Grain-Boundary-Rich RuO2 Porous Nanosheet for Efficient and Stable Acidic Water Oxidation.

RuO2 has been considered as the most likely acidic oxygen evolution reaction (OER) catalyst to replace IrO2, but its performance, especially long-term stability under harsh acidic conditions, is still unacceptable. Here, we propose a grain boundary (GB) engineering strategy by fabricating the ultrathin porous RuO2 nanosheet with abundant of grain boundaries (GB-RuO2) as an efficient acid OER catalyst. The involvement of GB induces significant tensile stress and creates an unsaturated coordination environment, effectively optimizing the adsorption of intermediates and stabilizing active site structure during OER process. Notably, the GB-RuO2 not only exhibits a low overpotential (η10= 187 mV) with an ultra-low Tafel slope (34.5 mV dec-1), but also steadily operates for over 550 h in 0.1 M HClO4. Quasi in situ/operando methods confirm that the improved stability is attributed to GB preventing Ru dissolution and greatly inhibiting the lattice oxygen oxidation mechanism (LOM). A proton exchange membrane water electrolysis (PEMWE) using the GB-RuO2 catalyst operates a low voltage of 1.669 V at 2 A cm-2 and operates stably for 100 h at 100 mA cm-2.

Bioconcentration of Inorganic and Methyl Mercury by Algae Revealed Using Dual-Mass Single-Cell ICP-MS with Double Isotope Tracers.

Algae are an entry point for mercury (Hg) into the food web. Bioconcentration of Hg by algae is crucial for its biogeochemical cycling and environmental risk. Herein, considering the cell heterogeneity, we investigated the bioconcentration of coexisting isotope-labeled inorganic (199IHg) and methyl Hg (201MeHg) by six typical freshwater and marine algae using dual-mass single-cell inductively coupled plasma mass spectrometry (scICP-MS). First, a universal pretreatment procedure for the scICP-MS analysis of algae was developed. Using the proposed method, the intra- and interspecies heterogeneities and the kinetics of Hg bioconcentration by algae were revealed at the single-cell level. The heterogeneity in the cellular Hg contents is largely related to cell size. The bioconcentration process reached a dynamic equilibrium involving influx/adsorption and efflux/desorption within hours. Algal density is a key factor affecting the distribution of Hg between algae and ambient water. Cellular Hg contents were negatively correlated with algal density, whereas the volume concentration factors almost remained constant. Accordingly, we developed a model based on single-cell analysis that well describes the density-driven effects of Hg bioconcentration by algae. From a novel single-cell perspective, the findings improve our understanding of algal bioconcentration governed by various biological and environmental factors.

Microbial production of sulfur-containing amino acids using metabolically engineered Escherichia coli.

L-Cysteine and L-methionine, as the only two sulfur-containing amino acids among the canonical 20 amino acids, possess distinct characteristics and find wide-ranging industrial applications. The use of different organisms for fermentative production of L-cysteine and L-methionine is gaining increasing attention, with Escherichia coli being extensively studied as the preferred strain. This preference is due to its ability to grow rapidly in cost-effective media, its robustness for industrial processes, the well-characterized metabolism, and the availability of molecular tools for genetic engineering. This review focuses on the genetic and molecular mechanisms involved in the production of these sulfur-containing amino acids in E. coli. Additionally, we systematically summarize the metabolic engineering strategies employed to enhance their production, including the identification of new targets, modulation of metabolic fluxes, modification of transport systems, dynamic regulation strategies, and optimization of fermentation conditions. The strategies and design principles discussed in this review hold the potential to facilitate the development of strain and process engineering for direct fermentation of sulfur-containing amino acids.

Predicting left ventricular remodeling post-MI through coronary physiological measurements based on computational fluid dynamics.

