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1.
J Sci Food Agric ; 2024 Jun 28.
Artículo en Inglés | MEDLINE | ID: mdl-38940514

RESUMEN

BACKGROUND: Glasswort represents a novel alternative to KCl for replacing sodium in meat products. To evaluate the effects of Na reduction on the quality changes of a traditional dry cured belly due to storage, fresh bellies were dry-salted with 2% NaCl (BCON), with 2% of a mixture containing 50% NaCl and 50% KCl (BKCl) or with 1% of a mixture of 90% NaCl and 10% powdered glasswort (BGW), dry-cured, sliced, vacuum packaged and stored under refrigeration for 60 days. RESULTS: The BKCl and BGW bellies were lower in sodium by one-third to one-half compared to BCON (with 1.6 g Na/100 g). Neither BKCl, nor BGW significantly differed from BCON in free fatty acids (FFA) before and after storage, whereas BGW showed almost twice as much 2-methylbutanal content as BCON. All bellies showed microbiological stability during storage. Micrococcaceae was the most abundant microbial group with values of 105 to 106 colony-forming units g-1. The BGW presented higher Micrococcaceae counts (approximately one log unit) but lower microbial biodiversity than BCON. CONCLUSION: The two alternative dry salting methods reduced the sodium content in bellies, at the same time as ensuring chemical and microbiological stability during refrigerated vacuum storage. © 2024 The Author(s). Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

2.
Graefes Arch Clin Exp Ophthalmol ; 260(10): 3173-3183, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-35467125

RESUMEN

PURPOSE: To analyze the recovery course of foveal microstructures in eyes with nonsurgical healing of full-thickness macular hole (FTMH). METHODS: By serial OCT scans, the temporal healing sequences were analyzed in ocular trauma, vitreomacular traction (VMT), cystoid macular edema (CME), and the remaining group. We evaluated correlations between the final best-corrected spectacle visual acuity and reconstruction time of external limiting membrane (ELM), and inner segment/outer segment (IS/OS). RESULTS: The healing (mean±standard deviation in months) most involved fusion at the level of the outer nuclear layer (ONL) (6.3±10.5) followed by restoration of ELM (9.1±13.8), and lastly, by IS/OS regeneration (13.1±19.5). In severe blunt ocular trauma, healing was fast and involved subretinal zipper glue-like reapposition with resulting outer retinal atrophy. Best spectacle-corrected visual acuity correlated with normalization of the clivus (p=0.012), faster ELM (p=0.006), and IS/OS reconstitution (p=0.024). Recurrence of FTMH occurred when the healing was halted (3 eyes) or was aberrant by lamellar hole epiretinal proliferation (LHEP) (3 eyes) or by the persistence of VMT (1 eye). CONCLUSION: Recovery sequences proceeded from the ONL to the deeper layers with BCVA correlating absolutely and temporally with the restoration of outer retinal layer integrity.


Asunto(s)
Perforaciones de la Retina , Fóvea Central , Humanos , Perforaciones de la Retina/diagnóstico , Perforaciones de la Retina/cirugía , Estudios Retrospectivos , Tomografía de Coherencia Óptica , Trastornos de la Visión , Agudeza Visual , Vitrectomía
3.
Sensors (Basel) ; 21(11)2021 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-34064285

RESUMEN

We report on recent advances in the use of inexpensive polymer optical fibres (POFs) for sensing applications in avionics. The sensors analysed in this manuscript take advantage of the unique properties of polymers, such as high flexibility, elasticity, and sensitivity, and they range from strain, elongation, and vibration interrogators to level and temperature meters, leading to cost-effective techniques for structural health monitoring in aircraft structures. We also highlight recent power-supply methods using Power-over-POF in order to feed sensors remotely, and we discuss the constraints imposed by connectors on the performance of POF networks in aircrafts.

