Synthesis of Asymmetric Diaryl Sulfides via HI-Mediated C(sp2)-H Sulfenylation of Arenes with Sodium Sulfinates.

A novel hydroiodic acid-promoted metal-free C(sp2)-H sulfenylation of electron-rich arenes was developed using stable and easy-to-handle sodium sulfinates as sulfur sources. Diverse kinds of asymmetric aryl sulfides were afforded in good yields from various commercially available aromatic substrates under mild conditions. Comprehensive mechanistic experiments demonstrate that RSO2SR and RSSR are the key intermediates responsible for the redox process.

Double strengthening induced by grain boundary segregation of solute elements in gradient nano Ni-Co alloys.

Gradient induced unusual strain hardening achieves the equilibrium of the strength and plasticity of alloys, and is an important strategy for the optimization of the mechanical properties of metals and alloys. The segregation of solute elements can greatly improve the grain boundary stability, inhibit grain coarsening and promote the mechanical strength of the alloy. In our efforts, the segregation structure of the solute element Co was designed and added to the gradient nano Ni-Co alloy, and the two strengthening strategies were applied simultaneously in one structure. The mechanical strength of the alloy achieved a second increase based on the unique combination of gradient induced strain hardening and high plasticity, especially the yield strength of alloy increase amplitude reach to 42%. This provides a positive direction for the alloy strengthening strategy. In the process of secondary strengthening, the micro-mechanism is divided into two stages: in the first stage, the gradient strain provides the alloy with geometrically necessary dislocations and a multi-axial stress state, and the existence of large numbers of geometrically necessary dislocations creates good conditions for the second stage strengthening. In the second stage, the solute segregation induced stable grain boundaries produce a strong pinning effect on the geometrically necessary dislocation, which realizes the coupling of grain boundary strengthening and dislocation strengthening. This provides a new strengthening strategy and positive theoretical guidance for the experimental preparation of advanced alloys with excellent properties.

Innate Immune Responses to Sporothrix schenckii: Recognition and Elimination.

Sporothrix schenckii (S. schenckii), a ubiquitous thermally dimorphic fungus, is the etiological agent of sporotrichosis, affecting immunocompromised and immunocompetent individuals. Despite current antifungal regimens, sporotrichosis results in prolonged treatment and significant mortality rates in the immunosuppressed population. The innate immune system forms the host's first and primary line of defense against S. schenckii, which has a bi-layered cell wall structure. Many components act as pathogen-associated molecular patterns (PAMPs) in pathogen-host interactions. PAMPs are recognized by pattern recognition receptors (PRRs) such as toll-like receptors, C-type lectin receptors, and complement receptors, triggering innate immune cells such as neutrophils, macrophages, and dendritic cells to phagocytize or produce mediators, contributing to S. schenckii elimination. The ultrastructure of S. schenckii and pathogen-host interactions, including PRRs and innate immune cells, are summarized in this review, promoting a better understanding of the innate immune response to S. schenckii and aiding in the development of protective and therapeutic strategies to combat sporotrichosis.

Copper-Catalyzed Azide-Alkyne Cycloaddition-Oriented Multifunctional Bio-Orthogonal Linker BPPA: Design, Synthesis and Evaluation.

The multifunctional linker molecules are crucial for the bio-orthogonal reaction for proteomic target profiling. Herein, we wish to present a novel type of biotin-based tetra-functional bio-orthogonal linkers 3a-3h named BPPA which, possessing a unique photolabile phenacyl ester motif, were readily prepared in 85-90% yields by a simple and green one-step protocol from commercially available and inexpensive reagents of biotin acids and 4'-ethynyl/azido 2-bromoacetophenones. The typical click reaction of BPPA linkers 3a and 3e via copper-catalyzed azide-alkyne cycloaddition (CuAAC) took place easily, resulting in the corresponding BPPA-triazole adducts 4a and 4b in nearly quantitative yields. A further cleavability evaluation of 4a and 4b demonstrated that the expected C-O bond detachment could be accomplished efficiently and rapidly by UV irradiation or by ammonia hydrolysis, respectively, resulting in the residual (hydroxyl)acetylphenyl triazole fragment supposed to be attached to proteins during biological manipulations. The BPPA linkers, with dual clickable options of either the terminal azide or alkyne clickable group, exhibit high potentials for various CuAAC-oriented bio-orthogonal reactions.

