Break oily water emulsion during petroleum enhancing production processes using green approach for the synthesis of SnCuO@FeO nanocomposite from microorganisms.

The aim of this work was to synthesize a green nanoparticle SnCuO@FeO nanocomposite core-shell to break oily water emulsions during petroleum-enhancing production processes as an alternative to chemical and physical processes. In this study, eight bacterial isolates (MHB1-MHB8) have been isolated from tree leaves, giant reeds, and soil samples. The investigation involved testing bacterial isolates for their ability to make FeO nanoparticles and choosing the best producers. The selected isolate (MHB5) was identified by amplification and sequencing of the 16S rRNA gene as Bacillus paramycoides strain OQ878685. MHB5 produced the FeO nanoparticles with the smallest particle size (78.7 nm) using DLS. XRD, FTIR, and TEM were used to characterize the biosynthesized nanoparticles. The jar experiment used SnCuO@FeO with different ratios of Sn to CuO (1:1, 2:1, and 3:1) to study the effect of oil concentration, retention time, and temperature. The most effective performance was observed with a 1:1 ratio of Sn to CuO, achieving an 85% separation efficiency at a concentration of 5 mg/L, for a duration of 5 min, and at a temperature of 373 K. Analysis using kinetic models indicates that the adsorption process can be accurately described by both the pseudo-first-order and pseudo-second-order models. This suggests that the adsorption mechanism likely involves a combination of film diffusion and intraparticle diffusion. Regarding the adsorption isotherm, the Langmuir model provides a strong fit for the data, while the D-R model indicates that physical interactions primarily govern the adsorption mechanism. Thermodynamic analysis reveals a ∆H value of 18.62 kJ/mol, indicating an exothermic adsorption process. This suggests that the adsorption is a favorable process, as energy is released during the process. Finally, the synthesized green SnCuO@FeO nanocomposite has potential for use in advanced applications in the oil and gas industry to help the industry meet regulatory compliance, lower operation costs, reduce environmental impact, and enhance production efficiency.

Methods for Functional Physiological Phenotyping and High-Order Data Quantification.

This chapter presents the application of Plantarray, a high-throughput platform commercially available for noninvasive monitoring of plant functional physiology phenotyping (FPP). The platform continuously measures water flux in the soil-plant-atmosphere for each plant in dynamic environments. To better interpret the massive phenotypic data acquired with FPP, several quantitative analysis methods were demonstrated for various types of data. Simple mathematical models were utilized to fit characteristic parameters of plant transpiration response to drought stress. Additionally, ecophysiological models were employed to quantify the sensitivity of transpiration to radiation and vapor pressure deficit (VPD) as component traits and predict more complex higher-order traits. The established protocols provide a tangible tool for integrating FPP and model analysis to address complex traits.

Exceptional stability of ultrasmall cubic copper metal nanoclusters - a molecular dynamics study.

The fabrication of shape-selective coinage metal nanoclusters (MNCs) has promising applications due to their exceptional physical and chemical molecule-like properties. However, the stability of the specific geometry of the nanoclusters, such as their cubic shapes, is unclear and has been unraveled by assessing the nanoclusters' interactions with different environments. In this work, we investigate the morphological stability of cubic structured, coinage metal nanoclusters of varying sizes ranging from 14 to 1099 atoms. The impact of solvent environments like water and the presence of ionic liquids (IL) on the stabilization of the MNCs were assessed using molecular dynamics (MD) simulations. In general, smaller MNCs composed of less than 256 atoms encountered structural distortion easily compared to the larger ones, which preserved their cubic morphology with minimal surface aberrations in water. However, in the presence of 4M 1-butyl-1,1,1-trimethyl ammonium methane sulfonate [N1114][C1SO3] IL solution, the overall cubic shape of the MNCs was successfully preserved. Strikingly, it is observed that in contrast to the noble MNCs like Au and Ag, the cubic morphology for Cu MNCs with sizes less than 256 atoms exhibited significant stability even in the absence of IL.

Studying the Collective Functional Response of a Receptor in Alchemical Ligand Binding Free Energy Simulations with Accelerated Solvation Layer Dynamics.

