Response Evaluation of Seismically Isolated Lattice Domes using Amplification Factors

p. 355-365Seismic responses of raised lattice domes with substructures are known to be very complicated, and it is known that not only horizontal response but also vertical response is excited under horizontal seismic input. Such action causes damage on structures and nonstructural elements such as ceiling and suspended lightning equipments. A seismic isolation system is known to be effective to reduce such responses. In this paper, simple response evaluation methods for lattice domes supported by substructures with seismic isolation bearings are proposed using response amplification factors and linearization techniques with the same concept proposed by authors. Their validities are discussed against the results of time history analyses.Takamatsu, K.; Takeuchi, T.; Kumagai, T.; Ogawa, T. (2009). Response Evaluation of Seismically Isolated Lattice Domes using Amplification Factors. Editorial Universitat Politècnica de València. http://hdl.handle.net/10251/652

Postoperative Radiographic Early-Onset Adjacent Segment Degeneration after Single-Level L4–L5 Posterior Lumbar Interbody Fusion in Patients without Preoperative Severe Sagittal Spinal Imbalance

Study Design Retrospective study. Purpose To investigate the relationship between preoperative total spinal sagittal alignment and the early onset of adjacent segment degeneration (ASD) after single-level posterior lumbar interbody fusion (PLIF) in patients with normal sagittal spinal alignment. Overview of Literature Postoperative early-onset ASD is one of the complications after L4–L5 PLIF, a common surgical procedure for lumbar degenerative disease in patents without severe sagittal imbalance. A better understanding of the preoperative characteristics of total spinal sagittal alignment associated with early-onset ASD could help prevent the condition. Methods The study included 70 consecutive patients diagnosed with lumbar degenerative disease who underwent single-level L4–L5 PLIF between 2011 and 2015. They were divided into two groups based on the radiographic progression of L3–L4 degeneration after 1-year follow-up: the ASD and the non-ASD (NASD) group. The following radiographic parameters were preoperatively and postoperatively measured: sagittal vertebral axis (SVA), thoracic kyphosis (TK), lumbar lordosis, pelvic tilt, and pelvic incidence (PI). Results Eight of the 70 patients (11%) experienced ASD after PLIF (three males and five females; age, 64.4±7.7 years). The NASD group comprised 20 males and 42 females (age, 67.7±9.3 years). Six patients of the ASD group showed decreased L3–L4 disc height, one had L3–L4 local kyphosis, and one showed both changes. Preoperative SVA, PI, and TK were significantly smaller in the ASD group than in the NASD group (p <0.05). Conclusions A preoperative small SVA and TK with small PI were the characteristic alignments for the risk of early-onset ASD in patients without preoperative severe sagittal spinal imbalance undergoing L4–L5 single-level PLIF

Promoting coronavirus disease 2019 (COVID-19) vaccination among healthcare personnel: A multifaceted intervention at a tertiary-care center in Japan

OBJECTIVE: The coronavirus disease 2019 (COVID-19) vaccine may hold the key to ending the pandemic, but vaccine hesitancy is hindering the vaccination of healthcare personnel (HCP). We examined their perceptions of the COVID-19 vaccine and implemented an intervention to increase vaccination uptake. DESIGN: Before-and-after trial. PARTICIPANTS AND SETTING: Healthcare personnel at a 790-bed tertiary-care center in Tokyo, Japan. INTERVENTIONS: A prevaccination questionnaire was administered to HCP to examine their perceptions of the COVID-19 vaccine. A multifaceted intervention was then implemented involving (1) distribution of informational leaflets to all HCP, (2) hospital-wide announcements encouraging vaccination, (3) a mandatory lecture, (4) an educational session about the vaccine for pregnant or breastfeeding HCP, and (5) allergy testing for HCP at risk of allergic reactions to the vaccine. A postvaccination survey was also performed. RESULTS: Of 1,575 HCP eligible for enrollment, 1,224 (77.7%) responded to the questionnaire, 533 (43.5%) expressed willingness to be vaccinated, 593 (48.4%) were uncertain, and 98 (8.0%) expressed unwillingness to be vaccinated. The latter 2 groups were concerned about the vaccine\u27s safety rather than its efficacy. After the intervention, the overall vaccination rate reached 89.7% (1,413 of 1,575), and 88.9% (614 of 691) of the prevaccination survey respondents answered unwilling to or unsure about eventually receiving a vaccination. In the postvaccination questionnaire, factors contributing to increased COVID-19 vaccination included information and endorsement of vaccination at the medical center (274 of 1,037, 26.4%). CONCLUSIONS: This multifaceted intervention increased COVID-19 vaccinations among HCP at a Japanese hospital. Frequent support and provision of information were crucial for increasing the vaccination rate and may be applicable to the general population as well

