Fear of COVID-19, intolerance of uncertainty, psychological capital, and positive future expectations: Tests of mediating relationships with healthcare workers.

COVID-19 has a profound impact on the mental health of healthcare workers, especially those combatting the disease. The current study examined the mediating role of psychological capital in the relationship between fear of COVID-19 and intolerance of uncertainty and positive future expectations in healthcare workers during the pandemic. 310 healthcare workers (51.9 % males, Mage = 34.2 ± 7.6) completed measures of fear of COVID-19, psychological capital, intolerance of uncertainty, and positive future expectations The results showed that fear of COVID-19 had a significant negative predictive impact on psychological capital and a significant positive predictive impact on intolerance of uncertainty. Psychological capital had a significant negative predictive impact on intolerance of uncertainty and a significant positive predictive impact on positive future expectations. Most importantly, the results indicated that psychological capital mediated the association of fear of COVID-19 with intolerance of uncertainty and positive future expectations. The results improve our understanding of the role of psychological capital in the relationship between fear of COVID-19 and intolerance of uncertainty and positive future expectations. Also, results have possible wider implications for equipping healthcare workers with the psychological tools to cope with stressors, including those linked to public health threats such as pandemics.

Hip Abductor Weakness and Its Association With New or Worsened Knee Pain: Data From the Multicenter Osteoarthritis Study.

OBJECTIVE: Hip abductors, important for controlling pelvic and femoral orientation during gait, may affect knee pain. Our objective was to evaluate the relation of hip abductor strength to worsened or new-onset frequent knee pain. Given previously noted associations of knee extensor strength with osteoarthritis in women, we performed sex-specific analyses. METHODS: We used data from the Multicenter Osteoarthritis study. Hip abductor and knee extensor strength was measured. Knee pain was assessed using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) questionnaire and a question about frequent knee pain at baseline (144-month visit), and 8, 16, and 24 months thereafter. Knee pain outcomes were worsened knee pain (2-point increase in WOMAC pain) and incident frequent knee pain (answering yes to the frequent knee pain question among those without frequent knee pain at baseline). Leg-specific analyses tested hip abductor strength as a risk factor for worsened and new frequent knee pain, adjusting for potential covariates. Additionally, we stratified by knee extensor strength (high versus low). RESULTS: Among women, compared to the highest quartile of hip abductor strength, the lowest quartile had 1.7 (95% confidence interval [95% CI] 1.1-2.6) times the odds of worsened knee pain; significant associations were limited to women with high knee extensor strength (odds ratio 2.0 [95% CI 1.1-3.5]). We found no relation of abductor strength to worsening knee pain in men or with incident frequent knee pain in men or women. CONCLUSION: Hip abductor weakness was associated with worsening knee pain in women with strong knee extensors, but not with incident frequent knee pain in men or women. Knee extensor strength may be necessary, but not sufficient, to prevent pain worsening.

Uncovering the social determinants of brain injury rehabilitation.

Social determinants of health (SDH), such as social isolation and loneliness, are often more frequently experienced in brain injury survivors. The paper explores the personal experiences of loneliness among brain injury survivors during lockdown to negate health inequalities and improve rehabilitation for this population in the future. Twenty-four brain injury survivors participated in semi-structured interviews and questionnaires relating to loneliness, resilience and wellbeing. Three themes (the experience of loneliness, loneliness during the pandemic and loneliness after the pandemic) explored survivors' experiences of loneliness generally post-brain injury, but also chronicle how these feelings developed in lockdown and survivors' feelings regarding society returning to 'normal'. Future interventions should focus on reframing survivors' beliefs regarding societal expectations and minimise the pressure they experience to keep up with their peers physically and emotionally. Additionally, we recommend creating accessible peer support options for all brain injury survivors as an important step for alleviating loneliness.

Changes in Walking Biomechanics after a 30-Min Exercise Bout in Sedentary Compared with Active Young Women.

