Comparative investigation of methods for determining the lateral stiffness of coupled RC shears walls

In this study, the lateral stiffness of coupled RC shear walls is studied using the continuum method, equivalent frame and finite element methods. For this purpose, asix-story coupled shear walls with typical dimensions are considered and the lateral displacements of system are calculated under a variety of lateral loads such as: uniform, triangular distributed and concentrated loads, then the results are compared with together. The results show that under the rectangular and concentrated loadings, equivalent frame and continuum indicate more displacements compared finite element approach; therefore, these methods approximate less lateral stiffness for coupled RC shear walls. In addition, equivalent frame technique in most cases, except triangular loading, compared with continuous medium method determines more soft behavior for the structure.Keywords: 1-Coupled RC shear wall 2-Lateral stiffness 3-Equivalent frame 4-Continuum method 5-finite elemen

Characterization of radio active aerosols in Tehran research reactor containment

The objectives of this research were to determine the levels of radioactivity in the Tehran research reactor containment and to investigate the mass-size distribution, composition, and concentration of radio nuclides during operation of the reactor. A cascade impactor sampler was used to determine the size-activity distributions of radioactive aerosols in each of the sampling stations. Levels of α and β activities were determined based on a counting method using a liquid scintillation counter and smear tests. The total average mass fractions of fine particles (particle diameter dp <1 µm) in all of the sampling stations were approximately 26.75 , with the mean and standard deviation of 52.15 ± 19.75 µg/m3. The total average mass fractions of coarse particles were approximately 73.2, with the mean and standard deviation of 71.34 ± 24.57 µg/m3. In addition to natural radionuclides, artificial radionuclides, such as 24Na,91Sr,131I,133I,103Ru,82Br, and 140La, may be released into the reactor containment structure. Maximum activity was associated with accumulation-mode particles with diameters less than 400 nm. The results obtained from liquid scintillation counting suggested that the mean specific activity of alpha particles in fine and coarse-modes were 89.7 and 10.26 , respectively. The mean specific activity of beta particles in fine and coarse-modes were 81.15 and 18.51 , respectively. A large fraction ofthe radionuclides' mass concentration in the Tehran research reactor containment was associated with coarse-mode particles, in addition, a large fraction of the activity in the aerosol particles was associated with accumulation-mode particles. © 2015, Vinca Inst Nuclear Sci. All rights reserved

Pedicle subtraction osteotomy with patient-specific instruments

Background Although the utility of patient-specific instruments (PSI) has been well established for complex osteotomies in orthopedic surgery, it is yet to be comparatively analyzed for complex spinal deformity correction, such as pedicle subtraction osteotomy (PSO). Methods Six thoracolumbar human cadavers were used to perform nine PSOs using the free-hand (FH) technique and nine with PSI (in total 18 PSOs). Osteotomy planes were planned on the basis of preoperative computed tomography (CT). A closing-wedge angle of 30° was targeted for each PSO. Postoperative CT scans were obtained to measure segmental lordosis correction and the deviation from the planned 30° correction as well as the osseous gap of posterior elements. Results The time required to perform a PSO was 18:22 (range 10:22–26:38) min and 14:14 (range 10:13–22:16) min in the PSI and FH groups, respectively (p = 0.489). The PSI group had a significantly higher lordosis gain (29°, range 23–31° vs. 21°, range 13–34°; p = 0.015). The lordosis gain was significantly more accurate with PSI (deviation angle: 1°; range 0–7°) than with the FH technique (9°; range 4–17°; p = 0.003). PSI achieved a significantly smaller residual osseous gap of the posterior elements (5 mm; range 0–9 mm) than the FH group (11 mm; range 3–27 mm; p = 0.043). With PSI, an angular difference of 3° (range 1–12°), a translational offset of 1 (range 0–6) mm at the level of the lamina, and a vertebral body entry point deviation of 1 (range 0–4) mm was achieved in the osteotomies. Conclusions PSI-guided PSO can be a more feasible and accurate approach in achieving a planned lordosis angle than the traditional FH technique in a cadaver model. This approach further reduced osseous gaps, potentially promoting higher fusion rates in vivo

Event-Related Potentials in an Associative Word Pair Learning Paradigm

The study investigated the effect of unintentional learning of semantically unrelated word pairs on event-related brain potentials. Two experiments were conducted, in whose acquisition phase participants listened to five pairs of semantically unrelated words, each pair being repeated twenty times. In the test phase of Experiment 1, these “old” pairs were presented mixed with “new” pairs containing other words. In the test phase of Experiment 2, a third condition was added in which the first word in a pair was one of the words presented during acquisition but the second word was new. In both experiments, the second word in new word pairs elicited an N400 and a late (550–1000 ms) frontal positivity. The amplitude of the N400 to new second words in Experiment 2 was significantly larger when the first word in the pair was an old (previously learnt) word, as compared with the condition in which both first and second words were new. The results indicate that, in addition to a repetition effect, unintentional learning of word pairs results in building new associations between previously unrelated words. © 2021 Elsevier Ltd.The study was supported by the German Research Society (Deutsche Forschungsgemeinschaft), Grant KO-1753/13

Study Protocol: Short Against Long Antibiotic Therapy for Infected Orthopaedic Sites - SALATIO Trials

