Chlorophyll Fluorescence Imaging for Environmental Stress Diagnosis in Crops.

The field of plant phenotype is used to analyze the shape and physiological characteristics of crops in multiple dimensions. Imaging, using non-destructive optical characteristics of plants, analyzes growth characteristics through spectral data. Among these, fluorescence imaging technology is a method of evaluating the physiological characteristics of crops by inducing plant excitation using a specific light source. Through this, we investigate how fluorescence imaging responds sensitively to environmental stress in garlic and can provide important information on future stress management. In this study, near UV LED (405 nm) was used to induce the fluorescence phenomenon of garlic, and fluorescence images were obtained to classify and evaluate crops exposed to abiotic environmental stress. Physiological characteristics related to environmental stress were developed from fluorescence sample images using the Chlorophyll ratio method, and classification performance was evaluated by developing a classification model based on partial least squares discrimination analysis from the image spectrum for stress identification. The environmental stress classification performance identified from the Chlorophyll ratio was 14.9% in F673/F717, 25.6% in F685/F730, and 0.209% in F690/F735. The spectrum-developed PLS-DA showed classification accuracy of 39.6%, 56.2% and 70.7% in Smoothing, MSV, and SNV, respectively. Spectrum pretreatment-based PLS-DA showed higher discrimination performance than the existing image-based Chlorophyll ratio.

Particulate matter 10 induces oxidative stress and apoptosis in rhesus macaques skin fibroblast.

Background: Particulate matter (PM) is a major air pollutant that affects human health worldwide. PM can pass through the skin barrier, thus causing skin diseases such as heat rash, allergic reaction, infection, or inflammation. However, only a few studies have been conducted on the cytotoxic effects of PM exposure on large-scale animals. Therefore, herein, we investigated whether and how PM affects rhesus macaque skin fibroblasts. Methods: Rhesus macaque skin fibroblasts were treated with various concentrations of PM10 (1, 5, 10, 50, and 100 µg/mL) and incubated for 24, 48, and 72 h. Then, cell viability assay, TUNEL assay, and qRT-PCR were performed on the treated cells. Further, the reactive oxygen species, glutathione, and cathepsin B levels were determined. The MTT assay revealed that PM10 (>50 µg/mL) proportionately reduced the cell proliferation rate. Results: PM10 treatment increased TUNEL-positive cell numbers, following the pro-apoptosis-associated genes (CASP3 and BAX) and tumor suppressor gene TP53 were significantly upregulated. PM10 treatment induced reactive oxidative stress. Cathepsin B intensity was increased, whereas GSH intensity was decreased. The mRNA expression levels of antioxidant enzyme-related genes (CAT, GPX1 and GPX3) were significantly upregulated. Furthermore, PM10 reduced the mitochondrial membrane potential. The mRNA expression of mitochondrial complex genes, such as NDUFA1, NDUFA2, NDUFAC2, NDUFS4, and ATP5H were also significantly upregulated. In conclusion, these results showed that PM10 triggers apoptosis and mitochondrial damage, thus inducing ROS accumulation. These findings provide potential information on the cytotoxic effects of PM10 treatment and help to understand the mechanism of air pollution-induced skin diseases.

Impact of COVID-19 pandemic on patients with cardio/cerebrovascular disease who visit the emergency department.

INTRODUCTION: The coronavirus disease 2019 (COVID-19) pandemic situation is a state that has had a great impact on the medical system and society. To respond to the pandemic situation, various methods, such as a pre-triage system, are being implemented in the emergency medical field. However, there are insufficient studies on the effects of this pandemic situation on patients visiting the emergency department (ED), especially those with cardio/cerebrovascular diseases (CVD)1 classified as time-dependent emergencies. METHODS: We performed a retrospective analysis of a cohort of patients from April 2020 to December 2020 (April 2020 was when the pre-triage system was established) compared to a parallel comparison patient cohort from 2019. The primary outcome was in-hospital mortality. CVD was defined by the patient's final diagnosis. RESULTS: During the same period, the number of patients who had visited the ED after COVID-19 had decreased to 79.1% of the number of patients who had visited the ED before COVID-19. The overall patient mortality and the mortality in the patients cardiovascular disease had both increased, while the mortality from cerebrovascular disease did not increase. Meanwhile, the ED length of stay had increased in all patients but did not increase in the patients with cardiovascular disease. CONCLUSION: As with prior studies conducted in other regions, in our study, the total number of ED visits were decreased compared to before COVID-19. The overall mortality had increased, particularly in the patients with cardiovascular disease.

Stability of Engineered Micro or Nanobubbles for Biomedical Applications.

A micro/nanobubble (MNB) refers to a bubble structure sized in a micrometer or nanometer scale, in which the core is separated from the external environment and is normally made of gas. Recently, it has been confirmed that MNBs can be widely used in angiography, drug delivery, and treatment. Thus, MNBs are attracting attention as they are capable of constructing a new contrast agent or drug delivery system. Additionally, in order to effectively use an MNB, the method of securing its stability is also being studied. This review highlights the factors affecting the stability of an MNB and the stability of the MNB within the ultrasonic field. It also discusses the relationship between the stability of the bubble and its applicability in vivo.

How Should We Assign Large Infiltrative Hepatocellular Carcinomas for Staging?

