Molecules Of Different Sizes Research Articles

Molecular sieving of semiconductive NTU-9 coatings on titanium dioxide nanowire arrays: Augmented yet selective photoelectrochemical response enabled by boosting charge separation and transfer in confined space

Radial heterostructures with titanium dioxide (TiO2) nanowire as core and NTU-9 as shell are synthesized via a surfactant-free approach based on the favorable bonding of linkers with TiO2 nanowire. Relative to the traditional growth strategy of surface modification, the thin NTU-9 shell with ordered arrangement of two-dimensional networks is uniformly formed on the sidewalls of TiO2 nanowire through the orientational growth process. Using the core–shell nanowire arrays as photoanodes, wide-range light absorption and high charge carrier separation efficiency are achieved due to the conjugation of NTU-9, leading to enhanced water oxidation performance in photoelectrochemical (PEC) water splitting. Under appropriately low applied potentials, the photogenerated holes are preferable to accumulate at TiO2/NTU-9/electrolyte three-phase interface and thus the long-range ordered NTU-9 shell can also serve as a size-exclusion filter to improve selectivity toward molecules of different sizes. Consequently, the TiO2/NTU-9 core–shell nanowire array exhibits an augmented and selective PEC response for small size molecules (e.g.,H2O2) at a very low potential (–0.25 V vs Ag/AgCl), outperforming the pure TiO2 nanowire array and the counterpart with a grain-boundary-rich NTU-9 shell that is prepared by pretreatment of the TiO2 nanowires with PVP functionalization.

Small fragments of hyaluronan are increased in individuals with obesity and contribute to low-grade inflammation through TLR-mediated activation of innate immune cells

Background and aimExtracellular matrix (ECM) components released during excessive fat mass expansion are considered potential endogenous danger/alarm signals contributing to innate immune system activation. The aim of the current study was to specifically measure plasma levels of low molecular weight (LMW) hyaluronan (HA) and to evaluate its role as pro-inflammatory damage-associated molecular pattern (DAMP) on leukocyte response in the context of human obesity.Subjects and methodsParticipants were selected according to their body mass index (BMI, kg/m2) as non-obese (BMI < 29.9, n = 18) and obese (BMI > 29.9, n = 33). Plasma samples were size-dependent fractionated using ion-exchange chromatography to specifically obtain LMW HA fractions that were subsequently quantified by ELISA. Cell incubation experiments with synthetic HA molecules were performed on freshly Ficoll-isolated neutrophils (PMN) and peripheral blood monocytes (PBMC). Leukocyte and adipose tissue gene expression was assessed by real-time PCR and NF-κB activation by western blot. Plasma cytokine levels were measured by fluorescent bead-based (Luminex) immunoassay.ResultsWe observed a statistically significant increase in the circulating levels of HA fragments of LMW in individuals with obesity which were consistent with significant up-regulated expression of the LMW HA synthesizing enzyme hyaluronan synthase-1 (HAS-1) in obese adipose tissue. Gene expression assessment of HA receptors revealed up-regulated levels for TLR2 in both obese PMN and PBMC. Synthetic HA molecules of different sizes were tested on leukocytes from healthy donors. LMW HA fragments (15–40 kDa) and not those from intermediate molecular sizes (75–350 kDa) induced a significant up-regulation of the expression of major pro-inflammatory cytokines such as IL-1β, MCP-1 and IL-8 in PBMC. Importantly, LMW HA was able to induce the phosphorylation of IKK α/β complex supporting its pro-inflammatory role through NF-κB activation.ConclusionCirculating LMW HA molecules are elevated in obesity and may play an important role in triggering low-grade inflammation and the development of metabolic complications.

