Four-step Strategy Research Articles

Leveraging machine learning to expedite screening of single-atom catalysts in electrochemical nitrate reduction to ammonia

The electrochemical reduction of nitrate to ammonia, which is a potentially valuable process for pollution mitigation and NH3 production, faces challenges in developing high-performance catalysts. By integrating machine learning (ML) and density functional theory (DFT), we successfully established ML models using thousands of calculated properties (formation energy, NO3– adsorption, and Gibbs free energy of the critical step) from the literature and predicted the catalytic performance of 1891 previously unknown single-atom catalysts (SACs) for the nitrate reduction reaction (NO3RR), employing a four-step screening strategy (stability, NO3– adsorption, activity, and selectivity) and identifying 10 promising materials. We then verified the properties of these SACs, which exceeded the benchmark materials, thereby validating the ML model, and elucidated the origin of their high NO3RR activity based on their inner electronic structures. This study not only presents prominent candidates and novel descriptors for NO3RR but also establishes an efficient, rapid, and cost-effective methodology for the discovery and design of more valuable SACs.

Flexible design of renewable hydrogen production systems through identifying bottlenecks under uncertainty

Renewable hydrogen production technology within the energy sector stands as a vital avenue towards decarbonization in process industries. However, for systems characterized by high penetration of renewable energy, the challenges posed by uncertain parameters impacting stable production present significant obstacles to the large-scale application of hydrogen production from renewable energy. To address the issues, this work proposed a comprehensive four-step strategy for the bottleneck identification and optimization of the renewable hydrogen production systems (RHPS), which encompasses four models including system configuration optimization, flexibility analysis, bottleneck identification, and debottlenecking models. The effectiveness of the proposed strategy is substantiated through a case study. The results indicate that positive fluctuations on supply side and negative fluctuations on demand side contribute to bolstering the flexibility of RHPS. When the RHPS possesses sufficient flexibility, the critical fluctuation amplitude for photovoltaic power is −36 %, whereas for wind turbine power, it stands at −32 %. It highlights that when the photovoltaic power fluctuates, the ability of RHPS to maintain its own stability is stronger than when the wind turbine power fluctuates. Furthermore, when the fluctuations of supply side are positive, the rate of change in critical fluctuation amplitudes on the supply side is 4.63 times than that of the demand side. This underscores that the power decline in the supply side has a more pronounced detrimental effect on the stability of RHPS than an increase in the demand side. The proposed strategy for optimizing RHPS offers valuable theoretical insights for the system design and retrofitting under uncertainty.

Ti3C2Tx/Ni0.2Mn0.4Zn0.4Fe2O4 ferrite nanocomposites: Dual-loss mechanism with engineered composition for microwave absorption

Ni0.2Mn0.4Zn0.4Fe2O4 (NMZF) nanoparticles were anchored on the surface of MXene(Ti3C2Tx) to form Ti3C2Tx/NMZF nanocomposites for optimization of microwave absorption performance. The Ti3C2Tx/NMZF nanocomposites were synthesized by using a four-step strategy, including sonication, stirring, hydrothermal reduction and vacuum drying. More than 40 percent of the NMZF nanoparticles in this nanocomposite were assembled to form a conductive network. Meanwhile, the multilayer MXene acted as a framework to host the NMZF nanoparticles, providing dipolar polarization, interfacial polarization and eddy current loss. Benefiting from the structure design of MXene, combined with magnetic materials and optimized impedance matching, the Ti3C2Tx/NMZF exhibited a minimum reflection loss (RLmin) of −57.39 dB, with a thickness of 2.97 mm and an effective absorption bandwidth (EAB) of 3.2 GHz. Therefore, such a facile method could be used to construct nanocomposites with microwave absorption performance (-57.39 dB, 3.2 GHz), so as to address microwave pollution issues.

High-Throughput screening of TM1TM2/N6–1 (TM = Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Mo) as effective electrocatalysts for nitrogen fixation

The electrochemical nitrogen reduction reaction (NRR) is an emerging nitrogen fixation method in recent years. Double-atom catalysts compensate for the disadvantage of single-atom catalysts having only one active site, improving catalytic reaction activity. Herein, using a four-step high-throughput screening strategy with density functional theory (DFT) calculations, 45 homonuclear and heteronuclear catalysts, namely, transition metal dimers anchored on nitrogen-doped graphene (TM1TM2/N6–1, TM = Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Mo), were systematically studied to evaluate their catalytic performance for NRR. Our results showed that 16 catalysts stand out, among them, ScMo/N6–1 has an ultralow limiting potential of -0.09 V and a Faradaic efficiency of 100 %. This work provides a group of promising candidates and a reasonable high-throughput design strategy for NRR catalysts.