Early detection of left ventricular remodeling (LVR) is crucial. While cardiac magnetic resonance (CMR) provides valuable information, it has limitations. Coronary angiography-derived fractional flow reserve (caFFR) and index of microcirculatory resistance (caIMR) offer viable alternatives. 157 patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention were prospectively included. 23.6% of patients showed LVR. Machine learning algorithms constructed three LVR prediction models: Model 1 incorporated clinical and procedural parameters, Model 2 added CMR parameters, and Model 3 included echocardiographic and functional parameters (caFFR and caIMR) with Model 1. The random forest algorithm showed robust performance, achieving AUC of 0.77, 0.84, and 0.85 for Models 1, 2, and 3. SHAP analysis identified top features in Model 2 (infarct size, microvascular obstruction, admission hemoglobin) and Model 3 (current smoking, caFFR, admission hemoglobin). Findings indicate coronary physiology and echocardiographic parameters effectively predict LVR in patients with STEMI, suggesting their potential to replace CMR.

Investigating the Effects of Perampanel on Autophagy-mediated Regulation of GluA2 and PSD95 in Epilepsy.

Epilepsy is a chronic neurological disorder characterized by recurrent seizures. Despite various treatment approaches, a significant number of patients continue to experience uncontrolled seizures, leading to refractory epilepsy. The emergence of novel anti-epileptic drugs, such as perampanel (PER), has provided promising options for effective epilepsy treatment. However, the specific mechanisms underlying the therapeutic effects of PER remain unclear. This study aimed to investigate the intrinsic molecular regulatory mechanisms involved in the downregulation of GluA2, a key subunit of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors, following epileptic seizures. Primary mouse hippocampal neurons were cultured and subjected to an epilepsy cell model. The expression levels of GluA2 and autophagy-related proteins were assessed using Western blotting and real-time fluorescent quantitative PCR. Immunofluorescence and immunohistochemistry techniques were employed to investigate the nuclear translocation of CREB-regulated transcriptional coactivator 1 (CRTC1). Additionally, status epilepticus animal models were established to further validate the findings. The epilepsy cell model exhibited a significant decrease in GluA2 expression, accompanied by elevated levels of autophagy-related proteins. Immunofluorescence analysis revealed the nuclear translocation of CRTC1, which correlated with the expression of autophagy-related genes. Treatment with an autophagy inhibitor reversed the decreased expression of GluA2 in the epilepsy cell model. Furthermore, the calcium/calmodulin-dependent protein phosphatase inhibitor FK506 and CaN overexpression affected the dephosphorylation and nuclear translocation of CRTC1, consequently influencing GluA2 expression. Animal model results further supported the involvement of these molecular mechanisms in epilepsy. Our findings suggest that the downregulation of GluA2 following epileptic seizures involves the activation of autophagy and the regulation of CRTC1 nuclear translocation. These intrinsic molecular regulatory mechanisms provide potential targets for developing novel therapeutic strategies to alleviate refractory epilepsy and preserve cognitive functions in patients.

Hyperaccumulator extracts promoting the phytoremediation of rare earth elements (REEs) by Phytolacca americana: role of active microbial community in rhizosphere hotspots.

The increased usage of rare earth elements (REEs) leads to the extensive exploitation of rare earth mines, and the REEs pollution in soil caused by the legacy mine tailings has brought great harm to environment and human health. Although Phytolacca americana can remove REEs from contaminated soil to some extent, there is still an urgent problem to improve its efficiency. Hyperaccumulator extract is a new organic material with potential in metal phytoextraction, but its role in REEs phytoremediation and the related underlying processes remain unclear. In this study, hyperaccumulator extracts from P. americana root (PR), stem (PS), leaf (PL) and EDTA were used to improve the phytoremediation efficiency of REEs with P. americana. Soil zymography was applied to assess the enzyme hotspots' spatial distribution in the rhizosphere, and the hotspots' microbial communities were also identified. The results indicated that the application of hyperaccumulator extracts improved the biomass and REEs uptake of P. americana, and the highest REEs content in plant was observed in the treatment of PS, which increased 299% compared to that of the control. Hotspots area of ß-glucosidase, leucine aminopeptidase and acid phosphatase were concentrated in the pant rhizosphere along the roots and increased 2.2, 5.3 and 2.2 times after PS application compared to unamended soils. The PS application increased the relative abundance of Proteobacteria, Cyanobacteria, Bacteroidota and Firmicutes phyla in rhizosphere. Soil fungi have a higher contribution on promoting REEs activation than that of bacteria. Available P and extractable REEs were leading predictors for the plant biomass and REEs concentrations. The co-occurrence network showed that the application of PS creates a more efficient and stable microbial network compared to other treatments. In conclusion, stem-derived hyperaccumulator extract is excellent in stimulating REEs phytoremediation with P. americana by improving hotspots microbial activities and form a healthy rhizosphere microenvironment.

