Publications by authors named "Juan Valverde"

39 Publications

Transfer Learning in Magnetic Resonance Brain Imaging: A Systematic Review.

J Imaging 2021 Apr 1;7(4). Epub 2021 Apr 1.

A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, 70150 Kuopio, Finland.

(1) Background: Transfer learning refers to machine learning techniques that focus on acquiring knowledge from related tasks to improve generalization in the tasks of interest. In magnetic resonance imaging (MRI), transfer learning is important for developing strategies that address the variation in MR images from different imaging protocols or scanners. Additionally, transfer learning is beneficial for reutilizing machine learning models that were trained to solve different (but related) tasks to the task of interest. The aim of this review is to identify research directions, gaps in knowledge, applications, and widely used strategies among the transfer learning approaches applied in MR brain imaging; (2) Methods: We performed a systematic literature search for articles that applied transfer learning to MR brain imaging tasks. We screened 433 studies for their relevance, and we categorized and extracted relevant information, including task type, application, availability of labels, and machine learning methods. Furthermore, we closely examined brain MRI-specific transfer learning approaches and other methods that tackled issues relevant to medical imaging, including privacy, unseen target domains, and unlabeled data; (3) Results: We found 129 articles that applied transfer learning to MR brain imaging tasks. The most frequent applications were dementia-related classification tasks and brain tumor segmentation. The majority of articles utilized transfer learning techniques based on convolutional neural networks (CNNs). Only a few approaches utilized clearly brain MRI-specific methodology, and considered privacy issues, unseen target domains, or unlabeled data. We proposed a new categorization to group specific, widely-used approaches such as pretraining and fine-tuning CNNs; (4) Discussion: There is increasing interest in transfer learning for brain MRI. Well-known public datasets have clearly contributed to the popularity of Alzheimer's diagnostics/prognostics and tumor segmentation as applications. Likewise, the availability of pretrained CNNs has promoted their utilization. Finally, the majority of the surveyed studies did not examine in detail the interpretation of their strategies after applying transfer learning, and did not compare their approach with other transfer learning approaches.
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http://dx.doi.org/10.3390/jimaging7040066DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8321322PMC
April 2021

Preharvest Treatment with Oxalic Acid Improves Postharvest Storage of Lemon Fruit by Stimulation of the Antioxidant System and Phenolic Content.

Antioxidants (Basel) 2021 Jun 15;10(6). Epub 2021 Jun 15.

Department of Food Technology, EPSO, University Miguel Hernández, 03312 Alicante, Spain.

Lemon trees ( (L.) Burm. F) were treated monthly with oxalic acid (OA) at 0.1, 0.5, and 1 mM from initial fruit growth on the tree until harvest in2019. The experiment was repeated in 2020, with the application of OA 1 mM (according to the best results of 2019). In both years, fruit from OA-treated trees and the controls were stored for 35 days at 10 °C. Results showed that all treatments reduced weight loss (WL) and maintained higher firmness, total soluble solids (TSS), and total acidity (TA) than in the controls. Meanwhile, colour (hue angle) did not show significant differences. The activity of antioxidant enzymes, catalase (CAT), ascorbate peroxidase (APX), and peroxidase (POD) in the flavedo of the fruit from the OA-treated trees was higher than in the controls at harvest and after 35 days of storage. Similarly, the total phenolic content (TPC) in the flavedo and juice of the fruit from the OA-treated trees were higher than in the controls. The increase in the activity of the antioxidant enzymes and TPC started with the first preharvest OA treatment and were maintained during fruit development on the tree until harvest. Preharvest OA treatments enhanced the antioxidant system of the lemon fruits, reducing the postharvest incidence of decay. Thus, OA could be a useful tool to increase the quality and functional properties of lemon fruits.
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http://dx.doi.org/10.3390/antiox10060963DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8232715PMC
June 2021

Melatonin Treatment to Pomegranate Trees Enhances Fruit Bioactive Compounds and Quality Traits at Harvest and during Postharvest Storage.

Antioxidants (Basel) 2021 May 21;10(6). Epub 2021 May 21.

Department of Applied Biology, EPSO, University Miguel Hernández. Ctra. Beniel km. 3.2, 03312 Orihuela, Alicante, Spain.

The effect of melatonin pomegranate tree treatments on fruit quality and bioactive compounds with antioxidant activity at harvest and during storage at 10 °C for 60 days was assayed in two consecutive years, 2019 and 2020. In the first year, trees were treated with 0.1, 0.3 and 0.5 mM of melatonin along the developmental fruit growth cycle, and results showed that bioactive compounds (total phenolics and total and individual anthocyanins) and antioxidant activity at harvest were higher in fruits from melatonin-treated trees than in controls. Other fruit quality parameters, such as firmness, total soluble solids and aril red colour, were also increased as a consequence of melatonin treatment. In fruit from control tress, firmness and acidity levels decreased during storage, while increases occurred on total soluble solids, leading to fruit quality reductions. These changes were delayed, and even maintenance of total acidity was observed, in fruit from melatonin-treated trees with respect to controls, resulting in a fruit shelf-life increase. Moreover, concentration of phenolics and anthocyanins and antioxidant activity were maintained at higher levels in treated than in control fruits during the whole storage period. In general, all the mentioned effects were found at the highest level with the 0.1 mM melatonin dose, and then it was selected for repeating the experiment in the second year and results of the first year were confirmed. Thus, 0.1 mM melatonin treatment could be a useful tool to enhance aril content on bioactive compounds with antioxidant activity and health beneficial effects and to improve quality traits of pomegranate fruit, at harvest and during postharvest storage.
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http://dx.doi.org/10.3390/antiox10060820DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8224012PMC
May 2021

SARS-CoV-2 prevalence associated to low socioeconomic status and overcrowding in an LMIC megacity: A population-based seroepidemiological survey in Lima, Peru.

EClinicalMedicine 2021 Apr 30;34:100801. Epub 2021 Mar 30.

