription levels of mRNA of antimicrobial peptide-related genes and phenoloxidase activity in hemolymph in L. migratoria were suppressed within 15 days of P. locustae infection. Overall, our data suggest that P. locustae create a conducive environment for its own proliferation in the host by disrupting the immune defense against it. These findings provide useful information for the potential application of P. locustae as a biocontrol agent.
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Locusta migratoria , Microsporídios , Animais , Locusta migratoria/genética , Microsporídios/fisiologia , PeroxidaseRESUMO
Objective of this study is to summarize surgical outcomes of patients with anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) in a single center. The clinical data of 89 children undergoing surgical treatment in Beijing Children's Hospital from January 2007 to January 2022 were retrospectively analyzed. seven patients underwent ECMO support for acute left heart failure after operation, and 2 patients were discharged after weaning successfully. Eight patients died in the early postoperative period, all of them were infants, of which 5 patients underwent ECMO support, 2 patients died of cerebral hemorrhage, 2 patients died of multiple organ dysfunction, and 4 patients died of left heart failure. Three patients died late, 3 patients were lost to follow-up, and 78 patients (96.3%) completed long-term follow-up. A logistic regression model multivariate analysis showed that postoperative moderate or severe mitral regurgitation (MR) (OR 26.948 P = 0.024) and prolonged aortic cross-clamp time (OR 1.038 P = 0.050) were independent risk factors of early mortality. Compared with the Non-MVP group (20/36), the MVP group (patients with moderate or severe MR who underwent MVP at the same time) (16/36) had more significant improvement in early postoperative LEVEF [(50.68 ± 13.85)% vs (40.50 ± 13.58)% P = 0.033] and had a lower proportion of moderate or severe MR after operation (2/16 vs 11/20 P = 0.014). Children with ALCAPA can obtain a good prognosis by reconstructing the blood supply of both coronary arteries. Mitral valvuloplasty (MVP) is more helpful in improving the prognosis of children with moderate or severe MR and mitral valve structural disease. Reasonable placement of ECMO can help reduce the mortality of critically ill children after operation, but be alert to complications in the central system.
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Síndrome de Bland-White-Garland , Anomalias dos Vasos Coronários , Insuficiência Cardíaca , Doenças das Valvas Cardíacas , Insuficiência da Valva Mitral , Lactente , Criança , Humanos , Síndrome de Bland-White-Garland/complicações , Anomalias dos Vasos Coronários/cirurgia , Anomalias dos Vasos Coronários/complicações , Artéria Pulmonar , Estudos Retrospectivos , Insuficiência da Valva Mitral/cirurgia , Insuficiência Cardíaca/complicações , Doenças das Valvas Cardíacas/complicações , Resultado do TratamentoRESUMO
Evidence on the effectiveness and comparative effectiveness of stent implantation and balloon angioplasty for native coarctation of the aorta (CoA) and recurrent CoA separately is lacking. The present meta-analysis was performed to assess the efficacy and safety of stent implantation and balloon angioplasty in native (NaCo) and recurrent (ReCo) CoA.A systematic computerized literature search was conducted to retrieve all relevant studies of stent implantation and balloon angioplasty for CoA. Both single-arm and comparative studies were included. Data on NaCo and ReCo were pooled separately.A post-procedure gradient of ≤ 20 mmHg was achieved in 97% and 92% of patients undergoing stent implantation and balloon angioplasty for NaCo, and in 98% and 90% for ReCo, respectively. A post-procedure gradient of ≤ 10 mmHg was achieved in 97% and 83% of patients undergoing stent implantation and balloon angioplasty for NaCo, and in 86% and 78% for ReCo, respectively. Comparative results confirmed that stent implantation provided a significantly higher success rate compared with balloon angioplasty (odds ratio [OR] = 2.09; 95% confidence interval [CI] = 1.13-3.86; P = 0.019) in treating NaCo. Incidences of all-cause complications, mortality, reintervention, and aneurysm formation were similar between the groups. Patients undergoing stent implantation had a significantly lower incidence of dissection (OR = 0.15; 95% CI = 0.02-0.92; P = 0.040).Current evidence indicates that stent implantation might have superior efficacy compared with balloon angioplasty for the treatment of NaCo with higher success rates and similar complication rates. However, whether this superior effect is also present in ReCo patients needs further evaluation.
