Hydrophilic Substances Research Articles

Green synthesis of nano particles from biodegradable waste extracts and their applications

Nanoparticles have become a significant component of advancing industries from technology to medicine and the environment. However, the synthesis of nanoparticles can impact their ability to function effectively within real-world applications, and this can cause negative consequences. This novel approach that utilizes processes such as regulation, control, clean-up, and remediation aims to increase the eco-friendly level of these essential particles. By reducing harmful by-products produced through the process of conventional nanoparticle synthesis, there will be less toxic unsustainable products created. The use of natural resources such as organic systems will aid in achieving the goal of creating a greener and more sustainable economy; however, it will require industrial assistance with the adoption of these alternative approaches. Metallic nanoparticles can be synthesized in a more sustainable and ‘green’ process through utilizing plant alternatives or biological materials such as bacteria, fungi, algae, and plant extracts. This greener approach can be a single step or ‘one pot’ process which requires a lower energy level than conventional processes. Another benefit is that this reduction method is more cost-efficient. Green-synthesized nanoparticles have clinical applications. When silver nanoparticles were treated against S. aureus, their antibacterial activity was at its peak. Nanoparticles used as drug carriers are highly stable, can incorporate both hydrophobic and hydrophilic substances, and can be delivered via a variety of routes also including oral application and inhalation.

Insight into sludge dewatering by periodate driven directly with Fe(Ⅱ): Extracellular polymeric substances solubilization and mineralization

The production of waste activated sludge is expanding in tandem with the significant growth in the global population. It is important to explore sludge pretreatment technology to achieve sludge reduction. In this study, deep sludge dewatering was achieved by using Fe2+-catalyzed periodate (Fe2+/PI) conditioning. The result showed that capillary suction time was reduced by 48.27% under the optimum Fe2+ and PI dosages. ·OH, FeⅣ, O2·-, 1O2, and IO3· generated from the reaction between Fe2+ and PI, while ·OH (49.79%) and FeⅣ (47.76%) contributed significantly to sludge dewatering. Investigations of the mechanism revealed that the synergistic action of radical species oxidation and iron species flocculation in Fe2+/PI conditioning led to the mineralization and aggregation of hydrophilic substances in extracellular polymeric substances. The hydrophobic groups on the protein surface were more exposed to soluble extracellular polymeric substances and reduced protein-water interaction. The variations in zeta potential and particle size also verified the presence of a synergistic effect of oxidation and flocculation. The morphology observations revealed that the increased frictional forces generated when water flowed over the raw sludge (RS) surface prevented the rapid passage of internal water. In addition, the hydrophobic and electrostatic interactions in the sludge samples were essential influences that promoted flocculation and sedimentation of the sludge. This research aids engineers by providing a new option to better optimize sludge management while also deepening understanding of the Fe2+/PI conditioning involved in sludge dewatering.

Insight into control mechanism of polymeric ferric titanium composite coagulant on membrane fouling: Role of natural organic matters

A series of polymerized ferric titanium coagulants (PFTC) with different basicity and Ti/Fe molar ratio were prepared, aiming to remove natural organic matters (NOM) as the main pollutants causing membrane fouling in water treatment process. The effects of basicity and Ti/Fe molar ratio on the structure of PFTC hydrolysates were preliminarily explored through the changes in peak intensity in Fourier transform infrared spectra and peak displacement in X-ray photoelectron spectroscopy spectra. The hydrolysis processes of Fe (III) and Ti (IV) were proposed based on hydrolysis polymerization curve and chemical distribution of PFTC. The coagulation results indicated that PFTC with low basicity and moderate Ti/Fe molar ratio could efficiently remove UV254, DOC and turbidity. When the amount of OH– or Ti (IV) was excessively high, the hydrolysates of PFTC transferred from oligomers to medium polymerized or colloidal species. PFTC could efficiently remove small hydrophilic substances through hydrogen bonding or sweeping effects of amorphous hydroxyl complexes, while PFTC with high basicity exhibited relatively low efficiency for UV254 and DOC removal. Finally, it was found that the control performance of PFTC on membrane fouling mainly depended on its efficiency in removing NOMs. This study will provide new insight into the development of composite coagulant and the precise control of membrane fouling.

