Core-Shell Au@Nanoplastics as a Quantitative Tracer to Investigate the Bioaccumulation of Nanoplastics in Freshwater Ecosystems.

Studies on the adverse effects of nanoplastics (NPs, particle diameter <1000 nm) including physical damage, oxidative stress, impaired cell signaling, altered metabolism, developmental defects, and possible genetic damage have intensified in recent years. However, the analytical detection of NPs is still a bottleneck. To overcome this bottleneck and obtain a reliable and quantitative distribution analysis in complex freshwater ecosystems, an easily applicable NP tracer to simulate their fate and behavior is needed. Here, size- and surface charge-tunable core-shell Au@Nanoplastics (Au@NPs) were synthesized to study the environmental fate of NPs in an artificial freshwater system. The Au core enables the quantitative detection of NPs, while the polystyrene shell exhibits NP properties. The Au@NPs showed excellent resistance to environmental factors (e.g., 1% hydrogen peroxide solution, simulating gastric fluid, acids, and alkalis) and high recovery rates (>80%) from seawater, lake water, sewage, waste sludge, soil, and sediment. Both positively and negatively charged NPs significantly inhibited the growth of duckweed (Lemna minor L.) but had little effect on the growth of cyanobacteria (Microcystis aeruginosa). In addition, the accumulation of positively and negatively charged NPs in cyanobacteria occurred in a concentration-dependent manner, with positively charged NPs more easily taken up by cyanobacteria. In contrast, negatively charged NPs were more readily internalized in duckweed. This study developed a model using a core-shell Au@NP tracer to study the environmental fate and behavior of NPs in various complex environmental systems.

Synthetic Strategies for Polymer Particles with Surface Concavities.

Over the past decade or so, there has been increasing interest in the synthesis of polymer particles with surface concavities, which mainly include golf ball-like, dimpled and surface-wrinkled polymer particles. Such syntheses generally can be classified into direct polymerization and post-treatment on preformed polymer particles. This review aims to provide an overview of the synthetic strategies of such particles. Some selected examples are given to present the formation mechanisms of the surface concavities. The applications and future development of these concave polymer particles are also briefly discussed.

An injectable, biodegradable calcium phosphate cement containing poly lactic-co-glycolic acid as a bone substitute in ex vivo human vertebral compression fracture and rabbit bone defect models.

Purpose/Aim of the study: To evaluate the biomechanical characteristics and biocompatibility of an injectable, biodegradable calcium phosphate cement (CPC) containing poly lactic-co-glycolic acid (PLGA). MATERIALS AND METHODS: A vertebral compression fracture model was established using 20 human cadaveric vertebrae (T11-L3) divided into CPC/PLGA composite versus PMMA groups for biomechanical testing. In addition, 35 New Zealand rabbits were used to evaluate biodegradability and osteoconductive properties of CPC/PLGA using a bone defect model. In vitro cytotoxicity was evaluated by culturing with L929 cells. RESULTS: The CPC/PLGA composite effectively restored vertebral biomechanical properties. Compared with controls, the maximum load and compression strength of the CPC/PLGA group were lower, and stiffness was lower after kyphoplasty (all p <.05). Degradation was much slower in the control CPC compared with CPC/PLGA group. The bone tissue percentage in the CPC/PLGA group (44.9 ± 23.7%) was significantly higher compared with control CPC group (25.7 ± 10.9%) (p <.05). The viability of cells cultured on CPC/PLGA was greater than 70% compared with the blanks. CONCLUSIONS: Our biodegradable CPC/PLGA composite showed good biomechanical properties, cytocompatibility, and osteoconductivity and may represent an ideal bone substitute for future applications.

Microplastics alter the microbiota-mediated phosphorus profiles at sediment-water interface: Distinct microbial effects between sediment and plastisphere.