Patient-perceived progression in multiple system atrophy: natural history of quality of life

BackgroundHealth-related quality of life (Hr-QoL) scales provide crucial information on neurodegenerative disease progression, help improve patient care and constitute a meaningful endpoint for therapeutic research. However, Hr-QoL progression is usually...

A strategy integrating improved mass defect filtering, diagnostic product ions, and molecular network for rapid screening and systematic characterization of steroidal alkaloids in Fritillaria ussuriensis

An ultra-performance liquid chromatography-high-resolution mass spectrometry (UPLC-HRMS) method was employed to efficiently and rapidly analyze the chemical composition of steroidal alkaloids in Fritillaria ussuriensis Maxim (FM). The integration of nitrogen rule and improved mass defect filtering eliminated 84.61% of interfering MS1 peaks and facilitated subtype classification. Subsequently, six diagnostic product ions (DPIs) for Fritillaria alkaloids were summarized, guiding structural identification. Additionally, the adoption of molecular networks to infer potential compounds forms a new four-step comprehensive strategy for systematic screening and identification of Fritillaria alkaloids. By screening with the MDF window constructed from the Fritillaria alkaloids MS database combined with the nitrogen rule, a significant number of interfering MS1 peaks were eliminated, and different subtypes were distinguished. In FM, the number of positive-mode MS1 peaks was reduced by 84.61% (from 8,728 to 1,343). By summarizing the fragmentation behaviors of 22 reference standards, the fragmentation pathways and DPIs of five types of steroidal alkaloids were confirmed, providing the first evidence for DPIs of cevanine-seven-membered type Fritillaria alkaloids. Structural confirmation of MS1 peaks was carried out using an in-house database and DPIs. Furthermore, a feature-based molecular network (FBMN) was employed to cluster similar compounds into network clusters for rapid classification and to infer potential steroidal alkaloids using known compounds. A total of 103 Fritillaria alkaloids (65 cevanine type, 7 cevanine-seven-membered type, 18 jervine type, 5 veratramine type, 5 secosolanidine type, and 3 solanidine type) were identified, including 4 potential new compounds and 20 compounds that have been identified for the first time. This innovative comprehensive strategy, which includes NRF, improved MDF, DPIs, and FBMN, can be applied to rapidly screen, classify components, and conduct comprehensive characterization of complex samples such as herbal medicines.

Reducing Overpotential of Lithium-Oxygen Batteries by Diatomic Metal Catalyst Orbital Matching Strategy.

Aprotic Li-O2 batteries have sparked attention in recent years due to their ultrahigh theoretical energy density. Nevertheless, their practical implementation is impeded by the sluggish reaction kinetics at the cathode. Comprehending the catalytic mechanisms is pivotal to developing efficient cathode catalysts for high-performance Li-O2 batteries. Herein, the intrinsic activity map of Li-O2 batteries is established based on the specific adsorption mode of O2 induced by diatomic catalyst orbital matching and the transfer-acceptance-backdonation mechanism, and the four-step screening strategy based on the intrinsic activity map is proposed. Guided by the strategy, FeNi@NC and FeCu@NC promising durable stability with a low overpotential are screened out from 27 Fe-Metal diatomic catalysts. Our research not only provides insights into the fundamental understanding of the reaction mechanism of Li-O2 batteries but also accelerates the rational design of efficient Li-O2 batteries based on the structure-activity relationship.

Nyaa, ‘motlhanka wa Jehofa’! (Stop it, ‘man of God’!): An Ubuntu Pentecostal response to gender-based violence within the Neo-prophetic Movement in South Africa

Background: Statistics from the Pew Research Centre indicate that in sub-Saharan Africa, 796 million out of 822 m people claim the same Christian religious affiliation. Pentecostal Christians total 107 m. These figures suggest that religion shapes the worldview of many sub-Saharan inhabitants. Many are adherents of Ubuntu, which does not dichotomise lived experiences from the influence of the spiritual (the Supreme Being, spirits, and the ancestors). On the one hand, the World Health Organization has labelled South Africa as the rape capital of the world because it accounts for the highest figure of gender-based violence (GBV) globally. Intimate partner violence (IPV) and non-partner violence, characterised by rape and attempted rape, constitute a significant portion of sexual violence, which is the primary and highest category of GBV in South Africa. The second, third, and fourth categories are physical violence, socio-economic and financial violence, and psychological/emotional violence. Various South African courts have sentenced several pastors from the Neo-prophetic Movement (NPM) for non-partner violence.Objectives: The aim of this study is to reflect on non-partner violence within the NPM in South Africa and to respond to this scourge by applying Ubuntu Pentecostalism as a framework.Method: This article thus poses the question: How might South African Pentecostals address the scourge of non-partner violence within the NPM? It, thus, uses Ubuntu Pentecostalism.Results: The article shows that is that is possible to mobilise members of NPM and the surrounding community to counteract the scourge of non-partner violence among NPM in South Africa.Conclusion: The article concludes by providing a four-step strategy to curb th scourge of non-partner violence in the NPM in South Africa.Contribution: This strategy contributes to curbing the scourge of non-partner violence within the NPM in South Africa.

