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A new method for synthesizing cross-linked 4,4-difluoro-4-bora-3a,4a-diaza-s-indacenes (BODIPYs) using a radical-based thiol-ene click reaction is developed. This method is simple, efficient, and cost-effective, and it produces polymers with unique optical, electrochemical, and surface morphology properties. Significant blue shifts in absorption and photoinduced electron transfer in emissions are observed in the cross-linked BODIPY thin films. Cross-linking also leads to the restriction of conjugation, which results in the breakage of the terminal vinyl group, an increase in the oxidation potential, and a slight upshift in the HOMO position. As a result, the electrochemical band gap is widened from 1.88 to 1.94 eV for polymer bearing N,N-dimethylamino-BODIPY and from 1.97 to 2.02 eV for polymer bearing N,N-diphenylamino-BODIPY moieties. Monomer thin films form planar surfaces due to crystallinity, while amorphous cross-linked BODIPY polymers form more rough surfaces. Additionally, photopatterning on the film surface is successfully performed using different patterned masks. This new method for synthesizing cross-linked BODIPYs has the potential to be used in a variety of applications, including organic electronics, bioimaging, and photocatalysis.
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Compostos de Boro , Elétrons , Oxirredução , Transporte de Elétrons , Compostos de Boro/química , PolímerosRESUMO
Borderline personality disorder (BPD) is characterized by increased mood reactivity and affective instability. Since core structures involved in emotion processing, such as the amygdala, demonstrate strong lateralization, BPD is an interesting target for laterality research. So far, a systematic integration of findings on lateralization in BPD is missing. Therefore, we systematically reviewed studies published until February 2024 in PubMed, Web of Science, and PsycInfo databases that measured hemispheric asymmetries and behavioral lateralization in patients with BPD. Inclusion criteria were (a) diagnosis of BPD and (b) results on hemispheric or behavioral asymmetries. Specifically for neuroimaging studies, hemispheres need to be assessed separately. Review articles and studies with disorders other than BPD were excluded. Risk of bias was assessed with the Newcastle Ottawa Scale for non-randomized, non-comparative intervention studies. A total of 21 studies met the inclusion criteria. Thirteen studies investigated structural hemispheric asymmetries, five functional hemispheric asymmetries, two examined handedness, and one studied hemispheric asymmetry in visuospatial attention. Overall, studies examining structural asymmetries in BPD report bilateral volume reduction in the amygdala and hippocampus but a right-sided reduction in the orbitofrontal cortex. For functional lateralization, asymmetrical de/activation patterns in the default mode network in BPD and reduced right-frontal asymmetry were evident. Also, studies indicate a trend towards increased non-right-handedness in BPD. Risk factors for BPD, such as childhood abuse, may play a crucial role in the development of structural and functional alterations. However, the generalization of results may be limited by small sample sizes and varying study designs.
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BACKGROUND: Developmental dyslexia (DD) is a neurodevelopmental disorder that is characterized by difficulties with all aspects of information acquisition in the written word, including slow and inaccurate word recognition. The neural basis behind DD has not been fully elucidated. METHOD: The study included 22 typically developing (TD) children, 16 children with isolated spelling disorder (SpD), and 20 children with DD. The cortical thickness, folding index, and mean curvature of Broca's area, including the triangular part of the left inferior frontal gyrus (IFGtriang) and the opercular part of the left inferior frontal gyrus, were assessed to explore the differences of surface morphology among the TD, SpD, and DD groups. Furthermore, the structural covariance network (SCN) of the triangular part of the left inferior frontal gyrus was analyzed to explore the changes of structural connectivity in the SpD and DD groups. RESULTS: The DD group showed higher curvature and cortical folding of the left IFGtriang than the TD group and SpD group. In addition, compared with the TD group and the SpD group, the structural connectivity between the left IFGtriang and the left middle-frontal gyrus and the right mid-orbital frontal gyrus was increased in the DD group, and the structural connectivity between the left IFGtriang and the right precuneus and anterior cingulate was decreased in the DD group. CONCLUSION: DD had atypical structural connectivity in brain regions related to visual attention, memory and which might impact the information input and integration needed for reading and spelling.
