Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 340
Filtrar
1.
ChemSusChem ; : e202400038, 2024 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-38771426

RESUMO

Perovskite solar cells (PSCs) are usually modified and passivated to improve their performance and stability. The interface modification and bulk doping are the two basic strategies. Fluorine (F)-containing materials are highly favored because of their unique hydrophobicity and coordination ability. This review discusses the basic characteristics of F, and the basic principles of improving the photovoltaic performance and stability of PSC devices using F-containing materials. We systematically summarized the latest progress in the application of F-containing materials to achieve efficient and stable PSCs on several key interface layers. It is believed that this work will afford significant understanding and inspirations toward the future application directions of F-containing materials in PSCs, and provide profound insights for the development of efficient and stable PSCs.

2.
Comput Biol Med ; 176: 108620, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38761500

RESUMO

Predicting three-dimensional (3D) protein structures has been challenging for decades. The emergence of AlphaFold2 (AF2), a deep learning-based machine learning method developed by DeepMind, became a game changer in the protein folding community. AF2 can predict a protein's three-dimensional structure with high confidence based on its amino acid sequence. Accurate prediction of protein structures can dramatically accelerate our understanding of biological mechanisms and provide a solid foundation for reliable drug design. Although AF2 breaks through the barriers in predicting protein structures, many rooms remain to be further studied. This review provides a brief historical overview of the development of protein structure prediction, covering template-based, template-free, and machine learning-based methods. In addition to reviewing the potential benefits (Pros) and considerations (Cons) of using AF2, this review summarizes the diverse applications, including protein structure predictions, dynamic changes, point mutation, integration of language model and experimental data, protein complex, and protein-peptide interaction. It underscores recent advancements in efficiency, reliability, and broad application of AF2. This comprehensive review offers valuable insights into the applications of AF2 and AF2-inspired AI methods in structural biology and its potential for clinically significant drug target discovery.

3.
J Food Sci ; 2024 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-38720576

RESUMO

Salted egg yolks from salted duck eggs are widely utilized in the domestic and international food industry as both raw materials and ingredients. When salted egg yolks are not fully cured and matured, they exist in a fluid state, with a mixture of solid and liquid internally. Due to this composition, they are susceptible to deterioration during storage and usage, necessitating their detection and classification. In this study, a dataset specifically for salted egg yolks was established, and the ConvNeXt-T model, employed as the benchmark model, underwent two notable improvements. First, a lightweight location-aware circular convolution (ParC) was introduced, utilizing a ParC-block to replace a portion of the original ConvNeXt-T block. This enhancement aimed to overcome the limitations of convolution in extracting global feature information while integrating the global sensing capability of vision transformer and the localization capability of convolution. Additionally, the activation function was modified through substitution. These improvements resulted in the final model. Experimental results indicate that the enhanced model exhibits faster convergence on the custom salted egg yolk dataset compared to the baseline model. Furthermore, a significant reduction of model parameters by a factor of 4 led to a 2.167 percentage point improvement in the accuracy of the test set. The ParC-ConvNeXt-SMU-T model achieved an accuracy of 96.833% with 26.8 million parameters. Notably, the improved model demonstrates exceptional effectiveness in recognizing salted egg yolks. PRACTICAL APPLICATION: This study can be widely applied in the process of salted egg yolk production and quality inspection, which can improve the actual sorting efficiency of salted egg yolks and reduce the labor cost at the same time. It can also be used for nondestructive testing of salted egg yolks by governmental enterprises and other regulatory authorities.

