SACM - Germany
Permanent URI for this collectionhttps://drepo.sdl.edu.sa/handle/20.500.14154/9655
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Item Restricted Bandscheibenvorfälle der Lendenwirbelsäule (Kinetik, Diagnostik, Therapie und Prävention)(Saudi Digital Library, 2026) Bin Shafi, Lulu; Bernd, HeimrichDiese Arbeit analysiert Bandscheibenvorfälle der Lendenwirbelsäule aus biomedizinisch-technischer Perspektive mit Fokus auf biomechanische und kinetische Belastungsmechanismen. Im Zentrum stehen die quantitative Beschreibung axialer Druck-, ventrodorsaler Scher- und Rotationskräfte sowie deren Einfluss auf das mechanische Verhalten der Bandscheibe und degenerative Veränderungen. Diagnostische Verfahren werden im Hinblick auf ihre Aussagekraft zur Darstellung struktureller Veränderungen und funktioneller Zusammenhänge bewertet, während therapeutische und präventive Ansätze hinsichtlich ihrer Wirkung auf die Belastungsmodulation untersucht werden. Ziel ist die systematische Verknüpfung von mechanischer Belastung, strukturellen Veränderungen und klinischer Anwendung. This thesis analyzes lumbar disc herniation from a biomedical engineering perspective, focusing on biomechanical and kinetic loading mechanisms. Emphasis is placed on the quantitative characterization of axial compression, ventrodorsal shear, and rotational forces and their influence on disc mechanics and degeneration. Diagnostic methods are evaluated with regard to their ability to visualize structural changes and functional relationships, while therapeutic and preventive strategies are examined in terms of their impact on load modulation. The aim is to establish a systematic link between mechanical loading, structural changes, and clinical application.2 0Item Restricted From the Spouses' Perspective the Influence of Women's Employment on Family Stability and Divorce Rates: A Study within the Saudi Arabia Context.(Saudi Digital Library, 2023) Althobaiti, Fuad; Fenella, FleischmannThis study investigates the perceived effects of women's employment on family stability and divorce rates from the perspectives of spouses within the Saudi Arabia context. With a focus on the qualitative methodology, this research aims to provide an in-depth understanding of the ground realities in Saudi Arabia societies where old traditions often take precedence (Asbah, Nasra & Abu-Baker, 2014). Given the family-driven nature of Saudi culture, this study holds significance as it subjectively evaluates family patterns and explores potential factors in marital life that may contribute to high divorce rates among working women. A descriptive approach is employed to analyze the divorce phenomenon among working women and examine the impact of social change in Saudi society. The individual interview method is utilized to gain insight into men's perspectives on women's work and its influence on family structure. Participants are given the freedom and reassurance to express themselves openly during data collection. The findings reveal that traditional customs and conservative mindsets are significant factors in the rising divorce rates. The rapid social reforms and adoption of modern culture have intensified challenges within Saudi Arabia society. Furthermore, social media has emerged as both a positive and negative influence on marital relationships. The Saudi government's initiatives to promote education and understanding of family structure have been met with resistance and led to family disputes and compatibility issues among couples. So, this study highlights the need for further efforts to address the challenges faced by working women in Saudi Arabia by fostering understanding and acceptance of women's rights and the importance of maintaining healthy family structures. By promoting gender equality and supporting women's empowerment, it is hoped that the rising divorce rates among working women can be addressed and reduced in the future.46 0Item Restricted Ed-Derâri’l-Lâmi’ât fi Müntaḫabâti’l-Lugât: İnceleme-Metin-Sözlük(Saudi Digital Library, 2026) Faidhallah, Faisal Abdulrashid M; Gülden, Sağol YüksekkayaThis thesis has been prepared on Ed-Derârî’l-Lami‘ât fî Müntaḫabâti’l-Lügât, which Muhammed İbni Ali El-Ünsî wrote in AH 1318 / AD 1900 for the purpose of teaching Turkish to Arabs and which was printed in AH 1320 / AD 1902 at the Cerîdet Beirut Printing House in Beirut. The study aims to