44 research outputs found

    Acrylic bone cements modified with graphene oxide: Mechanical, physical, and antibacterial properties

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    Bacterial infections are a common complication after total joint replacements (TJRs), the treatment of which is usually based on the application of antibiotic-loaded cements; however, owing to the increase in antibiotic-resistant microorganisms, the possibility of studying new antibacterial agents in acrylic bone cements (ABCs) is open. In this study, the antibacterial effect of formulations of ABCs loaded with graphene oxide (GO) between 0 and 0.5 wt. % was evaluated against Gram-positive bacteria: Bacillus cereus and Staphylococcus aureus, and Gram-negative ones: Salmonella enterica and Escherichia coli. It was found that the effect of GO was dependent on the concentration and type of bacteria: GO loadings ≥0.2 wt. % presented total inhibition of Gram-negative bacteria, while GO loadings ≥0.3 wt. % was necessary to achieve the same effect with Gram-positives bacteria. Additionally, the evaluation of some physical and mechanical properties showed that the presence of GO in cement formulations increased wettability by 17%, reduced maximum temperature during polymerization by 19%, increased setting time by 40%, and increased compressive and flexural mechanical properties by up to 17%, all of which are desirable behaviors in ABCs. The formulation of ABC loading with 0.3 wt. % GO showed great potential for use as a bone cement with antibacterial properties

    Effect of pretreatment with low-frequency ultrasound on quality parameters in gulupa (Passiflora edulis sims) pulp

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    The Gulupa (Passiflora edulis f. edulis Sims) is an expression of South America’s tropics’ biodiversity, and a source of B vitamins and amino acids. It is a climacteric export fruit for which it is necessary to incorporate emerging technologies for its conservation and transport. This work investigated the effect of ultrasound on gulupa pulp and verified the stability of the characters of interest in the shelf life of 20 days. Six treatments and a control sample were used, evaluated in triplicate, and varied in frequency (30 and 40 kHz) with an exposure time of 10, 20, and 30 min. A statistical analysis of unidirectional variances and Dunnett’s test was used. It was found that the ultrasound treatments did not affect the pH or the titratable acidity. Soluble solid results presented a significant increase (p < 0.05) (from 13.4 to 14.8% w/v) in the antioxidant capacity (from 1.13 to 1.54 µmol Trolox Equivalent (TE)/g by the ABTS•+ (2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) Cationic Radical Assay and from 3.3 to 3.7 µmol TE/g by the DPPH· (2,2-diphenyl-1-picrilhydrazil) Radical Scavenging Assay). During the shelf life, ascorbic acid was the parameter that varied most (p < 0.05). It decreased from 42.7 to 21.6 mg ascorbic acid/100 g of pulp in the control sample. However, a smaller decrease was observed (23.8–24.5 mg ascorbic acid/100 g of pulp) in the 40 kHz treatments. The smallest global color difference (∆E) for the control was found in the 40 kHz treatment at 30 min through the entire shelf life (day 0 to 20). Ultrasound treatment offers a new strategy to improve and extend the shelf life of chilled gulupa pulp

    Packham's Triumph Pears (Pyrus communis L.) Post-Harvest Treatment during Cold Storage Based on Chitosan and Rue Essential Oil

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    Pears (Pyrus communis L.) cv. Packham's Triumph are very traditional for human consumption, but pear is a highly perishable climacteric fruit with a short shelf-life affected by several diseases with a microbial origin. In this study, a protective effect on the quality properties of pears was evidenced after the surface application of chitosan-Ruta graveolens essential oil coatings (CS + RGEO) in four different concentrations (0, 0.5, 1.0 and 1.5 %, v/v) during 21 days of storage under 18 °C. After 21 days of treatment, a weight loss reduction of 10% (from 40.2 ± 5.3 to 20.3 ± 3.9) compared to the uncoated pears was evident with CS + RGEO 0.5%. All the fruits' physical-chemical properties evidenced a protective effect of the coatings. The maturity index increased for all the treatments. However, the pears with CS + RGEO 1.5% were lower (70.21) than the uncoated fruits (98.96). The loss of firmness for the uncoated samples was higher compared to the coated samples. The pears' most excellent mechanical resistance was obtained with CS + RGEO 0.5% after 21 days of storage, both for compression resistance (7.42 kPa) and force (22.7 N). Microbiological studies demonstrated the protective power of the coatings. Aerobic mesophilic bacteria and molds were significantly reduced (in 3 Log CFU/g compared to control) using 15 µL/mL of RGEO, without affecting consumer perception. The results presented in this study showed that CS + RGEO coatings are promising in the post-harvest treatment of pears

    Bioactive micro-constituents of ackee arilli (Blighia sapida K.D. Koenig)

