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1.
Braz. j. oral sci ; 20: e214873, jan.-dez. 2021. ilus
Artigo em Inglês | LILACS, BBO - Odontologia | ID: biblio-1254742

RESUMO

Aim: To compare the marginal fit of lithium disilicate CAD/CAM crowns and heat-pressed crowns fabricated using milled wax patterns, and evaluate its effect on stress distribution in implantsupported rehabilitation. Methods: A CAD model of a mandibular first molar was designed, and 16 lithium disilicate crowns (8/group) were obtained. The crown-prosthetic abutment set was evaluated in a scanning electron microscopy. The mean misfit for each group was recorded and evaluated using Student's t-test. For in silico analysis, a virtual cement thickness was designed for the two misfit values found previously, and the CAD model was assembled on an implant-abutment set. A load of 100 N was applied at 30° on the central fossa, and the equivalent stress was calculated for the crown, titanium components, bone, and resin cement layer. Results: The CAD/CAM group presented a significantly (p=0.0068) higher misfit (64.99±18.73 µm) than the heat-pressed group (37.64±15.66 µm). In silico results showed that the heat-pressed group presented a decrease in stress concentration of 61% in the crown and 21% in the cement. In addition, a decrease of 14.5% and an increase of 7.8% in the stress for the prosthetic abutment and implant, respectively, was recorded. For the cortical and cancellous bone, a slight increase in stress occurred with an increase in the cement layer thickness of 5.9% and 5.7%, respectively. Conclusion: The milling of wax patterns for subsequent inclusion and obtaining heat-pressed crowns is an option to obtain restorations with an excellent marginal fit and better stress distribution throughout the implant-abutment set


Assuntos
Microscopia Eletrônica de Varredura , Desenho Assistido por Computador , Adaptação Marginal Dentária , Prótese Dentária Fixada por Implante , Análise de Elementos Finitos , Materiais Dentários
2.
Sensors (Basel) ; 21(17)2021 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-34502718

RESUMO

In the paper, an attempt was made to use methods of artificial neural networks (ANN) and Fourier transform infrared spectroscopy (FTIR) to identify raspberry powders that are different from each other in terms of the amount and the type of polysaccharide. Spectra in the absorbance function (FTIR) were prepared as well as training sets, taking into account the structure of microparticles acquired from microscopic images with Scanning Electron Microscopy (SEM). In addition to the above, Multi-Layer Perceptron Networks (MLPNs) with a set of texture descriptors (machine learning) and Convolution Neural Network (CNN) with bitmap (deep learning) were devised, which is an innovative attitude to solving this issue. The aim of the paper was to create MLPN and CNN neural models, which are characterized by a high efficiency of classification. It translates into recognizing microparticles (obtaining their homogeneity) of raspberry powders on the basis of the texture of the image pixel.


Assuntos
Rubus , Aprendizado de Máquina , Microscopia Eletrônica de Varredura , Polissacarídeos , Pós , Espectroscopia de Infravermelho com Transformada de Fourier
3.
Int J Mol Sci ; 22(16)2021 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-34445393

RESUMO

In this article, a novel method of simultaneous carborane- and gadolinium-containing compounds as efficient agents for neutron capture therapy (NCT) delivery via magnetic nanocarriers is presented. The presence of both Gd and B increases the efficiency of NCT and using nanocarriers enhances selectivity. These factors make NCT not only efficient, but also safe. Superparamagnetic Fe3O4 nanoparticles were treated with silane and then the polyelectrolytic layer was formed for further immobilization of NCT agents. Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), energy dispersive X-ray (EDX), ultraviolet-visible (UV-Vis) and Mössbauer spectroscopies, dynamic light scattering (DLS), scanning electron microscopy (SEM), vibrating-sample magnetometry (VSM) were applied for the characterization of the chemical and element composition, structure, morphology and magnetic properties of nanocarriers. The cytotoxicity effect was evaluated on different cell lines: BxPC-3, PC-3 MCF-7, HepG2 and L929, human skin fibroblasts as normal cells. average size of nanoparticles is 110 nm; magnetization at 1T and coercivity is 43.1 emu/g and 8.1, respectively; the amount of B is 0.077 mg/g and the amount of Gd is 0.632 mg/g. Successful immobilization of NCT agents, their low cytotoxicity against normal cells and selective cytotoxicity against cancer cells as well as the superparamagnetic properties of nanocarriers were confirmed by analyses above.


