Evaluation and management of benign tumors of the eye and eyelid.

Benign tumors of the eye and eyelid are common in children and adults, and they rarely undergo malignant transformation. Their workup and management have evolved over the years with increasing advancements in surgical and laser therapies. This contribution focuses on describing the following benign eye and eyelid tumors and their diagnostic and treatment approaches: congenital and acquired melanocytic nevi; nevus of Ota (Hori nevus); conjunctival papilloma; seborrheic keratosis; epidermoid cyst; dermoid cyst; milium; xanthelasma; hemangioma (cherry angioma and pyogenic granuloma); neurofibroma; neurilemmoma (schwannoma); and fibroepithelial polyp. Surgical removal is the primary treatment approach for many of these benign tumors. With advancements in laser technologies, there are now several laser types that can be used in the treatment of these benign eye and eyelid tumors. Other treatment modalities include cryosurgery, electrosurgery, and topical or intralesional medications. We hope this review will provide a reference to dermatologists and ophthalmologists in their approach to evaluation and management of benign eye and eyelid tumors.

In Silico, In Vitro, and In Vivo Evaluation of Caffeine-Coated Nanoparticles as a Promising Therapeutic Avenue for AML through NF-Kappa B and TRAIL Pathways Modulation.

BACKGROUND: Advancements in nanoscience have led to a profound paradigm shift in the therapeutic applications of medicinally important natural drugs. The goal of this research is to develop a nano-natural product for efficient cancer treatment. METHODS AND RESULTS: For this purpose, mesoporous silica nanoparticles (MSNPs) were formulated, characterized, and loaded with caffeine to develop a targeted drug delivery system, i.e., caffeine-coated nanoparticles (CcNPs). In silico docking studies were conducted to examine the binding efficiency of the CcNPs with different apoptotic targets followed by in vitro and in vivo bioassays in respective animal models. Caffeine, administered both as a free drug and in nanomedicine form, along with doxorubicin, was delivered intravenously to a benzene-induced AML model. The anti-leukemic potential was assessed through hematological profiling, enzymatic biomarker analysis, and RT-PCR examination of genetic alterations in leukemia markers. Docking studies show strong inter-molecular interactions between CcNPs and apoptotic markers. In vitro analysis exhibits statistically significant antioxidant activity, whereas in vivo analysis exhibits normalization of the genetic expression of leukemia biomarkers STMN1 and S1009A, accompanied by the restoration of the hematological and morphological traits of leukemic blood cells in nanomedicine-treated rats. Likewise, a substantial improvement in hepatic and renal biomarkers is also observed. In addition to these findings, the nanomedicine successfully normalizes the elevated expression of GAPDH and mTOR induced by exposure to benzene. Further, the nanomedicine downregulates pro-survival components of the NF-kappa B pathway and upregulated P53 expression. Additionally, in the TRAIL pathway, it enhances the expression of pro-apoptotic players TRAIL and DR5 and downregulates the anti-apoptotic protein cFLIP. CONCLUSIONS: Our data suggest that MSNPs loaded with caffeine, i.e., CcNP/nanomedicine, can potentially inhibit transformed cell proliferation and induce pro-apoptotic TRAIL machinery to counter benzene-induced leukemia. These results render our nanomedicine as a potentially excellent therapeutic agent against AML.

Attenuating Colorectal Cancer Using Nine Cultivars of Australian Lupin Seeds: Apoptosis Induction Triggered by Mitochondrial Reactive Oxygen Species Generation and Caspases-3/7 Activation.

