Self-Assembly of Polymer Tethered Molecular Nanoparticle Shape Amphiphiles in Selective Solvents

Well-defined giant molecular shape amphiphiles possessing a hydrophilic head with definite shape and size and a linear, hydrophobic polymeric tail with a length suitable to resemble the typical structure of a small-molecule surfactant were synthesized recently and were able to self-assemble into various morphologies in selective solvents. We investigated the self-assembly of shape amphiphiles consisting of a hydrophilic head and one or more hydrophobic tails using the dissipative particle dynamics (DPD) approach. The micellar morphology can transform from vesicles to worm-like cylinders and further to spheres by increasing the interaction parameter between the hydrophilic heads. The simulation results are in agreement with the experimental observations. Furthermore, the self-assembled aggregates exhibit a rich variety of morphological structures, such as spheres, vesicles, worm-like cylinders, pupa-like micelles, disk-like micelles, and segmented rod-like micelles, etc. We demonstrate how to create various morphologies through varying the interaction parameter between hydrophilic head and solvents, the length of hydrophobic tail, the size of hydrophilic head, and the number of hydrophobic tails. Most importantly, we find an interesting strategy for constructing segmented rod-like micelles through changing the size of the hydrophilic head, while using simple polymer tethered molecular nanoparticle amphiphiles as the elementary building blocks. In addition, vesicles prefer to form for more hydrophobic tails under identical conditions in solutions

Self-Assembly of Polymer Tethered Molecular Nanoparticle Shape Amphiphiles in Selective Solvents

Well-defined giant molecular shape amphiphiles possessing a hydrophilic head with definite shape and size and a linear, hydrophobic polymeric tail with a length suitable to resemble the typical structure of a small-molecule surfactant were synthesized recently and were able to self-assemble into various morphologies in selective solvents. We investigated the self-assembly of shape amphiphiles consisting of a hydrophilic head and one or more hydrophobic tails using the dissipative particle dynamics (DPD) approach. The micellar morphology can transform from vesicles to worm-like cylinders and further to spheres by increasing the interaction parameter between the hydrophilic heads. The simulation results are in agreement with the experimental observations. Furthermore, the self-assembled aggregates exhibit a rich variety of morphological structures, such as spheres, vesicles, worm-like cylinders, pupa-like micelles, disk-like micelles, and segmented rod-like micelles, etc. We demonstrate how to create various morphologies through varying the interaction parameter between hydrophilic head and solvents, the length of hydrophobic tail, the size of hydrophilic head, and the number of hydrophobic tails. Most importantly, we find an interesting strategy for constructing segmented rod-like micelles through changing the size of the hydrophilic head, while using simple polymer tethered molecular nanoparticle amphiphiles as the elementary building blocks. In addition, vesicles prefer to form for more hydrophobic tails under identical conditions in solutions

Additional file 1 of The association between triglyceride glucose-body mass index and all-cause mortality in critically ill patients with atrial fibrillation: a retrospective study from MIMIC-IV database

Supplementary Figure 1. Kaplan-Meier survival analysis curves for all-cause mortality. Kaplan-Meier curves and cumulative incidence of 90-day (A) and 180-day (B) all-cause mortality stratified by TyG-BMI index

Tale of Alkyl Chains: Chain-Length Effect-Directed Formation of Complex Self-Assembly Behaviors at the Liquid/Solid Interface for Unsymmetrically Substituted Fluorenone Derivatives

Structural diversity induced by the chain-length effect in the field of two-dimensional self-assembly has gained immense attention because of its potential application in nanoscience and crystal engineering. By modifying the two side chains in a certain molecule by one carbon atom and gradually increasing the alkyl chain length, seven fluorenone derivatives (F–C_<i>n</i>C_<i>n</i>+1, <i>n</i> = 11–17) were synthesized. At the 1-octanoic acid/graphite interface, diverse nanostructures of hexamer-I, tetramer, dimer, alternate-I, hexamer-II, and alternate-II were recorded. The arrangement for the two side chains which differ from each other only by one carbon atom was discussed from the viewpoint of thermodynamics and kinetics. The alkyl chain in the same length was speculated to show selective identification during the self-assembly process, which was favored in consideration of dense packing and maximizing the molecular interplay. Three forces such as dipole–dipole, hydrogen bonding, and van der Waals (vdWs) interactions cooperatively or competitively exert their roles on stabilizing the assembled monolayers. For the purpose of further understanding the self-assembly mechanisms, we performed force field calculations, which revealed that the strength of the hydrogen bonds was related to the arrangement of the fluorenone units, whereas the vdWs interaction showed a close relationship with the alkyl chain length. This work displays an efficient method on fabricating complex self-assembly networks, and we believe that it will promote the study of the chain-length effect in supramolecular chemistry and interfacial science

Anti-PABPC1 Co-Immunoprecipitation for Examining the miRNAs Directly Targeting the 3′-UTR of <i>EED</i> mRNA

