The efficient synthesis of two-dimensional molybdenum disulfide (2D MoS2) at low temperatures is essential for use in flexible devices. In this study, 2D MoS2 was grown directly at a low temperature ...of 200 °C on both hard (SiO2) and soft substrates (polyimide (PI)) using chemical vapor deposition (CVD) with Mo(CO)6 and H2S. We investigated the effect of the growth temperature and Mo concentration on the layered growth by Raman spectroscopy and microscopy. 2D MoS2 was grown by using low Mo concentration at a low temperature. Through optical microscopy, Raman spectroscopy, X-ray photoemission spectroscopy, photoluminescence, and transmission electron microscopy measurements, MoS2 produced by low-temperature CVD was determined to possess a layered structure with good uniformity, stoichiometry, and a controllable number of layers. Furthermore, we demonstrated the realization of a 2D MoS2-based flexible gas sensor on a PI substrate without any transfer processes, with competitive sensor performance and mechanical durability at room temperature. This fabrication process has potential for burgeoning flexible and wearable nanotechnology applications.
We investigated the larvicidal potential of 10 plant essential oils (EOs) against the Asian tiger mosquito Aedes albopictus. Among the EOs, larvicidal activity against Ae. albopictus was strongest in ...those derived from massoia (Massoia aromatica) and nutmeg (Myristica fragrans). Larvicidal activities of massoia and nutmeg EOs against Ae. albopictus were 95.0% and 85.0% at 50 μg/mL, respectively. A total of 4 and 14 compounds were identified from massoia and nutmeg, respectively, and two massoia lactones, C10 and C12, were isolated from massoia EO. Among the identified compounds, benzyl salicylate, terpinolene, C12 massoia lactone, sabinene, benzyl benzoate, methyl eugenol, and C10 massoia lactone exhibited the strong larvicidal activity. Cellulose nanocrystal (CNC)-stabilized Pickering emulsions of massoia and nutmeg EOs were developed to overcome the insolubility of EOs in water. CNC/massoia and CNC/nutmeg emulsions were stable for at least 10 days, and larvicidal activities of CNC/massoia PE and CNC/nutmeg were higher than those of crude massoia and nutmeg EOs. This study presents a CNC-stabilized PE, a suitable formulation for EOs, as a potential larvicide against Ae. albopictus.
We describe the epidemiology of a coronavirus disease (COVID-19) outbreak in a call center in South Korea. We obtained information on demographic characteristics by using standardized epidemiologic ...investigation forms. We performed descriptive analyses and reported the results as frequencies and proportions for categoric variables. Of 1,143 persons who were tested for COVID-19, a total of 97 (8.5%, 95% CI 7.0%-10.3%) had confirmed cases. Of these, 94 were working in an 11th-floor call center with 216 employees, translating to an attack rate of 43.5% (95% CI 36.9%-50.4%). The household secondary attack rate among symptomatic case-patients was 16.2% (95% CI 11.6%- 22.0%). Of the 97 persons with confirmed COVID-19, only 4 (1.9%) remained asymptomatic within 14 days of quarantine, and none of their household contacts acquired secondary infections. Extensive contact tracing, testing all contacts, and early quarantine blocked further transmission and might be effective for containing rapid outbreaks in crowded work settings.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, ODKLJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Aims
The dopamine transporter (DAT) actively translocates dopamine that is released from the presynaptic neurons across the membranes of nerve terminals into the extracellular space. We hypothesized ...that glucose loading‐induced changes in striatal DAT levels could be associated with food intake in humans.
Materials and methods
An intravenous bolus injection of 18F‐FP‐CIT was administered after infusion of glucose or placebo (normal saline), and emission data were acquired over 90 minutes in 33 healthy males. For a volume‐of‐interest‐based analysis, an atlas involving sub‐striatal regions of ventral striatum (VST), caudate nucleus and putamen was applied. DAT availability and binding potential (BPND) were measured using a simplified reference tissue method with cerebellum as the reference.
Results
The glucose‐loaded BPND from the VST negatively correlated with body mass index (BMI), whereas the placebo‐loaded BPND from the VST did not. After loading with glucose, there were substantial increases in BPNDs: 18.3%, 71.7% and 34.0% on average in the VST, caudate nucleus and putamen, respectively.
