Search Results (56)

Temporary anchorage devices (TADs) have become integral in contemporary orthodontic biomechanics, providing reliable skeletal anchorage independent of dental support or patient compliance. This narrative review synthesizes the current evidence regarding TADs classification, design parameters, biomechanical principles, clinical insertion protocols, complication management, and technological innovations. We reviewed foundational literature and recent clinical studies with emphasis on factors affecting primary and secondary stability, including insertion torque, angulation, cortical bone characteristics, and soft-tissue considerations. Self-drilling techniques are generally preferred for maxillary sites, while pre-drilling remains indicated in dense mandibular bone to reduce thermal risk and torque overload. Clinical success is optimized when insertion torque is maintained between 5 and 10 N·cm and site-specific anatomy is respected. Reported survival rates exceed 85–95% when proper protocols are followed. While TADs are associated with relatively low complication rates, failures are usually early and linked to excessive torque, poor hygiene, or inflammation. New technologies such as cone-beam computed tomography-guided placement, 3D-printed surgical guides, and AI-based planning tools offer promising avenues for safer and more individualized treatment. In conclusion, TADs represent a predictable and versatile option for skeletal anchorage in orthodontics, provided that mechanical design, biological adaptation, and clinical handling are coherently integrated into patient-specific strategies. Full article

This article introduces an innovative hybrid methodology that integrates deterministic Mixed-Integer Linear Programming optimization with stochastic Agent-Based Simulation to address the PDP-TW. The approach is applied to real-world operational data from a luggage-handling company in Lisbon, covering 158 service requests from January 2025. The MILP model generates optimal routing and task allocation plans, which are subsequently stress-tested under realistic uncertainties, such as variability in travel and service times, using ABS implemented in AnyLogic. The framework is iterative: violations of temporal or capacity constraints identified during the simulation are fed back into the optimization model, enabling successive adjustments until robust and feasible solutions are achieved for real-world scenarios. Additionally, the study incorporates transshipment scenarios, evaluating the impact of using warehouses as temporary hubs for order redistribution. Results include a comparative analysis between deterministic and stochastic models regarding operational efficiency, time window adherence, reduction in travel distances, and potential decreases in CO₂ emissions. This work provides a contribution to the literature by proposing a practical and robust decision-support framework aligned with contemporary demands for sustainability and efficiency in urban logistics, overcoming the limitations of purely deterministic approaches by explicitly reflecting real-world uncertainties. Full article

Construction site layout planning (CSLP) plays a pivotal role in determining the overall efficiency and cost-effectiveness of construction projects. Material handling operations, which constitute a significant portion of indirect project costs, heavily depend on the spatial arrangement of temporary facilities such as site offices, storage yards, and equipment zones. Poorly planned layouts can lead to excessive travel distances, increased material handling times, and operational delays, all of which contribute to inflated costs and reduced productivity. Therefore, optimizing the layout of construction sites to minimize transportation distances and enhance workflow is a critical task for project managers, contractors, and other stakeholders. The challenge in CSLP lies in the complexity of simultaneously satisfying multiple, often conflicting, requirements such as space constraints, safety regulations, and functional proximities. This complexity is compounded by the dynamic nature of construction activities and the presence of numerous facilities to be allocated within limited and irregularly shaped site boundaries. Mathematically, this problem can be formulated as a Quadratic Assignment Problem (QAP), a well-known NP-hard combinatorial optimization problem. The QAP seeks to assign a set of facilities to specific locations in a manner that minimizes the total cost, typically modeled as the sum of products of flows (e.g., material movement) and distances between assigned locations. However, due to the computational complexity of QAP, exact solutions become impractical for medium to large-scale site layouts. In recent years, metaheuristic algorithms have gained traction for effectively tackling such complex optimization problems. Among these, the Advanced Jaya Algorithm (A-JA), a recent population-based metaheuristic, stands out for its simplicity, parameter-free nature, and robust search capabilities. This study applies the A-JA to solve the CSLP modeled as a QAP, aiming to minimize the total weighted travel distance of material handling within the site. The algorithm’s performance is validated through two realistic case studies, showcasing its strong search capabilities and competitive results compared to traditional optimization methods. This promising approach offers a valuable decision-support tool for construction managers seeking to enhance site operational efficiency. Full article