<div><p>MicroRNAs (miRNAs) are small, noncoding RNA molecules that regulate post-transcriptional gene expression by base pairing with partially complementary sequences within target messenger RNAs (mRNAs). Although the target genes and the precise biological functions of individual miRNAs remain largely unknown, miRNAs have been implicated in diverse biological processes, including both normal and pathological states. As a single stranded mRNA can be directly targeted by multiple miRNAs, and as the target sites may exist in the 3′-untranslated region (UTR), 5′-UTR, or the coding regions, it is essential to develop an effective method to identify the full-scale miRNA regulatory pattern of each particular gene. In this study, we employed a biochemical approach to identify the miRNA profiles that regulate the expression of embryonic ectoderm development (EED) protein by using anti-PABPC1 ribonucleoprotein (<i>RNP</i>) co-immunoprecipitation (Co-IP). The full length <i>EED</i> mRNA was subcloned into an expression vector and transiently transfected into a Flag-PABPC1 stable expression cell line. Subsequent to cross-linking and an anti-Flag <i>Co-IP</i>, the miRNAs that directly targeted <i>EED</i> were identified. We found that the best time point to distinguish the positive miRNAs from the background was 18 hours after the plasmid transfection. As expected, the miRNAs that directly target <i>EED</i> were found to interact with <i>EED</i> mRNA through the miRNA-induced silencing complex (miRISC). Meanwhile, the <i>EED</i> mRNA was bound by Flag-PABPC1. This method depends on the integrity of the miRISC complex and achieves greater efficiency when ultraviolet irradiation is used for the process of cross-linking. By using anti-PABPC1 RIP, we identified <i>EED</i> to be a new target gene of miR-16; a finding further confirmed using a dual-luciferase assay. In summary, our data indicate that anti-PABPC1 RIP is a validated and direct biochemical method to provide data about specific miRNA-mRNA interactions, as well as global miRNA patterns regulating the mRNAs.</p></div

MiR-16 and miR-101 suppress EED expression through targeting to the 3′-UTR of <i>EED</i>.

<p>(A) The predicted results of miRanda indicated that <i>EED</i> is targeted by miR-16 and miR-101, whereas the TargetScan online tools indicated that there could be a direct interaction between miR-16 and <i>EED</i> mRNA. (B) Confirmation of the relationship between <i>EED</i> and miR-101/miR-16. Cells were co-transfected with the miRNA mimic control, the miR-101 mimic, the miR-16 mimic, or the miR-181b mimic, and the Luc-EED for the dual-luciferase assay. PRL-TK containing <i>Renilla</i> luciferase was co-transfected with the 3′-UTR of <i>EED</i> for data normalization. *<i>P</i><0.05, **<i>P</i><0.01.</p

β‑C(sp³)–H Arylation of α‑Hydroxy Acid Derivatives Utilizing Amino Acid as a Directing Group

The Pd­(II)-catalyzed arylation of unactivated β-C­(sp³)–H bonds in α-hydroxy aliphatic acid with a variety of aryl iodides was developed utilizing an amino acid auxiliary as a directing group. This protocol provides access to biologically active β-arylated-α-hydroxy acid derivatives

Construction of a quality control system.

<p>(A) A schematic diagram for the subcloning of the 3′-UTR of <i>Lin28</i> and <i>ERBB2</i> into the pGL3 vector. (B) HEK293T cells were co-transfected with Let-7b or miR-125a and the 3′-UTR of <i>Lin28</i> or <i>ERBB2</i> for the dual-luciferase assay. PRL-TK plasmid expressing the <i>Renilla</i> luciferase was used as a transfection control. The luciferase activity was detected 48 h after transfection, and the results were analyzed using the Student’s t-test. *<i>P</i><0.05, **<i>P</i><0.01.</p

The integrated RISC complex is needed for miRNA recruitment.

<p>(A) Western blot analysis of the co-IPed products. Co-IPs were performed on cells transfected with the reporter plasmid LIN28 or LIN28-Del. As expected, the Flag-PABPC1 proteins were co-IPed with the anti-Flag antibody. Meanwhile, the anti-Flag antibody could not pull down the wild type PABPC1 in the HEK293T cell lysate. AGO2 and PAN2 were detected in the co-IPed products using anti-PAN2 and anti-AGO antibodies, respectively. RNase A was added to determine whether the co-IPed RISC-related components were affected by RNA degradation. In the RNase A-treated groups, the amounts of AGO2 and PAN2 were reduced, implying that the binding interactions between PABPC1 and AGO2 or PABPC1 and PAN2 are partially mRNA-dependent. (B) Knock down of endogenous AGO2 using siRNA. HEK293T cells were transfected with AGO2 siRNAs. At the end of the transfection (48 h), the cells were lysed and AGO2 expression was detected with a western blot. The knockdown effect was most effective in siAGO2-2. (C) Comparison of the miR-125a/Let-7b contents among the AGO2 knockdown groups and control groups. Cells were transfected with AGO2 siRNA. A scramble sequence and non-meaning short RNA was used as control. Cells were subsequently (after 48 h) divided into two dishes and transfected with the wild type or mutant LIN28 or ERBB2 plasmids, respectively. Anti-Flag co-IP was performed 18 h after the transfection and miR-125a and Let-7b were detected by RT-qPCR. The results were analyzed with the Student’s t-test and <i>P<</i>0.05 was considered statistically significant.</p

Absolute Quantification of H5-Subtype Avian Influenza Viruses Using Droplet Digital Loop-Mediated Isothermal Amplification

Human infection with avian influenza A H5N1 viruses can cause severe diseases with high mortality rate and continues to pose a significant threat to global public health. Rapid diagnosis is needed for identifying the types of influenza viruses for making timely treatment decisions. Here, we demonstrate absolute quantification of H5-subtype influenza viruses by digital loop-mediated isothermal amplification (dLAMP) on our recently developed cross-interface emulsification (XiE) method. Our results show that XiE-based dLAMP is highly specific and displays comparable sensitivity to real-time PCR (qPCR) and digital PCR (dPCR). Notably, dLAMP is more tolerant to inhibitory substances than PCR methods and demonstrated similar detection efficiency to qPCR for real H5N1 samples. Therefore, it can serve as a robust and precise alternative to qPCR or dPCR and is especially suitable for environmental and clinical samples with hard-to-remove contaminants. We believe that our dLAMP method offers great potential for rapid and accurate diagnosis of influenza and other infectious diseases