Effects of eccentricity on seismic behavior of non-seismically designed reinforced concrete beam-column joint

The staggering numbers of eccentric reinforced concrete beam-column joints without seismic design details were used in existing RC frame building due to geometrical constraints, which implied high susceptibility of the building structures to anticipated seismic risk. Three exterior RC beam-column joints were fabricated and tested, which were applied reversed cyclic loads to simulate seismic action. In this study, the effects of stirrup ratio in joints and the eccentricity which is defined as the distance between the axis of the beam and column on seismic performance are investigated. The test results provide a further understanding of the failure mode and shear strength of exterior beam-column joints. It is shown that the eccentricity will significantly reduce the seismic performance and shear strength of the joints, which will cause the brittle failure of frame buildings, while the stirrups in the joint core can improve the seismic performance. To verify the availability of current codes in predicting the shear strength of eccentric beam-column joints with non-seismic detailed, the experimental results are compared with the predicted shear force of two nonseismic codes (HK code and Eurocode 2) and three seismic codes (Eurocode 8, NZS 3101 and ACI 318-14). The comparison results indicate that the existing non-seismic and seismic design codes of practice do not predict the shear strength of the exterior non-seismically designed joints precisely

Questionnaire survey on point‐of‐care ultrasound utilization during cardiac arrest among emergency physicians in Hong Kong

Introduction: Although point‐of‐care ultrasound (POCUS) is recognized as a useful diagnostic and prognostic tool during the management of out‐of‐hospital cardiac arrest (OHCA), opposing viewpoints exist. The objectives of this study are to investigate the knowledge, attitude, and practice (KAP) in POCUS utilization during OHCA among emergency medicine (EM) physicians in Hong Kong and to identify their barriers. Methods: A cross‐sectional questionnaire was conducted among EM physicians in 9 accident and emergency departments in Hong Kong. The questionnaire assessed participants' demographics, knowledge, attitude, practices, and barriers on this issue. Composite scores for KAP were calculated. Subgroup analysis and multiple regression analysis were used to explore the correlation between KAP and participants' demographics. Participants' barriers were evaluated by binary and open‐ended questions. Results: A total of 224 questionnaires were distributed and 150 questionnaires were returned (response rate: 67.0%). Statistically significant associations of knowledge and attitude with practice were demonstrated (both p < 0.001). Independent predictors of more frequent POCUS use in OHCA included EM fellowship status (p = 0.005), receiving training on this issue (p < 0.001), and working in large hospitals (p = 0.007). The top‐ranked barriers were chaotic environment (74%), no structural education on this practice (63%), and the lack of staff (61%). Conclusions: The knowledge and attitude of performing POCUS during OHCA were demonstrated to enhance EM physicians' practice. By improving physicians' knowledge and removing the possible barriers they are facing, POCUS can be optimally utilized during OHCA to improve patient care

Quantitative Anatomy of C7 Vertebra in Southern Chinese for Insertion of Lateral Mass Screws and Pedicle Screws

Study DesignRetrospective study.PurposeTo analyze the quantitative anatomy of C7 vertebra for insertion of lateral mass screws and pedicle screws in Southern Chinese patients.Overview of LiteratureC7 lateral mass is smaller when compared to other subaxial cervical levels, which limits the length of lateral mass screws that can be used. Some studies have suggested pedicle screws for better fixation. But, this option is limited by the narrow pedicle width.MethodsWe have obtained computed tomography (CT) cervical spine data in 0.625 mm slices from our radiology department. The patients were adults. CTs were from May to August, 2015. The lateral mass screw length was measured using Margerl's technique and pedicle width and pedicle screw trajectory were determined in three-dimensional reformated images.ResultsCT scans of cervical spines of 94 patients were obtained and 188 lateral masses and pedicles of C7 vertebrae were measured. The mean lateral mass screw length was 13.2 mm (standard deviation [SD] 1.6 mm), mean outer pedicle width was 5.9 mm (SD 1.0 mm) and mean pedicle screw trajectory was 29.4 degrees (SD 3.6 degrees). Most (91.0%) of the pedicles had an outer diameter ≥4.5 mm.ConclusionsThe mean lateral mass screw length was longer when compared with other similar studies, while the mean outer pedicle width was narrower. Nearly 10% of the pedicles were unable to accommodate 3.5 mm screws. These findings favor the use of lateral mass screws to provide a safe and stable fixation for C7 vertebrae in Southern Chinese patients, while the final choice of fixation method should only be confirmed after careful preoperative planning with CT scan