Microplastics (MPs) are ubiquitous in freshwater sediments, raising concern about their potential impacts on ecosystem services. However, the specific impacts of microbiota mediated by MPs in sediment and plastisphere compartments on P availability remain elusive. This investigation conducted a series of microcosm experiments utilizing eutrophic lake sediment amended with fuel-based polyethylene terephthalate (PET), bio-based polylactic acid (PLA) MPs, and a natural cobblestone substrate to unravel their effects. The findings highlighted that MPs induced alterations in bacterial communities in both sediment and plastisphere, consequently modifying P availabilities at the sediment-water interface (SWI). In comparison to non-biodegradable PET, biodegradable PLA MPs presented higher proportions of specific bacteria and functional genes associated with P profiles, such as Firmicutes, Ignavibacteriota, and P mineralizing genes in the sediment and plastisphere. This, in turn, elevated the levels of soluble reactive P in the porewater by 54.19 % (0-1 cm), 55.81 % (1-3 cm), and 18.24 % (3-5 cm), respectively. Additionally, PLA obviously altered P immobilization capacity and bioavailability, increasing the organic P fraction. Whereas, inert cobblestone exhibited negligible influence on P biogeochemical processes during the incubation. Moreover, the biofilm communities and those in the surrounding sediment specifically contributed to the changes in P profiles at the SWI. The functional genes associated with P profiles in the sediment mainly concentrate on P mineralization and P uptake/transport. In the plastisphere, P activation genes are obviously affected under MP exposure. This study fills the knowledge gap concerning the repercussions of MPs on ecosystem services.

New insights into changes in phosphorus profile at sediment-water interface by microplastics: Role of benthic bioturbation.

Microplastics (MPs) have attracted increasing attention due to their ubiquitous occurrence in freshwater sediments and the detrimental effects on benthic invertebrates. However, a clear understanding of their downstream impacts on ecosystem services is still lacking. This study examines the effects of bio-based polylactic acid (PLA), fuel-based polyethylene terephthalate (PET), and biofilm-covered PET (BPET) MPs on the bioturbator chironomid larvae (Tanypus chinensis), and the influence on phosphorus (P) profiles in microcosms. The changes in biochemical responses and metabolic pathways indicated that MPs disrupted energy synthesis by causing intestinal blockage and oxidative stress in T. chinensis, leading to energy depletion and impaired bioturbation activity. The impairment further resulted in enhanced sedimentary P immobilization. For larval treatments, the internal-P loadings were respectively 11.4%, 8.6%, and 9.0% higher in the PLA, PET, and BPET groups compared to the non-MP control. Furthermore, the influence of bioturbation on P profiles was MP-type dependent. Both BPET and PLA treatments displayed more obvious impacts on P profiles compared to PET due to the changes in MP bioavailability or sediment microenvironment. This study connects individual physiological responses to broader ecosystem services, showing that MPs alter P biogeochemical processes by disrupting the bioturbation activities of chironomid larvae.

Impact of COVID-19 pandemic on microplastic occurrence in aquatic environments: A three-year study in Taihu Lake Basin, China.

The impact of the Coronavirus Disease 2019 (COVID-19) pandemic on microplastic (MP) occurrence in aquatic environments deserves an in-depth study. In this study, the occurrence of MPs and environmental flux of plastics before (2019) and during (2020 and 2021) the pandemic were comparatively investigated in various aquatic compartments in the Taihu Lake Basin in China. The field-based investigations from 2019 to 2021 for Taihu Lake have shown that, at the onset of the outbreak, the MP abundance declined at a rate of 62.3 %, but gradually recovered to the pre-pandemic level. However, the amount of plastics being released into aquatic environments showed a declining trend in 2020 and 2021 compared to those in 2019, with decrease rates of 13.7 % and 15.8 %, respectively. Characterization analysis of MP particles and source apportionment framework implied that while the contributions of tire abrasion and domestic waste to MP occurrence were depleted owing to the reduction in human activity during the pandemic, weathering and fragmentation of retained plastics contributed to the recovery of stored MPs. This study provides insights into the anthropogenic influences on MP occurrence, and supports policymakers in managing and controlling plastic contamination in large freshwater systems in the "new normal" phase.

Effects of plastisphere on phosphorus availability in freshwater system: Critical roles of polymer type and colonizing habitat.