introduce the work, to set out its lexicographic position and functioning, and to provide a reliable text-and-index in terms of word-formation and text transmission. The thesis consists of five chapters: In the Introduction, the author and his works, language policy in the Ottoman period, the structure of schools in the Arab countries during the Ottoman era, the lexicographic milieu, and the dictionaries and grammars written for teaching Turkish to Arabs are discussed. In the lexicographic analysis, the work is evaluated within a contemporary theoretical framework, and the classification has been carried out based on Atkins and Rundell’s typology. In the word-formation chapter, the affixes appearing in the headwords have been analyzed based on the vocalization used by the author; usages that do not accord with the phonetic features of the period have been identified and explained in that chapter. In the Text chapter, the headwords have been transferred from Ottoman Turkish (Arabic script) into Turkish in Latin script, considering the author’s vocalization. The text has been arranged in four columns: Turkish in Latin script, Ottoman Turkish in Arabic script, the Arabic equivalents, and the Turkish equivalents. The index has been prepared in two parts. The first index is arranged in four columns: the Latin-script headwords appear in the left columns and the Arabic-script headwords in the right columns; indexing has been carried out according to the order of the Arabic alphabet. The second index has been compiled solely from Turkish Latin-script headwords and is organized according to the order of the Turkish alphabet.4 0Item Restricted CULTURAL TOURISM AS AN ECONOMIC DIVERSIFICATION TOOL IN SAUDI ARABIA: STAKEHOLDER PRESPECTIVE ON VISION 2030’S FEASIBILITY AND CHALLENGE(Saudi Digital Library, 2026) Alaflah, Sumayyah Mahmoud; Anastasiadou, DinaThis dissertation evaluates stakeholder perceptions of cultural tourism as an economic diversification tool under Saudi Arabia's Vision 2030. The study assesses the sector's perceived economic potential and identifies the most critical barriers to its successful implementation. A quantitative-dominant mixed-methods approach was employed, using a structured online survey of 100 key stakeholders. Data was analyzed using descriptive statistics and thematic analysis. Findings reveal a strong consensus that cultural heritage is an underutilized asset (Mean = 3.73). A critical nuance emerged on barriers: 'Accessibility and Infrastructure' was ranked the most urgent challenge (30%), while 'Human Capital and Training' was the dominant long-term strategic theme. The data also exposes a significant "implementation gap" in community engagement: while stakeholders strongly support involvement (Mean = 4.06), 67% perceive communities are not currently involved. The study concludes that while stakeholders support Vision 2030, its success is contingent on resolving these tensions. A two-stage policy approach is recommended: an immediate focus on the urgent infrastructure deficit, followed by sustained investment in the significant human capital gap. Success ultimately depends on aligning the national Vision with local stakeholder insights and participation.25 0Item Restricted The supplementary effect of transcranial direct current stimulation during upper limb motor practice on consolidation in healthy older adults(Saudi Digital Library, 2023) Mazi, Aseel; Nieuwboer, Alice; Vandendoorent, BrittBackground: Ageing affects the consolidation of learned motor skills. Transcranial direct current stimulation (tDCS) of the dorsolateral prefrontal cortex in conjunction with motor sequence learning (MSL) improves consolidation. However, the effects of tDCS of the primary motor cortex (M1) on consolidation are still unclear. Additionally, it seems that the conventional tDCS montage (CONV-tDCS) generates a relatively non-focal stimulation compared to high-definition tDCS (HD-tDCS). So far, it is unknown whether the effects of tDCS depends on its montage. Objective: First, to compare tDCS and sham of the M1 during MSL on dual task (DT) performance as a measure of consolidation. Second, to compare CONV-tDCS and HD-tDCS of the M1 during MSL on DT performance. We hypothesize that tDCS, particularly HD-tDCS, when added to MSL grants superior DT performance compared to sham in older adults. Methods: This study was a sham-controlled