Management of decontamination in chemical accidents: a laboratory model

Rapid and efficient decontamination of the skin is a major task for emergency rescue services in the event of a chemical accident involving humans. While rinsing the skin with water (and soap) has been the standard procedure, some skepticism has developed in recent years regarding the situational suitability of this method. The efficacy of three different decontamination materials/techniques (Easyderm® cleaning cloth, water-soaked all-purpose sponge, rinsing with water) in removing Capsaicin, Bromadiolone, Paraquat and 2,2′-dichlorodiethylether (DCEE) from porcine skin was compared. Different cleaning motions (wiping, twisting, pressing) with the Easyderm® were evaluated for their effectiveness in removing Capsaicin from porcine skin. Finally, the impact of different exposure times of the skin to Capsaicin on the decontamination process were investigated. Contaminant recovery rates (CRRs) were analysed in the skin and in each decontamination material using high-performance-liquid-chromatography (HPLC; used for Capsaicin, Bromadiolone, Paraquat) or gas chromatography (GC; used for DCEE). Wiping the skin with the amphiphilic Easyderm® was most effective for decontamination of Capsaicin and DCEE, while the water rinsing method gave the best results for removing Paraquat and Bromadiolone. Both wiping with the Easyderm® and rotating the Easyderm® were significantly more effective in cleaning Capsaicin-contaminated skin than pressing the Easyderm® on the contamination area alone. Prolonged exposure times of the porcine skin to Capsaicin were associated with a decrease in efficacy of the following decontamination. Emergency rescue services should have materials available that can remove both hydrophilic and hydrophobic substances from skin. Since not all of our results for comparing different decontamination materials were as distinct as we expected, there are likely several other factors determining the efficacy of skin decontamination in some cases. Time is key; therefore, first responders should try to begin the decontamination process as soon as possible after arriving at the scene.

Nano crystalline cellulose based drug delivery system for some non-steroidal anti-inflammatory drugs: Synthesis, characterization and in-vitro simulation studies

Nano crystalline cellulose (NCC) created a breakthrough in biomedical field because of its important characteristics like large surface area, good mechanical strength, biocompatibility, renewability and feasibility of incorporation to both hydrophilic and hydrophobic substances. In the present study NCC based drug delivery systems (DDSs) of some non-steroidal anti-inflammatory drugs (NSAIDs) were obtained by covalent bonding between hydroxyl groups of NCC with carboxyl group of NSAIDs. Developed DDSs were characterized by means of FT-IR, XRD, SEM and thermal analysis. In-vitro release study and fluorescence study showed that these systems are stable up to 18 h in upper gastrointestinal (GI) tract at pH 1.2 and released NSAIDs in sustained manner over the period of 3 h in intestine at pH 6.8–7.4. Present study performed with the aim to reuse bio-waste even in the form of DDSs is of greater therapeutic efficacy with reduced dosing frequency that overcome physiological adversities involved with NSAIDs.

Development of the observation of membrane fusion with label-free liposomes by calcium imaging

Liposomes are artificial vesicles composed of lipid bilayers that have enabled drugs to be encapsulated and delivered to tumor tissue. Membrane-fusogenic liposomes fuse with the plasma membranes of cells to deliver encapsulated drugs directly to the cytosol, which makes it a promising method for rapid and highly efficient drug delivery. In a previous study, liposomal lipid bilayers were labeled with fluorescent probes, and colocalization of labeled lipids with plasma membrane was observed under a microscope. However, there was concern that fluorescent labeling would affect lipid dynamics and cause liposomes to acquire membrane fusogenic ability. In addition, encapsulation of hydrophilic fluorescent substances in the inner aqueous phase sometimes requires an additional step of removing unencapsulated substances after preparation, and there is a risk of leakage. Herein, we propose a new method to observe cell interaction with liposomes without labeling. Our laboratory has developed two types of liposomes with different cellular internalization pathways, i.e., endocytosis and membrane fusion. We found that cytosolic calcium influx would be triggered following the internalization of cationic liposomes, and different cell entry routes led to different calcium responses. Thus, the correlation between cell entry routes and calcium responses could be utilized to study liposome-cell interactions without fluorescent labeling lipids. Briefly, liposomes were added to phorbol 12-myristate 13-acetate (PMA)-primed THP-1 cells, and calcium influx was measured by time-lapse imaging using a fluorescent indicator (Fura 2-AM). Liposomes with high membrane fusogenic ability elicited a strong transient calcium response immediately after adding liposomes, whereas those taken up mainly by endocytosis elicited multiple weak calcium responses. In order to verify the cell entry routes, we also tracked the intracellular distribution of fluorescent-labeled liposomes in PMA-primed THP-1 cells using a confocal laser scanning microscope. It was shown that for fusogenic liposomes, colocalization with plasma membrane occurred at the same time as calcium elevation, whereas for liposomes with a high endocytosis potential, fluorescent dots were observed in the cytoplasm, suggesting the cell internalization by endocytosis. These results suggested that the calcium response patterns correspond to cell entry routes, and membrane fusion can be observed by calcium imaging.

