Limited Space Research Articles

Anatomical limits of the parapharyngeal space using a transoral endoscopic approach - Radioanatomical study in cadaver.

The aim of this study is to obtain the anatomical limits of the parapharyngeal space by transoral surgical approach, in order to objectively determine the types of lesions according to location, where this type of approach is more indicated. A prospective, experimental, radio-anatomical study was performed on 10 cryopreserved human heads(20 sides). A transoral approach of the parapharyngeal space was performed determining its anatomical limits by CT navigation. A statistical analysis of the registered variables was carried out. Intraoral endoscopic dissection of the parapharyngeal space was possible in all anatomical pieces (10 heads, 20 sides). The surgical technique was started by placing a laryngopharyngoscopic retractor. The scalpel incision was made from the posterior border of the hard palate, extending along the lateral border of the soft palate, following the glossopalatine arch and ending at the base of the tongue, in its posterolateral region. Under direct vision with a 0º rigid endoscope, we proceeded to the dissection by planes, identifying all the relevant vasculonervous, osseous and muscular structures. Once all the anatomical references were located, the planned measurements were taken using the surgical navigator. The endoscopic intraoral approach constitutes a feasible, safe and direct access route to the parapharyngeal space. This approach would be especially indicated in lesions of the parapharyngeal space (PPS) that do not exceed the styloid and pterygoid processes cranially, do not have significant retrostylial extension and do not substantially reach the lower area of the PPS.

Probing Spatiotemporal Effects of Intertrack Recombination with a New Implementation of Simultaneous Multiple Tracks in TRAX-CHEM.

Among the most investigated hypotheses for a radiobiological explanation of the mechanism behind the FLASH effect in ultra-high dose rate radiotherapy, intertrack recombination between particle tracks arriving at a close spatiotemporal distance has been suggested. In the present work, we examine these conditions for different beam qualities and energies, defining the limits of both space and time where a non-negligible chemical effect is expected. To this purpose the TRAX-CHEM chemical track structure Monte Carlo code has been extended to handle several particle tracks at the same time, separated by pre-defined spatial and temporal distances. We analyzed the yields of different radicals as compared to the non-interacting track conditions and we evaluated the difference. We find a negligible role of intertrack for spatial distances larger than 1 μm, while for temporal distances up to μs, a non-negligible interaction is observed especially at higher LET. In addition, we emphasize the non-monotonic behavior of some relative yield as a function of the time separation, in particular of H2O2, due to the onset of a different reaction involving solvated electrons besides well-known OH· recombination.

Non-minimal elliptic threefolds at infinite distance II: asymptotic physics

We interpret infinite-distance limits in the complex structure moduli space of F-theory compactifications to six dimensions in the light of general ideas in quantum gravity. The limits we focus on arise from non-minimal singularities in the elliptic fiber over curves in a Hirzebruch surface base, which do not admit a crepant resolution. Such degenerations take place along infinite directions in the non-perturbative brane moduli space in F-theory. A blow-up procedure, detailed generally in Part I of this project [1], gives rise to an internal space consisting of a union of log Calabi-Yau threefolds glued together along their boundaries. We geometrically classify the resulting configurations for genus-zero single infinite-distance limits. Special emphasis is put on the structure of singular fibers in codimension zero and one. As our main result, we interpret the central fiber of these degenerations as endpoints of a decompactification limit with six-dimensional defects. The conclusions rely on an adiabatic limit to gain information on the asymptotically massless states from the structure of vanishing cycles. We also compare our analysis to the heterotic dual description where available. Our findings are in agreement with general expectations from quantum gravity and provide further evidence for the Emergent String Conjecture.

