Cluster characteristics of embodied carbon emissions in the international trade of metals: a sectoral-regional modeling perspective.

To be able to formulate any plausible strategies for sustainability, it is critical to establish a clear understanding of the international metals trade system complexity and the consequences in emergent embodied carbon emissions (ECE). For this purpose, we proposed a two-layer framework based on the multi-regional input-output model for calculating ECE: the intermediate production and final consumption trade layers. The proposed framework model combines the construction of a clustering index system and conducting cluster analysis from both the regional and sectoral dimensions. It is shown that developed regions transfer carbon emissions to developing regions via metals trading. This happens especially in the intermediate production stage at a level of 1.35 times higher than the final consumption stage. Furthermore, the metal sector suffers the most from carbon transfers from manufacturing, with the most carbon emissions transferred to mining. Moreover, considering environmental and technological factors to cluster regions and sectors into four and three clusters. China and Russia are in a cluster under greater pressure to reduce emissions as compared to other nations. Also, the construction and manufacturing form a cluster that their reduction of carbon emissions will effectively reduce the ECE of the metal sector. As a result, policy implications for reducing carbon emissions are investigated for each cluster in the international trade of metals contributing to the ultimate goal of global sustainable development.

Towards the Development of a System Dynamics Model for the Prediction of Lower Extremity Injuries.

Acute noncontact Lower Extremity (LE) injuries constitute a significant problem in team sports. Despite extensive research, current knowledge on the risk factors of LE injuries is limited to static simplistic models of instantaneous cause and effect relationships ignoring the time dimension and the embedded complexity of LE injuries. Even though complex systems approaches have been used in various cases to improve policy and intervention effectiveness, there is limited research on predicting and managing LE injuries. This creates an opportunity to fill the gap in the current literature by applying the System Dynamics (SD) methodology to model LE injuries. The proposed approach allows for synthesizing risk factors and examining their interaction. This paper makes the first step towards such an approach by developing a causal loop model revealing the etiology of LE injuries. A causal loop model for LE injuries is developed via an extensive literature review and brainstorming with experts. In contrast to the traditional static approaches, the proposed model reveals some of the complexity and nonlinear relationships of the various sports injury risk factors. The derived causal loop model may then be used to quantify these interactions and develop a simulation model. This will be achieved by operationalizing and incorporating the main risk factors that impact LE injuries in an integrated sports injury prediction model. In this way, plausible strategies for preventing LE injuries can be tested prior implementation and thereby achieve optimization of intervention programs.

Conceptual understanding in science learning and the role of four psychometric variables: a person-centered approach.

The present study investigated conceptual understanding in learning science in relation to four cognitive variables: logical thinking, field-dependence/field-independence, and divergent and convergent thinking. The participants were fifth- and sixth-grade elementary school pupils involved in different mental tasks, where they had to describe and interpret phenomena related to changes of matter. This brief report presents data from the students' understanding of evaporation, and the method of analysis, a person-centered approach, is explicated. Latent class analysis (LCA) was applied to reveal distinct clusters of cases sharing similar patterns of responses. The use of LCA aligns with theoretical conjectures related to a stepwise conceptual change process, and the hypothetical steps correspond to the identified discrete latent classes (LCs). Subsequently, the LCs were associated with the four cognitive variables as covariates, thus providing empirical evidence for the role of the above-mentioned individual differences in children's learning in sciences. Methodological issues and theoretical implications are discussed.

Determining the Nutrient Content of Hydroponically-Cultivated Microgreens with Immersible Silicon Photonic Sensors: A Preliminary Feasibility Study.

