Histamine- and pruritogen-induced itch is inhibited by a TRPM8 agonist: a randomized vehicle-controlled human trial.

BACKGROUND: Allergies often present challenges in managing itch and the effects of histamine. Cooling agents that act via transient receptor potential melastatin 8 (TRPM8) agonism have shown potential in itch management. However, animal studies on itch have limitations, as animals cannot communicate subjective events and their fur-coated skin differs from that of humans. Human studies offer more direct and reliable information. OBJECTIVES: To investigate the effects of a specific TRPM8 agonist gel (cryosim-1) on itch induced by various pruritogens in human skin. METHODS: Calcium imaging experiments determined the binding of cryosim-1 and histamine to their respective receptors. Thirty healthy volunteers underwent skin prick tests with pruritogens and a control vehicle. Itch and pain intensity were measured using a numerical rating scale (NRS) across 10 min. Participants were randomly assigned to pretreatments with vehicle or TRPM8 agonist gel. Tests were repeated at a later date, and skin moisture, transepidermal water loss and mechanical sensitivity were measured. RESULTS: The in vitro study confirmed that histamine is not a TRPM8 agonist and cryosim-1 does not act as an agonist or antagonist on the human histamine 1 receptor. The TRPM8 agonist gel significantly reduced the itch intensity for all pruritogens compared with the vehicle-only gel. It also reduced itch NRS and the integrated itch score. Mechanical sensitivity was also reduced. CONCLUSIONS: The specific TRPM8 agonist gel effectively suppressed human skin itch induced by various pruritogens. These versatile actions suggest that cooling agents may be promising treatments for multiple forms of itch stimuli.

Managing itching and the effects of histamine can be difficult for people with allergies. Cooling the skin or applying menthol provides some relief from itch, but the way they work is not fully understood. Cooling agents interact with a protein called TRPM8 (also known as the 'cold and menthol receptor') and have shown potential for the management of itch. However, much of the research has been done on animals and has limitations when compared with human studies. Antihistamine medications can help with histamine-induced itching, but they may not work for other causes of itch. This study investigated the effects of a specific TRPM8 agonist (a chemical that activates a receptor to produce a biologic response) gel called cryosim-1 on itch in human skin. To do this, we conducted tests on 30 healthy people using five different substances that cause itching. Participants rated the itch intensity and pain using a scale and we measured various aspects of their skin. The results showed that all substances caused significant itching compared to a control substance, but itchiness gradually decreased over time. Histamine and compound 48/80 also caused pain. However, when participants applied the TRPM8 activator gel before exposure, they experienced less itching and lower itch intensity versus the gel without the activator. There were no significant differences in pain between the TRPM8 activator and the gel without it. In summary, our findings showed that activating TRPM8 receptors with a specific substance effectively relieved itching caused by various irritants on human skin. This suggests its potential as a treatment for itch-related conditions. Further research is needed to understand its mechanisms better and evaluate its effectiveness in real-life situations.

Exploration of a multifunctional biocontrol agent Streptomyces sp. JCK-8055 for the management of apple fire blight.

Apple fire blight, caused by the bacterium Erwinia amylovora, is a devastating disease of apple and pear trees. Biological control methods have attracted much attention from researchers to manage plant diseases as they are eco-friendly and viable alternatives to synthetic pesticides. Herein, we isolated Streptomyces sp. JCK-8055 from the root of pepper and investigated its mechanisms of action against E. amylovora. Streptomyces sp. JCK-8055 produced aureothricin and thiolutin, which antagonistically affect E. amylovora. JCK-8055 and its two active metabolites have a broad-spectrum in vitro activity against various phytopathogenic bacteria and fungi. They also effectively suppressed tomato bacterial wilt and apple fire blight in in vivo experiments. Interestingly, JCK-8055 colonizes roots as a tomato seed coating and induces apple leaf shedding at the abscission zone, ultimately halting the growth of pathogenic bacteria. Additionally, JCK-8055 can produce the plant growth regulation hormone indole-3-acetic acid (IAA) and hydrolytic enzymes, including protease, gelatinase, and cellulase. JCK-8055 treatment also triggered the expression of salicylate (SA) and jasmonate (JA) signaling pathway marker genes, such as PR1, PR2, and PR3. Overall, our findings demonstrate that Streptomyces sp. JCK-8055 can control a wide range of plant diseases, particularly apple fire blight, through a combination of mechanisms such as antibiosis and induced resistance, highlighting its excellent potential as a biocontrol agent. KEY POINTS: • JCK-8055 produces the systemic antimicrobial metabolites, aureothricin, and thiolutin. • JCK-8055 treatment upregulates PR gene expression in apple plants against E. amylovora. • JCK-8055 controls plant diseases with antibiotics and induced resistance.

