University of Ioannina
  • Ioánnina, Greece
Recent publications
Areas of cutaneous field cancerization (CFC) occur in sun-damaged skin and are prone to skin cancer development. Actinic keratosis (AK) is the pathognomonic lesion of CFC. Therefore, the reliable and non-invasive AK burden assessment is essential to assist clinicians in delivering patient-tailored therapeutic interventions and support the objective evaluation of emerging therapeutic modalities. Herein, we introduce a system for automated AK detection in CFC areas. For the differentiation of AK from healthy skin areas and co-localized benign growths (Seborrheic Keratosis/Lentigo Solaris; SK/LS), cross-polarized digital photographs of afflicted skin surfaces were taken, and a convolutional neural network (AKCNN) whose convolution part was optimally transferred from a pre-trained VGG16 was implemented. For the detection of multifocal AK in wide skin regions, superpixels were employed to generate region patches for the subsequent evaluation. AKCNN was implemented and evaluated in 19739, 43067, and 12,205 image patches of AK, SK/LS, and healthy skin, respectively, originating from 46 patients. AKCNN performance was assessed in two ways: (a) patch classification using the macro averaged F1 score and (b) AK burden evaluation in broad skin areas using an adapted region-based F1 (aF1) score. Using raw clinical images, AKCNN exhibited a macro F1 of 0.78 at patch level and a region-based aF1 of 0.81, with good tolerance against image scaling. The proposed system efficiently uses cross-polarized clinical photography to assess the AK burden within the CFC.
The European Union has built an interdependent framework to promote sustainability transition through commitment in resource efficiency (RE) actions as echoed in the European Green Deal. Although the factors affecting firms' decision to adopt a green strategy have been extensively explored, those affecting commitment remain unexplored. Thus, we study whether commitment of European SMEs to RE actions fosters sustainability transition and, what drives such commitment. Data includes more than 37,000 European SMEs from 2013 through 2017, combined with country-specific characteristics explored via a probit model with sample selection. Findings indicate that during the study period there has been a change in the structure of incentives of the firms, as in the beginning of the period, adoption of RE actions and future engagement were considered as independent decisions. We document that commitment is driven RE enhancers such as the implementation of new technological paradigms, cooperation, and specialized business advice while resource productivity, green energy, and competitiveness further foster commitment. Findings advocate that commitment in RE actions to achieve sustainability transition is a feasible reality. Efforts of policymakers should focus on further enabling RE committed firms by reducing policy red tape.
Currently, there is no established waste management plan that includes resource recovery from used disposable nappies (DNs), apart from incineration and landfilling, which both alternatives present serious downsides. By separating the DN constituents (biodegradable, super absorbent polymer (SAP), and plastics), as proposed in the current study, valuable resources can be recovered displacing the production of fertilizers, energy from fossil-fuels, adsorption materials, and fossil-derived plastics. In this work, the techniques to achieve this recovery are presented (physicochemical pretreatment, anaerobic digestion, dark fermentation, adsorption and dissolution/precipitation), alongside experimental results for the recovered materials and the anaerobic co-digestion with expired foodstuff, indicating a maximum recovery of 1.33 mol H2/mol glucose, or 17.2 g/L volatile fatty acids (fermentation), and 14 NL CH4/Lfeed. The recovered SAP exhibited a maximum adsorption capacity to methylene blue of 1 g/g, while a mixture of recovered plastics exhibited a tensile strength of 18 MPa and a melting point of 164°C. Such a holistic approach could significantly contribute to the valorization of this kind of wastes, with the simultaneous production of valuable products and the significant reduction of the environmental impact, leading to the circular economy model transition.
We develop a theoretical framework, which facilitates the investigation of spillover effects on productive performance under the lens of path dependence, technological relatedness, and complexity. We distinguish between hierarchical structured knowledge pools and allow for the moderation role of the absorptive capacity of the examined production entities. We employ a panel dataset from country specific industrial structures of thirteen manufacturing and transportation industries in seventeen EU countries during the pre-crisis 1999–2006 period. Path dependence proves to be ubiquitous and relatedness highly influential. Absorptive capacity frames different patterns related to technological complexity and sectoral idiosyncrasies.
