Search results for: cells integration
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 5763

Search results for: cells integration

4743 Molecular Portraits: The Role of Posttranslational Modification in Cancer Metastasis

Authors: Navkiran Kaur, Apoorva Mathur, Abhishree Agarwal, Sakshi Gupta, Tuhin Rashmi

Abstract:

Aim: Breast cancer is the most common cancer in women worldwide, and resistance to the current therapeutics, often concurrently, is an increasing clinical challenge. Glycosylation of proteins is one of the most important post-translational modifications. It is widely known that aberrant glycosylation has been implicated in many different diseases due to changes associated with biological function and protein folding. Alterations in cell surface glycosylation, can promote invasive behavior of tumor cells that ultimately lead to the progression of cancer. In breast cancer, there is an increasing evidence pertaining to the role of glycosylation in tumor formation and metastasis. In the present study, an attempt has been made to study the disease associated sialoglycoproteins in breast cancer by using bioinformatics tools. The sequence will be retrieved from UniProt database. A database in the form of a word document was made by a collection of FASTA sequences of breast cancer gene sequence. Glycosylation was studied using yinOyang tool on ExPASy and Differential genes expression and protein analysis was done in context of breast cancer metastasis. The number of residues predicted O-glc NAc threshold containing 50 aberrant glycosylation sites or more was detected and recorded for individual sequence. We found that the there is a significant change in the expression profiling of glycosylation patterns of various proteins associated with breast cancer. Differential aberrant glycosylated proteins in breast cancer cells with respect to non-neoplastic cells are an important factor for the overall progression and development of cancer.

Keywords: breast cancer, bioinformatics, cancer, metastasis, glycosylation

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4742 ORR Electrocatalyst for Batteries and Fuel Cells Development with SiO2/Carbon Black Based Composite Nanomaterials

Authors: Maryam Kiani

Abstract:

This study focuses on the development of composite nanomaterials based on SiO2 and carbon black for oxygen reduction reaction (ORR) electrocatalysts in batteries and fuel cells. The aim was to explore the potential of these composite materials as efficient catalysts for ORR, which is a critical process in energy conversion devices. The SiO2/carbon black composite nanomaterials were synthesized using a facile and scalable method. The morphology, structure, and electrochemical properties of the materials were characterized using various techniques, including scanning electron microscopy (SEM), X-ray diffraction (XRD), and electrochemical measurements. The results demonstrated that the incorporation of SiO2 into the carbon black matrix enhanced the ORR performance of the composite material. The composite nanomaterials exhibited improved electrocatalytic activity, enhanced stability, and increased durability compared to pure carbon black. The presence of SiO2 facilitated the formation of active sites, improved electron transfer, and increased the surface area available for ORR. This study contributes to the advancement of battery and fuel cell technology by offering a promising approach for the development of high-performance ORR electrocatalysts. The SiO2/carbon black composite nanomaterials show great potential for improving the efficiency and durability of energy conversion devices, leading to more sustainable and efficient energy solutions.

Keywords: oxygen reduction reaction, batteries, fuel cells, electrrocatalyst

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4741 Series Connected GaN Resonant Tunneling Diodes for Multiple-Valued Logic

Authors: Fang Liu, JunShuai Xue, JiaJia Yao, XueYan Yang, ZuMao Li, GuanLin Wu, HePeng Zhang, ZhiPeng Sun

Abstract:

III-Nitride resonant tunneling diode (RTD) is one of the most promising candidates for multiple-valued logic (MVL) elements. Here, we report a monolithic integration of GaN resonant tunneling diodes to realize multiple negative differential resistance (NDR) regions for MVL application. GaN RTDs, composed of a 2 nm quantum well embedded in two 1 nm quantum barriers, are grown by plasma-assisted molecular beam epitaxy on free-standing c-plane GaN substrates. Negative differential resistance characteristic with a peak current density of 178 kA/cm² in conjunction with a peak-to-valley current ratio (PVCR) of 2.07 is observed. Statistical properties exhibit high consistency showing a peak current density standard deviation of almost 1%, laying the foundation for the monolithic integration. After complete electrical isolation, two diodes of the designed same area are connected in series. By solving the Poisson equation and Schrodinger equation in one dimension, the energy band structure is calculated to explain the transport mechanism of the differential negative resistance phenomenon. Resonant tunneling events in a sequence of the series-connected RTD pair (SCRTD) form multiple NDR regions with nearly equal peak current, obtaining three stable operating states corresponding to ternary logic. A frequency multiplier circuit achieved using this integration is demonstrated, attesting to the robustness of this multiple peaks feature. This article presents a monolithic integration of SCRTD with multiple NDR regions driven by the resonant tunneling mechanism, which can be applied to a multiple-valued logic field, promising a fast operation speed and a great reduction of circuit complexity and demonstrating a new solution for nitride devices to break through the limitations of binary logic.

Keywords: GaN resonant tunneling diode, multiple-valued logic system, frequency multiplier, negative differential resistance, peak-to-valley current ratio

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4740 Anti-Angiogenic Effects of the Macrovipera lebetina obtusa Snake Crude Venom and Obtustatin

Authors: Narine Ghazaryan, Joana Catarina Macedo, Sara Vaz, Naira Ayvazyan, Elsa Logarinho

Abstract:

Macrovipera lebetina obtusa (MLO) is a poisonous snake in Armenia. Obtustatin represents the shortest known monomeric disintegrin, isolated from the snake venom of MLO, and is known to specifically inhibit α1β1 integrin. Its oncostatic effect is due to the inhibition of angiogenesis, which likely arises from α1β1 integrin inhibition in the endothelial cells. To explore the therapeutic potential of the MLO snake venom and obtustatin, we studied activity of obtustatin and MLO venom in vitro, by testing their efficacy in human dermal microvascular endothelial cells (HMVEC-D) and in vivo, using chick embryo chorioallantoic membrane assay (CAM assay). Our in vitro results showed that obtustatin in comparison with MLO venom did not exhibit cytotoxic activity in HMVEC-D cells in comparison to MLO venom. But in vivo results have shown that 4µg /embryo (90 µM) of obtustatin inhibited angiogenesis induced by FGF2 by 17% while MLO snake venom induced 22% reduction of the angiogenic index. The concentration of obtustatin in the crude MLO venom was 0.3 nM, which is 300.000 times less than the concentration of the obtustatin itself. Given this enormous difference in concentration, it is likely that some components of the crude venom contribute to the observed anti-angiogenic effect. Hypotheses will be ascertained to justify this action: components in the MLO venom may increase obtustatin efficacy or have independent but synergic anti-angiogenic activities.