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Dislexia , Criança , Humanos , Dislexia/diagnóstico por imagem , Encéfalo/diagnóstico por imagem , Leitura , Mapeamento Encefálico , Lobo Frontal , Imageamento por Ressonância MagnéticaRESUMO
Dental caries is a commonly occurring non-communicable disease throughout the world that might compromise the quality of any individual's life. Glass ionomer cements (GIC) are the most acceptable restorative materials due to their ease of manipulation, minimal tooth loss and least invasive strategy; however, they lack mechanical stability that has become a point of concern. Nanoparticles (NPs) are an outstanding option for modifying and enhancing the properties of dental materials. The focus of this study was to prepare novel, biocompatible titania dioxide (TiO2) NPs as a dental-restorative material using an efficient probiotic Bacillus coagulans. The prepared NPs were incorporated into glass ionomer restorative material at varying concentrations and investigated for cell viability percentage, microhardness and surface morphology. Results indicated that pure 100% anatase phase TiO2 NPs with particle size of 21.84 nm arranged in smooth, spherical agglomerates and clusters forms. These NPs depicted cell viability > 90%, thus confirming their non-cytotoxic behavior. GIC restorative materials reinforced by 5% titania (TiO2) NPs demonstrated the highest microhardness in comparison to the control group and other experimental groups of the study. Surface morphology analysis revealed a reduction in cracks in this novel dental-restorative material supporting its compatible biological nature with better hardness strength and negligible crack propagation. Overall, these results indicated that TiO2 NPs produced using a biological approach could be easily used as restorative materials in dental applications.
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Bacillus coagulans , Cimentos de Ionômeros de Vidro , Dureza , Teste de Materiais , Nanopartículas , Probióticos , Propriedades de Superfície , Titânio , Titânio/química , Cimentos de Ionômeros de Vidro/química , Sobrevivência Celular , Microscopia Eletrônica de Varredura , Restauração Dentária Permanente/métodos , Humanos , Tamanho da PartículaRESUMO
Aluminum (Al) placed in hot water (HW) at 90 °C is roughened due to its reaction with water, forming Al hydroxide and Al oxide, as well as releasing hydrogen gas. The roughened surface is thus hydrophilic and possesses a hugely increased surface area, which can be useful in applications requiring hydrophilicity and increased surface area, such as atmospheric moisture harvesting. On the other hand, when using HW to roughen specified areas of an Al substrate, ways to protect the other areas from HW attacks are necessary. We demonstrated that self-assembled monolayers (SAMs) of a fluorinated phosphonic acid (FPA, CF3(CF2)13(CH2)2P(=O)(OH)2) derivatized on the native oxide of an Al film protected the underneath metal substrate from HW attack. The intact wettability and surface morphology of FPA-derivatized Al subjected to HW treatment were examined using contact angle measurement, and scanning electron microscopy and atomic force microscopy, respectively. Moreover, the surface and interface chemistry of FPA-derivatized Al before and after HW treatment were investigated by time-of-flight secondary ion mass spectrometry (ToF-SIMS), verifying that the FPA SAMs were intact upon HW treatment. The ToF-SIMS results therefore explained, on the molecular level, why HW treatment did not affect the underneath Al at all. FPA derivatization is thus expected to be developed as a patterning method for the formation of hydrophilic and hydrophobic areas on Al when combined with HW treatment.
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BACKGROUND: Porcine infection with Porcine circovirus type 2 (PCV2) causes immunosuppression, which is easy to cause concurrent or secondary infection, making the disease complicated and difficult to treat, and causing huge economic losses to the pig industry. Total polysaccharide from the rhizoma of Atractylodes macrocephala Koidz. (PAMK) is outstanding in enhancing non-specific immunity and cellular immunity, and effectively improving the body's disease resistance, indicating its potential role in antiviral immunotherapy. RESULTS: PAMK had the characteristics of compact, polyporous and agglomerated morphology, but does not have triple helix conformation. PCV2 infection led to the increase in LC3-II, degradation of p62 and the increase of viral Cap protein expression and viral copy number. PAMK treatment significantly alleviated PCV2-induced autophagy and inhibited PCV2 replication. Moreover, PAMK treatment significantly attenuated the increase of PINK1 protein expression and the decrease of TOMM20 protein expression caused by PCV2 infection, alleviated Parkin recruitment from cytoplasm to mitochondria and intracellular reactive oxygen species accumulation, restored mitochondrial membrane charge, alleviated viral Cap protein expression. CONCLUSION: PAMK alleviates PCV2-induced mitophagy to suppress PCV2 replication by inhibiting the Pink 1/Parkin pathway. These findings may provide new insights into the prevention and treatment of PCV2. © 2023 Society of Chemical Industry.