In cemented endoprosthetics, closed prepacked mixing systems represent the most advanced generation of cementing technology. (1) Background: The purpose of the present study is to evaluate four approved prepacked systems—Palacos^® R+G pro, SmartMix™ Cemvac GHV, Optipac^® Refobacin and Cemex^® System Genta—with a focus on practical handling and intraoperative hygiene. (2) Method: The systems were evaluated according to established standard test methods for bone cements (ISO 5833), including dough time, setting time, additional mechanical tests and the level of system closure. (3) Results: The results show that all systems are safe to use and meet the general requirements, but there are relevant differences in terms of intraoperative hygiene. The Palacos R+G pro system shows significantly shorter doughing and setting times, which helps to minimize wound exposure during surgery and thus significantly reduces the overall operating time and the risk of bacterial contamination. Two of the systems cannot be classified as completely closed “pre-packaged systems.” In two cases, the system must be temporarily opened before mixing to insert the mixing element, which may result in a temporary but clinically relevant impairment of sterility and a corresponding potential risk of contamination. (4) Conclusion: From a hygienic point of view, systems that remain completely closed throughout the entire preparation process can offer advantages in terms of infection prevention. This was the case for all systems tested. Short handling times, reduced exposure of the surgical site and a shorter overall duration of the procedure could further improve intraoperative safety and reduce the risk of contamination. In terms of intraoperative hygiene, the Palacos R+G pro system achieved the best results compared to the three other systems tested due to its rapid readiness for use and comparatively short setting time (according to ISO 5833). Cemex System Genta performed worst in this respect due to its late doughing time and setting time. Full article

Agricultural production waste (APW) is characterized by pollution, increasing volume, spatial dispersion, and temporal and spatial variability in its generation. The improper handling of APW poses a growing risk to the environment and public health. This paper focuses on the planning of APW recycling networks, primarily analyzing the selection of temporary storage sites and treatment facilities, as well as vehicle scheduling and route optimization. First, to minimize the required number of temporary storage sites, a set coverage model was established, and an immune algorithm was used to derive preliminary site selection results. Subsequently, the analytic hierarchy process and fuzzy comprehensive evaluation method were employed to refine and determine the optimal site selection results for recycling treatment facilities. Second, based on the characteristics of APW, with the minimization of recycling transportation costs as the optimization objective, an ant colony algorithm was used to establish a corresponding vehicle scheduling route optimization model, yielding the optimal solution for recycling vehicle scheduling and transportation route optimization. This study not only improved the recycling efficiency of APW but also effectively reduced the recycling costs of APW. Full article

One of the goals of map generalization is to achieve real-time visualization of massive entities while adapting to zoom-in/zoom-out conditions. Unlike traditional map generalization, this type of scaling operation does not simplify the data to produce a final result; it only outputs temporary visualization data. To meet the current visualization scale requirements, we insert a simplification algorithm prior to visualization to process the data. Taking point simplification as an example, this study proposes a novel massive point selection method and optimizes the entire algorithmic process, enabling the method to quickly and efficiently handle point selection for datasets ranging from tens of thousands to millions of points. The method employs a geometric construction, namely a Delaunay triangulation, is applied to discover the distribution characteristics with real-time efficiency. Initially, we construct the Delaunay triangulation of the point cluster. Subsequently, we calculate the mean distance of each point as the selection feature. Finally, we incorporate a ‘fixed point’ concept to rank and stabilize the points during the selection process. Experimental results indicate that our method not only achieves commendable performance in considering spatial structure, comparable to both traditional and state-of-the-art methods but also demonstrates significantly higher efficiency. This method can efficiently handle point selection for datasets ranging from tens of thousands to millions of points in a short time, thereby greatly enhancing the practicality of the algorithm in complex point selection scenarios. Full article

