The risk factors of environmental contamination by SARS-CoV-2 are largely unknown. We analyzed 1,320 environmental samples obtained from COVID-19 patients over 1 year. The risk factors for contamination of COVID-19 patients’ surrounding environment were higher viral load in the respiratory tract and shorter duration from symptom onset to sample collection.

Two aphid-transmitted RNA viruses, broad bean wilt virus 2 (BBWV2) and cucumber mosaic virus (CMV), are the most prevalent viruses in Korean pepper fields and cause chronic damage in pepper production. In this study, we employed a screening system for pathotype-specific resistance of pepper germplasm to BBWV2 and CMV by utilizing infectious cDNA clones of different pathotypes of the viruses (two BBWV2 strains and three CMV strains). We first examined pathogenic characteristics of the BBWV2 and CMV strains in various plant species and their phylogenetic positions in the virus population structures. We then screened 34 commercial pepper cultivars and seven accessions for resistance. While 21 pepper cultivars were resistant to CMV Fny strain, only two cultivars were resistant to CMV P1 strain. We also found only one cultivar partially resistant to BBWV2 RP1 strain. However, all tested commercial pepper cultivars were susceptible to the resistance-breaking CMV strain GTN (CMV-GTN) and BBWV2 severe strain PAP1 (BBWV2-PAP1), suggesting that breeding new cultivars resistant to these virus strains is necessary. Fortunately, we identified several pepper accessions that were resistant or partially resistant to CMV-GTN and one symptomless accession despite systemic infection with BBWV2-PAP1. These genetic resources will be useful in pepper breeding programs to deploy resistance to BBWV2 and CMV.

Two advanced, automated crystal orientation mapping techniques suited for nanocrystalline materials—precession electron diffraction (PED) in transmission electron microscopy (TEM) and on-axis transmission Kikuchi diffraction (TKD) in scanning electron microscopy (SEM)—are evaluated by comparing the orientation maps obtained from the identical location on a 30 nm-thick nanocrystalline tungsten (W) thin film. A side-by-side comparison of the orientation maps directly showed that the large-scale orientation features are almost identical. However, there are differences in the fine details, which arise from the fundamentally different nature of the spot pattern and Kikuchi line pattern in terms of the excitation volume and the angular resolution. While TEM-PED is more reliable to characterize grains oriented along low-index zone axes, the high angular resolution of SEM-TKD allows the detection of small misorientation between grains and thus yields better quantification and statistical analysis of grain orientation. Given that both TEM-PED and SEM-TKD orientation mapping techniques are complementary tools for nanocrystalline materials, one can be favorably selected depending on the requirements of the analysis, as they have competitive performance in terms of angular resolution and texture quantification.

Given the dynamic characteristic of an individual’s drinking behaviours, comprehensive consideration of alcohol consumption variation using repeated measures may improve insight into the nature of its association with blood pressure (BP) change. We examined the association between longitudinal alcohol consumption (trajectory and quantity) and changes in BP and pulse pressure (PP) among Korean aged ≥ 40 years living in rural areas. Totally, 1682 hypertension-free participants who completed all three health examinations (median, 5·3 years) were included. All three visits were used to determine the cumulative trajectory of and quantity of alcohol consumption and the latest two visits and the last visit were used for the recent trajectory and the most recent quantity of alcohol consumption, respectively. Changes in BP and PP from the baseline to the third visit were used as outcome. In men, ≥30 ml/d cumulative average alcohol consumption was associated with the greatest increase in systolic BP (SBP) in both baseline outcome-unadjusted (2·9 mmHg, P = 0·032) and -adjusted models (3·6 mmHg, P = 0·001), and the given association for the most recent alcohol consumption was observed in the baseline outcome-adjusted model (3·9 mmHg, P = 0·003). For PP, similar associations were observed only in the baseline outcome-adjusted model. No meaningful associations in diastolic BP in men and any BP or PP in women existed. The quantity of alcohol consumption rather than the trajectory may be significantly related to raised SBP, and a possible short-term influence of the most recent alcohol consumption may exist when baseline SBP is adjusted in men.

