Charge Inversion, Water Splitting, and Vortex Suppression Due to DNA Sorption on Ion-Selective Membranes and Their Ion-Current Signatures

The physisorption of negatively charged single-stranded DNA (ssDNA) of different lengths onto the surface of anion-exchange membranes is sensitively shown to alter the anion flux through the membrane. At low surface concentrations, the physisorbed DNAs act to suppress an electroconvection vortex instability that drives the anion flux into the membrane and hence reduce the overlimiting current through the membrane. Beyond a critical surface concentration, determined by the total number of phosphate charges on the DNA, the DNA layer becomes a cation-selective membrane, and the combined bipolar membrane has a lower net ion flux, at low voltages, than the original membrane as a result of ion depletion at the junction between the cation- (DNA) and anion-selective membranes. However, beyond a critical voltage that is dependent on the ssDNA coverage, water splitting occurs at the junction to produce a larger overlimiting current than that of the original membrane. These two large opposite effects of polyelectrolyte counterion sorption onto membrane surfaces may be used to eliminate limiting current constraints of ion-selective membranes for liquid fuel cells, dialysis, and desalination as well as to suggest a new low-cost membrane surface assay that can detect and quantify the number of large biomolecules captured by probes functionalized on the membrane surface

Charge Inversion, Water Splitting, and Vortex Suppression Due to DNA Sorption on Ion-Selective Membranes and Their Ion-Current Signatures

The physisorption of negatively charged single-stranded DNA (ssDNA) of different lengths onto the surface of anion-exchange membranes is sensitively shown to alter the anion flux through the membrane. At low surface concentrations, the physisorbed DNAs act to suppress an electroconvection vortex instability that drives the anion flux into the membrane and hence reduce the overlimiting current through the membrane. Beyond a critical surface concentration, determined by the total number of phosphate charges on the DNA, the DNA layer becomes a cation-selective membrane, and the combined bipolar membrane has a lower net ion flux, at low voltages, than the original membrane as a result of ion depletion at the junction between the cation- (DNA) and anion-selective membranes. However, beyond a critical voltage that is dependent on the ssDNA coverage, water splitting occurs at the junction to produce a larger overlimiting current than that of the original membrane. These two large opposite effects of polyelectrolyte counterion sorption onto membrane surfaces may be used to eliminate limiting current constraints of ion-selective membranes for liquid fuel cells, dialysis, and desalination as well as to suggest a new low-cost membrane surface assay that can detect and quantify the number of large biomolecules captured by probes functionalized on the membrane surface

Arsenic Demethylation by a C·As Lyase in Cyanobacterium <i>Nostoc</i> sp. PCC 7120

Arsenic, a ubiquitous toxic substance, exists mainly as inorganic forms in the environment. It is perceived that organoarsenicals can be demethylated and degraded into inorganic arsenic by microorganisms. Few studies have focused on the mechanism of arsenic demethylation in bacteria. Here, we investigated arsenic demethylation in a typical freshwater cyanobacterium <i>Nostoc</i> sp. PCC 7120. This bacterium was able to demethylate monomethylarsenite [MAs­(III)] rapidly to arsenite [As­(III)] and also had the ability to demethylate monomethylarsenate [MAs­(V)] to As­(III). The <i>NsarsI</i> encoding a C·As lyase responsible for MAs­(III) demethylation was cloned from <i>Nostoc</i> sp. PCC 7120 and heterologously expressed in an As-hypersensitive strain Escherichia coli AW3110 (Δ<i>arsRBC</i>). Expression of <i>NsarsI</i> was shown to confer MAs­(III) resistance through arsenic demethylation. The purified NsArsI was further identified and functionally characterized in vitro. NsArsI existed mainly as the trimeric state, and the kinetic data were well-fit to the Hill equation with <i>K</i>_0.5 = 7.55 ± 0.33 μM for MAs­(III), <i>V</i>_max = 0.79 ± 0.02 μM min^–1, and <i>h</i> = 2.7. Both of the NsArsI truncated derivatives lacking the C-terminal 10 residues (ArsI10) or 23 residues (ArsI23) had a reduced ability of MAs­(III) demethylation. These results provide new insights for understanding the important role of cyanobacteria in arsenic biogeochemical cycling in the environment

