bluuebunny/crossref_metadata_2025 huggingface dataset:
Food Insecurity and Water Insecurity in Rural Zimbabwe: Development of Multidimensional Household Measures
Authors: Koyratty Nadia , Jones Andrew , Schuster Roseanne , Kordas Katarzyna , Li Chin-Shang , Mbuya Mduduzi , Boateng Godfred , Ntozini Robert , Chasekwa Bernard , Humphrey Jean , Smith Laura ,   on behalf of the SHINE Trial Team
Published: June 2021

Background: With millions of people experiencing malnutrition and inadequate water access, FI and WI remain topics of vital importance to global health. Existing unidimensional FI and WI metrics do not all capture similar multidimensional aspects, thus restricting our ability to assess and address food- and water-related issues. Methods: Using the Sanitation, Hygiene and Infant Nutrition Efficacy (SHINE) trial data, our study conceptualizes household FI (N = 3551) and WI (N = 3311) separately in a way that captures their key dimensions. We developed measures of FI and WI for rural Zimbabwean households based on multiple correspondence analysis (MCA) for categorical data. Results: Three FI dimensions were retained: ‘poor food access’, ‘household shocks’ and ‘low food quality and availability’, as were three WI dimensions: ‘poor water access’, ‘poor water quality’, and ‘low water reliability’. Internal validity of the multidimensional models was assessed using confirmatory factor analysis (CFA) with test samples at baseline and 18 months. The dimension scores were associated with a group of exogenous variables (SES, HIV-status, season, depression, perceived health, food aid, water collection), additionally indicating predictive, convergent and discriminant validities. Conclusions: FI and WI dimensions are sufficiently distinct to be characterized via separate indicators. These indicators are critical for identifying specific problematic insecurity aspects and for finding new targets to improve health and nutrition interventions.
Help-Seeking from a National Youth Helpline in Australia: An Analysis of Kids Helpline Contacts
Authors: Watling David , Batchelor Samantha , Collyer Brian , Mathieu Sharna , Ross Victoria , Spence Susan H. , Kõlves Kairi
Published: June 2021

Counselling helplines or hotlines are key support services for young people with mental health concerns or in suicide and self-harm crises. We aimed to describe young peoples’ use of a national youth helpline (Kids Helpline, Australia, KHL) to understand how usage changed over time. A descriptive analysis was conducted on 1,415,228 answered contacts between 2012–2018. We described the trend of service usage over the observed period, the types of youth who used the service, and the problems young people contacted the service about. Phone (APC = −9.1, KHL: −10.4 to −7.8, p < 0.001) and email (APC = −13.7, 95%CI: −17.1 to −10.2, p < 0.001) contacts decreased over time whereas webchat contacts increased (APC = 16.7, 95%CI: 11.7 to 22.0, p < 0.001). With this increase in webchat contacts, there was an associated increase in total webchat contact duration. Concerns raised in contacts to the service were primarily related to emotional wellbeing and mental health concerns (53.2% phone, 57.3% webchat, 58.2% email) followed by social relationship issues (20.4% phone, 20.3% webchat, 16.8% email) and family relationships (19.4% phone, 17.2% webchat, 21.8% email). The increased preference for online text-based information and counselling services can help inform development of services for young people and allocation of staff/service training and resources.
The Deviation of the Behaviors of Rice Farmers from Their Stated Willingness to Apply Biopesticides—A Study Carried Out in Jilin Province of China
Authors: Guo Hongpeng , Sun Fanhui , Pan Chulin , Yang Baiming , Li Yin
Published: June 2021

The substitution of chemical pesticides by biopesticides is crucial to ensure the quality of agricultural products and to foster environmental sustainability. This study takes the willingness and the behaviors of rice farmers on the application of biopesticides as the research object. The survey questionnaire was designed based on the theory of rational small-scale farmers from three aspects: “individual and family characteristics of farmers”, “cognition of farmers” and “external factors”. The survey was then conducted on 163 rice farmers in seven prefecture-level cities in Jilin Province of China. The logistic model was used to analyze the influencing factors resulting in the deviation of the behaviors of the rice farmers from their initial willingness on the application of biopesticides. The explanatory structure model (ISM) was used to analyze the logical hierarchical relationship among various influencing factors. The results show that: (1) For 45% of the farmers surveyed, there’s a deviation between their willingness and behaviors regarding the application of biopesticides; (2) Among the significant factors leading to the deviation between farmers’ willingness and behaviors concerning the application of biopesticides, the surface-level direct factor is biopesticide awareness. The mid-level indirect factors are agricultural product quality and safety awareness and the deep-level root cause is farmers’ education level. (3) The primary reason for the deviation of the farmers’ behaviors from their willingness is their lack of knowledge about biopesticides and the biopesticides’ incomplete market structure. Based on the comprehensive analysis, it is recommended to improve the professionalization of the farmers, to strengthen the publicity of green production and to accelerate the formulation of the biopesticides market to further promote the usage of biopesticides.
Oral Health-Related Knowledge, Attitudes and Behaviours of Elementary School Teachers
Authors: Yılmaz Gülçin , Riad Abanoub , Krsek Martin , Kurt Hanefı , Attia Sameh
Published: June 2021