Ultrathin Covalent Organic Framework Anchored on Graphene for Enhanced Organic Pollutant Removal

AbstractCovalent organic frameworks (COFs) are of great potential as adsorbents owing to their tailorable functionalities, low density and high porosity. However, their intrinsically stacked two‐dimensional (2D) structure limits the full use of their complete surface for sorption, especially the internal pores. The construction of ultrathin COFs could increase the exposure of active sites to the targeted molecules in a pollutant environment. Herein, an ultrathin COF with a uniform thickness of ca. 2 nm is prepared employing graphene as the surface template. The resulting hybrid aerogel with an ultralow density (7.1 mg cm−3) exhibits the ability to remove organic dye molecules of different sizes with high efficiency. The three‐dimensional (3D) macroporous structure and well‐exposed adsorption sites permit rapid diffusion of solution and efficient adsorption of organic pollutants, thereby, greatly contributing to its enhanced uptake capacity. This work highlights the effect of COF layer thickness on adsorption performance.

Ultrathin Covalent Organic Framework Anchored on Graphene for Enhanced Organic Pollutant Removal.

Covalent organic frameworks (COFs) are of great potential as adsorbents owing to their tailorable functionalities, low density and high porosity. However, their intrinsically stacked two‐dimensional (2D) structure limits the full use of their complete surface for sorption, especially the internal pores. The construction of ultrathin COFs could increase the exposure of active sites to the targeted molecules in a pollutant environment. Herein, an ultrathin COF with a uniform thickness of ca. 2 nm is prepared employing graphene as the surface template. The resulting hybrid aerogel with an ultralow density (7.1 mg cm−3) exhibits the ability to remove organic dye molecules of different sizes with high efficiency. The three‐dimensional (3D) macroporous structure and well‐exposed adsorption sites permit rapid diffusion of solution and efficient adsorption of organic pollutants, thereby, greatly contributing to its enhanced uptake capacity. This work highlights the effect of COF layer thickness on adsorption performance.

Nanostructured regulation of the surface properties and hydrophobicity of nickel and iron by solid-state reduction and modifying methods

metal samples obtained by solid-state hydride synthesis (SHS) of metals and layering of different-sized molecules (LDM) of ammonium and organosilicon compounds has been carried out. It was found that the dispersed metal products of SHS are significantly more hydrophobic (on average, by an order of magnitude) compared to metals modified in vapors of industrial water repellents. It has been established that among the metal products of SHS based on nickel, copper, and iron with a carbosiloxane nanofilm on the surface, the samples based on iron are the most hydrophobic and heat-resistant in air. The most hydrophilic and chemically active samples were nickel-based, which had a fairly developed surface (about 50 m2/g). The revealed patterns of regulation of the surface properties and hydrophobicity of metal synthesis products are associated with the strongest interatomic metal-silicon chemical interaction in the surface layer of iron-based samples, confirmed by XPS spectroscopy. When a metal product is obtained by successive reduction of the initial solid- phase raw material (ore) in methyldichlorosilane (MDCS) vapor and in a methane stream, MDCS performs the functions of a reducing agent and modifier of the metal surface. The metal at the time of appearance, being in a reducing medium, has a reactive surface and actively interacts with MDCS molecules containing chemically stable Si-C groups, with the formation of a strong chemisorption bond between the metal and the protective carbosiloxane film formed during synthesis, no more than 4&ndash;5 nm. Such a mechanism of the process under SHS conditions makes it possible to carry out the reduction and useful modification of the metal within the framework of a single technological process and in one reactor.This research paper was recommended for publication by the organizing committee&nbsp;of the International Conference on Nanophysics and Nanomaterials,&nbsp;24-25 November 2021, Saint Petersburg, Mining University.

Evaluation of Zeolite Acidity by 31P MAS NMR Spectroscopy of Adsorbed Phosphine Oxides: Quantitative or Not?

