Effects of lipids on the rate-limiting steps in the dark-to-light transition of Photosystem II core complex of Thermostichus vulcanus.

In our earlier works, we have shown that the rate-limiting steps, associated with the dark-to-light transition of Photosystem II (PSII), reflecting the photochemical activity and structural dynamics of the reaction center complex, depend largely on the lipidic environment of the protein matrix. Using chlorophyll-a fluorescence transients (ChlF) elicited by single-turnover saturating flashes, it was shown that the half-waiting time (Δτ 1/2) between consecutive excitations, at which 50% of the fluorescence increment was reached, was considerably larger in isolated PSII complexes of Thermostichus (T.) vulcanus than in the native thylakoid membrane (TM). Further, it was shown that the addition of a TM lipid extract shortened Δτ 1/2 of isolated PSII, indicating that at least a fraction of the 'missing' lipid molecules, replaced by detergent molecules, caused the elongation of Δτ 1/2. Here, we performed systematic experiments to obtain information on the nature of TM lipids that are capable of decreasing Δτ 1/2. Our data show that while all lipid species shorten Δτ 1/2, the negatively charged lipid phosphatidylglycerol appears to be the most efficient species - suggesting its prominent role in determining the structural dynamics of PSII reaction center.

Insights into interaction of triazine herbicides with three kinds of different alkyl groups (simetryne, ametryn and terbutryn) with human serum albumin via multi-spectral analysis.

In this study, the interaction of triazine herbicides with three kinds of different alkyl groups (simetryne, ametryn and terbutryn) with human serum albumin (HSA) are investigated through UV-vis, fluorescence, and circular dichroism (CD) spectra. The mechanisms on the fluorescence quenching of HSA initiated by triazine herbicides are obtained using Stern-Volmer, Lineweaver-Burk and Double logarithm equations. The quenching rate constant (Kq), Stern-Volmer quenching constant (Ksv), binding constant (KA), thermodynamic parameters such as enthalpy change (∆H), entropy change (∆S) and Gibbs free energy (∆G) and number of binding site (n) are calculated and compared. The variations in the microenvironment of amino acid residues are studied by synchronous fluorescence spectroscopy. The binding sites and subdomains are identified using warfarin and ibuprofen as site probes. The conformational changes of HSA are measured using CD spectra. The results reveal that the triazine herbicides with different alkyl groups can interact with HSA by static quenching. The combination of the three herbicides and HSA are equally proportional, and the binding processes are spontaneous. Hydrophobic interaction forces play important roles in simetryne-HSA and ametryn-HSA, while the interaction of terbutryn-HSA is Van der Waals forces and hydrogen bonding. Moreover, the three herbicides can bind to HSA at site I (sub-domain IIA) more than site II (subdomain IIIA), and combine with tryptophan (Trp) more easily than tyrosine (Tyr) residues, respectively. By comparison, the order of interaction strength is terbutryn-HSA > ametryn-HSA > simetryne-HSA. Terbutryn can destroy the secondary structure of HSA more than simetryne and ametryn, and the potential toxicity of terbutryn is higher. It is expected that the interactions of triazine herbicides with HSA via multi-spectral analysis can offer some valuable information for studying the toxicity and the harm of triazine herbicides on human health at molecular level in life science.

Interaction of different chloro-substituted phenylurea herbicides (diuron and chlortoluron) with bovine serum albumin: Insights from multispectral study.

In this work, the interaction between different chloro-substituted phenylurea herbicides (diuron (DIU) and chlortoluron (CHL)) and BSA were investigated and compared at three different temperatures (283 K, 298 K and 310 K) adopting UV-vis, fluorescence, and circular dichroism spectra. The quenching mechanism of the interaction was also proposed. The energy transfer between BSA and DIU/CHL was investigated. The binding sites of DIU/CHL and BSA and the variations in the microenvironment of amino acid residues were studied. The changes of the secondary structure of BSA were analyzed. The results indicate that both DIU and CHL can significantly interact with BSA, and the degree of the interaction between DIU/CHL and BSA increases with the increase of the DIU/CHL concentration. The fluorescence quenching of BSA by DIU/CHL results from the combination of static and dynamic quenching. The DIU/CHL has a weak to moderate binding affinity for BSA, and the binding stoichiometry is 1:1. Their binding processes are spontaneous, and hydrophobic interaction, hydrogen bonds and van der Waals forces are the main interaction forces. DIU/CHL has higher affinity for subdomain IIA (Site I) of BSA than subdomain IIIA (Site II), and also interacts with tryptophan more than tyrosine residues. The energy transfer can occur from BSA to DIU/CHL. By comparison, the strength of the interaction of DIU-BSA is always greater than that of CHL-BSA, and DIU can destroy the secondary structure of BSA molecules greater than CHL and thus the potential toxicity of DIU is higher due to DIU with more chlorine substituents than CHL. It is expected that this study on the interaction can offer in-depth insights into the toxicity of phenylurea herbicides, as well as their impact on human and animal health at the molecular level.

