Spreadsheet Research Articles

Insitu magnetic-field-assisted bioprinting process using magnetorheological bioink to obtain engineered muscle constructs

Tissue-engineered anisotropic cell constructs are promising candidates for treating volumetric muscle loss (VML). However, achieving successful cell alignment within macroscale 3D cell constructs for skeletal muscle tissue regeneration remains challenging, owing to difficulties in controlling cell arrangement within a low-viscosity hydrogel. Herein, we propose the concept of a magnetorheological bioink to manipulate the cellular arrangement within a low-viscosity hydrogel. This bioink consisted of gelatin methacrylate (GelMA), iron oxide nanoparticles, and human adipose stem cells (hASCs). The cell arrangement is regulated by the responsiveness of iron oxide nanoparticles to external magnetic fields. A bioprinting process using ring magnets was developed for in situ bioprinting, resulting in well-aligned 3D cell structures and enhanced mechanotransduction effects on hASCs. In vitro analyses revealed upregulation of cellular activities, including myogenic-related gene expression, in hASCs. When implanted into a VML mouse model, the bioconstructs improved muscle functionality and regeneration, validating the effectiveness of the proposed approach.

4D Bioprinting Shape‐Morphing Tissues in Granular Support Hydrogels: Sculpting Structure and Guiding Maturation

AbstractDuring embryogenesis, organs undergo dynamic shape transformations that sculpt their final shape, composition, and function. Despite this, current organ bioprinting approaches typically employ bioinks that restrict cell‐generated morphogenetic behaviors resulting in structurally static tissues. This work introduces a novel platform that enables the bioprinting of tissues that undergo programmable and predictable 4D shape‐morphing driven by cell‐generated forces. This method utilizes embedded bioprinting to deposit collagen‐hyaluronic acid bioinks within yield‐stress granular support hydrogels that can accommodate and regulate 4D shape‐morphing through their viscoelastic properties. Importantly, precise control over 4D shape‐morphing is possible by modulating factors such as the initial print geometry, cell phenotype, bioink composition, and support hydrogel viscoelasticity. Further, shape‐morphing is found to actively sculpt cell and extracellular matrix alignment along the principal tissue axis through a stress‐avoidance mechanism. To enable predictive design of 4D shape‐morphing patterns, a finite element model is developed that accurately captures shape evolution at both the cellular and tissue levels. Finally, it is demonstrated that programmed 4D shape‐morphing enhances the structural and functional properties of iPSC‐derived heart tissues. This ability to design, predict, and program 4D shape‐morphing holds great potential for engineering organ rudiments that recapitulate morphogenetic processes to sculpt their final shape, composition, and function.

Boost efficiency with buffer and bottom stack optimization in Cu2BaSn(S,Se)4 solar cells by simulation

Cu2BaSn(S,Se)4 is gaining tremendous attention as a potential absorber due to its non-toxicity, earth abundance, and low antisite defects opposing Cu2ZnSn(S,Se)4. However, the highest experimental efficiency of 6.17 % is achieved with the device structure Al:ZnO/Mg:ZnO/Zn1-xCdxS/Cu2BaSn(S,Se)4/Mo where the drawback is large open circuit voltage (VOC) loss stemming from the large cliff at the absorber/buffer interface and back contact recombination. Therefore, finding a suitable non-toxic buffer with modification of the bottom stack is crucial. In this regard, Cu2BaSn(S,Se)4 solar cells based on diverse buffers are numerically simulated using SCAPS-1D with Ni as back contact and introducing back surface field (BSF) at the absorber/Ni interface. At first, a baseline model validating the experimental efficiency is designed. The application of Ni enhanced efficiency to 7.92 % due to the formation of ohmic contact. Further, it is improved to 9.91 % with anti-reflection coating. Afterward, a total of 780 solar cells were designed with six buffer and eight BSF combinations by optimizing the absorber, buffer, and interface properties where the highest efficiency of 28.11 % with incredible fill factor (90 %) and less VOC loss (0.24 V) is accomplished for the Al:ZnO/Mg:ZnO/TiO2/Cu2BaSn(S,Se)4/CuI/Ni solar cell. Further, the importance of BSF is analyzed via energy band diagrams, Mott-Schottky and Nyquist plots. The outcomes disclosed that the BSF greatly influences the energy band alignment, built-in potential, depletion width, and recombination resistance of solar cells, underscoring its significance in improving performance. Overall, the present work proposes an efficient strategy to modify the device configuration of Cu2BaSn(S,Se)4 solar cells to enhance their efficiency.