Assuntos
Terapia por Captura de Nêutron de Boro/métodos , Boro/farmacologia , Gadolínio/farmacologia , Boro/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos da radiação , Sobrevivência Celular/efeitos da radiação , Difusão Dinâmica da Luz , Gadolínio/química , Humanos , Células MCF-7 , Nanopartículas de Magnetita , Microscopia Eletrônica de Varredura , Células PC-3 , Tamanho da Partícula , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
4.
Zhongguo Zhong Yao Za Zhi ; 46(13): 3319-3329, 2021 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-34396751

RESUMO

The basic features of glandular and non-glandular trichomes on leaves of Artemisia argyi( germplasms from Qichun,Ningbo,Tangyin,and Anguo,respectively) and related species A. stolonifera were observed by scanning electron microscopy( SEM)and compared. There were significant differences in trichome characteristics of leaves at all parts of A. argyi and A. stolonifera,which were closely related to the difference in chemical components. The length of non-glandular trichomes and size of glandular trichomes on middle leaves were the stablest. A. argyi and A. stolonifera can be distinguished by the density of glandular trichome. Additionally,the four germplasms of A. argyi can be discriminated via the density and curvature of non-glandular trichome. The density of non-glandular trichomes was the highest in A. stolonifera. For A. argyi,the germplasm from Qichun had the highest density of non-glandular trichomes on the abaxial surfaces of upper leaves and that from Ningbo had the largest non-glandular trichome curvature. With regard to the germplasm from Anguo,the T-shaped non-glandular trichomes of long stalks on the adaxial surfaces of the middle leaves were lodging-susceptible,and those with slender heads were wave-like. Statistics results of A. argyi and A. stolonifera are as follows: largest glandular trichomes on the adaxial and abaxial surfaces and highest glandular trichome density on the abaxial surfaces of the lower leaves in A. argyi germplasm from Ningbo,highest density of non-glandular trichomes on the abaxial surfaces of upper leaves in A. stolonifera,and highest density of glandular trichomes and non-glandular trichomes on the adaxial surfaces of the upper leaves in A. argyi germplasm from Qichun. According to the observation result under fluorescence microscope( FM),flavonoids were closely related to the size and density of non-glandular trichomes and size of glandular trichomes. The fluorescence intensity was the strongest and fluorescence area was the largest for flavonoids in A. argyi germplasms from Qichun and Tangyin,while the fluorescence for flavonoids was the weakest in A. stolonifera. It was the first time to observe and analyze the trichome ultrastructure of A. argyi leaves at different positions by SEM and FM. This study clarifies the differences between A. stolonifera and four famous A. argyi germplasms,which provides new evidence for the microscopic identification of A. argyi and its related species and serves as a reference for the study of the relationship of A. argyi structure with its components and functions.


Assuntos
Artemisia , Tricomas , Flavonoides , Microscopia Eletrônica de Varredura , Folhas de Planta
5.
Nat Commun ; 12(1): 4733, 2021 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-34354068

RESUMO

Developing an anti-infective shape-memory hemostatic sponge able to guide in situ tissue regeneration for noncompressible hemorrhages in civilian and battlefield settings remains a challenge. Here we engineer hemostatic chitosan sponges with highly interconnective microchannels by combining 3D printed microfiber leaching, freeze-drying, and superficial active modification. We demonstrate that the microchannelled alkylated chitosan sponge (MACS) exhibits the capacity for water and blood absorption, as well as rapid shape recovery. We show that compared to clinically used gauze, gelatin sponge, CELOX™, and CELOX™-gauze, the MACS provides higher pro-coagulant and hemostatic capacities in lethally normal and heparinized rat and pig liver perforation wound models. We demonstrate its anti-infective activity against S. aureus and E. coli and its promotion of liver parenchymal cell infiltration, vascularization, and tissue integration in a rat liver defect model. Overall, the MACS demonstrates promising clinical translational potential in treating lethal noncompressible hemorrhage and facilitating wound healing.


