Rational Design of Two-Dimensional Hydrocarbon Polymer as Ultrathin-Film Nanoporous Membranes for Water Desalination

Membrane-based water desalination has drawn considerable attention for its potential in addressing the increasingly limited water resources, but progress remains limited due to the inherent constraints of conventional membrane materials. In this work, by employing state-of-the-art molecular simulation techniques, we demonstrated that two-dimensional hydrocarbon polymer membranes, materials that possess intrinsic and tunable nanopores, can provide opportunities as molecular sieves for producing drinkable water from saline sources. Moreover, we identified a unique relationship between the permeation and selectivity for membranes with elliptical pores, which breaks the commonly known trade-off between the pore size and desalination performance. Specifically, increase in the area of elliptical pores with a controlled minor diameter can offer an improved water flux without compromising the ability to reject salts. Water distributions and water dynamics at atomic levels with the potential of mean force profiles for water and ions were also analyzed to understand the dependence of permeation and selectivity on the pore geometry. The outcomes of this work are instrumental to the future development of ultrathin-film reverse osmosis membranes and provide guidelines for the design of membranes with more effective and efficient pore structures

Mutation trend analysis of signature and non-signature amino acid residues in the functional domains of the proteins of 2009 H1N1pdm during the influenza pandemic in 2009.

<p>Note: the number in brackets indicates the percent (%) of sequences with the mutated amino acid in total number of the sequences collected in the period; ‘-’ means unavailable in non-H1N1 virus.</p

Comparison of the amino acid signatures in the proteins of 2009 H1N1pdm with those in human, swine, and avian IAVs, as well as those causing past influenza pandemics.

<p>Note: Only the dominant residues were listed. The human-like amino acid signatures in the 2009 H1N1pdm were highlighted in bold and italic.</p

Schematic representation of the functional domains with mutated residues in the 2009 H1N1pdm proteins.

<p><b>Left panels</b>: bird's eye view of protein structures of 2009 H1N1pdm collected at the pre-epidemic period in 2009; <b>Middle panels</b>: close-up view of the mutated amino acid residues in proteins of 2009 H1N1pdm collected at the pre-epidemic period in 2009; <b>Right panels</b>: close-up view of the mutated amino acid residues in proteins of 2009 H1N1pdm collected at the late period in 2009. The amino acid numberings were based on influenza virus A/Puerto Rico/8/1934 (H1N1) <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0009549#pone.0009549-Chen1" target="_blank">[6]</a>. The residues in viruses collected in the pre-epidemic period are colored in red, and those in viruses collected in the late period are colored in yellow. <b>A–C:</b> NP trimer and monomer. <b>D–F:</b> NA tetramer and monomer. Drug target domain (DTD) is highlighted in dark blue. H260 [274 in A/Vietnam/1203/04(H5N1)] is a critical residue for the NA inhibitor, oseltamivir. NA H274Y mutation results in resistance of 2009 H1N1pdm and other influenza viruses to oseltamivir. <b>G–I</b>: HA trimer and monomer. Receptor binding domain (RBD) was highlighted in wheat color, while other part is in green color. <b>J–L</b>: Dimer and monomer of effector domain (ED) in NS1.</p

The identity of amino acid signatures in the proteins of pandemic IAVs and human, swine, and avian IAVs.

<p>The identity of amino acid signatures in the proteins of pandemic IAVs and human, swine, and avian IAVs.</p

Controllable Multigeometry Nanoparticles <i>via</i> Cooperative Assembly of Amphiphilic Diblock Copolymer Blends with Asymmetric Architectures

Multigeometry nanoparticles with high complexity in composition and structure have attracted significant attention for enhanced functionality. We assess a simple but versatile strategy to construct hybrid nanoparticles with subdivided geometries through the cooperative assembly of diblock copolymer blends with asymmetric architectures. We report the formation of multicompartmental, vesicular, cylindrical, and spherical structures from pure AB systems. Then, we explore the assemblies of binary AB/AC blends, where the two incompatible, hydrophobic diblock copolymers subdivide into self-assembled local geometries, and the complexity of the obtained morphologies increases. We expand the strategy to ternary AB/AC/AD systems by tuning the effect of phase separation of different hydrophobic domains on the surface or internal region of the nanoparticle. The kinetic control of the coassembly in the initial stage is crucial for controlling the final morphology. The interactions of copolymers with different block lengths and chemistries enable the stabilization of interfaces, rims and ends of subdomains in the hybrid multigeometry nanoparticles. With further exploration of size and shape, the dependence of local geometry on the volume fraction is discussed. We show an efficient approach for controllable multigeometry nanoparticle construction that will be useful for multifunctional and hierarchical nanomaterials

Tunable Permeability of Cross-Linked Microcapsules from pH-Responsive Amphiphilic Diblock Copolymers: A Dissipative Particle Dynamics Study