As Australian lupin cultivars are rich sources of polyphenols, dietary fibers, high-quality proteins, and abundant bioactive compounds with significant antioxidant, antidiabetic, and anticancer activities, this research work is aimed at investigating the colon cancer alleviation activity of nine cultivars of lupin seeds on HCT116 and HT29 colon carcinoma cell lines through anti-proliferation assay, measurement of apoptosis, and identification of the mechanism of apoptosis. Nine cultivars were pre-screened for anti-proliferation of HCT116 and HT29 cells along with consideration of the impact of heat processing on cancer cell viability. Mandelup and Jurien showed significant inhibition of HCT116 cells, whereas the highest inhibition of HT29 cell proliferation was attained by Jurien and Mandelup. Processing decreased the anti-proliferation activity drastically. Lupin cultivars Mandelup, Barlock, and Jurien (dose: 300 µg/mL) induced early and late apoptosis of colon cancer cells in Annexin V-FITC assay. The mechanism of apoptosis was explored, which involves boosting of caspases-3/7 activation and intracellular reactive oxygen species (ROS) generation in HCT116 cells (Mandelup and Barlock) and HT29 cells (Jurien and Mandelup). Thus, the findings showed that lupin cultivars arrest cell cycles by inducing apoptosis of colorectal carcinoma cells triggered by elevated ROS generation and caspases-3/7 activation.

Evaluating the Impact of Formal Dermatopathology Fellowship Training on Practice Patterns and Characteristics Among Dermatologists Submitting Claims for Medicare Pathology Examinations in 2017.

Objective: Dermatopathology training is incorporated into dermatology residency programs, yet some individuals choose to pursue additional fellowship training in dermatopathology. We sought to characterize the impact of dermatopathology training on practice patterns of dermatologists performing pathology exams in the Medicare population. Methods: We conducted a cross-sectional review of the 2017 Medicare Public Use File to identify all residency-trained dermatologists performing microscopic pathology exams in 2017. Formal dermatopathology fellowship training was identified through the American Board of Medical Specialties website. Results: There were 2,150 dermatologists performing pathology examinations in 2017; of these, 592 (27.5%) had formal dermatopathology fellowship training. Fellowship training was associated with a higher mean annual pathology exam volume. Those without fellowship training were more likely to practice in the West, in non-academic settings, and in non-metropolitan counties. Limitations: Residency-trained pathologists are not included in the sample. Additionally, some dermatopathology labs may submit claims as an entire organization, rather than at the level of each physician. Conclusion: Fellowship-trained dermatopathologists perform pathology exams at a higher rate than their non-fellowship-trained colleagues and are concentrated in academic practice settings. The findings support the important role of fellowship-trained dermatopathologists in evaluating a wide array of skin pathologies.

Gentians, natural remedies for future of visceral pain control; an ethnopharmacological review with an in silico approach.

Different gentian preparations are used as traditional remedies for internal pain control in: Persian traditional medicine (PTM), Chinese traditional medicine (CTM) and Ancient Greek medicine (AGM) from the time of the Roman Empire. Objective: To present a survey of the ethnopharmacological applications of gentians recorded as being used in Eastern and Western traditional medical systems (PTM, CTM and AGM) and their pharmacological effects, chemical composition as well as an in silico investigation of the possible active component/s for the alleviation of internal pain via molecular docking studies. Major traditional medicine literature (PTM, CTM and AGM, 50 AD- 1770) and ethnobotanical studies for the application of gentians were reviewed. Nine European species representing 5 of the 13 sections currently attributed to Gentiana were selected. Chemical compounds and pharmacological activity data of these species were gathered from different databases including Google Scholar, PubChem, PubMed and Web of Science (between 1972 and 2020). The possible active constituents of gentians on visceral pain receptors were investigated, in silico. In all investigated literature, traditional uses of gentian were indicated to have anti-nociceptive effects on visceral pain and possess diuretic action. According to our computational study, acylated flavonoid glycosides, viz. trans-feruloyl-2"-isovitexin (33), trans-feruloyl-2"-isovitexin-4'-O-ß-D-glucoside (34), iso-orientin-4'-O-glucoside (38), trans-caffeoyl-2"-iso-orientin-4'-O-ß-D-glucoside (39), iso-orientin-2"-O-ß-D-glucoside (40) and isoscoparin (41), might be responsible for visceral pain reduction by interacting with the purinergic receptor (P2X3) and vanilloid receptor 1 (TrpV1). This finding shows a good correlation with different traditional gentian uses in Persian, Chinese and European ethnomedicine for visceral pain control.