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    Abstract: Ackee (Blighia sapida K. D. Koenig) is an exotic fruit widely consumed in the Caribbean countries. While there is extensive research on the presence of hypoglycin A, other bioactive compounds have not been studied. We identified and quantified the changes in bioactive molecules (total phenol, ascorbic acid, hypoglycin A, squalene, D: A-Friedooleanan-7-ol, (7.alpha.), and oleic acid), antioxidant potential, and volatile compounds during two stages of ripe. A clear reduction in hypoglycin A, ascorbic acid, and total polyphenols during the maturation process were observed. On the contrary, oleic acid, squalene, and D: A-Friedooleanan-7-ol, (7.alpha.) contents increased about 12, 12, and 13 times, respectively with advancing maturity. These bioactive molecules were positively correlated with radical scavenging (DDPH and ABTS). Solid phase microextraction (SPME) and gas chromatography coupled mass spectrometry (GC/MS) analysis revealed more than 50 compounds with 3-penten-2-one and hexanal as the major compounds in the fully ripe stage. The results suggested that ripe ackee arilli could serve as an appreciable source of natural bioactive micro-constituents

    Why Are Outcomes Different for Registry Patients Enrolled Prospectively and Retrospectively? Insights from the Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF).

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    Background: Retrospective and prospective observational studies are designed to reflect real-world evidence on clinical practice, but can yield conflicting results. The GARFIELD-AF Registry includes both methods of enrolment and allows analysis of differences in patient characteristics and outcomes that may result. Methods and Results: Patients with atrial fibrillation (AF) and ≥1 risk factor for stroke at diagnosis of AF were recruited either retrospectively (n = 5069) or prospectively (n = 5501) from 19 countries and then followed prospectively. The retrospectively enrolled cohort comprised patients with established AF (for a least 6, and up to 24 months before enrolment), who were identified retrospectively (and baseline and partial follow-up data were collected from the emedical records) and then followed prospectively between 0-18 months (such that the total time of follow-up was 24 months; data collection Dec-2009 and Oct-2010). In the prospectively enrolled cohort, patients with newly diagnosed AF (≤6 weeks after diagnosis) were recruited between Mar-2010 and Oct-2011 and were followed for 24 months after enrolment. Differences between the cohorts were observed in clinical characteristics, including type of AF, stroke prevention strategies, and event rates. More patients in the retrospectively identified cohort received vitamin K antagonists (62.1% vs. 53.2%) and fewer received non-vitamin K oral anticoagulants (1.8% vs . 4.2%). All-cause mortality rates per 100 person-years during the prospective follow-up (starting the first study visit up to 1 year) were significantly lower in the retrospective than prospectively identified cohort (3.04 [95% CI 2.51 to 3.67] vs . 4.05 [95% CI 3.53 to 4.63]; p = 0.016). Conclusions: Interpretations of data from registries that aim to evaluate the characteristics and outcomes of patients with AF must take account of differences in registry design and the impact of recall bias and survivorship bias that is incurred with retrospective enrolment. Clinical Trial Registration: - URL: http://www.clinicaltrials.gov . Unique identifier for GARFIELD-AF (NCT01090362)

    Risk profiles and one-year outcomes of patients with newly diagnosed atrial fibrillation in India: Insights from the GARFIELD-AF Registry.

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    BACKGROUND: The Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF) is an ongoing prospective noninterventional registry, which is providing important information on the baseline characteristics, treatment patterns, and 1-year outcomes in patients with newly diagnosed non-valvular atrial fibrillation (NVAF). This report describes data from Indian patients recruited in this registry. METHODS AND RESULTS: A total of 52,014 patients with newly diagnosed AF were enrolled globally; of these, 1388 patients were recruited from 26 sites within India (2012-2016). In India, the mean age was 65.8 years at diagnosis of NVAF. Hypertension was the most prevalent risk factor for AF, present in 68.5% of patients from India and in 76.3% of patients globally (P < 0.001). Diabetes and coronary artery disease (CAD) were prevalent in 36.2% and 28.1% of patients as compared with global prevalence of 22.2% and 21.6%, respectively (P < 0.001 for both). Antiplatelet therapy was the most common antithrombotic treatment in India. With increasing stroke risk, however, patients were more likely to receive oral anticoagulant therapy [mainly vitamin K antagonist (VKA)], but average international normalized ratio (INR) was lower among Indian patients [median INR value 1.6 (interquartile range {IQR}: 1.3-2.3) versus 2.3 (IQR 1.8-2.8) (P < 0.001)]. Compared with other countries, patients from India had markedly higher rates of all-cause mortality [7.68 per 100 person-years (95% confidence interval 6.32-9.35) vs 4.34 (4.16-4.53), P < 0.0001], while rates of stroke/systemic embolism and major bleeding were lower after 1 year of follow-up. CONCLUSION: Compared to previously published registries from India, the GARFIELD-AF registry describes clinical profiles and outcomes in Indian patients with AF of a different etiology. The registry data show that compared to the rest of the world, Indian AF patients are younger in age and have more diabetes and CAD. Patients with a higher stroke risk are more likely to receive anticoagulation therapy with VKA but are underdosed compared with the global average in the GARFIELD-AF. CLINICAL TRIAL REGISTRATION-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01090362

    Large expert-curated database for benchmarking document similarity detection in biomedical literature search