Quantifying the Energy Spillover between Photosystems II and I in Cyanobacterial Thylakoid Membranes and Cells.

The spatial separation of photosystems I and II (PSI and PSII) is thought to be essential for efficient photosynthesis by maintaining a balanced flow of excitation energy between them. Unlike the thylakoid membranes of plant chloroplasts, cyanobacterial thylakoids do not form tightly appressed grana stacks that enforce strict lateral separation. The coexistence of the two photosystems provides a ground for spillover-excitation energy transfer from PSII to PSI. Spillover has been considered as a pathway of energy transfer from the phycobilisomes to PSI and may also play a role in state transitions as means to avoid overexcitation of PSII. Here, we demonstrate a significant degree of energy spillover from PSII to PSI in reconstituted membranes and isolated thylakoid membranes of Thermosynechococcus (Thermostichus) vulcanus and Synechocystis sp. PCC 6803 by steady-state and time-resolved fluorescence spectroscopy. The quantum yield of spillover in these systems was determined to be up to 40%. Spillover was also found in intact cells but to a considerably lower degree (20%) than in isolated thylakoid membranes. The findings support a model of coexistence of laterally separated microdomains of PSI and PSII in the cyanobacterial cells as well as domains where the two photosystems are energetically connected. The methodology presented here can be applied to probe spillover in other photosynthetic organisms.

Punicalagin alleviates the hyperproliferation of keratinocytes in psoriasis through inhibiting SKP2 expression.

Psoriasis is a chronic inflammatory skin disorder characterized by abnormal keratinocytes proliferation and multiple immune cells infiltration in the dermis and epidermis. Although most psoriasis-related researches have been concentrated on the interleukin-23 (IL-23)/interleukin-17 (IL-17) axis, new data suggest that keratinocytes also play a pivotal role in psoriasis. Previously, we found that punicalagin (PUN), a bioactive ellagitannin extracted from Pericarpium Granati (the pericarpium of Punica granatum L.), exerts a therapeutic effect on psoriasis. However, the underlying mechanism, especially its potential modulatory effect on keratinocytes, remains obscure. Our study aims to reveal the potential regulatory effect and its underlying cellular mechanism of PUN on the hyperproliferation of keratinocytes. We used tumor necrosis factor α (TNF-α), IL-17A and interleukin-6 (IL-6) to induce abnormal proliferation of HaCaT cells (Human Keratinocytes Cells) in vitro. Then, we evaluated the effects of PUN through MTT assay, EdU staining and cell cycle detection. Finally, we explored the underlying cellular mechanisms of PUN via RNA-sequencing, WB in vitro and in vivo. Here, we found that PUN can directly and dose-dependently decrease TNF-α, IL-17A and IL-6-induced abnormal proliferation of HaCaT cells in vitro. Mechanically, PUN suppresses the hyperproliferation of keratinocytes through repressing S-phase kinase-associated protein 2 (SKP2) expression in vitro and in vivo. Moreover, overexpression of SKP2 can partly abolish PUN-mediated inhibition of aberrantly proliferative keratinocytes. These results illustrate that PUN can reduce the severity of psoriasis through directly repressing SKP2-mediated abnormal proliferation of keratinocytes, which gives new insight into the therapeutic mechanism of PUN on psoriasis. Moreover, these findings imply that PUN might be a promising drug candidate for the treatment of psoriasis.

Circulating Exosomes Mediate Neurodegeneration Following Hepatic Ischemia-reperfusion Through Inducing Microglial Pyroptosis in the Developing Hippocampus.

