Pigment Formation Research Articles

Melatonin Ameliorates Cadmium Toxicity in Tobacco Seedlings by Depriving Its Bioaccumulation, Enhancing Photosynthetic Activity and Antioxidant Gene Expression

Soil remediation for cadmium (Cd) toxicity is essential for successful tobacco cultivation and production. Melatonin application can relieve heavy metal stress and promote plant growth; however, it remains somewhat unclear whether melatonin supplementation can remediate the effects of Cd toxicity on the growth and development of tobacco seedlings. Herein, we evaluated the effect of soil-applied melatonin on Cd accumulation in tobacco seedlings, as well as the responses in growth, physiological and biochemical parameters, and the expression of stress-responsive genes. Our results demonstrate that melatonin application mitigated Cd stress in tobacco, and thus promoted plant growth. It increased root fresh weight, dry weight, shoot fresh weight and dry weight by 58.40%, 163.80%, 34.70% and 84.09%, respectively, compared to the control. Physiological analyses also showed significant differences in photosynthetic rate and pigment formation among the treatments, with the highest improvements recorded for melatonin application. In addition, melatonin application alleviated Cd-induced oxidative damage by reducing MDA content and enhancing the activities of enzymatic antioxidants (CAT, SOD, POD and APX) as well as non-enzymatic antioxidants (GSH and AsA). Moreover, confocal microscopic imaging confirmed the effectiveness of melatonin application in sustaining cell integrity under Cd stress. Scanning Electron Microscopy (SEM) observations illustrated the alleviative role of melatonin on stomata and ultrastructural features under Cd toxicity. The qRT-PCR analysis revealed that melatonin application upregulated the expression of photosynthetic and antioxidant-related genes, including SNtChl, q-NtCSD1, NtPsy2 and QntFSD1, in tobacco leaves. Together, our results suggest that soil-applied melatonin can promote tobacco tolerance to Cd stress by modulating morpho-physiological and biochemical changes, as well as the expression of relevant genes.

Laccase: A Green Biocatalyst Offers Immense Potential for Food Industrial and Biotechnological Applications.

Laccase, a multipurpose biocatalyst, is widely distributed across all kingdoms of life and plays a key role in essential biological processes such as lignin synthesis, degradation, and pigment formation. These functions are critical for fungal growth, plant-pathogen interactions, and maintenance of soil health. Due to its broad substrate specificity, multifunctional nature, and environmentally friendly characteristics, laccase is widely employed as a catalyst in various green chemistry initiatives. With its ability to oxidize a diverse range of phenolic and nonphenolic compounds, laccase has also been found to be useful as a food additive and for assessing food quality parameters. Ongoing advancements in research and technology are continually expanding the recognition of laccase's potential to address global environmental, health, and energy challenges. This review aims to provide critical insights into the applications of laccases in the biotechnology and food industry.

Additions/removals of seeds before fermentation alters Cabernet Sauvignon wine color via modulating anthocyanins and derivatives

The advance of the grape harvest caused by global warming has to some extent resulted in poor or unstable wine color, this study investigated the potential benefits of grape seeds on wine color to mitigate this negative effect. Anthocyanins and their derivatives, and chromatic characteristics were measured by targeted UHPLC-QqQ-MS/MS and CIELab methods, respectively. The addition of seeds was beneficial to the formation of polymeric pigments and flavanyl-pyranoanthocyanins, while decreased the accumulation of other yranoanthocyanins, monomeric anthocyanins, and acylated anthocyanins during fermentation. All pigment levels in seed wine can be better maintained over time. Compared with the removal of seeds during fermentation, the addition of seeds significantly enhanced the color intensity, bluish hues, and Chroma, while an appropriate amount of seeds favored wine red hue. PLSR showed that the addition/removal of seeds during fermentation could alter red wine chromatic characteristics via modulating anthocyanin profiles. These results can be used as reference to further explore the technological applications of seeds during fermentation for optimizing the potential benefits on red wine color.