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Angioplastia Coronária com Balão , Angioplastia com Balão , Coartação Aórtica , Humanos , Coartação Aórtica/cirurgia , Aorta , Angioplastia com Balão/métodos , Recidiva , Stents , Resultado do TratamentoRESUMO
Phytochemical investigation of 70% EtOH extract of the seeds of Capsella bursa-pastoris led to the isolation of a new cyclobutane organic acid (1), and fourteen known compounds, including two organosulfur compounds (2, 3), two quinonoids (4, 5), five flavonoids (6-10), three sterols (11-13) and two other types (14, 15). The structures of the compounds were elucidated by extensive spectroscopic analyses as well as comparison of their spectroscopic data with those reported in the literature. The antioxidant capacities of all compounds and extractive fractions were evaluated by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging test and ferric reducing antioxidant power (FRAP) assay. Then the antioxidative substances were evaluated for their neuroprotective effects against H2O2-induced HT22 cell injury. The results indicated the strong scavenging ability to free radical of the extractive fractions and compounds 1-3, 8-10 and 13, and the ferric reducing antioxidant power of the extractive fractions and compounds 1-3, 8 and 10, which were close to or higher than that of the positive control trolox. The EtOAc fraction, n-BuOH fraction, and compounds 1, 3 and 8 can protect HT-22 cells from oxidative damage.
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Antioxidantes , Capsella , Antioxidantes/análise , Peróxido de Hidrogênio , Extratos Vegetais/química , Compostos Fitoquímicos/farmacologia , Sementes/químicaRESUMO
Impaired insulin release is the key feature of type 2 diabetes. Insulin secretion, mainly mediated by SNARE proteins, is closely related to the blood glucose level. However, the mechanism underlying how glucose controls SNARE proteins to regulate insulin release is largely unexplained. Herein, we investigated the effects of glucose on the subcellular localization and spatial distribution on the plasma membrane (PM) of t-SNAREs (SNAP-25 and STX-1A) using a live-cell confocal microscope and the single-molecule localization imaging technique. Live-cell confocal and dSTORM imaging first revealed that SNAP-25 was mostly localized to the PM as clusters under the basal glucose concentration condition and demonstrated significant colocalization with STX-1A clusters. Furthermore, our data showed that the elevated glucose concentration increased the expression of SNAP-25 and induced more and larger SNAP-25 clusters on the PM, whereas glucotoxicity severely inhibited SNAP-25 transport to the PM and caused fewer and smaller SNAP-25 clusters on the PM. Additionally, we found that glucotoxicity also had an inhibitory effect on the colocalization between SNAP-25 and STX-1A, indicating a decrease of their interactions. Our study sheds light on the regulatory effects of glucose on the functional organization of t-SNAREs at a subcellular and molecular level, thus providing new insights into the mechanisms by which SNAREs regulate insulin release.
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Diabetes Mellitus Tipo 2 , Insulina , Humanos , Insulina/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Proteína 25 Associada a Sinaptossoma/metabolismo , Secreção de Insulina , Membrana Celular/metabolismo , Glucose/metabolismoRESUMO
Solid amine adsorbents are promising materials to mitigate global warming. In this study, a commercially available melamine-formaldehyde sponge was adopted as a support to prepare a kind of solid amine adsorbent using polyethylenimine as a functional component and ethylene glycol diglycidyl ether as a cross-linker. The adsorbent, with abundant tunnels and a high amine loading amount, had a high adsorption capacity. When the amine loading was 89.6 wt%, the as-prepared adsorbent showed a high adsorption capacity of 7.29 mmol/g at 20 °C in the presence of water. The spent adsorbent could be easily regenerated by heating it at 90 °C, resulting in lower energy consumption. It has been proved by the Avrami model that physical and chemical adsorption coexist in the adsorption of CO2 on this adsorbent. Simulation with the intraparticle diffusion model has revealed that the rate-controlling step in the adsorption process was the gas film diffusion period when the adsorption temperature was below 30 °C, while it was the adsorption equilibrium period when the adsorption temperature was above 30 °C.