Numerical simulation method for the assessment of the effect of molar activity on the pharmacokinetics of radioligands in small animals

BackgroundIt is well recognized that the molar activity of a radioligand is an important pharmacokinetic parameter, especially in positron emission tomography (PET) of small animals. Occupation of a significant number of binding sites by radioligand molecules results in low radioligand accumulation in a target region (mass effect). Nevertheless, small-animal PET studies have often been performed without consideration of the molar activity or molar dose of radioligands. A simulation study would therefore help to assess the importance of the mass effect in small-animal PET. Here, we introduce a new compartmental model-based numerical method, which runs on commonly used spreadsheet software, to simulate the effect of molar activity or molar dose on the pharmacokinetics of radioligands.ResultsAssuming a two-tissue compartmental model, time-concentration curves of a radioligand were generated using four simulation methods and the well-known Runge–Kutta numerical method. The values were compared with theoretical values obtained under an ultra-high molar activity condition (pseudo-first-order binding kinetics), a steady-state condition and an equilibrium condition (second-order binding kinetics). For all conditions, the simulation method using the simplest calculation yielded values closest to the theoretical values and comparable with those obtained using the Runge–Kutta method. To satisfy a maximum occupancy less than 5%, simulations showed that a molar activity greater than 150 GBq/μmol is required for a model radioligand when 20 MBq is administered to a 250 g rat and when the concentration of binding sites in target regions is greater than 1.25 nM.ConclusionsThe simulation method used in this study is based on a very simple calculation and runs on widely used spreadsheet software. Therefore, simulation of radioligand pharmacokinetics using this method can be performed on a personal computer and help to assess the importance of the mass effect in small-animal PET. This simulation method also enables the generation of a model time-activity curve for the evaluation of kinetic analysis methods.

Social Cohesion and COVID-19: Integrative Review.

Nations of considerable wealth and sophisticated health care infrastructures have experienced high rates of illness and death from COVID-19. Others with limited economic means and less developed health systems have achieved much lower burdens. To build a full understanding, an appraisal of the contribution of social relationships is necessary. Social cohesion represents a promising conceptual tool. This study aimed to examine scholarship on social cohesion during the COVID-19 pandemic: specifically, the constructions of social cohesion being deployed, the variables chosen for representation, and the effects of and on social cohesion being reported. The PubMed, Scopus, and JSTOR databases were searched for relevant journal articles and gray literature. A total of 100 studies met the inclusion criteria. Data were extracted and analyzed from these using spreadsheet software. Several constructions of social cohesion were found. These concerned interpersonal relationships, sameness and difference, collective action, perceptions or emotions of group members, structures and institutions of governance, locally or culturally specific versions, and hybrid or multidimensional models. Social cohesion was reported to be influential on health outcomes, health behaviors, resilience, and emotional well-being, but there was some potential for it to drive undesirable outcomes. Scholarship reported increases or decreases in quantitative measures of social cohesion, a temporary "rally round the flag" effect early in the pandemic, the variable impacts of policy on social cohesion, and changing interpersonal relationships due to the pandemic conditions. There are numerous issues with the literature that reflect the well-documented limitations of popular versions of the concept. Social cohesion has been used to express a range of different aspects of relationships during the pandemic. It is claimed to promote better health outcomes, more engagement with positive health behaviors, and greater resilience and emotional well-being. The literature presents a range of ways in which it has been altered by the pandemic conditions. There are significant weaknesses to this body of knowledge that greatly impede its overall quality.

Engineering Biomimetic Microvascular Capillary Networks in Hydrogel Fibrous Scaffolds via Microfluidics-Assisted Co-Axial Wet-Spinning.