Background Depression and Degenerative Spine Disease (DSD) frequently co-exist. Pooled prevalence estimates of depression before and after lumbar fusion surgery has not been analyzed before. The purpose of this systematic review was to estimate the pre- and post-operative prevalence of depression in patients with DSD undergoing lumbar fusion. Methods A literature review until April 30th 2022 was performed. All studies on DSD patients undergoing lumbar spine fusion surgery with either a history of formal diagnosis of depression or a recording of depression using a validated tool were included. Patients with other psychiatric conditions or undergoing a different form of spinal surgery were excluded. Risk of bias of the included studies was evaluated using the Newcastle-Ottawa Scale. Results Fifteen (15) studies with a total of 98.375 patients met the inclusion and exclusion criteria and were included in the analysis. The prevalence estimate of depression in patients before surgery was 15,35 % (95% CI: 10,56–20,86%). In the 7 studies including patients who had undergone lumbar fusion, the pooled prevalence was estimated 11,46% (95% CI: 8,11–15,30%). Conclusion An increased prevalence of depression in patients undergoing lumbar spine fusion was noted. Given the correlation between depression and poor surgical outcomes, strategies should be identified to prevent and treat depression in these patients.
Lithium-Sulfur Batteries is promising energy storage systems due to their superior capacity and energy density. A promising solution for drawbacks such as low sulfur utilization and cycling stability is the use of porous carbon as sulfur carrier. On the other hand, cyclic economy and green ideas is of great importance nowadays. Carbon-sulfur cathodes from waste valorization, abundant, and low-cost precursors is an attractive approach. Herein, an activated carbon (AC-Poc) derived from “Posidonia oceanica” sea-waste, was studied as a matrix for the development of a novel carbon–sulfur composite cathode (AC-Poc/S) for the first time. AC-Poc can be used as an effective sulfur host, due to its high specific BET surface area (1264 m²∙g⁻¹) hierarchical porous structure, and total pore volume 0.81 cm³∙g⁻¹. AC-Poc/S reveals an outstanding initial capacity of 1539 mAh∙g⁻¹ as cathode material, combined with high reversible capacity at 0.2 C. Furthermore, the discharge capacity of 390 mAh/g at 2 C reveals good rate capability, even at increased C-rate. AC-Poc/S composite exhibits excellent sulfur utilization (92 %) alongside with sufficiently well electrochemical performance. These results combined with the easy synthesis method of the activated carbon from an abundant and low-cost precursor make AC-Poc/S a very promising material for LSBs applications.
Dexamethasone (DEX) is a synthetic steroid hormone that, owing to its endocrine disruptive effects, has the potential to be detrimental. DEX must be successfully removed during drinking water treatment to preserve human and aquatic animals' health. This study investigates the thermally activated persulfate (TAP) process for the efficient decomposition of DEX. The effectiveness of several variables such as pH, persulfate dose, DEX concentration, reaction temperature, and water matrices was studied. Removal of 500 μg/L DEX reached 100 % by using 100 mg/L of persulfate in ultrapure water (pH = 7) at 50 °C, within 45 min of reaction time. DEX removal usually followed exponential decay. The removal efficiency of DEX in the TAP process was pH-dependent, as 61 % of DEX was removed at a pH value of 9. In contrast, complete degradation was achieved under acidic and near neutral conditions. Moreover, environmentally relevant degradation experiments showed that, in principle, the presence of bicarbonate ions and humic acid had a negative effect on DEX decomposition by reducing the percentage removal of the target compound by >50 %. Six transformation products derived from DEX oxidation were identified using high-resolution LC-MS. TAP system could be proposed as a promising application for removing steroid hormones n real water matrices after process optimization in real conditions.
