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•Design and development of novel pH-sensitive two-photon ratiometric carbon dot-based probe was presented.•Probe possessed remarkable thermal stability, photostability, two-photon NIR ...excitation capability, and biocompatibility.•Probe demonstrated superb reversibility and ratiometric response to pH changes (4–10), upon single wavelength excitation.•Precise real-time monitoring and quantification of the intracellular pH values in 2D and 3D environments was performed.
Designing a two-photon ratiometric pH-sensitive nanoprobe for real time monitoring of intracellular pH in biological environment is of great importance for better understanding the pathogenesis of diseases and the design of intracellular drug delivery-based system. However, the development of such probe remains a challenge. Here, we report for the first time the design and development of the two-photon ratiometric carbon dot-based nanoprobe and demonstrate its capability to monitor and quantify the intracellular cytoplasmic pH value, in real time. The nanoprobe comprised of a fluorescent carbon dot functionalized with a pH-responsive fluorescein dye (FACD). With increasing pH, FACD exhibits a clear ratiometric change in the emission intensity ratio, with sensitivity across a wide pH range in both extracellular and intracellular compartments. FACD is non-toxic to adipose stem cells in cell imaging experimental conditions and exhibits remarkable thermal stability, photostability, and two-photon near-infrared excitation capability. Using real-time dual-channel two-photon confocal microscopy we demonstrate the great potential of FACD as an efficient nanoprobe with high accuracy for the intracellular sensing of pH in living adipose stem cells seeded on either cell-culture dishes or on a 3D printed bioactive scaffold.
•Emotion recognition technology is a very promising idea for decision systems.•Environment assessment based on isolated attributes is unreliable.•EMOTIF provides a new quality of information in the ...form of Fused Features.•EMOTIF enables assessment of the phenomena diversity based on emotion similarity.•The synergy of ER, CV, and NN allows useful information about the environment to be acquired.
It is widely known that the decisions being made concern objects representing a set of characteristics whose importance is unique for every decision-maker. However, including this aspect in analyses is a challenge for many researchers. Classically applied information analysis methods fail to consider the synergy of these characteristics and ignore the impact of behavioural aspects that are inseparable from the decision-maker. The study proposed a solution based on an emotion detection technology using Computer Vision and Neural Networks. The presented approach comprises three main components: the detection of emotions using CNN – acquiring input vector value elements to the model for evaluation of space features; MLP for the assessment of anthropogenic and natural space features; and the verification of the utilitarian nature, usability, and suitability for the use of the developed solution. The novelty of the paper relates to the proposition of the new approaches by demonstrating that the assessment of the impact of an object’s features is a synergistic, inseparable conglomerate (Fusion Features), which thus indicates the greater usability of the results such studies in the analysis of a particular phenomenon, structure, or system.
Stem cell regenerative potential owing to the capacity to self-renew as well as differentiate into other cell types is a promising avenue in regenerative medicine. Stem cell niche not only provides ...physical scaffolding but also possess instructional capacity as it provides a milieu of biophysical and biochemical cues. Extracellular matrix (ECM) has been identified as a major dictator of stem cell lineage, thus understanding the structure of
in vivo
ECM pertaining to specific tissue differentiation will aid in devising
in vitro
strategies to improve the differentiation efficiency. In this review, we summarize details about the native architecture, composition and mechanical properties of
in vivo
ECM of the early embryonic stages and the later adult stages. Native ECM from adult tissues categorized on their origin from respective germ layers are discussed while engineering techniques employed to facilitate differentiation of stem cells into particular lineages are noted. Overall, we emphasize that
in vitro
strategies need to integrate tissue specific ECM biophysical cues for developing accurate artificial environments for optimizing stem cell differentiation.
Since the environmental complexity of a 3D environment significantly increases as compared to a 2D environment, previous studies on 3D path planning have mostly focused on efficiency in generating a ...3D path. In this context, the present study proposes a method, COSPS (Critical Obstacles and Surrounding Point Set), which can lower the complexity for efficient 3D path planning by determining a subset of obstacles in terms of their importance for planning a path, and by finding a subset of grid points that can fully surround those obstacles in 3D. Due to this reduction of obstacles and points, a path can be efficiently generated, as a graph is constructed with a smaller number of points, rather than with the total number of points in 3D. To observe the effect of the proposed method on 3D path planning as compared to well-known methods that consider all obstacles and points, the simulation experiment was conducted for multiple 3D maps with different sizes, shapes, and distribution of obstacles. The results demonstrated that the proposed method can generate a feasible path and significantly enhance the efficiency of 3D path planning without compromising the quality of the solution in terms of path length.
