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1.
Food Chem ; 343: 128404, 2021 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-33406570

RESUMEN

Various drying techniques play an important role in foodstuff preservation. However, the role of different drying techniques on garlic quality is limited. The purpose of this study was to investigate the effect of vacuum freeze-drying (VFD), hot air drying (HAD), infrared hot air drying (IRHAD), relative humidity drying (RHD) and pulsed vacuum drying (PVD) on the physical, rehydration, flavor, bioactive compounds and antioxidant characteristics of garlic slices. Results showed that garlic slices treated with VFD had an attractive color, low shrinkage, low hardness, and the lowest rehydration capacity. The volume shrinkage ratio, thermal stability and storage stability of garlic slices after HAD were the highest. Different dried garlic samples had different specific flavor fingerprints. IRHAD and RHD dried samples showed the highest rehydration capacity, content of bioactive compounds and antioxidant activity. The findings could provide a scientific basis to help in future large-scale production of good quality dried garlic products.


Asunto(s)
Antioxidantes/química , Aromatizantes/química , Almacenamiento de Alimentos/métodos , Ajo/química , Color , Desecación , Ajo/metabolismo , Dureza , Análisis de Componente Principal , Temperatura , Termogravimetría , Agua/química , Agua/metabolismo
2.
Food Chem ; 343: 128406, 2021 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-33406571

RESUMEN

This study was the first to examine the effects of γ-[Glu](1≤n≤5)-Gln (GGP, a taste enhancer; added at 0.5% or 5.0%) on the breadmaking using frozen dough. γ-[Glu](1≤n≤5)-Gln was produced using the method established in our research center. The addition of GGP at either level increased yeast viability, freezable water content and storage and loss moduli, decreased the free sulfhydryl content of dough during the frozen storage and freeze-thaw cycles, and improved the microstructure of frozen dough and texture of the baked bread. The addition of GGP at 0.5% led to a dough having the highest extensibility, and most complete and uniform starch-gluten network, and a baked bread crumb with the lowest hardness, best texture, and most uniform organization. These results indicated that GGP has great potential as a food-derived cryoprotectant/antifreeze agent for the baking industry.


Asunto(s)
Pan/análisis , Culinaria/métodos , Péptidos/química , Harina/análisis , Congelación , Dureza , Espectroscopía de Resonancia Magnética , Microscopía Electrónica de Rastreo , Reología , Compuestos de Sulfhidrilo/análisis , Agua/análisis , Levaduras/fisiología
3.
Food Chem ; 335: 127629, 2021 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-32736156

RESUMEN

Folate deficiencies are prevalent in countries with insufficient food diversity. Rice fortification is seen as a viable way to improve the daily intake of folates. This work reports an efficient process of rice fortification involving ultrasonic treatment and absorption of the folic acid fortificant. Increased porosity due to sonication allowed the efficient absorption of folic acid into the brown rice kernel up to 5.195 × 104 µg/100 g, a 1,982-fold increase from its inherent content. The absorbed folic acid in brown rice has 93.53% retention after washing and cooking. Fortification of ultrasound-treated milled rice with folic acid was also efficient affording 6.559 × 104 µg/100 g, a 4,054-fold increase from its basal content. The effect of fortification caused a decrease in the thermal and pasting temperatures. The fortification also caused yellow coloration, decrease in hardness, and increase in the adhesiveness of the rice. The resulting fortified brown rice showed improved textural properties favorable for consumers.


Asunto(s)
Absorción Fisicoquímica , Ácido Fólico/química , Alimentos Fortificados/análisis , Oryza/química , Ondas Ultrasónicas , Adhesividad , Color , Dureza
4.
Food Chem ; 337: 127682, 2021 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-32795852

RESUMEN

Consumers are increasingly interested in low-fat meat products. Therefore, there is demand for new fat replacers that improve the quality of low-fat meat products. Whey protein isolate (WPI; 10% (w/v)) and sodium dodecyl sulfate (SDS; 0-0.09% (w/v)) were used to produce WPI-SDS gel as a fat replacer of low-fat meat products. Characteristics of WPI-SDS gel were evaluated using SDS-PAGE, FT-IR, viscometer, and texture analyzer. Addition of SDS to WPI increased gelation while reducing aggregation. Addition of 0.06% SDS to WPI-SDS gel has the highest viscosity and hardness, while 0.09% SDS decreased the heat stability of WPI. Quality characteristics including cooking loss, emulsion stability, hardness, and chewiness were significantly improved in WPI-SDS gel-supplemented low-fat sausages. Particularly, the highest hardness and chewiness were obtained in the low-fat sausage added with WPI-SDS gel containing 0.06% SDS. Our results suggest that WPI-SDS gel can be used as a fat replacer in low-fat meat products.


