Fabrication and evaluation of Lambda-Cyhalothrin nanosuspoemulsion with pH- and temperature-responsive based on polyethylene wax as carrier.

Using polyethylene wax (PW) as the coating matrix, the lambda-cyhalothrin-PW nanosuspoemulsion (LC-PW) with a particle size of 80-150nm was prepared through high-speed stirring, hot melt emulsification and ultrasonic dispersion. The formulation and composition of the LC-PW were optimized, the morphology of the LC-PW was analyzed by dynamic light scattering (DLS) and TEM, and the structure of the LC-PW was characterized by UV and IR. The anti-photolysis test showed that LC-PW had a good anti-photolysis performance. Furthermore, LC-PW could sustainably release Lambda-cyhalothrin, which was pH- and temperature dependent. The insecticidal activity analysis in the greenhouse indicated that the toxic strength between LC-PW and LC-SC (lambda-cyhalothrin-suspension concentrate) to Mythimna separata was similar within the same concentration ranges tested, but the insecticidal duration of LC-PW was significantly longer than LC-SC. Thus, the new type of LC-PW with the properties of anti-photolysis and controlled release is suitable for application in the field as a better insecticide.

Effect of heat treatment on the bio-corrosion properties and wear resistance of antibacterial Co-29Cr-6Mo-xCu alloys.

Co-Cr-Mo alloys have been widely used in hip implants due to their good corrosion resistance and good wear resistance. However, complaint is still raising due to infection and inflammation. The addition of Cu has been proven to be an effective way to develop a new kind of Co-based alloy with good antibacterial properties. In this paper, the effect of heat treatment on the corrosion property, the tribology property and the antibacterial property of Cu containing Co-based alloys were investigated in detail. The microstructure observation showed that the as-cast alloys mainly consisted of a dendritic matrix with carbide dispersion at grain boundaries and a fine Cu-rich phase in the matrix and at the carbide/matrix interface. The carbide precipitates and the distribution of Cu phases affected significantly the friction coefficient and wear resistance of Co-xCu alloy. Annealing at 1060 °C/24 h promoted the precipitation of carbide and in turn increased the hardness and wear resistance markedly. Heat treatments, including annealing, solid solution and ageing treatment, enhanced the corrosion resistance of Co-xCu alloy without reduction in antibacterial properties. However, the addition of Cu increased the corrosion resistance and antibacterial properties but reduced the wear resistance especially at high Cu content.

Toxicological Research on Nano and Microplastics in Environmental Pollution: Current Advances and Future Directions.

This review explains the sources of nanoplastics (NPs) and microplastics (MPs), their release, fate, and associated health risks in the aquatic environment. In the 21st century, scientists are grappling with a major challenge posed by MPs and NPs. The global production of plastic has skyrocketed from 1.5 million tons in the 1950s to an astonishing 390.7 million tons in 2021. This pervasive presence of these materials in our environment has spurred scientific inquiry into their potentially harmful effects on living organisms. Studies have revealed that while MPs, with their larger surface area, are capable of absorbing contaminants and pathogens from the surroundings, NPs can easily be transferred through the food chain. As a result, living organisms may ingest them and accumulate them within their bodies. Due to their minuscule size, NPs are particularly difficult to isolate and quantify. Furthermore, exposure to both NPs and MPs has been linked to various adverse health effects in aquatic species, including neurological impairments, disruption of lipid and energy metabolism, and increased susceptibility to cytotoxicity, oxidative stress, inflammation, and reactive oxygen species (ROS) production. It is alarming to note that MPs have even been detected in commercial fish, highlighting the severity of this issue. There are also challenges associated with elucidating the toxicological effects of NPs and MPs, which are discussed in detail in this review. In conclusion, plastic pollution is a pressing issue that governments should tackle by ensuring proper implementation of rules and regulations at national and provincial levels to reduce its health risks.

Genomic insight into domestication of rubber tree.