Biofilm covered microplastics (BMPs) can act as vectors for the transport of exogenous microbial groups to aquatic ecosystem. However, a consensus regarding the formation and development of BMPs and their effect on phosphorus (P) availability has not been reached. Herein, plastic particles made of fuel-based (PET) and biobased polymers (PLA) were deployed in water and hyporheic zones of an urban river for biofilm colonization. Then, BMPs were transferred to lab incubation to study their effects on the P availability. The results showed that different microplastic biofilms had various bacteria and phytoplankton compositions. Additionally, BMPs induced a shift in the microbial co-occurrence patterns co-differentiated by polymer type and colonizing habitats. Network analyses revealed that the structure of PLA BMPs was more robust, while PET colonized in the hyporheic zone reduced network complexity with looser connections between species, and stronger negatively correlated interactions. However, PET formed denser biofilms by the excretion of extracellular polymeric substances from microalgae, which contributed to the better capacity of P utilization. PET colonized in the water/hyporheic zone significantly decreased soluble reactive phosphate by 42.5 % and 30.8 %, respectively. The abovementioned results indicated that BMPs have the potential to disrupt nutrient availability. This study broadens our perspectives for the ecological effects of BMPs in the aquatic environment.

Effects of size and surface charge on the sedimentation of nanoplastics in freshwater.

The environmental issues caused by nanoplastics (NPs) are increasingly noticeable. Environmental behavior study of the NPs could provide vital information for their environmental impact assessment. However, associations between NPs' inherent properties and their sedimentation behaviors were seldom investigated. In this study, six types of PSNPs (polystyrene nanoplastics) with different charges (positive and negative) and particle sizes (20-50 nm, 150-190 nm and 220-250 nm) were synthesized, and their sedimentations under different environmental factors, (e.g., pH value, ionic strength (IS), electrolyte type and natural organic matter) were investigated. Results displayed that both particle size and surface charge would affect the sedimentation of PSNPs. The maximum sedimentation ratio of 26.48% was obtained in positive charged PSNPs with size of 20-50 nm, while the minimum sedimentation ratio of 1.02% was obtained in negative charged PSNPs with size of 220-250 nm at pH 7.6. The pH value shift (range of 5-10) triggered negligible changes of sedimentation ratio, the average particle size and the Zeta potential. Small size PSNPs (20-50 nm) showed higher sensitivity to IS, electrolyte type and HA condition than large size PSNPs. At high IS value ( [Formula: see text]  = 30 mM or ISNaCl = 100 mM), the sedimentation ratios of the PSNPs all increased differently according to their properties, and the sedimentation promoting effect of CaCl2 was more significant on negative charged PSNPs than positive charged PSNPs. When [Formula: see text] increased from 0.9 to 9 mM, the sedimentation ratios of negative charged PSNPs increased by 0.53%-23.49%, while that of positive charged PSNPs increased by less than 10%. Besides, humic acid (HA) addition (1-10 mg/L) would lead to a stable suspension status for PSNPs in water with different degree and perhaps different mechanism due to their charge characteristics. These results showed new light on influence factor studies of NPs' sedimentation and would be helpful for further knowledge of NPs' environmental behaviors.

Aging of poly (lactic acid)/poly (butylene adipate-co-terephthalate) blends under different conditions: Environmental concerns on biodegradable plastic.

Biodegradable plastics (BPs) have been used to replace conventional plastics owing to their environmental harmless and ease of degradation. However, the aging processes of BPs in different environments remain unclear. In this study, we used poly (lactic acid)/poly (butylene adipate-co-terephthalate) (PLA/PBAT) films as model BPs and investigated the 30-d aging behavior of PLA/PBAT films under four conditions (i.e., air without ultraviolet (UV) irradiation, water without UV irradiation, air with UV irradiation, and water with UV irradiation). Our results showed that the aging of PLA/PBAT films was insignificant in all groups except the water with UV irradiation group. In the physical characterization, the PLA/PBAT films exhibited layered structures in water with UV irradiation condition, and the submicron- and nano-sized particles adhered to the bigger-sized fragments. In the chemical characterization, the carbonyl index (CI) of PLA/PBAT films in water with UV irradiation condition decreased from 3.84 to 1.36, and the oxygen-to-carbon (O/C) ratio reached a maximum of 1.78 at 20 d and declined to 0.49 at 30 d, indicating that the oxygen-containing functional groups underwent bond breaking and showed a rapid aging process. This is mainly attributed to the combined effect of hydrolysis and photolysis increases the contact area of PLA/PBAT films and accelerates the aging process. Furthermore, based on two-dimensional correlation spectroscopy (2D-COS) analysis, we suggest that free radicals generated in water with UV irradiation conditions also accelerate the aging process of PLA/PBAT films. This study explored the aging processes of PLA/PBAT films under different conditions, which could aid in clarifying the environmental behavior and provide further information to assess the potential risks of BPs.

