Silver Telluride Colloidal Quantum Dot Solid for Fast Extended Shortwave Infrared Photodetector.

Extended shortwave infrared (eSWIR) photodetectors that employ solution-processable semiconductors have attracted attention for use in applications such as ranging, night vision, and gas detection. Colloidal quantum dots (CQDs) are promising materials with facile bandgap tunability across the visible-to-mid-infrared wavelengths. However, toxic elements, such as Hg and Pb, and the slow response time of CQD-based IR photodetectors, limit their commercial viability. This article presents a novel eSWIR photodetector that is fabricated using silver telluride (Ag2Te) CQDs. Effective thiolate ligand exchange enables a lower trap density and improved carrier mobility in CQD solids. Furthermore, a vertical p-n photodiode architecture with a favorable energy-level landscape is utilized to facilitate charge extraction, resulting in a fast, room-temperature-operable, and toxic-element-free CQD photodetector. The best eSWIR Ag2Te CQD photodetector exhibits a fall time of 72 ns, representing the fastest response time among all prior CQD-based eSWIR photodetectors, including those containing toxic elements, such as Pb and Hg.

Hindfoot joint kinematics analysis after the resection of talocalcaneal coalition.

BACKGROUND: The subtalar joint movement between the talus and calcaneus is restricted in patients with talocalcaneal coalition (TCC). When the motion of the subtalar joint is restricted, shock absorption in the foot decreases, leading to pain during walking. Resection methods to maintain subtalar motion by removing abnormal unions have been proposed. The purpose of this study was to analyze the joint kinematics of patients who underwent TCC resection and to quantitatively evaluate the results of the surgery based on the measured kinematics. METHODS: Joint kinematics of five patients with TCC were obtained using a biplane fluoroscopic imaging system and an intensity-based two-/three-dimensional registration method. The joint kinematics of the tibiotalar and subtalar joints and the tibiocalcaneal motion during the stance phase of walking were obtained. From the kinematics of the hindfoot joints, the inversion/eversion range of motion (ROM) of the patients before and after resection was statistically analyzed using the Wilcoxon signed-rank test to test whether TCC resection improved the ROM. RESULTS: During the loading response period, the eversion ROM of the subtalar joint and tibiocalcaneal motion significantly increased postoperatively. In addition, a significant postoperative increase was observed in the subtalar and tibiocalcaneal inversion ROM during the pre-swing period. SIGNIFICANCE: TCC resection surgery increased the ROM of the subtalar joint, which in turn contributed to the increase in tibiocalcaneal ROM. Increased subtalar and tibiocalcaneal ROM could result in increased shock attenuation and may be a contributing factor to pain relief during walking.

Ultranarrow Mid-infrared Quantum Plasmon Resonance of Self-Doped Silver Selenide Nanocrystal.

The infrared quantum plasmon resonance (IR QPR) of nanocrystals (NCs) exhibits the combined properties of classical and quantum mechanics, potentially overcoming the limitations of conventional optical features. However, research on the development of localized surface plasmon resonance (LSPR) from colloidal quantum dots has stagnated, owing to the challenge of increasing the carrier density of semiconductor NCs. Herein, we present the mid-IR QPR of a self-doped Ag2Se NC with an exceptionally narrow bandwidth. Chemical modification of the NC surface with chloride realizes this narrow QPR bandwidth by achieving a high free-carrier density in the NC. The mid-IR QPR feature was thoroughly analyzed by using various experimental methods such as Fourier transform (FT) IR spectroscopy, X-ray photoelectron spectroscopy, and current-voltage measurements. In addition, the optical properties were theoretically analyzed using the plamon-in-a-box model and a modified hydrodynamic model that revealed the effect of coupling with the intraband transition and the limited nature of electron density in semiconductor NCs. Integrating the quantum effect into the plasmonic resonance reduces the peak bandwidth to 19.7 meV, which is an extremely narrow bandwidth compared with that of the LSPR of conventional metal oxide or metal chalcogenide NCs. Our results demonstrate that self-doped silver selenide quantum dots are excellent systems for studying mid-IR QPR.

A zero-dimensional/two-dimensional Ag-Ag2S-CdS plasmonic nanohybrid for rapid photodegradation of organic pollutant by solar light.