Controllable synthesis of disulfides and thiosulfonates from sodium sulfinates mediated by hydroiodic acid using ethanol and H2O as solvents.

A controllable and rapid synthesis of disulfides and thiosulfonates from sodium sulfinates mediated by hydroiodic acid is presented for the first time. In these reactions, ethanol and H2O are employed as solvents to generate different products, thiosulfonates can be further transformed to corresponding disulfides in an ethanol reaction system. Moreover, these simple methods are environmentally benign and can be performed under mild conditions with a short reaction time, showing good functional group tolerance.

Efficacy of laser therapy combined with topical antifungal agents for onychomycosis: a systematic review and meta-analysis of randomised controlled trials.

INTRODUCTION: Onychomycosis is a common fungal infection of the nail. Laser and topical antifungal agent combination therapy is an emerging treatment for onychomycosis. The objective of this study was to systematically evaluate the efficacy and safety of laser and topical antifungal agent combination therapy for onychomycosis. METHODS: The PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure, Wanfang and VIP databases were searched from inception to November 2021. Randomised controlled trials (RCTs) on laser therapy combined with topical antifungal agents for onychomycosis were included. The Cochrane Collaboration tool was used to assess the risk of bias, and Revman 5.3 software was used in the meta-analysis. RESULTS: Twelve studies involving 869 patients were included in this meta-analysis. The results showed that compared with topical antifungal agents alone, laser and topical antifungal agent combination therapy was superior in terms of the complete cure rate (RR 6.04,95% CI (2.17, 16.85), P = 0.0006), mycological cure rate (RR 1.27, 95% CI (1.10, 1.48), P = 0.001), clinical effective rate (RR 1.38, 95% CI (1.20, 1.57), P < 0.00001) and patient satisfaction rate (RR 1.47,95% CI (1.17, 1.84), P = 0.0009).The subgroup analysis of outcome indicators, including mycological cure rate and clinical effective rate, demonstrated that both carbon dioxide (CO2) laser therapy combined with topical antifungal therapy and 1064-nm neodymium-doped:yttrium aluminium garnet (Nd:YAG) laser therapy combined with topical antifungal therapy showed better results than topical antifungal therapy alone. No adverse events were identified except for three studies reporting transient burning sensation without treatment and mild to moderate pain, both of which were well tolerated. CONCLUSION: The present study indicated that laser and topical antifungal agent combination therapy is effective for onychomycosis. However, more large-scale and well-designed RCTs are warranted.

An Improved Frequency Domain Guided Thermal Imager Strips Removal Algorithm Based on LRSID.

The thermal imaging image of the Sustainable Development Science Satellite (SDGSAT-1) is mainly used for high-resolution observations of the ground width, due to the influence of blind elements and non-uniformity of the detector, and the system is a pendulum sweep imaging mode, resulting in fringed noise in the image. In this paper, a Fringing algorithm based on LRSID (low-rank-based single-image decomposition) algorithm is proposed, which can effectively remove the lateral and vertical fringe noise of the thermal imager and maintain the detail and clarity of the image. First, pretreatment of the obvious light and dark stripes then, based on LLSID algorithm, the vertical direction pinstripes and horizontal stripes are processed; finally, the fringed frequency band of the original image is replaced in the frequency domain with the image frequency domain processed by the LRSID algorithm, and then the Fourier inverse transformation is performed to obtain the final image. Using the method proposed in this paper, the simulated and actual SDGSAT-1 thermal imaging camera remote sensing stripes images are removed, and the visual and quantitative indicators are compared with the processing results of other algorithms, and the results show that the proposed algorithm has the best performance to remove the stripes, which can effectively remove horizontal and vertical fringes at the same time, and retain the detail and clarity of the image.

