The solid‐state nanopore has attracted much attention as a next‐generation DNA sequencing tool or a single‐molecule biosensor platform with its high sensitivity of biomolecule detection. The platform ...has advantages of processability, robustness of the device, and flexibility in the nanopore dimensions as compared with the protein nanopore, but with the limitation of insufficient spatial and temporal resolution to be utilized in DNA sequencing. Here, the fundamental principles of the solid‐state nanopore are summarized to illustrate the novelty of the device, and improvements in the performance of the platform in terms of device fabrication are explained. The efforts to reduce the electrical noise of solid‐state nanopore devices, and thus to enhance the sensitivity of detection, are presented along with detailed descriptions of the noise properties of the solid‐state nanopore. Applications of 2D materials including graphene, h‐BN, and MoS2 as a nanopore membrane to enhance the spatial resolution of nanopore detection, and organic coatings on the nanopore membranes for the addition of chemical functionality to the nanopore are summarized. Finally, the recently reported applications of the solid‐state nanopore are categorized and described according to the target biomolecules: DNA‐bound proteins, modified DNA structures, proteins, and protein oligomers.
The solid‐state nanopore has attracted much attention as a next‐generation DNA sequencing tool or a single‐molecule biosensor platform with its high sensitivity of biomolecule detection. The history, fundamental principles, improvements in the performance, and the recently reported applications of the solid‐state nanopore are highlighted, with a focus on devices, materials, and fabrication methods.
Recent advances in flexible and stretchable electronics have led to a surge of electronic skin (e-skin)–based health monitoring platforms. Conventional wireless e-skins rely on rigid integrated ...circuit chips that compromise the overall flexibility and consume considerable power. Chip-less wireless e-skins based on inductor-capacitor resonators are limited to mechanical sensors with low sensitivities. We report a chip-less wireless e-skin based on surface acoustic wave sensors made of freestanding ultrathin single-crystalline piezoelectric gallium nitride membranes. Surface acoustic wave–based e-skin offers highly sensitive, low-power, and long-term sensing of strain, ultraviolet light, and ion concentrations in sweat. We demonstrate weeklong monitoring of pulse. These results present routes to inexpensive and versatile low-power, high-sensitivity platforms for wireless health monitoring devices.
Chip-less electronic skin
Flexible electronic materials, or e-skins, can be limited by the need to include rigid components. A range of techniques have emerged to bypass this problem, including approaches for wireless communication and charging based on silicon, carbon nanotubes, or conducting polymers. Kim
et al
. show that epitaxially grown, single-crystalline gallium nitride films on flexible substrates can be used for chip-less, flexible e-skins. The main advantage is that the material is flexible and breathable, thus providing better comfort. The devices convert electrical energy into surface acoustic waves using a piezoelectric resonator. The resonator is sensitive to changes in strain, mass changes due to the absorption or loss of ions, and ultraviolet light, all of which can be used for different sensing measurements. —MSL
Single-crystalline gallium nitride nanomembranes enable high-sensitivity surface acoustic wave sensors for wireless electronic skin.
Background and Aim
Gastric intestinal metaplasia (GIM) is a high‐risk factor for the development of gastric cancer. Narrow‐band imaging (NBI) enables endoscopic grading of GIM (EGGIM). In the era of ...climate change, gastrointestinal endoscopists are expected to reduce greenhouse gas emissions and medical waste. Based on the diagnostic performance of NBI endoscopy, this study measured the environmental impact and reduced cost of implementing EGGIM during gastroscopy.
Methods
Using NBI endoscopy in 242 patients, EGGIM classification and operative link on GIM (OLGIM) staging were prospectively performed in five different areas (lesser and greater curvatures of the corpus and antrum, and the incisura angularis). We estimated the environmental impact and cost reduction of the biopsy procedures and pathological processing if EGGIM were used instead of OLGIM.
Results
The diagnostic accuracy of NBI endoscopy for GIM was 93.0–97.1% depending on the gastric area. When a high EGGIM score ≥ 5 was the cut‐off value for predicting OLGIM stages III–IV, the area under the curve was 0.862, sensitivity was 81.9%, and specificity was 90.4%. The reduction in the carbon footprint by EGGIM was −0.4059 kg carbon dioxide equivalents per patient, equivalent to 1 mile driven by a gasoline‐powered car. The cost savings were calculated to be $47.36 per patient.
Conclusions
EGGIM is a reliable method for identifying high‐risk gastric cancer patients, thereby reducing the carbon footprint and medical costs in endoscopy practice.
Background and Aim
The Helicobacter pylori eradication rate using conventional triple therapy has decreased due to clarithromycin (CAM) resistance in H. pylori. Recently, dual priming oligonucleotide ...(DPO)‐based multiplex polymerase chain reaction (PCR) can be used to detect H. pylori and point mutations in the 23S ribosomal RNA gene causing CAM resistance. This study aimed to evaluate the success rate and cost‐effectiveness of tailored H. pylori eradication using DPO‐PCR.
Methods
The H. pylori‐positive patients diagnosed by a rapid urease test or DPO‐PCR were enrolled from a single academic hospital. The patients with positive rapid urease test results received a CAM‐based triple regimen. In the tailored therapy group that underwent DPO‐PCR testing, patients with A2142G and/or A2143G point mutations were treated with a bismuth‐containing quadruple regimen. The cost‐effectiveness of H. pylori eradication success was evaluated according to the average cost per patient and the incremental cost‐effectiveness ratio.
