Energy absorption investigation of square CFRP honeycomb reinforced by PMI foam fillers under quasi-static compressive load

Hao Zhou,Rui Guo,Kuo Bao,Haiyang Wei,Rongzhong Liu 국제구조공학회 2019 Steel and Composite Structures, An International J Vol.33 No.6

A type of hybrid core made up of thin-walled square carbon fiber reinforced polymer (CFRP) honeycomb and Polymethacrylimide (PMI) foam fillers was proposed and prepared. Numerical model of the core under quasi static compression was established and validated by corresponding experimental results. The compressive properties of the core with different configurations were analyzed through numerical simulations. The effect of the geometrical parameters and foam fillers on the compressive response and energy absorption of the core were analyzed. The results show that the PMI foam fillers can significantly improve the compressive strength and energy absorption capacity of the square CFRP honeycomb. The geometrical parameters have marked effects on the compressive properties of the core. The research can give a reference for the application of PMI foam materials in energy absorbing structures and guide the design and optimization of lightweight and energy efficient cores of sandwiches.

Initial Factors Influencing Duration of Hospital Stay in Adult Patients With Peritonsillar Abscess

Yu-Hsi Liu,Hsing-Hao Su,Yi-Wen Tsai,Yu-Yi Hou,Kuo-Ping Chang,Chao-Chuan Chi,Ming-Yee Lin,Pi-Hsiung Wu 대한이비인후과학회 2017 Clinical and Experimental Otorhinolaryngology Vol.10 No.1

Objectives. To review cases of peritonsillar abscess and investigate the initial clinical factors that may influence the duration of hospitalization. To determine the predictive factors of prolonged hospital stay in adult patients with peritonsillar abscess. Methods. Subjects were adults hospitalized with peritonsillar abscess. We retrospectively reviewed 377 medical records from 1990 to 2013 in a tertiary medical center in southern Taiwan. The association between clinical characteristics and the length of hospital stay was analyzed with independent t-test, univariate linear regression and multiple linear regression analysis. Results. The mean duration of hospitalization was 6.2±6.0 days. With univariate linear regression, a prolonged hospital stay was associated with several variables, including female gender, older ages, nonsmoking status, diabetes mellitus, hypertension, band forms in white blood cell (WBC) counts, and lower hemoglobin levels. With multiple linear regression analysis, four independent predictors of hospital stay were noted: years of age (P<0.001), history of diabetes mellitus (P<0.001), ratio of band form WBC (P<0.001), and hemoglobin levels (P<0.001). Conclusion. In adult patients with peritonsillar abscess, older ages, history of diabetes mellitus, band forms in WBC counts and lower hemoglobin levels were independent predictors of longer hospitalization.

Formation of Solid-Solution Cu-to-Cu Joints Using Ga Solder and Pt under Bump Metallurgy for Three-Dimensional Integrated Circuits

Shih-kang Lin,Hao-miao Chang,Cheng-liang Cho,Yu-chen Liu,Yi-kai Kuo 대한금속·재료학회 2015 ELECTRONIC MATERIALS LETTERS Vol.11 No.4

Three-dimensional (3D) integrated circuits (ICs) are the most important packaging technology for next-generation semiconductors. Cu-to-Cu throughsilicon via interconnections with micro-bumps are key components in the fabrication of 3D ICs. However, significant reliability concerns have been raised due to the formation of brittle intermetallic compounds in the entire 3D IC joints. This study proposes a Ga-based Cu-to-Cu bonding technology with Pt under bump metallurgy (UBM). A systematic analysis of reactive wetting between Ga solders and polycrystalline, single-crystalline, and Ptcoated Cu substrates was conducted. Pt UBM as a wetting layer was identified to be a key component for Ga-based Cu-to-Cu bonding. Pt-coated Cu substrates were bonded using Ga solders with various Ga-to-Pt ratios (n) at 300°C. When n ≥ 4, the Cu/Pt/Ga/Pt/Cu interface evolves to Cu/facecentered cubic (fcc)/γ1-Cu9Ga4/fcc/Cu, Cu/fcc/γ1-Cu9Ga4 + Ga7Pt3/fcc/Cu, and finally Cu/fcc + Ga7Pt3/Cu structures. The desired ductile solid solution joint formed with discrete Ga7Pt3 precipitates. When n ≤ 1, a Cu/Ga7Pt3/Cu joint formed without Cu actively participating in the reactions. The reaction mechanism and microstructure evolution were elaborated with the aid of CALPHAD thermodynamic modeling.

