Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 64
Filtrar
1.
Materials (Basel) ; 17(9)2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38730778

RESUMO

To enhance the physical and mechanical characteristics of steam-cured concrete, an orthogonal experimental design was utilized to examine the effects of varying contents of fly ash (0 wt%, 10 wt%, 15 wt%, 20 wt%), silica fume (0 wt%, 5 wt%, 10 wt%, 15 wt%), basalt fiber (0 vol%, 0.05 vol%, 0.1 vol%, 0.2 vol%), and polypropylene fiber (0 vol%, 0.05 vol%, 0.1 vol%, 0.2 vol%) on its mechanical properties. Utilizing range and variance analyses, this study identified four preliminary optimized compositions of concrete incorporating fly ash, silica fume, basalt fiber, and polypropylene fiber. On this basis, in order to determine the optimal mix proportion, the mechanical performances, the pore characteristics, and the microstructure of four optimized mix proportions were analyzed. According to the results of macroscopic, fine, and microscopic multi-scale tests, the addition of 15 wt% fly ash, 10 wt% silica ash, 0.2 vol% basalt fiber, and 0.1 vol% polypropylene fiber to the steamed concrete is the best to improve the performance of the steamed concrete. Compared to ordinary concrete, the compressive strength increases by 28%, the tensile strength increases by 40%, and the porosity decreases by 47.2%.

2.
Biomed Pharmacother ; 175: 116670, 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38692065

RESUMO

Neutrophils are heterogeneous and plastic, with the ability to polarize from antitumour to protumour phenotype and modulate tumour microenvironment components. While some advances have been made, the neutrophil-targeting therapy remains underexplored. Activation of formyl peptide receptors (FPRs) by formylated peptides is needed for local control of infection through the recruitment of activated neutrophils while the potential contribution of antitumour activity remains underexplored. Here, we demonstrate that neutrophils can be harnessed to suppress tumour growth through the action of the formyl peptide (FP) on the formyl peptide receptor (FPR). Mechanistically, FP efficiently recruits neutrophils to produce reactive oxygen species production (ROS), resulting in the direct killing of tumours. Antitumour functions disappeared when neutrophils were depleted by anti-Ly6G antibodies. Interestingly, extensive T-cell activation was observed in mouse tumours treated with FP, showing the potential to alter the immune suppressed tumour microenvironment (TME) and further sensitize mice to anti-PD1 therapy. Transcriptomic and flow cytometry analyses revealed the mechanisms of FP-sensitized anti-PD1 therapy, mainly including stimulated neutrophils and an altered immune-suppressed tumour microenvironment. Collectively, these data establish FP as an effective combination partner for sensitizing anti-PD1 therapy by stimulating tumour-infiltrated neutrophils.

3.
ACS Appl Mater Interfaces ; 16(10): 12897-12906, 2024 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-38412379

RESUMO

The "von Neumann bottleneck" is a formidable challenge in conventional computing, driving exploration into artificial synapses. Organic semiconductor materials show promise but are hindered by issues such as poor adhesion and a high elastic modulus. Here, we combine polyisoindigo-bithiophene (PIID-2T) with grafted poly(dimethylsiloxane) (PDMS) to synthesize the triblock-conjugated polymer (PIID-2T-PDMS). The polymer exhibited substantial enhancements in adhesion (4.8-68.8 nN) and reductions in elastic modulus (1.6-0.58 GPa) while maintaining the electrical characteristics of PIID-2T. The three-terminal organic synaptic transistor (three-terminal p-type organic artificial synapse (TPOAS)), constructed using PIID-2T-PDMS, exhibits an unprecedented analog switching range of 276×, surpassing previous records, and a remarkable memory on-off ratio of 106. Moreover, the device displays outstanding operational stability, retaining 99.6% of its original current after 1600 write-read events in the air. Notably, TPOAS replicates key biological synaptic behaviors, including paired-pulse facilitation (PPF), short-term plasticity (STP), and long-term plasticity (LTP). Simulations using handwritten digital data sets reveal an impressive recognition accuracy of 91.7%. This study presents a polyisoindigo-bithiophene-based block copolymer that offers enhanced adhesion, reduced elastic modulus, and high-performance artificial synapses, paving the way for the next generation of neuromorphic computing systems.

