Stabilization and improved functionality of three-dimensional perfusable microvascular networks in microfluidic devices under macromolecular crowding

Ho-Ying Wan,Jack Chun Hin Chen,Qinru Xiao,Christy Wingtung Wong,Boguang Yang,Benjamin Cao,Rocky S. Tuan,Susan K. Nilsson,Yi-Ping Ho,Michael Raghunath,Roger D. Kamm,Anna Blocki 한국생체재료학회 2023 생체재료학회지 Vol.27 No.00

Background There is great interest to engineer in vitro models that allow the study of complex biological processes of the microvasculature with high spatiotemporal resolution. Microfluidic systems are currently used to engineer microvasculature in vitro, which consists of perfusable microvascular networks (MVNs). These are formed through spontaneous vasculogenesis and exhibit the closest resemblance to physiological microvasculature. Unfortunately, under standard culture conditions and in the absence of co-culture with auxiliary cells as well as protease inhibitors, pure MVNs suffer from a short-lived stability. Methods Herein, we introduce a strategy for stabilization of MVNs through macromolecular crowding (MMC) based on a previously established mixture of Ficoll macromolecules. The biophysical principle of MMC is based on macromolecules occupying space, thus increasing the effective concentration of other components and thereby accelerating various biological processes, such as extracellular matrix deposition. We thus hypothesized that MMC will promote the accumulation of vascular ECM (basement membrane) components and lead to a stabilization of MVN with improved functionality. Results MMC promoted the enrichment of cellular junctions and basement membrane components, while reducing cellular contractility. The resulting advantageous balance of adhesive forces over cellular tension resulted in a significant stabilization of MVNs over time, as well as improved vascular barrier function, closely resembling that of in vivo microvasculature. Conclusion Application of MMC to MVNs in microfluidic devices provides a reliable, flexible and versatile approach to stabilize engineered microvessels under simulated physiological conditions.

Flexural behavior of reinforced lightweight concrete beams under reversed cyclic loading

Chien, Li-Kai,Kuo, Yi-Hao,Huang, Chung-Ho,Chen, How-Ji,Cheng, Ping-Hu Techno-Press 2014 Structural Engineering and Mechanics, An Int'l Jou Vol.52 No.3

This paper presents the results of an experimental investigation on the flexural behavior of doubly reinforced lightweight concrete (R.L.C.) beams tested under cyclic loading. A total of 20 beam specimens were tested. Test results are presented in terms of ductility index, the degradation of strength and stiffness, and energy dissipation. The flexural properties of R.L.C. beam were compared to those of normal concrete (R.C.) beams. Test results show that R.L.C. beam with low and medium concrete strength (20, 40MPa) performed displacement ductility similar to the R.C. beam. The ductility can be improved by enhancing the concrete strength or decreasing the tension reinforcement ratio. Using lightweight aggregate in concrete is advantageous to the dynamic stiffness of R.L.C. beam. Enhancement of concrete strength and increase of reinforcement ratio will lead to increase of the stiffness degradation of beam. The energy dissipation of R.L.C beam, similar to R.C. beam, increase with the increase of tension reinforcement ratio. The energy dissipation of unit load cycle for smaller tension reinforcement ratio is relatively less than that of beam with higher reinforcement ratio.

Flexural behavior of reinforced lightweight concrete beams under reversed cyclic loading

Li-Kai Chien,Yi-Hao Kuo,Chung-Ho Huang,How-Ji Chen,Ping-Hu Cheng 국제구조공학회 2014 Structural Engineering and Mechanics, An Int'l Jou Vol.52 No.3

This paper presents the results of an experimental investigation on the flexural behavior of doubly reinforced lightweight concrete (R.L.C.) beams tested under cyclic loading. A total of 20 beam specimens were tested. Test results are presented in terms of ductility index, the degradation of strength and stiffness, and energy dissipation. The flexural properties of R.L.C. beam were compared to those of normal concrete (R.C.) beams. Test results show that R.L.C. beam with low and medium concrete strength (20, 40MPa) performed displacement ductility similar to the R.C. beam. The ductility can be improved by enhancing the concrete strength or decreasing the tension reinforcement ratio. Using lightweight aggregate in concrete is advantageous to the dynamic stiffness of R.L.C. beam. Enhancement of concrete strength and increase of reinforcement ratio will lead to increase of the stiffness degradation of beam. The energy dissipation of R.L.C beam, similar to R.C. beam, increase with the increase of tension reinforcement ratio. The energy dissipation of unit load cycle for smaller tension reinforcement ratio is relatively less than that of beam with higher reinforcement ratio.