Centro Nacional de Epidemiología, Prevención y Control de Enfermedades, Peruvian Ministry of Health, Jr. Daniel Olaechea N°. 199, Jesús María, Lima, Peru.

Background: Worldwide, Peru has one of the highest infection fatality rates of COVID-19, and its capital city, Lima, accumulates roughly 50% of diagnosed cases. Despite surveillance efforts to assess the extent of the pandemic, reported cases and deaths only capture a fraction of its impact due to COVID-19's broad clinical spectrum. This study aimed to estimate the seroprevalence of SARS-CoV-2 in Lima, stratified by age, sex, region, socioeconomic status (SES), overcrowding, and symptoms.

Methods: We conducted a multi-stage, population-based serosurvey in Lima, between June 28th and July 9th, 2020, after 115 days of the index case and after the first peak cases. We collected whole blood samples by finger-prick and applied a structured questionnaire. A point-of-care rapid serological test assessed IgM and IgG antibodies against SARS-CoV-2. Seroprevalence estimates were adjusted by sampling weights and test performance. Additionally, we performed RT-PCR molecular assays to seronegatives and estimated the infection prevalence.

Findings: We enrolled 3212 participants from 797 households and 241 sample clusters from Lima in the analysis. The SARS-CoV-2 seroprevalence was 20·8% (95%CI 17·2-23·5), and the prevalence was 25·2% (95%CI 22·5-28·2). Seroprevalence was equally distributed by sex (aPR=0·96 [95%CI 0·85-1·09,  = 0·547]) and across all age groups, including ≥60 versus ≤11 years old (aPR=0·96 [95%CI 0·73-1·27,  = 0·783]). A gradual decrease in SES was associated with higher seroprevalence (aPR=3·41 [95%CI 1·90-6·12, <0·001] in low SES). Also, a gradual increase in the overcrowding index was associated with higher seroprevalence (aPR=1·99 [95%CI 1·41-2·81, <0·001] in the fourth quartile). Seroprevalence was also associated with contact with a suspected or confirmed COVID-19 case, whether a household member (48·9%, aPR=2·67 [95%CI 2·06-3·47, <0·001]), other family members (27·3%, aPR=1·66 [95%CI 1·15-2·40,  = 0·008]) or a workmate (34·1%, aPR=2·26 [95%CI 1·53-3·35, <0·001]). More than half of seropositive participants reported never having had symptoms (56·1%, 95% CI 49·7-62·3).

Interpretation: This first estimate of SARS-CoV-2 seroprevalence in Lima shows an intense transmission scenario, despite the government's numerous interventions early established. Susceptibles across age groups show that physical distancing interventions must not be relaxed. SES and overcrowding households are associated with seroprevalence. This study highlights the importance of considering the existing social inequalities for implementing the response to control transmission in low- and middle-income countries.
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http://dx.doi.org/10.1016/j.eclinm.2021.100801DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8009628PMC
April 2021

Automated joint skull-stripping and segmentation with Multi-Task U-Net in large mouse brain MRI databases.

Neuroimage 2021 04 14;229:117734. Epub 2021 Jan 14.

A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio 70210, Finland.

Skull-stripping and region segmentation are fundamental steps in preclinical magnetic resonance imaging (MRI) studies, and these common procedures are usually performed manually. We present Multi-task U-Net (MU-Net), a convolutional neural network designed to accomplish both tasks simultaneously. MU-Net achieved higher segmentation accuracy than state-of-the-art multi-atlas segmentation methods with an inference time of 0.35 s and no pre-processing requirements. We trained and validated MU-Net on 128 T2-weighted mouse MRI volumes as well as on the publicly available MRM NeAT dataset of 10 MRI volumes. We tested MU-Net with an unusually large dataset combining several independent studies consisting of 1782 mouse brain MRI volumes of both healthy and Huntington animals, and measured average Dice scores of 0.906 (striati), 0.937 (cortex), and 0.978 (brain mask). Further, we explored the effectiveness of our network in the presence of different architectural features, including skip connections and recently proposed framing connections, and the effects of the age range of the training set animals. These high evaluation scores demonstrate that MU-Net is a powerful tool for segmentation and skull-stripping, decreasing inter and intra-rater variability of manual segmentation. The MU-Net code and the trained model are publicly available at https://github.com/Hierakonpolis/MU-Net.
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http://dx.doi.org/10.1016/j.neuroimage.2021.117734DOI Listing
April 2021

RatLesNetv2: A Fully Convolutional Network for Rodent Brain Lesion Segmentation.

Front Neurosci 2020 22;14:610239. Epub 2020 Dec 22.

A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland.

We present a fully convolutional neural network (ConvNet), named RatLesNetv2, for segmenting lesions in rodent magnetic resonance (MR) brain images. RatLesNetv2 architecture resembles an autoencoder and it incorporates residual blocks that facilitate its optimization. RatLesNetv2 is trained end to end on three-dimensional images and it requires no preprocessing. We evaluated RatLesNetv2 on an exceptionally large dataset composed of 916 T2-weighted rat brain MRI scans of 671 rats at nine different lesion stages that were used to study focal cerebral ischemia for drug development. In addition, we compared its performance with three other ConvNets specifically designed for medical image segmentation. RatLesNetv2 obtained similar to higher Dice coefficient values than the other ConvNets and it produced much more realistic and compact segmentations with notably fewer holes and lower Hausdorff distance. The Dice scores of RatLesNetv2 segmentations also exceeded inter-rater agreement of manual segmentations. In conclusion, RatLesNetv2 could be used for automated lesion segmentation, reducing human workload and improving reproducibility. RatLesNetv2 is publicly available at https://github.com/jmlipman/RatLesNetv2.
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http://dx.doi.org/10.3389/fnins.2020.610239DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7783408PMC
December 2020

Thymol Encapsulated into HP-β-Cyclodextrin as an Alternative to Synthetic Fungicides to Induce Lemon Resistance against Sour Rot Decay.