Assuntos
Quitosana , Hemorragia/terapia , Técnicas Hemostáticas/instrumentação , Tampões de Gaze Cirúrgicos , Cicatrização , Alquilação , Animais , Infecções Bacterianas/prevenção & controle , Coagulação Sanguínea , Quitosana/análogos & derivados , Quitosana/química , Fígado/lesões , Hepatopatias/patologia , Hepatopatias/terapia , Regeneração Hepática , Masculino , Teste de Materiais , Microscopia Eletrônica de Varredura , Porosidade , Ratos , Suínos , Porco Miniatura
6.
Int J Oral Maxillofac Implants ; 36(4): 650-659, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34411204

RESUMO

PURPOSE: To evaluate whether a hydrophilic surface treatment compared with a hydrophobic implant surface can enhance osseointegration by analysis of calcium deposition, bone-to-implant contact (BIC), bone volume (BV), and upregulation of genes involved in bone formation. MATERIALS AND METHODS: Sixty implants (n = 60) with a hydrophobic (SAE) or hydrophilic (SAE-HD) surface treatment were placed bilaterally in each femur of 3-month-old male mice (n = 30). Scanning electron microscopy (SEM) and energy-dispersive x-ray spectroscopy (EDS) were utilized for quantifying the presence of calcium on the implant surface 7 days after implant placement. The specimens were analyzed after 14 and 21 days for BIC and BV by Nano CT scanning followed by histologic evaluation. Additionally, 1, 3, and 7 days postsurgery, femurs were harvested, implants were explanted, and gene expression (Sp7, Bsp, Sost, IL-1α, and IL-10) by quantitative real-time polymerase chain reaction was studied. Moreover, implants were characterized for surface roughness area. Data were statistically analyzed with two-way analysis of variance (ANOVA) followed by the Tukey test (P < .05). RESULTS: The amount of calcium on the surface was higher for SAE-HD after 7 days. Nano CT revealed significantly more BV in the SAE-HD than the SAE surface. The histologic assessment showed increased BIC in SAE-HD in comparison to SAE. SAEHD showed significantly increased levels of genes involved in bone formation. CONCLUSION: Both surfaces were able to modulate bone responses toward osteoblast differentiation. SAE-HD presented a better response compared with SAE.


Assuntos
Implantes Dentários , Titânio , Animais , Implantes Experimentais , Masculino , Camundongos , Microscopia Eletrônica de Varredura , Osseointegração , Propriedades de Superfície
7.
Nat Commun ; 12(1): 4838, 2021 08 10.
Artigo em Inglês | MEDLINE | ID: mdl-34376698

RESUMO

Macropinosomes are formed by shaping actin-rich plasma membrane ruffles into large intracellular organelles in a phosphatidylinositol 3-kinase (PI3K)-coordinated manner. Here, we utilize lattice lightsheet microscopy and image visualization methods to map the three-dimensional structure and dynamics of macropinosome formation relative to PI3K activity. We show that multiple ruffling morphologies produce macropinosomes and that the majority form through collisions of adjacent PI3K-rich ruffles. By combining multiple volumetric representations of the plasma membrane structure and PI3K products, we show that PI3K activity begins early throughout the entire ruffle volume and continues to increase until peak activity concentrates at the base of the ruffle after the macropinosome closes. Additionally, areas of the plasma membrane rich in ruffling had increased PI3K activity and produced many macropinosomes of various sizes. Pharmacologic inhibition of PI3K activity had little effect on the rate and morphology of membrane ruffling, demonstrating that early production of 3'-phosphoinositides within ruffles plays a minor role in regulating their morphology. However, 3'-phosphoinositides are critical for the fusogenic activity that seals ruffles into macropinosomes. Taken together, these data indicate that local PI3K activity is amplified in ruffles and serves as a priming mechanism for closure and sealing of ruffles into macropinosomes.


Assuntos
Membrana Celular/metabolismo , Microscopia de Fluorescência/métodos , Fosfatidilinositol 3-Quinases/metabolismo , Pinocitose/fisiologia , Animais , Membrana Celular/efeitos dos fármacos , Células Cultivadas , Cromonas/farmacologia , Inibidores Enzimáticos/farmacologia , Células HEK293 , Humanos , Macrófagos/citologia , Macrófagos/metabolismo , Macrófagos/ultraestrutura , Camundongos , Microscopia Eletrônica de Varredura , Morfolinas/farmacologia , Fosfatidilinositóis/metabolismo , Pinocitose/efeitos dos fármacos , Células RAW 264.7
8.
Sensors (Basel) ; 21(16)2021 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-34450902

RESUMO

This study aims at evaluating the efficiency of sensor fusion, based on neural networks, to estimate the microstructural characteristics of both the weld bead and base material in GMAW processes. The weld beads of AWS ER70S-6 wire were deposited on SAE 1020 steel plates varying welding voltage, welding speed, and wire-feed speed. The thermal behavior of the material during the process execution was analyzed using thermographic information gathered by an infrared camera. The microstructure was characterized by optical (confocal) microscopy, scanning electron microscopy, and X-ray Diffraction tests. Finally, models for estimating the weld bead microstructure were developed by fusing all the information through a neural network modeling approach. A R value of 0.99472 was observed for modelling all zones of microstructure in the same ANN using Bayesian Regularization with 17 and 15 neurons in the first and second hidden layers, respectively, with 4 training runs (which was the lowest R value among all tested configurations). The results obtained prove that RNAs can be used to assist the project of welded joints as they make it possible to estimate the extension of HAZ.


