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1.
Int Dent J ; 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38631944

RESUMO

OBJECTIVES: Investigate the geographical distribution of private dental practices in major Chinese cities and analyze the variables influencing this distribution. METHODS: This study used Python to extract various types of Point of Interest (POI) data spanning from 2016 to 2022 from the AutoNavi map. A 1km*1km grid was constructed to establish the study sample. Additional spatial pattern data, including nighttime lighting, population, and air quality data, were integrated into this grid. Global Moran's I index was used to analyze the spatial autocorrelation. The spatial lag model was used to explore the influencing factors of private dental practice distribution. RESULTS: This study reveals a specific clustering pattern for private dental practices in major Chinese cities. The primary influencing factors include nighttime lights, population density, and housing prices, suggesting that dental practices are typically concentrated in highly developed regions with dense populations and high housing costs. Additionally, we discovered that patterns vary across different metropolises, with the most pronounced clustering patterns and substantial inequalities found in the most developed areas. CONCLUSIONS: This study establishes that factors such as regional development and population density positively correlate with private dental practice. Additionally, it reveals a strong mutual correlation in the clustering of dental practices, which does not show a substantial correlation with public resources. Finally, it suggests that the spatial heterogeneity pattern implies a rising necessity to tackle inequality issues within urban areas as economic development progresses.

2.
Opt Express ; 32(6): 9562-9572, 2024 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-38571187

RESUMO

We demonstrated a high-performance partially corrugated waveguide distributed feedback (PCW-DFB) laser with high output power, low relative intensity noise (RIN) and narrow linewidth. By introducing offset quantum-well structure that provides enough threshold gain difference for single transverse mode operation, the laser can achieve single mode behavior with an 8-µm-wide ridge waveguide. The laser has been designed by the simulation model based on the coupled wave equations, and the fabricated PCW-DFB laser with the cavity length of 1.3 mm exhibited an output power higher than 190 mW. Stable single mode characteristics have been achieved with a side-mode suppression-ratio (SMSR) over 55 dB. The RIN was less than -160.5 dB/Hz at an injection current of 470 mA, and the linewidth reached 45 kHz.

3.
Small Methods ; : e2400118, 2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38597770

RESUMO

The rising global population and improved living standards have led to an alarming increase in non-communicable diseases, notably cardiovascular and chronic respiratory diseases, posing a severe threat to human health. Wearable sensing devices, utilizing micro-sensing technology for real-time monitoring, have emerged as promising tools for disease prevention. Among various sensing platforms, graphene-based sensors have shown exceptional performance in the field of micro-sensing. Laser-induced graphene (LIG) technology, a cost-effective and facile method for graphene preparation, has gained particular attention. By converting polymer films directly into patterned graphene materials at ambient temperature and pressure, LIG offers a convenient and environmentally friendly alternative to traditional methods, opening up innovative possibilities for electronic device fabrication. Integrating LIG-based sensors into health monitoring systems holds the potential to revolutionize health management. To commemorate the tenth anniversary of the discovery of LIG, this work provides a comprehensive overview of LIG's evolution and the progress of LIG-based sensors. Delving into the diverse sensing mechanisms of LIG-based sensors, recent research advances in the domain of health monitoring are explored. Furthermore, the opportunities and challenges associated with LIG-based sensors in health monitoring are briefly discussed.