BACKGROUND: Poor neurodevelopmental outcomes after pediatric liver transplantation seriously affect the long-term quality of life of recipients, in whom hepatic ischemia reperfusion (HIR) is considered to play a pivotal role. However, the link between HIR and brain injury remains unclear. Because circulating exosomes are considered as the key mediators of information transmission over long distances, we aimed to assess the role of circulating exosomes in HIR-induced hippocampal injury in young rats. METHODS: We administered exosomes extracted from the sera of HIR model rats to normal young rats via the tail vein. Western blotting, enzyme-linked immunosorbent assay, histological examination, and real-time quantitative polymerase chain reaction were used to evaluate the role of exosomes in neuronal injury and activation of microglial pyroptosis in the developing hippocampus. Primary microglial cells were cocultured with exosomes to further assess the effect of exosomes on microglia. To further explore the potential mechanism, GW4869 or MCC950 was used to block exosome biogenesis or nod-like receptor family protein 3, respectively. RESULTS: Serum-derived exosomes played a crucial role in linking HIR with neuronal degeneration in the developing hippocampus. Microglia were found to be the target cells of ischemia-reperfusion derived exosomes (I/R-exosomes). I/R-exosomes were taken up by microglia and promoted the occurrence of microglial pyroptosis in vivo and in vitro. Moreover, the exosome-induced neuronal injury was alleviated by suppressing the occurrence of pyroptosis in the developing hippocampus. CONCLUSIONS: Microglial pyroptosis induced by circulating exosomes plays a vital role in developing hippocampal neuron injury during HIR in young rats.

The protective effect of lncRNA NEAT1/miR-122-5p/Wnt1 axis on hippocampal damage in hepatic ischemic reperfusion young mice.

Hepatic ischemic reperfusion (HIR) is a common pathophysiological process in many surgical procedures such as liver transplantation (LT) and hepatectomy. And it is also an important factor leading to perioperative distant organ damage. Children undergoing major liver surgery are more susceptible to various pathophysiological processes, including HIR, since their brains are still developing and the physiological functions are still incomplete, which can lead to brain damage and postoperative cognitive impairment, thus seriously affecting the long-term prognosis of the children. However, the present treatments of mitigating HIR-induced hippocampal damage are not proven to be effective. The important role of microRNAs (miRNAs) in the pathophysiological processes of many diseases and in the normal development of the body has been confirmed in several studies. The current study explored the role of miR-122-5p in HIR-induced hippocampal damage progression. HIR-induced hippocampal damage mouse model was induced by clamping the left and middle lobe vessels of the liver of young mice for 1 h, removing the vessel clamps and re-perfusing them for 6 h. The changes in the level of miR-122-5p in the hippocampal tissues were measured, and its influences on the activity as well as apoptotic rate of neuronal cells were investigated. Short interfering RNA modified with 2'-O-methoxy substitution targeting long-stranded non-coding RNA (lncRNA) nuclear enriched transcript 1 (NEAT1) as well as miR-122-5p antagomir were used to further clarify the role played by the corresponding molecules in hippocampal injury in young mice with HIR. The result obtained in our study was that the expression of miR-122-5p in the hippocampal tissue of young mice receiving HIR is reduced. Upregulated expression of miR-122-5p reduces the viability of neuronal cells and promotes the development of apoptosis, thereby aggravating the damage of hippocampal tissue in HIR young mice. Additionally, in the hippocampal tissue of young mice receiving HIR, lncRNA NEAT1 exerts some anti-apoptotic effects by binding to miR-122-5p, promoting the expression of Wnt1 pathway. An essential observation of this study was the binding of lncRNA NEAT1 to miR-122-5p, which upregulates Wnt1 and inhibits HIR-induced hippocampal damage in young mice.

Universal cover-time distributions of random motion in bounded granular gases.

The exhaustive random exploration of a complex domain is a fundamental issue in many natural, social, and engineering systems. The key characterizing quantity is the cover time, which is the time to visit every site in the system. One prototypical experimental platform is the confined granular gas, where the random motion of granular particles mimics the wandering of random walkers in a confined region. Here, we investigate the cover-time distribution of the random motion of tracer particles in granular gases confined in four containers to account for different boundary and angle effects and examine whether the cover time of the heterogeneous random motion of the granular gases can be rescaled into the universal Gumbel distribution according to a recent theory [Dong et al., arXiv:2210.05122 (2022)]. It is found that for long cover times, the experimental results are in full accord, while for short cover times, the agreement is reasonable, with noticeable deviations that can be attributed to spatial correlations of the sites in the covering process. Our results, thus, call for further theoretical investigations in order to take into full account these nonideal issues.

