Sleep Disorder at High Altitude

In this chapter, we discuss the occurrence, mechanism, clinical manifestations, outcomes, and managements of a commonly encountered sleep disorder of someone traveling in high altitude for working and sight-seeing. Humans ascending to altitudes above 2500 m usually suffer from substantial disturbances in sleep quality as difficulty in sleep onset, frequent awakenings, respiratory disturbance, and a feeling of drowsiness on the next day. Data obtained from polysomnographic studies demonstrated several variations of sleep architecture in those healthy subjects ascending to high altitude during sleep, including periodic breathing and decreased non-rapid eye movement deep sleep stage 3 and 4 (in new nomenclature N3), which were usually accompanied by and the lowered arterial O2 and restricted ventilation. Hypoxia is most severe during sleep and in correspondence to periodic breathing and sleep disturbance at high altitude. Poor sleep quality impairs cognition and executive abilities at high altitude though it may largely be improved after full time of acclimatization. Evidence-based choices for clinicians to treat sleep disorder at high altitude are relatively scarce at present. Supplemental oxygen and dietary nitrate are effective in alleviating nocturnal hypoxia. There is strong evidence supporting the efficacy and safety of acetazolamide and nonbenzodiazepines in minimizing periodic breathing and improving sleep quality at high altitude

Mediastinal Teratoma with Neuroendocrine Features in 34-Year-Old Male with Syncope

Neuroendocrine tumors that arise in an extragonadal teratoma are extremely rare. Somatic-type malignancy, defined as any sarcoma, carcinoma, leukemia, or lymphoma developing in a germ cell tumor, occurs in approximately 2% of all germ cell tumors. Our case represents a mediastinal mass that was incidentally found in a patient with syncope. Surgical resection confirmed mature teratoma with neuroendocrine features

A Suspended Aerial Manipulation Avatar for Physical Interaction in Unstructured Environments

This paper presents an aerial platform capable of performing physically interactive tasks in unstructured environments with human-like dexterity under human supervision. This aerial platform consists of a humanoid torso attached to a hexacopter. A two-degree-of-freedom head and two five-degree-of-freedom arms equipped with softhands provide the requisite dexterity to allow human operators to carry out various tasks. A robust tendon-driven structure is purposefully designed for the arms, considerably reducing the impact of arm inertia on the floating base in motion. In addition, tendons provide flexibility to the joints, which enhances the robustness of the arm preventing damage in interaction with the environment. To increase the payload of the aerial system and the battery life, we use the concept of Suspended Aerial Manipulation, i.e., the flying humanoid can be connected with a tether to a structure, e.g., a larger airborne carrier or a supporting crane. Importantly, to maximize portability and applicability, we adopt a modular approach exploiting commercial components for the aerial base hardware and autopilot, while developing an outer stabilizing control loop to maintain the attitude, compensating for the tether force and for the humanoid head and arm motions. The humanoid can be controlled by a remote operator, thus effectively realizing a Suspended Aerial Manipulation Avatar. The proposed system is validated through experiments in indoor scenarios reproducing post-disaster tasks.Comment: Comments: contents revised and re-organized, figures updated, references added, typos correcte

Tunable photochemical deposition of silver nanostructures on layered ferroelectric CuInP2_2S6

2D layered ferroelectric materials such as CuInP$_2$S6 (CIPS) are promising candidates for novel and high-performance photocatalysts, owning to their ultrathin layer thickness, strong interlayer coupling, and intrinsic spontaneous polarization, while how to control the photocatalytic activity in layered CIPS remains unexplored. In this work, we report for the first time the photocatalytic activity of ferroelectric CIPS for the chemical deposition of silver nanostructures (AgNSs). The results show that the shape and spatial distribution of AgNSs on CIPS are tunable by controlling layer thickness, environmental temperature, and light wavelength. The ferroelectric polarization in CIPS plays a critical role in tunable AgNS photodeposition, as evidenced by layer thickness and temperature dependence experiments. We further reveal that AgNS photodeposition process starts from the active site creation, selective nanoparticle nucleation/aggregation, to the continuous film formation. Moreover, AgNS/CIPS heterostructures prepared by photodeposition exhibit excellent resistance switching behavior and good surface enhancement Raman Scattering activity. Our findings provide new insight into the photocatalytic activity of layered ferroelectrics and offer a new material platform for advanced functional device applications in smart memristors and enhanced chemical sensors.Comment: 18 pages, 5 figure