Sorption of selected pharmaceutical compounds on polyethylene microplastics: Roles of pH, aging, and competitive sorption.

Microplastics (MPs) as the carrier of pharmaceuticals in aquatic environments have been concerned in recent years. However, the influences of environmental factors on the sorption of pharmaceuticals onto MPs, particularly the effect of the simultaneous sorption by MPs of different pharmaceuticals in multi-solute systems are still unclear. This study investigated the influences of pH, aging of MPs, and competition of pharmaceuticals on the sorptions of sulfamethoxazole (SMX), propranolol (PRP), and sertraline (SER) onto polyethylene MPs. In the 96 h pH-dependent experiments, the sorptions of the three pharmaceuticals were mainly driven by hydrophobic interaction. Besides, the ionization states of the three pharmaceuticals varied with the pH ranging from 2.00 to 12.00, and electrostatic interaction would affect the sorption affinities of the pharmaceuticals in different ionization states. In the aged MPs experiments, the MPs aged by UV irradiation showed a stronger sorption capacity than the pristine ones. Across the MPs under different UV irradiation durations, the 6 d aged MPs showed the highest sorption percentages of 23.0% and 17.6% for SER and PRP, respectively; for SMX, the highest sorption percentage of 5.4% was recorded with the 10 d aged MPs. In the multi-solute systems, the sorption kinetics of the three pharmaceuticals fit well with the pseudo-second-order model. The sorption quantities of the three pharmaceuticals onto MPs followed the order of SER cations (18.70 µg g-1) > SMX anions (7.83 µg g-1) > PRP cations (3.80 µg g-1) at pH 7.00. The good fitting of the Freundlich model suggested a multilayer sorption of the three pharmaceuticals onto MPs. The SER with higher hydrophobicity would preferentially be adsorbed onto MPs and influenced the subsequently sorption processes of the other pharmaceuticals via electrostatic interactions. This may change the environmental fate of the contaminants, which should be carefully considered in future work.

Effects of nanoplastics on microalgae and their trophic transfer along the food chain: recent advances and perspectives.

Nanoplastics (NPs) have drawn increasing attention in recent years due to their potential threats to aquatic ecosystems. Microalgae are primary producers, which play important roles in the normal functioning of ecosystems. According to the source of production and laboratory experiments, both NPs and microalgae are likely to be widely found in various water environments, so they have a great chance of interacting with each other. Although tremendous efforts have been made to explore these potential interactions, a timely and critical review is still missing. In this paper, the effects of NPs on microalgae and their trophic transfer along the food chain are summarized. The toxic impact of NPs on microalgae is tightly associated with the concentrations, sizes and surface charge of NPs, as well as the microalgal species. In addition, NPs could also interact with many other contaminants, thus leading to combined effects on microalgae. NP exposure might block substance and energy exchange between microalgae and their surrounding environment, lead to a shading effect on microalgae, promote the production of reactive oxygen species (ROS) or induce direct physical damage on microalgae, thereby inhibiting the growth of microalgae. Moreover, NPs could also be trophically transferred along the food chain through microalgae and subsequently affect the species at a higher trophic level. Yet importantly, current understanding of the interactions between NPs and microalgae is still quite limited, and needs to be further studied.

Interactive effects of microplastics and selected pharmaceuticals on red tilapia: Role of microplastic aging.

