Search

Marine sediments serve as crucial reservoirs for polycyclic aromatic hydrocarbons (PAHs), and their PAH signatures offer valuable historical pollution records. This article provides a comprehensive review of the pollution status of 16 priority PAHs in more than 1000 sediments from the East China Sea (ECS). It focuses on the PAH sources, spatiotemporal distributions, driving factors, and ecological risks, with information derived from peer-reviewed papers published between 2003 and 2023. The results revealed that vehicular emissions, mixed combustion sources of coal, biomass, and coke, as well as petrogenic sources, were the primary contributors to PAH pollution in the ECS sediments, accounting for 50%, 34%, and 16%, respectively. Human activities, hydrodynamic mechanisms, and environmental variables such as particle size and organic matter, collectively influenced the distribution of PAHs. Additionally, the population size and economic development played a key role in the temporal distribution of PAHs in the ECS sediments. The ecotoxicity assessment of PAHs in sediments indicated a low risk level. These outcomes are expected to provide environmentalists with detailed and up-to-date insights into sedimentary PAHs in the ECS, helping to develop suitable monitoring plans and strategies for promoting better management of ECS environment. [Display omitted] • The PAHs in >1000 sediments of the ECS over the past 20 years were reviewed. • The population size and economy played a key role in the PAH historical trend. • LMW PAHs occasionally experience negative ecological effects. • Accurate quantification of the contribution of PAH sources is strongly suggested. • Long-term monitoring of PAHs is suggested for optimizing environmental models. [ABSTRACT FROM AUTHOR]

Biosurfactants combine physicochemical properties with biological activities. Although biosurfactants are often expressed by microorganisms, an increasing amount is produced by chemical synthesis. As many exist in the form of homologous compounds, it is often difficult to purify biosurfactants. But this has not limited the efforts to develop their commercial applications. In this short review, we have featured the recent advances in three important types of biosurfactants, lipopeptides, nucleolipids, and glycolipids. We have focused on comparing some of the key properties and functionalities between modern synthetic versions and their corresponding natural counterparts. We end the review by outlining the needs for not only strengthening their basic structure–property relationships through further research but also developing better technologies, irrespective of direct chemical synthesis or biological synthesis of biosurfactants through constructions of genetically engineered strains, to help advance the commercial use of biosurfactants. [ABSTRACT FROM AUTHOR]

To investigate the effect of apatinib when treating advanced gastric cancer (GC) as well as the mechanism of preventing infection. Methods: From January 2017 to December 2018, 100 advanced GC patients had failed to receive second-line or above treatment in XX Hospital were divided into two groups according to the experimental requirements: the experimental group and the blank group. The experimental group was treated with small molecule targeted drug apatinib, while the blank group was only treated with ordinary drugs. After 4 weeks of treatment, the diagnosis and evaluation were carried out every eight weeks. In this study, the mechanism of infection prevention and prognosis was studied through the internal treatment of GC patients with apatinib. Results: until the end of the fourth week, a significant difference can be seen in the treatment effect between the experimental group as well as the blank group. In the experimental group, the proportion of partial remission + disease stability reached about 73%, while that in the blank group was only about 33%. In addition, apatinib was better than the blank group in the control of adverse reactions like hypertension, proteinuria, myelosuppression as well as diarrhea. In addition, apatinib was better than the blank group when treating AFP positive GC. In terms of the therapeutic effect of apatinib, it is much better than that of the negative group. In addition, apatinib is also better than the blank group in drug resistance for GC patients. It is found that apatinib's anti infection mechanism is to prevent the phosphorylation of vascular endothelial growth factor receptor-2 (VEGFR-2) as well as stop the downstream signal pathway, so as to inhibit the tumor angiogenesis, tumor growth and metastasis, so as to achieve treatment and reduce the probability of infection. Conclusion: the therapeutic effect of small molecule targeting drug apatinib on gastric cancer is better than that of other drugs, whether in therapeutic effect, drug resistance, adverse reactions or infection control. This study has important reference significance for the follow-up treatment of apatinib and cancer. [ABSTRACT FROM AUTHOR]