Herein, the two synthesis strategies are employed for rational design of 0D/2DAg-Ag2S-CdS heterojunctions towards photocatalytic degradation of methyl orange (MO) under simulated solar light. As the first strategy, a ternary Ag-Ag2S-CdS nanosheet (NS) heterojunction was fabricated via combined cation exchange and photo-reduction (CEPR) method (Ag-Ag2S-CdS/CEPR). The second strategy employed coprecipitation (CP) method (Ag-Ag2S-CdS/CP). Strikingly, SEM, TEM and HR-TEM images are manifested the first strategy is beneficial for retaining the original thickness (20.2 nm) of CdS NSs with a dominant formation of metallic Ag, whereas the second strategy increases the thickness (33.4 nm) of CdS NSs with a dominant formation of Ag2S. The Ag-Ag2S-CdS/CEPR exhibited 1.8-fold and 3.5-fold enhancement in photocatalytic activities as compared to those of Ag-Ag2S-CdS/CP and bare CdS NSs, respectively. This enhanced photocatalytic activity could be ascribed to fact that the first strategy produces a high-quality interface with intimate contact between the Ag-Ag2S-CdS heterojunctions, resulting in enhanced separation of photo-excited charge carriers, extended light absorption, and enriched active-sites. Furthermore, the degradation efficiency of Ag-Ag2S-CdS/CEPR was significantly reduced to ∼5% in the presence of BQ (•O2- scavenger), indicating that •O2- is the major active species that can decompose MO dye under simulated solar light.

False-negative joint aspiration of septic arthritis of the hip in neonates.

In neonates, timely detection of septic arthritis of the hip can be challenging. Joint aspiration can be a useful diagnostic procedure, but scanty fluid in a septic joint has been reported, leading false-negative results. This study aimed to investigate clinical course of neonates with septic arthritis of the hip despite initial negative findings on joint aspiration. The neonates who surgically treated for septic arthritis of the hip between 2003 and 2013 for septic arthritis of the hip despite initial negative joint aspiration were retrospectively reviewed. Clinical presentations, MRI, intraoperative findings, functional and radiographic outcomes were evaluated. Six neonates were included with a mean follow-up of 12 years (range 5-15 years). All patients showed negative results on joint aspirations performed with ultrasound guidance or fluoroscopy. The mean duration between the onset of symptoms and initial surgery was 15.2 days (range 4-25 days). Four patients (67%) had extracapsular abscesses that were connected to perforated joint capsules on MRI. Intraoperatively, all patients were found to have hip joint instability with a ruptured capsule. Five (83%) patients experienced a complicated recovery. Four patients required reconstructive hip surgery, or further procedures to correct leg length discrepancy. Neonates with false-negative aspiration typically had a delay in appropriate surgical treatment. These cases suggest that the absence of aspirable fluid contents in the hip joint does not rule out septic arthritis in neonates. Our findings highlight the importance of considering spontaneous hip joint capsular perforation as the cause of extra-articular drainage of pus and instability.

Gallium Doping Effects for Improving Switching Performance of p-Type Copper(I) Oxide Thin-Film Transistors.

Copper(I) oxide (Cu2O), which is obtained from copper(II) oxide (CuO) through a reduction process, is a p-type oxide material with a band gap of 2.1-2.4 eV. However, the switching performance of typical Cu2O thin-film transistors (TFTs) is poor because the reduction process increases the concentration of oxygen vacancies (VO), which interfere with the conduction of hole carriers. Ga with high oxygen affinity was doped in Cu2O thin films to decrease VO during the reduction process. As a result, the VO concentration of 1.56 at % for Ga-doped Cu2O (Ga:Cu2O) thin films decreased from 20.2 to 7.5% compared to pristine Cu2O thin films. Accordingly, the subthreshold swing or S-factor, on/off-current ratio (Ion/off), saturation mobility (µsat), and threshold voltage (Vth) of Ga:Cu2O TFTs were improved compared to pristine Cu2O TFTs with values of 7.72 from 12.50 V/dec, 1.22 × 104 from 2.74 × 102, 0.74 from 0.46 cm2/Vs, and -4.56 from -8.06 V, respectively. These results indicate that Ga plays an important role in improving the switching performance of p-type Cu2O TFT.

The effect of a mental health promotion program on Korean firefighters.

