Hole/Crack Identification in Circular Piezoelectric Plates

AbstractThe piezoelectric material generates an electric field when it is deformed by an external force. On account of this electro-mechanical coupling, piezoelectric material plays an important role in the development of sensors as well as actuators. The governing equations of electro-mechanical characteristics are expressed by extended Stroh formalism. The boundary element method is applied to solve the finite domain problem in which the Green function derived according to boundary conditions is embedded. The essential nonlinear identification problem is solved by using the multiple loading modes and stepwise optimization to search for the global minimum solution. This paper successfully identifies the hole/crack size, location, and orientation in finite circular piezoelectric plates by using the strain/electric field data, stress/electric displacement data, or displacement/electric charge data from static loadings. The numerical results that confirm the effectiveness of the proposed method for hole/crack identification in circular piezoelectric plates are presented in details

Design of a bionic-inspired exoskeleton robot for lower limb assist

The design of an intelligent exoskeleton robot with pneumatic artificial muscles for human lower limb motion assist using electromyography (EMG) is presented. There are four topics addressed in this paper. Decoding electromyography is the first topic. When muscles are active, they produce an electrical activity. EMG is a record of this electrical activity that reflects human’s movement. Through regression analysis a model is obtained to extract motion commands from EMG. It would be an advantage to employ EMG as a control signal for the exoskeleton control. Second, the pneumatic artificial muscle, air muscle for short, is a simple and powerful actuator. When actuated with compressed air, it contracts and provides a pulling force. As a result of its behavior in a similar way to a biological muscle, air muscle is adapted for a bionic actuator of the assist robot. The force models of air muscles are investigated by experiments in a workbench. Third, for the control of a bionic-inspired robot, the multimodal sensory feedback including EMG and inertial sensors is necessary. By using EMG as a force-proportional measurement between human and robot, a control system combined a sensor-fusion approach and a compliant mechanism enables exoskeleton to carry out human-robot collaboration. Finally, a prototype of power-assist exoskeleton robot for lower limb is completed and evaluated by experiments successfully

Spatial Mapping of Morphology and Electronic Properties of Air‐Printed Pentacene Thin Films

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/107549/1/adfm201303983.pd

Safety and efficacy of endovascular recanalization for symptomatic non-acute atherosclerotic intracranial large artery occlusion

Background and objectiveThe optimal treatment for patients with symptomatic non-acute atherosclerotic intracranial large artery occlusion (ILAO) despite medical treatment is not well established. We aimed to assess the safety, efficacy, and feasibility of angioplasty and stenting for these patients.MethodsA total of 251 consecutive patients with symptomatic non-acute atherosclerotic ILAO treated with interventional recanalization were retrospectively collected in our center from March 2015 to August 2021. The rate of successful recanalization, perioperative complications, and follow-up outcomes were evaluated.ResultsSuccessful recanalization was achieved in 88.4% (222/251) of the patients. A total of 24 (24/251, 9.6%) symptomatic complications occurred among 251 procedures. In the 193 patients with clinical follow-up during 19.0 ± 14.7 months, 11 (11/193, 5.7%) patients developed ischemic stroke and four (4/193, 2.1%) patients developed transient ischemic attack (TIA). In the 106 patients with vascular imaging follow-up during 6.8 ± 6.6 months, seven (7/106, 6.6%) patients had restenosis and 10 (10/106, 9.4%) patients had reocclusion.ConclusionThis study suggests that interventional recanalization may be a feasible, basically safe, and an effective alternative in carefully selected patients with symptomatic non-acute atherosclerotic ILAO who have failed medical management

A Nationwide Survey of Lymphangioleiomyomatosis in Korea: Recent Increase in Newly Diagnosed Patients