5.
J Dairy Sci ; 98(5): 2833-42, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-25726117

RESUMEN

Six batches of Oaxaca cheese (a Mexican pasta filata cheese) from 3 dairy plants were sampled and vacuum-packaged at 8°C up to 24d. Counts of principal microbial groups, pH, levels of sugars, organic acids, lipolytic and proteolytic indices, and texture, color, and meltability values of cheeses were studied at d 1, 8, 16 and 24 of storage. A descriptive sensory analysis of selected taste, odor, and texture characteristics was also carried out. The main changes in the cheeses during the storage were decreases in pH, hardness, elasticity, and whiteness, and an increase in meltability. Neither lipolytic nor proteolytic activities were evident during the storage of cheeses. Storage time resulted in a gradual quality loss of unmelted cheeses. This loss of quality might be related to the decrease of hardness and the appearance off-flavors.


Asunto(s)
Queso/análisis , Queso/microbiología , Microbiología de Alimentos , Refrigeración , Almacenamiento de Alimentos , México , Vacio
6.
Foods ; 13(6)2024 Mar 21.
Artículo en Inglés | MEDLINE | ID: mdl-38540941

RESUMEN

The aim of this study was to develop a plant-based fermented beverage from discarded bread flour and to analyze its characteristics as a novel functional product. Eight cereal-based probiotic beverages were produced by inoculating discarded bread flour with a monoculture of Lactobacillus rhamnosus or a co-culture consisting of lactic acid bacteria and Bifidobacterium. Two additional factors, namely, the addition of amylolytic enzymes and matrix desalting, were studied alongside the type of culture. The organic acid content and microbial growth were monitored during fermentation and storage (15 and 21 days). Proximal composition, gamma-aminobutyric acid, and volatile compounds were measured in the final product. Sensory analysis was only conducted on the enzymatically treated samples. The estimated shelf life of the bread beverage was 15 days. The variables studied significantly influenced the amountof organic acids and specific volatile compounds responsible for the aroma of fermented beverages. The beverage produced via co-culturing was preferred by consumers in the sensory test.

7.
Foods ; 13(10)2024 May 19.
Artículo en Inglés | MEDLINE | ID: mdl-38790881

RESUMEN

The aims of this study were to describe and compare the meat quality characteristics of male and female kids from the "Serrana" and "Preta de Montesinho" breeds certified as "Cabrito Transmontano" and reinforce the performance of near-infrared reflectance (NIR) spectra in predicting these quality characteristics and discriminating among breeds. Samples of Longissimus thoracis (n = 32; sixteen per breed; eight males and eight females) were used. Breed significantly affected meat quality characteristics, with only color and fatty acid (FA) (C12:0) being influenced by sex. The meat of the "Serrana" breed proved to be more tender than that of the "Preta de Montesinho". However, the meat from the "Preta de Montesinho" breed showed higher intramuscular fat content and was lighter than that from the "Serrana" breed, which favors its quality of color and juiciness. The use of NIR with the linear support vector machine regression (SVMR) classification model demonstrated its capability to quantify meat quality characteristics such as pH, CIELab color, protein, moisture, ash, fat, texture, water-holding capacity, and lipid profile. Discriminant analysis was performed by dividing the sample spectra into calibration sets (75 percent) and prediction sets (25 percent) and applying the Kennard-Stone algorithm to the spectra. This resulted in 100% correct classifications with the training data and 96.7% accuracy with the test data. The test data showed acceptable estimation models with R2 > 0.99.

8.
Orphanet J Rare Dis ; 19(1): 148, 2024 Apr 06.
Artículo en Inglés | MEDLINE | ID: mdl-38582886

RESUMEN

BACKGROUND: Most patients suffering from Leber hereditary optic neuropathy carry one of the three classic pathologic mutations, but not all individuals with these genetic alterations develop the disease. There are different risk factors that modify the penetrance of these mutations. The remaining patients carry one of a set of very rare genetic variants and, it appears that, some of the risk factors that modify the penetrance of the classical pathologic mutations may also affect the phenotype of these other rare mutations. RESULTS: We describe a large family including 95 maternally related individuals, showing 30 patients with Leber hereditary optic neuropathy. The mutation responsible for the phenotype is a novel transition, m.3734A > G, in the mitochondrial gene encoding the ND1 subunit of respiratory complex I. Molecular-genetic, biochemical and cellular studies corroborate the pathogenicity of this genetic change. CONCLUSIONS: With the study of this family, we confirm that, also for this very rare mutation, sex and age are important factors modifying penetrance. Moreover, this pedigree offers an excellent opportunity to search for other genetic or environmental factors that additionally contribute to modify penetrance.