Keywords: angiogenesis, alpa1 beta 1 integrin, Macrovipera lebetina obtusa, obtustatin

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4739 The Effect of Combined Fluid Shear Stress and Cyclic Stretch on Endothelial Cells

Authors: Daphne Meza, Louie Abejar, David A. Rubenstein, Wei Yin

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Endothelial cell (ECs) morphology and function is highly impacted by the mechanical stresses these cells experience in vivo. Any change in the mechanical environment can trigger pathological EC responses. A detailed understanding of EC morphological response and function upon subjection to individual and simultaneous mechanical stimuli is needed for advancement in mechanobiology and preventive medicine. To investigate this, a programmable device capable of simultaneously applying physiological fluid shear stress (FSS) and cyclic strain (CS) has been developed, characterized and validated. Its validation was performed both experimentally, through tracer tracking, and theoretically, through the use of a computational fluid dynamics model. The effectiveness of the device was evaluated through EC morphology changes under mechanical loading conditions. Changes in cell morphology were evaluated through: cell and nucleus elongation, cell alignment and junctional actin production. The results demonstrated that the combined FSS-CS stimulation induced visible changes in EC morphology. Upon simultaneous fluid shear stress and biaxial tensile strain stimulation, cells were elongated and generally aligned with the flow direction, with stress fibers highlighted along the cell junctions. The concurrent stimulation from shear stress and biaxial cyclic stretch led to a significant increase in cell elongation compared to untreated cells. This, however, was significantly lower than that induced by shear stress alone, indicating that the biaxial tensile strain may counteract the elongating effect of shear stress to maintain the shape of ECs. A similar trend was seen in alignment, where the alignment induced by the concurrent application of shear stress and cyclic stretch fell in between that induced by shear stress and tensile stretch alone, indicating the opposite role shear stress and tensile strain may play in cell alignment. Junctional actin accumulation was increased upon shear stress alone or simultaneously with tensile stretch. Tensile stretch alone did not change junctional actin accumulation, indicating the dominant role of shear stress in damaging EC junctions. These results demonstrate that the shearing-stretching device is capable of applying well characterized dynamic shear stress and tensile strain to cultured ECs. Using this device, EC response to altered mechanical environment in vivo can be characterized in vitro.

Keywords: cyclic stretch, endothelial cells, fluid shear stress, vascular biology

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4738 Improving the Bioprocess Phenotype of Chinese Hamster Ovary Cells Using CRISPR/Cas9 and Sponge Decoy Mediated MiRNA Knockdowns

Authors: Kevin Kellner, Nga Lao, Orla Coleman, Paula Meleady, Niall Barron

Abstract:

Chinese Hamster Ovary (CHO) cells are the prominent cell line used in biopharmaceutical production. To improve yields and find beneficial bioprocess phenotypes genetic engineering plays an essential role in recent research. The miR-23 cluster, specifically miR-24 and miR-27, was first identified as differentially expressed during hypothermic conditions suggesting a role in proliferation and productivity in CHO cells. In this study, we used sponge decoy technology to stably deplete the miRNA expression of the cluster. Furthermore, we implemented the CRISPR/Cas9 system to knockdown miRNA expression. Sponge constructs were designed for an imperfect binding of the miRNA target, protecting from RISC mediated cleavage. GuideRNAs for the CRISPR/Cas9 system were designed to target the seed region of the miRNA. The expression of mature miRNA and precursor were confirmed using RT-qPCR. For both approaches stable expressing mixed populations were generated and characterised in batch cultures. It was shown, that CRISPR/Cas9 can be implemented in CHO cells with achieving high knockdown efficacy of every single member of the cluster. Targeting of one miRNA member showed that its genomic paralog is successfully targeted as well. The stable depletion of miR-24 using CRISPR/Cas9 showed increased growth and specific productivity in a CHO-K1 mAb expressing cell line. This phenotype was further characterized using quantitative label-free LC-MS/MS showing 186 proteins differently expressed with 19 involved in proliferation and 26 involved in protein folding/translation. Targeting miR-27 in the same cell line showed increased viability in late stages of the culture compared to the control. To evaluate the phenotype in an industry relevant cell line; the miR-23 cluster, miR-24 and miR-27 were stably depleted in a Fc fusion CHO-S cell line which showed increased batch titers up to 1.5-fold. In this work, we highlighted that the stable depletion of the miR-23 cluster and its members can improve the bioprocess phenotype concerning growth and productivity in two different cell lines. Furthermore, we showed that using CRISPR/Cas9 is comparable to the traditional sponge decoy technology.

Keywords: Chinese Hamster ovary cells, CRISPR/Cas9, microRNAs, sponge decoy technology

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4737 The Decision-Making Process of the Central Banks of Brazil and India in Regional Integration: A Comparative Analysis of MERCOSUR and SAARC (2003-2014)

Authors: Andre Sanches Siqueira Campos

Abstract:

Central banks can play a significant role in promoting regional economic and monetary integration by strengthening the payment and settlement systems. However, close coordination and cooperation require facilitating the implementation of reforms at domestic and cross-border levels in order to benchmark with international standards and commitments to the liberal order. This situation reflects the normative power of the regulatory globalization dimension of strong states, which may drive or constrain regional integration. In the MERCOSUR and SAARC regions, central banks have set financial initiatives that could facilitate South America and South Asia regions to move towards convergence integration and facilitate trade and investments connectivities. This is qualitative method research based on a combination of the Process-Tracing method with Qualitative Comparative Analysis (QCA). This research approaches multiple forms of data based on central banks, regional organisations, national governments, and financial institutions supported by existing literature. The aim of this research is to analyze the decision-making process of the Central Bank of Brazil (BCB) and the Reserve Bank of India (RBI) towards regional financial cooperation by identifying connectivity instruments that foster, gridlock, or redefine cooperation. The BCB and The RBI manage the monetary policy of the largest economies of those regions, which makes regional cooperation a relevant framework to understand how they provide an effective institutional arrangement for regional organisations to achieve some of their key policies and economic objectives. The preliminary conclusion is that both BCB and RBI demonstrate a reluctance to deepen regional cooperation because of the existing economic, political, and institutional asymmetries. Deepening regional cooperation is constrained by the interests of central banks in protecting their economies from risks of instability due to different degrees of development between countries in their regions and international financial crises that have impacted the international system in the 21st century. Reluctant regional integration also provides autonomy for national development and political ground for the contestation of Global Financial Governance by Brazil and India.