Mixed Mosaic Membranes Prepared by Layer-by-Layer Assembly for Ionic Separations

Charge mosaic membranes, which possess distinct cationic and anionic domains that traverse the membrane thickness, are capable of selectively separating dissolved salts from similarly sized neutral solutes. Here, the generation of charge mosaic membranes using facile layer-by-layer assembly methodologies is reported. Polymeric nanotubes with pore walls lined by positively charged polyethylenimine moieties or negatively charged poly(styrenesulfonate) moieties were prepared <i>via</i> layer-by-layer assembly using track-etched membranes as sacrificial templates. Subsequently, both types of nanotubes were deposited on a porous support in order to produce mixed mosaic membranes. Scanning electron microscopy demonstrates that the facile deposition techniques implemented result in nanotubes that are vertically aligned without overlap between adjacent elements. Furthermore, the nanotubes span the thickness of the mixed mosaic membranes. The effects of this unique nanostructure are reflected in the transport characteristics of the mixed mosaic membranes. The hydraulic permeability of the mixed mosaic membranes in piezodialysis operations was 8 L m^–2 h^–1 bar^–1. Importantly, solute rejection experiments demonstrate that the mixed mosaic membranes are more permeable to ionic solutes than similarly sized neutral molecules. In particular, negative rejection of sodium chloride is observed (<i>i</i>.<i>e</i>., the concentration of NaCl in the solution that permeates through a mixed mosaic membrane is higher than in the initial feed solution). These properties illustrate the ability of mixed mosaic membranes to permeate dissolved ions selectively without violating electroneutrality and suggest their utility in ionic separations

Additional file 1 of Short-term effects of tropical cyclones on the incidence of dengue: a time-series study in Guangzhou, China

Additional file 1: Table S1. The detail information of tropical cyclones during the study period. Table S2. The lag and cumulative effects of tropical storm and typhoon on dengue incidence among subgroups. Figure. S1. The lag effects of tropical cyclones on dengue incidence when changing the meteorological factors in the model. Figure. S2. The lag effects of tropical cyclones on dengue incidence when changing the df (2–5) for WAT, WCP, WARH, and time. Figure. S3. The lag effects of tropical cyclones on dengue incidence when adding the term of first-order lagged variable of residual error in the model. Figure. S4. The lag effects of tropical cyclones on dengue incidence when using negative binomial regression rather than quasi-Poisson regression. Figure. S5. Lag effects (A) and cumulative effects (B) of tropical cyclones on dengue incidence within lag 6 weeks

Elucidating the Synergistic Effects of Temperature Rise Inhibitor at the Water Tricalcium Silicate Interface

Organic–inorganic composites play a crucial role in modulating concrete properties, encompassing interfacial interactions and their synergistic mechanisms. Unraveling these interactions presents a formidable challenge. In this study, molecular dynamics simulations were employed to probe the intricate structure, competition, and equilibrium state of interfacial connections involving a temperature rise inhibitor (TRI), C3S, and water. Computational results reveal that the interplay of different bonding networks significantly influences the equilibrium state of the C3S–TRI interfacial interactions, marked by dynamic adsorption–desorption equilibria. The interaction between C3S and TRI manifests in intricate calcium–oxygen and hydrogen bonding networks, which are both easily disturbed by water molecules. Oxygen sites in water serve as binding sites for calcium atoms in C3S and hydrogen atoms in TRI, thereby attenuating the C3S–TRI bonding. Simultaneously, hydrogen sites in water engage with oxygen sites in the TRI, diminishing calcium–oxygen bonding and prompting the detachment of TRI from the C3S surface. Moreover, these hydrogen sites interact with the oxygen sites on the C3S surface, inducing lattice structure alterations and removal of calcium atoms from C3S. As TRI detaches into the liquid phase, it forms complexes with calcium ions, reducing the migration rate of calcium ions within the liquid phase. This study represents the inaugural comprehensive evaluation of the interfacial interaction mechanism between TRI, C3S, and water, offering fundamental insights into the impact of TRI on the evolution of the C3S phase. These findings contribute to a deeper understanding of the complex interplay governing concrete properties, paving the way for enhanced control and optimization in concrete technology

Main characteristics and baselines of the included studies.

Main characteristics and baselines of the included studies.</p

Patient selection during data extraction from the Zilver PTX trial [16].

Patient selection during data extraction from the Zilver PTX trial [16].</p

Definitions of the outcomes during follow up extracted from the included studies.

Definitions of the outcomes during follow up extracted from the included studies.</p

Fig 4 -

Forest plot of TLR-free survival (random effects model, P = 0.089) (A); Sensitivity analysis of the model assuming that each study is omitted separately [ln (HR)] (B); Funnel plot with pseudo 95% confidence limits (C). Abbreviations: HR, hazard ratio; CI, confidence interval; REML, restricted maximum likelihood; BMSI, bare metal stent implantation; DESI, drug-eluting stent implantation; TLR, target lesion revascularization.</p