Assuntos
Soldagem , Teorema de Bayes , Microscopia Eletrônica de Varredura , Redes Neurais de Computação , Aço
9.
Food Res Int ; 147: 110524, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34399502

RESUMO

Cultivars and fertilization levels influence rice productivity and can be associated with grain quality. Thus, it is possible to make decisions regarding the choice of cultivars and application of fertilizer levels based on the type of milling, a necessary post-harvest process that may minimize the nutrient load in the grains and result in loss in quality. This study relates the physicochemical composition and morphological quality of brown and polished milled rice grains, cultivar types, and different levels of soil fertilization using near-infrared spectroscopy analysis, X-ray diffraction and scanning electron microscopy. Statistical tools were used to test the various treatments and identify the relationship between factors and variables. A high fertilization level is related to increasing crude protein composition and starch for cultivar IRGA 431 CL associated with polished rice. However, the combination of cultivar IRGA 424 RI and brown rice demonstrated a higher grain resistance, and different percentages of whole, chalky, and damaged rice. The correlation between ash × crude protein and starch × crude fiber was found to be positive for brown rice and negative for the polished rice. Further, an increase in starch content was inversely proportional to the ash content, whereas an increase in crude protein was inversely proportional to the low-fat content in milled rice. The crystalline characteristics of rice starch were preserved at high fertilization levels associated with polished grains that demonstrated high starch content. Polished grains, however, showed more pores and cavities, and consequently greater permeabilities in the surface. It is recommended that batches of grains produced from cultivar IRGA 431 CL with high levels of fertilization be subjected to polished rice milling to achieve high protein and starch quality. However, grains from cultivar IRGA 424 RI with high levels of fertilization are recommended for brown rice milling owing to the high percentage of physical defects observed.


Assuntos
Oryza , Fertilização , Microscopia Eletrônica de Varredura , Espectroscopia de Luz Próxima ao Infravermelho , Difração de Raios X
10.
Beijing Da Xue Xue Bao Yi Xue Ban ; 53(4): 770-775, 2021 Aug 18.
Artigo em Chinês | MEDLINE | ID: mdl-34393243

RESUMO

OBJECTIVE: To evaluate the effects of femtosecond laser treated microgrooved surface on microscopic topography, phase transformation, and three-points flexural strength of zirconia, and to provide reference for surface microstructure optimization of zirconia implant. METHODS: According to different surface treatment methods, 57 computer aided design/computer aided manufacture (CAD/CAM) zirconia bars (20.0 mm×4.0 mm×1.4 mm) were evenly divided into three groups: sintered group, no treatment after sintering, taken as control; sandblasted group, sandblasted with 110 µm aluminium oxide (Al2O3) after sintering; microgrooved group, femtosecond laser fabricated microgrooves with 50 µm width, 30 µm depth, and 100 µm pitch. Surface microscopic topography was observed with scanning electron microscope (SEM) and 3D laser microscope. Further, surface roughness in each group and microgroove size were measured. Crystal phase was analyzed with X-ray diffraction. Specimens were subjected to three- points flexural strength test, and Weibull distribution was used to analyze their strength characteristics. RESULTS: SEM showed that sintered surface was flat with clear grain structure; sandblasted surface exihibited bumps and holes with sharp margins and irregular shape; microgrooves were regularly aligned without evident defect, and nano-scale particles were observed on the surface inside of the microgrooves. Ra value of microgrooved group [(9.42±0.28)] µm was significantly higher than that of sandblasted group [(1.04±0.03) µm] and sintered group [(0.60±0.04) µm], and there was statistical difference between sandblasted group and sintered group (P < 0.001). The microgroove size was precise with (49.75±1.24) µm width, (30.85±1.02) µm depth, and (100.58±1.94) µm pitch. Crystal phase analysis showed that monoclinic volume fraction of sandblasted group (18.17%) was much higher than that of sintered group (1.55%), while microgrooved group (2.21%) was similar with sintered group. The flexural strength of sandblasted group (986.22±163.25) MPa had no statistical difference with that of sintered group (946.46±134.15) MPa (P=0.847), but the strength in microgrooved group (547.92±30.89) MPa dropped significantly compared with the other two groups (P < 0.001). Weibull modulus of sintered, sandblasted, microgrooved groups were 7.89, 6.98, and 23.46, respectively. CONCLUSION: Femtosecond laser was able to form micro/nanostructured microgrooves on zirconia surface, which deleteriously affected the flexural strength of zirconia.