Practical catalytic enantioselective synthesis of 2,3-dihydroquin-azolinones by chiral brønsted acid catalysis.

Herein, we report on the highly efficient and practical synthesis of 2,3-dihydroquinazolinones directly from diverse aldehydes with excellent yields and enantioselectivity. Particularly, this protocol affords better enantiocontrol for aliphatic aldehydes (up to 99% yield, 97% ee), which always gave unsatisfactory results in the previous studies. Moreover, this catalytic system shows wide tolerance to different functional groups such as alkenyl, nitro and halogens. Most importantly, its practicability is well elucidated via the gram-scale synthesis of different types of products at 0.1 mol% catalyst loading and the simplified work-up procedure. To better understand the reaction pathway and origin of the enantioselectivity, DFT calculations were also performed.

Optimizing neuromelanin contrast in the substantia nigra and locus coeruleus using a magnetization transfer contrast prepared 3D gradient recalled echo sequence.

Neuromelanin (NM) loss in the substantia nigra (SN) and locus coeruleus (LC) is being investigated as an imaging biomarker for Parkinson's disease (PD) using magnetization transfer contrast (MTC) magnetic resonance imaging. The MTC pulse operates in a way to suppress tissue with high macromolecular content thereby highlighting the presence of NM in the LC and the SN. The MTC pulse also leads to a reduction in the effective T1 of the tissue. In the past, a 3D gradient echo (GRE) sequence has usually been run with a single flip angle (FA) generally to highlight the T1 shortening effect when trying to visualize NM. We contend that the NM will be best seen with a low FA (relative to the Ernst angle) because the NM has high water content relative to the surrounding tissues. Therefore, the goal of this paper was to optimize the NM contrast in the SN and LC as a function of flip angle using a 3D GRE MTC strategically acquired gradient echo (STAGE) imaging approach. In order to accomplish this, short repeat time (62 â€‹ms), 3D GRE imaging data were collected for 7 different flip angles ranging from 5° to 40° for 14 healthy volunteers (age range 24-43 years, mean â€‹± â€‹SD â€‹= â€‹34.8 â€‹± â€‹6.0 years, 6 males). By measuring the contrast-to-noise ratio between these structures and the surrounding tissues, we found that the FA showing the best NM contrast was 15° - 20° for the SN and 20° - 25° for the LC. Using STAGE imaging with just two flip angles (15° and 30°) made it possible to quantify not only tissue properties such as T1 and proton density but also to generate synthetic MTC images at an arbitrary FA. These synthetic images make it possible to optimize the contrast for any changes in tissue property that might occur in the LC or SN as a function of age or disease. In conclusion, practically, two scans could be collected in roughly 7 â€‹min each for both FAs in a standard clinical imaging setting to evaluate the signal intensity and volume of the NM in the LC and SN.

Role of TSP-1 as prognostic marker in various cancers: a systematic review and meta-analysis.

BACKGROUND: Published studies present conflicting data regarding the impact of Thrombospondin-1 (TSP-1) expression on prognosis of various cancers. We performed this meta-analysis to illustrate the preliminary predictive value of TSP-1. METHODS: Twenty-four studies with a total of 2379 patients were included. A comprehensive literature search was performed by using PubMed, Cochrane Library, Web of Science, Embase, and hand searches were also conducted of relevant bibliographies. Pooled hazard ratios (HRs) with 95% confidence intervals (CIs) for patient survival and disease recurrence were initially identified to explore relationships between TSP-1 expression and patient prognosis. RESULTS: A total of 24 eligible studies were included in this meta-analysis. Our results showed that high level of TSP-1 was correlated significantly with poor overall survival (OS) (HR = 1.40, 95% CI: 1.17 ~ 1.68; P<0.001). However, high TSP-1 expression predicted no significant impact on progression-free survival (PFS)/ metastasis-free survival (MFS) (HR = 1.35, 95%CI: 0.87-2.10; P = 0.176) and disease-free survival (DFS)/ recurrence-free survival (RFS) (HR = 1.40, 95%CI: 0.77-2.53; P = 0.271). In addition, we performed subgroup analyses which showed that high TSP-1 expression predicted poor prognosis in breast cancer and gynecological cancer. Additionally, the relatively small number of studies on PFS/MFS and DFS/RFS is a limitation. The data extracted through Kaplan-Meier curves may not be accurate. Moreover, only English articles were included in this article, which may lead to deviations in the results. CONCLUSIONS: Our findings indicated high TSP-1 expression may act as a promising biomarker of poor prognosis in cancers, especially in breast cancer and gynecological cancer.

