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Guangtao Fu,1,&ast; Rongjie Wu,1,2,&ast; Ruiying Zhang,1,&ast; Duanyong Chen,1 Haotao Li,1 Qiujian Zheng,1,3 Yuanchen Ma1 1Department of Orthopedics, Guangdong Provincial People’s Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, People’s Republic of China; 2Shantou University Medical College, Shantou, People’s Republic of China; 3The Second School of Clinical Medicine, Southern Medical University, Guangzhou, People’s Republic of China&ast;These authors contributed equally to this workCorrespondence: Yuanchen Ma, Tel +86-18688889132, Email myc998@qq.com; Qiujian Zheng, Tel +86-13802740561, Email zhengqiujian@gdph.org.cnBackground: Vitamin D deficiency is a common comorbidity in geriatric hip fracture patients. However, there is still an ongoing debate regarding the influence of preoperative Vitamin D status on postoperative mortality in hip fracture patients.Methods: Elderly patients (≥ 60 years) who underwent surgical interventions for unilateral hip fracture from 2015 to 2020 in our center were included. We retrospectively retrieved the demographic data from the electronic medical database. Preoperative serum total 25-hydroxy-Vitamin D was set as the independent variable and patients were classified as the Vitamin D deficiency (< 20ng/mL) and the control groups consequently. Clinical outcomes include all-cause mortality, walking ability, and major postoperative complications in the first postoperative year. Propensity score matching (PSM) was performed in a ratio of 1:1 in the two groups for further comparison.Results: A total of 210 patients were included and 121 patients (57.6%) were diagnosed with Vitamin D deficiency. Patients in the Vitamin D deficiency group were much older and therefore preferred peripheral nerve block, and had significantly higher proportions of females, preoperative dementia, higher ASA grade, and lower baseline serum albumin level. Overall, 79 patients were identified in the Vitamin D deficiency and control groups after PSM, respectively. Patients diagnosed with Vitamin D deficiency showed a significantly higher one-year mortality (21.5% vs 6.3%, P=0.011) and a much lower one-year independent walking rate (67.1% vs.84.8%, P=0.016) after the matching. Regarding the dataset before PSM and after PSM, the AUC for serum Vitamin D for predicting one-year mortality was 0.656 (P=0.006) and 0.695 (P=0.002), respectively.Conclusion: Our retrospective PSM-design study provides new evidence that Vitamin D deficiency was associated with a significantly higher mortality and poor walking ability in the first year after surgical intervention based on southern Chinese populations.Keywords: vitamin D deficiency, mortality, hip fracture, propensity score match, Chinese population

Objective The current study aims to investigate the factors that could predict response to intra-articular corticosteroid injection (IACI) in patients with knee osteoarthritis (KOA). Methods Data of participants were retrieved from the Osteoarthritis Initiative database. Participants with at least one IACI treatment on single or bilateral knees within the first 5 years of follow-up were retrospectively included. Demographic data, clinical and radiographic variables were collected at both baseline and the first follow-up after IACI treatment. Positive response to IACI treatment was defined as >20% reduction of Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain score from V0 to V1. All the variables with P < 0.2 after the comparison between the response and non-response groups were included in a multivariable logistic regression model to identify independent response predictive patient-specific valuables. Receiver operating characteristic curves were performed to establish the cutoff values of independent predictors. Results The current study included a total of 385 participants (473 knees), with 155 and 318 knees classified into the response group and non-response group, respectively. Those with satisfied responses to IACI treatment had significantly higher WOMAC pain score ( P < 0.001), disability score ( P = 0.002), and stiffness score ( P = 0.015) at the baseline. Baseline WOMAC pain score showed significant association with positive response to IACI treatment in multivariate logistic analysis and the best cutoff value was 5 points. The rate of analgesics utilization was lower ( P = 0.014) in the response group than the non-response group after the IACI treatment. Conclusion KOA patients with a baseline WOMAC pain score ≥5 are more likely to benefit from IACI treatment.

