Intense pulsed light annealing of solution-based indium-gallium-zinc-oxide semiconductors with printed Ag source and drain electrodes for bottom gate thin film transistors.

In this study, an intense pulsed light (IPL) annealing process for a printed multi-layered indium-gallium-zinc-oxide (IGZO) and silver (Ag) electrode structure was developed for a high performance all-printed inorganic thin film transistor (TFT). Through a solution process using IGZO precursor and Ag ink, the bottom gate structure TFT was fabricated. The spin coating method was used to form the IGZO semiconductor layer on a heavily-doped silicon wafer covered with thermally grown silicon dioxide. The annealing process of the IGZO layer utilized an optimized IPL irradiation process. The Ag inks were printed on the IGZO layer by screen printing to form the source and drain (S/D) pattern. This S/D pattern was dried by near infrared radiation (NIR) and the dried S/D pattern was sintered with intense pulsed light by varying the irradiation energy. The performances of the all-printed TFT such as the field effect mobility and on-off ratio electrical transfer properties were measured by a parameter analyzer. The interfacial analysis including the contact resistance and cross-sectional microstructure analysis is essential because diffusion phenomenon can occur during the annealing and sintering process. Consequently, this TFT device showed noteworthy performance (field effect mobility: 7.96 cm2/V s, on/off ratio: 107). This is similar performance compared to a conventional TFT, which is expected to open a new path in the printed metal oxide-based TFT field.

A new Korean Research Investment for Global Health Technology (RIGHT) Fund to advance innovative neglected-disease technologies.

In 2018, the government of the Republic of Korea (ROK), South Korean life science companies, and a group of international funders led by the Bill & Melinda Gates Foundation launched a new and innovative funding agency to support neglected-disease research and development (R&D). The new venture is known as the Research Investment for Global Health Technology (RIGHT) Fund.

Intense Pulsed Light Annealing Process of Indium-Gallium-Zinc-Oxide Semiconductors via Flash White Light Combined with Deep-UV and Near-Infrared Drying for High-Performance Thin-Film Transistors.

In this study, an intense pulsed light (IPL) process for annealing an indium-gallium-zinc-oxide (IGZO) semiconductor was conducted via flash white light combined with near-infrared (NIR) and deep-ultraviolet (DUV) drying to form a thin-film transistor (TFT). The IGZO thin-film semiconductor was fabricated using a solution-based process on a doped-silicon wafer covered with silicon dioxide. In order to optimize the IPL irradiation condition for the annealing process, the flash white light irradiation energy was varied from 70 to 130 J/cm2. Drying by NIR and DUV irradiation was employed and optimized to improve the performance of the TFT during IPL annealing. A TFT with a bottom-gate and top-contact structure was formed by depositing an aluminum electrode on the source and drain on the IPL-annealed IGZO. The electrical transfer characteristic of the TFT was measured using a parameter analyzer. The field effect mobility of the saturation regime and on/off current ratio were evaluated. Changes of the metal-oxide bonds in the IGZO thin film were analyzed using X-ray photoelectron spectroscopy to verify the effect of NIR and DUV drying and IPL annealing. Also, the distributions of the carrier concentration on the IPL-annealed IGZO were measured through a hall-effect system to deeply investigate the transition of the electrical characteristic of the TFT. From the results, it was found that the bond between oxygen and the gallium compound was activated via DUV irradiation. The NIR- and DUV-assisted IPL-annealed IGZO-based TFT showed highly enhanced electrical performance with a 7.7 cm2/V·s mobility and a 3 × 106 on/off ratio.

A highly reliable copper nanowire/nanoparticle ink pattern with high conductivity on flexible substrate prepared via a flash light-sintering technique.