4.
J Environ Manage ; 354: 120263, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38387360

RESUMO

Biogenic carbon emissions, including carbon dioxide (CO2) and methane (CH4), have emerged as a major concern during organic pollutant degradation within constructed wetlands (CWs). Since these organic compounds primarily originate from the photosynthetic fixation of atmospheric CO2, it potentially introduces uncertainty when assessing the greenhouse effect of biogenic carbon emissions in CWs based on direct field observations. To objectively assessing this effect, this study proposed a new strategy by quantifying CO2-equivalent (CO2-eq) changes as carbon passes through CWs and tested it in various types of CWs based on 64 literature records. The findings reveal that CWs can contribute to CO2-eq additions, yet are only responsible for 15.6% derived from direct field observations. The type of CWs plays a crucial role in these CO2-eq additions, with vertical flow CWs causing the lowest levels (6.8%), followed by surface flow CWs (14.2%). In contrast, horizontal flow CWs are associated with the strongest CO2-eq addition (25.7%). The findings provide new insights for the objective assessment of the greenhouse effect of biogenic carbon emissions in CWs, which will be beneficial for future life cycle assessment.


Assuntos
Poluentes Ambientais , Áreas Alagadas , Efeito Estufa , Dióxido de Carbono/análise , Metano , Óxido Nitroso/análise
5.
Food Chem ; 445: 138657, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38354640

RESUMO

Rice varieties of different subspecies types (indica rice and japonica rice) across various geographical origins (Hunan, Jiangsu, and Northeast China) were monitored using microsatellite markers (simple sequence repeats, SSR). 110 representative rice cultivars were collected from the main crop areas. Multiple methods including clustering analysis (neighbor-joining (NJ) method, unweighted pair-group method with arithmetic mean (UPGMA) method), principal component analysis (PCA) and model-based grouping were applied. The study revealed that 25 pairs of SSR markers exhibited a broad range of polymorphism information content (PIC) values, ranging from 0.240 to 0.830. Furthermore, our study successfully achieved a higher overall mean correct rate of 99.09% in determining the geographical origin of rice. Simultaneously, it accurately classified indica rice and japonica rice. These findings are significant as they provide an SSR fingerprint of 110 high-quality rice cultivars, serving as a valuable scientific resource for the detection of rice adulteration and traceability of its origin.


Assuntos
Variação Genética , Oryza , Oryza/genética , Polimorfismo Genético , Repetições de Microssatélites/genética , Análise de Componente Principal , Filogenia
6.
Nat Commun ; 15(1): 1681, 2024 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-38395989

RESUMO

Large-scale quantum computers will inevitably need quantum error correction to protect information against decoherence. Traditional error correction typically requires many qubits, along with high-efficiency error syndrome measurement and real-time feedback. Autonomous quantum error correction instead uses steady-state bath engineering to perform the correction in a hardware-efficient manner. In this work, we develop a new autonomous quantum error correction scheme that actively corrects single-photon loss and passively suppresses low-frequency dephasing, and we demonstrate an important experimental step towards its full implementation with transmons. Compared to uncorrected encoding, improvements are experimentally witnessed for the logical zero, one, and superposition states. Our results show the potential of implementing hardware-efficient autonomous quantum error correction to enhance the reliability of a transmon-based quantum information processor.

7.
Sci Data ; 11(1): 216, 2024 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-38365784

RESUMO

Crop residue cover plays a key role in the protection of black soil by covering the soil in the non-growing season against wind erosion and chopping for returning to the soil to increase organic matter in the future. Although there are some studies that have mapped the crop residue coverage by remote sensing technique, the results are mainly on a small scale, limiting the generalizability of the results. In this study, we present a novel corn residue coverage (CRC) dataset for Northeast China spanning the years 2013-2021. The aim of our dataset is to provide a basis to describe and monitor CRC for black soil protection. The accuracy of our estimation results was validated against previous studies and measured data, demonstrating high accuracy with a coefficient of determination (R2) of 0.7304 and root mean square error (RMSE) of 0.1247 between estimated and measured CRC in field campaigns. In addition, it is the first of its kind to offer the longest time series, enhancing its significance in long-term monitoring and analysis.