31P magic angle spinning nuclear magnetic resonance (MAS NMR) spectroscopy of adsorbed alkyl-substituted phosphine oxides has witnessed tremendous progress during the last years and has become one of the most informative and sensitive methods of zeolite acidity investigation. However, quantitative evaluation of the number of sites is still a challenge. This study clarifies the main origin of errors occurring during NMR experiments, introduces the appropriate standards (both internal and external), and determines the relaxation parameters and the conditions for the acquisition and integration of spectra. As a result, a methodology for the quantitative measurement of the content of Brønsted and Lewis sites and the amount of internal and external silanol groups is established. The application of probe molecules of different sizes (namely, trimethylphosphine oxide (TMPO), tri-n-butylphosphine oxide (TBPO), and tri-n-octylphosphine oxide (TOPO)) is shown to be a good tool for distinguishing between the active sites inside the zeolite pores, mesopores, and on the outer crystal surface. The methodology proposed is verified on BEA zeolites different in composition, texture, and morphology.

Polyarylester thin films with narrowed pore size distribution via metal-phenolic network modulated interfacial polymerization for precise separation

Traditional nanofiltration (NF) membranes meet a bottleneck in throughput due to the lack of flexibility in pore structure control of the polyamide selective layer. This work developed a highly-permselective NF membrane by creating a controlled polyarylester selective layer via a facile method of metal-phenolic network (MPN) modulated interfacial polymerization between 5,5,6′,6′-tetrahydroxy-3,3,3′,3′-tetramethyl spirobisindane (TTSBI) and trimesoyl chloride (TMC). It was hypothesized that in the presence of FeCl3, the catechol groups of TTSBI first formed a Fe3+/TTSBI complex to construct the MPN and subsequently reacted with TMC, eliminating structural defects in the selective layer. The solution chemistry studies and membrane optimization results verified the significant role of Fe3+ in forming metal-phenolic coordination and thus defectless pore structure. The resulted Fe-TTSBI-TMC membrane exhibited greatly reduced pore size of 0.68 nm and narrow pore size distribution. The rigid and twisted feature of TTSBI endowed the polyarylester layer with high porosity. This ingeniously designed synergistic effect rendered the resulted membrane with a high pure water permeability of 15 L m−2 h−1 bar−1, about 3 times higher than typical polyamide NF membrane prepared by piperazine and TMC; while achieved high salt and molecular rejections (e.g., 98% rejection of Na2SO4, 100% rejection of vitamin B12), exhibiting superior perm-selective properties as compared to most NF membranes incorporating microporous materials. Accurate separation between molecules of different sizes of vitamin B2 and vitamin B12 was achieved with 100% efficiency. Hence, this work provides a promising alternative for skillful control of NF membrane pore structure towards efficient and precise molecular separation.

Quantitative Resonance Theory Based on the Clar Sextet Model.

Despite its great explanatory power in understanding the chemistry of polycyclic aromatic hydrocarbons (PAHs) and related systems, the Clar sextet rule still remains an intuitive and qualitative model with notable exceptions in some cases. Here we develop a quantitative theory of chemical resonance based on semilocalized Clar-type resonance structures (named the Clar resonators) consisting of variable numbers of Clar sextets and C═C bonds. The constructed wave functions of the Clar resonators are used to expand the actual wave function of the π-conjugated system obtained from a DFT or Hartree-Fock calculation. The resultant weights and one-electron energies of the Clar resonators can serve as a quantitative measure of the importance of these resonators. Implementing the theory in our open-source python code EzReson and applying it to over a thousand PAH molecules of different sizes and shapes, we show that the weight of the Clar resonators increases exponentially with increasing number of sextets and that their energy decreases linearly with the latter, thus confirming the general validity of the Clar rule. On the basis of such a large-scale resonance analysis, we propose three extended Clar rules, along with a unified quantitative model, that are able to evaluate the importance of all Clar resonators and the ring aromaticity for PAHs. Using the present theories, we uncover the essential role that the minor Clar resonators may play in correctly understanding the resonance stabilization and local aromaticity of rings, which was totally overlooked in the original Clar model.