Improving outcomes for patients with hard-to-heal wounds following adoption of the Wound Hygiene Protocol: real-world evidence.

To evaluate the impact of a four-step biofilm-based wound care strategy, Wound Hygiene Protocol (WHP: cleanse, debride, refashion, and dress), on hard-to-heal wounds. This was a prospective, real-world analysis of hard-to-heal wounds managed with the WHP that incorporated Aquacel Ag+ (Convatec Ltd., UK) dressings. Data were captured electronically between April 2021 and December 2022. The primary endpoint was change in wound volume from baseline to final assessment. A total of 693 wounds in 669 patients (median patient age: 74 years) were included in the analysis with a median treatment time of 31 days. Most health professionals were general nurses (50%) or nurse practitioners (38%). Patient homes (27%) and community clinics (27%) were the most common clinical settings. Venous leg ulcers (26%) and pressure ulcers/injuries (17%) were the most common wound type. Duration was >12 months in 21% of wounds. At baseline, the mean wound volume was 57.8cm3. At the final assessment, mean wound volume was 17.2cm3, corresponding to an 80% reduction from baseline; p<0.001). At baseline, 66% of wounds were static or deteriorating. At final assessment, this had decreased to 5%, and 94% had improved or healed. Exudate levels were moderate or high in 69% of wounds at baseline which decreased to 25% at final assessment (p<0.001). Suspected biofilm and local wound infection decreased from 79% and 43%, respectively, at baseline, to 18% and 3%, respectively, at final assessment (p<0.001 for both). The WHP is a new proposed standard of care that successfully treated hard-to-heal wounds by addressing the key local barriers to wound healing.

Designing asymmetrical TMN4 sites via phosphorus or sulfur dual coordination as high-performance electrocatalysts for oxygen evolution reaction

The development ofhighly efficient oxygen evolution reaction (OER) catalysts based on more cost-effective and earth-abundant elements is of great significance and still faces a huge challenge. In this work, a series of transition metal (TM)embedding a newly-defined monolayer carbon nitride phase is theoretically profiled and constructed as a catalytic platform for OER studies. Typically, a four-step screening strategy was proposed to rapidly identified high performance candidates and the coordination structure and catalytic performance relationship was thoroughly analyzed. Moreover, the eliminating criterion was established to condenses valid range based on the Gibbs free energy of OH*. Our results reveal that the as-constructed 2FeCN/P exhibits superior activity toward OER with an ultralow overpotential of 0.25 V, at the same time, the established 3FeCN/S configuration performed well as abifunctional OER/ORR electrocatalysis with extremely low overpotential ηOER/ηORR of 0.26/0.48 V. Overall, this work provides an effective framework for screening advanced OER catalysts, which can also be extended to other complex multistep catalytic reactions.

Hybrid-order topological superconductivity in a topological metal 1T’-MoTe2

One key challenge in the field of topological superconductivity (Tsc) has been the rareness of material realization. This is true not only for the first-order Tsc featuring Majorana surface modes, but also for the higher-order Tsc, which host Majorana hinge and corner modes. Here, we propose a four-step strategy that mathematically derives comprehensive guiding principles for the search and design for materials of general higher-order Tsc phases. Specifically, such recipes consist of conditions on the normal state and pairing symmetry that can lead to a given higher-order Tsc state. We demonstrate this strategy by obtaining recipes for achieving three-dimensional higher-order Tsc phases protected by the inversion symmetry. Following our recipe, we predict that the observed superconductivity in centrosymmetric MoTe2 is a hyrbid-order Tsc candidate, which features both surface and corner modes. Our proposed strategy enables systematic materials search and design for higher-order Tsc, which can mobilize the experimental efforts and accelerate the material discovery for higher-order Tsc phases.