Musculoskeletal engineering has been considered as a promising approach to customize regenerated tissue (such as bone, cartilage, tendon, and ligament) via a self-healing performance. Recent advances have demonstrated the great potential of bioactive materials for regenerative medicine. Silk fibroin (SF), a natural polymer, is regarded as a remarkable bioactive material for musculoskeletal engineering thanks to its biocompatibility, biodegradability, and tunability. To improve tissue-engineering performance, silk fibroin is hybridized with other biomaterials to form silk-fibroin-based hybrid biomaterials, which achieve superior mechanical and biological performance. Herein, we summarize the recent development of silk-based hybrid biomaterials in musculoskeletal tissue with reasonable generalization and classification, mainly including silk fibroin-based inorganic and organic hybrid biomaterials. The applied inorganics are composed of calcium phosphate, graphene oxide, titanium dioxide, silica, and bioactive glass, while the polymers include polycaprolactone, collagen (or gelatin), chitosan, cellulose, and alginate. This article mainly focuses on the physical and biological performances both

Background: After spinal cord transection injury, the inflammatory microenvironment formed in the injury site and the cascade of secondary injury results in limited regeneration of injured axons and the apoptosis of neurons in the sensorimotor cortex (SMC). It is crucial to reverse these adverse processes for the recovery of voluntary movement. In this study, transcranial intermittent theta-burst stimulation (iTBS) was used for the treatment of complete spinal cord transection in rats. The mechanism of transcranial iTBS as a new non-invasive neural regulation paradigm in promoting axonal regeneration and motor function repair was explored. Methods: Rats from the iTBS group were treated with transcranial iTBS 72h after spinal cord injury (SCI). Each rat was received behavioral testing. Inflammation, neuronal apoptosis, neuroprotective effect, regeneration and synaptic plasticity were measured by immunofluorescence staining, western blotting and mRNA sequencing 2 or 4w after SCI. Each rat was received anterograde tracings in the SMC or the long descending propriospinal neurons and tested for motor evoked potentials. Regeneration of corticospinal tract (CST) and 5-hydroxytryptamine (5-HT) nerve fibers were detected eight weeks after SCI. Results: Compared with the control group and the sham iTBS group, rats of the iTBS group showed reduced inflammatory responses and neuronal apoptosis in the SMC two weeks after treatment. After four weeks, the neuroimmune microenvironment at the injury site was improved, and neuroprotective effects were seen to promote axonal regeneration and synaptic plasticity. Significantly, eight weeks after treatment, transcranial iTBS also increased the regeneration of CST, 5-HT nerve fibers, and the long descending propriospinal tract (LDPT). Moreover, motor evoked potentials and hindlimb motor function were significantly improved at eight weeks. Conclusions: Collectively, our results verified that iTBS has the potential to provide neuroprotective effects at early injury stages and pro-regeneration effects related to the 1) CST–5-HT; 2) CST–LDPT; and 3) CST–5-HT–LDPT descending motor pathways and revealed the relationships among neural pathway activation, neuroimmune regulation, neuroprotection, and axonal regeneration, as well as the interaction network of key genes. The proposed non-invasive transcranial iTBS treatment is expected to provide a serviceable practical and theoretical support for spinal cord injury.

This paper set out to establish the dynamics model of shaft torsional vibration for direct-drive wind turbine with the phenomenon of unstable shaft system torsional vibration. The stability of the equilibrium point of the dynamical model is investigated, and the Routh–Hurwitz stability criterion is used to obtain a range of values for the bifurcation control parameters. For the stable equilibrium point, the stability domain of the system is calculated by constructing the Lyapunov function. The sensitivity analysis of system parameters is carried out to obtain the law of the effect of system parameters on system stability of the torsional vibration system. The results are substituted for example calculations, and the results verify the correctness of the theoretical analysis conclusions. It is proved that it is feasible to analyze the torsional vibration characteristics of the direct-drive wind turbine shaft system by using the principle of Routh–Hurwitz stability, etc., which provides a reference for the structural design of direct-drive wind turbine.

Purpose: To explore the value of metagenomics next-generation sequencing (mNGS) for deep sternal wound infection (DSWI) diagnosis. Methods: mNGS was used to diagnose DSWI after cardiac transplantation; DSWI was treated with surgical debridement, wound care, and antibiotic therapy guided by mNGS. Results: Coinfection of methicillin-resistant Staphylococcus aureus (MRSA) and cytomegalovirus (CMV) was detected in this patient. The infection was controlled and the wound healed successfully with the specific medicine based on mNGS results for 3 weeks. Conclusion: mNGS is effective to achieve precise, individualized, and rapid treatment for wound infection.