Contact angle of water on a model heterogeneous surface. A density functional approach

We use a density functional approach to calculate the contact angle of the water model on a heterogeneous, graphite-like surface. The surface heterogeneity results from the pre-adsorption of a layer of spherical species. The pre-adsorbed molecules can also be a mixture of molecules of different sizes. The presence of pre-adsorbed layer causes geometrical and energetical heterogeneity of the surfaces. Two cases are considered. The pre-adsorbed molecules can either behave like hard-sphere obstacles, or they can also attract the molecules of water. In the first case, an increase of the amount of pre-adsorbed species leads to an increase of the wetting temperature, but this increase does not depend linearly on the amount of obstacles. In the case of obstacles exerting attractive forces on water molecules, the curves describing the dependence between the amount of pre-adsorbed species and the contact angle can exhibit a maximum. In addition, we have also studied how the pre-adsorbed species influence the local densities of gaseous and liquid phases in contact with a modified solid surface.

Integrity Assessment of Isolated Plant Mitochondria.

The integrity of isolated mitochondria can be estimated functionally using enzymatic activities or the permeability of mitochondrial membranes to molecules of different sizes. Thus, the permeability of the outer membrane to the protein cytochrome c, the permeability of the inner membrane to protons, and the permeability of the inner membrane to NAD+, NADH and organic acids using soluble matrix dehydrogenases as markers have all been used. These assays all have limitations to how the data can be converted into a measure of integrity, are differently sensitive to artifacts and require widely variable amounts of material. Therefore, each method has a restricted utility for estimating integrity, depending on the type of mitochondria analysed. Here, we review the advantages and disadvantages of different integrity assays and present protocols for integrity assays that require relatively small amounts of mitochondria. They are based on the permeability of the outer membrane to cytochrome c, and the inner membrane to protons or NAD(H). The latter has the advantage of utilizing a membrane-bound activity (complex I) and the pore-forming peptide alamethicin to gain access to the matrix space. These methods together provide a toolbox for the determination of functionality and quality of isolated mitochondria.

A Scalable Graph Neural Network Method for Developing an Accurate Force Field of Large Flexible Organic Molecules

An accurate force field is the key to the success of all molecular mechanics simulations on organic polymers and biomolecules. Accurate correlated wave function (CW) methods scale poorly with system size, so this poses a great challenge to the development of an extendible ab initio force field for large flexible organic molecules at the CW level of accuracy. In this work, we combine the physics-driven nonbonding potential with a data-driven subgraph neural network bonding model (named sGNN). Tests on polyethylene glycol, polyethene, and their block polymers show that our strategy is highly accurate and robust for molecules of different sizes and chemical compositions. Therefore, one can develop a parameter library of small molecular fragments (with sizes easily accessible to CW methods) and assemble them to predict the energy of large polymers, thus opening a new path to next-generation organic force fields.

English

This study investigated whether concurrent presence of lipopolysaccharide (LPS) and histamine (HIS) have the potential to increase permeability of the ruminal epithelium at physiological pH and acidotic ruminal pH. Nine 2.5-year-old female lactating Saanen dairy goats (42.79 ± 5.61 kg of BW; Mean ± SD) were used as a ruminant model. ruminal epithelium of goats were collected and mounted in Ussing chambers on their mucosal side in different gradient buffer solutions (pH 7.4, 5.5 and 5.2) containing LPS (0, 30 and 60 KEU·mL-1) or HIS (0, 0.5 and 10 ng·mL-1). The rumen epithelial electrophysiological indexes, such as short-circuit (Isc), tissue conductance (Gt) and the permeability of marker molecules of different sizes (horseradish peroxidase, HRP and fluorescein 5(6)-isothiocyanate, FITC) from the mucosal to the serosal side, were measured. Both Isc and Gt were increased, accompanied by enhanced flux of FITC, with a decrease of mucosal pH (P &lt; 0.05). The addition of LPS at mucosal pH 5.2 significantly increased Isc, Gt and FITC flux rates and decreased potential difference (PD) (P &lt; 0.05). Additionally, the concurrent presence of LPS and HIS at both physiological and acidotic ruminal pH also significantly increased the permeability of ruminal epithelium asevidenced by increasing Isc, Gt and FITC flux rates and decreasing PD. In summary, our results have shown that concurrent presence of LPS 60 KEU‧mL-1 and HIS 10 ng‧mL-1 at mucosal pH 5.5 can increase the permeability of ruminal epithelium. The combination of low pH and both high LPS and HIS may increase vulnerability to aggravated rumen epithelial barrier dysfunction. © 2021 Friends Science Publishers