8.
J Med Internet Res ; 25: e47217, 2023 12 19.
Artigo em Inglês | MEDLINE | ID: mdl-38113097

RESUMO

BACKGROUND: Chatbots have become ubiquitous in our daily lives, enabling natural language conversations with users through various modes of communication. Chatbots have the potential to play a significant role in promoting health and well-being. As the number of studies and available products related to chatbots continues to rise, there is a critical need to assess product features to enhance the design of chatbots that effectively promote health and behavioral change. OBJECTIVE: This scoping review aims to provide a comprehensive assessment of the current state of health-related chatbots, including the chatbots' characteristics and features, user backgrounds, communication models, relational building capacity, personalization, interaction, responses to suicidal thoughts, and users' in-app experiences during chatbot use. Through this analysis, we seek to identify gaps in the current research, guide future directions, and enhance the design of health-focused chatbots. METHODS: Following the scoping review methodology by Arksey and O'Malley and guided by the PRISMA-ScR (Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews) checklist, this study used a two-pronged approach to identify relevant chatbots: (1) searching the iOS and Android App Stores and (2) reviewing scientific literature through a search strategy designed by a librarian. Overall, 36 chatbots were selected based on predefined criteria from both sources. These chatbots were systematically evaluated using a comprehensive framework developed for this study, including chatbot characteristics, user backgrounds, building relational capacity, personalization, interaction models, responses to critical situations, and user experiences. Ten coauthors were responsible for downloading and testing the chatbots, coding their features, and evaluating their performance in simulated conversations. The testing of all chatbot apps was limited to their free-to-use features. RESULTS: This review provides an overview of the diversity of health-related chatbots, encompassing categories such as mental health support, physical activity promotion, and behavior change interventions. Chatbots use text, animations, speech, images, and emojis for communication. The findings highlight variations in conversational capabilities, including empathy, humor, and personalization. Notably, concerns regarding safety, particularly in addressing suicidal thoughts, were evident. Approximately 44% (16/36) of the chatbots effectively addressed suicidal thoughts. User experiences and behavioral outcomes demonstrated the potential of chatbots in health interventions, but evidence remains limited. CONCLUSIONS: This scoping review underscores the significance of chatbots in health-related applications and offers insights into their features, functionalities, and user experiences. This study contributes to advancing the understanding of chatbots' role in digital health interventions, thus paving the way for more effective and user-centric health promotion strategies. This study informs future research directions, emphasizing the need for rigorous randomized control trials, standardized evaluation metrics, and user-centered design to unlock the full potential of chatbots in enhancing health and well-being. Future research should focus on addressing limitations, exploring real-world user experiences, and implementing robust data security and privacy measures.


Assuntos
Saúde Digital , Promoção da Saúde , Humanos , Comunicação , Benchmarking , Lista de Checagem , Ensaios Clínicos Controlados Aleatórios como Assunto
9.
J Agric Food Chem ; 71(49): 19434-19444, 2023 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-38014643

RESUMO

Tree-crop intercropping is of great significance in food security, land protection, and sustainable agriculture. However, the mechanisms of allelopathy between plant species during intercropping are still limited. This study focuses on the allelopathic effects in the intercropping between Camellia oleifera and Arachis hypogaea L. in southern China. We use different parts of the C. oleifera extract to evaluate their impact on peanut seed germination. The results showed that it has inhibitory effects on peanut germination and growth, with the fruit shell having the strongest inhibitory effect. Three main allelopathic substances affecting A. hypogaea germination and growth were identified using gas chromatography-mass spectrometry (GC-MS) analysis, namely, 2,4-di-tert-butylphenol, hexanal, and benzaldehyde. Transcriptomics and metabolomics analyses revealed their effects on glutathione metabolism pathways and specific gene expression. In summary, this study reveals the allelopathic interaction mechanism between C. oleifera and A. hypogaea, which helps to better understand the role of allelopathy in intercropping practices between trees and crops.


