Your browser doesn't support javascript.
loading
Montrer: 20 | 50 | 100
Résultats 1 - 20 de 477
Filtrer
1.
Front Immunol ; 15: 1355566, 2024.
Article de Anglais | MEDLINE | ID: mdl-38835775

RÉSUMÉ

Dendritic cell (DC)-based vaccines have emerged as a promising strategy in cancer immunotherapy due to low toxicity. However, the therapeutic efficacy of DC as a monotherapy is insufficient due to highly immunosuppressive tumor environment. To address these limitations of DC as immunotherapeutic agent, we have developed a polymeric nanocomplex incorporating (1) oncolytic adenovirus (oAd) co-expressing interleukin (IL)-12 and granulocyte-macrophage colony-stimulating factor (GM-CSF) and (2) arginine-grafted bioreducible polymer with PEGylated paclitaxel (APP) to restore antitumor immune surveillance function in tumor milieu and potentiate immunostimulatory attributes of DC vaccine. Nanohybrid complex (oAd/APP) in combination with DC (oAd/APP+DC) induced superior expression level of antitumor cytokines (IL-12, GM-CSF, and interferon gamma) than either oAd/APP or DC monotherapy in tumor tissues, thus resulting in superior intratumoral infiltration of both endogenous and exogenous DCs. Furthermore, oAd/APP+DC treatment led superior migration of DC to secondary lymphoid organs, such as draining lymph nodes and spleen, in comparison with either monotherapy. Superior migration profile of DCs in oAd/APP+DC treatment group resulted in more prolific activation of tumor-specific T cells in these lymphoid organs and greater intratumoral infiltration of T cells. Additionally, oAd/APP+DC treatment led to lower subset of tumor infiltrating lymphocytes and splenocytes being immunosuppressive regulatory T cells than any other treatment groups. Collectively, oAd/APP+DC led to superior induction of antitumor immune response and amelioration of immunosuppressive tumor microenvironment to elicit potent tumor growth inhibition than either monotherapy.


Sujet(s)
Adenoviridae , Cellules dendritiques , Thérapie virale de cancers , Virus oncolytiques , Paclitaxel , Cellules dendritiques/immunologie , Animaux , Paclitaxel/pharmacologie , Adenoviridae/génétique , Souris , Virus oncolytiques/immunologie , Virus oncolytiques/génétique , Thérapie virale de cancers/méthodes , Association thérapeutique , Lignée cellulaire tumorale , Humains , Souris de lignée C57BL , Vaccins anticancéreux/immunologie , Immunothérapie/méthodes , Facteur de stimulation des colonies de granulocytes et de macrophages/métabolisme , Femelle , Microenvironnement tumoral/immunologie , Microenvironnement tumoral/effets des médicaments et des substances chimiques
2.
Nano Lett ; 24(23): 6906-6915, 2024 Jun 12.
Article de Anglais | MEDLINE | ID: mdl-38829311

RÉSUMÉ

Herein, a multifunctional nanohybrid (PL@HPFTM nanoparticles) was fabricated to perform the integration of chemodynamic therapy, photothermal therapy, and biological therapy over the long term at a designed location for continuous antibacterial applications. The PL@HPFTM nanoparticles consisted of a polydopamine/hemoglobin/Fe2+ nanocomplex with comodification of tetrazole/alkene groups on the surface as well as coloading of antimicrobial peptides and luminol in the core. During therapy, the PL@HPFTM nanoparticles would selectively cross-link to surrounding bacteria via tetrazole/alkene cycloaddition under chemiluminescence produced by the reaction between luminol and overexpressed H2O2 at the infected area. The resulting PL@HPFTM network not only significantly damaged bacteria by Fe2+-catalyzed ROS production, effective photothermal conversion, and sustained release of antimicrobial peptides but dramatically enhanced the retention time of these therapeutic agents for prolonged antibacterial therapy. Both in vitro and in vivo results have shown that our PL@HPFTM nanoparticles have much higher bactericidal efficiency and remarkably longer periods of validity than free antibacterial nanoparticles.


Sujet(s)
Antibactériens , Nanoparticules , Antibactériens/pharmacologie , Antibactériens/composition chimique , Animaux , Nanoparticules/composition chimique , Souris , Escherichia coli/effets des médicaments et des substances chimiques , Polymères/composition chimique , Indoles/composition chimique , Indoles/pharmacologie , Thérapie photothermique , Humains , Staphylococcus aureus/effets des médicaments et des substances chimiques , Peptides antimicrobiens/composition chimique , Peptides antimicrobiens/pharmacologie , Peroxyde d'hydrogène/composition chimique , Peroxyde d'hydrogène/pharmacologie
3.
BMC Oral Health ; 24(1): 712, 2024 Jun 20.
Article de Anglais | MEDLINE | ID: mdl-38902697

