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A method was developed to identify and trace the geographic sources of Erigeron breviscapus using high-resolution mass spectrometry and chemometrics. The representative samples were collected from the geographic area of Honghe Dengzhanhua and other areas in Yunnan province and Guizhou province. The data points could be determined well using the PCA and PLS-DA diagram. A total of 46 characteristic compounds were identified from Honghe Dengzhanhua and within Guizhou province, but 37 compounds were different from Honghe Dengzhanhua and other counties in Yunnan province. Two biomarkers were found from three regions. Their structures were inferred as 8-amino-7-oxononanoic acid and 8-hydroxyquinoline, and they had the same molecular composition. This may suggest that a possible synthesis pathway can be proven in the future.

The traction motor is a crucial component of high-speed electric multiple units, and its operational reliability is directly impacted by the temperature increase in the bearings. To accurately predict and simulate the temperature change process of traction motor bearings during operation, a fluid–solid–thermal simulation analysis model of grease-lubricated deep groove ball bearings was constructed. This model aimed to simulate the temperature rise of the bearing and the grease flow process, which was validated through experiments. The results from the simulation analysis and tests indicate that the temperature in the contact zone between the bearing rolling element and the raceway, as well as the ring temperature, initially increases to a peak and then gradually decreases, eventually stabilizing once the bearing’s heat generation power and heat transfer power reach equilibrium. Furthermore, the established fluid–solid–thermal coupling simulation analysis model can accurately predict the amount of grease required for effective lubrication in the bearing cavity, which stabilizes along with the bearing temperature. The findings of this research can serve as a theoretical foundation and technical support for monitoring the health status of high-speed EMU traction motor bearings.

With the advancement of industries such as high-speed railways, new energy vehicles, and wind power, bearings are frequently exposed to various electric field environments, leading to the need for lubricating oil films of bearings to withstand voltage. One of the major issues caused by the breakdown discharge process of the lubricating oil film in bearings is the generation of local instantaneous high temperatures. This temperature rise is a key factor contributing to problems such as high operating temperature of bearings, surface damage in the contact area, and degradation of lubrication performance. This research article focuses on the comprehensive influence of bearing friction and electrical factors. It establishes a heat source calculation model and a temperature field simulation model specifically for current-carrying bearings. This study analyzes both the overall temperature rise of bearings and the local temperature rise resulting from breakdown discharge. Furthermore, the accuracy of the simulation analysis is verified through experiments. The temperature field simulation and experimental results consistently indicate that electrical environmental factors can cause an increase in the overall temperature rise of a bearing. Additionally, the breakdown and discharge of the lubricating oil film generate local instantaneous high temperatures in the contact area of the bearing.

Abstract Background Femoral neck fractures have a higher incidence in older people with poor prognosis, inducing serious social problems. Common treatment methods include total hip arthroplasty, bipolar hemiarthroplasty, double-screw fixation, multiple-screw fixation, and dynamic hip system. Methods We searched through four electronic databases, including PubMed, Web of Science, Cochrane Library, and Embase databases, for articles regarding femoral neck fractures, bone screw, and hip prosthesis published up to February 11, 2020. All included articles were used for quality evaluation and data extraction. Extracted data were expressed as odds ratios or weighted mean differences, with 95% confidence intervals. We conducted a network meta-analysis for Harris hip score, complications, 1-year mortality rate, reoperation rate, intraoperative blood loss, and duration of operation using STATA version 16.0 software. Results Twenty-two randomized controlled trials and nine cohort studies included in this study involved 3861 patients. Total hip arthroplasty significantly improved the postoperative function of patients with femoral neck fractures. The surface under the cumulative ranking curve value of the Harris hip score for more than 1 year after total hip arthroplasty was 98.2. Conclusions This meta-analysis indicated no significant difference in mortality among different treatment groups. Total hip arthroplasty can provide satisfactory outcomes in hip joint function, and double-screw fixation results in the lowest intraoperative risk. In general, total hip arthroplasty results in a lower incidence of adverse events and is especially recommended for patients with femoral neck fractures. This article has been retrospectively registered on the International Platform of Registered Systematic Review and Meta-analysis Protocols (INPLASY) on November 27, 2020. Registration number: INPLASY2020110123.