Advanced prodrug approaches for neurodegenerative diseases

The prodrug technique is still one of the most effective ways to increase hydrophilic substances' medicinal, pharmacodynamic and pharmacokinetic properties. Prodrugs produced in current history have shown good pharmacokinetic characteristics, allowing for a more consistent release and fewer changes in plasma levels. Developing new prodrugs having a desirable ADME (Absorption Distribution Metabolism and Elimination) properties and that still can cross the Blood brain barrier (BBB) and pharmacologically active an appealing task for medicinal chemists. The loss of brain neuron activity characterizes neurodegenerative illnesses, resulting in progressive Gradual cognitive impairment (GCI). Some of the common neurodegenerative diseases are PD (Parkinson's disease), AD (Alzheimer's disease), MS (Multiple sclerosis), ALS (amyotrophic lateral sclerosis) & HD (Huntington's disease) are examples of neurodegenerative illnesses with a variety of etiologies and morphological and pathophysiological aspects. The current review is concerned with current advances in prodrug approaches for the treatment and prevention of the most prevalent neurological illnesses, as well as their absorption, selective CNS targeting and chemical and enzymatic stability.

Characterization of Spanlastic System Loaded Green Tea Extract as Antioxidant for Skin

Background: Green tea possesses abundant polyphenols that exert antioxidant activity. However, green tea’s hydrophilicity and instability limit its penetration into the skin layers. Recently, a non-ionic surfactant-based elastic nanovesicular system called spanlastic can enhance the delivery of hydrophilic and unstable substances. Spanlastic composed of vesicle builder and edge activator, which influence the characteristics of the vesicle. Objective: The study aimed to evaluate the influence of the ratio of the components on the characterization of green tea extract-loaded spanlastic using three different weight ratio of vesicle builder and edge activator that is 7:3, 8:2, and 9:1. Methods: Spanlastic is prepared by ethanol injection methods using Span 60 as vesicle builder (VB) and Tween® 60 as edge activator (EA). The characterization includes visually observed organoleptic, particle size (PS) and polydispersity index (PDI) using dynamic light scattering, entrapment efficiency (EE) and drug loading (DL) using total phenolic content assay. The most optimum ratio will be tested its zeta potential value using Zetasizer and viscosity using Brookfield Cone and Plate. Results: Selected spanlastic formula composed of Span 60 and Tween® 60 at a weight ratio of 8:2 has given characteristics as follows: entrapment efficiency 60.85±1.70%; drug loading 11.07±0.65%; the particle size is 419.70±7.42 nm; and PDI value 0.26±0.05. The prepared spanlastic has a greenish liquid form, with a zeta potential value of 28.53±2.78 mV and viscosity of 14.65±0.32 cP. Conclusion: The optimum weight ratio of vesicle builder and edge activator for green tea extract spanlastic is Span 60:Tween® 60 8:2.