Self-adhesivity in lattices of abstract conditional independence models

We introduce an algebraic concept of the frame for abstract conditional independence (CI) models, together with basic operations with respect to which such a frame should be closed: copying and marginalization. Three standard examples of such frames are (discrete) probabilistic CI structures, semi-graphoids and structural semi-graphoids. We concentrate on those frames which are closed under the operation of set-theoretical intersection because, for these, the respective families of CI models are lattices. This allows one to apply the results from lattice theory and formal concept analysis to describe such families in terms of implications among CI statements.The central concept of this paper is that of self-adhesivity defined in algebraic terms, which is a combinatorial reflection of the self-adhesivity concept studied earlier in context of polymatroids and information theory. The generalization also leads to a self-adhesivity operator defined on the meta-level of CI frames. We answer some of the questions related to this approach and raise other open questions.The core of the paper is in computations. The combinatorial approach to computation might overcome some memory and space limitation of software packages based on polyhedral geometry, in particular, if SAT solvers are utilized. We characterize some basic CI families over 4 variables in terms of canonical implications among CI statements. We apply our method in information-theoretical context to the task of entropic region demarcation over 5 variables.

Selected Aspects of the Neuroimmunology of Cell Therapies for Neurologic Disease: Perspective.

Neurologic disease remains a cause of incalculable suffering, a formidable public health burden, and a wilderness of complex biology and medicine. At the same time, advances in basic science, technology, and the clinical development toolkit bring meaningful benefit for patients along with realistic hope for those whose conditions remain inadequately treated. This perspective focuses on cell-based therapies for neurologic disease, with particular emphasis on neuroimmunologic disorders and on the immunologic considerations of cell therapy for nonimmune conditions. I will consider the use of chimeric antigen receptor (CAR)-T effector cells and regulatory T-cell therapies for autoimmune conditions. I will briefly discuss the immune aspects of pluripotent stem cell (PSC)-derived neuronal therapies. With apologies for the omission, we do not discuss mesenchymal stem cells, glial progenitor cells, or CAR-NK cells, primarily for space limitations.

Stress, microbiota, and the gut-brain axis in mental and digestive health.

The prevailing mind-body dualism in contemporary medicine, rooted in reductionism and the fragmentation of knowledge, has impeded the development of a conceptual model that can adequately address the complexity of illnesses. Integrating biomedical data into a cohesive model that considers the mind-body-context interconnections is essential. This integration is not merely theoretical; rather, it has significant clinical implications. This is exemplified by chronic stress-related mental and digestive disorders. The onset and development of these disorders are intimately linked to chronic psychological stress via the brain-gut-microbiota axis. The present article examines the evidence and mechanisms indicating that stress is a primary factor and a potentiator of symptom severity in common mental health and digestive diseases, with a particular focus on human studies. However, due to space limitations, only a very general overview of preventive and therapeutic clinical strategies is provided. It is hoped that the recurring phrase, "Everything that happens to you is due to stress," will become more comprehensible to the physician after reading this manuscript.

Structural performance evaluation of mobile solar-powered battery swap station for electric motorcycles

This study introduces a structural design and static analysis of a Mobile Battery Swap Station for electric motorcycles, powered by solar energy, to address the critical need for sustainable and off-grid charging infrastructure. As the adoption of electric motorcycles continues to grow, driven by the demand for eco-friendly transportation alternatives, the lack of widespread and accessible charging infrastructure poses a significant barrier to their widespread use. In many regions, the expansion of traditional grid-connected charging stations is hindered by high installation costs, space limitations in urban environments, and logistical challenges in remote or underserved areas. The design focuses on a robust, mobile frame made from hollow iron of AISI 1010 steel, supporting the integration of photovoltaic (PV) panels to supply renewable energy directly to the battery-swapping system. Using Finite Element Analysis (FEA), the station’s structural integrity was evaluated under a uniformly distributed load of 700 kg, simulating real-world loading conditions for components essential to electric motorcycle operations, including PV mounts and battery racks. Results show a maximum displacement of 4.541 mm, a peak stress of 57.716 MPa, and a Factor of Safety (FOS) of 2.9, confirming the design’s ability to securely and stably support the necessary equipment for battery swapping. This mobile, solar-powered solution advances sustainable infrastructure for electric motorcycles, enabling flexible, grid-independent battery swapping that is particularly beneficial in urban areas and remote locations. This station contributes to greener mobility solutions tailored for electric motorcycles, aligning with broader efforts to support eco-friendly transportation systems

