Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 832
Filtrar
1.
Sensors (Basel) ; 23(2)2023 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-36679422

RESUMO

k nearest neighbours (kNN) queries are fundamental in many applications, ranging from data mining, recommendation system and Internet of Things, to Industry 4.0 framework applications. In mining, specifically, it can be used for the classification of human activities, iterative closest point registration and pattern recognition and has also been helpful for intrusion detection systems and fault detection. Due to the importance of kNN queries, many algorithms have been proposed in the literature, for both static and dynamic data. In this paper, we focus on exact kNN queries and present a comprehensive survey of exact kNN queries. In particular, we study two fundamental types of exact kNN queries: the kNN Search queries and the kNN Join queries. Our survey focuses on exact approaches over high-dimensional data space, which covers 20 kNN Search methods and 9 kNN Join methods. To the best of our knowledge, this is the first work of a comprehensive survey of exact kNN queries over high-dimensional datasets. We specifically categorise the algorithms based on indexing strategies, data and space partitioning strategies, clustering techniques and the computing paradigm. We provide useful insights for the evolution of approaches based on the various categorisation factors, as well as the possibility of further expansion. Lastly, we discuss some open challenges and future research directions.


Assuntos
Algoritmos , Mineração de Dados , Humanos , Análise por Conglomerados , Resolução de Problemas
2.
Eur J Neurol ; 2023 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-36692876

RESUMO

BACKGROUND: It has been suggested that trimethylamine N-oxide (TMAO) is related to Parkinson's disease (PD) in observational studies. However, the direction of this association is inconsistent. An exploratory Mendelian randomisation study was conducted to investigate whether TMAO and its precursors have a causal relationship with PD. METHODS: We obtained summary statistics for single nucleotide polymorphisms related to circulating levels of TMAO, betaine, carnitine, choline, and the corresponding data for the risk, age at onset, and progression of PD from the genome-wide association studies. Inverse variance weighting was used as the primary method for effect estimation. The false discovery rate (FDR) was applied to the correction of multiple testing. The P-value of association < 0.05 but above the FDR-corrected threshold was deemed suggestive evidence of a possible association. A range of robust MR methods were used for sensitivity analysis. RESULTS: We observed suggestive evidence of inverse causal effect of TMAO on motor fluctuations (OR=0.851, 95%CI (0.731,0.990), P=0.037) and carnitine on insomnia (OR=0.817, 95%CI (0.700,0.954), P=0.010), and positive causal effect of betaine on Hoehn-Yahr stage (OR=1.397, 95%CI (1.112,1.756), P=0.004), Unified Parkinson's Disease Rating Scale (UPDRS) III score (ß=0.138, 95%CI (0.051,0.225), P=0.002), motor fluctuations (OR=1.236, 95%CI (1.011,1.511), P=0.039), and choline on UPDRS IV (ß=0.106, 95%CI (0.026,0.185), P=0.009) and modified Schwab and England Activities of Daily Living Scale score (ß=0.806, 95%CI (0.127,1.484), P=0.020). CONCLUSIONS: Our findings provide suggestive evidence that TMAO and its precursors have a causal effect on the progression of PD. Further investigation of the underlying mechanisms is required.

3.
Int J Biol Macromol ; 226: 813-822, 2023 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-36528141

RESUMO

The infection-prone wound pathology microenvironment leads to ulceration and difficult healing of diabetic wounds, which seriously affects the quality of survival of patients. In this study, natural polymer materials gelatin and polylysine were used as substrates. By introducing iron/tannic acid (FeIIITA) composite nanoparticles with excellent photothermal properties into the system, the glutamine residues of gelatin were crosslinked with the primary ammonia of polylysine by glutamine aminotransferase. A nanocomposite hydrogel with excellent antibacterial ability and NO production was constructed it was used to improve the clinical problems of diabetes wounds that were difficult to vascularize and easy to be infected. Under the premise of maintaining its structural stability, the hydrogel can be customized to meet the needs of different mechanical strengths by adjusting the ratios to match different diabetic wounds. Meanwhile, the photothermal effect of FeIIITA nanoparticles can synergize with the endogenous antibacterial ability of polylysine to improve the antibacterial efficacy of hydrogels. The potential of hydrogel to promote intracellular NO production was confirmed by fluorescent staining. Microneedle patches prepared from hydrogel can be applied to diabetic wounds, which can achieve NO deep release. Its anti-inflammatory and angiogenic abilities are also useful in achieving effective healing of diabetic wounds.