Assuntos
Cerâmica , Resistência à Flexão , Materiais Dentários , Humanos , Lasers , Teste de Materiais , Microscopia Eletrônica de Varredura , Propriedades de Superfície , Ítrio , Zircônio
11.
Int J Mol Sci ; 22(15)2021 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-34360570

RESUMO

Cancer cell invasion through tissue barriers is the intrinsic feature of metastasis, the most life-threatening aspect of cancer. Detailed observation and analysis of cancer cell behaviour in a 3D environment is essential for a full understanding of the mechanisms of cancer cell invasion. The inherent limits of optical microscopy resolution do not allow to for in-depth observation of intracellular structures, such as invadopodia of invading cancer cells. The required resolution can be achieved using electron microscopy techniques such as FIB-SEM. However, visualising cells in a 3D matrix using FIB-SEM is challenging due to difficulties with localisation of a specific cell deep within the resin block. We have developed a new protocol based on the near-infrared branding (NIRB) procedure that extends the pattern from the surface grid deep inside the resin. This 3D burned pattern allows for precise trimming followed by targeted 3D FIB-SEM. Here we present detailed 3D CLEM results combining confocal and FIB-SEM imaging of cancer cell invadopodia that extend deep into the collagen meshwork.


Assuntos
Neoplasias da Mama/patologia , Fibrossarcoma/patologia , Imageamento Tridimensional/métodos , Microscopia Eletrônica de Varredura/métodos , Podossomos/patologia , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Invasividade Neoplásica , Células Tumorais Cultivadas
12.
Br J Nurs ; 30(15): S12-S23, 2021 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-34379466

RESUMO

Several studies have demonstrated improved clinical outcomes in pressure ulcer prevention using the SEM scanner, but none have compared it with other methods. In one of Scotland's health boards, 'hot spot' wards had been unable to reduce the number of hospital-acquired pressure ulcers (HAPUs) after several years of focused improvement work. In addition, other wards showed high use of dynamic therapy systems with associated costs. This review compares the use of a first generation SEM scanner versus a mattress and equipment selection pathway over a 6-week period. The findings show that the SEM scanner wards had zero HAPU while the equipment pathway wards developed a total of 4 HAPU. The two SEM scanner wards showed a 11% and 33% reduction in dynamic therapy use, while the pathway wards showed an average 40% increase. Consideration should be given to using SEM scanners to support staff decision-making to reduce HAPU development and dynamic therapy usage.


Assuntos
Microscopia Eletrônica de Varredura , Lesão por Pressão , Leitos , Equipamentos e Provisões , Hospitais , Humanos , Lesão por Pressão/diagnóstico , Lesão por Pressão/prevenção & controle
13.
Nat Commun ; 12(1): 4657, 2021 08 02.
Artigo em Inglês | MEDLINE | ID: mdl-34341359

RESUMO

Correlative imaging and quantification of intracellular nanoparticles with the underlying ultrastructure is crucial for understanding cell-nanoparticle interactions in biological research. However, correlative nanoscale imaging of whole cells still remains a daunting challenge. Here, we report a straightforward nanoscopic approach for whole-cell correlative imaging, by simultaneous ionoluminescence and ultrastructure mapping implemented with a highly focused beam of alpha particles. We demonstrate that fluorescent nanodiamonds exhibit fast, ultrabright and stable emission upon excitation by alpha particles. Thus, by using fluorescent nanodiamonds as imaging probes, our approach enables quantification and correlative localization of single nanodiamonds within a whole cell at sub-30 nm resolution. As an application example, we show that our approach, together with Monte Carlo simulations and radiobiological experiments, can be employed to provide unique insights into the mechanisms of nanodiamond radiosensitization at the single whole-cell level. These findings may benefit clinical studies of radio-enhancement effects by nanoparticles in charged-particle cancer therapy.