(1) The aim of this in vitro study was to investigate the handling of proximal-cervical undermined enamel margins on the adhesive performance of differently fabricated and differently cemented ceramic inlays and partial crowns (2) Methods: 192 extracted third molars received MOD (n = 96) and partial crown (n = 96) preparations. A mesial 2 × 2 × 4 mm cervical groove was created in dentin to simulate a deeper (dentin) caries excavation. This dentin groove was either left (G/groove), filled with composite (F/filling), or completely removed (D/dentin). Distal proximal boxes did not receive a groove and served as controls within the same tooth. Labside (e.max Press) restorations additionally went through a temporary phase. Labside and chairside (e.max CAD) inlays and partial crowns were then adhesively luted with Syntac/Variolink Esthetic (SV) or Adhese Universal/Variolink Esthetic (AV). Initially, and again after thermomechanical loading (TML: 1 million cycles at 50 N, 25,000 thermocycles at 5 °C/55 °C), specimens were molded and the resulting 24 groups of epoxy replicas (n = 8) were gold-sputtered and examined for marginal gaps using scanning electron microscopy (200× magnification). Light microscopy (10× magnification) was used to measure proximal cervical crack propagation in adjacent enamel. (3) Results: Regardless of the adhesive system, D groups generally showed significantly lower marginal quality (79–88%; p < 0.05), with the universal adhesive performing better than the multi-step adhesive system (p < 0.05). Subgroups G and F were similar in marginal quality (94–98%; p > 0.05) and not worse than the controls (p > 0.05) regardless of the adhesive system, but showed less cracking in F than in G (p < 0.05). In general, fewer cracks were observed in chairside CAD/CAM restorations than in laboratory-fabricated restorations (p < 0.05). Partial crowns showed better marginal quality (96–98%) and less cracking than inlays (p < 0.05). (4) Conclusions: If the dentin level is lower than the enamel level in ceramic preparations after caries excavation in the proximal box, the resulting undermined enamel should not be removed. In terms of enamel integrity, partial crowns outperformed inlays. Full article

The numismatic collection in the Auckland War Memorial Museum Tāmaki Paenga Hira, Auckland, New Zealand, is an extensive although little-known collection. As part of a wider rehousing project for the coins, a trial was conducted to rehouse the Greek and Roman coins to establish the best storage and analysis practices. Records were also created or updated during this process to make them visible online and enable their use in future research. Best practice standards include handling and measurement practice, retaining all existing information about the collection, and, where possible, reuniting coins with their acquisition information. The project’s end goal is to create populated records in the museum database (Vernon) for the entire numismatic collection, either through updating existing records, creating records using available acquisition information, or creating records with temporary numbers where that information has been lost. This report gives a brief history of the collection and the rehousing process and suggests future research avenues. Full article

Effective Construction Site Layout Planning (CSLP) ensures the organized placement and sizing of temporary facilities, enhancing workflow and logistical efficiency. Poorly planned layouts, however, can increase material handling times, create bottlenecks, and reduce productivity, ultimately leading to higher costs. The main objective of this study is to introduce a BIM-based hybrid framework for CSLP that integrates Systematic Layout Planning (SLP) with a Genetic Algorithm (GA), developed through a Design Science Research approach. This Construction Site Optimization Framework (CSOF) addresses CSLP as a multi-objective optimization problem, prioritizing efficient positioning of facilities while accounting for workflow intensity, safety, and manager preferences. The framework’s continuous-space modeling supports a realistic approach, moving beyond fixed-location models. Exploratory case studies demonstrated CSOF’s effectiveness, achieving 30.79% to 40.98% reductions in non-value-adding travel distances and adaptability across varied site conditions. In this way, this research provides a decision-support tool that balances automation with decision-maker input, enhancing layout efficiency and operational flexibility in construction site management. Full article