Assuntos
Diabetes Mellitus , Hidrogéis , Humanos , Hidrogéis/farmacologia , Hidrogéis/química , Gelatina/química , Polilisina/farmacologia , Cicatrização , Diabetes Mellitus/tratamento farmacológico , Antibacterianos/química
4.
Cancer Lett ; 554: 216031, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36481214

RESUMO

Pancreatic cancer is an increasingly growing source of cancer-related deaths and is often diagnosed at advanced stages. Its treatment is difficult because of the poor results of conventional treatments, such as surgery, chemotherapy, and radiotherapy. Microbiota and their products can regulate the microenvironment of pancreatic tumors, the biological behavior of pancreatic cancer cells, and the functionality of the immune system. Promising results have been achieved in treating pancreatic cancer by regulating microbiota. However, intratumoral microbiota is still in its infancy as a new field of discovery for pancreatic cancer. This review summarizes the mechanisms by which intratumoral microbiota causes pancreatic cancer tumorigenesis, progression, and metastasis and demonstrates their significant potential in diagnosing and treating pancreatic cancer. Additionally, we present an outlook on the future of intratumoral microbiota in treating pancreatic cancer.


Assuntos
Microbiota , Neoplasias Pancreáticas , Humanos , Microambiente Tumoral , Neoplasias Pancreáticas/diagnóstico , Neoplasias Pancreáticas/terapia , Neoplasias Pancreáticas/patologia , Pâncreas/patologia
5.
Chemosphere ; 313: 137647, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36574786

RESUMO

Harmful algal blooms (HABs) from seawater have a severe threat to human health, aquaculture, and coastal nuclear power safety. Thus, it is highly desirable to explore environmentally friendly, efficient, and economic methods for controlling HABs. Herein, the arbutin-modified cellulose nanocrystals (AT-CNC) activated persulfate (PS), as a novel heterogeneous Fenton-like process, was proposed to remove Phaeocystis globosa (P. globosa) from seawater. The AT-CNC was synthesized via the surface modification of AT on CNC. The effects of AT dosage, CNC dosage, and PS dosage on the removal performance of P. globosa were investigated. With the addition of 530 mg/L AT-CNC (6 wt% AT/CNC of AT loading) and 120 mg/L PS, the removal percentage of chlorophyll a (Rc), optical density at 680 nm (Ro) and turbidity (Rt) reached 97.7%, 91.9% and 85.2% at 24 h. According to electron paramagnetic resonance (EPR) spectra and radical quenching tests, the predominant free radicals inactivating P. globosa were hydroxyl radicals (•OH). Additionally, the flocculation of the inactivated algae cells by AT-CNC was also critical for removing P. globosa. Moreover, a positive environmental impact was achieved in the AT-CNC-PS system due to the reduction of nitrogen, phosphorus and organic carbon contents. Based on the excellent removal performance for P. globosa, we believe that the AT-CNC activated persulfate is a promising option for HABs control.