RÉSUMÉ

OBJECTIVE: To evaluate the effects of different polishing techniques and coffee staining on the color stability of four commercially available bleach-shade composite resins, namely microhybrid, nanohybrid, nanofilled, and injectable nanohybrids. MATERIAL AND METHODS: A total of 224 discs (8 mm diameter and 2 mm thickness) were fabricated from four different bleach-shade composite resins, namely microhybrid (Gradia Direct Anterior), nanohybrid (Palfique LX5), nanofilled (Filtek Universal), and injectable nanohybrid (flowable G-aenial universal injectable). The composite resin groups were polished via four techniques: no polishing, 4-step polishing using aluminum oxide discs, 3-step polishing using silicon rubber diamond discs, and one-step polishing. Half of each group was immersed in water, while the other half was immersed in coffee for 12 days (n = 7). Colors were measured using a clinical spectrophotometer, and color differences were calculated (ΔE). The results were analyzed statistically. RESULTS: The alterations in color were significantly influenced by the techniques employed for finishing and polishing techniques, composite resin type, and degree of coffee staining. Regardless of the polishing technique and storage medium, different material types showed a significant color change (ΔE) at P < 0.001. Filtek exhibited the most significant color change, followed by Gradia and Palfique, with no significant differences between them. In addition, Different polishing techniques resulted in significant color changes (P < 0.001). The highest degree of color change was seen in the no-polishing group, followed by the 4-step and 1-step polishing groups, with negligible differences between each other. Also, Storage media had a significant effect on ΔE values. CONCLUSION: Appropriate finishing and polishing procedures can improve the color stability of bleach-shaded composite resins. Coffee has a deleterious effect on color; however, injectable flowable nanohybrid composites are more resistant to staining.


Sujet(s)
Oxyde d'aluminium , Café , Couleur , Résines composites , Polissage dentaire , Propriétés de surface , Résines composites/composition chimique , Polissage dentaire/méthodes , Oxyde d'aluminium/composition chimique , Test de matériaux , Spectrophotométrie , Techniques in vitro , Humains , Diamant/composition chimique , Nanocomposites/composition chimique , Agents de blanchiment des dents/composition chimique , Eau/composition chimique , Matériaux dentaires/composition chimique , Facteurs temps
4.
Spectrochim Acta A Mol Biomol Spectrosc ; 321: 124703, 2024 Jun 21.
Article de Anglais | MEDLINE | ID: mdl-38936206

RÉSUMÉ

Unsafe food additives pose a significant threat to global health, especially in developing countries. Many existing methods rely on clean laboratories, complicated optics equipment, trained personnel and lengthy detection time, which are not suitable for onsite food safety inspections in emergency situations, peculiarly in impoverished areas. In this paper, a fast and visual onsite method is designed for the detection and quantification of additives in food safety by engineering a nanohybrid (MoS2/SDBS/Cu-CuFe2O4)-based catalysis. Interestingly, the nanohybrid presents peroxidase-like mimetic activity toward the substrate containing 3,3',5,5'-tetramethylbenzidine (TMB) and hydrogen peroxide (H2O2), which are then integrated simply into a detection kit. The blue oxidated TMB in this kit can be converted completely to colorless by some bio-molecule additives in commercial food, such as glutathione (GSH), cysteine (Cys), and ascorbic acid (AA). Remarkably, this process takes just less than 2 min and the detection limits are 2.8 nM, 5.5 nM and 47 nM, respectively. These results show excellent repeatability with a statistical analysis with (*P < 0.05) over 30 tests. Next, the images of the color changes can be captured clearly using a smartphone by red-green-blue (RGB) channels, which provides an opportunity for the development of field-operation device. Additionally, our approach is applied to some targets-indicative foods, showing a recovery range between 95.8 % and 104.2 %, offering an attractive and promising pathway for future practical food safety inspection applications. More importantly, this method can easily be extended to the detection of reducing substances in other analytical fields.

5.
J Conserv Dent Endod ; 27(5): 552-555, 2024 May.
Article de Anglais | MEDLINE | ID: mdl-38939539

RÉSUMÉ

Objective: The purpose of this study is to comparatively evaluate the effect of discoloration of nanohybrid composite by four different phytopigments. Materials and Methods: Fifty disk-shaped samples of nanohybrid (3M Filtek Z350) resin composites were prepared using an acrylic template of dimension 5 mm × 3 mm. They were randomly divided into five groups and immersed in solutions of tomato powder, beetroot powder, java plum powder, and turmeric powder. Distilled water was used as the control group. The samples were placed in respective solutions for 3 h daily and stored in artificial saliva for the rest of the day for 28 days. Color values (L*, a*, b*) were measured by colorimeter using the CIE L*a*b* system at the end of the 7th and 28th days of immersion. Color differences ΔE*ab were statistically analyzed. Results: All the samples showed a change in color of nanohybrid composite resin to varying degrees. The mean ΔE*ab value obtained with beetroot solution was the highest among all the groups at the end of the 7th and 28th days, depicting that beetroot solution showed maximum mean color variation, followed by java plum solution, turmeric solution, and tomato solution. Conclusion: All the phytopigments used in this study have the potential to discolor the nanohybrid composite resin, with beetroot causing the most severe discoloration.