Background: elementary schoolteachers play a central role in shaping their students’ beliefs, attitudes, and behaviours related to health and oral hygiene. This study was designed to evaluate Turkish schoolteachers’ levels of oral health knowledge, attitudes, and behaviours. Methods: A cross-sectional survey-based study was conducted among elementary schoolteachers in Istanbul using a validated self-administered questionnaire. The questionnaire was composed of 36 multiple-choice items categorised into six sections, and the participants were recruited using convenience sampling. (3) Results: A total of 385 elementary schoolteachers participated in this study. The majority were female (62.2%), qualified with a licensure degree (81.3%) and working in public schools (86.5%). Female gender and greater work experience were found to be promoters for oral health knowledge and positive attitudes. The correlation between their perceived knowledge and actual knowledge was very weak, thus suggesting that the teachers are inclined to overestimate their knowledge. Conclusions: The Turkish elementary schoolteachers showed satisfactory oral health knowledge and attitudes toward oral health education. The teachers’ knowledge about dental trauma management was inadequate, necessitating urgent educational interventions, especially for physical education teachers, who are at the greatest risk of encountering such events during their work. The oral hygiene behaviours were not associated with teachers’ oral health knowledge, attitudes, or practice, thus requiring further investigation.
Poor Sleep Quality and Its Relationship with Individual Characteristics, Personal Experiences and Mental Health during the COVID-19 Pandemic
Authors: Varma Prerna , Burge Malisa , Meaklim Hailey , Junge Moira , Jackson Melinda L.
Published: June 2021

While the COVID-19 has dramatically altered our lifestyle and sleep practices, the links between sleep, individual characteristics, personal experiences and mental health during the pandemic require further examination. This cross-sectional, multi-methods study examined differences in language used to describe personal experiences, and mental health, based on sleep quality during the early stages of the pandemic. N = 1745 participants (mean age 42.97 ± 14.46 years) from 63 countries responded to the survey. Sleep quality was assessed using the Pittsburgh Sleep Quality Index and mental health was examined using the Patient Health Questionnaire-9, the State Trait Anxiety Inventory, the Perceived Stress Scale and the UCLA-Loneliness Scale. Quantitative analysis of qualitative, language content of personal experiences was conducted using free-text responses and comments to a question on the survey. Almost 50% of the participants reported poor sleep quality, which was linked to a more negative emotional tone and greater mentions of money or finance related words. Good sleepers reported more positive emotional tone in their experiences. Greater reports of clinical state anxiety, moderate depression and moderate stress were observed in poor sleepers, even after accounting for demographics and pandemic-related factors such as loneliness, financial concerns and risk of contracting COVID-19 disease. Results from this study highlight an urgent need for sleep-related public health interventions. Practitioner education, sleep screening for those with mental health conditions, and encouraging people to adopt digital tools may help to reduce the burden of poor sleep on mental health. While the pandemic itself is a stressful and uncertain time, improving sleep can support positive emotion regulation, improving mood and consequential action.
Quantitative and Qualitative Comparison of 2D and 3D Projection Techniques for High-Dimensional Data
Authors: Tian Zonglin , Zhai Xiaorui , van Steenpaal Gijs , Yu Lingyun , Dimara Evanthia , Espadoto Mateus , Telea Alexandru
Published: June 2021

Projections are well-known techniques that help the visual exploration of high-dimensional data by creating depictions thereof in a low-dimensional space. While projections that target the 2D space have been studied in detail both quantitatively and qualitatively, 3D projections are far less well understood, with authors arguing both for and against the added-value of a third visual dimension. We fill this gap by first presenting a quantitative study that compares 2D and 3D projections along a rich selection of datasets, projection techniques, and quality metrics. To refine these insights, we conduct a qualitative study that compares the preference of users in exploring high-dimensional data using 2D vs. 3D projections, both without and with visual explanations. Our quantitative and qualitative findings indicate that, in general, 3D projections bring only limited added-value atop of the one provided by their 2D counterparts. However, certain 3D projection techniques can show more structure than their 2D counterparts, and can stimulate users to further exploration. All our datasets, source code, and measurements are made public for ease of replication and extension.
Self-Consistent Energy Normalization for Quasistatic Reactor Calculations
Authors: Griesheimer David P. , Douglass Steven J. , Stedry Mark H.
Published: June 2021

Use of the quasistatic (keff) approximation for producing steady-state solutions for non-critical fission systems is known to result in an imbalance between energy release and deposition within the system. In this paper, we formally quantify this imbalance and present a self-consistent energy normalization technique that preserves nuclear energy release per reaction, as well as enforces energy balance between release and deposition mechanisms, regardless of the criticality state of the system. The proposed technique is straightforward to implement in any type of transport solver through the use of a simple energy rebalance factor. Theoretical and numerical results are presented that demonstrate the energy deposition bias for non-critical systems and the effectiveness of the proposed energy normalization technique.
Information Acquisition and Its Incentives in an E-Commerce Supply Chain under the Offline Showroom Model
Authors: Li Mengli , Zhang Xumei
Published: June 2021