Self-assembly in soft matter with multiple length scales

Spontaneous self-assembly in molecular systems is a fundamental route to both biological and engineered soft matter. Simple micellization, emulsion formation, and polymer mixing are well understood. However, the principles behind emergence of structures with competing length scales in soft matter systems remain unknown. Examples include droplet-inside-droplet assembly in many biomacromolecular systems undergoing liquid-liquid phase separation, analogous multiple emulsion formation in oil-surfactant-water formulations, and polymer core-shell particles with internal structure. We develop here a microscopic theoretical model based on effective interactions between the constituents of a soft matter system to explain self-organization both at single and multiple length scales. The model identifies how spatial ordering at multiple length scales emerges due to competing interactions between the system components, e.g., molecules of different sizes and different chemical properties. As an example of single and multiple length scale assembly, we map out a generic phase diagram for a solution with two solute species differing in their mutual and solvent interactions. We further connect the phase diagram to a molecular system via molecular simulations of a block-copolymer system that has a transition from regular single-core polymer particles to multicore aggregates that exhibit multiple structural length scales. The findings provide guidelines to understanding the length scales rising spontaneously in biological self-assembly but also open venues to the development and engineering of biomolecular and polymeric functional materials and pharmaceutical formulations.Received 20 January 2021Accepted 25 March 2021DOI:https://doi.org/10.1103/PhysRevResearch.3.L022008Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.Published by the American Physical SocietyPhysics Subject Headings (PhySH)Research AreasClassical statistical mechanicsClusteringPhase diagramsSelf-assemblyThermodynamicsCondensed Matter, Materials & Applied PhysicsStatistical PhysicsPolymers & Soft Matter

Tight junctions and their regulation by non-coding RNAs.

Tight junction (TJ) is a “zippering up” junction structure located at the uppermost portion of adjacent epithelial/endothelial cells in organs and tissues. TJs maintain the relative stability of intracellular substances and functions by closing or opening intercellular pathways, coordinating the entry and exit of molecules of different sizes and charges, and regulating the permeability of paracellular barrier. TJs also prevent microbial invasion, maintain epithelial/endothelial cell polarity, and regulate cell proliferation. TJs are widely present in the skin and mucosal epithelial barriers, intestinal epithelial barrier, glomerular filtration barrier, bladder epithelial barrier, blood-brain barrier, brain-blood tumor barrier, and blood-testis barrier. TJ dysfunction in different organs can lead to a variety of diseases. In addition to signal pathways, transcription factors, DNA methylation, histone modification, TJ proteins can also be regulated by a variety of non-coding RNAs, such as micro-RNAs, long-noncoding RNAs, and circular RNAs, directly or indirectly. This review summarizes the structure of TJs and introduces the functions and regulatory mechanisms of TJs in different organs and tissues. The roles and mechanisms of non-coding RNAs in the regulation of TJs are also highlighted in this review.

Efficient and gentle delivery of molecules into cells with different elasticity via Progressive Mechanoporation.