Undibacterium cyanobacteriorum sp. nov., an auxin-producing bacterium isolated from fresh water during cyanobacterial bloom period.

A novel Gram-negative, white-pigmented, and auxin-producing strain, 20NA77.5T, was isolated from fresh water during cyanobacterial bloom period. Pairwise comparison of the 16S rRNA gene sequences showed that strain 20NA77.5T belonged to the genus Undibacterium and exhibited the highest sequence similarity to the type strains of Undibacterium danionis (98.00%), Undibacterium baiyunense (97.93%), Undibacterium macrobrachii (97.92%), and Undibacterium fentianense (97.71%). The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between strain 20NA77.5T and its related type strains were below 79.93 and 23.80%, respectively. The predominant fatty acids (> 10% of the total fatty acids) were C16:0 and summed feature 3 (C16:1ω7c and/or C16:1ω6c). The genomic DNA G + C content of strain 20NA77.5T was found to be 48.61%. Based on the phylogenetic distinctness, chemotaxonomic features, and phenotypic features, strain 20NA77.5T is considered to represent a novel species of the genus Undibacterium, for which the name Undibacterium cyanobacteriorum sp. nov is proposed. The type strain is 20NA77.5T (= KCTC 8005T = LMG 33136T).

Pathogenesis and Treatment of Pruritus Associated with Chronic Kidney Disease and Cholestasis.

Itching is an unpleasant sensation that provokes the desire to scratch. In general, itching is caused by dermatologic diseases, but it can also be caused by systemic diseases. Since itching hampers patients' quality of life, it is important to understand the appropriate treatment and pathophysiology of pruritus caused by systemic diseases to improve the quality of life. Mechanisms are being studied through animal or human studies, and various treatments are being tested through clinical trials. We report current trends of two major systemic diseases: chronic kidney disease and cholestatic liver disease. This review summarizes the causes and pathophysiology of systemic diseases with pruritus and appropriate treatments. This article will contribute to patients' quality of life. Further research will help understand the mechanisms and develop new strategies in the future.

7-Hydroxy-2-octenoic acid-ethyl ester mixture as an UV protectant secondary metabolite of an endolichenic fungus isolated from Menegazzia terebrata.

Enodolichenic fungi (ELF) are considered a promising bio-resource since they produce a variety of novel secondary metabolites with bioactivities. Ultraviolet (UV) radiation in sunlight containing UVA and UVB can cause acute and chronic skin diseases, and the demand for UV protectants in sunscreens has been increasing. Such situations evoke the strong interest of researchers in seeking effective UV protectants from natural products. In this study, we obtained partially purified 7-hydroxy-2-octenoic acid-ethyl ester (7E) from the secondary metabolites of ELF000548, which has UVA absorption activity. The antioxidant properties were performed by in vitro tests. The superoxide anion scavenging activity and inhibition of linoleic acid peroxidation of the 7E mixture were higher than ascorbic acid (ASA) and butyl hydroxyl anisole (BHA). Furthermore, the compound recovered the damage caused by UVB irradiation and inhibited melanin synthesis. Additionally, the 7E mixture exhibited no cytotoxicity toward the mouse melanoma cell lines, B16F1 and B16F10, except for the normal cell line, HaCaT. In general, these results are the first report about bioactivities of 7E, and those demonstrated that this compound might be a UV protectant to go further study.