Ligand binding free energy simulations (LB-FES) that involve sampling of protein functional conformations have been longstanding challenges in research on molecular recognition. Particularly, modeling of the conformational transition pathway and design of the heuristic biasing mechanism are severe bottlenecks for the existing enhanced configurational sampling (ECS) methods. Inspired by the key role of hydration in regulating conformational dynamics of macromolecules, this report proposes a novel ECS approach that facilitates binding-associated structural dynamics by accelerated hydration transitions in combination with the λ-exchange of free energy perturbation (FEP). Two challenging protein-ligand binding processes involving large configurational transitions of the receptor are studied, with hydration transitions at binding sites accelerated by Hamiltonian-simulated annealing of the hydration layer. Without the need for pathway analysis or ad hoc barrier flattening potential, LB-FES were performed with FEP/λ-exchange molecular dynamics simulation at a minor overhead for annealing of the hydration layer. The LB-FES studies showed that the accelerated rehydration significantly enhances the collective conformational transitions of the receptor, and convergence of binding affinity calculations is obtained at a sweet-spot simulation time scale. Alchemical LB-FES with the proposed ECS strategy is free from the effort of trial and error for the setup and realizes efficient on-the-fly sampling for the collective functional response of the receptor and bound water and therefore presents a practical approach to high-throughput screening in drug discovery.

The antimicrobial fibupeptide lugdunin forms water-filled channel structures in lipid membranes.

Recently, a novel cyclo-heptapeptide composed of alternating D,L-amino acids and a unique thiazolidine heterocycle, called lugdunin, was discovered, which is produced by the nasal and skin commensal Staphylococcus lugdunensis. Lugdunin displays potent antimicrobial activity against a broad spectrum of Gram-positive bacteria, including challenging-to-treat methicillin-resistant Staphylococcus aureus (MRSA). Lugdunin specifically inhibits target bacteria by dissipating their membrane potential. However, the precise mode of action of this new class of fibupeptides remains largely elusive. Here, we disclose the mechanism by which lugdunin rapidly destabilizes the bacterial membrane potential using an in vitro approach. The peptide strongly partitions into lipid compositions resembling Gram-positive bacterial membranes but less in those harboring the eukaryotic membrane component cholesterol. Upon insertion, lugdunin forms hydrogen-bonded antiparallel ß-sheets by the formation of peptide nanotubes, as demonstrated by ATR-FTIR spectroscopy and molecular dynamics simulations. These hydrophilic nanotubes filled with a water wire facilitate not only the translocation of protons but also of monovalent cations as demonstrated by voltage-clamp experiments on black lipid membranes. Collectively, our results provide evidence that the natural fibupeptide lugdunin acts as a peptidic channel that is spontaneously formed by an intricate stacking mechanism, leading to the dissipation of a bacterial cell's membrane potential.

Genetic analysis of nephrogenic diabetes insipidus patients: A study on the Iranian population.

INTRODUCTION: Nephrogenic diabetes insipidus (NDI) is a rare genetic disease that causes water imbalance. The kidneys play a crucial role in regulating body fluids by controlling water balance through urine excretion. This highlights their essential function in managing the body's water levels, but individuals with NDI may have excess urine production (polyuria), that leads to excessive thirst (polydipsia). Untreated affected individuals may exhibit poor feeding and failure to thrive. This disease is caused by mutations in the AVPR2 and the AQP2 genes which have the X-linked and autosomal recessive/dominant inheritance, respectively. Both of these genes are expressed in the kidney. METHODS: Twelve Iranian patients from 10 consanguineous families were studied in this project. DNA was extracted from the whole blood samples of the patients and their parents. All coding exons and exon-intron boundaries of the AVPR2 and AQP2 genes were sequenced in the affected individuals, and the identified variants were investigated in the parents. All variants were analyzed according to the ACMG (American College of Medical Genetics and Genomics) guidelines. RESULTS: In this study, 6 different mutations were identified in the patients, including 5 in the AQP2 gene (c.439G>A, c.538G>A, c.140C>T, c.450T>A, and the novel c.668T>C) and 1 in the AVPR2 gene (c.337C>T) in the present study. DISCUSSION: As expected, all the detected mutations in this study were missense. According to the ACMG guideline, the identified mutations were categorized as pathogenic or likely pathogenic. Unlike previous studies which showed more than 90% of mutations were in the AVPR2 gene, and only less than 10% of the mutations were in the AQP2 gene, it was found that more than 90% of our identified mutations located in the AQP2 gene, and only one mutation was observed in the AVPR2 gene, which seems it may be a result of the high rate of consanguineous marriages in the Iranian population. We observed genotype-phenotype correlation in some of our affected individuals, and some of the mutations were observed in unrelated families from same ethnicity which could be suggestive of a founder mutation.