4.
NPJ Precis Oncol ; 8(1): 81, 2024 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-38553598

RESUMO

The biology of metastatic breast cancer (MBC) is understudied, primarily due to the difficulty of procuring multiple samples from patients with oligometastatic breast cancer. We developed a rapid postmortem tissue procurement program that allows the collection and analysis of numerous metastatic lesions, subclinical locations, and potential pre-metastatic niches that fall within this scope. We conducted a rapid postmortem tissue collection study on 9 patients with MBC. Patients and their families consented to donate tissues immediately after death in an IRB-approved study. Various disease subtypes, progression histories, organ involvement, and final causes of death are reported. In patients with hormone receptor-positive (HR+) disease, estrogen receptor (ER), progesterone receptor (PR), HER2, and Ki-67 expression were heterogeneous across metastatic lesions within individual patients. Disease phenotype at the end of life trended toward complete loss of HR expression. Nearly all (n = 7) patients exhibited extensive tumor involvement of additional organs that had not been previously diagnosed clinically and were not retrospectively visible on recent imaging. Of these seven individuals, three included organs uncommonly associated with MBC: kidney, spleen, pancreas, and ovary. Finally, we identified clinically undetectable micrometastases in several organs uncommonly involved in MBC. Our findings raise several clinically relevant questions regarding the mechanisms of metastatic progression. Insights from this study argue for better surveillance strategies for monitoring MBC. We highlight the need to capture more accurate biomarker information in the context of heterogeneous disease and urge the consideration of treatment strategies that combine multiple targeted therapies.

5.
Stem Cell Reports ; 19(3): 399-413, 2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38428414

RESUMO

Degenerative bone disorders have a significant impact on global health, and regeneration of articular cartilage remains a challenge. Existing cell therapies using mesenchymal stromal cells (MSCs) have shown limited efficacy, highlighting the necessity for alternative stem cell sources. Here, we have identified and characterized MSX1+ mesenchymal progenitor cells in the developing limb bud with remarkable osteochondral-regenerative and microenvironment-adaptive capabilities. Single-cell sequencing further revealed the presence of two major cell compositions within the MSX1+ cells, where a distinct PDGFRAlow subset retained the strongest osteochondral competency and could efficiently regenerate articular cartilage in vivo. Furthermore, a strategy was developed to generate MSX1+PDGFRAlow limb mesenchyme-like (LML) cells from human pluripotent stem cells that closely resembled their mouse counterparts, which were bipotential in vitro and could directly regenerate damaged cartilage in a mouse injury model. Together, our results indicated that MSX1+PDGFRAlow LML cells might be a prominent stem cell source for human cartilage regeneration.


Assuntos
Cartilagem Articular , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais , Humanos , Camundongos , Animais , Células-Tronco , Terapia Baseada em Transplante de Células e Tecidos , Mesoderma , Transplante de Células-Tronco Mesenquimais/métodos , Diferenciação Celular , Fator de Transcrição MSX1/genética
6.
Front Bioeng Biotechnol ; 12: 1356580, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38456006

RESUMO

Tooth loss or damage poses great threaten to oral and general health. While contemporary clinical treatments have enabled tooth restoration to a certain extent, achieving functional tooth regeneration remains a challenging task due to the intricate and hierarchically organized architecture of teeth. The past few decades have seen a rapid development of three-dimensional (3D) printing technology, which has provided new breakthroughs in the field of tissue engineering and regenerative dentistry. This review outlined the bioactive materials and stem/progenitor cells used in dental regeneration, summarized recent advancements in the application of 3D printing technology for tooth and tooth-supporting tissue regeneration, including dental pulp, dentin, periodontal ligament, alveolar bone and so on. It also discussed current obstacles and potential future directions, aiming to inspire innovative ideas and encourage further development in regenerative medicine.

7.
Res Sq ; 2024 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-38343849

RESUMO

The prevalence of knee osteoarthritis (OA) is widespread and the heterogeneous patient factors and clinical symptoms in OA patients impede developing personalized treatments for OA patients. In this study, we used unsupervised and supervised machine learning to organize the heterogeneity in knee OA patients and predict disease progression in individuals from the Osteoarthritis Initiative (OAI) dataset. We identified four distinct knee OA phenotypes using unsupervised learning that were defined by nutrition, disability, stiffness, and pain (knee and back) and were strongly related to disease fate. Interestingly, the absence of supplemental vitamins from an individual's diet was protective from disease progression. Moreover, we established a phenotyping tool and prognostic model from 5 variables (WOMAC disability score of the right knee, WOMAC total score of the right knee, WOMAC total score of the left knee, supplemental vitamins and minerals frequency, and antioxidant combination multivitamins frequency) that can be utilized in clinical practice to determine the risk of knee OA progression in individual patients. We also developed a prognostic model to estimate the risk for total knee replacement and provide suggestions for modifiable variables to improve long-term knee health. This combination of unsupervised and supervised data-driven tools provides a framework to identify knee OA phenotype in a clinical scenario and personalize treatment strategies.