randomized double-blind trial with a crossover for tDCS montage. Fifty-two participants were allocated to the active or sham tDCS group. Two sessions of twenty minutes of 1mA tDCS or sham of the M1 were administered during a serial reaction time task (SRTT). DT performance on the SRTT (DT-SRTT) was evaluated by adding an auditory Stroop task. The primary outcome was the mean reaction time on the DT-SRTT after the intervention. Results: The linear mixed model revealed no effect of group (p=.570) or montage (p=.946) on the DT-SRTT. Nevertheless, the mean reaction time of the single task SRTT (ST-SRTT) and DT-SRTT showed a significant improvement over time (p<0.001). Conclusion: DT performance improved with practice in older adults, irrespective of applying tDCS. We conclude that tDCS of the M1 has no surplus benefit on consolidation.17 0Item Restricted Examining the methane potential of a fiberbank sediment using two-stage anaerobic digestion system.(Saudi Digital Library, 2025) ALfaraj, Ali; Isaksson, SimonPrior to the introduction of the environmental protection act by the Swedish government in 1969, the pulp and paper (P&P) industry discharged its process wastewater directly into the waterbodies, leading to an environmental impact in the form of fiberbank sediment. The fiberbank sediment consists of a high amount of biodegradable material and toxic compounds from industrial processing, posing environmental risks such as greenhouse gas (GHG) emission and the release of toxic substances into the surrounding environment. The traditional remediation methods of contaminated sediment such as dredging and landfilling are not feasible due to the potential of emission of GHG in storage. To address this issue, anaerobic digestion (AD) in two stage configurations is proposed as pre-treatment before storage. The feasibility of the proposed solution was evaluated through laboratory experiments using CSTR reactors and by co-digestion of fiber bank sediment with primary sludge from a wastewater treatment facility. In the acidogenesis stage, an 80:20 ratio of fiberbank sediment (FB) to primary sludge (PS) was found to be optimal for maximizing volatile fatty acid (VFA) production. In the methanogenesis stage, 5% of digestate from the acidogenic reactor was mixed with 95% PS on VS basis. The result showed statistically significantly higher volumetric methane production (VMP) of the test reactor (5.1 ± 0.7 L CH4 / L) compared to control reactor (4.6 ± 0.7 L CH4 / L). In contrast, the specific methane production (SMP) showed no significant difference between the test reactor (295 ± 35) compared to control reactor (306 ±37), indicating similar efficiency of biodegradability between the test reactor and control.9 0Item Restricted Comparing human fetal liver-derived mesenchymal stromal cells to human adult bone marrow-derived mesenchymal stromal cells(Saudi Digital Library, 2019) Toonsi, Mawaddah; Götherström, Cecilia; Abomaray, Fawaz; Walther Jallow, LilianBackground: Mesenchymal stromal cells (MSC) can be isolated from various tissue sources and can be derived from adult and fetal tissues. Depending on their age, MSC have different therapeutic potentials. In this study human fetal liver MSC (fMSC) were compared to adult bone marrow MSC (aMSC) regarding their phenotype and function. Methods: fMSC and aMSC were compared in terms of their size using CASY TT and their senescence using ß-galactosidase staining. Population doublings (PD) and population doubling time (PDT) were also examined. Following induction of osteogenic differentiation, calcium deposits were stained using Alizarin red S. Finally, flow cytometry was used to examine the cells’ phenotype and purity. Results: fMSC had a significantly lower peak diameter compared to aMSC. Moreover, fMSC displayed a greater number of PD and a shorter PDT in comparison to aMSC, and the percentage of fMSC undergoing senescence was significantly lower than aMSC. Furthermore, fMSC that were induced into osteoblasts deposited more calcium salts, and hence stained more positive for Alizarin red S relative to aMSC. Finally, both cell sources were positive for the MSC markers CD90 and CD73 and negative for the non-MSC markers CD45, CD31 and HLA class II. Conclusions: The results of the study demonstrate that fMSC possess a greater proliferative and osteogenic differentiation capacity compared to aMSC. Altogether, fMSC may be a