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Atractylodes , Circovirus , Animais , Suínos , Atractylodes/química , Circovirus/genética , Circovirus/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Polissacarídeos/química , Replicação ViralRESUMO
Objective: This study aims to develop a medical patch surface material featuring a microporous polyurethane (PU) membrane and to assess the material's properties and biological performance. The goal is to enhance the clinical applicability of pelvic floor repair patch materials. Methods: PU films with a microporous surface were prepared using PU prepolymer foaming technology. The films were produced by optimizing the PU prepolymer isocyanate index (R value) and the relative humidity (RH) of the foaming environment. The surface morphology of the PU microporous films was observed by scanning electron microscopy, and the chemical properties of the PU microporous films, including hydrophilicity, were analyzed using infrared spectroscopy, Raman spectroscopy, and water contact angle measurements. In vitro evaluations included testing the effects of PU microporous film extracts on the proliferation of L929 mouse fibroblasts and observing the adhesion and morphology of these fibroblasts. Additionally, the effect of the PU microporous films on RAW264.7 mouse macrophages was studied. Immune response and tissue regeneration were assessed in vivo using Sprague Dawley (SD) rats. Results: The PU films exhibited a well-defined and uniform microporous structure when the R value of PU prepolymer=1.5 and the foaming environment RH=70%. The chemical structure of the PU microporous films was not significantly altered compared to the PU films, with a significantly lower water contact angle ([55.7±1.5]° ) compared to PU films ([69.5±1.7]° ) and polypropylene (PP) ([ 104.3±2.5]°), indicating superior hydrophilicity. The extracts from PU microporous films demonstrated good in vitro biocompatibility, promoting the proliferation of L929 mouse fibroblasts. The surface morphology of the PU microporous films facilitated fibroblast adhesion and spreading. The films also inhibited the secretion of tumor necrosis factor-α (TNF-α) and interleukin (IL)-1ß by RAW264.7 macrophages while enhancing IL-10 and IL-4 secretion. Compared to 24 hours, after 72 hours of culture, the expression levels of TNF-α and IL-1ß were reduced in both the PU film and PU microporous film groups and were significantly lower than those in the PP film group (P<0.05), with the most notable decreases observed in the PU microporous film group. IL-10 and IL-4 levels increased significantly in the PU microporous film group, surpassing those in the PP film group (P<0.01), with the most pronounced increase in IL-4. The PU microporous film induced mild inflammation with no significant fibrous capsule formation in vivo. After 60 days of implantation, the film partially degraded, showing extensive collagen fiber growth and muscle formation in its central region. Conclusion: The PU microporous film exhibits good hydrophilicity and biocompatibility. Its surface morphology enhances cell adhesion, regulates the function of RAW264.7 macrophages, and promotes tissue repair, offering new insights for the design of pelvic floor repair and reconstruction patch materials.
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Fibroblastos , Polipropilenos , Poliuretanos , Ratos Sprague-Dawley , Poliuretanos/química , Animais , Camundongos , Ratos , Polipropilenos/química , Fibroblastos/citologia , Materiais Biocompatíveis/química , Telas Cirúrgicas , Células RAW 264.7 , Propriedades de Superfície , Linhagem Celular , Porosidade , Teste de Materiais , Proliferação de Células/efeitos dos fármacos , Macrófagos/citologiaRESUMO
Cell recognition methods are in high demand in cell biology and medicine, and the method based on atomic force microscopy (AFM) shows a great value in application. The difference in mechanical properties or morphology of cells has been frequently used to detect whether cells are cancerous, but this detection method cannot be a general means for cancer cell detection, and the traditional artificial feature extraction method also has its limitations. In this work, we proposed an analytic method based on the physical properties of cells and deep learning method for recognizing cell types. The residual neural network used for recognition was modified by multi-scale convolutional fusion, attention mechanism and depthwise separable convolution, so as to optimize feature extraction and reduce operation costs. In the method, the collected cells were imaged by AFM, and the processed images were analyzed by the optimized convolutional neural network. The recognition results of two groups of cells (HL-7702 and SMMC-7721, SGC-7901 and GES-1) by this method show that the recognition rate of dataset with the combination of cell surface morphology, adhesion and Young's modulus is higher, and the recognition rate of the dataset with optimal resolution is higher. Our study indicated that the recognition of physical properties of cells using deep learning technology can serve as a universal and effective method for the automated analysis of cell information.