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Excessive application of chemical nitrogen (N) fertilizer and inefficient N management are still common in the North China Plain, leading to large reactive N (Nr) losses and pollution, threatening environmental security and public health. Three improved N management practices (33% reduction in N applied (OU), OU combined with partial organic fertilizer substitution (UOM) and the urea in UOM amended with a urease inhibitor (ULOM)) together with no N application (CK) and farmers' conventional practice (CU) were tested on a maize-wheat rotation at Quzhou, Hebei, North China Plain (NCP). Nr emissions were related to WFPS (Water Filled Pore Space), soil mineral N (NH4+-N and NO3--N) and soil temperature. Nr emissions and yield-scaled Nr emissions were significantly reduced by partial substitution of organic fertilizer for chemical fertilizer: NH3 emissions were reduced by 55.8-62.4%. Using a urease inhibitor (Limus®), further reduced NH3 emissions by 40.2-64.5%. Yield-scaled NH3 emissions were, on average, reduced by 60.0% and 55.2% in the maize and wheat growing season, respectively, relative to the UOM treatment. Long-term application of organic fertilizer had a significant positive effect on N use efficiency (NUE). Overall, the study shows that appropriated N management such as reducing the N application rate, partial substitution of chemical N by organic N and using a urease inhibitor can reduce Nr emissions and promote NUE in the North China Plain. The methods corresponding to the ULOM and UOM treatments were the most and second most effective, respectively, with high net economic benefits.
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Fertilizantes , Óxido Nitroso , Agricultura/métodos , China , Produtos Agrícolas , Fertilizantes/análise , Nitrogênio/análise , Solo , Triticum , Urease , Zea maysRESUMO
The rational design of highly active hexagonal boron nitride (h-BN) catalysts at the atomic level is urgent for aerobic reactions. Herein, a doping impurity atom strategy is adopted to increase its catalytic activities. A series of doping systems involving O, C impurities and B, N antisites are constructed and their catalytic activities for molecular O2 have been studied by density functional theory (DFT) calculations. It is demonstrated that O2 is highly activated on ON and BN defects, and moderately activated on CB and CN defects, however, it is not stable on NB and OB defects. The subsequent application in oxidative desulfurization (ODS) reactions proves the ON and C-doped (CB , CN ) systems to be good choice for sulfocompounds oxidization, especially for dibenzothiophene (DBT). While the BN antisite is not suitable for such aerobic reaction due to the extremely stable B-O* -B species formed during the oxidation process.
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Due to the hydrophilic nature of concrete, moisture and corrosive ions adsorbed on its surface pose a severe challenge to the durability of concrete structures; therefore, investigating the wettability of a concrete surface is an indispensable prerequisite for designing durable and sustainable concrete. This paper utilizes molecular dynamics to simulate the concentration-induced wettability alteration of nanoscale NaCl droplets on a CSH surface, and verifies the feasibility and rationality of predicting the contact angle of a droplet on the CSH surface based on the surface tension. Results suggest that the wetting ability of droplets on the CSH surface is weakened with the increase of the NaCl mass fraction. Microscopic analysis reveals that water molecules clustered around Na+ and Cl- ions to form an ion hydration shell (Na+-Ow and Cl--Hw pairs); the binding energy barrier of these ion pairs is much larger than the dissociation energy barrier, which enhances the associative ability of the NaCl droplets. The particles on the CSH surface attract Na+ and Cl- ions by forming Oh(Os)-Na+ and Ca(Ho)-Cl- connections with droplets, which further weakens the spreading ability of water molecules on the CSH surface.
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The incorporation of a corrosion inhibitor into a cement-based material can enhance the durability of the reinforced concrete. In this study, molecular dynamics simulation is utilized to study the interfacial structure and dynamic behavior of a solution with three migrating corrosion inhibitors (MCI) functionalized by hydroxyl (-OH), carboxyl (-COO-), and phenyl (-PH) groups in calcium silicate hydrate (CSH) gel pores. The transport rate of inhibitors is greatly dependent on the polarity of the functional group: -PH > -OH > -COO-. The slow migration rate of the inhibitor with -OH and -COO- is attributed to the chemical bond formed between CSH and MCI. The silicate chains near the CSH surface can provide plenty of non-bridging oxygen sites to accept the H-bond from the hydroxyl group in the inhibitor molecule. The surface calcium atom can capture the -COO- by forming an ionic COO-Ca bond. Furthermore, the hydration structure of the inhibitor molecule also influences its transport properties. The inhibitor functionalized by the carboxyl group, associating with the neighboring water molecules, forms ion-water clusters, and the inhibitor molecule and its hydration shell with a long resident time retard the migration rate. Hopefully, this study is able to provide molecules for the development of a migration-type corrosion inhibitor to elongate the service life of cement-based materials.