Assuntos
Partículas alfa , Núcleo Celular/efeitos da radiação , Quebras de DNA de Cadeia Dupla/efeitos da radiação , Histonas/metabolismo , Nanodiamantes/efeitos da radiação , Proteína 1 de Ligação à Proteína Supressora de Tumor p53/metabolismo , Núcleo Celular/genética , Núcleo Celular/metabolismo , Células HeLa , Células Hep G2 , Humanos , Microscopia Confocal/métodos , Microscopia Eletrônica de Varredura/métodos , Nanodiamantes/química , Nanodiamantes/ultraestrutura , Fosforilação/efeitos da radiação
14.
Environ Sci Pollut Res Int ; 28(34): 46910-46933, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34263399

RESUMO

Fly ash is readily available and cheaply generated as 47a by-product of the combustion of organic matter. A tremendous amount of fly ash is generated worldwide, and its disposal has imposed 47a severe environmental concern. Its good adsorption capacities attracted several researchers to study the use of fly ash as 47a support for photocatalysts for the degradation of contaminants from wastewater. Undoubtedly the photocatalysts supported on fly ash have represented excellent degradation efficiencies due to the synergistic effect of adsorption and photocatalytic capacity. The utilization of fly ash as 47a precursor has solved the problem of disposal and added value to the waste by-product. Various preparation techniques for fly ash-based nanocomposites such as the sol-gel method, hydrothermal method, solvothermal method, precipitation and co-precipitation, modified metalorganic decomposition, electrospinning, incipient impregnation, and wet chemical synthesis, along with 47a brief study of their characterization using scanning electron microscopy, X-ray diffraction technique and Fourier transform infrared (FTIR) spectroscopy, and the mechanism of photodegradation of dyes have been discussed in this paper. The literature shows that SiO2, TiO2, and Al2O3 present in fly ash play an essential role in the photodegradation of dyes. Factors affecting the degradation of dyes, their kinetic studies, and methods to enhance photodegradation efficiency have also been discussed.


Assuntos
Poluentes Ambientais , Nanocompostos , Poluentes Químicos da Água , Adsorção , Cinza de Carvão , Cinética , Microscopia Eletrônica de Varredura , Dióxido de Silício , Poluentes Químicos da Água/análise , Difração de Raios X
15.
Int J Mol Sci ; 22(13)2021 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-34209889

RESUMO

Excessive misuse of antibiotics and antimicrobials has led to a spread of microorganisms resistant to most currently used agents. The resulting global threats has driven the search for new materials with optimal antimicrobial activity and their application in various areas of our lives. In our research, we focused on the formation of composite materials produced by the dispersion of titanium(IV)-oxo complexes (TOCs) in poly(ε-caprolactone) (PCL) matrix, which exhibit optimal antimicrobial activity. TOCs, of the general formula [Ti4O2(OiBu)10(O2CR')2] (R' = PhNH2 (1), C13H9 (2)) were synthesized as a result of the direct reaction of titanium(IV) isobutoxide and 4-aminobenzoic acid or 9-fluorenecarboxylic acid. The microcrystalline powders of (1) and (2), whose structures were confirmed by infrared (IR) and Raman spectroscopy, were dispersed in PCL matrixes. In this way, the composites PCL + nTOCs (n = 5 and 20 wt.%) were produced. The structure and physicochemical properties were determined on the basis of Raman microscopy, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), electron paramagnetic resonance spectroscopy (EPR), and UV-Vis diffuse reflectance spectroscopy (DRS). The degree of TOCs distribution in the polymer matrix was monitored by scanning electron microscopy (SEM). The addition of TOCs micro grains into the PCL matrix only slightly changed the thermal and mechanical properties of the composite compared to the pure PCL. Among the investigated PCL + TOCs systems, promising antibacterial properties were confirmed for samples of PCL + n(2) (n = 5, 20 wt.%) composites, which simultaneously revealed the best photocatalytic activity in the visible range.