Microgreens have gained attention for their exceptional culinary characteristics and high nutritional value. The present study focused on a novel approach for investigating the easy extraction of plant samples and the utilization of immersible silicon photonic sensors to determine, on the spot, the nutrient content of microgreens and their optimum time of harvest. For the first time, it was examined how these novel sensors can capture time-shifting spectra caused by the molecules' dynamic adhesion onto the sensor surface. The experiment involved four types of microgreens (three types of basil and broccoli) grown in a do-it-yourself hydroponic installation. The sensors successfully distinguished between different plant types, showcasing their discriminative capabilities. To determine the optimum harvest time, this study compared the sensor data with results obtained through standard analytical methods. Specifically, the total phenolic content and antioxidant activity of two basil varieties were juxtaposed with the sensor data, and this study concluded that the ideal harvest time for basil microgreens was 14 days after planting. This finding highlights the potential of the immersible silicon photonic sensors for potentially replacing time-consuming analytical techniques. By concentrating on obtaining plant extracts, capturing time-shifting spectra, and assessing sensor reusability, this research paves the way for future advancements in urban farming.

A Punctuated Equilibrium Model for Conceptual Change and the Role of Neo-Piagetian Constructs: Methodology, Empirical Evidence, and Theoretical Perspectives.

This study explores the hypothesis related to a punctuated equilibrium process for conceptual change in science learning, in conjunction with the effects of four cognitive variables: logical thinking and field-dependence/field-independence, divergent and convergent thinking. The participants were fifth and sixth-grade elementary school pupils involved in different tasks, who were asked to describe and interpret chemical phenomena. Latent Class Analysis (LCA) was applied to children's responses, and three clusters or latent classes (LC1, LC2, and LC3) were identified, corresponding to hierarchical levels of conceptual understanding. The ensued LCs align with the theoretical conjecture about a stepwise conceptual change process that might go through various stages or mental models. These levels or stages are conceptualized as attractors, and changes between them were modeled as cusp catastrophes using the four cognitive variables as controls. The analysis showed that logical thinking acted as asymmetry factor, while field-dependence/field-independence, divergent and convergent thinking acted as bifurcation variables. This analytic approach presents a methodology for investigating conceptual change as a punctuated equilibrium process that adds to the nonlinear dynamical research with important implications for theories of conceptual change in science education and psychology as well. Discussion on the new perspective embracing the meta-theoretical framework of complex adaptive systems (CDS) is provided.

Toughening Effect of 2,5-Furandicaboxylate Polyesters on Polylactide-Based Renewable Fibers.

This work presents the successful preparation and characterization of polylactide/poly(propylene 2,5-furandicarboxylate) (PLA/PPF) and polylactide/poly(butylene 2,5-furandicarboxylate) (PLA/PBF) blends in form of bulk and fiber samples and investigates the influence of poly(alkylene furanoate) (PAF) concentration (0 to 20 wt%) and compatibilization on the physical, thermal, and mechanical properties. Both blend types, although immiscible, are successfully compatibilized by Joncryl (J), which improves the interfacial adhesion and reduces the size of PPF and PBF domains. Mechanical tests on bulk samples show that only PBF is able to effectively toughen PLA, as PLA/PBF blends with 5-10 wt% PBF showed a distinct yield point, remarkable necking propagation, and increased strain at break (up to 55%), while PPF did not show significant plasticizing effects. The toughening ability of PBF is attributed to its lower glass transition temperature and greater toughness than PPF. For fiber samples, increasing the PPF and PBF amount improves the elastic modulus and mechanical strength, particularly for PBF-containing fibers collected at higher take-up speeds. Remarkably, in fiber samples, plasticizing effects are observed for both PPF and PBF, with significantly higher strain at break values compared to neat PLA (up to 455%), likely due to a further microstructural homogenization, enhanced compatibility, and load transfer between PLA and PAF phases following the fiber spinning process. SEM analysis confirms the deformation of PPF domains, which is probably due to a "plastic-rubber" transition during tensile testing. The orientation and possible crystallization of PPF and PBF domains contribute to increased tensile strength and elastic modulus. This work showcases the potential of PPF and PBF in tailoring the thermo-mechanical properties of PLA in both bulk and fiber forms, expanding their applications in the packaging and textile industry.

Effect of Monomer Type on the Synthesis and Properties of Poly(Ethylene Furanoate).