In 2007, the Korean Interstitial Lung Disease Society had collected clinical data of patients who have diagnosed as Lymphangioleiomyomatosis (LAM) since 1990 through nationwide survey, which showed that LAM patients had increased sharply after 2004. The present study was performed to show the clinical features of Korean patients with LAM, and to establish the reason for the recent increase in the diagnosis. All 63 patients were women and the mean age at diagnosis was 36 yr. The most common presenting symptom was dyspnea and 8 patients had tuberous sclerosis complex. The survival rate at 5 yr after diagnosis was 84%. Compared with patients diagnosed after 2004 (n=34), the patients diagnosed before 2004 (n=29) complained with dyspnea more (P=0.016) and had lower FEV1% predicted (P=0.003), and DLco% predicted (P=0.042). The higher proportion of patients diagnosed after 2004 showed the normal chest radiography, and they were detected by routine chest CT screening (P=0.016). This study showed that clinical features of Korean patients with LAM were not different from those reported elsewhere. It is concluded that the reason for the increase of newly diagnosed patients is the result of increase in detection of the early stage LAM by the widespread use of chest CT screening

Clinical and epidemiological characteristics of Korean patients with hepatitis C virus genotype 6

Background/AimsThe distribution of hepatitis C virus (HCV) genotypes varies geographically. In Korea, genotypes 1 and 2 comprise more than 90% of HCV infections, while genotype 6 is very rare. This study compared the clinical and epidemiological characteristics of patients with genotype 6 HCV infection with those infected with HCV genotypes 1 and 2.MethodsThis was a prospective, multicenter HCV cohort study that enrolled 1,173 adult patients, of which 930 underwent HCV genotype analysis, and only 9 (1.0%) were found to be infected with genotype 6 HCV. The clinical and epidemiological parameters of the genotypes were compared.ResultsThe patients with genotype 6 HCV had a mean age of 41.5 years, 77.8% were male, and they had no distinct laboratory features. A sustained virologic response (SVR) was observed in four (67%) of six patients who received antiviral therapy. Risk factors such as the presence of a tattoo (n=6, 66.7%), more than three sexual partners (n=3, 33.3%), and injection drug use (n=3, 33.3%) were more common among genotype 6 patients than among genotypes 1 or 2.ConclusionsThe epidemiology and treatment response of patients infected with genotype 6 HCV differed significantly from those with genotypes 1 or 2, warranting continuous monitoring

Rare Exonic Minisatellite Alleles in MUC2 Influence Susceptibility to Gastric Carcinoma

BACKGROUND: Mucins are the major components of mucus and their genes share a common, centrally-located region of sequence that encodes tandem repeats. Mucins are well known genes with respect to their specific expression levels; however, their genomic levels are unclear because of complex genomic properties. In this study, we identified eight novel minisatellites from the entire MUC2 region and investigated how allelic variation in these minisatellites may affect susceptibility to gastrointestinal cancer. METHODOLOGY/PRINCIPLE FINDINGS: We analyzed genomic DNA from the blood of normal healthy individuals and multi-generational family groups. Six of the eight minisatellites exhibited polymorphism and were transmitted meiotically in seven families, following Mendelian inheritance. Furthermore, a case-control study was performed that compared genomic DNA from 457 cancer-free controls with DNA from individuals with gastric (455), colon (192) and rectal (271) cancers. A statistically significant association was identified between rare exonic MUC2-MS6 alleles and the occurrence of gastric cancer: odds ratio (OR), 2.56; 95% confidence interval (CI), 1.31-5.04; and p = 0.0047. We focused on an association between rare alleles and gastric cancer. Rare alleles were divided into short (40, 43 and 44) and long (47, 50 and 54), according to their TR (tandem repeats) lengths. Interestingly, short rare alleles were associated with gastric cancer (OR = 5.6, 95% CI: 1.93-16.42; p = 0.00036). Moreover, hypervariable MUC2 minisatellites were analyzed in matched blood and cancer tissue from 28 patients with gastric cancer and in 4 cases of MUC2-MS2, minisatellites were found to have undergone rearrangement. CONCLUSIONS/SIGNIFICANCE: Our observations suggest that the short rare MUC2-MS6 alleles could function as identifiers for risk of gastric cancer. Additionally, we suggest that minisatellite instability might be associated with MUC2 function in cancer cells