Molecules 2020 Sep 22;25(18). Epub 2020 Sep 22.

Department of Food Technology, University Miguel Hernández (UMH), Ctra. Beniel km. 3.2, Orihuela, 03312 Alicante, Spain.

Consumers demand the use of eco-friendly fungicides to treat fruit and vegetables and governmental authorities have unauthorized the application of chemical antifungals for the efficient control of sour rot. In the present research, the microwave irradiation (MW) method was used to encapsulate thymol into 2-hydroxylpropyl-beta-cyclodextrin (HP-β-CD) and the effect of these HP-β-CD on controlling sour rot in citrus fruit, caused by , was evaluated. Amounts of 25 and 50 mM of HP-β-CD-thymol were used, and compared with propiconazole, to control the decay of inoculated lemon fruit. The treatments were performed in curative and preventive experiments. The incidence and severity of in 25 and 50 mM HP-β-CD-thymol-treated fruit were reduced in both experiments. The preventive 50 mM HP-β-CD-thymol treatment showed the best effect, reducing the sour rot, respiration rate and fruit weight loss during storage at 20 °C. HP-β-CD-thymol increased polyphenol concentration and the activity of antioxidant enzymes, such as catalase (CAT), ascorbate peroxidase (APX) and peroxidase (POD) in lemon peel, and the highest effects were found with the 50-mM dose. In conclusion, the results show that the use of thymol encapsulated by MW into HP-β-CD could be an effective and sustainable tool, a substitute to the synthetic fungicides, for control in citrus fruit.
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http://dx.doi.org/10.3390/molecules25184348DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7570568PMC
September 2020

Enhancing antioxidant systems by preharvest treatments with methyl jasmonate and salicylic acid leads to maintain lemon quality during cold storage.

Food Chem 2021 Feb 9;338:128044. Epub 2020 Sep 9.

Department of Food Technology, EPSO, University Miguel Hernández, Ctra. Beniel km. 3.2, 03312 Orihuela, Alicante, Spain. Electronic address:

The effects of preharvest treatments with 0.1 mM methyl jasmonate (MeJA) and 0.5 mM salicylic acid (SA) on quality parameters of lemon fruit and their relationship with antioxidant systems, gene expression and bioactive compounds at harvest and during cold storage were evaluated. Results showed that total antioxidant activity, total phenolic content and the major individual phenolics (hesperidin and eriocitrin) were always higher in treated fruit than in controls. The activity of the antioxidant enzymes catalase, peroxidase and ascorbate peroxidase was also increased at harvest by SA and MeJA treatments, especially the last enzyme, for which the expression of its codifying gene was also enhanced. In addition, treated fruit had lower weight and firmness losses, respiration rate and production of ethylene than controls. Moreover, sugars and organic acids were maintained at higher concentration in flavedo and juice as a consequence of preharvest SA and MeJA treatments, showing an effect on maintaining fruit quality properties.
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http://dx.doi.org/10.1016/j.foodchem.2020.128044DOI Listing
February 2021

Preharvest application of methyl salicylate, acetyl salicylic acid and salicylic acid alleviated disease caused by Botrytis cinerea through stimulation of antioxidant system in table grapes.

Int J Food Microbiol 2020 Dec 31;334:108807. Epub 2020 Jul 31.

Department of Food Technology, EPSO, University Miguel Hernández, Ctra. Beniel km. 3.2, 03312 Orihuela, Alicante, Spain. Electronic address:

The main goal of this study was to describe impact of preharvest application of methyl salicylate (MeSA), acetyl salicylic acid (ASA) and salicylic acid (SA) on the reduction of disease caused by Botrytis cinerea in two table grape cultivars ('Crimson' and 'Magenta'). Based on previous studies, MeSA and SA were applied at 0.1 and 0.01 mM for both cultivars, while ASA was applied at 1 mM in 'Crimson' and 0.1 mM in 'Magenta'. At time of harvest, berry maturity-quality attributes, bioactive compounds and antioxidant enzymes were determined. In addition, grapes were artificially inoculated with B. cinerea spores, and the berries were ranked for visual decay incidence after 5 days of inoculation. Salicylates preharvest treatments led to higher total acidity, content of bioactive compounds and activity of antioxidant enzymes in treated than in control berries. The application of salicylate derivatives induced resistance to B. cinerea spoilage, since higher percentage of berries with no symptoms was observed and on the contrary, the highest percentages of berries were obtained in control grapes. All preharvest treatments with SA, ASA and MeSA alleviated postharvest disease caused by B. cinerea probably due to increasing levels of phenolic compounds and activity of antioxidant enzymes, although the best results were obtained with MeSA at 0.1 mM. Also, for this treatment and dose, higher quality properties, such as higher concentrations of ascorbic, succinic and fumaric acids, were observed compared with no treated-grapes.
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http://dx.doi.org/10.1016/j.ijfoodmicro.2020.108807DOI Listing
December 2020

Pre-harvest methyl jasmonate treatments increase antioxidant systems in lemon fruit without affecting yield or other fruit quality parameters.

J Sci Food Agric 2019 Aug 16;99(11):5035-5043. Epub 2019 May 16.

Department of Applied Biology, EPSO, University Miguel Hernández, Alicante, Spain.

Background: Jasmonic acid (JA) and its volatile derivative methyl jasmonate (MeJA) are hormones involved in the regulation of many processes in plants and act (when applied as a post- or pre-harvest treatment) to increase fruit bioactive compounds with antioxidant potential. However, there is no literature available regarding the effect of pre-harvest MeJA treatment on lemon fruit antioxidant systems, which was the aim of the present study.