Elucidation of the nematicidal mode of action of grammicin on Caenorhabditis elegans.

Grammicin (Gra) is derived from the endophytic fungus Xylaria grammica EL000614 and shows nematicidal activity against the devastating root-knot nematode Meloidogyne incognita in-vitro, in planta, and in-field experiments. However, the mechanism of the nematicidal action of Gra remains unclear. In this study, Gra exposure to the model genetic organism Caenorhabditis elegans affected its L1, L2/3, L4, and young adult stages. In addition, Gra treatment increased the intracellular reactive oxygen species (ROS) levels of C. elegans and M. incognita. Molecular docking interaction analysis indicated that Gra could bind and interact with GCS-1, GST-4, and DAF-16a in order of low binding energy, followed by SOD-3, SKN-1, and DAF-16b. This implies that the anthelmintic action of Gra is related to the oxidative stress response. To validate this mechanism, we examined the expression of the genes involved in the oxidative stress responses following treatment with Gra using transgenic C. elegans strains such as the TJ356 strain zIs356 [daf-16p::daf-16a/b::GFP + rol-6 (su1006)], LD1 ldIs7 [skn-1p::skn-1b/c::GFP + rol-6 (su1006)], LD1171 ldIs3 [gcs-1p::GFP + rol-6 (su1006)], CL2166 dvIs19 [(pAF15) gst-4p::GFP::NLS], and CF1553 strain muIs84 [(pAD76) sod-3p::GFP + rol-6 (su1006)]. Gra treatment caused nuclear translocation of DAF-16/FoxO and enhanced gst-4::GFP expression, but it had no change in sod-3::GFP expression. These results indicate that Gra induces oxidative stress response via phase II detoxification without reduced cellular redox machinery. Gra treatment also inhibited the nuclear localization of SKN-1::GFP in the intestine, which may lead to a condition in which oxidative stress tolerance is insufficient to protect C. elegans by the inactivation of SKN-1, thus inducing nematode lethality. Furthermore, Gra caused the mortality of two mutant strains of C. elegans, CB113 and DA1316, which are resistant to aldicarb and ivermectin, respectively. This indicates that the mode of action of Gra is different from the traditional nematicides currently in use, suggesting that it could help develop novel approaches to control plant-parasitic nematodes.

Inhibition of Oomycetes by the Mixture of Maleic Acid and Copper Sulfate.

Since the protective activity of the Bordeaux mixture against plant disease caused by oomycetes was discovered, copper compounds have been used for more than a century as an effective plant protection strategy. However, the application of excessive copper can cause adverse effects through long-term heavy metal accumulation in soils. Therefore, it is necessary to develop new strategies to reduce or replace copper in pesticides based on organic and low-input farming systems. Organic acids are eco-friendly. In this study, we tested the antifungal and anti-oomycete activity of maleic acid (MA) and copper sulfate (CS) against 13 plant pathogens. Treatment with a mixture of MA and CS showed strong anti-oomycetes activity against Phytophthora xcambivora, P. capsici, and P. cinnamomi. Moreover, the concentration of CS in the activated mixture of MA and CS was lower than that in the activated CS only, and the mixture showed synergy or partial synergy effects on the anti-oomycete activity. Application of a wettable powder formulation of MA and CS mixture (MCS 30WP; 26.67% MA and 3.33% CS) had excellent protective activity in pot experiments with control values of 73% Phytophthora blight on red pepper, 91% damping-off on cucumber, and 84% Pythium blight on creeping bentgrass, which are similar to those of the CS wettable powder formulation (6.67% CS) containing two times the CS content of MCS 30WP. These observations suggest that the synergistic effect of the MA and CS combination is a sustainable alternative for effective management of destructive oomycete diseases.

Darier Disease with Psoriasis.