Assuntos
Alelopatia , Arachis , Arachis/química , Agricultura/métodos , Germinação , Produtos Agrícolas
10.
Adv Sci (Weinh) ; 10(35): e2302116, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37890462

RESUMO

Epstein-Barr virus (EBV) is associated with various malignancies and infects >90% of the global population. EBV latent proteins are expressed in numerous EBV-associated cancers and contribute to carcinogenesis, making them critical therapeutic targets for these cancers. Thus, this study aims to develop mRNA-based therapeutic vaccines that express the T-cell-epitope-rich domain of truncated latent proteins of EBV, including truncatedlatent membrane protein 2A (Trunc-LMP2A), truncated EBV nuclear antigen 1 (Trunc-EBNA1), and Trunc-EBNA3A. The vaccines effectively activate both cellular and humoral immunity in mice and show promising results in suppressing tumor progression and improving survival time in tumor-bearing mice. Furthermore, it is observed that the truncated forms of the antigens, Trunc-LMP2A, Trunc-EBNA1, and Trunc-EBNA3A, are more effective than full-length antigens in activating antigen-specific immune responses. In summary, the findings demonstrate the effectiveness of mRNA-based therapeutic vaccines targeting the T-cell-epitope-rich domain of EBV latent proteins and providing new treatment options for EBV-associated cancers.


Assuntos
Infecções por Vírus Epstein-Barr , Neoplasias , Camundongos , Animais , Herpesvirus Humano 4/genética , Infecções por Vírus Epstein-Barr/terapia , Epitopos de Linfócito T , Vacinas de mRNA , Proteínas de Membrana , RNA Mensageiro/genética
11.
Environ Sci Technol ; 57(36): 13356-13365, 2023 09 12.
Artigo em Inglês | MEDLINE | ID: mdl-37653579

RESUMO

To understand the nanotoxicity effects on plants, it is necessary to systematically study the distribution of NPs in vivo. Herein, elemental and particle-imaging techniques were used to unravel the size effects of ZnO NPs on phytotoxicity. Small-sized ZnO NPs (5, 20, and 50 nm) showed an inhibitory effect on the length and biomass of rice (Oryza sativa L.) used as a model plant. ZnO NP nanotoxicity caused rice root cell membrane damage, increased the malondialdehyde content, and activated antioxidant enzymes. As a control, the same dose of Zn2+ salt did not affect the physiological and biochemical indices of rice, suggesting that the toxicity is caused by the entry of the ZnO NPs and not the dissolved Zn2+. Laser ablation inductively coupled plasma optical emission spectroscopy analysis revealed that ZnO NPs accumulated in the rice root vascular tissues of the rhizodermis and procambium. Furthermore, transmission electron microscopy confirmed that the NPs were internalized to the root tissues. These results suggest that ZnO NPs may exist in the rice root system and that their particle size could be a crucial factor in determining toxicity. This study provides evidence of the size-dependent phytotoxicity of ZnO NPs.


Assuntos
Oryza , Óxido de Zinco , Tamanho da Partícula , Óxido de Zinco/toxicidade , Antioxidantes , Biomassa
12.
J Sci Food Agric ; 103(13): 6706-6718, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37276023

RESUMO

BACKGROUND: Alfalfa (Medicago sativa L.) has been used widely in preparing silage. However, forage legumes are prone to contamination by spoilage bacteria during fermentation. Nisin has broad-spectrum antibacterial properties and has been applied as an inhibitor of rumen methane emissions. However, little research has been carried out on the application of nisin in silage. This study therefore aimed to investigate the impacts of different nisin concentrations on the bacterial community and fermentation dynamics, in vitro ruminal fermentation characteristics, microbiota, and methane emissions of alfalfa silage. RESULTS: The detection limits of organic acid in nisin-treated silages were not reached in 0.09 g kg-1 nisin (0.09 level) from days 1 to 7 of ensiling. With increasing nisin concentrations, the silage dry matter increased linearly (P < 0.05), and dry matter loss decreased linearly (P < 0.05). Moreover, both the 0.06 g kg-1 nisin (0.06 level) and 0.09 level treatments increased the relative abundance of Pediococcus acidilactici during ensiling. Concurrently, as the nisin concentrations increased, ruminal methane production decreased linearly (P < 0.05), while the relative abundances of ruminal Succinivibrio, Fibrobacter succinogenes and Ruminobacter amylophilus increased linearly (P < 0.05). The populations of ruminal total bacteria, methanogens, protozoa, and fungi decreased linearly with increasing nisin concentrations (P < 0.05). CONCLUSION: The addition of nisin delayed the fermentation process, preserved more nutrients in alfalfa silage, and promoted fermentation dominated by P. acidilactici in the late phase of ensiling. Moreover, nisin reduced in vitro rumen methane emissions without adverse effects on dry matter digestibility. © 2023 Society of Chemical Industry.


