Spreadsheet Research Articles

Electrospinning of Polycaprolactone Nanofibrous Scaffolds Containing Folic Acid for Nerve Tissue Engineering

Objective: The aim of the study was to employ electrospinning technology to fabricate aligned nanofibrous scaffolds of polycaprolactone (PCL) containing folic acid (FA) for nerve tissue engineering. Material and Methods: Scanning electron microscopy (SEM) was used to assess the diameter distribution and degree of alignment of the nanofibers. Fourier transform infrared spectroscopy (FTIR) and powder X-ray diffraction (PXRD) were used to analyze the chemical and crystalline structures of the scaffold. Additionally, the content and release behavior of FA in the PCL fibrous scaffolds were examined. Finally, the biocompatibility of the scaffolds was evaluated using rat Schwann cells, assessing cell proliferation, alignment, and morphology. Results: The study revealed that the nanofiber diameters ranged from 210.07 to 227.36 nm, and the scaffolds maintained an amorphous form with no effects on their chemical structure following the electrospinning process. The investigation demonstrated that PCL fibers could accommodate FA loading within a range of 99.25-102.49% w/w and that the release profile of FA followed Higuchi model. Moreover, the FA-containing PCL nanofibrous scaffolds significantly enhanced rat Schwann cell proliferation during the initial two days of culture when compared to a normal PCL nanofiber scaffold. The hydrophilic properties of folic acid are thought to have facilitated directional growth along the electrospun nanofibers, contributing to the observed results. Conclusion: Finally, PCL-containing FA nanofibrous scaffolds may be applicable to nerve tissue engineering.

Independent regulation of Z-lines and M-lines during sarcomere assembly in cardiac myocytes revealed by the automatic image analysis software sarcApp

Sarcomeres are the basic contractile units within cardiac myocytes, and the collective shortening of sarcomeres aligned along myofibrils generates the force driving the heartbeat. The alignment of the individual sarcomeres is important for proper force generation, and misaligned sarcomeres are associated with diseases, including cardiomyopathies and COVID-19. The actin bundling protein, α-actinin-2, localizes to the ‘Z-Bodies” of sarcomere precursors and the ‘Z-Lines’ of sarcomeres, and has been used previously to assess sarcomere assembly and maintenance. Previous measurements of α-actinin-2 organization have been largely accomplished manually, which is time-consuming and has hampered research progress. Here, we introduce sarcApp, an image analysis tool that quantifies several components of the cardiac sarcomere and their alignment in muscle cells and tissue. We first developed sarcApp to utilize deep learning-based segmentation and real space quantification to measure α-actinin-2 structures and determine the organization of both precursors and sarcomeres/myofibrils. We then expanded sarcApp to analyze ‘M-Lines’ using the localization of myomesin and a protein that connects the Z-Lines to the M-Line (titin). sarcApp produces 33 distinct measurements per cell and 24 per myofibril that allow for precise quantification of changes in sarcomeres, myofibrils, and their precursors. We validated this system with perturbations to sarcomere assembly. We found perturbations that affected Z-Lines and M-Lines differently, suggesting that they may be regulated independently during sarcomere assembly.

Independent regulation of Z-lines and M-lines during sarcomere assembly in cardiac myocytes revealed by the automatic image analysis software sarcApp.

Sarcomeres are the basic contractile units within cardiac myocytes, and the collective shortening of sarcomeres aligned along myofibrils generates the force driving the heartbeat. The alignment of the individual sarcomeres is important for proper force generation, and misaligned sarcomeres are associated with diseases, including cardiomyopathies and COVID-19. The actin bundling protein, α-actinin-2, localizes to the 'Z-Bodies" of sarcomere precursors and the 'Z-Lines' of sarcomeres, and has been used previously to assess sarcomere assembly and maintenance. Previous measurements of α-actinin-2 organization have been largely accomplished manually, which is time-consuming and has hampered research progress. Here, we introduce sarcApp, an image analysis tool that quantifies several components of the cardiac sarcomere and their alignment in muscle cells and tissue. We first developed sarcApp to utilize deep learning-based segmentation and real space quantification to measure α-actinin-2 structures and determine the organization of both precursors and sarcomeres/myofibrils. We then expanded sarcApp to analyze 'M-Lines' using the localization of myomesin and a protein that connects the Z-Lines to the M-Line (titin). sarcApp produces 33 distinct measurements per cell and 24 per myofibril that allow for precise quantification of changes in sarcomeres, myofibrils, and their precursors. We validated this system with perturbations to sarcomere assembly. We found perturbations that affected Z-Lines and M-Lines differently, suggesting that they may be regulated independently during sarcomere assembly.