The Practice and Exploration of Virtual Reality Technology in Distance Education

With the rapid development of information technology, virtual reality (VR) technology has gradually transformed from the concept of science fiction to reality, and become an important driving force for innovation and development in the field of education. As an immersive technology, VR can break the limitations of time and space in traditional teaching modes and create an immersive learning experience for learners. This technology can not only make the learning process more vivid and interesting, but also improve students’ learning efficiency and initiative through interaction and immersion. Especially in the field of distance education, the application of VR technology is redefining teaching methods, increasing the efficiency of educational resource sharing, and enhancing the fairness and accessibility of education. This paper will take VR technology as the starting point, analyze its basic principles and technical characteristics, and deeply discuss the diversified practices of VR in distance education, including teaching scene simulation, interactive experience optimization, other aspects of educational resources equity, etc.

Multifunctional Space Conversion and Environmental Design in Modern Interior Design

In order to solve the contradictory nature of the limitations of small house space and multiple functional needs, this paper actively explores the variable space planning strategy in interior design. The environmental design scheme is proposed to realize the indoor ecological functional needs by utilizing space design with minimum energy consumption. The analysis of the functional needs of residential users reveals that it is feasible to meet the functional needs of different groups and different stages of residential use by dividing and combining indoor functional spaces. According to the results of a survey in a first-tier city, the average expectation of bedroom and living room area for 30-70m² houses is 20.7m² and 15.8m² respectively, which means that when small houses are designed, the important functional spaces such as bedrooms and living rooms under the limiting dimensions are prioritized to be combined. The results of the case study of four local houses of different sizes verify the effectiveness of the proposed strategy. 92.28% and 94.54% of space utilization is achieved in house 1 and house 2 respectively, while the energy efficiency of house 4 reaches 61.42%.

The Utilization of Independent Teaching Platform to Improve Teachers’ Competencies

The Independent Teaching Platform is a digital media that provides various learning resources, training, and connections between teachers. Through this platform, teachers can access the latest learning content, collaborate with fellow teachers, and take professional training without space and time limits. With easy and quick access, teachers have the opportunity to continuously develop their knowledge and skills. This article discusses the concrete benefits of utilizing Independent Teaching Platform, such as improved understanding of the latest teaching methods, implementation of technology in learning, and improved creativity in delivering material. In addition, this platform also creates a collaborative space among teachers, enabling the exchange of ideas and experiences that can improve the quality of teaching collectively. The method in writing this article uses a systematic literature review in order to get the sources the researcher wants in detail. The results of the review of this article are that teachers get many benefits that are used to improve competencies in teaching and managing learning in the classroom more actively, innovatively and creatively. However, there are constraints in some remote or outermost areas/regions such as: limited access to qualified teachers, inadequate infrastructure, and geographical isolation.

CubeSat Imaging Payload Design for Environmental Monitoring of Greenland

Climate change affects the Earth’s ecosystem, and understanding human impact on sparsely populated polar regions is crucial, especially in glacial dynamics. Nanosatellites can play an essential role in monitoring remote regions due to their flexibility in adding remote sensors for Earth observation. However, they have hardware constraints such as physical space limitations, low power generation, and low bandwidth, as well as environmental challenges of vacuum, heat, cold and radiation. This paper details the preliminary system design of an imaging payload integrated into a nanosatellite for monitoring field study sites in Greenland. The payload is capable of supporting advanced image processing and Machine Learning (ML) applications. Key design elements, including the selection of imaging sensors, onboard processing units, and data transmission systems, which are optimized for the constraints of a nanosatellite platform, are presented. As a result, we presented a novel imaging payload system design, which shows a significant step towards leveraging space technology for environmental research.