6.
Chemistry ; : e202400777, 2024 Jun 26.
Article de Anglais | MEDLINE | ID: mdl-38924153

RÉSUMÉ

Following a new approach, we prepared a nanoink with two separate photothermally responsive absorption bands. One is the localized surface plasmon resonance (LSPR) absorption of gold nanoparticles (AuNP, d =17 nm), the second is the absorption band of two cyanine (Cy) dyes, Cy7-C6 or Cy7-C11, grafted to the AuNP surface through thiolated bridges of different lengths: the close proximity to the Au surface induces full quenching of the Cy fluorescence, resulting in thermal relaxation on irradiation. Attempts to full coat AuNP with the lipophilic Cy7-C6 and Cy7-C11 lead to precipitation from aqueous solutions. We thus prepared AuNP with partial pegylation (30, 50, or 70%), using a long chain thiol-terminated PEG bearing a -COOH function. Addition until saturation of either Cy7-C6 or Cy7-C11 to the partially pegylated AuNP gave the AuNP@Cy/PEGX% hybrids (X = 30, 50, 70) that are stable in water and in the water/alcohol mixtures used to prepare the nanoinks. Further overcoating of AuNP@Cy7-C6/PEG50% with PAH (polyallylamine hydrochloride) avoids LSPR hybridization in the dry nanoink printouts, that present two separate bands. When irradiated with laser sources near their absorption maxima, the printouts of the AuNP@Cy7-C6/PEG50%@PAH nanoink respond on two channels, giving different temperature increases depending on the irradiation wavelength.

7.
Dent Mater ; 40(6): 984-992, 2024 Jun.
Article de Anglais | MEDLINE | ID: mdl-38724333

RÉSUMÉ

OBJECTIVE: to compare conventional nanohybrid (Ceram.x Spectra) and ormocer-based (Admira fusion) dental composite resins effects on human dental pulp stem cells (hDPSCs) in terms of cytotoxicity, self-renewal, migration and osteogenic differentiation. METHODS: hDPSCs were cultured in presence of different dilutions (undiluted, form 1:2 to 1:100) of CeramX (CX) and Admira fusion (AD) eluates and viability assay in standard or osteogenic conditions were performed. Samples and eluates were prepared according to ISO 10993-12. In addition, apoptosis, self-renewal and migration activity evaluations were carried out. Osteogenic differentiation potential was tested by Alkaline Phosphatase Activity, alizarin red staining and gene expression of specific markers (ALP, RUNX2, OCN, OPN and COL1α1). Statistical analysis was performed by means of a One-way analysis of variance (One-way ANOVA) followed by a Tukey's test for multiple comparison; results were presented as mean ± standard error of mean (SEM). RESULTS: Admira Fusion demonstrated to be highly biocompatible and showed positive effects on hDPSCs proliferation and differentiation; on the contrary, conventional nanohybrid composite showed to be more cytotoxic and without any notable effect on stem cells differentiation. Moreover, the obtained results were further corroborated by a significant upregulation of osteogenic differentiation markers obtained in presence of ormocer-based composite resin eluate. Specifically, in AD 1:50 group expression levels of ALP, Runx2, Col1α1 were double than control (ALP, p = 0.045; Runx2, p = 0.003; Col1α1, p = 0.001) and CX 1:50 (ALP, p = 0.006; RUNX2, p = 0.029; Col1α1, p = 0.005). Moreover, in the same group, OPN and OCN resulted about 5 times more expressed as compared to control (OPN, p = 0.009; OCN, p = 0.0005) and CX 1:50 (OPN, p = 0.012; OCN, p = 0.0006). SIGNIFICANCE: The less cytotoxicity obtained by AD than conventional nanohybrid composite may be attributed to a reduced monomers release in the oral environment, supporting the hypothesis of limited adverse effect and enhanced healing potential, mainly when the material is positioned in close contact with pulp tissue.