Recently, the showroom model has developed fast for allowing consumers to evaluate a product offline and then buy it online. This paper aims at exploring the optimal information acquisition strategy and its incentive contracts in an e-commerce supply chain with two competing e-tailers and an offline showroom. Based on signaling game theory, we build a mathematical model by considering the impact of experience service and competition intensity on consumers’ demand. We find that, on the one hand, information acquisition promotes supply chain members to obtain demand information directly or indirectly, which leads to forecast revenue. On the other hand, information acquisition promotes supply chain members to distort optimal decisions, which results in signal cost. The optimal information acquisition strategy depends on the joint impact of forecast revenue, signal cost and demand forecast cost. Notably, in some conditions, the offline showroom will not acquire demand information even when its cost is equal to zero. We also design two different information acquisition incentive contracts to obtain Pareto improvement for all supply chain members.
Analysis of EDM Performance, through a Thermal–Electrical Model with a Trunk-Conical Discharge Channel, Using a Steel Tool and an Aluminium Workpiece
Authors: Almacinha José A. S. , Fernandes Alice M. G. , Maciel Duarte A. , Seca Ricardo J. M. , Marafona José D. R.
Published: June 2021

In this article, a finite element (FE) thermal–electrical model with a trunk-conical discharge channel is employed to simulate individual EDM discharges with a time-on of 18 μs up to 320 μs, which are subsequently compared with the experimental results to validate the model. The discharge channel is a trunk-conical electrical conductor which dissipates heat by the Joule heating effect, being the correspondent factor equal to 1. Instead of the usual copper–iron electrode combination, steel (DIN CK45) and aluminium alloys (DIN 3.4365) are the implemented materials on both the tool and the workpiece, respectively. The numerical results were measured using the melting temperature of the materials as the boundary of material removal. The results obtained with the thermal–electrical model, namely the tool wear ratio, the tool wear rate, the material removal rate, and the surface roughness, are in good agreement with experimental results, showing that the new FE model is capable of predicting accurately with different materials for the electrodes.
Interface Joint Strength between SS316L Wrought Substrate and Powder Bed Fusion Built Parts
Authors: Weaver Jason M. , Linn John R. , Miles Michael P.
Published: June 2021

Metal powder bed fusion (PBF) additive manufacturing (AM) builds metal parts layer by layer upon a substrate material. The strength of this interface between the substrate and the printed material is important to characterize, especially in applications where the substrate is retained and included in the finished part. Ensuring that this interface between the original and the printed material has adequate material properties enables the use of this PBF AM process to repair existing structures and create new parts using both AM and conventional manufacturing. This paper studies the tensile and torsional shear strengths of wrought and PBF-built SS316L specimens and compares them to specimens that are composed of half wrought material and half PBF material. These specimens were created by building new material via PBF onto existing wrought SS316L blocks, then cutting the specimens to include both materials. The specimens are also examined using optical microscopy and electron backscatter diffraction (EBSD). The PBF specimens consistently exhibited higher strength and lower ductility than the wrought specimens. The hybrid PBF/wrought specimens performed similarly to the wrought material. In none of the specimens did any failure appear to occur at or near the interface between the wrought substrate and the PBF material. In addition, most of the deformation in the PBF/wrought specimens appeared to be limited to the wrought portion of the specimens. These results are consistent with optical microscopy and EBSD showing smaller grain size in the PBF material, which correlates to increased strength in SS316L due to the Hall–Petch relationship. With the strength at the interface meeting or exceeding the strength of the original wrought material, this process shows great promise as a method for adding additional features or repairing existing structures using metal PBF AM.
Analysis of Crack Width Development in Reinforced Concrete Beams
Authors: Goszczyńska Barbara , Trąmpczyński Wiesław , Tworzewska Justyna
Published: June 2021

The reliability and durability of reinforced concrete structures depend on the amount of concrete cracking. The risk associated with cracks generates a need for diagnostic methods for the evaluation of reinforced concrete structures. This paper presents the results of a study of 10 single-span reinforced concrete beams to follow the process of crack formation and changes in their width. The beams were loaded to failure with two forces in a monotonic manner with unloading and in a cyclic manner. Continuous observation of the crack formation process was provided by the digital image correlation system. The simplified method for estimating the maximum crack width is proposed. The presented results confirmed the stochastic character of the process of crack formation and development. The maximum crack widths calculated on the basis of the proposed formula were on the safe side in relation to those calculated according to Eurocode 2. It was also confirmed that the distances between cracks do not depend on the loading manner. Hence the density function describing the distribution of distances between cracks can be used to assess the condition of reinforced concrete elements. The research has also shown the suitability of the DIC system (ARAMIS) for testing concrete elements.
Freeze-Dried Matrices Composed of Degradable Polymers with Surfactant-Loaded Microparticles Based on Pectin and Sodium Alginate
Authors: Stachowiak Natalia , Kowalonek Jolanta , Kozlowska Justyna
Published: June 2021

Gelatin/polyvinylpyrrolidone/hydroxyethyl cellulose/glycerol porous matrices with microspheres made of sodium alginate or pectin and sodium alginate were produced. A surfactant was loaded into these microparticles. The microspheres were characterized using optical microscopy, scanning electron microscopy SEM, and laser diffraction particle size analyzer. For the matrices, the density, porosity, swelling capacity, dissolution in phosphate saline buffer were determined and SEM, mechanical, and thermogravimetric studies were applied. The results showed that the size of the two-component microspheres was slightly larger than that of single-ingredient microparticles. The images confirmed the spherical shape of the microparticles. The prepared matrices had high water uptake ability and porosity due to the presence of hydrophilic polymers. The presence of microparticles in the matrices caused a decrease in these parameters. Degradation of the composites with the microspheres was significantly faster than the matrix without them. The addition of microparticles increased the stiffness and toughness of the prepared materials. The efficiency of the thermal decomposition main stage was reduced in the samples with microspheres, whereas a char residue increased in these composites.
The Applications of Enamel Matrix Derivative in Implant Dentistry: A Narrative Review
Authors: Alberti Alice , Francetti Luca , Taschieri Silvio , Corbella Stefano
Published: June 2021