Asunto(s)
Culinaria , Productos de la Carne/análisis , Dodecil Sulfato de Sodio/química , Proteína de Suero de Leche/química , Geles , Dureza , Viscosidad
5.
Food Chem ; 338: 127799, 2021 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-32798816

RESUMEN

An emerging blanching technology, namely vacuum-steam pulsed blanching (VSPB) was employed to blanch the carrots and its effects on blanching efficiency, microstructure and ultrastructure, drying kinetics, colour, texture, phytochemicals (phenolics and ß-carotene) and antioxidant capacity of carrot slices were explored and compared with the traditional hot water blanching. Results showed that both blanching treatments enhanced the drying velocity and shortened the drying time by 25.9% compared with untreated samples. VSPB yielded higher blanching efficiency, better colour (more red and yellow), greater antioxidant capacity and higher preservation of phytochemicals compared with hot water blanched samples. Especially, compared to hot water blanched carrots, the p-hydroxybenzoic acid, ferulic acid, and caffeic acid content of VSPB samples increased of 106.6%, 42.0%, and 19.0%, respectively. Interestingly, the chlorogenic acid content in the blanched carrot increased more than 220 times compared to fresh samples. Ultrastructure and microstructure observation clarify the mechanism of quality enhancement of VSPB.


Asunto(s)
Antioxidantes/química , Daucus carota/química , Daucus carota/ultraestructura , Desecación/métodos , Industria de Procesamiento de Alimentos/métodos , Fitoquímicos/análisis , Antioxidantes/análisis , Color , Ácidos Cumáricos/análisis , Calidad de los Alimentos , Dureza , Cinética , Microscopía Electrónica de Transmisión , Fenoles/análisis , Fitoquímicos/química , Vapor , Temperatura , Vacio , Agua/química , beta Caroteno/análisis
6.
Food Chem ; 339: 127875, 2021 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-32866701

RESUMEN

Gluten protein based snacks have been a major concern for allergen, low nutrition and physio-chemical properties. In this study, wheat flour (WF) was replaced with cassava starch (CS) at different levels [10, 20, 30, 40 and 50%(w/w)] to prepare fried snacks. The addition of CS significantly (P < 0.05) increased hardness and pasting properties while gluten network, oil uptake, water holding capacity, and expansion were decreased. Fourier transform infrared spectroscopy revealed that the secondary structure of amide I, α-helix (1650-1660 cm-1), along with amide II region (1540 cm-1) changed when CS was added. Starch-protein complex was identified by X-ray diffraction analysis while no starch-protein-lipid complex was observed. The micrographs from scanning electron microscopy showed that starch-protein matrix was interrupted when ≥40%(w/w) CS was added. Furthermore, in vitro calcium bioavailability was decreased slightly with the addition of CS. The results suggest the feasibility of adding 40% CS as an alternative to WF in snacks.


Asunto(s)
Digestión , Glútenes/química , Manihot/química , Bocadillos , Triticum/química , Harina/análisis , Dureza , Almidón/química , Agua/química
7.
Food Chem ; 339: 128078, 2021 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-33152871

RESUMEN

The purpose of this work was to characterize the dynamic texture perception and study the mechanisms occurring in bolus from chewing to swallowing during white bread oral processing. Results indicated that the microstructural and chemical composition properties determined the oral processing behaviors. At the initial stage of oral processing, the roughness, hardness, and dryness perception were the dominant attributes. At the end of oral processing the adhesiveness and softness perception were dominant, which correlated to the higher bolus water content and adhesive properties. The softness and adhesiveness perception were the key factors that trigger swallowing. In vitro artificial mastication experiments confirmed that mucin rapidly increased the adhesive force of bolus at the initial stage of oral processing, whereas α-amylase gradually increased the adhesive force. These results can help to better understand the dynamic texture perception and its change mechanisms during oral processing.