The effects of a hirudin/liposome complex on a diabetic nephropathy rat model.

BACKGROUND: Hirudin, an extract from Hirudo spp., is an anticoagulant used to treat a variety of renal diseases, including diabetic nephropathy (DN). Currently, hirudin has to be used at high dosages to treat DN because it poorly targets the kidneys, although at high dosages it can have severe side effects. Developing a targeted drug delivery system for hirudin, then, could boost its positive therapeutic effects while lowering the risk of side effects. Liposomes have been demonstrated to have significant renal targeting potential, but here we show that a hirudin-loaded liposome is an effective delivery method for patients with DN. METHOD: In this study, we prepared a hirudin/liposome complex and tested its efficacy by injecting it into a rat model. We then compared the renal accumulation of hirudin between complex-injected rat models and rat models that received injections of hirudin alone. We also investigated the mechanisms behind the complex's effects. RESULT: The hirudin/liposome complex increased the accumulation of hirudin in kidney tissues and relieved the renal injury in DN rat models. Moreover, the hirudin/liposome complex down-regulated the expression of TGF-ß1 and VEGF in the kidneys. CONCLUSION: We demonstrated that a hirudin/liposome complex can have a significant positive effect on DN. The mechanism may be that the complex inhibits the expression of VEGF and TGF-ß1.

Diffusion tensor imaging parameters for the early diagnosis of radiation-induced brain injury in patients with nasopharyngeal carcinoma: a meta-analysis.

PURPOSE: To estimate diffusion tensor imaging (DTI) parameters for early diagnosis during the stage of radiation-induced brain injury (RBI) in nasopharyngeal carcinoma (NPC) patients.PubMed, Embase, Web of Science and Cochrane Library were searched up to March 2019. Eligible studies comparing early brain injuries with controls of temporal lobe in NPC patients before and after radiotherapy which collected the DTI parameters such as apparent diffusion coefficient (ADC), fractional anisotropy (FA), axial diffusibility (λa), radial diffusibility (λr), mean diffusion (MD) were included. CONCLUSION: Seven studies (N = 21) were selected from the studies in the databases. Overall, FA, λa, λr values were significant difference between early RBI and healthy control (HC) in NPC patients after radiotherapy (MD= -0.03, 95% CI= -0.05∼-0.01; p = .008 in FA, MD= -0.07, 95% CI= -0.11∼-0.02; p = .002 in λa and MD = 0.02, 95% CI = 0.00 ∼ 0.04; p = .04 in λr). The meta regression analysis about dose dependence with FA value was: -0.057 ∼ 0.0003 in 95% CI, I2=74.70%, P = 0.052 (adjust p = .029). The overall heterogeneity is p < .001, I2=91% in FA, P = 0.08, I2=61% in λa and p = .04, I2=69% in λr. DTI parameters such as the reduced FA value, the decreased λa value, and the increased λr value were significant in the early period of RBI in NPC patients after radiotherapy, which becoming a more sensitive method in diagnosing the early stage of RBI.

How lignocellulose degradation can promote the quality and function of dietary fiber from bamboo shoot residue by Inonotus obliquus fermentation.