• The hydrodynamic efficiency of a land-fixed OWC device in 2D and 3D scenarios is compared. • Effects of different incident wave amplitude, incident wave direction and front wall draught on hydrodynamic performance of an OWC device are investigated. • The correlation between 3D effects and the hydrodynamic efficiency of the OWC device is accentuated. • The hydrodynamic efficiency near the resonant frequency exceeds unity in the 3D setup. The hydrodynamic performance of a land-fixed oscillating water column (OWC) wave energy device was thoroughly investigated under various wave conditions and geometric parameters through both experimental and numerical studies in a three-dimensional (3D) wave tank. The study involved the measurement and comparison of water surface elevation, air pressure in the OWC chamber, and hydrodynamic efficiency with the results obtained from the 3D Higher-Order Boundary Element Method (HOBEM). The influences of 3D effects, incident wave amplitude, front wall draught, and incident wave angle on the hydrodynamic performance of the OWC device were analyzed. The results demonstrate that, under actual sea conditions, the 3D effects significantly affect the hydrodynamic efficiency of the OWC, making it exceed unity near the resonance frequency. On the other hand, the incident wave angle was found to have minimal effect on the resonant frequency and varied trend of efficiency. However, the hydrodynamic efficiency decreases with increasing incident wave angle. These results highlight the importance of the consideration of the 3D effects and incident wave angles in optimizing the design and performance of fixed OWC wave energy devices. [ABSTRACT FROM AUTHOR]

[Display omitted] • PCL-co-TA was synthesized with tannic acid as the crosslinking agent. • PCL-co-TA exhibited the ROS-stimuli and neutral pH-stimuli response degradation. • PCL-co-TA integrated the ideal drug release and the antibacterial property. The versatile potential of polycaprolactone (PCL) as degradable implant materials has been wildly studied. Nevertheless, it is still elusive to tailor the degradation rates as well as the evolution of the mechanical performance in vivo. Taking into account the implant materials require different performance as the stage goes on, this work conceived a novel degradation strategy possessing multiple-stimuli response degradation capability, through incorporating tannic acid (TA) as the cross-linking agent into PCL via facile condensation polymerization. The water contents and degradation rates of the PCL-co-TA composite increased with the increase of TA content. Besides the degradation stimulated by reactive oxygen species (ROS), the PCL-co-TA composite shows accelerated degradation in neutral and basic solution with obvious surface erosion and continuous mass loss within 90 days, however, its mechanical properties maintain stable during this period. Moreover, the PCL-co-TA composite shows controllable drug release capacity with linear release for over 40 days and stable antimicrobial properties for both E.coli and S.aureus. This work provides a novel principle to design degradable implant materials with on-demand degradation behavior. The PCL-co-TA composite shows advanced specificity, sensitivity and diversity of controlling the degradation, demonstrates the great potential applications for tissue engineering and intelligent medicine device. [ABSTRACT FROM AUTHOR]

Polyimide hollow fiber membrane module has been tested under low temperature for efficient CO 2 separation. Parametric study was carried out to evaluate separation performance of the designed cryogenic-membrane hybrid system. In detail, the effect of stage cut, feed pressure, operating temperature and CO 2 concentration on gas permeance, CO 2 /N 2 selectivity, CO 2 purity and recovery were investigated. The experimental results indicated that operating temperature played an important role in the separation performance. Reducing stage cut would result in the increase of permeance (up to 302 GPU), CO 2 /N 2 selectivity (up to 20) and CO 2 purity (up to 59%), especially under the low temperature (−20 °C). The variation of gas permeance depended on the competition between the compression and swelling effect of the free volume. When the operating temperature and feed pressure were set at −20 °C and 700 kPa, the CO 2 recovery could be improved to 93%. Although the permeance, CO 2 /N 2 selectivity and recovery adversely decreased with the increase of feed CO 2 concentration, the CO 2 purity could be increased to 40% with the feed pressure of 400 kPa. The cryogenic-membrane hybrid system presented a potential in enhancing the CO 2 removal efficiency. [ABSTRACT FROM AUTHOR]

Introduction Focal nodular hyperplasia (FNH) is a benign lesion of the liver which is usually found in healthy adults, however, FNH is rare in children, and comprises only 2% of all pediatric liver tumors. Herein, we report the case of a 6-year-old child (male) with a huge FNH which size is more than 10 cm. This could be the biggest FNH among all children’s FNH cases ever reported. Case presentation A 6-year-old boy was found a hepatic space-occupying lesion two years ago. As the time went by, the lesion became bigger gradually. The last CT examination showed the size of the tumor to be 10.5 × 9.9 cm in the right hepatic lobe. This child underwent surgical resection of the tumor which was confirmed as FNH (11 × 8 × 7 cm) by pathology. Conclusion FNH is a benign lesion of the liver, and it is characterized by hepatocyte hyperplasia and a central stellate scar. It is uncommon for FNH to be diagnosed in children. Such huge FNH (about 11 cm) is extremely rare. Surgical operation may be the effective method to cure huge FNH. [ABSTRACT FROM AUTHOR]

