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We report the combined antibacterial/tissue regeneration responses to thermal burns promoted by functional chitosan/silver nanocomposites (CS/nAg) with ultralow silver content ...(0.018wt.%, 7–30nm). Our approach allows one to produce CS/nAg nanocomposites without silver nanoparticles (nAg) agglomeration, with bactericide potency higher than 1wt.% of nAg (ca. 10nm) content and, promoting the healing process in controlled thermal burns. CS/nAg films exhibit high antibacterial activity against S. aureus and P. aeruginosa after 1.5h of incubation, demonstrating the bacterial penetration into hydrated films and their interaction with nAg. Additionally, exceptional healing of induced thermal burns was obtained by increasing myofibroblasts, collagen remodeling, and blood vessel neoformation. These factors are associated with epiderma regeneration after 7days of treatment with no nAg release. Our results corroborate the controlled synthesis of nAg embedded in CS matrix with combined antibacterial/biocompatibility properties aiming to produce functional nanocomposites with potential use in wound dressing and health care applications.
Fungus-growing ants have been found recently to be symbiotic with actinomycetes living on the ant’s cuticle; these bacteria are inhibitory to soil fungi that are detrimental to the ants’ fungus ...gardens. In order to investigate whether actinomycetes found on the cuticle of attine ants also had inhibitory properties against plant pathogenic fungi, we isolated 32 strains of actinomycetes from fungus-growing ants (
Atta, Trachymyrmex
, and
Cyphomyrmex
), from the Mexican states of Coahuila, Nuevo León and Tamaulipas. Of the actinomycetes tested against selected plant pathogenic fungi (
Alternaria solani, Aspergillus flavus, Colletotrichum lindemuthianum, Rhizoctonia solani, Sclerotium
sp.) on Czapek-Dox agar medium, 13 isolates inhibited at least one of the fungi.
C. lindemuthianum
was inhibited by 11 actinomycetes, and
Rhizoctonia
by three. An actinomycete strain isolated from
Cyphomyrmex rimosus
inhibited all five fungi tested.
Fungus-growing ants have been found recently to be symbiotic with actinomycetes living on the ant's cuticle; these bacteria are inhibitory to soil fungi that are detrimental to the ants' fungus ...gardens. In order to investigate whether actinomycetes found on the cuticle of attine ants also had inhibitory properties against plant pathogenic fungi, we isolated 32 strains of actinomycetes from fungus-growing ants (Atta, Trachymyrmex, and Cyphomyrmex), from the Mexican states of Coahuila, Nuevo Leon and Tamaulipas. Of the actinomycetes tested against selected plant pathogenic fungi (Alternaria solani, Aspergillus flaws, Colletotrichum lindemuthianum, Rhizoctonia solani, Sclerotium sp.) on Czapek-Dox agar medium, 13 isolates inhibited at least one of the fungi. C. lindemuthianum was inhibited by 11 actinomycetes, and Rhizoctonia by three. An actinomycete strain isolated from Cyphomyrmex rimosus inhibited all five fungi tested.
The adsorption isotherms of fluoride from an aqueous solution on plain and aluminum-impregnated activated carbons were measured in this study. The impregnated carbon was prepared by impregnation with ...an aluminum nitrate solution at a fixed pH, followed by calcination under nitrogen at temperatures above 300°C. The adsorption of fluoride on impregnated carbon was shown to be dependent upon both the pH of the impregnating solution and the temperature of calcination. Impregnated carbon was shown to have a fluoride adsorption capacity of 3 to 5 times that of plain activated carbon.
Pinus patula
is a species commonly used for reforestation in Mexico. However, efficient methods for the mass production seedlings are required. Micropropagation particularly by somatic embryogenesis ...provides an option for the rapid multiplication of high-quality, genetically improved material. This study induces somatic embryogenesis in this species using the thin cell layer (TCL) technique. Two sources of explants (complete immature embryos; lTCL segments from immature embryos) were evaluated. The efficiency of TCL from longitudinal sections lTCL and transverse tTCL was evaluated. The results show using thin cell layers from immature embryos cultivated in 16 light/8 dark hours achieves induction of somatic embryos. A higher percentage of embryogenic callus was obtained when tTCL segments were used as an explant source. These results produced somatic embryos from tTCL segments of an immature embryo without germinating the seed, making the process more time efficient. In addition, this technique can be used to generate somatic embryogenesis in forest species that have low germination rates.
Background/Aims
: The effect of interferon on the reduction of liver fibrosis is controversial. We aimed to compare semiquantitative methods with a quantitative digital image analysis system to ...assess liver fibrosis in biopsies from patients with chronic hepatitis and different responses to interferon.
Methods
: We studied 98 liver biopsies with chronic hepatitis C before and after recombinant interferon alfa-2 treatment, using conventional histological assessment, grading of histological activity, scoring/staging of fibrosis (Knodell and Scheuer), and quantification of fibrosis with image analysis (FibroQuant).
Results
: Sustained-responders to interferon showed a significant reduction in histological lesions and in their Knodell and Scheuer activity indexes. The semiquantitative systems showed no reduction in fibrosis. The FibroQuant application showed a significant reduction in porto-periportal and septal areas among sustained-responders (
P
<0.001) and non-responders (
P
<0.05), and in porto-periportal and septal fibrosis areas only in sustained-responders (
P
<0.001), whereas the percentage of fibrosis increased in non-responders (
P
<0.001).