The present study used red tilapia (Oreochromis niloticusas) as the model fish to compare the interactive effects between aged and virgin microplastics (MPs) with the antibiotic sulfamethoxazole (SMX) and the ß-blocker propranolol (PRP). To this end, the ultraviolet irradiation was used to simulate the MP aging in the environment. The accumulations of MPs and pharmaceuticals, and changes in enzyme activities and genes expressions in tilapia were also evaluated. Some physical properties of MPs changed during the aging process, reflected by 0.27- and 0.16-fold increases in the specific surface area and average pore volume, respectively. And more carbonyl formation was observed on the surface of aged MPs. Compared to the 14-d coexposure with virgin MPs, the MP aging increased the accumulation of PRP by 82.3% in the brain, whereas decreased the concentration of SMX by 46.1% in the gills. The stress on tilapia caused by the MPs and PRP was alleviated by the aging process, largely related to the lower neurotoxicity and reduced lipid peroxidation damages. However, the coexposure to aged MPs and SMX would result in higher inhibitions of cytochrome P450 enzymes activities. The results of the transcriptomics showed that the MP aging mainly influenced the expression of genes related to the metabolic process, immune system process, and the genetic information process in tilapia under the coexposure to MPs and pharmaceuticals. Collectively, our results suggest that the MP aging could induce complex changes in the interactive effects between MPs and pharmaceuticals on aquatic organisms.

Toxicological effects of nano- and micro-polystyrene plastics on red tilapia: Are larger plastic particles more harmless?

Nanoplastics (NPs) and microplastics (MPs) are a heterogeneous class of pollutants with diverse sizes in aquatic environments. To evaluate the hazardous effects of N/MPs with different sizes, the accumulation, oxidative stress, cytochrome P450 (CYP) enzymes, neurotoxicity, and metabolomics changes were investigated in the red tilapia exposed to three sizes of polystyrene (PS) N/MPs (0.3, 5, and 70 - 90 µm). After 14-d exposures, the largest particles (70 - 90 µm) showed the highest accumulation levels in most cases. Exposures to PS-MPs (5 and 70 - 90 µm) caused a more severe oxidative stress in red tilapia than PS-NPs. The activity of CYP3A-related enzyme was obviously inhibited by PS-NPs, whereas the CYP enzymes in the liver may not be sensitive to MP exposures. In the brain, only 5 µm PS-MPs significantly inhibited the acetylcholinesterase activity. After exposures, the treatments with 0.3, 5, and 70 - 90 µm N/MPs resulted in 31, 40, and 23 significantly differentially expressed metabolites, respectively, in which the pathway of tyrosine metabolism was significantly affected by all the three PS-N/MP exposures. Overall, the PS particles within the µm size posed more severe stress to red tilapia. Our results suggest that the toxicity of N/MPs may not show a simply monotonic negative correlation with their sizes.

Interactive effects of polystyrene microplastics and roxithromycin on bioaccumulation and biochemical status in the freshwater fish red tilapia (Oreochromis niloticus).

There are hundreds of thousands metric tons of microplastics (MPs) present in aquatic environments. The MPs coexist with other pollutants in water bodies, such as pharmaceuticals, and may carry and transfer them into aquatic organisms, consequently causing unpredictable ecological risks. The purpose of the present study was to evaluate the effect of the presence of polystyrene microplastics (PS-MPs) on the distribution and bioaccumulation of roxithromycin (ROX) in freshwater fish red tilapia (Oreochromis niloticus) as well as their interactive biochemical effects in red tilapia. PS-MPs were found to enhance the bioaccumulation of ROX in fish tissues compared to ROX-alone exposure. In the treatment of PS-MPs (100 µg L-1) combined with ROX (50 µg L-1), the highest concentrations of ROX reached 39,672.9 ±â€¯6311.4, 1767.9 ±â€¯277.8, 2907.5 ±â€¯225.0, and 4307.1 ±â€¯186.5 µg kg-1 in gut, gills, brain, and liver, respectively. Furthermore, compared to the ROX alone, the neurotoxicity caused by ROX was alleviated due to the presence of MPs after 14 d of exposure. The activities of cytochrome P450 (CYP) enzymes [7-ethoxyresorufin O-deethylase (EROD) and 7-benzyloxy-4-trifluoromethyl-coumarin O-dibenzyloxylase (BFCOD)] in fish livers exposed to all co-exposure treatments exhibited great variability compared to ROX alone after 14 d of exposure, suggesting that the presence of MPs may affect the metabolism of ROX in tilapia. Compared with ROX alone, the superoxide dismutase (SOD) activity increased significantly, and malondialdehyde (MDA) contents decreased in the co-exposure treatments, showing that oxidative damage in situations of co-exposure to MPs and ROX was mitigated in fish livers after 14 d of exposure. Collectively, the presence of MPs could affect the fate and toxicity of other organic pollutants in fish. The results emphasize the importance to study the interactions between MPs and other organic pollutants in aquatic environments.