Dehydration of Lipid Membranes Drives Redistribution of Cholesterol Between Lateral Domains.

Cholesterol-rich lipid rafts are found to facilitate membrane fusion, central to processes like viral entry, fertilization, and neurotransmitter release. While the fusion process involves local, transient membrane dehydration, the impact of reduced hydration on cholesterol's structural organization in biological membranes remains unclear. Here, we employ confocal fluorescence microscopy and atomistic molecular dynamics simulations to investigate cholesterol behavior in phase-separated lipid bilayers under controlled hydration. We unveiled that dehydration prompts cholesterol release from raft-like domains into the surrounding fluid phase. Unsaturated phospholipids undergo more significant dehydration-induced structural changes and lose more hydrogen bonds with water than sphingomyelin. The results suggest that cholesterol redistribution is driven by the equalization of biophysical properties between phases and the need to satisfy lipid hydrogen bonds. This underscores the role of cholesterol-phospholipid-water interplay in governing cholesterol affinity for a specific lipid type, providing a new perspective on the regulatory role of cell membrane heterogeneity during membrane fusion.

Enhanced Solubility and Bioavailability of Clotrimazole in Aqueous Solutions with Hydrophobized Hyperbranched Polyglycidol for Improved Antifungal Activity.

The poor solubility of clotrimazole in the aqueous medium and the uncontrolled removal of the drug-loaded suppository content limit its effectiveness in the treatment of vulvovaginal candidiasis. We present here the aqueous formulations of clotrimazole in the form of non-Newtonian structured fluids, i.e., Bingham plastic or pseudoplastic fluids constructed of hyperbranched polyglycidol, HbPGL, with a hydrophobized core with aryl groups such as phenyl or biphenyl. The amphiphilic constructs were obtained by the modification of linear units containing monohydroxyl groups with benzoyl chloride, phenyl isocyanate, and biphenyl isocyanate, while the terminal 1,2-diol groups in the shell were protected during the modification step, followed by their deprotection. The encapsulation of clotrimazole within internally hydrophobized HbPGLs using a solvent evaporation method followed by water addition resulted in structured fluids formation. Detailed Fourier-transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) analyses performed for aryl-HbPGLs with clotrimazole revealed the difference in drug compatibility among polymers. Clotrimazole in biphenyl-enriched HbPGL, unlike phenyl derivatives, was molecularly distributed in both the dry and the hydrated states, resulting in transparent formulations. The shear-thinning properties of the obtained fluid formulations make them injectable and thus suitable for the intravaginal application. Permeability tests performed with the usage of the Franz diffusion cell showed a 5-fold increase in the permeability constant of clotrimazole compared to drugs loaded in a commercially available disposable tablet and a 50-fold increase of permeability in comparison to the aqueous suspension of clotrimazole. Furthermore, the biphenyl-modified HbPGL-based drug liquid showed enhanced antifungal activity against both Candida albicans and Candida glabrata that was retained for up to 7 days, in contrast to the phenyl-HbPGL derivatives and the tablet. With their simple formulation, convenient clotrimazole/biphenyl-HbPGL formulation strategy, rheological properties, and enhanced antifungal properties, these systems are potential antifungal therapeutics for gynecological applications. This study points in the synthetic direction of improving the solubility of poorly water-soluble aryl-enriched pharmaceuticals.

Preparation of high-efficiency HILIC capillary columns utilizing slurry packing at 2100 bar.

Complex mixture analysis requires high-efficiency chromatography columns. Although reversed phase liquid chromatography (RPLC) is the dominant approach for such mixtures, hydrophilic interaction liquid chromatography (HILIC) is an important complement to RPLC by enabling the separation of polar compounds. Chromatography theory predicts that small particles and long columns will yield high efficiency; however, little work has been done to prepare HILIC columns longer than 25 cm packed with sub-2 µm particles. In this work, we tested the slurry packing of 75 cm long HILIC columns with 1.7 µm bridged-ethyl-hybrid amide HILIC particles at 2,100 bar (30,000 PSI). Acetonitrile, methanol, acetone, and water were tested as slurry solvents, with acetonitrile providing the best columns. Slurry concentrations of 50-200 mg/mL were assessed, and while 50-150 mg/mL provided comparable results, the 150 mg/mL columns provided the shortest packing times (9 min). Columns prepared using 150 mg/mL slurries in acetonitrile yielded a reduced minimum plate height (hmin) of 3.3 and an efficiency of 120,000 theoretical plates for acenaphthene, an unretained solute. Para-toluenesulfonic acid produced the lowest hmin of 1.9 and the highest efficiency of 210,000 theoretical plates. These results identify conditions for producing high-efficiency HILIC columns with potential applications to complex mixture analysis.