Cryo-EM structure of the human Asc-1 transporter complex.

The Alanine-Serine-Cysteine transporter 1 (Asc-1 or SLC7A10) forms a crucial heterodimeric transporter complex with 4F2hc (SLC3A2) through a covalent disulfide bridge. This complex enables the sodium-independent transport of small neutral amino acids, including L-Alanine (L-Ala), Glycine (Gly), and D-Serine (D-Ser), within the central nervous system (CNS). D-Ser and Gly are two key endogenous glutamate co-agonists that activate N-methyl-d-aspartate (NMDA) receptors by binding to the allosteric site. Mice deficient in Asc-1 display severe symptoms such as tremors, ataxia, and seizures, leading to early postnatal death. Despite its physiological importance, the functional mechanism of the Asc-1-4F2hc complex has remained elusive. Here, we present cryo-electron microscopy (cryo-EM) structures of the human Asc-1-4F2hc complex in its apo state, D-Ser bound state, and L-Ala bound state, resolved at 3.6 Å, 3.5 Å, and 3.4 Å, respectively. Through detailed structural analysis and transport assays, we uncover a comprehensive alternating access mechanism that underlies conformational changes in the complex. In summary, our findings reveal the architecture of the Asc-1 and 4F2hc complex and provide valuable insights into substrate recognition and the functional cycle of this essential transporter complex.

Tectorigenin protects against cardiac fibrosis in diabetic mice heart via activating the adiponectin receptor 1-mediated AMPK pathway.

Diabetic cardiomyopathy (DCM) is a common severe complication of diabetes that occurs independently of hypertension, coronary artery disease, and valvular cardiomyopathy, eventually leading to heart failure. Previous studies have reported that Tectorigenin (TEC) possesses extensive anti-inflammatory and anti-oxidative stress properties. In this present study, the impact of TEC on diabetic cardiomyopathy was examined. The model of DCM in mice was established with the combination of a high-fat diet and STZ treatment. Remarkably, TEC treatment significantly attenuated cardiac fibrosis and improved cardiac dysfunction. Concurrently, TEC was also found to mitigate hyperglycemia and hyperlipidemia in the DCM mouse. At the molecular level, TEC is involved in the activation of AMPK, both in vitro and in vivo, by enhancing its phosphorylation. This is achieved through the regulation of endothelial-mesenchymal transition via the AMPK/TGFß/Smad3 pathway. Furthermore, it was demonstrated that the level of ubiquitination of the adiponectin receptor 1 (AdipoR1) protein is associated with TEC-mediated improvement of cardiac dysfunction in DCM mice. Notably the substantial reduction of myocardial fibrosis. In conclusion, TEC improves cardiac fibrosis in DCM mice by modulating the AdipoR1/AMPK signaling pathway. These findings suggest that TEC could be an effective therapeutic agent for the treatment of diabetic cardiomyopathy.

The Therapeutic Effect of Buyang Huanwu Decoction on Mild Cognitive Impairment (MCI) in Patients with Diabetes.

OBJECTIVE: This study aims to comprehensively verify the efficacy of Buyang Huanwu Decoction in improving cognitive function in patients with diabetes. METHODS: Patients clinically diagnosed with mild cognitive impairment (MCI) assigned to either the placebo group or the Buyang Huanwu Decoction group. After strict screening and exclusions, a total of 156 participants completed the clinical trial, with 76 in the placebo group and 80 in the Buyang Huanwu Decoction group. RESULTS: After treatment, Buyang Huanwu Decoction group showed higher Mini-Mental State Examination and Montreal Cognitive Assessment scores compared to placebo (p < 0.05). Memory and Executive Screening, Boston Naming Test, and Animal Fluency Test scores were also higher in the treatment group (p < 0.05). No significant differences were found in DST and CDT scores (p > 0.05). Trail Making Test scores were lower in the treatment group (p < 0.05). No significant difference was observed between the two groups in terms of complications (p > 0.05). CONCLUSION: Patients receiving Buyang Huanwu Decoction treatment demonstrated improvement in cognitive function, showing positive effects and providing preliminary evidence for the role of Buyang Huanwu Decoction in improving cognitive function in patients with diabetes. This suggests its potential for clinical application and further promotion.