Assuntos
Microbiota , Nisina , Animais , Feminino , Silagem/análise , Leite/química , Medicago sativa/microbiologia , Lactação , Dieta , Rúmen/metabolismo , Fermentação , Metano/metabolismo , Nisina/farmacologia , Digestão , Bactérias
13.
Environ Res ; 233: 116472, 2023 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-37348631

RESUMO

Inland waters are significant sources of atmospheric greenhouse gas (GHG) emissions. The thin boundary layer (TBL) model is often employed as a means of estimating GHG diffusion in inland waters based on gas transfer velocity (k) at the air-water interface, with k being subject to regulation by near-surface turbulence that is primarily driven by wind speed in many cases. This wind speed-based estimation of k (wind-k), however, can introduce substantial uncertainty for turbulent waterways where wind speed does not accurately represent overall turbulence. In this study, GHG diffusion in the Beijing-Hangzhou Grand Canal (China), the first and longest man-made canal in the world, was estimated using the TBL model, revealing that this model substantially underestimated GHG diffusion when relying on wind-k. Strikingly, the carbon dioxide, methane, and nitrous oxide diffusions were respectively underestimated by 159%, 162%, and 124% when using this model. These findings are significant for developing more reliable approaches to evaluate GHG emissions from inland waterways.


Assuntos
Gases de Efeito Estufa , Humanos , Dióxido de Carbono/análise , Vento , Metano/análise , China , Óxido Nitroso , Efeito Estufa
14.
Environ Sci Technol ; 57(21): 8035-8043, 2023 05 30.
Artigo em Inglês | MEDLINE | ID: mdl-37200099

RESUMO

Microplastics (MPs), as a new persistent pollutant, can be emitted and accumulated in urban environments, but there is no detailed information on the driving factors of MP pollution. In this study, through a large-scale wetland soil survey, the features of MPs were characterized in each urban area. The results showed an average abundance to be 379 n/kg in wetland soil. Polypropylene, fiber or fragment, and black color were common composition, shape, and color, respectively. The spatial distribution information showed that MP abundance was significantly relevant to the distance from the urban economic center. Furthermore, the correlation and regression analysis revealed that MP abundance was related to soil heavy metal and atmospheric particle (PM10 and PM2.5) concentrations (P < 0.05), while the promotion of socioeconomic activities (urbanization level, population density, etc.) may aggravate the pollution degree. Additionally, by using structural equation modeling, it was found that the urbanization level was the dominant factor driving the MP pollution degree, with a total effect coefficient of 0.49. Overall, this work provides multi-sided environmental information regarding MP pollution in urban ecosystems, which is significant for follow-up studies of MP pollution control and restoration.


Assuntos
Microplásticos , Poluentes Químicos da Água , Plásticos/análise , Áreas Alagadas , Ecossistema , Solo , Monitoramento Ambiental/métodos , Poluentes Químicos da Água/análise
15.
J Med Internet Res ; 25: e46084, 2023 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-37184899

RESUMO

BACKGROUND: Scholars have used data from in-person interviews, administrative systems, and surveys for sexual violence research. Using Twitter as a data source for examining the nature of sexual violence is a relatively new and underexplored area of study. OBJECTIVE: We aimed to perform a scoping review of the current literature on using Twitter data for researching sexual violence, elaborate on the validity of the methods, and discuss the implications and limitations of existing studies. METHODS: We performed a literature search in the following 6 databases: APA PsycInfo (Ovid), Scopus, PubMed, International Bibliography of Social Sciences (ProQuest), Criminal Justice Abstracts (EBSCO), and Communications Abstracts (EBSCO), in April 2022. The initial search identified 3759 articles that were imported into Covidence. Seven independent reviewers screened these articles following 2 steps: (1) title and abstract screening, and (2) full-text screening. The inclusion criteria were as follows: (1) empirical research, (2) focus on sexual violence, (3) analysis of Twitter data (ie, tweets or Twitter metadata), and (4) text in English. Finally, we selected 121 articles that met the inclusion criteria and coded these articles. RESULTS: We coded and presented the 121 articles using Twitter-based data for sexual violence research. About 70% (89/121, 73.6%) of the articles were published in peer-reviewed journals after 2018. The reviewed articles collectively analyzed about 79.6 million tweets. The primary approaches to using Twitter as a data source were content text analysis (112/121, 92.5%) and sentiment analysis (31/121, 25.6%). Hashtags (103/121, 85.1%) were the most prominent metadata feature, followed by tweet time and date, retweets, replies, URLs, and geotags. More than a third of the articles (51/121, 42.1%) used the application programming interface to collect Twitter data. Data analyses included qualitative thematic analysis, machine learning (eg, sentiment analysis, supervised machine learning, unsupervised machine learning, and social network analysis), and quantitative analysis. Only 10.7% (13/121) of the studies discussed ethical considerations. CONCLUSIONS: We described the current state of using Twitter data for sexual violence research, developed a new taxonomy describing Twitter as a data source, and evaluated the methodologies. Research recommendations include the following: development of methods for data collection and analysis, in-depth discussions about ethical norms, exploration of specific aspects of sexual violence on Twitter, examination of tweets in multiple languages, and decontextualization of Twitter data. This review demonstrates the potential of using Twitter data in sexual violence research.