Darier disease is an autosomal dominant disorder with dark crusty patches and is classified as hereditary acantholytic dermatosis. Keratotic papules and crust are often present on the scalp, forehead, chest, back, upper arms, elbows, groin, and behind the ears, predominantly in seborrheic areas. A 48-year-old male patient presented skin lesions with pruritus on the trunk and both upper and lower extremities. He first noticed the lesion 15 years before. On physical examination, there were multiple erythematous papules with crust on the trunk and red-brown colored keratotic plaque on both extremities. The suspected histopathological diagnosis was psoriasis vulgaris. The patient's skin lesions and pruritus were significantly improved after the psoriasis treatment. While continuing psoriasis treatment, the patient showed sudden worsening of the skin lesions on the scalp, abdomen, and fingernails (V-shaped nicks) with pruritus. Punch biopsy was performed on the abdominal lesion again and the final diagnosis was Darier disease. The patient was then treated using alitretinoin while maintaining the use of guselkumab for psoriasis. There are only a few cases that we found in which patients with Darier disease also had psoriasis. We report this rare case of Darier disease with psoriasis and propose that an additional biopsy might be necessary for accurate diagnosis and proper treatment.

Moisturizer in Patients with Inflammatory Skin Diseases.

As interest in skin increases, the cosmetic market is also growing. It is difficult to choose between the numerous types of basic cosmetics on the market. This article aims to provide advice and guidance on which products to recommend according to a patient's skin condition. Appropriate application of a moisturizer attempts not only to improve the dryness, but also improve the skin's natural barrier function to protect the skin from internal and external irritants to keep the skin healthy. Moisturizers consist of various ingredients, including occlusive agents, emollients, humectants, lipid mixture, emulsifiers, and preservatives. Pathophysiology of dry skin is also discussed to provide readers with the background they need to choose the right moisturizer for themselves. As moisturizers play an important role as adjuvant in the treatment of common skin diseases, such as atopic dermatitis, contact dermatitis, psoriasis, acne and rosacea, which type of moisturizer is appropriate for each disease was also dealt with. Basic cosmetics, especially moisturizers, should be recommended in consideration of the ingredients, effectiveness and safety of each product, and the skin condition of each patient.

First Report of Shot-Hole on Flowering Cherry Caused by Burkholderia contaminans and Pseudomonas syringae pv. syringae.

Shot-hole disease (SH) is one of the most common and important diseases affecting flowering cherry (FC; Prunus × yedoensis Matsumura; Somei-yoshino) trees in South Korea every year, resulting in premature defoliation and reduced flowering in the following year. However, pathogens associated with the disease remain unknown, which has rendered disease management challenging. Here, the pathogens associated with SH, their biochemical characteristics, and their host range were elucidated. Detached-leaf and in planta assays revealed that two biofilm-forming bacteria-namely, Burkholderia contaminans and Pseudomonas syringae pv. syringae-caused SH of FC trees. These pathogens were recorded for the first time as the causes of SH of FC trees in South Korea. Additionally, the two pathogens induced similar disease symptoms in several stone fruit belonging to the genus Prunus, including peach (Prunus persica), plum (P. salicina), and apricot (P. mume), with peach being the most susceptible. These results indicate that B. contaminans and P. syringae pv. syringae caused SH on FC trees and presented a broad spectrum of hosts. Furthermore, Xanthomonas arboricola pv. pruni, the causative agent of leaf spot on stone fruit, incited brown spots and shot holes on FC leaves. Therefore, FC trees are susceptible to infections by various pathogenic bacteria, including B. contaminans, P. syringae pv. syringae, and X. arboricola pv. pruni. These findings will be of great importance as a reference for effective management of SH in the face of possible cross-infection between Prunus spp. in the future.

First Report of Epicoccum tobaicum Associated with Leaf Spot on Flowering Cherry in South Korea.