Keywords: Brazil, central banks, decision-making process, global financial governance, India, MERCOSUR, connectivity, payment system, regional cooperation, SAARC

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4736 Mannosylated Oral Amphotericin B Nanocrystals for Macrophage Targeting: In vitro and Cell Uptake Studies

Authors: Rudra Vaghela, P. K. Kulkarni

Abstract:

The aim of the present research was to develop oral Amphotericin B (AmB) nanocrystals (Nc) grafted with suitable ligand in order to enhance drug transport across the intestinal epithelial barrier and subsequently, active uptake by macrophages. AmB Nc were prepared by liquid anti-solvent precipitation technique (LAS). Poloxamer 188 was used to stabilize the prepared AmB Nc and grafted with mannose for actively targeting M cells in Peyer’s patches. To prevent shedding of the stabilizer and ligand, N,N’-Dicyclohexylcarbodiimide (DCC) was used as a cross-linker. The prepared AmB Nc were characterized for particle size, PDI, zeta potential, X-ray diffraction (XRD) and surface morphology using scanning electron microscope (SEM) and evaluated for drug content, in vitro drug release and cell uptake studies using caco-2 cells. The particle size of stabilized AmB Nc grafted with WGA was in the range of 287-417 nm with negative zeta potential between -18 to -25 mV. XRD studies revealed crystalline nature of AmB Nc. SEM studies revealed that ungrafted AmB Nc were irregular in shape with rough surface whereas, grafted AmB Nc were found to be rod-shaped with smooth surface. In vitro drug release of AmB Nc was found to be 86% at the end of one hour. Cellular studies revealed higher invasion and uptake of AmB Nc towards caco-2 cell membrane when compared to ungrafted AmB Nc. Our findings emphasize scope on developing oral delivery system for passively targeting M cells in Peyer’s patches.

Keywords: leishmaniasis, amphotericin b nanocrystals, macrophage targeting, LAS technique

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4735 Asymptomatic Intercostal Schwannoma in a Patient with COVID-19: The First of Its Kind

Authors: Gabriel Hunduma

Abstract:

Asymptomatic intra-thoracic neurogenic tumours are rare. Tumours arising from the intercostal nerves of the chest wall are exceedingly rare. This paper reports an incidental discovery of a neurogenic intercostal tumour while being investigated for Coronavirus Disease 2019 (COVID-19). A 54-year-old female underwent a thoracotomy and resection for an intercostal tumour. Pre-operative images showed an intrathoracic mass, and the biopsy revealed a schwannoma. The most common presenting symptom recorded in literature is chest pain; however, our case remained asymptomatic despite the size of the mass and thoracic area it occupied. After an extensive search of the literature, COVID-19 was found to have an influence on the development of certain cells in breast cancer. Hence there is a possibility that COVID-19 played a role in progressing the development of the schwannoma cells.

Keywords: thoracic surgery, intercostal schwannoma, chest wall oncology, COVID-19

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4734 An Exploration of the Integration of Guided Play With Explicit Instruction in Early Childhood Mathematics

Authors: Anne Tan, Kok-Sing Tang, Audrey Cooke

Abstract:

Play has always been a prominent pedagogy in early childhood. However, there is growing evidence of success in students’ learning using explicit instruction, especially in literacy in the early years. There is also limited research using explicit instruction in early childhood mathematics, and play is usually prominently mentioned. This proposed research aims to investigate the possibilities and benefits of integrating guided play with explicit instruction in early childhood mathematics education. While play has traditionally been a prominent pedagogy in early childhood, there is growing evidence of success in student learning through explicit instruction, particularly in literacy. However, limited research exists on the integration of explicit instruction in early childhood mathematics, where play remains prominently mentioned. This study utilises a multiple case study methodology to gather data and provide immediate opportunities for curriculum improvement. The research will commence with semi-structured interviews to gain insights into educators' background knowledge. Highly structured observations will be conducted to record the frequency and manner in which guided play is integrated with specific elements of explicit instruction during mathematics teaching in early childhood. To enhance the observations, video recordings will be made using cameras with video settings and Microsoft Teams meeting recordings. In addition to interviews and observations, educators will maintain journals and use the Microsoft Teams platform for self-reflection on the integration of guided play and explicit instruction in their classroom practices and experiences. The study participants will include educators with early childhood degrees and students in years one and two. The primary goal of this research is to inform the benefits of integrating two high-impact pedagogies, guided play, and explicit instruction, for enhancing student learning outcomes in mathematics education. By exploring the integration of these pedagogical approaches, this study aims to contribute to the development of effective instructional strategies in early childhood mathematics education.

Keywords: early childhood, early childhood mathematics, early childhood numbers, guided play, play-based learning, explicit instruction

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4733 Financial Markets Integration between Morocco and France: Implications on International Portfolio Diversification

Authors: Abdelmounaim Lahrech, Hajar Bousfiha

Abstract:

This paper examines equity market integration between Morocco and France and its consequent implications on international portfolio diversification. In the absence of stock market linkages, Morocco can act as a diversification destination to European investors, allowing higher returns at a comparable level of risk in developed markets. In contrast, this attractiveness is limited if both financial markets show significant linkage. The research empirically measures financial market’s integration in by capturing the conditional correlation between the two markets using the Generalized Autoregressive Conditionally Heteroscedastic (GARCH) model. Then, the research uses the Dynamic Conditional Correlation (DCC) model of Engle (2002) to track the correlations. The research findings show that there is no important increase over the years in the correlation between the Moroccan and the French equity markets, even though France is considered Morocco’s first trading partner. Failing to prove evidence of the stock index linkage between the two countries, the volatility series of each market were assumed to change over time separately. Yet, the study reveals that despite the important historical and economic linkages between Morocco and France, there is no evidence that equity markets follow. The small correlations and their stationarity over time show that over the 10 years studied, correlations were fluctuating around a stable mean with no significant change at their level. Different explanations can be attributed to the absence of market linkage between the two equity markets.