The Inaccuracy of Surface Landmarks for the Anterior Approach to the Cervical Spine in Southern Chinese Patients

Study Design Observational study. Purpose To assess the correlational accuracy between the traditional anatomic landmarks of the neck and their corresponding vertebral levels in Southern Chinese patients. Overview of Literature Recent studies have demonstrated discrepancies between traditional anatomic landmarks of the neck and their corresponding cervical vertebra. Methods The center of the body of the hyoid bone, the upper limit of the lamina of the thyroid cartilage, and the lower limit of the cricoid cartilage were selected as representative surface landmarks for this investigation. The corresponding vertebral levels in 78 patients were assessed using computed tomography. Results In both male and female patients, almost none of the anatomical landmarks demonstrated greater than 50% correlation with any vertebral level. The most commonly corresponding vertebra of the hyoid bone, the lamina of the thyroid cartilage, and the cricoid cartilage were the C4 (47.5%), C5 (35.9%), and C7 (42.3%), respectively, which were all different from the classic descriptions in textbooks. The vertebral levels corresponding with the thyroid and cricoid cartilage were significantly different between genders. Conclusions The surface landmarks of the neck were not accurate enough to be used as the sole determinant of vertebral levels or incision sites. Intra-operative fluoroscopy is necessary to accurately locate each of the cervical vertebral levels

Stand-Alone Cervical Cages in 2-Level Anterior Interbody Fusion in Cervical Spondylotic Myelopathy: Results from a Minimum 2-Year Follow-up

Study Design A retrospective review of patients who underwent 2-level anterior cervical discectomy and fusion (ACDF) with standalone polyetheretherketone (PEEK) cages for cervical spondylotic myelopathy (CSM). Purpose To evaluate the efficacy of stand-alone PEEK cage in 2-level cervical interbody fusion for CSM. Overview of Literature ACDF is a standard surgical procedure to treat degenerative disc disease. However, the use of additional anterior plating for 2-level ACDF remains controversial. Methods We reviewed outcomes of patients who underwent 2-level ACDF with stand-alone PEEK cages for CSM over a 7-year period (2007–2015) in a regional hospital. Japanese Orthopaedic Association (JOA) score, fusion rate, subsidence rate, cage migration, and cervical alignment by the C2–7 angle as well as the local segmental angle (LSA) of the cervical spine were assessed. Results In total, 31 patients (mean age, 59 years; range, 36–87 years) underwent 2-level ACDF with a cage-only construct procedure between 2007 and 2015. The minimum follow-up was 24 months; mean follow-up was 51 months. C3–5 fusion was performed in 45%, C4–6 fusion in 32%, and C5–7 fusion in 23%. Mean JOA score improved from 10.1±2.2 to 13.9±2.1 (p<0.01) at the 24-month follow-up. Fusion was achieved in all patients. Subsidence occurred in 22.5% of the cages but was not associated with differences in JOA scores, age, sex, or levels fused. Lordosis of the C2–7 angle and LSA increased after surgery, which were maintained for up to 1 year but subsequently disappeared after 2 years, yet the difference was not statistically significant. No cage migration was noted; two patients developed adjacent segment disease requiring posterior laminoplasty 3 years after ACDF. Conclusions The use of a stand-alone PEEK cage in a 2-level cervical interbody fusion achieves satisfactory improvements in both clinical outcomes and fusion

Application of Prenatal Whole Exome Sequencing for Structural Congenital Anomalies—Experience from a Local Prenatal Diagnostic Laboratory