Comprehensive analysis of Hibisci mutabilis Folium extract's mechanisms in alleviating UV-induced skin photoaging through enhanced network pharmacology and experimental validation.

Skin photoaging induced by ultraviolet A (UVA) and ultraviolet B (UVB) radiation manifests as skin roughness, desquamation, pigmentation, and wrinkle formation. Current treatments, such as sunscreen, hormones, and antioxidants, have limitations and side effects. Traditional Chinese Medicine Hibisci Mutabilis Folium (HMF), or Mu-Fu-Rong-Ye in Chinese name, refers to the dried leaves of the plant Hibiscus mutabilis L., which belongs to the Malvaceae family. It has been used traditionally to treat acute mastitis, parotitis, neurodermatitis, burns. The reported activities of HMF include anti-inflammatory and anti-oxidant effects. However, the therapeutic potential of HMF in preventing and treating UV-induced skin photoaging remains unexplored. This study aimed to investigate the protective effects of HMF extract (EHMF) against UV-induced skin photoaging and the underlying mechanisms of action, by using network pharmacology and experimental verification. Network pharmacology was employed to identify the effective chemical components of EHMF. Potential targets were identified via PPI network analysis. Representative compounds were characterized using UPLC-MS/MS. In vitro validation involved assessing HaCaT cell viability, observing live/dead cell staining through fluorescence microscopy, and measuring inflammatory factors using ELISA. For in vivo validation, a UV-induced skin photoaging mice model was treated transdermally with EHMF or Methotrexate daily for 7 days. Dermatitis severity, skin morphology, and collagen fiber pathology were evaluated. Inflammatory cytokine and protein expression in dorsal skin lesions was confirmed using Elisa Kits, Western blot and immunohistochemistry. A total of 22 active ingredients of EHMF were identified. GO enrichment and KEGG pathway analyses revealed a focus on inflammatory signaling pathways. In vitro experiments showed that EHMF significantly reduced UV-induced inflammatory factors in HaCaT cells and improved cell survival rates. In vivo, EHMF alleviated back skin lesions in UV-exposed mice, reducing epidermal and dermal thickening and pathological inflammatory cell infiltration. It also decreased abnormal MMP-9 expression and collagen fiber proliferation, along with levels of inflammatory factors like TNF-α, IL-6, IL-17, and EGFR. Western blot and immunohistochemistry results indicated that the over-activation of the AKT-STAT3 signaling pathway was inhibited. EHMF effectively reduced UV-induced skin damage, inflammation, and wrinkles, providing strong support for its clinical application as a dermatological agent.

TRANSPARENT TESTA 16 collaborates with the MYB-bHLH-WD40 transcriptional complex to produce brown fiber cotton.

Naturally colored cotton (NCC; Gossypium spp.) does not require additional chemical dyeing and is an environmentally friendly textile material with great research potential and applications. Our previous study using linkage and association mapping identified TRANSPARENT TESTA 2 (Gh_TT2) as acting on the proanthocyanin synthesis pathway. However, limited information is available about the genetic regulatory network of NCC. Here, we verified the effectiveness of Gh_TT2 and the roles of Gh_TT2 and red foliated mutant gene (Re) in pigment formation and deposition of brown fiber cotton (BFC). Variations in Gh_TT2 derived from interspecific hybridization between Gossypium barbadense acc. Pima 90-53 and Gossypium hirsutum acc. Handan208 resulted in gene expression differences, thereby causing phenotypic variation. Additionally, the MYB-bHLH-WD complex was found to be negatively modulated by TRANSPARENT TESTA 16/ARABIDOPSIS BSISTER (TT16/ABS). RNA-seq suggested that differential expression of homologous genes of key enzymes in the proanthocyanin synthesis pathway strongly contributes to the color rendering of natural dark brown and light brown cotton. Our study proposes a regulatory model in BFC, which will provide theoretical guidance for the genetic improvement of NCC.

