Vertical oxide thin-film transistor with interfacial oxidation.

A vertical oxide thin-film transistor was developed with interfacial oxidation for low voltage operation. The gate metal was used as a spacer for the definition of the transistor's channel as well as the gate electrode. After definition of the vertical side wall, an IGZO (In-Ga-Zn Oxide) layer was deposited, followed by the interfacial oxidation to form a thin gate insulator. Ta was used for the gate material due to the low Gibbs free energy and high dielectric constant of tantalum oxide. A 15 nm tantalum oxide layer was obtained by the interfacial oxidation of Ta at 400 °C under oxygen atmosphere. The thin gate oxide made it possible to operate the transistor under 1 V. The low operation voltage enables low power consumption, which is essential for mobile application.

Interfacial Oxidized Gate Insulators for Low-Power Oxide Thin-Film Transistors.

Low power consumption is essential for wearable and internet-of-things applications. An effective way of reducing power consumption is to reduce the operation voltage using a very thin and high-dielectric gate insulator. In an oxide thin-film transistor (TFT), the channel layer is an oxide material in which oxygen reacts with metal to form a thin insulator layer. The interfacial oxidation between the gate metal and In-Ga-Zn oxide (IGZO) was investigated with Al, Ti, and Mo. Positive bias was applied to the gate metal for enhanced oxygen diffusion since the migration of oxygen is an important factor in interfacial oxidation. Through interfacial oxidation, a top-gate oxide TFT was developed with low source-drain voltages below 0.5 V and a gate voltage swing less than 1 V, which provide low power consumption.

Reduced matrix metalloproteinase and collagen transcription mediated by the TGF-ß/Smad pathway in passaged normal human dermal fibroblasts.

BACKGROUND: Transforming growth factor-ß (TGF-ß) is a major regulator of extracellular matrix (ECM) events, particularly collagen production. AIM: We explored whether the expression of matrix metalloproteinases (MMPs) and collagen are transcriptionally regulated by the TGF-ß and Smad signaling pathways, and the roles played by NF-κB and mitogen-activated protein kinase (MAPK) signaling in normal, aged, human dermal fibroblasts. METHODS: We quantified mRNA and protein expression using real-time PCR and immunoblotting of proteins from cells in passage 5-15. RESULTS: The levels of mRNAs encoding TGF-ß1, TGF-ß3, and TGF-ß receptor type I (TGFß RI) decreased with increasing passage number. The levels of mRNAs encoding TGF-ß2, TGFß RII, and TGFß RIII increased to passage 10 but decreased by passage 15. The levels of mRNAs encoding Smad-2, -3, -4, and -7 decreased with increasing passage number. The level of mRNA encoding MMP-1 increased with increasing passage number, and the levels of mRNAs encoding MMP-2, TIMP-1, and TIMP-2 increased to passage 10 but decreased by passage 15. The levels of mRNAs encoding collagen types I and II decreased with increasing passage number. At the protein level, NF-κB, IκBα, p38, ERK, Akt, and JNK became increasingly phosphorylated at higher passage numbers. CONCLUSION: Our results suggest that reductions in the expression levels of MMPs and collagen types I and III in aging human dermal fibroblasts reflect reduced expression of TGF-ß/Smad and TGF-ß receptors, thus compromising the TGF-ß receptor-binding capacity of fibroblasts; the NF-κB and Akt-JNK/MAPK signaling pathways may play active roles in this process.

Using reflectance confocal microscopy to observe in vivo melanolysis after treatment with the picosecond alexandrite laser and Q-switched Nd:YAG laser in melasma.

OBJECTIVES: Melasma is an acquired type of hyperpigmentation that is characterized by the appearance of scattered light- to dark-brown macules and patches on the face. Recently, several lasers have been proposed as treatment options for melasma. In particular, the picosecond alexandrite laser is an ideal laser for selective photothermal melanolysis. The aim of our study was to compare the effectiveness in melanolysis of a single treatment of the picosecond alexandrite laser with that of the Q-switched Nd:YAG laser using reflectance confocal microscopy imaging of the melasma lesions. MATERIALS AND METHODS: We performed a spilt-face study using the picosecond alexandrite laser and Q-switched Nd:YAG laser in eight patients with melasma. Both melasma lesions and surrounding normal skin were examined under reflectance confocal microscopy 1 and 24 hours after treatment. The melanin intensity of each skin layer was investigated. RESULTS: At baseline, melasma has irregular melanin distribution and a higher melanin density than surrounding normal skin under reflectance confocal microscopy. After a single treatment with either the picosecond alexandrite laser or the Q-switched Nd:YAG laser, both melanin-induced reflectance and melanin index decreased. CONCLUSION: Our findings suggest that it is feasible to assess the distribution of melanin by reflectance confocal microscopy and observe the melanolysis in melasma lesion after laser treatment. Lasers Surg. Med. 51:423-429, 2019. © 2018 Wiley Periodicals, Inc.

