Investigation of SARS-CoV-2 lineages and mutations circulating in a university-affiliated hospital in South Korea analyzed using Oxford Nanopore MinION sequencing.

Objectives: Despite the introduction of vaccines, treatments, and massive diagnostic testing, the evolution of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has continued to overcome barriers that had slowed its previous spread. As the virus evolves towards increasing fitness, it is critical to continue monitoring the occurrence of new mutations that could evade human efforts to control them.

Methods: We performed whole-genome sequencing using Oxford Nanopore MinION sequencing on 58 SARS-CoV-2 isolates collected during the ongoing coronavirus disease 2019 pandemic at a tertiary hospital in South Korea and tracked the emergence of mutations responsible for massive spikes in South Korea.

Genotypes of Clinical Isolates Are Associated with Phenol-Soluble Modulin (PSM) Production.

Phenol-soluble modulins (PSMs) are important virulence factors that cause cytolysis, mast cell degranulation, and stimulate inflammatory responses. In this study, PSM production by clinical isolates was measured by liquid chromatography/mass spectrometry (LC-MS) and correlated with staphylococcal protein A () type and staphylococcal cassette chromosome (SCC) type. Of 106 clinical isolates, 50 (47.

Thymol Reduces -Mediated Virulence Factor Phenol-Soluble Modulin Production in .

is a major human bacterial pathogen that carries a large number of virulence factors. Many virulence factors of are regulated by the accessory gene regulator () quorum-sensing system. Phenol-soluble modulins (PSMs) are one of the -mediated virulence determinants known to play a significant role in pathogenesis.

Comparison of peaks in the matrix-assisted laser desorption ionization time-of-flight mass spectrometry spectra of Staphylococcus aureus grown on various blood agar plates.

Matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS) is routinely used for bacterial identification in clinical laboratories. Bacterial protein expression may differ according to their growth conditions, especially the culture medium composition. We aimed to study the peak variations of Staphylococcus aureus grown on various blood agar plates (BAP), especially phenol-soluble modulin-mec (PSM-mec) peak (m/z 2409) associated with mecA gene conferring methicillin resistance.

Comparative evaluation of Nanopore polishing tools for microbial genome assembly and polishing strategies for downstream analysis.

Assembling high-quality microbial genomes using only cost-effective Nanopore long-read systems such as Flongle is important to accelerate research on the microbial genome and the most critical point for this is the polishing process. In this study, we performed an evaluation based on BUSCO and Prokka gene prediction in terms of microbial genome assembly for eight state-of-the-art Nanopore polishing tools and combinations available. In the evaluation of individual tools, Homopolish, PEPPER, and Medaka demonstrated better results than others.

Long-Range Order Self-Assembly of Conjugated Block Copolymers at Inclined Air-Liquid Interfaces.

Here, we report that long-range order, direction-controlled, ultrathin conjugated polymer films can be formed by the self-assembly of conjugated block copolymers (i.e., poly(3-hexylthiophene)--poly(ethylene glycol)) at inclined air-water interfaces.

Biofilm Formation by Clinical Isolates is Differentially Affected by Glucose and Sodium Chloride Supplemented Culture Media.

() causes persistent biofilm-related infections. Biofilm formation by is affected by the culture conditions and is associated with certain genotypic characteristics. Here, we show that glucose and sodium chloride (NaCl) supplementation of culture media, a common practice in studies of biofilms , influences both biofilm formation by 40 clinical isolates (methicillin-resistant and methicillin-sensitive ) and causes variations in biofilm quantification.

Rapid Discrimination of Methicillin-Resistant by MALDI-TOF MS.

Methicillin-resistant (MRSA) is a serious pathogen in clinical settings and early detection is critical. Here, we investigated the MRSA discrimination potential of matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) using 320 clinical isolates obtained in 2005-2014 and 181 isolates obtained in 2018. We conducted polymerase chain reactions (PCR) for staphylococcal cassette chromosome (SCC) typing and MALDI-TOF MS to find specific markers for methicillin resistance.

Binary Self-Assembly of Conjugated Block Copolymers and Quantum Dots at the Air-Liquid Interface into Ordered Functional Nanoarrays.