Multi-UAV systems are attracting, especially in the last decade, the attention of researchers and companies of very different fields due to the great interest in developing systems capable of ...operating in a coordinated manner in complex scenarios and to cover and speed up applications that can be dangerous or tedious for people: search and rescue tasks, inspection of facilities, delivery of goods, surveillance, etc. Inspired by these needs, this work aims to design, implement and analyze a trajectory planning and collision avoidance strategy for multi-UAV systems in 3D environments. For this purpose, a study of the existing techniques for both problems is carried out and an innovative strategy based on Fast Marching Square—for the planning phase—and a simple priority-based speed control—as the method for conflict resolution—is proposed, together with prevention measures designed to try to limit and reduce the greatest number of conflicting situations that may occur between vehicles while they carry out their missions in a simulated 3D urban environment. The performance of the algorithm is evaluated successfully on the basis of certain conveniently chosen statistical measures that are collected throughout the simulation runs.
Eye-tracking based usability testing and User Experience (UX) research are widespread in the development processes of various types of software; however, there exist specific difficulties during ...usability tests of three-dimensional (3D) software. Analysing the screen records with gaze plots, heatmaps of fixations, and statistics of Areas of Interests (AOI), methodological problems occur when the participant wants to rotate, zoom, or move the 3D space. The data gained regarded the menu bar is mainly interpretable; however, the data regarded the 3D environment is hardly so, or not at all. Our research tested four software applications with the aforementioned problem in mind: ViveLab and Jack Digital Human Modelling (DHM) and ArchiCAD and CATIA Computer Aided Design (CAD) software. Our original goal was twofold. Firstly, with these usability tests, we aimed to identify issues in the software. Secondly, we tested the utility of a new methodology which was included in the tests. This paper summarizes the results on the methodology based on individual experiments with different software applications. One of the main ideas behind the methodology adopted is to tell the participants (during certain subtasks of the tests) not to move the 3D space while they perform the given tasks at a certain point in the usability test. During the experiments, we applied a Tobii eye-tracking device, and after the task completion, each participant was interviewed. Based on these experiences, the methodology appears to be both useful and applicable, and its visualisation techniques for one or more participants are interpretable.
SignificanceAs the research focus of future agricultural machinery, agricultural wheeled robots are developing in the direction of intelligence and multi-functionality. Advanced environmental ...perception technologies serve as a crucial foundation and key components to promote intelligent operations of agricultural wheeled robots. However, considering the non-structured and complex environments in agricultural on-field operational processes, the environmental information obtained through conventional 2D perception technologies is limited. Therefore, 3D environmental perception technologies are highlighted as they can provide more dimensional information such as depth, among others, thereby directly enhancing the precision and efficiency of unmanned agricultural machinery operation. This paper aims to provide a detailed analysis and summary of 3D environmental perception technologies, investigate the issues in the development of agricultural environmental perception technologies, and clarify the future key development directions of 3D environmental perception technologies regarding agricultural machinery, especially the agricultural wheeled robot.ProgressFirstly, an overview of the general status of wheeled robots was introduced, considering their dominant influence in environmental perception technologies. It was concluded that multi-wheel robots, especially four-wheel robots, were more suitable for the agricultural environment due to their favorable adaptability and robustness in various agricultural scenarios. In recent years, multi-wheel agricultural robots have gained widespread adoption and application globally. The further improvement of the universality, operation efficiency, and intelligence of agricultural wheeled robots is determined by the employed perception systems and control systems. Therefore, agricultural wheeled robots equipped with novel 3D environmental perception technologies can obtain high-dimensional environmental information, which is significant for improving the accuracy of decision-making and control. Moreover, it enables them to explore effective ways to address the challenges in intelligent environmental perception technology. Secondly, the recent development status of 3D environmental perception technologies in the agriculture field was briefly reviewed. Meanwhile, sensing equipment and the corresponding key technologies were also introduced. For the wheeled robots reported in the agriculture area, it was noted that the applied technologies of environmental perception, in terms of the primary employed sensor solutions, were divided into three categories: LiDAR, vision sensors, and multi-sensor fusion-based solutions. Multi-line LiDAR had better performance on many tasks when employing point cloud processing algorithms. Compared with LiDAR, depth cameras such as binocular cameras, TOF cameras, and structured light cameras have been comprehensively investigated for their application in agricultural robots. Depth camera-based perception systems have shown superiority in cost and providing abundant point cloud information. This study has investigated and summarized the latest research on 3D environmental perception technologies employed by wheeled robots in agricultural machinery. In the reported application scenarios of agricultural environmental perception, the state-of-the-art 3D environmental perception approaches have mainly focused on obstacle recognition, path recognition, and plant phenotyping. 