Keywords: equity market linkage, DCC GARCH, international portfolio diversification, Morocco, France

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4732 Electrochemical and Photoelectrochemical Study of Polybithiophene–MnO2 Composite Films

Authors: H. Zouaoui, D. Abdi, B. Nessark, F. Habelhames, A. Bahloul

Abstract:

Among the conjugated organic polymers, the polythiophenes constitute a particularly important class of conjugated polymers, which has been extensively studied for the relation between the geometrical structure and the optic and electronic properties, while the polythiophene is an intractable material. They are, furthermore, chemically and thermally stable materials, and are very attractive for exploitation of their physical properties. The polythiophenes are extensively studied due to the possibility of synthesizing low band gap materials by using substituted thiophenes as precursors. Low band gap polymers may convert visible light into electricity and some photoelectrochemical cells based on these materials have been prepared. Polythiophenes (PThs) are good candidates for polymer optoelectronic devices such as polymer solar cells (PSCs) polymer light-emitting diodes (PLEDs) field-effect transistors (FETs) electrochromics and biosensors. In this work, MnO2 has been synthesized by hydrothermal method and analyzed by infrared spectroscopy. The polybithiophene+MnO2 composite films were electrochemically prepared by cyclic voltammetry technic on a conductor glass substrate ITO (indium–tin-oxide). The composite films are characterized by cyclic voltammetry, impedance spectroscopy and photoelectrochemical analyses. The results confirmed the presence of manganese dioxide nanoparticles in the polymer layer. An application has been made by using these deposits as an electrode in a photoelectrochemical cell for measuring photocurrent tests. The composite films show a significant photocurrent intensity 80 μA.cm-2.

Keywords: polybithiophene, MnO2, photoelectrochemical cells, composite films

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4731 Integrating Artificial Intelligence in Social Work Education: An Exploratory Study

Authors: Nir Wittenberg, Moshe Farhi

Abstract:

This mixed-methods study examines the integration of artificial intelligence (AI) tools in a first-year social work course to assess their potential for enhancing professional knowledge and skills. The incorporation of digital technologies, such as AI, in social work interventions, training, and research has increased, with the expectation that AI will become as commonplace as email and mobile phones. However, policies and ethical guidelines regarding AI, as well as empirical evaluations of its usefulness, are lacking. As AI is gradually being adopted in the field, it is prudent to explore AI thoughtfully in alignment with pedagogical goals. The outcomes assessed include professional identity, course satisfaction, and motivation. AI offers unique reflective learning opportunities through personalized simulations, feedback, and queries to complement face-to-face lessons. For instance, AI simulations provide low-risk practices for situations such as client interactions, enabling students to build skills with less stress. However, it is essential to recognize that AI alone cannot ensure real-world competence or cultural sensitivity. Outcomes related to student learning, experience, and perceptions will help to elucidate the best practices for AI integration, guiding faculty, and advancing pedagogical innovation. This strategic integration of selected AI technologies is expected to diversify course methodology, improve learning outcomes, and generate new evidence on AI’s educational utility. The findings will inform faculty seeking to thoughtfully incorporate AI into teaching and learning.

Keywords: artificial intelligence (AI), social work education, students, developing a professional identity, ethical considerations

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4730 Wharton's Jelly-Derived Mesenchymal Stem Cells Modulate Heart Rate Variability and Improve Baroreflex Sensitivity in Septic Rats

Authors: Cóndor C. José, Rodrigues E. Camila, Noronha L. Irene, Dos Santos Fernando, Irigoyen M. Claudia, Andrade Lúcia

Abstract:

Sepsis induces alterations in hemodynamics and autonomic nervous system (ASN). The autonomic activity can be calculated by measuring heart rate variability (HRV) that represents the complex interplay between ASN and cardiac pacemaker cells. Wharton’s jelly mesenchymal stem cells (WJ-MSCs) are known to express genes and secreted factors involved in neuroprotective and immunological effects, also to improve the survival in experimental septic animals. We hypothesized, that WJ-MSCs present an important role in the autonomic activity and in the hemodynamic effects in a cecal ligation and puncture (CLP) model of sepsis. Methods: We used flow cytometry to evaluate WJ-MSCs phenotypes. We divided Wistar rats into groups: sham (shamoperated); CLP; and CLP+MSC (106 WJ-MSCs, i.p., 6 h after CLP). At 24 h post-CLP, we recorded the systolic arterial pressure (SAP) and heart rate (HR) over 20 min. The spectral analysis of HR and SAP; also the spontaneous baroreflex sensitivity (measure by bradycardic and tachycardic responses) were evaluated after recording. The one-way ANOVA and the post hoc Student– Newman– Keuls tests (P< 0.05) were used to data comparison Results: WJ-MSCs were negative for CD3, CD34, CD45 and HLA-DR, whereas they were positive for CD73, CD90 and CD105. The CLP group showed a reduction in variance of overall variability and in high-frequency power of HR (heart parasympathetic activity); furthermore, there is a low-frequency reduction of SAP (blood vessels sympathetic activity). The treatment with WJ-MSCs improved the autonomic activity by increasing the high and lowfrequency power; and restore the baroreflex sensitive. Conclusions: WJ-MSCs attenuate the impairment of autonomic control of the heart and vessels and might therefore play a protective role in sepsis. (Supported by FAPESP).

Keywords: baroreflex response, heart rate variability, sepsis, wharton’s jelly-derived mesenchymal stem cells

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4729 Twist2 Is a Key Regulator of Cell Proliferation in Acute Lymphoblastic Leukaemia

Authors: Magdalena Rusady Goey, Gordon Strathdee, Neil Perkins

Abstract:

Background: Acute lymphoblastic leukaemia (ALL) is the most frequent type of childhood malignancy, accounting for 25% of all cases. TWIST2, a basic helix-loop-helix transcription factor, has been implicated in ALL development. Prior studies found that TWIST2 undergoes epigenetic silencing in more than 50% cases of ALL through promoter hypermethylation and suggested that re-expression of TWIST2 may inhibit cell growth/survival of leukaemia cell lines. TWIST2 has also been implicated as a regulator of NF-kappaB activity, which is constitutively active in leukaemia. Here, we use a lentiviral transductions system to confirm the importance of TWIST2 in controlling leukaemia cell growth and to investigate whether this is achieved through altered regulation of NF-kappaB activity. Method: Re-expression of TWIST2 in leukaemia cell lines was achieved using lentiviral-based transduction. The lentiviral vector also expresses enhanced green fluorescent protein (eGFP), allowing transduced cells to be tracked using flow cytometry. Analysis of apoptosis and cell proliferation were done using annexinV and VPD450 staining, respectively. Result and Discussion: TWIST2-expressing cells were rapidly depleted from a mixed population in ALL cell lines (NALM6 and Reh), indicating that TWIST2 inhibited cell growth/survival of ALL cells. In contrast, myeloid cell lines (HL60 and K562) were comparatively insensitive to TWIST2 re-expression. Analysis of apoptosis and cell proliferation found no significant induction of apoptosis, but did find a rapid induction of proliferation arrest in TWIST2-expressing Reh and NALM6 cells. Initial experiment with NF-kappaB inhibitor demonstrated that inhibition of NF-kappaB has similar impact on cell proliferation in the ALL cell lines, suggesting that TWITST2 may induce cell proliferation arrest through inhibition of NF-kappaB. Conclusion: The results of this study suggest that epigenetic inactivation of TWIST2 in primary ALL leads to increased proliferation, potentially by altering the regulation of NF-kappaB.