Results: MeJA treatment (0.1, 0.5 and 1.0 mmol L ) increased antioxidant compounds, such as phenolics, in the juice and flavedo of 'Fino' and 'Verna' lemons at harvest, with the most effective concentration being 0.1 mmol L in both cultivars. In addition, catalase (CAT), peroxidase (POD) and ascorbate peroxidase (APX) activities were also increased by MeJA treatment, with the highest increases being also found with 0.1 mmol L . The increases in APX and CAT were maintained from one treatment to another during fruit development on the tree, whereas the increase on POD disappeared after 8-10 days of each treatment. For both antioxidant systems, the highest increases were found in lemon harvested at the commercial ripening stage. By contrast, crop yield, fruit ripening process and quality parameters were generally not affected by MeJA treatment.

Conclusion: Preharvest MeJA treatment could be a useful tool for increasing antioxidant potential and the health beneficial effects of lemon fruit consumption, given the relationship between these properties and phenolic content. Moreover, the increased concentration of phenolics and the activity of antioxidant enzymes in the flavedo of MeJA treated fruit could increase lemon tolerance to chilling injury and decay during postharvest storage. © 2019 Society of Chemical Industry.
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http://dx.doi.org/10.1002/jsfa.9746DOI Listing
August 2019

[Survival analysis in people diagnosed with HIV/AIDS in Puerto Rico].

Rev Puertoriq Med Salud Publica 2018 ;66:8-14

Bioestadístico en el Departamento de Epidemiología de la Johns Hopkins University.

After the introduction of HAART, the HIV/AIDS epidemiological trends has shown an increasing in the survival rates. HAART has dramatically improved the life expectancy of HIV/AIDS. The objective of this study was to estimate survival in people diagnosed with HIV/AIDS in Puerto Rico (PR) from 2003-2011. A population-based study using the PR HIV Surveillance System was implemented. A total of N = 9,290 people were diagnosed with HIV/AIDS in PR for 2003-2011 period. Cox regression models for survival analysis were assessed. Survival at 6 years after diagnosis in HIV patients was 0.87 (CI95%: 0.09, 0.72) when compare with AIDS patients at same time of diagnosis was 0.57 (CI95%: 0.55, 0.60) p<0.001. Intravenous drug users [IDU] have less probability of survival at 5 years after diagnosis when compare with other transmission modes 0.69 (CI95%: 0.67, 0.71) p<0.001. Assertive prevention strategies must be developed and implemented in PR for IDU's in order to increase their survival rates.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6097805PMC
January 2018

FPGA-Based High-Performance Embedded Systems for Adaptive Edge Computing in Cyber-Physical Systems: The ARTICo³ Framework.

Sensors (Basel) 2018 Jun 8;18(6). Epub 2018 Jun 8.

Centro de Electrónica Industrial, Universidad Politécnica de Madrid, José Gutiérrez Abascal 2, 28006 Madrid, Spain.

Cyber-Physical Systems are experiencing a paradigm shift in which processing has been relocated to the distributed sensing layer and is no longer performed in a centralized manner. This approach, usually referred to as Edge Computing, demands the use of hardware platforms that are able to manage the steadily increasing requirements in computing performance, while keeping energy efficiency and the adaptability imposed by the interaction with the physical world. In this context, SRAM-based FPGAs and their inherent run-time reconfigurability, when coupled with smart power management strategies, are a suitable solution. However, they usually fail in user accessibility and ease of development. In this paper, an integrated framework to develop FPGA-based high-performance embedded systems for Edge Computing in Cyber-Physical Systems is presented. This framework provides a hardware-based processing architecture, an automated toolchain, and a runtime to transparently generate and manage reconfigurable systems from high-level system descriptions without additional user intervention. Moreover, it provides users with support for dynamically adapting the available computing resources to switch the working point of the architecture in a solution space defined by computing performance, energy consumption and fault tolerance. Results show that it is indeed possible to explore this solution space at run time and prove that the proposed framework is a competitive alternative to software-based edge computing platforms, being able to provide not only faster solutions, but also higher energy efficiency for computing-intensive algorithms with significant levels of data-level parallelism.
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http://dx.doi.org/10.3390/s18061877DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6022175PMC
June 2018

Comparison of the adjuvant activity of emulsions with different physicochemical properties on the antibody response towards the venom of West African carpet viper (Echis ocellatus).

Toxicon 2017 Mar 12;127:106-111. Epub 2017 Jan 12.

Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica. Electronic address:

Adjuvant emulsions are widely used to enhance the antibody response of the animals used as immunoglobulin source for producing antivenoms. Usually, the adjuvant activity of emulsions is attributed both to their ability to trigger "danger" signals from cells in which they induce death, and to form depots from which immunogens are slowly released. However, there is contradictory evidence suggesting that adjuvant activity of emulsions is independent of the dispersion type and the rate of immunogen release. In order to test how physical properties of emulsions, composed of mineral oil and water, affect their ability to enhance the antibody response towards snake venoms, we compared water-in-oil (W/O) emulsions prepared at volume ratios of 70/30, 50/50 or 30/70, a 50/50 oil-in-water (O/W) emulsion, and a water-in-oil-in-water (W/O/W) multiple emulsion. Comparison included their droplet-size, viscosity, rate of immunogen release and ability to enhance the antibody response of mice immunized with the venom of the African viperid snake Echis ocellatus. It was found that all emulsions released a low amount of venom, and that the 50/50 (W/O) and the multiple emulsion (W/O/W) were those that induced the higher anti-venom antibody response. Our results suggest that the ability of emulsions to enhance the anti-venom response is not associated to their ability to form depots from which the venom is slowly released.
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http://dx.doi.org/10.1016/j.toxicon.2017.01.011DOI Listing
March 2017

Impact on Vitamin D2, Vitamin D4 and Agaritine in Agaricus bisporus Mushrooms after Artificial and Natural Solar UV Light Exposure.

Plant Foods Hum Nutr 2016 Sep;71(3):314-21

National Food Institute, Technical University of Denmark, Søborg, Denmark.