8.
Glob Chang Biol ; 30(2): e17182, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38348761

RESUMO

Biodiversity is considered important to the mitigation of global change impacts on ecosystem multifunctionality in terrestrial ecosystems. However, potential mechanisms through which biodiversity maintains ecosystem multifunctionality under global change remain unclear. We grew 132 plant communities with two levels of plant diversity, crossed with treatments based on 10 global change factors (nitrogen deposition, soil salinity, drought, plant invasion, simulated grazing, oil pollution, plastics pollution, antibiotics pollution, heavy metal pollution, and pesticide pollution). All global change factors negatively impacted ecosystem multifunctionality, but negative impacts were stronger in high compared with low diversity plant communities. We explored potential mechanisms for this unexpected result, finding that the inhibition of selection effects (i.e., selection for plant species associated with high ecosystem functioning) contributed to sensitivity of ecosystem multifunctionality to global change. Specifically, global change factors decreased the abundance of novel functional plants (i.e., legumes) in high but not low diversity plant communities. The negative impacts of global change on ecosystem multifunctionality were also mediated by increased relative abundance of fungal plant pathogens (identified from metabarcoding of soil samples) and their negative relationship with the abundance of novel functional plants. Taken together, our experiment highlights the importance of protecting high diversity plant communities and legumes, and managing fungal pathogens, to the maintenance of ecosystem multifunctionality in the face of complex global change.


Assuntos
Ecossistema , Fabaceae , Biodiversidade , Plantas , Solo , Poluição Ambiental
9.
Angew Chem Int Ed Engl ; 63(15): e202400414, 2024 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-38348904

RESUMO

Bipolar membranes (BPMs) have emerged as a promising solution for mitigating CO2 losses, salt precipitation and high maintenance costs associated with the commonly used anion-exchange membrane electrode assembly for CO2 reduction reaction (CO2RR). However, the industrial implementation of BPM-based zero-gap electrolyzer is hampered by the poor CO2RR performance, largely attributed to the local acidic environment. Here, we report a backbone engineering strategy to improve the CO2RR performance of molecular catalysts in BPM-based zero-gap electrolyzers by covalently grafting cobalt tetraaminophthalocyanine onto a positively charged polyfluorene backbone (PF-CoTAPc). PF-CoTAPc shows a high acid tolerance in BPM electrode assembly (BPMEA), achieving a high FE of 82.6 % for CO at 100 mA/cm2 and a high CO2 utilization efficiency of 87.8 %. Notably, the CO2RR selectivity, carbon utilization efficiency and long-term stability of PF-CoTAPc in BPMEA outperform reported BPM systems. We attribute the enhancement to the stable cationic shield in the double layer and suppression of proton migration, ultimately inhibiting the undesired hydrogen evolution and improving the CO2RR selectivity. Techno-economic analysis shows the least energy consumption (957 kJ/mol) for the PF-CoTAPc catalyst in BPMEA. Our findings provide a viable strategy for designing efficient CO2RR catalysts in acidic environments.