Calcium oxide nanoparticles ameliorate cadmium toxicity in alfalfa seedlings by depriving its bioaccumulation, enhancing photosystem II functionality and antioxidant gene expression

Cadmium (Cd) is a highly toxic and carcinogenic pollutant that poses significant risks to living organisms and the environment, as it is absorbed by the plant roots and accumulates in different parts of crop during its production. A promising sustainable strategy to counteract these threats to use calcium oxide nanoparticles (CaO-NPs) as soil supplements in fodder crops. This approach has shown notable morpho-physiological and biochemical improvements under metal toxicity conditions. However, the specific mechanisms driving Cd tolerance, particularly at physio-biochemical level and antioxidant related genes expression in fodder crops including alfalfa remain unexplored. CaO-NPs supplementation can trigger various signaling pathways that lead to enhance the photosynthetic pigments formation, stomatal conductance, CO2 assimilation rate and quantum yield of photosystem II. In this study, we evaluated various doses of CaO-NPs (0, 25, 50, and 100 mg kg−1) for their efficacy in reducing Cd bioavailability and toxicity in alfalfa plants. Our results demonstrated that Ca2+ and Cd2+, which share the same ionic radius, compete for ion transport through channels. The small size and high availability of CaO-NPs facilitate their rapid translocation within plant tissues, reducing metal uptake by 61 % in shoots and 30 % in roots. Notably, application of CaO-NPs at 100 mg kg−1 significantly increased shoot length (44 %) and root lengths (35 %) as compared to Cd-treated control plants. The highest dose of CaO-NPs also improved photosynthetic efficiency and gas exchange attributes including (gs, Tr, Pn and Ci) by 66 %, 27 %, 33 % and Ci 21 %, respectively, compared with the Cd treated control. Moreover, CaO-NPs (at 100 mg kg−1) alleviated metal-induced oxidative stress by boosting antioxidant enzyme activity like SOD (25 %) POD (42 %), CAT (72 %) and APX (87 %) and diminishing reactive oxygen species (ROS) production when compared with sole Cd treatment. Scanning and transmission electron microscopy revealed that CaO-NPs positively impacted stomatal conductance and mitigated Cd toxicity in leaf ultrastructure. Additionally, the highest dose of CaO-NPs markedly upregulated the expression of antioxidant-related genes, MsCu/Zn SOD, MtPOD, MtCAT, and MtAPX in roots and shoots by 0.67 and 1.03 fold-change (FC), 0.61 and 0.53 FC, 0.54 and 0.88 FC, and 0.46 and 0.66 FC, respectively. In conclusion, CaO-NPs demonstrate significant potential for environmentally friendly mitigation of Cd stress in alfalfa by reducing its uptake, thereby supporting sustainable agriculture.

Congenital hypertrophy of the retinal pigment epithelium (clinical cases)

Congenital hypertrophy of the retinal pigment epithelium is a benign pigmented formation on the globe fundus, which has a characteristic appearance during ophthalmoscopy and is not prone to significant growth as well as malignancy. Nevertheless, one of the forms of congenital hypertrophy of the retinal pigment epithelium is associated with familial adenomatous polyposis, therefore, for timely follow-up examination of patients, it is necessary to know the differential diagnostic criteria of various forms of this disease. The article presents three clinical cases and as well as summarizes information about various forms of congenital hypertrophy of the retinal pigment epithelium.

MpDLDH gene is crucial for regulating growth and pigment biosynthesis through acetyl-CoA modulation in Monascus purpureus