Enamel matrix derivative (EMD) has been successfully used for periodontal regeneration in intrabony defects. Recently, its use for peri-implant bone regeneration has also been hypothesized. The aim of this paper is to review preclinical and clinical studies investigating the use of EMD in correspondence with titanium implants, alone or as an adjunct to other biomaterials. Clinical trials and case series with more than five cases were included. Seven in vitro studies evaluated the effect of EMD, placed on titanium surfaces: An increase in proliferation and viability of osteoblasts was observed in all but two studies. An increase in TGF-β1 and osteocalcin production, alkaline phosphatase activity, and angiogenesis was also reported. Nine animal studies investigated the use of EMD at implant placement or for bone regeneration of peri-implant bone defects, and some of them reported a significant increase in bone formation or bone-to-implant contact. In four of eleven clinical trials on humans, EMD was successfully used at implant placement. The other seven evaluated the use of EMD in protocols for the treatment of peri-implantitis. In conclusion, the results of EMD seem promising, but further randomized clinical trials are needed to evaluate its efficacy.
Revealing Inflammatory Indications Induced by Titanium Alloy Wear Debris in Periprosthetic Tissue by Label-Free Correlative High-Resolution Ion, Electron and Optical Microspectroscopy
Authors: Podlipec Rok , Punzón-Quijorna Esther , Pirker Luka , Kelemen Mitja , Vavpetič Primož , Kavalar Rajko , Hlawacek Gregor , Štrancar Janez , Pelicon Primož , Fokter Samo K.
Published: June 2021

The metallic-associated adverse local tissue reactions (ALTR) and events accompanying worn-broken implant materials are still poorly understood on the subcellular and molecular level. Current immunohistochemical techniques lack spatial resolution and chemical sensitivity to investigate causal relations between material and biological response on submicron and even nanoscale. In our study, new insights of titanium alloy debris-tissue interaction were revealed by the implementation of label-free high-resolution correlative microscopy approaches. We have successfully characterized its chemical and biological impact on the periprosthetic tissue obtained at revision surgery of a fractured titanium-alloy modular neck of a patient with hip osteoarthritis. We applied a combination of photon, electron and ion beam micro-spectroscopy techniques, including hybrid optical fluorescence and reflectance micro-spectroscopy, scanning electron microscopy (SEM), Energy-dispersive X-ray Spectroscopy (EDS), helium ion microscopy (HIM) and micro-particle-induced X-ray emission (micro-PIXE). Micron-sized wear debris were found as the main cause of the tissue oxidative stress exhibited through lipopigments accumulation in the nearby lysosome. This may explain the indications of chronic inflammation from prior histologic examination. Furthermore, insights on extensive fretting and corrosion of the debris on nm scale and a quantitative measure of significant Al and V release into the tissue together with hydroxyapatite-like layer formation particularly bound to the regions with the highest Al content were revealed. The functional and structural information obtained at molecular and subcellular level contributes to a better understanding of the macroscopic inflammatory processes observed in the tissue level. The established label-free correlative microscopy approach can efficiently be adopted to study any other clinical cases related to ALTR.
Solvent-Free Synthesized Monolithic Ultraporous Aluminas for Highly Efficient Removal of Remazol Brilliant Blue R: Equilibrium, Kinetic, and Thermodynamic Studies
Authors: Xu Huan , Boeuf Guilhem , Jia Zixian , Zhu Kairuo , Nikravech Mehrdad , Kanaev Andrei , Azouani Rabah , Traore Mamadou , Elm’selmi Abdellatif
Published: June 2021

In this study, ultraporous aluminas (UPA) were synthesized as new effective adsorbents for Remazol Brilliant Blue R (RBBR) removal from aqueous solutions. The UPA monoliths were grown via facile oxidation process, followed by isochronous annealing treatment in air at different temperatures, through which γ, θ, and α phase polycrystalline fibrous grains of UPA can be accordingly obtained. The experimental factors that affect the material adsorption performances including initial pH, contact time, and temperature were comprehensively studied by batch experiments. The RBBR adsorption isotherms of UPA(γ) and UPA(θ) powders were found almost identical, while UPA(α) powders showed low effectiveness. To obtain the desirable mechanical stability of the UPA monolith with considerable RBBR adsorption capacity, UPA(θ) powders were further studied. The UPA(θ) powders exhibited maximum RBBR adsorption at pH 2 due to the positively charged surface under acidic conditions. Compared with the Lagergren pseudo-first-order model, the pseudo-second-order model was found to explain the adsorption kinetics better. Despite the film diffusion dominating the adsorption process, the contributions of the intraparticle diffusion and chemical reactions were also found significant. The adsorption equilibrium data at different temperatures were fitted by the Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich (D–R) isotherm models. The Langmuir model was found the most effective in the description of equilibrium data, and the maximum RBBR adsorption capacity retained by UPA(θ) powders was 122.55 mg·g−1 at 295 K. Thermodynamic parameters (ΔG0, ΔH0, and ΔS0) indicated the adsorption process was spontaneous and exothermic in nature.
Temperature Profile in Starch during Irradiation. Indirect Effects in Starch by Radiation-Induced Heating
Authors: Braşoveanu Mirela , Nemţanu Monica R.
Published: June 2021