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Comunicação Celular , Redes Neurais de Computação , Microscopia de Força Atômica/métodos , Módulo de ElasticidadeRESUMO
Microplastics, which comprise one of the omnipresent threats to human health, are diverse in shape and composition. Their negative impacts on human and ecosystem health provide ample incentive to design and execute strategies to trap and degrade diversely structured microplastics, especially from water. This work demonstrates the fabrication of single-component TiO2 superstructured microrobots to photo-trap and photo-fragment microplastics. In a single reaction, rod-like microrobots diverse in shape and with multiple trapping sites, are fabricated to exploit the asymmetry of the microrobotic system advantageous for propulsion. The microrobots work synergistically to photo-catalytically trap and fragment microplastics in water in a coordinated fashion. Hence, a microrobotic model of "unity in diversity" is demonstrated here for the phototrapping and photofragmentation of microplastics. During light irradiation and subsequent photocatalysis, the surface morphology of microrobots transformed into porous flower-like networks that trap microplastics for subsequent degradation. This reconfigurable microrobotic technology represents a significant step forward in the efforts to degrade microplastics.
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Halide perovskites are emerging emitters with excellent optoelectronic properties. Contrary to the large grain fabrication goal in perovskite solar cells, perovskite light-emitting diodes (PeLEDs) based on small grain enable efficient radiative recombination because of relatively higher charge carrier densities due to spatial confinement. However, achieving small-sized grain growth with superior crystal quality and film morphology remains a challenge. In this work, we demonstrated a nanostructured stamp thermal imprinting strategy to boost the surface coverage and improve the crystalline quality of CsPbBr3 film, particularly confine the grain size, leading to the improvement of luminance and efficiency of PeLEDs. We improved the thermal imprinting process utilizing the nanostructured stamp to selectively manipulate the nucleation and growth in the nanoscale region and acquire small-sized grain accompanied by improved crystal quality and surface morphology of the film. By optimizing the imprinting pressure and the period of the nanostructures, appropriate grain size, high surface coverage, small surface roughness and improved crystallization could be achieved synchronously. Finally, the maximum luminance and efficiency of PeLEDs achieved by nanostructured stamp imprinting with a period of 320â nm are 67600â cd/m2 and 16.36â cd/A, respectively. This corresponds to improvements of 123 % in luminance and 100 % in efficiency, compared to that of PeLEDs without the imprinting.
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The production of reinforced composite materials can generally benefit greatly from the use of natural cellulosic woody fibers as good sustainable resources. Natural plants like hemp, cotton, and bamboo are great options for knitters and crocheters looking to make eco-friendly goods. The current study examines the properties of natural fiber obtained from the stem of the Acacia pennata (AP) plant, as well as its basic physico-chemical, structural, thermal, and mechanical characteristics. The key goal of this work was to investigate how alkali treatment affected the AP fibers' morphology, chemical composition, tensile capabilities, morphological changes, structural changes, and thermal degradation (APFs). The SEM image and pXRD analyses support the improved surface roughness of the fiber, and that was seen after the alkaline treatment. From XRD analysis, the fiber crystallinity index (54.65%) was improved and it was connected to their SEM pictograms in comparison to untreated APF. Alkali-treated AP fibers include a higher percentage of chemical components including cellulose (51.38%) and ash (5.13%). Alkali-treated AP fibers have a lower amount of hemi-cellulose (30.30%), lignin (20.96%), pectin (8.77%), wax (0.12%), and moisture (13.44%) than untreated APF. Their low density and high cellulosic content will improve their ability to fiber matrices. The thermal behavior of AP fiber at various temperatures was demonstrated by TG-DTA analysis, and tensile strength was also investigated.