INTRODUCTION: Patellofemoral pain (PFP) is a common overuse injury associated with physical activity, including walking. The risk for PFP may increase if walking biomechanics change during a bout of walking. Because walking for exercise is often recommended to previously sedentary adults, this would be a cause for concern. The purpose of this study was to determine any differences in walking biomechanics associated with PFP between sedentary and active young women initially and after 30 min of walking for exercise. METHODS: Fifteen sedentary and 15 active young women walked overground for five trials of three-dimensional gait analysis before and after a 30-min treadmill walk. Peak knee flexion angle and extensor moment were compared between groups and before and after the 30-min walk. RESULTS: Comparing groups at baseline, peak knee flexion angle and peak knee extensor moment were not statistically significantly different between groups. After the 30-min walk, peak knee flexion angle and extensor moment increased slightly in both groups. CONCLUSIONS: Smaller, not larger, peak knee flexion angle and extensor moment during walking have been associated with increased risk of PFP. Therefore, sedentary and active young women can walk for 30 min without further detrimental changes to walking biomechanics that may increase their risk of PFP.

Exposure to dialect variation in an artificial language prior to literacy training impairs reading of words with competing variants but does not affect decoding skills.

Many bidialectal children grow up speaking a variety (e.g., a regional dialect) that differs from the variety in which they subsequently acquire literacy. Previous computational simulations and artificial literacy learning experiments with adults have demonstrated lower accuracy in reading contrastive words for which dialect variants exist compared with noncontrastive words without dialect variants. At the same time, exposure to multiple varieties did not affect learners' ability to phonologically decode untrained words; in fact, longer literacy training resulted in a benefit from dialect exposure as competing variants in the input may have increased reliance on grapheme-phoneme conversion. However, these previous experiments interleaved word learning and reading/spelling training, yet children typically acquire substantial oral language knowledge prior to literacy training. Here we used artificial literacy learning with adults to examine whether the previous findings replicate in an ecologically more valid procedure where word learning precedes literacy training. We also manipulated training conditions to explore interventions thought to be beneficial for literacy acquisition, such as providing explicit social cues for variety use and literacy training in both varieties. Our findings replicated the reduced accuracy for reading contrastive words in those learners who had successfully acquired the dialect variants prior to literacy training. This effect was exacerbated when literacy training also included dialect variation. Crucially, although no benefits from the interventions were found, dialect exposure did not affect reading and spelling of untrained words suggesting that phonological decoding skills can remain unaffected by the existence of multiple word form variants in a learner's lexicon. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Athletes after anterior cruciate ligament reconstruction demonstrate asymmetric intracortical facilitation early after surgery.

Quadriceps dysfunction persists after anterior cruciate ligament reconstruction (ACLR), yet the etiology remains elusive. Inhibitory and facilitatory intracortical networks (ie, intracortical excitability) may be involved in quadriceps dysfunction, yet the investigation of these networks early after ACLR is sparse. The purposes of this study were to examine (a) changes in intracortical excitability in athletes after ACLR compared to uninjured athletes during the course of postoperative rehabilitation, (b) the association between intracortical excitability and quadriceps strength in athletes after ACLR. Eighteen level I/II athletes after ACLR between the ages of 18 to 30 years and eighteen healthy sex, age, and activity matched athletes were tested at three-time points: (a) 2 weeks after surgery, (b) achievement of a "quiet knee" defined as full range of motion and minimal effusion, (c) return to running time point defined as achievement of a quadriceps index ≥80% and at least 12 weeks post-ACLR. Short-interval intracortical inhibition (SICI) and intracortical facilitation (ICF), measured via transcranial magnetic stimulation and isometric quadriceps strength were examined bilaterally at each time point. There was a significant group × limb interaction (P = .017) for ICF. The ACLR group demonstrated asymmetric ICF (greater in the nonsurgical limb) compared to controls and a significant relationship between SICI and quadriceps strength of the surgical limb at the quiet knee time point (P = .018). ACLR individuals demonstrate differential effects on ICF between limbs. Also, SICI is associated with isometric quadriceps strength after ACLR, suggesting increased inhibition of the motor cortex may contribute to impaired quadriceps strength following ACLR.

Examination of Corticospinal and Spinal Reflexive Excitability During the Course of Postoperative Rehabilitation After Anterior Cruciate Ligament Reconstruction.