The microvascular bed plays a crucial role in establishing nutrient exchange and waste removal, as well as maintaining tissue metabolic activity in the human body. However, achieving microvascularization of engineered 3D tissue constructs is still an unsolved challenge. In this work, we developed biomimetic cell-laden hydrogel microfibers recapitulating oriented microvascular capillary-like networks by using a 3D bioprinting technique combined with microfluidics-assisted coaxial wet-spinning. Highly packed and aligned bundles embedding a coculture of human bone marrow-derived mesenchymal stem cells (MSCs) and human umbilical vein endothelial cells (HUVECs) were produced by simultaneously extruding two different bioinks. To this aim, core-shell fibers were wet-spun in a coagulation bath to collect the scaffolds later on a rotary drum. Initially, the versatility of the proposed system was assessed for the extrusion of multimaterial core-shell hydrogel fibers. Subsequently, the platform was validated for the in vitro biofabrication of samples promoting optimal cell alignment along the fiber axis. After 3 weeks of culture, such fiber configuration resulted in the development of an oriented capillary-like network within the fibrin-based core and in the endothelial-specific CD31 marker expression upon MSC/HUVEC maturation. Synergistically, the vertical arrangement of the coaxial nozzle coupled with the rotation of the fiber collector facilitated the rapid creation of tightly packed bundles characterized by a dense, oriented, and extensively branched capillary network. Notably, such findings suggest that the proposed biofabrication strategy can be used for the microvascularization of tissue-specific 3D constructs.

Developing a Performance-Based Assessment to Measure Pre-Service Secondary Teachers’ Digital Competence to Use Digital Mathematics Tools

AbstractDigital competence is an increasingly important component of teacher competence. So far, self-reports are a commonly used, efficient, but potentially problematic assessment method. Standardized and valid assessments to measure digital competence for teachers—particularly of a concrete subject—and proximally to performance are lacking. To address this, we developed a performance-based assessment for pre-service mathematics teachers based on the TPACK and DigCompEdu frameworks, both widely used in teacher education. The test focuses on digital competence related to mathematics tools such as computer algebra systems, dynamic geometry, and spreadsheet software, where technical-mathematical and pedagogical competences are required. This report presents the assessment design and provides validity evidence regarding the internal structure of the test, its sensitivity to intervention, and the relation of the scores to external variables, like affective-motivational aspects or prior experiences with tools based on a study with N = 118 pre-service teachers. First, we confirmed a two-dimensional structure of technical-mathematical and pedagogical aspects of digital competence through a confirmatory factor analysis. Second, expectations regarding the relation to external variables were partially confirmed. Third, we identified the sensitivity of the assessment to an intervention. Especially as expected, the relations between scores and self-assessment results were mixed. Our results indicate that the assessment is suitable for measuring pre-service mathematics teachers’ digital competence in two aspects close to performance. We discuss possible uses to evaluate learning opportunities in teacher education.

Unfolding Electrolyzer Characteristics to Reveal Solar-to-Chemical Efficiency Potential: Rapid Analysis Method Bridging Electrochemistry and Photovoltaics.

Development of photovoltaic-electrochemical (PV-EC) systems for energy storage and industry decarbonization requires multidisciplinary collaborative efforts of different research groups from both photovoltaic and electrochemical research communities. Consequently, the evaluation of the solar-to-chemical or solar-to-fuel efficiency of a new electrolyzer (EC) as a part of a PV-EC system is a time-consuming task that is challenging in a routine optimization loop. To address this issue, a new rapid assessment method is proposed. This method employs power balance requirements to unfold the input EC characteristics into the parameter space of PV-EC systems. The system parameters, composed with the EC output characteristics, yield the solar-to-chemical efficiency attainable by the electrolyzer in combination with any PV device under any irradiance at any relative PV-to-EC scaling and any mode of power coupling. This comprehensive overview is achieved via a mathematically simple conversion of the EC characteristics in any spreadsheet software. The method, designed to streamline the development and minimize the efforts of both the photovoltaic and electrochemical communities, is demonstrated via the analysis of CO2-reduction electrolyzer characteristics and verified with dedicated PV-EC experiments.