Understanding the genetic basis of rubber tree (Hevea brasiliensis) domestication is crucial for further improving natural rubber production to meet its increasing demand worldwide. Here we provide a high-quality H. brasiliensis genome assembly (1.58 Gb, contig N50 of 11.21 megabases), present a map of genome variations by resequencing 335 accessions and reveal domestication-related molecular signals and a major domestication trait, the higher number of laticifer rings. We further show that HbPSK5, encoding the small-peptide hormone phytosulfokine (PSK), is a key domestication gene and closely correlated with the major domestication trait. The transcriptional activation of HbPSK5 by myelocytomatosis (MYC) members links PSK signaling to jasmonates in regulating the laticifer differentiation in rubber tree. Heterologous overexpression of HbPSK5 in Russian dandelion (Taraxacum kok-saghyz) can increase rubber content by promoting laticifer formation. Our results provide an insight into target genes for improving rubber tree and accelerating the domestication of other rubber-producing plants.

Biodegradation performance and biofouling control of a halophilic biocarriers-MBR in saline pharmaceutical (ampicillin-containing) wastewater treatment.

This work develops a halophilic biocarriers-MBR for saline pharmaceutical wastewater treatment. The system has effectively treated the ampicillin-containing saline wastewater for 32 days, when the ampicillin concentration is lower than 20 mg/L. The system can tolerate the saline organic wastewater with a reasonable biodegradability (removals of COD over 75%) when the ampicillin concentration is 50 mg/L. The system has a bad performance in biodegradation (COD removals around 60-70%) and fouled within 16 days at a high ampicillin concentration of 100 mg/L. At high transmembrane pressures over 30 KPa, some ampicillin molecules may permeate through the membrane causing decreases in the ampicillin removal. The concentrations of protein and carbohydrate in EPS and SMP have increased over time and with increasing the ampicillin concentration. The method of biofouling control in MBR for the ampicillin situations has been proposed based on monitoring the concentrations of EPS and SMP. The drying-assisted monitoring of membrane biofoulants has showed a better efficiency than the monitoring of transmembrane pressure for membrane anti-biofouling in the treatment of pharmaceutical saline wastewaters where a spectroscopic detection can be hardly applied. This work may benefit relative research works for the control of biodegradation performance and membrane biofouling to better treat saline pharmaceutical wastewaters.

Acute and chronic effects of polystyrene microplastics on brine shrimp: First evidence highlighting the molecular mechanism through transcriptome analysis.

Microplastics contamination is one of the leading environmental catastrophes for the marine ecosystem, but the molecular toxicity mechanism of those microplastics remains elusive. This study aims to determine the acute and chronic toxicity after exposure to polystyrene microplastics in brine shrimp with various concentrations. Our results demonstrated that acute exposure to polystyrene microplastics induced no significant effects on the survival of brine shrimp. Interestingly, the concentration-dependent increase in both bioaccumulation and the generation of reactive oxygen species (ROS) was observed after acute and chronic exposure. Moreover, the histopathology analysis revealed the deformation of epithelial cells in the midgut region after both acute exposures at 100 mg/L and chronic exposure at 1 mg/L to polystyrene microplastics. To elucidate the underlying mechanisms of microplastics-mediated toxicity, the transcriptome analysis was performed after chronic exposure, and the result showed 721 differentially expressed genes (DEGs) associated with 156 known KEGG pathways. 292 DEGs genes were significantly upregulated and 429 genes were significantly downregulated. The transcriptome analysis further revealed the DEGs related pathways. Taken together, this study not only highlighted the negative effects but also provided detailed sequencing data from transcriptome profiling to enhance our understanding of the molecular toxicity of polystyrene microplastics in brine shrimp.

Real-time monitoring of the membrane biofouling based on spectroscopic analysis in a marine MBBR-MBR (moving bed biofilm reactor-membrane bioreactor) for saline wastewater treatment.

A MBBR-MBR system has been developed with marine microorganisms enriched for saline wastewater treatment in this work, showing high COD and NH3-N removals. The behaviour of fouling-related components (EPS and SMP) has been studied as functions of operating time (40-90 days), salinity (0-30 g/L NaCl) and backflow ratio (0-300%, from MBR to MBBR). High biodegradability of the MBBR-MBR at optimal conditions can induce more biodegradation of humic acid-like (λex/λem: 350nm/430 nm) and fulvic acid-like (260nm/445 nm) molecules to soluble microbial by-product-like molecules (275nm/325 nm), reducing the membrane biofouling rate. The biodegradation process is suggested by the excitation-emission matrix (EEM) images. In the study of sudden salinity shock, results show that real-time monitoring the concentration of biofoulants is more effective (operative time extended by 60%) than monitoring the transmembrane pressure (operative time extended by 33%) to prevent membrane fouling. Due to an early warning from the real-time monitoring, the coming membrane-fouling is predictable and the operating conditions, such as backflow ratio, can be changed to minimize the biofouling rate.