When developing a distributed application, several issues need to be handled, and software components should include some mechanisms to make their execution resilient when network faults, delays, or tampering occur. For example, synchronous calls represent a too-tight connection between a client requesting a service and the service itself, whereby potential network delays or temporary server overloads would keep the client side hanging, exposing it to a domino effect. The proposed approach assists developers in dealing with such issues by providing an automatic tool that enhances a distributed application using simple blocking calls and makes it robust in the face of adverse events. The proposed devised solution consists in automatically identifying the parts of the application that connect to remote services using simple synchronous calls and substituting them with a generated customized snippet of code that handles potential network delays or faults. To accurately perform the proposed transformation, the devised tool finds application code statements that are data-dependent on the results of the original synchronous calls. Then, for the dependent statements, a solution involving guarding code, proper synchronization, and timeouts is injected. We experimented with the analysis and transformation of several applications and report a meaningful example, together with the analysis of the results achieved. Full article

Introduction: Postpartum hemorrhage (PPH) is a critical birth complication, and is stated by the World Health Organization (WHO) as among the five most frequent causes of death during pregnancy. External aortic compression (EAC) is recommended by the WHO as an intervention to achieve temporary bleeding control. An increasing number of births outside hospital underlines the importance of competence in handling potential birth complications, such as PPH. The aim of this study was to assess prehospital personnel’s education, training, knowledge, and experiences regarding PPH and EAC across Norway. Methods: Prehospital personnel were invited to respond to a questionnaire through social media. Questions included those on education, training, knowledge, and experience regarding PPH and EAC. The Statistical Package for the Social Sciences (SPSS) version 28 was used to analyze the data, using descriptive statistics. Results: Over a two-month period, 211 prehospital personnel responded to the questionnaire, of whom 55.5% were male. The respondents had an average of 10.3 years of prehospital experience. About half of the respondents had received education (48.6%) and training (62.4%) in PPH management. Still, 95.7 percent reported a need for more education and training. On knowledge questions, only half of the responses were correct (43.7% to 60.5%). Only 21 percent of the respondents had experienced patients with PPH, and of these only 3.8 percent had used EAC. Bimanual uterine compression was the most frequent intervention used (62.5%) across hospital trusts. Conclusions: Even if prehospital personnel receive education and training in the management of PPH and EAC, almost all report needing more. The results indicate a national variation, which may be discussed as to whether it is appropriate. Full article

The advantage of 3DCP technologies is the ability to fabricate free-form structures. However, printing openings in concrete structures are limited by the presence of overhanging sections. While various 3D printing and additive manufacturing technologies have established methods for handling overhangs with temporary supports, many existing techniques for 3D concrete printing still rely on wooden planks and corbelling, which restrict the design flexibility and slope angles. The objective of this study is to develop a removable and sustainable support material with high printability performance. This support material serves as temporary support for overhang sections in 3D-printed structures and can be removed once the primary concrete has hardened sufficiently. This study observed that increasing the recycled glass content in the mixture raises both the dynamic and static yield stresses, with only mixtures containing up to 60% recycled glass remaining pumpable. Optimization of the mixture design aimed to balance high flowability and buildability, and the results indicated that a mixture with 60% recycled glass content is optimal. The effectiveness of the optimized support material was validated through the successful printing of a structure featuring a free-form opening and overhang section. Full article