10.
EBioMedicine ; 101: 105035, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38401418

RESUMO

BACKGROUND: While mutation-derived neoantigens are well recognized in generating anti-tumour T cell response, increasing evidences highlight the complex association between tumour mutation burden (TMB) and tumour infiltrating lymphocytes (TILs). The exploration of non-TMB determinants of active immune response could improve the prognosis prediction and provide guidance for current immunotherapy. METHODS: The transcriptomic and whole exome sequence data in The Cancer Genome Atlas were used to examine the relationship between TMB and exhausted CD8+ T cells (Tex), as an indicator of tumour antigen-specific T cells across nine major cancer types. Computational clustering analysis was performed on 4510 tumours to identify different immune profiles. NanoString gene expression analysis and single cell RNA-seq analysis using fresh human breast cancer were performed for finding validation. FINDINGS: TMB was found to be poorly correlated with active immune response in various cancer types. Patient clustering analysis revealed a group of tumours with abundant Tex but low TMB. In those tumours, we observed significantly higher expression of the stimulator of interferon genes (STING) signalling. Dendritic cells, particularly those of BATF3+ lineage, were also found to be essential for accumulation of Tex within tumours. Mechanistically, loss of genomic and cellular integrity, marked by decreased DNA damage repair, defective replication stress response, and increased apoptosis were shown to drive STING activation. INTERPRETATION: These results highlight that TMB alone does not fully predict tumour immune profiles, with STING signalling compensating for low TMB in non-hypermutated tumours to enhance anti-tumour immunity. Translating these results, STING agonists may benefit patients with non-hypermutated tumours. STING activation may serve as an additional biomarker to predict response to immune checkpoint blockades alongside TMB. Our research also unravelled the interplay between genomic instability and STING activation, informing potential combined chemotherapy targeting the axis of genomic integrity and immunotherapy. FUNDING: City of Hope Christopher Family Endowed Innovation Fund for Alzheimer's Disease and Breast Cancer Research in honor of Vineta Christopher; Breast Cancer Alliance Early Career Investigator Award; National Cancer Institute of the National Institutes of Health under award number R01CA256989 and R01CA240392.


Assuntos
Neoplasias da Mama , Humanos , Feminino , Mutação , Prognóstico , Neoplasias da Mama/genética , Neoplasias da Mama/terapia , Biomarcadores Tumorais/genética , Antígenos de Neoplasias/genética
11.
Cell Rep Med ; 5(2): 101420, 2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38382468

RESUMO

Tumor-associated macrophages (TAMs) are the predominant cells that express programmed cell death ligand 1 (PD-L1) within human tumors in addition to cancer cells, and PD-L1+ TAMs are generally thought to be immunosuppressive within the tumor immune microenvironment (TIME). Using single-cell transcriptomic and spatial multiplex immunofluorescence analyses, we show that PD-L1+ TAMs are mature and immunostimulatory with spatial preference to T cells. In contrast, PD-L1- TAMs are immunosuppressive and spatially co-localize with cancer cells. Either higher density of PD-L1+ TAMs alone or ratio of PD-L1+/PD-L1- TAMs correlate with favorable clinical outcome in two independent cohorts of patients with breast cancer. Mechanistically, we show that PD-L1 is upregulated during the monocyte-to-macrophage maturation and differentiation process and does not require external IFN-γ stimulus. Functionally, PD-L1+ TAMs are more mature/activated and promote CD8+ T cells proliferation and cytotoxic capacity. Together, our findings reveal insights into the immunological significance of PD-L1 within the TIME.


Assuntos
Neoplasias da Mama , Macrófagos Associados a Tumor , Humanos , Feminino , Macrófagos Associados a Tumor/metabolismo , Neoplasias da Mama/metabolismo , Antígeno B7-H1/genética , Linfócitos T CD8-Positivos/metabolismo , Macrófagos , Microambiente Tumoral
12.
Opt Express ; 32(3): 3123-3137, 2024 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-38297541

RESUMO

This study investigates the thermal compensation mechanism in dual-mode Si3N4 microresonators that demonstrates the ease of generation of single-solitons with nearly octave-wide spectral bandwidth. The deterministic creation of soliton frequency combs is achieved by merely switching the wavelength of a tunable laser or a semiconductor diode laser in a single step. The pump frequency detuning range that can sustain the soliton state is 30 gigahertz (GHz), which is approximately 100 times the resonance linewidth. Interestingly, these dual-mode resonators also support the coexistence of primary combs and solitons, enabling their utilization as functional microwave synthesizers. Furthermore, these resonators readily facilitate the generation of diverse multi-solitons and soliton crystals. This work presents a simplified system to access high-performance and versatile Kerr solitons, with wide-ranging applications in optical metrology, microwave photonics, and LiDAR.