Present research deals with exposure of granular starch to the accelerated electron of 5.5 MeV energy in order to examine: (i) the temperature evolution in starch within an irradiation process and (ii) the indirect effects generated in starch by radiation-induced heating. The temperature evolution in potato and corn starches within the irradiation process was investigated by placing two different sensors inside each starch batch and recording the temperature simultaneously. Each starch batch was sampled into distinct location sectors of different absorbed radiation levels. The output effects in each sample were analyzed through physicochemical properties such as moisture content, acidity and color attributes. The outcomes showed that a starch temperature profile had different major stages: (i) heating during irradiation, (ii) post-irradiation heating, up to the maximum temperature is reached, and (iii) cooling to the room temperature. A material constant with signification of a relaxation time was identified by modeling the temperature evolution. Changes of the investigated properties were induced both by irradiation and radiation-induced heating, depending on the starch type and the batch sectors. Changes in the irradiated batch sectors were explained by irradiation and radiation-induced heating whereas changes in the sector of non-irradiated starch were attributed only to the heating.
Nature-Inspired Structures Applied in Heat Transfer Enhancement and Drag Reduction
Authors: Zhu Zhangyu , Li Juan , Peng Hao , Liu Dongren
Published: June 2021

Heat exchangers are general equipment for energy exchange in the industrial field. Enhancing the heat transfer of a heat exchanger with low pump energy consumption is beneficial to the maximum utilization of energy. The optimization design for enhanced heat transfer structure is an effective method to improve the heat transfer coefficient. Present research shows that the biomimetic structures applied in different equipment could enhance heat transfer and reduce flow resistance significantly. Firstly, six biomimetic structures including the fractal-tree-like structure, conical column structure, hybrid wetting structure, scale structure, concave-convex structure and superhydrophobic micro-nano structure were summarized in this paper. The biomimetic structure characteristics and heat transfer enhancement and drag reduction mechanisms were analyzed. Secondly, four processing methods including photolithography, nanoimprinting, femtosecond laser processing and 3D printing were introduced as the reference of biomimetic structure machining. Finally, according to the systemic summary of the research review, the prospect of biomimetic heat transfer structure optimization was proposed.
Immunosensor Based on Zinc Oxide Nanocrystals Decorated with Copper for the Electrochemical Detection of Human Salivary Alpha-Amylase
Authors: Martins Beatriz Rodrigues , Sampaio Tainá Marques , de Farias Ana Karoline Silva Rocha , de Paula Martins Rheltheer , Teixeira Renata Roland , Oliveira Robson Tadeu Soares , Oliveira Carlo Jose Freire , da Silva Marcos Vinícius , Rodrigues Virmondes , Dantas Noelio Oliveira , Espindola Foued Salmen , Silva Anielle Christine Almeida , Alves-Balvedi Renata Pereira
Published: June 2021

(1) Background: Nanocrystals (NCs)-based electrochemical sensors have been proposed for biomarkers detection, although immunosensors using ZnO NCs decorated with copper are still scarce. (2) Methods: Electrochemical immunodetection of human salivary alpha-amylase (HSA) used ZnO, CuO, and ZnO:xCu (x = 0.1, 0.4, 1.0, 4.0, and 12.0) NCs. (3) Results: Substitutional incorporation of Cu2+ in the crystalline structure of ZnO and formation of nanocomposite were demonstrated by characterization. Graphite electrodes were used and the electrochemical signal increased by 40% when using ZnO:1Cu and 4Cu (0.25 mg·mL−1), in an immunosensor (0.372 mg·mL−1 of anti-alpha-amylase and 1% of casein). Different interactions of HSA with the alpha-amylase antibody were registered when adding the NCs together, either before or after the addition of saliva (4 μL). The immunosensor changed specificity due to the interaction of copper. The ZnO:1Cu and ZnO:4Cu samples showed 50% interference in detection when used before the addition of saliva. The immunosensor showed 100% specificity and a sensitivity of 0.00196 U·mL−1. (4) Conclusions: Results showed that the order of NCs addition in the sensors should be tested and evaluated to avoid misinterpretation in detection and to enable advances in the validation of the immunosensor.
PESIN Conjugates for Multimodal Imaging: Can Multimerization Compensate Charge Influences on Cell Binding Properties? A Case Study
Authors: Hübner Ralph , Paretzki Alexa , von Kiedrowski Valeska , Maspero Marco , Cheng Xia , Davarci Güllü , Braun Diana , Damerow Helen , Judmann Benedikt , Filippou Vasileios , Dallanoce Clelia , Schirrmacher Ralf , Wängler Björn , Wängler Carmen
Published: June 2021