Assuntos
Anti-Infecciosos/síntese química , Compostos Organometálicos/síntese química , Poliésteres/química , Titânio/química , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Varredura Diferencial de Calorimetria , Catálise , Microscopia Eletrônica de Varredura , Compostos Organometálicos/química , Compostos Organometálicos/farmacologia , Processos Fotoquímicos , Espectroscopia de Infravermelho com Transformada de Fourier , Resistência à Tração , Difração de Raios X
16.
Ann Parasitol ; 67(2): 151-159, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34331851

RESUMO

The ischnoceran louse, Felicola rohani Werneck, 1956 is reported for the first time from India on the Indian grey mongoose - Herpestes edwardsii (Geoffroy Saint-Hilaire, 1818) and the amblyceran louse, Heterodoxus spiniger (Enderlein, 1909) is recorded for the first time from that host species. The lice were collected from freshly accidentally killed specimen of the host, preserved and kept at the Museum of Estuarine Biology Regional Centre, Zoological Survey of India, Gopalpur-on-sea, Ganjam Odisha. Detailed morphological descriptions of the lice, based on light and scanning electron microscopy, are presented in this paper.


Assuntos
Amblíceros , Herpestidae , Infestações por Piolhos , Ftirápteros , Animais , Índia , Infestações por Piolhos/veterinária , Microscopia Eletrônica de Varredura
17.
Molecules ; 26(11)2021 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-34199868

RESUMO

A large quantity of longan fruits (Dimocarpus longan Lour.) produced annually are processed into many products, one of which is black longan, from which the dried, dark-brown meat has been used medicinally in traditional medicine, while the starch-containing seeds are discarded. In this study, starch samples (BLGSs) were isolated from seeds of black longan fruits prepared using varied conditions. The in vitro digestibility was determined in comparison with those extracted from fresh (FLGS) and dried (DLGS) seeds. Scanning electron microscopy (SEM), X-ray diffraction (XRD), differential scanning calorimetry (DSC), and Fourier transform infrared (FTIR) spectroscopy were employed to evaluate the starch properties. The results showed that the yields of FLGS, DLGS, and BLGSs were 20%, 23%, and 16-22% w/w, respectively. SEM images showed starch granules of mixed shapes, with sizes up to 15 µm in all samples. XRD patterns confirmed an A-type crystallinity for FLGS and DLGS, with strong refraction peaks at 2θ = 15°, 17°, 18°, and 23°, while BLGSs also showed detectable peaks at 2θ = 10° and 21°, which suggested V-type structures. Thermal properties corroborated the changes by showing increases in peak gelatinization temperature (Tp) and enthalpy energy (ΔH) in BLGSs. The paste viscosity of BLGSs (5% w/w) decreased by 20-58% from that of FLGS. The FTIR peak ratio at 1045/1022 and 1022/995 cm-1 also indicated an increase in ordered structure in BLGSs compared to FLGS. The significant increase in the amounts of slowly digestible starch (SDS) and resistant starch (RS) in BLGSs compared to FLGS, especially at a prolonged incubation time of 20 (4.2×) and 30 days (4.1×), was proposed to be due to the heat-induced formation of starch inclusion with other components inside the seed during the black longan production process. Thus, black longan seed could be a new source of starch, with increased RS content, for potential use in the food and related industries.


Assuntos
Amido Resistente/análise , Sapindaceae/química , Amido/análise , Varredura Diferencial de Calorimetria , Dessecação , Microscopia Eletrônica de Varredura , Sementes/química , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
18.
Molecules ; 26(13)2021 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-34201878

RESUMO

Composites of metal-organic frameworks and carbon materials have been suggested to be effective materials for the decomposition of chemical warfare agents. In this study, we synthesized UiO-66-NH2/zeolite-templated carbon (ZTC) composites for the adsorption and decomposition of the nerve agents sarin and soman. UiO-66-NH2/ZTC composites with good dispersion were prepared via a solvothermal method. Characterization studies showed that the composites had higher specific surface areas than pristine UiO-66-NH2, with broad pore size distributions centered at 1-2 nm. Owing to their porous nature, the UiO-66-NH2/ZTC composites could adsorb more water at 80% relative humidity. Among the UiO-66-NH2/ZTC composites, U0.8Z0.2 showed the best degradation performance. Characterization and gas adsorption studies revealed that beta-ZTC in U0.8Z0.2 provided additional adsorption and degradation sites for nerve agents. Among the investigated materials, including the pristine materials, U0.8Z0.2 also exhibited the best protection performance against the nerve agents. These results demonstrate that U0.8Z0.2 has the optimal composition for exploiting the degradation performance of pristine UiO-66-NH2 and the adsorption performance of pristine beta-ZTC.