Sujet(s)
Différenciation cellulaire , Prolifération cellulaire , Résines composites , Pulpe dentaire , Ostéogenèse , Cellules souches , Humains , Pulpe dentaire/cytologie , Pulpe dentaire/effets des médicaments et des substances chimiques , Différenciation cellulaire/effets des médicaments et des substances chimiques , Cellules souches/effets des médicaments et des substances chimiques , Résines composites/toxicité , Résines composites/composition chimique , Prolifération cellulaire/effets des médicaments et des substances chimiques , Cellules cultivées , Ostéogenèse/effets des médicaments et des substances chimiques , Survie cellulaire/effets des médicaments et des substances chimiques , Céramiques organiquement modifiées , Apoptose/effets des médicaments et des substances chimiques , Test de matériaux , Phosphatase alcaline/métabolisme , Mouvement cellulaire/effets des médicaments et des substances chimiques
8.
Chemosphere ; 360: 142399, 2024 Jul.
Article de Anglais | MEDLINE | ID: mdl-38801903

RÉSUMÉ

Herin, a new nanohybrid acid catalyst was fabricated for the efficient biodiesel production. At the first, magnetic porous nanosheets of graphitic carbon nitride (g-C3N4@Fe3O4) was prepared and then functionalized with sulfonic acid. Next, the preparation of the catalyst was completed by mixing this surface modified support with n-methyl imidazolium butyl sulfonate zwitterion to achieve non-covalent immobilized acidic ionic liquid on g-C3N4@Fe3O4 support. The catalyst underwent characterization through various techniques such as 1H and 13C NMR, FTIR, SEM, TEM, TGA, EDX and BET which revealing that the magnetic support loaded acidic ionic liquids via a robust charge interaction effect enabling the one-pot production of biodiesel from low-quality oils. Furthermore, the catalyst could be simply recovered using a permanent magnet and reused multiple times without a significant decline in catalytic activity. Consequently, the solid catalyst based on ionic liquids holds promise for the sustainable and eco-friendly production of biodiesel from low-quality oils. Furthermore, Response Surface Methodology (RSM) and Artificial Neural Networks (ANN) were used to model the yield and various process parameters. The findings underscore the enhanced predictive capabilities of ANN in comparison to RSM.


Sujet(s)
Biocarburants , Graphite , Liquides ioniques , , Liquides ioniques/composition chimique , Catalyse , Graphite/composition chimique , Composés de l'azote/composition chimique
9.
Environ Res ; 252(Pt 4): 119121, 2024 Jul 01.
Article de Anglais | MEDLINE | ID: mdl-38734291

RÉSUMÉ

Extensive utilization of pesticides and herbicides to boost agricultural production increased the environmental health risks, which can be mitigate with the aid of highly sensitive detection systems. In this study, an electrochemical sensor for monitoring the carcinogenic pesticides in the environmental samples has been developed based on sulfur-doped graphitic-carbon nitride-gold nanoparticles (SCN-AuNPs) nanohybrid. Thermal polycondensation of melamine with thiourea followed by solvent exfoliation via ultrasonication leads to SCN formation and electroless deposition of AuNPs on SCN leads to SCN-AuNPs nanohybrid synthesis. The chemical composition, S-doping, and the morphology of the nanohybrid were confirmed by various microscopic and spectroscopic tools. The as-synthesized nanohybrid was fabricated with glassy carbon (GC) electrode for determining the carcinogenic hydrazine (HZ) and atrazine (ATZ) in field water samples. The present sensor exhibited superior electrocatalytic activity than GC/SCN and GC/AuNPs electrodes due to the synergism between SCN and AuNPs and the amperometric studies showed the good linear range of detection of 20 nM-0.5 mM and 500 nM-0.5 mM with the limit of detection of 0.22 and 69 nM (S/N = 3) and excellent sensitivity of 1173.5 and 13.96 µA mM-1 cm-2 towards HZ and ATZ, respectively. Ultimately, the present sensor is exploited in environmental samples for monitoring HZ and ATZ and the obtained results are validated with high-performance liquid chromatography (HPLC) technique. The excellent recovery percentage and close agreement with the results of HPLC analysis proved the practicability of the present sensor. In addition, the as-prepared materials were utilized for the photocatalytic degradation of ATZ and the SCN-AuNPs nanohybrid exhibited higher photocatalytic activity with the removal efficiency of 93.6% at 90 min. Finally, the degradation mechanism was investigated and discussed.


Sujet(s)
Cancérogènes , Or , Graphite , Nanoparticules métalliques , Polluants chimiques de l'eau , Or/composition chimique , Polluants chimiques de l'eau/analyse , Polluants chimiques de l'eau/composition chimique , Nanoparticules métalliques/composition chimique , Graphite/composition chimique , Cancérogènes/analyse , Atrazine/analyse , Atrazine/composition chimique , Soufre/composition chimique , Soufre/analyse , Techniques électrochimiques/méthodes , Hydrazines/analyse , Hydrazines/composition chimique , Composés de l'azote/composition chimique , Composés de l'azote/analyse , Nitriles/composition chimique , Nitriles/analyse , Surveillance de l'environnement/méthodes
10.
Dent J (Basel) ; 12(5)2024 May 07.
Article de Anglais | MEDLINE | ID: mdl-38786526