Fetal structural congenital abnormalities (SCAs) complicate 2–3% of all pregnancies. Whole-exome sequencing (WES) has been increasingly adopted prenatally when karyotyping and chromosomal microarray do not yield a diagnosis. This is a retrospective cohort study of 104 fetuses with SCAs identified on antenatal ultrasound in Hong Kong, where whole exome sequencing is performed. Molecular diagnosis was obtained in 25 of the 104 fetuses (24%). The highest diagnostic rate was found in fetuses with multiple SCAs (29.2%), particularly those with involvement of the cardiac and musculoskeletal systems. Variants of uncertain significance were detected in 8 out of the 104 fetuses (7.7%). Our study shows the utility of WES in the prenatal setting, and the extended use of the technology would be recommended in addition to conventional genetic workup

Vitamin D3 and carbamazepine protect against Clostridioides difficile infection in mice by restoring macrophage lysosome acidification

Clostridioides difficile infection (CDI) is a common cause of nosocomial diarrhea. TcdB is a major C. difficile exotoxin that activates macrophages to promote inflammation and epithelial damage. Lysosome impairment is a known trigger for inflammation. Herein, we hypothesize that TcdB could impair macrophage lysosomal function to mediate inflammation during CDI. Effects of TcdB on lysosomal function and the downstream pro-inflammatory SQSTM1/p62-NFKB (nuclear factor kappa B) signaling were assessed in cultured macrophages and in a murine CDI model. Protective effects of two lysosome activators (i.e., vitamin D3 and carbamazepine) were assessed. Results showed that TcdB inhibited CTNNB1/β-catenin activity to downregulate MITF (melanocyte inducing transcription factor) and its direct target genes encoding components of lysosomal membrane vacuolar-type ATPase, thereby suppressing lysosome acidification in macrophages. The resulting lysosomal dysfunction then impaired autophagic flux and activated SQSTM1-NFKB signaling to drive the expression of IL1B/IL-1β (interleukin 1 beta), IL8 and CXCL2 (chemokine (C-X-C motif) ligand 2). Restoring MITF function by enforced MITF expression or restoring lysosome acidification with 1α,25-dihydroxyvitamin D3 or carbamazepine suppressed pro-inflammatory cytokine expression in vitro. In mice, gavage with TcdB-hyperproducing C. difficile or injection of TcdB into ligated colon segments caused prominent MITF downregulation in macrophages. Vitamin D3 and carbamazepine lessened TcdB-induced lysosomal dysfunction, inflammation and histological damage. In conclusion, TcdB inhibits the CTNNB1-MITF axis to suppress lysosome acidification and activates the downstream SQSTM1-NFKB signaling in macrophages during CDI. Vitamin D3 and carbamazepine protect against CDI by restoring MITF expression and lysosomal function in mice. Abbreviations: ATP6V0B: ATPase H+ transporting V0 subunit b; ATP6V0C: ATPase H+ transporting V0 subunit c; ATP6V0E1: ATPase H+ transporting V0 subunit e1; ATP6V1H: ATPase H+ transporting V1 subunit H; CBZ: carbamazepine; CDI: C. difficile infection; CXCL: chemokine C-X-X motif ligand; IL: interleukin; LAMP1: lysosomal-associated membrane protein 1; LC3: microtubule-associated protein 1 light chain 3; LEF: lymphoid enhancer binding factor 1; MITF: melanocyte inducing transcription factor; NFKB: nuclear factor kappa B; PMA: phorbol 12-myristate 13-acetate; TcdA: Clostridial toxin A; TcdB: Clostridial toxin B; TFE3: transcription factor E3; TFEB: transcription factor EB.Published versionThis work was supported by the National Natural Science Foundation of China [82070576] and the Hong Kong Food and Health Bureau (FHB) Commissioned Health and Medical Research Fund [CID-CUHK-C]

Association of baseline factors with incident fracture.

<p>Association of baseline factors with incident fracture.</p

Association of different types of androgen deprivation therapy with bone health.

<p>Association of different types of androgen deprivation therapy with bone health.</p

Baseline characteristics of patients.

<p>Baseline characteristics of patients.</p