Disturbance or insufficiency of the tear film challenges the regulatory systems of the ocular surfaces. The reaction of the surfaces includes temporary mechanisms engaged in the preservation of homeostasis. However, strong or persisting challenges can lead to the potential exhaustion of the coping capacity. This again activates the vicious circle with chronic inflammation and autocatalytic deterioration. Hence, the factors challenging the homeostasis should be addressed in time. Amongst them are a varying osmolarity, constant presence of small lesions at the epithelium, acidification, attrition with mechanical irritation, and onset of pain and discomfort. Each of them and, especially when occurring simultaneously, impose stress on the coping mechanisms and lead to a stress response. Many stressors can culminate, leading to an exhaustion of the coping capacity, outrunning normal resilience. Reaching the limits of stress tolerance leads to the manifestation of a lubrication deficiency as the disease we refer to as dry eye disease (DED). To postpone its manifestation, the avoidance or amelioration of stress factors is one key option. In DED, this is the target of lubrication therapy, substituting the missing tear film or its components. The latter options include the management of secondary sequelae such as the inflammation and activation of reparative cascades. Preventive measures include the enhancement in resilience, recovery velocity, and recovery potential. The capacity to handle the external load factors is the key issue. The aim is to guard homeostasis and to prevent intercellular stress responses from being launched, triggering and invigorating the vicious circle. Considering the dilemma of the surface to have to cope with increased time of exposure to stress, with simultaneously decreasing time for cellular recovery, it illustrates the importance of the vicious circle as a hub for ocular surface stress. The resulting imbalance triggers a continuous deterioration of the ocular surface condition. After an initial phase of the reaction and adaption of the ocular surface to the surrounding challenges, the normal coping capacity will be exhausted. This is the time when the integrated stress response (ISR), a protector for cellular survival, will inevitably be activated, and cellular changes such as altered translation and ribosome pausing are initiated. Once activated, this will slow down any recovery, in a phase where apoptosis is imminent. Premature senescence of cells may also occur. The process of prematurization due to permanent stress exposures contributes to the risk for constant deterioration. The illustrated flow of events in the development of DED outlines that the ability to cope, and to recover, has limited resources in the cells at the ocular surface. The reduction in and amelioration of stress hence should be one of the key targets of therapy and begin early. Here, lubrication optimization as well as causal treatment such as the correction of anatomical anomalies (leading to anatomical dry eye) should be a prime intent of any therapy. The features of cellular stress as a key hub for the vicious circle will be outlined and discussed. Full article

Aluminum thermal welding joints are widely used in the maintenance welding of heavy-haul railways due to their easy handling and high efficiency. However, due to their inherent welding characteristics, welding results in certain differences in the material’s physical properties at the welding zone compared to adjacent base materials, leading to the occurrence of short-wave irregularity under long-term wheel–rail interactive forces. In order to explore the evolution characteristics of weld irregularity, dynamic characteristics, and plastic deformation under long-term wheel–rail impact, a detailed tracking test was conducted on a normal aluminum weld, and the process from being put on the track to being damaged and replaced was evaluated. At the same time, a rigid–flexible coupling model was established for subsequent analysis, and plastic damage was analyzed using the finite element model. The results show that the service life of the weld can be divided into three different stages: the initial stage, the intermediate stage, and the damage stage. In the damage stage, a temporary separation occurred between the wheel and rail, leading to a sudden change in the wheel–rail interaction. The weight of 250 MT at the weld reached the repairment control limit. The concentration effect of equivalent plastic deformation was most serious at 2~5 mm below the rail head. Full article

In this paper, the concept of symmetry is utilized in the promising trajectory planning design of autonomous ground vehicles—that is, the construction and the solution of improved artificial potential field-based trajectory planning approach are symmetrical. Despite existing artificial potential fields (APF) achievements on trajectory planning in autonomous ground vehicles (AGV), applying the traditional approach to dynamic traffic scenarios is inappropriate without considering vehicle dynamics environment and road regulations. This paper introduces a highly efficient approach for planning trajectories using improved artificial potential fields (IAPF) to handle dynamic road participants and address the issue of local minima in artificial potential fields. To begin with, potential fields are created with data obtained from other sensors. By incorporating rotational factors, the potential field will spin when the obstacle executes a maneuver; then, a safety distance model is also developed to limit the range of influence in order to minimize the computational burden. Furthermore, during the planning process, virtual forces using the gradient descent method are generated to direct the vehicle’s movement. During each timestep, the vehicle will assess whether it is likely to encounter a local minimum in the future. Once a local minimum is discovered, the method will create multiple temporary objectives to guide the vehicle toward the global minimum. Consequently, a trajectory that is both collision-free and feasible is planned. Traffic scenarios are carried out to validate the effectiveness of the proposed approach. The simulation results demonstrate that the improved artificial potential field approach is capable of generating a secure trajectory with both comfort and stability. Full article