Effect of exogenous application of L-mimosine on physiological, cytogenetic, biochemical and anatomical characteristics of Allium cepa L

Mimosine [β-(3‑hydroxy-4-pyridone-1-yl)-l-alanine] is a toxic non- protein amino acid, and one of its major effects is to suppress plant growth and development. Since mimosine is a compound responsible for many interesting biological activities, intensive studies have begun to be carried out on it in recent years. The current work investigated toxic effects of exogenously given 1, 2 and 3 mM l-mimosine doses on some physiological, cytogenetic, biochemical, and anatomical parameters of Allium cepa L. bulbs. For this purpose, the germination percentage (GP), root length (RL), root number (RN), and fresh weight (FW) were determinated as physiological parameters to be examined experimentally; the micronucleus (MN) frequency, chromosomal aberrations (CAs), and mitotic index (MI) were chosen as cytogenetic parameters; and the catalase (CAT) and superoxide dismutase (SOD) activities, malondialdehyde (MDA) level, and free proline (PR) content were determinated as biochemical parameters to be investigated. In addition, the changes in the root anatomical structure of the bulbs were examined under the microscope by taking cross-sections. Onion bulbs were divided into four groups as three treatments and one control (C). For seven days, the bulbs in the treatment groups were germinated with three different doses of l-mimosine (1, 2 and 3 mM), while the bulbs in the C group were germinated with tap water. Consequently, all three doses of l-mimosine caused a decrease (p < 0.05) in all investigated physiological parameter (GP, RL, RN and FW) values compared to C. Furthermore, every l-mimosine dosage resulted in a reduce (p < 0.05) in MI and an increase (p < 0.05) in MN and CA frequency compared to C group. l-mimosine application promoted CAs such as irregular mitosis, stick chromosome, lagging chromosome, protruded out chromosome, pole deviation and alignment in root meristem cells. Exposure to l-mimosine resulted in dose-related increases (p < 0.05) in SOD and CAT enzyme activity as well as MDA and PR levels compared to C group, indicating that l-mimosine also induced toxicity by causing oxidative stress in cells. Also, especially exposure to a dose of 3 mM l-mimosine caused the anatomical damages such as deformations of the epidermis and cortex cells, necrosis, buildup of certain chemical compounds in the cortex cells, thickening of the cortex cell wall, formation of vacuoles in the cell nuclei and flattened cell nuclei in the root tip meristem cells. In summary, since l-mimosine showed an inhibitory effect in the Allium cepa L. test material, it was concluded that the compound induced multi-dimensional toxicity, and the Allium test proved to be a highly valuable tool in identifying this toxicity.

Review on the development of the organoids

Abstract. Organoids, a novel field, were first experimentally supported in 2007 and began to be engineered around 2020. Organoids can be developed from stem cells or organ progenitor cells through the process of differentiation, or they can be created by changing the alignment of pluripotent stem cells throughout the process of cell differentiation. Organoids are exploited for the purpose of scientific research in the areas of human development, illness, screening of medications, and gene therapy. The study utilized a literature review method to examine the evolution of organoid production, new application, and technological advancements. Organoids have advanced from basic tissue engineering organs to being used for modeling diseases and providing more therapeutic options. Their progress is noteworthy and has the potential to be a significant approach in biological medicine research in the future.

Carbon dots induced homeotropic alignment in a negative dielectric nematic liquid crystal material