Entropy Tug-of-War Determines Solvent Effects in the Liquid-Liquid Phase Separation of a Globular Protein.

Liquid-liquid phase separation (LLPS) plays a key role in the compartmentalization of cells via the formation of biomolecular condensates. Here, we combined atomistic molecular dynamics (MD) simulations and terahertz (THz) spectroscopy to determine the solvent entropy contribution to the formation of condensates of the human eye lens protein γD-Crystallin. The MD simulations reveal an entropy tug-of-war between water molecules that are released from the protein droplets and those that are retained within the condensates, two categories of water molecules that were also assigned spectroscopically. A recently developed THz-calorimetry method enables quantitative comparison of the experimental and computational entropy changes of the released water molecules. The strong correlation mutually validates the two approaches and opens the way to a detailed atomic-level understanding of the different driving forces underlying the LLPS.

Tumor-activated in situ synthesis of single-atom catalysts for O2-independent photodynamic therapy based on water-splitting.

Single-atom catalysts (SACs) have attracted interest in photodynamic therapy (PDT), while they are normally limited by the side effects on normal tissues and the interference from the Tumor Microenvironment (TME). Here we show a TME-activated in situ synthesis of SACs for efficient tumor-specific water-based PDT. Upon reduction by upregulated GSH in TME, C3N4-Mn SACs are obtained in TME with Mn atomically coordinated into the cavity of C3N4 nanosheets. This in situ synthesis overcomes toxicity from random distribution and catalyst release in healthy tissues. Based on the Ligand-to-Metal charge transfer (LMCT) process, C3N4-Mn SACs exhibit enhanced absorption in the red-light region. Thereby, a water-splitting process is induced by C3N4-Mn SACs under 660 nm irradiation, which initiates the O2-independent generation of highly toxic hydroxyl radical (·OH) for cancer-specific PDT. Subsequently, the ·OH-initiated lipid peroxidation process is demonstrated to devote effective cancer cell death. The in situ synthesized SACs facilitate the precise cancer-specific conversion of inert H2O to reactive ·OH, which facilitates efficient cancer therapy in female mice. This strategy achieves efficient and precise cancer therapy, not only avoiding the side effects on normal tissues but also overcoming tumor hypoxia.

Root surface roughness evaluation following application of different periodontal instruments and Er:YAG laser: A profilometry and SEM study.

AIM: The aim of the present study was to evaluate the efficacy of 30°-angled Er:YAG laser tip and different periodontal instruments on root surface roughness and morphology in vitro. METHODS: Eighteen bovine teeth root without carious lesion were decoronated from the cementoenamel junction and seperated longitidunally. A total of 36 obtained blocks were mounted in resin blocks and polished with silicon carbide papers under water irrigation. These blocks were randomly assigned into 3 treatment groups. In Group 1, 30°-angled Er:YAG laser (2.94 µm) tip was applied onto the blocks with a 20 Hz, 120 mJ energy output under water irrigation for 20 s. In Groups 2 and 3, the same treatment was applied to the blocks with new generation ultrasonic tip and conventional curette apico-coronally for 20 s with a sweeping motion. Surface roughness and morphology were evaluated before and after instrumentation with a profilometer and SEM, respectively. RESULTS: After instrumentation, profilometric analysis revealed significantly higher roughness values compared to baseline in all treatment groups(p < 0.05). Laser group revealed the roughest surface morphology followed by conventional curette and new generation ultrasonic tip treatment groups (p < 0.05). In SEM analysis, irregular surfaces and crater defects were seen more frequently in the laser group. CONCLUSION: Results of the study showed that the use of new generation ultrasonic tip was associated with smoother surface morphology compared to 30°-angled Er-YAG laser tip and conventional curette. Further in vitro and in vivo studies with an increased sample size are necessary to support the present study findings.