Engineered muscle from micro-channeled PEG scaffold with magnetic Fe3O4 fixation towards accelerating esophageal muscle repair

Engineered scaffolds are used for repairing damaged esophagus to allow the precise alignment and movement of smooth muscle for peristalsis. However, most of these scaffolds focus solely on inducing cell alignment through directional apparatus, often overlooking the promotion of muscle tissue formation and causing reduced esophageal muscle repair effectiveness. To address this issue, we first introduced aligned nano-ferroferric oxide (Fe3O4) assemblies on a micropatterned poly(ethylene glycol) (PEG) hydrogel to form micro-/nano-stripes. Further modification using a gold coating was found to enhance cellular adhesion, orientation and organization within these micro-/nano-stripes, which consequently prevented excessive adhesion of smooth muscle cells (SMCs) to the thin PEG ridges, thereby effectively confining the cells to the Fe3O4-laid channels. This architectural design promotes the alignment of the cytoskeleton and elongation of actin filaments, leading to the organized formation of muscle bundles and a tendency for SMCs to adopt synthetic phenotypes. Muscle patches are harvested from the micro-/nano-stripes and transplanted into a rat esophageal defect model. In vivo experiments demonstrate the exceptional viability of these muscle patches and their ability to accelerate the regeneration of esophageal tissue. Overall, this study presents an efficient strategy for constructing muscle patches with directional alignment and muscle bundle formation of SMCs, holding significant promise for muscle tissue regeneration.

Aligned skeletal muscle assembly on a biofunctionalized plant leaf scaffold.

Decellularized plant scaffolds have drawn attention as alternative tissue culture platforms due to their wide accessibility, biocompatibility, and diversity of innate microstructures. Particularly, in this work, monocot leaves with innate uniaxial micropatterned topography were utilized to promote cell alignment and elongation. The leaf scaffold was biofunctionalized with poly(PEGMEMA-r-VDM-r-GMA) copolymer that prevented non-specific protein adsorption and was modified with cell adhesive RGD peptide to enable cell adhesion and growth in serum-free media. The biofunctionalized leaf supported the adhesion, growth, and alignment of various human cells including embryonic stem cells (hESC) derived muscle cells. The hESC-derived myogenic progenitor cells cultured on the biofunctionalized leaf scaffold adopted a parallel orientation and were elongated along the leaf topography. These cells showed significant early myogenic differentiation and muscle-like bundled myotube formation. The aligned cells formed compact myotube assemblies and showed uniaxial muscle contraction under chemical stimulation, a critical requirement for developing functional skeletal muscle tissue. Polymer-functionalized plant leaf scaffolds offer a novel human cell culture platform and have potential in human tissue engineering applications that require parallel alignment of cells. STATEMENT OF SIGNIFICANCE: Plant scaffolds are plentiful sources in nature and present a prefabricated construct to present topographical cues to cells. Their feature width is ideal for human cell alignment and elongation, especially for muscle cells. However, plant scaffolds lack proteins that support mammalian cell culture. We have developed a polymer coated leaf scaffold that enables cell adhesion and growth in serum-free media. Human muscle cells cultured on the biofunctionalized leaf, aligned along the natural parallel micro-patterned leaf topography, and formed muscle-like bundled myotube assemblies. These assemblies showed uniaxial muscular contraction, a critical requirement for developing functional skeletal muscle tissue. The biodiversity of the plant materials offers a novel human cell culture platform with potential in human tissue engineering.