OBJECTIVE: To investigate corticospinal and spinal reflexive excitability and quadriceps strength in healthy athletes and athletes after anterior cruciate ligament reconstruction (ACLR) over the course of rehabilitation. DESIGN: Prospective cohort study. METHODS: Eighteen athletes with ACLR and 18 healthy athletes, matched by sex, age, and activity, were tested at (1) 2 weeks after surgery, (2) the "quiet knee" time point, defined as full range of motion and minimal effusion, and (3) return to running, defined as achieving a quadriceps index of 80% or greater. We measured (1) corticospinal excitability, using resting motor threshold (RMT) and motor-evoked potential amplitude at a stimulator intensity of 120% of RMT (MEP120) to the vastus medialis, (2) spinal reflexive excitability, calculating the ratio of the maximal Hoffmann reflex to the maximal M-wave to the vastus medialis, and (3) isometric quadriceps strength. RESULTS: The ACLR group had higher RMTs in the nonsurgical limb and higher MEP120 in the surgical limb at all time points. The healthy-athlete group did not have interlimb differences. The RMT was positively associated with quadriceps strength 2 weeks after surgery; MEP120 was associated with quadriceps strength at all time points. CONCLUSION: Compared to healthy athletes, athletes after ACLR had altered corticospinal excitability that did not change from 2 weeks after surgery to the time of return to running. J Orthop Sports Phys Ther 2020;50(9):516-522. Epub 1 Aug 2020. doi:10.2519/jospt.2020.9329.

How does dialect exposure affect learning to read and spell? An artificial orthography study.

Correlational studies have demonstrated detrimental effects of exposure to a mismatch between a nonstandard dialect at home and a mainstream variety at school on children's literacy skills. However, dialect exposure often is confounded with reduced home literacy, negative teacher expectation, and more limited educational opportunities. To provide proof of concept for a possible causal relationship between variety mismatch and literacy skills, we taught adult learners to read and spell an artificial language with or without dialect variants using an artificial orthography. In 3 experiments, we confirmed earlier findings that reading is more error-prone for contrastive words; that is, words for which different variants exist in the input, especially when learners also acquire the joint meanings of these competing variants. Despite this contrastive deficit, no detriment from variety mismatch emerged for reading and spelling of untrained words, a task equivalent to nonword reading tests routinely administered to young schoolchildren. With longer training, we even found a benefit from variety mismatch on reading and spelling of untrained words. We suggest that such a dialect benefit in literacy learning can arise when competition between different variants leads learners to favor phonologically mediated decoding. Our findings should help to assuage educators' concerns about detrimental effects of linguistic diversity. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Lower Quadriceps Rate of Force Development Is Associated With Worsening Physical Function in Adults With or at Risk for Knee Osteoarthritis: 36-Month Follow-Up Data From the Osteoarthritis Initiative.

OBJECTIVE: To determine the association between quadriceps rate of force development (RFD) and decline in self-reported physical function and objective measures of physical performance. DESIGN: Longitudinal cohort study. SETTING: Community-based sample from 4 urban areas. PARTICIPANTS: Osteoarthritis Initiative participants with or at risk for knee osteoarthritis, who had no history of knee/hip replacement, knee injury, or rheumatoid arthritis (N=2630). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Quadriceps RFD (N/s) was measured during isometric strength testing. Worsening physical function was defined as the minimal clinically important difference for worsening self-reported Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) physical function subscale score, 20-m walk time, and repeated chair stand time over 36 months. RESULTS: Compared with the slowest tertile of RFD, the fastest tertile had a lower risk for worsening of WOMAC physical function subscale score at 36-month follow-up, with an odds ratio (OR) of .68 (95% confidence interval [CI], .51-.92) after adjustment for age, sex, body mass index, depression, history of chronic diseases, and knee pain. In women, in comparison with the slowest tertile of RFD, the fastest tertile had a lower risk for worsening of WOMAC physical function subscale score at 36-month follow-up, with an adjusted OR of .57 (95% CI, .38-.86). This decreased risk did not reach statistical significance in men (OR, 0.81; 95% CI, 0.52-1.27). No statistically significant associations were detected between baseline RFD and walk or chair stand times. CONCLUSIONS: Our results indicate that higher RFD is associated with decreased risk for worsening self-reported physical function but not with decreased risk for worsening of physical performance.

Knee Extensor Rate of Torque Development Before and After Arthroscopic Partial Meniscectomy, With Analysis of Neuromuscular Mechanisms.