Investigations of AGEs' inhibitory and nephroprotective potential of ursolic acid towards reduction of diabetic complications.

In diabetes, interactions between AGEs (advanced glycation end products) and RAGEs (receptors of AGEs) are responsible for chronic complications and the current work reports the potential of ursolic acid as a RAGE inhibitor. The three-dimensional crystal structure of RAGE was first docked with target molecules by 'AutodockVina' using GROMOS 96 4381 parameters. Druggability and pharmacokinetic properties were calculated from the SwissADME server. In vitro bovine serum albumin (BSA)-glucose fluorescence and BSA-methylglyoxal fluorescence assays were also performed. Finally, alloxan-induced diabetic mice were administered ursolic acid and metformin standards (at 1, 50, 100 mg/kg) for 50 days. Blood glucose levels, several blood parameters, blood lipid profiles, supernatants of homogenized kidney and plasma of mice were examined. In the computational study, ursolic acid showed greater binding affinity (-7.5 kcal/mol) for RAGE with an ADMET profiles and lead-likeness compared to metformin as a standard antidiabetic. In the in vitro fluorescence assays, the IC50 value for ursolic acid was much less than that of metformin standard. During the in vivo study, significant reduction in the levels of blood glucose, HbA1C (glycated hemoglobin), creatinine, uric acid, BUN (blood urea nitrogen), AST (aspartate aminotransferase), ALT (alanine aminotransferase), ALP (alkaline phosphatase) were observed in the ursolic acid and metformin-treated mice. Substantial inhibition of AGEs' formation in the plasma and kidney were also detected. Finally, the histopathological examinations of the kidney revealed reversal of cellular necrosis. Hence, ursolic acid is proved to be a potent AGE inhibitory agent in managing the diabetic complications.

Enhanced periphyton biodegradation of endocrine disrupting hormones and microplastic: Intrinsic reaction mechanism, influential humic acid and microbial community structure elucidation.

Endocrine-disrupting compounds (EDCs), as well as microplastics, have drawn global attention due to their presence in the aquatic ecosystem and persistence in wastewater treatment plants (WWTPs). In the present study, for simultaneous bio-removal of two EDCs, 17α-ethinylestradiol (EE2), bisphenol A (BPA), and a microplastic, polypropylene (PP) four kinds of periphytic biofilms were employed. Additionally, the effect of humic acid (HA) on the removal efficacy of these biofilms was evaluated. It was observed that EE2 and BPA (0.2 mg L-1 each) were completely (∼100%) removed within 36 days of treatment; and the biodegradation of EE2, BPA, and PP was significantly enhanced in the presence of HA. Biodegradation of EE2 and BPA was evaluated through Ultra-high performance liquid chromatography (UHPLC), and Gas chromatography coupled with tandem mass spectrometry (GC-MS/MS) was used to determine the mechanism of degradation. Gel permeation chromatography (GPC) and SEM had validated the biodegradation of PP (5.2-14.7%). MiSeqsequencing showed that the community structure of natural biofilm changed after the addition of HA, as well as after the addition of EDCs and PP. This change in community structure might be a key factor regarding variable biodegradation percentages. The present study revealed the potential of periphytic biofilms for the simultaneous removal of pollutants of different chemical natures, thus provides a promising new method for wastewater treatment applications.

A novel biotechnology based on periphytic biofilms with N-acyl-homoserine-lactones stimulation and lanthanum loading for phosphorus recovery.

This study presents an approach for developing periphytic biofilm with N-acyl-homoserine-lactones (AHLs) stimulation and lanthanum (La, a rare earth element) loading, to achieve highly efficient and stable phosphorus (P) recovery from wastewater. AHLs stimulated biofilm growth and formation, also improved stable P entrapment by enhancing extracellular polymeric substance (EPS) production and optimizing P-entrapment bacterial communities. Periphytic biofilms loading La is based on ligand exchanges, and La loading achieved initial rapid P entrapment by surface adsorption. The combination of AHLs stimulation and La loading achieved 99.0% P entrapment. Interestingly, the enhanced EPS production stimulated by AHLs protected biofilms against La. Moreover, a method for P and La separately recovery from biofilms was developed, achieving 89-96% of P and 88-93% of La recovery. This study offers a promising biotechnology to reuse La from La-rich wastewater and recover P by biofilm doped with La, which results in a win-win situation for resource sustainability.