Clinical observation and analysis of rash caused by lacosamide in children with epilepsy.

PURPOSE: To draw clinical attention to rashes caused by lacosamide. METHODS: This retrospective analysis included patients admitted to the Department of Pediatrics, Second Affiliated Hospital of Xi'an Jiaotong University between January 2021 and September 2023. We focused on patients who developed rashes after lacosamide treatment and analyzed all patients who exhibited rashes after lacosamide treatment to analyze the risk factors. RESULTS: In total, 190 patients received lacosamide, of whom four developed allergies (2.1 %). Three patients had severe rashes, and two patients had high fever. All of these adverse events improved after the withdrawal of lacosamide. Of the 13 patients reported to date, including the four patients in this study, eight used various antiseizure medicines, including seven patients who used four or more antiseizure medicines. Four patients underwent testing for HLA-B*1502, and two patients were positive. Patients developed rashes within 1-10 days after treatment initiation, and the duration of the rash ranged 2-37 days. CONCLUSIONS: Lacosamide-induced rash was detected in 2.1 % of patients in our cohort. Rashes are potentially serious, and prompt evaluation is required. Rashes are more likely to occur when multiple antiseizure medicines are used simultaneously, typically within 10 days of treatment initiation.

Bioinspired adhesive hydrogel based on serotonin-modified gelatin and oxidized hyaluronic acid for rapid hemostasis and wound healing.

A hybrid hydrogel system (GSOHA) consisting of serotonin-grafted gelatin and oxidized hyaluronic acid (OHA) was developed in this study to efficiently control bleeding and prevent bacterial infections during surgery and trauma. The study results showed that the incorporation of serotonin successfully produced hydrogels with rapid hemostatic, antibacterial, and antioxidant properties. The GSOHA hydrogel exhibited considerably stronger tissue adhesion (15.55 ± 0.36 kPa) to porcine skin than the commercial fibrin glue (1.09 ± 0.04 kPa). In addition, the hydrogel could rapidly absorb blood cells and stimulate cell conjugation with serotonin addition. In vitro experiments using endothelial cells and erythrocytes demonstrated the excellent biocompatibility and hemocompatibility of the hydrogel. Most importantly, the GSOHA hydrogel accelerated the wound healing process in a full-thickness skin defect mice model, and the histological staining results demonstrated that GSOHA significantly promoted collagen deposition and vascularization. In conclusion, this study demonstrated the significant potential of the GSOHA hydrogel as an adhesive dressing for rapid hemostasis and wound healing.

Structural insight into the assembly and working mechanism of helicase-primase D5 from Mpox virus.

The Mpox pandemic, caused by the Mpox virus (or monkeypox virus, MPXV), has gained global attention. The D5 protein, a putative helicase-primase found in MPXV, plays a vital role in viral replication and genome uncoating. Here we determined multiple cryo-EM structures of full-length hexameric D5 in diverse states. These states were captured during ATP hydrolysis while moving along the single-stranded DNA (ssDNA) track. Through comprehensive structural analysis combined with the helicase activity system, we revealed that when the primase domain is truncated or the interaction between the primase and helicase domains is disrupted, the double-stranded DNA (dsDNA) unwinds into ssDNA, suggesting a critical regulatory role of the primase domain. Two transition states bound with ssDNA substrate during unwinding reveals that two ATP molecules were consumed to drive DNA moving forward two nucleotides. Collectively, our findings shed light on the molecular mechanism that links ATP hydrolysis to the DNA unwinding in poxviruses.

The cryo-EM structure of homotetrameric attachment glycoprotein from langya henipavirus.