Abstract Recently, doping guest materials such as quantum dots (QDs) into liquid crystals (LCs) has been of great interest since their addition substantially enhances the properties of LC and opens new avenues for scientific advancement. Here, we report the induction of homeotropic alignment in cells without alignment layers of the negative dielectric nematic liquid crystal, N-(4-Methoxybenzylidene)-4-butylaniline (MBBA) by doping with carbon dots (CDs ∼2.8 ± 0.72 nm). The CDs-MBBA composites (CDs concentration: 0.002, 0.01, 0.03, 0.1 and 0.3 wt%) were investigated using optical polarising microscopy, electro-optical and dielectric techniques. Polarizing optical micrographs and voltage dependent optical transmission revealed the induced homeotropic alignment for all the composites under investigation. Interestingly, the least concentrated sample, 0.002 wt% exhibited partial homeotropic alignment. However, due to light leakage, the optical transmission value below threshold voltage was relatively higher than the rest of the composites. MBBA is a negative dielectric material, hence the application of a voltage across the cell was able to switch the alignment from a dark to a bright state for all composites. However, above a certain voltage (&gt;threshold voltage), the bright state produced some instabilities. The value of dielectric permittivity was observed to decrease with increasing concentration, confirming the effect of CDs in producing homeotropic alignment in MBBA. Measurements as a function of temperature were conducted to examine the thermal stability of the induced alignment. The alignment was found to be stable throughout the nematic phase of MBBA. The induction of such alignment without conventional alignment (i.e., rubbing of polyimides) technique can be helpful in addressing the evolving display demands by making liquid crystal displays (LCDs) and other display devices cost effective.

Influence of Socio-Economic Indicators on the Volume of Foreign Trade in the Regions

The presented paper addresses the principles of forming foreign trade volume in the regions of Russia. During the study, based on open statistical data from reports of the Federal State Statistics Service and using a data analysis tool embedded in the Excel spreadsheet program, the authors developed a regression model that includes seven factor indicators describing socio-economic criteria that are presumed to significantly influence the foreign trade volume in the constituent entities of the Russian Federation. In building and evaluating the regression model, standard econometric analysis procedures were applied, including the stage of model quality assessment, during which insignificant variables were excluded based on criteria such as P-value and standard error. After performing all necessary adjustments to the obtained model, the authors conclude that the foreign trade volume of a region directly depends on its attractiveness to international migrants, the level of education development, and the volume of natural resources. The paper also highlights the limitations of the proposed model, which lie in the limited consideration of the education factor, represented only in quantitative terms and through accessibility, without accounting for the quality of education. Thus, the proposed model identifies key drivers of regional foreign trade potential growth, perceived as foreign trade volume, but requires further refinement, especially in terms of incorporating the quality of education, which will allow for more accurate determination of priority areas in regional economic policy.

ROS Scavenging and Osteogenic Differentiation Potential of L-Methionine-Substituted Poly(Organophosphazene) Electrospun Fibers.

This study investigated the application of poly[bis (ethylmethionato) phosphazene] (PαAPz-M) electrospun fibers in tissue engineering, focusing on their reactive oxygen species (ROS) scavenging capabilities and material-directed cell behavior, including the influence of their degradation products on cell viability and differentiation, and the scaffold topography's influence on cell alignment. The ROS scavenging ability of PαAPz-M was assessed by DPPH assay, and then PαAPz-M's protection against exogenous ROS was studied. The results showed enhanced cell viability on PαAPz-M fiber mats under oxidative stress conditions. This study also investigated the effects of the degradation products of PαAPz-M on cell viability and osteogenic differentiation. It was observed that the late-stage degradation product, phosphoric acid, can significantly influence the osteogenic differentiation of MSCs. In contrast, methionine, which is the early-stage degradation product, showed a minimal influence. Additionally, the study fabricated fiber mats that can lead to enhanced cell alignment while maintaining high porosity. Collectively, this study expanded the applications of PαAPz-M fiber mat protection against oxidative stress and guiding osteogenic differentiation and cell alignment.

RADIATION PATIENT AND WORKER DOSE APPLICATION (SI PADI)