Commercial mushroom production can expose mushrooms post-harvest to UV light for purposes of vitamin D2 enrichment by converting the naturally occurring provitamin D2 (ergosterol). The objectives of the present study were to artificially simulate solar UV-B doses occurring naturally in Central Europe and to investigate vitamin D2 and vitamin D4 production in sliced Agaricus bisporus (button mushrooms) and to analyse and compare the agaritine content of naturally and artificially UV-irradiated mushrooms. Agaritine was measured for safety aspects even though there is no rationale for a link between UV light exposure and agaritine content. The artificial UV-B dose of 0.53 J/cm(2) raised the vitamin D2 content to significantly (P < 0.001) higher levels of 67.1 ± 9.9 μg/g dry weight (DW) than sun exposure (3.9 ± 0.8 μg/g dry DW). We observed a positive correlation between vitamin D4 and vitamin D2 production (r(2) = 0.96, P < 0.001) after artificial UV irradiation, with vitamin D4 levels ranging from 0 to 20.9 μg/g DW. The agaritine content varied widely but remained within normal ranges in all samples. Irrespective of the irradiation source, agaritine dropped dramatically in conjunction with all UV-B doses both artificial and natural solar, probably due to its known instability. The biological action of vitamin D from UV-exposed mushrooms reflects the activity of these two major vitamin D analogues (D2, D4). Vitamin D4 should be analysed and agaritine disregarded in future studies of UV-exposed mushrooms.
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http://dx.doi.org/10.1007/s11130-016-0562-5DOI Listing
September 2016

Preharvest salicylic acid and acetylsalicylic acid treatments preserve quality and enhance antioxidant systems during postharvest storage of sweet cherry cultivars.

J Sci Food Agric 2017 Mar 5;97(4):1220-1228. Epub 2016 Aug 5.

Department of Food Technology, EPSO, University Miguel Hernández, Ctra. Beniel km. 3.2, 03312, Orihuela, Alicante, Spain.

Background: Sweet cherries are much appreciated by consumers as a result of their organoleptic quality attributes and antioxidant properties, although they deteriorate rapidly after harvest. Different preharvest strategies have been carried out to increase their quality at the time of harvest. We present data regarding the effect of preharvest salicylic acid (SA) and acetyl salicylic acid (ASA) treatments on sweet cherry quality during postharvest storage.

Results: At harvest and during postharvest storage, sweet cherry fruits ('Sweet Heart', 'Sweet Late' and 'Lapins') from SA (0.5 mmol L ) and ASA (1 mmol L ) treated trees had a higher colour (lower chroma index), firmness, total soluble solids, total phenolics, total anthocyanins and hydrophilic total antioxidant activity. In addition, the activity of the antioxidant enzymes catalase, peroxidase, superoxide dismutase and ascorbate peroxidase was also enhanced in SA- and ASA-treated cherries.

Conclusion: Both SA and ASA preharvest treatments could be promising tools for improving sweet cherry quality at harvest and after storage, with an additional effect on delaying the postharvest ripening process by increasing the levels of antioxidant compounds and the activity of the antioxidant enzymes. © 2016 Society of Chemical Industry.
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http://dx.doi.org/10.1002/jsfa.7853DOI Listing
March 2017

Cardioprotective potential of Irish macroalgae: generation of glycine betaine and dimethylsulfoniopropionate containing extracts by accelerated solvent extraction.

Planta Med 2015 Jun 27;81(8):679-84. Epub 2015 May 27.

Irish Seaweed Research Group, Ryan Institute, Environmental, Marine and Energy Research, National University of Ireland, Galway, Ireland.

Accelerated solvent extraction (ASE®) was used to generate 18 macroalgal extracts from Irish seaweeds. The glycine betaine and dimethylsulfoniopriopionate content of the generated ASE® extracts were estimated using (1)H-NMR and confirmed for selected extracts using ultra performance liquid chromatography and mass spectrometry. Dimethylsulfoniopriopionate was only identified in the ASE® extract generated from Codium fragile ISCG0029. Glycine betaine was identified in the ASE® extract generated from Ulva intestinalis ISCG0356 using (1)H-NMR. Mass spectrometry analysis found that the seaweed species Cytoseira nodicaulis ISCG0070, Cytoseira tamariscofolia ISCG0283, and Polysiphonia lanosa ISCG0462 also had a glycine betaine content that ranged from 1.39 ng/ml to 105.11 ng/ml. Generated ASE® macroalgal extracts have potential for use as functional food ingredients in food products.
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http://dx.doi.org/10.1055/s-0035-1546018DOI Listing
June 2015

Variation in bioactive content in broccoli (Brassica oleracea var. italica) grown under conventional and organic production systems.

J Sci Food Agric 2015 Apr 30;95(6):1163-71. Epub 2014 Jul 30.

Teagasc, Ashtown Food Research Centre, Ashtown, Dublin 15, Ireland; Monaghan Mushrooms, Tyholland, Co., Monaghan, Ireland.

Background: Broccoli and other cruciferous vegetables contain a number of bioactive compounds, in particular glucosinolates and polyphenols, which are proposed to confer health benefits to the consumer. Demand for organic crops is at least partly based on a perception that organic crops may contain higher levels of bioactive compounds; however, insufficient research has been carried out to either support or refute such claims.

Results: In this study we examined the effect of conventional, organic, and mixed cultivation practices on the content of total phenolics, total flavonoids, and total and individual glucosinolates in two varieties of broccoli grown over 2 years in a split-plot factorial systems comparison trial. Levels of total phenolics and total flavonoids showed a significant year-on-year variation but were not significantly different between organic and conventional production systems. In contrast, levels of the indolyl glucosinolates glucobrassicin and neoglucobrassicin were significantly higher (P < 0.05) under fully organic compared to fully conventional management.

Conclusion: Organic cultivation practices resulted in significantly higher levels of glucobrassicin and neoglucobrassicin in broccoli florets; however, other investigated compounds were unaffected by production practices.
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http://dx.doi.org/10.1002/jsfa.6804DOI Listing
April 2015

Quality and antioxidant properties on sweet cherries as affected by preharvest salicylic and acetylsalicylic acids treatments.