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Acacia , Álcalis/química , Celulose/química , Lignina/química , Resistência à TraçãoRESUMO
BACKGROUND: The surface morphology of colorectal polyps is well correlated with submucosal invasion in Eastern Countries but not in North America. We aimed to investigate associations between the Paris classification, surface morphology, and Kudo pit pattern to submucosal invasion in advanced endoscopic resection techniques. METHODS: We retrospectively analyzed prospectively collected data of consecutive advanced endoscopic procedures conducted by a single surgeon between August 2017 and October 2018. The data included patients' demographics, the endoscopic finding of polyps (Paris, Kudo, and surface morphology), and pathology results. RESULTS: The study consisted of 138 lesions, and the mean age was 67 ± 10 years. The most common polyp locations were cecum (n = 41, 30%) followed by ascending colon (n = 28, 20%), and sigmoid colon (n = 18, 13%).The median polyp size was 30 mm (25-40). The en-bloc resection rate was 96%, and 11 (8%) polyps had adenocarcinoma with submucosal invasion. Nine patients (6.5%) had late bleeding, and 3 (2.2%) perforation occurred. Polyps with pit pattern of Kudo IV (n = 4, 36.4%) and Kudo V (n = 6, 54.5%) were associated with submucosal invasion. CONCLUSIONS: Surface morphology and pit pattern can predict submucosal invasion in the North American patient population. Polyp morphology may aid polyp selection for advanced endoscopic interventions.
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Adenocarcinoma , Pólipos do Colo , Neoplasias Colorretais , Humanos , Pessoa de Meia-Idade , Idoso , Pólipos do Colo/cirurgia , Estudos Retrospectivos , Colonoscopia/métodos , Colo Sigmoide/patologia , Adenocarcinoma/cirurgia , Adenocarcinoma/patologia , Neoplasias Colorretais/cirurgiaRESUMO
Schistosomiasis is the second most prevailing parasitic disease worldwide. Although praziquantel is considered an effective drug in the treatment against schistosomiasis to some extent, there is an emerging drug resistance that widely recorded. Therefore, there is an urgent need to develop effective and safe anti-schistosomal drugs. In this study, Cornulaca monacantha (C. monacantha), a sub-saharan plant, was extracted using aqueous ethanol and characterized by High-Performance Liquid Chromatography (HPLC). Major constituents of the extract are belonging to flavonoids, tannins and phenolic glycosides. Worms' viability and surface morphology of Schistosoma mansoni (S. mansoni) adult worms treated with the extract were assessed using in vitro viability assay, Scanning Electron Microscopy (SEM), and histological examination. The extract (80-350 µg/ml) reduced viability percentage of worms by 40-60% and caused degeneration of both oral and ventral suckers, tegumental, sub-tegumental and muscular damage. Molecular docking approach was utilized to assess the binding affinities of the extracted compounds with S. mansoni alpha-carbonic anhydrase (SmCA), an essential tegument protein. Pharmacokinetic analysis using SwissADME showed that 7 compounds have high drug similarity. This study confirms the in vitro schistomicidal activity of C. monacantha extract against S. mansoni adult worms and suggests potential SmCA inhibition.
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Esquistossomose mansoni , Esquistossomose , Animais , Simulação de Acoplamento Molecular , Schistosoma mansoni , Praziquantel/farmacologia , Microscopia Eletrônica de Varredura , Esquistossomose mansoni/tratamento farmacológicoRESUMO
In this study, scanning electron microscopy (SEM) was used to study the cell structure of SARS-CoV-2 infected cells. Our measurements revealed infection remodeling caused by infection, including the emergence of new specialized areas where viral morphogenesis occurs at the cell membrane. Intercellular extensions for viral cell surfing have also been observed. Our results expand knowledge of SARS-CoV-2 interactions with cells, its spread from cell to cell, and their size distribution. Our findings suggest that SEM is a useful microscopic method for intracellular ultrastructure analysis of cells exhibiting specific surface modifications that could also be applied to studying other important biological processes.