BACKGROUND: There is worldwide interest in the mental health of firefighters, since they are more prone to exposure to traumatic stress and psychiatric disorders. AIMS: This study aimed to assess their mental health and provide individualized support to local firefighters through a mental health promotion program. METHOD: Eighteen hundred and fifty-nine active Korean firefighters in 2015 and 2017 (502 and 1,357, respectively) participated in the 'Visiting Counselling Centre for Firefighters' program commissioned by the National Fire Agency. The program consisted of self-administered questionnaires, a group education session, an individual counseling session for every participant, four counseling sessions for certain participants and additional brief intensive counseling (BIC). We administered the Post-traumatic stress disorder Checklist (PCL), Beck's Depression Inventory (BDI), Beck's Anxiety Inventory (BAI), Beck Scale for Suicidal ideation (BSS), Insomnia Severity Index (ISI), Korean version of the Alcohol Use Disorders Identification Test (AUDIT-K) and the abbreviated World Health Organization Quality of Life (WHOQOL-BREF) before and after the program. Additional analysis was performed to determine whether BIC participation further improved the psychopathological outcome. RESULTS: The participants showed meaningful improvement in all psychopathological scales; the PCL, BDI, BAI, BSS, ISI, AUDIT-K and WHOQOL-BREF scores all significantly improved. Meanwhile, BIC participation improved certain psychopathological symptoms at a higher degree; the BDI, BAI, BSS and AUDIT-K scores significantly improved. CONCLUSION: The mental health promotion program improved the mental health of the participating active firefighters in Korea. Meanwhile, BIC participation improved certain psychopathological symptoms at a higher degree. A comprehensive approach for supporting the mental health of firefighters should be considered.

Incidence & Risk Factors of Postoperative Delirium After Spinal Surgery in Older Patients.

Although postoperative delirium is a common complication in older patients, few papers have described risk factors after of spinal surgery. The purpose of this study was to analyze various perioperative risk factors for delirium after spinal surgery in older patients. This study was performed on retrospective data collection with prospective design. We analyzed 138 patients over 65 years of age who underwent spinal surgery. Preoperative factors were cognitive function (Mini-Mental State Examination-Korean (MMSE-K) and the Korean version of the Delirium Rating Scale-Revised-98 (K-DRS 98)), age, sex, type of admission, American Society of Anesthesiologist classification, metabolic equivalents, laboratory findings, visual analog scale, and Oswestry Disability Index. Intraoperative factors were operation time, blood loss, and type of procedure. Postoperative factors were blood transfusion and type of postoperative pain control. Postoperative delirium developed in 25 patients (18.16%). Patients were divided into two groups: Group with delirium (group A) and group without delirium (group B). MMSE-K scores in Group A were significantly lower than in Group B (p < 0.001). K-DRS 98 scores were significantly higher in Group A than Group B (p < 0.001). The operation time was longer in Group A than Group B (p = 0.059). On multivariate regression analysis, the odds ratio of K-DRS 98 was 2.43 (p = 0.010). After correction for the interaction between age and MMSE-K, patients younger than 73 years old had a significantly lower incidence of delirium with higher MMSE-K score (p = 0.0014). Older age, low level of preoperative cognitive function, long duration of surgery, and transfusion were important risk factors of postoperative delirium after spinal surgery. It is important to recognize perioperative risk factors and manage appropriately.

Switching Enhancement via a Back-Channel Phase-Controlling Layer for p-Type Copper Oxide Thin-Film Transistors.

P-type copper oxide (CuxO) thin-film transistors (TFTs) with enhanced switching characteristics were fabricated by introducing a sputter-processed capping layer capable of controlling the back-channel phase (labeled as phase-controlling layer, PCL). By optimizing the processing conditions (the deposition power and postdeposition annealing parameters), the switching characteristics of the TFTs achieved a subthreshold swing of 0.11 V dec-1, an on/off current ratio (Ion/Ioff) of 2.81 × 108, and a field-effect mobility (µFET) of 0.75 cm2 V-1 s-1, a considerable enhancement in performance compared to that of CuxO TFTs without the PCL. Through optical/electrical analyses and technology computer-aided design simulations, we determined that the performance improvements were because of the CuxO back-channel phase reconstruction through PCL deposition and subsequent annealing. The two factors that occurred during the process, sputtering damage and heat treatment, played key roles in creating the phase reconstruction by inducing a local phase transition that sharply reduced the off-current via controlling back-channel hole conduction. As a sample application, we fabricated a complementary metal oxide semiconductor inverter based on our optimized CuxO TFT and an InGaZnO TFT that demonstrated a large inverter voltage gain of >14. The proposed approach opens up advancements in low-power circuit design by expanding the utilization range of oxide TFTs.