FormaT5: Abstention and Examples for Conditional Table Formatting with Natural Language

Formatting is an important property in tables for visualization, presentation, and analysis. Spreadsheet software allows users to automatically format their tables by writing data-dependent conditional formatting (CF) rules. Writing such rules is often challenging for users as it requires understanding and implementing the underlying logic. We present FormaT5, a transformer-based model that can generate a CF rule given the target table and a natural language description of the desired formatting logic. We find that user descriptions for these tasks are often under-specified or ambiguous, making it harder for code generation systems to accurately learn the desired rule in a single step. To tackle this problem of under-specification and minimise argument errors, FormaT5 learns to predict placeholders though an abstention objective. These placeholders can then be filled by a second model or, when examples of rows that should be formatted are available, by a programming-by-example system. To evaluate FormaT5 on diverse and real scenarios, we create an extensive benchmark of 1053 CF tasks, containing real-world descriptions collected from four different sources. We release our benchmarks to encourage research in this area. Abstention and filling allow FormaT5 to outperform 8 different neural approaches on our benchmarks, both with and without examples. Our results illustrate the value of building domain-specific learning systems.

Association of thyroid function and obesity with chronic obstructive pulmonary disease: An observational cross-sectional study

Background: Chronic obstructive pulmonary disease (COPD), defined by GOLD as a preventable and treatable disease with some significant extra pulmonary effects, is a very common clinical entity in clinical practice. COPD is associated with significant extra pulmonary (systemic) effects. Systemic inflammation may be mainly driven by risk factor – cigarette smoking and it persists after smoking cessation. COPD is associated with severe extrapulmonary (systemic) manifestations and comorbidities such as cardiac, osteoporosis, gastroesophageal reflux disease, Thyroid Dysfunctions, and obesity. Body mass index (BMI) has also been identified as an independent prognostic factor for COPD. Aims and Objectives: This study was conducted to determine the proportion of hypothyroidism and obesity in COPD patients and their association with GOLD stage. Materials and Methods: This was an observational cross-sectional study assessing, COPD patients to determine proportions of thyroid disorder and obesity within a period of 1 year. Data were coded and recorded in MS Excel spreadsheet program. SPSS v23 (IBM Corp.) was used for data analysis. Results: The following variables were significantly associated (P<0.05) with the variable “GOLD Stage: Weight (kg), BMI, and obesity. 30 (35.3%) COPD patient having abnormal thyroid profile and all 30 (35.3%) were diagnosed as hypothyroid. Conclusion: From the study, it was found that BMI of patient decreases with increase in GOLD COPD staging. This indicates that obesity might have some protective effect in COPD but this need to be further evaluated.

High-throughput design of cultured tissue moulds using a biophysical model: optimising cell alignment

The technique presented here identifies tethered mould designs, optimised for growing cultured tissue with very highly-aligned cells. It is based on a microscopic biophysical model for polarised cellular hydrogels. There is an unmet need for tools to assist mould and scaffold designs for the growth of cultured tissues with bespoke cell organisations, that can be used in applications such as regenerative medicine, drug screening and cultured meat. High-throughput biophysical calculations were made for a wide variety of computer-generated moulds, with cell-matrix interactions and tissue-scale forces simulated using a contractile network dipole orientation model. Elongated moulds with central broadening and one of the following tethering strategies are found to lead to highly-aligned cells: (1) tethers placed within the bilateral protrusions resulting from an indentation on the short edge, to guide alignment (2) tethers placed within a single vertex to shrink the available space for misalignment. As such, proof-of-concept has been shown for mould and tethered scaffold design based on a recently developed biophysical model. The approach is applicable to a broad range of cell types that align in tissues and is extensible for 3D scaffolds.