A Quenched Double‐Hydrophilic Coating for the Enhancement of Water Retention of Hydrogels

AbstractWith the emergence of various hydrogels with excellent functions, the air‐drying of hydrogels has attracted extensive attention. Improving the water retention capacity is critical in the application of hydrogels. Herein, inspired by the dense aggregation structure of natural hydrophilic macromolecules, hydrophilic substances (gelatin and glycerol) are first applied to enhance the water retention capacity of hydrogels by constructing a quenched double‐hydrophilic coating. The weight retention ratio of the modified hydrogels is increased to 72.5% at 25 °C and 40 RH% after 5 days. Furthermore, the construction of hydrophilic coating on the surface does not affect the mechanical properties, and the modified hydrogels still retain strong water retention capacity after loading. In addition, this approach is applicable to hydrogels with different shapes and types, and various materials can be selected. Therefore, the proposed method provides new insights for expanding the application scope and service life of hydrogels.

Chalcopyrite-activated sodium percarbonate oxidation for sludge dewaterability enhancement: Synergetic roles of •OH and 1O2

Efficient dewatering of sewage sludge is an energy- and carbon-saving procedure of sludge treatment in wastewater treatment facilities. Due to the limiting factors of hydrophilic extracellular polymeric substances, it is crucial to weaken the water-holding capacity and hydrophilicity for high-performance sludge-water separation. The current study successfully put forward a combination process of chalcopyrite + sodium percarbonate (SPC) to proficiently facilitate sludge dewaterability. Results showed that after the optimized treatment, the water removal efficiency augmented from 51.3 to 94.9%, while the water content of sludge cake declined from 90.1 to 52.0 wt%. Mechanism investigation demonstrated that the chalcopyrite + SPC system could consecutively generate reactive oxygen species via strong Fe3+/Fe2+ and Cu2+/Cu+ conversion cycles. The dominant reactive radical •OH and non-radical 1O2 could effectively degrade the macromolecular EPS into low-molecular biopolymers, decrease the high-polarity hydrophilic protein secondary structure and amino acids, and further reduce water-holding interfacial affinity. Afterward, the electrostatic force and interfacial free energy were decreased and turned out to enhance self-flocculation and flowability. Accordingly, bound water reduction and sludge-water separation efficiency were promoted. Furthermore, the chalcopyrite + SPC system could be viewed as a surrogate to Fenton/Fenton-like strategies for sludge dewaterability with economic advantage and low environmental risk. These findings inspire the application prospect of the chalcopyrite + SPC conditioning technique, which expects to save energy and reduce carbon emissions.

Hydrogel-forming microarray patches with solid dispersion reservoirs for transdermal long-acting microdepot delivery of a hydrophobic drug.

Hydrogel-forming microarray patches (HF-MAPs) are used to circumvent the skin barrier and facilitate the noninvasive transdermal delivery of many hydrophilic substances. However, their use in the delivery of hydrophobic agents is a challenging task. This work demonstrates, for the first time, the successful transdermal long-acting delivery of the hydrophobic atorvastatin (ATR) via HF-MAPs using poly(ethylene)glycol (PEG)-based solid dispersion (SD) reservoirs. PEG-based SDs of ATR were able to completely dissolve within 90 s in vitro. Ex vivo results showed that 2.05 ± 0.23 mg of ATR/0.5 cm2 patch was delivered to the receiver compartment of Franz cells after 24 h. The in vivo study, conducted using Sprague Dawley rats, proved the versatility of HF-MAPs in delivering and maintaining therapeutically-relevant concentrations (> 20 ng·mL-1) of ATR over 14 days, following a single HF-MAP application for 24 h. The long-acting delivery of ATR suggests the successful formation of hydrophobic microdepots within the skin, allowing for the subsequent sustained delivery as they gradually dissolve over time, as shown in this work. When compared to the oral group, the use of the HF-MAP formulation improved the overall pharmacokinetics profile of ATR in plasma, where significantly higher AUC values resulting in ~10-fold higher systemic exposure levels were obtained. This novel system offers a promising, minimally-invasive, long-acting alternative delivery system for ATR that is capable of enhancing patient compliance and therapeutic outcomes. It also proposes a unique promising platform for the long-acting transdermal delivery of other hydrophobic agents.