Mie Aceh “M”: a Smes Halal Culinary Strategy in Jakarta

Mie Aceh “M” is a halal SMEs business, which possible to continue to be sustainable, at any situation and condition, by incorporating all advancements in the digital realm into their operations, businesses can evolve and thrive. This research employs a mixed-method approach, featuring descriptive analysis, to identify the most efficient and effective strategy required. Utilizing a SWOT analysis (Strengths, Weaknesses, Opportunities, Threats) as the evaluation tool, with an "Internal-External" weighting step, coupled with a "Four-Step Strategy," the study aims to determine the appropriate business strategies for halal culinary SMEs, specifically "Mie Aceh “M." The objective is to assess the existing strengths of the SMEs, achieve sustainable business management goals, address identified weaknesses, capitalize on opportunities, and mitigate threats. It underscores the importance of digital marketing and product innovation to adapt to changing market dynamics. Furthermore, it suggests maintaining and expanding the "cost leadership strategy" previously implemented.

Rational design of single-atom catalysts for efficient H2O2 production via a four-step strategy

Electrocatalysis presents an efficient and eco-friendly approach for the two-electron oxygen reduction reaction (2e− ORR) to produce hydrogen peroxide (H2O2).

Supervised machine learning improves general applicability of eDNA metabarcoding for reservoir health monitoring

Effective and standardized monitoring methodologies are vital for successful reservoir restoration and management. Environmental DNA (eDNA) metabarcoding sequencing offers a promising alternative for biomonitoring and can overcome many limitations of traditional morphological bioassessment. Recent attempts have even shown that supervised machine learning (SML) can directly infer biotic indices (BI) from eDNA metabarcoding data, bypassing the cumbersome calculation process of BI regardless of the taxonomic assignment of eDNA sequences. However, questions surrounding the general applicability of this taxonomy-free approach to monitoring reservoir health remain unclear, including model stability, feature selection, algorithm choice, and multi-season biomonitoring. Here, we firstly developed a novel biological integrity index (Me-IBI) that integrates multitrophic interactions and environmental information, based on taxonomy-assigned eDNA metabarcoding data. The Me-IBI can better distinguish the actual health status of the Three Gorges Reservoir (TGR) than physicochemical assessments and have a clear response to human activity. Then, taking this reliable Me-IBI as a supervised label, we compared the impact of selecting different numbers of features and SML algorithms on the stability and predictive performance of the model for predicting ecological conditions in multiple seasons using taxonomy-free eDNA metabarcoding data. We discovered that even with a small number of features, different SML algorithms can establish a stable model and obtain excellent predictive performance. Finally, we proposed a four-step strategy for standardized routine biomonitoring using SML tools. Our study firstly explores the general applicability problem of the taxonomy-free eDNA-SML approach and establishes a solid foundation for the large-scale and standardized biomonitoring application.

High-throughput mechanistic study of highly selective hydrogen-bonded organic frameworks for electrochemical nitrate reduction to ammonia

Hydrogen-bonded organic frameworks (HOFs), an emerging porous macrocyclic materials linked by hydrogen-bond, hold potential for gas separation and storage, sensors, optical, and electrocatalysts. Here, HOF-based electrocatalysts are rationally developed for nitrates reduction to ammonia, allowing not only to regulate wastewater pollution but also to accomplish carbon-neutral ammonia (NH3) synthesis. We preform high-throughput computational screening of thirty-six HOFs with various metals as active sites, denoted as HOF-M1, for nitrate reduction reaction (NO3RR) toward NH3. We have implemented a hierarchical four-step screening strategy, and ultimately, HOF-Ti1 was selected based on its exceptional catalytic activity and selectivity in the NO3RR process. Through additional analysis, we discovered that the d band center of the active metal sites serves as an effective parameter for designing and predicting the performance of HOFs in NO3RR. This research not only showcases the immense potential of electrocatalysis in transforming NO3RR into NH3 but also provides researchers with a compelling incentive to undertake further experimental investigations.

The metabolic pathways and products of ten Aconitum alkaloids in Sanwujiao Pills from eight organs of mice by UHPLC-Q-TOF-MS/MS.