Universal cover-time distribution of heterogeneous random walks.

The cover-time problem, i.e., the time to visit every site in a system, is one of the key issues of random walks with wide applications in natural, social, and engineered systems. Addressing the full distribution of cover times for random walk on complex structures has been a long-standing challenge and has attracted persistent efforts. Usually it is assumed that the random walk is noncompact, to facilitate theoretical treatments by neglecting the correlations between visits. The known results are essentially limited to noncompact and homogeneous systems, where different sites are on an equal footing and have identical or close mean first-passage times, such as random walks on a torus. In contrast, realistic random walks are prevailingly heterogeneous with diversified mean first-passage times. Does a universal distribution still exist? Here, by considering the most general situations of noncompact random walks, we uncover a generalized rescaling relation for the cover time, exploiting the diversified mean first-passage times that have not been accounted for before. This allows us to concretely establish a universal distribution of the rescaled cover times for heterogeneous noncompact random walks, which turns out to be the Gumbel universality class that is ubiquitous for a large family of extreme value statistics. Our analysis is based on the transfer matrix framework, which is generic in that, besides heterogeneity, it is also robust against biased protocols, directed links, and self-connecting loops. The finding is corroborated with extensive numerical simulations of diverse heterogeneous noncompact random walks on both model and realistic topological structures. Our technical ingredient may be exploited for other extreme value or ergodicity problems with nonidentical distributions.

Explore the Potential Ingredients for Detoxification of Honey-Fired Licorice (ZGC) Based on the Metabolic Profile by UPLC-Q-TOF-MS.

Licorice is well known for its ability to reduce the toxicity of the whole prescription in traditional Chinese medicine theory. However, honey-fired licorice (ZGC for short), which is made of licorice after being stir-fried with honey water, is more commonly used for clinical practice. The metabolism in vivo and detoxification-related compounds of ZGC have not been fully elucidated. In this work, the chemical constituents in ZGC and its metabolic profile in rats were both identified by high ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS). The network pharmacology was applied to predict the potential detoxifying ingredients of ZGC. As a result, a total of 115 chemical compounds were identified or tentatively characterized in ZGC aqueous extract, and 232 xenobiotics (70 prototypes and 162 metabolites) were identified in serum, heart, liver, kidneys, feces, and urine. Furthermore, 41 compounds absorbed in serum, heart, liver, and kidneys were employed for exploring the detoxification of ZGC by network pharmacology. Ultimately, 13 compounds (five prototypes including P5, P24, P30, P41 and P44, and 8 phase Ⅰ metabolites including M23, M47, M53, M93, M100, M106, M118, and M134) and nine targets were anticipated to be potential mediums regulating detoxification actions. The network pharmacology analysis had shown that the ZGC could detoxify mainly through regulating the related targets of cytochrome P450 and glutathione. In summary, this study would help reveal potential active ingredients in vivo for detoxification of ZGC and provided practical evidence for explaining the theory of traditional Chinese medicine with modern technology.

Effects of mutations of D1-R323, D1-N322, D1-D319, D1-H304 on the functioning of photosystem II in Thermosynechococcus vulcanus.

Photosystem II (PSII) has a number of hydrogen-bonding networks connecting the manganese cluster with the lumenal bulk solution. The structure of PSII from Thermosynechococcus vulcanus (T. vulcanus) showed that D1-R323, D1-N322, D1-D319 and D1-H304 are involved in one of these hydrogen-bonding networks located in the interfaces between the D1, CP43 and PsbV subunits. In order to investigate the functions of these residues in PSII, we generated seven site-directed mutants D1-R323A, D1-R323E, D1-N322R, D1-D319L, D1-D319R, D1-D319Y and D1-H304D of T. vulcanus and examined the effects of these mutations on the growth and functions of the oxygen-evolving complex. The photoautotrophic growth rates of these mutants were similar to that of the wild type, whereas the oxygen-evolving activities of the mutant cells were decreased differently to 63-91% of that of the wild type at pH 6.5. The mutant cells showed a higher relative activity at higher pH region than the wild type cells, suggesting that higher pH facilitated proton egress in the mutants. In addition, oxygen evolution of thylakoid membranes isolated from these mutants showed an apparent decrease compared to that of the cells. This is due to the loss of PsbU during purification of the thylakoid membranes. Moreover, PsbV was also lost in the PSII core complexes purified from the mutants. Taken together, D1-R323, D1-N322, D1-D319 and D1-H304 are vital for the optimal function of oxygen evolution and functional binding of extrinsic proteins to PSII core, and may be involved in the proton egress pathway mediated by YZ.