Background: We describe and evaluate our outbreak of carbapenem-resistant K. pneumoniae transmitted by contaminated duodenoscopes during endoscopic retrograde cholangiopancreatography (ERCP) procedures. Methods: An outbreak investigation was performed when Klebsiella pneumoniae carbapenemase-producing K. pneumoniae (KPC-KP) were identified from bile specimens of 4 patients. The investigation included medical record review, practice audits, and surveillance cultures of duodenoscopes and environmental sites. If available, clinical specimens were obtained from patients who had undergone ERCP in the previous 3 months. Carbapenem-resistant Enterobacteriaceae (CRE) screening cultures were performed to identify additional patients until no CRE cases were detected during 2 consecutive weeks. Pulsed-field gel electrophoresis (PFGE) of KPC-KP isolates was implemented. Results: In total, 12 cases were identified with exposure to duodenoscope from February 2019 through April 2019, including 6 cases with infections and 6 asymptomatic carriers. Case-control analysis showed that 2 specific duodenoscopes would be associated with the KPC-KP outbreak. Duodenoscope reprocessing procedures did not deviate from manufacturer recommendations for reprocessing. After ethylene oxide (EO) gas sterilization, the outbreak was terminated. Conclusions: Meticulous cleaning protocol and enhanced surveillance are necessary to prevent outbreaks of CRE. Notably, enhanced cleaning measures, such as sterilization for duodenoscopes, would be required after procedures with KPC-KP carriers.

Funding: None

Disclosures: None

The tensile yield strength of high-density polyethylene using instrumented indentation tests with a flat-ended cylindrical indenter was evaluated. The variation in the field expressed by stress and strain beneath the flat-ended cylindrical indenter is investigated using a new expanding cavity model to study the relation between tension and indentation. This model starts from the separation of forces into the compressive force on the material and the frictional one, which is generated during indentation on the sides of indenter. The authors propose a method to correct the frictional force based on the saturation of indentation hardening and obtain load–depth curve with compressive component only. For conversion of indentation force and displacement, our new representation model is applied. By modifying Johnson's model, the new assumption of conservation of indentation plastic volume is suggested. This model proves and supports conventional relations of the strain rates between indentation and tension theoretically. These are verified through the experiments: instrumented indentation and uniaxial tensile test. The authors find a good agreement between the tensile yield strengths at various strain rates.

Tricuspid atresia with absent pulmonary valve and intact ventricular septum is an extremely rare cardiac malformation, historically associated with a poor prognosis. Only a few cases with successful surgical palliation have been reported in the literature. We present the case of an 8-month-old infant with this malformation who underwent successful bidirectional cavopulmonary anastomosis with complete exclusion of the right ventricle.

Residual stress is generally evaluated using indentation by comparing the indentation curves of stressed and stress-free states. Here, we suggest a new method that can evaluate surface residual stress without indentation testing on stress-free specimen using stress-independent indentation parameters and an analysis of indentation contact morphology for the stress-free state. We found that several indentation parameters are independent of the stress by Vickers indentation testing on various stress states. The indentation contact morphology can be represented by indentation parameters including stress-independent ones, and by applying the stress-independent parameters obtained from the stressed state to the indentation contact depth function, we can estimate an indentation curve for stress-free state. The estimated curve matches well with the experimental stress-free indentation curve, and it was also confirmed that the applied stress values evaluated by comparing the estimated curve with the stressed indentation curve agree well with the reference values obtained from strain gauge.

We suggest a new method to evaluate stress directionality, the ratio of principal stresses, using nanoindentation by introducing a modified Berkovich indenter that is extended in one direction from the Berkovich indenter. In a nonequibiaxial stress state, the indentation load-depth curves are shifted differently as the extended axis of the indenter is placed in accordance with each principal direction. The indentation load-difference is proportional to each principal stress and the slopes are defined by the normal and parallel conversion factors whose ratio is constant at 0.58. The suggested method was verified by indentation tests using five nonequibiaxial stressed specimens. The evaluated stress directionality results show agreement with the applied reference values within ±20%. Furthermore, we calculated the conversion factor ratios for other modified Berkovich indenters extended to different degrees through finite element analysis and confirmed that the conversion factor ratio was inversely proportional to the extension of the modified Berkovich indenter.