Impact of Pathway Shape and Length on the Validity of the 6-Minute Walking Test: A Systematic Review and Meta-Analysis

Although guidelines are established for performing the six-minute walking test (6MWT), it is not always possible to implement this test in any setting, due to physical and space limitations. Yet, variations in the conditions of the test could be responsible for heterogeneous outcomes. However, the impact of the condition of the 6MWT is not clearly established in literature. The objective is to determine the influence of different implementation conditions on the validity of the 6MWT. Seventeen articles were retained after a literature review, including 597 participants. Seven articles mention that performing the test on a predetermined short back-and-forth pathway led to lower performance than when the test was performed on pathways of greater distances. The walking distance covered on a rectangular path or on a 10-m eight-form path is greater than with the back and forth on a five- to ten-meter path. Seven articles suggest that the performance achieved on a treadmill is generally lower than that obtained while walking on the ground. Evidence shows that the conditions while performing the 6MWT significantly influence the score, hence the validity of the results. The use of a ground pathway, comprising the longest linear distance possible, seems critical to ensure good validity.

A Branch-and-Price-and-Cut Algorithm for the Inland Container Transportation Problem with Limited Depot Capacity

As an effective solution to the first- and last-mile logistics of door-to-door intermodal container transportation, inland container transportation involves transporting containers by truck between terminals, depots, and customers within a local area. This paper is the first to focus specifically on the inland container transportation problem with limited depot capacity, where the storage of empty containers is constrained by physical space limitations. To reflect a more realistic scenario, we also consider the initial stock levels of empty containers at the depot. The objective of this problem is to schedule trucks to fulfill inland container transportation orders such that the overall cost is minimum and the depot is neither out of stock or over stocked at any time. A novel graphical representation is introduced to model the constraints of empty containers and depot capacity in a linear form. This problem is then mathematically modeled as a mixed-integer linear programming formulation. To avoid discretizing the time horizon and effectively achieve the optimal solution, we design a tailored branch-and-price-and-cut algorithm where violated empty container constraints for critical times are dynamically integrated into the restricted master problem. The efficiency of the proposed algorithm is enhanced through the implementation of several techniques, such as a heuristic label-setting method, decremental state-space relaxation, and the utilization of high-quality upper bounds. Extensive computational studies are performed to assess the performance of the proposed algorithm and justify the introduction of enhancement strategies. Sensitivity analysis is additionally conducted to investigate the implications of significant influential factors, offering meaningful managerial guidance for decision-makers.

Recommendations for the optimization of student led free vision screening programs

PurposeTo report the summary characteristics of operational models associated with Student Led Free Vision Screening Programs (SLFVSP) and to identify opportunities for program optimization.MethodsAn 81-question mixed methods survey was distributed to SLFVSP leaders nationwide and Medical Student Educators within the American University Ophthalmology Professors (AUPO) Association. Survey responses were analyzed using Mann Whitney U and Fisher’s Exact tests. Themes considering the assets and liabilities of SLFVSPs were summarized using self-reported qualitative data from survey responses. Qualitative and quantitative themes considering were then synthesized into a Strengths, Weaknesses, Opportunities, & Threats (SWOT) analysis for a collective appraisal of SLFVSP operations. Finally, drivers were identified to generate change ideas to improve SLFVP operations through a collaborative, quality improvement model.ResultsA total of 16 survey responses were included from programs operational for a median of 6 years. Most respondent programs (n = 9) reported year-long operations; no preference between weekday (n = 8) and weekend (n = 7) screening activities was identified. Programs obtained funding from a diverse array of internal and external sources. There was no significant difference in wait time for scheduled appointments compared to a walk-in strategy; overall door-to-door visit times ranged from 15 min to 120 min. Screenings were held in several locations, most commonly in Federally Qualified Health Centers (n = 8) and religious centers (n = 6). Most screening event volunteers were first- and second-year medical students. The qualitative thematic analysis demonstrated that the most commonly self-reported asset was improving access to scarce vision screening services (n = 7) while the most commonly self-reported liability was difficulty recruiting faculty and/or resident for oversight (n = 5). The SWOT analysis revealed while the participant SLFVSPs were bolstered by site experience, community and corporate partnerships for glasses and space to hold vision screening, and institutional support from academic ophthalmology departments, limitations included difficulty with recruitment, space limitations, and poor follow-up care infrastructure.ConclusionCollaborative standardization of SLFVSP operations can promote targeted staff training, organizational stewardship, and consensus building to ensure SLFVSP can offer sustainable vision screening programs that build vision equity at the community level.