Langya Henipavirus (LayV) infection is an emerging zoonotic disease that has been causing respiratory symptoms in China since 2019. For virus entry, LayV's genome encodes the fusion protein F and the attachment glycoprotein G. However, the structural and functional information regarding LayV-G remains unclear. In this study, we revealed that LayV-G cannot bind to the receptors found in other HNVs, such as ephrin B2/B3, and it shows different antigenicity from HeV-G and NiV-G. Furthermore, we determined the near full-length structure of LayV-G, which displays a distinct mushroom-shaped configuration, distinguishing it from other attachment glycoproteins of HNV. The stalk and transmembrane regions resemble the stem and root of mushroom and four downward-tilted head domains as mushroom cap potentially interact with the F protein and influence membrane fusion process. Our findings enhance the understanding of emerging HNVs that cause human diseases through zoonotic transmission and provide implication for LayV related vaccine development.

Mechanical performance and water resistance of biochar admixture lightweight magnesium oxychloride cement.

The applications of magnesium oxychloride cement (MOC) have been extensively studied recently due to its eco-friendly and high-strength nature. However, one of the significant limitations of MOC is its poor water resistance. To address this limitation, this study explored the prospect of incorporating biochar particles (up to 25 % of the dry mass of MgO) to form lightweight MOC with improved water resistance. The compressive (fc) and flexural (ff) strengths were investigated after 28-day curing and under 56-day water attack. The fc of MOC after immersion was determined under both wet (directly after immersion) and dry (air-dried to constant weights) conditions. The results indicated that the inclusion of 5 % and 10 % biochar increased the 28-day fc, while the addition of biochar decreased ff regardless of its dosage. Microscopic examination uncovered that the increase in strength resulted from the promoted production of phase 5 (5 Mg(OH)2·MgCl2·8H2O) and the reduction in unreacted MgO. The inclusion of 5 % and 10 % biochar increased the compressive and flexural strength retention ratios after 56-day immersion. The ff with 5 % biochar inclusion after immersion was higher compared to that of pure MOC. Moreover, the inclusion of biochar had minimal effects on the thermal degradation of MOC. The above results suggest that biochar can be a potential additive to enhance the mechanical behaviour and water resistance of MOC. As fc of immersed MOC increased during air-drying, a new equation was developed to describe variations in fc of MOC subject to different degrees of saturation during drying.

Glycemic Status and Myocardial Strain by Cardiac MRI in Patients With ST-Segment Elevation Myocardial Infarction.

BACKGROUND: It is uncertain how various degree of glycemic status affect left ventricular (LV) myocardial strain in ST-segment elevation myocardial infarction (STEMI) patients undergoing primary percutaneous coronary intervention (PPCI). PURPOSE: To investigate the relationship of glycemic status and myocardial strain in STEMI patients. STUDY TYPE: Prospective cohort study. POPULATION: 282 STEMI patients with cardiac magnetic resonance imaging 5 ± 2 days post-PPCI. Patients were divided into three groups based on the level of glycated hemoglobin A1c (HbA1c) (group 1: HbA1c < 5.7%; group 2: 5.7% ≤ HbA1c < 6.5%; group 3: HbA1c ≥ 6.5%). FIELD STRENGTH/SEQUENCE: 3.0-T; late gadolinium enhancement, balanced steady-state free precession cine sequence, black blood fat-suppressed T2-weighted. ASSESSMENT: LV function, myocardial strain, and infarct characteristics (infarct size, microvascular obstruction, and intramyocardial hemorrhage) were compared among the three groups by one-way analysis of variance (ANOVA) or Wilcoxon rank sum test. Intraobserver and interobserver reproducibility of LV myocardial strain was evaluated. STATISTICAL TESTS: ANOVA or Wilcoxon rank sum test, Pearson chi-square or Fisher's exact test, Spearman's correlation analyses and multivariable linear regression analysis. A two-tailed P value <0.05 was considered statistically significant. RESULTS: Infarct characteristics were similar among the three groups (P = 0.934, P = 0.097, P = 0.533, respectively). Patients with HbA1c ≥ 6.5% had decreased LV myocardial strain compared with HbA1c 5.7%-6.4%, as evidenced by global radial (GRS), global circumferential (GCS), and global longitudinal (GLS) strain. However, no significant differences in myocardial strain were observed between patients with HbA1c 5.7%-6.4% and HbA1c < 5.7% (P = 0.716; P = 0.294; P = 0.883, respectively). After adjustment for confounders, HbA1c as a continuous variable (beta coefficient [ß] = -0.676; ß = 0.172; ß = 0.205, respectively) and HbA1c ≥ 6.5% (ß = -3.682; ß = 0.552; ß = 0.681, respectively) were both independently associated with decreased GRS, GCS, and GLS. DATA CONCLUSION: Patients with uncontrolled blood glucose (categorized in group HbA1c ≥ 6.5%) had worse myocardial strain. The level of HbA1c appeared to be independently associated with decreased myocardial strain in STEMI patients. LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY STAGE: 2.