RÉSUMÉ

The purpose of this randomized, split-mouth-designed controlled and single-blinded clinical study was to evaluate the 3-year clinical performance of Class I and Class II resin composite restorations placed with or without cavity lining with a flowable composite. Fifty patients with treatment needs in two premolars or molars were included. One of the teeth was restored using the nanohybrid composite (Grandio®SO, control group), in the test group a high viscosity flowable composite was additionally applied as a first layer. In both groups, the same self-etch adhesive system was applied. Clinical evaluation after 3 years was carried out using the modified USPHS/Ryge criteria. At the 3-year follow-up the recall rate was 92%. Four restorations failed in the test group (8.7%), three due to the loss of vitality and one after fracture. The control group exhibited a cumulative success rate of 100%, while the test group achieved a success rate of 91.3%. This led to significant differences in the annual failure rate (AFR) between the two groups, with rates of 0% and 2.9% (p < 0.05; Mann-Whitney U-test). After 3 years the cumulative survival rate including all restorations was 95.7%. Statistical analysis revealed significant differences for the parameters: tooth vitality, marginal discoloration, success rate, and AFR. The other parameters exhibited no significant differences. Consequently, the nanohybrid composite demonstrated excellent performance over a 3-year period, whereas the utilization of a flowable composite for the cavity lining did not appear to exert a beneficial influence on clinical outcomes.

11.
J Contemp Dent Pract ; 25(3): 221-225, 2024 Mar 19.
Article de Anglais | MEDLINE | ID: mdl-38690693

RÉSUMÉ

AIM: This study aimed to assess the color stability of bioactive restorative materials vs nanohybrid resin composites after 3 months of immersion in three frequently consumed beverages. MATERIALS AND METHODS: Thirty disk-shaped specimens of Giomer dental restorative material (Shofu, Japan) and nanohybrid resin composite (Tokuyama, Japan) were performed using a Teflon mold. Super-Snap system (Shofu, Japan) was utilized to finish and polish the specimens to be preserved for 24 hours in distilled water at 37°C. The samples had been divided into three subgroups (Coffee, tea, Pepsi) (n = 5). The initially displayed color measurements of the samples were performed using a spectrophotometer (VITA Easyshade® V). After 7 days, 30 days, and 90 days, color measurements were repeated, and the E of each sample was estimated. E of each sample was calculated. RESULTS: The Giomer group showed statistically significant higher E values than the nanohybrid resin composite where the p-value was ≤0.0001. Tea subgroup showed the highest statistically significant E values in both groups where the p-value was ≤ 0.0001. The highest statistically significant color change was recorded at 3 months. CONCLUSION: The color of bioactive restorative material is less stable if compared with nanohybrid resin composite. CLINICAL SIGNIFICANCE: As tea and coffee are popular beverages, particularly in Middle Eastern nations, dentists must advise patients about the color change of resin restorations. Patients are advised to brush their teeth immediately after consuming these beverages. How to cite this article: Saber EH, Abielhassan MH, Abed YA, et al. Color Stability of Bioactive Restorative Material vs Nanohybrid Resin Composite: An In Vitro Study. J Contemp Dent Pract 2024;25(3):221-225.


Sujet(s)
Couleur , Résines composites , Test de matériaux , Thé , Résines composites/composition chimique , Techniques in vitro , Café , Spectrophotométrie , Restaurations dentaires permanentes , Nanocomposites/composition chimique , Matériaux dentaires/composition chimique , Humains , Boissons
12.
Sci Total Environ ; 929: 172533, 2024 Jun 15.
Article de Anglais | MEDLINE | ID: mdl-38649050

RÉSUMÉ

The advent of Nanohybrid (NH) fertilizers represents a groundbreaking advancement in the pursuit of precision and sustainable agriculture. This review abstract encapsulates the transformative potential of these innovative formulations in addressing key challenges faced by modern farming practices. By incorporating nanotechnology into traditional fertilizer matrices, nanohybrid formulations enable precise control over nutrient release, facilitating optimal nutrient uptake by crops. This enhanced precision not only fosters improved crop yields but also mitigates issues of over-fertilization, aligning with the principles of sustainable agriculture. Furthermore, nanohybrid fertilizers exhibit the promise of minimizing environmental impact. Their controlled release mechanisms significantly reduce nutrient runoff, thereby curbing water pollution and safeguarding ecosystems. This dual benefit of precision nutrient delivery and environmental sustainability positions nanohybrid fertilizers as a crucial tool in the arsenal of precision agriculture practices. The intricate processes of uptake, translocation, and biodistribution of nutrients within plants are examined in the context of nanohybrid fertilizers. The nanoscale features of these formulations play a pivotal role in governing the efficiency of nutrient absorption, internal transport, and distribution within plant tissues. Factors affecting the performance of nanohybrid fertilizers are scrutinized, encompassing aspects such as soil type, crop variety, and environmental conditions. Understanding these variables is crucial for tailoring nanohybrid formulations to specific agricultural contexts, and optimizing their impact on crop productivity and resource efficiency. Environmental considerations are integral to the review, assessing the broader implications of nanohybrid fertilizer application. This review offers a holistic overview of nanohybrid fertilizers in precision and sustainable agriculture. Exploring delivery mechanisms, synthesis methods, uptake dynamics, biodistribution patterns, influencing factors, and environmental implications, it provides a comprehensive understanding of the multifaceted role and implications of nanohybrid fertilizers in advancing modern agricultural practices.