Study Design Descriptive, prospective single-cohort longitudinal study. Background Though rapid torque development is essential in activities of daily living and sports, it hasn't been specifically tested by most physical therapists or incorporated into rehabilitation programs until late in the treatment process. Little evidence is available on quadriceps torque development capacity before and after arthroscopic knee surgery. Objectives To study knee extensor rate of torque development, contributing mechanisms, and associations with strength and patient-reported outcomes before and during the first 6 weeks after arthroscopic partial meniscectomy. Methods Twenty subjects (mean ± SD age, 42.3 ± 13.7 years; body mass index, 26.6 ± 3.1 kg/m2) were tested before surgery, and at 2 and 5 weeks after surgery. Quadriceps muscle volume, strength, activation, rate of torque development, and patient-reported outcomes were evaluated across the study period. Results Significant side-to-side differences in quadriceps strength and voluntary rate of torque development were observed at each time point (P<.05). Changes in muscle activity were associated with changes in rapid torque development capacity. Side-to-side rate of torque development deficits after surgery were associated with lower patient-reported outcomes scores. Conclusion Diminished rapid torque development capacity is common in arthroscopic meniscal debridement patients. This reduced capacity is associated with an inability to quickly recruit and drive the quadriceps muscles (neural mechanisms) and not muscle atrophy or other peripheral factors tested. Patient-reported outcomes are associated with quadriceps rate of torque development, but not strength or muscle size. Rapid torque development warrants greater attention in rehabilitation. J Orthop Sports Phys Ther 2017;47(12):945-956. Epub 9 Oct 2017. doi:10.2519/jospt.2017.7310.

Chronic Granulomatous Disease Presenting as Aspergillus Fumigatus Pneumonia in a Previously Healthy Young Woman.

BACKGROUND Chronic Granulomatous Disease (CGD) is a rare immunodeficiency disease caused by a genetic defect in the NADPH (nicotinamide adenine dinucleotide phosphate) oxidase enzyme, resulting in increased susceptibility to bacterial and fungal infections. The inheritance can be X-linked or autosomal recessive. Patients usually present with repeated infections early in life. We present an unusual case of a 23-year-old patient diagnosed with CGD. CASE REPORT A 23-year-old white woman with no previous history of recurrent infections presented with complaints of fever, shortness of breath, and diffuse myalgia. She had been treated twice for similar complaints recently, but without resolution. She was febrile, tachypneic, tachycardic, and hypoxic at presentation. Physical examination revealed diffuse inspiratory rales. Laboratory results showed leukocytosis. Her initial chest X-ray and CT chest showed reticular nodular interstitial lung disease pattern. Despite being on broad-spectrum antibiotics for 5 days, she continued to require supplemental oxygen and continued to be tachypneic, with minimal activity. Initial diagnostic tests, including bronchoscopy with biopsy and lavage, did not reveal a diagnosis. She then underwent a video-assisted thoracoscopic surgery (VATS) lung biopsy. The biopsy slides showed suppurative granulomatous inflammation affecting greater than 50% of the parenchymal lung surface. Fungal hyphae consistent with Aspergillus were present in those granulomas. A diagnosis of CGD was made and she was started on Voriconazole. She improved with treatment. Her neutrophil burst test showed negative burst on stimulation, indicating phagocytic dysfunction consistent with CGD. Autosomal recessive CGD was confirmed by genetic testing. CONCLUSIONS CGD can present in adulthood without any previous symptoms and signs. Clinicians should consider this disease in patients presenting with recurrent or non-resolving infections. Timely treatment and prophylaxis has been shown to reduce serious infections as well as mortality in these patients.

Anterior Cruciate Ligament Reconstruction Rehabilitation: MOON Guidelines.

CONTEXT: Anterior cruciate ligament (ACL) reconstruction rehabilitation has evolved over the past 20 years. This evolution has been driven by a variety of level 1 and level 2 studies. EVIDENCE ACQUISITION: The MOON Group is a collection of orthopaedic surgeons who have developed a prospective longitudinal cohort of the ACL reconstruction patients. To standardize the management of these patients, we developed, in conjunction with our physical therapy committee, an evidence-based rehabilitation guideline. STUDY DESIGN: Clinical review. LEVEL OF EVIDENCE: Level 2. RESULTS: This review was based on 2 systematic reviews of level 1 and level 2 studies. Recently, the guideline was updated by a new review. Continuous passive motion did not improve ultimate motion. Early weightbearing decreases patellofemoral pain. Postoperative rehabilitative bracing did not improve swelling, pain range of motion, or safety. Open chain quadriceps activity can begin at 6 weeks. CONCLUSION: High-level evidence exists to determine appropriate ACL rehabilitation guidelines. Utilizing this protocol follows the best available evidence.