Controlling the nanoscale morphology of conducting polymer/nanoparticle hybrid films is a highly desired but challenging task. Here, we report that such functional hybrid films with unprecedented structural order can be formed through the self-assembly of conjugated block copolymers and CdSe quantum dots at the air-water interface. The one-step assembly of quantum dots and block copolymers composed of polythiophene and polyethylene glycol (P3HT--PEG) at the fluidic interface generated a highly ordered assembly structure of P3HT nanowires and one-dimensional quantum dot arrays.

High blood glucose independent of pre-existing diabetic status predicts mortality in patients initiating peritoneal dialysis therapy.

Purpose: Poor glycemic control associates with increased mortality in diabetic (DM) dialysis patients, but it is less well established whether high blood glucose (BG) independent of pre-existing diabetic status associates with mortality in dialysis patients. We assessed factors affecting BG at the start of peritoneal dialysis (PD) and its mortality-predictive impact in Korean PD patients.

Methods: In 174 PD patients (55 % males, 56 % DM), BG, nutritional status, comorbidity (CMD), and residual renal function (RRF) were assessed in conjunction with dialysis initiation.

The microfluidic chip module for the detection of murine norovirus in oysters using charge switchable micro-bead beating.

Sample preparation has recently been an issue in the detection of food poisoning pathogens, particularly viruses such as norovirus (NoV), in food because of the complexity of foods and raw fresh materials. Here, we demonstrate a total analytical microfluidic chip module to automatically perform a series of essential processes (cell concentration, lysis (RNA extraction), nucleic acid amplification, and detection) for the fast but sensitive detection of norovirus in oysters. The murine NoV spiked oyster was stomached using a standard method.

Mortality predictive role of serum uric acid in diabetic hemodialysis patients.

Objectives: It is controversial to what extent serum uric acid (SUA) is associated with mortality in patients with chronic kidney disease undergoing hemodialysis (HD). We analyzed the predictive role of SUA in the mortality of diabetic and nondiabetic chronic kidney disease patients starting on maintenance HD therapy.

Design And Subjects: SUA was measured at the initiation of HD therapy in 319 patients (137 females and 193 diabetic patients) with mean age of 60 ± 14 years and mean estimated glomerular filtration rate of 7.

Effect of preoperative warming during cesarean section under spinal anesthesia.

Background: Postoperative hypothermia and shivering is a frequent event in patients during cesarean section under spinal anesthesia. We assessed the effect of preoperative warming during cesarean delivery under spinal anesthesia for prevention of hypothermia and shivering.

Methods: Forty five patients undergoing elective cesarean section were randomly assigned to three groups.

Nano barcoding cell-based biosensor using fluorophor-embedded silica nanotubes.

A simple and reliable drug screening method was developed using peptide hydrogel cell beads coded by quantum dot-embedded silica nanotubes. Very long silica nanotubes were fabricated upon a nanoporous alumina template using sol-gel techniques. The physical shapes of the nanotubes were measured by TEM (Transmission Electron Microscope).

Causes of poor appetite in patients on peritoneal dialysis.

Anorexia is common in patients with chronic kidney disease and is a main contributor to the high prevalence of protein-energy wasting in them. The peritoneal dialysis (PD) procedure may further impair appetite by causing abdominal discomfort and also through the absorption of the osmotic agent and other factors. An increased peritoneal solute transport rate has been linked to protein-energy wasting and also to the malnutrition, inflammation, and atherosclerosis syndrome, which has been associated to poor appetite and plays a role in most premature deaths in these patients.

The relationship between symphysis-fundal height and intravenous ephedrine dose in spinal anesthesia for elective cesarean section.

Background: A decreased lumbosacral subarachnoidal space volume is a major factor in the cephalad intrathecal spread of local anesthetics in term parturients and their subarachnoidal space is decreased due to the compressive effect of huge uteri. Therefore, they show a higher level of sensory block and hypotensive episodes. The purpose of this study is to investigate whether the symphysis-fundal height (SFH) correlates with the highest sensory level and the amount of ephedrine administered under spinal anesthesia.

Risk factors for mortality in diabetic peritoneal dialysis patients.

Background: It is well established that the survival rate of diabetic end-stage renal disease patients remains the lowest among all primary diagnoses probably because of higher prevalence of cardiovascular diseases (CVD) associated with diabetes. This study was designed to evaluate the impact of CVD and other risk factors individually or in combination on mortality in diabetic peritoneal dialysis (PD) patients.