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    Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

    Eco-Friendly Biocontrol Strategies of Alternaria Phytopathogen Fungus: A Focus on Gene-Editing Techniques

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    Agricultural food production is greatly affected by postharvest diseases worldwide, such as the diseases caused by Alternaria species, which are very common in several crops. The management of fungal infections around the world largely relies on fungicides. In this context, the control of diseases such as early blight caused by Alternaria solani in potatoes and Alternaria linariae in tomatoes has mainly consisted of the application of fungicides, with negative impacts on the environment and human health. Recently, the application of 'omics' and gene editing through the CRISPR/Cas9 system and RNAi technologies demonstrated their effectiveness as emerging greener alternatives for controlling phytopathogenic fungi. Additionally, coatings based on essential oils and microbial antagonists suggest alternative strategies for controlling phytopathogenic fungi that are respectful of the environment. This review presents an exhaustive literature review focused on using greener alternatives to the traditional management of postharvest diseases associated with Alternaria species, such as inhibiting pathogenicity from their phytopathogenic genes using gene editing based on CRISPR/Cas9 and RNAi technologies. The review also presents coatings based on essential oils and microbial antagonists as greener strategies for Alternaria control. Biological processes of maximum efficiency can replace chemical methods for controlling phytopathogenic fungi, preserving healthy conditions in agricultural lands and ecosystems. This is possible with the rise of 'omic' technologies, the CRISPR/Cas9 tool, and RNAi technology. Greener control methods of Alternaria fungi can increase agricultural production, improving the economy and global health

    Bioactive micro-constituents of ackee arilli (Blighia sapida K.D. Koenig)

    No full text
    Ackee (Blighia sapida K. D. Koenig) is an exotic fruit widely consumed in the Caribbean countries. While there is extensive research on the presence of hypoglycin A, other bioactive compounds have not been studied. We identified and quantified the changes in bioactive molecules (total phenol, ascorbic acid, hypoglycin A, squalene, D: A-Friedooleanan-7-ol, (7.alpha.), and oleic acid), antioxidant potential, and volatile compounds during two stages of ripe. A clear reduction in hypoglycin A, ascorbic acid, and total polyphenols during the maturation process were observed. On the contrary, oleic acid, squalene, and D: A-Friedooleanan-7-ol, (7.alpha.) contents increased about 12, 12, and 13 times, respectively with advancing maturity. These bioactive molecules were positively correlated with radical scavenging (DDPH and ABTS). Solid phase microextraction (SPME) and gas chromatography coupled mass spectrometry (GC/MS) analysis revealed more than 50 compounds with 3-penten-2-one and hexanal as the major compounds in the fully ripe stage. The results suggested that ripe ackee arilli could serve as an appreciable source of natural bioactive micro-constituents

    Preparation and characterization of novel poly (lactic acid)/calcium oxide nanocomposites by electrospinning as a potential bone tissue scaffold

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    Calcium oxide nanoparticles (n-CaO) ca. 22 nm were obtained from eggshell waste. The n-CaO was incorporated into the PLA matrix in 10 and 20 wt% of filler content by electrospinning process to get PLA/n-CaO fibers with homogenous morphology and diameter as a potential use in scaffold for bone tissue regeneration. The incorporation of n-CaO into PLA modifies the mechanical properties, having a reinforcement effect on the matrix. The Young modulus for PLA/n-CaO nanocomposites increased between 122 and 138 % concerning neat PLA fibers, showing a more rigid behavior. The PLA/n-CaO nanocomposite fibers showed in vitro bioactivity, capable of inducing the precipitation of hydroxyapatite (HA) layer in the fiber surface after seven days in SBF solution. The biocidal and biological properties of PLA/n-Cao with 20 wt% showed a 30 % reduction in bacterial viability against S. aureus and 11 % against E. coli after 6 h of bacterial exposure. Furthermore, the fibers did not show a cytotoxic effect on the bone marrow ST-2 cell line, allowing cell adhesion and proliferation in the RPMI medium. The PLA/n-CaO with 20 wt% of nanoparticles showed a higher capacity to promote osteogenic differentiation, significantly increasing the alkaline phosphatase (ALP) expression after seven days compared to PLA and cell control. The in vivo analysis corroborated the biocompatibility of the prepared scaffolds; the presence of n-CaO in PLA reduced the formation of fibrous encapsulation of the material, improving the healing process. These results validated using n-CaO to enhance the functionality of polymer matrices as a PLA, bringing bioactive, biocide, and biocompatible properties, opening a new and interesting route to develop new biomaterials as a scaffold for bone tissue engineering.P.A. Zapata thanks the financial support of FONDECYT under Reg- ular Project 1220093. D. Canales thanks the financial support of FON- DECYT under postdoctoral project No. 3210810. Finally, D. Canales is immensely grateful to Katharina Schuhladen, Sonja Kuth, Lena Vogt, Irem Unalam, and Florian Ruther, members of the Institute of Bio- materials of the University of Erlangen-Nuremberg for their support in the mechanical and biological analysis
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