Sujet(s)
Agriculture , Engrais , Agriculture/méthodes , Produits agricoles , Nanotechnologie , Développement durable
13.
J Pharm Bioallied Sci ; 16(Suppl 1): S427-S430, 2024 Feb.
Article de Anglais | MEDLINE | ID: mdl-38595483

RÉSUMÉ

Background: Surface roughness and hardness are key factors that influence the clinical performance and durability of denture teeth. Understanding variations in these properties among different denture teeth materials can assist in selecting the most suitable materials for optimal patient outcomes. This study aimed to investigate the surface roughness and hardness of four commonly used denture teeth materials: acrylic resin, composite resin, porcelain, and nanohybrid composite. Materials and Methods: Ten specimens were prepared for each denture teeth material, resulting in a total of 40 specimens. Surface roughness was assessed using a profilometer, and measurements were recorded in micrometers (µm). Hardness was determined using a Vickers hardness tester, and results were expressed as Vickers hardness numbers (VHN). The surface roughness and hardness data were analyzed using appropriate statistical tests (e.g., analysis of variance), with significance set at P < 0.05. Results: The results revealed significant differences in both surface roughness and hardness among the different denture teeth materials (P < 0.05). Acrylic resin exhibited the highest surface roughness (mean ± standard deviation: 3.45 ± 0.78 µm) and the lowest hardness (mean ± standard deviation: 45.6 ± 2.3 VHN). Composite resin demonstrated intermediate values of surface roughness (mean ± standard deviation: 1.87 ± 0.54 µm) and hardness (mean ± standard deviation: 65.2 ± 3.9 VHN). Porcelain demonstrated the smoothest surface (mean ± standard deviation: 0.94 ± 0.28 µm) and the highest hardness (mean ± standard deviation: 78.5 ± 4.1 VHN). Nanohybrid composite displayed surface roughness and hardness values similar to composite resin. Conclusion: This study demonstrated significant variations in surface roughness and hardness among the different denture teeth materials evaluated. Acrylic resin exhibited the roughest surface and lowest hardness, while porcelain demonstrated the smoothest surface and highest hardness. Composite resin and nanohybrid composite exhibited intermediate values. These findings provide valuable insights for prosthodontic practitioners in selecting denture teeth materials based on specific clinical requirements, aiming to achieve optimal aesthetics, reduced plaque accumulation, and improved wear resistance.

14.
Article de Anglais | MEDLINE | ID: mdl-38592435

RÉSUMÉ

Colloidal quantum dots/graphene (QD/Gr) nanohybrids have been studied intensively for photodetection in a broadband spectrum including ultraviolet, visible, near-infrared, and shortwave infrared (UV-vis-NIR-SWIR). Since the optoelectronic process in the QD/Gr nanohybrid relies on the photogenerated charge carrier transfer from QDs to graphene, understanding the role of the QD-QD and QD-Gr interfaces is imperative to the QD/Gr nanohybrid photodetection. Herein, a systematic study is carried out to probe the effect of these interfaces on the noise, photoresponse, and specific detectivity in the UV-vis-NIR-SWIR spectrum. Interestingly, the photoresponse has been found to be negligible without a 3-mercaptopropionic acid (MPA) ligand exchange, moderate with a single ligand exchange after all QD layers are deposited on graphene, and maximum if it is performed after each QD layer deposition up to five layers of total QD thickness of 260-280 nm. Furthermore, exposure of graphene to C-band UV (UVC) for a short period of 4-5 min before QD deposition leads to improved photoresponse via removal of polar molecules at the QD/Gr interface. With the combination of the MPA ligand exchange and UVC exposure, optimal optoelectronic properties can be obtained on the PbS QD/Gr nanohybrids with high specific detectivity up to 2.6 × 1011, 1.5 × 1011, 5 × 1010, and 1.9 × 109 Jones at 400, 550, 1000, and 1700 nm, respectively, making the nanohybrids promising for broadband photodetection.