The association of lipoprotein (a) with coronary artery calcification: A systematic review and meta-analysis.

BACKGROUND AND AIMS: Coronary artery calcification (CAC) is a crucial pathophysiological characteristic of atherosclerosis. The association between lipoprotein (a) [Lp(a)] and CAC is inconsistent. We aimed to assess the relationship between Lp(a) and CAC by exploring the association between elevated Lp(a) and CAC prevalence, the relationship between Lp(a) level and CAC prevalence, and the correlation between elevated Lp(a) and CAC progression. METHODS: We searched the PubMed, Web of Science, and EMBASE databases up to November 01, 2023. Studies exploring the association between serum Lp(a) and CAC (quantified using the Agatston score) were included. Association between Lp(a) level or elevated Lp(a) (higher than the cutoff values of 30 mg/dL, 50 mg/dL, or the highest quartile ranging from 33 to 38.64 mg/dL) and prevalence [CAC score >0 or >100, log (CAC score+1) >0] or progression (an increase in CAC score >0 or ≥100) of CAC were analysed. Odds ratios and 95% confidence intervals were calculated using a random-effects model. RESULTS: 40,073 individuals from 17 studies were included. Elevated Lp(a) was associated with a higher prevalence of CAC (OR, 1.31; 95% CI, 1.06 to 1.61; p = 0.01). As a continuous variable, Lp(a) level was positively correlated with the prevalence of CAC (OR, 1.05; 95% CI, 1.02 to 1.08; p = 0.003). Furthermore, elevated Lp(a) was associated with greater CAC progression (OR, 1.54; 95% CI, 1.23 to 1.92; p = 0.0002). CONCLUSIONS: This meta-analysis suggested that Lp(a) is associated with prevalence and progression of CAC. Further studies are required to explore whether Lp(a)-lowering therapy could prevent or inhibit CAC, ultimately reducing coronary artery disease risk.

Effects of microplastic contamination on the hydraulic, water retention, and desiccation crack properties of a natural clay exposed to leachate.

Microplastic (MP) can significantly affect soil behaviour and the ecosystem. This paper presents an experimental study to investigate the effects of MP contamination and leachate exposure on the desiccation cracks, hydraulic conductivity, and water retention properties of the natural black clay. The leachate was from a landfill in Australia. The black clay was incorporated with up to 2.0% MPs by weight (w/w) with diverse dimensions and mixed with water/leachate. The measured properties include saturated hydraulic conductivity (ksat), soil-water characteristic curves, moisture evaporation rates, and crack intensity factors. The results suggest that the inclusion of MPs significantly increases ksat, and this increase is more obvious for soils with larger dimensions and contents of MPs, e.g., ksat of the black clay with 2.0% of 500 µm MP increases significantly by 206% (p < 0.05). The black clay exposed to leachate exhibits a slight increase in ksat due to the low viscosity of leachate. The existence of MPs decreases the residual moisture contents and air-entry pressures, and so does the water retention capacity (v/v %) of the black clay. The exposure to leachate increases the air-entry pressures by 6.0%-15.8% of the clay. The evaporation rates increase with the dimensions and concentrations of MPs. The highest evaporation rate (0.96 g/h) can be observed in samples exposed to 2.0% 500 µm MP with water addition. For all samples, the crack intensity factors increase when MP content is between 0.2% and 1.0% and decreases slightly after that. After being exposed to leachate, the evaporation rates and crack intensity factors of the black clay are decreased by 2.4%-12.6% and 3.6%-13.7%, respectively.

