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Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infection with a high case fatality rate. The serious clinical features need to be further defined. We performed a retrospective analysis among SFTS patients in South Korea during 2016-2021 to update the current status. The basic epidemiology of all reported cases was analyzed, and the detailed clinical data of the subjects were further collected from study hospitals selected in terms of their geographic location and capability of SFTS care. Cases of SFTS were reported across the country and were greatly increased since the initial endemic phase, even under the passive surveillance system. The case fatality rate remained at approximately 16.8%. Coinfections at admission were present in 7.8% of the patients. Major complications included bleeding (15.2%), hemophagocytic lymphohistiocytosis (6.7%), bacteremia or candidemia (4.0%), and invasive pulmonary aspergillosis (1.7%). It took a median 4 days from the onset of illness to hospital admission. Rapid clinical deterioration was observed with a median 1 day for intensive care unit admission, 3 days for mechanical ventilation, 4 days for renal replacement therapy, and 5 days for death, all after the hospitalization. Multivariate analysis showed that the fatality was associated with older age, bacteremia, or candidemia during hospitalization, and the presence of several variables at admission such as fever, altered mentality, aspartate aminotransferase >200 IU/L, serum creatinine level >1.2 mg/dL, and prolonged prothrombin time and activated partial thromboplastin time. Treatment options to improve clinical outcomes are limited, despite best supportive care. Specific treatment is urgently needed to change the fatal course.
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Acinetobacter baumannii (AB) has emerged as a major pathogen in vulnerable and severely ill patients. It remains unclear whether early mortality (EM) due to AB bacteremia is because of worse clinical characteristics of the infected patients or the virulence of the pathogen. In this study, we aimed to investigate the effect of AB virulence on EM due to bacteremia. This retrospective study included 138 patients with AB bacteremia (age: ≥ 18 years) who were admitted to a tertiary care teaching hospital in South Korea between 2015 and 2019. EM was defined as death occurring within 7 days of bacteremia onset. The AB clinical isolates obtained from the patients' blood cultures were injected into 15 Galleria mellonella larvae each, which were incubated for 5 days. Clinical isolates were classified into high- and low-virulence groups based on the number of dead larvae. Patients' clinical data were combined and subjected to multivariate Cox regression analyses to identify the risk factors for EM. In total, 48/138 (34.8%) patients died within 7 days of bacteremia onset. The Pitt bacteremia score was the only risk factor associated with EM. In conclusion, AB virulence had no independent effect on EM in patients with AB bacteremia.
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Infecções por Acinetobacter , Acinetobacter baumannii , Bacteriemia , Humanos , Acinetobacter baumannii/patogenicidade , Bacteriemia/microbiologia , Bacteriemia/mortalidade , Animais , Masculino , Feminino , Infecções por Acinetobacter/mortalidade , Infecções por Acinetobacter/microbiologia , Virulência , Fatores de Risco , Idoso , Estudos Retrospectivos , Pessoa de Meia-Idade , Mariposas/microbiologia , República da Coreia/epidemiologia , Idoso de 80 Anos ou mais , Larva/microbiologia , Modelos Animais de Doenças , AdultoRESUMO
Biochar was generally used to reduce the macronutrient releases and to mitigate N2O gas emissions in cropland. This experiment evaluated the trend of major plant nutrient releases using the modified Hyperbola model and the greenhouse gas emissions by incorporating different poultry manure compost biochar with organic resources. The treatments consisted of the control as the organic fertilizer materials, the incorporated poultry manure compost biochar with organic fertilizer materials (PMCBF), and the incorporated plasma-activated poultry manure compost biochar with organic fertilizer materials (PAMBF) under redox conditions. The results showed that the cumulated highest concentrations of NH4-N and NO3-N were 2168.6 mg L-1 and 21.7 mg L-1 in the control, respectively. Compared with the control, the predicted reduction rates of NH4-N release from the PMCBF and PAMBF were 26.2% and 15.4%, respectively. In the control, the cumulated highest concentrations of PO4-P and K in leachate were 681.04 mg L-1 and 120.5 mg L-1, respectively. The predicted reduction rates of PO4-P and K were 55.1% and 15.5%, respectively, under the PAMBF compared to the control. The modified Hyperbola model with cumulated NH4-N, PO4-P, and K-releases under the treatments was a good fit (p < 0.0001). For greenhouse gas (GHG) emissions, the lowest cumulative N2O was 59.59 mg m-2 in the soil incorporated with PMCBF, and its reduction rate was 23.5% compared with the control. The findings of this study will contribute to more profound insights into the potential application of PAMBF and PMCBF as bio-fertilizers adapted to mitigate NH4-N, PO4-P, and K releases and N2O emissions, offering scientific evidence for organic farming strategies.
