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The frequent occurrence of coal burst seriously threatens the safe and efficient recovery of coal resources. The research on the mechanism of coal burst is the basis of prediction and disaster prevention. Aiming at the coal burst event under the condition that the stress environment is stable and not affected by dynamic load, the concept of local mine stiffness (LMS) is introduced. Taking the mining area with complex mining layout of the mine as the engineering background, the mechanical response of coal pillar in the process of large-scale mining is analyzed by comprehensively using numerical analysis and field measurement, The evolution of LMS in this process is investigated. It is pointed out that the mining leads to the reduction of LMS, the rapid accumulation of energy in the coal seam and its roof and floor system, and the rapid release of energy when the coal pillar is unstable, resulting in impact damage. The engineering verification is carried out by comparing the evolution of LMS with the mining and the field measured ground sound and microseismic data. The research shows that:①the deformation, load and elastic energy accumulation of coal pillar increase with the overall mining operation, but the LMS decreases. The mining space size and the distance between the mining space and the research area are the main influencing factors. The response degree of the two to the mining of the working face is significantly greater than that of the roadway excavation. The significant influence range of the mining of the working face on the LMS reduction is 3.67 times that of the roadway excavation, and the LMS reduction under the unit advancing distance is 6.41 times that of the roadway excavation.②The good correspondence between the evolution of local mine stiffness with the advancement of the working face and the on-site ground sound and microseismic data indicates that the reduction of local mine stiffness caused by coal mining directly affects the failure mode of coal pillars. The energy in the coal seams and their roof and floor systems accumulates rapidly with the reduction of local mine stiffness and is released rapidly when the bearing capacity of coal pillars decreases, resulting in impact damage. ③After using large-diameter drilling to weaken the coal body, the microseismic energy and frequency are significantly reduced, indicating that large-diameter drilling destroys the coal body in this area, reduces its post peak stiffness, and effectively realizes the impact prevention effect.

Fault-slip rockbursts are a major type of rockbursts in coal mine roadways, posing great hazards. Currently, there is a lack of systematic research on the entire process of fault-slip rockbursts, and prediction and prevention remain fundamental challenges. To achieve experimental simulation of fault-slip rockbursts, a testing system was developed, along with the development of low-strength high-brittleness similar simulation materials. A large-scale similar model containing faults and roadways was prepared, and a series of verification experiments were conducted, realizing the simulation of roadway shock failure and fault shear slip. The testing system is equipped with a triaxial six-face loading function, with a vertical loading capacity of 20 MPa and a model size of 1.50 m×0.75 m×0.75 m. The main frame innovatively adopts a key plate connection, ensuring high rigidity of the main frame. A honeycomb loading shell structure was invented, achieving oil cylinder group loading, which can meet the requirements of fault-slip rockburst simulation. A similar material suitable for fault-slip rockburst simulation was developed, which uses water glass as the binder, sodium fluosilicate as the curing agent, and talcum powder as the aggregate. The similar material has characteristics of both low strength and high brittleness, with a uniaxial compressive strength ranging from 3.44 to 7.81 MPa, an impact energy index of 9.2, and an elastic energy index of 8.83. Based on the test system and low-strength and high-brittleness materials, the bursting failure simulation of roadway under static load was realized, and the feasibility of simulating bursting failure of roadway using low-strength and high-brittleness materials was verified. The loading conditions of the critical equilibrium state of the roadway were obtained, with the continuous shedding of the roadway's side as a significant precursor characteristic of roadway damage. The shear slip of rough serrated faults was realized, confirming that the shear slip of rough faults would cause significant dynamic load disturbances to the roadway, obtaining a reasonable loading method for fault slip. The method of loading the top of the dynamic zone first and unloading the bottom later can achieve instantaneous slip of the fault and eliminate the influence on the static zone stress state.

In response to the poor active support effect of the surface protection components in soft coal roadway and the continuous expansion of the broken range of local exposed surrounding rock, which leads to the failure of anchor rod and cables, a mesh grouting surface type prestressed application technology has been developed. The authors conducted post mesh grouting tests on different specifications and models of metal mesh, and obtained the mechanical response characteristics of the support system during the application of active surface prestressing. Based on this, the post mesh grouting tests on the roof and two sides of the mesh under on-site conditions were carried out, verifying the applicability of post mesh grouting technology. The research results indicate that: ① There is a gap between the metal mesh and the coal wall, which leads to poor active support ability. The continuous expansion of the broken range of the exposed surrounding rock is the main controlling factor for the failure of anchor rod and anchor cable support. Filling the uneven structure around the contact surface between the metal mesh and the coal wall, increasing the active support ability of the protective surface components, and comprehensively sealing the surrounding rock are the technical means to improve the anchor mesh support system; ② Injecting and filling between the metal mesh and the surrounding rock can achieve the application of surface active pre-stress. The trend of surface stress change is mainly divided into: the initial stage of constant surface stress, the stage of increasing surface stress, and the stage of reducing surface stress to stable state; ③ During the process of grouting behind the mesh, the trend of changes in surface stress values is closely related to the grouting pressure and deformation of the metal mesh. During the process of increasing surface stress, the grouting pressure and deformation of the metal mesh also increase accordingly; ④ Grouting behind the mesh can effectively alleviate the stress concentration of the cable tray. During the process of increasing the surface stress value, the pre-tightening force of the cable with stress concentration can show a small decrease trend, while the pre-tightening force of the cable with relatively uniform stress shows a synchronous upward trend during the process of increasing the surface stress value. The technologies developed are expected to become supporting technologies for rock bolt support, providing technical and theoretical references for the treatment of complex and difficult roadway.

This study explores the effects of dynamic and static loading on rock bolt performance a key factor in maintaining the structural safety of coal mine roadways susceptible to coal bursts. Employing a house-made load frame to simulate various failure scenarios, pretension-impact-pull tests on rock bolts were conducted to scrutinize their dynamic responses under varied static load conditions and their failure traits under combined loads. The experimental results denote that with increased impact energy, maximum and average impact loads on rock bolts escalate significantly under pretension, initiating plastic deformation beyond a certain threshold. Despite minor reductions in the yield load due to impact-induced damage, pretension aids in constraining post-impact deformation rate and fluctuation degree of rock bolts. Moreover, impact-induced plastic deformation causes internal microstructure dislocation, fortifying the stiffness of the rock bolt support system. The magnitude of this fortification is directly related to the plastic deformation induced by the impact. These findings provide crucial guidance for designing rock bolt support in coal mine roadway excavation, emphasizing the necessity to consider both static and dynamic loads for improved safety and efficiency.

IntroductionPost-acute COVID syndrome (PACS) is a growing concern, given its impact on mental health and quality of life. However, its effects on cerebral white matter remain poorly understood, particularly in non-hospitalized cohorts. The goals of this cross-sectional, observational study were to examine (1) whether PACS was associated with distinct alterations in white matter microstructure, compared to symptom-matched non-COVID viral infection; and (2) whether microstructural alterations correlated with indices of post-COVID emotional health.MethodsData were collected for 54 symptomatic individuals who tested positive for COVID-19 (mean age 41 ± 12 yrs., 36 female) and 14 controls who tested negative for COVID-19 (mean age 41 ± 14 yrs., 8 female), with both groups assessed an average of 4–5 months after COVID testing. Diffusion magnetic resonance imaging data were collected, and emotional health was assessed via the NIH emotion toolbox, with summary scores indexing social satisfaction, well-being and negative affect.ResultsDespite similar symptoms, the COVID-19 group had reduced mean and axial diffusivity, along with increased mean kurtosis and neurite dispersion, in deep white matter. After adjusting for social satisfaction, higher levels of negative affect in the COVID-19 group were also correlated with increased mean kurtosis and reduced free water in white matter.DiscussionThese results provide preliminary evidence that indices of white matter microstructure distinguish PACS from symptomatic non-COVID infection. Moreover, white matter effects seen in PACS correlate with the severity of emotional sequelae, providing novel insights into this highly prevalent disorder.

