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Medium-term mortality after hip fractures and COVID-19:A prospective multicentre UK study

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Chinese Journal of Traumatology 2022年第3期25卷 161-165页

作者： Gareth Chan Ashish Narang Arash Aframian Zaid Ali Joseph Bridgeman Alastair Carr Laura Chapman Henry Goodier Catrin Morgan Chang Park Sarah Sexton Kapil Sugand thomas walton Michael Wilson Ajay Belgaumkar Kieran Gallagher Koushik Ghosh Charles Gibbons Joshua Jacob Andrew Keightley Zuhair Nawaz Khaled Sarraf Christopher Wakeling William Kieffer Benedict Rogers Brighton&Sussex University Hospitals NHS Trust Brighton&Sussex Medical SchoolFainter CampusBrighton UK Surrey&Sussex Healthcare NHS Trust Canada&venueRedhillUK Chelsea&Westminster Hospital NHS Foundation Trust LondonUK Ashford&St frier's Hospital NHS Foundation TrustChertseyUK Western Sussex Hospitals NHS Foundation Trust(Sr Richard's Hospital)ChichesterUK Poole General Hospital&the Royal Bournemouth Hospital froleUK Imperial College Healthcare NHS Trust LondonUK Western Sussex Hospitals NHS Foundation Trust(Worthing Hospital) WorthingUK Royal Surrey Hospital NHS Foundation Trust GuildfordUK Frimley Health NHS Foundation Trust FrimleyUK

Purpose:The COVID-19 pandemic has caused 1.4 million deaths globally and is associated with a 3-4 times increase in 30-day mortality after a fragility hip fracture with concurrent COVID-19 ***,death from COVID-19 infection occurs between 15 and 22 days after the onset of symptoms,but this period can extend up to 8 *** study aimed to assess the impact of concurrent COVID-19 infection on 120-day mortality after a fragility hip ***:A multi-centre prospective study across 10 hospitals treating 8%of the annual burden of hip fractures in England between 1st March and 30th April,2020 was *** whose surgical treatment was payable through the National Health Service Best Practice Tariff mechanism for"fragility hip fractures"were included in the ***'120-day mortality was assessed relative to their perioperative COVID-19 *** analysis was performed using SPSS version ***:A total of 746 patients were included in this study,of which 87(11.7%)were COVID-19 *** rates at 30-and 120-day were significantly higher for COVID-19 positive patients relative to COVID-19 negative patients(p<0.001).However,mortality rates between 31 and 120-day were not significantly different(p=0.107),16.1%and 9.4%respectively for COVID-19 positive and negative patients,odds ratio 1.855(95%CI 0.865-3.978).Conclusion:Hip fracture patients with concurrent COVID-19 infection,provided that they are alive at day-31 after injury,have no significant difference in 120-day *** the growing awareness and concern of "long-COVID"and its widespread prevalence,this does not appear to increase mediumterm mortality rates after a hip fracture.

关键词： Hip fractures Femoral fractures COVID-19 Coronavirus Mortality

Tuning beneficial calcineurin phosphatase activation to counterα-synuclein toxicity in a yeast model of Parkinson’s disease

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Neural Regeneration Research 2025年第1期20卷 199-200页

作者： Srishti Chawla Mikael Molin thomas Nystrom Institute for Biomedicine Sahlgrenska AcademyCentre for Ageing and Health-AgeCapUniversity of GothenburgGothenburgSweden Department of Life Sciences Chalmers University of TechnologyGothenburgSweden

Calcineurin(CN)is a calcium-and calmodulindependent serine/threonine that has been studied in many model organisms including yeast,filamentous fungi,plants,and *** biological functions range from ion homeostasis and virulence in lower eukaryotes to T-cell activation in humans by human nuclear factors of activated *** is a heterodimeric protein consisting of a catalytic subunit,calcineurin A(Cna1p),which contains an active site with a dinuclear metal center,and a regulatory Ca^(2+) binding subunit called calcineurin B(Cnb1p)required to activate *** calcineurin B subunit has been highly conserved through evolution:For example,the mammalian calcineurin B shows 54%identity with calcineurin B from Saccharomyces cerevisiae.

关键词： activation dinuclear conserved

Microglia:a promising therapeutic target in spinal cord injury

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Neural Regeneration Research 2025年第2期20卷 454-463页

作者： Xiaowei Zha Guoli Zheng thomas Skutella Karl Kiening Andreas Unterberg Alexander Younsi Department of Neurosurgery Heidelberg University HospitalHeidelbergGermany Department of Neuroanatomy Institute for Anatomy and Cell BiologyHeidelberg UniversityHeidelbergGermany

Microglia are present throughout the central nervous system and are vital in neural repair,nutrition,phagocytosis,immunological regulation,and maintaining neuronal *** a healthy spinal cord,microglia are accountable for immune surveillance,however,when a spinal cord injury occurs,the microenvironment drastically changes,leading to glial scars and failed axonal *** this context,microglia vary their gene and protein expression during activation,and proliferation in reaction to the injury,influencing injury responses both favorably and unfavorably.A dynamic and multifaceted injury response is mediated by microglia,which interact directly with neurons,astrocytes,oligodendrocytes,and neural stem/progenitor *** a clear understanding of their essential nature and origin,the mechanisms of action and new functions of microglia in spinal cord injury require extensive *** review summarizes current studies on microglial genesis,physiological function,and pathological state,highlights their crucial roles in spinal cord injury,and proposes microglia as a therapeutic target.

