Objective: Precise minimally invasive surgery (MIS) has significant advantages over traditional open surgery in clinic. Although pre-/intraoperative diagnosis images can provide necessary guidance ...for therapy, hand-eye discoordination occurs when guidance information is displayed away from the surgical area. In this study, we introduce a real three-dimensional (3-D) see-through guidance system for precision surgery. Methods: To address the resolution and viewing angle limitation as well as the accuracy degradation problems of autostereoscopic 3-D display, we design a high quality and high accuracy 3-D integral videography (IV) medical image display method. Furthermore, a novel see-through microscopic device is proposed to assist surgeons with the superimposition of real 3-D guidance onto the surgical target is magnified by an optical visual magnifier module. Results: Spatial resolutions of 3-D IV image in different depths have been increased 50%~70%, viewing angles of different image sizes have been increased 9%~19% compared with conventional IV display methods. Average accuracy of real 3-D guidance superimposed on surgical target was 0.93 mm ± 0.41 mm. Preclinical studies demonstrated that our system could provide real 3-D perception of anatomic structures inside the patient's body. Conclusion: The system showed potential clinical feasibility to provide intuitive and accurate in situ see-through guidance for microsurgery without restriction on observers' viewing position. Significance: Our system can effectively improve the precision and reliability of surgical guidance. It will have wider applicability in surgical planning, microscopy, and other fields.
Endoplasmic reticulum (ER) stress-induced neuronal apoptosis is a crucial pathological process of spinal cord injury (SCI). In our previous study, icariin (ICA) showed neuroprotective effects in SCI. ...However, the relationships between ER stress and ICA in SCI are unclear yet. Therefore, whether ICA could ameliorate SCI via attenuating ER stress was investigated
and
. Adult mice were established SCI model and received vehicle solution or ICA by gavage once per day
. The primary cultured cells were treated with or without thapsigargin (TG), ICA or LY294002 to induce ER stress
. Motor dysfunction, neuronal apoptosis, tissue damage and inhibition of PI3K/AKT pathway were induced by ER stress after SCI. But ICA administration significantly enhanced motor recovery and protected spinal cord tissues against infraction and hemorrhage, etc. post injury. Meanwhile, the expression of ER stress markers ATF6, IRE1α, GRP78, XBP1 and eIF2α was decreased, while the level of p-AKT/AKT was increased by ICA. Furthermore, ICA significantly inhibited the expression of ER stress apoptotic proteins caspase-12, CHOP, Bax/Bcl-2, caspase-9 and caspase-3. Moreover, immunofluorescence double staining indicated that ICA reduced GRP78, CHOP and TUNEL positive neurons following SCI. However, this beneficial effect of ICA was abolished by PI3K/AKT inhibitor LY294002
. Finally, ICA preserved the ultra-structure of ER by transmission electron microscope histologically. This study suggested that the neuroprotective effect of ICA on motor recovery and neuronal survival was related to attenuating ER stress via PI3K/AKT signaling pathway after SCI.
The demand for pipeline inspection has promoted the development of pipeline robots and associated localization and communication technologies. Among these technologies, ultra-low-frequency (30-300 ...Hz) electromagnetic waves have a significant advantage because of their strong penetration, which can penetrate metal pipe walls. Traditional low-frequency transmitting systems are limited by the size and power consumption of the antennas. In this work, a new type of mechanical antenna based on dual permanent magnets was designed to solve the above problems. An innovative amplitude modulation scheme that involves changing the magnetization angle of dual permanent magnets is proposed. The ultra-low-frequency electromagnetic wave emitted by the mechanical antenna inside the pipeline can be easily received by the antenna outside to localize and communicate with the robots inside. The experimental results showed that when two N38M-type Nd-Fe-B permanent magnets with a volume of 3.93 cm
each were used, the magnetic flux density reached 2.35 nT at 10 m in the air and the amplitude modulation performance was satisfactory. Additionally, the electromagnetic wave was effectively received at 3 m from the 20# steel pipeline, which preliminarily verified the feasibility of using the dual-permanent-magnet mechanical antenna to achieve localization of and communication with pipeline robots.
This research aimed to propose a three-dimensional (3D) augmented reality navigation method with point cloud-based image-patient registration that could merge virtual images in the real environment ...for dental implants using a 3D image overlay and to evaluate its feasibility.
A total of 12 rapid prototyping mandibular models were fabricated using a 3D printing method and were divided into two groups: 3D augmented reality-guided group and traditional two-dimensional (2D) image-guided group. A point cloud-based preoperative image-to-patient registration method was introduced to replace the traditional point-to-point registration. After the registration, dental implant surgery was performed in the two model groups using an augmented reality-guided navigation method and a traditional two-dimensional image-guided navigation method. The planned and actual postoperative implant positions were compared for measuring positional implantation errors. The surgery time was also recorded and compared between the two groups.
In the model experiment, the root-mean-square deviation of registration was 0.54 mm, and the implant surgery results showed < 1.5-mm mean linear deviation and < 5.5-degree angular deviation. The augmented reality-guided implantation showed smaller horizontal, vertical, and angular errors in the apical areas of the central incisor and the canine region. The surgery time using the augmented reality-guided navigation method was significantly shorter than that using the two-dimensional (2D) image-guided navigation method (P < .05). Moreover, the volunteer experiment demonstrated that the preoperative 3D models in situ accurately overlaid onto the surgical site.
The proposed point cloud-based registration method can achieve excellent registration accuracy. Dental implant placement guided by the proposed 3D augmented reality navigation method showed better accuracy and applicability, as well as higher efficiency, than the traditional 2D image navigation method.