Atopic labial pigmentation: a new diagnostic feature in Asian patients with atopic dermatitis.

BACKGROUND: Pigmented lesions on the lips can be caused by physiological or pathological factors, along with exogenous or endogenous factors. Many patients with atopic dermatitis (AD) and labial pigmentation are seen in clinical practice. The aim of our study was to further explore the association of labial pigmentation and AD. METHODS: We performed a retrospective chart review of patients who visited the Department of Dermatology at Kyung Hee Medical Center, Seoul, Korea, from January 1 to December 31, 2016. The study consisted of 178 patients with AD and a control group of 178 age- and sex-matched patients without AD. RESULTS: The patients with AD had both a significantly higher prevalence of labial pigmented lesions and a significantly higher number of labial pigmented lesions than was observed in the control group. Moreover, the pigmented lesions were found mainly in the middle section of the upper lip and showed multifocal distribution. The patients with AD and labial pigmentation were significantly younger at the onset of AD, showed a greater association with allergic disorder, and had a higher immunoglobulin E (IgE) level than patients without labial pigmentation. CONCLUSION: Our findings strongly suggest that labial pigmentation occurs in patients with AD. Although labial pigmentation was not present in all patients with AD, this might be a particularly helpful diagnostic feature of AD in Asian patients.

Injury analysis of patients according to impact patterns involved in pedestrian traffic crashes.

OBJECTIVES: In cases of car-to-person pedestrian traffic crashes (PTCs), the principal issue is determining at what point the car collided with the pedestrian. Accordingly, the objective of the present study was to use the medical records of patients injured in PTCs to investigate the characteristics of crash types and the areas and injury severity and to determine whether there are differences in injuries due to the angle, motion, and position at the point of impact. METHODS: The present study examined 231 PTC patients admitted to the emergency room (ER) between January and December 2014. Electronic medical records from the hospital were used to divide the patient data according to Abbreviated Injury Scale (AIS) codes for injured areas based on sex, age, time of the crash, outcomes after ER treatment, and major symptoms. Among 231 patients, police reports on 67 crash cases, involving 70 people, were obtained with the help of local police departments, and these reports were used to reconstruct details of the actual crash. For statistical analysis, a chi-square test and a one-way analysis of variance calculation were used to compare the Injury Severity Score (ISS) based on groups and stages, with a statistical significance level set to P < .05. RESULTS: With respect to patients who were admitted for PTC, 52.4% were females and 47.6% were males. The frequency of crashes was high in middle-aged and elderly groups, as well as for youths between 10 and 19 years old. With respect to outcomes after ER treatment, discharge to home after symptom improvement was the most common outcome (24.6%). Admissions to the intensive care unit (25.1%) and to the general ward (23.8%) were also high. In terms of major symptoms, the most common injuries were to the head, resulting from a rotatory motion post impact (35.9%), and injuries to the legs, resulting from the impact of a direct collision with an object (25.1%). CONCLUSIONS: This study demonstrated that injuries to the chest and abdomen were the most severe in the fender vault group and head and neck injuries were the most severe in the roof vault group. In particular, the Injury Severity Score was highest in the roof vault group.

Nonablative fractional laser-assisted daylight photodynamic therapy with topical methyl aminolevulinate for moderate to severe facial acne vulgaris: Results of a randomized and comparative study.

BACKGROUND: Photodynamic therapy (PDT) has been reported as an effective alternative treatment for patients with acne. PURPOSE: To evaluate the efficacy and safety of DL-PDT in moderate to severe acne and to compare outcomes with those of laser-assisted daylight photodynamic therapy. METHODS: Patients were randomly assigned to either a DL-PDT group (D group) or a fractional laser-assisted DL-PDT group (F group). The outcomes were assessed by measuring acne lesion counts and severity grade at 4, 8, 12, and 16 weeks after therapy commenced. RESULTS: Twenty-eight subjects completed the study. Compared with baseline, the mean inflammatory lesion counts significantly decreased by 36.0% in the D group and 51.8% in the F group at 8 weeks (P<.001). The mean acne severity grades in both groups significantly decreased starting at 4 weeks (P=.012), and the beneficial effects lasted 16 weeks. CONCLUSION: DL-PDT with MAL shows clinically good responses to inflammatory lesions and is well tolerated in patients with moderate to severe acne.