Development and testing of a new flexible, easily and widely applicable chemical water quality index (CWQI)

Water quality indices (WQIs) are numeric parameters that summarize the overall quality status of freshwaters compared to quality standards by aggregating multiple physicochemical data into a single value. Among the available WQIs in the literature, several criticalities were recognized including: (a) mathematical complexity of the computation, (b) lack of inclusivity, (c) arbitrary weight assignment method, and (d) site-specificity of most of the indexes. The proposed index, the Chemical Water Quality Index (CWQI), aims to overcome these flaws and provides a computation based on simple mathematic equations that are easily manageable on spreadsheet software. The computation is divided into two steps: (i) parametrization of the variables and (ii) index determination. The parametrization consists of assigning a score (s) from ∼1 to 10 to each chemical variable based on (i) measured concentrations and (ii) quality targets (e.g., the limits provided by the European legislation for drinking waters). In the second step, a weight (w), directly proportional to the score (s), is assigned to each parameter, allowing to overcome any bias related to subjective assignments from the user. The resulting CWQI ranges from ∼1 (very good quality) to 10 (extremely poor quality). The reliability and accuracy of the CWQI were assessed by (i) applying the computation to 1,810 waters and (ii) comparing our results with another available WQI. The CWQI outputs showed an optimal response with the number of variables exceeding the quality target with high correlation coefficients (r = 0.94; R2 = 0.89). Due to the simplicity of its computation, the absence of arbitrariness in the weightage of selected variables, and the independence of the proposed approach regarding the choice of the chemical parameters, CWQI can be easily and universally applied.

Three-Dimensional Bioprinting in Soft Tissue Engineering for Plastic and Reconstructive Surgery.

Skeletal muscle tissue engineering (TE) and adipose tissue engineering have undergone significant progress in recent years. This review focuses on the key findings in these areas, particularly highlighting the integration of 3D bioprinting techniques to overcome challenges and enhance tissue regeneration. In skeletal muscle TE, 3D bioprinting enables the precise replication of muscle architecture. This addresses the need for the parallel alignment of cells and proper innervation. Satellite cells (SCs) and mesenchymal stem cells (MSCs) have been utilized, along with co-cultivation strategies for vascularization and innervation. Therefore, various printing methods and materials, including decellularized extracellular matrix (dECM), have been explored. Similarly, in adipose tissue engineering, 3D bioprinting has been employed to overcome the challenge of vascularization; addressing this challenge is vital for graft survival. Decellularized adipose tissue and biomimetic scaffolds have been used as biological inks, along with adipose-derived stem cells (ADSCs), to enhance graft survival. The integration of dECM and alginate bioinks has demonstrated improved adipocyte maturation and differentiation. These findings highlight the potential of 3D bioprinting techniques in skeletal muscle and adipose tissue engineering. By integrating specific cell types, biomaterials, and printing methods, significant progress has been made in tissue regeneration. However, challenges such as fabricating larger constructs, translating findings to human models, and obtaining regulatory approvals for cellular therapies remain to be addressed. Nonetheless, these advancements underscore the transformative impact of 3D bioprinting in tissue engineering research and its potential for future clinical applications.

Fabrication of a Magnetically Driven Cell-Stretching Device for Predefined Cell Alignment in Vitro

Various devices have been developed that use stretching silicone sheets to evaluate cellular mechanotransduction. However, few studies have explored predefined cell alignments using mechanical stimuli for engineering applications, including cell sheets and drug screenings. Therefore, we proposed a magnetically driven cell-stretching device for predefined cell alignment in vitro, which consisted mainly of a circular silicone membrane with a neodymium magnet and standard cell culture dish. As the proposed device was incorporated into a cell culture dish, there may be a small risk of contamination in long-term incubation experiments. The device was fabricated by assembling a polydimethylsiloxane membrane and silicone ring. The fabricated device showed that the membrane strain increased with increasing voltage application to the electromagnet, and indicated that cell alignment occurs when strain exceeds 0.8%. Following cyclic stimulation of cells adhered to a membrane for 4 h in a CO2 incubator with 1.05% strain at 0.1 Hz, cell alignment with the predefined direction increased by 20.4% compared to that before stimulation. The findings imply that the proposed device may be utilized for predefined cell alignment.