Leader-Member Exchange across two hierarchical levels of leadership: concurrent influences on work characteristics and employee psychological health.

Leader-Member Exchange (LMX) theory suggests that the quality of the leader-employee relationship is linked to employee psychological health. Leaders who reside at different hierarchical levels have unique roles and spheres of influence and potentially affect employees' work experiences in different ways. Nevertheless, research on the impact of leadership on employee psychological health has largely viewed leaders as a homogeneous group. Expanding on LMX theory, we argue that (1) LMX sourced at the levels of the line manager (LM) and senior management (SM) team will be differentially linked to employee psychological health (assessed as worn-out) and that (2) these relationships will be mediated by perceived work characteristics (reward and recognition, workload management, quality of relationships with colleagues and physical environment). Structural equation modelling on data from 337 manual workers partially supported the hypotheses. Perceptions of the physical environment mediated the relationship between LMX at the LM level and employee psychological health, whereas perceptions of workload management mediated the relationship between LMX at the SM level and psychological health. These findings corroborate arguments that leaders are not a uniform group and as such the effects of LMX on employees will depend on leadership hierarchy. Implications for expanding leadership theory are discussed.

Efficacy of blood flow-restricted, low-load resistance training in women with risk factors for symptomatic knee osteoarthritis.

OBJECTIVE: To assess whether concurrent blood flow restriction (BFR) during low-load resistance training is an efficacious and tolerable means of improving quadriceps strength and volume in women with risk factors for symptomatic knee osteoarthritis (OA). DESIGN: Randomized, double-blinded, controlled trial. SETTING: Exercise training clinical research laboratory. PARTICIPANTS: Women over age 45 years with risk factors for symptomatic knee OA. METHODS: Participants were randomized to either low-load resistance training (30% 1RM) alone (control) or with concurrent BFR and completed 4 weeks of 3 times per week leg-press resistance training. Those randomized to BFR wore a cuff that progressively restricted femoral blood flow over the weeks of training. Intergroup differences in outcome measures were compared using regression methods, while adjusting for BMI. MAIN OUTCOME MEASURES: Isotonic bilateral leg press strength, isokinetic knee extensor strength, and quadriceps volume by magnetic resonance imaging were assessed before and after participation. Secondary measures included lower limb muscle power (leg press and stair climb). Knee pain was assessed to determine tolerance. RESULTS: Of 45 women who consented to study participation, 40 completed the program. There were no significant intergroup differences in baseline characteristics except that body mass index was lower in the BFR group (P = .0223). Isotonic 1RM improved significantly more in the BFR group (28.3 ± 4.8 kg) than in the control group (15.6 ± 4.5 kg) (P = .0385). Isokinetic knee extensor strength scaled to body mass increased significantly more in the BFR group (0.07 ± 0.03 nm/kg) than in the control group (-0.05 ± 0.03 nm/kg) (P = .0048). Changes in quadriceps volume, leg press power, and knee-related pain did not significantly differ between groups. CONCLUSIONS: Addition of BFR to a 30% 1RM resistance training program was effective in increasing leg press and knee extensor strength in women at risk for knee OA, in comparison with the same program without BFR.

Solid-state NMR analysis of a complex crystalline phase of ronacaleret hydrochloride.