Abstract The post-peak characteristics of coal serve as a direct reflection of its failure process and are essential parameters for evaluating brittleness and bursting liability. Understanding the significant factors that influence post-peak characteristics can offer valuable insights for the prevention of coal bursts. In this study, the Synthetic Rock Mass method is employed to establish a numerical model, and the factors affecting coal post-peak characteristics are analyzed from four perspectives: coal matrix mechanical parameters, structural weak surface properties, height-to-width ratio, and loading rate. The research identifies four significant influencing factors: deformation modulus, density of discrete fracture networks, height-to-width ratio, and loading rate. The response and sensitivity of post-peak characteristics to single-factor and multi-factor interactions are assessed. The result suggested that feasible prevention and control measures for coal bursts can be formulated through four approaches: weakening the mechanical properties of coal pillars, increasing the number of structural weak surfaces in coal pillars, reducing the width of coal pillars, and optimizing mining and excavation speed. The efficacy of measures aimed at weakening the mechanical properties of coal is successfully demonstrated through a case study on coal burst prevention using large-diameter borehole drilling.

BackgroundThis study aimed to develop a nomogram capable of predicting the probability of femoral head collapse based on an 18-year follow-up cohort of convalescent severe acute respiratory syndrome (SARS) patients with glucocorticoid-induced osteonecrosis of the femoral head (ONFH).MethodsData on the natural history of 120 patients (205 hips) who underwent glucocorticoid-induced ONFH at China-Japan Friendship Hospital (CJFH) in 2003 were retrospectively collected. Follow-up was conducted from June 2003 to October 2021. A nomogram was developed in a training cohort and validated in another cohort.ResultsA total of 205 hips were included for analysis, with 143 hips in the training cohorts and 62 hips in the validation cohorts. After 18 years of follow-up, 53 femoral heads collapsed, while 152 femoral heads spontaneously repaired to some extent (necrotic areas reduced or vanished). Following multivariate regression analysis, the Association Research Circulation Osseous (ARCO) staging, necrosis index (NI), and CJFH Classification were entered into the nomogram. The nomogram showed robust discrimination, with an AUC of 0.907 (95% CI: 0.85–0.96). The calibration curves showed an agreement between the probability as predicted by the nomogram and the actual probability. Application of the nomogram in the validation cohort also yielded good discrimination (AUC, 0.876, 95% CI: 0.7751–0.9761) and calibration.ConclusionThe nomogram successfully predicted femoral head collapse in glucocorticoid-induced ONFH. With the nomogram, the prognosis for an individual patient with glucocorticoid-induced ONFH can be determined, which can lead to a rational therapeutic choice.

Abstract Background Knee injuries are prevalent, and early diagnosis is crucial for guiding clinical therapy. MRI is the diagnostic gold standard for bone marrow edema (BME) in patients with acute knee injuries, yet there are still limitations. Dual-energy CT, a possible viable replacement, is being explored (DECT). Methods We systematically retrieved studies from EMBASE, Scopus, PUBMED, and the Cochrane Library and collected gray literatures. In accordance with the PRISMA-DTA standards, a systematic review was conducted between the study's initiation and July 31, 2021, utilizing an MRI reference standard and at least 10 adult patients with acute knee injuries to evaluate the diagnostic effectiveness of DECT for diagnosing BME. Two reviewers collected the study's details independently. For the meta-analysis, a bivariate mixed-effects regression model was utilized, and subgroup analysis was employed to determine the sources of variability. Results The research included nine studies that examined 290 individuals between the ages of 23 and 53 with acute knee injuries who had DECT and MRI. Overall, the sensitivity, specificity, and AUC of the BME were 85% (95% confidence interval [CI]: 77–90%), 96% (95% CI: 93–97%), and 0.97 (95% CI: 0.95–0.98), respectively. To account for the assumed diversity of research, there were no statistically significant differences between the comparison groups in terms of specificity and sensitivity. Conclusion DECT is a viable alternative to MRI for individuals with acute knee injuries when MRI is inappropriate or unavailable.

In the original publication [...]

Abstract Background Neuropsychiatric symptoms (NPS) are a core feature of most neurodegenerative and cerebrovascular diseases. White matter hyperintensities and brain atrophy have been implicated in NPS. We aimed to investigate the relative contribution of white matter hyperintensities and cortical thickness to NPS in participants across neurodegenerative and cerebrovascular diseases. Methods Five hundred thirteen participants with one of these conditions, i.e. Alzheimer’s Disease/Mild Cognitive Impairment, Amyotrophic Lateral Sclerosis, Frontotemporal Dementia, Parkinson’s Disease, or Cerebrovascular Disease, were included in the study. NPS were assessed using the Neuropsychiatric Inventory – Questionnaire and grouped into hyperactivity, psychotic, affective, and apathy subsyndromes. White matter hyperintensities were quantified using a semi-automatic segmentation technique and FreeSurfer cortical thickness was used to measure regional grey matter loss. Results Although NPS were frequent across the five disease groups, participants with frontotemporal dementia had the highest frequency of hyperactivity, apathy, and affective subsyndromes compared to other groups, whilst psychotic subsyndrome was high in both frontotemporal dementia and Parkinson’s disease. Results from univariate and multivariate results showed that various predictors were associated with neuropsychiatric subsyndromes, especially cortical thickness in the inferior frontal, cingulate, and insula regions, sex(female), global cognition, and basal ganglia-thalamus white matter hyperintensities. Conclusions In participants with neurodegenerative and cerebrovascular diseases, our results suggest that smaller cortical thickness and white matter hyperintensity burden in several cortical-subcortical structures may contribute to the development of NPS. Further studies investigating the mechanisms that determine the progression of NPS in various neurodegenerative and cerebrovascular diseases are needed.

Introduction: Cerebral small vessel disease (SVD) is a common co-pathology in elderly and individuals with dementia. Neuroimaging markers of SVD include white matter hyperintensities (WMH) and MRI-visible perivascular spaces (PVS). However, the mechanisms underlying changes in these markers over time, whether ischemic or beta-amyloid (Aβ)-related, remain elusive. Here, we evaluated the effects of microstructural injury in the normal-appearing white matter and Aβ in the cerebral cortex on the progression of WMH and PVS over three years. Methods: Data was obtained from two independent cohorts: (i) TRIAD, comprising cognitively normal, MCI, and AD dementia participants (baseline: N=199, follow-up year 1 and 2: N=102 and 62); and (ii) MITNEC-C6, comprising “real-world” patients with mixed dementia and moderate-to- severe WMH burden (baseline: N=52, 2 years follow-up: N=25). We quantified global WMH and PVS volumes from FLAIR and T1w MRI. At baseline, we examined associations between these volumes and diffusion MRI-derived free water. Longitudinally, we employed linear [mixed-effect] models to investigate the relation of WMH or PVS volume changes over time with baseline free water, using cortical Aβ-PET, age, sex, and APOE-ε4 as covariates. Results: In TRIAD and MITNEC-C6 respectively, mean ages were 72±6 and 77±8 y, 60% and 42% were female, and 41% and 48% were Aβ-positive. At baseline, higher free water in normal- appearing white matter was associated with higher WMH volume (β_TRIAD=+0.34±0.06, P_TRIAD

Introduction: MRI-visible perivascular spaces (PVS) are a neuroimaging feature of cerebral small vessel disease and are commonly observed in patients with cerebrovascular and neurodegenerative disease. However, it is unclear whether PVS burden is associated with cognition. The aim of this study was to investigate the potential associations between PVS volumes, brain atrophy, white matter hyperintensities (WMH), and speeded executive function, in patients from the Ontario Neurodegenerative Disease Research Initiative (ONDRI). Methods: ONDRI participants (n=333) clinically diagnosed with Alzheimer's disease/mild cognitive impairment (ADMCI), frontotemporal dementia (FTD), and cerebrovascular diseases (CVD), with clinical, neuropsychological, MRI, plasma biomarkers (glial fibrillary acidic protein (GFAP); neurofilament light, (NfL); p-tau181; Aβ42/40), and available apolipoprotein E epsilon 4 (APOE E4) status, were included in this analysis. MRI-based measurements for brain parenchymal fraction (BPF), lacunes, PVS and WMH were extracted using the ONDRI imaging pipeline. The neuropsychological test scores were standardized (z-transformed), speeded executive function z- scores were computed as the mean of digit symbol modalities test and trail making test part B timed z-scores. The variables selected in bivariate analysis (p