Monascus spp. are traditional medicinal and edible filamentous fungi in Asian countries. Monascus pigments (MPs) are the most well-known beneficial secondary metabolites produced by Monascus and used as natural food colorants with a long history. However, the understanding of the MPs biosynthesis remains limited due to their complexity and diversity, and the known MPs biosynthetic gene cluster (BGC) is also incomplete. In this study, we re-predicted the MPs BGC based on the genome sequence of Monascus purpureus and found seven new genes that may be involved in MPs biosynthesis. Among them, MpDLDH encodes a putative dihydrolipoamide dehydrogenase, which is the E3 subunit of pyruvate dehydrogenase (PDH) multiunit complex for catalyzing pyruvate to acetyl-CoA. MpDLDH knockout significantly decreased the acetyl-CoA content, and resulted in small pale colony, dramatically reduced biomass, few conidia, and absence of cleistothecia. MpDLDH deletion seriously repressed MPs biosynthesis, but did not change its composition. In addition to the increase of intracellular MPs production and acetyl-CoA in the late growth stage on solid medium, MpDLDH overexpression had no obvious effect on the phenotypes. Since acetyl-CoA is the crucial substrate for both MPs biosynthesis and tricarboxylic acid cycle, it is believed that MpDLDH of MPs BGC plays a key role in regulating cell growth, development and pigment formation through participating in the assembly of PDH complex to modulate the production of acetyl-CoA. These findings may deepen our understanding of the regulatory mechanisms between MPs biosynthesis and cell growth in Monascus species.

TCONS_00025035-miR-101-UROS is potentially involved in the regulation of heme synthesis pathway and influences mantle melanin deposition by targeting porphyrin in Manila clam (Ruditapes philippinarum)

Shell color is an important economic trait and one of the target traits in breeding and production. Non-coding RNA (ncRNA) refers to RNA molecules transcribed from the genome and do not encoding proteins, which can regulate the expression of target genes after transcription and participate in the regulation of many important traits, such as the formation of shell color and body color. In this study, we detected the porphyrins in the shells of three Manila clams with different shell colors, explored the expression pattern and function of Uroporphyrinogen III synthetase (UROS) in the shell color pigmentation of Ruditapes philippinarum, and found that it might be involved in the synthesis of porphyrins and potentially in the synthesis of melanin. The results showed that the expression levels of heme synthesis-related genes such as UROS, Uroporphyrinogen decarboxylase (UROD), Ferrochelatase (FECH), Hephaestin (HEPH), and pigment synthesis-related genes (Peroxidasin PXDN) in the positive group were significantly reduced compared with the control group after injection of UROS dsRNA, indicating that UROS plays a crucial role in the porphyrin synthesis pathway. Additionally, transmission electron microscopy and melanin extraction experiments also proved that it might participate in the synthesis of melanin. We further explored and verified the relationship between TCONS_00025035-miR-101-UROS and identified the changes in the expression level of UROS through RNA interference and injection of miR-101 antagomir, respectively. Our results imply that miR-101 antagonists affect the expression of UROS. Furthermore, dual-luciferase reporter gene experiments confirmed the relationship between TCON_00025035, miR-101, and UROS. The regulatory relationship between TCONS_00025035 and miR-101 is negative, and the regulatory relationship between miR-101 and UROS is also negative. In summary, we verified the function of UROS through RNA interference, qPCR, in situ hybridization, and melanin content detection. We speculated that there was a negative relationship between miR-101 and UROS, and there was also a negative relationship between TCONS_00025035 and miR-101. TCONS_00025035 might regulate UROS through the regulation of miR-101, and UROS might also regulate other pigmentation-related genes and affect the formation of pigments, thereby influencing porphyrin and melanin formation in Manila clam.

The underlying molecular mechanisms of hormonal regulation of fruit color in fruit-bearing plants.

Fruit color is a key feature of fruit quality, primarily influenced by anthocyanin or carotenoid accumulation or chlorophyll degradation. Adapting the pigment content is crucial to improve the fruit's nutritional and commercial value. Genetic factors along with other environmental components (i.e., light, temperature, nutrition, etc.) regulate fruit coloration. The fruit coloration process is influenced by plant hormones, which alsoplay a vital role in various physiological and biochemical metabolic processes. Additionally, phytohormones play a role in the regulation of a highly conserved transcription factor complex, called MBW (MYB-bHLH-WD40). The MBW complex, which consists of myeloblastosis (MYB), basic helix-loop-helix (bHLH), and WD40 repeat (WDR) proteins, coordinates the expression of downstream structural genes associated with anthocyanin formation. In fruit production, the application of plant hormones may be important for promoting coloration. However, concerns such as improper concentration or application time must be addressed. This article explores the molecular processes underlying pigment formation and how they are influenced by various plant hormones. The ABA, jasmonate, and brassinosteroid increase anthocyanin and carotenoid formation, but ethylene, auxin, cytokinin, and gibberellin have positive as well as negative effects on anthocyanin formation. This article establishes the necessary groundwork for future studies into the molecular mechanisms of plant hormones regulating fruit color, ultimately aiding in their effective and scientific application towards fruit coloration.