Assuntos
Delitos Sexuais , Mídias Sociais , Humanos , Comunicação , Aprendizado de Máquina , Inquéritos e Questionários
16.
J Colloid Interface Sci ; 646: 855-862, 2023 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-37235931

RESUMO

Development of new anti-counterfeiting technology to increase the difficulty of imitation and decoding is becoming increasingly important, but still remains challenging yet. In this work, we report the design of new fluorescence photoswitches based on photochromic tungsten oxide quantum dots (WO3 QDs) for dual-mode anti-counterfeiting applications. Complexing photochromic WO3 QDs with fluorescent gold nanoclusters (AuNCs) enables the construction of a photoswitchable fluorescence system (WO3-AuNCs) based on fluorescence resonance energy transfer. Detailed spectral and photophysical characterization showed that WO3 QDs well-retain the photochromic properties within the WO3-AuNCs composite. Importantly, photoresponsive and highly reversible switching of both color and fluorescence signals was successfully achieved by simply alternating the irradiation with UV and visible light. Potential utility of photoswitchable WO3-AuNCs composite as novel dual-mode anti-counterfeiting materials has been successfully demonstrated, including photoswitchable ink, rewritable paper and number encryption. Compared with other anti-counterfeiting materials, the present photochromic WO3 QDs-based fluorescent switches are easily synthesized and handled, and they can provide dual security mode (color and fluorescence). This work provides a generable WO3 QDs-assisted strategy of fabricating advanced fluorescence photoswitches for versatile optical counterfeiting applications.

17.
Int J Biol Macromol ; 236: 123983, 2023 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-36907307

RESUMO

This work demonstrated a successful strategy that simple ionic liquids (ILs) mediated pretreatment could effectively reduce crystallinity of cellulose from 71 % to 46 % (by C2MIM.Cl) and 53 % (by C4MIM.Cl). The IL-mediated regeneration of cellulose greatly promoted its reactivity for TEMPO-catalyzed oxidation, which the resulting COO- density (mmol/g) increased from 2.00 for non-IL-treated cellulose to 3.23 (by C2MIM.Cl) and 3.42 (C4MIM.Cl); and degree of oxidation enhanced from 35 % to 59 % and 62 %, respectively. More significantly, the yield of oxidized cellulose increased from 4 % to 45-46 %, by 11-fold. IL-regenerated cellulose can also be directly subjected to alkyl/alkenyl succinylation without TEMPO-mediated oxidation, producing nanoparticles with properties similar to oxidized celluloses (55-74 nm in size, -70-79 mV zeta-potential and 0.23-0.26 PDI); but in a much higher overall yield (87-95 %) than IL-regeneration-coupling-TEMPO-oxidation (34-45 %). Alkyl/alkenyl succinylated TEMPO-oxidized cellulose showed 2-2.5 times higher ABTS* scavenging ability than non-oxidized cellulose; however, alkyl/alkenyl succinylation also resulted in a significant decline in Fe2+ chelating property.