Introduction: White matter hyperintensities (WMH) and MRI-visible perivascular spaces (PVS) are neuroimaging features of cerebral small vessel disease (CSVD). PVS are believed to play a role in cerebral metabolic waste clearance, particularly during sleep, and emerging evidence suggests that sleep disturbances are among the earliest symptoms of dementia. However, PVS quantification remains challenging and not accessible, particularly in complex patients with neurovascular and neurodegenerative disease. We developed and validated an automated deep learning-based PVS quantification method using multi-site patient MRI with varying degrees of CSVD burden. Additionally, we examined the correlation between PVS volumes and age in patients undergoing treatment for sleep apnea. Methods: MRI (training/validation data=141; testing=15) were obtained from various multi-site studies (ONDRI, CAHHM, Leducq SVD-PVS, CAIN). We developed a deep learning convolutional neural net (CNN) model with a U-net architecture for PVS segmentation using T1-weighted images. Ground truth data used for model training were generated by first applying the RORPO filter to extract small tubular structures, then refinement of the RORPO output around WMH, followed by removal of probable non-PVS objects from the RORPO-based output using Freesurfer regions of interest, and finally manually correcting the remaining errors. After ground truth generation and model training, the final CNN output was used to examine the association between PVS volumes and age in patients with sleep apnea (n=42). Results: After CNN training, our PVS tool completes full segmentation in under 3 minutes (NVIDIA RTX3090). It achieved excellent performance on the test data, with a mean Dice score of 0.95, indicating outstanding agreement with ground truth. When applied to the patients undergoing interventional sleep apnea treatment, a strong positive relationship was found between total PVS volume and age (r=0.57 [0.38 0.72]). Discussion: Our findings suggest that our automated PVS segmentation method can quickly and accurately quantify PVS in neurodegenerative and neurovascular patients with varying degrees of CSVD burden. The strong association between age and PVS in patients with sleep apnea further demonstrates the utility of our method and underscores the importance of further investigating the role of PVS in the context of sleep, aging, and neurodegenerative processes.

The methylation of adenosine base at the nitrogen-6 position is referred to as “N6-methyladenosine (m6A)” and is one of the most prevalent epigenetic modifications in eukaryotic mRNA and noncoding RNA (ncRNA). Various m6A complex components known as “writers,” “erasers,” and “readers” are involved in the function of m6A. Numerous studies have demonstrated that m6A plays a crucial role in facilitating communication between different cell types, hence influencing the progression of diverse physiological and pathological phenomena. In recent years, a multitude of functions and molecular pathways linked to m6A have been identified in the osteogenic, adipogenic, and chondrogenic differentiation of bone mesenchymal stem cells (BMSCs). Nevertheless, a comprehensive summary of these findings has yet to be provided. In this review, we primarily examined the m6A alteration of transcripts associated with transcription factors (TFs), as well as other crucial genes and pathways that are involved in the differentiation of BMSCs. Meanwhile, the mutual interactive network between m6A modification, miRNAs, and lncRNAs was intensively elucidated. In the last section, given the beneficial effect of m6A modification in osteogenesis and chondrogenesis of BMSCs, we expounded upon the potential utility of m6A-related therapeutic interventions in the identification and management of human musculoskeletal disorders manifesting bone and cartilage destruction, such as osteoporosis, osteomyelitis, osteoarthritis, and bone defect.

The loading mine stiffness and the post-peak stiffness of a coal pillar are important factors affecting the occurrence of coal bursts. In order to systematically study the mechanism of coal bursts and pillar bursts based on local mine stiffness theory, a laboratory-scale coal burst experiment system has been developed. The system is mainly composed of static loading system, energy storage system, variable stiffness loading system, excavation system and multi-source information monitoring system. The main innovations of the test system are as follows: ① An excavation device is added to the loading system, which can induce the stress concentration of the specimen and the reduction of local mine stiffness through excavation in the pressure-holding state. Coal bursts will occur when the specimen is stressed to its bearing capacity and the local system stiffness is lower than the post-peak stiffness of the specimen. ② The loading system is equipped with an energy storage device of oil cylinder airbag accumulator, which can store energy during loading. ③ A variable stiffness loading device is set up to adjust different loading stiffnesses by adjusting the initial airbag pressure of airbag accumulator. ④ The experiment system can reproduce the whole process of specimen from loading-stabilization-excavation-burst in laboratory, which makes it possible to monitor the strain of coal pillar during the whole process of coal bursts and observe the burst process. The accuracy and reliability of the simulation equipment are verified by preliminary laboratory tests on high-strength concrete blocks and realistic coal samples. The test results show that under the condition of low stiffness loading, the unstable failure of coal pillars can be effectively induced by excavating bottom samples, and the failure position extends from the low stiffness side to the high stiffness side. The damaged central residual coal pillar is dumbbell shaped under the action of top and bottom plate friction, and is cut off at the center by a transverse sawtooth crack penetrating the sample, resulting in a significant reduction in the bearing capacity of the coal pillar. The development of the experiment system can reproduce the whole process of coal bursts from loading, pressure stabilization, excavation and unstable failure in the laboratory from the perspective of local mine stiffness, and can provide an experimental basis for the mechanism of coal bursts in coal mines.

Abstract Grouting is an effective method to improve the integrity and stability of fractured rocks that surround deep roadways. After years of research and practice, various theories and a complete set of grouting technologies for deep roadways with fractured rocks have been developed and are widely applied in Chinese coal mining production. This paper systematically summarizes and analyzes the research results concerning the theory, design, materials, processes, and equipment for the grouting and reinforcement of fractured rocks surrounding deep roadways. Specifically, in terms of grouting methods, pregrouting, grouting‐while‐excavation, and postgrouting methods are explored; in terms of grouting theory, backfill grouting, compaction grouting, infiltration grouting, and fracture grouting theories are studied. In addition, this paper also studies grouting borehole arrangement, water‐cement ratio, grouting pressure, grouting volume, grout diffusion radius, and other grouting parameters and their determination methods. On this basis, this paper explores the physical and mechanical properties of organic and organic‐inorganic composite grouting materials, and assess grouting reinforcement quality testing methods and instruments. Taken as the field cases, the application of pregrouting in front of heading faces, grouting‐while‐excavation, and postgrouting in the Kouzidong coal mine are then introduced, and the effects of the grouting reinforcements are evaluated. This paper proposes a development direction for grouting technology based on problems existing in the grouting reinforcement of fractured rocks surrounding deep roadways.

Abstract Introduction Post‐acute coronavirus disease 2019 (COVID‐19) syndrome (PACS) is a growing concern, with headache being a particularly debilitating symptom with high prevalence. The long‐term effects of COVID‐19 and post‐COVID headache on brain function remain poorly understood, particularly among non‐hospitalized individuals. This study focused on the power‐law scaling behavior of functional brain dynamics, indexed by the Hurst exponent (H). This measure is suppressed during physiological and psychological distress and was thus hypothesized to be reduced in individuals with post‐COVID syndrome, with greatest reductions among those with persistent headache. Methods Resting‐state blood oxygenation level‐dependent (BOLD) functional magnetic resonance imaging data were collected for 57 individuals who had COVID‐19 (32 with no headache, 14 with ongoing headache, 11 recovered) and 17 controls who had cold and flu‐like symptoms but tested negative for COVID‐19. Individuals were assessed an average of 4–5 months after COVID testing, in a cross‐sectional, observational study design. Results No significant differences in H values were found between non‐headache COVID‐19 and control groups., while those with ongoing headache had significantly reduced H values, and those who had recovered from headache had elevated H values, relative to non‐headache groups. Effects were greatest in temporal, sensorimotor, and insular brain regions. Reduced H in these regions was also associated with decreased BOLD activity and local functional connectivity. Conclusions These findings provide new insights into the neurophysiological mechanisms that underlie persistent post‐COVID headache, with reduced BOLD scaling as a potential biomarker that is specific to this debilitating condition.