Intracellular delivery of cargo molecules such as membrane-impermeable proteins or drugs is crucial for cell treatment in biological and medical applications. Recently, microfluidic mechanoporation techniques have enabled transfection of previously inaccessible cells. These techniques create transient pores in the cell membrane by shear-induced or constriction contact-based rapid cell deformation. However, cells deform and recover differently from a given extent of shear stress or compression and it is unclear how the underlying mechanical properties affect the delivery efficiency of molecules into cells. In this study, we identify cell elasticity as a key mechanical determinant of delivery efficiency leading to the development of “progressive mechanoporation” (PM), a novel mechanoporation method that improves delivery efficiency into cells of different elasticity. PM is based on a multistage cell deformation, through a combination of hydrodynamic forces that pre-deform cells followed by their contact-based compression inside a PDMS-based device controlled by a pressure-based microfluidic controller. PM allows processing of small sample volumes (about 20 μL) with high-throughput (>10 000 cells per s), while controlling both operating pressure and flow rate for a reliable and reproducible cell treatment. We find that uptake of molecules of different sizes is correlated with cell elasticity whereby delivery efficiency of small and big molecules is favoured in more compliant and stiffer cells, respectively. A possible explanation for this opposite trend is a different size, number and lifetime of opened pores. Our data demonstrates that PM reliably and reproducibly delivers impermeable cargo of the size of small molecule inhibitors such as 4 kDa FITC-dextran with >90% efficiency into cells of different mechanical properties without affecting their viability and proliferation rates. Importantly, also much larger cargos such as a >190 kDa Cas9 protein–sgRNA complex are efficiently delivered high-lighting the biological, biomedical and clinical applicability of our findings.

Construction of crystal defect sites in UiO-66 for adsorption of dimethyl phthalate and phthalic acid

The influence of constructed crystal defect sites in the metal-organic framework on the adsorptive removal of phthalic acid and dimethyl phthalate from aqueous solution has been investigated by etching UiO-66 with three monocarboxylic acids (MAs), including acetic acid (AA), trifluoroacetic acid (TFA) and trichloroacetic acid (TCA). The incomplete replacement of bridging ligands in UiO-66s by MAs, leading to the departure of partial ligands and metal clusters to create mesopores in metal organic frameworks, was determined by thermogravimetric analysis (TGA), nuclear magnetic resonance ( 1 H NMR) and N 2 adsorption-desorption. The results showed that mediate defect would increase the specific surface area and introduce mesopores to some extent, and the crystal structure was gradually destroyed as the excess concentration of MAs. Among UiO-66 samples, the UiO-66 etched by AA with concentration of 1.6 mol/L (UiO-66-1.6AA) had the highest specific surface area while the UiO-66-0.2TCA had the largest pore volume, which significantly enhanced the adsorption capacity for DMP and PA (18.05% up of PA and 41.59% up of DMP to UiO-66) respectively. The experimental data followed the pseudo-first-order kinetic and Langmuir model. In addition, regeneration study showed that the adsorption capacity of PA and DMP on UiO-66-0.2TCA and UiO-66-1.6AA can still remain over 83 and 90% after five cycles, respectively. The crystal defect sites introduction of mesopores by etching method would be an effective strategy to adsorptive removal of organic pollutants in aqueous solution. • UiO-66 was etched by acetic acid, trifluoroacetic acid and trichloroacetic acid. • Etching shaped hierarchical pore structure in UiO-66. • Defective sites had various influence on adsorption capacity of PA and DMP. • Etching method significantly enhanced adsorption for molecules of different sizes.

Macroporous Polymer Monoliths for Affinity Chromatography and Solid-Phase Enzyme Processing.