Using dissipative particle dynamics simulation, we probe the tunable permeability of cross-linked microcapsules made from pH-sensitive diblock copolymers poly­(ethylene oxide)-<i>b</i>-poly­(<i>N</i>,<i>N</i>-diethylamino-2-ethyl methacrylate) (PEO-<i>b</i>-PDEAEMA). We first examine the self-assembly of non-cross-linked microcapsules and their pH-responsive collapse and then explore the effects of cross-linking and block interaction on the swelling or deswelling of cross-linked microcapsules. Our results reveal a preferential loading of hydrophobic dicyclopentadiene (DCPD) molecules in PEO-<i>b</i>-PDEAEMA copolymers. Upon reduction of pH, non-cross-linked microcapsules fully decompose into small wormlike clusters as a result of large self-repulsions of protonated copolymers. With increasing degree of cross-linking, the morphology of the microcapsule becomes more stable to pH change. The highly cross-linked microcapsule shell undergoes significant local polymer rearrangement in acidic solution, which eliminates the amphiphilicility and therefore enlarges the permeability of the shell. The responsive cross-linked shell experiences a disperse-to-buckle configurational transition upon reduction of pH, which is effective for the steady or pulsatile regulation of shell permeability. The swelling rate of the cross-linked shell is dependent on both electrostatic and nonelectrostatic interactions between the pH-sensitive groups as well as the other groups. Our study highlights the combination of cross-linking structure and block interactions in stabilizing microcapsules and tuning their selective permeability

Additional file 1: of Combination of Chymostatin and Aliskiren attenuates ER stress induced by lipid overload in kidney tubular cells

Figure A1. mRNA levels of RAS components in HK2 cells treated with palmitic acid. A. The mRNA levels of chymase, angiotensinogen, ACE in PA-treated HK2 cells with chymostatin and/or aliskiren. B. The mRNA levels of AT1R in PA-treated HK2 cells with chymostatin and/or aliskiren. Representative results of three independent experiments are shown. ATG: angiotensinogen; ACE: angiotensin converting enzyme; AT1R: angiotensin type 1 receptor; CTL, controls; PA, palmitic acid treatment group; PA + CMT, palmitic acid plus chymostatin treatment; PA + Ali, palmitic acid plus aliskiren treatment; PA + CMT + Ali, palmitic acid plus chymostatin and aliskiren treatment. * p < 0.05 compared with controls; # p < 0.05 compared with PA. (PPTX 52 kb

Characterization of Chinese <i>Haemophilus parasuis</i> Isolates by Traditional Serotyping and Molecular Serotyping Methods

<div><p><i>Haemophilus parasuis</i> is classified mainly through serotyping, but traditional serotyping always yields non-typable (NT) strains and unreliable results via cross-reactions. Here, we surveyed the serotype prevalence of Chinese <i>H</i>. <i>parasuis</i> isolates using traditional serotyping (gel immuno-diffusion test, GID) and molecular serotyping (multiplex PCR, mPCR). We also investigated why discrepant results between these methods were obtained, and investigated mPCR failure through whole-genome sequencing. Of the 100 isolate tested, 73 (73%) and 93 (93%) were serotyped by the GID test and mPCR, respectively, with a concordance rate of 66% (66/100). Additionally, mPCR reduced the number of NT isolates from 27 (27%) for the GID testing, to seven (7%). Eleven isolates were sequenced, including nine serotype-discrepant isolates from mPCR and GID typing (excluding strains that were NT by GID only) and two NT isolates from both methods, and their <i>in silico</i> serotypes were obtained from genome sequencing based on their capsule loci. The mPCR results were supported by the <i>in silico</i> serotyping of the seven serotype-discrepant isolates. The discrepant results and NT isolates determined by mPCR were attributed to deletions and unknown sequences in the serotype-specific region of each capsule locus. Compared with previous investigations, this study found a similar predominant serotype profile, but a different prevalence frequency for <i>H</i>. <i>parasuis</i>, and the five most prevalent serotypes or strain groups were serotypes 5, 4, NT, 7 and 13 for mPCR, and serotypes 5, NT, 4, 7 and 13/10/14 for GID. Additionally, serotype 7 was recognized as a principal serotype in this work.</p></div

Additional file 2: of Combination of Chymostatin and Aliskiren attenuates ER stress induced by lipid overload in kidney tubular cells

Figure A2. Combination treatment with chymostatin and aliskiren couldn’t prevent ER stress in HK2 cells treated with tunicamycin (2 μg/ml). A. Tunicamycin induced upregulation of the ER markers (BiP and CHOP) expression in HK2 cells, neither pretreatment with chymostatin (5X10−5M) nor aliskiren (10− 8 M) attenuated ER stress induced by TM. B. Quantitative analysis of ER stress marker levels normalized to β-actin. Representative results of three independent experiments are shown. * p < 0.05 compared with controls. # p < 0.05 compared with TM. CTL, controls; TM, tunicamycin treatment group; TM + CMT, tunicamycin plus valsartan treatment; TM + Ali, tunicamycin plus aliskiren treatment; TM + CMT + Ali, tunicamycin plus chymostatin and aliskiren treatment. (PPTX 73 kb