Background: Few studies address the appropriate duration of post-surgical antibiotic therapy for orthopedic infections; with or without infected residual implants. We perform two similar randomized-clinical trials (RCT) to reduce the antibiotic use and associated adverse events. Methods: Two unblinded RCTs in adult patients (non-inferiority with a margin of 10%, a power of 80%) with the primary outcomes "remission" and "microbiologically-identical recurrences" after a combined surgical and antibiotic therapy. The main secondary outcome are antibiotic-related adverse events. The RCTs allocate the participants between 3 vs. 6 weeks of post-surgical systemic antibiotic therapy for implant-free infections; and between 6 vs. 12 weeks for residual implant-related infections. We need a total of 280 episodes (randomization schemes 1:1) with a minimal follow-up 12 months. We perform two interim analyses starting approximately after 1 and 2 years. The study approximatively lasts 3 years. Discussion: Both parellel RCT will enable to prescribe less antibiotics for future orthopedic infections in adult patients. Trial registration: ClinicalTrial.gov NCT05499481. Registered on 12 August 2022. Protocol version: 2 (19 May 2022

Performance and scientific collaboration of Iran Occupational Health Journal: A scientometric analysis

Background: Of common scientometric indices is evaluating the performance and scientific collaboration of journals and organizations. Iran Occupational Health Journal belongs to Iran University of Medical Sciences and committed to providing scientific evidence for improving occupational health. Based on the importance of health at work, this study aimed to evaluate the Journal�s performance and scientific collaboration in the field. Methods: This is a scientometric study using both citation and content analyses. Complete enumeration survey method and Scimago data were used to collect all information about published articles between 2012 and 2017. Content analysis was performed to find about the articles� dominant subject area. The data on the number of authors, the authors' organizational affiliation, the type of articles, and the affiliated centers with the most number of articles were reported. Data were analyzed using Excel 2016 software. Results: The Journal�s performance in various indices such as reducing the time between receive and accept of papers has had an improving trend for 6 consecutive years. The Journal has published mostly in subjects of ergonomics (59 articles) and then safety (52 articles). The Journal�s SJR in Scopus has had an increasing trend from 0.101 in 2012 to 0.220 in 2017. Conclusion: Based on the collected data and Scimago indices, the performance of Iran Occupational Health Journal has shown an improving trend over the studied years. The priorities of published subjects in the Journal are in agreement with the research priorities for occupational health in Iran. Thus, the Journal�s continuous improvement regarding examined criteria is highly expected. © 2019 Iran University of Medical Sciences. All rights reserved

Analysis of hand-forearm anthropometric components in assessing handgrip and pinch strengths of school-aged children and adolescents: a partial least squares (PLS) approach

Background: The purpose of this study was to examine the influence of hand-forearm anthropometric dimensions on handgrip and pinch strengths among 7�18 years children and adolescents and to investigate the extent to which these variables can be used to predict hand strength. Methods: Four types of hand strengths including handgrip, tip to tip, key, and three-jaw chuck pinches were measured in 2637 healthy children and adolescents (1391 boys and 1246 girls) aged 7�18 years using standard adjustable Jamar hydraulic hand dynamometer and pinch gauge. A set of 17 hand-forearm anthropometric dimensions were also measured with an accurate digital caliper and tape measure. Results: No significant differences were found between the hand strengths of boys and girls up to the age of 10 years. Gender related differences in handgrip and pinches were observed from the age of 11 years onwards, with boys always being stronger. The dominant hand was stronger than the non-dominant hand (8 for handgrip and by about 10 for all three types of pinches). The strongest correlations were found between the hand length and hand strengths (r > 0.83 for handgrip and three all pinches; p < 0.001, 2-tailed). Based on the partial least squares (PLS) analysis, 8 out of 17 anthropometric indices including hand length, hand circumference, thumb length, index finger length, middle finger length, and forearm length had considerable loadings in the PLS analysis, which together accounted for 46 of the total variance. Conclusions: These results may be used by health professionals in clinical settings as well as by designers to create ergonomic hand tools. © 2021, The Author(s)

Augmented Reality-Guided Lumbar Facet Joint Injections

OBJECTIVES The aim of this study was to assess feasibility and accuracy of augmented reality-guided lumbar facet joint injections. MATERIALS AND METHODS A spine phantom completely embedded in hardened opaque agar with 3 ring markers was built. A 3-dimensional model of the phantom was uploaded to an augmented reality headset (Microsoft HoloLens). Two radiologists independently performed 20 augmented reality-guided and 20 computed tomography (CT)-guided facet joint injections each: for each augmented reality-guided injection, the hologram was manually aligned with the phantom container using the ring markers. The radiologists targeted the virtual facet joint and tried to place the needle tip in the holographic joint space. Computed tomography was performed after each needle placement to document final needle tip position. Time needed from grabbing the needle to final needle placement was measured for each simulated injection. An independent radiologist rated images of all needle placements in a randomized order blinded to modality (augmented reality vs CT) and performer as perfect, acceptable, incorrect, or unsafe. Accuracy and time to place needles were compared between augmented reality-guided and CT-guided facet joint injections. RESULTS In total, 39/40 (97.5%) of augmented reality-guided needle placements were either perfect or acceptable compared with 40/40 (100%) CT-guided needle placements (P = 0.5). One augmented reality-guided injection missed the facet joint space by 2 mm. No unsafe needle placements occurred. Time to final needle placement was substantially faster with augmented reality guidance (mean 14 ± 6 seconds vs 39 ± 15 seconds, P < 0.001 for both readers). CONCLUSIONS Augmented reality-guided facet joint injections are feasible and accurate without potentially harmful needle placement in an experimental setting