Impact of Linker Composition on VHL PROTAC Cell Permeability.

The discovery of cell permeable and orally bioavailable von Hippel-Lindau (VHL) proteolysis targeting chimeras (PROTACs) is challenging as their structures locates them at, or beyond, the outer limits of oral druggable space. We have designed a set of nine VHL PROTACs and found that the linker had a profound impact on passive cell permeability. Determination of the solution ensembles in a nonpolar solvent revealed that high permeability was correlated to the ability of the PROTACs to adopt folded conformations that have a low solvent accessible 3D polar surface area. Our results suggest that the design of cell permeable VHL PROTACs could focus on linkers that facilitate shielding of polar surface area in the VHL ligand in a nonpolar but not in a polar environment. In addition, we found that not only intramolecular hydrogen bonds, but also NH-π and π-π interactions contribute to the stabilization of low-polarity conformations, and thereby to high cell permeability.

Chinese dentists’ restorative preferences and choices for endodontically treated teeth: a representative survey

BackgroundThe optimal restoration protocol for endodontically treated teeth (ETT) remains a subject of debate. This survey aims to assess the current level of awareness, knowledge, and prevailing opinions among dental practitioners in China regarding the application of endocrown versus the post/core/crown ensemble for post-endodontic restoration strategies.MethodsA validated questionnaire, encompassing three sections, was distributed electronically to dentists practicing in China. The initial section collected demographic characteristics of the participants, while the subsequent sections assessed their knowledge and preferences regarding ETT restoration techniques in various clinical scenarios. Distribution of the survey was facilitated through the social media platform WeChat, with a total of 600 invitations sent out. Data analysis was conducted using SPSS Statistical Software, employing frequency and Chi-square tests to determine statistical significance at the P < 0.05 threshold.ResultsA total of 400 valid questionnaires were collected. The amount of remaining tooth structure was identified as the most influential factor in determining the restoration strategies, contributing to 26.1%. Over 72.8% of the surveyed dentists acknowledged the reinforcing effect of intraradicular posts on ETT. More than half of the participants reported the application of endocrowns within their post-endodontics management. The preference for endocrowns was pronounced in cases where more than 50% of the tooth’s structure remained or when occlusal space limitations were present. The Chi-Square test revealed that the participants’ knowledge regarding endocrown restoration was significantly influenced by their age, educational background, and experience (p < 0.05).ConclusionsThe clinical decision-making process for the restoration of endodontically treated teeth (ETT) by dental practitioners primarily relies on the amount of remaining tooth structure. Most surveyed dentists believe that the presence of a post can reinforce ETT. A majority of participants consider the Endocrown as a viable alternative restorative treatment for ETT.

A sound insulation cooling fin for broadband noise control and ventilation

Abstract The noise generated by the ultrathin centrifugal fan in a laptop can significantly impact user comfort. While optimizing the fan itself for noise control is important, addressing noise propagation is also crucial. Due to space limitations inside a laptop, adding an extra component for noise control is nearly impossible. Therefore, modifying the cooling fin outside of the fan outlet for sound insulation can be an effective solution. A sound insulation cooling fin is proposed to provide broadband noise insulation while maintaining proper ventilation. Through the introduction of a coupled area change passage, noise at specific frequencies at the passage outlet can be managed to be insulated due to the destructive interference. The effectiveness of the unit’s sound insulation is verified through an impedance tube measurement. Moreover, combining different units can create a multi-peak sound insulation effect which is suitable for various noise conditions. To meet the demand of real situations, a reversal design flow combining neural network and nonlinear constrained optimization algorithm is developed. As a result, a sound cooling fin combing 2 sound insulation units featuring 4013 Hz and 6000 Hz is fabricated and the actual insulation performance is measured in an anechoic chamber. The sound transmission loss at the designed frequency range reaches 5 dB, aligning well with the simulation results. The sound insulation cooling fin has the potential to be widely used for noise control in small-scale electronic devices.