Influence of selected phenolic acids on advanced lipid oxidation end products generation in model systems

The objective of this study was to assess the inhibitory impacts of chlorogenic acid (CGA), ferulic acid (FA), and vanillic acid (VA) on advanced lipid oxidation end products (ALEs) generation in bovine serum albumin-linoleic acid models. The addition of 160 μg/mL CGA and VA significantly blocked the formation of lipofuscin-like pigments (LFLP), reducing them by 22.141% ± 1.823% and 12.156% ± 1.296% respectively. It is worth noting that the best inhibition of LFLP by FA was observed at 40 μg/mL (13.105% ± 0.731%). Compared to the control (25.280 ± 1.580 mg/kg protein), thiobarbituric acid reactive substances values were the lowest in the samples containing 160 μg/mL CGA (2.107 ± 0.912 mg/kg protein), 40 μg/mL FA (6.847 ± 1.824 mg/kg protein), and 160 μg/mL VA (10.007 ± 0.912 mg/kg protein) (P < 0.05). These results suggest that CGA has a more potent inhibitory effect on ALEs formation compared to FA and VA. Therefore, CGA, FA, and VA can be considered as safe dietary phenolic acids for reducing ALEs formation.

DERMOSCOPIC FEATURES OF BASAL CELL CARCINOMA: SYSTEMATIC REVIEW

Abstract Background: Basal cell carcinoma is one of the most common cancers worldwide, it is a locally destructive and slowly spreading tumor arising from the epidermis or hair follicles, in which the peripheral cells are similar to the cells of the basal layer of the epidermis and which rarely metastasize. Despite its slow growth and low potential for metastasis, basal cell carcinoma (BCC) is one of the most pressing problems in dermato-oncology due to its high incidence rates, variety of clinical forms and frequent relapses after any treatment methods. Currently, the most accessible non-invasive method for examining skin tumors is dermatoscopy. Aim: The purpose of this review is to highlight the dermoscopic features encountered in basal cell carcinoma and to outline the role of dermoscopy for diagnosis this cancer. Methodology: The systematic review included articles from Google Scholar, Medline, Scopus, Web Of Sciences, PubMed was conducted. For the search, the following keywords were included: dermoscopy of pigmented form of basal cell carcinoma; dermoscopy of nonpigmented form of basal cell carcinoma. Results: Conducted a preliminary search and reviewed 62 titles and abstracts in this review and 27 full-text articles were selected of high methodological quality. Dermoscopy is a non-invasive technique, which allows early diagnosis based on the presence of typical vascular structures, pigmented structures, and ulceration and the absence of specific melanocytic structures. However, the use of dermoscopic technique is limited by the lack of prognostically significant dermatoscopic criteria confirming the different morphological nature of tumor growth. Conclusion: The current systematic review demonstrated, based on the observed features, this method allows for differential diagnosis of malignant and benign, as well as melanocytic and non-melanocytic skin neoplasms, as well as diagnosis of tumors at the earliest stage of their development.