Flowering cherry (FC, Prunus x yedoensis Matsumura; Somei-yoshino cherry) is an ornamental tree, planted across South Korea and producing stunning flowers in spring. The seasonal blooms are annually celebrated during cherry blossom festivals in many locations across the country. The leaf spot disease is among the most common and important diseases affecting FC trees every year, resulting in premature defoliation and reduced flowering of cherry blossoms in the following year. In May 2018, brown spots (2 to 5 mm), circular to irregular and with dark borders were observed on FC leaves in Hadong, Gyeongsangnamdo, South Korea (35°07'48.9"N, 127°46'53.8"E), with a disease incidence of 55%. Single lesions often coalesced and were sometimes perforated, leaving shot holes. Sampled leaves were surface sterilized with 1% NaOCl for 1 min and 70% ethanol for 30 s, and then rinsed twice with sterile distilled water. About 2-mm-long infected leaf pieces from the margins of lesions were put onto water agar (WA, 1.5% agar) plates and incubated at 25oC for 72 h. Mycelia grown from symptomatic tissue were transferred to PDA plates, and five similar fungal isolates were obtained from hyphal tips. They produced a strong reddish-orange diffusible pigment on PDA after 5 d and exudates after 8 d. Conidia were globular to pear-shaped, dark, verrucose, multicellular, and 14.8 to 23.5 µm in diameter (av. = 18.7 µm, n = 30) for isolate JCK-CSHF10. These morphological characteristics were consistent with the Epicoccum genus. Three loci, ITS, tub2, and rpb2, from three isolates JCK-CSHF8, JCK-CSHF9, and JCK-CSHF10 were amplified using the primer pairs ITS1F/LR5 (Gardes and Bruns 1993; Vilgalys and Hester 1990), Btub2Fd/Btub4Rd (Woudenberg et al. 2009), and RPB2-5F2/RPB2-7cR (Liu et al. 1999; Sung et al. 2007), respectively. The ITS, tub2, and rpb2 sequences of the three isolates were deposited in Genbank (MW368668-MW368670, MW392083-MW392085, and MW392086-MW392088, respectively), showing 99.6 to 100% identity to E. layuense (E33), a later synonym for E. tobaicum (Hou et al. 2020). The phylogenetic tree using concatenated sequences of the three loci placed the three isolates in a cluster of E. tobaicum (CBS 232.59, CGMCC 3.18362, and CBS 384.36; Hou et al. 2020). Taken together, the three isolates were identified as E. tobaicum. The pathogenicity of JCK-CSHF10 was tested on 15 healthy leaves on three FC trees (cv. Somei-yoshino, 1.2 m in height) kept in a greenhouse. Five-mm-diameter plugs from 7-d-old fungal cultures grown on PDA or mycelia-free PDA plugs as controls were placed on the abaxial side of a leaf at three points, previously wounded by a sterile needle (Zlatkovic et al. 2016). Inoculation sites were covered with moist cotton plugs. Trees were then covered with a clear plastic bag and maintained in high humidity at 25oC in darkness for 24 h, followed by a 12-h photoperiod. Brown spots appeared on inoculated leaves after 7 d, identical to those observed in the field, while control leaves remained symptomless. This experiment was repeated three times. A fungus with the same morphology as JCK-CSHF10 was recovered from lesions, thus confirming Koch's postulates. E. layuense (syn. E. tobaicum) has been reported as a leaf spot-causing agent on Perilla sp. (Chen et al. 2017) and Camellia sinensis (Chen et al. 2020). To date, there is no report on the occurrence of E. tobaicum from leaf spots on FC. To our knowledge, this is the first report of E. tobaicum causing leaf spot on FC in South Korea.

Simultaneous Target Classification and Moving Direction Estimation in Millimeter-Wave Radar System.

In this study, we propose a method to identify the type of target and simultaneously determine its moving direction in a millimeter-wave radar system. First, using a frequency-modulated continuous wave (FMCW) radar sensor with the center frequency of 62 GHz, radar sensor data for a pedestrian, a cyclist, and a car are obtained in the test field. Then, a You Only Look Once (YOLO)-based network is trained with the sensor data to perform simultaneous target classification and moving direction estimation. To generate input data suitable for the deep learning-based classifier, a method of converting the radar detection result into an image form is also proposed. With the proposed method, we can identify the type of each target and its direction of movement with an accuracy of over 95%. Moreover, the pre-trained classifier shows an identification accuracy of 85% even for newly acquired data that have not been used for training.