Assuntos
Haptófitas , Humanos , Arbutina/farmacologia , Clorofila A , Proliferação Nociva de Algas , Água do Mar
6.
J Agric Food Chem ; 2022 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-36468551

RESUMO

Tetrahydroxy stilbene glucoside (TSG) is a bioactive ingredient with powerful anti-inflammatory and neuroprotective properties. However, the detailed mechanisms concerning the neuroprotective effect of TSG are not fully understood. This study aims to address the molecular mechanism involved in the protective effects of TSG on murine ischemic stroke. We found that TSG meliorated the phenotypes of ischemic stroke in vivo, which was correlated with the increased percentage of infiltrated M2 macrophages in brain after stroke. Mechanistically, TSG regulated macrophage polarization by significantly downregulating the transcriptional levels of M1 marker genes (iNOS and IL-1ß) but upregulating that of the M2 marker genes (arg-1 and IL-4) following lipopolysaccharide/interferon-γ stimulation. Consistently, TSG reversed the metabolic profiling of M1 macrophage toward the M2 status at intracellular energy levels. Surprisingly, the knockdown of an established metabolic enzyme pyruvate kinase M2 (PKM2) that is important for M1 switch in macrophages abolished the promotive effect of TSG on the M2 polarization. Further investigation revealed that TSG markedly downregulated the intracellular ratio of dimer/monomer to the tetramer of PKM2 without affecting its total protein expression, leading to a suppressed nuclear translocation of functioning PKM2 in macrophages for M1 differentiation. Taken together, we identified a novel mechanism for macrophage M2 polarization regulation by a small-molecule chemical that controls the quality (conformation) rather than the quantity (expression) of an intracellular M1-promoting metabolic enzyme, which offers a better understanding of the mechanisms of macrophage plasticity and has serious implication in translational strategies for the treatment of macrophage-mediated neurological diseases with natural bioactive products.

7.
PLoS One ; 17(12): e0277906, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36454795

RESUMO

Facing increasingly severe environmental problems, as the largest developing country, achieving regional carbon emission reduction is the performance of China's fulfillment of the responsibility of a big government and the key to the smooth realization of the global carbon emission reduction goal. Since China's carbon emission data is updated slowly, in order to better formulate the corresponding emission reduction strategy, it is necessary to propose a more accurate carbon emission prediction model on the basis of fully analyzing the characteristics of carbon emissions at the provincial and regional levels. Given this, this paper first calculated the carbon emissions of eight economic regions in China from 2005 to 2019 according to relevant statistical data. Secondly, with the help of kernel density function, Theil index and decoupling index, the dynamic evolution characteristics of regional carbon emissions are discussed. Finally, an improved particle swarm optimization radial basis function (IPSO-RBF) neural network model is established to compare the simulation and prediction models of China's carbon emissions. The results show significant differences in carbon emissions in different regions, and the differences between high-value and low-value areas show an apparent expansion trend. The inter-regional carbon emission difference is the main factor in the overall carbon emission difference. The economic region in the middle Yellow River (ERMRYR) has the most considerable contribution to the national carbon emission difference, and the main contributors affecting the overall carbon emission difference in different regions are different. The number of regions with strong decoupling between carbon emissions and economic development is increasing in time series. The results of the carbon emission prediction model can be seen that IPSO-RBF neural network model optimizes the radial basis function (RBF) neural network, making the prediction result in a minor error and higher accuracy. Therefore, when exploring the path of carbon emission reduction in different regions in the future, the IPSO-RBF neural network model is more suitable for predicting carbon emissions and other relevant indicators, laying a foundation for putting forward more scientific and practical emission reduction plans.


Assuntos
Carbono , Desenvolvimento Econômico , Redes Neurais de Computação , China , Simulação por Computador
8.
Front Bioeng Biotechnol ; 10: 1078626, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36561049

RESUMO

The shortage of phosphorus (P) as a resource represents a major challenge for the sustainable development of agriculture. Manure has a high P content and is a potential substitute for mineral P fertilizers. However, little is known about the effects on soil P availability and soil microbial P transformation of substituting manure for mineral P fertilizers. In this study, variations in soil P availability and bacterial P mobilization were evaluated under treatment with manure as compared to mineral P fertilizers. In the greenhouse fruit and vegetable production system that provided the setting for the study, substitution of manure for mineral P (PoR treatment) resulted in a similar level of soil total P and a similar fruit and vegetable yield as compared to traditional fertilization, but a significantly increased level of soil available P. In addition, PoR treatment enhanced bacterial organic P mineralization potential and decreased inorganic P dissolution potential. These results demonstrate that manure application increases the availability of soil P primarily by enhancing soil microbial Po mineralization, indicating the potential feasibility of applying manure instead of mineral P fertilizers in greenhouse farming.