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COVID-19 , SARS-CoV-2 , Animais , Chlorocebus aethiops , Microscopia Eletrônica de Varredura , Linhagem Celular , Células VeroRESUMO
Metal nanostructure-treated polymers are widely recognized as the key material responsible for a specific antibacterial response in medical-based applications. However, the finding of an optimal bactericidal effect in combination with an acceptable level of cytotoxicity, which is typical for metal nanostructures, prevents their expansion from being more significant so far. This study explores the possibility of firmly anchoring silver nanoparticles (AgNPs) into polyetherether ketone (PEEK) with a tailored surface morphology that exhibits laser-induced periodic surface structures (LIPSS). We demonstrated that laser-induced forward transfer technology is a suitable tool, which, under specific conditions, enables uniform decoration of the PEEK surface with AgNPs, regardless of whether the surface is planar or LIPSS structured. The antibacterial test proved that AgNPs-decorated LIPSS represents a more effective bactericidal protection than their planar counterparts, even if they contain a lower concentration of immobilized particles. Nanostructured PEEK with embedded AgNPs may open up new possibilities in the production of templates for replication processes in the construction of functional bactericidal biopolymers or may be directly used in tissue engineering applications.
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Nanopartículas Metálicas , Nanopartículas Metálicas/química , Prata/química , Polietilenoglicóis/química , Cetonas/química , Antibacterianos/farmacologia , Antibacterianos/químicaRESUMO
Lytic polysaccharide monooxygenases (LPMOs) can oxidatively break the glycosidic bonds of crystalline cellulose, providing more actionable sites for cellulase to facilitate the conversion of cellulose to cello-oligosaccharides, cellobiose and glucose. In this work, a bioinformatics analysis of BaLPMO10 revealed that it is a hydrophobic, stable and secreted protein. By optimizing the fermentation conditions, the highest protein secretion level was found at a IPTG concentration of 0.5 mM and 20 h of fermentation at 37 °C, with a yield of 20 mg/L and purity > 95%. The effect of metal ions on the enzyme activity of BaLPMO10 was measured, and it was found that 10 mM Ca2+ and Na+ increased the enzyme activity by 47.8% and 98.0%, respectively. However, DTT, EDTA and five organic reagents inhibited the enzyme activity of BaLPMO10. Finally, BaLPMO10 was applied in biomass conversion. The degradation of corn stover pretreated with different steam explosions was performed. BaLPMO10 and cellulase had the best synergistic degradation effect on corn stover pretreated at 200 °C for 12 min, improving reducing sugars by 9.2% compared to cellulase alone. BaLPMO10 was found to be the most efficient for ethylenediamine-pretreated Caragana korshinskii by degrading three different biomasses, increasing the content of reducing sugars by 40.5% compared to cellulase alone following co-degradation with cellulase for 48 h. The results of scanning electron microscopy revealed that BaLPMO10 disrupted the structure of Caragana korshinskii, making its surface coarse and poriferous, which increased the accessibility of other enzymes and thus promoted the process of conversion. These findings provide guidance for improving the efficiency of enzymatic digestion of lignocellulosic biomass.
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Celulase , Oxigenases de Função Mista , Oxigenases de Função Mista/metabolismo , Biomassa , Polissacarídeos/metabolismo , Celulose/metabolismo , Celulase/metabolismo , Celobiose , HidróliseRESUMO
Novel imine-tethering cationic surfactants, namely (E)-3-((2-chlorobenzylidene)amino)-N-(2-(decyloxy)-2-oxoethyl)-N,N-dimethylpropan-1-aminium chloride (ICS-10) and (E)-3-((2-chlorobenzylidene)amino)-N,N-dimethyl-N-(2-oxo-2-(tetradecyloxy)ethyl)propan-1-aminium chloride (ICS-14), were synthesized, and the chemical structures were elucidated by various spectroscopic approaches. The surface properties of the target-prepared imine-tethering cationic surfactants were investigated. The effects of both synthesized imine surfactants on carbon steel corrosion in a 1.0 M HCl solution were investigated by weight loss (WL), potentiodynamic polarization (PDP), and scanning electron microscopy (SEM) methods. The outcomes show that the inhibition effectiveness rises with raising the concentration and diminishes with raising the temperature. The inhibition efficiency of 91.53 and 94.58 % were attained in the presence of the optimum concentration of 0.5 mM of ICS-10 and ICS-14, respectively. The activation energy (Ea) and heat of adsorption (Qads) were calculated and explained. Additionally, the synthesized compounds were investigated using density functional theory (DFT). Monte Carlo (MC) simulation was utilized to understand the mechanism of adsorption of inhibitors on the Fe (110) surface.