Asunto(s)
ADN Mitocondrial , Atrofia Óptica Hereditaria de Leber , Humanos , ADN Mitocondrial/genética , Atrofia Óptica Hereditaria de Leber/genética , Linaje , Mutación/genética , Fenotipo
9.
J Dairy Sci ; 96(6): 3461-70, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23548294

RESUMEN

The aim of this work was to identify and characterize lactobacilli strains from Mexican Oaxaca cheese. Twenty-seven lactobacilli isolated from Oaxaca cheese were identified at species level by 16S rRNA sequencing. Selected isolates were further characterized by ribotyping. Isolates were screened, among others, by acidifying capacity, antibiotic resistance, and activity against pathogens. Lactobacillus plantarum was predominant in Oaxaca cheese. The intraspecies variability of Lb. plantarum isolates was great. Multiple antibiotic resistances were observed. Eight isolates showed antimicrobial activity against the pathogenic species tested. Four Lb. plantarum strains showing low antibiotic resistance index, antimicrobial activity against enterotoxigenic Staphylococcus aureus and Listeria innocua stains, amine-negative decarboxylase activity, and resistance to NaCl and bile salt solutions, could be preselected to complete studies focused on designing a culture for use in pasteurized-milk Oaxaca cheese manufacturing.


Asunto(s)
Queso/microbiología , Manipulación de Alimentos/métodos , Lactobacillus/clasificación , Leche/microbiología , Animales , Carga Bacteriana , Genotipo , Lactobacillus/genética , Lactobacillus/aislamiento & purificación , Lactobacillus plantarum/genética , Lactobacillus plantarum/aislamiento & purificación , Fenotipo , ARN Bacteriano/química , ARN Ribosómico 16S/química
10.
Animals (Basel) ; 13(2)2023 Jan 12.
Artículo en Inglés | MEDLINE | ID: mdl-36670801

RESUMEN

Beef derived from grass-fed cattle is a specific quality criterion. The effect of grass silage intake on quality characteristics, i.e., fatty acids, fat-soluble vitamins, and lipid-derived volatile composition of intramuscular and perirenal fat from fattening bull weaners were studied. Visible (VIS) and near-infrared (NIR) spectra were also obtained from perirenal fat. Perirenal fat analysis was performed for feeding differentiation purposes. A total of 22 Tudanca breed 11-month-aged bulls were finished on three different diets: grass silage and a commercial concentrate ad libitum (GS-AC), grass silage ad libitum and the commercial concentrate restricted to half of the intake of the GS-AC group (GS-LC), and barley straw and concentrate ad libitum (Str-AC). Feeding had a significant effect (p < 0.05) on γ-linolenic acid and the ratio n-6/n-3 fatty acids. Furthermore, ß-carotene content was greater in beef from silage groups than in the Str-AC group. Feeding also affected the perirenal fat composition. Beef from silage-fed bulls and straw-fed bulls could be differentiated by fatty acid percentages, especially 18:0, t-18:1, and c9-18:1, ß-carotene content, b* colour value, and carotenoid colour index. However, the VIS or NIR spectra data showed poor differentiating performance, and the volatile composition did not have appreciable differentiation power.