BackgroundThrough the standardization of residency training in certain Chinese medical education institutions, it was discovered that the current evaluation system falls short in accurately assessing residents’ professional skills in clinical practice. Therefore, we developed the list of Entrustable Professional Activities (EPAs) in orthopaedic residency training to explore a new evaluation system.MethodsThe process of constructing EPAs includes seven steps. 40 orthopaedic residents were randomly assigned to two groups (20 in each). The experimental group used the EPAs evaluation system while the control group employed the traditional Mini Clinical Exercise (Mini-CEX) system. Post-residency, theoretical and practical tests were conducted to measure training effectiveness. Additionally, a survey gauged teaching satisfaction, knowledge mastery, and course engagement in both groups.ResultsThe control group scored an average of 76.05 ± 10.58, while the experimental group achieved 83.30 ± 8.69 (p

Energy-absorbing rockbolts have been widely adopted in burst-prone excavation support, and their serviceability is closely related to the frequency and magnitude of seismic events. In this research, the split-tube drop test with varying impact energy was conducted to reproduce the dynamic performance of MP1 rockbolts under a wide range of seismic event magnitudes. The test results showed that the impact process could be subdivided into four distinct stages, i.e. mobilization, strain hardening, plastic flow (ductile), and rebound stage, of which strain hardening and plastic flow are the primary energy absorbing stages. As the impact energy per drop increases from 8.1 to 46.7 kJ, the strain rate of the shank varies between 1.20 and 2.70 s−1, and the average impact load is between 240 and 270 kN, which may be considered as constant. The MP1 rockbolt has a cumulative maximum energy absorption (CMEA) of 31.9–40.0 kJ/m, with an average of 35.0 kJ/m, and the elongation rate is 11.4%–14.7%, with an average of 12.7%, both of which are negatively correlated with the impact energy per drop. Regression analysis shows that energy absorption and shank elongation, as well as momentum input and impact duration, conform to the linear relationship. The complete dynamic capacity envelope of MP1 rockbolts is proposed, which reflects the dynamic bearing capacity, elongation, and distinct stages. This study is helpful to better understand the dynamic characteristics of energy-absorbing rockbolts and assist design engineers in robust reinforcement systems design to mitigate rockburst damage in seismically active underground excavations.

This paper reviews the major achievements in terms of mechanical behaviors of coal measures, mining stress distribution characteristics and ground control in China's deep underground coal mining. The three main aspects of this review are coal measure mechanics, mining disturbance mechanics, and rock support mechanics. Previous studies related to these three topics are reviewed, including the geomechanical properties of coal measures, distribution and evolution characteristics of mining-induced stresses, evolution characteristics of mining-induced structures, and principles and technologies of ground control in both deep roadways and longwall faces. A discussion is made to explain the structural and mechanical properties of coal measures in China's deep coal mining practices, the types and distribution characteristics of in situ stresses in underground coal mines, and the distribution of mining-induced stress that forms under different geological and engineering conditions. The theory of pre-tensioned rock bolting has been proved to be suitable for ground control of deep underground coal roadways. The use of combined ground control technology (e.g. ground support, rock mass modification, and destressing) has been demonstrated to be an effective measure for rock control of deep roadways. The developed hydraulic shields for 1000 m deep ultra-long working face can effectively improve the stability of surrounding rocks and mining efficiency in the longwall face. The ground control challenges in deep underground coal mines in China are discussed, and further research is recommended in terms of theory and technology for ground control in deep roadways and longwall faces.

Abstract Background To assess the geometrical risk factors for meniscal injuries. We hypothesized that the narrowness of the intercondylar notch and the smaller tibial spine could increase the risk of meniscal injuries. Methods We retrospectively studied two hundred and seven patients examined for knee magnetic resonance images. Two experienced orthopedists evaluated the severity of meniscal injuries. The notch width, bicondylar notch width, notch width index, condyle width of the femur, tibial spine height, and intercondylar angle were measured in magnetic resonance image slides by two blinded orthopedists. Results A total of 112 patients with a meniscus injury and 95 patients were as healthy control in all two hundred and seven patients. The NWI (P = 0.027) in patients with meniscus injuries was significantly different from the control group. A 1 SD (0.04 mm) increase in NWI was associated with a 0.4-fold increase in the risk of meniscal injury. A 1 SD (0.04 mm) increase in NWI was associated with a 0.64-fold increase in the risk of grade 3 meniscal injury. Furthermore, NWI and medial spine height are decreased significantly in grade 2 (P

Background: The process of necroptosis mediated by tumor necrosis factor alpha (TNF-α) might play an important role in the onset and development of the osteonecrosis of the femoral head (ONFH). The dysfunctions of bone microvascular endothelial cells (BMECs) have been identified as an important part of pathological processes in the steroid-induced ONFH. An aptamer is a single-stranded DNA or RNA oligonucleotide sequence. Previous studies have designed or screened various aptamers that could bind to specific targets or receptors in order to block their effects. Objective: There are two main objectives in this study: 1) to establish a TNF-α -induced ONFH model in human BMECs in vitro, 2) to verify the effects of the TNF-α aptamer (AptTNF-α) on blocking TNF-α activity in the ONFH model. Methods: Clinical samples were collected for Hematoxylin and Eosin (HE) staining, immunohistochemistry and further BMEC isolation. After cell culture and identification, the cell viability of BMECs after incubation with TNF-α was assessed by Cell Counting Kit-8 (CCK8). The necroptosis of BMECs was detected by the TUNEL and Annexin V-FITC/PI staining. The attenuation of TNF-α cytotoxicity by AptTNF-α was evaluated by CCK8 at first. Then, the molecular mechanism was explored by the quantitative real-time polymerase chain reaction and western blotting. Results: The expression level of TNF-α was significantly up-regulated in bone tissues of ONFH patients. The identification of BMECs was verified by the high expressions of CD31 and vWF. Results from CCK8, TUNEL staining and Annexin V-FITC/PI assay demonstrated reduced cell viability and increased necroptosis of BMECs after TNF-α stimulation. Further investigations showed that TNF-α cytotoxicity could be attenuated by the AptTNF-α in a dose-dependent manner. Necroptosis mediated by TNF-α in the ONFH model was regulated by the receptor-interacting protein kinase 1 (RIPK1)/receptor-interacting protein kinase 3 (RIPK3)/mixed lineage kinase domain-like protein (MLKL) signalling pathway. Conclusion: We established a TNF-α-induced ONFH model in human BMECs in vitro. Our study also demonstrated that the AptTNF-α could protect BMECs from necroptosis by inhibiting the RIP1/RIP3/MLKL signalling pathway.The Translational Potential of this Article: The effective protection from cell necroptosis provided by the DNA aptamer demonstrated its translational potential as a new type of TNF-α inhibitor in clinical treatments for patients with ONFH.

Background: Studies have shown that high-energy focused extracorporeal shock wave therapy (HF-ESWT) has a certain therapeutic effect on glucocorticoid-induced osteonecrosis of the femoral head (ONFH). This study aimed to observe the efficacy and safety of HF-ESWT as a precautionary measure to reduce the probability of glucocorticoid-induced ONFH. Methods: A prospective randomized controlled trial was designed to evaluate whether HF-ESWT (Group A) can significantly prevent the incidence of glucocorticoid-induced ONFH relative to a control group without shockwave intervention (Group B). MRI was used to assess whether all participants experienced ONFH at 3, 6, and 12 months after the intervention. Continuous scoring was used to evaluate the intervention results: the 10-cm visual analog scale (VAS) was used to evaluate pain, and the hip Harris score (HHS) was used to evaluate the function of the hip joint. Any adverse events were recorded. Results: 153 patients (89 females and 64 males) who had been allocated to group A (75 patients) or Group B (78 patients) were included in the final analysis. The patients were 45.0 ​± ​13.0 years old. There were significant differences between the two groups in MRI diagnosis of ONFH patients (2 cases in Group A, 9 cases in Group B; p ​= ​0.034). Significant differences between groups were found in bilateral hip function measured using the HHS at 6 months (Left p ​= ​0.026; Right p ​= ​0.033) and 12 months (Left p ​= ​0.018; Right p ​= ​0.038). However, there was no difference in the functional results measured at 3 months and the VAS at any points. Conclusions: This study confirms that HF-ESWT can be successfully used to reduce the probability of glucocorticoid-induced ONFH. Pain and hip dysfunction are common clinical manifestations when ONFH is unavoidable. Therefore, HF-ESWT can be recommended for the prevention and intervention of ONFH high-risk populations receiving high-dose glucocorticoid therapy. The Translational potential of this article: The effective prevention of HF-ESWT on ONFH after high-dose glucocorticoid application demonstrated its transformation potential as a preventive method in the clinical prevention of glucocorticoid-induced ONFH.