Aryl Hydrocarbon Receptor Repressor Is Hypomethylated in Psoriasis and Promotes Psoriasis-like Inflammation in HaCaT Cells.

It is known that DNA hypomethylation of aryl hydrocarbon receptor repressor (AhRR), one of the epigenetic markers of environmental pollutants, causes skin diseases. However, the function and mechanisms are still unknown. We aimed to determine whether AhRR is hypomethylated in PBMC of psoriasis patients, as well as to examine the expression of psoriasis-related inflammatory cytokines and antimicrobial peptides after 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) treatment in HaCaT cells overexpressing or silencing AhRR. AhRR was determined by qPCR, Western blot, immunohistochemistry, and immunocytochemistry in skin tissue and HaCaT cells. DNA methylation of AhRR was performed by Infinium Human Methylation450 BeadChip in PBMC of psoriasis patients and methylation-specific PCR (MSP) in HaCaT cells. NF-κB pp50 translocation and activity were performed by immunocytochemistry and luciferase reporter assay, respectively. We verified AhRR gene expression in the epidermis from psoriasis patients and healthy controls. AhRR hypomethylation in PBMC of psoriasis patients and pAhRR-HaCaT cells was confirmed. The expression level of AhRR was increased in both TCDD-treated HaCaT cells and pAhRR-HaCaT cells. NF-κB pp50 translocation and activity increased with TCDD. Our results showed that AhRR was hypomethylated and overexpressed in the lesional skin of patients with psoriasis, thereby increasing AhRR gene expression and regulating pro-inflammatory cytokines through the NF-κB signaling pathway in TCDD-treated HaCaT cells.

Nematicidal Activity of Grammicin Biosynthesis Pathway Intermediates in Xylaria grammica KCTC 13121BP against Meloidogyne incognita.

Grammicin, a polyketide metabolite produced by the endolichenic fungus Xylaria grammica KCTC 13121BP, shows strong nematicidal activity against Meloidogyne incognita. This study was performed to elucidate the grammicin biosynthesis pathway of X. grammica KCTC 13121BP and to examine the nematicidal activity of the biosynthesis intermediates and derivatives against M. incognita. Two grammicin biosynthesis intermediates were isolated from a T-DNA insertion transformant (strain TR-74) of X. grammica KCTC 13121BP and identified as 2-(hydroxymethyl)cyclohexa-2,5-diene-1,4-dione (compound 1) and 2,5-dihydroxybenzaldehyde (compound 2), which were also reported to be intermediates in the biosynthesis pathway of patulin, an isomer of grammicin. This indicates that the grammicin biosynthesis pathway overlaps almost with that of patulin, except for the last few steps. Among 13 grammicin biosynthesis intermediates and their derivatives (except grammicin), toluquinol caused the highest M. incognita J2 mortality, with an LC50/72 h value of 11.13 µg/mL, which is similar to grammicin with an LC50/72 h value of 15.95 µg/mL. In tomato pot experiments, the wettable powder type formulations (WP) of toluquinol (17.78 µg/mL) and grammicin (17.78 µg/mL) also effectively reduced gall formation on the roots of tomato plants with control values of 72.22% and 77.76%, respectively, which are much higher than abamectin (16.67%), but lower than fosthiazate (100%). The results suggest that toluquinol can be used directly as a biochemical nematicide or as a lead molecule for the development of new synthetic nematicides for the control of root-knot nematode diseases.

EEG-Based Evidence of Mirror Neuron Activity from App-Mediated Stroke Patient Observation.