Nowadays, monolithic stationary phases, because of their special morphology and enormous permeability, are widely used for the development and realization of fast dynamic and static processes based on the mass transition between liquid and solid phases. These are liquid chromatography, solid-phase synthesis, microarrays, flow-through enzyme reactors, etc. High-performance liquid chromatography on monoliths, including the bioaffinity mode, represents unique technique appropriate for fast and efficient separation of biological (macro)molecules of different sizes and shapes (proteins, nucleic acids, peptides), as well as such supramolecular systems as viruses.In the edited chapter, the examples of the application of commercially available macroporous monoliths for modern affinity processing are presented. In particular, the original methods developed for efficient isolation and fractionation of monospecific antibodies from rabbit blood sera, the possibility of simultaneous affinity separation of protein G and serum albumin from human serum, the isolation of recombinant products, such as protein G and tissue plasminogen activator, respectively, are described in detail. The suggested and realized multifunctional fractionation of polyclonal pools of antibodies by the combination of several short monolithic columns (disks) with different affinity functionalities stacked in the same cartridge represents the original and practically valuable method that can be used in biotechnology. In addition, macroporous monoliths were adapted to the immobilization of such different enzymes as polynucleotide phosphorylase, ribonuclease A, α-chymotrypsin, chitinolytic biocatalysts, β-xylosidase, and β-xylanase. The possibility of use of immobilized enzyme reactors based on monoliths for different purposes is demonstrated.

Surface properties of heterogeneous polycyclic aromatic hydrocarbon clusters

In this paper we investigate the impact of molecular inhomogeneity on the surface properties of soot particles. Using replica exchange molecular dynamics and solvent-excluded surface analysis, we evaluate detailed surface properties directly from particles containing polycyclic aromatic hydrocarbon molecules of different sizes. The temperature-dependent behaviour of surface roughness and number densities of reactive sites are evaluated for particles from 1–5 nm in diameter. The percentage of carbon atoms and zig-zag sites on the particle surface are found to be independent of molecular composition, while molecule heterogeneity influences the accessible hydrogen atoms and free-edge sites. These relationships allow the prediction of surface composition for a given particle diameter. The surface densities of carbon and hydrogen atoms are explained by the morphological changes and molecule size contributions for solid-like and liquid-like configurations. Small molecules contribute significantly to the particle surface properties at low temperatures, regardless of the proportion of molecule sizes, which results in an increased density of accessible carbon atoms for heterogeneous particles. Interestingly, the surface density of edge carbon atoms and free-edge sites can be predicted from the average molecule size alone. The density of hydrogen atoms on the surface follows the average expected values from the constituent molecule sizes, suggesting that for particles containing many different molecule sizes the α parameter corresponding to the HACA mechanism converges to a linear temperature-dependent trend. This quantitative evaluation of the accessibility of reactive sites for heterogeneous particles provides important information for understanding soot particle growth and oxidation.

Toward the Highly Ordered Lamellar Hybrid Membrane for Molecular Sieving by One-Pot Self-Assembly of Hybrid Hyperbranched Polymer

Ordered lamellar hybrid membranes are of great interest, due to their application as functional materials, including molecular sieving, biosensors, optical devices, and drug, as well as gene delive...

Engineering antibody-based molecules for HIV treatment and cure.

Immunotherapy strategies alternative to current antiretroviral therapies will need to address viral diversity while increasing the immune system's ability to efficiently target the latent virus reservoir. Antibody-based molecules can be designed based on broadly neutralizing and non-neutralizing antibodies that target free virions and infected cells. These multispecific molecules, either by IgG-like or non-IgG-like in structure, aim to target several independent HIV-1 epitopes and/or engage effector cells to eliminate the replicating virus and infected cells. This detailed review is intended to stimulate discussion on future requirements for novel immunotherapeutic molecules. Bispecific and trispecific antibodies are engineered as a single molecules to target two or more independent epitopes on the HIV-1 envelope (Env). These antibody-based molecules have increased avidity for Env, leading to improved neutralization potency and breadth compared with single parental antibodies. Furthermore, bispecific and trispecific antibodies that engage cellular receptors with one arm of the molecule help concentrate inhibitory molecules to the sites of potential infection and facilitate engagement of immune effector cells and Env-expressing target cells for their elimination. Recently engineered antibody-based molecules of different sizes and structures show promise in vitro or in vivo and are encouraging candidates for HIV treatment.