To explore whether the severity of contralateral knee osteoarthritis (OA) is associated with OA progression in ipsilateral knee with early OA.Knees in early OA (Kellgren-Lawrence grade (KLG):1-2) with intact baseline demographic and clinical data were retrieved from OAI database and defined as target knees. The target knees were divided into the exposure group (contralateral knees KLG 3 to 4) and the control group (contralateral knees KLG 0 to 2). Both groups underwent propensity score matching (PSM) concerning demographic data, as well as radiographic and clinical outcomes at the baseline. The primary outcome was the upgrade of KLG in the target knee in the first 12 and 24 months. The secondary outcome was the incidence of knee arthroplasty in ipsilateral knee during the first 108 months.One thousand seven hundred fifty-two knees were included, with 449 in the exposure cohort and 1276 in the control cohort. Four hundred thirty-four knees in each group were matched after PSM. Target knees in the exposure cohort showed a significantly higher rate of radiographic progression in the first 12 months (12.9% vs. 5.1%, P 0.001) and 24 months (19.6% vs. 8.1%, P 0.001). As for the risk of future arthroplasty, a significant difference was also found between the two groups (7.8% vs. 4.0%, P = 0.02). Kaplan-Meier analysis showed that the 108-month accumulated knee survival rate was significantly lower in the exposure group (P = 0.01).The ipsilateral knee with early-stage OA is prone to have worse early to mid-, and long-term prognosis in the circumstance of contralateral radiographic advanced knee OA. Key Points •Identifying early knee osteoarthritis (OA) with a high risk of radiographic progression and future arthroplasty enables early personalized intervention. •This is a novel study to investigate the relationship between the risk of future arthroplasty and contralateral knee status. •Propensity score matching holds promise to minimize selection bias in observational studies. •Knees with early OA are prone to have a high risk of radiographic progression and future arthroplasty in the circumstance of contralateral advanced knee OA.

Knee osteoarthritis (OA) progresses in a heterogeneous way, as a majority of the patients gradually worsen over decades while some undergo rapid progression and require knee replacement. The aim of this study was to develop a predictive model that enables quantified risk prediction of future knee replacement in patients with early-stage knee OA. Patients with early-stage knee OA, intact MRI measurements, and a follow-up time larger than 108 months were retrieved from the Osteoarthritis Initiative database. Twenty-five candidate predictors including demographic data, clinical outcomes, and radiographic parameters were selected. The presence or absence of knee replacement during the first 108 months of the follow-up was regarded as the primary outcome. Patients were randomly divided into derivation and validation groups in the ratio of three to one. Nomograms were developed based on multivariable logistic regressions of derivation group via R language. Those models were further tested in the validation group for external validation. A total of 839 knees were enrolled, with 98 knees received knee replacement during the first 108 months. Glucocorticoid injection history, knee OA in the contralateral side, extensor muscle strength, area of cartilage deficiency, bone marrow lesion, and meniscus extrusion were selected to develop the nomogram after multivariable logistic regression analysis. The bias-corrected C-index and AUC of our nomogram in the validation group were 0.804 and 0.822, respectively. Our predicting model provided simplified identification of patients with high risk of rapid progression in knee OA, which showed adequate predictive discrimination and calibration. • Knee OA progresses in a heterogeneous way and rises to a challenge when making treatment strategies. • Our predicting model provided simplified identification of patients with high risk of rapid progression in knee OA.

According to the production order, the engine parts workshop of a company mainly produces four parts: valve hydraulic tappet, camshaft, camshaft gear and bearing cover. With the increasing demand of production, the production capacity brought by the original workshop equipment layout gradually cannot meet the increasing demand. In this paper, based on the WITNESS simulation software, we are preparing to collect the data of engine parts and components production workshop in order to get the data information of each element by simulation, and reasoning the unreasonable parts where the busy rate is too high and put forward several improvement methods. Through WITNESS software simulation, respectively, we can analyse whether there will have improvement and conclude the optimal improvement project. As the busy rate of lathe group and milling machine group of the original workshop layout is more than 80%, while the statistics are less than 60% by using the optimal plan to improve the existing layout, reaching a reasonable busy rate. It can be concluded that it is feasible to solve the problem of high work step busy rate and improve the overall production efficiency of the workshop through reasonable equipment layout optimization.

A parking guidance system can help a driver quickly find an available parking space. Most currently available parking guidance systems require wire deployment in installation, thus entailing high installation costs. In this chapter, we discuss the network design of a low-power parking guidance system. We developed a tiered communication architecture including Wireless Sensor Network (WSN), General Packet Radio Service (GPRS) network and Internet to realize wireless parking space availability data transmission, and thus installation complexity can be greatly reduced. In order to reduce the battery replacement frequency of the WSN, we designed a power-minimized Medium Access Control (MAC) protocol. The proposed MAC protocol divides one network working cycle into four dedicated intervals to realize robust network organization and energy-efficient data delivery. Experimental results showed that the proposed MAC protocol can extend the battery lifetime of the WSN to more than ten years. Based on the collected parking space availability data, we built a portable parking guidance terminal to let drivers locate available parking spaces conveniently.