Abstract Accurate estimation of the triaxial compression behavior of jointed coal is essential for coal mining. Few studies addressed the triaxial compression behavior of large-scale rock mass, especially with real joint geometry. We employed a numerical synthetic rock mass (SRM) method to study the triaxial compression behavior of jointed coal. Jointed-coal specimens were constructed based on in-situ joint measurements and microparameter calibration against laboratory experiments. A series of triaxial compression tests under different loading orientations and confining pressures were numerically performed to obtain joint and confining-pressure effects on the triaxial compression behavior and reveal the failure mechanism of jointed coal. Results suggest that the triaxial compression behavior of the jointed coal has strong joint and confining-pressure effects. Joints weaken the strength and elastic modulus, reduce the lateral deformation, and affect the geometries of the shear-rupture surface. An increase in the confining pressure causes the peak and residual strength increase significantly. With an increase in the confining pressure, the elastic modulus increases sharply at low confining pressure, the mechanical behavior transitions from brittleness to ductility, the failure mode transitions from shear-rupture surface to plastic flow, and the joint effect diminishes and even disappears. The jointed coal fails by means of a shear-rupture surface under triaxial compression loading with a confining pressure (which is not too high), and the geometries of the shear-rupture surface vary with the distribution of joints.

Background: Phase-contrast imaging (PCI) with synchrotron hard X-ray was used to observe the changes in bone tissue morphology and microstructure in rabbit models of early glucocorticoid-induced osteonecrosis of the femoral head (ONFH), and to evaluate the intervention effect of Icariin.Methods: Fifty mature New Zealand rabbits (weighing 2.5–3.0 kg) were randomly divided into a control group (n = 10), a glucocorticoid group (n = 20), and an Icariin group (n = 20). The glucocorticoid group and the Icariin group were sequentially injected with lipopolysaccharide (LPS) and methylprednisolone (MPS) to establish a glucocorticoid-induced ONFH animal model. The Icariin group was given Icariin solution when methylprednisolone was injected for the first time, and the control group and glucocorticoid group were given the same amount of normal saline. Animals were sacrificed after 6 weeks, and bilateral femoral head specimens were taken for research. The right femoral head was observed by PCI with synchrotron hard X-ray technology, and the left femoral head was verified by Micro-CT scanning and HE staining.Results: Forty-three animals (nine in the control group, sixteen in the glucocorticoid group, and eighteen in the Icariin group) were included in the study. PCI with synchrotron hard X-ray revealed that the trabecular bone in the glucocorticoid group was thinned, broken, and structurally damaged, whereas the trabecular bone in the Icariin group had normal volume, thickness, and a relatively intact structure. Micro-CT scan reconstruction and HE staining were used to verify the reliability of this technique in identifying osteonecrosis.Conclusion: The effects of Icariin were observed in an early glucocorticoid-induced ONFH rabbit model using PCI with synchrotron hard X-ray. Icariin weakens the destructive effect of glucocorticoids on bone tissue structure, improves bone tissue morphology, and stabilizes bone microstructure. This technique may provide a definitive, non-invasive alternative to histological examination for the diagnosis of early ONFH.

IntroductionThe long-term impact of COVID-19 on brain function remains poorly understood, despite growing concern surrounding post-acute COVID-19 syndrome (PACS). The goal of this cross-sectional, observational study was to determine whether there are significant alterations in resting brain function among non-hospitalized individuals with PACS, compared to symptomatic individuals with non-COVID infection.MethodsData were collected for 51 individuals who tested positive for COVID-19 (mean age 41±12 yrs., 34 female) and 15 controls who had cold and flu-like symptoms but tested negative for COVID-19 (mean age 41±14 yrs., 9 female), with both groups assessed an average of 4-5 months after COVID testing. None of the participants had prior neurologic, psychiatric, or cardiovascular illness. Resting brain function was assessed via functional magnetic resonance imaging (fMRI), and self-reported symptoms were recorded.ResultsIndividuals with COVID-19 had lower temporal and subcortical functional connectivity relative to controls. A greater number of ongoing post-COVID symptoms was also associated with altered functional connectivity between temporal, parietal, occipital and subcortical regions.DiscussionThese results provide preliminary evidence that patterns of functional connectivity distinguish PACS from non-COVID infection and correlate with the severity of clinical outcome, providing novel insights into this highly prevalent disorder.

Background Cerebral small vessel disease is associated with higher ratios of soluble‐epoxide hydrolase derived linoleic acid diols (12,13‐dihydroxyoctadecenoic acid [DiHOME] and 9,10‐DiHOME) to their parent epoxides (12(13)‐epoxyoctadecenoic acid [EpOME] and 9(10)‐EpOME); however, the relationship has not yet been examined in stroke. Methods and Results Participants with mild to moderate small vessel stroke or large vessel stroke were selected based on clinical and imaging criteria. Metabolites were quantified by ultra‐high‐performance liquid chromatography–mass spectrometry. Volumes of stroke, lacunes, white matter hyperintensities, magnetic resonance imaging visible perivascular spaces, and free water diffusion were quantified from structural and diffusion magnetic resonance imaging (3 Tesla). Adjusted linear regression models were used for analysis. Compared with participants with large vessel stroke (n=30), participants with small vessel stroke (n=50) had a higher 12,13‐DiHOME/12(13)‐EpOME ratio (β=0.251, P=0.023). The 12,13‐DiHOME/12(13)‐EpOME ratio was associated with more lacunes (β=0.266, P=0.028) but not with large vessel stroke volumes. Ratios of 12,13‐DiHOME/12(13)‐EpOME and 9,10‐DiHOME/9(10)‐EpOME were associated with greater volumes of white matter hyperintensities (β=0.364, P

Tendinopathy refers to a type of tendon disease with a multifactorial spectrum. Recent research has begun to reveal the effects of inflammation on the tendinopathic process, especially in the first stage of tendinopathy. Radial extracorporeal shock wave therapy (rESWT) has been successfully used to treat orthopedic diseases. However, the molecular mechanisms underlying the anti-inflammatory effects of rESWT on tumor necrosis factor-α treated tenocytes have not been fully elucidated. In this study, we applied total protein tandem mass tag-labeled quantitative proteomics with liquid chromatography-mass spectrometer/mass spectrometer technology to identify differentially expressed proteins (DEPs) among inflammatory tenocytes, rESWT inflammatory tenocytes, and controls using three biological replicates. Human tenocytes were used and they were cultured in vitro. In total, 1028 and 40 DEPs were detected for control versus inflammatory tenocytes and for inflammatory tenocytes versus rESWT inflammatory tenocytes, respectively. Further, we identified integrin α2, selenoprotein S, and NLR family CARD domain-containing protein 4 as pivotal molecular targets of the anti-inflammatory effects of rESWT. This is the first study to provide a reference proteomic map for inflammatory tenocytes and rESWT inflammatory tenocytes. Our findings provide crucial insight into the molecular mechanisms underscoring the anti-inflammatory effects of rESWT in tendinopathy.

Abstract Background Periprosthetic joint infection is a grievous complication after arthroplasty that greatly affects the quality of life of patients. Rapid establishment of infection diagnosis is essential, but great challenges still exist. Methods We conducted research in the PubMed, Embase, and Cochrane databases to evaluate the diagnostic accuracy of D-lactate for PJI. Data extraction and quality assessment were completed independently by two reviewers. The pooled sensitivity, specificity, likelihood ratios, diagnostic odds ratio (DOR), summarized receiver operating characteristic curve (sROC), and area under the sROC curve (AUC) were constructed using the bivariate meta-analysis framework. Results Five eligible studies were included in the quantitative analysis. The pooled sensitivity and specificity of D-lactate for the diagnosis of PJI were 0.82 (95% CI 0.70–0.89) and 0.76 (95% CI 0.69–0.82), respectively. The value of the pooled diagnostic odds ratio (DOR) of D-lactate for PJI was 14.18 (95% CI 6.17–32.58), and the area under the curve (AUC) was 0.84 (95% CI 0.80–0.87). Conclusions According to the results of our meta-analysis, D-lactate is a valuable synovial fluid marker for recognizing PJI, with high sensitivity and specificity.

Abstract Background During a seizure, there is a powerful and forceful contraction of muscles which may lead to fractures or joint dislocations. However, multiple periprosthetic hip fractures and joint dislocations secondary to seizures have not been reported. Case presentation A 49-year-old male developed spontaneous and bilateral multiple periprosthetic hip fractures and joint dislocations (including displaced fracture of the proximal right femur, avulsion fracture of the left lesser trochanter, left acetabular fracture and bilateral joint dislocations) secondary to generalized convulsive seizures which occurred within few hours after bilateral total hip arthroplasties (THAs). Bilateral open reconstruction and fixation were performed on the 21st day after primary THAs and on 2-year follow-up, the patient showed satisfactory functional outcome. Conclusions Multiple periprosthetic hip fractures and joint dislocations secondary to seizure are extremely rare, and treatment targets for these injuries should focus on fracture healing and limb function recovery. Craniocerebral operation could bring an elevated risk of seizure; meanwhile, subsequent corticosteroid replacement threapy was complicated by secondary osteoporosis. Therefore, anti-osteoporotic and anti-epileptic therapy should be considered in this type of patients to avoid fracture and dislocation after arthroplasty.