Fibrous and filmy microplastics exert opposite effects on the mobility of nanoplastics in saturated porous media.

This study explored the influence of fibrous and filmy polyethylene terephthalate (PET) on the transportation of nanoplastics (NPs) in saturated porous media. With the strong electrostatic repulsion, the negatively charged PET fibers (-57.5 mV) improved the transport of NPs, and the mass percentage of NPs recovered from the effluent (Meff) increased from 69.3% to 86.7%. However, PET films (-49.7 mV) showed the opposite result, that is, Meff decreased from 69.3% to 57.0%. X-ray micro-computed tomography quantitatively revealed the change in effective porosity of porous media before and after adding various PET MPs. The addition of 10 mm fiber increased the porosity from 0.39 to 0.43, whereas the addition of 10 × 10 mm2 film reduced the porosity from 0.39 to 0.29. The fiber-facilitated transport of NPs is presumably due to the formation of new connected pores between fibers and sand grains, whereas the film-inhibited transport of NPs may be due to the partial truncation of transport path of NPs. Overall, the effect of coexisting MPs on the mobility of NPs strongly relies on the shape and size of MPs.

Ultrafast excitation quenching by the oxidized photosystem II reaction center.

Photosystem II (PSII) is the pigment-protein complex driving the photoinduced oxidation of water and reduction of plastoquinone in all oxygenic photosynthetic organisms. Excitations in the antenna chlorophylls are photochemically trapped in the reaction center (RC) producing the chlorophyll-pheophytin radical ion pair P+ Pheo-. When electron donation from water is inhibited, the oxidized RC chlorophyll P+ acts as an excitation quencher, but knowledge on the kinetics of quenching is limited. Here, we used femtosecond transient absorption spectroscopy to compare the excitation dynamics of PSII with neutral and oxidized RC (P+). We find that equilibration in the core antenna has a major lifetime of about 300 fs, irrespective of the RC redox state. Two-dimensional electronic spectroscopy revealed additional slower energy equilibration occurring on timescales of 3-5 ps, concurrent with excitation trapping. The kinetics of PSII with open RC can be described well with previously proposed models according to which the radical pair P+ Pheo- is populated with a main lifetime of about 40 ps, which is primarily determined by energy transfer between the core antenna and the RC chlorophylls. Yet, in PSII with oxidized RC (P+), fast excitation quenching was observed with decay lifetimes as short as 3 ps and an average decay lifetime of about 90 ps, which is shorter than the excited-state lifetime of PSII with open RC. The underlying mechanism of this extremely fast quenching prompts further investigation.

Characterization of the Rate-Limiting Steps in the Dark-To-Light Transitions of Closed Photosystem II: Temperature Dependence and Invariance of Waiting Times during Multiple Light Reactions.

Rate-limiting steps in the dark-to-light transition of Photosystem II (PSII) were discovered by measuring the variable chlorophyll-a fluorescence transients elicited by single-turnover saturating flashes (STSFs). It was shown that in diuron-treated samples: (i) the first STSF, despite fully reducing the QA quinone acceptor molecule, generated only an F1(

Occurrence, distribution, and partitioning of antibiotics in surface water and sediment in a typical tributary of Yellow River, China.