11.
Front Vet Sci ; 10: 1150996, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37255997

RESUMEN

Introduction: Suckling lamb meat is highly appreciated in European Mediterranean countries because of its mild flavor and soft texture. In suckling lamb carcasses, perirenal and pelvic fat depots account for a large fraction of carcass fat accumulation, and their proportions are used as an indicator of carcass quality. Material and Methods: This study aimed to characterize the genetic mechanisms that regulate fat deposition in suckling lambs by evaluating the transcriptomic differences between Spanish Assaf lambs with significantly different proportions of kidney knob and channel fat (KKCF) depots in their carcasses (4 High-KKCF lambs vs. 4 Low-KKCF lambs). Results: The analyzed fat tissue showed overall dominant expression of white adipose tissue gene markers, although due to the young age of the animals (17-36 days), the expression of some brown adipose tissue gene markers (e.g., UCP1, CIDEA) was still identified. The transcriptomic comparison between the High-KKCF and Low-KKCF groups revealed a total of 80 differentially expressed genes (DEGs). The enrichment analysis of the 49 DEGs with increased expression levels in the Low-KKCF lambs identified significant terms linked to the biosynthesis of lipids and thermogenesis, which may be related to the higher expression of the UCP1 gene in this group. In contrast, the enrichment analysis of the 31 DEGs with increased expression in the High-KKCF lambs highlighted angiogenesis as a key biological process supported by the higher expression of some genes, such as VEGF-A and THBS1, which encode a major angiogenic factor and a large adhesive extracellular matrix glycoprotein, respectively. Discussion: The increased expression of sestrins, which are negative regulators of the mTOR complex, suggests that the preadipocyte differentiation stage is being inhibited in the High-KKCF group in favor of adipose tissue expansion, in which vasculogenesis is an essential process. All of these results suggest that the fat depots of the High-KKCF animals are in a later stage of development than those of the Low-KKCF lambs. Further genomic studies based on larger sample sizes and complementary analyses, such as the identification of polymorphisms in the DEGs, should be designed to confirm these results and achieve a deeper understanding of the genetic mechanisms underlying fat deposition in suckling lambs.

12.
Animals (Basel) ; 13(22)2023 Nov 09.
Artículo en Inglés | MEDLINE | ID: mdl-38003083

RESUMEN

Twenty-two Assaf male lambs (29.2 ± 0.9 kg live weight and 89 ± 0.2 days of age), distributed in two experimental groups, were used to evaluate the use of either feed-grade conventional urea (Control diet; n = 11) or slow-release urea (SRU diet; n = 11) as sources of dietary nitrogen on animal performance, ruminal fermentation, blood acid-base status, plasmatic metabolic profile, and carcass and meat quality. Animals were housed individually and fed ad libitum. At the end of the fattening period (day 70), the animals were slaughtered to compare the fermentation patterns in ruminal digesta and to evaluate the carcass and meat characteristics. No statistically significant differences (p > 0.05) were observed between treatments in the dry matter intake, final live weight, average daily gain, and feed conversion rate. Regarding the ruminal fermentation parameters, the molar proportion of propionic acid was higher (p < 0.05) and that of butyric acid was lower (p < 0.05) with the SRU than with the Control diet. There were no significant differences (p > 0.05) between experimental treatments in the blood acid-base status and biochemical profile, except for the concentration of urea in plasma, which was significantly (p < 0. 05) greater in SRU than in Control lambs. No statistically significant differences were observed between treatments (p > 0.05) in the carcass and meat characteristics. In conclusion, the use of slow-release urea as a replacement for feed-grade conventional urea in the diet of Assaf fattening lambs, under the experimental conditions of this study, did not improve animal performance and increased the feeding costs.