Abstract Background Bone marrow infiltration (BMI) is a devastating stage of paediatric lymphoma. Prompt diagnosis of BMI in newly diagnosed paediatric lymphoma patients is critical but can be very challenging at present. Methods We systematically retrieved studies from PubMed, EMBASE, and the Cochrane Library. Data extraction and quality assessment were performed by two reviewers independently. A total of nine eligible studies were included in the quantitative analysis. Results The pooled sensitivity and specificity of FDG-PET/CT for diagnosing BMI in newly diagnosed paediatric lymphoma patients were 0.97 (95% confidence interval [CI], 0.93 to 0.99) and 0.99 (95% CI, 0.98 to 0.99), respectively. The pooled PLR, NLR, and DOR were 79.9 (95% CI, 42.7 to 149.6), 0.03 (95% CI, 0.01 to 0.17), and 2414.6 (95% CI, 989.6 to 5891.4), respectively. The AUC of FDG-PET/CT for BMI was 1.00 (95% CI, 0.99 to 1.00). Compared with FDG-PET/CT, BMB had a lower pooled sensitivity (0.44, 95% CI, 0.34 to 0.55) and comparable pooled specificity (1.00, 95% CI, 0.92 to 1.00). Conclusion Compared with BMB, FDG-PET/CT was a more valuable diagnostic method for evaluating BMI in paediatric Hodgkin and non-Hodgkin lymphoma patients with extremely high diagnostic accuracy.

Abstract Background We aimed to compare second-generation patellofemoral arthroplasty (2G PFA) with total knee arthroplasty (TKA) in treating isolated patellofemoral osteoarthritis (PFOA) by assessing the percentages of revisions, complications, and patient-reported outcome measures (PROMs). Methods Studies that compared the outcomes of 2G PFA and TKA in the treatment of isolated PFOA were searched in electronic databases, including MEDLINE, Embase, and Web of Science. Two researchers independently identified eligible studies, extracted the data, and evaluated the quality of the literature. Pooled risk ratios (RRs) or weighted mean differences with 95% confidence intervals were calculated using either fixed or random effects models. Descriptive analysis was used when data could not be pooled. Results A total of six studies were included in the review. For the revision percentage and complications, there were no significant differences between 2G PFA and TKA (RR = 2.29, 95% CI 0.69–7.58, P = 0.17; RR = 0.56, 95% CI 0.23–1.40, P = 0.22, respectively). Second, the results demonstrated that the differences in the Oxford Knee Score (OKS) and the University of California, Los Angeles (UCLA) activity score between 2G PFA and TKA were not significant (WMD −4.68, 95% CI −16.32 to 6.97, p = 0.43; WMD 0.16, 95% CI −1.21 to 1.53, P = 0.82). The Knee Injury and Osteoarthritis Outcome Score (KOOS), the American Knee Society Score (AKSS), and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) were presented in a narrative form due to methodological heterogeneity. Conclusion For isolated PFOA, 2G PFA demonstrated similar results to TKA with respect to the percentages of revisions, complications, and PROMs.

Abstract Objective We aimed to evaluate the safety and efficacy of intra-articular (IA) magnesium (Mg) for postoperative pain relief after arthroscopic knee surgery. Methods We searched PubMed, Embase, Medline, Cochrane library, and Web of Science to identify randomized controlled trials that compared postoperative pain outcomes with or without IA Mg after knee arthroscopy. The primary outcomes were pain intensity at rest and with movement at different postoperative time points and cumulative opioid consumption within 24 h after surgery. Secondary outcomes included the time to first analgesic request and side effects. Results In total, 11 studies involving 677 participants met the eligibility criteria. Pain scores at rest and with movement 2, 4, 12, and 24 h after surgery were significantly lower, doses of supplementary opioid consumption were smaller, and the time to first analgesic requirement was longer in the IA Mg group compared with the control group. No significant difference was detected regarding adverse reactions between the groups. Conclusions Intra-articular magnesium is an effective and safe coadjuvant treatment for relieving postoperative pain intensity after arthroscopic knee surgery. Protocol registration at PROSPERO: CRD42020156403.

The mechanical equation on the mechanical characteristics of rock bolt in rock mass with bedding separation is established, based on the bond slip relationship of anchoring interface by the load transfer method. The validity of the numerical simulation is verified by the analytical solution of mechanical equation, when the bond slip relationship is linear. Further, the nonlinear bond slip relationship of anchoring interface is input into Flac3D by FISH. The mechanical characteristics of rock bolt are studied with the single and multiple bedding separation by numerical simulation. The results show that the axial force and the interfacial shear stress distribution curves on both sides are symmetrically distributed with the single bedding separation in rock mass, when the bedding separation is located in the center of the anchoring segment. When the bedding separation positions are not located in the center of the anchoring segment, the bedding separation value at different positions versus the axial force curves shows a single peak distribution. The axial force of rock bolt is mainly controlled by the side with the shorter anchoring length. Compared with the single bedding separation in rock mass, the additional stress of rock bolt occurred by the multiple bedding separation will superimpose each other. This paper leads to a better understanding for the load transfer mechanism for grouted rock bolt systems in rock mass with bedding separation and provides a reference for scientific support design and evaluation method.

Osteonecrosis of the femoral head (ONFH) is a common clinical disease with a high disability rate. Injury of bone microvascular endothelial cells (BMECs) caused by glucocorticoid administration is one of the important causes of ONFH, and there is currently a lack of effective clinical treatments. Extracellular vesicles derived from bone stem cells (BMSC-EVs) can prevent ONFH by promoting angiogenesis and can inhibit cell apoptosis by regulating autophagy via the PI3K/Akt/mTOR signaling pathway. The present study aimed to investigate the effect of extracellular vesicles derived from bone marrow stem cells (BMSC) on a glucocorticoid-induced injury of BMECs and possible mechanisms. We found that BMSC-EVs attenuated glucocorticoid-induced viability, angiogenesis capacity injury, and the apoptosis of BMECs. BMSC-EVs increased the LC3 level, but decreased p62 (an autophagy protein receptor) expression, suggesting that BMSC-Exos activated autophagy in glucocorticoid-treated BMECs. The protective effects of BMSC-EVs on the glucocorticoid-induced injury of BMECs was mimicked by a known stimulator of autophagy (rapamycin) and could be enhanced by co-treatment with an autophagy inhibitor (LY294002). BMSC-EVs also suppressed the PI3K/Akt/mTOR signaling pathway, which regulates cell autophagy, in glucocorticoid-treated BMECs. In conclusion, the results indicate that BMSC-EVs prevent the glucocorticoid-induced injury of BMECs by regulating autophagy via the PI3K/Akt/mTOR pathway.

Glucocorticoids could induce injury and apoptosis of bone microvascular endothelial cells (BMECs) in the femoral head, which is associated with the development of osteonecrosis and osteoporosis. Icariin is a prenylated flavonol glycoside isolated from Epimedium brevicornum, serving as the main active pharmaceutical constituent to treat bone loss. Currently, the impact of the autocrine activity of extracellular vesicles (EVs) induced by icariin on the glucocorticoid-induced injury of BMECs is still to be confirmed. In this study, EVs were isolated from BMECs treated with and without icariin by super-speed centrifugation. Although icariin treatment would not significantly change the size and total protein content of BMECs-derived EVs, expression of EVs-carried vascular endothelial growth factor (VEGF) and transforming growth factor β1 (TGF-β1) was enhanced and numerous miRNAs involved in cell proliferation and apoptosis were upregulated (e.g., hsa-miR-1469 and hsa-miR-133a-5p) or downregulated (e.g., hsa-miR-10b-5p) (p < 0.05). A total of 29 differentially expressed inflammatory factors were detected between the EVs secreted by BMECs from the Icariin-treated group and the Model group. The EVs secreted by BMECs could improve cell viability, decrease cell apoptosis, and promote cell migration and angiogenesis under the intervention of glucocorticoids. Meanwhile, icariin intervention could reinforce these protective effects of BMECs-derived EVs. To sum up, the present study indicates that icariin acts as a promising candidate for treating glucocorticoid-induced injury of BMECs and bone diseases, partially through the autocrine activity of EVs. In vivo or animal studies are still required to better understand the function of BMECs-derived EVs.