Asunto(s)
Pan , Deglución , Masticación , Sensación , Adhesividad , Dureza , Humanos , Triticum
8.
Food Chem ; 336: 127709, 2021 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-32763738

RESUMEN

The microbiological, microstructural, and physicochemical impact of aqueous ozone mixing (AOM) on semi-dried buckwheat noodles (SBWN) was elucidated in this study. Microbiological measurements declared that AOM reduced the initial total plate count (TPC) of SBWN significantly (P < 0.05) with a prolonged shelf-life of 2 ~ 5 days. Meanwhile, AOM reduced the cooking loss and water absorption along with the enhancement of hardness and tension force. Scanning electron microscopy (SEM) showed that the protein network of surface and cross section became continuous and compact, and wrapped starch granules more effectively. Moreover, an obvious increase in the intensity of the high molecular protein bands was observed in the sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) patterns. Furthermore, the sodium dodecyl sulfate extractable protein (SDSEP) under non-reducing condition obviously decreased, and then the SDSEP under reducing condition changed insignificantly (P > 0.05). These results indicated that AOM mainly promoted the protein cross-linking of SBWN by disulfide bond (SS) cross-links.


Asunto(s)
Fagopyrum/química , Industria de Procesamiento de Alimentos/métodos , Ozono/química , Culinaria , Disulfuros/química , Electroforesis en Gel de Poliacrilamida , Harina/análisis , Calidad de los Alimentos , Almacenamiento de Alimentos , Dureza , Microscopía Electrónica de Rastreo , Proteínas de Plantas/química , Agua/química
9.
Int J Nanomedicine ; 15: 10099-10112, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33363369

RESUMEN

Background: Gastric ulcer is a prevalent disease with various etiologies, including non-steroidal anti-inflammatory drugs and alcohol consumption. This study aimed to explore the dual gastric protection effect of tadalafil and limonene as a self-nanoemulsifying system (SNES)-based orodispersible tablets. Methods: Tadalafil-loaded limonene-based SNES was prepared, and the optimum formula was characterized in terms of particle size (PS), polydispersity index (PDI), and zeta potential (ZP) then loaded on various porous carriers to formulate lyophilized orodispersible tablets (ODTs). The ODTs were evaluated via determining hardness, friability, content uniformity, wetting, and disintegration time. The selected ODT was examined for its gastric ulcer protective effect against alcohol-induced ulcers in rat model. Ulcer score and ulcer index were computed for rats stomachs that were inspected macroscopically and histopathologically. Results: The prepared SNES had droplet size of 104 nm, polydispersity index of 0.2, and zeta potential of -15.4 mV. From the different ODTs formulated, the formula with superior wetting time: 23.67 s, outstanding disintegration time: 28 s, accepted hardness value: 3.11 kg/cm2 and friability: 0.6% was designated. A significant gastroprotective effect of the unloaded and tadalafil-loaded ODTs was recognized compared to the omeprazole pre-treated group. Moreover, the histopathological analysis displayed very mild inflammation in the limonene-based ODTs group and intact structure in the tadalafil-loaded pre-treated animals. Conclusion: Limonene gastroprotective effect functioned along with tadalafil in the form of SNES-incorporated ODTs could serve as a promising revenue for better efficacy in gastric ulcer prevention.