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Cloretos , Aço , Aço/química , Corrosão , Carbono , Ácidos , TensoativosRESUMO
This work aimed to study the influence of the polybutylene succinate (PBS) content on the physical, thermal, mechanical, and chemical properties of the obtained polylactic acid (PLA)/PBS composite fibers. PLA/PBS blend fibers were prepared by a simple melt-blown process capable of yielding nanofibers. Morphological analysis revealed that the fiber size was irregular and discontinuous in length. Including PBS affected the fiber size distribution, and the fibers had a smoother surface with increased amounts of added PBS. Differential scanning calorimetry analysis (DSC) revealed that the crystallization temperature of the PLA sheet (105.8 °C) was decreased with increasing PBS addition levels down to 91.7 °C at 10 wt.% PBS. This suggests that the addition of PBS may affect PLA crystallization, which is consistent with the X-ray diffraction analysis that revealed that the crystallinity of PLA (19.2%) was increased with increasing PBS addition up to 28.1% at 10 wt% PBS. Moreover, adding PBS increased the tensile properties while the % elongation at break was significantly decreased.
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The objective of this study was to propose a new coating film for biodegradable polymers and environmentally friendly processing. Here, a novel implementation of solid lipid nanoparticles (SLN) into a biodegradable alginate (ALG) film composition created a new gastric-resistant film for an enteric-release tablet. Experiments were performed on a water-soluble substance (thiamine nitrate) to characterize the effects of SLN upon the addition of the ALG coating formulation. The coated tablets or cast films were characterized based on delayed-release properties, surface morphology, moisture resistance, and chemical interactions. The SLN-ALG film displayed gastric-resistant properties (< 10% drug substance dissolved at pH 1.2) and rapid disintegration in the intestinal medium (pH 6.8). Morphological analysis using a microscope and scanning electron microscope confirmed the uniformity and smoothness of the SLN-ALG film, which improved the mechanical properties of the film. Fourier transform infrared spectroscopy and differential scanning calorimetry indicated that SLN contributed to the formation of the film, which maintained free carboxylic groups, making the SLN-ALG film a higher acid resistance, but soluble in pH 6.8 buffer. These promising results suggest a novel nanotechnology-based coating formulation for various enteric-release dosage forms. Because of their biodegradability, the proposed ingredients and processes are safe and environment-friendly.
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Alginatos , Polímeros , Alginatos/química , Comprimidos , Água/química , Ácidos , Comprimidos com Revestimento Entérico/químicaRESUMO
There is a 'coffee ring' in the Bacillus subtilis biofilm center, and the colony biofilm morphologies are distinct inside and outside the 'coffee ring'. In this paper, we study this morphological difference and explain the reasons of the 'coffee ring' formation and further the causes to the morphological variation. We developed a quantitative method to characterize the surface morphology, the outer area is thicker than the inner area of the 'coffee ring', and the thickness amplitude in outer area is larger than inner area of the 'coffee ring'. We adopt a logistic growth model to obtain how the environmental resistance influence the colony biofilm thickness. Dead cells provide gaps for stress release and make folds formation in colony biofilm. we developed a technique for optical imaging and matching cells with the BRISK algorithm to capture the distribution and movement of motile cells and matrix producing cells in the colony biofilm. Matrix producing cells are mainly distribute in the outside of the 'coffee ring', and the extracellular matrix (ECM) prevents the motile cells moving outward from center. Motile cells mainly locate inside the ring, a small amount of dead motile cells outside the 'coffee ring' give rise to radial folds formation. There are no ECM blocking cell movements inside the ring, which result in uniform folds formation. The distribution of ECM and different phenotypes lead to the formation of the 'coffee ring', which is verified by using eps and flagellar mutants.