Keywords: leukaemia, acute lymphoblastic leukaemia, NF-kappaB, TWIST2, lentivirus

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4728 Comparison of Cardiomyogenic Potential of Amniotic Fluid Mesenchymal Stromal Cells Derived from Normal and Isolated Congenital Heart Defective Fetuses

Authors: Manali Jain, Neeta Singh, Raunaq Fatima, Soniya Nityanand, Mandakini Pradhan, Chandra Prakash Chaturvedi

Abstract:

Isolated Congenital Heart Defect (ICHD) is the major cause of neonatal death worldwide among all forms of CHDs. A significant proportion of fetuses with ICHD die in the neonatal period if no treatment is provided. Recently, stem cell therapies have emerged as a potential approach to ameliorate ICHD in children. ICHD is characterized by cardiac structural abnormalities during embryogenesis due to alterations in the cardiomyogenic properties of a pool of cardiac progenitors/ stem cells associated with fetal heart development. The stem cells present in the amniotic fluid (AF) are of fetal origin and may reflect the physiological and pathological changes in the fetus during embryogenesis. Therefore, in the present study, the cardiomyogenic potential of AF-MSCs derived from fetuses with ICHD (ICHD AF-MSCs) has been evaluated and compared with that of AF-MSCs of structurally normal fetuses (normal AF-MSCs). Normal and ICHD AF-MSC were analyzed for the expression of cardiac progenitor markers viz., stage-specific embryonic antigen-1 (SSEA-1), vascular endothelial growth factor 2 (VEGFR-2) and platelet-derived growth factor receptor-alpha (PDGFR-α) by flow cytometry. The immunophenotypic characterization revealed that ICHD AF-MSCs have significantly lower expression of cardiac progenitor markers VEGFR-2 (0.14% ± 0.6 vs.48.80% ± 0.9; p <0.01), SSEA-1 (70.86% ± 2.4 vs. 88.36% ±2.7; p <0.01), and PDGFR-α (3.92% ± 1.8 vs. 47.59% ± 3.09; p <0.01) in comparison to normal AF-MSCs. Upon induction with 5’-azacytidine for 21 days, ICHD AF-MSCs showed a significantly down-regulated expression of cardiac transcription factors such as GATA-4 (0.4 ± 0.1 vs. 6.8 ± 1.2; p<0.01), ISL-1 (2.3± 0.6 vs. 14.3 ± 1.12; p<0.01), NK-x 2-5 (1.1 ± 0.3 vs. 14.1 ±2.8; p<0.01), TBX-5 (0.4 ± 0.07 vs. 4.4 ± 0.3; p<0.001), and TBX-18 (1.3 ± 0.2 vs. 4.19 ± 0.3; p<0.01) when compared with the normal AF-MSCs. Furthermore, immunocytochemical staining revealed that both types of AF-MSCs could differentiate into cardiovascular lineages and express cardiomyogenic, endothelial, and smooth muscle actin markers, viz., cardiac troponin (cTNT), CD31, and alpha-smooth muscle actin (α-SMA). However, normal AF-MSCs showed an enhanced expression of cTNT (p<0.001), CD31 (p<0.01), and α-SMA (p<0.05), compared to ICHD AF-MSCs. Overall, these results suggest that the ICHD-AF-MSCs have a defective cardiomyogenic differentiation potential and that the defects in these stem cells may have a role in the pathogenesis of ICHD.

Keywords: amniotic fluid, cardiomyogenic potential, isolated congenital heart defect, mesenchymal stem cells

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4727 Impact of the Photovoltaic Integration in Power Distribution Network: Case Study in Badak Liquefied Natural Gas (LNG)

Authors: David Hasurungan

Abstract:

This paper objective is to analyze the impact from photovoltaic system integration to power distribution network. The case study in Badak Liquefied Natural Gas (LNG) plant is presented in this paper. Badak LNG electricity network is operated in islanded mode. The total power generation in Badak LNG plant is significantly affected to feed gas supply. Meanwhile, to support the Government regulation, Badak LNG continuously implemented the grid-connected photovoltaic system in existing power distribution network. The impact between train operational mode change in Badak LNG plant and the growth of photovoltaic system is also encompassed in analysis. The analysis and calculation are performed using software Power Factory 15.1.

Keywords: power quality, distribution network, grid-connected photovoltaic system, power management system

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4726 Towards the Effectiveness/ Performance of Spatial Communication within the Composite Interior Spaces: Wayfinding System in the Saudi National Museum as a Case Study

Authors: Afnan T. Bagasi, Donia M. Bettaieb, Abeer Alsobahi

Abstract:

The wayfinding system is related to the course of the museum journey for visitors directly and indirectly. The design aspects of this system play an important role, making it an effective and communication system within the museum space. However, translating the concepts that pertain to its design, such as Intelligibility that is based on integration and connectivity in museum space design, needs more customization in the form of specific design considerations with reference to the most important approaches. Those approaches link the organizational and practical aspects to the semiotic and semantic aspects related to the space syntax by targeting the visual and perceived consistency of visitors. In this context, the study aims to identify how to apply the concept of intelligibility and clarity by employing integration and connectivity to design a wayfinding system in museums as a kind of composite interior space. Using the available plans and images to extrapolate the design considerations used to design the wayfinding system in the Saudi National Museum as a case study, a descriptive-analytical method was used to understand the basic organizational and morphological principles of the museum space through four main aspects in space design: morphological, semantic, semiotic, and pragmatic. The study's findings will assist designers, professionals, and researchers in the field of museum design in understanding the significance of the wayfinding system by delving into it through museum spaces by highlighting the essential aspects using a clear analytical method.

Keywords: wayfinding system, museum journey, intelligibility, integration, connectivity

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4725 Stochastic Modeling of Secretion Dynamics in Inner Hair Cells of the Auditory Pathway

Authors: Jessica A. Soto-Bear, Virginia González-Vélez, Norma Castañeda-Villa, Amparo Gil

Abstract:

Glutamate release of the cochlear inner hair cell (IHC) ribbon synapse is a fundamental step in transferring sound information in the auditory pathway. Otoferlin is the calcium sensor in the IHC and its activity has been related to many auditory disorders. In order to simulate secretion dynamics occurring in the IHC in a few milliseconds timescale and with high spatial resolution, we proposed an active-zone model solved with Monte Carlo algorithms. We included models for calcium buffered diffusion, calcium-binding schemes for vesicle fusion, and L-type voltage-gated calcium channels. Our results indicate that calcium influx and calcium binding is managing IHC secretion as a function of voltage depolarization, which in turn mean that IHC response depends on sound intensity.