Recently, anionic charges were found to negatively influence the in vitro gastrin-releasing peptide receptor (GRPR) binding parameters of dually radioisotope and fluorescent dye labeled GRPR-specific peptide dimers. From this, the question arose if this adverse impact on in vitro GRP receptor affinities could be mitigated by a higher valency of peptide multimerization. For this purpose, we designed two different hybrid multimodal imaging units (MIUs), comprising either one or two click chemistry-compatible functional groups and reacted them with PESIN (PEG3-BBN7–14, PEG = polyethylene glycol) dimers to obtain a dually labeled peptide homodimer or homotetramer. Using this approach, other dually labeled peptide monomers, dimers, and tetramers can also be obtained, and the chelator and fluorescent dye can be adapted to specific requirements. The MIUs, as well as their peptidic conjugates, were evaluated in terms of their photophysical properties, radiolabeling efficiency with 68Ga and 64Cu, hydrophilicity, and achievable GRP receptor affinities. Here, the hydrophilicity and the GRP receptor binding affinities were found to be especially strongly influenced by the number of negative charges and peptide copies, showing logD (1-octanol-water-distribution coefficient) and IC50 (half maximal inhibitory concentration) values of −2.2 ± 0.1 and 59.1 ± 1.5 nM for the homodimer, and −1.9 ± 0.1 and 99.8 ± 3.2 nM for the homotetramer, respectively. From the obtained data, it can be concluded that the adverse influence of negatively charged building blocks on the in vitro GRP receptor binding properties of dually labeled PESIN multimers can, at least partly, be compensated for by the number of introduced peptide binding motives and the used molecular design.
Considerations in the Design of Non-Clinical Development Programmes to Support Non-Viral Genetically Modified Mesenchymal Stromal Cell Therapies
Authors: Iansante Valeria , Brooks Andrew , Coney Lee
Published: June 2021

Due to their immune suppressive pharmacology, regenerative capacity, and immune privileged status, mesenchymal stromal cells (MSCs) are an attractive cell type to treat a variety of diseases. Genetically engineered MSCs are currently in non-clinical and clinical development for a wide range of applications including the delivery of pro-drugs and therapeutic proteins or modified to enhance their regenerative potential. Unmodified MSCs have been shown to have good safety profiles in clinical development. The introduction of exogenous transgenes introduces possible additional risks that need to be assessed in non-clinical studies prior to initiating clinical studies. The use of ex vivo non-viral genetic modification approaches potentially reduces the risks associated with viral vector transfection approaches, including the potential for cell transformation. This review provides an overview of the regulatory-compliant non-clinical proof-of-concept and safety studies required to take MSC-based gene therapy products from the bench to the clinic.
Biopolymer Composites with Ti/Au Nanostructures and Their Antibacterial Properties
Authors: Slepička Petr , Fajstavr Dominik , Krejčová Markéta , Rimpelová Silvie , Slepičková Kasálková Nikola , Kolská Zdeňka , Švorčík Václav
Published: June 2021

In this study, we have aimed at the preparation and characterization of poly-l-lactic acid (PLLA) composites with antibacterial properties. Thin bilayers of titanium and gold of various thickness ratios were deposited on PLLA by a cathode sputtering method; selected samples were subsequently thermally treated. The surface morphology of the prepared composites was studied by atomic force, scanning electron, and laser confocal microscopy. The chemical properties of the composites were determined by X-ray photoelectron and energy-dispersive X-ray spectroscopy in combination with contact angle and zeta potential analyses. The antibacterial properties of selected samples were examined against a Gram-negative bacterial strain of E. coli. We have found that a certain combination of Au and Ti nanolayers in combination with heat treatment leads to the formation of a unique wrinkled pattern. Moreover, we have developed a simple technique by which a large-scale sample modification can be easily produced. The dimensions of wrinkles can be tailored by the sequence and thickness of the deposited metals. A selected combination of gold, titanium, and heat treatment led to the formation of a nanowrinkled pattern with excellent antibacterial properties.
Improved Therapeutic Efficiency against Obesity through Transdermal Drug Delivery Using Microneedle Arrays
Authors: Xie Yixuan , Shao Ruomei , Lin Yali , Wang Chunnan , Tan Ying , Xie Weidong , Sun Shuqing
Published: June 2021

In this paper, we prepared patches that were composed of a degradable microneedle (MN) array with a soft backing provided for the skin tissue. We then performed a transdermal delivery of anti-obesity drugs to evaluate the effectiveness of β3 adrenergic receptor CL316243 in obesity treatment in overweight mice induced by a high-fat diet. Eighty male National Institutes of Health (NIH) mice were randomly divided into four obese groups or the control group. The obesity groups were given a high-fat diet for 15–18 weeks to establish an obese model. Afterward, the obese groups were divided into the following four groups: the control group, the unloaded MN group, the CL-316243 MN group, and the injection group. For the injection group, the group of mice was injected subcutaneously with CL316243 (1 mg/(kg·day)) for 15 days. Furthermore, the CL-316243 MN group was given a lower dose (0.1 mg/(kg·day)) for 15 days. After weighing the mice, we used Western blotting to detect the expression of uncoupling protein 1 (UCP1) in the adipose tissue around the mouse viscera. The results stated that the weight of the CL-316243 MN group and the injection group dropped, and the UCP1 protein expression of brown adipose tissue (BAT) significantly increased. The results demonstrated the β3 adrenergic receptor agonist CL316243 could be carried into the body through MN, and the dose applied was considerably smaller than the injection dose. The reason for this may arise from the CL-316243 being delivered by MN arrays to subcutaneous adipose tissue more efficiently, with an even distribution, compared to that of the injection dose. This technique provides a new and feasible way to treat obesity more effectively.
Functionality and Acceptance of the EsoCap System—A Novel Film-Based Drug Delivery Technology: Results of an In Vivo Study
Authors: Rosenbaum Christoph , Grimm Michael , Krause Julius , Rump Adrian , Kessler Rebecca , Hosten Norbert , Weitschies Werner
Published: June 2021