4.
Bioresour Technol ; 401: 130711, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38641302

RESUMO

Lithium carboxymethyl cellulose (CMC-Li) is a promising novel water-based binder for lithium-ion batteries. The direct synthesis of CMC-Li was innovatively developed using abundant wood dissolving pulp materials from hardwood (HW) and softwood (SW). The resulting CMC-Li-HW and CMC-Li-SW binders possessed a suitable degree of substitutions and excellent molecular weight distributions with an appropriate quantity of long- and short-chain celluloses, which facilitated the construction of a reinforced concrete-like bonding system. When used as cathode binders in LiFePO4 batteries, they uniformly coated and dispersed the electrode materials, formed a compact and stable conductive network with high mechanical strength and showed sufficient lithium replenishment. The prepared LiFePO4 batteries exhibited good mechanical stability, low charge transfer impedance, high initial discharge capacity (∼180 mAh/g), high initial Coulombic efficiency (99 %), excellent cycling performance (<3% loss over 200 cycles) and good rate capability, thereby outperforming CMC-Na and the widely used cathode binder polyvinylidene fluoride.


Assuntos
Carboximetilcelulose Sódica , Fontes de Energia Elétrica , Eletrodos , Lítio , Madeira , Lítio/química , Madeira/química , Carboximetilcelulose Sódica/química , Fosfatos/química , Íons , Ferro
5.
Plants (Basel) ; 13(8)2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38674475

RESUMO

Climate change inevitably affects vegetation growth in the Tibetan Plateau (TP). Understanding the dynamics of vegetation phenology and the responses of vegetation phenology to climate change are crucial for evaluating the impacts of climate change on terrestrial ecosystems. Despite many relevant studies conducted in the past, there still remain research gaps concerning the dominant factors that induce changes in the start date of the vegetation growing season (SOS). In this study, the spatial and temporal variations of the SOS were investigated by using a long-term series of the Normalized Difference Vegetation Index (NDVI) spanning from 2001 to 2020, and the response of the SOS to climate change and the predominant climatic factors (air temperature, LST or precipitation) affecting the SOS were explored. The main findings were as follows: the annual mean SOS concentrated on 100 DOY-170 DOY (day of a year), with a delay from east to west. Although the SOS across the entire region exhibited an advancing trend at a rate of 0.261 days/year, there were notable differences in the advancement trends of SOS among different vegetation types. In contrast to the current advancing SOS, the trend of future SOS changes shows a delayed trend. For the impacts of climate change on the SOS, winter Tmax (maximum temperature) played the dominant role in the temporal shifting of spring phenology across the TP, and its effect on SOS was negative, meaning that an increase in winter Tmax led to an earlier SOS. Considering the different conditions required for the growth of various types of vegetation, the leading factor was different for the four vegetation types. This study contributes to the understanding of the mechanism of SOS variation in the TP.

6.
Sci Total Environ ; 928: 172534, 2024 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-38636852

RESUMO

Soil aggregates are crucial for reducing soil erosion and enhancing soil organic carbon sequestration. However, knowledge regarding influences of different slope positions on compositions and carbon content for different soil aggregates is limited. Soil samples were collected from various slope positions including dip slope, anti-dip slope and valley depression in the Longtan karst valley of Southwest China. Contents of macroaggregate (> 0.25 mm), microaggregate (0.053-0.25 mm) and silt and clay fraction (< 0.053 mm), and aggregate-associated carbon contents under the three slope positions were measured. Compared to the anti-dip slope, the mean weight diameter under the dip slope and valley depression decreased by 28.48 % and 58.79 %, respectively, while the geometric mean diameter decreased by 39.01 % and 62.57 %, respectively. The mean carbon content in silt and clay fraction was 27.59 % and 21.00 % lower than the macroaggregate- and microaggregate-associated carbon content, respectively. Under the valley depression and dip slope, soil organic carbon contents in bulk soil (37.67 % and 10.36 %, respectively), microaggregate (37.56 % and 4.95 %), and silt and clay fraction (39.99 % and 12.84 %, respectively) were significantly lower than those under the anti-dip slope. However, the difference in macroaggregate-associated carbon content among the three slope positions was not significant. The silt and clay fraction was the major contributor to soil carbon pool in bulk soil in the study area because of its high content. Compared to the anti-dip slope, contribution of macroaggregates to soil carbon pool under the dip slope and valley depression decreased by 25.53 % and 47.95 %, respectively, whereas the contribution of silt and clay fraction increased by 22.68 % and 42.66 %, respectively. These results suggested that the anti-dip slope surpassed both the dip slope and valley depression in carbon sequestration and soil and water conservation in karst regions.