13.
Foods ; 12(23)2023 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-38231830

RESUMEN

This study involved a comprehensive examination of sensory attributes in dry-cured Bísaro loins, including odor, androsterone, scatol, lean color, fat color, hardness, juiciness, chewiness, flavor intensity and flavor persistence. An analysis of 40 samples revealed a wide variation in these attributes, ensuring a robust margin for multivariate calibration purposes. The respective near-infrared (NIR) spectra unveiled distinct peaks associated with significant components, such as proteins, lipids and water. Support vector regression (SVR) models were methodically calibrated for all sensory attributes, with optimal results using multiplicative scattering correction pre-treatment, MinMax normalization and the radial base kernel (non-linear SVR model). This process involved partitioning the data into calibration (67%) and prediction (33%) subsets using the SPXY algorithm. The model parameters were optimized via a hybrid algorithm based on particle swarm optimization (PSO) to effectively minimize the root-mean-square error (RMSECV) derived from five-fold cross-validation and ensure the attainment of optimal model performance and predictive accuracy. The predictive models exhibited acceptable results, characterized by R-squared values close to 1 (0.9616-0.9955) and low RMSE values (0.0400-0.1031). The prediction set's relative standard deviation (RSD) remained under 5%. Comparisons with prior research revealed significant improvements in prediction accuracy, particularly when considering attributes like pig meat aroma, hardness, fat color and flavor intensity. This research underscores the potential of advanced analytical techniques to improve the precision of sensory evaluations in food quality assessment. Such advancements have the potential to benefit both the research community and the meat industry by closely aligning their practices with consumer preferences and expectations.

14.
Cutan Ocul Toxicol ; 31(2): 167-70, 2012 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22035458

RESUMEN

BACKGROUND: Tacrolimus has been associated with several ocular adverse effects, such as optic neuropathy. METHODOLOGY/PRINCIPAL FINDINGS: A 56-year-old woman noted sudden, severe, painless visual loss in her left eye. She had undergone liver transplantation for alcoholic related cirrhosis 6 months before. Her chronic immunosuppressive regimen consisted of prednisone and tacrolimus at dosage of 1.5 mg orally once daily. Consequently, the patient developed a left optic neuropathy. CONCLUSION/SIGNIFICANCE: We report the first case of unilateral optic neuropathy associated with oral tacrolimus medication. Surgeons and ophthalmologists must evaluate ocular symptoms in the post-transplantation period, and suspicion should be maintained even if unilaterality or asymmetry of symptoms against a toxic etiology.


Asunto(s)
Inmunosupresores/efectos adversos , Enfermedades del Nervio Óptico/inducido químicamente , Tacrolimus/efectos adversos , Ceguera/inducido químicamente , Ceguera/diagnóstico , Femenino , Humanos , Trasplante de Hígado , Persona de Mediana Edad , Enfermedades del Nervio Óptico/diagnóstico , Tomografía de Coherencia Óptica
15.
Foods ; 11(23)2022 Nov 26.
Artículo en Inglés | MEDLINE | ID: mdl-36496624

RESUMEN

Sodium chloride (NaCl) is a key ingredient in the processing of traditional dry-cured meat products by improving microbial safety, sensory attributes and technological properties. However, increasing concern about the consumption of sodium and health has been supporting the development of low-sodium meat products. Several strategies to reduce sodium in dry-cured meat product have been tested, although the followed approaches sometimes result in undesirable characteristics concerning flavor, texture and mouthfeel. The use of halophytic plants such as glasswort (Salicornia herbacea) in food matrices has been suggested as a novel strategy to reduce sodium content, due its salty flavor. The main aim of the present study is to produce traditional dry-cured pork bellies from the Bísaro breed using glasswort as a NaCl partial replacer, and compare it with dry-cured bellies salted either with NaCl or a mix of NaCl + KCl. Control bellies (BC) were salted with 100% of NaCl, the second formulation (BK) had 50% of NaCl and 50% of KCl, and the third formulation (BG) had 90% of NaCl and 10% of glasswort powder (GP). After production, the bellies were evaluated for aw, pH, CIELab coordinates, weight loss, proximal composition, TBARS, collagen and chloride contents, fatty acid profile and sensory attributes. The use of BG in dry-cured pork bellies did not affect processing indicators such as weight loss, aw and pH. Concerning CIELab, only the coordinates L* and hue angle from the external surface color of BG were statistically different from BC and BK. As expected, ash and NaCl contents differed from BG to the other two formulations. SFA and indexes AI and TI were lower, whereas the MUFA and h/H ratio were higher in BG than other treatments, leading to a product with a healthier lipid profile. The sensory evaluation revealed differences in appearance, taste and flavor among treatments, but did not indicate any negative effects of BG in the product attributes. This study reinforces the potential of BG as a natural sodium reducer for the production of traditional dry-cured pork bellies.