Climate change impacts on mesophotic regions of the Great Barrier Reef.

Climate change projections for coral reefs are founded exclusively on sea surface temperatures (SST). While SST projections are relevant for the shallowest reefs, neglecting ocean stratification overlooks the striking differences in temperature experienced by deeper reefs for all or part of the year. Density stratification creates a buoyancy barrier partitioning the upper and lower parts of the water column. Here, we mechanistically downscale climate models and quantify patterns of thermal stratification above mesophotic corals (depth 30 to 50 m) of the Great Barrier Reef (GBR). Stratification insulates many offshore regions of the GBR from heatwaves at the surface. However, this protection is lost once global average temperatures exceed ~3 °C above preindustrial, after which mesophotic temperatures surpass a recognized threshold of 30 °C for coral mortality. Bottom temperatures on the GBR (30 to 50 m) from 2050 to 2060 are estimated to increase by ~0.5 to 1 °C under lower climate emissions (SSP1-1.9) and ~1.2 to 1.7 °C under higher climate emissions (SSP5-8.5). In short, mesophotic coral reefs are also threatened by climate change and research might prioritize the sensitivity of such corals to stress.

Assessing Weak Anion Binding to Small Peptides.

Since Hofmeister's seminal studies in the late 19th century, it has been known that salts and buffers can drastically affect the properties of peptides and proteins. These Hofmeister effects can be conceived of in terms of three distinct phenomena/mechanisms: water-salt interactions that indirectly induce the salting-out of a protein by water sequestration by the salt, and direct salt-protein interactions that can either salt-in or salt-out the protein. Unfortunately, direct salt-protein interactions responsible for Hofmeister effects are weak and difficult to quantify. As such, they are frequently construed of as being nonspecific. Nevertheless, there has been considerable effort to better specify these interactions. Here, we use pentapeptides to demonstrate the utility of the H-dimension of nuclear magnetic resonance (NMR) spectroscopy to assess anion binding using N-H signal shifts. We qualify binding using these, demonstrating the upfield shifts induced by anion association and revealing how they are much larger than the corresponding downfield shifts induced by magnetic susceptibility and other ionic strength change effects. We also qualify binding in terms of how the pattern of signal shifts changes with point mutations. In general, we find that the observed upfield shifts are small compared with those induced by anion binding to amide-based hosts, and MD simulations suggest that this is so. Thus, charge-diffuse anions associate mostly with the nonpolar regions of the peptide rather than directly interacting with the amide N-H groups. These findings reveal the utility of 1H NMR spectroscopy for qualifying affinity to peptides─even when affinity constants are very low─and serve as a benchmark for using NMR spectroscopy to study anion binding to more complex systems.

Water Conservation Overrides Osmotic Diuresis During SGLT2 Inhibition in Patients With Heart Failure.

BACKGROUND: Sodium-glucose cotransporter 2 inhibitors are believed to improve cardiac outcomes due to their osmotic diuretic potential. OBJECTIVES: The goal of this study was to test the hypothesis that vasopressin-driven urine concentration overrides the osmotic diuretic effect of glucosuria induced by dapagliflozin treatment. METHODS: DAPA-Shuttle1 (Hepato-renal Regulation of Water Conservation in Heart Failure Patients With SGLT-2 Inhibitor Treatment) was a single-center, double-blind, randomized, placebo-controlled trial, in which patients with chronic heart failure NYHA functional classes I/II and reduced ejection fraction were randomly assigned to receive dapagliflozin 10 mg daily or placebo (1:1) for 4 weeks. The primary endpoint was change from baseline in urine osmolyte concentration. Secondary endpoints included changes in copeptin levels and solute free water clearance. RESULTS: Thirty-three randomized, sodium-glucose cotransporter 2 inhibitor-naïve participants completed the study, 29 of whom (placebo: n = 14; dapagliflozin: n = 15) provided accurate 24-hour urine collections (mean age 59 ± 14 years; left ventricular ejection fraction 31% ± 9%). Dapagliflozin treatment led to an isolated increase in urine glucose excretion by 3.3 mmol/kg/d (95% CI: 2.51-4.04; P < 0.0001) within 48 hours (early) which persisted after 4 weeks (late; 2.7 mmol/kg/d [95% CI: 1.98-3.51]; P < 0.0001). Dapagliflozin treatment increased serum copeptin early (5.5 pmol/L [95% CI: 0.45-10.5]; P < 0.05) and late (7.8 pmol/L [95% CI: 2.77-12.81]; P < 0.01), leading to proportional reductions in free water clearance (early: -9.1 mL/kg/d [95% CI: -14 to -4.12; P < 0.001]; late: -11.0 mL/kg/d [95% CI: -15.94 to -6.07; P < 0.0001]) and elevated urine concentrations (late: 134 mmol/L [95% CI: 39.28-229.12]; P < 0.01). Therefore, urine volume did not significantly increase with dapagliflozin (mean difference early: 2.8 mL/kg/d [95% CI: -1.97 to 7.48; P = 0.25]; mean difference late: 0.9 mL/kg/d [95% CI: -3.83 to 5.62]; P = 0.70). CONCLUSIONS: Physiological-adaptive water conservation eliminated the expected osmotic diuretic potential of dapagliflozin and thereby prevented a glucose-driven increase in urine volume of approximately 10 mL/kg/d · 75 kg = 750 mL/kg/d. (Hepato-renal Regulation of Water Conservation in Heart Failure Patients With SGLT-2 Inhibitor Treatment [DAPA-Shuttle1]; NCT04080518).