7.
Artigo em Inglês | MEDLINE | ID: mdl-38685787

RESUMO

BACKGROUND: Periodontitis is a common complication of diabetes, with advanced glycation end products (AGEs) playing a key role in its pathogenesis. Albiflorin, a monoterpene glycoside, has shown potential anti-inflammatory and antioxidant properties. This study aims to investigate the effects of albiflorin on AGEs-induced gingival fibroblasts and its underlying mechanisms. OBJECTIVE: This study aimed to evaluate the role of albiflorin in mitigating ROS production, inflammation, and MMP-1 expression in AGEs-induced gingival fibroblasts. METHODS: The viability of gingival fibroblasts treated with albiflorin and AGEs was assessed using CCK-8 assays. ROS levels were measured by DCF staining, and the expression of inflammatory markers and MMP-1 was evaluated by ELISA and qPCR. The involvement of the NF-κB and Nrf2 pathways was examined by immunoblotting. RESULTS: Albiflorin enhanced the viability of AGEs-induced gingival fibroblasts and reduced ROS production. It also decreased the expression of IL-6, IL-8, RAGE, and MMP-1, suggesting an anti- inflammatory effect. Mechanistically, albiflorin modulated the NF-κB and Nrf2 pathways in AGEs-induced gingival fibroblasts. CONCLUSION: Albiflorin exhibited protective effects against AGEs-induced oxidative stress and inflammation in gingival fibroblasts, highlighting its potential as a therapeutic agent for periodontitis in diabetic patients. The modulation of the NF-κB and Nrf2 pathways by albiflorin provides insight into its mechanism of action.

8.
J Environ Manage ; 357: 120749, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38552517

RESUMO

The traditional solidification/stabilization (S/S) technology, Ordinary Portland Cement (OPC), has been widely criticized due to its poor resistance to chloride and significant carbon emissions. Herein, a S/S strategy based on magnesium potassium phosphate cement (MKPC) was developed for the medical waste incineration fly ash (MFA) disposal, which harmonized the chlorine stabilization rate and potential carbon emissions. The in-situ XRD results indicated that the Cl- was efficiently immobilized in the MKPC system with coexisting Ca2+ by the formation of stable Ca5(PO4)3Cl through direct precipitation or intermediate transformation (the Cl- immobilization rate was up to 77.29%). Additionally, the MFA-based MKPC also demonstrated a compressive strength of up to 39.6 MPa, along with an immobilization rate exceeding 90% for heavy metals. Notably, despite the deterioration of the aforementioned S/S performances with increasing MFA incorporation, the potential carbon emissions associated with the entire S/S process were significantly reduced. According to the Life Cycle Assessment, the potential carbon emissions decreased to 8.35 × 102 kg CO2-eq when the MFA reached the blending equilibrium point (17.68 wt.%), while the Cl- immobilization rate still remained above 65%, achieving an acceptable equilibrium. This work proposes a low-carbon preparation strategy for MKPC that realizes chlorine stabilization, which is instructive for the design of S/S materials.