The antibiotic distributions, partitioning, and migration pathways in river basins have withdrawn great attention in the past decades. This study investigates 26 antibiotics of five classifications in surface water and sediment samples at 23 sites in Fenhe River, a typical tributary of Yellow River. There are 21 antibiotics found in the water samples at the concentration from 113.8 to 1106.0 ng/L, in the decreasing order of SAs > QNs > MLs > TCs > CAs. Fifteen antibiotics were detected in the sediment at the concentrations from 25.11 to 73.22 µg/kg following the decreasing order of SAs > MLs > TCs > QNs > CAs. The antibiotic concentrations vary greatly in surface water, generally lower in upstream and in reservoirs, and reaching highest in the midstream of the Fenhe River after passing Taiyuan and Jinzhong, and then lower again in the downstream. The antibiotic concentrations in sediment have a less variation in the entire river basin, but become high in the downstream. The results show the water-sediment partitioning coefficients of antibiotics generally were lower than those in other areas, having a migration path from the water to suspended solids, and then accumulated in sediment. The water-sediment partitioning coefficients also vary across the basin. The water-sediment partitioning coefficients of sulfacetamide and tetracycline are higher than the water-sediment partitioning coefficients of other antibiotics, with less variation across the basin, the water-sediment partitioning coefficients of azithromycin, enrofloxacin, and roxithromycin are low in the midstream of the river, and high at the river source and downstream. The water-sediment partitioning coefficients are significantly affected by the pH of sediment and the particle size of sediment. The prediction models of water-sediment partitioning coefficients for antibiotics are constructed with the selected effecting factors. The simulation values of antibiotics except chlortetracycline and erythromycin are highly consistent with the observed values, indicating that the prediction model is reliable.

Overt and occult hepatitis B infection after neonatal vaccination: mother-to-infant transmission and HBV vaccine effectiveness.

OBJECTIVES: Overt and occult hepatitis B infection (HBI) among mothers and infants were investigated, and the effectiveness of vaccination against HBI was evaluated based on transmission types. METHODS: A hospital-based cohort was built with 2,734 mothers and 330 mother-infant pairs. Their demographic data were collected. Serological HBV markers, nested-PCR for HBV genes, viral load detection, and phylogenetic analysis were done. RESULTS: The overall prevalence of HBI among mothers was 12.1% (330/2,734), with 10.4% for the overt type and 1.8% for the occult type. In 330 out of 1,650 (20%) mother-infant pairs, the overall, type-I (from overt mother to overt infant), type-II (from overt mother to occult infant), and type-Ⅲ (from occult mother to occult infant) transmissions were 1.9% (1/54), 5.6% (3/54) and 0.0% (0/7). The refinement of HBI classification improved the estimate of vaccine effectiveness against HBI from 74.4%-80.9% to 94.4%, which was more prominent for type-II. One mother-infant pair with type-II transmission shared nearly identical complete sequences. However, the high rate of lost-to-follow-up could not be ignored. CONCLUSIONS: During the transition period, HBV is mainly transmitted from the overt type of HBI mother to infant. Intensive prenatal screening for mothers is vital.

Functional Alterations in Resting-State Visual Networks in High-Tension Glaucoma: An Independent Component Analysis.

BACKGROUND: High-tension glaucoma (HTG) is the most common type of primary open angle glaucoma and elevated intraocular pressure (IOP) is the major risk factor of the disease. The aim of this study was to assess alterations in resting-state visual networks in patients with HTG and investigate the effect of elevated IOP on the visual networks. METHODS: T1-weighted and resting-state functional MRI images were acquired from 36 HTG patients (aged 49.22 ± 15.26 years) and 20 healthy controls (aged 49.90 ± 5.62 years). Group independent component analysis (ICA) was utilized to evaluate altered functional connectivity (FC) in resting-state visual networks between HTG patients and healthy controls. Pearson correlation analysis between mean IOP and altered FCs in the visual networks was performed. RESULTS: ICA demonstrated decreased FCs in HTG group in the left calcarine cortex of the lateral visual network, in the bilateral lingual gyrus of the medial visual network and in the bilateral lingual gyrus of the occipital visual network compared with healthy controls. Furthermore, correlation analysis revealed negative correlation between mean IOP and altered FC within the lateral visual network. CONCLUSION: The results suggested reduced FCs between primary and higher visual cortices in HTG brain. The IOP elevation might be responsible for the functional alterations in the visual networks.

circ-ZUFSP regulates trophoblasts migration and invasion through sponging miR-203 to regulate STOX1 expression.