Design of Multi-Wing Deployment Mechanism Based on Multiple Performance Indicators and Topology: Theoretical and Experimental Study

The folding wing deployment mechanisms of aircraft are constrained by weight and space limitations, necessitating fewer actuators, multiple outputs, compact designs, and high efficiency. However, existing folding wing mechanisms often overlook the impact of performance in configuration design. Additionally, they struggle to achieve the synchronous unfolding of multiple wings using a single drive. This paper presents a design methodology for multi-wing deployment mechanisms based on configuration topology and multiple performance indicators. Specifically, seventeen configurations of multi-wing deployment mechanisms are developed based on functional requirements, along with expression methods for performance indicators, including compactness, mechanism stiffness, dynamic sensitivity, motion transmission, and joint transmission efficiency. The optimal configuration for the multi-wing deployment mechanism is identified utilizing the fuzzy comprehensive evaluation. Moreover, the transmission efficiency of multiple configurations is calculated across different scale parameters. Simulation analyses and prototype experiments are conducted to validate the design. The results indicate that the transmission efficiency of the optimized configuration consistently exceeds that of the other configurations. Maximum efficiencies surpass those of the other configurations by 2.4% and 5.7%. Importantly, this study introduces a quantitative expression method for multiple performance indicators at the configuration design stage. This approach enables the integration of various performance metrics with configuration designs. Overall, this research provides a novel approach for the innovative design of multi-wing deployment mechanisms in aircraft. Additionally, considering performance in the selection of mechanism configurations during engineering design offers valuable insights and potential applications.

Perancangan Website E-Commerce Deal! Dalam Jual-Beli Barang Bekas

In this digital era, e-commerce websites are growing very rapidly. Technological advances have a major impact on economic growth including businesses around the world, including Indonesia. E-commerce is one of the advanced technologies that greatly encourages the progress of digital business in Indonesia. Technological advances not only present new opportunities but also change the way people interact in business activities. E-commerce, as a form of technological innovation, plays an important role in supporting the growth of the digital economy by providing convenience in buying and selling transactions without space and time limits. Therefore, designing an optimal e-commerce website is a strategic step to meet the needs of the growing market. This study aims to design an e-commerce website that is not only functional and responsive, but also user-friendly, by paying attention to aesthetic aspects, ease of navigation, and security in transactions. With this approach, the designed website is expected to be able to provide a comfortable, safe, and satisfying online shopping experience, as well as contribute to increasing business competitiveness in the digital era.

Safety and accuracy assessment of static computer assisted localized piezoelectric alveolar decortication: an in vitro study

ObjectivesTo assess the safety and accuracy of static computer assisted corticotomy surgery (sCACS) in comparison with freehand piezocision.Materials and methodsA randomized in vitro study was conducted. A total of 260 interradicular corticotomies were performed in 20 identical printed models. sCACS was performed in half of the models, while the rest underwent freehand localized decortication. Accuracy was measured in the three spatial axes by overlapping the digital planning with a previous cone-beam computed tomography (CBCT) scan of the patient and a postoperative CBCT of the models. Safety was determined as the number of damaged root surfaces. Descriptive and bivariate analyses were performed.ResultsFreehand corticotomies increased the likelihood of iatrogenic root damage 2.21-fold (95%CI: 1.30 to 3.77; p = 0.004). Both groups showed some degree of deviation compared to digital planning. Nevertheless, the accuracy of sCACS was significantly greater in sagittal (B = -0.21 mm, 95%CI: -0.29 to -0.12; p < 0.001), axial (B = -0.32 mm, 95%CI: -0.48 to -0.18; p < 0.001) and angular deviation (B = -2.02º; 95%CI: -2.37 to -1.66; p < 0.001) compared to freehand surgery, with the exception of depth.ConclusionsThe precision and safety of sCACS are greater than the freehand technique.Clinical relevanceCorticotomies are performed in crowded areas where there is usually space limitation. Clinicians should consider the systematic use of surgical guides, since minimal deviations can cause iatrogenic root damage in areas where malocclusions are present.