Assuntos
Compostos de Magnésio , Resíduos de Serviços de Saúde , Metais Pesados , Fosfatos , Compostos de Potássio , Eliminação de Resíduos , Cinza de Carvão , Magnésio , Cálcio , Potássio , Cloro , Carbono , Cloretos , Incineração/métodos , Metais Pesados/análise , Resíduos Sólidos , Material Particulado , Eliminação de Resíduos/métodos
9.
Gynecol Endocrinol ; 40(1): 2312895, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38444321

RESUMO

OBJECTIVE: To investigate the differences in the metabolic indicators and sex hormones between obese and non-obese patients with polycystic ovary syndrome (PCOS), and their impacts on endometrial receptivity (ER). METHODS: We selected 255 individuals with PCOS, and categorized them into the obese groups, including the OP group (obese patients with PCOS) and the ON group (obese patients without PCOS), and selected 64 individuals who were categorized in the non-obese groups, namely, the control groups, which comprise the NP group (non-obese patients with PCOS) and the NN group(non-obese patients without PCOS). The one-way analysis of variance (ANOVA) and Mann-Whitney U tests were used to compare the metabolic indicators, and sex hormone-associated and ER-associated indicators between the groups. The correlation between the aforementioned clinical markers and ER was analyzed using the Pearson's correlation coefficient. RESULTS: (1) In comparison with the NP group, the OP group exhibited higher levels (p < .01) of free androgen index (FAI), anti-müllerian hormone (AMH), fasting insulin (FINS), insulin level within 60 min, 120 min, and 180 min-60minINS, 120minINS, and 180minINS, respectively, fasting blood glucose (FBG), blood glucose level within two hours (2hGlu), homeostatic model assessment for insulin resistance (HOMA-IR), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), waist-to-hip ratio (WHR), waist circumference, hip circumference, the ratio of the maximum blood flow velocity of the uterine artery during systole to the blood flow velocity of the uterine artery at the end of diastole (uterine artery S/D), and blood flow resistance index (RI) of the uterine artery. In comparison with the NP group, the OP group exhibited lower levels (p < .01) of sex hormone binding globulin (SHBG), dehydroepiandrosterone (DHEA), high molecular weight adiponectin (HMWA), and high-density lipoprotein cholesterol (HDL-C). (2) In the PCOS group, RI was significantly positively correlated with FAI, FINS, 120minINS, HOMA-IR, and WHR (p < .01), and significantly negatively correlated with SHBG, HDL-C, and HMWA (p < .01); uterine artery S/D was significantly positively correlated with FAI, FINS, 2hGlu, HOMA-IR, LDL-C, and WHR (p < .01), significantly positively correlated with 120minINS and FBG (p < .05), and significantly negatively correlated with SHBG and HMWA (p < .01). CONCLUSION: (1) The OP group exhibited obvious metabolic disorders and poor ER, which was manifested as low levels of SHBG and HMWA, and high levels of FAI, HOMA-IR, WHR, uterine artery S/D, and RI. (2) In patients with PCOS, there was a substantial correlation between ER-associated indicators RI and uterine artery S/D and FAI, FINS, 120minINS, HOMA-IR, WHR, SHBG, and HMWA.


Assuntos
Glicemia , Síndrome do Ovário Policístico , Feminino , Humanos , LDL-Colesterol , Síndrome do Ovário Policístico/complicações , Adiponectina , Insulina , HDL-Colesterol
10.
ChemSusChem ; : e202301497, 2024 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-38446050

RESUMO

Interface modification and bulk doping are two major strategies to improve the photovoltaic performance of perovskite solar cells (PSCs). Dipolar molecules are highly favored due to their unique dipolarity. This review discusses the basic concepts and characteristics of dipoles. In addition, the role of dipoles in PSCs and the corresponding conventional characterization methods for dipoles are introduced. Then, we systematically summarize the latest progress in achieving efficient and stable PSCs in dipole materials at several key interfaces. Finally, we look forward to the future application directions of dipole molecules in PSCs, aiming at providing deep insight and inspiration for developing efficient and stable PSCs.