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Carvão Vegetal , Compostagem , Fertilizantes , Esterco , Óxido Nitroso , Aves Domésticas , Carvão Vegetal/química , Animais , Fertilizantes/análise , Óxido Nitroso/análise , Compostagem/métodos , Poluentes Atmosféricos/análise , Solo/química , Nutrientes/análise , Gases de Efeito Estufa/análiseRESUMO
BACKGROUND: Medical waste bins are a potential source of microbial contamination in the hospital environment, while there is no clear guidance for the management of them. We aimed to assess the impact of medical waste bins on patient's environment. METHODS: This experimental study simulated microbial contamination by performing medical procedures on a patient model with fluorescent lotion. The waste bin was set as initially empty or two-thirds filled with waste, open or with a lid. The percentage of fluorescent-contaminated area in designated patient's environments was analyzed by 2 independent observers. RESULTS: Among a total of 120 experiments, the sides of the bins were more contaminated in open-occupied bins compared to open-empty bins and in open-occupied bins compared to lid-occupied bins (median 1.9175% vs 0.0916% [P = .001] and 1.9175% vs 0.0899% [P = .003], respectively). The top of the bedside equipment trolley for preparing medical procedures was more contaminated in lid-occupied bins than open-occupied bins (median 0.0080% vs 0.0040%, P = .013). DISCUSSION: In addition to reducing contamination of the bin itself, the manually operated lid had a potential risk of contributing to microbial transmission by contaminating the equipment trolley. CONCLUSIONS: Medical waste bins should be kept no more than two-thirds full, and caution should be taken when using the manually operated lid, to avoid cross-contamination.
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Resíduos de Serviços de Saúde , Humanos , Eliminação de Resíduos de Serviços de Saúde/métodos , Hospitais , Microbiologia Ambiental , Infecção Hospitalar/prevenção & controle , Infecção Hospitalar/microbiologiaRESUMO
Objective: Intracerebral hemorrhage (ICH) accompanies higher mortality rates than other type of stroke. This study aimed to investigate the association between hospital volume and mortality for cases of ICH. Methods: We used nationwide data from 2013 to 2018 to compare high-volume hospitals (≥32 admissions/year) and low-volume hospitals (<32 admissions/year). We tracked patients' survival at 3-month, 1-year, 2-year, and 4-year endpoints. The survival of ICH patients was analyzed at 3-month, 1-year, 2-year, and 4-year endpoints using Kaplan-Meier survival analysis. Multivariable logistic regression analysis and Cox regression analysis were performed to determine predictive factors of poor outcomes at discharge and death. Results: Among 9,086 ICH patients who admitted to hospital during 18-month period, 6,756 (74.4%) and 2,330 (25.6%) patients were admitted to high-volume and low-volume hospitals. The mortality of total ICH patients was 18.25%, 23.87%, 27.88%, and 35.74% at the 3-month, 1-year, 2-year, and 4-year, respectively. In multivariate logistic analysis, high-volume hospitals had lower poor functional outcome at discharge than low-volume hospitals (odds ratio, 0.80; 95% confidence interval, 0.72-0.91; p < 0.001). In the Cox analysis, high-volume hospitals had significantly lower 3-month, 1-year, 2-year, and 4-year mortality than low-volume hospitals (p < 0.05). Conclusion: The poor outcome at discharge, short- and long-term mortality in ICH patients differed according to hospital volume. High-volume hospitals showed lower rates of mortality for ICH patients, particularly those with severe clinical status.
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Truncation resonances are resonant frequencies that occur within bandgaps and are a prominent feature of finite phononic crystals. While recent studies have shed light on the existence conditions and modal characteristics of truncation resonances in discrete systems, much remains to be understood about their behavior in continuous structures. To address this knowledge gap, this paper investigates the existence and modal characteristics of truncation resonances in periodic bilayer beams, both numerically and experimentally. Specifically, the effect of symmetry of the unit cells, boundary conditions, material/geometric properties, and the number of unit cells are studied. To this end, we introduce impedance and phase velocity ratios based on the material and geometric properties and show how they affect the existence of truncation resonances, relative location of the truncation resonances within the bandgap, and spatial attenuation or degree of localization of the truncation resonance mode shapes. Finally, the existence and mode shapes of truncation resonances are experimentally validated for both longitudinal and flexural cases using three-dimensional (3D) printed periodic beams. This paper highlights the potential impact of these results on the design of finite phononic crystals for various applications, including energy harvesting and passive flow control.