13.
Qual Life Res ; 33(3): 817-829, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38167749

RESUMO

PURPOSE: To develop the mapping functions from the Impact of Weight on Quality of Life-Lite (IWQOL-Lite) scores onto the EQ-5D-5L and SF-6Dv2 utility values among the overweight and obese population in China. METHODS: A representative sample of the overweight and obese population in China stratified by age, sex, body mass index (BMI), and area of residence was collected by online survey and the sample was randomly divided into development (80%) and validation (20%) datasets. The conceptual overlap between the IWQOL-Lite and the EQ-5D-5L or SF-6Dv2 was evaluated by Spearman's correlation coefficients. Five models, including OLS, Tobit, CLAD, GLM, and PTM were explored to derive mapping functions using the development dataset. The model performance was assessed using MAE, RMSE, and the percentage of AE > 0.05 and AE > 0.1 in the validation dataset. RESULTS: A total of 1000 respondents (48% female; mean [SD] age: 51.7 [15.3]; mean [SD] BMI: 27.4 [2.8]) were included in this study. The mean IWQOL-Lite scores and the utility values of EQ-5D-5L and SF-6Dv2 were 78.5, 0.851, and 0.734, respectively. The best-performing models predicting EQ-5D-5L and SF-6Dv2 utilities both used IWQOL-Lite total score as a predictor in the CLAD model (MAE: 0.083 and 0.076 for the EQ-5D-5L and SF-6Dv2; RMSE: 0.125 and 0.103 for the EQ-5D-5L and SF-6Dv2; AE > 0.05: 20.5% and 27.5% for the EQ-5D-5L and SF-6Dv2; AE > 0.10: 9.5% and 15.0% for the EQ-5D-5L and SF-6Dv2). CONCLUSION: CLAD models with the IWQOL-Lite total score can be used to predict both the EQ-5D-5L and SF-6Dv2 utility values among overweight and obese population in China.


Assuntos
Sobrepeso , Qualidade de Vida , Humanos , Feminino , Pessoa de Meia-Idade , Masculino , Qualidade de Vida/psicologia , Inquéritos e Questionários , China , Obesidade
14.
Sci Total Environ ; 912: 169100, 2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38086483

RESUMO

Common reed (Phragmites australis) is a widely utilized plant for wetland restoration and construction, facing challenges posed by high salinity as a stressor. Among the diverse P. australis lineages, functional traits variation provides a valuable genetic resource for identifying salt-tolerant individuals. However, previous investigations on P. australis salt tolerance have been restricted to regional scales, hindering the identification of key functional traits associated with salt tolerance in natural habitats. To address this gap, we conducted a greenhouse experiment to assess and compare the salt tolerance of four major temperate P. australis lineages worldwide. We utilized the maximum quantum yield of photosystem II (Fv/Fm) as a health indicator, while final biomass and wilt status served as indicators of salt tolerance across lineages. Our findings revealed significant differentiation in plant functional traits among different lineages, but no significant effect of interaction between salinity and lineage on most traits. Correlation analyses between salt-tolerance indicators and functional traits in the control group indicated that biomass, leaf width, and relative leaf water content are potential predictors of salt tolerance. However, ecological strategies, physiological traits, and latitudinal origin did not exhibit significant correlations with salt tolerance. Our study provides valuable indicator traits for effectively screening salinity-tolerant genotypes of P. australis in field settings, and holds significant potential for enhancing wetland construction and biomass production in marginal lands.


Assuntos
Tolerância ao Sal , Áreas Alagadas , Humanos , Plantas , Poaceae , Fenótipo
15.
Diabet Med ; 41(1): e15251, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37915225