11.
Sci Rep ; 14(1): 5945, 2024 03 11.
Artigo em Inglês | MEDLINE | ID: mdl-38467770

RESUMO

Acute kidney injury (AKI) represents a significant challenge to global public health problem and is associated with poor outcomes. There is still considerable debate about the effect of mean blood glucose (MBG) and coefficient of variation (CV) of blood glucose on the short-term mortality of AKI patients. This retrospective cohort study aimed to explore the association between glycemic variability and short-term mortality in patients with AKI. Data from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database were analyzed, including 6,777 adult AKI patients. MBG and CV on the first day of ICU admission were calculated to represent the overall glycemic status and variability during the ICU stay in AKI patients. The primary outcome indicator was ICU 30-day mortality of AKI patients. Multivariate Cox regression analysis and smoothed curve fitting were used to assess the relationship between blood glucose levels and mortality. Eventually, the ICU 30-day mortality rate of AKI patients was 23.5%. The increased MBG and CV were significantly correlated with ICU 30-day mortality (hazards ratio (HR) = 1.20, 95% confidence interval (CI) 1.14-1.27; HR = 1.08, 95% CI 1.03-1.13). The smoothed curve fitting showed a U-shaped relationship between MBG on the first day of ICU admission and ICU 30-day mortality (inflection point = 111.3 mg/dl), while CV had a linear relationship with 30-day ICU mortality. Thus, we conclude that MBG and CV were significantly associated with short-term mortality in intensive care patients with AKI. Tighter glycemic control may be an effective measure to improve the prognosis of patients with AKI.


Assuntos
Injúria Renal Aguda , Glicemia , Adulto , Humanos , Estudos Retrospectivos , Unidades de Terapia Intensiva , Cuidados Críticos
12.
Biomed Pharmacother ; 174: 116501, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38554527

RESUMO

Osteoarthritis (OA) is a chronic joint disease, characterized by degenerative destruction of articular cartilage. Chondrocytes, the unique cell type in cartilage, mediate the metabolism of extracellular matrix (ECM), which is mainly constituted by aggrecan and type II collagen. A disintegrin and metalloproteinase with thrombospondin 5 (ADAMTS5) is an aggrecanase responsible for the degradation of aggrecan in OA cartilage. CCAAT/enhancer binding protein ß (C/EBPß), a transcription factor in the C/EBP family, has been reported to mediate the expression of ADAMTS5. Our previous study showed that 5,7,3',4'-tetramethoxyflavone (TMF) could activate the Sirt1/FOXO3a signaling in OA chondrocytes. However, whether TMF protected against ECM degradation by down-regulating C/EBPß expression was unknown. In this study, we found that aggrecan expression was down-regulated, and ADAMTS5 expression was up-regulated. Knockdown of C/EBPß could up-regulate aggrecan expression and down-regulate ADAMTS5 expression in IL-1ß-treated C28/I2 cells. TMF could compromise the effects of C/EBPß on OA chondrocytes by activating the Sirt1/FOXO3a signaling. Conclusively, TMF exhibited protective activity against ECM degradation by mediating the Sirt1/FOXO3a/C/EBPß pathway in OA chondrocytes.


Assuntos
Proteína ADAMTS5 , Proteína beta Intensificadora de Ligação a CCAAT , Condrócitos , Matriz Extracelular , Osteoartrite , Transdução de Sinais , Proteína ADAMTS5/metabolismo , Proteína ADAMTS5/genética , Humanos , Matriz Extracelular/metabolismo , Matriz Extracelular/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Condrócitos/metabolismo , Condrócitos/efeitos dos fármacos , Condrócitos/patologia , Osteoartrite/metabolismo , Osteoartrite/patologia , Proteína beta Intensificadora de Ligação a CCAAT/metabolismo , Masculino , Sirtuína 1/metabolismo , Agrecanas/metabolismo , Flavonoides/farmacologia , Interleucina-1beta/metabolismo , Linhagem Celular , Proteína Forkhead Box O3/metabolismo , Cartilagem Articular/metabolismo , Cartilagem Articular/patologia , Cartilagem Articular/efeitos dos fármacos , Pessoa de Meia-Idade , Idoso , Regulação para Baixo/efeitos dos fármacos
14.
Int J Biol Macromol ; 263(Pt 1): 130236, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38367786