Background and Objectives: The mirror neuron system in the sensorimotor region of the cerebral cortex is equally activated during both action observation and execution. Action observation training mimics the functioning of the mirror neuron system, requiring patients to watch and imitate the actions necessary to perform activities of daily living. StrokeCare is a user-friendly application based on the principles of action observation training, designed to assist people recovering from stroke. Therefore, when observing the daily life behavior provided in the StrokeCare app, whether the MNS is activated and mu inhibition appears. Materials and Methods: We performed electroencephalography (EEG) on 24 patients with chronic stroke (infarction: 11, hemorrhage: 13) during tasks closely related to daily activities, such as dressing, undressing, and walking. The StrokeCare app provided action videos for patients to watch. Landscape imagery observation facilitated comparison among tasks. We analyzed the mu rhythm from the C3, CZ, and C4 regions and calculated the mean log ratios for comparison of mu suppression values. Results: The EEG mu power log ratios were significantly suppressed during action observation in dressing, undressing, walking, and landscape conditions, in decreasing order. However, there were no significant activity differences in the C3, C4 and CZ regions. The dressing task showed maximum suppression after a color spectrum was used to map the relative power values of the mu rhythm for each task. Conclusions: These findings reveal that the human mirror neuron system was more strongly activated during observation of actions closely related to daily life activities than landscape images.

Unveiling the Relationship between the Perovskite Precursor Solution and the Resulting Device Performance.

For the fabrication of perovskite solar cells (PSCs) using a solution process, it is essential to understand the characteristics of the perovskite precursor solution to achieve high performance and reproducibility. The colloids (iodoplumbates) in the perovskite precursors under various conditions were investigated by UV-visible absorption, dynamic light scattering, photoluminescence, and total internal reflection fluorescence microscopy techniques. Their local structure was examined by in situ X-ray absorption fine structure studies. Perovskite thin films on a substrate with precursor solutions were characterized by transmission electron microscopy, X-ray diffraction analysis, space-charge-limited current, and Kelvin probe force microscopy. The colloidal properties of the perovskite precursor solutions were found to be directly correlated with the defect concentration and crystallinity of the perovskite film. This work provides guidelines for controlling perovskite films by varying the precursor solution, making it possible to use colloid-engineered lead halide perovskite layers to fabricate efficient PSCs.

Nematicidal activity of 5-iodoindole against root-knot nematodes.

Multi-drug resistance in nematodes is a serious problem as lately several resistant phenotypes have emerged following the intermittent usage of synthetic nematicides. Contemporary research continues to focus on developing and/or repurposing small molecule inhibitors that are eco-friendly. Here, we describe the repurposing of the indole derivative, 5-iodoindole, as a nematicide for the root-knot nematode, Meloidogyne incognita. 5-Iodoindole effectively killed juveniles and freshly hatched juveniles by inducing multiple vacuole formation. Notably, at higher dosage (50 µg/mL), 5-iodoindole induced rapid juvenile death within 6 h. Microscopic analysis confirmed that the rapid death was due to the generation of reactive oxygen species (ROS). Computational docking attributed this ROS production to the antagonistic effect of 5-iodoindole on glutathione S-transferase (GST), which is known to play a critical role in the suppression of ROS in nematode models. Furthermore, 5-iodoindole also effectively reduced the gall formations and eggs masses of M. incognita on Solanum lycopersicum roots in pot experiments, and importantly it did not harm the physiological properties of the plant. Overall, the study provides valuable insights on the use of 5-iodoindole as an alternate measure to control root-knot nematodes. Overall, our findings suggest the efficacy of 5-iodoindole should be studied under field conditions.

Biological control of tomato bacterial wilt by oxydifficidin and difficidin-producing Bacillus methylotrophicus DR-08.