16.
Biomolecules ; 12(10)2022 10 03.
Artículo en Inglés | MEDLINE | ID: mdl-36291625

RESUMEN

Diversified strategies to incorporate healthier lipids in processed meat products are being developed. Alternative fat sources to replace animal fat associated with the reduction of fat content are some of the methods used to obtain healthier meat products well recognized by consumers. In order to create a healthier product that can also be consumed in the Halal and Kosher consumer markets, an experimental study was developed to assess the effects of replacing the pork fat (4%) with the same amount of hydrogel emulsion incorporating olive oil or sunflower oil. Three burgers were randomly selected from each lot manufactured and analyzed in triplicate. Burgers were physicochemical analyzed for pH, water activity, composition, fatty acid profile, color, yield, texture, oxidative stability, and volatile compounds and compared according to the fat source. Burgers with hydrogel emulsions can be considered reduced-fat meat products with a healthier fatty acid profile than pork fat burgers. The use of hydrogel emulsions did not negatively affect the quality characteristics assessed in the product and improved the oxidative stability during the storage of cooked burgers. By the characteristics and formulations evaluated, the replacement of pork fat with olive oil hydrogel emulsion proved to be the most effective strategy for obtaining a healthier goat meat product.


Asunto(s)
Productos de la Carne , Olea , Carne de Cerdo , Carne Roja , Animales , Porcinos , Productos de la Carne/análisis , Aceite de Girasol , Emulsiones/química , Aceite de Oliva , Hidrogeles , Cabras , Aceites de Plantas/química , Ácidos Grasos , Agua/química
17.
Front Genet ; 13: 1035063, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36386829

RESUMEN

In sheep, differences were observed regarding fat accumulation and fatty acid (FA) composition between males and females, which may impact the quality and organoleptic characteristics of the meat. The integration of different omics technologies is a relevant approach for investigating biological and genetic mechanisms associated with complex traits. Here, the perirenal tissue of six male and six female Assaf suckling lambs was evaluated using RNA sequencing and whole-genome bisulfite sequencing (WGBS). A multiomic discriminant analysis using multiblock (s)PLS-DA allowed the identification of 314 genes and 627 differentially methylated regions (within these genes), which perfectly discriminate between males and females. These candidate genes overlapped with previously reported QTLs for carcass fat volume and percentage of different FAs in milk and meat from sheep. Additionally, differentially coexpressed (DcoExp) modules of genes between males (nine) and females (three) were identified that harbour 22 of these selected genes. Interestingly, these DcoExp were significantly correlated with fat percentage in different deposits (renal, pelvic, subcutaneous and intramuscular) and were associated with relevant biological processes for adipogenesis, adipocyte differentiation, fat volume and FA composition. Consequently, these genes may potentially impact adiposity and meat quality traits in a sex-specific manner, such as juiciness, tenderness and flavour.