Development of a hyaluronic acid—collagen bioink for shear-induced fibers and cells alignment

Human tissues are characterized by complex composition and cellular and extracellular matrix (ECM) organization at microscopic level. In most of human tissues, cells and ECM show an anisotropic arrangement, which confers them specific properties. In vitro, the ability to closely mimic this complexity is limited. However, in the last years, extrusion bioprinting showed a certain potential for aligning cells and biomolecules, due to the application of shear stress during the bio-fabrication process. In this work, we propose a strategy to combine collagen (col) with tyramine-modified hyaluronic acid (THA) to obtain a printable col-THA bioink for extrusion bioprinting, solely-based on natural-derived components. Collagen fibers formation within the hybrid hydrogel, as well as collagen distribution and spatial organization before and after printing, were studied. For the validation of the biological outcome, fibroblasts were selected as cellular model and embedded in the col-THA matrix. Cell metabolic activity and cell viability, as well as cell distribution and alignment, were studied in the bioink before and after bioprinting. Results demonstrated successful collagen fibers formation within the bioink, as well as collagen anisotropic alignment along the printing direction. Furthermore, results revealed suitable biological properties, with a slightly reduced metabolic activity at day 1, fully recovered within the first 3 d post-cell embedding. Finally, results showed fibroblasts elongation and alignment along the bioprinting direction. Altogether, results validated the potential to obtain collagen-based bioprinted constructs, with both cellular and ECM anisotropy, without detrimental effects of the fabrication process on the biological outcome. This bioink can be potentially used for a wide range of applications in tissue engineering and regenerative medicine in which anisotropy is required.

Visual Outcomes of Cataract Surgery at the Eye Foundation Community Hospital in Nigeria

Aims: To determine the visual outcome of cataract surgeries postoperatively at first day, one and three months. 
 Study Design: Retrospective, case series study.
 Place and Duration of Study: Eye Foundation Community Hospital, Ilese-Ijebu-Imushin, Ogun state of Nigeria. 3-month duration from June 1st 2019 to August 31st 2019.
 Methodology: All patients 18 years and above operated for cataract surgery without comorbidity were included in the study. Type of surgery done were manual small incision cataract surgery (MSICS) and phacoemulsification. Patient data were entered into excel spread sheet created for the study. From where it was cleaned up and exported in to statistical package for social sciences 20. Visual outcome was assessed on the first day, first month and at third month post operatively. Snellen visual acuity was converted to log MAR. P value = 0.05 is determined as statistically significant. 
 Results: Two hundred and fifty (250) patients or eyes were analysed in this study. Two hundred and twenty patients (88%) had MSICS, 30 (12%) had phacoemulsification. Preoperatively, majority (150, 60%) presented with visual acuity less than 3/60 followed by patients with visual acuity between 6/18 to 6/60 (76, 30.4%). Nineteen patients (7.6%) had visual acuity of 6/18 or better. Mean preoperative log MAR was 1.6 ± 0.8 (equivalent to count finger). 3-month post op, two hundred and fourteen (85.6%) had uncorrected visual acuity of 6/18 or better while 231 patients (92.4%) had best corrected (with pinhole) visual acuity of 6/18 or better. (P=0.004 and 0.038 respectively). 
 Conclusion: There is an appreciable improvement in the visual outcome following cataract surgery.

Strategies for Anisotropic Fibrillar Hydrogels: Design, Cell Alignment, and Applications in Tissue Engineering.

Efficient cellular alignment in biomaterials presents a considerable challenge, demanding the refinement of appropriate material morphologies, while ensuring effective cell-surface interactions. To address this, biomaterials are continuously researched with diverse coatings, hydrogels, and polymeric surfaces. In this context, we investigate the influence of physicochemical parameters on the architecture of fibrillar hydrogels that significantly orient the topography of flexible hydrogel substrates, thereby fostering cellular adhesion and spatial organization. Our Review comprehensively assesses various techniques for aligning polymer fibrils within hydrogels, specifically interventions applied during and after the cross-linking process. These methodologies include mechanical strains, precise temperature modulation, controlled fluidic dynamics, and chemical modulators, as well as the use of magnetic and electric fields. We highlight the intrinsic appeal of these methodologies in fabricating cell-aligning interfaces and discuss their potential implications within the fields of biomaterials and tissue engineering, particularly concerning the pursuit of optimal cellular alignment.

Covalent Immobilization of Collagen Type I to a Polydimethylsiloxane Surface for Preventing Cell Detachment by Retaining Collagen Molecules under Uniaxial Cyclic Mechanical Stretching Stress.