Keywords: inner hair cells, Monte Carlo algorithm, Otoferlin, secretion

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4724 Ellagic Acid Enhanced Apoptotic Radiosensitivity via G1 Cell Cycle Arrest and γ-H2AX Foci Formation in HeLa Cells in vitro

Authors: V. R. Ahire, A. Kumar, B. N. Pandey, K. P. Mishra, G. R. Kulkarni

Abstract:

Radiation therapy is an effective vital strategy used globally in the treatment of cervical cancer. However, radiation efficacy principally depends on the radiosensitivity of the tumor, and not all patient exhibit significant response to irradiation. A radiosensitive tumor is easier to cure than a radioresistant tumor which later advances to local recurrence and metastasis. Herbal polyphenols are gaining attention for exhibiting radiosensitization through various signaling. Current work focuses to study the radiosensitization effect of ellagic acid (EA), on HeLa cells. EA intermediated radiosensitization of HeLa cells was due to the induction γ-H2AX foci formation, G1 phase cell cycle arrest, and loss of reproductive potential, growth inhibition, drop in the mitochondrial membrane potential and protein expression studies that eventually induced apoptosis. Irradiation of HeLa in presence of EA (10 μM) to doses of 2 and 4 Gy γ-radiation produced marked tumor cytotoxicity. EA also demonstrated radio-protective effect on normal cell, NIH3T3 and aided recovery from the radiation damage. Our results advocate EA to be an effective adjuvant for improving cancer radiotherapy as it displays striking tumor cytotoxicity and reduced normal cell damage instigated by irradiation.

Keywords: apoptotic radiosensitivity, ellagic acid, mitochondrial potential, cell-cycle arrest

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4723 Investigation of Graphene-MoS₂ Nanocomposite as Counter Electrode in Dye-Sensitized Solar Cells

Authors: Mozhgan Hosseinnezhad, Kamaladin Gharanjig, Mehdi Ghahari

Abstract:

Dye-sensitized solar cells are sustainable tool for generating electrical energy using sunlight. To develop this technology, obstacles such as cost and the use of expensive compounds must be overcome. Herein, we employed a MoS₂/graphene composite instead of platinum in the DSSCs. Platinum is an efficient and conventional counter electrode in the preparation of DSSCs, for this purpose, the effect of the presence of platinum electrode was also studied under similar conditions. The prepared nanocomposite product was checked by analysis methods to confirm the correctness of the construction and the desired structure. Finally, the DSSCs were fabricated using MoS₂/graphene composite, and to compare the results, the DSSCs were also prepared using platinum. The results showed that the prepared composite has a similar performance compared to platinum and can replace it.

Keywords: efficiency, dye-sensitized solar cell, nano-composite MoS₂, platinum free

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4722 Assessing the Impact of Low Carbon Technology Integration on Electricity Distribution Networks: Advancing towards Local Area Energy Planning

Authors: Javier Sandoval Bustamante, Pardis Sheikhzadeh, Vijayanarasimha Hindupur Pakka

Abstract:

In the pursuit of achieving net-zero carbon emissions, the integration of low carbon technologies into electricity distribution networks is paramount. This paper delves into the critical assessment of how the integration of low carbon technologies, such as heat pumps, electric vehicle chargers, and photovoltaic systems, impacts the infrastructure and operation of electricity distribution networks. The study employs rigorous methodologies, including power flow analysis and headroom analysis, to evaluate the feasibility and implications of integrating these technologies into existing distribution systems. Furthermore, the research utilizes Local Area Energy Planning (LAEP) methodologies to guide local authorities and distribution network operators in formulating effective plans to meet regional and national decarbonization objectives. Geospatial analysis techniques, coupled with building physics and electric energy systems modeling, are employed to develop geographic datasets aimed at informing the deployment of low carbon technologies at the local level. Drawing upon insights from the Local Energy Net Zero Accelerator (LENZA) project, a comprehensive case study illustrates the practical application of these methodologies in assessing the rollout potential of LCTs. The findings not only shed light on the technical feasibility of integrating low carbon technologies but also provide valuable insights into the broader transition towards a sustainable and electrified energy future. This paper contributes to the advancement of knowledge in power electrical engineering by providing empirical evidence and methodologies to support the integration of low carbon technologies into electricity distribution networks. The insights gained are instrumental for policymakers, utility companies, and stakeholders involved in navigating the complex challenges of energy transition and achieving long-term sustainability goals.

Keywords: energy planning, energy systems, digital twins, power flow analysis, headroom analysis

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4721 Integration, a Tool to Develop Critical Thinking Skills of Undergraduate Veterinary Students

Authors: M. L. W. P. De Silva, R. A. C. Rabel, N. Smith, L. McIntyre, T. J Parkinson, K. A. N. Wijayawardhane

Abstract:

Curricular integration is an important concept in medical education for developing students’ ability to create connections between different medical disciplines. Problem-Based Learning (PBL) is one of the vehicles through which such integration can be achieved. During the recent review of the veterinary curriculum at the University of Peradeniya, a series of courses in Integrative Veterinary Science (IVS) were introduced, in which PBL was the primary teaching methodology. The objectives of this study were to evaluate students’ opinions on PBL as a teaching method: it should be noted that, within the context of secondary and tertiary education in Sri Lanka, this would be an entirely novel learning experience for the students. Opinions were sought at the conclusion of IVS sessions where students of semesters 2, 4, 6, and 7 (of an 8-semester program) were exposed to a two, 2-hour PBL-based case scenario. The PBL-based case scenario in semesters 2, 4, and 7 were delivered using material previously developed by an experienced PBL practitioner, whilst material for semester 6 was prepared de novo by a less experienced practitioner. Each student (semesters 2: n=38, 4: n=37, 6: n=55, and 7: n=40) completed a questionnaire which asked whether: (i) the course had improved their critical thinking skills; (ii) the learning environment was sufficiently comfortable to express/share student’s opinion; (iii) there was sufficient facilitator guidance; (iv) the online study environment enhanced learning; and (v) the students were overall satisfied with the PBL approach and IVS concept. Responses were given on a 5-point Likert-scale (strongly agree (SA), agree (A), neutral (N), disagree (D), and strongly disagree (SD)). SA and A responses were summed to provide an overall ‘satisfactory’ response. Results were subjected to frequency-distribution statistical analysis. A total of 88.5% of students gave SA+A scores to their overall satisfaction. The proportion of SA+A scores differed between different semesters, such that 95% of semester 2, 4, and 7 students gave SA+A scores, whereas only 69% of semester 6 students did so for their respective sessions. Overall, 96% of the students gave SA+A scores to the question relating to the improvement of critical thinking skills: semester 6 students’ scores were marginally, but not significantly, lower (91% SA+A) than those in other semesters. The difference of scores between semester 6 and the other semesters may be attributed to the different PBL-material used and/or the different experience levels of the practitioners that developed the study material. The use of PBL as a means of teaching IVS curriculum-integration courses was well-received by the students in terms of their overall satisfaction and their perceptions of improved critical thinking skills. Importantly, this was achieved in the face of a methodology that was entirely novel to the students. Finally, the delivery of the PBL medium was readily mastered by the practitioner to whom it was also a novel methodology.