9.
Langmuir ; 38(51): 16183-16193, 2022 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-36520051

RESUMO

Multilayer hyperbolic metamaterial (HMM)-based SERS substrates have received special consideration because they accommodate various propagation modes such as surface plasmonic polaritons (SPP). However, the SPP modes are difficult to generate in HMM due to their weak electric field enhancement. In this article, we designed novel SERS substrates consisting of graphene-covered AgNPs and HMM. The graphene-covered AgNPs work as an external coupling structure for hyperbolic metamaterials due to this structure exhibiting significant plasmonic effects as well as unique optical features. The localized surface plasmonic resonance (LSPR) of the graphene-covered AgNPs excited the SPP and thus formed a strong hot spot zone in the nanogap area of the graphene. The Raman experiment was performed using rhodamine 6G (R6G) and crystal violet (CV), which showed high stability and a maximum enhancement factor of 2.12 × 108. The COMSOL simulation further clarified that enhanced SERS performance was due to the presence of monolayer graphene and provided an atomically flat surface for organic molecules in a more controllable manner. Interestingly, the proposed SERS structure carries out quantitative detection of thiram in soil and can satisfy the basic environmental need for pesticide residue in the soil.

10.
Dig Liver Dis ; 2022 Dec 24.
Artigo em Inglês | MEDLINE | ID: mdl-36572570

RESUMO

The asparaginase-like protein 1 (ASRGL1) catalyzes the hydrolysis of L-asparagine to L-aspartic acid and ammonia. Emerging evidences have shown a strong correlation between ASRGL1 expression and tumorigenesis. However, the expression and biological function of ASRGL1 in hepatocellular carcinoma (HCC) are still unclear. Here, we explored anti-tumor activity and fundamental mechanisms of ASRGL1 blockade in the HCC progression. Expression levels of ASRGL1 in patients with HCC were higher than those in the adjacent normal tissue. In addition, increased expression of ASRGL1 in HCC patients was correlated with poor overall survival. Knockdown of ASRGL1 gene in HepG2 and Li-7 cell lines inhibited cell proliferation, migration and invasion, but promoted apoptosis in vitro. ASRGL1 knockdown suppressed tumor growth in vivo. Conversely, ASRGL1 overexpression promoted cell proliferation, migration and invasion in HepG2 cells. Through bioinformatics analysis, we found that ASRGL1 might participate in the regulation of the cell cycle. Flow cytometry analysis conformed that ASRGL1 knockdown captured the cell cycle during the G2/M phase. ASRGL1 blockade promoted P53 protein expression and reduced expression of cyclin B and CDK1 proteins, as well as failed to binding. Moreover, CDK1 overexpression was able to reverse the decreased proliferation, migration and invasion of HepG2 cells induced by ASRGL1 knockdown. Collectively, our studies indicate that ASRGL1 blockade functions to inhibit cyclin B/CDK1-dependent cell cycle, leading to G2-to-M phase transition failure and tumor suppression in HCC.

