Due to its flexibility, transparency, easy fabrication, and high negative polarity, polydimethylsiloxane (PDMS) has been considered as one of the most appropriate materials for the use in ...triboelectric nanogenerator (TENG) applications. Here, we report the significantly enhanced triboelectric surface charge of PDMS simply by sprinkling of NaOH solution. Fresh PDMS-based TENGs generated an open-circuit voltage of 3.8V and a closed-circuit current of 65nA after the contact/separation from an indium tin oxide (ITO) electrode. After sprinkling the PDMS surface with 1M NaOH, in contrast, the resulting TENG generated voltage of 10.4V and current of 179nA. Exposing the PDMS to ultraviolet-ozone prior to sprinkling with NaOH solution resulted in a triboelectric voltage and current of 49.3V and 1.16μA, respectively, which are almost 15-fold larger than those of fresh PDMS. The origin of the enhanced triboelectric charge is related with an increase of polar SiO bonds at the expense of non-polar Si–CH3 bonds in PDMS. This work demonstrates a cost-effective method for producing large-area and high-efficiency PDMS-based TENGs and helps clarify the triboelectric mechanism of PDMS.
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•Enhance the triboelectric charge of PDMS by sprinkling of NaOH solution.•Increase of Si‐O bonds with ultraviolet-ozone and NaOH treatments.•Large-area and low-cost TENG application using transparent and flexible PDMS.
This study investigated the effect of temperature on the aspect-ratio etching of SiO2 in CF4/H2/Ar plasma using patterned samples of a 200 nm trench in a low-temperature reactive-ion etching system. ...Lower temperatures resulted in higher etch rates and aspect ratios for SiO2. However, the plasma property was constant with the chuck temperature, indicated by the line intensity ratio from optical emission spectroscopy monitoring of the plasma. The variables obtained from the characterization of the etched profile for the 200 nm trench after etching were analyzed as a function of temperature. A reduction in the necking ratio affected the etch rate and aspect ratio of SiO2. The etching mechanism of the aspect ratio etching of SiO2 was discussed based on the results of the surface composition at necking via energy-dispersive X-ray spectroscopy with temperature. The results suggested that the neutral species reaching the etch front of SiO2 had a low sticking coefficient. The bowing ratio decreased with lowering temperature, indicating the presence of directional ions during etching. Therefore, a lower temperature for the aspect ratio etching of SiO2 could achieve a faster etch rate and a higher aspect ratio of SiO2 via the reduction of necking than higher temperatures.
A new cathode material, K2V3O8, is reported reports as a new active material for potassium storage. The K2V3O8 is stabilized into tetragonal structure with P4bm space group, and we verify the unique ...crystal structure that is coordinated with four hendecahedra of KO11, VO5, and VO4, in which one VO5 shares its four oxygens with four VO4 tetrahedra to produce four penta-shaped voids that allows insertion and extraction of potassium ions. The K2V3O8 modified with carbon exhibits a reversible capacity of 75 mAh (g-oxide)−1, and its electrochemical activity originates from the reversible de-/intercalation of potassium ions into/out of the hendecahedrally coordinated K2V3O8–carbon composite cathode, accompanied by a reversible V5+/4+ redox pair, which is retained for 200 cycles with 80% retention of its initial capacity.
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•Crystal structure of K2V3O8 is verified as a new cathode material for potassium storage.•The K2V3O8 modified with carbon exhibits a reversible capacity of 75 mAh g−1.•The K2V3O8 – carbon composite retains approximately 80% of capacity for 200 cycles.•Electrochemical reaction is progressed via a reversible V5+/4+ redox pair.•Potassium ions are extracted and inserted into and out of the crystal structure of K2V3O8.
Papaver plants can produce diverse bioactive alkaloids. Papaver rhoeas Linnaeus (common poppy or corn poppy) is an annual flowering medicinal plant used for treating cough, sleep disorder, and as a ...sedative, pain reliever, and food. It contains various powerful alkaloids like rhoeadine, benzylisoquinoline, and proaporphine. To investigate and identify alkaloids in the aerial parts of P. rhoeas, samples were collected at different growth stages and analyzed using liquid chromatography coupled with quadrupole time‐of‐flight tandem mass spectrometry. A liquid chromatography with mass spectrometry method was developed for the identification and metabolite profiling of alkaloids for P. rhoeas by comparing with Papaver somniferum. Eighteen alkaloids involved in benzylisoquinoline alkaloid biosynthesis were used to optimize the liquid chromatography gradient and mass spectrometry conditions. Fifty‐five alkaloids, including protoberberine, benzylisoquinoline, aporphine, benzophenanthridine, and rhoeadine‐type alkaloids, were identified authentically or tentatively by liquid chromatography coupled with quadrupole time‐of‐flight tandem mass spectrometry in samples taken during various growth stages. Rhoeadine alkaloids were observed only in P. rhoeas samples, and codeine and morphine were tentatively identified in P. somniferum. The liquid chromatography coupled with quadrupole time‐of‐flight tandem mass spectrometry method can be a powerful tool for the identification of diverse metabolites in the genus Papaver. These results may help understand the biosynthesis of alkaloids in P. rhoeas and evaluate the quality of this plant for possible medicinal applications.