Methods: In a retrospective study, 213 incident PD patients [118 had diabetes mellitus (DM), 94 were female, mean age 55 ± 13 years] underwent initial assessment of nutritional status, comorbid disease (CMD) survey, residual renal function (RRF), dialysis adequacy and peritoneal transport characteristics at a mean of 9 days (range, 3-24 days) after start of PD and were then followed for 30 ± 24 months (range, 3-115 months).

Optimal use of peritoneal dialysis in patients with diabetes.

The survival of patients with end-stage renal disease (ESRD) resulting from diabetes continues to improve, but the survival rate among diabetic ESRD patients remains the lowest among all primary diagnoses probably because of the higher prevalence of cardiovascular comorbidity associated with diabetes. Diabetes, age, and comorbidity all significantly modify the effect of treatment modality on patient survival. As compared with hemodialysis (HD), peritoneal dialysis (PD) offers an equal or lower risk of death across all subgroups during the first 1-2 years of dialysis.

Morphological investigations of cells that adhered to the irregular patterned polydimethylsiloxane (PDMS) surface without reagents.

Polydimethylsiloxane (PDMS) surface consisting irregular pattern was investigated to develop cell-based biochip using PDMS. PDMS surface was modified with nano- and micro-combined patterns using surface deformation technology. Hydrophobicity of nano-patterned PDMS surface was sustained.

Comparision of remifentanil and remifentanil/midazolam for outpatient anesthesia in prolotherapy.

Background: Prolotherapy is a therapeutic procedure used for chronic musculoskeletal and arthritic pain. It involves injecting an irritant solution to pain sites and causes patient discomfort, which can lead to treatment discontinuation. Remifentanil is an ultra short-acting micro-opiate receptor agonist that permits a rapid transition from intense analgesia to a minimal residual effect.

Impact of incremental risk factors on peritoneal dialysis patient survival: proposal of a simplified clinical mortality risk score.

Background/aim: Peritoneal dialysis (PD) patient survival is influenced by many factors and there is no consensus on the relative importance of these predictors, independently or combined. This study was designed to evaluate how these independent factors, alone or in various combinations, may influence PD patient survival.

Methods: A peritoneal equilibration test, subjective global assessment (SGA), and comorbid diseases (CMD) were assessed.

Poor outcomes for fast transporters on PD: the rise and fall of a clinical concern.

A rapid peritoneal solute transport rate (PSTR), generally termed a "high" PSTR, may in fact be associated with low small solute transport due to the low ultrafiltration rates with which it is associated; the term "fast" PSTR has, therefore, been proposed as a more accurate descriptive term. During the 1990s several studies showed that fast PSTR was associated with high mortality-presumably because it may lead to fluid overload, nutritional and metabolic alterations but also because it may be associated with other risk factors such as cardiovascular disease, other comorbid diseases, and inflammation. However, the consensus of today is that a fast PSTR is not as critical for patient survival as previously thought but that the prognosis depend on the type of fast PSTR: Type 1-an early inherent type which is associated with increased mortality mainly because it is associated with comorbidity and inflammation; these patients would have a poor prognosis also if they were treated by hemodialysis.

Identifying and managing malnutrition stemming from different causes.

Protein-energy malnutrition (PEM) is highly prevalent among peritoneal dialysis (PD) patients and is a strong predictor of morbidity and mortality. A wide range of factors can lead to PEM and associated wasting (PEM/W) in PD patients, but persistent inflammation and the presence of diabetes have been identified as the two main reasons. An important body of literature has been reporting studies of methods suitable for detecting malnutrition in its early phase so that appropriate intervention can be provided.

Peritoneal dialysis patient survival: a comparison between a Swedish and a Korean centre.

Background: Dialysis patient mortality remains high, and this high mortality may be due to many factors. In peritoneal dialysis (PD) patients, old age, co-morbid diseases, malnutrition, low residual renal function (RRF) and a high peritoneal transport rate have been shown to influence survival, but the relative importance of these factors may differ between different patient populations. Besides, centre practice patterns may differ between centres and may influence patient survival.

Is malnutrition an independent predictor of mortality in peritoneal dialysis patients?

Background: It has been established that malnutrition (MN) is a strong predictor of mortality in peritoneal dialysis (PD) patients. However, MN is often the consequence of co-morbid diseases (CMD), and the confounding effect of CMD on mortality in malnourished PD patients has not been clearly defined. In this study, we tested the hypothesis that MN without CMD may not be associated with significant mortality.