12.
Dig Dis ; 2022 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-36535266

RESUMO

BACKGROUND: Single nucleotide polymorphism (SNP) of candidate genes also affects the occurrence and prognosis of liver cancer. We mainly explored the effects of PIK3R3 and NOTCH2 polymorphisms on liver cancer risk among Chinese people. METHODS: Four SNPs (rs785468, rs785467, rs3795666, and rs17024525 in PIK3R3 and NOTCH2) from 709 liver cancer patients and 700 healthy controls were genotyped using the Agena MassARRAY system. The correlation between SNPs and liver cancer risk was evaluated using logistic regression analysis. The SNP-SNP interactions were conducted by the multifactor dimensionality reduction (MDR) method. RESULTS: The results revealed that PIK3R3-rs785467 reduced the likelihood of liver cancer among Chinese Han people (p < 0.05). In addition, PIK3R3-rs785467 decreased the susceptibility to liver cancer in different populations (females, non-smokers, and age > 55 years, p < 0.05). NOTCH2-rs3795666 reduced the susceptibility to liver cancer among males, drinkers, and patients aged ≥ 55 years (p < 0.05). CONCLUSIONS: Our results demonstrate that PIK3R3-rs785476 and NOTCH2-rs3795666 polymorphisms are responsible for decreasing the susceptibility of liver cancer development in the Chinese Han population.

13.
Eur Radiol ; 2022 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-36538072

RESUMO

OBJECTIVES: To evaluate AI biases and errors in estimating bone age (BA) by comparing AI and radiologists' clinical determinations of BA. METHODS: We established three deep learning models from a Chinese private dataset (CHNm), an American public dataset (USAm), and a joint dataset combining the above two datasets (JOIm). The test data CHNt (n = 1246) were labeled by ten senior pediatric radiologists. The effects of data site differences, interpretation bias, and interobserver variability on BA assessment were evaluated. The differences between the AI models' and radiologists' clinical determinations of BA (normal, advanced, and delayed BA groups by using the Brush data) were evaluated by the chi-square test and Kappa values. The heatmaps of CHNm-CHNt were generated by using Grad-CAM. RESULTS: We obtained an MAD value of 0.42 years on CHNm-CHNt; this result indicated an appropriate accuracy for the whole group but did not indicate an accurate estimation of individual BA because with a kappa value of 0.714, the agreement between AI and human clinical determinations of BA was significantly different. The features of the heatmaps were not fully consistent with the human vision on the X-ray films. Variable performance in BA estimation by different AI models and the disagreement between AI and radiologists' clinical determinations of BA may be caused by data biases, including patients' sex and age, institutions, and radiologists. CONCLUSIONS: The deep learning models outperform external validation in predicting BA on both internal and joint datasets. However, the biases and errors in the models' clinical determinations of child development should be carefully considered. KEY POINTS: • With a kappa value of 0.714, clinical determinations of bone age by using AI did not accord well with clinical determinations by radiologists. • Several biases, including patients' sex and age, institutions, and radiologists, may cause variable performance by AI bone age models and disagreement between AI and radiologists' clinical determinations of bone age. • AI heatmaps of bone age were not fully consistent with human vision on X-ray films.

14.
ACS Appl Mater Interfaces ; 14(51): 56975-56985, 2022 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-36524828

RESUMO

Organic semiconductors have been discovered to exhibit impressive surface-enhanced Raman scattering (SERS) activity recently. However, owing to the underdeveloped candidate materials and relatively low SERS sensitivity, practical application of SERS detection based on organic materials is still a challenge. Herein, we explored ways to further enhance the SERS sensitivity of π-conjugated fluorinated 7,7,8,8-tetracyanoquinodimethane derivatives (FnTCNQ, n = 2, 4) by utilizing the charge-localization effect induced by two-dimensional (2D) MoS2 flakes. A strong Raman signal enhancement in SERS has been realized via an organic/2D heterostructure constructed by FnTCNQ nanostructures grown on a 2D MoS2 flake. Moreover, F2TCNQ and F4TCNQ show different SESR sensitivities due to different numbers of cyano groups leading to different charge transfer (CT) directions. The SERS enhancement factor (EF) of methylene blue (MB) molecules on the optimal F4TCNQ/MoS2 nanocomposite substrate can reach as high as 2.531 × 106, and the concentration of the limit of detection (LOD) is as low as 10-10 M. The SERS results for MB, rhodamine 6G (R6G), and 4-aminothiophenol (4-ATP) molecules demonstrate that high versatility, low cost, good stability, and easy preparation will make the FnTCNQ/MoS2 SERS platform promising for the detection of trace molecules. The studies on the complex microscopic interaction of organic/2D composite nanomaterials will provide some novel insights into improved SERS performance and mechanisms.