Melanoma: An update on systemic therapies.

Despite advances in early detection as described in part 1 of this continuing medical education series, melanoma continues to be a large contributor to cutaneous cancer-related mortality. In a subset of patients with unresectable or metastatic disease, surgical clearance is often not possible; therefore, systemic and local therapies are considered. The second article in this series provides dermatologists with an up-to-date working knowledge of the treatment options that may be prescribed by oncologists for patients with unresectable stage III, stage IV, and recurrent melanoma.

Melanoma: How and when to consider clinical diagnostic technologies.

In response to rising rates of melanoma worldwide, novel noninvasive melanoma detection techniques are emerging to facilitate the early detection of melanoma and decrease unnecessary biopsies of benign pigmented lesions. Because they often report similar study findings, it may be difficult to determine how best to incorporate these technologies into clinical practice based on their supporting studies alone. The first article in this continuing medical education series provides practical advice on how and when to use various noninvasive melanoma detection techniques in clinical practice.

Vitamin D: Skin, sunshine, and beyond.

Vitamin D is a steroid hormone of importance to the field of dermatology. Skin is unique in that it is the site of vitamin D synthesis upon sun exposure and a target organ for its activity. We explore the physiology and metabolic mechanism of action of vitamin D, as well as its effects on the skin. We also discuss the current evidence of the efficacy and safety of oral and topical vitamin D analogues on skin conditions such as psoriasis, atopic dermatitis, vitiligo, sunburn, actinic keratosis, and fibrosing skin disorders. Based on currently available scientific evidence, the National Academy of Medicine's recommended dietary allowance for vitamin D ranges from 400 IU to 800 IU daily based on age categories.

Comparative assessment of nutritional, thermal, rheological and functional properties of nine Australian lupin cultivars.

Lupin holds an important place among the legumes and the utilization of lupin as a dietary protein source is an excellent environmentally friendly alternative to animal-based products for human nutrition. In the present study, nutritional, thermal, rheological and functional properties of nine Australian lupin cultivars have been assayed in order to find the most valuable one, both nutritiously and industrially. The set comprised six Lupinus angustifolius L. viz., Barlock, Gunyadi, Jenabillup, Jindalee, Jurien, Mandelup and three Lupinus albus L. viz., Luxor, Rosetta, WK388 cultivars. The tests included analysis of color, macronutrient and micronutrient composition, pasting, textural and thermal properties, electrophoretic profile of protein isolates, swelling power, water and oil absorption capacity, emulsifying capacity, emulsion stability, creaming stability, foaming capacity and stability of the cultivars' dehulled seed flours. The results indicated substantial variation in macro and micro-nutritional value as well as satisfactory swelling ability, solubility, surface hydrophobicity, foaming ability, emulsifying capacity and gelation property of lupin flours. Superior nutritional, thermal, rheological and functional potential was demonstrated by the L. albus cultivars compared to the L. angustifolius cultivars with the exception of Mandelup.

Interactions between periphytic biofilms and dissolved organic matter at soil-water interface and the consequent effects on soil phosphorus fraction changes.

Dissolved organic matter (DOM) plays vital roles in carbon and other nutrient transformation at soil-water interfaces (SWI) in paddy fields. It is associated with the growth and withering of periphytic biofilms. However, the interactions between DOM and periphytic biofilms remain largely unknown. In this study, a microcosm experiment with different initial DOM contents elucidated that the biomass, and biomass nitrogen and phosphorus contents were greatly influenced by humic-like substances (C2 and C3), while the growth of periphytic biofilms increased the contents of humic-like (C1 and C2) and tryptophan-like substances (C5) in soil. Moreover, the decomposition of periphytic biofilms significantly increased soil pH, DOM, C2, C3 and C5 contents, but caused decrease in Eh, with consequent reduce in water soluble phosphorus (WSP) and release of algal available phosphorus (AAP). Results from this study revealed how DOM interacts with periphytic biofilms and the consequent effects on changes of bioactive phosphorus fractions, and provide practical information for designing periphytic biofilm based biofertilizer from the perspective of soil DOM.