Sanwujiao pill (SWJP) is a Chinese herbal preparation widely used in China. It is an essential medicine for treating rheumatism and blood stasis. However, its safety in clinical use has always been the focus of patients because it contains toxic herbs of Aconitum carmichaelii Debx. and A. vilmorinianum Kom. To further reveal the pharmaceutical and toxic effect substances and the action mechanism of SWJPs, the metabolites and their pathways of ten Aconitum alkaloids (AAs) in the preparation at different time points after oral administration in eight organs of mice were investigated. The biosamples were investigated by a four-step strategy of UPLC-Q-TOF-MS /MS technology. Aconitine (AC), mesaconitine (MA), and hypaconitine (HA) were not detected in any organs. The highest concentrations of the other seven AAs occurred at 0.5 h. Yunaconitine (YAC) was not detected in the brain; all seven AAs had the lowest concentration in the brain, and the metabolism was slow in the stomach. Twelve predicted metabolites were identified, the kidney and stomach were their primary distribution locations, and the most metabolites were found at 0.5h. The main metabolic pathways of the ten AAs were demethylation, deethylation, deoxygenation, hydroxylation, and deacetylation. This is the first report about the metabolism of ten AAs in SWJPs in mice. Significantly, the metabolic pathways and products of four hidden toxic AAs were analyzed in vivo for the first time. The results were of great significance for the safety and effectiveness of SWJPs in clinical application.

A Small-Scale Farming Intervention Plan for Inclusive Economic Development in Rural South Africa

Small-scale commercial farming firms play a critical role in achieving the objectives of the African Union’s Agenda 2063, and the United Nations Sustainable Development Goals (SDGs) in the rural economies of Sub-Saharan Africa. South Africa has a sizeable number of households engaged in small-scale agriculture to supply rural market demand. Small scale commercial agriculture has become a key source of revenue, employment, and food security for communities in rural areas. As such, the South African government has been assisting small-scale farmers financially via the Micro-Agriculture Finance Institutions of South Africa and the Department of Agriculture, Forestry, and Fisheries. This support aims to alleviate poverty, create jobs, and improve food security by promoting small-scale commercial farming, primarily in rural areas. Despite this assistance, there is no clear strategy for achieving significant and evidence-based development. This study outlines a four-step intervention strategy for promoting small-scale commercial farming as a strategy for rural economic development in South Africa. These steps include defining a small-scale farming development strategy, and delineating production, performance, policy, and control measures.

Patients’ experiences of living with patellar instability before and after surgery: a qualitative interview study

ObjectivesTo explore the experience of living with patellar instability before and after surgery.DesignQualitative individual semistructured interviews of patients with patellar instability using a four-step thematic cross-case analysis strategy (systematic text...

Synthesis and antibacterial analysis of C-6 amino-functionalised chitosan derivatives

Synthesis of 6-O-(3-alkylamino-2-hydroxypropyl) derivatives of chitosan was achieved using a four-step strategy of N-protection, O-epoxide addition, epoxide ring opening using an amine and N-deprotection. Benzaldehyde and phthalic anhydride were used for the N-protection step, producing N-benzylidene and N-phthaloyl protected derivatives, respectively, resulting in two corresponding final 6-O-(3-alkylamino-2-hydroxypropyl) derivative series, BD1-BD6 and PD1-PD14. All the compounds were characterized using FTIR, XPS and PXRD studies and tested for antibacterial efficacy. The phthalimide protection strategy was found to be easier to apply and effective in terms of the synthetic process and improvement in antibacterial activity. Amongst the newly synthesized compounds, PD13 (6-O-(3-(2-(N,N-dimethylamino)ethylamino)-2-hydroxypropyl)chitosan) was the most active with eight times greater activity compared to the unmodified chitosan and, PD7 6-O-(3-(3-(N-(3-aminopropyl)propane-1,3-diamino)propylamino)-2-hydroxypropyl)chitosan) having a four-fold activity than chitosan, was found to be the second most potent derivative. This work has produced new chitosan derivatives those are more potent than chitosan itself and show promise in antimicrobial applications.

Two-dimensional conjugated metal–organic frameworks TM3(HAT)2: a new family of promising single-atom electrocatalysts for efficient nitrogen fixation

Achieving efficient nitrogen reduction reaction (NRR) under mild conditions is desirable but still challenging due to the lack of high-performance catalysts. Herein, we report the feasibility of a new type of two-dimensional conjugated metal–organic frameworks (cMOFs) featuring dense single-metal-atom sites, namely TM3(HAT)2 monolayers (TM = transition metal from groups 4 to 10, HAT = 1,4,5,8,9,12-hexaazatriphenylene), as NRR catalysts. We construct an efficient four-step screening strategy and identify the W3(HAT)2 monolayer as a candidate with considerable stability, activity, and selectivity based on density functional theory (DFT) computations. The analysis of bonding, integrated-crystal orbital Hamilton population, and Bader charge uncovers the NRR activity origin of the TM3(HAT)2 monolayers and elucidates the structure–performance correlations. Meanwhile, our results show that a simple descriptor ϕ based on the inherent nature of the TM atoms can be applied to accelerate the screening of candidates without explicit DFT calculations. This work highlights a feasible strategy to prescreen and design high-performance cMOF-based electrocatalysts.