Rational design of hybrid sensor arrays combined synergistically with machine learning for rapid response to a hazardous gas leak environment in chemical plants.

Combinations of semiconductor metal oxide (SMO) sensors, electrochemical (EC) sensors, and photoionization detection (PID) sensors were used to discriminate chemical hazards on the basis of machine learning. Sensing data inputs were exploited in the form of either numerical or image data formats, and the classification of chemical hazards with high accuracy was achieved in both cases. Even a small amount of gas sensing or purging data (input for ∼30 s) input can be exploited in machine-learning-based gas discrimination.

Synergistic Integration of Machine Learning with Microstructure/Composition-Designed SnO and WO Breath Sensors.

A high-performance semiconductor metal oxide gas sensing strategy is proposed for efficient sensor-based disease prediction by integrating a machine learning methodology with complementary sensor arrays composed of SnO- and WO-based sensors. The six sensors, including SnO- and WO-based sensors and neural network algorithms, were used to measure gas mixtures. The six constituent sensors were subjected to acetone and hydrogen environments to monitor the effect of diet and/or irritable bowel syndrome (IBS) under the interference of ethanol.

The effect of ultrasonic and multisonic irrigation on root canal microbial communities: An ex vivo study.

Aim: To analyse the effect of ultrasonic irrigant activation (UIA) and the GentleWave (GW) multisonic irrigation (GW) with minimal instrumentation on the root canal microbial diversity in an ex vivo model that used extracted molars with a history of pulp necrosis.

Methodology: Twenty-three mandibular molars were prepared ex vivo for collection of superficial (surface control), pre-treatment and post-treatment samples 24 h after extraction. Samples were divided into two groups: UIA using 6% NaOCl (n = 11) and GW group (n = 12).

Biocompatible and Oxidation-Resistant Ti C T MXene with Halogen-Free Surface Terminations.

Surface chemistry influences not only physicochemical properties but also safety and applications of MXene nanomaterials. Fluorinated Ti C T MXene, synthesized using conventional HF-based etchants, raises concerns regarding harmful effects on electronics and toxicity to living organisms. In this study, well-delaminated halogen-free Ti C T flakes are synthesized using NaOH-based etching solution.

Band Alignment Enabling Effective Charge Transfer for the Highly Enhanced Raman Scattering and Fluorescence of Metal-Nanoparticle-Decorated Conjugated Polymer Nanowires.

The charge transfer (CT) process has attracted much attention due to its contribution to the improvement of spectroscopic phenomena such as Raman scattering and fluorescence. A current challenge is understanding what factors can influence CT. Here, it is demonstrated that the enhancement factor (EF) of CT (∼2000) can reach the level of electromagnetic enhancement (∼1680) when resonant CT is carried out by (Fermi level energy) band alignment between a metal nanoparticle (NP) and conjugated polymer (polypyrrole (PPy)) nanowire (NW).

Plasmon expedited response time and enhanced response in gold nanoparticles-decorated zinc oxide nanowire-based nitrogen dioxide gas sensor at room temperature.

A highly sensitive and rapidly responsive nitrogen dioxide (NO) gas sensor based on gold (Au) nanoparticles (NPs)-decorated zinc oxide (ZnO) nanowires (NWs) is presented. The Au NPs decoration was conducted onto ZnO NWs with and without a (3-aminopropyl)triethoxysilane (APTES) layer on their surface by using the electrostatic force. The samples without the APTES layer exhibited high NO gas sensitivity (i.

Comparison of Mutagenic Activities of Various Ultra-Fine Particles.

Air pollution is increasing, along with consumption of fossil fuels such as coal and diesel gas. Air pollutants are known to be a major cause of respiratory-related illness and death, however, there are few reports on the genotoxic characterization of diverse air pollutants in Korea. In this study, we investigated the mutagenic activity of various particles such as diesel exhaust particles (DEP), combustion of rice straw (RSC), pine stem (PSC), and coal (CC), tunnel dust (TD), and road side dust (RD).