Food Chem 2014 Oct 1;160:226-32. Epub 2014 Apr 1.

Department of Food Technology, EPSO, University Miguel Hernández, Ctra. Beniel km. 3.2, 03312 Orihuela, Alicante, Spain.

The effects of salicylic acid (SA) or acetylsalicylic acid (ASA) treatments during on-tree cherry growth and ripening on fruit quality attributes, especially those related with the content on bioactive compounds and antioxidant activity were analysed in this research. For this purpose, two sweet cherry cultivars, 'Sweet Heart' and 'Sweet Late', were used and SA or ASA treatments, at 0.5, 1.0 and 2.0mM concentrations, were applied at three key points of fruit development (pit hardening, initial colour changes and onset of ripening). These treatments increased fruit weight and ameliorated quality attributes at commercial harvest, and led to cherries with higher concentration in total phenolics and in total anthocyanins, as well as higher antioxidant activity, in both hydrophilic and lipophilic fractions. Thus, preharvest treatments with SA or ASA could be promising tools to improve sweet cherry quality and health beneficial effects for consumers.
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http://dx.doi.org/10.1016/j.foodchem.2014.03.107DOI Listing
October 2014

Simultaneous determination of sulphoraphane and sulphoraphane nitrile in Brassica vegetables using ultra-performance liquid chromatography with tandem mass spectrometry.

Phytochem Anal 2014 Mar-Apr;25(2):141-6. Epub 2013 Oct 16.

School of Food Science and Environmental Health, Dublin Institute of Technology, Cathal Brugha Street, Dublin 1, Ireland.

Introduction: Several analytical methods exist for the determination of sulphoraphane or sulphoraphane nitrile from biological matrices and plant extracts. However, no UPLC-MS/MS method exists for the simultaneous detection of both.

Objective: To develop and validate an UPLC-MS/MS method for the simultaneous analysis of sulphoraphane and sulphoraphane nitrile from Brassica oleracea L. ssp. italica

Methods: This method was developed utilising an Acquity BEH C8 column with gradient elution combined with tandem mass spectrometry, using positive electrospray ionisation in multiple reaction monitoring mode.

Results: The retention times for sulphoraphane and sulphoraphane nitrile were 0.4 and 0.6 min respectively, and total run time was 3 min. The method was validated for linearity, sensitivity, precision, accuracy, matrix effects and recovery. The method was employed to determine glucoraphanin hydrolysis products in broccoli and the predominant product was found to vary depending on the variety tested. It was also applied to the accurate determination of sulphoraphane and sulphoraphane nitrile in broccoli samples hydrolysed under different conditions. It was observed that the formation of sulphoraphane and sulphoraphane nitrile was influenced by the temperature of the reaction.

Conclusion: The validated UPLC-MS/MS method for simultaneous detection of sulphoraphane and sulphoraphane nitrile was shown to be applicable to broccoli plants and is expected to be applicable to other cruciferous sources.
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http://dx.doi.org/10.1002/pca.2480DOI Listing
September 2014

Absolute configuration of falcarinol (9Z-heptadeca-1,9-diene-4,6-diyn-3-ol) from Pastinaca sativa.

Nat Prod Commun 2013 Aug;8(8):1123-6

Department of Agroforestry Sciences, School of Technical Agricultural Engineering, University of Seville, Ctra de Utrera, C.P. 41013, Spain.

Falcarinol (9Z-heptadeca-1,9-diene-4,6-diyn-3-ol; (1) is a polyacetylene commonly found in several plant families. The absolute configuration of naturally occurring 1 is not clear and contradictory results have been reported in the literature. Determination of the absolute configuration of 1 from Pastinaca sativa L. was carried out. Isolation of 95% pure 1 was performed via successive fractionation and preparative-HPLC. A racemic mixture comprised of 3R-1 and 3S-1 was synthesized in order to confirm the absolute configuration of the isolated natural product using chiral HPLC. Based on a combination of chiral HPLC and specific rotation, 1 present in P. saliva was found to have a 3R absolute configuration (i.e. (3R, 9Z)-heptadeca-1,9-diene-4,6-diyn-3-ol).
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August 2013

Chitosan-containing bread made using marine shellfishery byproducts: functional, bioactive, and quality assessment of the end product.

J Agric Food Chem 2013 Sep 4;61(37):8790-6. Epub 2013 Sep 4.

Food BioSciences Department, ‡Food Safety Department, and #Food Chemistry Department, Teagasc, the Irish Agricultural and Food Development Authority , Ashtown, Dublin 15, Republic of Ireland.

Chitosan is nature's second most abundant polymer after cellulose and forms the structural support in crustacean shell material and Basidomycete mushroom stalks. Chitosan is a known antimicrobial agent but, to date, was not examined as an antimicrobial agent in bread formulations for the prevention of mold or rope formation. The aim of this work was to investigate the effects of chitosan generated from prawn shell byproducts on the color, moisture, and texture and crumb formation of bread. A secondary aim of this work was to determine the antimicrobial effect of chitosan added to bread at a rate of 1% against the rope spoilage pathogen Bacillus cereus along with natural molds. The addition of chitosan to bread with a molecular mass of 124000 ± 10000 g/mol and 19% deacetylated was found to inhibit B. cereus growth and rope formation in bread when monitored over 3-5 days. Natural mold growth was also significantly delayed in bread made using chitosan substitution of flour at 1% compared to the control bread, where mold was observed growing on the bread surface after 72 h when bread was incubated at 30 °C.
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http://dx.doi.org/10.1021/jf402248aDOI Listing
September 2013

Potential of cultivar and crop management to affect phytochemical content in winter-grown sprouting broccoli (Brassica oleracea L. var. italica).