15.
J Colloid Interface Sci ; 666: 47-56, 2024 Jul 15.
Article de Anglais | MEDLINE | ID: mdl-38583209

RÉSUMÉ

Solar light-driven hydrogen peroxide (H2O2) production through the two-electron oxygen reduction reaction (ORR) from the earth-abundant O2 and water is a potential alternative to the energy-consuming anthraquinone oxidation process, although the activity of the common photocatalysts is still insufficient to satisfy the industrial demands. Poor accessibility of O2 to surface/interface and fast carrier recombination is the limiting-factor for catalytic systems. Herein, we develop a nanohybrid photocatalysts by introducing 1D conducting polymer of polypyrrole (PPy) nanotube on In4SnS8 to promote H2O2 evolution under visible light, obtaining up to 254.8 µM in 2 h, which is 2.4- and 13-fold larger than that of individual In4SnS8 and PPy. The detailed characterizations of hybrid structure, O2 adsorption behaviors, charge carrier dynamics over PPy/In4SnS8 in conjunction with computational calculations corroborate that the modification of PPy could enlarge the amount of O2 adsorption amount, expedite the cycle of O2 adsorption/desorption and accelerate the transportation of electrons from In4SnS8 to the interface, eventually speeding up H2O2 photoproduction via indirect 2e- ORR pathway. This work establishes a paradigm of regulating the interfacial microenvironment by polymer for boosting H2O2 photogeneration through high selectivity of ORR.

16.
Nanomaterials (Basel) ; 14(8)2024 Apr 13.
Article de Anglais | MEDLINE | ID: mdl-38668170

RÉSUMÉ

Scleroglucan (SG) is resistant to harsh reservoir conditions such as high temperature, high shear stresses, and the presence of chemical substances. However, it is susceptible to biological degradation because bacteria use SG as a source of energy and carbon. All degradation effects lead to viscosity loss of the SG solutions, affecting their performance as an enhanced oil recovery (EOR) polymer. Recent studies have shown that nanoparticles (NPs) can mitigate these degradative effects. For this reason, the EOR performance of two new nanohybrids (NH-A and NH-B) based on carboxymethyl-scleroglucan and amino-functionalized silica nanoparticles was studied. The susceptibility of these products to chemical, mechanical, and thermal degradation was evaluated following standard procedures (API RP 63), and the microbial degradation was assessed under reservoir-relevant conditions (1311 ppm and 100 °C) using a bottle test system. The results showed that the chemical reactions for the nanohybrids obtained modified the SG triple helix configuration, impacting its viscosifying power. However, the nanohybrid solutions retained their viscosity during thermal, mechanical, and chemical degradation experiments due to the formation of a tridimensional network between the nanoparticles (NPs) and the SG. Also, NH-A and NH-B solutions exhibited bacterial control because of steric hindrances caused by nanoparticle modifications to SG. This prevents extracellular glucanases from recognizing the site of catalysis, limiting free glucose availability and generating cell death due to substrate depletion. This study provides insights into the performance of these nanohybrids and promotes their application in reservoirs with harsh conditions.

17.
Dent J (Basel) ; 12(4)2024 Apr 03.
Article de Anglais | MEDLINE | ID: mdl-38668004

RÉSUMÉ

INTRODUCTION: The aim of this in vitro study was to compare the quality of marginal sealing at the cervical margins of indirect and direct composite resin restorations in mesio-occluso-distal (MOD) cavities. MATERIAL AND METHOD: MOD preparations were performed on 30 extracted teeth. The mesial cervical margin of each tooth was relocated using a flow composite resin (Enamel Plus HRi Flow, Micerium, Avegno, GE, Italy), then the samples were divided into three groups. In group A, the cavities were directly restored using a nanohybrid composite resin (Miris 2 Coltène Whaledent, Altstaetten, Switzerland) and a universal adhesive (ScotchBond Universal, 3M ESPE, St. Paul, MN, USA) by the etch-and-rinse strategy, for group B, the restoration procedure was similar but the self-etch strategy was used, and the samples in group C were filled using the inlay technique. Each sample was stored for 48 h in a 2% methylene blue solution, then it was cut in a mesio-distal direction using a Struers Secotom 50 device (Cleveland, OH, USA). The marginal sealing and adhesive interface were assessed for each sample at the cervical margin by optical microscopy (OM) and scanning electron microscopy (SEM). One-way ANOVA and Bonferroni post-hoc tests were used with a significance level of 0.05. RESULTS: Significant differences were recorded within groups A and C, between mesial and distal margins (p = 0.02 in group A and p = 0.043 in group C). CONCLUSIONS: The marginal sealing is more effective in MOD inlay restoration compared to direct restorations. Relocation of the cervical margin with flow composite resin and the use of different adhesive strategies do not improve the marginal sealing.