Экстрагирование гидрофильных компонентов кожуры и жома плодов граната

Pomegranate (Punica granatum L.) processing focuses on the extraction of polyphenols from peel. However, pomegranate peel is also rich in other biologically active water-soluble components, and their commercial extraction remains understudied. The research objective was to evaluate the degree of extraction of hydrophilic substances, such as simple sugars, organic acids, and polyphenols, from raw pomegranate peel and pulp under different experimental conditions in order to select the optimal extraction parameters.
 The study featured pomegranates of the Iridanaly variety (Geokchay, Azerbaijan). Raw peel and pulp were crushed to the state of a coarse gruel. Extraction occurred by maceration at a hydromodulus of 1:2 and a temperature of 40 or 60°C with pure water and aqueous ethanol solutions (10–14 % vol.). The process lasted 30, 60, or 90 min in one or two stages with separate extraction at each stage. The research involved standard physicochemical methods.
 In 31.0 ± 2.0 g/100 g of dry peel, the hydrophilic fraction accounted for 85.32%; in 35.7 ± 2.8 g/100 g of dry pulp, it was 59.36%. Only 54.6% solids were extracted from raw peel after 30 min of extraction with pure water at a hydromodulus of 1:2 and 60°C. Pomegranate peel contained hydrophilic colloids, which caused water absorption and reduced the yield. The optimal extraction included an aqueous solution of ethanol with an ethanol concentration of 10–14 % vol. and two thirty-minute stages. The coagulating effect of ethyl alcohol on water-soluble pectin made it possible to increase the degree of extraction of water-soluble substances to 83.93 and 91.4% of their initial content in raw peel and raw pulp, respectively. Such extraction yielded 4 kg of mixed extract from 1 kg of raw pulp. The extract was boiled under vacuum and yielded 260 g of concentrate with 60 wt.% solids, including 46.70 g/100 g simple sugars, 4.73 g/100 g organic acids, 3.70 g/100 g polyphenols, and 10.10 mg/100 g vitamin C.
 The extraction of raw pomegranate peel and pulp with aqueous ethanol (10–14 % vol.) provided the maximal degree of extraction of hydrophilic substances and facilitated the separation of the resulting extracts. However, strong alcohol solutions may increase the cost of distillation of alcohol from the extract. To eliminate this shortcoming, the extraction can be carried out with pure water and a pectolytic enzyme.

Synthesis and applications of polymer cubosomes and hexosomes

AbstractThe synthesis and use of polymer cubosomes have received significant attention in recent years. Polymer cubosomes are highly stable colloidal particles with triply periodic minimal surface. Inherently, polymer cubosomes have several advantages over other nanostructures like micelles and vesicles as they are quite uniform and porous structures. Due to the large specific surface area of the interior and bicontinuous nature, they have the capacity to load significant amounts of hydrophobic and hydrophilic substances. Additionally, their properties make them suitable for use as nanotemplates, catalyst supports, and nanovehicles for the separation and regulated release of biomolecules. Regarding their synthesis, block copolymers that may form cubosomes are still few in number, in part because different block copolymers require various self‐assembly conditions. In order to create polymer cubosomes, five different self‐assembly techniques have been reported, including the co‐solvent method, flash nanoprecipitation, evaporation‐induced self‐assembly, solvent‐diffusion‐evaporation‐mediated self‐assembly, and polymerization‐induced self‐assembly. This review article describes various synthetic techniques for creating polymer cubosomes and goes into further depth on recent uses for polymer cubosomes. It is anticipated that this article may offer some helpful guidance to researchers interested in the different applications of polymer cubosomes.

Biocompatible microemulsions based on oleic acid modified with piperidinium surfactants

A number of microemulsions based on oleic acid and Tween 80, modified with piperidinium surfactants, have been obtained and characterized. The effect of additives on the size, stability, and solubilization effect of the formed systems with respect to hydrophilic (rhodamine B) and hydrophobic (indomethacin) substances was studied. By varying the ratio of components, it was possible to form microemulsions that differ greatly in viscosity: from easy-flowing compositions to gels. The kinetic parameters describing release process of substrates from microemulsions have been obtained. In vivo tests of the anti-inflammatory action of microemulsions loaded with indomethacin have shown that the presence of piperidinium surfactants enhances the therapeutic effect of the drug. In vivo tests of the anti-inflammatory action of microemulsions loaded with indomethacin have shown that the presence of piperidinium surfactants enhances the therapeutic effect of the drug.