Exploring the Hawaiian Ala Wai Watershed with Zebrafish.

The Ala Wai Canal is an artificial waterway in the tourist district of Waikiki in Honolulu, HI. Originally built to collect runoff from industrial, residential, and green spaces dedicated to recreation, the Ala Wai Canal has since experienced potent levels of toxicity due to this runoff entering the watershed and making it hazardous for both marine life and humans at current concentration, including Danio rerio (zebrafish). A community of learners at educations levels from high school to postbaccalaureate from Oahu, HI was connected through the Consortium for Increasing Research and Collaborative Learning Experiences (CIRCLE) distance research program. This team conducted research with an Investigator and team from Mayo Clinic in Rochester, MN, with the Ala Wai Canal as its primary subject. Through CIRCLE, research trainees sent two 32 oz bottles of Ala Wai- acquired water to a partnered laboratory at the Mayo Clinic in which zebrafish embryos were observed at differing concentrations of the sampled water against a variety of developmental and behavioral assays. Research trainees also created atlases of developmental outcomes in zebrafish following exposure to environmental toxins and tables of potential pesticide contaminants to enable the identification of the substances linked to structural defects and enhanced stress during Ala Wai water exposure experiments.

Selective Sparse Sampling of Water Droplets in Oil with Acoustic Tweezers.

In microfluidics, water droplets are often used as independent biochemical microreactor units, enabling the implementation of massively parallel screening assays where only a few of the reacting water droplets yield a positive result. However, sampling the product of these few successful reactions is an unsolved challenge. One possible solution is to use acoustic tweezers, which are lab-free, easily miniaturized, and biocompatible manipulation tools, and existing acoustic tweezers manipulating particles or cells, and water droplet manipulation in oil with an acoustic tweezer is absent. The first challenge in attempting to recover a few water droplets from a large batch is the selective manipulation of water droplets in an oil system. In this paper, we trap and manipulate single water droplets in oil using integrated single-beam (focused beam/vortex beam) acoustic tweezers for the first time. We find that water droplets with a diameter smaller than half a wavelength are trapped by acoustic vortices, while larger ones are better captured by focused acoustic beams. It is the first step to extract the target water droplet microreactors (positive ones) in an oil system and analyze their content. Compared to previous techniques, such as fluorescence-activated cell sorting (FACS), our technique is sparse, meaning that the sampling time is proportional to the number of droplets required and very insensitive to the total number of microreactors, making it well suited for large-scale screening assays.

Corals survive severe bleaching event in refuges related to taxa, colony size, and water depth.

