Browsing by Author "Chang S.-H."

Cutaneous sinus tracts in the face and neck region are often dental in origin. The purpose of this study was to characterize the clinical features and treatment of 37 consecutive cases of odontogenic cutaneous sinus tracts, collected and reviewed in a 15-year period. More than half of the patients (21 cases, 57%) were referred from medical doctors, particularly plastic surgeons and dermatologists. The sinus tracts were associated with caries (26 cases), incomplete endodontic treatment (7), crown fracture (2), vertical root fracture (1) and impacted mandibular third molar (1). They occurred most often in adolescents and adults (30 cases, 81%). The most common causative teeth were mandibular teeth (34 teeth, 85%). The chin, submental, and cheek areas were the most common sites of sinus tracts (30 cases, 81%). The majority of causative teeth (32 teeth, 80%) were treated endodontically. All fistulas healed uneventfully after proper dental treatment, without cosmetic surgery. In 63% (20 cases) of the recorded cases, complete resolution occurred within 8 weeks. Half of the patients had had fistulas for more than 6 months before receiving dental treatment, demonstrating that delays in proper diagnosis and treatment were common. As most patients suffered from unnecessary medication or surgery due to the delay of dental treatment, early dental consultation and treatment is important. Conventional endodontic treatment should be the treatment of choice if the tooth is salvageable. The increasing incidence of incomplete endodontic treatment in association with the occurrence of sinus tracts indicates that standardized endodontic therapy should be emphasized for prevention.

We report on the development of a PDMS-SMA composite whose surface micro wrinkles can be dynamically programmed by an electrical current supplied to the SMA wire. It is advantageous over other techniques for surface topographical modulation, including portability, real-time programmability, no requirement for specific surface chemistry, operability under ambient conditions, and relative ease of control. A simplified mechanical model is also developed to describe the force-deflection balance of the PDMS-SMA composite. The wavelengths and amplitudes of the wrinkles when different currents applied to the SMA are characterized, and the experimental results agree with the theoretical model. The developed composite device can be applied to programmable modulations of surface adhesion, friction, wettability, etc. ? 2014 IOP Publishing Ltd.

This study systematically investigated the effect of various Al/Cu ratios on the optical, electrical, and electrochemical properties of sputter-deposited CuAlx-0.2Ca0.2O (x = 1, 1.25, 1.5, 1.75, 2) thin films. The as-sputtered Cu-Al-Ca-O films were all amorphous regardless of Al/Cu ratio. Both the transmittance and resistivity of the Cu-Al-Ca-O films increased with increasing Al/Cu ratios. Heterojunction diodes fabricated using Al-doped ZnO, ZnO, and Cu-Al-Ca-O thin films of various Al/Cu ratios exhibited high breakdown-voltage values when Cu-Al-Ca-O thin films with high Al/Cu ratios. Optimal rectification ratio and electrical properties were determined in diodes that had CuAl1.3Ca0.2O as their p-layer deposited film. Cu-Al-Ca-O films with high Al/Cu ratios exhibited low average corrosion current density (icorr) values and high breakdown-voltages (Ebr) values, indicating that the corrosion resistance of Cu-Al-Ca-O film increases with increasing Al/Cu ratios. ? 2014 Elsevier B.V. All rights reserved.

In this paper nanoimprint molds with 50nm and 100nm feature size nanostructure were fabricated. The periodic pattern of a positive resist was formed on silicon wafer by electron beam lithography, and then the nanostructure of Si was etched using an inductively coupled plasma reactive ion etching (ICP-RIE) system. During the etching process, different ratio of C 4F8 gas was added to the original etching gases SF 6ZO2. By increasing the C4F8 gas, the sidewall protection was improved. The C4F8 gas also increased the etching resistance of the electron beam resist, and the nanoscale resist patterns were maintained through the etching process. The resist was removed after etching, and then the 50nm periodic nanostructure with aspect ratio 6 was obtained. To achieve nanoimprinting process with less damage, the possible sources of stresses resulting from the molding/demolding process, film solidification and thermomechanical mismatch during cooling were studied. ? 2006 IEEE.

This study investigated the surface and electrochemical properties of carbon cloth electrodes surface-modified by using atmospheric pressure plasma jets (APPJs) for applications involving microbial fuel cells (MFCs). APPJ treatment made the carbon cloth highly hydrophilic and did not introduce any observable cracks or flaws. MFCs configured with APPJ-treated carbon cloth electrodes exhibited electrochemical performance (maximum power density of 7.56?mW?m?2) superior to that of MFCs configured with untreated carbon cloth electrodes (maximum power density of 2.38?mW?m?2). This boost in performance can be attributed to the formation of abundant carboxyl and ammonium functional groups on the surface of APPJ-treated carbon cloth, which promoted the formation of anodic biofilms and the adhesion of bacteria, while facilitating the transfer of electrons from the bacteria to the electrodes. APPJ surface modification is non-toxic and environmentally friendly (no exogenous chemicals are required), which is particularly beneficial as the introduction of toxins might otherwise inhibit bacterial growth and metabolism. The APPJ surface modification process is rapid, cost-effective, and applicable to substrates covering a large area, making it ideal for the fabrication of large-scale MFCs and bioelectrochemical bioenergy devices. ? 2016 Elsevier B.V.

A double-HZO ferroelectric FET (FeFET) with near-ideal potentiation linearity αP = 0.07) and applicable conductance ratio GMax/Gmin, Δ G) > 16 was demonstrated by using opposite polarity assistance detrapping (OPAD) stimulation in this study. Double-HZO can provide diverse coercive field for analog FE synaptic operation, and the OPAD scheme helps electron detrapping to avoid trapped charge interference. In addition, the reproducibility of the OPAD has been validated, which is promising for future deep neural network (DNN) circuit design. © 1963-2012 IEEE.

Background and Purpose: Primary immunodeficiency diseases (PIDs) are rare disorders. Unusual infections often guide the initial investigation for immunodeficiency. Methods: In order to ascertain the organisms that lead to a predisposition for PIDs, we reviewed the charts of 92 children diagnosed with PIDs at the National Taiwan University Hospital between March 1984 and March 2004. Results: Pneumonia was diagnosed in 92%, 81%, and 76.5% of patients with antibody, combined, and cellular deficiencies, respectively. Other major illnesses were similar in the 3 groups and included bronchiolitis, acute gastroenteritis, otitis media, and bacteremia. Skin abscess, pneumonia, and lymphadenitis (54.5%, 45%, and 27% of cases, respectively) were the most common infections in patients with phagocyte defects. Organisms were speciated in only 44.8% of infection episodes. Most viral infections were diagnosed by traditional and time-consuming viral culture. Prophylactic antibiotics were prescribed to 9 out of the 92 patients with PIDs. Conclusions: Early recognition of PIDs requires that practitioners be aware of the infection characteristics, and subsequent reliable and rapid molecular diagnosis are needed in such immunocompromised patients. ? 2006 Journal of Microbiology, Immunology and Infection.