There are no methods for specific local application of active substances to the mucosa of the esophagus to treat eosinophilic esophagitis or other esophageal diseases. This publication describes the principal in vivo functionality and acceptance of a novel modular drug delivery concept, called EsoCap system, by 12 healthy volunteers. For the first time, the EsoCap system enables targeted placement on the esophageal mucosa of a mucoadhesive polymer film. Acceptance was determined by means of a standardized questionnaire after administration and functionality of the device by MRI scans. Two different setups of the EsoCap system were tested: one setup with a density of 0.4 g/cm3 and one with a density of 1.0 g/cm3. Acceptability of the dosage form was also confirmed in addition to functionality, by measuring the applied film length. It was found that acceptance of the variant with the higher density was significantly better. This novel drug delivery technology could enable a targeted, local and long-lasting therapy of the esophagus for the first time, depending on the polymer film used.
Evaluation on Structural Properties and Performances of Graphene Oxide Incorporated into Chitosan/Poly-Lactic Acid Composites: CS/PLA versus CS/PLA-GO
Authors: Mohamad Siti Noor Kamilah , Ramli Irmawati , Abdullah Luqman Chuah , Mohamed Nor Hasimah , Islam Md. Saiful , Ibrahim Nor Azowa , Ishak Nor Shafizah
Published: June 2021

In this work, to fabricate a novel composite consisting of chitosan/poly-lactic acid doped with graphene oxide (CS/PLA-GO), composites were prepared via solution blending method to create various compositions of CS and PLA (90/10, 70/30 and 50/50CS/PLA-GO). Graphene oxide (GO) was added into a PLA solution prior to blending it with chitosan (CS). The surface morphology and structural properties of synthesized composites were characterized using FT-IR, SEM and XRD analysis. The performances of synthesized composites on thermal strength, mechanical strength, water absorption, and microbial activity were also evaluated through standard testing methods. The morphology of 70/30CS/PLA-GO became smoother with the addition of GO due to enhanced interfacial adhesion between CS, PLA and GO. The presence of GO has also improved the miscibility of CS and PLA and has superior properties compared to CS/PLA composites. Moreover, the addition of GO has boosted the thermal stability of the composite, with a significant enhancement of Td and Tg. The highest Td and Tg were accomplished at 389 °C and 76.88 °C, respectively, for the 70/30CS/PLA-GO composite in comparison to the CS and PLA that recorded Td at 272 °C and 325 °C and Tg at 61 °C and 60 °C, respectively. In addition, as reinforcement, GO provided a significant influence on the tensile strength of composites where the tensile modulus showed remarkable improvement compared to pure CS and CS/PLA composites. Furthermore, CS/PLA-GO composites showed excellent water-barrier properties. Among other compositions, 70/30CS/PLA revealed the greatest decrement in water absorption. From the antibacterial results, it was observed that 90/10CS/PLA-GO and 70/30CS/PLA-GO showed an inhibitory effect and had wide inhibition zones which were 8.0 and 8.5 mm, respectively, against bacteria Bacillus Subtillis B29.
Structural Characterization of Pectic Polysaccharides in the Cell Wall of Stevens Variety Cranberry Using Highly Specific Pectin-Hydrolyzing Enzymes
Authors: Spadoni Andreani Eugenio , Karboune Salwa , Liu Lan
Published: June 2021

The potential of poly- and oligosaccharides as functional ingredients depends on the type and glycosidic linkages of their monosaccharide residues, which determine their techno-functional properties, their digestibility and their fermentability. To isolate the pectic polysaccharides of cranberry, alcohol insoluble solids were first obtained from pomace. A sequential extraction with hot phosphate buffer, chelating agents (CH), diluted (DA) and concentrated sodium hydroxide was then carried out. Pectic polysaccharides present in CH and DA extracts were purified by anion exchange and gel filtration chromatography, then sequentially exposed to commercially available pectin-degrading enzymes (endo-polygalacturonase, pectin lyase and endo-arabinanase/endo-galactanase/both). The composition and linkages of the generated fragments revealed important characteristic features, including the presence of homogalacturonan with varied methyl esterification extent, branched type I arabinogalactan and pectic galactan. The presence of arabinan with galactose branches was suggested upon the analysis of the fragments by LC-MS.
Transcutaneous Drug Delivery Systems Based on Collagen/Polyurethane Composites Reinforced with Cellulose
Authors: Anghel Narcis , Dinu Valentina Maria , Verestiuc Liliana , Spiridon Irene Alexandra
Published: June 2021