Lead-free (Ba,Sr)TiO3-based ceramics with superior tunable properties by the semi-solution method

High-performance dielectric tunable materials with both high dielectric tunability and low dielectric loss are urgently needed for new-generation electronic tunable devices. In the present study, a new system, (Ba0.675Sr0.325)1−xLaxTi1−xMnxO3 (x = 0.25%, 0.5%, 0.75%, and 1.0%), was designed. The acceptor dopant Mn was added to lower dielectric loss, while the donor dopant La was introduced to enhance dielectric tunability. The samples were prepared using the conventional solid-state (CS) reaction method and the semi-solution (SS) method. The experimental results showed that the morphology of the ceramics was optimized by further improving the processing procedure. Dense microstructures, homogeneous grains, and uniform dopant distributions could be achieved successfully by the semi-solution method. Moreover, a significant enhancement in the tunable properties was realized owing to the improved microstructure mentioned above. The optimum tunable properties occurred in the samples prepared by the semi-solution method at x = 0.75%, with a high dielectric tunability of 85.0%, a low dielectric loss of 0.0011, and an excellent figure of merit (FOM) of 773. The tunable properties of (Ba,Sr)TiO3 (BST) ceramics were even superior to those of lead-based materials, with an FOM of approximately 700. All the results suggested that the semi-solution method rendered BST ceramics more promising for applications in tunable devices

A SUSPENDED AERIAL MANIPULATION AVATAR FOR UNSTRUCTURED ENVIRONMENTS

Aerial robots possess unique advantages. Being able to fly like birds and to approach the workspace from above, grants aerial robot unparalleled agility. As their applications in inspection continue to be explored, the potential of aerial robots to interact with the environment continues to emerge. However, at the current stage of development, two major challenges hinder their practical applications. The first challenge involves the unknown threats present in unstructured environments where the robot is meant to explore. The requirement for interaction further complicates safety issues and control problem. The second challenge concerns payload limitations and battery duration, as maintaining the aircraft in the hover state consumes most of the system energy, regardless of manipulation. In this context, my Ph.D. dissertation presents the concept and implementation of a novel suspended aerial manipulation avatar, aiming to address the obstacles for aerial robotic systems. My work is mainly reflected in four aspects. i) I developed a robotic upper-body system with a human-like design and enhanced robustness for aerial manipulation applications. By introducing a tendon-driven design, the weight distribution of the arm is optimized, reducing the displacement of the center of gravity from the body center during its movement. The introduction of compliance in the arm and neck joints enables the system to cope with unexpected impacts during interaction, and the integration of soft hands further improves the system's versatility in handling different tasks. ii) To ensure the widespread adoption and ease of implementation of my design, I chose an off-the-shelf hexarotor as the aerial platform. On this line, I developed a methodology to model the system and determine its parameters, aligning with the goal of enhancing portability. Moreover, I implemented an open-source digital twin of the proposed system, facilitating further research and control investigations. iii) I proposed a variable-length suspension design that partially compensates for the overall weight of the system, thereby greatly increasing payload capacity. Simultaneously, it preserves the agility of the aerial base, achieving an enhanced workspace. iv) Furthermore, I implemented an immersive teleoperation scheme, allowing the human operator to engage with the robot as if they were flying and present in the workspace, effectively making the robot an "avatar." This design fully exploits the dexterity of the system, enabling it to handle accidental events in unstructured environments. The four pieces of work described above constitute, in their entirety and integration, the concept of "suspended aerial manipulation avatar" that I propose in this thesis. Building upon the specific implementation, I explored, analyzed and discussed on the system modeling and control. Experimental results effectively validate the proposed design, showcasing its potential in post-disaster rescue and reconstruction scenarios, and highlighting its promising applications in other related fields

Clinical study on the selection of endoscopes and microscopes for transsphenoidal surgery of non-aggressive pituitary macroadenoma and microadenoma and the influencing factors of hyposmia after endoscopic transsphenoidal surgery