Answering complex questions involving multiple relations over knowledge bases is a challenging task. Many previous works rely on dependency parsing. However, errors in dependency parsing would influence their performance, in particular for long complex questions. In this paper, we propose a novel skeleton grammar to represent the high-level structure of a complex question. This lightweight formalism and its BERT-based parsing algorithm help to improve the downstream dependency parsing. To show the effectiveness of skeleton, we develop two question answering approaches: skeleton-based semantic parsing (called SSP) and skeleton-based information retrieval (called SIR). In SSP, skeleton helps to improve structured query generation. In SIR, skeleton helps to improve path ranking. Experimental results show that, thanks to skeletons, our approaches achieve state-of-the-art results on three datasets: LC-QuAD 1.0, GraphQuestions, and ComplexWebQuestions 1.1. • A skeleton grammar to sketch a complex question. • A BERT-based skeleton parser. • A large skeleton bank for complex questions. • A skeleton and semantic parsing based KBQA system. • A skeleton and information retrieval based KBQA system. [ABSTRACT FROM AUTHOR]

Peptide nucleic acid (PNA) has many applications in molecular biology and biotechnology, and research continues on modifying the PNA backbone to improve its functionality. We synthesized PNA in our case, artificial DNA that contains neutral succimamide as internucleoside linkages and applied it to mismatch recognition. We embedded the succinamide linkages into DNA by incorporating thymidine–succinamide–thymidine (TST) phosphoramidite at specific sites via standard DNA synthesis. Ultraviolet spectroscopy and melting temperature experiments suggested that such mixed-backbone DNA forms a B-type duplex with natural DNA. We observed a 20 kJ/mol decrease in enthalpy when we incorporated a succinamide linkage into a DNA–PNA duplex. We examined mismatch recognition of the mixed-backbone DNA, and observed that TST embedded DNA recognizes T-C mismatches. The replacement of anionic phosphate unit in DNA with neutral succinamide linker leads to significant T-C mismatch discrimination. Image 1 • In this work, we replaced the anionic phosphate units in DNA with neutral succinamide linker, obtained a series of mixed backbone artificial DNA. • The mixed backbone DNA contains succinamide linker exhibited high sensitivity in detecting T-C mismatch. • We also noted that the structure modification could improve the DNA's enzymatic resistance toward exonuclease. [ABSTRACT FROM AUTHOR]

Abstract: Physiologic and phenotypic alterations in the context of antibiotic resistance have been extensively studied in some bacteria. However there are not enough data addressing these alterations due to macrolide resistance in Campylobacter jejuni. The present study examined the fitness cost imposed by different macrolide resistance mutations and the phenotypic alterations due to exposure to macrolides in C. jejuni. C. jejuni was induced with different macrolide agents to obtain different macrolide resistance mutations. The results revealed that the mutations significantly imposed defect variations on the doubling time and the relative fitness in the resistant strains when competed against the susceptible strain. Furthermore macrolides through induction or exposure to sub-MIC concentrations impaired the motility of C. jejuni in 0.4% MH agar plates. Electron microscope analysis revealed the absence of flagellar filaments from strains exposed to macrolides. SDS-PAGE demonstrated that macrolides have no effect on protein synthesis and immunoblotting analysis further confirmed that flagellin was fully synthesized within C. jejuni strains exposed to macrolides. Nevertheless C. jejuni strains exposed to macrolides demonstrated defect in their excreted flagellin into the supernatant compared to strains not exposed to macrolides. Accordingly we speculated that macrolides inhibited flagellar filament formation in the strains exposed to macrolides via affecting the secretion of flagellin without affecting the amount synthesized within the bacteria. Taken together these findings demonstrated that different macrolide resistance mutations imposed different fitness costs and exposure to macrolides resulted in phenotypic alterations such as inhibition of flagellar filament formation and loss of motility in C. jejuni. [Copyright &y& Elsevier]

Abstract: The combination of [Cp*IrCl2]2 with N-(2-aminoethyl)-4-(trifluoromethyl)benzenesulfonamide constitutes an efficient catalyst for selective transfer hydrogenation of a variety of quinoxalines in water with HCOONa as the hydrogen source, affording the corresponding tetrahydroquinoxalines in good to excellent yields. The catalyst is air-stable, and the reduction could be performed without nitrogen protection. The aqueous phase reduction is shown to be highly pH-dependent, with acidic pH leading to better results. There exits a pH window for optimum rate, and the use of HOAc/NaOAc buffer solution is essential for maintaining a stable pH during the reaction. [Copyright &y& Elsevier]