Biodegradable atrial septal defect occluders: A current review.

Atrial septal defect (ASD) is a common structural congenital heart disease. With the development of interventional closure devices and transcatheter techniques, interventional closure therapy has become the most well-accepted therapeutic alternative worldwide, as it offers a number of advantages over conventional therapies such as improved safety, easier operation, lower complication rates and invasiveness, and shorter anesthetic time and hospitalizations. During the past decades, various types of occluders based on nondegradable shape memory alloys have been used in clinical applications. Considering that the permanent existence of foreign nondegradable materials in vivo can cause many potential complications in the long term, the research and development of biodegradable occluders has emerged as a crucial issue for interventional treatment of ASD. This review aims to summarize partially or fully biodegradable occlusion devices currently reported in the literature from the aspects of design, construction, and evaluation of animal experiments. Furthermore, a comparison is made on the advantages and disadvantages of the materials used in biodegradable ASD occlusion devices, followed by an analysis of the problems and limitations of the occlusion devices. Finally, several strategies are proposed for future development of biodegradable cardiac septal defect occlusion devices. STATEMENT OF SIGNIFICANCE: Although occlusion devices based on nondegradable alloys have been widely used in clinical applications and saved numerouspatients, biodegradable occlusion devices may offer some advantages such as fewer complications, acceptable biocompatibility, and particularly temporary existence, thereby leaving "native" tissue behind, which will certainly become the development trend in the long term. This review summarizes almost all partially or fully biodegradable occlusion devices currently reported in the literature from the aspects of design, construction, and evaluation of animal experiments. Furthermore, a comparison is made on the advantages and disadvantages of the materials used in biodegradable ASD occlusion devices, followed by an analysis of the problems and limitations of the occlusion devices. Finally, several strategies are proposed for future development of biodegradable cardiac septal defect occlusion devices.

Sorption and desorption of selected pharmaceuticals by polyethylene microplastics.

The aim of the present study was to evaluate the sorption and desorption of sulfamethoxazole (SMX), propranolol (PRP) and sertraline (SER) by polyethylene (PE) microplastics in water. After the 96 h mixture, the sorption percentages of pharmaceuticals on PE microplastics decreased according to the following order: SER (28.61%) > PRP (21.61%) > SMX (15.31%). The sorption kinetics were fitted well with the pseudo-second-order model. Both linear and Freundlich models were able to describe the sorption isotherm. The results suggest that the sorption process of the pharmaceuticals may be adequately described by their hydrophobicity and electrostatic interactions. The desorption results showed that 8% and 4% of PRP and SER, respectively, were released from the microplastics within 48 h, but the sorption of SMX was irreversible. The results indicate the potential risks of PRP and SER for bioaccumulation in aquatic organisms via ingestion of the microplastics in aquatic environments.

Accumulation, tissue distribution, and biochemical effects of polystyrene microplastics in the freshwater fish red tilapia (Oreochromis niloticus).

While the presence of microplastics (MPs) in marine environments has been detected worldwide, the importance of MPs pollution in freshwater environments has also been emphasized in recent years. However, the body of knowledge regarding the biological effects of MPs on freshwater organisms is still much more limited than on marine organisms. The aim of the present study was to evaluate the accumulation and tissue distribution of MPs in the freshwater fish red tilapia (Oreochromis niloticus), as well as the biochemical effects of MPs on O. niloticus. During 14 days of exposure to 0.1 µm polystyrene-MPs at concentrations of 1, 10, and 100 µg L-1, the MPs concentrations in various tissues of O. niloticus generally increased over time following the order gut > gills > liver ≈ brain. Moreover, the acetylcholinesterase (AChE) activity in the fish brain was inhibited by MPs exposure, with a maximum inhibition rate of 37.7%, suggesting the potential neurotoxicity of MPs to freshwater fish. The activities of cytochrome P450 (CYP) enzymes [7-ethoxyresorufin O-deethylase (EROD) and 7-benzyloxy-4-trifluoromethyl-coumarin O-dibenzyloxylase (BFCOD)] in the fish liver exhibited clear temporal variabilities, with significant decreases followed by elevations compared to the control. The alterations of the EROD and BFCOD activities indicate the potential involvement of CYP enzymes for the metabolism of MPs. The activity of antioxidative enzyme superoxide dismutase (SOD) in the liver was significantly induced throughout the exposure period, while the malondialdehyde (MDA) content did not vary with MPs exposure, suggesting that the antioxidative enzymatic system in O. niloticus could prevent oxidative damage. These results highlight the ingestion and accumulation of MPs in different tissues of freshwater fish, which lead to perturbations in fish biological systems and should be considered in environmental risk assessment.