Courtship performance, not ornamentation, predicts mating success in two sister-species of wolf spider with divergent phenotypes

Mate choice is posited to explain the evolution and maintenance of numerous secondary sexual traits, including ornamentation. This study explores the role of ornamentation in the mating success of two sister-species of wolf spider with divergent ornamentation. Mature male Schizocosa crassipalpata lack ornamentation while males of its closest living relative, S. bilineata, express both dark pigmentation and foreleg brushes. Following phenotypic manipulations of foreleg ornamentation – i.e. adding ornamentation in the form of dark pigment to non-ornamented males (S. crassipalpata, Aim 1) and removing ornamentation in varying degrees from highly ornamented males (S. bilineata, Aim 2 – shaving brushes; Aim 3 – shaving brushes and painting over dark pigment in vibration present/absent environments) – we found no evidence that ornamentation alone improves male mating success in either species, regardless of the vibratory signaling environment. In both S. bilineata experiments, however, higher courtship rates resulted in higher mating success, suggesting selection for courtship performance. Furthermore, females were more likely to turn, a presumed receptivity display, in response to males that courted at a higher rate. Also, similar to findings in another relative (S. stridulans), we found indications that ornamentation may function to ease a male’s reliance on courtship performance – i.e., at low courtship rates, only ornamented males can secure a mating. Our phenotypic manipulations also influenced courtship behavior in S. bilineata. Shaved males began courting earlier and courted more often over a longer time than intact males, yet ultimately acquired similar matings. This increased courtship effort likely compensated for reduced ornamentation. Finally, the vibratory environment appears crucial for female–male dialogue in S. bilineata, as vibratory absent environments resulted in increased female attacks and decreased male courtship rates. Together, our data suggest that S. crassipalpata females do not possess a preference for ornamentation and that S. bilineata females do not use ornamentation alone in mating decisions. Instead, our results are consistent with a hypothesis that ornamentation in Schizocosa evolved, and is likely maintained, due to its interactions with dynamic movement displays (i.e. leg movements), which can themselves be plastically altered based on the signaler’s phenotype as well as the signaling environment.

Endometabolic profiling of pigmented glacier ice algae: the impact of sample processing

IntroductionGlacier ice algae, mainly Ancylonema alaskanum and Ancylonema nordenskiöldi, bloom on Greenland Ice Sheet bare ice surfaces. They significantly decrease surface albedo due to their purple-brown pigmentation, thus increasing melt. Little is known about their metabolic adaptation and factors controlling algal growth dynamics and pigment formation. A challenge in obtaining such data is the necessity of melting samples, which delays preservation and introduces bias to metabolomic analysis. There is a need to evaluate the physiological response of algae to melting and establish consistent sample processing strategies for metabolomics of ice microbial communities.ObjectivesTo address the impact of sample melting procedure on metabolic characterization and establish a processing and analytical workflow for endometabolic profiling of glacier ice algae.MethodsWe employed untargeted, high-resolution mass spectrometry and tested the effect of sample melt temperature (10, 15, 20 °C) and processing delay (up to 49 h) on the metabolome and lipidome, and complemented this approach with cell counts (FlowCam), photophysiological analysis (PAM) and diversity characterization.Results and ConclusionWe putatively identified 804 metabolites, with glycerolipids, glycerophospholipids and fatty acyls being the most prominent superclasses (> 50% of identified metabolites). Among the polar metabolome, carbohydrates and amino acid-derivatives were the most abundant. We show that 8% of the metabolome is affected by melt duration, with a pronounced decrease in betaine membrane lipids and pigment precursors, and an increase in phospholipids. Controlled fast melting at 10 °C resulted in the highest consistency, and is our recommendation for future supraglacial metabolomics studies.

Study of Anti-Corosion Properties of Pigments Fe2O3-Al2O3-MgO Obtained by Coprecipitation