In this work, copper nanowires (NWs) and Cu nanoparticles (NPs) were employed to increase the reliability of a printed electrode pattern under mechanical bending fatigue. The fabricated Cu NW/NP inks with different weight fractions of Cu NWs were printed on a polyimide substrate and flash light-sintered within a few milliseconds at room temperature under ambient conditions. Then, 1000 cycles of outer and inner bending fatigue tests were performed using a lab-made fatigue tester. The flash light-sintered Cu NW/NP ink film with 5 wt % Cu NWs prepared under the flash light-sintering conditions (12.5 J·cm­2 irradiation energy, 10 ms pulse duration, and one pulse) showed a lower resistivity (22.77 µΩ·cm) than those of the only Cu NPs and Cu NWs ink (94.01 µΩ·cm and 104.15 µΩ·cm, respectively). In addition, the resistance change (ΔR·R0(­1)) of the 5 wt % Cu NWs Cu NW/NP film was greatly enhanced to 4.19 compared to the 92.75 of the Cu NPs film obtained under mechanical fatigue conditions over 1000 cycles and an outer bending radius of 7 mm. These results were obtained by the densification and enhanced mechanical flexibility of flash light-sintered Cu NW/NP network, which resulted in prevention of crack initiation and propagation. To characterize the Cu NW/NP ink film, X-ray diffraction and scanning electron microscopy were used.

Safety of Monitoring Exercise for Early Hospital-based Cardiac Rehabilitation.

OBJECTIVE: To survey the cardiovascular complications induced by cardiac monitoring exercise during 10 years of our cardiac rehabilitation (CR) clinic and report on the safety of monitoring exercise training for early hospital-based CR. METHOD: All cardiac patients who participated in our exercise program from January 2000 through December 2009 were recruited as study subjects. We stratified the exercise risks of cardiac events and conducted the monitoring exercise with individualized prescriptions. We measured all cardiac complications, including death, symptoms, abnormal hemodynamic responses, and electrocardiogram (ECG) abnormality during exercise training, for 10 years. A total of 975 patients (68% male; mean age, 58.9±10.6) were included in this study. Initial indications for CR were recent percutaneous transluminal coronary angioplasty (PTCA) (75%), post-cardiac surgery (coronary bypass graft, 13.2%), valvular surgery and other cardiac surgery (4.2%), and others (7.6%). RESULTS: The study population underwent 13,934 patient-hours of monitoring exercise. No death, cardiac arrest or acute myocardial infarction (AMI) occurred during exercise (0/13,934 exercise-hours). Fifty-nine patients experienced 70 cardiovascular events during the 13,934 exercise-hours (1/199 exercise-hours); there were 17 cases of angina only (1/820 exercise-hours), 31 cases of ECG abnormalities only (1/449 exercise-hours), 12 cases of angina with ECG abnormalities (1/1,161 exercise-hours), and 10 cases of abnormal hemodynamic responses (1/1,393 exercise-hours). CONCLUSION: Early hospital-based CR is safe enough that no death, cardiac arrest or AMI occurred during the 13,934 patient-hours of monitoring exercise. However, risk stratification for exercise-induced cardiovascular events, proper exercise prescriptions, and intensive ECG monitoring are required prior to initiation of the monitoring exercise.

Genetic diversity among Korean Candida albicans bloodstream isolates: assessment by multilocus sequence typing and restriction endonuclease analysis of genomic DNA by use of BssHII.

Multilocus sequence typing (MLST) has been successfully applied to the epidemiology of Candida albicans isolates not only within the hospital setting but also in multiple locations nationwide. We performed MLST to investigate the genetic relatedness among bloodstream infection (BSI) isolates of C. albicans recovered from 10 Korean hospitals over a 12-month period. The 156 isolates yielded 112 unique diploid sequence types (DSTs). While 95 DSTs were each derived from a single isolate, 17 DSTs were shared by 61 isolates (39.1%). Interestingly, 111 (71.1%) isolates clustered within previously known clades, and 29 (18.6%) clustered within a new clade that includes strains of Asian origin previously typed as singletons. This MLST study was complemented by restriction endonuclease analysis of genomic DNA using BssHII (REAG-B) in order to evaluate whether strains with identical DSTs and originating from the same hospital corresponded to nosocomial clusters. Importantly, only those isolates with a strong epidemiological relationship showed ≥95% identical REAG-B types. Our results indicate that REAG-B typing can be complementary to MLST but should be limited to the investigation of isolates of identical DSTs and when interhuman transmission is suspected.

Prognostic influences of cardiac rehabilitation in korean acute myocardial infarction patients.