Bone union after spinal fusion surgery using local bone in long-term bisphosphonate users: a prospective comparative study.

Bisphosphonates are the most commonly used drugs for osteoporosis and long-term use of bisphosphonates may affect fusion rate after spinal fusion surgery. There was significant delayed union after 6 months in long-term bisphosphonates users; however, there were no significant difference in fusion rate of long-term bisphosphonate users. Therefore, spinal fusion surgery should not be hesitated in long-term bisphosphonates users. PURPOSE: Bisphosphonates (BPs) are the most popular class of drugs for treatment of postmenopausal osteoporosis. Long-term use of BPs may also inhibit the spinal fusion process after posterior lumbar interbody fusion (PLIF). We compared bone fusion rates of long-term BPs users and non-users after undergoing spinal fusion surgery. METHODS: A total of 97 postmenopausal women who were candidates for single-level PLIF were recruited from 2015 to 2016. Participants were divided into two groups, with 63 patients in a long-term BPs user group and 34 patients in a non-user group. Serum C-terminal cross-linking telopeptide (CTX) levels were checked for bone resorption markers. Bone fusion rates were calculated at 6 months and 1 and 2 years after the surgery. Clinical outcomes were measured using the Oswestry Disability Index (ODI) and visual analog scale (VAS). RESULTS: Serum CTX level was dramatically decreased in the long-term BPs user group (p < 0.05). Fusion rates at 6 months after surgery were 42% in the non-user group and 26% in the long-term BPs user group (p = 0.035). However, fusion rates were 82% in the long-term BPs user group and 87% in the non-user group at 2 years after surgery (p > 0.05). There was no significant difference between the two groups in ODI or VAS. CONCLUSIONS: Even though there was significant delayed union after 6 months in long-term BPs users, at the 2-year postoperative follow-up, there was no significant difference in bone fusion rate between the two groups. Long-term BPs users showed fusion rates greater than 80% and clinical outcome improvements that were comparable to those in non-users. No significant effect on fusion rate after PLIF was found in long-term BPs users.

Efficacy of psychological treatment for headache disorder: a systematic review and meta-analysis.

BACKGROUND: Headache disorder is not only a common complaint but also a global burden. Pharmacotherapeutic and non-pharmacotherapeutic approaches have been developed for its treatment and prophylaxis. The present study included a systematic review of psychological treatments for primary headache disorder accessible in Korea. METHODS: We included English and Korean articles from EMBASE, MEDLINE, Cochrane library database, SCOPUS, ScienceDirect, Web of Science, CINAHL, PsycArticles and Korean database, KoreaMed and KMBASE which studied primary headache and medication-overuse headache. The primary efficacy measure was the number of headache days per month, while secondary efficacy measures were the number of headache attacks per week, headache index, treatment response rate, and migraine disability assessment. The meta-analysis was performed using R 3.5.1. to obtain pooled mean difference and pooled relative risk with 95% confidence interval (CI) for continuous data and dichotomous data, respectively. RESULTS: From 12,773 identified articles, 27 randomized clinical trials were identified. Primary outcome showed significant superiority of psychological treatments (pooled mean difference = - 0.70, 95% CI [- 1.22, - 0.18]). For the secondary outcomes, the number of headache attacks (pooled mean difference = - 1.15, 95% CI [- 1.63, - 0.67]), the headache index (pooled mean difference = - 0.92, 95% CI [- 1.40 to - 0.44]) and the treatment response rate (pooled relative risk = 3.13, 95% CI [2.24, 4.37]) demonstrated significant improvements in the psychological treatment group over the control group. CONCLUSION: Psychological treatments for primary headache disorder reduced headache frequency and the headache index. Future research using standardized outcome measures and strategies for reducing bias is needed.

Dual-Functional Superoxide Precursor To Improve the Electrical Characteristics of Oxide Thin Film Transistors.