Marine heatwaves are increasing in frequency and duration, threatening tropical reef ecosystems through intensified coral bleaching events. We examined a strikingly variable spatial pattern of bleaching in Moorea, French Polynesia following a heatwave that lasted from November 2018 to July 2019. In July 2019, four months after the onset of bleaching, we surveyed > 5000 individual colonies of the two dominant coral genera, Pocillopora and Acropora, at 10 m and 17 m water depths, at six forereef sites around the island where temperature was measured. We found severe bleaching increased with colony size for both coral genera, but Acropora bleached more severely than Pocillopora overall. Acropora bleached more at 10 m than 17 m, likely due to higher light availability at 10 m compared to 17 m, or greater daily temperature fluctuation at depth. Bleaching in Pocillopora corals did not differ with depth but instead varied with the interaction of colony size and Accumulated Heat Stress (AHS), in that larger colonies (> 30 cm) were more sensitive to AHS than mid-size (10-29 cm) or small colonies (5-9 cm). Our findings provide insight into complex interactions among coral taxa, colony size, and water depth that produce high spatial variation in bleaching and related coral mortality.

Enzymatic and non-enzymatic removal of organic micropollutants with spent mushroom substrate of Agaricus bisporus.

Water bodies are increasingly contaminated with a diversity of organic micropollutants (OMPs). This impacts the quality of ecosystems due to their recalcitrant nature. In this study, we assessed the removal of OMPs by spent mushroom substrate (SMS) of the white button mushroom (Agaricus bisporus) and by its aqueous tea extract. Removal of acesulfame K, antipyrine, bentazon, caffeine, carbamazepine, chloridazon, clofibric acid, and N, N-diethyl-meta-toluamide (DEET) by SMS and its tea was between 10 and 90% and 0-26%, respectively, in a 7-day period. Sorption to SMS particles was between 0 and 29%, which can thus not explain the removal difference between SMS and its tea, the latter lacking these particles. Carbamazepine was removed most efficiently by both SMS and its tea. Removal of OMPs (except caffeine) by SMS tea was not affected by heat treatment. By contrast, heat-treatment of SMS reduced OMP removal to < 10% except for carbamazepine with a removal of 90%. These results indicate that OMP removal by SMS and its tea is mediated by both enzymatic and non-enzymatic activities. The presence of copper, manganese, and iron (0.03, 0.88, and 0.33 µg L-1, respectively) as well as H2O2 (1.5 µM) in SMS tea indicated that the Fenton reaction represents (part of) the non-enzymatic activity. Indeed, the in vitro reconstituted Fenton reaction removed OMPs > 50% better than the teas. From these data it is concluded that spent mushroom substrate of the white button mushroom, which is widely available as a waste-stream, can be used to purify water from OMPs.

Response of the root anatomical structure of Carex moorcroftii to habitat drought in the Western Sichuan Plateau of China.

MAIN CONCLUSION: The anatomical structures of Carex moorcroftii roots showing stronger plasticity during drought had a lower coefficient of variation in cell size in the same habitats, while those showing weaker plasticity had a higher coefficient of variation. The complementary relationship between these factors comprises the adaptation mechanism of the C. moorcroftii root to drought. To explore the effects of habitat drought on root anatomy of hygrophytic plants, this study focused on roots of C. moorcroftii. Five sample plots were set up along a soil moisture gradient in the Western Sichuan Plateau to collect experimental materials. Paraffin sectioning was used to obtain root anatomy, and one-way ANOVA, correlation analysis, linear regression analysis, and RDA ranking were applied to analyze the relationship between root anatomy and soil water content. The results showed that the root transverse section area, thickness of epidermal cells, exodermis and Casparian strips, and area of aerenchyma were significantly and positively correlated with soil moisture content (P < 0.01). The diameter of the vascular cylinder and the number and total area of vessels were significantly and negatively correlated with the soil moisture content (P < 0.01). The plasticity of the anatomical structures was strong for the diameter and area of the vascular cylinder and thickness of the Casparian strip and epidermis, while it was weak for vessel diameter and area. In addition, there was an asymmetrical relationship between the functional adaptation of root anatomical structure in different soil moisture and the variation degree of root anatomical structure in the same soil moisture. Therefore, the roots of C. moorcroftii can shorten the water transport distance from the epidermis to the vascular cylinder, increase the area of the vascular cylinder and the number of vessels, and establish a complementary relationship between the functional adaptation of root anatomical structure in different habitats and the variation degree of root anatomical structure in the same habitat to adapt to habitat drought. This study provides a scientific basis for understanding the response of plateau wetland plants to habitat changes and their ecological adaptation strategies. More scientific experimental methods should be adopted to further study the mutual coordination mechanisms of different anatomical structures during root adaptation to habitat drought for hygrophytic plants.