Emergency medical service systems in Sri Lanka: problems of the past, challenges of the future.

INTRODUCTION: The concept of emergency medical services (EMS) is new to Sri Lanka. This article describes the development, delivery, and future ideas for EMS in Sri Lanka. Sri Lanka also faces frequent natural hazards that justify the establishment of an EMS service. METHODOLOGY: Data and information regarding emergency medical care in Sri Lanka were collected and reviewed from resources including websites and research papers. RESULTS: Currently, there are no qualified emergency medical physicians in Sri Lanka. However, a specialist training program for emergency physicians was initiated in 2012. There is no formal system to train emergency medical technicians (EMTs). Sri Lankans usually use taxies or their private vehicles to get to the hospital in the case of an emergency. All of the hospitals have ambulances that they can use to transport patients between hospitals. Most hospitals have emergency treatment units. Those at larger hospitals tend to be better than those at smaller hospitals. Although there is a disaster management system, it is not focused on emergency medical needs. DISCUSSION: Many aspects of the EMS system in Sri Lanka need improvement. To start, the emergency telephone number should cover the entire country. Training programs for EMTs should be conducted regularly. In addition, ambulances should be allocated for prehospital care. In the process of these developmental changes, public awareness programs are essential to improve the function of the EMS system. CONCLUSION: Despite many current shortcomings, Sri Lanka is capable of developing a successful EMS system.

Development of a 3D cell printed construct considering angiogenesis for liver tissue engineering.

Several studies have focused on the regeneration of liver tissue in a two-dimensional (2D) planar environment, whereas actual liver tissue is three-dimensional (3D). Cell printing technology has been successfully utilized for building 3D structures; however, the poor mechanical properties of cell-laden hydrogels are a major concern. Here, we demonstrate the printing of a 3D cell-laden construct and its application to liver tissue engineering using 3D cell printing technology through a multi-head tissue/organ building system. Polycaprolactone (PCL) was used as a framework material because of its excellent mechanical properties. Collagen bioink containing three different types of cells-hepatocytes (HCs), human umbilical vein endothelial cells , and human lung fibroblasts--was infused into the canals of a PCL framework to induce the formation of capillary--like networks and liver cell growth. A co-cultured 3D microenvironment of the three types of cells was successfully established and maintained. The vascular formation and functional abilities of HCs (i.e., albumin secretion and urea synthesis) demonstrated that the heterotypic interaction among HCs and nonparenchymal cells increased the survivability and functionality of HCs within the collagen gel. Therefore, our results demonstrate the prospect of using cell printing technology for the creation of heterotypic cellular interaction within a structure for liver tissue engineering.

Identification of bacterial guanylate cyclases.

The ability of bacteria to use cGMP as a second messenger has been controversial for decades. Recently, nucleotide cyclases from Rhodospirillum centenum, GcyA, and Xanthomonas campestris, GuaX, have been shown to possess guanylate cyclase activities. Enzymatic activities of these guanylate cyclases measured in vitro were low, which makes interpretation of the assays ambiguous. Protein sequence analysis at present is insufficient to distinguish between bacterial adenylate and guanylate cyclases, both of which belong to nucleotide cyclases of type III. We developed a simple method for discriminating between guanylate and adenylate cyclase activities in a physiologically relevant bacterial system. The method relies on the use of a mutant cAMP receptor protein, CRPG , constructed here. While wild-type CRP is activated exclusively by cAMP, CRPG can be activated by either cAMP or cGMP. Using CRP- and CRPG -dependent lacZ expression in two E. coli strains, we verified that R. centenum GcyA and X. campestris GuaX have primarily guanylate cyclase activities. Among two other bacterial nucleotide cyclases tested, one, GuaA from Azospillrillum sp. B510, proved to have guanylate cyclase activity, while the other one, Bradyrhizobium japonicum CyaA, turned out to function as an adenylate cyclase. The results obtained with this reporter system were in excellent agreement with direct measurements of cyclic nucleotides secreted by E. coli expressing nucleotide cyclase genes. The simple genetic screen developed here is expected to facilitate identification of bacterial guanylate cyclases and engineering of guanylate cyclases with desired properties.