Henriciella marina gen. nov., sp. nov., a Novel Member of the Family Hyphomonadaceae Isolated from the East Sea

Zhe-Xue Quan,Dan-Ning Zeng,Yi-Ping Xiao,노성운,Young-Do Nam,Ho-Won Chang,윤정훈,오희목,배진우 한국미생물학회 2009 The journal of microbiology Vol.47 No.2

A bacterial strain, designated Iso4T, was isolated from the East Sea of Korea and was subjected to a polyphasictaxonomy study including phenotypic and chemotaxonomic characteristics as well as 16S rRNAgene sequence analysis. Cells of the strain were Gram-negative, motile, non-budding, non-stalked, andstrictly aerobic. Strain Iso4T grew optimally at 20°C in the presence of 1~2% (w/v) NaCl and at pH 6.9~7.6. The major respiratory quinone was Q-10 and the major cellular fatty acids were C18:1 ω7c (53.5%),C17:1 ω5c (11.7%), C17:1 ω6c (8.1%), C16:0 (7.8%), C17:0 (4.8%), C15:0 (2.9%), and C16:1 ω5c (2.2%). The DNAG+C content of strain Iso4T was 56.2 mol%. Phylogenetic analysis based on 16S rRNA gene sequencesshowed that strain Iso4T formed a monophyletic clade in the family Hyphomonadaceae, supported by highbootstrap value and was most closely related to the genus Hyphomonas (92~94%), a member of marinebacteria in the family. The phenotypic, genotypic, and chemotaxonomic evidences also suggest strain Iso4Trepresents a novel genus and species in the family Hyphomonadaceae, for which the name Henriciella gen. nov., sp. nov. is proposed. The type strain is Iso4T (=KCTC 12513T =DSM 19595T =JCM 15116T).

The Effect of a Scenario-Based Spiritual Care Course on Spiritual Care Competence among Clinical Nurses

Suh-Ing Hsieh,Li-Ling Hsu,Hui-Ling Lin,Chen-Yi Kao,Yi-Ping Tseng,Li-Yun Szu,Ching-Yun Lee,Lun-Hui Ho,Shu-Ling Yeh,Shu-Hua Kao,Yen-Fang Chou,Tzu-Hsin Huang 한국성인간호학회 2021 성인간호학회 학술대회 Vol.2021 No.8

Aim(s): Clinical nurses are facing patients’ biopsychosocial and spiritual problems at diverse clinical settings, but they are lack of knowledge, skills, and confidence on providing spiritual care. However, no studies adopted simulated educational program and objective structure clinical examination (OSCE) to educate nurses and to assess the outcomes. Therefore, this study was to validate the effect of a scenario-based spiritual care course on spiritual care competence in clinical nurses. Methods: This non-equivalent quasi-experimental study with a pre-test and two post-tests (end of the intervention and three months later) was conducted between August 2019 and February 2021 (11 sessions). The recruitment posters with a QR code were distributed to different units at three branches of a large medical institute for recruiting clinical nurses, who provided direct patient care. The attendees of one-day scenario-based spiritual care course are the experimental group (n=53) and the control group (n=85) was matched with the experimental group (1:1-3 ratio) by similar units, ages, working experience, and clinical ladder. Instruments include basic information, self-evaluated and head nurses evaluated spiritual care competence scale (SCCS), spiritual perspective scale (SPS), and spiritual care perspective scale-revised (SCPSR) for both groups and reflective log, course satisfaction scale, OSCE checklist, and standardized patient feedback scale for the experimental group. The data were analyzed using descriptive statistics, repeated measures ANOVA, linear regression, and paired t test. Results: After controlling for pre-test scores and interest in attending spirituality/spiritual care, the experimental group showed significant higher SPS (p=0.012) and self-evaluated SCCS (p=0.002) and lower SCPSR (p=0.015) than the control group at the 2nd post-test. Repeated measure ANOVA also showed significant within-subject effects across three time points of the experimental group on SPS (p<0.001), SCPSR (p<0.001), and self-evaluated SCCS (p<0.001), but paired t test showed non-significant differences on SPS, SCPSR, and self-evaluated SCCS between pre-test and post-test with an exception of head nurse evaluated SCCS (p=0.035). The mean overall course satisfaction of the experimental group was 4.34±0.62. The mean global performance of OSCE was 3.40±0.91 and the majority of experimental group was pass (43.4%) and good (35.8%). 64.5% and 26.1% of standardized patients were partial and strongly agreed with examinees’ performance in spiritual care assessment respectively. Conclusions: The scenario-based spiritual care course is effectively to enhance clinical nurses’ spiritual care competence. It may cultivate clinical preceptors with better spiritual care pedagogy through simulation and OSCE for bedside teaching of nurse post-graduate year.