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The bluetongue virus (BTV) is a significant animal pathogen with economic implications in the ruminant industry. Despite global reports on BTV detection and epidemiologic investigations, limited studies have focused on the virus in the ROK. In this study, BTV epidemiological research was conducted on blood samples from cattle and goat farms across nine regions during 2013-2014. The results showed that 3.33% of bovine blood samples (194/5824) and 0.19% of goat blood samples (2/1075) tested positive for BTV antibodies using ELISA. In Jeju-do, BTV RNA amplification occurred in 51 of 422 samples (12.1%) using real-time reverse transcription (RT-qPCR). The isolation of one sample revealed it as serotype 3, as indicated by the sequence of segments 2 (Seg-2) and 6 (Seg-6), associated with the eastern BTV topotype. However, based on Seg-1, -3, -4, -5, -7, -8, -9, and -10 analyses, the BTV-3/JJBB35 strain is more closely related to distinct BTV strains. These findings imply BTV circulation and that the Korean-isolated BTV might originate from Asian BTV strains due to multiple reassortment events. This study provides foundational data for ongoing BTV monitoring and disease-control policies in the ROK.
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BACKGROUNDS: Remdesivir (RDV) is an antiviral agent approved for the treatment of coronavirus disease 2019 (COVID-19); however, is not recommended for patients with renal impairment. Due to limitations associated with prospective clinical trials, real-world data on the safety and efficacy of RDV in patients with renal impairment are necessary. METHODS: Propensity score-matched (PSM) retrospective analysis was conducted between March 2020 and September 2022 in COVID-19 patients with an eGFR < 30 mL/min in four Korean hospitals. The RDV treatment group was matched to the untreated control group. The safety and clinical outcomes in patients who received RDV were analyzed. RESULTS: A total of 564 patients were enrolled; 229 patients received RDV either for treatment or prophylaxis. On day 5, no difference in nephrotoxicity was observed between the two groups, and liver enzyme levels were within the normal range. In multivariate analysis for new dialysis, RDV treatment was not a risk factor for new dialysis. Among the 564 patients, 417 were indicated for a 5-day course of RDV treatment and 211 patients were treated with RDV. After PSM, no differences in the clinical outcomes were observed between the two groups. CONCLUSION: RDV use in COVID-19 patients with renal impairment did not result in significant nephrotoxicity or hepatotoxicity.
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COVID-19 , Insuficiência Renal , Humanos , Tratamento Farmacológico da COVID-19 , Pontuação de Propensão , Estudos Prospectivos , Estudos Retrospectivos , Insuficiência Renal/complicações , Antivirais/efeitos adversosRESUMO
BACKGROUND AND PURPOSE: The association between physical activity and dementia has been shown in various observational studies. We aimed to determine the risk of dementia in the elderly with lower-body fractures. METHODS: We reconstructed a population-based matched cohort from the National Health Insurance Service-Senior Cohort data set that covers 511,953 recipients of medical insurance in South Korea. RESULTS: Overall 53,776 subjects with lower-body fractures were identified during 2006-2012, and triplicate control groups were matched randomly by sex, age, and years from the index date for each subject with a fracture. There were 3,573 subjects (6.6%) with and 7,987 subjects (4.9%) without lower-body fractures who developed dementia from 2008 up to 2015. Lower-body fractures were independently associated with a subsequent dementia diagnosis with a higher adjusted hazard ratio (aHR) (1.55, 95% confidence interval [CI]=1.49-1.62) compared with upper-body fractures (aHR=1.19, 95% CI=1.14-1.23). CONCLUSIONS: These results support the protective role of physical activity against dementia and highlight the importance of promoting fracture prevention in the elderly.
