The unique properties and practical utility of carbon-based materials have transformed the modern scientific fields of electrical energy storage (EES), environmental science, and materials chemistry. ...Their outstanding mechanical properties and extraordinary conductivity provide enormous potential for applications in divers areas. However, impurities derived from precursors and uncontrollable variations in the properties of natural carbonaceous materials have created a growing demand for synthetic carbon-based alternatives. The high purity and structural controllability of carbon aerogels make them promising alternatives as a remedy of those hindrance. The unique features of carbon aerogels enable them to be employed as energy storage materials, catalytic scaffolds, and adsorbents. Furthermore, Knudsen effect and hydrophobicity of carbon aerogels promote the applications for organic pollutant separators and thermal insulators. The aims of this review are to provide a brief overview of the history and fundamental concepts surrounding carbon aerogels and to present a comprehensive summary of recent developments for their application.
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Exceptional power conversion efficiency (PCE) of 25.7% in perovskite solar cells (PSCs) has been achieved, which is comparable with their traditional rivals (Si‐based solar cells). However, ...commercialization‐worthy efficiency and long‐term stability remain a challenge. In this regard, there are increasing studies focusing on the interface engineering in PSC devices to overcome their poor technical readiness. Herein, the roles of electrode materials and interfaces in PSCs are discussed in terms of their PCEs and perovskite stability. All the current knowledge on the factors responsible for the rapid intrinsic and external degradation of PSCs is presented. Then, the roles of carbonaceous materials as substitutes for noble metals are focused on, along with the recent research progress in carbon‐based PSCs. Furthermore, a sub‐category of PSCs, that is, flexible PSCs, is considered as a type of exceptional power source due to their high power‐to‐weight ratios and figures of merit for next‐generation wearable electronics. Last, the future perspectives and directions for research in PSCs are discussed, with an emphasis on their commercialization.
The roles of electrode materials and interfaces in perovskite solar cell (PSC) devices are discussed in terms of perovskite stability. The various factors responsible for rapid degradation in PSCs are provided. Then, the roles of carbonaceous materials for carbon‐based PSC as a substitute for noble metals are addressed, along with the recent progress.
The use of CRISPR-Cas9 as a therapeutic reagent is hampered by its off-target effects. Although rationally designed S. pyogenes Cas9 (SpCas9) variants that display higher specificities than the ...wild-type SpCas9 protein are available, these attenuated Cas9 variants are often poorly efficient in human cells. Here, we develop a directed evolution approach in E. coli to obtain Sniper-Cas9, which shows high specificities without killing on-target activities in human cells. Unlike other engineered Cas9 variants, Sniper-Cas9 shows WT-level on-target activities with extended or truncated sgRNAs with further reduced off-target activities and works well in a preassembled ribonucleoprotein (RNP) format to allow DNA-free genome editing.
Very recently, MXene‐based wearable hydrogels have emerged as promising candidates for epidermal sensors due to their tissue‐like softness and unique electrical and mechanical properties. However, it ...remains a challenge to achieve MXene‐based hydrogels with reliable sensing performance and prolonged service life, because MXene inevitably oxidizes in water‐containing system of the hydrogels. Herein, catechol‐functionalized poly(vinyl alcohol) (PVA‐CA)‐based hydrogels is proposed to inhibit the oxidation of MXene, leading to rapid self‐healing and superior strain sensing behaviors. Sufficient interaction of hydrophobic catechol groups with the MXene surface reduces the oxidation‐accessible sites in the MXene for reaction with water and eventually suppresses the oxidation of MXene in the hydrogel. Furthermore, the PVA‐CA‐MXene hydrogel is demonstrated for use as a strain sensor for real‐time motion monitoring, such as detecting subtle human motions and handwriting. The signals of PVA‐CA‐MXene hydrogel sensor can be accurately classified using deep learning models.
This study provides an avenue for the synthesis of oxidation‐resistant MXene‐based catechol‐grafted poly (vinyl alcohol) hydrogels (PVA‐CA‐MXene hydrogel) with prolonged service life intended for strain sensors in real‐time motion monitoring, such as detecting subtle human motions and handwriting. The signals of PVA‐CA‐MXene hydrogel sensor are further accurately classified using deep learning models.
•The role of drone food delivery services is expected to grow.•Perceived innovativeness affecting attitude toward using drone food delivery services were identified.•The attitude had a positive ...influence on intentions to use, word-of-mouth intentions, and willingness to pay more.•The moderating role of gender and age was found.
Drone food delivery services refer to services that use drones to deliver food to customers as the role of services becomes more important in the food service industry, because drone food delivery services are not affected by traffic, so they can deliver food quickly. However, there is still a lack of research about drone food delivery services. Thus, this study examined the importance and necessity of drone food delivery services using the concept of perceived innovativeness. In Korea, a total of 324 samples collected in order to test the proposed model including fifteen hypotheses. The data analysis results showed that perceived innovativeness has a positive influence on attitude toward using drone food delivery services and behavioral intentions including intentions to use and word-of-mouth intentions. In addition, the attitude played an important role in the formation of behavioral intentions. Lastly, this study found the important moderating role of gender and age.