This work aimed to produce bio-based poly(ethylene furanoate) (PEF) with a high molecular weight using 2,5-furan dicarboxylic acid (FDCA) or its derivative dimethyl 2,5-furan dicarboxylate (DMFD), targeting food packaging applications. The effect of monomer type, molar ratios, catalyst, polycondensation time, and temperature on synthesized samples' intrinsic viscosities and color intensity was evaluated. It was found that FDCA is more effective than DMFD in producing PEF with higher molecular weight. A sum of complementary techniques was employed to study the structure-properties relationships of the prepared PEF samples, both in amorphous and semicrystalline states. The amorphous samples exhibited an increase in glass transition temperature of 82-87 °C, and annealed samples displayed a decrease in crystallinity with increasing intrinsic viscosity, as analyzed by differential scanning calorimetry and X-ray diffraction. Dielectric spectroscopy showed moderate local and segmental dynamics and high ionic conductivity for the 2,5-FDCA-based samples. The spherulite size and nuclei density of samples improved with increased melt crystallization and viscosity, respectively. The hydrophilicity and oxygen permeability of the samples were reduced with increased rigidity and molecular weight. The nanoindentation test showed that the hardness and elastic modulus of amorphous and annealed samples is higher at low viscosities due to high intermolecular interactions and degree of crystallinity.

Recent Advances in the Investigation of Poly(lactic acid) (PLA) Nanocomposites: Incorporation of Various Nanofillers and their Properties and Applications.

Poly(lactic acid) (PLA) is considered the most promising biobased substitute for fossil-derived polymers due to its compostability, biocompatibility, renewability, and good thermomechanical properties. However, PLA suffers from several shortcomings, such as low heat distortion temperature, thermal resistance, and rate of crystallization, whereas some other specific properties, i.e., flame retardancy, anti-UV, antibacterial or barrier properties, antistatic to conductive electrical characteristics, etc., are required by different end-use sectors. The addition of different nanofillers represents an attractive way to develop and enhance the properties of neat PLA. Numerous nanofillers with different architectures and properties have been investigated, with satisfactory achievements, in the design of PLA nanocomposites. This review paper overviews the current advances in the synthetic routes of PLA nanocomposites, the imparted properties of each nano-additive, as well as the numerous applications of PLA nanocomposites in various industrial fields.

Neo-Piagetian Predictors of Students' Performance in Science Learning: Evidence from Primary Education.

This study explores primary school pupils' knowledge recall and interpretation skills regarding chemical and physical phenomena, in relation to three psychometric variables: logical thinking, field dependence/field independence, and divergent thinking. The participants (N = 375) were in the fifth and sixth grades (aged 11-12) taking an introductory course in science, and they were involved in three tasks related to combustion, dissolution, and mixture separation. The pupils had to complete an instrument, in which they were asked to describe and interpret the phenomena involved in the tasks. Two achievement variables were recorded separately, one relating to knowledge recall and the other to the interpretation of the phenomena. In addition, the participants completed the corresponding psychometric tests. Correlational and multiple linear regression analysis showed that the dependent measures were associated with the cognitive variables, while path and mediation analysis showed the direct and indirect effects of the neo-Piagetian constructs on the dimensions of knowledge and interpretations. The main implications of the findings are theoretical and concern the role of the operationalized mental resources in learning the specific subject matter. Moreover, the results inform teaching practices and curricula designs, and they point out the learning difficulties ascending from the individual differences under study. Further discussion on conceptual change is provided.

Blending PLA with Polyesters Based on 2,5-Furan Dicarboxylic Acid: Evaluation of Physicochemical and Nanomechanical Properties.

Poly(lactic acid) (PLA) is a readily available, compostable biobased polyester with high strength and toughness, and it is excellent for 3D printing applications. Polymer blending is an economic and easy way to improve its properties, such as its slow degradation and crystallization rates and its small elongation, and thus, make it more versatile. In this work, the effects of different 2,5-furan dicarboxylic acid (FDCA)-based polyesters on the physicochemical and mechanical properties of PLA were studied. Poly(butylene furan 2,5-dicarboxylate) (PBF) and its copolymers with poly(butylene adipate) (PBAd) were synthesized in various comonomer ratios and were blended with 70 wt% PLA using melt compounding. The thermal, morphological and mechanical properties of the blends are investigated. All blends were immiscible, and the presence of the dispersed phases improved the crystallization ability of PLA. Mechanical testing revealed the plasticization of PLA after blending, and a small but measurable mass loss after burying in soil for 7 months. Reactive blending was evaluated as a compatibilizer-free method to improve miscibility, and it was found that when the thermal stability of the blend components allowed it, some transesterification reactions occurred between the PLA matrix and the FDCA-based dispersed phase after 20 min at 250 °C.