We investigated a method to simultaneously improve the mobility and reliability of solution-processed zinc tin oxide thin film transistors (ZTO TFTs) using a dual-functional potassium superoxide precursor. Potassium cations in the potassium superoxide (KO2) precursor act as carrier suppliers in the ZTO thin film to improve the carrier (electron) concentration, which allows the potassium-doped ZTO TFT to exhibit high mobility. The anions in the precursor exist as superoxide radicals that reduce oxygen vacancies during the formation of thin oxide film. Consequently, the KO2-treated ZTO TFTs exhibited improved mobility and reliability compared with pristine ZTO TFTs, with an increase in field effect mobility from 5.57 to 8.74 cm2/V s and a decrease in the threshold voltage shift from 7.18 to 3.85 V, after a positive bias temperature stress test conducted over 5000 s.

Enhancement of Switching Characteristic for p-Type Oxide Semiconductors Using Hypochlorous Acid.

We explored the effects of hypochlorous acid (HClO) oxidation on p-type oxide semiconductors. HClO generates oxygen radicals (O·) (strong reactive oxygen species) that affect the chemical state of p-type copper oxide (CuO x) thin films by reacting with CuO x. On robust oxidation by HClO, the numbers of Cu-O bonds increased and the numbers of copper vacancies serving as hole carriers decreased. In the modified CuO x thin-film transistors (TFTs), switching was evident. The subthreshold swing was 0.70 V/dec, the on-/off-current ratio was 4.86 × 104, and the field effect mobility was 2.83 × 10-3 cm2/V·s. Pristine CuO x TFTs did not exhibit switching.

Improvement in Electrical Characteristics of Eco-friendly Indium Zinc Oxide Thin-Film Transistors by Photocatalytic Reaction.

Eco-friendly solution-processed oxide thin-film transistors (TFTs) were fabricated through photocatalytic reaction of titanium dioxide (PRT). The titanium dioxide (TiO2) surface reacts with H2O under ultraviolet (UV) light irradiation and generates hydroxyl radicals (OH•). These hydroxyl radicals accelerate the decomposition of large organic compounds such as 2-methoxyethanol (2ME; one of the representative solvents for solution-processed metal oxides), creating smaller organic molecular structures compared with 2ME. The decomposed small organic materials have low molar masses and low boiling points, which help improving electrical properties via diminishing defect sites in oxide channel layers and fabricating low-temperature solution-processed oxide TFTs. As a result, the field-effect mobility improved from 4.29 to 10.24 cm2/V·s for IGZO TFTs and from 2.78 to 7.82 cm2/V·s for IZO TFTs, and the Vth shift caused by positive bias stress and negative bias illumination stress over 1000 s under 5700 lux decreased from 6.2 to 2.9 V and from 15.3 to 2.8 V, respectively. In theory, TiO2 has a permanent photocatalytic reaction; as such, hydroxyl radicals are generated continuously under UV irradiation, improving the electrical characteristics of solution-processed IZO TFTs even after four iterations of TiO2 recycling in this study. Thus, the PRT method provides an eco-friendly approach for high-performance solution-processed oxide TFTs.

Analysis of the Bipolar Resistive Switching Behavior of a Biocompatible Glucose Film for Resistive Random Access Memory.

Resistive random access memory (RRAM) devices are fabricated through a simple solution process using glucose, which is a natural biomaterial for the switching layer of RRAM. The fabricated glucose-based RRAM device shows nonvolatile bipolar resistive switching behavior, with a switching window of 103 . In addition, the endurance and data retention capability of glucose-based RRAM exhibit stable characteristics up to 100 consecutive cycles and 104 s under constant voltage stress at 0.3 V. The interface between the top electrode and the glucose film is carefully investigated to demonstrate the bipolar switching mechanism of the glucose-based RRAM device. The glucose based-RRAM is also evaluated on a polyimide film to verify the possibility of a flexible platform. Additionally, a cross-bar array structure with a magnesium electrode is prepared on various substrates to assess the degradability and biocompatibility for the implantable bioelectronic devices, which are harmless and nontoxic to the human body. It is expected that this research can provide meaningful insights for developing the future bioelectronic devices.

Boosting Visible Light Absorption of Metal-Oxide-Based Phototransistors via Heterogeneous In-Ga-Zn-O and CH3NH3PbI3 Films.