Asunto(s)
Composición de Medicamentos , Limoneno/química , Sustancias Protectoras/farmacología , Estómago/efectos de los fármacos , Tadalafilo/administración & dosificación , Tadalafilo/farmacología , Administración Oral , Animales , Sistemas de Liberación de Medicamentos , Emulsiones/química , Liofilización , Dureza , Masculino , Porosidad , Ratas Wistar , Solubilidad , Estómago/patología , Úlcera Gástrica/tratamiento farmacológico , Úlcera Gástrica/patología , Comprimidos , Tadalafilo/uso terapéutico , Termodinámica , Agua/química
10.
PLoS One ; 15(12): e0231606, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33382707

RESUMEN

Keratin intermediate filaments are the principal structural element of epithelial cells. Their importance in providing bulk cellular stiffness is well recognized, but their role in the mechanics of cell cortex is less understood. In this study, we therefore compared the cortical stiffness of three keratinocyte lines: primary wild type cells (NHEK2), immortalized wild type cells (NEB1) and immortalized mutant cells (KEB7). The cortical stiffness was measured by lateral indentation of cells with AOD-steered optical tweezers without employing any moving mechanical elements. The method was validated on fixed cells and Cytochalasin-D treated cells to ensure that the observed variations in stiffness within a single cell line were not a consequence of low measurement precision. The measurements of the cortical stiffness showed that primary wild type cells were significantly stiffer than immortalized wild type cells, which was also detected in previous studies of bulk elasticity. In addition, a small difference between the mutant and the wild type cells was detected, showing that mutation of keratin impacts also the cell cortex. Thus, our results indicate that the role of keratins in cortical stiffness is not negligible and call for further investigation of the mechanical interactions between keratins and elements of the cell cortex.


Asunto(s)
Citoesqueleto de Actina/metabolismo , Filamentos Intermedios/metabolismo , Queratinocitos/metabolismo , Queratinas/metabolismo , Microtúbulos/metabolismo , Citoesqueleto de Actina/ultraestructura , Línea Celular , Citocalasina D/farmacología , Elasticidad/efectos de los fármacos , Expresión Génica , Dureza/efectos de los fármacos , Humanos , Filamentos Intermedios/ultraestructura , Queratinocitos/efectos de los fármacos , Queratinocitos/ultraestructura , Queratinas/genética , Microtúbulos/ultraestructura , Pinzas Ópticas , Especificidad de Órganos
11.
Oper Dent ; 45(6): E280-E288, 2020 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-33215201

RESUMEN

CLINICAL RELEVANCE: Acid-functional monomers in self-adhesive resin cements may decrease their self-curing polymerization ability. Light irradiation optimizes polymerization performance. SUMMARY: Purpose: The aim of this study was to investigate Knoop microhardness of self-adhesive resin cements under dual- and self-curing modes in simulated canals for describing the polymerization behavior.Methods and Materials: Slots in lightproof silicone cylinders with one open end were filled with the following eight materials: a traditional resin cement (Duolink), a core build-up resin material (MultiCore Flow), and six self-adhesive resin cements (RelyX Unicem 2, G-Cem Automix, Maxcem, Biscem, Multilink Speed, and PermaCem 2.0). The resins were exposed to light through the open end and then stored in a lightproof box. The Knoop hardness gradient for each resin was measured after 1 hour and 120 hours. Surface readings were obtained at 1-mm intervals from 1 mm to 10 mm away from the open ends. The data were analyzed by two-way analysis of variance and the Student-Newman-Keuls test (α=0.05).Results: All the resin materials had stable Knoop hardness numbers (KHNs) at a certain depth; their KHNs in the self-curing mode did not change (p>0.05). The region above this certain depth was regarded as having undergone the dual-curing mode, and the KHN decreased gradually with depth (p<0.05). Between 1 and 120 hours postexposure, the ratio of the KHN at a 5-mm depth (self-cured) to that at a 1-mm depth (dual-cured) increased in Duolink and MultiCore Flow. However, the ratios of the six adhesive resin cements varied.Conclusion: Without light, most self-adhesive resin cements differed from traditional dual-cured resin materials in terms of Knoop micro-hardness, and they had a lesser capacity for chemical-induced curing.


