Application of tryptophan-like fluorescence index to quantify the trace organic compounds removal in wastewater ozonation.

The effectiveness of ozonation, one of the techniques known for destroying organic contaminants from wastewater, depends on the composition of the wastewater matrix. The required ozone (O) dose is determined based on the target compounds during ozonation. Hydroxyl radicals are quantified using a probe compound.

Electronic tongue for the simple and rapid determination of taste and odor compounds in water.

Taste and odor (T&O) compounds present in natural water bodies could originate from algae. In this study, alga-generated compounds that can cause T&O issues in water, such as geosmin (GE), 2-Methylisoborneol (MIB), 2,4,6-Trichloroanisole (TCA), 2-Methylbenzofuran (MB), 2-Isopropyl-3-methoxypyrazine (IPMP), 2-Isobutyl-3-methoxypyrazine (IBMP), cis-3-Hexenyl acetate (HA), trans,trans-2,4-Heptadienal (HD), trans,cis-2,6-Nonadienal (ND), and trans-2-Decenal (DN), were determined through solid-phase microextraction coupled with gas chromatography/mass spectrometry (HS-SPME GC/MS) and electronic tongue (E-tongue), and the results from the two techniques were compared. Although HS-SPME GC/MS facilitates the detection and quantification of T&O compounds with high precision and accuracy, the sample preparation and handling is difficult and the analysis time (1 h) is longer than those of other analytical methods.

Evaluation of the prediction of micropollutant elimination during bromide ion-containing industrial wastewater ozonation using the R value.

The composition of the wastewater matrix influences the oxidation potential of ozonation, a technique widely recognized efficient removal of micropollutants. Here, we developed a chemical kinetic model to determine the ozone dose required to minimize bromate production in wastewater containing bromine ions while achieving target removal rates. In wastewater ozonation, ozone decomposition comprises instantaneous ozone consumption and subsequent decomposition at first-order reaction rates.

Fluorescence excitation-emission matrix spectroscopy coupled with parallel factor analysis to determine chlorine decay constants in urban water distribution system.

This study applied a method for estimating chlorine decay constant (k) in urban water distribution systems using fluorescence excitation-emission matrix spectroscopy-parallel factor analysis (FEEM-PARAFAC), considering that it accounts for the influence of organic matter in the target area. The simultaneous impacts of seasonal variations on chlorine consumption and dissolved organic matter (DOM) composition were investigated for a year in three full-scale water distribution systems in I city (areas S, K, and G). Bulk decay constants (kb) were obtained through bottle tests, and the kb value was observed to differ by season and significantly affected by temperature.

Comparative evaluation of 2-isopropyl-3-methoxypyrazine, 2-isobutyl-3-methoxypyrazine, and 2,4,6-trichloroanisole degradation by ultraviolet/chlorine and ultraviolet/hydrogen peroxide processes.

2-Isopropyl-3-methoxypyrazine (IPMP), 2-Isobutyl-3-methoxypyrazine (IBMP), and 2,4,6-Trichloroanisole (TCA) are the primary emerging taste and odor (T&O) compounds in water systems with low thresholds (ng L). The selected T&O compounds are known to be difficult to remove using conventional water treatment processes. In this study, we compared the removal characteristics of the three T&O compounds using UV/Cl and UV/HO.

Hydroxyl radical scavenging factor measurement using a fluorescence excitation-emission matrix and parallel factor analysis in ultraviolet advanced oxidation processes.

The performance of the UV/HO advanced oxidation process (AOP) is dependent on water quality parameters, including the UV absorbance coefficient at 254 nm and hydroxyl radical (•OH) water background demand (scavenging factor, s). The •OH scavenging factor represents the •OH scavenging rate of the background substances in the water matrix, and it is known to be one of the key parameters to predict the performance of the UV/HO process. The •OH scavenging factor has been determined experimentally by using a probe compound such as pCBA and rhodamine B.

Clinical and ictal characteristics of infantile seizures: EEG correlation via long-term video EEG monitoring.

Purpose: The semiology of infantile seizures often shows different characteristics from that of adults. We performed this study to describe clinical and ictal characteristics of infantile seizures at less than two years of age.

Methods: A retrospective study was done for infants with epilepsy (ages: 1-24months) who underwent long-term video electroencephalography (EEG) monitoring at Samsung medical center between November 1994 and February 2012.

The efficacy and tolerability of rufinamide in intractable pediatric epilepsy.

Background And Purpose: Rufinamide (RUF) is a novel antiepileptic drug (AED) and its efficacy has been proven in Lennox-Gastaut syndrome (LGS). However, there is a lack of data regarding the efficacy in pediatric intractable epilepsies other than LGS. The purpose of the study was to explore the efficacy and tolerability of RUF in pediatric patients with intractable epilepsies as well as LGS.

Clinical features and genetic analysis of children with hyperekplexia in Korea.

Hyperekplexia is a rare inherited neurologic disorder that is characterized by hypertonia and an exaggerated startle response to sudden external stimuli. Until now, 5 genes are known to be associated with hyperekplexia: GLRA1, SLC6A5, GLRB, GPHN, and ARHGEF9. In this report, we performed a clinical and genetic analysis of 4 Korean children with hyperekplexia.

Genetic analysis of dystrophin gene for affected male and female carriers with Duchenne/Becker muscular dystrophy in Korea.

Duchenne and Becker muscular dystrophy (DMD/BMD) are X-linked recessive disorders caused by mutation in dystrophin gene. We analyzed the results of a genetic test in 29 DMD/BMD patients, their six female relatives, and two myopathic female patients in Korea. As the methods developed, we applied different procedures for dystrophin gene analysis; initially, multiplex polymerase chain reaction was used, followed by multiplex ligation-dependent probe amplification (MLPA).

Clinical and genetic analysis of three Korean children with pyridoxine-dependent epilepsy.

Pyridoxine-dependent epilepsy (PDE) is a rare autosomal recessive disorder that causes intractable seizures, especially in neonates and infants. Patients are typically resistant to typical antiepileptic drugs (AEDs) but respond dramatically to pyridoxine. Mutations in the ALDH7A1 gene are associated with the pathogenesis of PDE.

The role of ketogenic diet in the treatment of refractory status epilepticus.

Ketogenic diet (KD) is known to be effective in intractable epilepsy. However, the role of KD in refractory status epilepticus (RSE) has not been well described. The aim of this study is to explore the role of KD in patients with RSE.

Effect of the number of residual walls on fracture resistances, failure patterns, and photoelasticity of simulated premolars restored with or without fiber-reinforced composite posts.

Introduction: This study compared the fracture resistances and the failure patterns of 100 simulated mandibular premolars of a different number of coronal walls (zero to four walls) with or without fiber-reinforced composite (FRC) posts. In addition, the photoelastic stress distribution was analyzed.

Methods: The fracture resistance was measured at a 45 degrees angle with a crosshead speed of 1mm/min, and the failure patterns were observed.