Keywords: critical thinking skills, integration, problem based learning, veterinary education

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4720 New Roles of Telomerase and Telomere-Associated Proteins in the Regulation of Telomere Length

Authors: Qin Yang, Fan Zhang, Juan Du, Chongkui Sun, Krishna Kota, Yun-Ling Zheng

Abstract:

Telomeres are specialized structures at chromosome ends consisting of tandem repetitive DNA sequences [(TTAGGG)n in humans] and associated proteins, which are necessary for telomere function. Telomere lengths are tightly regulated within a narrow range in normal human somatic cells, the basis of cellular senescence and aging. Previous studies have extensively focused on how short telomeres are extended and have demonstrated that telomerase plays a central role in telomere maintenance through elongating the short telomeres. However, the molecular mechanisms of regulating excessively long telomeres are unknown. Here, we found that telomerase enzymatic component hTERT plays a dual role in the regulation of telomeres length. We analyzed single telomere alterations at each chromosomal end led to the discoveries that hTERT shortens excessively long telomeres and elongates short telomeres simultaneously, thus maintaining the optimal telomere length at each chromosomal end for an efficient protection. The hTERT-mediated telomere shortening removes large segments of telomere DNA rapidly without inducing telomere dysfunction foci or affecting cell proliferation, thus it is mechanistically distinct from rapid telomere deletion. We found that expression of hTERT generates telomeric circular DNA, suggesting that telomere homologous recombination may be involved in this telomere shortening process. Moreover, the hTERT-mediated telomere shortening is required its enzymatic activity, but telomerase RNA component hTR is not involved in it. Furthermore, shelterin protein TPP1 interacts with hTERT and recruits it on telomeres to mediate telomere shortening. In addition, telomere-associated proteins, DKC1 and TCAB1 also play roles in this process. This novel hTERT-mediated telomere shortening mechanism not only exists in cancer cells, but also in primary human cells. Thus, the hTERT-mediated telomere shortening is expected to shift the paradigm on current molecular models of telomere length maintenance, with wide-reaching consequences in cancer and aging fields.

Keywords: aging, hTERT, telomerase, telomeres, human cells

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4719 Federal Character Principle and the Challenges of National Integration in Nigeria: A Comparative Analysis of Some Federal Appointments under Jonathan and Buhari Administrations

Authors: Simon O. Obadahun, Samuel Otohinoyi

Abstract:

The Nigerian state is heterogeneous both in character and content. Efforts to manage this diversity has so far not yielded the desired result. This paper examines the Federal Character Principle as one of the instruments intended to manage our obvious diversity such that no part of the country is marginalized or feels marginalized or sidelined. The paper observed that the Federal Character Principle have not achieved its set objectives, which is national unity and loyalty. It draws from secondary sources and discovered that there are factors that make an equitable distribution of public appointments difficult which is beyond the powers of the federal character commission. The major argument of this paper is that if the Federal Character Commission as an organization expected to enforce this principle is not restructured and given more power to sanction individuals and organizations that are found of circumventing the relevant guidelines in this regards, the hope of national unity and loyalty will continue to be a mirage.

Keywords: appointments, federalism, federal character, national integration

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4718 Potentiality of a Community of Practice between Public Schools and the Private Sector for Integrating Sustainable Development into the School Curriculum

Authors: Aiydh Aljeddani, Fran Martin

Abstract:

The critical time in which we live requires rethinking of many potential ways in order to make the concept of sustainability and its principles an integral part of our daily life. One of these potential approaches is how to attract community institutions, such as the private sector, to participate effectively in the sustainability industry by supporting public schools to fulfill their duties. A collaborative community of practice can support this purpose and can provide a flexible framework, which allows the members of the community to participate effectively. This study, conducted in Saudi Arabia, aimed to understand the process of a collaborative community of practice of involving the private sector as a member of this community to integrate the sustainability concept in school activities and projects. This study employed a qualitative methodology to understand this authentic and complex phenomenon. A case study approach, ethnography and some elements of action research were followed in this study. The methods of unstructured interviews, artifacts, observation, and teachers’ field notes were used to collect the data. The participants were three secondary teachers, twelve chief executive officers, and one school administrative officer. Certain contextual conditions, as shown by the data, should be taken into consideration when policy makers and school administrations in Saudi Arabia desire to integrate sustainability into school activities. The first of these was the acknowledgement of the valuable role of the members’ personality, efforts, abilities, and experiences, which played vital roles in integrating sustainability. Second, institutional culture, which was not expected to emerge as an important factor in this study, has a significant role in the integration of sustainability. Credibility among the members of the community towards the integration of the sustainability concept and its principles through school activities is another important condition. Fourth, some chief executive officers’ understanding of Corporate Social Responsibility (CSR) towards contribution to sustainability agenda was shallow and limited and this could impede the successful integration of sustainability. Fifth, a shared understanding between the members of the community about integrating sustainability was a vital condition in the integration process. The study also revealed that the integration of sustainability could not be an ongoing process if implemented in isolation of the other community institutions such as the private sector. The study finally offers a number of recommendations to improve on the current practices and suggests areas for further studies.