Recurrent spontaneous abortion (RSA), defined as two or more consecutive pregnancy losses before 12 weeks of gestation with or without previous live births. Circular RNAs (circRNAs) are a novel class of endogenous noncoding RNAs that play important roles in gene expression regulation and trophoblasts function during embryo development. This study aimed to evaluate the function mechanism of circRNAs regulating trophoblasts function in the occurrence and progression RSA. Through overexpression and down-regulation of circ-ZUFSP, we investigated the effect of circ-ZUFSP on the function of trophoblasts and found loss of circ-ZUFSP suppressed trophoblasts migration and invasion in vitro. Moreover, loss of circ-ZUFSP regulated trophoblasts migration and invasion via regulation of miR-203. Furthermore, STOX1 was revealed to a target of miR-203, and down-regulation of STOX1 reversed circ-ZUFSP enhanced cell invasion, suggesting that circ-ZUFSP might regulate STOX1 expression through sponging miR-203 in HTR-8/SVneo cells. In addition, low expression of circ-ZUFSP, STOX1 and high expression of miR-203 were testified in placental tissues of RSA mice. Our study demonstrated a molecular mechanism of circ-ZUFSP regulating trophoblasts migration and invasion, which might provide a novel indicator for early diagnosis and potential treatment of RSA.

Insight into the role of ion-pairing in the adsorption of imidazolium derivative-based ionic liquids by activated carbon.

The association of the cation and anion of ionic liquids (ILs) dominates the absorbability of ILs by activated carbon (AC). Nevertheless, the mechanism behind the role of ion-pairs is largely unknown. In this study, the adsorption of a series of imidazolium derivative-based ILs by AC was involved in response to the octanol-water partition coefficient (KOW), hydrogen bonding acidity (α), ion-pair binding constants (KIP), binding energy of ion-pairs (Ebinding) and density functional theory (DFT) calculation of ILs. A significant positive correlation between lg KOW and Kd and between KIP and lg KOW was observed (p < 0.05). However, both Ebinding and α was inversely proportional to KIP. Hence, the substitution of oxygen-containing functional groups, such as carboxyethyl, 1-methoxyethyl, and 1-(ethoxycarbonyl)methyl, on imidazolium ring enhanced the hydrogen bond interaction with water molecules and then weakened the binding of imidazolium cation and [NTf2]-, thereby reducing the adsorption of ILs to AC. DFT calculation further revealed that the polar substitution improved the electron density and electronegativity of imidazolium skeleton. By contrast, the ILs functionalized with non-polar groups (e.g., butyl, allyl, and benzyl) generally displayed high KIP values and low α values. Consequently, the formation of hydrogen bond between the oxygen-containing functional groups of IL cation and water would facilitate the dissociation of IL ion-pairs and then decrease the adsorption of ILs on AC.

Protein corona-mediated transport of nanoplastics in seawater-saturated porous media.

The offshore aquaculture environment is a potential water area with high concentrations of tiny plastics and feeding proteins. In this study, the negatively charged bovine serum albumin (BSA) and the positively charged lysozyme (LSZ) were used to explore the effects of protein corona on the aggregation, transport, and retention of polystyrene nanoplastics (NPs; 200, 500, and 1000 nm) in sea sand saturated with seawater of 35 practical salinity units (PSU). The BSA corona, which was formed by the adsorption of BSA on the surface of NPs, drove the dispersion of NPs (200 and 500 nm) due dominantly to the induced colloidal steric hindrance. For example, the aggregate sizes of 500 nm NP decreased from 1740 ± 87 nm to 765 ± 8 nm at 40 min, which resulted in the enhanced transportation of NP. The calculated interaction energies indicated the BSA corona-induced high energy barriers (>104 KBT) between 1000 nm NPs and sand surface, demonstrating the BSA-enhanced transport of 1000 nm NPs. The mass percentage recovered from the effluent (Meff) increased from 33.4% to 61.7%. Inversely, the LSZ corona triggered the aggregation of 200 nm NPs into the large aggregates via electrostatic adsorption and bridging effect, thereby inhibiting the transport of 200 nm NPs. Nevertheless, no LSZ corona was formed on the surface of 500 and 1000 nm NPs due to extremely low protein adsorption. Accordingly, LSZ cannot affect the stability and transport of these NPs. In the diluted seawater (3.5 PSU), the strong electrostatic attraction between positively charged LSZ and 500 nm NPs significantly increased and the LSZ corona formed, which induced the aggregation of 500 nm NPs. The Meff of NPs therefore decreased from 53.1% to 11.2%. Overall, the protein corona-mediated transport of NPs in seawater-saturated porous media depends on protein type, NP size, and seawater salinity.