Conclusion
Striatal DAT changes after glucose loading, and BMI is associated with glucose‐loaded DAT availability, not with placebo‐loaded DAT availability. DAT might have a role in the reward system of eating behavior.
We aimed to investigate the risks of Alzheimer's (AD) and Parkinson's disease (PD) in the 10 years following diagnosis of open-angle glaucoma (OAG) using a nationwide cohort. This propensity ...score-matched retrospective cohort study included 1,025,340 subjects from the Korean National Health Insurance Service National Sample Cohort database. The OAG group (n = 1,469) included patients who were initially diagnosed with OAG between 2004 and 2007, and the subjects in the comparison group were matched in a 1:5 ratio using propensity scores. Cox regression analyses were performed to investigate the risks of developing AD or PD. The diagnosis of OAG was significantly associated with an increased incidence of AD (hazard ratio HR = 1.403, 95% confidence interval CI 1.180-1.669, p < 0.001), but not PD (HR = 0.995, 95% CI 0.620-1.595, p = 0.983) after adjusting for possible confounding factors. In subgroup analyses, participants with OAG aged ≥65 years were more likely to develop AD compared with those aged <65 years, and female OAG patients had a greater risk of developing AD than males. Patients diagnosed with OAG have a higher risk of developing AD, but not PD, and the risk differed according to age and sex.
Abstract
The Coronavirus disease 2019 (COVID-19) has been spreading worldwide with rapidly increased number of deaths. Hyperinflammation mediated by dysregulated monocyte/macrophage function is ...considered to be the key factor that triggers severe illness in COVID-19. However, no specific targeting molecule has been identified for detecting or treating hyperinflammation related to dysregulated macrophages in severe COVID-19. In this study, previously published single-cell RNA-sequencing data of bronchoalveolar lavage fluid cells from thirteen COVID-19 patients were analyzed with publicly available databases for surface and imageable targets. Immune cell composition according to the severity was estimated with the clustering of gene expression data. Expression levels of imaging target molecules for inflammation were evaluated in macrophage clusters from single-cell RNA-sequencing data. In addition, candidate targetable molecules enriched in severe COVID-19 associated with hyperinflammation were filtered. We found that expression of
SLC2A3,
which can be imaged by
18
Ffluorodeoxyglucose, was higher in macrophages from severe COVID-19 patients. Furthermore, by integrating the surface target and drug-target binding databases with RNA-sequencing data of severe COVID-19, we identified candidate surface and druggable targets including
CCR1
and
FPR1
for drug delivery as well as molecular imaging. Our results provide a resource in the development of specific imaging and therapy for COVID-19-related hyperinflammation.
We developed a new surface-enhanced Raman scattering (SERS)-based aptasensor platform capable of quantifying severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) lysates with a high ...sensitivity. In this study, a spike protein deoxyribonucleic acid (DNA) aptamer was used as a receptor, and a self-grown Au nanopopcorn surface was used as a SERS detection substrate for the sensible detection of SARS-CoV-2. A quantitative analysis of the SARS-CoV-2 lysate was performed by monitoring the change in the SERS peak intensity caused by the new binding between the aptamer DNA released from the Au nanopopcorn surface and the spike protein in the SARS-CoV-2 virion. This technique enables detecting SARS-CoV-2 with a limit of detection (LoD) of less than 10 PFU/mL within 15 min. The results of this study demonstrate the possibility of a clinical application that can dramatically improve the detection limit and accuracy of the currently commercialized SARS-CoV-2 immunodiagnostic kit.