Investigation of Molecular Weight, Polymer Concentration and Process Parameters Factors on the Sustained Release of the Anti-Multiple-Sclerosis Agent Teriflunomide from Poly(ε-caprolactone) Electrospun Nanofibrous Matrices.

In the current work, a series of PCL polyesters with different molecular weights was synthesized and used for the fabrication of nanofibrous patches via electrospinning, as sustained release matrices for leflunomide's active metabolite, teriflunomide (TFL). The electrospinning conditions for each sample were optimized and it was found that only one material with high Mn (71,000) was able to produce structures with distinct fibers devoid of the presence of beads. The successful preparation of the fibers was determined by scanning electron microscopy (SEM).TFL (10, 20 and 30 wt%) in three different concentrations was incorporated into the prepared nanofibers, which were used in in vitro drug release experiments. The drug-loaded nanofibrous formulations were further characterized by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and powder X-ray diffractometry (XRD).It was found that TFL was incorporated in an amorphous form inside the polymeric nanofibers and that significant molecular interactions were formed between the drug and the polyester. Additionally, in vitro dissolution studies showed that the PCL/TFL-loaded nanofibers exhibit a biphasic release profile, having an initial burst release phase, followed by a sustained release until 250 h. Finally, a kinetic analysis of the obtained profiles revealed that the drug release was directly dependent on the amount TFL incorporated into the nanofibers.

Can thromboprophylaxis build a link for cancer patients undergoing surgical and/or chemotherapy treatment? The MeTHOS cohort study.

BACKGROUND: Patients with active cancer have a 4-sevenfold increased risk for venous thromboembolism (VTE) especially during systematic anticancer treatment. Simultaneously, surgery is an additional risk factor. METHODS: The Metaxas's Hospital THromboprophylaxis program in Oncological & Surgical Patients (MeTHOS) is a prospective, phase IV, observational, non-interventional cohort study, aiming to record the thromboprophylaxis practice patterns in high-risk active cancer patients undergoing surgical and/or chemotherapy treatment. RESULTS: We are reporting results from 291 ambulatory patients (median age: 67 years, Q1-Q3: 59-73 years, 54.6% males) who received anti-neoplastic treatment and administered thromboprophylaxis. 59.8% had cardiovascular disease (mostly hypertension), 76.6% were reported as having at least one comorbidity, while 27.5% and 15.8% accumulated two and three comorbidities, respectively. 94.9% of the patients were receiving highly thrombogenic agents such as platinum-based agents, 5-FU, immunotherapy, antiangiogenics/anti-VEGF, or erythropoietin. 26.5% of the patients were initially surgically treated. In terms of anticoagulation, all patients were treated with tinzaparin (fixed dose, 10,000 Anti-Xa IU, OD). The median anticoagulation duration was 6.2 months. Six thrombotic events were observed (2.06%, 95% CI: 0.76-4.43%): 5 were DVT, and one PE. With respect to safety, 7 bleeding events occurred (2.6%, 95% CI: 1.0-5.3%); 6 of them were minor. CONCLUSIONS: Thromboprophylaxis with LMWH in patients with active cancer and high thrombotic burden was safe and effective. Intermediate dose of tinzaparin seems to be an appropriate agent for cancer-associated thromboprophylaxis management. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov: NCT04248348.

Synthesis and Photolytic Assessment of Nitroindolinyl-Caged Calcium Ion Chelators.