Assuntos
Celulose Oxidada , Líquidos Iônicos , Nanopartículas , Líquidos Iônicos/química , Celulose/química , Celulose Oxidada/química , Nanopartículas/química , Oxirredução
18.
Biomater Sci ; 11(6): 2200-2210, 2023 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-36745434

RESUMO

While immunotherapy has emerged as a promising strategy to treat melanoma, the limited availability of immunotherapeutic agents in tumors due to the immunosuppressive tumor microenvironment dampens its efficacy. Pyroptosis is a gasdermin-mediated programmed necrosis that triggers the inflammatory tumor microenvironment and enhances the efficacy of tumor immunotherapy. Here, we prove that the CXCR4 antagonist T22 peptide specially targeted and became internalized into CXCR4+ melanoma cells. Then we report a self-assembling nanotoxin that can be used to spatiotemporally target CXCR4-expression melanoma cells and enable tunable cellular pyroptosis. Specific activation of caspase 3 signal transduction triggers gasdermin-E-mediated pyroptosis. This nanotoxin induces pyroptotic cell death resulting in enhanced antitumor efficacy and minimized systemic side effects toward melanoma in vivo. This study offers new insights into how to engineer nanotoxins with tunable pyroptosis activity through specifically targeting CXCR4 for biomedical applications.


Assuntos
Melanoma , Piroptose , Humanos , Gasderminas , Apoptose , Melanoma/tratamento farmacológico , Melanoma/metabolismo , Transdução de Sinais , Microambiente Tumoral , Receptores CXCR4/metabolismo
19.
Animals (Basel) ; 13(3)2023 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-36766274

RESUMO

The objective of this study was to investigate the effects of inoculating two bacteriocin-producing strains, Lactiplantibacillus plantarum ATCC14917 and LP1-4, at ensiling on the in vitro ruminal fermentation characteristics and methane production of alfalfa silage with two dry matter (DM)contents. Before ensiling, fresh alfalfa was wilted to a moderate DM content (355 g/kg) and a high DM content (428 g/kg). The wilted alfalfa was treated with (1) distilled water (control), (2) commercial strain L. plantarum MTD/1 (MTD/1), (3) bacteriocin-producing L. plantarum ATCC14917 (ATCC14917), and (4) a bacteriocin-like substance producing L. plantarum LP1-4 (LP1-4) at 1 × 105 colony forming units (CFU)/g fresh weight. After 90 d of ensiling, the silages were used for in vitro rumen fermentation. Inoculation with the two bacteriocin-producing strains at ensiling remarkably reduced (p < 0.05) in vitro ruminal CH4 production and enhanced DM digestibility compared with the control group regardless of DM content. For silages with high DM content, inoculation with the bacteriocin-producing strains even increased (p < 0.05) in vitro ruminal total volatile fatty acid production. Therefore, the bacteriocin-producing inoculants have a great potential to mitigate ruminal methane emission but without an adverse effect on rumen fermentation of the inoculated alfalfa silage.

20.
J Hazard Mater ; 447: 130762, 2023 04 05.
Artigo em Inglês | MEDLINE | ID: mdl-36638676

RESUMO

Microplastic threats to biodiversity, health and ecological safety are adding to concern worldwide, but the real impacts on the functioning of organisms and ecosystems are obscure owing to their inert characteristics. Here we investigated the long-lasting ecological effects of six prevalent microplastic types: polyethylene (PE), polypropylene (PP), polyamide (PA), polystyrene (PS), polyethylene terephthalate (PET), and polyvinyl chloride (PVC) on soil bacteria at a 2 % (w/w) level. Due to the inertia and lack of available nitrogen of these microplastics, their effects on bacteriome tended to converge after one year and were strongly different from their short-term effects. The soil volumes around microplastics were very specific, in which the microplastic-adapted bacteria (e.g., some genera in Actinobacteria) were enriched but the phyla Bacteroidetes and Gemmatimonadetes declined, resulting in higher microbial nitrogen requirements and reduced organic carbon mineralization. The reshaped bacteriome was specialized in the genetic potential of xenobiotic and lipid metabolism as well as related oxidation, esterification, and hydrolysis processes, but excessive oxidative damage resulted in severe weakness in community genetic information processing. According to model predictions, microplastic effects are indirectly derived from nutrients and oxidative stress, and the effects on bacterial functions are stronger than on structure, posing a heavy risk to soil ecosystems.


Assuntos
Microplásticos , Plásticos , Microplásticos/toxicidade , Plásticos/toxicidade , Ecossistema , Solo , Polipropilenos , Bactérias/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...