Abstract Background The treatment of defects on the volar surface of the finger has been scarcely reported, and its utility for digital resurfacing remains unclear. This study compared the outcomes of free medial plantar artery flap (MPAF) and dorsal digital–metacarpal flap (DDMF) in finger reconstruction. Methods This retrospective cohort study included 24 patients with soft-tissue defects on the volar surface of the finger from March 2014 to March 2017. The patients were divided into two groups: the MPAF group and the DDMF group. The operation time, complications, such as flap necrosis, graft loss, infection, paresthesia, and donor-site morbidity, as well as two-point discrimination (2-PD) were carefully recorded. The Michigan Hand Outcomes Questionnaire was used for conduct follow-up assessment. Results After more than 12 months of follow-up, the MPAF group had a longer operative time compared with DDMF group, but there was no significant difference between postoperative complications and 2-PD test result in patients without nerve injury. And in terms of overall function, Modified VSS score and 2-PD test (the patients with nerve injury), There were relatively obvious statistical differences, MPAF was superior to DDMF (p

Peripheral nerve injury (PNI) is common and, unlike damage to the central nervous system injured nerves can effectively regenerate depending on the location and severity of injury. Peripheral myelinating glia, Schwann cells (SCs), interact with various cells in and around the injury site and are important for debris elimination, repair, and nerve regeneration. Following PNI, Wallerian degeneration of the distal stump is rapidly initiated by degeneration of damaged axons followed by morphologic changes in SCs and the recruitment of circulating macrophages. Interaction with fibroblasts from the injured nerve microenvironment also plays a role in nerve repair. The replication and migration of injury-induced dedifferentiated SCs are also important in repairing the nerve. In particular, SC migration stimulates axonal regeneration and subsequent myelination of regenerated nerve fibers. This mobility increases SC interactions with other cells in the nerve and the exogenous environment, which influence SC behavior post-injury. Following PNI, SCs directly and indirectly interact with other SCs, fibroblasts, and macrophages. In addition, the inter- and intracellular mechanisms that underlie morphological and functional changes in SCs following PNI still require further research to explain known phenomena and less understood cell-specific roles in the repair of the injured peripheral nerve. This review provides a basic assessment of SC function post-PNI, as well as a more comprehensive evaluation of the literature concerning the SC interactions with macrophages and fibroblasts that can influence SC behavior and, ultimately, repair of the injured nerve.

Due to the high demand for structural reliability, Structural Health Monitoring (SHM) has drawn intensive attention. Fiber Bragg Grating (FBG) sensor with many advantages has become one of the most promising sensing elements in this area. However, the axial sensitivity, as the main parameter of the FBG sensor, has received little attention. This paper tried to explore the influence of the ply stacking of composite on the axial sensitivity of the FBG sensor. The calibration test, the repeatability test, and the influence test had been carried out in this paper. Thereinto, the theoretical axial strain sensitivity of the FBG sensor (1.06312 pm/με) was obtained by the calibration test. The repeatability test verified that the effect of preparation and operating conditions on the test results could be ignored, while the influence test was used to demonstrate that the three kinds of stacking could affect the axial sensitivities of the FBG sensors. The experimental results showed that: the axial sensitivities of two FBG sensors embedded between 45°/45° layers were equal. But, a difference was observed between the FBG sensors embedded between the layers of 0°/0°, 45°/45°, and 90°/90°. The maximum relative difference was about 2.587%. It indicated that the laying sequence of the FBG sensor influenced the axial sensitivity of the FBG sensor. Subsequently, the ANSYS software was adopted to simulate the deformation distribution of the sensor under a tensile load of 800N. A good agreement was observed between the numerical prediction and experimental results.