Keywords: community of practice, public schools, private sector, sustainable development

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4717 Ramification of Pemphigus Vulgaris Sera and the Monoclonal Antibody Against Desmoglein-3 on Nrf2 Expression in Keratinocyte Cultures

Authors: Faris Mohsin Alabeedi

Abstract:

Pemphigus Vulgaris (PV) is a life-threatening autoimmune blistering disease characterized by the presence of autoantibodies directed against the epidermis's surface proteins. There are two forms of PV, mucocutaneous and mucosal-dominant PV. Disruption of the cell junctions is a hallmark of PV due to the autoantibodies targeting the desmosomal cadherins, desmoglein-3 (Dsg3) and desmoglein-1, leading to acantholysis in the skin and mucous membrane. Although the pathogenesis of PV is known, the detailed molecular events remain not fully understood. Our recent study has shown that both the PV sera and pathogenic anti-Dsg3 antibody AK23 can induce ROS and cause oxidative stress in cultured keratinocytes. In line with our finding, other independent studies also demonstrate oxidative stress in PV. Since Nrf2 plays a crucial role in cellular anti-oxidative stress response, we hypothesize that the expression of Nrf2 may alter in PV. Thus, treatment of cells with PV sera or AK23 may cause changes in Nrf2 expression and distribution. The purpose of this study was to examine the effect of AK23 and PV sera on Nrf2 in a normal human keratinocyte cell line, such as NTERT cells. Both a time-course and dose-dependent experiments with AK23, alongside the matched isotype control IgG, were performed in keratinocyte cultures and analysed by immunofluorescence for Nrf2 and Dsg3. Additionally, the same approach was conducted with the sera from PV patients and healthy individuals that served as a control in this study. All the fluorescent images were analysed using ImageJ software. Each experiment was repeated twice. In general, variations were observed throughout this study. In the dose-response experiments, although enhanced Dsg3 expression was consistently detected in AK23 treated cells, the expression of Nrf2 showed no consistent findings between the experiments, although changes in its expression were noticeable in cells treated with AK23. In the time-course study, a trend with induction of Nrf2 over time was shown in control cells treated with mouse isotype IgG. Treatment with AK23 showed a reduction of Nrf2 in a time-dependent manner, especially at the 24-hour time point. However, the earlier time points, such as 2 hours and 6 hours with AK23 treatments, detected somewhat variations. Finally, PV sera caused a decrease of Dsg3, but on the other hand, variations were observed in Nrf2 expression in PV sera treated cells. In general, PV sera seemed to cause a reduction of Nrf2 in the majority of PV sera treated samples. In addition, more pronounced cytoplasmic expression of Nrf2 has been observed in PV sera treated cells than those treated with AK23, suggesting that polyclonal and monoclonal IgG might induce a different effect on Nrf2 expression and distribution. Further experimental studies are crucial to obtain a more coincide global view of Nrf2-mediated gene regulation. In particular, Pemphigus Voulgaris studies assessing how the Nrf2-dependent network changes from a physiological to a pathological condition can provide insight into disease mechanisms and perhaps initiate further treatment approaches.

Keywords: pemphigus vulgaris, monoclonal antibody against desmoglein-3, Nrf2 oxidative stress, keratinocyte cultures

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4716 TimeTune: Personalized Study Plans Generation with Google Calendar Integration

Authors: Chevon Fernando, Banuka Athuraliya

Abstract:

The purpose of this research is to provide a solution to the students’ time management, which usually becomes an issue because students must study and manage their personal commitments. "TimeTune," an AI-based study planner that provides an opportunity to maneuver study timeframes by incorporating modern machine learning algorithms with calendar applications, is unveiled as the ideal solution. The research is focused on the development of LSTM models that connect to the Google Calendar API in the process of developing learning paths that would be fit for a unique student's daily life experience and study history. A key finding of this research is the success in building the LSTM model to predict optimal study times, which, integrating with the real-time data of Google Calendar, will generate the timetables automatically in a personalized and customized manner. The methodology encompasses Agile development practices and Object-Oriented Analysis and Design (OOAD) principles, focusing on user-centric design and iterative development. By adopting this method, students can significantly reduce the tension associated with poor study habits and time management. In conclusion, "TimeTune" displays an advanced step in personalized education technology. The fact that its application of ML algorithms and calendar integration is quite innovative is slowly and steadily revolutionizing the lives of students. The excellence of maintaining a balanced academic and personal life is stress reduction, which the applications promise to provide for students when it comes to managing their studies.

Keywords: personalized learning, study planner, time management, calendar integration

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4715 Knowledge Integration from Concept to Practice: An Exploratory Study of Designing a Flood Resilient Urban Park in Viet Nam

Authors: To Quyen Le, Oswald Devisch, Tu Anh Trinh, Els Hannes

Abstract:

Urban centres worldwide are affected differently by flooding. In Vietnam this impact is increasingly negative caused by a process of rapid urbanisation. Traditional spatial planning and flood mitigation planning are not able to deal with this growing threat. This article therefore proposes to focus on increasing the participation of local communities in flood control and management. It explores, on the basis of a design studio exercise, how lay knowledge on flooding can be integrated within planning processes. The article presents a theoretical basis for the structured criterion for site selection for a flood resilient urban park from the perspective of science, then discloses the tacit and explicit knowledge of the flood-prone area and finally integrates this knowledge into the design strategies for flood resilient urban park design.

Keywords: analytic hierarchy process, AHP, design resilience, flood resilient urban park, knowledge integration

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4714 Voltage Polarity in Electrospinning: Way to Control Surface Properties of Polymer Fibers

Authors: Urszula Stachewicz

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Surface properties of materials are the key parameter in many applications, especially in the biomedical field, to control cell-material interactions. In our work, we want to achieve the controllability of surface properties of polymer fibers via a single-step electrospinning process by alternating voltage polarities. Voltage polarity defines the charge accumulated on the surface of the liquid jet and the surface of the fibers. Positive polarity attracts negatively charged groups to fibers’ surface, whereas negative polarity moves the negatively charged functional groups away from the surface. This way, we can control the surface chemistry, wettability, and additionally surface potential of electrospun fibers. Within our research, we characterized surface chemistry using X-ray photoelectron microscopy (XPS) and surface potential with Kelvin probe force microscopy (KPFM) on electrospun fibers of commonly used polymers such as PCL, PVDF, and PMMA, often used as biomaterials. We proved the significant effect of fibers' surface potential on cell integration with the scaffolds and further cells development for the regeneration processes based on the osteoblast and fibroblast culture studies. Acknowledgments: The study was conducted within ‘Nanofiber-based sponges for atopic skin treatment’ project, which is carried out within the First TEAM programme of the Foundation for Polish Science co-financed by the European Union under the European Regional Development Fund, project no POIR.04.04.00-00- 4571/18-00.

Keywords: cell attachment, fibers, fibroblasts, osteoblast, proliferation, surface potential

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