Cervical Kyphotic Deformity after Laminoplasty in Patients with Cervical Ossification of Posterior Longitudinal Ligament with Normal Sagittal Spinal Alignment

Background: Preoperative cervico-thoracic kyphosis and cervical regional positive imbalance are the risk factors for postoperative cervical kyphosis after expansive laminoplasty (ELAP). However, the relationship between preoperative global sagittal spinal alignment and postoperative cervical kyphosis in patients with cervical ossification of the posterior longitudinal ligament (OPLL) is unclear. The purpose of this study was to investigate the relationship between the onset of postoperative cervical kyphosis after ELAP and the preoperative global spinal sagittal alignment in patients with OPLL with normal sagittal spinal alignment. Methods: Sixty-nine consecutive patients without preoperative cervical kyphosis who underwent ELAP for OPLL and cervical spondylotic myelopathy (CSM) were enrolled. The global sagittal alignment radiography preoperatively and 1 year postoperatively were examined. The subjects were divided into a postoperative cervical lordosis group (LG) or a kyphosis group (KG) at 1 year postoperatively. The preoperative global sagittal spinal alignment between LG and KG in CSM and OPLL was compared. Results: The occurrence of cervical kyphosis after ELAP was 7 of 27 cases (25.9%) in OPLL and 13 of 42 cases (31.0%) in CSM. In patients with CSM in the KG, C7 the sagittal vertical axis (SVA) was smaller than in the LG. In patients with cervical OPLL in the KG, C2-C7 angle, C2-C7 SVA, and thoracic kyphosis (TK) were smaller than those in the LG. In OPLL, the age of the KG was younger than that of LG; however, this was not a significant difference in CSM. Conclusion: In patients with cervical OPLL without preoperative global spinal sagittal imbalance, preoperative small C2-C7 angle, C2-C7 SVA, TK, and younger age were typical characteristics of postoperative cervical kyphosis after ELAP

Resistance of Hydrogenated Titanium-Doped Diamond-Like Carbon Film to Hyperthermal Atomic Oxygen

The effect of irradiation by a hyperthermal-atomic-oxygen beam on hydrogenated titanium-doped diamond-like carbon (hydrogenated Ti-DLC) films, applied as a solid lubricant for equipment used in low-earth orbit was investigated. Unlike the film thickness of hydrogenated non-doped DLC films, that of hydrogenated Ti-DLC films was found to be constant after the films were exposed to atomic oxygen. In addition, bulk composition of the hydrogenated Ti-DLC film stayed constant, and in particular, hydrogen content in the film did not decrease. These results indicate that a hydrogenated Ti-DLC film can keep its low friction properties under vacuum. Surface chemical analysis showed that a titanium-oxide layer is form on the film by exposure to atomic oxygen. The thickness of the titanium oxide layer was estimated to be about 5 nm from the element distribution in the depth direction of the hydrogenated Ti-DLC films. The titanium-oxide layer was interpreted to protect the bulk film from erosion by hyperthermal atomic oxygen

Radiographic Assessment of Spinopelvic Sagittal Alignment from Sitting to Standing Position

Introduction: Most people in modern societies spend the majority of their time sitting. However, sagittal spinal alignment is usually analyzed in the standing position. For understanding the symptoms associated with postural changes, this alignment is better to be analyzed in various positions. The purpose of this study was to investigate lumbo-pelvic relationships between standing up and sitting (sit-to-stand) motion. Methods: The study subjects were 25 healthy young adult volunteers without any spinal symptoms. The following parameters were measured, namely, intervertebral range of motion (IV ROM), lumbar lordotic angle (L1L5), sacral slope (SS), pelvic tilt (PT), and pelvic incidence (PI), on lateral whole-spine radiographs while sitting upright, sitting anterior flexed (anteflexed), standing anteflexed, and standing upright. Results: The measurements of spinopelvic parameters during sit-to-stand motion (sitting upright, sitting anteflexed, standing anteflexed, standing upright, respectively) were as follows: L1L5 (7.9, −4.4, 3.1, 31.9) and PT (31.5, 26.5, 11.9, 7.7). Regarding IV ROM, the lumbar segmental ROM after seat-off was wider than before seat-off (sitting anteflexed). In particular, the L4-L5 segments had a wide ROM from standing anteflexed to standing upright. Conclusions: The pelvis was retroverted in the sitting upright position and gradually anteverted during sit-to-stand motion. Lumbar lordosis decreased in the sitting upright position, temporarily decreased further (sitting anteflexed), and then increased in the standing position (standing anteflexed and standing upright). The mechanical loads on lumbosacral segments were greater after seat-off due to the reverse movement between upper lumbar and pelvic segments