Nonalcoholic fatty liver disease (NAFLD) has been associated with relative skeletal muscle mass in several cross‐sectional studies. We explored the effects of relative skeletal muscle mass and ...changes in relative muscle mass over time on the development of incident NAFLD or the resolution of baseline NAFLD in a large, longitudinal, population‐based 7‐year cohort study. We included 12,624 subjects without baseline NAFLD and 2943 subjects with baseline NAFLD who underwent health check‐up examinations. A total of 10,534 subjects without baseline NAFLD and 2631 subjects with baseline NAFLD were included in analysis of changes in relative skeletal muscle mass over a year. Subjects were defined as having NAFLD by the hepatic steatosis index, a previously validated NAFLD prediction model. Relative skeletal muscle mass was presented using the skeletal muscle mass index (SMI), a measure of body weight–adjusted appendicular skeletal muscle mass, which was estimated by bioelectrical impedance analysis. Of the 12,624 subjects without baseline NAFLD, 1864 (14.8%) developed NAFLD during the 7‐year follow‐up period. Using Cox proportional hazard analysis, compared with the lowest sex‐specific SMI tertile at baseline, the highest tertile was inversely associated with incident NAFLD (adjusted hazard ratio AHR = 0.44, 95% confidence interval CI = 0.38‐0.51) and positively associated with the resolution of baseline NAFLD (AHR = 2.09, 95% CI = 1.02‐4.28). Furthermore, compared with the lowest tertile of change in SMI over a year, the highest tertile exhibited a significant beneficial association with incident NAFLD (AHR = 0.69, 95% CI = 0.59‐0.82) and resolution of baseline NAFLD (AHR = 4.17, 95% CI = 1.90‐6.17) even after adjustment for baseline SMI. Conclusion: Increases in relative skeletal muscle mass over time may lead to benefits either in the development of NAFLD or the resolution of existing NAFLD.
Abstract
Background
Positive results from real-time reverse-transcription polymerase chain reaction (rRT-PCR) in recovered patients raise concern that patients who recover from coronavirus disease ...2019 (COVID-19) may be at risk of reinfection. Currently, however, evidence that supports reinfection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has not been reported.
Methods
We conducted whole-genome sequencing of the viral RNA from clinical specimens at the initial infection and at the positive retest from 6 patients who recovered from COVID-19 and retested positive for SARS-CoV-2 via rRT-PCR after recovery. A total of 13 viral RNAs from the patients’ respiratory specimens were consecutively obtained, which enabled us to characterize the difference in viral genomes between initial infection and positive retest.
Results
At the time of the positive retest, we were able to acquire a complete genome sequence from patient 1, a 21-year-old previously healthy woman. In this patient, through the phylogenetic analysis, we confirmed that the viral RNA of positive retest was clustered into a subgroup distinct from that of the initial infection, suggesting that there was a reinfection of SARS-CoV-2 with a subtype that was different from that of the primary strain. The spike protein D614G substitution that defines the clade “G” emerged in reinfection, while mutations that characterize the clade “V” (ie, nsp6 L37F and ORF3a G251V) were present at initial infection.
Conclusions
Reinfection with a genetically distinct SARS-CoV-2 strain may occur in an immunocompetent patient shortly after recovery from mild COVID-19. SARS-CoV-2 infection may not confer immunity against a different SARS-CoV-2 strain.
We conducted serial whole-genome sequencing of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Our results highlight possible SARS-CoV-2 reinfection with a genetically distinct SARS-CoV-2 strain in patients shortly after recovery from mild coronavirus disease 2019 (COVID-19).
Herein, Ag-ZnO core-shell nanoparticles (NPs) with enhanced photocatalytic activity were prepared by coating Ag metal cores with ZnO semiconductor shells through atomic layer deposition (ALD). ...Instrumental analysis revealed that the ultra-thin and conformal nature of the shell allowed the core-shell NPs to simultaneously exploit the photocatalytic properties of ZnO and the plasmonic properties of Ag. In a rhodamine B photodegradation test performed under artificial sunlight, Ag-ZnO core-shell NPs exhibited better photocatalytic performance than other prepared photocatalysts, namely ZnO NPs and ALD-ZnO coated ZnO NPs. The performance enhancement was ascribed to the effect of noble metal-semiconductor heterojunctions, which increased the efficiency of electron-hole separation, i.e., the Ag core effectively captured excited electrons at the ZnO surface, which resulted in the elevated production of hydroxyl radicals from holes remaining at ZnO. A three-dimensional finite-difference time-domain simulation of the Ag-ZnO NPs with variable shell thickness showed that ZnO shells on Ag metal cores increase the intensity of light around NPs, allowing the plasmonic cores to fully utilize incident light.