Objectives. The necessity of fibular fixation in distal tibia-fibula fractures remains controversial. This study aimed to assess its impact on radiographic outcomes as well as rates of nonunion and infection. Methods. A systematic search of the electronic databases of PubMed, Embase, and Cochrane library was performed to identify studies comparing the outcomes of reduction and internal fixation of the tibia with or without fibular fixation. Radiographic outcomes included malalignment and malrotation of the tibial shaft. Data regarding varus/valgus angulation, anterior/posterior angulation, internal/external rotation deformity, and the rates of nonunion and infection were extracted and then polled. A meta-analysis was performed using the random-effects model for heterogeneity. Results. Additional fibular fixation was statistically associated with a decreased rate of rotation deformity (OR = 0.13; 95% CI 0.02–0.82, p=0.03). However, there was no difference in the rate of malreduction between the trial group and the control group (OR = 0.86; 95% CI 0.27–2.74, p=0.80). There was also no difference in radiographic outcomes of varus-valgus deformity rate (OR = 0.17; 95% CI 0.03–1.00, p=0.05) or anterior-posterior deformity rate (OR = 0.76; 95% CI 0.02–36.91, p=0.89) between the two groups. Meanwhile, statistical analysis showed no significant difference in the nonunion rate (OR = 0.62; 95% CI 0.37–1.02, p=0.06) or the infection rate (OR = 0.81; 95% CI 0.18–3.67, p=0.78) between the two groups. Conclusions. Additional fibular fixation does not appear to reduce the rate of varus-valgus deformity, anterior-posterior deformity, or malreduction. Meanwhile, it does not appear to impair the union process or increase the odds of infection. However, additional fibular fixation was associated with decreased odds of rotation deformity compared to controls.

BackgroundRegional changes to cortical thickness in individuals with neurodegenerative and cerebrovascular diseases (CVD) can be estimated using specialized neuroimaging software. However, the presence of cerebral small vessel disease, focal atrophy, and cortico-subcortical stroke lesions, pose significant challenges that increase the likelihood of misclassification errors and segmentation failures.PurposeThe main goal of this study was to examine a correction procedure developed for enhancing FreeSurfer’s (FS’s) cortical thickness estimation tool, particularly when applied to the most challenging MRI obtained from participants with chronic stroke and CVD, with varying degrees of neurovascular lesions and brain atrophy.MethodsIn 155 CVD participants enrolled in the Ontario Neurodegenerative Disease Research Initiative (ONDRI), FS outputs were compared between a fully automated, unmodified procedure and a corrected procedure that accounted for potential sources of error due to atrophy and neurovascular lesions. Quality control (QC) measures were obtained from both procedures. Association between cortical thickness and global cognitive status as assessed by the Montreal Cognitive Assessment (MoCA) score was also investigated from both procedures.ResultsCorrected procedures increased “Acceptable” QC ratings from 18 to 76% for the cortical ribbon and from 38 to 92% for tissue segmentation. Corrected procedures reduced “Fail” ratings from 11 to 0% for the cortical ribbon and 62 to 8% for tissue segmentation. FS-based segmentation of T1-weighted white matter hypointensities were significantly greater in the corrected procedure (5.8 mL vs. 15.9 mL, p < 0.001). The unmodified procedure yielded no significant associations with global cognitive status, whereas the corrected procedure yielded positive associations between MoCA total score and clusters of cortical thickness in the left superior parietal (p = 0.018) and left insula (p = 0.04) regions. Further analyses with the corrected cortical thickness results and MoCA subscores showed a positive association between left superior parietal cortical thickness and Attention (p < 0.001).ConclusionThese findings suggest that correction procedures which account for brain atrophy and neurovascular lesions can significantly improve FS’s segmentation results and reduce failure rates, thus maximizing power by preventing the loss of our important study participants. Future work will examine relationships between cortical thickness, cerebral small vessel disease, and cognitive dysfunction due to neurodegenerative disease in the ONDRI study.

The Ontario Neurodegenerative Research Initiative (ONDRI) is a 3 years multi-site prospective cohort study that has acquired comprehensive multiple assessment platform data, including 3T structural MRI, from neurodegenerative patients with Alzheimer's disease, mild cognitive impairment, Parkinson's disease, amyotrophic lateral sclerosis, frontotemporal dementia, and cerebrovascular disease. This heterogeneous cross-section of patients with complex neurodegenerative and neurovascular pathologies pose significant challenges for standard neuroimaging tools. To effectively quantify regional measures of normal and pathological brain tissue volumes, the ONDRI neuroimaging platform implemented a semi-automated MRI processing pipeline that was able to address many of the challenges resulting from this heterogeneity. The purpose of this paper is to serve as a reference and conceptual overview of the comprehensive neuroimaging pipeline used to generate regional brain tissue volumes and neurovascular marker data that will be made publicly available online.

Background. Hip fractures of elderly patients are a public health problem worldwide, mostly lying in bed for a long time; therefore, the importance of life quality in such patients is an issue beyond question. Orem’s self-care model is a nursing pattern which is introduced with the purpose of improving the self-care ability of individuals, especially the patients suffering from diseases with limits on activity. Objective. The aim of this study was to determine the effects of Orem’s self-care program on life quality of senile patients with hip fractures. Methods. A randomized clinical trial study was conducted on 130 eligible old patients suffering from hip fractures who were selected using easy sampling methods and allocated randomly into two groups of experiment and control. The data were collected through validated questionnaires including visual analogue scale (VAS) and Barthel index for them. The experiment group was treated according to Orem’s self-care model, and the control group was treated on the basis of the traditional care model. The data of complications including pneumonia, deep venous thrombosis, urinary infection, wound problem, and bedsore were also gathered. Results. As revealed, mean scores of VAS and Barthel index one week after operation in the experiment group were significantly different from the control one (P

Objective. The purpose of this meta-analysis was to determine whether platelet-rich plasma (PRP) was better than hyaluronic acid (HA) for the treatment of knee osteoarthritis (OA) in overweight or obese patients. Design. Two reviewers independently used the keywords combined with free words to search English-based electronic databases according to Cochrane Collaboration guidelines, such as PubMed, Embase, ScienceDirect, and Cochrane library. The pooled data were analyzed using RevMan 5.3. Results. Ten randomized controlled trials (RCTs) with 1096 patients were included. During the first two months of follow-up, there was no significant difference between the two groups. At the 3rd, 6th, and 12th months of follow-up, the pooled analysis showed that PRP was better than HA for the treatment of knee OA in overweight or obese patients. There were significant differences between the two groups at Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) total score (3 months: MD = −1.35, [95% CI: −2.19 to −0.50], P=0.002, I2 = 0%; 6 months: MD = −7.62, [95% CI: −13.51 to −1.72], P=0.01, I2 = 88%; 12 months: MD = −12.11, [95% CI: −20.21 to −4.01], P=0.003, I2 = 94%). Conclusions. For overweight or obese patients with knee OA, intra-articular injection of PRP in a short time was not necessarily superior to HA, but long-term use was better than HA in pain and functional relief.

