Immune rejection is a major barrier to the successful human embryonic stem cell-derived retinal pigment epithelial (hESC-RPE) transplantation for age-related macular degeneration (AMD). Traditional strategies to mitigate immune rejection involve ablating major histocompatibility complex (MHC) molecules on hESC-RPE. An alternative approach is immune checkpoint overexpression, avoiding natural killer (NK) cell-mediated destruction due to MHC-I deficiency.
View Article and Find Full Text PDFIonic liquid (IL)-based gels (ionogels) have received considerable attention due to their unique advantages in ionic conductivity and their biphasic liquid-solid phase property. In ionogels, the negligibly volatile ionic liquid is retained in the interconnected 3D pore structure. On the basis of these physical features as well as the chemical properties of well-chosen ILs, there is emerging interest in the anti-bacterial and biocompatibility aspects.
View Article and Find Full Text PDFThe paper reports the first free-radical solid-phase polymerization (SPP) of acetylenes. Acetylene monomers were co-crystalized using halogen bonding, and the obtained cocrystals were polymerized. Notably, because of the alignment of acetylene monomers in the cocrystals, the adjacent C≡C groups were close enough to undergo radical polymerization effectively, enabling the radically low-reactive acetylene monomers to generate high-molecular-weight polyacetylenes that are unattainable in solution-phase radical polymerizations.
View Article and Find Full Text PDFUndesirable adhesion of microbes such as bacteria, fungi and viruses onto surfaces affects many industries such as marine, food, textile, and healthcare. In particular in healthcare and food packaging, the effects of unwanted microbial contamination can be life-threatening. With the current global COVID-19 pandemic, interest in the development of surfaces with superior anti-viral and anti-bacterial activities has multiplied.
View Article and Find Full Text PDFMembrane-based separations have been widely applied in gas, water and organic solvent purifications to reduce energy consumption and minimize environmental pollution. In recent years, graphene oxide (GO) membranes have attracted increasing attention due to their self-assembly ability and excellent stability. In this review, publications within the last 3 years on microscopically tuning the GO framework are summarized and reviewed.
View Article and Find Full Text PDFOxid Med Cell Longev
August 2022
From the standpoint of the ER (endoplasmic reticulum), we were interested in identifying hub genes that impact clinical prognosis for HCC (hepatocellular carcinoma) patients and developing an ER-related prognostic model. Using TCGA-LIHC (The Cancer Genome Atlas-Liver Hepatocellular Carcinoma) and GSE14520 datasets, we conducted a series of analyses, which included differential gene screening, clinical prognostic analysis, Lasso regression, nomogram prediction, tumour clustering, gene functional enrichment, and tumour infiltration of immune cells. Following our screening for ER-related genes ( = 1975), we conducted a Lasso regression model to obtain five hub genes, KPNA2, FMO3, SPP1, KIF2C, and LPCAT1, using TCGA-LIHC as a training set.
View Article and Find Full Text PDFPolyelectrolyte hydrogels are emerging materials for tissue engineering and regenerative medicine applications due to their tunable biochemical properties, electrical conductivity, biocompatibility and similar network structure to the extracellular matrix in mammalian bodies. In this review, representative polyelectrolyte hydrogels carrying anionic, cationic, ampholytic, zwitterionic and ionic liquid moieties are systemically cataloged to express their chemical structures and preparation strategies. Recent advance of polyelectrolyte hydrogels in tissue engineering and regenerative medicine for drug delivery, skin healing, bone regeneration, cardiac tissue repair and anti-biofouling coating are also highlighted.
View Article and Find Full Text PDFThe molecular weight distribution of polymer, termed dispersity (), is a fundamental parameter that determines polymer properties. Sodium azide (NaN) functions as a catalyst in organocatalyzed living radical polymerization when the reaction medium is nonpolar. In contrast, NaN can act as a nucleophile when the reaction medium is polar.
View Article and Find Full Text PDFAn air-tolerant reversible complexation mediated polymerization (RCMP) technique, which can be carried out without prior deoxygenation, is developed. The system contains a monomer, an alkyl iodide initiating dormant species, air (oxygen), an aldehyde, N-hydroxyphthalimide (NHPI), and a base. Oxygen is consumed via the NHPI-catalyzed conversion of the aldehyde (RCHO) to a carboxylic acid (RCOOH).
View Article and Find Full Text PDFA spontaneous male-sterile mutant ms01 was discovered from the excellent high-generation inbred line 'hx12-6-3' in wucai. Compared with wild-type 'hx12-6-3', ms01 displayed complete male sterility with degenerated stamens and no pollen. In this study, cytological observation revealed that the tapetum of the anthers of ms01 had degraded in advance, and microspore development had stagnated in the mononuclear stage, ultimately resulting in completely aborted pollen.
View Article and Find Full Text PDFResearch (Wash D C)
January 2021
Hydrogen energy, with environment amicable, renewable, efficiency, and cost-effective advantages, is the future mainstream substitution of fossil-based fuel. However, the extremely low volumetric density gives rise to the main challenge in hydrogen storage, and therefore, exploring effective storage techniques is key hurdles that need to be crossed to accomplish the sustainable hydrogen economy. Hydrogen physically or chemically stored into nanomaterials in the solid-state is a desirable prospect for effective large-scale hydrogen storage, which has exhibited great potentials for applications in both reversible onboard storage and regenerable off-board storage applications.
View Article and Find Full Text PDFACS Appl Mater Interfaces
June 2020
Poly(furfuryl methacrylate) (PFMA) brushes were cross-linked using bismaleimide cross-linkers via the Diels-Alder (DA) reaction at 70 °C, generating cross-linked PFMA brushes (PFMA brush gels). The cross-linked PFMA brushes were decross-linked at 110 °C via the retro-Diels-Alder (rDA) reaction, offering the temperature-responsive reversible PFMA brush gels. The wettability of the brush was tunable by cross-linking and decross-linking.