OBJECTIVE: To observe the prognostic influences of the cardiac rehabilitation (CR) program in Korean acute myocardial infarction (AMI) patients during the first year after an occurrence of the disease. METHOD: A total of 141 AMI patients who underwent percutaneous coronary intervention (PCI) were recruited consecutively for this study and divided into the CR group and the control group. The CR group completed the phase 2 CR program in the hospital for a period of 6-8 weeks and maintained self-exercise in their community by exercise prescription for a year after AMI. We performed a prospective comparison of the patients' demographic data, high sensitive C-reactive protein (hs-CRP) level after the 4-month CR program, and the rate of recurrence (AMI, re-hospitalization, positive coronary angiogram, needed revascularization procedure, or death) between the two groups. RESULTS: Compared to the control group (0.33±0.48 mg/dl), the hs-CRP level was lower in the CR group (0.18±0.32 mg/dl) after 4 months of exercise. The recurrence rate was lower (10%, 7/69) in the CR group, compared to the control group (24%, 17/72, p<0.05). The number of disease-free days was larger in the CR group (354±38.34), compared to the control group (316±99.96, p<0.05). In a comparison of statistical methods used for testing the equality of two survivor distributions, the CR group showed a lower recurrence rate than the control group (p<0.05). CONCLUSION: Participation in the CR program designed for AMI patients who underwent PCI-induced normalization of the serum hs-CRP level and lowering of the recurrence rate by 14% during the first year.

Retrodiscal approach of lumbar epidural block.

OBJECTIVE: To compare the technical strengths and weaknesses between retrodiscal (RD) and conventional subpedicular (SP) approaches of transforaminal epidural block (TF-EPB). METHOD: Sixty-one patients with L5 radiculopathy who planned to undergo TF-EPB were consecutively enrolled as study subjects. Subjects were randomly assigned to one of two groups. For the RD approach, the positioning of the patient and the C-arm were similar to that for lumbar discography. We compared the pattern of dye spreads, the frequency of complications during the procedures, and the effect of the pain block 2 weeks after the procedure between the two groups. RESULTS: For the RD group (n=24), the contrast dye diffused around the L5 and S1 nerve roots in 16 cases (67%), but it diffused around only the L5 root in 27 cases (73%) in the SP group (n=37) (p<0.05). Two weeks after the procedure, the visual analogue scale (VAS) decreased by the same amount in both groups (RD group: 3.1±1.6, SP group: 3.2±2.6). Symptoms of nerve root irritation occurred in 1 case of the RD group and in 10 cases of the SD group (p<0.05). CONCLUSION: The RD approach was as efficient as the SP approach for temporary diagnostic relief and offered considerable advantages, such as lower nerve root irritation possible lower risk of vascular injection. Thus, it could be a useful technique when a herniated disc segment is stuck or when the foraminal stenosis is severe.

[Species-specific differences in Rhodamine 6G accumulation of Candida isolates detected by flow cytometric analysis].

BACKGROUND: Fluorescent dye Rhodamine 6G (R6G) is a substrate of multidrug resistance pumps and its accumulation is reduced in some azole-resistant Candida isolates with the upregulation of multidrug efflux transporter genes. Despite reports on species-specific differences in azole susceptibility in various Candida species, only a few studies have been reported on the R6G accumulation among clinical isolates of Candida species. In this study, we compared R6G accumulation between six different Candida species. METHODS: The intracellular accumulation of R6G and minimal inhibitory concentrations (MICs) of three triazole agents were investigated in 48 strains of six Candida species (14 C. albicans, 9 C. tropicalis, 8 C. glabrata, 8 C. krusei, 7 C. parapsilosis, and 2 C. haemulonii). R6G accumulation was measured by using flow cytometry and the geometric mean of the fluorescence intensity (GMF) was used to compare the accumulation between the Candida isolates. RESULTS: The GMF values for the C. tropicalis, C. albicans, C. krusei, C. parapsilosis, and C. glabrata isolates were 167.3+/-18.5, 126.9+/-6.6, 88.5+/-18.5, 50.8+/-7.0, and 38.1+/-3.9, respectively. C. glabrata had a significantly lower mean GMF than all the other Candida species (P<0.05). While some Candida strains with trailing growth phenomenon and increased fluconazole MIC did not have a reduced GMF, three Candida strains with increased MICs to all three triazole agents had a reduced GMF. CONCLUSIONS: This study found species-specific differences in R6G accumulation in Candida. In addition, the intracellular R6G accumulation can be used to investigate the drug efflux mechanism in azole-resistant Candida strains.