To broaden the availability and application of metal-oxide (M-O)-based optoelectronic devices, we suggest heterogeneous phototransistors composed of In-Ga-Zn-O (IGZO) and methylammonium lead iodide (CH3NH3PbI3) layers, which act as the amplifier layer (channel layer) and absorption layer, respectively. These heterogeneous phototransistors showed low persistence photocurrent compared with IGZO-only phototransistors and exhibited high photoresponsivity of 61 A/W, photosensitivity of 3.48 × 106, detectivity of 9.42 × 1010 Jones, external quantum efficiency of 154% in an optimized structure, and high photoresponsivity under water exposure via the deposition of silicon dioxide as a passivation layer. On the basis of these electrical results and various analyses, we determined that CH3NH3PbI3 could be activated as a light absorption layer, current barrier, and plasma damage blocking layer, which would serve to widen the range of applications of M-O-based optoelectronic devices with high photoresponsivity and reliability under visible light illumination.

Simple Hydrogen Plasma Doping Process of Amorphous Indium Gallium Zinc Oxide-Based Phototransistors for Visible Light Detection.

A homojunction-structured amorphous indium gallium zinc oxide (a-IGZO) phototransistor that can detect visible light is reported. The key element of this technology is an absorption layer composed of hydrogen-doped a-IGZO. This absorption layer is fabricated by simple hydrogen plasma doping, and subgap states are induced by increasing the amount of hydrogen impurities. These subgap states, which lead to a higher number of photoexcited carriers and aggravate the instability under negative bias illumination stress, enabled the detection of a wide range of visible light (400-700 nm). The optimal condition of the hydrogen-doped absorption layer (HAL) is fabricated at a hydrogen partial pressure ratio of 2%. As a result, the optimized a-IGZO phototransistor with the HAL exhibits a high photoresponsivity of 1932.6 A/W, a photosensitivity of 3.85 × 106, and a detectivity of 6.93 × 1011 Jones under 635 nm light illumination.

Recent Changes in End-of-Life Decisions for Newborns in a Korean Hospital.

INTRODUCTION: Despite recent advances in neonatal intensive care in Korea, few studies exist on the end-of-life decisions in newborns. In this study, we sought to examine the status of end-of-life decisions in neonates, changes over time, and affecting factors. METHODS: This is a retrospective study of neonates who died between 2001 and 2015 in the neonatal intensive care unit of Dong-A University Hospital in Busan. The types of end-of-life decisions were divided into active resuscitation, withholding treatment, and withdrawing treatment. The study period was divided into 3 time frames using 5-year intervals to investigate changes over time. To identify the associated factors, we analyzed the demographic and clinical characteristics of the neonates and their parents using the χ2 test and independent t test. RESULTS: Of the neonatal deaths included in the analysis (n = 222), active resuscitation, withholding treatment, and withdrawing treatment groups accounted for 73.4%, 25.2%, and 1.4% of cases, respectively. When comparing changes over time, between period 1 (2001-2005), 2 (2006-2010), and 3 (2011-2015), the proportion of active resuscitation decreased significantly, from 80.9% to 60.8%, while that of nonactive resuscitation increased significantly from 19.1% to 39.2%. The factors associated with end-of-life decisions were the clinical condition of the neonate at the time of death, rather than general characteristics or socioeconomic factors. CONCLUSIONS: In Korea, changes in the decisions on end-of-life care in neonates are shifting from active resuscitation to nonactive resuscitation based on clinical conditions.

Silicon Cations Intermixed Indium Zinc Oxide Interface for High-Performance Thin-Film Transistors Using a Solution Process.

Solution-processed amorphous metal-oxide thin-film transistors (TFTs) utilizing an intermixed interface between a metal-oxide semiconductor and a dielectric layer are proposed. In-depth physical characterizations are carried out to verify the existence of the intermixed interface that is inevitably formed by interdiffusion of cations originated from a thermal process. In particular, when indium zinc oxide (IZO) semiconductor and silicon dioxide (SiO2) dielectric layer are in contact and thermally processed, a Si4+ intermixed IZO (Si/IZO) interface is created. On the basis of this concept, a high-performance Si/IZO TFT having both a field-effect mobility exceeding 10 cm2 V-1 s-1 and a on/off current ratio over 107 is successfully demonstrated.