Neuroactive amino acids derivatised at their carboxylate groups with a photolabile nitroindolinyl group are highly effective reagents for the sub-µs release of neuroactive amino acids in physiological solutions. However, the same does not apply in the case of calcium ion chelators. In this study, nitroindolinyl-caged BAPTA is found to be completely photostable, whereas nitroindolinyl-caged EDTA photolyses only when saturated with calcium ions.

Evaluating the Effects of Match-Induced Fatigue on Landing Ability; the Case of the Basketball Game.

This paper examines the effect of match-induced fatigue on lower limb biomechanics, in the case of a basketball game. For this purpose, sixteen male basketball athletes, ages 18 to 22, performed a jump-landing task prior and post a recreational basketball game. The Landing Error Scoring System (LESS) was used to examine the biomechanics of landing. The Vertical jump (VJ) and the Borg Rating of Perceived Exertion (RPE) scale pre- and post-game were employed to assess the level of fatigue induced by the basketball game. In order to compare pre and post measurements, t-tests for dependent samples were used. The performance of the VJ test post-game was found to be significantly lower (t (15) = 3.83, p = 0.002) showing a large effect (Cohen's d = 0.9) compared to pre-game measurements. Further, the LESS scores were significantly (t (15) = 2.33, p = 0.034) higher post-game with a medium effect (d = 0.5). The differences in LESS scores were due to errors in the landing technique which is bound to be influenced by biomechanics. Moreover, the Borg RPE scale was found to be significantly higher (t (15) = 10.77, p < 0.001) postgame showing a very large effect (d =2.6). It is important to note, that these significant differences occurred with a merely medium level of fatigue (6.6 ± 0.3 pre-game vs 11.9 ± 1.0 post-game). The results of this study would be of great benefit to sports science teams and coaches for formulating effective strategies to improve athletes' performance and reduce the likelihood of injury.

Assessing organizational culture in public mental healthcare service organizations.

PURPOSE: The purpose of this paper is to investigate aspects of organizational culture among the nursing staff of public mental health services organizations in Cyprus. Specifically, highlights are provided of possible differences on the attitudes of nurses regarding actual and desired aspects of organizational culture with respect to demographic characteristics such as gender, years of service and experience. DESIGN/METHODOLOGY/APPROACH: A descriptive explanatory type survey study was conducted in all public mental health services organizations of Cyprus. Specifically, a questionnaire was given to a representative sample of the nursing population, and data were collected and analyzed. The survey questionnaire was based on the organizational culture profile (OCP) methodology. Statistical analysis was carried out using correlational analysis, t-tests and analysis of variance (ANOVA). FINDINGS: Results showed that there are significant discrepancies between the actual organizational culture and what is desired by staff members of public mental health services organizations in Cyprus. Further, significant differences are identified between actual and desired organizational culture moderated by the type of work, which is determined by the workplace. ORIGINALITY/VALUE: Even though, organizational culture is a major research topic little has been done in the context of public mental healthcare organizations. Further, for the case of Cyprus, it is the first time that such a study is carried out. The results presented in this paper may provide the foundation for measures to be taken for improving the existing operation of public mental healthcare organizations.

An overview of current results with the vincristine-irinotecan-temozolomide combination with or without bevacizumab in pediatric, adolescence and adult solid tumors.

Malignant tumors in young patients present a significant therapeutic challenge for physicians, partially due to their rarity and a relative lack of data, at least compared to adult tumors. As a result, there is an urgent need to explore new possible therapeutic regimens, either by introducing novel agents or by exploring combinations of existing agents. Vincristine, Temozolomide and Irinotecan are chemotherapeutic drugs which have emerged over the last six decades as monotherapy or as part of therapeutic regimens in various solid tumors. Combining these agents can yield strong synergistic effects, as suggested by preclinical data and results from clinical trials. Furthermore, adding novel molecules, such as anti-VEGF factor Bevacizumab to the aforementioned regimens, has shown efficacy in a limited number of trials, which are thoroughly analyzed throughout this review. Data presented throughout this paper suggest that VIT(b) regimen should be further explored in solid tumors in pediatric and adolescent patients.