View Article and Find Full Text PDFLiquid vinyl monomers were converted into solid crystals via halogen bonding. They underwent solid-phase radical polymerizations through heating at 40 °C or ultraviolet photo-irradiation (365 nm). The X-ray crystallography analysis showed the high degree of monomer alignment in the crystals.
View Article and Find Full Text PDFAn effective method to synthesize azido-end polymethacrylates from tetrabutylammonium azide (BNN ) in a nonpolar solvent (toluene) was developed. Several low-mass alkyl halides were reacted with BNN in toluene as model reactions and the rate constants of these reactions were determined, to confirm fast BNN azidation for tertiary and secondary halides. The end-group transformation of halide-end polymethacrylates was effective and nearly quantitative.
View Article and Find Full Text PDFACS Appl Mater Interfaces
April 2019
This paper reports an effective method to prepare patterned polymer brushes on surfaces with tailored graft densities. High-density (concentrated), moderate-density (semidiluted), and low-density (diluted) polymer brushes were fabricated in patterned manners, offering defined three-dimensional patterned structures. This method uses a middle/near-UV (≥250 nm) lamp and needs only a short time (≤10 min) to fabricate prepatterns of the initiator, in sharp contrast to the previous high-energy lithography and time-consuming processes.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
April 2019
Molecular weight distribution of polymers, termed dispersity (Đ), is a fundamental parameter for determining polymer material properties. This paper reports a novel approach for controlling Đ by exploiting a temperature-selective radical generation in organocatalyzed living radical polymerization. The polymers with tailored Đ were synthesized in a batch system without the assistance of an external pump.
View Article and Find Full Text PDFCysteamine, which is an inexpensive and non-toxic aminothiol, was successfully employed as a photo-selective chain end transformation agent of iodo-terminated polymer chains (polymer-I). Polymer-I was selectively transformed to hydrogen-terminated (polymer-H) and thiol-terminated (polymer-SH) polymers with and without UV irradiation, respectively. This method is applicable to acrylate polymers.
View Article and Find Full Text PDFPhotocontrolled surface-initiated reversible complexation mediated polymerization (photo-SI-RCMP) was successfully applied to fabricate concentrated polymer brushes with complex patterning structures. Positive-type patterned polymer brushes were obtained by photo-SI-RCMP under visible light (550(±50) nm) using photomasks. A particularly interesting finding was that negative-type patterned polymer brushes were also obtainable in a facile manner.
View Article and Find Full Text PDFHerein, nontoxic and metabolizable choline iodide analogues, including choline iodide, acetylcholine iodide, and butyrylcholine iodide, were successfully utilized as novel catalysts for "green" living radical polymerization (LRP). Through the combination of several green solvents (ethyl lactate, ethanol, and water), this green LRP process yielded low-polydispersity hydrophobic, hydrophilic, zwitterionic, and water-soluble biocompatible polymethacrylates and polyacrylates with high monomer conversions. Well-defined hydrophobic-hydrophilic and hydrophilic-hydrophilic block copolymers were also synthesized.
View Article and Find Full Text PDFTemperature-selective radical generation from a newly designed alkyl diiodide (I-R -R -I) was studied. R -I and I-R had different reactivities for generating alkyl radicals in the presence of a tetraoctylammonium iodide (ONI) catalyst. Taking advantage of the temperature selectivity, we used the alkyl diiodide as a dual initiator in ONI-catalyzed living radical polymerization to uniquely synthesize CABC non-symmetric multi-block copolymers.
View Article and Find Full Text PDFHerein, a new reaction of an alkyl iodide (R-I) with an azide anion (N) to reversibly generate the corresponding alkyl radical (R) is reported. Via this new reaction, N was used as an efficient catalyst in living radical polymerization, yielding a well-defined polymer-iodide. A particularly interesting finding was the solvent selectivity of this reaction; namely, R-I and N generated R in nonpolar solvents, while the substitution product R-N was generated in polar solvents.
View Article and Find Full Text PDFRadiotherapy remains the important therapeutic strategy for patients with esophageal cancer (EC). At present, there is no uniform opinion or standard care on the range of radiotherapy in the treatment of EC patients. This study aimed to investigate the risk factors associated with lower cervical lymph node metastasis (LNM) and to explore the distribution pattern of lower cervical metastatic lymph nodes.
View Article and Find Full Text PDFBackground: To map detail distribution of metastatic supraclavicular (SCV) lymph nodes (LN) in esophageal cancer (EC) patients and determine the precise radiation therapy clinical target volume (CTV).
Methods: A total of 101 thoracic esophageal carcinoma patients after surgery experienced SCV LN metastasis were retrospectively examined. The SCV region is further divided into four subgroups.
A one-pot synthesis of polymer nitrile -oxides was achieved via the Michael addition of living polymer anions derived from vinyl monomers to commercially available -β-nitrostyrene and subsequent dehydration with concd HSO. The polymer nitrile -oxides are effective as grafting agents in catalyst- and solvent-free 1,3-dipolar cycloadditions to unsaturated-bond-containing polymers with high conversion and exhibit higher reactivity compared to that of nitrile -oxides prepared from 1,1-diphenylnitroethene. Application to the preparation of a functional glass surface was demonstrated using PBMA nitrile -oxide as a grafting agent.
View Article and Find Full Text PDFA general method for the one-pot synthesis of stable polymer nitrile N-oxides was developed by a combination of 1,1-diphenylnitroethene with a living anionic polymer. The polymer nitrile N-oxide served as a facile and effective grafting tool for use with polymers containing unsaturated bonds in a catalyst-free and solvent-free [2+3] cycloaddition.
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