Optimization of Suture-Free Laser-Assisted Vessel Repair by Solder-Doped Electrospun Poly(ε-caprolactone) Scaffold

Poor welding strength constitutes an obstacle in the clinical employment of laser-assisted vascular repair (LAVR) and anastomosis. We therefore investigated the feasibility of using electrospun poly(ε-caprolactone) (PCL) scaffold as reinforcement material in LAVR of medium-sized vessels. In vitro solder-doped scaffold LAVR (ssLAVR) was performed on porcine carotid arteries or abdominal aortas using a 670-nm diode laser, a solder composed of 50% bovine serum albumin and 0.5% methylene blue, and electrospun PCL scaffolds. The correlation between leaking point pressures (LPPs) and arterial diameter, the extent of thermal damage, structural and mechanical alterations of the scaffold following ssLAVR, and the weak point were investigated. A strong negative correlation existed between LPP and vessel diameter, albeit LPP (484 ± 111 mmHg) remained well above pathophysiological pressures. Histological analysis revealed that thermal damage extended into the medial layer with a well-preserved internal elastic lamina and endothelial cells. Laser irradiation of PCL fibers and coagulation of solder material resulted in a strong and stiff scaffold. The weak point of the ssLAVR modality was predominantly characterized by cohesive failure. In conclusion, ssLAVR produced supraphysiological LPPs and limited tissue damage. Despite heat-induced structural/mechanical alterations of the scaffold, PCL is a suitable polymer for weld reinforcement in medium-sized vessel ssLAVR

Systematic analysis of mitochondrial genes associated with hearing loss in the Japanese population: dHPLC reveals a new candidate mutation

<p>Abstract</p> <p>Background</p> <p>Variants of mitochondrial DNA (mtDNA) have been evaluated for their association with hearing loss. Although ethnic background affects the spectrum of mtDNA variants, systematic mutational analysis of mtDNA in Japanese patients with hearing loss has not been reported.</p> <p>Methods</p> <p>Using denaturing high-performance liquid chromatography combined with direct sequencing and cloning-sequencing, Japanese patients with prelingual (N = 54) or postlingual (N = 80) sensorineural hearing loss not having pathogenic mutations of m.1555A > G and m.3243A > G nor <it>GJB2 </it>were subjected to mutational analysis of mtDNA genes (<it>12S rRNA</it>, <it>tRNA</it>^{<it>Leu(UUR)</it>}, <it>tRNA</it>^{<it>Ser(UCN)</it>}, <it>tRNA</it>^<it>Lys</it>, <it>tRNA</it>^<it>His</it>, <it>tRNA</it>^{<it>Ser(AGY)</it>}, and <it>tRNA</it>^<it>Glu</it>).</p> <p>Results</p> <p>We discovered 15 variants in <it>12S rRNA </it>and one homoplasmic m.7501A > G variant in <it>tRNA</it>^{<it>Ser(UCN)</it>}; no variants were detected in the other genes. Two criteria, namely the low frequency in the controls and the high conservation among animals, selected the m.904C > T and the m.1105T > C variants in <it>12S rRNA </it>as candidate pathogenic mutations. Alterations in the secondary structures of the two variant transcripts as well as that of m.7501A > G in <it>tRNA</it>^{<it>Ser(UCN) </it>}were predicted.</p> <p>Conclusions</p> <p>The m.904C > T variant was found to be a new candidate mutation associated with hearing loss. The m.1105T > C variant is unlikely to be pathogenic. The pathogenicity of the homoplasmic m.7501T > A variant awaits further study.</p