RESUMO

BACKGROUND: Type 1 diabetes mellitus (T1DM) is one of the most burdensome chronic diseases in the world. Health utility values are an important tool for quantifying this disease burden and conducting cost-utility analyses. This review aimed to derive a reference set of health utility values for children and adolescents with T1DM. METHODS: We searched MEDLINE and Embase from inception to March 2023 for health utility values of T1DM children and adolescents (aged ≤18 years) measured using direct and indirect preference elicitation approaches. Utility estimates were pooled by meta-analyses with subgroup analyses to evaluate differences by populations and elicitation approaches. RESULTS: Six studies involving 1276 participants were included in this study. Meta-analysis showed the overall utility value of children and adolescents with T1DM was 0.91 (95% CI 0.89-0.93). The utility value of T1DM children and adolescents with complications was 0.90 (95% CI 0.88-0.92), which was lower than those without complications (0.96, 95% CI 0.95-0.97). The utility value of children (aged <13 years) was higher than adolescents (aged 13-18 years) (0.90 vs. 0.85). The utility value measured by the EQ-5D-3L (0.91) was higher than the HUI3 (0.89), the SF-6Dv1 (0.83), and the time trade-off (0.81). The parent proxy-reported was similar to the patient self-reported (0.91 vs. 0.91). CONCLUSIONS: This study developed a reference set of pooled utility estimates for children and adolescents with T1DM, which is helpful for understanding the overall health status of T1DM and conducting economic evaluations. Further studies are needed to explore the utilities of T1DM with different types of complications.


Assuntos
Diabetes Mellitus Tipo 1 , Criança , Humanos , Adolescente , Diabetes Mellitus Tipo 1/epidemiologia , Qualidade de Vida , Efeitos Psicossociais da Doença , Autorrelato , Análise Custo-Benefício
16.
Bioresour Technol ; 394: 130258, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38151206

RESUMO

The circular economy is essential as it encourages the reuse and recycling of resources while reducing waste, which ultimately helps to reduce environmental pollution and boosts economic efficiency. The current review highlights the management of agricultural and livestock residues and their conversion into valuable resources to combat environmental degradation and improve social well-being. The current trends in converting agricultural residues into useful resources emphasize the social benefits of waste management and conversion. It also emphasizes how waste conversion can reduce environmental degradation and enhance food security. Using agricultural residues can increase soil health and agricultural output while reducing pollution, greenhouse gas emissions, and resource depletion. Promoting sustainable waste-to-resource conversion processes requires a combination of strategies that address technical, economic, social, and environmental aspects. These multiple strategies are highlighted along with prospects and considerations.


Assuntos
Mudança Climática , Gerenciamento de Resíduos , Agricultura , Solo , Segurança Alimentar
17.
Nat Commun ; 14(1): 7383, 2023 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-37968299

RESUMO

Regulating electron transport rate and ion concentrations in the local microenvironment of active site can overcome the slow kinetics and unfavorable thermodynamics of CO2 electroreduction. However, simultaneous optimization of both kinetics and thermodynamics is hindered by synthetic constraints and poor mechanistic understanding. Here we leverage laser-assisted manufacturing for synthesizing CuxO bipyramids with controlled tip angles and abundant nanograins, and elucidate the mechanism of the relationship between electron transport/ion concentrations and electrocatalytic performance. Potassium/OH- adsorption tests and finite element simulations corroborate the contributions from strong electric field at the sharp tip. In situ Fourier transform infrared spectrometry and differential electrochemical mass spectrometry unveil the dynamic evolution of critical *CO/*OCCOH intermediates and product profiles, complemented with theoretical calculations that elucidate the thermodynamic contributions from improved coupling at the Cu+/Cu2+ interfaces. Through modulating the electron transport and ion concentrations, we achieve high Faradaic efficiency of 81% at ~900 mA cm-2 for C2+ products via CO2RR. Similar enhancement is also observed for nitrate reduction reaction (NITRR), achieving 81.83 mg h-1 ammonia yield rate per milligram catalyst. Coupling the CO2RR and NITRR systems demonstrates the potential for valorizing flue gases and nitrate wastes, which suggests a practical approach for carbon-nitrogen cycling.