Bacillus methylotrophicus DR-08 exhibited strong antibacterial activity against Ralstonia solanacearum, a causal agent of tomato bacterial wilt. This study aimed to identify the antibacterial metabolites and evaluate the efficacy of the strain as a biocontrol agent for tomato bacterial wilt. A butanol extract of the DR-08 broth culture completely inhibited the growth of 14 phytopathogenic bacteria with minimum inhibitory concentration (MIC) values of 1.95-500 µg/mL. R. solanacearum was highly sensitive to the DR-08 extract, with an MIC value of 12.62 µg/mL. Two antibacterial metabolites were isolated and identified as difficidin and oxydifficidin derivatives through bioassay-guided fractionation and instrumental analyses. Both metabolite derivatives inhibited the growth of most of the phytopathogenic bacteria tested and the oxydifficidin derivatives generally presented a stronger antibacterial activity than the difficidin derivatives. A 30% suspension concentrate of DR-08, at a 500-fold dilution, effectively suppressed the development of tomato bacterial wilt in pot and field experiments. It also effectively reduced the development of bacterial leaf spot symptoms on peach and red pepper. The results of this study suggests that B. methylotrophicus DR-08 can be utilized as a biocontrol agent for various bacterial plant diseases including tomato bacterial wilt.

Structure and antifungal activity of pelgipeptins from Paenibacillus elgii against phytopathogenic fungi.

Paenibacillus elgii JCK1400 shows strong antifungal activity against various plant pathogenic fungi in vitro, but little is known about its mode of action. Four antifungal lipopeptides were isolated from P. elgii JCK1400 using bioassay-directed fractionation. Their chemical structures were determined to be pelgipeptins (PGPs) using electrospray ionization tandem mass spectrometry (ESI-MS/MS) and nuclear magnetic resonance (NMR) spectroscopy. Among the four lipopeptides, PGP-C showed the strongest mycelial growth inhibitory activity against several plant pathogenic fungi-with minimum inhibitory concentration (MIC) values ranging from 4 to 32 µg mL-1-followed by PGP-D, -A, and -B. In pot experiments, PGP-C also effectively suppressed the development of important fungal diseases in crops. In particular, PGP-C was effective in controlling tomato grey mold and wheat leaf rust, with control values of 91% and 73%, respectively, at a concentration of 125 µg mL-1. The fermentation broth of the antagonistic bacterium reduced the development of creeping bentgrass dollar spot and Kentucky bluegrass brown patch in a dose-dependent manner. However, our study on the effect of PGP-C on the fungal cell membrane-using microscopic observation with propidium iodide (PI) fluorescence-indicated that PGP-C does not target the fungal cell walls, but instead targets the cell membranes. This is the first study to report the in vitro and in vivo antifungal activity of PGP-C against various plant pathogenic fungi. Our results suggest that P. elgii JCK1400, which produces PGPs, could serve as a potential biocontrol agent for plant diseases caused by various fungi.

The Impact of a Dynamic Two-Step Solution Process on Film Formation of Cs0.15 (MA0.7 FA0.3 )0.85 PbI3 Perovskite and Solar Cell Performance.

This paper provides deep understanding of the formation mechanism of perovskite film fabricated by sequential solution-based methods. It compares two sequential spin-coating methods for Cs0.15 (MA0.7 FA0.3 )0.85 PbI3 perovskite. First is the "static process," with a stoppage between the two spin-coating steps (1st PbI2 -CsI-dimethyl sulfoxide (DMSO)-dimethylformamide (DMF) and 2nd methylammonium iodide (MAI)-formamidinium iodide (FAI)-isopropyl alcohol). Second is the "dynamic process," where the 2nd precursor is dispensed while the substrate is still spinning from the 1st step. For the first time, such a dynamic process is used for Cs0.15 (MA0.7 FA0.3 )0.85 PbI3 perovskite. Characterizations reveal improved film formation with the dynamic process due to the "retainment" of DMSO-complex necessary for the intermediate phase which i) promotes intercalation between precursors and ii) slows down perovskite crystallization for full conversion. The comparison on as-deposited perovskite before annealing indicates a more ordered film using this dynamic process. This results in a thicker, more uniform film with higher degree of preferred crystal orientation and higher carrier lifetime after annealing. Therefore, dynamic-processed devices present better performance repeatability, achieving a higher average efficiency of 17.0% compared to static ones (15.0%). The new insights provided by this work are important for perovskite solar cells processed sequentially as the process has greater flexibility in resolving solvent incompatibility, allowing separate optimizations and allowing different deposition methods.