Lignocellulose constitutes the primary component of dietary fiber. We assessed how fermenting bamboo shoot residue with the medicinal white-rot fungus Inonotus obliquus affected the yield, composition, and functional attributes of dietary fiber by altering bamboo shoot residue lignocellulose's spatial structure and composition. I. obliquus secretes lignocellulolytic enzymes, which effectively enhance the degradation of holocellulose and lignin by 87.8% and 25.5%, respectively. Fermentation led to a more porous structure and reduced crystallinity. The yield of soluble dietary fiber increased from 5.1 g/100 g raw BSR to 7.1 g/100 g 9-day-fermented bamboo shoot residue. The total soluble sugar content of dietary fiber significantly increased from 9.2% to 13.8%, which improved the hydration, oil holding capacity, in vitro cholesterol, sodium cholate, and nitrite adsorption properties of dietary fiber from bamboo shoot residue. These findings confirm that I. obliquus biotransformation is promising for enhancing dietary fiber yield and quality.

Causality of unsaturated fatty acids and psoriasis a Mendelian randomization study.

Background: Many observational studies have identified a link between unsaturated fatty acids and psoriasis. However, they contain reverse causality and confounding factors, and there is no definite causal study between unsaturated fatty acids and psoriasis. Objectives: Analysis of causality between unsaturated fatty acids and psoriasis by Mendelian randomization. Methods: We used IEU Open GWAS Project, omega-3 PUFA and omega-6 PUFA data from 114,999 subjects, MUFA data from 13,535 subjects, and psoriasis data from 4,510 cases and 212,242 controls were included. We employed the inverse-variance weighted (IVW) method as the primary analytical approach and four additional MR methods. Moreover, we performed heterogeneity and horizontal pleiotropy assessments using Cochrane's Q and MR-Egger intercept tests, respectively. Finally, we performed sensitivity analyses to enhance our findings' precision and veracity. Results: IVW results showed no causal effect of omega-3 PUFA on psoriasis (p = 0.334; OR, 0.909; 95% CI, 0.748-1.104), omega-6 PUFA cause psoriasis (p = 0.046; OR, 1.174; 95% CI, 1.003-1.374), MUFA cause psoriasis (p = 0.032; OR, 1.218; 95% CI, 1.018-1.457), no causal effect of omega-3 PUFA in psoriasis (p = 0.695; OR, 0.989; 95% CI, 0.937-1.044), no causal effect of omega-6 PUFA in psoriasis (p = 0.643; OR, 1.013; 95% CI, 0.960-1.068), psoriasis is not causal to MUFA (p = 0.986; OR, 1.000; 95% CI, 0.949-1.055). Heterogeneity, horizontal pleiotropy, and sensitivity analyses showed reliable results. Conclusion: We found that circulating omega-6 PUFA and MUFA cause psoriasis, while omega-3 PUFA do not. Treatments that lower circulating omega-6 PUFA and MUFA are effective in psoriasis. After a better understanding of fatty acid intake and circulation, the population can be advised to regulate their diet.

Bibliometric analysis and description of research trends in the treatment of psoriasis with biologic agents in the past two decades (2004-2023).

BACKGROUND: Biologics are essential in treating psoriasis. In recent years, the pathogenesis exploration and development of new target drugs have provided a more complete evidence-based foundation for the biological treatment of psoriasis. This study aims to use bibliometrics to analyze the research status and development trends of biologics in psoriasis. METHODS: The bibliometric analysis of publications related to biologics in psoriasis from 2004 to 2023 was conducted using the Web of Science Core Collection (WoSCC) database as the search data source. To perform the bibliometric analysis and create visual knowledge graphs, CiteSpace, the Bibliometrix R package, and VOSviewers were utilized. RESULTS: The study included a total of 3800 articles. The United States had the highest number of publications. The leading authors and institutions were Steven R. Feldman and the University of Manchester, respectively, in the global partnership. The cluster plot divided all keywords into 11 categories. Currently, Secukinumab and Guselkumab are representative biological agents being studied due to their considerable efficacy and long-term safety. CONCLUSIONS: Targeted therapy has emerged as a significant trend in the current treatment of psoriasis. Early and active use of biologics can effectively control disease progression, prevent or delay the occurrence of comorbidities, and may even alter the natural course of psoriasis. However, further investigation is required to fully understand the specific mechanisms of psoriasis and the use of biological agents.