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This study investigated the effects on odontoblast differentiation of a 3D-printed poly-ϵ-caprolactone (PCL) scaffold that incorporated leptin. Material extrusion-type 3D printing with a 43 000-molecular weight PCL material was used to fabricate a PCL scaffold with a 6 mm diameter, 1 mm height, and 270-340 µm pore size. The experimental groups were PCL scaffolds (control group), PCL scaffolds with aminated surfaces (group A), and PCL scaffolds with leptin on the aminated surface (group L). The aminated surface was treated with 1,6-hexanediamine and verified by ninhydrin analysis. Leptin loading was performed using Traut's reagent and 4-(N-Maleimidomethyl)cyclohexane-1-carboxylic acid 3-sulfo-N-hydroxysuccinimide ester sodium salt (Sulfo-SMCC). Groups A and L showed significantly higher surface wettability, pulp cell adhesion, and proliferation than the control group. Group L exhibited increased alkaline phosphatase, calcification deposits, and mRNA and protein expression of dentin sialophosphoprotein and dentin matrix acidic phosphoprotein 1 compared with the control group. In this study, a 3D-printed PCL scaffold containing leptin was enhanced odontoblast differentiation and dental pulp cells adhesion and proliferation.
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Leptina , Alicerces Teciduais , Humanos , Polpa Dentária , Poliésteres , Diferenciação Celular , Impressão Tridimensional , Proliferação de Células , Engenharia TecidualRESUMO
Objective: Markers of neuroinflammation during ischemic stroke are well characterized, but additional markers of neural damage are lacking. The study identified associations of behavioral disorders after stroke with histologic neural damage and molecular biological change. Methods: 8-week-old, 25g male mice of the C57BL/6J strain were subjected to middle cerebral artery occlusion (MCAO) to induce ischemic stroke. The control group was a healthy wild type (WT), and the experimental group were designed as a low severity MCAO1 and a high severity MCAO2 based on post-stroke neurological scoring. All groups underwent behavioral tests, real-time polymerase chain reaction (rt-PCR), triphenyltetrazolium chloride (TTC) staining and hematoxylin and eosin (H&E) staining. One-way analysis of variance (ANOVA) was used to analyze statistical significance between groups. Results: In TTC staining, MCAO1 showed 29.02% and MCAO2 showed 38.94% infarct volume (p<0.0001). The pro-inflammatory cytokine interleukin (IL)-1ß was most highly expressed in MCAO2 (WT 0.44 vs MCAO1 2.69 vs MCAO2 5.02, p<0.0001). From the distance to target in the Barnes maze test, WT had a distance of 178 cm, MCAO1 had a distance of 276 cm, and MCAO2 had a distance of 1051 (p=0.0015). The latency to target was 13.3 seconds for WT, 27.9 seconds for MCAO1, and 87.9 seconds for MCAO2 (p=0.0007). Prospero homeobox 1 (Prox1) was most highly expressed in MCAO2 (p=0.0004). Doublecortin (Dcx) was most highly expressed in MCAO2 (p<0.0001). Conclusion: The study demonstrated that histological damage to neural cells and changes in brain mRNA expression were associated with behavioral impairment after ischemic stroke. Prox1 and Dcx may be biomarkers of neural damage associated with long-term cognitive decline, and increased expression at the mRNA level was consistent with neural damage and long-term cognitive dysfunction.
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The tunability of reaction pathways is required for exploring efficient and low cost catalysts for ammonia synthesis. There is an obstacle by the limitations arising from scaling relation for this purpose. Here, we demonstrate that the alkali earth imides (AeNH) combined with transition metal (TM = Fe, Co and Ni) catalysts can overcome this difficulty by utilizing functionalities arising from concerted role of active defects on the support surface and loaded transition metals. These catalysts enable ammonia production through multiple reaction pathways. The reaction rate of Co/SrNH is as high as 1686.7 mmol·gCo-1·h-1 and the TOFs reaches above 500 h-1 at 400 °C and 0.9 MPa, outperforming other reported Co-based catalysts as well as the benchmark Cs-Ru/MgO catalyst and industrial wüstite-based Fe catalyst under the same reaction conditions. Experimental and theoretical results show that the synergistic effect of nitrogen affinity of 3d TMs and in-situ formed NH2- vacancy of alkali earth imides regulate the reaction pathways of the ammonia production, resulting in distinct catalytic performance different from 3d TMs. It was thus demonstrated that the appropriate combination of metal and support is essential for controlling the reaction pathway and realizing highly active and low cost catalysts for ammonia synthesis.