Evidence concerning the accusation that melanoma is overdiagnosed.

BACKGROUND: Melanoma is one of the most commonly diagnosed malignancies in the United States and is responsible for the majority of deaths from skin cancer. OBJECTIVE: Since the 1970s, the incidence of melanoma has risen appreciably while melanoma-specific mortality has remained stable. This has raised a debate about potential overdiagnosis of melanoma. Herein, we review temporal trends in melanoma incidence and mortality and explore factors that may contribute to observed trends, including an aging population in the United States, ultraviolet exposure, increased numbers of biopsies by dermatologists and physician extenders, skin cancer screenings, histopathology criteria, and historic underdiagnosis. Additionally, we discuss melanoma overdiagnosis and the extent to which it may contribute to current trends. METHODS: The literature was reviewed. RESULTS: Several factors may contribute to an increased incidence of melanoma, including an aging population, ultraviolet exposure, increased skin biopsies, skin cancer screenings, histopathologic criteria, historic underdiagnosis, and current overdiagnosis. LIMITATIONS: Further studies are required to determine exactly which tumors are being overdiagnosed, and how to improve patient outcomes with adjustment to physician's practice. CONCLUSION: The rise in the incidence of melanoma observed since the 1970s is likely multifactorial.

Identification of bioactive metabolites and evaluation of in vitro anti-inflammatory and in vivo antinociceptive and antiarthritic activities of endophyte fungi isolated from Elaeocarpus floribundus blume.

ETHNOPHARMACOLOGICAL RELEVANCE: Functional disability associated with rheumatoid arthritis (RA), a chronic inflammatory autoimmune disease is a challenging concern in healthcare systems. Along with environmental factors and epigenetic disorders, multiple pathways are reported as prominent mechanism for the progression of RA symptoms including; pain, swelling and stiffness of joints. Elaeocarpus floribundus Blume has been used as a folklore medicine for RA from ancient times. This plant harbours a suite of endophytic fungi that produce a range of metabolites of potential interest. Thus, for the establishment of a scientific basis for this folklore use, it is essential to find out the involvement, if any, of the endophytic fungi living in this plant and the metabolites they elaborate, for the management of RA. AIM OF THE STUDY: This study was designed to isolate, identify and evaluate the in vitro anti-inflammatory and in vivo antinociceptive and antiarthritic activities of the compounds produced by the endophytic fungi living in different parts of Elaeocarpus floribundus Blume. MATERIALS AND METHODS: Endophytic fungi from different parts of the plant were isolated and cultured for the production of secondary metabolites. Chromatographically fractionated fungal extracts were assessed for anti-inflammatory and antinociceptive activities. For the evaluation of anti-inflammatory activity, in vitro cyclooxygenase (COX1/COX2) and 5-lipoxygenase (5-LOX) inhibitory assays were performed. For the evaluation of in vivo antinociceptive activity, hot plate acetic acid induced writhing, and formalin induced paw licking methods were adopted, whereas complete Freund's adjuvant (CFA) induced poly-arthritic method was adopted for the evaluation of antiarthritic activity. The most effective fraction was analyzed by liquid chromatography-mass spectroscopy (LC-MS) in search of the bioactive extracellular metabolites. RESULTS: Five endophytic fungi viz. Aspergillus fumigatus, Aspergillus niger, Rhizoctonia oryzae, Rhizopus oryzae, and Syncephalastrum racemosum were isolated. COX1/COX2 and 5-LOX inhibitory assays state that the Aspergillus niger fraction possesses the greatest activity against these enzymes of inflammatory process. In vivo antinociceptive showed significant (***P<0.001) reduction of pain in a dose dependent manner. As well, significant (***P<0.001) reduction of paw volume was observed in CFA induce poly-arthritic test. LC/MS analysis of the Aspergillus niger fraction revealed the presence of bioactive compounds including tensyuic acid, hexylitaconic acid, chlorogenic acid, nigragillin, TMC-256C1, asnipyrone B, asperenone, fumaric acid and fusarubin, all having reported pharmacological activities. CONCLUSION: The present study demonstrates that secondary metabolites produced by endophytic fungi living in various parts of Elaeocarpus floribundus Blume had potential to relief pain and inflammation. The endophytes were found to contain multiple biomolecules effective in rheumatoid arthritis. These findings provide a rationale for the folklore use of the plant in the management of rheumatoid arthritis.