关键词： astrocytes cytokines functional recovery immune regulation M1/M2 activation macrophages microglia neuroinflammation spinal cord injury therapy

A case study on the efficacy of different roof bolting schemes in Lhoist North America’s Crab Orchard Mine

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International Journal of Mining Science and Technology 2020年第1期30卷 99-104页

作者： Reece Kurre Gabriel walton Stantec Consulting Services Inc. Walnut CreekCA 94597USA Department of Geology and Geological Engineering Colorado School of MinesGoldenCO 80401USA

Roof bolting has long been used in underground mines across the world to provide ground *** roof bolts are cheap and easy to install with the use of specialized machines as a part of the production cycle. Lhoist North America’s Crab Orchard Mine is an underground room and pillar limestone mine that uses mechanically anchored roof bolts for ground support. The mine currently employs two different roof bolting patterns: a standard 1.5 × 1.5 m pattern, and another 0.8 × 0.8 m pattern for use in areas with particularly hazardous roof conditions. The purpose of this study is to evaluate the relative effectiveness of each bolting pattern. A series of numerical models were created using Roc Science’s RS2. The models were based on a symmetrical section of the mine at its deepest point, and were modeled using generalized Hoek-Brown failure criterion along with a discrete fracture network. A series of sensitivity analyses were performed on the models by varying parameters such as joint friction angle, crack persistence, joint randomization, and tensile strength of the limestone. Based on the results of the original models and sensitivity analyses, it appeared that the standard bolting pattern provided sufficient roof support capacity under almost all the expected conditions at the mine, since safety factors below the design value of 1.5 were only found for individual bolts in a few of the worst test cases *** results can help improve the mine’s productivity and reduce operating costs without compromising safety.

关键词： Numerical modeling Mining Roof bolting Roof stability Analysis RocScience’s RS2 Underground stone

Sleep as a window to understand and regulate Alzheimer's disease:emerging roles of thalamic reticular nucleus

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Neural Regeneration Research 2025年第6期20卷 1711-1712页

作者： Haoqi Sun Shiqian Shen Robert J.thomas M.Brandon Westover Can Zhang Department of Neurology Beth Israel Deaconess Medical CenterHarvard Medical SchoolBostonMAUSA Center for Translational Pain Research Department of AnesthesiaCritical Care and Pain MedicineMassachusetis General HospitalHarvard Medical SchoolBostonMAUSA Division of Pulmonary Critical Care and Sleep MedicineDepartment of MedicineBeth Israel Deaconess Medical CenterHarvard Medical SchoolBostonMAUSA Genetics and Aging Research Unit McCance Center for Brain HealthMass General Institute for Neurodegenerative DiseaseDepartment of NeurologyMassachusetts General HospitalHarvard Medical SchoolBostonMAUSA

Introduction:Alzheimer 's disease(AD) is a common neurodegenerative disorder and the primary cause of dementia. Considerable evidence supports the “amyloid hypothesis,” stating that the pathogenesis of AD is primarily caused by the deposition of amyloid-β(Aβ), which drives tau phosphorylation, neuroinflammation, and neurodegeneration in the brain. The amyloid hypothesis is strengthened by the significant and moderate benefit of lecanemab, a humanized antibody through an anti-amyloid mechanism,showing slowed clinical decline(van Dyck et al.,2023). The recent positive results of anti-amyloid trials have brought back focus on the amyloid hypothesis through biochemical, genetic, and pharmacological approaches(Zhang, 2023).

关键词： Alzheimer inflammation hypothesis

Challenges associated with numerical back analysis in rock mechanics

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Journal of Rock Mechanics and Geotechnical Engineering 2022年第6期14卷 2058-2071页

作者： Gabriel walton Sankhaneel Sinha Department of Geology and Geological Engineering Colorado School of MinesGoldenCO80401USA

Numerical back analysis is a valuable tool available to rock mechanics researchers and *** studies related to back analysis methods focused primarily on applications of increasingly sophisticated optimization algorithms(primarily machine learning algorithms)to rock mechanics *** methods have typically been applied to relatively simple problems;however,more complex back analyses continue to be conducted primarily through ad hoc manual trial-and-error *** paper provides a review of the basic concepts and recent developments in the field of numerical back analysis for rock mechanics,as well as some discussion of the relationship between back analysis and more broadly established frameworks for numerical *** challenges of flexible constraints,non-uniqueness,material model limitations,and disparate data sources are considered,and representative case studies are presented to illustrate their impacts on back *** role of back analysis(or“model calibration”)in bonded particle modelling(BPM),bonded block modelling(BBM),and synthetic rock mass(SRM)modelling is also considered,and suggestions are made for further studies on this topic.