Infiltrative gross morphology of hepatocellular carcinoma (HCC) is known to be associated with poor prognosis, but this is not considered for staging. A total of 774 HCC patients who underwent curative liver resection were retrospectively reviewed and the prognostic significance of infiltrative type HCC was assessed using the American Joint Committee on Cancer (AJCC) and Barcelona Clinic Liver Cancer (BCLC) staging systems. Seventy-four patients (9.6%) had infiltrative HCCs with a higher proportion of multifocal tumors, larger tumors, vessel invasion, increased tumor marker levels, and advanced T-stages than those with nodular HCC (all, p < 0.01). Infiltrative morphology was independently associated with lower overall survival (OS), but its impact was significant when the tumor size was ≥ 4 cm (p < 0.001). Under current AJCC and BCLC staging criteria, these large infiltrative HCCs were associated with significantly worse OS in early AJCC T-stages (T1b/T2, p < 0.001) and BCLC stage A/B (both, p < 0.01) but not in late AJCC (T3/T4) and BCLC C. The reassignment of this subtype to T3 and T4 increased the discriminatory ability of AJCC T-staging with lower AIC values (3090 and 3088 vs. 3109) and higher c-index (0.69 and 0.69 vs. 0.67), respectively (both, p < 0.001). Similarly, the reassignment of large infiltrative HCC to BCLC stages B and C also improved the prognostic performance. Large infiltrative HCCs should be assigned to more advanced stages in current staging systems for their prognostic impact.

Anomalous Ambipolar Transport of Organic Semiconducting Crystals via Control of Molecular Packing Structures.

Organic crystals deposited on 2-dimensional (2D) van der Waals substrates have been widely investigated due to their unprecedented crystal structures and electrical properties. van der Waals interaction between organic molecules and the substrate induces epitaxial growth of high quality organic crystals and their anomalous crystal morphologies. Here, we report on unique ambipolar charge transport of a "lying-down" pentacene crystal grown on a 2D hexagonal boron nitride van der Waals substrate. From in-depth analysis on crystal growth behavior and ultraviolet photoemission spectroscopy measurement, it is revealed that the pentacene crystal at the initial growth stage have a lattice-strained packing structure and unique energy band structure with a deep highest occupied molecular orbital level compared to conventional "standing-up" crystals. The lattice-strained pentacene few layers enable ambipolar charge transport in field-effect transistors with balanced hole and electron field-effect mobilities. Complementary logic circuits composed of the two identical transistors show clear inverting functionality with a high gain up to 15. The interesting crystal morphology of organic crystals on van der Waals substrates is expected to attract broad attentions on organic/2D interfaces for their electronic applications.

Multi-floor cascading ferroelectric nanostructures: multiple data writing-based multi-level non-volatile memory devices.

Multiple data writing-based multi-level non-volatile memory has gained strong attention for next-generation memory devices to quickly accommodate an extremely large number of data bits because it is capable of storing multiple data bits in a single memory cell at once. However, all previously reported devices have failed to store a large number of data bits due to the macroscale cell size and have not allowed fast access to the stored data due to slow single data writing. Here, we introduce a novel three-dimensional multi-floor cascading polymeric ferroelectric nanostructure, successfully operating as an individual cell. In one cell, each floor has its own piezoresponse and the piezoresponse of one floor can be modulated by the bias voltage applied to the other floor, which means simultaneously written data bits in both floors can be identified. This could achieve multi-level memory through a multiple data writing process.

A Facile Route for Patterned Growth of Metal-Insulator Carbon Lateral Junction through One-Pot Synthesis.

Precise graphene patterning is of critical importance for tailor-made and sophisticated two-dimensional nanoelectronic and optical devices. However, graphene-based heterostructures have been grown by delicate multistep chemical vapor deposition methods, limiting preparation of versatile heterostructures. Here, we report one-pot synthesis of graphene/amorphous carbon (a-C) heterostructures from a solid source of polystyrene via selective photo-cross-linking process. Graphene is successfully grown from neat polystyrene regions, while patterned cross-linked polystyrene regions turn into a-C because of a large difference in their thermal stability. Since the electrical resistance of a-C is at least 2 orders of magnitude higher than that for graphene, the charge transport in graphene/a-C heterostructure occurs through the graphene region. Measurement of the quantum Hall effect in graphene/a-C lateral heterostructures clearly confirms the reliable quality of graphene and well-defined graphene/a-C interface. The direct synthesis of patterned graphene from polymer pattern could be further exploited to prepare versatile heterostructures.

Simultaneous visualization of graphene grain boundaries and wrinkles with structural information by gold deposition.

Although line defects such as grain boundaries (GBs) and wrinkles are unavoidable in graphene, difficulties in identification preclude studying their impact on electronic and mechanical properties. As previous methods focus on a single type of line defect, simultaneous measurements of both GBs and wrinkles with detailed structural information have not been reported. Here, we introduce effective visualization of both line defects by controlled gold deposition. Upon depositing gold on graphene, single lines and double lines of gold nanoparticles (NPs) are formed along GBs and wrinkles, respectively. Moreover, it is possible to analyze whether a GB is stitched or overlapped, whether a wrinkle is standing or folded, and the width of the standing collapsed wrinkle. Theoretical calculations show that the characteristic morphology of gold NPs is due to distinct binding energies of line defects, which are correlated to disrupting diffusion of NPs. Our approach could be further exploited to investigate the defect structures of other two-dimensional materials.

Fast benchtop visualization of graphene grain boundaries using adhesive properties of defects.

Highly adhesive properties of graphene grain boundaries to permanganate lead to a very quick, easy and convenient method to visualize the grain boundaries simply using an optical microscope, which would be vital to improve specific properties of graphene.