Purpose Natural product Poria cocos possesses antitumor effect. This study will explore the molecular mechanism of Poria cocos combined with chemotherapy in the inhibition of gastric cancer cell EMT process. Methods The experiment was divided into blank control group, Poria cocos group, oxaliplatin group and Poria cocos combined with oxaliplatin group. Scratch and Transwell assay were used to detect cell migration and invasion respectively. RT-qPCR and Western Blot analyses were used to detect mRNA and protein expression of the epithelial-mesenchymal transition (EMT) related factors including Snail, Twist, Vimentin, E-cadherin and N-cadherin respectively. Morphologic assessment was performed with HPIAS-1000 automated image analysis system. Results The migration and invasion abilities of gastric cancer cells in the Poria cocos combined with oxaliplatin group were significantly decreased (P < 0.01). The mRNA and protein expression of Snail, Twist, Vimentin and N-cadherin were significantly decreased while the mRNA and protein expression of E-cadherin were significantly increased (P < 0.01) compared with blank control group. Nude mice model of gastric cancer was successfully established. Poria cocos combined with oxaliplatin could significantly inhibit gastric tumor progression. The expression of EMT related factors were consistent with in vitro study. Morphologic assessment showed that the nucleus area, perimeter, mean diameter, volume, long diameter and shape factor in the Poria cocos combined with oxaliplatin group were significantly different compared with the blank control group (P < 0.01) but not significantly different compared with the normal control. Conclusions Poria cocos combined with oxaliplatin could significantly inhibit the migration and invasion of gastric cancer cells. Through both in vitro and in vivo studies, it is confirmed that Poria cocos combined with oxaliplatin could significantly inhibit the EMT process of gastric cancer. Poria cocos combined with oxaliplatin could significantly affect the morphology changes of gastric cancer cells. These findings may provide a theoretical guidance for the clinical treatment of gastric cancer. [ABSTRACT FROM AUTHOR]

Supramolecular hydrogels exhibit promising potential in biological and clinical fields due to their special dynamic properties. However, most existing supramolecular hydrogels suffer from poor mechanical strength, which severely limits their applications. Here in this study, the Kinetically Interlocking Multiple-Units (KIMU) strategy was applied to the hyaluronan networks by introducing different supramolecular interaction motifs in an organized and alternative manner. Our strategy successfully elevated the energy barrier of crosslinker dissociation to 103.0 kJ mol-1 and increased the storage modulus of hydrogels by 78 % with the intrinsic dynamic properties preserved. It can be expected that this method would bring a convenient and effective route to fabricate novel supramolecular materials with excellent mechanical properties. [Display omitted] [ABSTRACT FROM AUTHOR]

• MPX has a good killing effect on A. pleuropneumoniae better than that of PR39. • MPX significantly reduces A. pleuropneumoniae biofilm formation. • MPX downregulates virulence gene expression of A. pleuropneumonia. • Sap A gene plays an important role in A. pleuropneumoniae resistance to MPX. • MPX significantly reduces lung damage induced by A. pleuropneumoniae infection in vivo. Actinobacillus pleuropneumoniae is the causative agent of highly contagious and fatal respiratory infections, causing substantial economic losses to the global pig industry. Due to increased antibiotic resistance, there is an urgent need to find new antibiotic alternatives for treating A. pleuropneumoniae infections. MPX is obtained from wasp venom and has a killing effect on various bacteria. This study found that MPX had a good killing effect on A. pleuropneumoniae and that the minimum inhibitory concentration (MIC) was 16 μg/mL. The bacterial density of A. pleuropneumoniae decreased 1000 times after MPX (1 × MIC) treatment for 1 h, and the antibacterial activity was not affected by pH or temperature. Fluorescence microscopy showed that MPX (1 × MIC) destroyed the bacterial cell membrane after treatment for 0.5 h, increasing membrane permeability and releasing bacterial proteins and Ca2+, Na+ and other cations. In addition, MPX (1 × MIC) treatment significantly reduced the formation of bacterial biofilms. Quantitative RT-PCR results showed that MPX treatment significantly upregulated the expression of the PurC virulence gene and downregulated that of ApxI, ApxII, and Apa1. In addition, the Sap A gene was found to play an important role in the tolerance of A. pleuropneumoniae to antimicrobial peptides. Therapeutic evaluation in a murine model showed that MPX protects mice from a lethal dose of A. pleuropneumoniae and relieves lung inflammation. This study reports the use of MPX to treat A. pleuropneumonia infections, laying the foundation for the development of new drugs for bacterial infections. [ABSTRACT FROM AUTHOR]