3D environmental perception technologies have the potential to enhance the ability of agricultural robot systems to understand and adapt to the complex, unstructured agricultural environment. Furthermore, they can effectively address several challenges that traditional environmental perception technologies have struggled to overcome, such as partial sensor information loss, adverse weather conditions, and poor lighting conditions. Current research results have indicated that multi-sensor fusion-based 3D environmental perception systems outperform single-sensor-based systems. This superiority arises from the amalgamation of advantages from various sensors, which concurrently serve to mitigate individual shortcomings.Conclusions and ProspectsThe potential of 3D environmental perception technology for agricultural wheeled robots was discussed in light of the evolving demands of smart agriculture. Suggestions were made to improve sensor applicability, develop deep learning-based agricultural environmental perception technology, and explore intelligent high-speed online multi-sensor fusion strategies. Currently, the employed sensors in agricultural wheeled robots may not fully meet practical requirements, and the system's cost remains a barrier to widespread deployment of 3D environmental perception technologies in agriculture. Therefore, there is an urgent need to enhance the agricultural applicability of 3D sensors and reduce production costs. Deep learning methods were highlighted as a powerful tool for processing information obtained from 3D environmental perception sensors, improving response speed and accuracy. However, the limited datasets in the agriculture field remain a key issue that needs to be addressed. Additionally, multi-sensor fusion has been recognized for its potential to enhance perception performance in complex and changeable environments. As a result, it is clear that 3D environmental perception technology based on multi-sensor fusion is the future development direction of smart agriculture. To overcome challenges such as slow data processing speed, delayed processed data, and limited memory space for storing data, it is essential to investigate effective fusion schemes to achieve online multi-source information fusion with greater intelligence and speed.
Effective cell number monitoring throughout the three-dimensional (3D) scaffold is a key factor in tissue engineering. There are many methods developed to evaluate cell number in 2D environments; ...however, they often encounter limitations in 3D. Therefore, there is a demand for reliable methods to measure cell proliferation in 3D surroundings. Here, we report a novel technique for the DNA content-based evaluation of cell proliferation using DNA-binding dye DAPI. We demonstrated the method’s compatibility with four different cell cultures: cancer lines MCF-7 and MH-22a, embryonic fibroblast cell line Swiss 3T3, and primary mesenchymal stem cell culture isolated from rat’s incisors. The DAPI based method was able to successfully evaluate cell proliferation in 2D, 2.5D, and 3D environments. Even though the proposed method does not discriminate between viable and dead cells, it might give a convenient snapshot of the cell number at a given time point. This should help to more reliably evaluate various processes proceeding in 2.5D and 3D cultures.
The study of visual search has focused on various guiding factors, but less attention has been given to how environmental factors affect visual search in virtual reality (VR). The visual search ...literature has primarily been based on 2D laboratory tasks, which lack the complexity of real-life search tasks. Thus, this study studies the effect of time pressure on visual search in a naturalistic environment. To do that, participants were immersed in a virtual living room using VR and tasked with finding objects under a time constraint. Eye gaze data was collected, and convex hull volumes and scanning rates were calculated and analyzed. The results show that time pressure reduced convex hull volume and increased scanning rate, indicating faster search speed and a gaze tunneling effect. Understanding how time pressure affects visual search can help improve training strategies and design better user interfaces for visual search critical domains.
Collision avoidance in 3D environments is important to the problem of planning safe trajectories for an autonomous vehicle. Existing literature on collision avoidance assumed that obstacle shapes are ...known a priori and modeled obstacles as spheres or bounding boxes. However, in 3D environments, an obstacle shape is unknown to the autonomous vehicle, and the vehicle detects an obstacle boundary using 3D sensors, such as 3D sonar. In this paper, we introduce control laws for collision avoidance, considering scenarios where a vehicle detects arbitrarily shaped and non-convex obstacles using sensors. Moreover, our control laws are designed considering motion constraints, such as the maximum turn rate and the maximum speed rate of the vehicle. The effectiveness of our control laws is verified using MATLAB simulations.
•Existing literature on collision avoidance assumed that obstacle shapes are known a priori and modeled obstacles as spheres or bounding boxes.•However, in 3D environments, an obstacle shape is unknown to the autonomous vehicle, and the vehicle detects an obstacle boundary using 3D sensors, such as 3D sonar.•In this paper, we introduce control laws for collision avoidance, considering scenarios where a vehicle detects arbitrarily shaped and non-convex obstacles using sensors.
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