more robust cell source compared to aMSC as a therapy for diseases, including those that require bone repair.14 0Item Restricted The Role of Gamma Delta T Cells in Haematopoietic Stem Cell Transplantation and Malignancies(Saudi Digital Library, 2025) Alagrafi, Faisal Sultan; Michael, Uhlin; Mikael, Sundin; supervisor, Main; Thomas, PoiretAllogeneic haematopoietic stem cell transplantation (aHCT) is a potentially curative immunotherapeutic approach for several lethal hematological disorders. However, morbidity and mortality rates remain high after aHCT due to complications such as relapse, graft-versus-host disease (GVHD), and infections. Successful aHCT requires rapid and effective immune reconstitution, particularly within the T-cell compartment, to protect against opportunistic infections and to eliminate residual tumor cells without aggravating GVHD during the immunocompromised period following transplantation. Early reconstitution of γδ T cells plays a substantial role in immune surveillance post-aHCT via mediating anti-infection and anticancer immunity, correlating with favorable clinical outcomes with less GVHD incidence. These unique features have attracted increasing attention towards harnessing γδ T cells as effector cells for cancer immunotherapy. This thesis presents three papers to bring further knowledge on the role of γδ T cells in the dimension of aHCT and their potential use in hematological malignancy therapy. Study I aimed to investigate long-term homeostatic steady-state γδ T cell reconstitution after aHCT, focusing on its associations with previous clinical outcomes. We performed an in-depth analysis of γδ T cell phenotypes, TCR-Y repertoire, and functional responses upon stimulation in 20 recipient/donor pairs using multiparametric flow cytometry and next-generation sequencing of the TCR-y chain. Results showed a comparable phenotypic profile between recipients and donors. Upon PMA/lonomycin stimulation, recipient γδ T cells secreted high levels of cytokines. Furthermore, the TRG repertoire in recipients was almost completely restored, with no significant differences in diversity, clonality, or gene segment usage compared to donors. However, we found an association between overrepresented donor-derived clonotypes and elevated HLA-DR expression in Vδ1 T cells with increased severity of chronic GVHD in some recipients. Study II focused on augmenting the antileukemic activity of expanded γδ T cells by CD34/CD3 bispecific T-cell engager (BTE) in vitro. We demonstrated that the CD34/CD3 BTE effectively activates and redirects γδ T cells (effector cells) against CD34-expressing leukemia cell lines (target cells), as evidenced by their specific cytotoxicity in a dose-dependent manner and high cytokine release. Furthermore, CD34/CD3 BTE induced γδ T cell-mediated killing of primary CD34+ AML blasts. In the presence of CD34/CD3, γδ T cells showed superior antileukemic activity compared to conventional aß T cells, while demonstrating no cytotoxic effects against CD34+ normal cells. In Study III, we aimed to further enhance the antileukemic activity of expanded yo T cells by sensitizing leukemia cells with thymoquinone (TQ) treatment. TQ is a phytochemical compound featuring epigenetic activity and immunomodulatory properties with growing evidence as a potent anticancer candidate. We observed that γδ T cells exhibited rapid and increased cytotoxicity when co-cultured with pre-treated leukemia cell lines with TQ compared to vehicle control and untreated conditions. This enhanced cytotoxicity could be attributed to the upregulated expression of NKG2D and DNAM-1 ligands on leukemia cells after TQ treatment. We also showed that TQ pretreatment in leukemia cell lines supports the condition of the γδ T cells-based CD34/CD3 approach. Altogether, this thesis investigated that long-term γδ T cell reconstitution reaches a homeostatic state with a normalized repertoire. Elevated HLA-DR expression on Vδ1 T cells in cGVHD recipients could be a potential therapeutic target, warranting further investigation. It also highlights the potential use of expanded γδ T cells in hematological malignancy therapy by targeting CD34 and sensitizing leukemia cell lines through thymoquinone for CD34/CD3 BTE treatment11 0Item Restricted Development of a phase-field model for corrosion and degradation in bioresorbable stents(Saudi Digital Library, 2022) Harban, Ibrahim