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ObjectiveTo examine the associations of knee injury, radiographic osteoarthritis severity, and quadriceps strength with knee pain exacerbation during walking.DesignWithin-person knee-matched case-control study.MethodsParticipants from the Osteoarthritis Initiative who completed a 20-m walking test at the 24-month visit were included. Pain exacerbation was defined as an increase in pain intensity of 1 or more on a numeric rating scale (0 as no pain and 10 as the worst imaginable pain) while completing the 20-m walking test. We used conditional logistic regression to assess the relation of recent knee injury, Kellgren-Lawrence (KL) grade, and quadriceps strength to unilateral knee pain exacerbation during walking.ResultsWe included 277 people who experienced unilateral knee pain exacerbation during the walking test. Recent knee injury was associated with pain exacerbation during walking, with an odds ratio of 3.4 (95% confidence interval [CI]: 1.3, 9.2). Compared with knees with a KL grade of 0, the odds ratios of pain exacerbation during walking were 1.3 (95% CI: 0.7, 2.7), 3.3 (95% CI: 1.5, 7.1), and 8.1 (95% CI: 3.1, 21.1) for knees with KL grades of 2, 3, and 4, respectively. Painful knees with a deficit in quadriceps strength of greater than or equal to 4% had a 1.4-fold (95% CI: 1.0, 1.9) higher risk of pain exacerbation during walking than their pain-free counterparts.ConclusionRecent knee injury, more severe radiographic osteoarthritis, and lower quadriceps strength were associated with an increased risk of knee pain exacerbation during walking. J Orthop Sports Phys Ther 2021;51(6):298-304. Epub 10 May 2021. doi:10.2519/jospt.2021.9735.

BackgroundOsteoarthritis (OA) is a chronic joint disease, with increasing global burden of disability and healthcare utilisation. Recent meta-analyses have shown a range of effects of OA on mortality, reflecting different OA definitions and study methods. We seek to overcome limitations introduced when using aggregate results by gathering individual participant-level data (IPD) from international observational studies and standardising methods to determine the association of knee OA with mortality in the general population.MethodsSeven community-based cohorts were identified containing knee OA-related pain, radiographs, and time-to-mortality, six of which were available for analysis. A two-stage IPD meta-analysis framework was applied: (1) Cox proportional hazard models assessed time-to-mortality of participants with radiographic OA (ROA), OA-related pain (POA), and a combination of pain and ROA (PROA) against pain and ROA-free participants; (2) hazard ratios (HR) were then pooled using the Hartung-Knapp modification for random-effects meta-analysis.Findings10,723 participants in six cohorts from four countries were included in the analyses. Multivariable models (adjusting for age, sex, race, BMI, smoking, alcohol consumption, cardiovascular disease, and diabetes) showed a pooled HR, compared to pain and ROA-free participants, of 1.03 (0.83, 1.28) for ROA, 1.35 (1.12, 1.63) for POA, and 1.37 (1.22, 1.54) for PROA.DiscussionParticipants with POA or PROA had a 35-37% increased association with reduced time-to-mortality, independent of confounders. ROA showed no association with mortality, suggesting that OA-related knee pain may be driving the association with time-to-mortality.FundingVersus Arthritis Centre for Sport, Exercise and Osteoarthritis and Osteoarthritis Research Society International.

BackgroundTo assess the association of co-existing MRI lesions with knee pain at rest or on joint loading.MethodsWe included participants from Osteoarthritis Initiative whose pain score, measured by WOMAC sub-scales, differed by ≥1 point at rest (in bed at night, sitting/lying down) or on joint loading (walking, stairs) between two knees. Cartilage morphology, bone marrow lesions, meniscus extrusion, meniscus morphology, Hoffa's synovitis and synovitis-effusion were assessed using the compartment-specific MRI Osteoarthritis Knee Score. We performed latent class analyses to identify subgroups of co-existing MRI lesions and fitted a conditional logistic regression model to examine their associations with knee pain.ResultsAmong 130 eligible participants, we identified five subgroups of knees according to patterns of co-existing MRI lesions: I. minimal lesions; II. mild lesions; III. moderate morphological lesions; IV. moderate multiple reactive lesions; and V. severe lesions. Compared with subgroup I, the odds ratios (ORs) and 95% confidence intervals (CI) of greater pain in bed at night were 1.6 (0.3, 7.2), 2.2 (0.5, 9.5), 6.2 (1.3, 29.6) and 11.2 (2.1, 59.2) for subgroups II-V, respectively. A similar association was observed between aforementioned subgroups and pain with sitting/lying down. The ORs (95% CI) of greater pain with walking were 1.0 (reference), 1.7 (0.5, 6.1), 0.7 (0.2, 2.3), 5.0 (1.4, 18.6) and 7.9 (2.0, 31.5) for subgroup I-V, respectively. The corresponding analysis for pain on stairs showed similar results.ConclusionsDistinct patterns of co-existing MRI lesions have different implications for the pathogenesis of osteoarthritic knee pain occurring with/without joint loading.