Free-space optical channel characterization and experimental validation in a coastal environment.

Over the years, free-space optical (FSO) communication has attracted considerable research interest owing to its high transmission rates via the unbounded and unlicensed bandwidths. Nevertheless, various weather conditions lead to significant deterioration of the FSO link capabilities. In this context, we report on the modelling of the channel attenuation coefficient (β) for a coastal environment and related ambient, considering the effect of coastal air temperature (T), relative humidity (RH) and dew point (TD) by employing a mobile FSO communication system capable of achieving a transmission rate of 1 Gbps at an outdoor distance of 70 m for optical beam wavelengths of 1310 nm and 1550 nm.

Comparison of the in vitro toxicological activity of various particulate matter.

Ultrafine particles (UFPs, < 2.5 µm) in air pollutants have been identified as a major cause of respiratory diseases, since they can affect the lung alveoli through the bronchus. In particular, if toxicants such as heavy metals and polycyclic aromatic hydrocarbons (PAHs) are present in UFPs, they can cause diseases such as asthma, chronic obstructive pulmonary disease, and lung cancer.

Comparative Biological Toxicity of Four Kinds of Air Pollution Particles.

Accumulating epidemiological evidence indicates that exposure to fine air pollution particles (APPs) is associated with a variety of adverse health effects. However, the exact physiochemical properties and biological toxicities of fine APPs are still not well characterized. We collected four types of fine particle (FP) (diesel exhaust particles [DEPs], natural organic combustion [NOC] ash, synthetic organic combustion [SOC] ash, and yellow sand dust [YSD]) and investigated their physicochemical properties and biological toxicity.

20-meter underwater wireless optical communication link with 1.5 Gbps data rate.

The video streaming, data transmission, and remote control in underwater call for high speed (Gbps) communication link with a long channel length (~10 meters). We present a compact and low power consumption underwater wireless optical communication (UWOC) system utilizing a 450-nm laser diode (LD) and a Si avalanche photodetector. With the LD operating at a driving current of 80 mA with an optical power of 51.

2.3 Gbit/s underwater wireless optical communications using directly modulated 520 nm laser diode.

We experimentally demonstrate a record high-speed underwater wireless optical communication (UWOC) over 7 m distance using on-off keying non-return-to-zero (OOK-NRZ) modulation scheme. The communication link uses a commercial TO-9 packaged pigtailed 520 nm laser diode (LD) with 1.2 GHz bandwidth as the optical transmitter and an avalanche photodiode (APD) module as the receiver.

Is surgery necessary for femoral insufficiency fractures after long-term bisphosphonate therapy?

Background: Prolonged use of bisphosphonates in patients with osteoporosis reportedly induces femoral insufficiency fractures. However, the natural course of these fractures and how to treat them remain unknown.

Questions/purposes: We determined the rates of fracture displacement and subsequent operations of undisplaced insufficiency fractures of the femur in patients treated with prolonged bisphosphonate therapy.

Increased intestinal macromolecular permeability and urine nitrite excretion associated with liver cirrhosis with ascites.

Aim: To determine intestinal permeability, the serum tumor necrosis factor (TNF)-alpha level and urine nitric oxide (NO) metabolites are altered in liver cirrhosis (LC) with or without ascites.

Methods: Fifty-three patients with LC and 26 healthy control subjects were enrolled in the study. The intestinal permeability value is expressed as the percentage of polyethylene glycol (PEG) 400 and 3350 retrieval in 8-h urine samples as determined by high performance liquid chromatography.

The child behavior checklist together with the ADHD rating scale can diagnose ADHD in Korean community-based samples.

Objective: The purpose of this study was to examine the clinical validities and efficiencies of the Child Behavior Checklist (CBCL) and the ADHD Rating Scale-IV (ARS) in identifying children with attention-deficit hyperactivity disorder (ADHD) in Korean community-based samples.

Method: A large sample of elementary school students (n = 1668) participated in this study. We used the CBCL and the ARS as the screening instruments.