15.
Artigo em Inglês | MEDLINE | ID: mdl-36554957

RESUMO

Under the background of rural revitalization in China, with the process of urbanization and the implementation of China's land system reform, rural workers gradually gain multiple income streams. However, increasing agricultural income remains the final guarantee for professional farmers to shake off poverty, and land is still their last security. We applied the OLS model and mediation model to a dataset of 3789 households in 25 provinces obtained from China Family Panel Studies (CFPS) to investigate the influence of farmland transfer and social capital on farmers' agricultural incomes. The results show that farmland "transfer in" and social capital significantly help to increase agricultural income directly, and farmland "transfer in" behavior plays a vital mediating role, influencing the positive effect of social capital on agricultural income. The study examined the logical social capital-agricultural land transfer-agricultural income correlation in the progression of rural society, from "hollow" to "reflux", under the continuous expansion of rural revitalization strategies, which is of great practical significance for re-recognizing the positive role of rural social capital and agricultural land transfer in improving the income of professional farmers and realizing the overall goal of rural revitalization. The results also provide a theoretical basis for guiding and leveraging the effective use of social capital to promote agricultural land transfer.


Assuntos
Capital Social , Humanos , Agricultura , Fazendas , População Rural , Fazendeiros , Renda , China
16.
Chem Biodivers ; : e202201174, 2022 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-36573597

RESUMO

Guaiazulene and related derivatives were famous for diverse biological activities. In an effort to discover new highly efficient candidate drugs derived from guaiazulene, four series of guaiazulene derivatives were designed, synthesized, and evaluated for antiproliferation, antiviral, anti-inflammatory and peroxisome proliferators-activated receptor γ (PPARγ) signalling pathway agonist activities. Among them, two guaiazulene condensation derivatives showed selective cytotoxic activities towards K562 cell with IC50 values 5.21 µM and 5.14 µM, respectively, accompanied by slight effects on normal cell viability. For the first time, one guaiazulene derivative from series I exhibited potent antiviral activity towards influenza A virus with IC50 of 17.5 µM. A guaiazulene-based chalcone showed higher anti-inflammatory activity than positive drug indomethacin with an inhibitory rate of 34.29 % in zebrafish model in vivo. One guaiazulene-based flavonoid could strongly agitate PPARγ pathway at 20 µM, indicating the potential of guaiazulene derivatives to reduce obesity development and ameliorate hepatic steatosis. Preliminary in silico ADME studies predicted the excellent drug-likeness properties of bioactive guaiazulene derivatives.

17.
Biomolecules ; 12(12)2022 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-36551229

RESUMO

Interleukin-18 (IL-18) can effectively activate natural killer (NK) cells and induce large concentrations of interferon-γ (IFN-γ). In healthy humans, IL-18 binding protein (IL-18BP) can inhibit the binding of IL-18 to IL-18R and counteract the biological action of IL-18 due to its high concentration and high affinity, thus preventing the production of IFN-γ and inhibiting NK-cell activation. Through previous studies and the phenomena observed by our group in pig-non-human primates (NHPs) liver transplantation experiments, we proposed that the imbalance in IL-18/IL-18BP expression upon transplantation encourages the activation, proliferation, and cytotoxic effects of NK cells, ultimately causing acute vascular rejection of the graft. In this research, we used Lewis-Brown Norway rat orthotopic liver transplantation (OLTx) as a model of acute vascular rejection. AAV8-Il18bp viral vectors as gene delivery vehicles were constructed for gene therapy to overexpress IL-18BP and alleviate NK-cell rejection of the graft after transplantation. The results showed that livers overexpressing IL-18BP had reduced damage and could function longer after transplantation, effectively improving the survival time of the recipients.