Validation of a Chinese version of the dental anxiety inventory

Objectives: To translate the English version of Dental Anxiety Inventory (DAxI) and its short-form (SDAxI) and to validate their use in Hong Kong Chinese. Methods: The DAxI and SDAxI were translated into Chinese. A total of 500 adults (18-64 years) were interviewed, the Chinese DAxI, Symptom Checklist 90 (SCL-90), Depression Anxiety Stress Scales (DASS) and State-Trait Anxiety Inventory (STAI) were completed. Based on their initial DAxI scores, 135 interviewees were invited to attend a dental examination 1 month later. Then, the subjects completed the DAxI again, together with Beck Anxiety Inventory (BAI) which measured the state anxiety level of the participants. Two months after the initial interview, all 500 subjects were asked to complete the DAxI again. Another 300 adults were recruited and interviewed for the SDAxI validation. Results: Cronbach's alpha of the Chinese DAxI and SDAxI were 0.77 and 0.80 and the test-retest correlation coefficients were 0.90 and 0.84, respectively. High correlation between BAI and DAxI scores and its stability over time supported construct validity of the Chinese DAxI. Small positive correlations between the DAxI and other subscales of the SCL-90, DASS and STAI supported discriminant validity of the instrument. The SDAxI demonstrated comparable validity and reliability with DAxI. Conclusion: The translated Chinese DAxI demonstrated good validity and reliability. It is available for use in dental anxiety research in adult Chinese. In situations where a short-form is desirable, the Chinese SDAxI is a simple, valid, reliable and interpretable scale for measuring dental anxiety in both research and dental practice. © Blackwell Munksgaard, 2005.postprin

GIS-based framework for supporting land use planning in urban renewal: case study in Hong Kong

Land use planning plays an important role in achieving sustainable urban development. One of the problems planners frequently encounter is the absence of an integrated quantitative approach to assessing land-use suitability and supporting land use planning (site level), particularly in urban renewal. This paper develops a geographic information system (GIS)-based framework to solve this problem. The framework consists of three main modules: land information database, planning/policy control mechanism, and model of land-use suitability analysis (LUSA). In the process of developing this framework, three tasks are completed. First, key factors affecting land-use decision making in urban renewal planning are identified and 20 of them are quantitatively examined from five perspectives of land attributes: inherent/physical, locational, social, economic, and environmental. Second, two submodels, namely, the criterion-value generation model and suitability assessment model are designed and built for LUSA in land redevelopment/urban renewal. Third, five types of land use, i.e., residential, commercial, industrial, government/institutional/community (G/IC), and open space in Hong Kong are defined and considered for land-use suitability grading. Several new planning approaches such as scenario planning, public participation, and collaborative interaction are included in this framework to improve planning processes by enhancing their adoption and application in urban (land use) planning. This proposed framework is found to be a useful tool for both practitioners and researchers involved in sustainable land use planning in urban renewal.Department of Building and Real Estat

A Review of Planning Support Systems for Urban Land Use Planning

This paper reviews the research work on a relatively particular area – planning support systems (PSS) for urban land use planning (ULUP) from their emergence to the present. To aid readers’ clear understanding of PSS, its definition is discussed in the beginning. The review summarizes the development of PSS from two perspectives: system components and system application. In terms of system components, namely, the major theories and technologies serving for building the PSS such as related planning theories, GIS and decision support systems (DSS) technologies are reviewed respectively. With respect to system application, the paper discusses in detail their application to urban (land use) planning and other specialized planning separately. Based on this systematic overview, the characteristics in different times, especially current advantages and shortcomings of the PSS are indicated. Moreover, several new research trends in the PSS area are also highlighted for guiding researchers in future studies

A decision making framework for sustainable land use in Hong Kong’s urban renewal projects

Purpose – Urban renewal projects provide an effective channel for adjusting land-use allocation and improving land-use efficiency, which effectively increases land supply. The purpose of this paper is to support the decision-making process of sustainable land use in urban renewal projects. A GIS-based framework, consisting of a planning support model and a land information database, has been developed in a typical high-density city – Hong Kong. Design/methodology/approach – A qualitative and quantitative combined methodology is designed for this research. Several research methods such as expert interviews, focus group meetings, and case studies and technical approaches such as GIS, MCA, and AHP are adopted in this research. Findings – General and sustainability criteria for land-use decision making in urban renewal along with associated data are identified, and an integrated approach to quantitatively assessing land-use suitability is developed. Research limitations/implications – The framework was developed in a loosely coupled form rather than a software package installed on a computer, and the development of the land information database was a time-consuming process as a large amount of data were collected, processed, and analyzed. Originality/value – Application of the proposed framework is reported by showing analyzed results of land-use suitability. The framework proves a useful tool for both practitioners and researchers involved in sustainable land use for urban renewal.Department of Building and Real Estat