Introduction Ovarian cancer is the most lethal gynecologic malignancy. Although treatment with hyperthermic intraperitoneal chemotherapy (HIPEC) has shown promising results, its role remains elusive. The aim of this study was to assess the comprehensive randomized evidence for the use versus non-use of HIPEC in primary and recurrent ovarian cancer. Materials and methods The Medline, Embase and Cochrane databases, as well as the European Society for Medical Oncology (ESMO) and American Society of Clinical Oncology (ASCO) conference abstracts of the last 5 years, were scrutinized in January 2022 for randomized, controlled trials that studied the use of HIPEC in ovarian cancer. Overall survival (OS), disease-free survival (DFS) and progression-free survival, as well as post-operative morbidity were the outcomes of interest. This study was reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) reporting guideline. Results Six randomized, controlled trials that randomized 737 patients were included in our analysis; of these, four studies (519 patients) were in primary and two (218 patients) in recurrent settings. In primary ovarian cancer, the combination of HIPEC with interval cytoreductive surgery (CRS) and neoadjuvant chemotherapy significantly improved the 5-year OS [393 patients, risk ratio (RR) = 0.77; 95% confidence interval (CI) 0.67-0.90; P value = 0.001] and DFS (hazard ratio = 0.60; 95% CI 0.41-0.87; P value = 0.008) compared with standard treatment alone. In the absence of neoadjuvant chemotherapy, the use of HIPEC + CRS was not associated with any survival advantage (126 patients, 4-year OS, RR = 0.93; 95% CI 0.57-1.53; P value = 0.781), but the sample size was smaller in this subset. Use of HIPEC in recurrent ovarian cancer did not provide any survival advantage (5-year OS: 218 patients, RR = 0.85; 95% CI 0.45-1.62; P value = 0.626). The risk for grade ≥3 adverse events was similar between HIPEC and no HIPEC (RR = 1.08; 95% CI 0.98-1.18; P value = 0.109). Conclusions In primary ovarian cancer the combination of HIPEC with interval CRS and neoadjuvant chemotherapy is a safe option that significantly improved 5-year OS and DFS. Its use in other settings should continue to be considered investigational.
The present study is exploring a pathway connecting emotion regulation with academic progress. Specifically, the pattern through which emotion regulation is implicated in learning and academic progress through academic emotions and sense of coherence. This cross-sectional study involves of 406 undergraduate social science students recruited from a university in western Greece. Participants anonymously and voluntarily completed a number of self-report measures. The Emotion Regulation Questionnaire, the Sense of Coherence Scale, the Student Experience of Emotions Inventory and the Approaches to Learning and Studying Inventory, were used to measure emotion regulation, sense of coherence, academic emotional experiences and approaches to learning, respectively. Α four-stage model was tested with structural equation modelling techniques. In particular, the model examined associations between emotion regulation, sense of coherence, academic emotions, approaches to learning and academic progress. The analysis revealed pathways through which these associations appear to be maintained and driven by emotion regulation. Emotion regulation is associated with students’ academic emotions that in turn are linked with approaches to learning and academic progress. Both positive and negative emotions appear to play a role in enabling an adaptive approach to learning. Moreover, sense of coherence may serve as an important meta-cognitive factor enabling students to approach the learning process more effectively. The findings are discussed in the light of the recent literature.
We investigate the geometry and topology of submanifolds under a sharp pinching condition involving extrinsic invariants like the mean curvature and the length of the second fundamental form. Homology vanishing results are given that strengthen and sharpen previous ones. In addition, an integral bound is provided for the Bochner operator of compact Euclidean submanifolds in terms of the Betti numbers.
  • Kleopatra BitzogliKleopatra Bitzogli
  • Edison JahajEdison Jahaj
  • Athanasios-Dimitrios BakasisAthanasios-Dimitrios Bakasis
  • [...]
  • Panayiotis G VlachoyiannopoulosPanayiotis G Vlachoyiannopoulos
Objectives: To assess the prevalence of autoantibodies (AAbs) in mechanically ventilated COVID-19 patients and to investigate whether AAbs influence the clinical outcome. Methods: Serum samples were drawn within the first 48 hours upon admission to the intensive care unit (ICU) from 217 consecutive patients, from January 1st, 2021, to May 10th, 2021, and investigated for the presence of AAbs using conventional techniques. Serum samples (n=117) of age- and sex-matched healthy individuals collected before COVID-19 pandemic were used as controls. Results: COVID-19 patients in the ICU had more commonly AAbs compared to age- and sex-matched controls (174/217, 80.2% vs. 73/117, 62.4%, p<0.001). Patients expressed more frequently ANAs (48.4% vs. 21.4%, p<0.001), anti-dsDNA (5.1% vs. 0%, p=0.01), anti-CCP (8.3% vs. 1.7%, p=0.014) and anti-CL IgM AAbs (21.7% vs. 9.4%, p=0.005) than controls, respectively. Simultaneous reactivity against at least three autoantigens, occurred in 144 out of 174 (82.8%) patients. The two groups did not differ in terms of clinicoepidemiologic characteristics or the mortality ratio within the ICU. Patients who died compared to convalescents were older, had higher ferritin, D-dimers levels, APACHE II score, lower oxygen saturation, higher prevalence of comorbidities and cognitive dysfunction. However, AAbs were not found to correlate with the clinical outcome. Conclusions: Patients with severe COVID-19 express AAbs more commonly compared to controls. No correlation was found between AAbs and disease outcome.