Effect of bioflocculation on fouling-related biofoulants in a membrane bioreactor during saline wastewater treatments.

A membrane bioreactor (MBR) was operated in two modes; with and without the inoculation of marine Arthrobacter cells, to investigate the effect of bioflocculation on membrane biofouling during saline wastewater treatments. The MBR-Arthrobacter system showed a higher resistance to membrane fouling than the normal MBR system. Lower concentrations of the fouling-related components and higher removal efficiencies of COD and NH3-N were observed in the MBR-Arthrobacter system. The bioflocculation of Arthrobacter preferred to settle down the humic acid-like, fulvic acid-like and aromatic proteins components (larger biomolecules) rather than the soluble microbial by-product-like components (smaller biomolecules).

Real-time monitoring of biofoulants in a membrane bioreactor during saline wastewater treatment for anti-fouling strategies.

This work presents a novel, fast and simple monitoring-responding method at the very early stages of membrane bio-fouling in a membrane bioreactor (MBR) during saline wastewater treatment. The impacts of multiple environmental shocks on membrane fouling were studied. The transmembrane pressure exceeded the critical fouling pressure within 8days in the case of salinity shock or temperature shock. In the case of DO shock, the transmembrane pressure exceeded the critical fouling pressure after 16days, showing the lower impact of DO shock on the MBR. In another study, the membrane fouling was observed within 4days responding to mixed environmental shocks. To decrease the potential of membrane bio-fouling, another bioreactor was integrated immediately with the MBR as a quickly-responded countermeasure, when an early warning of membrane bio-fouling was provided. After the bioreactor enhancement, the time required for membrane fouling increased from 4 to 10days.

Behaviour of fouling-related components in an enhanced membrane bioreactor using marine activated sludge.

This paper presents an experimental study on behaviour of fouling-related components during saline wastewater treatments in an enhanced mesoporous membrane bioreactor (MBR) system integrated with a biological contact oxidation reactor (BCOR). By monitoring the transmembrane pressure, the MBR system without BCOR assistance was observed to get membrane fouling easier during saline wastewater treatments. Typically, the concentration of total EPS gradually increased in the MBR system over the operation time, while no significant change in its concentration was observed in the BCOR-MBR system. The concentration of total SMP in the MBR system reached high levels earlier than the BCOR-MBR system, causing a significant membrane fouling. Besides, unlike a simple MBR system, the BCOR-MBR system produced more soluble microbial by-product-like components (simple) instead of fulvic acid-like or humic acid-like components (complex) during the saline wastewater treatments, resulting in higher resistance to a membrane fouling.

Poly(lactide-co-glycolide) microspheres for MRI-monitored delivery of sorafenib in a rabbit VX2 model.

Transcatheter arterial embolization and chemoembolization are standard locoregional therapies for hepatocellular carcinoma (HCC). However, these can result in tumor hypoxia, thus promoting tumor angiogenesis. The anti-angiogenic agent sorafenib is hypothesized to improve outcomes; however, oral administration limits patient tolerance. Therefore, the purpose of this study was to fabricate poly(lactide-co-glycolide) microspheres for local sorafenib delivery to tumors during liver-directed embolotherapies. Iron oxide nanoparticles (IONP) were co-encapsulated for magnetic resonance imaging (MRI) of microsphere delivery. Microspheres were fabricated using a double emulsion/solvent evaporation method and characterized for size, sorafenib and IONP content, and MRI properties. MRI was performed before and after intra-arterial microsphere infusions in a rabbit VX2 liver tumor model. The microspheres were 13 microns in diameter with 8.8% and 0.89% (w/w) sorafenib and IONP, respectively. 21% and 28% of the loaded sorafenib and IONP, respectively, released within 72 h. Rabbit VX2 studies demonstrated that sorafenib microspheres normalized VEGFR 2 activity and decreased microvessel density. Quantitative MRI enabled in vivo visualization of intra-hepatic microsphere distributions. These methods should avoid systemic toxicities, with MRI permitting follow-up confirmation of microsphere delivery to the targeted liver tumors.