Medical procedures for diagnostic and therapeutic purposes currently use many sources of ionizing radiation. Monitoring patient and radiation worker doses is needed to keep the radiation dose received to a minimum. The purpose of the patient and radiation worker dose application is to facilitate the task of Medical Physicists in conducting patient and radiation worker dose audits so that they become faster and more effective. The patient and radiation worker dose application is made based on dose audits conducted by Medical Physicists by monitoring patient doses on CT Scan examinations using CT dose index volume (CTDIvol) and dose length product (DLP) parameters on CT Scans and patient doses of the Siemens Somatom 128 slice Cathlab using Dose Area Product (DAP) data on the Philips Azurion 7 C-Arm. Radiation worker dose audits are conducted using evaluation data from TLD badges, TLD eyes, and pocket dosimeters of radiation workers working at Karawang Regional Hospital. Data processing uses a spreadsheet program. The menus on the dashboard are combined with formulas so that the data automatically appears in tables, graphs, or special formats as needed. The radiation patient and worker dose information system (Si Padi) was successfully developed at Karawang Regional Hospital to realize efforts to optimize radiation protection and safety for patients and radiation workers. Keywords: patient dose, radiation worker dose, dose audit, CT dose index (CTDI), dose length product (DLP), dose area product (DAP), Si Padi application.

Predictive model of spatial nematic order in confined cell populations

Two-dimensional tissues made of spindle-shaped cells have many applications in the fields of tissue engineering and biotechnology. The uniformity of the tissues is critically affected by topological defects, which are singular points of cell alignment. For systematic control and analysis of defect distributions, this paper proposes a numerical method to predict and quantify spatial distributions of defects in two-dimensional domains. In the proposed method, spindle-shaped cells are modeled as nematic liquid crystals, whose alignment and Frank elastic energy are explicitly expressed. The equilibrium distributions of the defects can then be calculated using a Markov chain Monte Carlo method. The proposed method was experimentally verified by culturing mouse myoblast (C2C12) cells on microwells. The order of the defect scattering was almost the same as for the proposed estimation method, indicating that the proposed method can be used for the systematic design of topographical guides for controlling defect distributions.

Optimization analysis of the particle focusing and separation parameters of a sheathless microfluidic device using standing surface acoustic waves

Flow-based particle separation usually requires a sheath flow for particle manipulation. Sheath fluid is a specialized buffer solution that directs the alignment of particles or cells into the center of the stream. By utilizing sheath flow, the particles or cells can be focused on the middle line of the microchannel, where they can be individually analyzed. However, the method requires an additional design for creating a suitable sheath flow. Purity and separation efficiency may also be influenced by the sheath flow. In this study, we present a sheathless device for particle focusing and separation using standing surface acoustic waves (SSAWs). The device comprises two regions: the focusing and separation regions. In the focusing region, particles in a continuous flow are aligned in the middle of the microchannel by SSAWs; in the separation region, tilted-angle SSAW-based particle separation is used to control particle migration. Varying particle sizes were focused in the focusing region and then separated in the separation region in the sheathless device. Experiments and simulations were also utilized to optimize a sheathless device. 10 and 20 μm particle focusing and separation were conducted in a sheathless device for the first time. We demonstrate that the separation of particles with a diameter of 10 and 20 μm has 90.8 ± 1.75% and 99.5 ± 0.8% separation efficiency, and 98 ± 3.4 and 97.9 ± 0.9% purity. Compared with other focusing and separation technologies, our device can also provide high purity, high separation efficiency, and high device density.

Experimental evaluation and simulation of myoblast cell alignment on the UV-irradiated liquid crystalline elastomers as a versatile tissue-engineered Scaffolding material

Efforts to develop versatile tissue-engineered scaffolds mimicking the functions of extracellular matrices (ECMs) have led to the emergence of liquid crystalline elastomers (LCEs) as promising materials. Here, thiol-acrylate-based LCEs forming a nematic phase upon UV irradiation were synthesized, and their biological compatibility was evaluated using C2C12 myoblast cells. Prior to UV exposure, some characteristics, e.g., phase transition temperature (TNI), order parameter, and reaction time, of the as-synthesized LCEs are characterized for property optimization. Fourier-transform infrared spectroscopy revealed that thiol-acrylate Michael addition polymerization was successful, judged by the disappearance of the characteristic peaks of thiol and acrylate groups. Differential scanning calorimetry thermograms and dynamic mechanical thermal analysis curves showed TNI values at ca. 49 °C, at which point the nematic phase is the dominant morphology. Moreover, the cross-linking density, the fixing, and the recovery ratios for the sample with optimal properties (i.e., LCE3) were determined to be 10.3 mol/cm3, 97.2 % and 91 %, respectively. Assessment of mesomorphism and roughness demonstrated the suitability of LCE3 for cell culture. Subsequent studies on adhesion, viability, differentiation, and proliferation of cultured myoblast cells, coupled with particle image velocimetry simulation, highlighted the potential of UV-irradiated LCE3 as a promising scaffold material for inducing surface morphology-induced cellular alignment and interactions.