关键词： Back analysis Numerical modelling Inversion Case studies

Modeling behaviors of a coal pillar rib using the progressive S-shaped yield criterion

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Journal of Rock Mechanics and Geotechnical Engineering 2020年第3期12卷 484-492页

作者： Sankhaneel Sinha Gabriel walton Colorado School of Mines GoldenCO80401USA

Spalling of pillar ribs has been a major hazard in the mining industry for *** the absence of rib support guidelines,accidents have continued to occur in recent *** effective support guidelines requires a complete understanding of complex pillar damage *** models represent a convenient tool for analyzing this problem,but the behavior of such models is dependent of the choice of the constitutive *** this study,a recently proposed constitutive model was used to simulate the rib fracturing process in a longwall chain pillar at West Cliff *** calibration,the model was able to capture the rib displacement profiles for multiple locations of the longwall face and the stress evolution 4 m into the *** rib bolts in the model were found to be yielding over 60% of their length under the headgate loading *** model also predicted a steady damage accumulation in the rib for certain face locations,which is consistent with the description of the rib at the *** was localized along the upper part of the pillar and underscored the role that the dirt band played in controlling rib deterioration at the *** ability of the numerical model to replicate field measurements provides confidence in the capabilities of the new constitutive ***,the need of using multi-point calibration is highlighted by comparing the results of the calibrated model to an alternative model calibrated to a smaller amount of data.

关键词： S-shaped yield criterion Coal pillar Back-analysis Numerical modeling

Integration of three-dimensional continuum model and two-dimensional bonded block model for studying the damage process in a granite pillar at the Creighton Mine,Sudbury,Canada

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Journal of Rock Mechanics and Geotechnical Engineering 2021年第2期13卷 275-288页

作者： Sankhaneel Sinha Gabriel walton Geology and Geological Engineering Colorado School of MinesGoldenCO80401USA

Bonded blockmodel(BBM)has shownpotential in replicating rockmass behavior aswell as the rockesupport interactionmechanism,but their practical application is limited totwo dimensions due to the high associated computational *** allow for the use of BBM in simulating three-dimensional(3D)problems,this study proposes an integrated 3D continuumetwo-dimensional(2D)discontinuum approach,in context of rock pillars.A cross-section of a granite pillar was simulated using a BBM with a load path from a calibrated mine-scale FLAC^(3D)*** support as employed in the mine was also incorporated in different stages during the *** was calibrated by varying the input parameters until the displacements at six locations within the pillarmatchedthosemeasuredby amulti-point borehole extensometer(MPBX)inthe *** calibratedmodel was subsequently used to understand how the support and load path influenced the damage evolution in the *** shear component of the load pathwas found to have amajor effect on the severity and extent of the damaged *** the support density was increased in the model,the lateral displacements along the pillar walls were significantly suppressed in a somewhat unpredictable *** explained by the interaction between the supports and the damaged regions at the corners,which ultimately modified the stresses along the pillar *** amount of displacement reduction obtained by increasing the support density illustrates the potential of BBMto be used as a support design tool.

关键词： Bonded block model(BBM) Rock pillars Supports Continuum-discontinuum integration

Understanding roof deformation mechanics and parametric sensitivities of coal mine entries using the discrete element method

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International Journal of Mining Science and Technology 2020年第1期30卷 123-129页

作者： Rami Abousleiman Gabriel walton Sankhaneel Sinha Department of Geology and Geological Engineering Colorado School of MinesGoldenCO 80218USA

Although conventional coal mine designs are conservative regarding pillar strength,local failures such as roof-falls and pillar bursts still affect mine safety and *** studies have identified that discontinuous,layered roof materials have some self-supporting *** research is a preliminary step towards understanding these mechanics in coal-measure *** others have considered broad conceptual models and simplified analogs for mine roof behavior,this study presents a unique numerical model that more completely represents in-situ roof *** discrete element method(DEM)is utilized to conduct a parametric analysis considering a range of in-situ stress ratios,material properties,and joint networks to determine the parameters controlling the stability of single-entries modeled in *** results are compared to empirical observations of roof-support effectiveness(ARBS)in the context of the coal mine roof rating(CMRR)*** such as immediate roof displacement,overall stability,and statistical relationships between model parameters and outcomes are presented *** practical applications of this line of research include:(1)roof-support optimization for a range of coal-measure rocks,(2)establishment of a relationship between roof stability and pillar stress,and(3)determination of which parameters are most critical to roof stability and therefore require concentrated evaluation.

关键词： Numerical modeling Discrete element method Coal mine roof rating Analysis of roof bolt systems Sensitivity analysis Strain softening ubiquitous joints Discrete fracture network