Stealth technology is used to enhance the survival of military equipment in the field of military surveillance, as it utilizes a combination of techniques to render itself undetectable by enemy radar ...systems. Radar absorbing materials (RAMs) are specialized materials used to reduce the reflection (or absorption) of radar signals to provide stealth capability, which is a core component of passive countermeasures in military applications. The properties of RAMs can be optimized by adjusting their composition, microstructure, and surface geometry. Carbon-based materials present a promising approach for the fabrication of ultrathin, versatile, and high-performance RAMs due to their large specific surface area, lightweight, excellent dielectric properties, high electrical conductivity, and stability under harsh conditions. This review begins with a brief history of stealth technology and an introduction to electromagnetic waves, radar systems, and radar absorbing materials. This is followed by a discussion of recent research progress in carbon-based RAMs, including carbon blacks, carbon fibers, carbon nanotubes, graphite, graphene, and MXene, along with an in-depth examination of the principles and strategies on electromagnetic attenuation characteristics. Hope this review will offer fresh perspectives on the design and fabrication of carbon-based RAMs, thereby fostering a deeper fundamental understanding and promoting practical applications.
Nutritional status of patients with COVID-19 Im, Jae Hyoung; Je, Young Soo; Baek, Jihyeon ...
International journal of infectious diseases,
11/2020, Letnik:
100
Journal Article
Recenzirano
Odprti dostop
Nutrients play a vital role in the defense against infectious diseases and the regulation of inflammation; however, little is known with regards to COVID-19.
We measured concentrations of vitamins ...B1, B6, B12, folate, vitamin D (25-hydroxyvitamin D), selenium, and zinc in 50 patients with COVID-19. Vitamin D deficiency was shown in 76% of patients and selenium deficiency in 42%. There was a significant difference compared to a control group of 150 people (vitamin D deficiency 43.3%).
Among 12 patients with respiratory distress, 11 (91.7%) had one or more nutrient deficiency.
The relationship between immunity and nutrition is well known and its role in coronavirus disease 2019 (COVID-19) is also being paid great attention. However, the nutritional status of COVID-19 patients is unknown. Vitamin B1, B6, B12, vitamin D (25-hydroxyvitamin D), folate, selenium, and zinc levels were measured in 50 hospitalized patients with COVID-19. Overall, 76% of the patients were vitamin D deficient and 42% were selenium deficient. No significant increase in the incidence of deficiency was found for vitamins B1, B6, and B12, folate, and zinc in patients with COVID-19. The COVID-19 group showed significantly lower vitamin D values than the healthy control group (150 people, matched by age/sex). Severe vitamin D deficiency (based on a cut-off of ≤10 ng/dl) was found in 24.0% of the patients in the COVID-19 group and 7.3% in the control group. Among 12 patients with respiratory distress, 11 (91.7%) were deficient in at least one nutrient. However, patients without respiratory distress showed a deficiency in 30/38 cases (78.9%; p = 0.425). These results suggest that a deficiency of vitamin D or selenium may decrease the immune defenses against COVID-19 and cause progression to severe disease. However, more precise and large-scale studies are needed.
Various applications of TiO2 photocatalysis in environment and energy fields.
Recently, many water treatment technologies, such as biological treatment, coagulation/precipitation techniques, Fenton ...oxidation treatments, and advanced oxidation techniques, have been assessed to address the worsening clean water shortage. This review summarizes these technologies and provides the background and principle of photocatalysis for advanced oxidation technology. In particular, this paper focuses on semiconductor TiO2 photocatalysts as well as the latest modifications of TiO2 photocatalyst, such as the introduction of metals or heteroatoms onto TiO2, physical modification of TiO2 for a variety of morphologies, and hybrid TiO2/nanocarbon composites, to improve the photocataytic activities for an advanced oxidation process. This review provides useful information to scientists and engineers in this field.
DddA-derived cytosine base editors (DdCBEs), composed of the split interbacterial toxin DddA
, transcription activator-like effector (TALE), and uracil glycosylase inhibitor (UGI), enable targeted ...C-to-T base conversions in mitochondrial DNA (mtDNA). Here, we demonstrate highly efficient mtDNA editing in mouse embryos using custom-designed DdCBEs. We target the mitochondrial gene, MT-ND5 (ND5), which encodes a subunit of NADH dehydrogenase that catalyzes NADH dehydration and electron transfer to ubiquinone, to obtain several mtDNA mutations, including m.G12918A associated with human mitochondrial diseases and m.C12336T that incorporates a premature stop codon, creating mitochondrial disease models in mice and demonstrating a potential for the treatment of mitochondrial disorders.
Based on impact range performance analysis and impact asymmetry analysis, this study aims to (1) examine the asymmetric effect of shopping tourism attributes on shopping destination satisfaction from ...the perspective of Chinese tourists and (2) prioritize attributes by identifying them as frustrators, dissatisfiers, hybrids, satisfiers, and delighters. The asymmetric relationships between shopping tourism attributes and shopping destination satisfaction offer an expanded view of the dynamic effects of attributes, while destination-specific attributes allow the researchers to examine the unexplored roles of government promotions and Korean pop culture/media in shopping tourism.
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