Two-step global sensitivity analysis of a non-local integro-differential model for Cancer-on-Chip experiments

The present work focuses on a non-local integro-differential model reproducing Cancer-on-chip experiments where tumor cells, treated with chemotherapy drugs, secrete chemical signals stimulating the immune response. The reliability of the model in reproducing the phenomenon of interest is investigated through a global sensitivity analysis, rather than a local one, to have global information about the role of parameters, and by examining potential non-linear effects in greater detail. Focusing on a region in the parameter space, the effect of 13 model parameters on the in silico outcome is investigated by considering 11 different target outputs, properly selected to monitor the spatial distribution and the dynamics of immune cells along the period of observation. In order to cope with the large number of model parameters to be investigated and the computational cost of each numerical simulation, a two-step global sensitivity analysis is performed. First, the screening Morris method is applied to rank the effect of the 13 model parameters on each target output and it emerges that all the output targets are mainly affected by the same 6 parameters. The extended Fourier Amplitude Sensitivity Test (eFAST) method is then used to quantify the role of these 6 parameters. As a result, the proposed analysis highlights the feasibility of the considered space of parameters, and indicates that the most relevant parameters are those related to the chemical field and cell-substrate adhesion. In turn, it suggests how to possibly improve the model description as well as the calibration procedure, in order to better capture the observed phenomena and, at the same time, reduce the complexity of the simulation algorithm. On one hand, the model could be simplified by neglecting cell–cell alignment effects unless clear empirical evidences of their importance emerge. On the other hand, the best way to increase the accuracy and reliability of our model predictions would be to have experimental data/information to reduce the uncertainty of the more relevant parameters.

Developing Excel VBA Functions for the Mathematical Modeling of Three-Dimensional Vectors

The current computer support for operations involving three-dimensional vectors is insufficient, even in widely used programs like Excel. These programs lack customised features specifically designed for vector operations. However, this limitation can be overcome by using the options provided by Visual Basic for Applications. By creating user functions, we can effectively calculate various results related to the mathematical application of vectors. These functions include determining the magnitude and absolute value of a vector, calculating the angle between two vectors or the cosine of that angle, finding the scalar product and vector product of two vectors, and evaluating the mixed product of three vectors. By incorporating these custom functions into the spreadsheet program, users can easily perform mathematical calculations pertaining to three-dimensional vectors.

Histological Evaluation of Polyacid-Modified Composite Resin and Conventional Composite Resin Used for Primary Molars Restoration.

Background: The present study evaluated the histological outcomes of two dental restorative materials, polyacid-modified composite resin (compomer) and conventional composite resin, in the primary molars of puppies. Materials and Methods: Twenty sound primary molars in four puppies were used. The puppies were rendered unconscious using general anesthesia. Similar cylindrical Class V cavities were prepared in 16 of the 20 selected primary molars. The teeth were divided into three groups: Group I: Eight cavities were restored with compomer; Group II: Eight cavities were restored with conventional composite resin; Group III: Four teeth remained untreated and were used as controls. In Groups I and II, four teeth were examined histologically after 2 weeks and the other four after 6 weeks. The histological findings were analyzed and compared to determine the effects of each type of resin material on the dentine and the pulp. Results: At 6 weeks, the specimens tested for compomer showed obvious destructive changes in the central region and the region of the pulp adjacent to the cavity. The specimens tested for conventional composite resin revealed, at 6 weeks, massive destruction of the pulp tissues and abscess formation was observed. All the specimens tested in the control group showed normal cellularity, normal vascularity, and proper alignment of odontoblast cells. Conclusions: The teeth restored with compomer demonstrated more favorable pulpal reactions when compared with the teeth restored with conventional composite resin after 6 weeks.