18.
Br J Ophthalmol ; 106(10): 1463-1468, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-33926863

RESUMEN

PURPOSE: To ascertain the anatomic factors that help achieve non-surgical sealing in full thickness macular hole (FTMH). METHODS: Retrospective collaborative study of FTMH that closed without surgical intervention. RESULTS: A total of 78 patients (mean age 57.9 years) included 18 patients with blunt ocular trauma, 18 patients that received topical or intravitreal therapies and 42 patients with idiopathic FTMH. Mean±SD of the initial corrected visual acuity (VA) in logMAR improved from 0.65±0.54 to 0.34±0.45 (p<0.001) at a mean follow-up of 33.8±37.1 months. FTMH reopened in seven eyes (9.0%) after a mean of 8.6 months. Vitreomacular traction was noted in 12 eyes (15.8%), perifoveal posterior vitreous detachment in 42 (53.8%), foveal epiretinal membrane in 10 (12.8%), cystoid macular oedema (CME) in 49 (62.8%) and subretinal fluid (SRF) in 20 (25.6%). By multivariate analysis, initial VA correlated to the height (p<0.001) and narrowest diameter of the hole (p<0.001) while final VA correlated to the basal diameter (p<0.001). Time for closure of FTMH (median 2.8 months) correlated to the narrowest diameter (p<0.001) and the presence of SRF (p=0.001). Mean time for closure (in months) was 1.6 for eyes with trauma, 4.3 for eyes without trauma but with therapy for CME, 4.4 for eyes without trauma and without therapy in less than 200 µm in size and 24.7 for more than 200 µm. CONCLUSION: Our data suggest an observation period in new onset FTMH for non-surgical closure, in the setting of trauma, treatment of CME and size <200 µm.


Asunto(s)
Perforaciones de la Retina , Heridas no Penetrantes , Fóvea Central , Humanos , Persona de Mediana Edad , Perforaciones de la Retina/diagnóstico , Perforaciones de la Retina/cirugía , Estudios Retrospectivos , Tomografía de Coherencia Óptica , Agudeza Visual , Vitrectomía , Heridas no Penetrantes/diagnóstico , Heridas no Penetrantes/cirugía
19.
Polymers (Basel) ; 13(19)2021 Oct 02.
Artículo en Inglés | MEDLINE | ID: mdl-34641212

RESUMEN

Large-core polymer optical fiber (POF) links have limitations in capacity and reach due to the fibers' high modal dispersion and attenuation. Most of these links use red laser diodes, even though the attenuation spectrum of poly(methyl methacrylate) (PMMA), the basic polymer used to manufacture these fibers, has a lower minimum in the green region. Therefore, we set out to explore the potential use of green light in transmission systems, comparing the performances of three step-index polymer optical fibers (SI-POFs) with different numerical apertures. We obtained measurements of intensity distribution, frequency response and bit error rate (BER), as functions of fiber length. We have also compared the fibers' frequency responses with red and green light for a few selected lengths. Our results confirm that SI-POFs attenuate less in response to green light, which can increase their length. This advantage is partially counterbalanced by a slightly higher dispersion that limits the capacity of the high-aperture fibers, particularly at relatively short lengths. Our conclusions are critical to understanding SI-POF behavior and to designing thorough SI-POF models that can aid the design of POF-based links for different scenarios.

20.
Foods ; 10(9)2021 Sep 13.
Artículo en Inglés | MEDLINE | ID: mdl-34574283

RESUMEN

Banana pseudo-stem (BPS), which is rich in fibre and polyphenols, is a potential functional ingredient for the food industry. In this study, BPS was added at concentrations of 1.5, 3.0, and 4.5 g/kg to a minced pork batter to evaluate its performance as a filler and to pork burger patties to evaluate its performance as a natural antioxidant. The effects of BPS were compared with those of carrageenan and ascorbate, which are a conventional binder and antioxidant, respectively. The performance of BPS was similar to that of carrageenan in terms of the cooking yield and texture of the cooked batter. BPS reduced the brightness of fresh patties and appeared to reduce oxidative discolouration during the frozen storage of raw patties. Moreover, BPS reduced the levels of thiobarbituric acid reactive substances (TBARS) during the refrigerated and frozen storage of cooked patties. A greater decrease in TBARS formation was observed with 4.5 g BPS/kg compared with 0.5 g sodium ascorbate/kg during refrigerated storage. In contrast to ascorbate, BPS promoted the presence of lipid-derived volatile compounds induced by thermal breakdown in the headspace of cooked patties. Nonetheless, this effect was reduced as the amount of BPS in the patties increased. In cooked minced meat products, BPS could increase cooking yields and lipid oxidative stability during storage and might result in a more intense flavour.

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