Assuntos
Vasos Sanguíneos , Terapia Genética , Rejeição de Enxerto , Sobrevivência de Enxerto , Interleucina-18 , Transplante de Fígado , Animais , Ratos , Rejeição de Enxerto/prevenção & controle , Interferon gama/genética , Interferon gama/metabolismo , Interleucina-18/genética , Interleucina-18/metabolismo , Transplante de Fígado/métodos , Ratos Endogâmicos Lew , Sobrevivência de Enxerto/genética , Vasos Sanguíneos/imunologia , Vetores Genéticos
18.
Int J Biol Macromol ; 223(Pt A): 939-949, 2022 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-36395937

RESUMO

Endoscopic submucosal dissection (ESD) is one of the most effective approaches for the minimally invasive treatment of early gastrointestinal cancers. Submucosal injections help safely and successfully remove lesions during ESD by elevating the mucosa and separating the submucosal muscle layer. Herein, we report dynamic injectable sodium alginate hydrogels (ISAHs) with shear-thinning for ESD surgery, which were easily fabricated by the sulfhydryl group of GSH-modified sodium alginate (SA-GSH) reacting with the aldehyde group of oxidized sodium alginate (OSA) at room temperature. ISAHs have advantageous self-healing abilities and antioxidant activity. Additionally, according to an in vitro test on porcine colorectal submucosal lifting, the submucosal elevation heights created by ISAHs were 13 % -18 % greater than those created by commercial ESD solutions (0.4 w/v% sodium hyaluronate). These properties and biocompatibility were confirmed in vitro and in vivo experiments. ISAHs will hopefully become a novel submucosal injectable hydrogel to assist ESD surgery.

19.
Int J Biol Macromol ; 223(Pt A): 950-960, 2022 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-36375676

RESUMO

Cutaneous wound management remains a major concern due to uncontrolled inflammation and bacterial infection in clinical care. A desirable hydrogel dressing with antibacterial and antioxidative properties can drive wound healing by inhibiting infection and inflammation. Herein, a multifunctional hydrogel based on polylysine-graft-cysteine (EPL-SH)/oxidized dextran (ODex) was fabricated for promoting skin tissue regeneration. The engineered hydrogel possessed versatile properties including tunable gelation time (60-300 s), typical rheological behavior, suitable swelling and degradation progress, injectable and self-healing ability. The unique hydrogels also displayed promising tissue adhesiveness, high cell affinity, excellent antioxidant and antimicrobial activity. Furthermore, the in vivo full-thickness skin defect experiment demonstrated the simple-to-implement injectable hydrogels could significantly promoting wound healing by improving the collagen deposition and angiogenesis. The manufacture of our multifunctional hydrogels dressing affords a new strategy for improving efficacy of cutaneous wound treatment.

20.
J Funct Biomater ; 13(4)2022 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-36412862

RESUMO

Magnesium has been extensively utilized to modify titanium implant surfaces based on its important function in promoting osteogenic differentiation. Autophagy has been proven to play a vital role in bone metabolism. Whether there is an association between autophagy and magnesium in promoting osteogenic differentiation remains unclear. In the present study, we focused on investigating the role of magnesium ions in early osteogenic activity and the underlying mechanism related to autophagy. Different concentrations of magnesium were embedded in micro-structured titanium surface layers using the micro-arc oxidation (MAO) technique. The incorporation of magnesium benefited cell adhesion, spreading, and viability; attenuated intracellular ATP concentrations and p-mTOR levels; and upregulated p-AMPK levels. This indicates the vital role of the ATP-related AMPK/mTOR signaling pathway in the autophagy process associated with osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) induced by magnesium modification on titanium surfaces. The enhanced osteogenic differentiation and improved cellular autophagy activity of BMSCs in their extraction medium further confirmed the function of magnesium ions. The results of the present study advance our understanding of the mechanism by which magnesium regulates BMSC osteogenic differentiation through autophagy regulation. Moreover, endowing implants with the ability to activate autophagy may be a promising strategy for enhancing osseointegration in the translational medicine field in the future.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...