RESUMO

The effects of microwave combined with L-malic acid treatment on the degree of substitution (DS), structure, physicochemical properties, and digestibility of sweet potato starch (A-type), potato starch (B-type), and pea starch (C-type) were evaluated. The order of DS obtained was: DSM-POS > DSM-SPS > DSM-PES. Fourier transform-infrared spectroscopy (FT-IR) showed that the obtained modified starch produced a new absorption band at 1735 cm-1. Scanning electron microscopy (SEM) and polarized light microscopy indicated that different types of native starches exhibited different granular morphologies and appeared to have different degrees of damage, but still had polarized crosses after modification. Sweet potato starch had the smallest particle size, while potato starch had the largest. X-ray diffractometry (XRD) showed that the modified starches still retained the same crystal structure as the native starches, but the relative crystallinity decreased. The apparent viscosity and swelling power of modified starches dropped, but their water/oil holding capacity, amylose content, and resistant starch content all increased. The results demonstrate that the degree of influence on the structure, physicochemical properties, and digestibility of different starches varies under the same modification conditions.


Assuntos
Ipomoea batatas , Malatos , Amido , Amido/química , Micro-Ondas , Ésteres , Espectroscopia de Infravermelho com Transformada de Fourier , Amilose/química , Ipomoea batatas/química , Difração de Raios X
15.
Mol Med ; 30(1): 23, 2024 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-38317106

RESUMO

BACKGROUND: Fluvoxamine is one of the selective serotonin reuptake inhibitors (SSRIs) that are regarded as the first-line drugs to manage mental disorders. It has been also recognized with the potential to treat inflammatory diseases and viral infection. However, the effect of fluvoxamine on autoimmune diseases, particularly type 1 diabetes (T1D) and the related cellular and molecular mechanisms, are yet to be addressed. METHOD: Herein in this report, we treated NOD mice with fluvoxamine for 2 weeks starting from 10-week of age to dissect the impact of fluvoxamine on the prevention of type 1 diabetes. We compared the differences of immune cells between 12-week-old control and fluvoxamine-treated mice by flow cytometry analysis. To study the mechanism involved, we extensively examined the characteristics of CD4+ T cells with fluvoxamine stimulation using RNA-seq analysis, real-time PCR, Western blot, and seahorse assay. Furthermore, we investigated the relevance of our data to human autoimmune diabetes. RESULT: Fluvoxamine not only delayed T1D onset, but also decreased T1D incidence. Moreover, fluvoxamine-treated NOD mice showed significantly attenuated insulitis coupled with well-preserved ß cell function, and decreased Th1 and Th17 cells in the peripheral blood, pancreatic lymph nodes (PLNs), and spleen. Mechanistic studies revealed that fluvoxamine downregulated glycolytic process by inhibiting phosphatidylinositol 3-kinase (PI3K)-AKT signaling, by which it restrained effector T (Teff) cell differentiation and production of proinflammatory cytokines. CONCLUSION: Collectively, our study supports that fluvoxamine could be a viable therapeutic drug against autoimmunity in T1D setting.


Assuntos
Doenças Autoimunes , Diabetes Mellitus Tipo 1 , Camundongos , Humanos , Animais , Diabetes Mellitus Tipo 1/tratamento farmacológico , Camundongos Endogâmicos NOD , Fluvoxamina/farmacologia , Fluvoxamina/uso terapêutico , Células Th17 , Fosfatidilinositol 3-Quinases , Células Th1
16.
J Cell Mol Med ; 28(5): e18083, 2024 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-38393307