The role of Cyclin Dependent Kinase Inhibitor 3 (CDKN3) in promoting human tumors: Literature review and pan-cancer analysis.

Background: Although many experiments and clinical studies have proved the link between the expression of CDKN3 and human tumors, we have not been able to identify any bioinformatics study in which the extensive tumor-promoting effect of CDKN3 was systematically analyzed. Objective: Explore the extensive tumor-promoting effects of CDKN3 and review the research progress of CDKN3 in cancer. Methods: We systematically reviewed the literature on CDKN3 and tumors. We explored the potential tumor-promoting effects of CDKN3 on different tumors in the TCGA database and the GTEx database using multiple platforms and websites. We studied the expression level of CDKN3, survival, prognosis, diagnosis, genetic variation, immune infiltration, and enrichment analysis using databases such as TIMER 2.0, GEPIA2, cBioPortal, and STRING. Results: We found that CDKN3 is highly expressed in most tumors. The expression of CDKN3 is closely related to the prognosis of some tumors. And CDKN3 may have diagnostic value. The conclusion of our literature review is roughly the same, but there are differences, which are worthy of further study. Moreover, CDKN3 may be related to immune cell infiltration in tumor tissues. The genetic alteration of LUAD, STAD, SARC, PCPG, and ESCA with "Amplification" as the main type. In addition, through enrichment analysis, we found that CDKN3 affects tumors mainly through the control of the cell cycle and mitosis. Conclusion: CDKN3 is highly expressed in most tumor tissues and has a statistical correlation with survival prognosis. It has extensive tumor-promoting effects that may be related to mechanisms such as immune infiltration.

Bibliometric analysis and description of research trends on T cells in psoriasis over the past two decades (2003-2022).

Background: It is now understood that T cells play a key role in the occurrence and development of psoriasis. Herein, a bibliometric analysis was conducted to summarize the content and trends of T cell-related research in psoriasis. Methods: A bibliometric analysis was conducted on publications pertaining to T cells in psoriasis between 2003 and 2022 retrieved from the Web of Science Core Collection (WoSCC) database using tools such as CiteSpace, the Bibliometrix R package, and VOSviewer. Results: The study included a total of 3595 articles authored by 14,188 individuals, including all coauthors in article bylines. The Laboratory for Investigative Dermatology at Rockefeller University, led by James G Krueger, has made significant contributions to this field through focusing on the pathogenesis of psoriasis and exploring the potential of using biological agents to treat psoriasis. Furthermore, targeted inhibitors have significantly impacted the treatment of psoriasis, with researchers focusing on small-molecule targeted drugs as a new area of research that could potentially replace biological agents. Conclusions: Research has established the efficacy and long-term safety of targeted inhibition of T cell-related targets. Deucravacitinib, a psoriasis treatment drug targeting TYK2 as an allosteric inhibitor, has attracted significant attention and raised high expectations.

Efficacy of fire needle combined with 308 nm excimer laser therapy for vitiligo: A systematic review and meta-analysis of randomized controlled trials.