Surface modification of polydimethylsiloxane (PDMS) with an extracellular matrix (ECM) is useful for enhancing stable cell attachment. However, few studies have investigated the correlation between the stability of deposited ECM and cell behavior on the PDMS surfaces in external stretched cell culture systems. Herein, covalent collagen type I (Col)-immobilized PDMS surfaces were fabricated using 3-aminopropyl-trimethoxysilane, glutaraldehyde, and Col molecules. The immobilized collagen molecules on the PDMS surface were more stable and uniform than the physisorbed collagen. The cells stably adhered to the Col-immobilized surface and proliferated even under uniaxial cyclic mechanical stretching stress (UnCyMSt), whereas the cells gradually detached from the Col-physisorbed PDMS surface, accompanied by a decrease in the number of deposited collagen molecules. Moreover, the immobilization of collagen molecules enhanced cell alignment under the UnCyMSt. This study reveals that cell adhesion, proliferation, and alignment under the UnCyMSt can be attributed to the retention of collagen molecules on the PDMS surface.

Analysis of Antibacterial Efficacy and Cellular Alignment Regulation on Plasma Nanotextured Chitosan Surfaces.

To address implant-related infections, antibacterial solutions specific to biomaterials are required to prevent bacterial proliferation. Traditional antibiotic usage has been found insufficient, motivating researchers to investigate alternative strategies such as surface modification and the application of antifouling or infection-resistant properties. A developing interest lies in designing surfaces that mimic natural antibacterial nanotopographies. In this study, we conducted a quantitative analysis of the outcomes from plasma nanotexturing, with particular emphasis on how the organization of topography influences antibacterial efficacy and the regulation of cell alignment. Plasma nanotexturing was applied to chitosan surfaces, which gradually transformed from nanopores to pillars and eventually into tilted pillars, as the plasma parameters (fluence and angle) increased. We used directed plasma nanosynthesis, a plasma-based technique that primarily induces topographical alterations on the surfaces. The surfaces were systematically characterized, incorporating methods such as scanning electron microscopy (SEM), atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS). A comprehensive comparison of the nanotextures was executed by utilizing a trapezoidal method to calculate aspect ratios and assess texture orientation by examining the gaps in the nanostructures. We evaluated antibacterial properties against E. coli and S. aureus strains and assessed the survival and alignment of human bone marrow mesenchymal stem cells. Our findings reveal a significant reduction in bacterial adhesion (>80%) and growth on nanotextured surfaces, underscoring their potential for clinical applications. Moreover, we measured cell alignment, presenting the results in both a color-coded and numerical format to demonstrate the preferential alignment orientation induced specially by the tilted nanotexture. These insights highlight the profound impacts of plasma nanotexturing, indicating its potential for innovative biomedical applications such as advanced wound healing and tissue engineering.

Biofabrication of Composite Tendon Constructs with the Fibrous Arrangement, High Cell Density, and Enhanced Cell Alignment.

Current tissue-engineered tendons are mostly limited to the replication of fibrous organizations of native tendons, which lack the biomimicry of a densely packed cell arrangement. In this study, composite tendon constructs (CTCs) with fibrous arrangement, high cell density, and enhanced cell alignment were developed by integrating the electrohydrodynamic jet 3D printing (e-jetting) technique and the fabrication of tissue strands (TSs). A tubular polycaprolactone (PCL) scaffold was created using e-jetting, followed by coating a thin layer of alginate. Human mesenchymal stem cells were then microinjected into the PCL scaffolds, aggregated into TSs, and formed CTCs with a core-shell structure. Owing to the presence of TSs, CTCs demonstrated the anatomically relevant cell density and morphology, and cells migrated from the TSs onto e-jetted scaffolds. Also, the mechanical strength of CTCs approached that of native tendons due to the existence of e-jetted scaffolds (Young's modulus: ∼21 MPa, ultimate strength: ∼5 MPa). During the entire culture period, CTCs maintained high survival rates and good structural integrity without the observation of necrotic cores and disintegration of two portions. In addition, CTCs that were cultured with uniaxial cyclic stretching revealed not only the increased expression of tendon-related proteins but also the enhanced cellular orientation. The promising results demonstrated the potential of this novel biofabrication strategy for building tissue-engineered tendon constructs with the proper biological, mechanical, and histological relevance..