[The common and variation peak ratio dual index sequence analysis on UV fingerprint spectra of Paeonia Lactiflora Pall].

Baishao and Chishao (Paeonia Lactiflora Pall.) and their close relative Danpi (Paeonia Suffruticosa Andr) samples were estimated quantitatively, based on their UV fingerprint spectra of the extracts obtained with chloroform, ethanol and water, by applying the common and variation peak ratio dual index sequence analysis method. The analytical results showed that the Baishao samples B2, B3 and B4 from the closest regions were the most similar samples. Their common peak ratios were larger than 70 percent and their variation peak ratios were less than 33.3 percent. However, there existed obvious differences among Baishao sample group 1 (B1 and B5), group 2 (B2, B3 and B4) and group 3 (B6) from different regions. The common peak ratios among group 1 (B1 and B5) and group 2(B2, B3 and B4) were lower than 60 percent, while those among group 1 (B1 and B5) and group 3 (B6) were less than 57 percent. The Baishao samples B1 and B5 from the same region collected in different years were of significant disparity, their common peak ratio was only 44.4 percent, but their variation peak ratios were larger than 100 percent. In fact, this method reaches the limitation of quantitative identification of herbs, and can distinguish at least two samples quantitatively.

Removal of cyanobacterial blooms in Taihu Lake using local soils. II. Effective removal of Microcystis aeruginosa using local soils and sediments modified by chitosan.

After sepiolite was modified with Fe3+ to increase its surface charge, the initial algal removal rate increased significantly, but its Q8h was not improved substantially at clay loadings below 0.1 g/L. Modification on netting and bridging properties of clays by either chitosan or polyacrylamide (PAM) dramatically increased flocculation (Q8h) of MA cells in freshwaters. Algal removal efficiencies of different solids, including Type III clays, local soils and sediments, were all improved to a similar level of >90% at a total loading of 0.011 g/L (contained 0.001 g/L chitosan) after they were modified with chitosan, making the idea of clearing up algal blooms using local soils/sediments possible. The mechanism of netting and bridging was confirmed to be the most important factor in improving the removal efficiency of cells, whereas clays also played important roles in the sedimentation of the floc.

Medicated Janus fibers fabricated using a Teflon-coated side-by-side spinneret.

A family of medicated Janus fibers that provides highly tunable biphasic drug release was fabricated using a side-by-side electrospinning process employing a Teflon-coated parallel spinneret. The coated spinneret facilitated the formation of a Janus Taylor cone and in turn high quality integrated Janus structures, which could not be reliably obtained without the Teflon coating. The fibers prepared had one side consisting of polyvinylpyrrolidone (PVP) K60 and ketoprofen, and the other of ethyl cellulose (EC) and ketoprofen. To modulate and tune drug release, PVP K10 was doped into the EC side in some cases. The fibers were linear and had flat morphologies with an indent in the center. They provide biphasic drug release, with the PVP K60 side dissolving very rapidly to deliver a loading dose of the active ingredient, and the EC side resulting in sustained release of the remaining ketoprofen. The addition of PVP K10 to the EC side was able to accelerate the second stage of release; variation in the dopant amount permitted the release rate and extent this phase to be precisely tuned. These results offer the potential to rationally design systems with highly controllable drug release profiles, which can complement natural biological rhythms and deliver maximum therapeutic effects.