[Reconstruction of rabbit corneal stroma using tissue engineering technique].

OBJECTIVE: Reconstruct corneal stroma by tissue engineering. METHODS: Primary corneal stromal cells were isolated from newborn rabbit cornea. When the cultured cells reaching confluence, the stromal cells were mixed with polyglycolic acid (PGA) to form a cell-scaffold construct. After 1 week in vitro culture, the constructs were implanted into mother rabbit corneal stroma. Parts of corneal stromal cells were transfected with GFP gene as mark of transplanted cells. Tissues were harvested at 8 weeks for transmission electron microscopy (TEM), histology and Western blot evaluation. In control, PGA alone was implanted into the other cornea. RESULTS: The engineered corneal stroma became transparent gradually over a period of 8 weeks. The histology of engineered stromal lamellar was relatively similar to that of natural one, no significant differences were found in the diameter of cornea collagen fiber [(29.4 +/- 4.7) nm] in experimental rabbits compared with control [(28.5 +/- 3.5) nm], Student's t-test: P = 0.1316 > 0.05. TEM demonstrated that collagen fibrils deposited in engineered stroma had a similar diameter compared to that of normal counterpart. In addition, Western blot showed the positive expression of type I collagen in the collagen fibrils. In contrast, no new stroma tissue was formed when PGA alone implanted. A green colored stroma was observed when engineered with GFP-labeled cells under fluorescence light microscope. CONCLUSION: The results demonstrate that nearly transparent corneal stroma can be obtained by the technique of cornea engineering.

Poly(lactide-co-glycolide) microspheres for MRI-monitored transcatheter delivery of sorafenib to liver tumors.

The multi-kinase inhibitor (MKI) sorafenib can be an effective palliative therapy for patients with hepatocellular carcinoma (HCC). However, patient tolerance is often poor due to common systemic side effects following oral administration. Local transcatheter delivery of sorafenib to liver tumors has the potential to reduce systemic toxicities while increasing the dose delivered to targeted tumors. We developed sorafenib-eluting PLG microspheres for delivery by intra-hepatic transcatheter infusion in an orthotropic rodent HCC model. The particles also encapsulated iron-oxide nanoparticles permitting magnetic resonance imaging (MRI) of intra-hepatic biodistributions. The PLG microspheres (diameter≈1µm) were loaded with 18.6% (w/w) sorafenib and 0.54% (w/w) ferrofluid and 65.2% of the sorafenib was released within 72h of media exposure. In vitro studies demonstrated significant reductions in HCC cell proliferation with increasing doses of the sorafenib-eluting microspheres, where the estimated IC50 was a 29µg/mL dose of microspheres. During in vivo studies, MRI permitted intra-procedural visualization of intra-hepatic microsphere delivery. At 72h after microsphere infusion, microvessel density was significantly reduced in tumors treated with the sorafenib-eluting microspheres compared to both sham control tumors (by 35%) and controls (by 30%). These PLG microspheres offer the potential to increase the efficacy of molecularly targeted MKI therapies while reducing systemic exposures via selective catheter-directed delivery to HCC.

[Correlations of extrocellular matrix metalloproteinase inducer and microvessel density to invasiveness of ameloblastoma].

BACKGROUND & OBJECTIVE: Matrix metalloproteinases (MMPs) are involved in local invasion of ameloblastomas. This study was to evaluate the role of matrix metalloproteinase inducer (EMMPRIN) in angiogenesis in ameloblastomas by analyzing EMMPRIN expression and microvessel density (MVD) in ameloblastomas and odontogenic cysts. METHODS: EMMPRIN expression and MVD in 41 specimens of ameloblastoma and 40 specimens of odontogenic cyst were examined by SP immuno-histochemistry. RESULTS: EMMPRIN was detected in all specimens of ameloblastomas and odontogenic cysts. The strong positive rate of EMMPRIN was significantly higher in ameloblastomas than in odontogenic cysts (85.4% vs. 62.5%, P<0.05). MDV was positively correlated to EMMPRIN expression to some extent (r=0.677, P<0.01). CONCLUSION: EMMPRIN may play an important role during the progression of ameloblastoma via controlling angiogenesis and degradation of extracellular MMPs.