During first outburst of COVID‐19, several strategies had been applied for surgical oncology patients to minimize COVID‐19 transmission. COVID‐19 infection seemed to compromise survival and major complication rates of surgical oncology patients. However, survival, tumor progression and recurrence rates of surgical oncology patients were associated to the consequences of COVID‐19 pandemic on their management. In addition, the severity of COVID‐19 infections has been downgraded. Therefore, management of surgical oncology patients should be reconsidered.
Personality variables contribute to the development of passion for studies leading undergraduates to different affective experiences. Academic hardiness, an affective personality trait, may have effect on undergraduates’ passion for studies. The purpose of the study (which uses a quantitative methodological approach) was twofold: (a) to examine the psychometric properties of Passion scale in Greek undergraduates and (b) to investigate the role of Academic Hardiness 3Cs in the Harmonious (HP) and Obsessive (OP) passion. A convenience sample of 293 undergraduates completed the following scales: (a) Passion scale, (b) Oxford Happiness Questionnaire, (c) The Positive and Negative Affect schedule, and (d) The revised Academic Hardiness scale. Initially, results from exploratory and confirmatory factor analyses provided support for the two-factor passion scale. Moreover, results from SEM analyses revealed that control and challenge were positively related to HP, whereas commitment was positively related to both HP and OP. A negative relationship was found between control and OP. OP was positively related with negative affect, which, in turn, was negatively related with undergraduates’ happiness. On the contrary, HP was positively related with positive affect, which, in turn, was positively related with happiness. Findings of the study are discussed, focusing on the adaptive nature of academic hardiness and harmonious passion in academic settings.
We introduce and study a new class of nonlinear coupled Hilfer differential equations with nonlocal boundary conditions involving Riemann–Liouville and Hadamard-type iterated fractional integral operators. By applying the Leray–Schauder alternative and Krasnosel’skiĭ’s fixed point theorem, two results presenting different criteria for the existence of solutions to the given problem are proven. The third result provides a sufficient criterion for the existence of a unique solution to the problem at hand. Numerical examples are constructed to demonstrate the application of the results obtained. Two graphs show asymmetric solutions when a Hilfer parameter is varied. The work presented in this paper is novel and significantly enriches the literature on the topic.
Gender issues, and gender equality in particular, can be regarded as cross-cutting issues in the implementation of the Sustainable Development Goals (SDGs), even though it is unclear how they are taken into account. This study addresses this information gap by performing an assessment of the emphasis on gender issues across all the other 16 SDGs, in addition to SDG5, through a literature review and case study analysis, the basis for the newly developed framework, highlighting specific actions associated to each SDG. The 13 countries addressed in the 16 case studies include China, India, or Australia and illustrate the inclusion of SDG5 into the SDGs. Using an SDG matrix, the SDG targets are analysed. Those where an emphasis on gender equality is important in allowing them to be achieved are listed. The novelty of our approach resides in offering an in-depth analysis of how gender issues interact with the other SDGs, proposing a new analysis framework clearly identifying SDGs 1, 4, 11, 12, 14 and 16 demanding further attention for successful SD gender implementation and illustrating specific areas where further actions may be necessary, which may be used by policy-makers, raising further awareness on gender equality contribution to achieve the SDGs. A set of recommendations aimed at placing gender matters more centrally in the SDGs delivery are presented as a final contribution. These focus on the need for greater awareness and attention to good practices, to achieve successful implementation initiatives. Supplementary information: The online version contains supplementary material available at 10.1007/s10668-022-02656-1.
