Ergonomic dual four-bar linkage knee exoskeleton for stair ascent assistance

Introduction: Robotic exoskeletons are emerging technologies that have demonstrated their effectiveness in assisting with Activities of Daily Living. However, kinematic disparities between human and robotic joints can result in misalignment between humans and exoskeletons, leading to discomfort and potential user injuries.Methods: In this paper, we present an ergonomic knee exoskeleton based on a dual four-bar linkage mechanism powered by hydraulic artificial muscles for stair ascent assistance. The device comprises two asymmetric four-bar linkage mechanisms on the medial and lateral sides to accommodate the internal rotation of the knee and address the kinematic discrepancies between these sides. A genetic algorithm was employed to optimize the parameters of the four-bar linkage mechanism to minimize misalignment between human and exoskeleton knee joints. The proposed device was evaluated through two experiments. The first experiment measured the reduction in undesired load due to misalignment, while the second experiment evaluated the device’s effectiveness in assisting stair ascent in a healthy subject.Results: The experimental results indicate that the proposed device has a significantly reduced undesired load compared to the traditional revolute joint, decreasing from 14.15 N and 18.32 N to 1.88 N and 1.07 N on the medial and lateral sides, respectively. Moreover, a substantial reduction in muscle activities during stair ascent was observed, with a 55.94% reduction in surface electromyography signal.Discussion: The reduced undesired load of the proposed dual four-bar linkage mechanism highlights the importance of the adopted asymmetrical design for reduced misalignment and increased comfort. Moreover, the proposed device was effective at reducing the effort required during stair ascent

Density imaging of heterochromatin in live cells using orientation-independent-DIC microscopy

© The Author(s), 2017. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Molecular Biology of the Cell 28 (2017): 3349-3359, doi:10.1091/mbc.E17-06-0359.In eukaryotic cells, highly condensed inactive/silenced chromatin has long been called “heterochromatin.” However, recent research suggests that such regions are in fact not fully transcriptionally silent and that there exists only a moderate access barrier to heterochromatin. To further investigate this issue, it is critical to elucidate the physical properties of heterochromatin such as its total density in live cells. Here, using orientation-independent differential interference contrast (OI-DIC) microscopy, which is capable of mapping optical path differences, we investigated the density of the total materials in pericentric foci, a representative heterochromatin model, in live mouse NIH3T3 cells. We demonstrated that the total density of heterochromatin (208 mg/ml) was only 1.53-fold higher than that of the surrounding euchromatic regions (136 mg/ml) while the DNA density of heterochromatin was 5.5- to 7.5-fold higher. We observed similar minor differences in density in typical facultative heterochromatin, the inactive human X chromosomes. This surprisingly small difference may be due to that nonnucleosomal materials (proteins/RNAs) (∼120 mg/ml) are dominant in both chromatin regions. Monte Carlo simulation suggested that nonnucleosomal materials contribute to creating a moderate access barrier to heterochromatin, allowing minimal protein access to functional regions. Our OI-DIC imaging offers new insight into the live cellular environments.This work was supported by MEXT and Japan Society for the Promotion of Science (JSPS) grants (Nos. 23115005 and 16H04746, respectively), as well as a Japan Science and Technology Agency (JST) CREST grant (No. JPMJCR15G2). R.I. and T.N. are JSPS Fellows. R.I. was supported by the SOKENDAI Short-Stay Study Abroad Program in fiscal year 2016

Vitamin D and serum 25-hydroxyvitamin D level

The changes in the serum 25-hydroxyvitamin D (25(OH)D) concentrations after daily 1000-IU vitamin D intake for 3 months (3-month-VD), 6 months (6-month-VD) and then 6-month cessation of vitamin D intake (6-month-VD cessation) were examined. The serum 25(OH)D levels in 11 male and 16 female subjects were 12.1 ± 3.5 ng / mL at baseline, increased to 27.1 ± 4.7 ng / mL at 3-month-VD, 28.5 ± 5.1 ng / mL at 6-month-VD and decreased to 16.4 ± 4.0 ng / mL at 6-month-VD cessation. The present study suggested that a vitamin D intake of 1000 IU / day is required to maintain the 25(OH) D concentration at 30 ng / mL or higher without vitamin D intoxication

Impact of the Patency of Inferior Mesenteric Artery on 7-Year Outcomes After Endovascular Aneurysm Repair

Purpose: The impact of preoperative patent inferior mesenteric artery (IMA) on late outcomes following endovascular aneurysm repair (EVAR) remains unclear. This study aimed to investigate the specific influence of IMA patency on 7-year outcomes after EVAR. Materials and Methods: In this retrospective cohort study, 556 EVARs performed for true abdominal aortic aneurysm cases between January 2006 and December 2019 at our institution were reviewed. Endovascular aneurysm repairs performed using a commercially available device with no type I or type III endoleak (EL) during follow-up and with follow-up ≥12 months were included. A total of 336 patients were enrolled in this study. The cohort was divided into the patent IMA group and the occluded IMA group according to preoperative IMA status. The late outcomes, including aneurysm sac enlargement, reintervention, and mortality rates, were compared between both groups using propensity-score-matched data. Results: After propensity score matching, 86 patients were included in each group. The median follow-up period was 56 months (interquartile range: 32–94 months). The incidence of type II EL at discharge was 50% in the patent IMA group and 19% in the occluded IMA group (p<0.001). The type II EL from IMA and lumbar arteries was significantly higher in the patent IMA group than in the occluded IMA group (p<0.001 and p=0.002). The rate of freedom from aneurysm sac enlargement with type II EL was significantly higher in the occluded IMA group than in the patent IMA group (94% vs 69% at 7 years; p<0.001). The rate of freedom from reintervention was significantly higher in the occluded IMA group than in the patent IMA group (90% vs 74% at 7 years; p=0.007). Abdominal aortic aneurysm–related death and all-cause mortality did not significantly differ between groups (p=0.32 and p=0.34). Conclusions: Inferior mesenteric artery patency could affect late reintervention and aneurysm sac enlargement but did not have a significant impact on mortality. Preoperative assessment and embolization of IMA might be an important factor for improvement in late EVAR outcomes. Clinical Impact: The preoperative patency of the inferior mesenteric artery was significantly associated with a higher incidence of sac enlargement and reintervention with type II endoleak following endovascular aneurysm repair, even after adjustment for patient background. Preoperative assessment and embolization of inferior mesenteric artery might be an important factor for improvement in late EVAR outcomes.Ide T, Shimamura K, Kuratani T, et al. Impact of the Patency of Inferior Mesenteric Artery on 7-Year Outcomes After Endovascular Aneurysm Repair. Journal of Endovascular Therapy. 2022. Copyright © 2022 The Author(s). doi:10.1177/15266028221121748