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BACKGROUND: The number of newly diagnosed cases of human immunodeficiency virus (HIV) infection in Korea, which had increased until 2019, has markedly decreased since the coronavirus disease 2019 pandemic started. This study evaluated whether the decrease is due to a reduction in the incidence of HIV infection and/or delayed diagnosis during the pandemic. MATERIALS AND METHODS: We reviewed the medical records of 587 newly diagnosed patients with HIV infection between February 2018 and January 2022 from four general hospitals, and their characteristics were compared between the pre-pandemic and pandemic periods. The lapse time from infection to diagnosis was estimated using an HIV modeling tool. RESULTS: The estimated mean times to diagnosis were 5.68 years (95% confidence interval [CI]: 4.45 - 6.51 years) and 5.41 years (95% CI: 4.09 - 7.03 years) before and during the pandemic, respectively (P = 0.016). The proportion of patients with acquired immunodeficiency syndrome-defining illnesses, expected to visit hospitals regardless of the pandemic, decreased from 17.2% before the pandemic to 11.9% during the pandemic (P = 0.086). CONCLUSION: The decrease in the number of newly diagnosed cases of HIV infection in Korea might have resulted from an actual decrease in the incidence of HIV infection rather than a worsening of underdiagnosis or delayed diagnosis.
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Topological materials have received much attention because of their robust topological surface states, which can be potentially applied in electronics and catalysis. Here, we show that the topological insulator bismuth selenide functions as an efficient catalyst for the oxidative carbonylation of amines with carbon monoxide and dioxygen to synthesize urea derivatives. For example, the carbonylation of butylamine can be completed over bismuth selenide nanoparticle catalyst in 4 hours at 20°C with a yield of 99%, whereas most noble metal-based catalysts do not function at such a low temperature. Density functional theory calculations further reveal that the topological surface states facilitate the activation of dioxygen through a triplet-to-singlet spin-conversion reaction, in which active oxygen species are formed with a barrier of 0.4 electron volts for the subsequent reactions with amine and carbon monoxide.
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BACKGROUND: Nirmatrelvir-ritonavir is highly effective in preventing severe coronavirus disease 2019 (COVID-19) in high-risk patients with mild-to-moderate severity. However, real-world performance data are limited, and the drug is not so acceptable to the COVID-19 patients at high risk who need it in Korea. METHODS: To evaluate the effectiveness of nirmatrelvir-ritonavir, we conducted a propensity score-matched retrospective cohort study on patients with mild-to-moderate COVID-19 at high risk for a severe disease who were hospitalized at four hospitals in South Korea from February 2022 to April 2022. A total of 236 patients in the treatment group (administered nirmatrelvir-ritonavir) and 236 in the matched control group (supportive care only) were analyzed for the primary outcome, i.e., the time to oxygen support-free survival. The secondary outcome was a composite result of disease progression. The reason for not prescribing nirmatrelvir-ritonavir to the indicated patients was also investigated. RESULTS: The treatment group showed significantly longer oxygen support-free survival than the matched control group (adjusted hazard ratio [aHR], 0.07; 95% confidence interval [CI], 0.01-0.31; P < 0.001). Multivariate Cox regression analysis showed that age (aHR, 1.03; 95% CI, 1.00-1.07), National Early Warning Score-2 at admission (aHR, 1.36; 95% CI, 1.08-1.71), nirmatrelvir-ritonavir treatment, female sex (aHR, 0.37; 95% CI, 0.15-0.88), and time from symptom onset to admission (aHR, 0.67; 95% CI, 0.48-0.95) were significantly associated with oxygen therapy. However, none of the factors were related to the composite outcome. In the unmatched control group, 19.9% of 376 patients had documented explanations for nirmatrelvir-ritonavir non-prescription, and 44.0% of these were due to contraindication criteria. In the treatment group, 10.9% of patients discontinued the medication primarily because of adverse events (71.4%), with gastrointestinal symptoms being the most common (50.0%). CONCLUSION: Nirmatrelvir-ritonavir treatment significantly reduced oxygen therapy requirements in high-risk patients with COVID-19 during the omicron variant surge in South Korea. Physicians are encouraged to consider the active use of nirmatrelvir-ritonavir and to be watchful for gastrointestinal symptoms during medication.
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COVID-19 , Humanos , Feminino , Tratamento Farmacológico da COVID-19 , Estudos Retrospectivos , Ritonavir/uso terapêutico , SARS-CoV-2RESUMO
While two-dimensional (2D) materials possess the desirable future of neuromorphic computing platforms, unstable charging and de-trapping processes, which are inherited from uncontrollable states, such as the interface trap between nanocrystals and dielectric layers, can deteriorate the synaptic plasticity in field-effect transistors. Here, we report a facile and effective strategy to promote artificial synaptic devices by providing physical doping in 2D transition-metal dichalcogenide nanomaterials. Our experiments demonstrate that the introduction of niobium (Nb) into 2D WSe2 nanomaterials produces charge trap levels in the band gap and retards the decay of the trapped charges, thereby accelerating the artificial synaptic plasticity by encouraging improved short-/long-term plasticity, increased multilevel states, lower power consumption, and better symmetry and asymmetry ratios. Density functional theory calculations also proved that the addition of Nb to 2D WSe2 generates defect tolerance levels, thereby governing the charging and de-trapping mechanisms of the synaptic devices. Physically doped electronic synapses are expected to be a promising strategy for the development of bioinspired artificial electronic devices.