Antidiabetic profiling, cytotoxicity and acute toxicity evaluation of aerial parts of Phragmites karka (Retz.).

ETHNOPHARMACOLOGICAL RELEVANCE: Phragmites karka (Retz.) of family Poaceae is a pristine tropical plant that is well known to the local healers for ailments of diabetes, fever, diarrhea and CNS depression but lacks the scientific evidence behind its traditional usage. Hence, we explicated this plant to find the scientific basis of its traditional utilization. AIM OF THE STUDY: The current study aims to find out the antidiabetic potential, toxicity after oral administration and in vitro cytotoxic activity of aerial parts of the plant on HeLa cells. METHODS: The plant was extracted with methanol by maceration and the crude extract was then subjected to solvent partitioning with modified Kupchan method for preparing several fractions. Phytochemical screening and total phenolic content of the plant was first determined through established procedures. Acute toxicity of the plant was studied by orally administering a single high dose (5000 mg/kg) of drug. Cytotoxicity of the methanolic plant extract was determined by measuring the percentage of cell viability on human cervical cancer cell lines, HeLa. In vitro antidiabetic activity was determined through iodine starch and DNSA (3,5-dinitrosalicylic acid) method of α-amylase inhibition. Finally, in vivo oral glucose tolerance test and alloxan induced antidiabetic activity test was performed at 150 and 300 mg/kg body weight doses of plant extract to confirm the in vivo antidiabetic activity. RESULTS: No mortality was demonstrated by Phragmites karka in the acute toxicity test. However, signs of cellular toxicity was observed and histopathological studies on major organs exhibited necrosis in liver and kidney. In vitro cytotoxicity assay revealed the death of HeLa cells by DCM (dichloromethane) and n-hexane fractions of plant extract at 100 and 10 µg/mL concentrations. The IC50 value of the fractions were later evaluated by MTT assay (316.1 and 96.7 µg/mL for n-hexane and DCM fractions, respectively). In the iodine starch and DNSA method of α-amylase enzyme inhibitory activity test, substantial inhibition of enzyme was observed with the IC50 values of 2.05 and 2.08 mg/mL, respectively. In the in vivo antidiabetic activity test, considerable reduction in blood glucose level of diabetic mice was detected in both oral glucose tolerance test and alloxan induced antidiabetic activity test. In addition, the microscopic examination of pancreas showed noticeable recovery of pancreatic ß cells and the blood lipid profile analysis represented a significant (p < 0.05) reduction of total cholesterol, LDL (low density lipoprotein) and triglyceride level in plant extract treated mice. CONCLUSION: Results of this study reveals that the Phragmites karka extract is toxic at cellular level after oral administration and cytotoxic when tested on HeLa cells. The plant also evidenced hypoglycemic property, possibly through the inhibition of α-amylase enzyme and recovered the pancreatic beta cells along with the improvement of lipid profile of diabetic mice. However, robust studies on this plant is required to isolate the bioactive compounds, elucidate structures and evaluate their mechanism of actions in support of our findings. CLASSIFICATION: Toxicology and Safety, Quality Traditional Medicine.

Functional sustainability of nutrient accumulation by periphytic biofilm under temperature fluctuations.