Asunto(s)
Cementos Dentales , Cementos de Resina , Dureza , Humanos , Curación por Luz de Adhesivos Dentales , Ensayo de Materiales , Polimerizacion , Auto-Curación de Resinas Dentales
12.
J Contemp Dent Pract ; 21(6): 673-677, 2020 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-33025937

RESUMEN

AIM: Simulated pulpal pressure (PP) has been shown to affect the bond strength and nanoleakage of different adhesives at dentin interfaces but the effect of simulated PP on polymerization of adhesives has not been studied yet. Furthermore, it has been proposed that strong and mild self-etch adhesives have different polymerization behaviors. This study aimed to evaluate the effect of simulated PP on polymerization of two self-etch adhesives, Adper Prompt L-Pop (APLP) and Adper Easy Bond (AEB), by means of the Knoop hardness test. MATERIALS AND METHODS: Sixty caries-free human molars were used to prepare deep dentin specimens with a mean remaining dentin thickness of 0.9 mm. The specimens were bonded in the absence or presence of PP. The specimens were assigned to four equal groups (n = 15) as follows: AEB/-PP, APLP/-PP, AEB/+PP, and APLP/+PP. Bonding procedures were completed; then the specimens' hardness was measured with the Knoop test. Data were analyzed with two-way ANOVA and the t test. RESULTS: In the absence of PP, the hardness of AEB was significantly higher than that of APLP (p < 0.001). In contrast, when PP was simulated, the hardness of APLP was higher than that of AEB (p = 0.002). The hardness of AEB was not influenced by the presence of PP (p = 0.153). Simulation of PP resulted in a significant improvement in the hardness of APLP (p < 0.001). CONCLUSION: The polymerization degree of strong self-etch adhesive was lower compared to mild self-etch adhesive. In the presence of hydrostatic PP, the polymerization degree of strong self-etch adhesive was higher than mild self-etch adhesive. CLINICAL SIGNIFICANCE: Dentin moisture caused by positive PP might improve polymerization of strong self-etch adhesives.


Asunto(s)
Cementos Dentales , Pulpa Dental , Dureza , Humanos , Diente Molar , Polimerizacion
13.
J Contemp Dent Pract ; 21(6): 678-682, 2020 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-33025938

RESUMEN

AIMS: The purpose of this study was to assess the influence of hot and dry weather on the hardness and surface roughness of four different maxillofacial silicone elastomeric materials (MFSEM) including two room-temperature vulcanized (RTV) and two high-temperature vulcanized (HTV) materials. MATERIALS AND METHODS: Eighty test specimens were fabricated according to the manufacturer's instructions into rectangular test specimens. The hardness and surface roughness were tested, after 6 months of exposure to natural hot and dry weather. The hardness was measured through the International Rubber Hardness Degree (IRHD) scale using an automated hardness tester. The surface roughness was measured using a novel 3D optical noncontact technique using a combination of a light sectioning microscope and a computer vision system. Statistical Package for Social Sciences software SPSS/version 24 was used for analysis and a comparison between two independent variables was done using an independent t test, while more than two variables were analyzed, F test (ANOVA) to be used followed by a post hoc test to determine the level of significance between every two groups. RESULTS: The hot and dry weather statistically influenced the hardness and surface roughness of MFSEM. Cosmesil M-511 showed the least hardness in test groups while A-2000 showed the hardest material (p < 0.05). A-2000 showed significant changes from rough in case of nonweathered to become smoother in weather followed by A-2186 (p < 0.05). Cosmesil M-511 showed the roughest material. CONCLUSION: Cosmesil M-511 showed the least hard MFSEM after outdoor weathering while A-2000, the highest and least material showed hardness and surface roughness, respectively. CLINICAL IMPLICATION: A-2000 had a high IRHD scale hardness. This makes this material more suitable for the replacement of ear and nose defects. Cosmesil M-511 is soft and easily adaptable material that makes the material more appropriate for the replacement of small facial defect with undercut area to be easily inserted and removed. Whilst A-2000 is smoother and finer in test specimens after weathering, Cosmesil M-511 became rougher after weathering.