J Sci Food Agric 2014 Jan 8;94(2):322-30. Epub 2013 Jul 8.

TFRCA, Ashtown, Dublin, 15, Ireland; Teagasc Kinsealy Research Centre, Dublin, 17, Ireland.

Background: Variety and crop management strategies affect the content of bioactive compounds (phenolics, flavonoids and glucosinolates) in green broccoli (calabrese) types, which are cultivated during summer and autumn in temperate European climates. Sprouting broccoli types are morphologically distinct and are grown over the winter season and harvested until early spring. Thus they show considerable potential for development as an import substitution crop for growers and consumers during the 'hungry gap' of early spring. The present study investigated the effect of variety and management practices on phytochemical content in a range of sprouting broccoli varieties.

Results: Yields were significantly higher in white sprouting broccoli varieties. Levels of phenolics and flavonoids were in the range 81.64-297.65 and 16.95-104.80 mg 100 g⁻¹ fresh weight, respectively, depending on year and cultivar, and were highest in variety 'TZ 5052' in both years. In-row spacing did not affect flavonoid content. Phenolic and flavonoid content generally increased with increasing floret maturity and levels were high in edible portions of the crop. Crop wastes (leaf and flower) contained 145.9-239.3 and 21.5-116.6 mg 100 g⁻¹ fresh weight total phenolics and flavonoids, respectively, depending on cultivar, tissue and year. Climatic factors had a significant effect on phenolic and flavonoid content. Levels of total and some individual glucosinolates were higher in sprouting broccoli than in the green broccoli variety 'Ironman'.

Conclusion: Levels of total phenolics, flavonoids and glucosinolates are higher in sprouting than green broccoli types. Sprouting broccoli represents an excellent source of dietary bioactive compounds.
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http://dx.doi.org/10.1002/jsfa.6263DOI Listing
January 2014

Effect of organic, conventional and mixed cultivation practices on soil microbial community structure and nematode abundance in a cultivated onion crop.

J Sci Food Agric 2013 Dec 7;93(15):3700-9. Epub 2013 Jun 7.

Teagasc Kinsealy Research Centre, Dublin, 17, Ireland; Horticulture Development Department, TFRCA, Ashtown, Dublin, 15, Ireland.

Background: Responses of the soil microbial and nematode community to organic and conventional agricultural practices were studied using the Teagasc Kinsealy Systems Comparison trial as the experimental system. The trial is a long-term field experiment which divides conventional and organic agriculture into component pest-control and soil treatment practices. We hypothesised that management practices would affect soil ecology and used community level physiological profiles, microbial and nematode counts, and denaturing gradient gel electrophoresis (DGGE) to characterise soil microbial communities in plots used for onion (Allium cepa L.) cultivation.

Results: Microbial activity and culturable bacterial counts were significantly higher under fully organic management. Culturable fungi, actinomycete and nematode counts showed a consistent trend towards higher numbers under fully organic management but these data were not statistically significant. No differences were found in the fungal/bacterial ratio. DGGE banding patterns and sequencing of excised bands showed clear differences between treatments. Putative onion fungal pathogens were predominantly sequenced under conventional soil treatment practices whilst putative soil suppressive bacterial species were predominantly sequenced from the organic pest-control treatment plots.

Conclusion: Organic management increased microbial activity and diversity. Sequence data was indicative of differences in functional groups and warrants further investigation.
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http://dx.doi.org/10.1002/jsfa.6206DOI Listing
December 2013

Feasibility study on the use of visible-near-infrared spectroscopy for the screening of individual and total glucosinolate contents in broccoli.

J Agric Food Chem 2012 Aug 20;60(30):7352-8. Epub 2012 Jul 20.

Food Colour and Quality Laboratory, Department of Nutrition and Food Science, Facultad de Farmacia, Universidad de Sevilla , 41012 Sevilla, Spain.

The potential of visible-near-infrared spectroscopy to determine selected individual and total glucosinolates in broccoli has been evaluated. Modified partial least-squares regression was used to develop quantitative models to predict glucosinolate contents. Both the whole spectrum and different spectral regions were separately evaluated to develop the quantitative models; in all cases the best results were obtained using the near-infrared zone between 2000 and 2498 nm. These models have been externally validated for the screening of glucoraphanin, glucobrassicin, 4-methoxyglucobrassicin, neoglucobrassicin, and total glucosinolates contents. In addition, discriminant partial least-squares was used to distinguish between two possible broccoli cultivars and showed a high degree of accuracy. In the case of the qualitative analysis, best results were obtained using the whole spectrum (i.e., 400-2498 nm) with a correct classification rate of 100% in external validation being obtained.
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http://dx.doi.org/10.1021/jf3018113DOI Listing
August 2012

Using SRAM based FPGAs for power-aware high performance wireless sensor networks.

Sensors (Basel) 2012 28;12(3):2667-92. Epub 2012 Feb 28.

Centro de Electronica Industrial, Universidad Politecnica de Madrid, Madrid 28006, Spain.

While for years traditional wireless sensor nodes have been based on ultra-low power microcontrollers with sufficient but limited computing power, the complexity and number of tasks of today's applications are constantly increasing. Increasing the node duty cycle is not feasible in all cases, so in many cases more computing power is required. This extra computing power may be achieved by either more powerful microcontrollers, though more power consumption or, in general, any solution capable of accelerating task execution. At this point, the use of hardware based, and in particular FPGA solutions, might appear as a candidate technology, since though power use is higher compared with lower power devices, execution time is reduced, so energy could be reduced overall. In order to demonstrate this, an innovative WSN node architecture is proposed. This architecture is based on a high performance high capacity state-of-the-art FPGA, which combines the advantages of the intrinsic acceleration provided by the parallelism of hardware devices, the use of partial reconfiguration capabilities, as well as a careful power-aware management system, to show that energy savings for certain higher-end applications can be achieved. Finally, comprehensive tests have been done to validate the platform in terms of performance and power consumption, to proof that better energy efficiency compared to processor based solutions can be achieved, for instance, when encryption is imposed by the application requirements.
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http://dx.doi.org/10.3390/s120302667DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3376580PMC
October 2012

Patterns of pharmacological maintenance treatment in a community mental health services bipolar disorder cohort study (SIN-DEPRES).