Uterine fibroid cell cytoskeletal organization is affected by altered G protein-coupled estrogen receptor-1 and phosphatidylinositol 3-kinase signaling

To determine if cyclic strain affects fibroid cell cytoskeletal organization, proliferation, and collagen synthesis differently than myometrial cells. Basic science study using primary cultures of patient-matched myometrial and fibroid cells. Academic Laboratory PATIENT(S): Premenopausal women undergoing myomectomy or hysterectomy for the treatment of symptomatic uterine fibroids. Application of uniaxial strain patterns mimicking periovulation, menses, or dysmenorrhea using the Flexcell® tension system or static control. Secondarily, inhibition of G protein-coupled ER1 (GPER1, G36), and phosphatidylinositol 3-kinase (PI3K, Ly294002). Cell alignment, cell number, and collagen content RESULT: (s): Menses-strained cells demonstrated the most variation in cell alignment, cell proliferation, and pro-collagen content between myometrial and fibroid cells. Pro-collagen content decreased in myometrial cells with increasing strain amplitude and decreasing frequency. GPER1 inhibition decreases cellular alignment in the presence of strain. (s): Mechanotransduction affecting cytoskeletal arrangement through the GPER1-PI3K pathway is altered in fibroid cells. These results highlight the importance of incorporating mechanical stimulation into the in vitro study of fibroid pathology.

Parameter identification of photovoltaic converter models

The work aims to develop a simple and effective method for identifying the parameters of photovoltaic converter (PV-cell) models for their wide practical application. An exponential model having one diode and five parameters is adopted as the basic model of the photovoltaic converter to facilitate its easy integration into MatLab/Simulink simulation software. To identify the parameters of models of photovoltaic converters, an original method based on finding the minimum of the root-mean-square error between model and experimental volt-ampere characteristics was used. The effectiveness of the method was confirmed by determining the parameters of different models of photovoltaic modules based on various technologies: thin-film Shell ST40, monocrystalline Shell SP70, and polycrystalline Kyocera KC200GT. A developed technique for constructing mathematical models of photovoltaic converters in order to reproduce their electrical characteristics is presented. The solution is easily implemented in Excel spreadsheet software with the “Search for Solution” add-on installed. The proposed universal method for identifying the parameters of photoconverter models can be used to build models of a wide range of photovoltaic modules and solar cells. The model current-voltage characteristics of the considered photovoltaic modules are shown to be in good agreement with experimental characteristics across a wide range of temperature and insolation conditions corresponding to their actual operation. Higher accuracy is achieved when using the proposed identification method to determine the electrical parameters of mathematical models of photovoltaic converters than when using other well-known analytical and numerical methods. The result is a simple and effective method for constructing mathematical models of photovoltaic converters, which does not require the use of programming or the development of specialized numerical algorithms, allowing it to be used to solve many technical problems related to the design and operation of photovoltaic systems.

Challenges and Opportunities in Online Computer Science & Engineering Education: A Study in Velammal College of Engineering & Technology, Madurai

Abstract: Owing to the entry of COVID-19, starting from the year 2000, India managed online education well for more than a year and a half. Now, the question is to understand whether the online mode of education is as effective as the face-to-face classes. This study intends to focus on identifying the challenges and finding the opportunities to enhance the quality of online engineering education with respect to Computer Science and Engineering (CSE) branch. A survey was conducted using a questionnaire involving the chosen 2nd year, 3rd year, and 4th year students of CSE department, Velammal College of Engineering & Technology, Madurai (VCET), who have had the experience of acquiring knowledge through both offline and online modes. The spreadsheet software was used to filter, organize as well as visualize quantitative data, and descriptive methodology was adopted for the data analysis. The result of the study will lay a scope to understand the existing gaps in online CSE education and the proposed ideas to fill the same enhancing the resources. Further, this study may play a pivotal role in making effective online CSE education at par with face-to-face classes completely possible and preferable. Keywords: COVID-19; CSE; digital skills; online education; Velammal College of Engineering & Technology.