A crystalline phase of the pharmaceutical compound ronacaleret hydrochloride is studied by solid-state nuclear magnetic resonance (SSNMR) spectroscopy and single-crystal X-ray diffraction. The crystal structure is determined to contain two independent cationic molecules and chloride anions in the asymmetric unit, which combine with the covalent structure of the molecule to yield complex SSNMR spectra. Experimental approaches based on dipolar correlation, chemical shift tensor analysis, and quadrupolar interaction analysis are employed to obtain detailed information about this phase. Density functional theory (DFT) calculations are used to predict chemical shielding and electric field gradient (EFG) parameters for comparison with experiment. (1)H SSNMR experiments performed at 16.4 T using magic-angle spinning (MAS) and homonuclear dipolar decoupling provide information about hydrogen bonding and molecular connectivity that can be related to the crystal structure. (19)F and (13)C assignments for the Z' = 2 structure are obtained using DFT calculations, (19)F homonuclear dipolar correlation, and (13)C-(19)F heteronuclear dipolar correlation experiments. (35)Cl MAS experiments at 16.4 T observe two chlorine sites that are assigned using calculated chemical shielding and EFG parameters. SSNMR dipolar correlation experiments are used to extract (1)H-(13)C, (1)H-(15)N, (1)H-(19)F, (13)C-(19)F, and (1)H-(35)Cl through-space connectivity information for many positions of interest. The results allow for the evaluation of the performance of a suite of SSNMR experiments and computational approaches as applied to a complex but typical pharmaceutical solid phase.

Effect of knee joint angle on side-to-side strength ratios.

Isometric knee extensor and flexor strength are typically tested at different joint angles due to the differences in length-tension relationships of the quadriceps and hamstring muscles. The efficiency of strength testing can be improved if the same angle can be used to test both the knee extensor and flexor muscle groups. The aim of this study was to determine an optimal angle for isometric knee strength testing by examining the effect of knee angle on side-to-side peak torque ratios. Eighteen active young people (9 males and 9 females) participated in this study. Knee extensor and knee flexor strength were tested on both sides at 30°, 60°, and 90° of knee flexion. The effect of knee flexion angle on side-to-side peak torque ratios, raw torque values, and side-to-side flexor-to-extensor torque ratios were assessed. Side-to-side knee extensor peak torque ratios and knee flexor-to-extensor torque ratios differed significantly by knee flexion angle (p = 0.024 and p = 0.011, respectively), but side-to-side knee flexor peak torque ratios did not differ significantly (p = 0.311). When considering both side-to-side peak torque ratios and flexor-to-extensor torque ratios, the values were more symmetrical (i.e., closer to 100%) only at 60° of knee flexion. Our results indicate that both the knee flexors and the knee extensors can be tested clinically at 60° of knee flexion. Our results also indicate that the hamstrings can be tested at any of the 3 angles if the examiner is interested in side-to-side ratios rather than raw torque values. These results may facilitate more efficient and flexible clinical knee strength testing.

Solid-state NMR analysis of a boron-containing pharmaceutical hydrochloride salt.

A novel crystalline form of the boron-containing antibacterial drug (S)-3-(aminomethyl)-7-(3-hydroxypropoxy)benzo[c] [1,2]oxaborol-1(3H)-ol hydrochloride is studied by solid-state nuclear magnetic resonance (SSNMR) and single-crystal X-ray diffraction techniques. After determination of the crystal structure by X-ray diffraction, SSNMR spectroscopy of this form is performed to obtain structural information using experimental approaches based on dipolar correlation, chemical shift analysis, and quadrupolar interaction analysis. 1H SSNMR experiments at 16.4 T using magic-angle spinning (MAS) and homonuclear dipolar decoupling, 2D SSNMR experiments based on (1)H­(13)C and (1)H­(11)B dipolar heteronuclear correlation, and density functional theory (DFT) calculations are combined in a novel approach to obtain a nearly complete assignment of the (1)H spectrum of this crystalline phase. (11)B and (35)Cl chemical shift and quadrupolar parameters are obtained using the analysis of MAS spectra and are found to be accurately reproduced using DFT calculations. NMR chemical shielding and electric field gradient parameters obtained using these methods are related to hydrogen-bonding trends in the crystal structure. The results illustrate the increasing capability of SSNMR techniques involving (1)H, (11)B, and (35)Cl SSNMR in the analysis of the crystal structure of a pharmaceutical compound containing covalently bonded boron.

Comparison of T1ρ, dGEMRIC, and quantitative T2 MRI in preoperative ACL rupture patients.