Assuntos
Carbono/química , Estruturas Metalorgânicas/química , Agentes Neurotóxicos/química , Compostos Organometálicos/química , Ácidos Ftálicos/química , Zeolitas/química , Adsorção , Estruturas Metalorgânicas/síntese química , Estruturas Metalorgânicas/ultraestrutura , Microscopia Eletrônica de Varredura , Porosidade , Sarina/química , Soman/química , Espectroscopia de Infravermelho com Transformada de Fourier , Água/química , Difração de Raios X
19.
Molecules ; 26(13)2021 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-34206777

RESUMO

Previous studies have revealed the numerous biological activities of the fruits of Illicium verum; however, the activities of its leaves and twigs have remained undiscovered. The study aimed to investigate the phytochemical components and antibacterial activity of the various extracts from the leaves and twigs of Illicium verum. The herbal extracts were prepared by supercritical CO2 extraction (SFE) and 95% ethanol extraction, followed by partition extraction based on solvent polarity. Analysis of antimicrobial activity was conducted through the usage of nine clinical antibiotic- resistant isolates, including Staphylococcus aureus, Pseudomonas aeruginosa and Acinetobacter baumannii. Among the tested samples, the SFE extracts exhibited broader and stronger antibacterial activities against the test strains, with a range of MIC between 0.1-4.0 mg/mL and MBC between 0.2-4.5 mg/mL. Observations made through scanning electron microscopy revealed potential mechanism of the antimicrobial activities involved disruption of membrane integrity of the test pathogens. Evaluation of the chemical composition by gas chromatography-mass spectrometry indicated the presence of anethole, anisyl aldehyde, anisyl acetone and anisyl alcohol within the SFE extracts, demonstrating significant correlations with the antibacterial activities observed. Therefore, the leaves and twigs of Illicium verum hold great potential in being developed as new natural antibacterial agents.


Assuntos
Antibacterianos/farmacologia , Anti-Infecciosos/farmacologia , Illicium/química , Extratos Vegetais/análise , Extratos Vegetais/farmacologia , Acinetobacter baumannii/efeitos dos fármacos , Acinetobacter baumannii/ultraestrutura , Antibacterianos/análise , Anti-Infecciosos/análise , Membrana Celular/efeitos dos fármacos , Membrana Celular/ultraestrutura , Sobrevivência Celular/efeitos dos fármacos , Cromatografia Gasosa , Espectrometria de Massas , Testes de Sensibilidade Microbiana , Microscopia Eletrônica de Varredura , Extratos Vegetais/química , Folhas de Planta/química , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/ultraestrutura , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/ultraestrutura
20.
Molecules ; 26(12)2021 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-34200814

RESUMO

Multi-drug resistant pathogens are a rising danger for the future of mankind. Iodine (I2) is a centuries-old microbicide, but leads to skin discoloration, irritation, and uncontrolled iodine release. Plants rich in phytochemicals have a long history in basic health care. Aloe Vera Barbadensis Miller (AV) and Salvia officinalis L. (Sage) are effectively utilized against different ailments. Previously, we investigated the antimicrobial activities of smart triiodides and iodinated AV hybrids. In this work, we combined iodine with Sage extracts and pure AV gel with polyvinylpyrrolidone (PVP) as an encapsulating and stabilizing agent. Fourier transform infrared spectroscopy (FT-IR), Ultraviolet-visible spectroscopy (UV-Vis), Surface-Enhanced Raman Spectroscopy (SERS), microstructural analysis by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and X-Ray-Diffraction (XRD) analysis verified the composition of AV-PVP-Sage-I2. Antimicrobial properties were investigated by disc diffusion method against 10 reference microbial strains in comparison to gentamicin and nystatin. We impregnated surgical sutures with our biohybrid and tested their inhibitory effects. AV-PVP-Sage-I2 showed excellent to intermediate antimicrobial activity in discs and sutures. The iodine within the polymeric biomaterial AV-PVP-Sage-I2 and the synergistic action of the two plant extracts enhanced the microbial inhibition. Our compound has potential for use as an antifungal agent, disinfectant and coating material on sutures to prevent surgical site infections.


Assuntos
Antibacterianos/química , Antibacterianos/síntese química , Aloe/química , Antifúngicos/química , Gentamicinas/química , Testes de Sensibilidade Microbiana , Microscopia Eletrônica de Varredura/métodos , Nistatina/química , Extratos Vegetais/química , Povidona/química , Salvia/química , Salvia officinalis/química , Espectrometria por Raios X/métodos , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Difração de Raios X/métodos
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