Int J Neuropsychopharmacol 2013 Apr 27;16(3):513-23. Epub 2012 Apr 27.

Bipolar Disorder Program, Institut Clínic de Neurociencies, Hospital Clínic, IDIBAPS, University of Barcelona, CIBERSAM, Barcelona, Spain.

Maintenance therapy in bipolar disorder (BD) is usually required to prevent relapses and improve residual symptoms. Therefore, in this study, we describe patterns of pharmacological maintenance treatment and identify associated clinical features. This prospective multicentre epidemiological study recruited a cohort of 739 consecutive out-patients with clinically stable BD. Clinical stability was assessed at baseline with the Clinical Global Impression scale for BD and depressive symptoms with the Hamilton Depression Rating Scale. Psychotropic medications were classified and analysed according to their mechanism as well as use. Logistic regression models were used to examine the associations between pharmacological strategies and clinical features. Longer time since last episode [odds ratio (OR) 1.002, p < 0.0001] and family history of psychiatric disorders (OR 1.911, p = 0.028) were associated with lithium in monotherapy; manic polarity of the most recent episode (OR 3.300, p = 0.006) and longer duration of clinical stability (OR 1.009, p = 0.034) with antipsychotic in monotherapy; depressive polarity of the most recent episode (OR 2.567, p = 0.003) and bipolar II disorder diagnosis (OR 2.278, p = 0.008) with antidepressant combination; no ongoing psychiatric co-morbidity (OR 0.230, p = 0.004) with lithium and anticonvulsant; manic polarity of the most recent episode (OR 3.774, p < 0.0001) with lithium and antipsychotic; manic polarity of the most recent episode (OR 2.907, p = 0.028) with lithium, anticonvulsant and antipsychotic. The pharmacological patterns followed published recommendations, except for the excessive use of antidepressants. This study reveals clinical factors closely related to prescription patterns.
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http://dx.doi.org/10.1017/S1461145712000405DOI Listing
April 2013

Maturity stage at harvest determines the fruit quality and antioxidant potential after storage of sweet cherry cultivars.

J Agric Food Chem 2009 Apr;57(8):3240-6

Department of Applied Biology, EPSO, University Miguel Hernández, Alicante, Spain.

Eleven sweet cherry cultivars were harvested at three maturity stages (S1 to S3) based on skin color and stored at 2 degrees C for 16 days and a further period of 2 days at 20 degrees C (shelf life, SL) to analyze quality (color, total soluble solids, and total acidity) and bioactive compounds (total phenolics and anthocyanins) and their relationship to total antioxidant activity (TAA), determined in hydrophilic (H-TAA) or lipophilic (L-TAA) fraction. For all cultivars and maturity stages, the ripening process advanced during postharvest storage with increases in color intensity and decreases in acidity, as well as enhancements in phenolics, anthocyanins, and TAA in both H-TAA and L-TAA, although important differences existed among cultivars. The results showed that sweet cherry should be harvested at stage S3 (4 days later than the commercial harvest date) since after 16 days of cold storage + SL, the highest antioxidant capacity was achieved for both H-TAA and L-TAA.
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http://dx.doi.org/10.1021/jf803949kDOI Listing
April 2009

1H NMR quantitative determination of photosynthetic pigments from green beans (Phaseolus vulgaris L.).

J Agric Food Chem 2008 Jan 15;56(2):314-20. Epub 2007 Dec 15.

Equipe INRA de Gastronomie Moléculaire, UMR 214, (INRA, Institut des sciences du vivant et de l'environnement [AgroParisTech]), 16 rue Claude Bernard, 75005 Paris.

Using 1H nuclear magnetic resonance spectroscopy (1D and 2D), the two types of photosynthetic pigments (chlorophylls, their derivatives, and carotenoids) of "green beans" (immature pods of Phaseolus vulgaris L.) were analyzed. Compared to other analytical methods (light spectroscopy or chromatography), 1H NMR spectroscopy is a fast analytical way that provides more information on chlorophyll derivatives (allomers and epimers) than ultraviolet-visible spectroscopy. Moreover, it gives a large amount of data without prior chromatographic separation.
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http://dx.doi.org/10.1021/jf070277jDOI Listing
January 2008

Tools to maintain postharvest fruit and vegetable quality through the inhibition of ethylene action: a review.

Crit Rev Food Sci Nutr 2007 ;47(6):543-60

Department Food Technology, University Miguel Hernández. Ctra. Beniel km. 3.2, Orihuela Alicante, Spain.

Ethylene is a plant hormone controlling a wide range of physiological processes in plants. During postharvest storage of fruit and vegetables ethylene can induce negative effects including senescence, over-ripening, accelerated quality loss, increased fruit pathogen susceptibility, and physiological disorders, among others. Apart from the endogenous ethylene production by plant tissues, external sources of ethylene (e.g. engine exhausts, pollutants, plant, and fungi metabolism) occur along the food chain, in packages, storage chambers, during transportation, and in domestic refrigerators. Thus, it is a great goal in postharvest to avoid ethylene action. This review focuses on tools which may be used to inhibit ethylene biosynthesis/action or to remove ethylene surrounding commodities in order to avoid its detrimental effects on fruit and vegetable quality. As inhibitors of ethylene biosynthesis and action, good results have been found with polyamines and 1-methylcyclopropene (1-MCP) in terms of maintenance of fruit and vegetable quality and extension of postharvest shelf-life. As ethylene scavengers, the best results can be achieved by adsorbers combined with catalysts, either chemical or biological (biofilters).
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http://dx.doi.org/10.1080/10408390600846390DOI Listing
October 2007
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