INTRODUCTION: Vitiligo is a common depigmenting skin disorder. This work is performed to systematically evaluate the efficacy and safety of fire needles combined with 308 nm excimer laser therapy in treating vitiligo. METHODS: We searched the PubMed, EMBASE, Cochrane Library, Web of Science, CNKI, Wanfang, and VIP databases. Randomized controlled trials (RCTs) on fire needles combined with 308 nm excimer laser therapy with 308 nm excimer laser therapy alone for vitiligo were included. The Cochrane Collaborative Network Tool was used to assess the risk of bias. Statistical analysis was completed using RevMan5.3 software and Stata 15.0 software. The GRADE system was used to evaluate the quality of evidence for outcomes. RESULTS: In this study, 10 RCTs and 1333 patients were included. The results showed that compared with 308 nm excimer laser therapy alone, fire needle combined with 308 nm excimer laser therapy is more effective in improving clinical effective rate (RR = 1.36, 95% CI [1.24, 1.50], p < 0.00001), serum CD4+ level (MD = 3.12, 95% CI [2.50, 3.74], p < 0.00001), CD4+/CD8+ ratio (MD = 0.24, 95% CI [0.09, 0.39], p = 0.001), and quality of life measured by the Dermatology Life Quality Index (DLQI) (MD = 3.76, 95% CI [3.33, 4.19], p < 0.00001), and reducing the Vitiligo Area Score Index (VASI) (MD = -5.47, 95% CI [-6.56, -4.37], p < 0.00001). The reported adverse events, including redness, swelling, pain, blisters, and itching, were controllable, and all these events were well tolerated. CONCLUSION: The current evidence indicates that fire needle combined with 308 nm excimer laser therapy is effective and safe for vitiligo. However, owing to the suboptimal quality of the included studies, more high-quality and large-scale RCTs are needed for comprehensive analysis and further validation.

Insight into the effect of exposed crystal facets of anatase TiO2 on HCHO catalytic oxidation of Mn-Ce/TiO2.

Indoor formaldehyde pollution seriously jeopardizes human health. The development of efficient and stable non-precious metal catalysts for low-temperature catalytic degradation of formaldehyde is a promising approach. In this study, TiO2 {001} and {101} supports were loaded with different ratios of Mn and Ce active components, and the effects of the ratios of the active components on the catalytic activity were investigated. The elemental oxidation states, redox capacities, active oxygen mobilities and acid site distributions of the catalysts were determined using characterization techniques such as XPS, H2-TPR, O2-TPD, and NH3-TPD. In situ infrared spectroscopy was utilized to reveal the differences in the two-step dehydrogenation reactions of dioxymethylene (DOM) in 5Mn1Ce/Ti-NS and 5Mn1Ce/Ti-NP. Density-functional theory was used to investigate the differences in the catalytic steps and maximum energy barriers of Mn-Ce/Ti-NS and Mn-Ce/Ti-NP for HCHO. The differences in catalytic activity due to the influence of the manganese and cerium active components on the {001} and {101} crystal faces of anatase titanium dioxide are comprehensively revealed. Exposure of the supported crystalline surfaces alters the catalytic activity centers and reaction pathways at the molecular level. This study provides experimental and theoretical guidance for the selection of exposed crystalline surfaces for loaded catalysts.

Efficient catalytic oxidation of formaldehyde by defective g-C3N4-anchored single-atom Pt: A DFT study.

Indoor volatile formaldehyde is a serious health hazard. The development of low-temperature and efficient nonhomogeneous oxidation catalysts is crucial for protecting human health and the environment but is also quite challenging. Single-atom catalysts (SACs) with active centers and coordination environments that are precisely tunable at the atomic level exhibit excellent catalytic activity in many catalytic fields. Among two-dimensional materials, the nonmagnetic monolayer material g-C3N4 may be a good platform for loading single atoms. In this study, the effect of nitrogen defect formation on the charge distribution of g-C3N4 is discussed in detail using density functional theory (DFT) calculations. The effect of nitrogen defects on the activated molecular oxygen of Pt/C3N4 was systematically revealed by DFT calculations in combination with molecular orbital theory. Two typical reaction mechanisms for the catalytic oxidation of formaldehyde were proposed based on the Eley-Rideal (E-R) mechanism. Pt/C3N4-V3N was more advantageous for path 1, as determined by the activation energy barrier of the rate-determining step and product desorption. Finally, the active centers and chemical structures of Pt/C3N4 and Pt/C3N4-V3N were verified to have good stability at 375 K by determination of the migration energy barriers and ab initio molecular dynamics simulations. Therefore, the formation of N defects can effectively anchor single-atom Pt and provide additional active sites, which in turn activate molecular oxygen to efficiently catalyze the oxidation of formaldehyde. This study provides a better understanding of the mechanism of formaldehyde oxidation by single-atom Pt catalysts and a new idea for the development of Pt as well as other metal-based single-atom oxidation catalysts.