Dissipative Particle Dynamic Simulation on Self-Assembly of Symmetric CBABC Pentablock Terpolymers in Solution.

Pentablock terpolymers are potential candidates for the self-assembly of multicompartment nanostructures. In this work, Dissipative Particle Dynamic simulation is employed to investigate how the equilibrium aggregate structures of C3B3A6B3C3 pentablock terpolymers are affected by polymer-solvent interactions in a solution. Multicompartment structures, such as layered micelles, onion-like micelles, onion-like vesicles, unilamellar vesicles, and vesicle-in-vesicle structures, are observed. Vesicles are obtained when the two end C-blocks or the central A-block are hydrophilic. The solvent encapsulation ability and vesicle membrane permeability are assessed. The unilamellar vesicle shows higher encapsulation efficiency and lower membrane permeability compared with the onion-like vesicles. Additionally, the two vesicles show different responses to shear. While the cargo release rate of the onion-like vesicle is not affected by shear, shear results in a slowdown of the release rate for the unilamellar vesicle. The membrane thickness of the unilamellar vesicle can be adjusted using the length of the central A-blocks. Vesicles with thicker membranes hold cargo more effectively.

Effect of Film Thickness on the Self-Assembly of CBABC Symmetric Pentablock Terpolymer Melts under 1D Confinement: A Dissipative Particle Dynamic Study.

The study investigates the impact of film thickness on the phase behavior of pentablock terpolymers, denoted as C3B3A6B3C3, when subjected to wall confinement by utilizing the dissipative particle dynamics method. Phase diagrams were constructed to elucidate how factors such as block-block interaction strength, film thickness, and wall properties affect the self-assembly structures. In cases where the wall exhibits no preference for any of the blocks, lamellae phases with orientations perpendicular to the wall are observed. The order-disorder transition (ODT) temperature is found to be influenced by the interaction between the polymer and the wall in thin confinement scenarios. When the wall displays a preference for specific blocks, the orientation of lamellae structures undergoes variations. Lamellae tend to align parallel to the wall when the wall favors A or C blocks, and they orient perpendicularly when B blocks are favored. Furthermore, the mechanical properties of the lamellae structures are related to the conformations of the polymer chains. Structures where chains predominantly adopt a loop conformation exhibit enhanced elastic properties. The ratio of looping to bridging conformations can be adjusted by altering the film thickness and wall selectivity.

Superoxide-Mediated Extracellular Mercury Reduction by Aerobic Marine Bacterium Alteromonas sp. KD01.

Microbial reduction plays a crucial role in Hg redox and the global cycle. Although intracellular Hg(II) reduction mediated by MerA protein is well documented, it is still unclear whether or how bacteria reduce Hg(II) extracellularly without its internalization. Herein, for the first time, we discovered the extracellular reduction of Hg(II) by a widely distributed aerobic marine bacterium Alteromonas sp. KD01 through a superoxide-dependent mechanism. The generation of superoxide by Alteromonas sp. KD01 was determined using 3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide and methyl cypridina luciferin analogue as probes via UV-vis and chemiluminescence detection, respectively. The results demonstrated that Hg(II) reduction was inhibited by superoxide scavengers (superoxide dismutase (SOD) and Cu(NO3)2) or inhibitors of reduced nicotinamide adenine dinucleotide (NADH) oxidoreductases. In contrast, the addition of NADH significantly improved superoxide generation and, in turn, Hg(II) reduction. Direct evidence of superoxide-mediated Hg(II) reduction was provided by the addition of superoxide using KO2 in deionized water and seawater. Moreover, we observed that even superoxide at an environmental concentration of 9.6 ± 0.5 nM from Alteromonas sp. KD01 (5.4 × 106 cells mL-1) was capable of significantly reducing Hg(II). Our findings provide a greater understanding of Hg(II) reduction by superoxide from heterotrophic bacteria and eukaryotic phytoplankton in diverse aerobic environments, including surface water, sediment, and soil.