The injury to the spinal cord is among the most complex fields of medical development. Spinal cord injury (SCI) leads to acute loss of motor and sensory function beneath the injury level and is linked to a dismal prognosis. Currently, while a strategy that could heal the injured spinal cord remains unforeseen, the latest advancements in polymer-mediated approaches demonstrate promising treatment forms to remyelinate or regenerate the axons and to integrate new neural cells in the SCI. Moreover, they possess the capacity to locally deliver synergistic cells, growth factors (GFs) therapies and bioactive substances, which play a critical role in neuroprotection and neuroregeneration. Here, we provide an extensive overview of the SCI characteristics, the pathophysiology of SCI, and strategies and challenges for the treatment of SCI in a review. This review highlights the recent encouraging applications of polymer-based scaffolds in developing the novel SCI therapy.

Based on the structural mechanics and rolling bearing dynamics, this paper presented a dynamics model of cylindrical roller bearing with flexible outer ring and a novel elastic support named groove elastic support(GES), and then the load distribution and cage slip ratio of cylindrical roller bearing with GES(BES) were analyzed. The findings are as following: (1) The number of loaded rollers of BES is more than that of cylindrical roller bearing with rigid support(BRS), and the largest contact load between roller and ring of BES is lower than that of BRS. (2) The number of loaded rollers of BES decreases with the groove number, arc beam thickness and outer ring’s thickness. The smaller radial load, ranging from 500N to 1400N in this paper, has no obvious effect on the number of loaded roller for BES and BRS; (3) Under the same condition, cage slip ratio of BES is much lower than that of BRS. Cage slip ratio of BES increases with the groove number, arc beam thickness and outer ring’s thickness. All results reveal that the GES has a large impact on the load distribution and cage slip ratio in cylindrical roller bearing, and will be beneficial to extend the bearing service life under the condition of high-speed and light-load.

The influence of size of the scatterer on the image contrast for polarization-based range-gated imaging in turbid media is investigated here by Monte Carlo method. Circularly polarized light would be more efficient to eliminate the noise photons for both the isotropic medium as well as the anisotropic medium, as compared with linearly polarized light. The improvement in contrast is pronounced for isotropic medium using either linear or circular polarization. The plausible explanations for these observations are also presented.

Introduction: Plantar fasciitis (PF) is a common cause of heel pain among the general population. The lack of standard practice guideline in Singapore presents challenges in education and clinical practice for this painful condition. These consensus statements and guideline were developed to streamline and improve the management of PF, covering key aspects such as diagnosis, investigations, risk factors, treatment modalities, monitoring and return to work/play. Method: A multidisciplinary expert panel consisting of 6 sports physicians, 2 orthopaedic surgeons, 2 podiatrists and 1 physiotherapist from SingHealth Duke-NUS Sport & Exercise Medicine Centre (SDSC) was convened based on their clinical and academic experience with PF. The Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach was used to evaluate the quality of the evidence and subsequently prepare a set of clinical recommen-dations pertaining to the management of PF. A modified Delphi process was used to reach consensus. Results: Eighteen consensus statements were developed to cover key components of PF management, from initial diagnosis to treatment modalities and finally, clinical progression. They were subsequently consolidated under a proposed treatment pathway guideline for PF. Conclusion: The SDSC consensus statements and guideline provide concise recommendations for the management of PF in Singapore. [ABSTRACT FROM AUTHOR]

In this article, we consider the band structure calculations of three-dimensional (3D) anisotropic photonic crystals (PhCs), especially those with nonorthogonal Bravais lattices. By directly working with the intrinsic coordinate system with {al}³l=1 as the basis and the covariant formulation of Maxwell's equations, the approach proposed here treats nonorthogonal and orthogonal Bravais lattices in an equal and unified manner and trivially incorporates the Bloch condition in the discretization. Yee's scheme does not require the coordinate system or mesh to be orthogonal, and assisted by linear interpolation, this scheme can handle anisotropic media, by which the frequency domain Maxwell's equations are discretized into a standard eigenvalue problem (SEP). With an alternative understanding of null-space deflation techniques, this SEP is transformed into several equivalent null-space free SEPs, whose smallest few positive eigenvalues and associated eigenvectors are calculated by an iterative eigensolver of the inner-outer type. Comparison with other methods for band structure calculations of 3D anisotropic and isotropic PhCs is made to demonstrate the effectiveness and strength of our present approach. [ABSTRACT FROM AUTHOR]