New particle reinforced aluminum matrix composites with the addition of refractory High Entropy Alloy, MoTaNbVW, fabricated via powder metallurgy process were assessed for their properties. Basic mechanical properties (modulus of elasticity, hardness) for the aluminum matrix, the pure aluminum and the reinforcement phase were assessed by means of dynamic nano-indentation technique. Nano-indentation based creep response was also evaluated in these three areas of interest. Hardness shows an increase with the addition of the particulates and so does the elastic moduli and the ratio of the energy absorbed in the elastic region. The creep response was approached in terms of dislocation mobility and critical volume for their nucleation. The produced Al–HEA composites were also studied for their sliding wear behavior and showed that with the increase in percentage of RHEA particulates the wear resistance increases. Microstructural considerations, wear track morphologies, and debris characteristics were used for the assessment of the involved wear mechanisms.
Neuronal plasma membrane proteins are essential for integrating cell extrinsic and cell intrinsic signals to orchestrate neuronal differentiation, growth and plasticity in the developing and adult nervous system. Here, we shed light on the family of plasma membrane proteins phospholipid phosphatase-related proteins (PLPPRs) (alternative name, PRGs; plasticity-related genes) that fine-tune neuronal growth and synaptic transmission in the central nervous system. Several studies uncovered essential functions of PLPPRs in filopodia formation, axon guidance and branching during nervous system development and regeneration, as well as in the control of dendritic spine number and excitability. Loss of PLPPR expression in knockout mice increases susceptibility to seizures, and results in defects in sensory information processing, development of psychiatric disorders, stress-related behaviors and abnormal social interaction. However, the exact function of PLPPRs in the context of neurological diseases is largely unclear. Although initially described as active lysophosphatidic acid (LPA) ecto-phosphatases that regulate the levels of this extracellular bioactive lipid, PLPPRs lack catalytic activity against LPA. Nevertheless, they emerge as atypical LPA modulators, by regulating LPA mediated signaling processes. In this review, we summarize the effects of this protein family on cellular morphology, generation and maintenance of cellular protrusions as well as highlight their known neuronal functions and phenotypes of KO mice. We discuss the molecular mechanisms of PLPPRs including the deployment of phospholipids, actin-cytoskeleton and small GTPase signaling pathways, with a focus on identifying gaps in our knowledge to stimulate interest in this understudied protein family.
Introduction Comprehensive characteristics of the glycemic profile for prediabetes derived by continuous glucose monitoring (CGM) are unknown. We evaluate the difference of CGM profiles between individuals with prediabetes and normoglycemic individuals, including the response to oral glucose tolerance test (OGTT). Methods Individuals with prediabetes matched for age, sex, and BMI with normoglycemic individuals were instructed to use professional CGM for 1 week. OGTT was performed on the second day. The primary outcomes were percentages of glucose readings time below range (TBR): <54 or <70 mg/dL, time in range (TIR): 70 to 180 mg/dL, and time above range (TAR): >180 or >250 mg/dL. Area under the curve (AUC) was calculated following the OGTT. Glucose variability was depicted by coefficient of variation (CV), SD, and mean amplitude of glucose excursion (MAGE). Wilcoxon sign-ranked test, McNemar mid P-test and linear regression models were employed. Results In all, 36 participants (median age 51 years; median body mass index [BMI] = 26.4 kg/m ² ) formed 18 matched pairs. Statistically significant differences were observed for 24-hour time in range (TIR; median 98.5% vs. 99.9%, P = .013), time above range (TAR) >180 mg/dl (0.4% vs. 0%, P = .0062), and 24-hour mean interstitial glucose (113.8 vs. 108.8 mg/dL, P = .0038) between people with prediabetes compared to normoglycemic participants. Statistically significant differences favoring the normoglycemic group were found for glycemic variability indexes (median CV 15.2% vs. 11.9%, P = .0156; median MAGE 44.3 vs. 33.3 mg/dL, P = 0.0043). Following OGTT, the AUC was significantly lower in normoglycemic compared to the prediabetes group (median 18615.3 vs. 16370.0, P = .0347 for total and 4666.5 vs. 2792.7, P = .0429 for incremental 2-hour post OGTT). Conclusion Individuals with prediabetes have different glucose profiles compared to normoglycemic individuals. CGM might be helpful in individuals with borderline glucose values for a more accurate reclassification.
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