Submerged leaves of live indoor foliage plants adsorb H1N1 influenza virus from suspension.

Control of hazardous indoor particles using plants has attracted interest due to the increasing worldwide air pollution and spread of pandemic-causing viruses. However, the interaction between human pathogenic viruses (HPVs) and live plants has not been examined largely due to issues in detecting tiny amounts of infectious viruses in a carrier (such as an aerosol) and the lack of suitable examination methods. In this study, as a novel evaluation method, the effect of submerged leaves of live plants on HPVs in water was examined, using the H1N1 influenza virus as a model. Selected plant foliage of a live plant was immersed in a small bag containing HPV water suspension. In an initial screening test, the activities of 20 different plant species on the virus suspension were evaluated using a rapid virus detection kit. Ten plant species had the capability to decrease virus concentrations in the water suspension within 72 h. Among the experimental plant species, Epipremnum aureum showed the highest virus decreasing characteristics when examined using both the kit and quantitative real time polymerase chain reaction. The capacity of immersed leaf of live E. aureum to decrease viral content was enhanced when the plant-containing pot was electrically grounded to the earth (approximately 70% decrease in virus concentration). The foliage sample analysis showed that virus adsorption to the plant foliage surface could be the major reason for the decrease in the suspension. These results suggest that the proposed method can be applied to select plants to further investigate plant-HPV interactions.

Correction: Lee, B.U. Minimum Sizes of Respiratory Particles Carrying SARS-CoV-2 and the Possibility of Aerosol Generation. Int. J. Environ. Res. Public Health 2020, 17, 6960.

The author would like to update a few calculation results in the Abstract and Section 4 "Calculation of Sizes of Respiratory Particles Containing SARS-CoV-2" in the previous publication [...].

Why Does the SARS-CoV-2 Delta VOC Spread So Rapidly? Universal Conditions for the Rapid Spread of Respiratory Viruses, Minimum Viral Loads for Viral Aerosol Generation, Effects of Vaccination on Viral Aerosol Generation, and Viral Aerosol Clouds.

This study analyzes the reasons the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Delta variant of concern (VOC) spreads so rapidly. Novel topics such as universal conditions for the rapid spread of respiratory viruses, minimum viral loads for viral aerosol generation, effects of vaccination on viral aerosol generation, and viral aerosol clouds were studied. The analyses were based on experimental results and analytic model studies. Four universal conditions, namely asymptomatic host, high viral load, stability of viruses in air, and binding affinity of viruses to human cells, need to be satisfied for the rapid spread of respiratory viruses. SARS-CoV-2 and its variants such as the Alpha VOC and Delta VOC satisfy the four fundamental conditions. In addition, there is an original principle of aerosol generation of respiratory viruses. Assuming that the aerosol-droplet cutoff particle diameter for distinguishing potential aerosols from earthbound respiratory particles is 100 µm, the minimum viral load required in respiratory fluids to generate viral aerosols is ~106 copies mL-1, which is within the range of the reported viral loads in the Alpha VOC cases and the Delta VOC cases. The daily average viral loads of the Delta VOC in hosts have been reported to be between ~109 copies mL-1 and ~1010 copies mL-1 during the four days after symptom onset in 1848 cases of the Delta VOC infection. Owing to the high viral load, the SARS-CoV-2 Delta VOC has the potential to effectively spread through aerosols. COVID-19 vaccination can decrease aerosol transmission of the SARS-CoV-2 Alpha VOC by reducing the viral load. The viral load can explain the conundrum of viral aerosol spreading. The SARS-CoV-2 Delta VOC aerosol clouds have been assumed to be formed in restricted environments, resulting in a massive numbers of infected people in a very short period with a high spreading speed. Strong control methods against bioaerosols should be considered in this SARS-CoV-2 Delta VOC pandemic. Large-scale environmental monitoring campaigns of SARS-CoV-2 Delta VOC aerosols in public places in many countries are necessary, and these activities could contribute to controlling the coronavirus disease pandemic.

Minimum Sizes of Respiratory Particles Carrying SARS-CoV-2 and the Possibility of Aerosol Generation.