Asunto(s)
Prótesis Maxilofacial , Dureza , Ensayo de Materiales , Propiedades de Superficie , Tiempo (Meteorología)
14.
Artículo en Inglés | MEDLINE | ID: mdl-32948068

RESUMEN

The age-adjusted death rates (AADRs) due to cancers were investigated in two historical regions of white wines (Tokaj and Balaton) and in Hódmezovásárhely (HMV) as a control territory in Hungary between 2000 and 2010 evaluating 111,910 persons. The results of AADRs due to the eight most frequent types/gastrointestinal cancers were as follows: Tokaj 2120/664, Balaton: 2417/824, HMV: 2770/821, nationwide: 2773/887. The values found in Tokaj and Balaton regions were significantly less than those of HMV and nationwide. However, the least values were found in Tokaj. This Tokaj-related strong difference was not found among the regions in the case of young populations with hematological diseases but only in the older people who have been consuming their wines for decades. Supposedly, this wine-specific anti-cancer phenomenon could be related to the chemical differences existing in the two types of white wines, namely, to the pro-oxidant molecules of Tokaj wines derived from Botrytis cinerea. The roles of red meat consumption, hardness of drinking water, mineral content of soil, and socioeconomic status were negligible. It should be stressed that these data are valid only for these populations, for this period. Noteworthily, the different types of wines may have different effects on mortality rates during long-lasting consumptions.


Asunto(s)
Agua Potable/química , Neoplasias/mortalidad , Vino , Anciano , Anciano de 80 o más Años , Dureza , Humanos , Hungría/epidemiología , Factores Socioeconómicos
15.
Proc Natl Acad Sci U S A ; 117(38): 23450-23459, 2020 09 22.
Artículo en Inglés | MEDLINE | ID: mdl-32913055

RESUMEN

Cuttlefish, a unique group of marine mollusks, produces an internal biomineralized shell, known as cuttlebone, which is an ultra-lightweight cellular structure (porosity, ∼93 vol%) used as the animal's hard buoyancy tank. Although cuttlebone is primarily composed of a brittle mineral, aragonite, the structure is highly damage tolerant and can withstand water pressure of about 20 atmospheres (atm) for the species Sepia officinalis Currently, our knowledge on the structural origins for cuttlebone's remarkable mechanical performance is limited. Combining quantitative three-dimensional (3D) structural characterization, four-dimensional (4D) mechanical analysis, digital image correlation, and parametric simulations, here we reveal that the characteristic chambered "wall-septa" microstructure of cuttlebone, drastically distinct from other natural or engineering cellular solids, allows for simultaneous high specific stiffness (8.4 MN⋅m/kg) and energy absorption (4.4 kJ/kg) upon loading. We demonstrate that the vertical walls in the chambered cuttlebone microstructure have evolved an optimal waviness gradient, which leads to compression-dominant deformation and asymmetric wall fracture, accomplishing both high stiffness and high energy absorption. Moreover, the distribution of walls is found to reduce stress concentrations within the horizontal septa, facilitating a larger chamber crushing stress and a more significant densification. The design strategies revealed here can provide important lessons for the development of low-density, stiff, and damage-tolerant cellular ceramics.


Asunto(s)
Materiales Biomiméticos/química , Huesos/química , Sepia/química , Animales , Fenómenos Biomecánicos , Cerámica/química , Diseño de Equipo , Dureza , Porosidad
16.
J Int Acad Periodontol ; 22(4): 231-235, 2020 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-32980835

RESUMEN

AIMS: This study evaluated the mechanical properties of mandibular bone tissue retrieved from postmenopausal women under alendronate treatment. METHODS: Twenty postmenopausal women were divided into two groups: healthy postmenopausal subjects (control group) and osteoporotic subjects treated with alendronate (alendronate group). Mandibular bone samples were retrieved with a trephine bur at the time of dental implant placement and fixed in 4% formalin. Samples were processed for hard tissue histology, and the bone surface was analyzed for nanohardness measurement. Nanohardness and elastic modulus were evaluated by using a Berkovich tip with elastic modulus of 1.016x106 MPa, Poisson coefficient of 0.3, and a load of 100 mN. Each cycle was configured with a load time of 18 seconds (speed of 1 mN/second), the discharge time of 18 seconds, and a rest time of 5 seconds during indentation at a depth of 10 µm. RESULTS: The control group presented the highest values for nanohardness and elastic modulus (p less than 0.05) in relation to the osteoporotic subjects. CONCLUSIONS: Within the limitations of the study, it can be concluded that treatment with alendronate negatively influenced the mechanical properties of mandibular bone in postmenopausal women by reducing bone nanohardness and elastic modulus.