This paper investigates the premium of ambiguous central bank communication with diversified policy stances on the cross-sectional asset prices. Distinguishing different inclinations (dovish, neutral and hawkish) in the communications of the People's Bank of China (PBC) governors through a field-specific lexicon approach, we construct the ambiguous communication index (ACI) based on the textual methodology. We find that ambiguous communication makes it difficult to predict policy stance and increases policy uncertainty, thus the ACI earns a significant negative premium in the cross-section of asset pricing. This paper contributes to the literature on policy uncertainty by proposing a new supplementary perspective, a feasible measure and empirical evidence of ambiguous communication. Furthermore, this contribution extends to the literature on policy communication by distinguishing the statistically and economically significant premium linked to ambiguous communication. [ABSTRACT FROM AUTHOR]

The closed pores play a critical role in improving the sodium storage capacity of hard carbon (HC) anode, however, their formation mechanism as well as the efficient modulation strategy at molecular level in the polymer‐derived HCs is still lacking. In this work, the steric hindrance effect has been proposed to create closed pores in the polymer‐derived HCs for the first time through grafting the aromatic rings within and between the main chains in the precursor. The experimental data and theoretical calculation demonstrate that steric‐hindrance effect from the aromatic ring side group can increase backbone rigidity and the internal free volumes in the polymer precursor, which can prevent the over graphitization and facilitate the formation of closed pores during the carbonization process. As a result, the as‐prepared HC anode exhibits a remarkably enhanced discharge capacity of 340.3 mAh/g at 0.1 C, improved rate performance (210.7 mAh/g at 5 C) as well as boosted cycling stability (86.4 % over 1000 cycles at 2 C). This work provides a new insight into the formation mechanisms of closed pores via steric hindrance engineering, which can shed light on the development of high‐performance polymer‐derived HC anode for sodium‐ion batteries. [ABSTRACT FROM AUTHOR]

AimTo evaluate whether knee alignment explains the higher prevalence of lateral compartment tibiofemoral radiographic osteoarthritis (TFROA) among rural Chinese compared with that among Whites.MethodsThe Wuchuan OA Study is a population-based longitudinal study of risk factors for knee OA. At baseline 1030 participants had home interviews, clinical examinations and weight-bearing posteroanterior semi-flexed radiographs of the tibiofemoral joints. Anatomic knee alignment was measured using an e-film workstation and divided into three categories: normal (182°-184°), valgus (> 184°), and varus (< 182°) alignment. A knee was defined as having medial or lateral compartmental ROA if its Kellgren and Lawrence grade was ≥ 2 and joint space narrowing ≥ 1 in the medial or lateral compartment, respectively. We examined the association between knee alignment with prevalent medial or lateral knee ROA separately using multiple logistic regression.ResultsAmong 1030 participants, the proportions of knees with normal, valgus and varus alignment were 29.9%, 56.5% and 13.7%, respectively. The prevalence of medial and lateral ROA was 16.0% and 4.3%, respectively. Valgus alignment was associated with prevalence of lateral compartment ROA (odds ratio [OR] = 5.0, 95% CI: 2.4-10.5), while varus alignment was associated with medial compartment ROA (OR = 6.1, 95% CI: 4.4-8.6). The ratio of prevalence of lateral versus medial compartment TFROA was greater in Wuchuan than that in the Framingham OA Study and valgus malalignment was more common in Wuchuan than in the Rotterdam study.ConclusionsThe prevalence of compartment-specific TFROA differs between rural Chinese and Whites. This difference is likely due to relatively high prevalence of valgus malalignment in rural Chinese compared with that in Whites.

The weak correlation between pain and structural changes in knee osteoarthritis is widely reported. In a previous within-person, knee-matched case-control study among Caucasians, the severity of radiographic osteoarthritis (ROA) was strongly associated with both the presence of frequent knee pain and pain severity. We studied the association between ROA and knee pain in five racial/ethnic populations by using the same method. Subjects were selected from China; Japan; Korea and the United States. Among subjects with knees discordant for either frequent knee pain or pain severity, we examined the relationship between ROA and the presence of frequent knee pain using conditional logistic regression, and between ROA and pain severity using a stratified proportional odds model with an amalgamating conditional likelihood. In total, 252 urban Chinese, 221 rural Chinese, 297 Japanese, 122 Korean, 1,735 Caucasian, and 394 African-American patients were included. There was a strong dose-response relationship between the severity of ROA and the prevalence of frequent knee pain in all five racial/ethnic populations. Even mild ROA was significantly associated with frequent knee pain. In addition, ROA was also strongly associated with the severity of knee pain. These results show that structural pathology is associated with knee pain in different ethnic populations.

Geological environment is a resource base, environmental base, and engineering base for human socioeconomic activities. The main function of the geological environment is to provide stable and safe living space and essential resources for the existence and development of human society. However, geological environmental problems become increasingly prominent in some provinces in China due to fragility of the geological environment, uneven population distribution, backward economic development, and massive construction projects. The function of geological environments in some provinces to support sustainable economic and social development is evidently insufficient, and the threshold values of their geological environmental bearing capacity nearly reach the upper limit. For example, Henan Province, China, an evaluation index system for geological environmental bearing capacity, was established from three aspects, as follows: natural hazard, geological disaster, and disaster control. The weights of evaluation indexes were calculated using the variation coefficient method. Finally, the geological environmental bearing capacity of Henan Province during 2010-2018 was measured through the comprehensive evaluation method. Results showed that the constructed evaluation index system for geological environmental bearing capacity, which consisted of 34 indexes, was scientific and reasonable. During 2010-2018, the geological environmental bearing capacity of Henan Province was superior or excellent. Geological environmental bearing capacity can be improved by reinforcing the construction of legal rules and laws for geological environmental protection, carrying out research work regarding geological environmental bearing capacity, launching geological environmental monitoring and early warning system construction, and implementing feasibility demonstration for the geological environment of major construction projects. The study results can provide practical guidance and reference to realize the predictive analysis of geological environmental bearing capacity and coordinate human socioeconomic activities and geological environment.