Quantitation of pesticides in bee bread collected from honey bee colonies in an agricultural environment in Switzerland

Pesticide contamination of bee products is a widespread phenomenon. Due to its composition, bee bread is affected by both lipophilic and hydrophilic substances. As proof of concept of a monitoring campaign and to better understand the extent of contamination, we developed an analytical method based on a modified QuEChERS extraction, with subsequent separation by liquid chromatography and detection by mass spectrometry. This allowed for the quantitation of 51 agricultural- or beekeeping-associated pesticides in bee bread. The workflow was applied to 60 samples taken biweekly throughout spring to autumn 2022 from five colonies at a Swiss apiary in an agricultural area. In total, 30 pesticides were identified (> LOD), among which 26 pesticides were quantitated. The total number of pesticides detected per colony ranged from 11 to 19. The most prevalent substances (> LOQ) were two neonicotinoid insecticides, acetamiprid and thiacloprid (max. 16 μg/kg and 37 μg/kg, respectively); seven fungicides, azoxystrobin (max. 72 μg/kg), boscalid (max. 50 μg/kg), cyprodinil (max. 1965 μg/kg), difenoconazole (max. 73 μg/kg), mandipropamid (max. 33 μg/kg), pyraclostrobin (max. 8 μg/kg) and trifloxystrobin (max. 38 μg/kg); and two herbicides, prosulfocarb (max. 38 μg/kg) and terbuthylazine (max. 26 μg/kg). The study revealed strong variability in pesticide occurrence and concentrations among colonies sampled at the same site and date. The applied biweekly sampling of bee bread from March to August was shown to be reliable in capturing peak contaminations and revealing the onset of certain pesticides in bee bread. The study provides an adequate practical approach for pesticide monitoring campaigns.

Biocompatible Microemulsions Based on Oleic Acid Modified with Piperidinium Surfactants

A series of microemulsions based on oleic acid and Tween 80, modified with piperidinium surfactants, have been obtained and characterized. The effect of additives on the size, stability, and solubilization effect of the formed systems with respect to hydrophilic (rhodamine B) and hydrophobic (indomethacin) substances have been investigated. Varying of the components ratio has allowed preparation of the microemulsions with strongly different viscosity: from easy-flowing formulations to gels. Kinetic parameters describing release of the substrates from the microemulsions have been obtained. In vivo tests of the anti-inflammatory action of the microemulsions loaded with indomethacin have shown that the presence of piperidinium surfactants enhances the therapeutic effect of the drug.

Cetirizine-based soft dosage forms

The development of rational dosage forms with cetirizine is an urgent task. Cetirizine is a second-generation antihistamine. In patients suffering from allergies, the use of cetirizine leads to a significant improvement in the course of the disease. Even in veterinary practice, taking cetirizine orally once a day provides sufficient antihistamine effect in animals. Currently, the following drugs with cetirizine are available: film-coated tablets, orodispersible tablets, as well as drops for oral administration. There are no transdermal dosage forms with cetirizine in Russia. The transdermal therapeutic system (TTS) is a metered-dose soft dosage form for external use in the form of gels, patches, or films, which releases the drug slowly. The TTS advantages are as follows: ease of use, the ability of the medicinal substance to quickly enter the bloodstream, the ability to regulate the release rate of the active substance and use hydrophilic and lipophilic substances. We have developed two transdermal therapeutic systems with cetirizine — a gel and a patch, and studied the pharmacological effects. The purpose of the study. The purpose of this work is to create external dosage forms containing cetirizine. The scientific novelty of the research is the design of formulations for antiallergic dosage. Materials and methods. Technological and pharmacological research methods were used. Results. The study showed that the developed gel and the patch with cetirizine have antiallergic properties comparable to the comparison drug (Psilo-balsam gel), while surpassing the reference drug in its effect on the formation of allergic exudative edema. Conclusion. External dosage forms — a transdermal therapeutic gel and a patch containing cetirizine have been created.