Engineering adenylate cyclases regulated by near-infrared window light.

Bacteriophytochromes sense light in the near-infrared window, the spectral region where absorption by mammalian tissues is minimal, and their chromophore, biliverdin IXα, is naturally present in animal cells. These properties make bacteriophytochromes particularly attractive for optogenetic applications. However, the lack of understanding of how light-induced conformational changes control output activities has hindered engineering of bacteriophytochrome-based optogenetic tools. Many bacteriophytochromes function as homodimeric enzymes, in which light-induced conformational changes are transferred via α-helical linkers to the rigid output domains. We hypothesized that heterologous output domains requiring homodimerization can be fused to the photosensory modules of bacteriophytochromes to generate light-activated fusions. Here, we tested this hypothesis by engineering adenylate cyclases regulated by light in the near-infrared spectral window using the photosensory module of the Rhodobacter sphaeroides bacteriophytochrome BphG1 and the adenylate cyclase domain from Nostoc sp. CyaB1. We engineered several light-activated fusion proteins that differed from each other by approximately one or two α-helical turns, suggesting that positioning of the output domains in the same phase of the helix is important for light-dependent activity. Extensive mutagenesis of one of these fusions resulted in an adenylate cyclase with a sixfold photodynamic range. Additional mutagenesis produced an enzyme with a more stable photoactivated state. When expressed in cholinergic neurons in Caenorhabditis elegans, the engineered adenylate cyclase affected worm behavior in a light-dependent manner. The insights derived from this study can be applied to the engineering of other homodimeric bacteriophytochromes, which will further expand the optogenetic toolset.

Cadaverine is transported into Vibrio vulnificus through its CadB in alkaline environment.

The exogenously-added cadaverine is effective in protecting Vibrio vulnificus from methyl viologen (MV)-induced superoxide stress at pH 8.5. Such a protective effect by cadaverine was not observed at pH 7.5. Consistently, the accumulated level of intracellular cadaverine at pH 8.5 is approximately four times as much as that of the control cell at pH 7.5. Cadaverine accumulation is not affected by MV. The protection of V. vulnificus by cadaverine from superoxide stress was abolished when cadB coding for lysine-cadaverine antiporter was interrupted. However, the cadaverine-mediated protection was complemented with cadB DNA. Therefore, CadB of V. vulnificus not only acts as a lysine-cadaverine antiporter at acid pH to neutralize the external medium but also mediates cadaverine uptake at alkaline pH to result in cell protection from superoxide stress.

Cadaverine protects Vibrio vulnificus from superoxide stress.

An electron paramagnetic resonance (EPR) signal characteristic of the 5,5'-dimethyl-1-pyrroline-N-oxide (DMPO)-OH spin adduct, which is formed from the reaction of DMPO with superoxide radicals generated by xanthine oxidase-mediated reaction, was significantly reduced by the cadaverine or Escherichia coli Mn-containing superoxide dismutase (MnSOD). Likewise, cytochrome c reduction by superoxide was inhibited by cadaverine, and the inhibition level increased in proportion to the level of cadaverine. The cadA mutant of Vibrio vulnificus, which does not produce cadaverine because of the lack of lysine decarboxylase, exhibits less tolerance to superoxide stress in comparison with wild type. The results indicate that cadaverine scavenges superoxide radicals, and protects cells from oxidative stress.

The virulence of Vibrio vulnificus is affected by the cellular level of superoxide dismutase activity.

The virulence of superoxide dismutase (SOD) mutants of Vibrio vulnificus, as tested by intraperitoneal injection into mice, decreases in the order of sodC mutant, sodA mutant, and sodB mutant lacking CuZnSOD, MnSOD, and FeSOD, respectively. The survival of SOD mutants under superoxide stress also decreases in the same order. The virulence of soxR mutant, which is unable to induce MnSOD in response to superoxide, is similar to that of the sodA mutant, as the survival of the soxR mutant under superoxide stress is similar to that of the sodA mutant. Consistently, the lowered survival of the soxR mutant is complemented not only with soxR but also with sodA. Thus, the virulence of V. vulnificus is significantly affected by the cellular level of SOD activity, and an increase in SOD level through MnSOD induction by SoxR under superoxide stress is essential for virulence.