Herein, a high‐quality gate stack (native HfO2 formed on 2D HfSe2) fabricated via plasma oxidation is reported, realizing an atomically sharp interface with a suppressed interface trap density (Dit ≈ ...5 × 1010 cm−2 eV−1). The chemically converted HfO2 exhibits dielectric constant, κ ≈ 23, resulting in low gate leakage current (≈10−3 A cm−2) at equivalent oxide thickness ≈0.5 nm. Density functional calculations indicate that the atomistic mechanism for achieving a high‐quality interface is the possibility of O atoms replacing the Se atoms of the interfacial HfSe2 layer without a substitution energy barrier, allowing layer‐by‐layer oxidation to proceed. The field‐effect‐transistor‐fabricated HfO2/HfSe2 gate stack demonstrates an almost ideal subthreshold slope (SS) of ≈61 mV dec−1 (over four orders of IDS) at room temperature (300 K), along with a high Ion/Ioff ratio of ≈108 and a small hysteresis of ≈10 mV. Furthermore, by utilizing a device architecture with separately controlled HfO2/HfSe2 gate stack and channel structures, an impact ionization field‐effect transistor is fabricated that exhibits n‐type steep‐switching characteristics with a SS value of 3.43 mV dec−1 at room temperature, overcoming the Boltzmann limit. These results provide a significant step toward the realization of post‐Si semiconducting devices for future energy‐efficient data‐centric computing electronics.
A high‐quality gate stack (native HfO2 on 2D HfSe2) is proposed for future low‐power computing applications. The proposed gate stack exhibits atomically sharp interface with suppressed gate leakage ensuring ideal operation (subthreshold slope (SS) ≈ 60 mV dec−1). Furthermore, steep‐switching operation (SS ≈ 3.43 mV dec−1) overcoming the fundamental Boltzmann limit is demonstrated at room temperature with gated‐region‐controlled structure.
Abstract
Colloidal Ag(In,Ga)S
2
nanocrystals (AIGS NCs) with the band gap tunability by their size and composition within visible range have garnered surging interest. High absorption cross-section ...and narrow emission linewidth of AIGS NCs make them ideally suited to address the challenges of Cd-free NCs in wide-ranging photonic applications. However, AIGS NCs have shown relatively underwhelming photoluminescence quantum yield (PL QY) to date, primarily because coherent heteroepitaxy has not been realized. Here, we report the heteroepitaxy for AIGS-AgGaS
2
(AIGS-AGS) core-shell NCs bearing near-unity PL QYs in almost full visible range (460 to 620 nm) and enhanced photochemical stability. Key to the successful growth of AIGS-AGS NCs is the use of the Ag-S-Ga(OA)
2
complex, which complements the reactivities among cations for both homogeneous AIGS cores in various compositions and uniform AGS shell growth. The heteroepitaxy between AIGS and AGS results in the Type I heterojunction that effectively confines charge carriers within the emissive core without optically active interfacial defects. AIGS-AGS NCs show higher extinction coefficient and narrower spectral linewidth compared to state-of-the-art heavy metal-free NCs, prompting their immediate use in practicable applications including displays and luminescent solar concentrators (LSCs).
Glycosylation is closely related to cellular metabolism and disease progression. In particular, glycan levels in cancer cells and tissues increase during cancer progression. This upregulation of ...glycosylation in cancer cells may provide a basis for the development of new biomarkers for the targeting and diagnosis of specific cancers. Here, they developed a detection technology for pancreatic cancer cell‐derived small extracellular vesicles (PC‐sEVs) based on lectin–glycan interactions. Lectins specific for sialic acids are conjugated to Janus nanoparticles to induce interactions with PC‐sEVs in a dielectrophoretic (DEP) system. PC‐sEVs are selectively bound to the lectin‐conjugated Janus nanoparticles (lectin–JNPs) with an affinity comparable to that of conventionally used carbohydrate antigen 19‐9 (CA19‐9) antibodies. Furthermore, sEVs‐bound Lectin–JNPs (sEVs‐Lec‐JNPs) are manipulated between two electrodes to which an AC signal is applied for DEP capture. In addition, the proposed DEP system can be used to trap the sEVs–Lec–JNP on the electrodes. Their results, which are confirmed by lectin–JNPs using the proposed DEP system followed by target gene analysis, provide a basis for the development of a new early diagnostic marker based on the glycan characteristics of PC‐sEVs. In turn, these novel detection methods could overcome the shortcomings of commercially available pancreatic cancer detection techniques.
Small extracellular vesicles derived from tumor cells are captured by lectin nanoparticles in the dielectrophoretic device via their unique glycan presentation on the surface.
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