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•The ALD technology is applied to fabricate Ag-ZnO nanoparticles for photocatalyst.•Stable ZnO shell layers with wurtzite structure are deposited on Ag core particles.•Ag-ZnO shows ~2.5 to 4 times enhanced photodegradation compared with pure ZnO.•SPR effect of Ag increases photocatalytic performance of Ag-ZnO photocatalyst.•Ultra-thin ZnO shells on Ag cores increase photocatalytic performance in UV-region.
Korean bellflower (
Campanula takesimana
Nakai) is a rare and perennial herb with medicinal and ornamental values, is endemic to the Ulleung Island of Korea. In this study, we investigated the ...dormancy-release and germination characteristics of
C
.
takesimana
(Campanulaceae) seeds by subjecting them to varying temperatures (5, 10, 15, 20, and 25°C and diurnal/nocturnal temperatures of 15/6, 20/10, and 25/15°C), cold stratification periods (0, 4, 8, or 12 weeks at 5°C), and gibberellic acid (GA
3
) concentrations (0, 10, 100, or 1,000 mg·L
-1
at 15/6°C and 25/15°C) to identify the ideal seed propagation conditions. The seeds were stimulated to germinate (at 25°C, 12-h photoperiod with fluorescent lamps at 40 ± 10 μmol∙m
-2
∙s
-1
) after cold stratification. To examine the germination characteristics, the seeds were tested for water imbibition and found to readily absorb water. The seeds exhibited underdeveloped embryos during dispersal, showed final germination of 37.00% ± 4.43 at 25°C and were not influenced by temperature. The seeds subjected to 0, 4, 8, or 12 weeks of cold stratification germinated at a success rate of 22.00% ± 4.76, 87.00% ± 6.80, 79.00% ± 2.52, and 77.00% ± 1.91, respectively. Additionally, the germination characteristics, which were based on final germination, mean germination time, and germination velocity (Timson index), were significantly greater in the seeds pretreated with 1,000 mg·L
-1
GA
3
at 25/15°C than in seeds pretreated with 0 mg·L
-1
GA
3
. Overall, the seeds broke dormancy with GA
3
and short-term cold stratification. Therefore, we concluded that
C
.
takesimana
seeds have non-deep, simple, morphophysiological dormancy, and pretreatment with cold stratification and GA
3
is required for effective seed propagation.
Purpose While prior studies have explored the relationship between visual appeal and purchasing decisions, the role of bookmarking has largely been underemphasized. This research aims to address this ...gap by focusing on the impact of bookmarking on consumer behavior, guided by the cognitive load theory and dual-system theory. Design/methodology/approach The authors executed a controlled experiment and analyzed the results using a two-stage regression method that linked visual appeal, bookmarking and purchase intent. Further empirical analysis was conducted to authenticate the authors' proposed model, utilizing real-world mobile commerce data from a clothing company. Findings This study's findings suggest that visual appeal influences purchase intent primarily through the full mediation of bookmarking, rather than exerting a direct influence. Furthermore, an increase in colorfulness corresponds positively with visual appeal, while visual complexity exhibits an inverted U-shaped relationship with it. Originality/value This study provides novel insights into the choice-set formation process through the theoretical lens of dual-system theory. Additionally, the authors employed an image processing technique to quantify a product's visual appeal as depicted in a photograph. This study also incorporates a comprehensive econometric analysis to connect the objective aspects of visual appeal with subjective responses.
We present GM2Calc, a public C++ program for the calculation of MSSM contributions to the anomalous magnetic moment of the muon,
(
g
-
2
)
μ
. The code computes
(
g
-
2
)
μ
precisely, by taking into ...account the latest two-loop corrections and by performing the calculation in a physical on-shell renormalization scheme. In particular the program includes a
tan
β
resummation so that it is valid for arbitrarily high values of
tan
β
, as well as fermion/sfermion-loop corrections which lead to non-decoupling effects from heavy squarks. GM2Calc can be run with a standard SLHA input file, internally converting the input into on-shell parameters. Alternatively, input parameters may be specified directly in this on-shell scheme. In both cases the input file allows one to switch on/off individual contributions to study their relative impact. This paper also provides typical usage examples not only in conjunction with spectrum generators and plotting programs but also as C++ subroutines linked to other programs.
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