Metal-organic framework based on hinged cube tessellation as transformable mechanical metamaterial

Mechanical metamaterials exhibit unusual properties, such as negative Poisson???s ratio, which are difficult to achieve in conventional materials. Rational design of mechanical metamaterials at the microscale is becoming popular partly because of the advance in three-dimensional printing technologies. However, incorporating movable building blocks inside solids, thereby enabling us to manipulate mechanical movement at the molecular scale, has been a difficult task. Here, we report a metal-organic framework, self-assembled from a porphyrin linker and a new type of Zn-based secondary building unit, serving as a joint in a hinged cube tessellation. Detailed structural analysis and theoretical calculation show that this material is a mechanical metamaterial exhibiting auxetic behavior. This work demonstrates that the topology of the framework and flexible hinges inside the structure are intimately related to the mechanical properties of the material, providing a guideline for the rational design of mechanically responsive metal-organic frameworks

H2 pressure swing adsorption for IGCC power plant and techno-economic analysis of integrating PSA to IGCC with carbon capture

Carbon capture and sequestration technologies emerge as the effectual remediation processes to reduce CO2 emissions from coal power plants. Integrated gasification combined cycle (IGCC) is a representative technology for utilizing coal as feedstock and is consequently playing a more important role to cover the global energy demand. The IGCC produces H2-rich mixture at high pressures (30-35 bar) after capturing CO2. It is reported that the high purity H2 recovered from the IGCC process can be economically supplied to a hydrogen turbine or fuel cell. And a PSA process is a strong candidate to produce high purity H2 from the IGCC effluent gas. However, due to higher operating pressure than the present H2 PSA processes, reducing the operating costs and efficiency has emerged as one of the key issues. Please click Additional Files below to see the full abstract

Retroperitoneal Hematoma after Transforaminal Selective Epidural Block: A Case Report

Transforaminal selective epidural block (TFSEB) technique is used for spinal pain management. Multiple recent reports cite TFSEB resulting in complications such as life-threatening infections, spinal fluid leaks, positional headaches, adhesive arachnoiditis, hydrocephalus, air embolism, urinary retention, allergic reactions, intravascular injections, stroke, blindness, neurological deficits/paralysis, hematomas, seizure and death. We present herein a case of TFSEB induced retroperitoneal hematoma resolution with conservative treatment

SSASS: Semi-Supervised Approach for Stenosis Segmentation

Coronary artery stenosis is a critical health risk, and its precise identification in Coronary Angiography (CAG) can significantly aid medical practitioners in accurately evaluating the severity of a patient's condition. The complexity of coronary artery structures combined with the inherent noise in X-ray images poses a considerable challenge to this task. To tackle these obstacles, we introduce a semi-supervised approach for cardiovascular stenosis segmentation. Our strategy begins with data augmentation, specifically tailored to replicate the structural characteristics of coronary arteries. We then apply a pseudo-label-based semi-supervised learning technique that leverages the data generated through our augmentation process. Impressively, our approach demonstrated an exceptional performance in the Automatic Region-based Coronary Artery Disease diagnostics using x-ray angiography imagEs (ARCADE) Stenosis Detection Algorithm challenge by utilizing a single model instead of relying on an ensemble of multiple models. This success emphasizes our method's capability and efficiency in providing an automated solution for accurately assessing stenosis severity from medical imaging data.Comment: MICCAI 2023 Conference ARCADE Challeng

MPSeg : Multi-Phase strategy for coronary artery Segmentation

Accurate segmentation of coronary arteries is a pivotal process in assessing cardiovascular diseases. However, the intricate structure of the cardiovascular system presents significant challenges for automatic segmentation, especially when utilizing methodologies like the SYNTAX Score, which relies extensively on detailed structural information for precise risk stratification. To address these difficulties and cater to this need, we present MPSeg, an innovative multi-phase strategy designed for coronary artery segmentation. Our approach specifically accommodates these structural complexities and adheres to the principles of the SYNTAX Score. Initially, our method segregates vessels into two categories based on their unique morphological characteristics: Left Coronary Artery (LCA) and Right Coronary Artery (RCA). Specialized ensemble models are then deployed for each category to execute the challenging segmentation task. Due to LCA's higher complexity over RCA, a refinement model is utilized to scrutinize and correct initial class predictions on segmented areas. Notably, our approach demonstrated exceptional effectiveness when evaluated in the Automatic Region-based Coronary Artery Disease diagnostics using x-ray angiography imagEs (ARCADE) Segmentation Detection Algorithm challenge at MICCAI 2023.Comment: MICCAI 2023 Conference ARCADE Challeng

Factors Associated with the Symptoms of Young Adults with L5 Spondylolysis

Study Design A retrospective cohort study. Purpose To investigate the factors affecting symptoms in young adults with L5 spondylolysis. Overview of Literature L5 spondylolysis is a common disease. However, not all patients diagnosed with L5 spondylolysis exhibit symptoms. This study examined the factors associated with the symptoms of young adults with L5 spondylolysis. Methods The medical records of 70 young adults (mean age, 31.1 years; range, 20–39 years) with L5 spondylolysis treated at the authors’ spine center between March 2008 and February 2015 were reviewed systematically. The symptomatic group (n=46) presented with symptoms, such as back pain and/or intermittent lower limb radiating pain, whereas the asymptomatic group (n=24) did not. Age, sex, body mass index (BMI), adjacent disc degeneration, facet degeneration, and measured spino-pelvic parameters (pelvic incidence, sacral slope, pelvic tilt, lumbar lordosis, sacral inclination, and sacral table angle) were investigated with respect to the presence of symptoms. Adjacent disc degeneration was evaluated using T2-weighted sagittal magnetic resonance imaging (MRI, Pfirrmann classification), whereas facet degeneration was evaluated using T2-weighted axial MRI (Grogan classification). Results Significant differences in the BMI (p =0.032), L4–5 disc degeneration (p =0.030), L5–S1 disc degeneration (p =0.046), L4–5 facet degeneration (p =0.041), and L5–S1 facet degeneration (p =0.027) were observed between the symptomatic and asymptomatic groups. However, multivariate logistic regression analysis revealed that L5–S1 disc degeneration (p =0.033) was the only significant factor. Conclusions BMI and adjacent disc and facet degeneration may be associated with the manifestation of disease symptoms in young adults with L5 spondylolysis, and the likelihood of the patient exhibiting symptoms increases with increasing severity of L5–S1 disc degeneration

Distribution and Conservation of Long-billed Plovers Charadrius placidus in Korea

AbstractThe Long-billed Plover Charadrius placidus of distribution was surveyed from 2002 to 2005, on rivers, streams and coasts of 38 areas within Korea. The Sum of highest numbers (sum of peak counts) of Long-billed Plovers at 24 sites was 198 individuals. Number of observed individuals during breeding period was 88 individuals, 129 individuals during the migration period, and 56 individuals during the wintering period. The Long-billed Plover breeds and migrates throughout Korea. They spend winter south of 37° latitude. Highest numbers (73 individuals) were observed at Daejeon. Therefore, streams and rivers of Korea are considered as an important habitat for the Long-billed Plover