Chlorine dioxide (ClO
2
), an alternative disinfectant to chlorine, has been widely applied in water and wastewater disinfection. This paper aims at presenting an overview of the inactivation ...kinetics and mechanisms of ClO
2
with viruses. The inactivation efficiencies vary greatly among different virus species. The inactivation rates for different serotypes within a family of viruses can differ by over 284%. Generally, to achieve a 4-log removal, the exposure doses, also being referred to as Ct values (mutiplying the concentration of ClO
2
and contact time) vary in the range of 0.06–10 mg L
−1
min. Inactivation kinetics of viruses show two phases: an initial rapid inactivation phase followed by a tailing phase. Inactivation rates of viruses increase as pH or temperature increases, but show different trends with increasing concentrations of dissolved organic matter (DOM). Both damages in viral proteins and in the 5′ noncoding region within the genome contribute to virus inactivation upon ClO
2
disinfection.
One of the most inspiring and puzzling developments in the organic electronics community in the last few years has been the emergence of solution-processable semiconducting polymers that lack ...significant long-range order but outperform the best, high-mobility, ordered semiconducting polymers to date. Here we provide new insights into the charge-transport mechanism in semiconducting polymers and offer new molecular design guidelines by examining a state-of-the-art indacenodithiophene-benzothiadiazole copolymer having field-effect mobility of up to 3.6 cm(2) V(-1) s(-1) with a combination of diffraction and polarizing spectroscopic techniques. Our results reveal that its conjugated planes exhibit a common, comprehensive orientation in both the non-crystalline regions and the ordered crystallites, which is likely to originate from its superior backbone rigidity. We argue that charge transport in high-mobility semiconducting polymers is quasi one-dimensional, that is, predominantly occurring along the backbone, and requires only occasional intermolecular hopping through short π-stacking bridges.
Air pollution by nitrogen oxides, NO
, is a major problem, and new capture and abatement technologies are urgently required. Here, we report a metal-organic framework (Manchester Framework Material ...520 (MFM-520)) that can efficiently confine dimers of NO
, which results in a high adsorption capacity of 4.2 mmol g
(298 K, 0.01 bar) with full reversibility and no loss of capacity over 125 cycles. Treatment of NO
@MFM-520 with water in air leads to a quantitative conversion of the captured NO
into HNO
, an important feedstock for fertilizer production, and fully regenerates MFM-520. The confinement of N
O
inside nanopores was established at a molecular level, and the dynamic breakthrough experiments using both dry and humid NO
gas streams verify the excellent stability and selectivity of MFM-520 and confirm its potential for precious-metal-free deNO
technologies.
The present study aimed 1) to examine the effects of epidemic-related job stressors, perceived social support and organizational support on the burnout and well-being of Chinese healthcare workers in ...the period of COVID-19 regular epidemic prevention and control and 2) to investigate the moderating effects of social support and organizational support on the relationship between job stressors and burnout and well-being within the theoretical framework of the Job Demands-Resources (JD-R) model.
A sample of healthcare workers (N = 3477) from 22 hospitals in Beijing, China participated in the cross-sectional investigation in October 2020 and reported epidemic-related job stressors, perceived social support, organizational support, burnout, anxiety and depression symptoms.
1) Medical doctors, females, people aged from 30 to 50, and those who worked in the second line during the pandemic reported higher scores of psychological symptoms and burnout in the period of regular epidemic prevention and control; 2) Epidemic-related job stressors positively predicted burnout, anxiety, and depression among healthcare workers; 3) Perceived social support and organizational support were negatively related to reported burnout, anxiety and depression symptoms; 4) Social support reduced the adverse effects of epidemic-related job stressors on anxiety and depression but enhanced the association between stressors and burnout; 5) Organizational support mitigated the adverse effects of epidemic-related job stressors on depression.
The results shed light on preventing burnout and enhancing the psychological well-being of healthcare workers under epidemic prevention and control measures by reducing epidemic-related job stressors and strengthening personal and organizational support systems.
Communication network brings new challenges such as time delay and data loss to wide-area damping control of power systems. The uncertainty caused by stochastic time delay of network communication ...increases the difficulty of wide-area control performance analysis. This paper proposes a mathematical expectation modeling approach to model and analyze wide-area controlled power systems considering the effect of stochastic time delay. In the proposed method, mathematical expectation of stochastic time delay distribution is derived to accurately model the impact of communication network on wide-area control performance. The theoretical frame of the proposed modeling approach is presented, and the effectiveness of the method is verified through the simulation of a power system with eight generators and 36 nodes.
Gesture interaction via surface electromyography (sEMG) signal is a promising approach for advanced human-computer interaction systems. However, improving the performance of the myoelectric interface ...is challenging due to the domain shift caused by the signal's inherent variability. To enhance the interface's robustness, we propose a novel adaptive information fusion neural network (AIFNN) framework, which could effectively reduce the effects of multiple scenarios. Specifically, domain adversarial training is established to inhibit the shared network's weights from exploiting domain-specific representation, thus allowing for the extraction of domain-invariant features. Effectively, classification loss, domain diversence loss and domain discrimination loss are employed, which improve classification performance while reduce distribution mismatches between the two domains. To simulate the application of myoelectric interface, experiments were carried out involving three scenarios (intra-session, inter-session and inter-subject scenarios). Ten non-disabled subjects were recruited to perform sixteen gestures for ten consecutive days. The experimental results indicated that the performance of AIFNN was better than two other state-of-the-art transfer learning approaches, namely fine-tuning (FT) and domain adversarial network (DANN). This study demonstrates the capability of AIFNN to maintain robustness over time and generalize across users in practical myoelectric interface implementations. These findings could serve as a foundation for future deployments.
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