This study calculates and elucidates the minimum size of respiratory particles that are potential carriers of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2); furthermore, it evaluates the aerosol generation potential of SARS-CoV-2. The calculations are based on experimental results and theoretical models. In the case of maximum viral-loading derived from experimental data of COVID-19 patients, 8.97 × 10-5% of a respiratory fluid particle from a COVID-19 patient is occupied by SARS-CoV-2. Hence, the minimum size of a respiratory particle that can contain SARS-CoV-2 is calculated to be approximately 9.3 µm. The minimum size of the particles can decrease due to the evaporation of water on the particle surfaces. There are limitations to this analysis: (a) assumption that the viruses are homogeneously distributed in respiratory fluid particles and (b) considering a gene copy as a single virion in unit conversions. However, the study shows that high viral loads can decrease the minimum size of respiratory particles containing SARS-CoV-2, thereby increasing the probability of aerosol generation of the viruses. The aerosol generation theory created in this study for COVID-19 has the potential to be applied to other contagious diseases that are caused by respiratory infectious microorganisms.

Cryogenic Aerosol Generation: Airborne Mist Particles Surrounding Liquid Nitrogen.

Aerosol mist particles generated near the surface of a liquid nitrogen container were measured and analyzed. The particles present at various distances from the boiling surface of liquid nitrogen were detected using an optical particle counter. In this experiment, 3 micrometer particles exhibited a more than 100-fold increase in concentration due to the liquid nitrogen surface. However, 0.3 micrometer and 10 micrometer particles showed smaller variations (2% to 79%) in their concentrations in the vicinity of liquid nitrogen. The distance from the boiling surface of the liquid nitrogen strongly affected the variations in particle concentration. The variations in aerosol concentrations were significant within 20 cm of the liquid nitrogen surface. These results can be considered as a useful quantitative environmental guideline in cryogenic studies that use liquid nitrogen, and this concept can be applied to cryogenic aerosol mist generation mechanisms.

Electrospray patterning of yeast cells for applications in alcoholic fermentation.

Yeast cells patterned by pulsed jet electrospray showed a high alcoholic fermentation rate. Multi-dimensional patterns of individual yeast cells were produced by varying the experimental parameters of the electrospray system. The electrospray process, which employed a vibrational electric field, could control patterns of viable yeast cells at a cellular resolution. This novel system for electrospraying viable cells can be applied to biological process engineering including whole cell biochip techniques and micro fermentation processes for biochemical studies.

Concentrations of Atmospheric Culturable Bioaerosols at Mountain and Seashore Sites.

Concentrations of atmospheric culturable bioaerosols at mountain and seashore sites were measured in field investigations by using a bio-culture sampler. The eastern Korean peninsula was selected for the measurements because of the short distance between the mountain site and the seashore site. Detectable concentrations of culturable fungal and bacterial bioaerosols (maximum 1065 CFU/m3) were quantitatively measured at the mountain and seashore sites. In addition, measurement of bioaerosols was conducted at an urban area as reference data. Significantly higher concentrations of bioaerosols were found at the mountain site. However, several fold smaller levels of bioaerosols were detected at the seashore site (t-test p-value < 0.05).

Antimicrobial Air Filters Using Natural Sea Salt Particles for Deactivating Airborne Bacterial Particles.

We developed an antimicrobial air filter using natural sea salt (NSS) particles. Airborne NSS particles were produced via an aerosol process and were continuously coated onto the surface of an air filter under various deposition times. The filtration efficiency and bactericidal performance of the NSS-coated filter against aerosolized bacterial particles (Staphylococcus epidermidis, Escherichia coli) were evaluated quantitatively. The filtration efficiency of the tested filter ranged from 95% to 99% depending on the deposition time, and the bactericidal performance demonstrated efficiencies of more than 98% against both tested bacterial bioaerosols when the NSS deposition ratio was more than 500 µg/cm2. The experimental results indicated that the NSS-coated filters have the potential to be used as effective antimicrobial air filters for decreasing environmental exposure to microbial contaminants.

Crystal structures of green fluorescent protein with the unnatural amino acid 4-nitro-L-phenylalanine.

The X-ray crystal structures of two superfolder green fluorescent protein (sfGFP) constructs containing a genetically incorporated spectroscopic reporter unnatural amino acid, 4-nitro-L-phenylalanine (pNO2F), at two unique sites in the protein have been determined. Amber codon-suppression methodology was used to site-specifically incorporate pNO2F at a solvent-accessible (Asp133) and a partially buried (Asn149) site in sfGFP. The Asp133pNO2F sfGFP construct crystallized with two molecules per asymmetric unit in space group P3221 and the crystal structure was refined to 2.05 Šresolution. Crystals of Asn149pNO2F sfGFP contained one molecule of sfGFP per asymmetric unit in space group P4122 and the structure was refined to 1.60 Šresolution. The alignment of Asp133pNO2F or Asn149pNO2F sfGFP with wild-type sfGFP resulted in small root-mean-square deviations, illustrating that these residues do not significantly alter the protein structure and supporting the use of pNO2F as an effective spectroscopic reporter of local protein structure and dynamics.

Mortality, liver transplantation and hepatic complications in patients with treatment-naïve chronic hepatitis B treated with entecavir vs tenofovir.

Few studies have directly compared the long-term clinical outcomes of entecavir (ETV) and tenofovir disoproxil fumarate (TDF). This study aimed to compare the risk of mortality, liver transplantation and hepatic complications including hepatocellular carcinoma (HCC) and hepatic decompensation between these drugs in treatment-naïve chronic hepatitis B (CHB). We performed a longitudinal observational analysis of data from 1325 consecutive adult CHB patients with a cumulative adherence of ≥80% to treatment with ETV (n = 721) or TDF (n = 604) at a tertiary referral hospital in Ulsan, Korea, from 1 January 2007 through 31 April 2017. Among the patients, 708 were analysed using propensity score matching with a ratio of 1:1. In the follow-up period of up to 5 years, five patients (0.4%) died, three patients (0.2%) underwent liver transplantation (LT) and 54 patients (4.1%) developed HCC. Hepatic decompensation occurred in 24 (1.8%) patients. ETV therapy did not significantly differ from TDF therapy regarding the risk of liver-related death or LT (HR 0.96; 95% CI, 0.23-4.07; log-rank P = 0.955), HCC (HR, 1.36; 95% CI, 0.72-2.56; log-rank P = 0.340) and hepatic decompensation (HR, 1.64; 95% CI, 0.67-4.00; log-rank P = 0.276). In the 708 propensity-matched pairs, ETV and TDF were also not significantly different with respect to the risk of mortality, LT and hepatic complications. In this longitudinal observational study of 1325 patients with CHB, ETV and TDF therapies were not significantly different regarding the risk of mortality, HCC, LT and hepatic decompensation.

Medication Nonadherence Increases Hepatocellular Carcinoma, Cirrhotic Complications, and Mortality in Chronic Hepatitis B Patients Treated With Entecavir.

OBJECTIVES: Optimal adherence to nucleoside analogue treatment is necessary to achieve undetectable levels of hepatitis B virus (HBV) DNA in patients with chronic hepatitis B (CHB), and to prevent cirrhotic complications. However, any large long-term follow-up study has not been investigated the effect of adherence to entecavir (ETV) treatment on specific liver-related events (LREs), namely, hepatocellular carcinoma (HCC), cirrhotic complications, and mortality. METHODS: This was a 10-year longitudinal observational study of treatment-naïve patients with CHB who received ETV treatment. The primary outcome was the cumulative probability of LREs. The cumulative level of adherence to medication was categorized as good (≥90%) or poor (<90%). RESULTS: Data from 894 treatment-naïve CHB patients who received ETV were analyzed. Overall mean adherence rates were 89.1%. Patients with poor adherence had a higher risk of virologic breakthrough (VBT) (HR, 22.42; 95% CI, 19.57-52.52; P < 0.001) than those with good adherence. Multivariate analyses showed a higher risk of liver-related (HR, 14.29; 95% CI, 3.49-58.47; P < 0.001) or all-cause (HR, 4.96; 95% CI, 2.19-11.27; P < 0.001) mortality, HCC (HR, 2.86; 95% CI, 1.76-4.64; P < 0.001), and cirrhotic complications (HR, 2.86; 95% CI, 1.93-4.25; P < 0.001) with poor adherence. Medication adherence was further stratified into three groups according to adherence rates of <70%, ≥70 to <90%, and ≥90%. The dose-response analyses of adherence rates showed that the risk of LREs increased progressively as medication adherence declined. In particular, the unfavorable effects of nonadherence were more pronounced in patients with cirrhosis. CONCLUSIONS: Poor adherence to medication was associated with a higher mortality and greater risk of HCC and cirrhotic complications, particularly among patients with liver cirrhosis.

Washable antimicrobial polyester/aluminum air filter with a high capture efficiency and low pressure drop.

Here, we introduce a reusable bifunctional polyester/aluminum (PET/Al) air filter for the high efficiency simultaneous capture and inactivation of airborne microorganisms. Both bacteria of Escherichia coli and Staphylococcus epidermidis were collected on the PET/Al filter with a high efficiency rate (∼99.99%) via the electrostatic interactions between the charged bacteria and fibers without sacrificing pressure drop. The PET/Al filter experienced a pressure drop approximately 10 times lower per thickness compared with a commercial high-efficiency particulate air filter. As the Al nanograins grew on the fibers, the antimicrobial activity against airborne E. coli and S. epidermidis improved to ∼94.8% and ∼96.9%, respectively, due to the reinforced hydrophobicity and surface roughness of the filter. Moreover, the capture and antimicrobial performances were stably maintained during a cyclic washing test of the PET/Al filter, indicative of its reusability. The PET/Al filter shows great potential for use in energy-efficient bioaerosol control systems suitable for indoor environments.

Association between non-alcoholic fatty liver disease and subclinical coronary atherosclerosis: An observational cohort study.

BACKGROUND & AIMS: There are limited data on the association between non-alcoholic fatty liver disease (NAFLD) and subclinical coronary atherosclerosis. This study investigated the influence of NAFLD on subclinical coronary atherosclerosis as detected by coronary computed tomography angiography (CCTA) in an asymptomatic population. METHODS: A total of 5,121 consecutive asymptomatic individuals with no prior history of coronary artery disease or significant alcohol intake voluntarily underwent abdominal ultrasonography and CCTA as part of a general health examination. Fatty liver was assessed by ultrasonography examination. The fatty liver index and NAFLD fibrosis score were also calculated. Coronary atherosclerotic plaques on CCTA were evaluated. The association between NAFLD and subclinical coronary atherosclerosis was determined by logistic regression analysis. RESULTS: Of the study participants, 1,979 (38.6%) had ultrasonography-diagnosed NAFLD. After adjustment for cardiovascular risk factors, there were no statistically significant differences in the adjusted odds ratios of NAFLD for calcified plaque (1.03; 95% CI 0.89-1.20; p = 0.673) and mixed plaque (1.15; 95% CI 0.93-1.42; p = 0.214). However, adjusted odds ratios for any atherosclerotic plaque (1.18; 95% CI 1.03-1.35; p = 0.016) and non-calcified plaque (1.27; 95% CI 1.08-1.48; p = 0.003) were significantly higher in NAFLD. In addition, there was a significant association of fatty liver index ≥30 with non-calcified plaque (1.37; 95% CI 1.14-1.65; p = 0.001) and NAFLD fibrosis score ≥-1.455 with non-calcified plaque (1.20; 95% CI 1.08-1.42; p = 0.030). CONCLUSIONS: In this large cross-sectional study of asymptomatic individuals undergoing CCTA, NAFLD was consistently associated with non-calcified plaque, suggesting an increased cardiovascular risk. LAY SUMMARY: In asymptomatic individuals, non-alcoholic fatty liver disease (NAFLD) was an independent risk factor for non-calcified plaque, which has been known as a vulnerable plaque associated with sudden and unexpected cardiac events. Therefore, appropriate medical therapy for NAFLD was required to reduce future cardiac events.

Clinical Course of Partial Virologic Response with Prolonged Tenofovir Therapy in Nuclos(t)ides-Naïve Patients with Chronic Hepatitis B.

BACKGROUND/AIMS: The clinical course of chronic hepatitis B (CHB) patients with partial virologic response (PVR) during tenofovir disoproxil fumarate (TDF) therapy remains unclear. METHODS: We retrospectively investigated the long-term clinical outcomes of TDF treatment in nucleos(t)ides-naïve CHB patients, particularly in those with PVR. RESULTS: A total of 391 patients treated with TDF therapy for more than 12 months were included. Virologic response (VR) was achieved in 341 patients (87.2%). PVR was evident in 127 (45.3%) of the 391 patients. Multivariate logistic regression analysis using selected baseline factors identified absolute HBV DNA levels at baseline (OR 0.496; 95% CI 1.369-1.969) and HBeAg positivity (OR 0.622; 95% CI 1.096-3.167) as factors significantly associated with PVR. During continuous prolonged TDF therapy, 127 (71.8%) of 177 patients with PVR achieved VR. The cumulative rates of VR in patients with PVR at 12, 24, and 36 months were 42.4, 79.7, and 90.2%, respectively. Serum HBV DNA level at week 24 was significantly associated with VR in patients with PVR. CONCLUSIONS: The vast majority of CHB patients with PVR achieved VR through prolonged TDF therapy, although the time to achieve VR was delayed in those with PVR. This suggests that adjustment of TDF therapy in patients with PVR is unnecessary.

Early Seizure Detection by Applying Frequency-Based Algorithm Derived from the Principal Component Analysis.

The use of automatic electrical stimulation in response to early seizure detection has been introduced as a new treatment for intractable epilepsy. For the effective application of this method as a successful treatment, improving the accuracy of the early seizure detection is crucial. In this paper, we proposed the application of a frequency-based algorithm derived from principal component analysis (PCA), and demonstrated improved efficacy for early seizure detection in a pilocarpine-induced epilepsy rat model. A total of 100 ictal electroencephalographs (EEG) during spontaneous recurrent seizures from 11 epileptic rats were finally included for the analysis. PCA was applied to the covariance matrix of a conventional EEG frequency band signal. Two PCA results were compared: one from the initial segment of seizures (5 sec of seizure onset) and the other from the whole segment of seizures. In order to compare the accuracy, we obtained the specific threshold satisfying the target performance from the training set, and compared the False Positive (FP), False Negative (FN), and Latency (Lat) of the PCA based feature derived from the initial segment of seizures to the other six features in the testing set. The PCA based feature derived from the initial segment of seizures performed significantly better than other features with a 1.40% FP, zero FN, and 0.14 s Lat. These results demonstrated that the proposed frequency-based feature from PCA that captures the characteristics of the initial phase of seizure was effective for early detection of seizures. Experiments with rat ictal EEGs showed an improved early seizure detection rate with PCA applied to the covariance of the initial 5 s segment of visual seizure onset instead of using the whole seizure segment or other conventional frequency bands.

Vigorous Periprocedural Hydration With Lactated Ringer's Solution Reduces the Risk of Pancreatitis After Retrograde Cholangiopancreatography in Hospitalized Patients.

BACKGROUND & AIMS: Vigorous intravenous fluid resuscitation (IVFR) was reported to reduce post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis in a pilot study. We performed a randomized, double-blind controlled trial to establish whether periprocedural vigorous IVFR reduces the risk of post-ERCP pancreatitis. METHODS: A total of 510 patients with native papilla at 3 tertiary referral centers in Korea were randomly assigned (1:1) to groups given vigorous IVFR (lactated Ringer's solution in an initial bolus of 10 mL/kg before the procedure, 3 mL/kg/h during the procedure, for 8 hours after the procedure, and a post-procedure bolus of 10 mL/kg) or a standard IVFR (lactated Ringer's solution at 1.5 mL/kg/h during and for 8 hours after the procedure). The primary end point of the study was the development of post-ERCP pancreatitis, and the secondary end point was severity of pancreatitis, hyperamylasemia, and fluid overload. RESULTS: The main indications for ERCP were choledocholithiasis (58%) and malignant biliary stricture (27%). Post-ERCP pancreatitis developed in 11 patients in the vigorous IVFR group (4.3%) and 25 patients in the standard IVFR group (9.8%) (relative risk, 0.41; 95% CI, 0.20-0.86; P = .016). Moderate or severe acute pancreatitis occurred in a significantly smaller proportion of patients in the vigorous IVFR group (0.4%) than in the standard IVFR group (2.0%; P = .040). One patient in the vigorous IVFR group developed peripheral edema. CONCLUSIONS: In a double-blind, randomized controlled trial, we found vigorous periprocedural intravenous hydration with lactated Ringer's solution to reduce the incidence and severity of post-ERCP pancreatitis in average-risk and high-risk cases. IVFR is not associated with increased adverse events. ClinicalTrials.gov number: NCT02308891.

Effects of human activities on concentrations of culturable bioaerosols in indoor air environments.

We studied the effects of human activity on concentrations of fungal and bacterial bioaerosols in indoor air environments. We conducted measurement experiments for concentrations of bioaerosols and aerosol particles in test chambers with people performing various activities inside. We found that the number of people and human activities had positive correlations with the concentrations of bacterial bioaerosols. However, the concentration of fungal bioaerosols was not influenced by human presence or activities. The findings regarding the concentrations of fungal and bacterial bioaerosols and the effects of human presence and activities will be useful for studying control methods against bioaerosols.