Background and objectiveTranssphenoidal surgery, including endoscopic and microscopic resection, is the first choice of treatment for pituitary tumors. With the widespread application of neuroendoscopy in recent decades, there has been a trend to replace microscopes. In clinical practice, we have found that in transsphenoidal surgery for non-invasive microadenomas and macroadenomas, microscopy can achieve a higher total resection rate, shorter operation time, lower incidence of postoperative complications, and faster recovery of olfaction. This study aimed to explore the selection of endoscopes and microscopes for non-aggressive transsphenoidal surgery for pituitary adenomas and the factors affecting olfactory recovery.MethodsFrom August 2019 to October 2022, 93 patients with non-aggressive microadenomas and macroadenomas via the transsphenoidal approach were selected from the First Affiliated Hospital of Harbin Medical University and treated with rich experience in pituitary tumor subspecialty microscopy and endoscopic surgery. Different surgical methods were used to divide the patients into microscopic (n = 35) and endoscopic (n = 58) groups. The total tumor removal rate, intraoperative blood loss, operation time and cost, postoperative hospital stay, recovery of visual function, postoperative changes in hormone levels, complication rate, and recovery from complications 3 months after the operation were compared between the two groups.ResultsThere were no significant differences in the tumor removal rate, postoperative visual acuity, and visual field recovery between the two groups (p > 0.05). There was a significant difference in the recovery rate of olfactory function between the two groups 3 months after the operation (p < 0.05), and there was no significant difference in the incidence of other complications (p > 0.05); Compared with the two groups, the microscope group had shorter operation time, longer postoperative hospital stay, less average operation cost and less blood loss, and the difference was statistically significant (p < 0.05). The position of the nasal septum mucosal flap incision was a risk factor for hyposmia 3 months after the operation.ConclusionMicrosurgery and endoscopic surgery are suitable surgical treatments for nonaggressive microadenomas and macroadenomas. The total tumor removal and postoperative hormone remission rates of the two surgical methods were approximately the same. However, the microsurgery group had a shorter operation time, less intraoperative blood loss, faster olfactory function recovery, and a lower average operation cost. The position of the nasal septal mucosal flap incision was a risk factor for hyposmia at 3 months postoperatively. Hyposmia is less likely to occur when the superior edge of the nasal septal mucosal flap incision is not higher than the lower edge of the ipsilateral superior turbinate

An Anthropomorphic Aerial Manipulator equipped with a Testbed for Indoor Experiments

During interventions in hazardous environments, debris often restricts the accessibility of ground robots. When this occurs, Unmanned Aerial Manipulators (UAMs) can intervene, avoiding all of these obstacles. However, when UAMs enter and interact with such environments, designers must ensure that they possess high stability and robustness. This work presents a teleoperated aerial manipulator for intervention in unstructured environments and a testbed to perform safely indoor experiments for evaluating the stability performance and manipulation tasks. The robot comprises an aerial platform, two arms that terminate with two Pisa/IIT Softhands, and a head equipped with stereo cameras. The testbed constrains the drone to move in a limited space and avoids that, in case of control loss, the drone falls or rambles in an indoor space, which may cause damage to the robot or humans

Effect of Ni

With the development of high voltage transmission, there is an urgent need to develop ZnO varistor ceramics with high anti-aging properties. The key is to manipulate the intrinsic defect concentration of ZnO varistor ceramics precisely. In this paper, ZnO varistor ceramics doped with different contents of Ni2O3 are taken to study the relationship between the microstructure and electrical properties, and the effect of ZnO varistor ceramics doped with different contents on intrinsic defect concentration is also considered. The results show that, best electrical performance is shown when the content of Ni2O3 is 1.2mol%, the electrical breakdown field E1mA is 356 V/mm, the nonlinear coefficient reaches 32, and the leakage current IL is 3.4 . While the amount of the doped Ni2O3 is more 0.8mol%, a new phase of Co2Cr5Sb5O4 phase is observed from X-ray diffraction. The SEM micrographs showed that the average grain size decreased monotonously from 14.56 m to 5.73 m with the amount of the doped Ni2O3 increased. According to the results of dielectric spectroscopy, the intrinsic defect concentration increased with the contents of the doped Ni2O3 increased. The increase of Zinc interstitial is much greater than that of Oxygen vacancies, which is harmful to Long-term aging characteristics of ZnO varistor ceramics