Elucidating the characteristic of leachates released from microplastics under different aging conditions: Perspectives of dissolved organic carbon fingerprints and nano-plastics

Despite numerous studies that have been devoted to investigating the aging behaviors of microplastics (MPs), dissolved organic carbon (DOC) and nano-plastics (NPs) released from MPs under different aging conditions were limited. Herein, the characterizations and underlying mechanisms of DOC and NPs leaching from MPs (PVC and PS) in the aquatic environment for 130 days under different aging conditions were investigated. The results showed that aging could reduce the abundance of MPs, and high temperature and UV aging generated small-sized MPs (< 100 μm), especially UV aging. DOC-releasing characteristics were related to MP type and aging condition. Meanwhile, MPs were prone to release protein-like and hydrophilic substances except for 60 °C aging of PS MPs. Additionally, 8.77 × 109–8.87 × 1010 and 4.06 × 109–3.94 × 1010 NPs/L were detected in leachates from PVC and PS MPs-aged treatments, respectively. High temperature and UV promoted the release of NPs, especially UV irradiation. Meanwhile, smaller sizes and rougher NPs were observed in UV-aged treatments, implying higher ecological risks of leachates from MPs under UV aging. This study highlights the leachate released from MPs under different aging conditions comprehensively, which could offset the knowledge gap between the MPs’ aging and their potential threats.

New insights into carbon mineralization in tropical paddy soil under land use conversion: Coupled roles of soil microbial community, metabolism, and dissolved organic matter chemodiversity

Although the impact of land conversion on carbon mineralization in paddy soils has received increasing attention, the coupled roles of soil microdiversity and chemodiversity in these processes are largely unknown. To address this issue, the land use conversion from paddy fields (PF) to vegetable fields (VF), rice-vegetable rotation (RV), and abandoned land (AL), were investigated in this study. The relationships between soil mineralization characteristics and microbial community, metabolism physiology and dissolved organic matter (DOM) chemodiversity were analyzed. After the conversion, soil mineralization enhanced in AL and RV, which were 217.49% and 183.02% of that in PF. In contrast, no significant change was observed in VF, although the anaerobic environment was transformed into an aerobic one and the fungal richness/ diversity increased in the soil. This was because soil mineralization was directly regulated by DOM quantity and microbial metabolism of labile carbon, and indirectly by DOM chemodiversity and microbial community. Specifically, the largest mineralization in AL was attributed to the strongest microbial metabolism of labile carbon, as AL had the largest DOC contents, hydrophilic substances (e.g., carboxyl, carbohydrate, and amino), and abundant eutrophic taxa (e.g., Actinobacteria and Proteobacteria). In contrast, no significant change in VF was mainly related to more condensed aromatics and oligotrophic microbes, and fewer DOC in soil, resulting in the dominance of microbial metabolism of soil recalcitrant carbon. The recalcitrant carbon metabolism also prevailed in RV. However, RV showed moderate soil mineralization due to having the proper DOM with high bioavailability. Collectively, the results provide molecular insights into the impact of land conversion on soil mineralization from a micro-chemodiversity perspective, which highlights the importance of nutrient supply and microbial metabolism strategy.

Complex exudates in inflorescences of Vriesea species reveal evidence of lipophilic secretions by scales of bromeliads

Trichomes are a key feature of bromeliads. These structures absorb water and minerals, potentially constituting an important element in plant-environment interactions. Recent studies have shown a glandular function associated with mucilage-secreting scales in inflorescences of bromeliads. During a prospective study of secretions in bromeliad inflorescences, we observed the presence of an oily exudate in three species of Vriesea sect. Xiphion. To verify whether scales in bromeliads can produce lipophilic secretions, we investigated the secretory activity in these species to identify the source and chemical nature of the secretions which spread over the inflorescences. We used standard methods of histochemistry, light, and electron microscopy applied to samples of floral bracts in two distinct phases of development. The secretions comprised hydrophilic and lipophilic substances secreted by trichomes on the adaxial side of bracts. The exudate was heterogeneous in V. aff. bituminosa and V. fenestralis, with a lipophilic phase composed of terpenoids and lipids. Vriesea aff. bituminosa also presented alkaloids. In V. platynema var. rosea, the lipophilic content was lipids. The secretory activity was restricted to the early stages of organ development and might be characterized by a temporal disjunction between the secretion of hydrophilic and lipophilic contents. The functions of the exudate seem to include protection against herbivores but might also relate to protection against pathogens, water loss and high irradiance. The secretion of lipophilic substances by the typical peltate trichome of bromeliads was reported here for the first time.