Temperature can fluctuate widely between different seasons, and this may greatly impact many biological processes. However, little is known about its influence on the functioning of benthic microbial communities. Here we investigated the nutrient accumulation capability of periphytic biofilm under temperature fluctuations (17-35°C). Periphytic biofilm maintained the same nutrient accumulation capacity after experiencing the 'warming-hot-cooling' temperature fluctuation under both lab and outdoor conditions as those without temperature disturbance. In response to temperature increase, both community composition and species richness changed greatly and the increase in biodiversity was identified as being the underlying mechanism boosting the sustainable function in nutrient accumulation, indicating zero net effects of community changes. These findings provide insights into the underlying mechanisms of how benthic microbial communities adapt to temperature fluctuations to maintain nutrient accumulation capacity and elucidate that periphytic biofilm plays important roles in influencing nutrient cycling in aquatic ecosystems under temperature changes such as seasonal fluctuations.

Electron transport, light energy conversion and proteomic responses of periphyton in photosynthesis under exposure to AgNPs.

Silver nanoparticles (AgNPs) including a mix of intact nanoparticle-Ag and 'free' Ag+ pose high risks to benthic photoautotrophs, but the photosynthetic responses of benthic microbial aggregates to AgNPs still remain largely unknown. Here, periphyton and Nostoc were used to elucidate the photosynthetic responses of benthic algae community to intact nanoparticle-Ag and Ag+. During exposure, both intact nanoparticle-Ag and Ag+ imposed negative effects on photosynthesis of benthic algae, but via different pathways. Specifically, Ag+ had stronger effects on damaging the oxygen-evolving complex (OEC) and thylakoid membrane than intact nanoparticle-Ag. Ag+ also suppressed electron transfer from QA to QB, and impaired phycobilisome. Intact nanoparticle-Ag inhibited the expression of PsbD and PsbL in PSII, but prompted the ROS scavenging capacity. In response to the stress of AgNPs, the benthic algae increased light energy absorption to maintain the electron transport efficiency, and up-regulated PSI reaction center protein (PsaA) to compensate the degraded PSII. These results reveal how intact nanoparticle-Ag and Ag+ influence electron transport, energy conversion and protein expression in the photosynthesis of periphyton, and provide deep insights into the responses of benthic photoautotrophs to different components of AgNPs.

Multifunctional Periphytic Biofilms: Polyethylene Degradation and Cd2+ and Pb2+ Bioremediation under High Methane Scenario.

Priority pollutants such as polyethylene (PE) microplastic, lead (Pb2+), and cadmium (Cd2+) have attracted the interest of environmentalists due to their ubiquitous nature and toxicity to all forms of life. In this study, periphytic biofilms (epiphyton and epixylon) were used to bioremediate heavy metals (HMs) and to biodegrade PE under high (120,000 ppm) methane (CH4) doses. Both periphytic biofilms were actively involved in methane oxidation, HMs accumulation and PE degradation. Epiphyton and epixylon both completely removed Pb2+ and Cd2+ at concentrations of 2 mg L-1 and 50 mg L-1, respectively, but only partially removed these HMs at a relatively higher concentration (100 mg L-1). Treatment containing 12% 13CH4 proved to be most effective for biodegradation of PE. A synergistic effect of HMs and PE drastically changed microbial biota and methanotrophic communities. High-throughput 16S rRNA gene sequencing revealed that Cyanobacteria was the most abundant class, followed by Gammaproteobacteria and Alphaproteobacteria in all high-methane-dose treatments. DNA stable-isotope probing was used to label 13C in a methanotrophic community. A biomarker for methane-oxidizing bacteria, pmoA gene sequence of a 13C-labeled fraction, revealed that Methylobacter was most abundant in all high-methane-dose treatments compared to near atmospheric methane (NAM) treatment, followed by Methylococcus. Methylomonas, Methylocystis, Methylosinus, and Methylocella were also found to be increased by high doses of methane compared to NAM treatment. Overall, Cd+2 had a more determinantal effect on methanotrophic activity than Pb2+. Epiphyton proved to be more effective than epixylon in HMs removal and PE biodegradation. The findings proved that both epiphyton and epixylon can be used to bioremediate HMs and biodegrade PE as an efficient ecofriendly technique under high methane concentrations.