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BACKGROUND: Domestic data on antiretroviral drug (ARV) resistance are limited, while alterations in ARV resistance are expected as the incidence of human immunodeficiency virus (HIV) infection increases. We evaluated the ten-year change in ARV resistance in people with HIV (PWH) in Korea. MATERIALS AND METHODS: Adults aged ≥19 years and diagnosed with HIV infection between January 2010 and December 2020 at a 750-bed municipal hospital were retrospectively reviewed. Data on clinical characteristics and resistance mutation test results were collected. The study population was divided into three-year intervals according to diagnosed year and their clinical characteristics were compared. RESULTS: A total of 248 PWH were analyzed, and ARV resistance was detected in 30 of them (12.1%). Resistance was detected most frequently in PWH aged ≤29 years (16, 6.5%), and the median percentage of resistance detection per year was 14.3% (interquartile range, 12.7 - 16.1). The trend of the overall prevalence of ARV resistance mutations slightly decreased and then increased over time (15.3% in 2012 - 2014, 9.6% in 2015 - 2017, and 12.9% in 2018 - 2020). The prevalence of the non-nucleoside reverse transcriptase inhibitor (NNRTI) resistance markedly decreased over time (15.3% in 2012 - 2014, 8.7% in 2015 - 2017, and 2.4% in 2018-2020), while that of protease inhibitor (PI) and integrase strand transfer inhibitor (INSTI) increased from 0 until 2018 to 3.5% and 8.2% in 2018 - 2020, respectively. CONCLUSION: The trend of NNRTI resistance has decreased over time, and resistance to PIs and INSTIs increased from 2018. Therefore, continuous monitoring of ARV resistance pattern is necessary.
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COVID-19 has caused huge disruptions to urban travel and mobility. As a critical transportation mode in cities, public transit was hit hardest. In this study, we analyze public transit usage of urban visitors with a nearly two-year smart card dataset collected in Jeju, South Korea - a major tourism city in the Asia Pacific. The dataset captures transit usage behavior of millions of domestic visitors who traveled to Jeju between January 1, 2019 and September 30, 2020. By identifying a few key pandemic stages based on COVID-19 timeline, we employ ridge regression models to investigate the impact of pandemic severity on transit ridership. We then derive a set of mobility indicators - from perspectives of trip frequency, spatial diversity, and travel range - to quantify how individual visitors used the transit system during their stay in Jeju. By further employing time series decomposition, we extract the trend component for each mobility indicator to study long-term dynamics of visitors' mobility behavior. According to the regression analysis, the pandemic had a dampening effect on public transit ridership. The overall ridership was jointly affected by national and local pandemic situations. The time series decomposition result reveals a long-term decay of individual transit usage, hinting that visitors in Jeju tended to use the transit system more conservatively as the pandemic endured. The study provides critical insights into urban visitors' transit usage behavior during the pandemic and sheds light on how to restore tourism, public transit usage, and overall urban vibrancy with some policy suggestions.
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Recent studies on plasmon-assisted chemical reactions postulate that the hot electrons of plasmon-excited nanostructures may induce a non-thermal vibrational activation of metal-bound reactants. However, the postulate has not been fully validated at the level of molecular quantum states. We directly and quantitatively prove that such activation occurs on plasmon-excited nanostructures: The anti-Stokes Raman spectra of reactants undergoing a plasmon-assisted reaction reveal that a particular vibrational mode of the reactant is selectively excited, such that the reactants possess >10 times more energy in the mode than is expected from the fully thermalized molecules at the given local temperature. Furthermore, a significant portion (â¼20%) of the excited reactant is in vibrational overtone states with energies exceeding 0.5 eV. Such mode-selective multi-quantum excitation could be fully modeled by the resonant electron-molecule scattering theory. Such observations suggest that the vibrationally hot reactants are created by non-thermal hot electrons, not by thermally heated electrons or phonons of metals. The result validates the mechanism of plasmon-assisted chemical reactions and further offers a new method to explore the vibrational reaction control on metal surfaces.