Promising pigments of the passivating type, in addition to phosphate ones, are other materials - oxyhydroxides, ferrites, molybdates, stanates, borates, tungstates, which are obtained using traditional technologies. condition. Researchers are becoming increasingly interested in the co-precipitation method, which makes it possible to vary the cationic and anionic composition of pigments and obtain nanodispersed products. In addition, developers of paints and varnishes are faced with the task of replacing toxic anti-corrosion chromium-, cadmium- and plumbum-containing pigments that are part of most modern inhibitory primers with pigments that are safe for human health. An alternative to such paint and varnish materials are oxide type fillers, which are anti-corrosion pigments, including oxyhydroxides, magnesium ferrites, cobalt aluminates, zinc ferrites, copper ferrites, magnesium aluminates, zinc aluminates, etc. The color of pigments and their anticorrosion properties depend on the chromophore ions included in the structure of the resulting compounds.Co-precipitation technology has a number of advantages over traditional ones and can radically reduce the cost of producing oxide materials. This process, based on the use of the internal chemical energy of the system, allows synthesis to be carried out at reduced temperatures, synthesis duration and energy costs. The simplicity of the equipment, the possibility of synthesizing a significant amount of the product of the desired phase and granulometric composition, and the environmental friendliness of the process also indicate the feasibility of using this method. Recently, attempts have been made to obtain pigments by co-precipitation, but no systematic studies have been carried out on the final products. The resulting products were in most cases poorly reproducible. In this regard, it becomes interesting to synthesize in a mode that would make it possible to obtain pigments with good color characteristics in a finely dispersed state, and eliminate the labor-intensive grinding stage, study the conditions for the formation of pigments with the structure of oxyhydroxides, the influence of their composition on color and anti-corrosion properties, study the patterns of formation of anti-corrosion properties, development of compositions for producing pigments using the co-precipitation method and subsequent heat treatment. Through experimental and theoretical studies, the influence of the nature of chromophore cations on the color tone, color purity, and anti-corrosion properties of pigments in the Fe-Al-Mg-O system has been established, which allows for the targeted synthesis of beige, red and yellow pigments with high anti-corrosion properties. The main technological properties of pigments are determined by the composition of metal-containing anions. The anti-corrosion properties of oxyhydroxide pigments are largely determined by the presence of hydroxide ions formed due to dissociation. The greatest effect is observed in the case of using metal compounds whose dissociation constants differ significantly. The protective effect is mainly determined by the slowdown of the anodic process. At the same time, anions containing aluminum atoms accelerate corrosion processes.

Clinical and Dermoscopic Diagnosis of Actinic Keratosis.

Actinic keratosis (AK) is one of the most frequent tumors of the skin; the diagnosis is basically clinical although in some cases it may be difficult to distinguish it from other keratinocytic or even melanocytic neoplasms when it presents in pigmented form. Over the years several clinical classifications and scores to objectify the burden of disease have been created. In this review the most frequent scores and classification systems are summarized along with dermoscopic criteria that allow diagnosis with greater sensitivity and specificity.

Studies of the Morphology of Hematite Synthesized from Waste Iron Sulfate.

Microwave-based reactions have gained traction in recent years due to their ability to enhance reaction rates and yield while reducing energy consumption. Also, according to the conception of 'waste to materials', various waste feeds are intensively sought to be tested. The experimental setup of this study involved varying pH levels, oxidation agents, and precipitation agents to optimize the synthesis process of iron red based on waste iron sulfate. The selection of oxidation and precipitation agents was found to significantly influence the pigment synthesis process. Various oxidizing agents, including hydrogen peroxide and atmospheric air, were evaluated for their effectiveness in promoting the oxidation of ferrous ions to ferric ions, essential for pigment formation. Additionally, different precipitation agents such as sodium hydroxide and ammonia solution were assessed for their ability to precipitate iron hydroxides and facilitate pigment particle formation. The characterization of synthesized pigments revealed promising results in terms of quality and color properties. Helium Ion Microscopy (HIM) analysis confirmed the formation of well-defined pigment particles with controlled morphology. X-ray diffraction (XRD) studies provided insights into the crystalline structure of the pigments, indicating the presence of characteristic iron oxide phases. By improving this technology, waste iron sulfate can be efficiently transformed into valuable iron pigments, offering a sustainable solution for waste management while meeting the growing demand for high-quality pigments.