ジンソクナ バイスタンダー シンパイ ソセイホウ ニヨリ トツゼンシ オ マヌガレ シャカイ フッキ デキタ コウコウセイ ノ 2 ショウレイ

Bystander CPR means that people who find cardiopulmonary arrest perform cardiopulmonary resuscitation on the spot. Quick CPR contributes to increase in the rate of returning to the society as well as one-month survival rate and neurological prognosis. We report our experience with two high school students who underwent quick Bystander CPR, avoided sudden death, and returned to the society. ［Case 1］ Eighteen-year-old man : He collapsed suddenly in his home. Bystander CPR was performed by his family until emergency crews arrived there. Automated external defibrillator （AED） worked twice and his heartbeat started again. In electrocardiogram, coved type ST elevation in lead V1 was observed, and he was diagnosed as Brugada syndrome. We implanted an implantable cardioverter-defibrillator. Since his condition was stable, he was discharged on the 19th day. ［Case 2］ Seventeen-year-old woman : She collapsed suddenly walking with her family. Her father confirmed that she had no response, and started Bystander CPR. Her father got AED quickly and AED worked once, and she started to breathe again. She was admitted to our hospital for a work-up. Torsades de pointes （TdP） was observed in monitor electrocardiogram, and her QTc time was 513 msec in 12‐lead electrocardiogram. She was diagnosed as congenital long QT syndrome because genetic test showed that she had LQT2. Her QTc time was improved （approximately 350 msec） by medication, and she was discharged on the 25th day. Utstein-style statistics in Japan shows that the rate of returning to the society can be doubled by performing Bystander CPR on patients with cardiopulmonary arrest. However, performing rate of Bystander CPR is less than 50％ in Japan. In order to increase survival rate of patients with cardiopulmonary arrest for the future, it is important to inform people about CPR and to promote CPR, and in fact, we have been promoting CPR

Clinical and radiological features related to the growth potential of meningioma

Clinical and radiological features that help predict the growth potential of meningioma would be beneficial. The purpose of this study is to clarify the characteristics related to proliferating potential using the MIB-1 staining index. We analyzed the relationship of MIB-1 staining indices to characteristics of 342 consecutive patients with meningioma surgically removed between 1995 and 2004 by logistic regression analysis. One hundred and forty-nine of the patients with meningioma were ≥60 in age; 89 male; 48 recurrent; 203 symptomatic; 157 at the skull base; 124 over 20 cm(3); 24 multiple; 136 with edema; 117 with calcification. The MIB-1 staining index in 56 of 296 grade I meningiomas in WHO classification was ≥ 3.0; in 27 of 28 grade II; and in 17 of 18 grade III, respectively. Logistic regression analysis demonstrated that male (odds ratio [OR], 2.374, p=0.003), recurrence (OR, 7.574, p=0.0001), skull base (OR, 0.540, p=0.035), calcification (OR, 0.498, p=0.019) were independent risk factors for a high MIB-1 staining index (≥3.0); age, symptomatic, volume, multiple, edema were not. Male, recurrence, non-skull base, absence of calcification are independent risk factors for a high proliferative potential. These should be taken into consideration when managing meningiomas

Infectious Pneumonia and Lower Airway Microorganisms in Patients with Rheumatoid Arthritis

The relationship between microorganisms present in the lower respiratory tract and the subsequent incidence of pneumonia in patients with rheumatoid arthritis is unclear. A retrospective cohort study was designed to include a total of 121 patients with rheumatoid arthritis who underwent bronchoscopy at three hospitals between January 2008 and December 2017. Data on patient characteristics, microorganisms detected by bronchoscopy, and subsequent incidences of pneumonia were obtained from electronic medical records. Patients were divided into groups based on the microorganisms isolated from the lower respiratory tract. The cumulative incidence of pneumonia was assessed using the Kaplan–Meier method, and decision tree analysis was performed to analyze the relation between the presence of microorganisms and the occurrence of pneumonia. The most frequently isolated microbes were Pseudomonas aeruginosa, Staphylococcus aureus, and Haemophilus influenzae. Patients whose samples tested negative for bacteria or positive for normal oral flora were included in the control group. The rate of the subsequent incidence of pneumonia was higher in the P. aeruginosa group than in the control group (p = 0.026), and decision tree analysis suggested that P. aeruginosa and patient performance status were two important factors for predicting the incidence of pneumonia. In patients with rheumatoid arthritis, the presence of P. aeruginosa in the lower respiratory tract was associated with the subsequent incidence of pneumonia