RESUMO

The connection between head and neck squamous cell carcinoma (HNSC) and M2 tumour-associated macrophages is not yet fully understood. We gathered gene expression profiles and clinical data from HNSC patients in the TCGA database. Using Consensus Clustering, we categorized these patients into M2 macrophage-related clusters. We developed a M2 macrophage-related signature (MRS) through statistical analyses. Additionally, we assessed gene expression in HNSC cells using single-cell sequencing data (GSE139324). We identified three distinct M2 macrophage-related clusters in HNSC, each with different prognostic outcomes and immune characteristics. Patients with different MRS profiles exhibited variations in immune infiltration, genetic mutations and prognosis. FCGR2A may play a role in creating an immunosuppressive tumour microenvironment and could potentially serve as a therapeutic target for HNSC. Our study demonstrated that M2 macrophage-related genes significantly impact the development and progression of HNSC. The M2 macrophage-related model offered a more comprehensive assessment of HNSC patient prognosis, genetic mutations and immune features. FCGR2A was implicated in immunosuppressive microenvironments and may hold promise for the development of novel immunotherapeutic strategies for HNSC.

17.
ACS Appl Mater Interfaces ; 16(8): 9768-9786, 2024 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-38349802

RESUMO

This study aims to overcome the drawbacks associated with hydroxyapatite (HAP) dense structures after sintering, which often result in undesirable features such as large grain size, reduced porosity, high crystallinity, and low specific surface area. These characteristics hinder osseointegration and limit the clinical applicability of the material. To address these issues, a new method involving the preparation of hollow hydroxyapatite (hHAP) microspheres has been proposed. These microspheres exhibit distinctive traits including weak crystallization, high specific surface area, and increased porosity. The weak crystallization aligns more closely with early mineralization products found in the human body and animals. Moreover, the microspheres' high specific surface area and porosity offer advantages for protein loading and facilitating osteoblast attachment. This innovative approach not only mitigates the limitations of conventional HAP structures but also holds the potential for improving the effectiveness of hydroxyapatite in biomedical applications, particularly in enhancing osseointegration. Three-dimensional printed hHAP/chitosan (CS) scaffolds with different hHAP concentration gradients were manufactured, and the physical and biological properties of each group were systematically evaluated. In vitro and in vivo experiments show that the hHAP/CS scaffold has excellent performance in bone remodeling. Furthermore, in-scaffold components, hHAP and CS were cocultured with bone marrow mesenchymal stem cells to explore the regulatory role of hHAP and CS in the process of bone healing and to reveal the cell-level specific regulatory network activated by hHAP. Enrichment analysis showed that hHAP can promote bone regeneration and reconstruction by recruiting calcium ions and regulating inflammatory reactions.


Assuntos
Quitosana , Durapatita , Animais , Humanos , Durapatita/farmacologia , Durapatita/química , Alicerces Teciduais/química , Cálcio , Osteogênese , Regeneração Óssea/fisiologia , Quitosana/química , Impressão Tridimensional , Porosidade , Íons
18.
Mater Today Bio ; 24: 100929, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38229884

RESUMO

The immune microenvironment plays a pivotal role in osteoanagenesis. Biomaterials can modulate osteogenic efficacy by inducing specific local immune reactions. As 3D-printing technology advances, digital light projection printing has emerged as a promising method for creating large scale, high-precision biomaterial scaffolds. By adjusting the solid content and the sintering conditions during printing, the pore size of biomaterials can be meticulously controlled. Yet, the systematic influence of pore size on the immune microenvironment remains uncharted. We fabricated 3D-printed hydroxyapatite bioceramic scaffolds with three distinct pore sizes: 400 µm, 600 µm, and 800 µm. Our study revealed that scaffolds with a pore size of 600 µm promote macrophage M2 polarization, which is achieved by upregulating interferon-beta and HIF-1α production. When these materials were implanted subcutaneously in rats and within rabbit skulls, we observed that the 600 µm scaffolds notably improved the long-term inflammatory response, fostered vascular proliferation, and augmented new bone growth. This research paves the way for innovative therapeutic strategies for treating large segmental bone defects in clinical settings.