Formation mechanism of blue pigment in boiled lotus rhizome discs: Insight into the chelation of polyphenols and iron

Boiled lotus rhizome discs (BLRDs), as common processed products of lotus rhizome, have gained increasing attention from consumers and food manufacturers. However, the blue pigment formed during boiling affects its appearance and reduces the appetite of BLRDs. In this study, the effects of polyphenols and iron contents on blue pigment formation in BLRDs in different regions and months were investigated. Results revealed that blue variation was more serious in March and April of the second year in Wuhan, and polyphenols and iron contents in these two months were significantly higher than those in other months. Then, UPLC and UV–Vis analysis showed that polyphenols causing the formation of blue pigment in BLRDs were L-dopa, gallocatechin, catechin, epigallocatechin, chlorogenic acid and epicatechin, among which L-dopa (52.450 mg/100 g in fresh lotus rhizome (FLR)) and gallocatechin (36.210 mg/100 g in FLR) possessed the greatest effect. Moreover, the ESI-Q-TOF-MS analysis of L-dopa-iron chelate and gallocatechin-iron chelate suggested that the blue pigment of BLRDs was mainly in the form of bis-complexes under boiling conditions. The study on formation mechanism of blue pigment in BLRDs can provide a reference for lotus rhizome processing.

Fruit ripening and postharvest changes in very early-harvested tomatoes.

It is well known that if a fruit is harvested extremely early its development and function are interrupted, and it may never attain full maturity and optimal quality. Reports revealing insights regarding the alterations of maturation, ripening and postharvest quality in very early picked fruits are rare. We examined the effects of early harvesting on tomatoes by characterizing different accessions at the molecular, physiological, and biochemical levels. We found that even very early-harvested fruits could achieve postharvest maturation and ripening though with some defects in pigment and cuticle formation, and seeds from very early-harvested fruits could still germinate and develop as normal and healthy plants. One critical regulator of tomato cuticle integrity, SlCER1-2, was shown to contribute to cuticle defects in very early-harvested fruits. Very early fruit harvest still allowing ripening and seed development indicate that the genetic and physiological programs of later maturation and ripening are set into motion early in fruit development and are not dependent on complete fruit expansion nor attachment to the plant.

Deletion of the polyketide synthase-encoding gene pks1 prevents melanization in the extremophilic fungus Cryomyces antarcticus.

Cryomyces antarcticus, a melanized cryptoendolithic fungus endemic to Antarctica, can tolerate environmental conditions as severe as those in space. Particularly, its ability to withstand ionizing radiation has been attributed to the presence of thick and highly melanized cell walls, which-according to a previous investigation-may contain both 1,8-dihydroxynaphthalene (DHN) and L-3,4 dihydroxyphenylalanine (L-DOPA) melanin. The genes putatively involved in the synthesis of DHN melanin were identified in the genome of C. antarcticus. Most important is capks1 encoding a non-reducing polyketide synthase (PKS) and being the ortholog of the functionally characterized kppks1 from the rock-inhabiting fungus Knufia petricola. The co-expression of CaPKS1 or KpPKS1 with a 4'-phosphopantetheinyl transferase in Saccharomyces cerevisiae resulted in the formation of a yellowish pigment, suggesting that CaPKS1 is the enzyme providing the precursor for DHN melanin. To dissect the composition and function of the melanin layer in the outer cell wall of C. antarcticus, non-melanized mutants were generated by CRISPR/Cas9-mediated genome editing. Notwithstanding its slow growth (up to months), three independent non-melanized Δcapks1 mutants were obtained. The mutants exhibited growth similar to the wild type and a light pinkish pigmentation, which is presumably due to carotenoids. Interestingly, visible light had an adverse effect on growth of both melanized wild-type and non-melanized Δcapks1 strains. Further evidence that light can pass the melanized cell walls derives from a mutant expressing a H2B-GFP fusion protein, which can be detected by fluorescence microscopy. In conclusion, the study reports on the first genetic manipulation of C. antarcticus, resulting in non-melanized mutants and demonstrating that the melanin is rather of the DHN type. These mutants will allow to elucidate the relevance of melanization for surviving extreme conditions found in the natural habitat as well as in space.