18.
Article de Anglais | MEDLINE | ID: mdl-38624155

RÉSUMÉ

The novel 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) groups immobilized on functional polymers or nanoparticles emerged as potential Pickering interfacial catalysts (PICs) for effective catalysis in biphasic systems. In this study, a snowman-shaped Janus-structured polymer with TEMPO-anchored nanohybrid particles (SM-JPP-TEMPO) was prepared and employed as a potential PIC in the Anelli-Montanari system for the selective oxidation of alcohol. The amphiphilic character of SM-JPP-TEMPO particles plays a dual role as an emulsifier and catalyst in the Pickering emulsion. As a result, it enables smaller droplets (102 µm) at the water-in-oil (W/O) interface and reduces the interfacial tension from 26.58 to 17.38 mN/m, which improves the stability of the Pickering emulsion system. This constructed Pickering emulsion microreactor offers a larger interface contact area and shortens the mass transfer distance of the substrate of cinnamyl alcohol, which significantly enhances the catalytic conversion at the Anelli-Montanari oxidation system, thus achieving remarkable conversion efficiency of (92.3%) with excellent selectivity (99%) in static (stirring-free) condition. It was found that the Janus nanohybrid catalyst (SM-JPP-TEMPO) enhanced 1.29-fold catalytic efficiency compared to the TEMPO grafted spherical polystyrene nanoparticle (PS-NPs-TEMPO) catalyst (72%). Moreover, after seven consecutive cycles, the Janus nanocatalyst (SM-JPP-TEMPO) maintained the conversion significantly. Hence, these results collectively highlight that the amphiphilic SM-JPP-TEMPO catalyst provides an efficient and eco-friendly strategy for the intensification of liquid-liquid biphasic reaction systems for potential applications in industries.

19.
Nanotheranostics ; 8(2): 202-218, 2024.
Article de Anglais | MEDLINE | ID: mdl-38444744

RÉSUMÉ

Plasmonic materials as non-invasive and selective treatment strategies are gaining increasing attention in the healthcare sector due to their remarkable optical and electronic properties, where the interface between matter and light becomes enhanced and highly localized. Some attractive applications of plasmonic materials in healthcare include drug delivery to target specific tissues or cells, hence reducing the side effects of the drug and improving their efficacy; enhancing the contrast and resolution in bioimaging; and selectively heating and destroying the cancerous cells while parting the healthy cells. Despite such advancements in photothermal therapy for cancer treatment, some limitations are still challenging. These include poor photothermal conversion efficiency, heat resistance, less accumulation in the tumor microenvironment, poor biosafety of photothermal agents, damage to the surrounding healthy tissues, post-treatment inflammatory responses, etc. Even though the clinical application of photothermal therapy is primarily restricted due to poor tissue penetration of excitation light, enzyme therapy is hindered due to less therapeutic efficacy. Several multimodal strategies, including chemotherapy, radiotherapy, photodynamic therapy, and immunotherapy were developed to circumvent these side effects associated with plasmonic photothermal agents for effective mild-temperature photothermal therapy. It can be prophesied that the nanohybrid platform could pave the way for developing cutting-edge multifunctional precise nanomedicine via an ecologically sustainable approach towards cancer therapy. In the present review, we have highlighted the significant challenges of photothermal therapy from the laboratory to the clinical setting and their struggle to get approval from the Food and Drug Administration (FDA).


Sujet(s)
Tumeurs , Thérapie photothermique , États-Unis , Humains , Tumeurs/thérapie , Systèmes de délivrance de médicaments , Température élevée , Immunothérapie , Microenvironnement tumoral
20.
Ecotoxicol Environ Saf ; 275: 116221, 2024 Apr 15.
Article de Anglais | MEDLINE | ID: mdl-38547728

RÉSUMÉ

Photocatalysis is gaining prominence as a viable alternative to conventional biohazard treatment technologies. Two-dimensional (2D) nanomaterials have become crucial for fabricating novel photocatalysts due to their nanosheet architectures, large surface areas, and remarkable physicochemical properties. Furthermore, a variety of applications are possible with 2D nanomaterials, either in combination with other functional nanoparticles or by utilizing their inherent properties. Henceforth, the review commences its exploration into the synthesis of these materials, delving into their inherent properties and assessing their biocompatibility. Subsequently, an overview of mechanisms involved in the photocatalytic degradation of pollutants and the processes related to antimicrobial action is presented. As an integral part of our review, we conduct a systematic analysis of existing challenges and various types of 2D nanohybrid materials tailored for applications in the photocatalytic degradation of contaminants and the inactivation of pathogens through photocatalysis. This investigation will aid to contribute to the formulation of decision-making criteria and design principles for the next generation of 2D nanohybrid materials. Additionally, it is crucial to emphasize that further research is imperative for advancing our understanding of 2D nanohybrid materials.


Sujet(s)
Polluants environnementaux , Nanoparticules , Nanostructures , Produits dangereux , Analyse des systèmes
SÉLECTION CITATIONS
DÉTAIL DE RECHERCHE
...