Asunto(s)
Alendronato , Posmenopausia , Módulo de Elasticidad , Femenino , Dureza , Humanos , Mandíbula
17.
PLoS One ; 15(9): e0225293, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32991576

RESUMEN

Grain hardness is an important quality trait of cereal crops. In wheat, it is mainly determined by the Hardness locus that harbors genes encoding puroindoline A (PINA) and puroindoline B (PINB). Any deletion or mutation of these genes leading to the absence of PINA or to single amino acid changes in PINB leads to hard endosperms. Although it is generally acknowledged that hardness is controlled by adhesion strength between the protein matrix and starch granules, the physicochemical mechanisms connecting puroindolines and the starch-protein interactions are unknown as of this time. To explore these mechanisms, we focused on PINA. The overexpression in a hard wheat cultivar (cv. Courtot with the Pina-D1a and Pinb-D1d alleles) decreased grain hardness in a dose-related effect, suggesting an interactive process. When PINA was added to gliadins in solution, large aggregates of up to 13 µm in diameter were formed. Turbidimetry measurements showed that the PINA-gliadin interaction displayed a high cooperativity that increased with a decrease in pH from neutral to acid (pH 4) media, mimicking the pH change during endosperm development. No turbidity was observed in the presence of isolated α- and γ-gliadins, but non-cooperative interactions of PINA with these proteins could be confirmed by surface plasmon resonance. A significant higher interaction of PINA with γ-gliadins than with α-gliadins was observed. Similar binding behavior was observed with a recombinant repeated polypeptide that mimics the repeat domain of gliadins, i.e., (Pro-Gln-Gln-Pro-Tyr)8. Taken together, these results suggest that the interaction of PINA with a monomeric gliadin creates a nucleation point leading to the aggregation of other gliadins, a phenomenon that could prevent further interaction of the storage prolamins with starch granules. Consequently, the role of puroindoline-prolamin interactions on grain hardness should be addressed on the basis of previous observations that highlight the similar subcellular routing of storage prolamins and puroindolines.


Asunto(s)
Grano Comestible/metabolismo , Gliadina/metabolismo , Dureza/fisiología , Proteínas de Plantas/metabolismo , Triticum/metabolismo , Producción de Cultivos , Dispersión Dinámica de Luz , Grano Comestible/química , Gliadina/química , Concentración de Iones de Hidrógeno , Nefelometría y Turbidimetría , Tamaño de la Partícula , Proteínas de Plantas/química , Agregado de Proteínas/fisiología , Unión Proteica/fisiología , Dominios Proteicos/fisiología , Secuencias Repetitivas de Aminoácido/fisiología , Almidón/química , Almidón/metabolismo , Resonancia por Plasmón de Superficie , Triticum/química
18.
Braz Dent J ; 31(4): 431-439, 2020 Sep 04.
Artículo en Inglés | MEDLINE | ID: mdl-32901721

RESUMEN

The aim of this study was to evaluate the Streptococcus mutans biofilm influence on the roughness (Ra), gloss (GU), surface hardness (KHN) and flexural strength (FS) of high viscosity bulk fill composites. Filtek Bulk Fill (FBF), Tetric N Ceram Bulk Fill (TNC), X-tra fil Bulk Fill (XF) and Filtek Z350 (FZ) were used. Ten discs of each composite were prepared for Ra, KHN and GU and 20 bars for the FS. After 24 h, specimens were polished and initial analyzes performed. Samples were sterilized and subjected to biodegradation for 7 days and final analyzes performed. Representative samples of each group were evaluated in Scanning Electron Microscope. Data were submitted to ANOVA two factors and Tukey test. XF presented the highest values (p<0.05) of Ra before and after biodegradation (0.1251; 0.3100), and FZ (0.1443) the lowest after biodegradation (p<0.05). The highest GU values (p<0.05) were observed for FZ (71.7; 62) and FBF (69.0; 64.6), and the lowest (p<0.05) for TNC (61.4; 53.3) and XF (58.5; 53.5), both before and after biodegradation. For KHN the highest values were obtained by XF (151.7; 106), and the (p< 0.05) lowest values for TNC (62.2; 51.8), both before and after biodegradation. The highest values (p<0.05) of FS were observed for FZ (127.6) and the lowest (p<0.05) for TNC (86.9); after biodegradation, XF (117.7) presented the highest (p<0.05) values compared to TNC and FZ." In conclusion, biodegradation increased Ra and decreased GU and KHN for all. Concerning FS, degradation provided a significant decreased value only for FZ.