Abstract Multiple treatment strategies have been developed for osteochondral lesions (OCLs) of the talus. The purpose of this retrospective study was to assess retrograde autologous bone marrow cell (BMC) transplantation via core drilling (CD) combined with focused extracorporeal shock wave treatment (ESWT) in undisplaced OCL of the talus. A total of 69 patients with unilateral osteochondral lesions of the talus (Hepple grade I–III) were divided into two groups: 41 patients received combined therapy of ESWT and BMC transplantation (group A), while 28 were administered BMC transplantation alone (group B). The patients were followed up clinically and radiographically for a minimum of 2 years. Mean follow-up was 4.1 ± 2.8 years. AOFAS scores increased more significantly while pain intensity levels decreased in group A after treatment, compared with group B values (P

Background. Patients with lumbar disc herniation (LDH) may present with motor disorders and various sensory disorders, among which pain and numbness are the most common ones. Percutaneous endoscopic lumbar discectomy (PELD) is reported to be both safe and effective. However, most of the previous studies focused on the recovery of pain, and the relief extent of numbness and weakness has rarely been reported. The Sciatica Bothersomeness Index (SBI) is a self-assessment tool for LDH patients. It has demonstrated acceptable reliability, construct validity, and responsiveness. Objectives. Our aim was to explore the curative effect of percutaneous endoscopic lumbar discectomy and to compare the various extent of relief among pain, numbness, and weakness. Methods. The medical records of patients admitted for LDH from September 2016 to December 2018 were collected, and the patients were followed up for 3 months to evaluate the relief of their clinical symptoms. Preoperative and postoperative total scores and subitem scores of SBI were compared to evaluate the relief of pain, numbness, and weakness. Surgical outcomes of PELD were evaluated by the Nakai score, and patients were divided into two groups accordingly, which were the relief group (excellent and good in the Nakai score) and the less relief group (fair and poor in the Nakai score). Risk factors for PELD outcomes and preoperative presence of numbness and/or weakness were analyzed by the logistic model, and p value less than 0.05 was considered significant. Results. A total of 86 patients met the inclusion criteria and acquired 3 months follow-up. Relief extent of pain, numbness, and weakness, was 82%, 41%, and 21%, respectively. There were 71 cases in the relief group and 15 cases in the less relief group. Results of the logistic regression analysis showed that the preoperative pain score of SBI (p=0.002; OR: 1.647 (1.199–2.261)) was a relatively independent risk factor for PELD outcomes, and multiplicativity of duration of preoperative symptoms and imaging grade [p=0.004; OR: 1.015 (1.005–1.026)] was a relatively independent risk factor for preoperative presence of numbness and/or weakness. Conclusions. PELD had a good curative effect in the treatment of LDH. Patients of LDH recovered best from pain, followed by numbness and weakness after PELD. Higher level of patients self-reported preoperative pain indicated a better surgical outcome for LDH patients, and preoperative long duration of symptoms together with a severe compression of nerve root significantly increased the risk of presenting numbness and/or weakness.

BACKGROUND:Musculoskeletal ultrasound is widely used in diagnosing gout, but its accuracy is debatable. We conducted a systematic review and meta-analysis to quantitatively evaluate the value of ultrasound in the diagnosis of gout. METHODS:We systematically searched for publications using Cochrane Library, PubMed/Medline and Embase and manually screened the references of eligible articles for additional relevant publications. Studies were included in this systematic review if they assessed the diagnostic accuracy of ultrasound in gout compared to that of the gold standard, demonstration of monosodium urate crystals in joint fluid or tophi. We then conducted quantitative analyses by extracting data from each study and calculating the pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR) and diagnostic odds ratio (DOR). The summary receiver operating characteristic curves (sROCs) were constructed to obtain the Q*-index and the area under the curve (AUC). RESULTS:Thirteen studies were included in this meta-analysis. The diagnostic performances of three distinctive ultrasonographic features of gout, double contour sign (DCS), the presence of tophi and the snowstorm sign, were evaluated. For person-based evaluations, the pooled sensitivity, specificity, DOR, AUC and Q* were as follows: for the DCS, 66% (95% confidence interval (CI) 62%-69%), 92% (95% CI 90%-94%), 25.91 (95% CI 11.80-56.89), 0.8163 and 0.7503, respectively; for the presence of tophi, 56% (95% CI 52%-60%), 94% (95% CI 92%-96%), 21.11 (95% CI 7.84-56.89), 0.8928 and 0.8236, respectively; for the snowstorm sign, 31% (95% CI 27%-36%), 91% (95% CI 88%-93%), 4.54(95% CI 3.13-6.58), 0.5946 and 0.5712, respectively; and for simultaneous consideration of these ultrasonographic features, 80% (95% CI 76%-83%), 83% (95% CI 79%-86%), 19.03 (95% CI 13.97-25.93), 0.889 and 0.8197, respectively. For the joint-/location-based evaluations, the pooled sensitivity, specificity, DOR, AUC and Q* were as follows: for the DCS, 75% (95% CI 68%-80%), 65% (95% CI 59%-70%), 16.90 (95% CI 5.10-56.03), 0.871 and 0.8014, respectively; and for the presence of tophi, 48% (95% CI 40%-57%), 96% (95% CI 91%-99%), 30.20 (95% CI 9.23-98.87), 0.8776 and 0.8081, respectively. CONCLUSIONS:In this meta-analysis, relatively high specificity but modest or low sensitivity were demonstrated in the diagnosis of gout using each of the three ultrasonographic features for person-based evaluations. Simultaneous consideration of these ultrasound findings may improve the diagnostic sensitivity. However, the double contour sign alone is weak in the differentiation of gout and non-gout for joint-/location-based evaluations. Further well-designed studies are still needed to support the current findings.

Because both faults and cleats exist in coal, sharp stress drops occur during loading when coal is deformed. These drops occur during the pre-peak stage and are accompanied by sudden energy releases. After a stress drop, the stress climbs slowly following a zigzag path and the energy accumulated during the pre-peak stage is unstable. A stress−strain curve is the basic tool used to evaluate the bursting liability of coal. Based on energy accumulation in an unsteady state, the pre-peak stress−strain curve is divided into three stages: pre-extreme, stress drop, and re-rising stage. The energy evolution of the specimen during each stage is analyzed. In this paper, an index called the effective elastic strain energy release rate (EESERR) index is proposed and used to evaluate the coal’s bursting liability. The paper shows that the propagation and coalescence of cracks is accompanied by energy release. The stress climb following a zigzag path prolongs the plastic deformation stage. This causes a significant difference between the work done by a hydraulic press during a laboratory uniaxial compression experiment and the elastic strain energy stored in the specimen during the experiment, so the evaluation result of the burst energy index would be too high. The determination of bursting liability is a comprehensive evaluation of the elastic strain energy accumulated in coal that is released when the specimen is damaged. The index proposed in this paper fully integrates the energy evolution of coal samples being damaged by loading, the amount of elastic strain energy released during the sample failure divided by the failure time is the energy release rate. The calculation method is simplified so that the uniaxial compressive strength and elastic modulus are included which makes the new index more universal and comprehensive. Theoretical analysis and physical compression experiments validate the reliability of the evaluation.

AIMS:This study aimed to analyze the clinical factors related to the failure of bone grafting through a window at the femoral head-neck junction. METHODS:In total, 119 patients (158 hips) underwent bone grafting for treatment of avascular necrosis of the femoral head. The patients were classified by their ARCO staging and CJFH classification. All patients were clinically and radiographically followed up every three months during the first year and every six months in the following year. The clinical follow-up comprised determination of pre- and postoperative Harris hip scores, while serial AP, frog lateral radiographs, and CT scan were used for the radiographic follow-up. RESULTS:The clinical failure of bone grafting was observed in 40 patients. The clinical failure rates in patients belonging to ARCO stage II period, IIIa, and III (b + c) were 25.9%, 16.2%, and 61.5%, respectively, while those in patients belonging to (C + M + L1) type and L2, L3 type disease groups were 1.7%, 38.9%, and 39%, respectively. The clinical failure rates in patients aged below 40 and those aged 40 and over were 20.5% and 39.0%, respectively (all P < 0.05). CONCLUSION:Disease type, disease stage, and patient age are risk factors for failure of bone graft surgery. Patients belonging to ARCO stage II and IIIa showed a good overall response rate, while patients belonging to ARCO stage IIIb and IIIc and those with necrotic lesions involving the lateral pillar (L2 and L3 type) showed high surgical failure rates.

[This corrects the article DOI: 10.1371/journal.pone.0156903.].

The purpose of this study was to compare the clinical outcomes of impacted bone graft with or without recombinant human bone morphogenetic protein-2 (rhBMP-2) for osteonecrosis of the femoral head (ONFH). We examined the effect of bone-grafting through a window at the femoral head-neck junction, known as the "light bulb" approach, for the treatment of ONFH with a combination of artificial bone (Novobone) mixed with or without rhBMP-2. A total of 42 patients (72 hips) were followed-up from 5 to 7.67 years (average of 6.1 years). The patients with and without BMP were the first group (IBG+rhBMP-2) and the second group (IBG), respectively. The clinical effectiveness was evaluated by Harris hip score (HHS). The radiographic follow-up was evaluated by pre-and postoperative X-ray and CT scan. Excellent, good, and fair functions were obtained in 36, 12, and 7 hips, respectively. The survival rate was 81.8% and 71.8% in the first and second group, respectively. However, the survival rate was 90.3% in ARCO stage IIb, c, and only 34.6% in ARCO stage IIIa (P