RATIONALE AND OBJECTIVES: T1ρ, inversion recovery sequence with a gadolinium contrast agent (dGEMRIC), and T2 mapping have shown sensitivity toward different osteoarthritic-associated compositional changes after joint injury, but have not been studied concomitantly in vivo. We hypothesized that these magnetic resonance imaging sequences can be used to measure early glycosaminoglycan (GAG) losses and collagen disruption in cartilage of anterior cruciate ligament (ACL) rupture patients. MATERIALS AND METHODS: Thirteen acute ACL rupture patients were each imaged during a 4-hour presurgery workup to acquire a fast-spin-echo-based T1ρ sequence, a multi-echo spin-echo T2 sequence, and T1-weighted dGEMRIC an average of 55.7 days after injury. After acquisition, the three sequences' relaxation times were analytically compared. RESULTS: Site-specific differences were evinced, but nonsignificant differences in mean relaxation time between layers of the same region and sequence were observed (analysis of variance, P < .05). Spearman's correlation coefficients of 0.542 (T1ρ vs. T2, P < .05), -0.026 (T1ρ vs. dGEMRIC, P = .585) and -0.095 (T2 vs. dGEMRIC, P < .05) were found. CONCLUSION: No appreciable focal GAG loss was detected by dGEMRIC, and T2 was generally elevated in the early acute phase of blunt trauma injury. In contrast, both general and focal elevations in T1ρ relaxation times were identified, indicating an acute increase in unbound water in the matrix after blunt trauma, and show that patient-specific cartilage changes occur within otherwise healthy, young patients. Further investigation into each sequence's long-term significance is warranted to help clinicians decide which sequence(s) will be the most useful for osteoarthritis prognosis given the challenge of concomitantly acquiring all three in a busy clinical setting.

Video game characteristics, happiness and flow as predictors of addiction among video game players: A pilot study.

AIMS: Video games provide opportunities for positive psychological experiences such as flow-like phenomena during play and general happiness that could be associated with gaming achievements. However, research has shown that specific features of game play may be associated with problematic behaviour associated with addiction-like experiences. The study was aimed at analysing whether certain structural characteristics of video games, flow, and global happiness could be predictive of video game addiction. METHOD: A total of 110 video game players were surveyed about a game they had recently played by using a 24-item checklist of structural characteristics, an adapted Flow State Scale, the Oxford Happiness Questionnaire, and the Game Addiction Scale. RESULTS: The study revealed decreases in general happiness had the strongest role in predicting increases in gaming addiction. One of the nine factors of the flow experience was a significant predictor of gaming addiction - perceptions of time being altered during play. The structural characteristic that significantly predicted addiction was its social element with increased sociability being associated with higher levels of addictive-like experiences. Overall, the structural characteristics of video games, elements of the flow experience, and general happiness accounted for 49.2% of the total variance in Game Addiction Scale levels. CONCLUSIONS: Implications for interventions are discussed, particularly with regard to making players more aware of time passing and in capitalising on benefits of social features of video game play to guard against addictive-like tendencies among video game players.

Analysis of a nanocrystalline polymer dispersion of ebselen using solid-state NMR, Raman microscopy, and powder X-ray diffraction.

PURPOSE: Nanocrystalline drug-polymer dispersions are of significant interest in pharmaceutical delivery. The purpose of this work is to demonstrate the applicability of methods based on two-dimensional (2D) and multinuclear solid-state NMR (SSNMR) to a novel nanocrystalline pharmaceutical dispersion of ebselen with polyvinylpyrrolidone-vinyl acetate (PVP-VA), after initial characterization with other techniques. METHODS: A nanocrystalline dispersion of ebselen with PVP-VA was prepared and characterized by powder X-ray diffraction (PXRD), confocal Raman microscopy and mapping, and differential scanning calorimetry (DSC), and then subjected to detailed 1D and 2D SSNMR analysis involving ¹H, ¹³C, and 77Se isotopes and ¹H spin diffusion. RESULTS: PXRD was used to show that dispersion contains nanocrystalline ebselen in the 35-60 nm size range. Confocal Raman microscopy and spectral mapping were able to detect regions where short-range interactions may occur between ebselen and PVP-VA. Spin diffusion effects were analyzed using 2D SSNMR experiments and are able to directly detect interactions between ebselen and the surrounding PVP-VA. CONCLUSIONS: The methods used here, particularly the 2D SSNMR methods based on spin diffusion, provided detailed structural information about a nanocrystalline polymer dispersion of ebselen, and should be useful in other studies of these types of materials.