Results
A total of 243 patients were allocated to the triple therapy group and 124 patients to the tailored therapy group. The first‐line eradication rate of H. pylori was significantly higher in the tailored therapy group than in the conventional triple therapy group (92.7% vs 76.5%, P < 0.001). The average costs per patient for tailored therapy were $307.37 and $299.59 for first‐line and second‐line treatments, respectively. Compared with triple therapy, the incremental cost‐effectiveness ratios of tailored therapy were $3.96 and −$3.81 per patient for first‐line and second‐line treatments, respectively.
Conclusion
In Korea, tailored H. pylori eradication using DPO‐PCR may be more cost‐effective than conventional triple therapy.
Identifying material parameters affecting properties of ferromagnets is key to optimized materials that are better suited for spintronics. Magnetic anisotropy is of particular importance in van der ...Waals magnets, since it not only influences magnetic and spin transport properties, but also is essential to stabilizing magnetic order in the two-dimensional limit. Here, we report that hole doping effectively modulates the magnetic anisotropy of a van der Waals ferromagnet and explore the physical origin of this effect. Fe3–x GeTe2 nanoflakes show a significant suppression of the magnetic anisotropy with hole doping. Electronic structure measurements and calculations reveal that the chemical potential shift associated with hole doping is responsible for the reduced magnetic anisotropy by decreasing the energy gain from the spin–orbit induced band splitting. Our findings provide an understanding of the intricate connection between electronic structures and magnetic properties in two-dimensional magnets and propose a method to engineer magnetic properties through doping.
We fabricated CZTSSe thin films using optimized SLG-Mo/Zn/Cu/Sn (MZCT) as a stacked structure and described the phenomenon of Zn elemental volatilization using the MZCT stacked structure. We ...introduced H2S gas to effectively control the S/(S + Se) ratio of the film in the sulfo-selenization process and to suppress Zn volatilization. Unlike during the selenization process, a stable ZnSSe thin film was formed on the precursor surface during the sulfo-selenization process. The formation of the ZnSSe thin film inhibited Zn volatilization, which facilitated control of the thin film stoichiometry and played an important role in crystal growth. In addition, the sulfo-selenization process using H2S forms a grading of the S/(S + Se) ratio in the depth direction in the ZnSSe layer. The ZnSSe layer with this property causes the band gap grading in the CZTSSe absorption layer. Finally, through our optimized annealing process, we realized a world record CZTSSe solar cell with a certified power conversion efficiency of 12.62% and a centimetre-scale (1.1761 cm2) efficiency of 11.28%.
A multichannel/multicolor visible light communication (VLC) system using entirely organic components, including organic light emitting diodes (OLEDs) and organic photodiodes (OPDs), is developed to ...demonstrate indoor lighting applications where the integration of OLEDs and OPDs has significant potential. To achieve this, tricolor (Red/Green/Blue(R/G/B))‐selective OPD arrays for the receiver and tricolor OLED arrays for the emitter are developed. For (R/G/B)‐selective OPDs, a Fabry–Pérot electrode to enhance color selectivity and a thick junction structure to effectively accommodate a wide range of driving voltages are introduced. For tricolor OLEDs, fluorescent‐emitting materials are used to enhance the operating frequency in addition to introducing a cavity structure to achieve narrow emission. Utilizing these spectrally refined tricolor OPDs/OLEDs, a VLC system is designed for indoor lighting applications, and a systematic analysis of their signal‐to‐interference ratio dependence on the distance or angle between the transmitter and receiver is performed. The study's findings indicate the importance of emission angle‐dependent wavelength shift of the OLED and the luminosity function, which varies with wavelength, in the R/G/B mixed‐white‐light‐based VLC systems. Finally, the feasibility of VLC using tricolor OPDs/OLEDs in the real‐life context of indoor white‐color lighting is demonstrated, showing that the transmitted data patterns well‐matched the received data patterns.
A visible light communication platform using (R/G/B)‐selective organic photodiode arrays as receivers and (R/G/B) organic light‐emitting diodes as emitters is developed and analyzed to study how the geometry effect of each organic receiver and emitter affects data transmission. Based on this, the first organic material‐based white‐light optical communication system is demonstrated.
Background
The ABC test measures serum pepsinogen and anti‐Helicobacter pylori IgG antibody levels to predict precancerous conditions in the stomach and gastric cancer. However, a limitation of this ...test is that the gastric cancer risk is not negligible in patients with a negative result.
Methods
Based on their ABC results, 1157 patients were classified into Groups A (n = 392), B (n = 479), C (n = 247), and D (n = 39). In Group A, 24.2% of patients had atrophic gastritis and/or intestinal metaplasia and had thus been incorrectly assigned to Group A. Patients in Group A were then assigned to derivation (n = 236) and validation (n = 156) cohorts by 3:2 random sampling. Logistic regression analyses were performed to identify the factors discriminating between a correct (true) and incorrect (false) Group A classification.
Results
A 4‐point discriminative model was constructed based on a high‐negative H. pylori IgG antibody titer and the patient's age (50–64 and ≥65 years). The areas under the receiver operating characteristic curve for the derivation and validation cohorts were 0.868 and 0.894, respectively. In the validation cohort, the addition of a discriminative model score ≥2 to the ABC method showed a similar accuracy for predicting gastric cancer risk compared with the ABC method alone (93.8% vs. 92.4%).
Conclusion
The 4‐point discriminative model may help identify patients with a normal serological test who are nonetheless at risk of developing gastric cancer.
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.
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