18.
Adv Mater ; : e2310037, 2023 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-37931925

RESUMO

Metalloporphyrins and metallophthalocyanines emerge as popular building blocks to develop covalent organic nanosheets (CONs) for CO2 reduction reaction (CO2 RR). However, existing CONs predominantly yield CO, posing a challenge in achieving efficient methanol production through multielectron reduction. Here, ultrathin, cationic, and cobalt-phthalocyanine-based CONs (iminium-CONs) are reported for electrochemical CO2 -to-CH3 OH conversion. The integration of quaternary iminium groups enables the formation of ultrathin morphology with uniformly anchored cobalt active sites, which are pivotal for facilitating rapid multielectron transfer. Moreover, the cationic iminium-CONs exhibit a lower activity for hydrogen evolution side reaction. Consequently, iminium-CONs manifest significantly enhanced selectivity for methanol production, as evidenced by a remarkable 711% and 270% improvement in methanol partial current density (jCH3OH ) compared to pristine CoTAPc and neutral imine-CONs, respectively. Under optimized conditions, iminium-CONs deliver a high jCH3OH of 91.7 mA cm-2 at -0.78 V in a flow cell. Further, iminium-CONs achieve a global methanol Faradaic efficiency (FECH3OH ) of 54% in a tandem device. Thanks to the single-site feature, the methanol is produced without the concurrent generation of other liquid byproducts. This work underscores the potential of cationic covalent organic nanosheets as a compelling platform for electrochemical six-electron reduction of CO2 to methanol.

19.
Heliyon ; 9(11): e21822, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-38034734

RESUMO

Aims: Nitrogen (N) supply and precipitation pattern (amount and frequency) both affect plant growth. However, N deposition is increasing and precipitation regimes are changing in the context of global change. An experiment was conducted to access how the growth of Robinia pseudoacacia, a widely distributed and cultivated N2-fixing alien species, is affected by both the pattern of precipitation and N supplies. Methods: Seedlings were grown in a glasshouse at four different N levels combined with different precipitation regimes, including three precipitation amounts, and two precipitation frequencies. After treatment for 75 days, plant height, biomass allocation, leaf and soil nutrient concentrations were measured. Results: Plants under high precipitation frequency had greater biomass compared with plants lower precipitation frequency, despite receiving the same amount of precipitation. Higher N supply reduced biomass allocation to nodules. Under low precipitation level, nodule growth and N2 fixation of R. pseudoacacia was more inhibited by high N deposition compared with plants under higher precipitation level. Even slightly N deposition under higher precipitation inhibited N2 fixation but it was insufficient to meet the N needs of the plants. Conclusions: Even at low levels, N deposition might inhibit N2 fixation of plants but low N in soil cannot meet the N requirements of plants, and caused N2 fixation limitation in plants during seedling stage. There was likely a transition from N2 fixation to acquisition of N from soil directly with root when N supply was increased.

20.
Biomed Mater ; 18(6)2023 10 27.
Artigo em Inglês | MEDLINE | ID: mdl-37852224

RESUMO

Hard tissues, especially teeth and bones, are highly mineralized and the large-scale defect or total loss of them is irreversible. There is still no ideal strategy for the reconstruction of various hard tissue defects that can achieve the balance between biological and mechanical properties. Polyether ether ketone (PEEK) has the potential to substitute for natural hard tissue in defect areas but is limited by its biological inertness. The addition of hydroxyapatite (HA) can significantly improve the osteogenic properties and osteointegration of PEEK materials. But the mechanical properties of HA/PEEK scaffolds are far from satisfaction making scaffolds easy to fracture. We put forward a strategy to balance the mechanical and biological properties of HA/PEEK scaffolds via the regulation of the inner crystallinity and HA mixing ratio and we systematically evaluated the modified HA/PEEK scaffolds through material characterization,in vitroandin vivoexperiments. And we found that the 20%HA/PEEK scaffolds with low crystallinity achieved the required strength and elasticity, and exhibited the characteristics of promoting the proliferation, migration and osteogenic differentiation of bone marrow mesenchymal stem cells. The results of the implantation of beagles' teeth, mandible and rib showed that the 20%HA/PEEK scaffold with low crystallinity could well withstand the local complex force in the defect area and combine well with natural bone tissue, which made it a candidate for a practical versatile hard tissue engineering scaffold.


Assuntos
Bioimpressão , Durapatita , Cães , Animais , Engenharia Tecidual/métodos , Osteogênese/fisiologia , Polietilenoglicóis , Cetonas , Tecidos Suporte
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