Identifying SARS-CoV-2 antiviral compounds by screening for small molecule inhibitors of Nsp5 main protease.

The coronavirus 2019 (COVID-19) pandemic, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), spread around the world with unprecedented health and socio-economic effects for the global population. While different vaccines are now being made available, very few antiviral drugs have been approved. The main viral protease (nsp5) of SARS-CoV-2 provides an excellent target for antivirals, due to its essential and conserved function in the viral replication cycle. We have expressed, purified and developed assays for nsp5 protease activity. We screened the nsp5 protease against a custom chemical library of over 5000 characterised pharmaceuticals. We identified calpain inhibitor I and three different peptidyl fluoromethylketones (FMK) as inhibitors of nsp5 activity in vitro, with IC50 values in the low micromolar range. By altering the sequence of our peptidomimetic FMK inhibitors to better mimic the substrate sequence of nsp5, we generated an inhibitor with a subnanomolar IC50. Calpain inhibitor I inhibited viral infection in monkey-derived Vero E6 cells, with an EC50 in the low micromolar range. The most potent and commercially available peptidyl-FMK compound inhibited viral growth in Vero E6 cells to some extent, while our custom peptidyl FMK inhibitor offered a marked antiviral improvement.

An improved method for the incorporation of fluoromethyl ketones into solid phase peptide synthesis techniques.

An improved and expedient technique for the synthesis of peptidyl-fluoromethyl ketones is described. The methodology is based on prior coupling of an aspartate fluoromethyl ketone to a linker and mounting it onto resin-bound methylbenzhydrylamine hydrochloride. Subsequently, by utilising standard Fmoc peptide procedures, a number of short Z-protected peptides were synthesised and assessed as possible inhibitors of the main protease from SARS-CoV-2 (3CLpro).

Nonlinear Dynamic Effects of Convergent and Divergent Thinking in the Conceptual Change Process: Empirical Evidence from Primary Education.

The present study explores the role of convergent and divergent thinking in learning sciences from the nonlinear dynamical system (NDS) perspective. The participants (N=375) were fifth and sixth graders, aged 11-12, who were taking an introductory course in science. Students' understanding of physical phenomena, such as melting, boiling and evaporation was investigated as a function of four neo-Piagetian constructs via the difference-equation cusp catastrophe model. The nonlinear models where logical thinking acted as the asymmetry factor and field dependence/ independence, convergent thinking and divergent thinking acted as bifurcation factors, were superior, explaining 43-44% of the variance, whereas their linear alternatives explained 0-18%. Empirical evidence regarding the role of the above neo-Piagetian constructs at these early ages is reported for the first time and contributes to theory development within the NDS framework. Further, discussion about the significance of the findings is provided.

CuO/PMMA Polymer Nanocomposites as Novel Resist Materials for E-Beam Lithography.

Polymer nanocomposites have emerged as a new powerful class of materials because of their versatility, adaptability and wide applicability to a variety of fields. In this work, a facile and cost-effective method to develop poly(methyl methacrylate) (PMMA)-based polymer nanocomposites with copper oxide (CuO) nanofillers is presented. The study concentrates on finding an appropriate methodology to realize CuO/PMMA nanocomposites that could be used as resist materials for e-beam lithography (EBL) with the intention of being integrated into nanodevices. The CuO nanofillers were synthesized via a low-cost chemical synthesis, while several loadings, spin coating conditions and two solvents (acetone and methyl ethyl ketone) were explored and assessed with regards to their effect on producing CuO/PMMA nanocomposites. The nanocomposite films were patterned with EBL and contrast curve data and resolution analysis were used to evaluate their performance and suitability as a resist material. Micro-X-ray fluorescence spectroscopy (µ-XRF) complemented with XRF measurements via a handheld instrument (hh-XRF) was additionally employed as an alternative rapid and non-destructive technique in order to investigate the uniform dispersion of the nanofillers within the polymer matrix and to assist in the selection of the optimum preparation conditions. This study revealed that it is possible to produce low-cost CuO/PMMA nanocomposites as a novel resist material without resorting to complicated preparation techniques.