Asunto(s)
Resistencia Flexional , Streptococcus mutans , Dureza , Ensayo de Materiales , Propiedades de Superficie
19.
Braz Oral Res ; 34: e086, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32785480

RESUMEN

This study evaluates how atenolol affects dental mineralization in offspring of female spontaneously hypertensive rats (fSHR) and normotensive Wistar rats (fW). fSHR and fW were treated with atenolol (100 mg/Kg/day, orally) during pregnancy and lactation. Non-treated fSHR and fW were the control groups. Enamel and dentin hardness were analyzed (Knoop, 15 g load, 10s) in mandibular incisor teeth (IT) and molar teeth (MT) obtained from the male offspring of atenolol-treated and non-treated fWistar and fSHR. Data were analyzed by ANOVA, followed by Tukey post hoc test (p < 0.05). Atenolol reduced the arterial blood pressure (SBP) in fSHR, but it did not change the SBP in fW. The offspring of non-treated fSHR had lower enamel (IT and MT) and dentin (IT) hardness than the offspring of non-treated fW (p < 0.05). Atenolol increased enamel and dentin hardness in the IT obtained from the offspring of fSHR and fW (p<0.05), but the offspring of fSHR presented higher values (p < 0.05). Atenolol did not alter enamel width in the IT obtained from any of the groups, but it increased enamel and dentin hardness in the IT obtained from the offspring of fSHR and fW. Atenolol affected the IT obtained from the offspring of fSHR. Atenolol increased only enamel hardness in the MT obtained from the offspring of fW. In conclusion, maternal hypertension reduces tooth hard tissues, and treatment with atenolol increases tooth hardness in male offspring of hypertensive and normotensive female rats.


Asunto(s)
Hipertensión , Animales , Atenolol , Esmalte Dental , Dentina , Femenino , Dureza , Masculino , Embarazo , Ratas , Ratas Wistar
20.
AAPS PharmSciTech ; 21(6): 232, 2020 Aug 13.
Artículo en Inglés | MEDLINE | ID: mdl-32794080

RESUMEN

The aims of the current study were to develop and evaluate clindamycin palmitate hydrochloride (CPH) 3D-printed tablets (printlets) manufactured by selective laser sintering (SLS). Optimization of the formulation was performed by studying the effect of formulation and process factors on critical quality attributes of the printlets. The independent factors studied were laser scanning speed, microcrystalline cellulose (MCC), and lactose monohydrate (LMH) concentration. The responses measured were printlets weight, hardness, disintegration time (DT), and dissolution in 30 min. The printlets were characterized for content uniformity, chemical interactions, crystallinity, drug distribution, morphology, and porosity. The laser scanning speed showed statistically significant effects on all the studied dependent responses (p < 0.05). MCC showed statistically significant effects on hardness, DT, and dissolution (p < 0.05), while LMH showed statistically significant effect on hardness and dissolution (p < 0.05). The model was validated by an independent formulation, and empirical values were in close agreement with model-predicted values. X-ray powder diffraction and differential scanning calorimetry data suggested a decrease in crystallinity of the LMH in the printlets. X-ray micro-CT scanning showed porous microstructure of the printlets with a porosity 24.4% and 31.1% for the printlets printed at 200 and 300 mm/s laser speed, respectively. In summary, the SLS method provides an opportunity to fabricate customized dosage forms as per patients' need.


Asunto(s)
Clindamicina/análogos & derivados , Rayos Láser , Impresión Tridimensional , Antibacterianos/análisis , Antibacterianos/síntesis química , Rastreo Diferencial de Calorimetría/métodos , Clindamicina/análisis , Clindamicina/síntesis química , Dureza , Humanos , Porosidad , Propiedades de Superficie , Comprimidos/química , Difracción de Rayos X/métodos
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