A Reagent-Ready-on-Chip Microfluidic Immunoassay System for Rapid Detection of Influenza A H1N1 and H3N2 Viruses

Kin Fong Lei,Jun-Liang Liu,Chia-Hao Huang,Rei-Lin Kuo,Ngan-Ming Tsang 한국바이오칩학회 2016 BioChip Journal Vol.10 No.1

Development of effective disease screening method is the best approach for the control of infectious diseases. However, conventional screening methods require to operate in well-equipped laboratory. That makes the screening operation expensive and time-consuming. In this work, a reagent-ready-on-chip microfluidic immunoassay system was developed and rapid detection of influenza A H1N1 and H3N2 viruses was demonstrated to show its simplicity and rapidity. The microfluidic system integrated 4 single-stroke thermopneumatic actuators and a reaction chamber. All related reagents were pre-installed in the system and manipulated automatically for indirect immunoassay. Detection of influenza A H1N1 and H3N2 viruses based on its internal structure protein, i.e., nucleoprotein (NP), was demonstrated using the system. Result was represented by colorimetric signal in the reaction chamber. The use of thermopneumatic actuation could achieve fluid manipulation without external assistive equipment and colorimetric result could be observed directly without the need of external dedicated detector. Influenza virus screening could be completed around 1 hour with less sample volume (20 μL) and reagent volume (50 μL). The system achieved one-step operation of immunoassay. It is highly integrated and has potential to be developed to portable devices to realize rapid diagnostics in remote environment and clinics without well-equipped facility. Development of effective disease screening method is the best approach for the control of infectious diseases. However, conventional screening methods require to operate in well-equipped laboratory. That makes the screening operation expensive and time-consuming. In this work, a reagent-ready-on-chip microfluidic immunoassay system was developed and rapid detection of influenza A H1N1 and H3N2 viruses was demonstrated to show its simplicity and rapidity. The microfluidic system integrated 4 single-stroke thermopneumatic actuators and a reaction chamber. All related reagents were pre-installed in the system and manipulated automatically for indirect immunoassay. Detection of influenza A H1N1 and H3N2 viruses based on its internal structure protein, i.e., nucleoprotein (NP), was demonstrated using the system. Result was represented by colorimetric signal in the reaction chamber. The use of thermopneumatic actuation could achieve fluid manipulation without external assistive equipment and colorimetric result could be observed directly without the need of external dedicated detector. Influenza virus screening could be completed around 1 hour with less sample volume (20 μL) and reagent volume (50 μL). The system achieved one-step operation of immunoassay. It is highly integrated and has potential to be developed to portable devices to realize rapid diagnostics in remote environment and clinics without well-equipped facility.

Comparison of the Infant and Adult Adipose-Derived Mesenchymal Stem Cells in Proliferation, Senescence, Anti-oxidative Ability and Differentiation Potential

Wu Szu-Hsien,Yu Jin-Huei,Liao Yu-Ting,Liu Kuo-Hao,Chiang En-Rung,Chang Ming-Chau,Wang Jung-pan 한국조직공학과 재생의학회 2022 조직공학과 재생의학 Vol.19 No.3

BACKGROUND: Infant adipose-derived mesenchymal stem cells (ADSCs) collected from excised polydactyly fat tissue, which was surgical waste, could be cultured and expanded in vitro in this study. In addition, the collecting process would not cause pain in the host. In this study, the proliferation, reduction of senescence, anti-oxidative ability, and differentiation potential in the infant ADSCs were compared with those in the adult ADSCs harvested from thigh liposuction to determine the availability of infant ADSCs. METHODS: Proliferation was determined by detecting the fold changes in cell numbers and doubling time periods. Senescence was analyzed by investigating the age-related gene expression levels and the replicative stress. The superoxide dismutase (SOD) gene expression, adipogenic, neurogenic, osteogenic, and tenogenic differentiation were compared by RTqPCR. The chondrogenic differentiation efficiency was also determined using RT-qPCR and immunohistochemical staining. RESULTS: The proliferation, SOD (SOD1, SOD2 and SOD3) gene expression, the stemness-related gene (c-MYC) and telomerase reverse transcriptase of the infant ADSCs at early passages were enhanced compared with those of the adults’. Cellular senescence related genes, including p16, p21 and p53, and replicative stress were reduced in the infant ADSCs. The adipogenic genes (PPARc and LPL) and neurogenic genes (MAP2 and NEFH) of the infant ADSC differentiated cells were significantly higher than those of the adults’ while the expression of the osteogenic genes (OCN and RUNX) and tenogenic genes (TNC and COL3A1) of both demonstrated opposite results. The chondrogenic markers (SOX9, COL2 and COL10) were enhanced in the infant ADSC differentiated chondrogenic pellets, and the expression levels of SODs were decreased during the differentiation process. CONCLUSION: Cultured infant ADSCs demonstrate less cellular senescence and replicative stress, higher proliferation rates, better antioxidant defense activity, and higher potential of chondrogenic, adipogenic and neurogenic differentiation.