Conclusions
: The Scheuer system is useful for the daily evaluation of fibrosis, but the FibroQuant application provides more objective data on the anti-fibrogenic effects of interferon, which include a reduction in the porto-periportal area in sustained-responders and non-responders, accompanied by a reduction in the area of fibrosis only when the viral replication has ceased.
Pandi's mushroom-tongue salamander (
) is one of the threatened amphibians in South America, as well as a flagship species for the Colombian conservation agenda. This species is endemic to the Andean ...cloud forests of the western slope of the Cordillera Oriental of Colombia, occurring only in the department of Cundinamarca within a narrow elevational range. At night,
can be seen perching on the upper side of leaves at heights ranging from ground level to 2.5 m. During the day, it can be found under leaf litter or cover objects. Few studies have provided relevant information that can help the Colombian government to formulate lines of action for the conservation of this species; consequently, its threat assessments so far have been based on very limited information.
We conducted surveys for salamanders in four municipalities of Cundinamarca, Colombia, using two approaches: visual encounter surveys (Guaduas and Villeta) and the basic sampling protocol for single-species occupancy modeling (Supatá and Venecia). Multivariate analyses were employed to explore the correlation between habitat structure and natural history traits, abundance, and detection/non-detection of
We evaluated the
activity pattern through kernel density curves for each sampling occasion and explored the variability of salamander abundance during their activity period by performing a nested ANOVA.
We report the discovery of two new populations of
which represent the most northwestern records known. A significant correlation between body length, body mass, and habitat structure was observed. Multivariate analyses indicated that leaf litter depth, mean temperature, percent vegetation cover, and altitude were the habitat variables that together explained 60.3% of the
abundance variability, as well as the main determinants of its optimal habitat.
exhibits an activity pattern characterized by two main activity peaks, in which niche time-partitioning was observed. Across the surveyed area, we found a healthy, stable, highly dense population of
(>1,300 individuals), with seasonal variability between development stages.
Given the high habitat specificity of
the species is highly vulnerable to local changes. Thus, we recommend that
be retained as Endangered (EN) on the IUCN Red List, based on the IUCN Criterion B, given its restricted extent of occurrence (ca. 2,500 km
) and the ongoing threats from agriculture, cattle ranching, logging, and urban development, which continue to reduce its suitable habitat.
There is an increasing demand in precooked chicken meat products for restaurants and catering services. Because cooked chicken meat develops lipid oxidation relatively fast, sous vide chicken meat ...was studied to assess its shelf-life. Six hundred Cobb x Ross broilers were fed for 6 wk with a basal corn-soybean meal diet including soybean, palm kernel, or animal-vegetable oil, each supplemented with 33 or 200 mg/kg of DL-α-tocopheryl acetate. Broilers were randomly assigned into 6 treatments and 4 repetitions with 25 birds each. Boneless breast or thigh muscle pieces were dissected into 5 x 5 x 5 cm cubes, vacuum-packed, cooked in water bath (until 74°C internal temperature), chilled, and stored at 4°C for 1, 5, 10, 25, and 40 d. For each storage day, each pouch contained 3 pieces of meat, either breast or thigh. Thiobarbituric acid reactive substances analysis, to quantify malonaldehyde (MDA) values, was conducted to estimate the lipid oxidation development. Nonheme iron values of cooked meat were analyzed. Fatty acid methyl esters analysis was performed in chicken muscle to determine its fatty acid composition. There was no interaction between dietary fat and vitamin E level in all of the variables studied except in nonheme iron. Dietary fat significantly influenced the fatty acid composition of the muscle (P < 0.01), but it did not affect the MDA values, regardless of differences in the muscle fatty acid composition between treatments. Supplementation of the high level of vitamin E significantly reduced the MDA values in both breast and thigh meat (P < 0.01). The maximum MDA values were observed at d 40 of storage in thigh and breast meat in animal-vegetable and soybean oil treatments with the low levels of vitamin E, 0.91 and 0.70 mg/kg, respectively. Nonheme iron values in thigh meat differed between treatments at 1 or 25 d of storage but not in breast meat. In conclusion, refrigerated sous vide chicken meat has a prolonged shelf-life, which is enhanced by dietary supranutritional supplementation of vitamin E.
Background: Adjuvant chemotherapy is not indicated in lymph node-negative colorectal adenocarcinoma (CRC), even though some cases will present recurrent disease. It is important to identify a ...subgroup of patients with the highest risk of relapse because of the potential benefit of adjuvant chemotherapy. The objective of this study is to define the prognostic factors and describe a method for the selection of this subgroup. Methods: A retrospective cohort of 124 patients with lymph node-negative CRC with complete surgical resection was studied. Cox’s proportional hazards model was used to define the prognostic factors associated with CRC-related survival and to develop a method for prediction of recurrence probability. Results: The cohort included 62 women and 62 men with mean age 55.8 years. The mean follow-up period was 11.7 years. T classification of the primary tumor, differentiation grade, carcinoembryonic antigen level, gender and the presence of neural invasion were significant prognostic factors according to the multivariate analysis (final model P = 0.00001). Using risk ratios for these prognostic factors, we defined a high-risk group of 78 patients and a low-risk group of 46 patients with 24 and 5 recurrences, respectively (recurrence rates of 30.8% and 10.9% respectively, P = 0.011). Conclusions: Using these factors, a prognostic scale was developed to predict high risk of recurrence in cases of completely resected CRC and to identify them as a subgroup of patients with potential benefit of adjuvant chemotherapy.
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