Designing composites based on natural polymers has attracted attention for more than a decade due to the possibility to manufacture medical devices which are biocompatible with the human body. Herein, we present some biomaterials made up of collagen, polyurethane, and cellulose doped with lignin and lignin-metal complex, which served as transcutaneous drug delivery systems. Compared with base material, the compressive strength and the elastic modulus of biocomposites comprising lignin or lignin-metal complex were significantly enhanced; thus, the compressive strength increased from 61.37 to 186.5 kPa, while the elastic modulus increased from 0.828 to 1.928 MPa. The release of ketokonazole from the polymer matrix follows a Korsmeyer–Peppas type kinetics with a Fickian diffusion. All materials tested were shown to be active against pathogenic microorganisms. The mucoadhesiveness, bioadhesiveness, mechanical resistance, release kinetic, and antimicrobial activity make these biocomposites to be candidates as potential systems for controlled drug release.
Wear Assessment of Tibial Inserts Made of Highly Cross-Linked Polyethylene Supplemented with Dodecyl Gallate in the Total Knee Arthroplasty
Authors: Zhang Min , Wang Jia-Yu , Su Jian , Wang Jian-Jun , Yan Shi-Tong , Luan Yi-Chao , Cheng Cheng-Kung
Published: June 2021

Background: the wear of tibial insert is still one of primary factors leading to failure of total knee arthroplasty (TKA). Dodecyl gallate (DG) has shown improvements in the oxidation stability of highly cross-linked polyethylene (HXLPE). This study aimed to assess the application of HXLPE supplemented with DG (HXLPE-DG) on the tibial insert in TKA concerning the wear resistance and the potential impact on implant fixation; Methods: tibial inserts made of HXLPE-DG were subjected to a 3 million loading-cycle wear test following ISO 14243-1:2009. The loss of mass and wear rate of the tibial inserts were calculated. The quantity, size,- and shape of wear particles were recorded; Results: the test specimens lost an average mass of 16.00 mg ± 0.94 mg, and were on an average wear rate of 3.92 mg/million cycles ± 0.19 mg/million cycles. The content of wear particles in the calf serum medium was 3.94 × 108 particles/mL ± 3.93 × 107 particles/mL, 96.66% ± 0.77% of the particles had an equivalent circular diameter less than 0.5 μm. The aspect ratio of wear particles was 1.40 (min: 1.01; max: 6.42). Conclusions: HXLPE-DG displayed advantages over the commonly used materials for tibial inserts and presented the potential of application in TKA.
Effect of Cellulose and Cellulose Nanocrystal Contents on the Biodegradation, under Composting Conditions, of Hierarchical PLA Biocomposites
Authors: Galera Manzano Luciano Miguel , Ruz Cruz Miguel Ángel , Moo Tun Nora Magally , Valadez González Alex , Mina Hernandez José Herminsul
Published: June 2021

In this work, the effect of microfibrillated cellulose (MFC) and cellulose nanocrystals (CNCs) on the biodegradation, under composting conditions, of hierarchical PLA biocomposites (HBCs) was studied using a full 22 factorial experimental design. The HBCs were prepared by extrusion processing and were composted for 180 days. At certain time intervals, the specimens were removed from the compost for their chemical, thermal and morphological characterizations. An ANOVA analysis was carried out at different composting times to study MFC and CNCs’ effects on biodegradation. The specimen’s mass loss and molecular weight loss were selected as independent variables. The results show that the presence of MFC enhances the PLA biodegradation, while with CNCs it decreases. However, when both cellulosic fibers are present, a synergistic effect was evident—i.e., in the presence of the MFC, the inclusion of the CNCs accelerates the HBCs biodegradation. Analysis of the ANOVA results confirms the relevance of the synergistic role between both cellulosic fibers over the HBC biodegradation under composting conditions. The results also suggest that during the first 90 days of incubation, the hydrolytic PLA degradation prevails, whereas, beyond that, the enzymatic microbial biodegradation dominates. The SEM results show MFC’s presence enhances the surface biodeterioration to a greater extent than the CNCs and that their simultaneous presence enhances PLA biodegradation. The SEM results also indicate that the biodegradation process begins from hydrophilic cellulosic fibers and promotes PLA biodegradation.
Detection of Upper and Lower Planetary-Boundary Layer Curves and Estimation of Their Heights from Ceilometer Observations under All-Weather Conditions: Case of Athens, Greece
Authors: Kambezidis Harry D. , Psiloglou Basil E. , Gavriil Ariadne , Petrinoli Kalliopi
Published: June 2021

The planetary-boundary layer (PBL) plays an important role in air-pollution studies over urban/industrial areas. Therefore, numerous experimental/modelling efforts have been conducted to determine the PBL height and provide statistics. Nowadays, remote-sensing techniques such as ceilometers are valuable tools in PBL-height estimation. The National Observatory of Athens operates a Vaisala CL31 ceilometer. This study analyses its records over a 2-year period and provides statistics about the PBL height over Athens. A specifically developed algorithm reads the CL31 records and estimates the PBL height. The algorithm detects an upper and a lower PBL curve. The results show maximum values of about 2500 m above sea level (asl)/3000 m asl in early afternoon hours in all months for upper PBL, and particularly the summer ones, under all-/clear-sky conditions, respectively. On the contrary, the lower PBL does not possess a clear daily pattern. Nevertheless, one morning and another afternoon peak can be identified. The intra-annual variation of the upper PBL height shows a peak in August in all-weather conditions and in September under clear-sky ones. Season-wise, the upper PBL height varies showing an autumn peak for all-weather cases, while the lower PBL height shows a winter maximum due to persistent surface-temperature inversions in this season.