19.
Pain ; 165(4): 848-865, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-37943063

RESUMO

ABSTRACT: The Center for Disease Control and Prevention estimates that 75% of reported cases of traumatic brain injury (TBI) are mild, where chronic pain and depression are 2 of the most common symptoms. In this study, we used a murine model of repeated mild TBI to characterize the associated pain hypersensitivity and affective-like behavior and to what extent microglial reactivity contributes to these behavioral phenotypes. Male and female C57BL/6J mice underwent sham or repeated mild traumatic brain injury (rmTBI) and were tested for up to 9 weeks postinjury, where an anti-inflammatory/neuroprotective drug (minocycline) was introduced at 5 weeks postinjury in the drinking water. Repeated mild traumatic brain injury mice developed cold nociceptive hypersensitivity and negative affective states, as well as increased locomotor activity and risk-taking behavior. Minocycline reversed negative affect and pain hypersensitivities in male but not female mice. Repeated mild traumatic brain injury also produced an increase in microglial and brain-derived neurotropic factor mRNA transcripts in limbic structures known to be involved in nociception and affect, but many of these changes were sex dependent. Finally, we show that the antiepileptic drug, gabapentin, produced negative reinforcement in male rmTBI mice that was prevented by minocycline treatment, whereas rmTBI female mice showed a place aversion to gabapentin. Collectively, pain hypersensitivity, increased tonic-aversive pain components, and negative affective states were evident in both male and female rmTBI mice, but suppression of microglial reactivity was only sufficient to reverse behavioral changes in male mice. Neuroinflammation in limbic structures seems to be a contributing factor in behavioral changes resulting from rmTBI.


Assuntos
Concussão Encefálica , Camundongos , Masculino , Feminino , Animais , Concussão Encefálica/complicações , Concussão Encefálica/psicologia , Doenças Neuroinflamatórias , Modelos Animais de Doenças , Minociclina/farmacologia , Minociclina/uso terapêutico , Gabapentina , Camundongos Endogâmicos C57BL , Dor
20.
Colloids Surf B Biointerfaces ; 234: 113660, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38042107

RESUMO

The occurrence of multidrug-resistant bacteria necessitates the development of new antibacterial agents. This study synthesized artemisinin-zinc nanoparticles (AZ NPs) using a simple green method and investigated their physicochemical properties, antibacterial activity, and oral biological activity. A spherical shape morphology of AZ NPs was observed by scanning and transmission electron microscopy, with a particle size of 73 ± 2.604 nm. Energy dispersive spectrometry analysis showed that the AZ NPs consisted mainly of Zn, C, N, and O elements. According to differential scanning calorimeter analysis, the AZ NPs were stable up to 450 °C. Fourier-transform infrared spectroscopy revealed that artemisinin successfully bound to zinc acetate. The AZ NPs showed antibacterial activity against Salmonella and Escherichia coli, with a minimum inhibitory concentration of 0.056 mg/mL for both and minimum bactericidal concentrations of 0.21 and 0.11 mg/mL, respectively. The mechanisms by which AZ NPs mediate membrane damage were revealed by the downregulation of gene expression, and potassium ion and protein leakage. In vivo safety trials of these drugs revealed low toxicity. After AZ NPs were administered to infected mice, the intestinal bacteria decreased significantly, liver and kidney function were restored, histopathological damage to the liver and spleen were reduced, and the expression of inflammatory cytokines decreased. Therefore, AZ NPs have the potential as an oral antibacterial agent and can be used in antibiotic development and in the pharmaceutical industry.


Assuntos
Artemisininas , Nanopartículas Metálicas , Animais , Camundongos , Zinco , Nanopartículas Metálicas/química , Antibacterianos/farmacologia , Antibacterianos/química , Espectroscopia de Infravermelho com Transformada de Fourier , Extratos Vegetais/química , Artemisininas/farmacologia , Testes de Sensibilidade Microbiana
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA