Paraquat was the most successful nonselective herbicide in Korea due to its rapid herbicidal activity. However, its high mammalian toxicity, frequent self-poisoning incidents, and a lack of effective ...antidotes led to a paraquat ban in Korea in 2012. Therefore, this review was conducted to revisit the toxicological profile of paraquat and to investigate the impacts of the paraquat ban on human health and agriculture in Korea. A review of toxicological information reconfirmed that paraquat is highly acutely toxic to humans, and ingestion, inhalation, or dermal administration of the herbicide can cause severe clinical signs and inevitably lead to death by respiratory failure. In Korea, the paraquat ban immediately decreased the suicide rate due to pesticides (mainly paraquat) by 46.1%, resulting in a 10% decrease of the total suicide rate. However, this also led to an increase in suicide attempts with other poisons such as carbon monoxide, suggesting that suicide attempts and rates of suicide by poisoning depend on not only the toxicity of the poison but also the accessibility of the poisoning agents. In agriculture, paraquat was quickly replaced by other nonselective herbicides such as glufosinate and glyphosate. Thus, the paraquat ban did not have a significant impact on agricultural practices but influenced the nonselective herbicide market; the use of glufosinate was higher than use of glyphosate due to glufosinate's rapid herbicidal activity, which is similar to that of paraquat. Though the paraquat ban can be considered as a national strategy to lower suicide rates, the increase in suicide attempts with other poisons suggests that multilateral efforts are required for not only keeping suicidal agents away from people but also minimizing motives for suicide.
Side reactions caused by reactive oxygen species (e.g., superoxide and singlet oxygen) are limiting factors in the lithium–oxygen batteries (LOBs). Superoxide dismutase mimetics (SODms), which ...suppress superoxide‐triggered side reactions by accelerating the disproportionation reaction during discharge, are introduced as soluble additives in the LOBs. However, although SODms promote the disproportionation reaction, which is the main pathway for singlet oxygen evolution, the correlation between SODms and singlet oxygen has not been verified. Here, 4‐carboxy‐TEMPO is selected as a representative SODm that effectively promotes the disproportionation reaction and chemically verifies acceleration of singlet oxygen evolution. Furthermore, by using quencher, it is reported that the release of singlet oxygen evolved by the SODm is decreased. Because this study closely examines the relationship between the additives and singlet oxygen, it is believed that this study provides an important reference for the development of additives for the practical application of LOBs.
To accomplish high capacity and reversibility in lithium–oxygen batteries (LOBs), it is essential to reduce the cell degradation caused by the reactive oxygen species such as superoxide and singlet oxygen. Superoxide dismutase mimetics (SODm) to reduce superoxide are discussed as additives for LOBs, and close investigation of the relationship between SODms and singlet oxygen is presented.
Hepatitis E virus (HEV), an emerging zoonotic pathogen, poses a significant public health concern worldwide. Recently, rat HEV (Rocahepevirus ratti genotype C1; HEV‐C1) has been reported to cause ...zoonotic infections and hepatitis in humans. Human infections with HEV‐C1 are considered to be underestimated worldwide due to limited knowledge of transmission routes, genome epidemiology, and the risk assessment of zoonosis associated with these viruses. A total of 186 wild Norway rats (Rattus norvegicus) were collected from the Republic of Korea (ROK) between 2011 and 2021. The prevalence of HEV‐C1 RNA was 8 of 180 (4.4%) by reverse‐transcription polymerase chain reaction. We first reported three nearly whole‐genome sequences of HEV‐C1 newly acquired from urban rats in the ROK. Phylogenetic analysis demonstrated that Korea‐indigenous HEV‐C1 formed an independent genetic group with those derived from R. norvegicus rats in other countries, indicating geographical and genetic diversity. Our findings provide critical insights into the molecular prevalence, genome epidemiology, and zoonotic potential of Rocahepevirus. This report raises awareness of the presence of Rocahepevirus‐related hepatitis E among physicians in the ROK.
Whole-genome sequencing of infectious agents enables the identification and characterization of emerging viruses. The MinION device is a portable sequencer that allows real-time sequencing in fields ...or hospitals. Hantaan orthohantavirus (Hantaan virus, HTNV), harbored by Apodemus agrarius, causes hemorrhagic fever with renal syndrome (HFRS) and poses a critical public health threat worldwide. In this study, we aimed to evaluate the feasibility of using nanopore sequencing for whole-genome sequencing of HTNV from samples having different viral copy numbers. Amplicon-based next-generation sequencing was performed in A. agrarius lung tissues collected from the Republic of Korea. Genomic sequences of HTNV were analyzed based on the viral RNA copy numbers. Amplicon-based nanopore sequencing provided nearly full-length genomic sequences of HTNV and showed sufficient read depth for phylogenetic analysis after 8 h of sequencing. The average identity of the HTNV genome sequences for the nanopore sequencer compared to those of generated from Illumina MiSeq revealed 99.8% (L and M segments) and 99.7% (S segment) identities, respectively. This study highlights the potential of the portable nanopore sequencer for rapid generation of accurate genomic sequences of HTNV for quicker decision making in point-of-care testing of HFRS patients during a hantavirus outbreak.
We propose a nondestructive method to estimate the peak wavelength of the active quantum well (QW) region of an as-grown vertical-cavity surface-emitting laser (VCSEL) epi-wafer based on room ...temperature electroluminescence (EL) measurements. Contacts for the electrical excitation are established using flexible conductive materials on the epilayers without the fabrication of metal electrodes. The angle dependence of the EL properties is investigated to analyze the detuned wavelength of the active QW region for the VCSEL structure. The wavelength offset caused by detuning obtained from the as-grown epi-wafer correlates with the laser threshold properties of the VCSEL chips fabricated from the epi-wafer. The results show the possibility of a nondestructive evaluation method without metal electrodes for as-grown VCSEL epi-wafers, particularly the active QW region, which has been challenging to optically analyze from completed VCSEL epi-structures.
During the coronavirus disease (COVID-19) pandemic, social distancing was effective in controlling disease spread across South Korea. The impact of national social distancing on the spread of common ...respiratory virus infections has rarely been investigated. We evaluated the weekly proportion of negative respiratory virus polymerase chain reaction (PCR) test results and weekly positive rates of each respiratory virus during the social distancing period (10th-41st weeks of 2020) and the corresponding period in different years, utilizing the national respiratory virus surveillance dataset reported by the Korean Center for Disease Control and Prevention. The proportions of negative respiratory virus PCR test results increased up to 87.8% and 86.1% during level 3 and level 2 of the social distancing period, respectively. The higher the level of social distancing, the higher the proportion of negative respiratory virus PCR test results. During the social distancing period, the mean weekly positive rates for parainfluenza virus, influenza virus, human coronavirus, and human metapneumovirus were significantly lower than those during the same period in 2015-2019 (0.1% vs. 9.3%, P <0.001; 0.1% vs. 7.2%, P <0.001; 0.4% vs. 2.3%, P <0.001; and 0.2% vs. 5.3%, P <0.001, respectively). The mean positive rate for rhinovirus/enterovirus during level 3 social distancing was lower than that in the same period in 2015-2019 (8.5% vs. 19.0%, P <0.001), but the rate during level 1 social distancing was higher than that in the same period in 2015-2019 (38.3% vs. 19.4%, P <0.001). The national application of social distancing reduced the spread of common respiratory virus infections during the COVID-19 pandemic.
Microglial activation plays a pivotal role in the pathogenesis of various neurologic disorders, such as cerebral ischemia, Alzheimer's disease, and Parkinson's disease. Thus, controlling microglial ...activation is a promising therapeutic strategy for such brain diseases. In the present study, we found that a ginseng saponin metabolite, compound K 20-O-D-glucopyranosyl-20(S)-protopanaxadiol, inhibited the expressions of inducible nitric-oxide synthase, proinflammatory cytokines, monocyte chemotactic protein-1, matrix metalloproteinase-3, and matrix metalloproteinase-9 in lipopolysaccharide (LPS)-stimulated BV2 microglial cells and primary cultured microglia. Subsequent mechanistic studies revealed that compound K suppressed microglial activation via inhibiting reactive oxygen species, mitogen-activated protein kinases, and nuclear factor-κB/activator protein-1 activities with enhancement of heme oxygenase-1/antioxidant response element signaling. To address the anti-inflammatory effects of compound K in vivo, we used two brain disease models of mice: sepsis (systemic inflammation) and cerebral ischemia. Compound K reduced the number of Iba1-positive activated microglia and inhibited the expressions of tumor necrosis factor-α and interleukin-1β in the LPS-induced sepsis brain. Furthermore, compound K reduced the infarct volume of ischemic brain induced by middle cerebral artery occlusion and suppressed microglial activation in the ischemic cortex. The results collectively suggest that compound K is a promising agent for prevention and/or treatment of cerebral ischemia and other neuroinflammatory disorders.
High efficiency and flexible inverted organic solar cells have been fabricated using solution-processed silver nanowire/zinc oxide composite transparent electrodes. The transparent electrodes showed ...a low sheet resistance of -13 ff）.sq-1 and high transmittance of -93% as well as superior mechanical flexibility. Power conversion efficiencies of -7.57% and -7.21% were achieved for devices fabricated on glass and plastic substrate, respectively. Moreover, the flexible devices did not show any degradation in their performance even after being folded with a radius of-480 μm.
Background
There are few data on the clinical implications of immunosuppressive protein expression in tumors and immune cell infiltration within the tumor microenvironment in patients with gastric ...cancer (GC).
Methods
In this study, 243 patients with curatively resected GC were included. The levels of immunosuppressive protein expression programmed cell death 1 ligand 1 (PD-L1), cytotoxic T-lymphocyte antigen 4 (CTLA-4), and indoleamine 2,3-dioxygenase (IDO) in tumors and the densities of immune cells CD3(+), CD4(+), CD8(+), or PD-1(+) cells within the tumor microenvironment were measured using immunohistochemical analysis.
Results
Positive PD-L1, CTLA-4, and IDO expression was observed in 43.6, 65.8, and 47.7 % of the patients, respectively. Expression of PD-L1, CTLA-4, and IDO was related to less advanced stage, intestinal type, and well/moderately differentiated adenocarcinoma (
P
< 0.05). PD-L1 expression was related to better disease-free survival (DFS) and overall survival (OS) in GC PD-L1(+) vs. PD-L1(−) tumors: 5-year DFS rate, 82.6 vs. 66.9 %; 5-year OS rate, 83.0 vs. 69.1 % (
P
values <0.05). Survival outcomes were also better in patients with a higher density of CD3(+) cells within the tumor microenvironment than in those with a lower density of CD3(+) cells 5-year DFS rate, 80.9 vs. 67.0 %; 5-year OS rate, 82.5 vs. 68.0 % (
P
values <0.05). In multivariate analysis, these two immune markers had a prognostic impact on survival, independent of other clinical variables.
Conclusions
GC patients with immunosuppressive protein expression (PD-L1, CTLA-4, or IDO) had distinct clinicopathological characteristics. PD-L1(+) expression and a high-CD3 tumor microenvironment are favorable prognostic markers in GC.
Purpose
To demonstrate robust myelin water fraction (MWF) mapping using an artificial neural network (ANN) with multi‐echo gradient‐echo (GRE) signal.
Methods
Multi‐echo gradient‐echo signals ...simulated with a three‐pool exponential model were used to generate the training data set for the ANN, which was designed to yield the MWF. We investigated the performance of our proposed ANN for various conditions using both numerical simulations and in vivo data. Simulations were conducted with various SNRs to investigate the performance of the ANN. In vivo data with high spatial resolutions were applied in the analyses, and results were compared with MWFs derived by the nonlinear least‐squares algorithm using a complex three‐pool exponential model.
Results
The network results for the simulations show high accuracies against noise compared with nonlinear least‐squares MWFs: RMS‐error value of 5.46 for the nonlinear least‐squares MWF and 3.56 for the ANN MWF at an SNR of 150 (relative gain = 34.80%). These effects were also found in the in vivo data, with reduced SDs in the region‐of‐interest analyses. These effects of the ANN demonstrate the feasibility of acquiring high‐resolution myelin water images.
Conclusion
The simulation results and in vivo data suggest that the ANN facilitates more robust MWF mapping in multi‐echo gradient‐echo sequences compared with the conventional nonlinear least‐squares method.
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