Abdullah; Döring, Daniela; Karras, IngoAccording to the World Health Organization (WHO), cardiovascular diseases—particularly chronic coronary heart disease (CHD) and myocardial infarction—are the leading causes of death in industrialized countries. In 2019, an estimated nine million people died from heart diseases, with 60% of these deaths attributable to CHD. Due to demographic change, an aging population is expected, leading to an increase in degenerative diseases and greater challenges for healthcare systems. Two treatment options currently exist for CHD: coronary artery bypass grafting (CABG), which is performed surgically and in hospital settings, and percutaneous transluminal coronary angioplasty (PTCA), introduced in 1977, where a stent is placed minimally invasively without requiring extended hospitalization. Although stent-based therapy has advantages over CABG in medical and economic terms, a recent meta-analysis shows the superiority of bypass surgery in improving 10-year survival rates, partly due to side effects of PTCA. Current research therefore focuses on bioresorbable materials for stent manufacturing, aiming to provide safer, more effective, and sustainable patient care compared to conventional permanent stents. While bioresorbable stents appear promising, their degradation behavior still leads to complications, preventing them from surpassing permanent stents at present. Ongoing projects aim to better predict corrosion processes and improve the safety of bioresorbable stents, with fracture mechanics and phase-field modeling representing promising approaches. This thesis analyzes the method of percutaneous transluminal coronary angioplasty (PTCA) and stent implantation in order to evaluate its advantages and disadvantages. The focus is on addressing the following research questions: What risks occur in percutaneous transluminal coronary angioplasty, and how can they be minimized? How can future stents be designed to optimally improve patient care?7 0Item Restricted Creating a Concept and Modelling a Lean Management Simulation Game in Plant Simulation(Saudi Digital Library, 2025) Harban, Ibrahim Abdullah; Näser, Peggy; Kober, DoreenMaterial flow technology has undergone significant development over time. While production processes were initially characterized by manual individual solutions, the introduction of mass production in the early 20th century—especially through Henry Ford’s assembly line principle—revolutionized industrial manufacturing. However, this production method also led to high inventories, long throughput times, and limited flexibility. In response to these challenges, Toyota developed the Toyota Production System (TPS) in the 1950s, which laid the foundation for Lean Management. By applying principles such as waste reduction, just-in-time production, and continuous improvement (Kaizen), more efficient and flexible manufacturing became possible. Today, Lean Production represents a global standard in industrial manufacturing, aiming at resource efficiency, quality enhancement, and delivery reliability. At the same time, material flow technology plays a crucial role in optimizing production and logistics processes, reducing costs, and strengthening competitiveness. Digitalization, especially discrete-event simulation, enables detailed analysis and optimization of material flow. Using software solutions such as Tecnomatix Plant Simulation, companies can model, simulate, and improve complex material flow systems prior to physical implementation. The aim of this thesis is to analyze the theoretical foundations of Lean Production and material flow technology, as well as their practical application in a simulation game. The focus is on evaluating the effectiveness of Lean tools such as 5S, SMED, TPM, and Poka Yoke, and on examining the influence of takt, flow, and pull principles on production performance. The results of the simulation game provide a basis for practice-oriented recommendations for implementing Lean Production in real production environments. Furthermore, the thesis investigates a simulation-based training system for conveying Lean methods. Through a simulation study, the effectiveness of optimization measures in a model factory is evaluated, aiming to derive relevant insights for improving production processes and quantifying the impact of Lean methods on material flow efficiency.13 0