Porphyrin-Based Conjugated Microporous Polymer Loaded with Nanoscale Zerovalent Iron for the Degradation of Organic Pollutants under Visible Light.

The degradation of organic dye from waterbodies is of great significance for clean production and environmental remediation. Herein, two porphyrin-based conjugated microporous polymers (CMPs) loaded with nanoscale zerovalent iron (named as Por-CMPs-1-2@nZVI) were successfully fabricated by Sonogashira-Hagihara coupling reactions and the liquid-phase method. The as-synthesized Por-CMPs-1-2@nZVI composites were characterized by various means of analysis, and it was confirmed that Por-CMPs-1-2 loaded with nZVI had good photocatalytic performance. Calculated by ultraviolet-visible spectrum, the band-gap energies of Por-CMPs-1@nZVI and Por-CMPs-2@nZVI were 1.45 and 1.32 eV, respectively, indicating that both can be activated by visible light. The photodegradation of organic dye experiments demonstrated that Por-CMPs-2@nZVI degraded 98.0% of 10 ppm Methylene Blue (MB) within 150 min, which is higher than that of Por-CMPs-1-2 and Por-CMPs-1@nZVI. The experiment of active substance capture and mechanism of ESR confirmed that superoxide anion and hydroxyl radical were the primary valid substances in the photodegradation process of MB. In addition, the preparation of membrane materials was shown to be a successful strategy to realize engineered scale-up production.

Impact of film thickness on the morphology of mesoporous carbon films using organic-organic self-assembly.

Mesoporous polymer and carbon thin films are prepared by the organic-organic self-assembly of an oligomeric phenolic resin with an amphiphilic triblock copolymer template, Pluronic F127. The ratio of resin to template is selected such that a body-centered cubic (Im3m) mesostructure is formed in the bulk. However, well-ordered mesoporous films are not always obtained for thin films (<100 nm), and this behavior is found to be directly correlated with the initial phenolic resin to template ratio. Furthermore, the symmetry of ordered phases is highly dependent on the number of layers of spheres in the film: Monolayers and bilayers are characterized by hexagonal close-packed (HCP) symmetry, while films with approximately 5 layers of spheres exhibit a mixture of HCP and face-centered orthorhombic (FCO) structures. Ultrathick films having more than 30 layers of spheres are similar to the bulk body-centered cubic symmetry with a preferential orientation of the closest-packed (110) plane parallel to the substrate. Film thickness and initial composition of the carbonizable precursors in the template are critical factors in determining the morphology of mesoporous carbon films. These results provide insight into why difficulties have been reported in producing ultrathin ordered mesoporous carbon films using cooperative organic-organic self-assembly.

Effects of miR-185-5p on replication of hepatitis C virus.

This article was designed to explore the effects and mechanisms of miR-185-5p on the replication of hepatitis C virus (HCV). Quantitative reverse transcription PCR (qRT-PCR) was performed for detecting the abundance of miR-185-5p and HCV RNA in HCV-infected primary hepatocytes and Huh7.5 cells. Dual-luciferase reporter gene assay was used for exploring the interaction between miR-185-5p and GALNT8. Western blot analyzed protein expression of GALNT8, NS3, and NS5A. miR-185-5p was remarkably downregulated in HCV-infected primary hepatocytes and Huh7.5 cells. miR-185-5p upregulation inhibited HCV RNA expression, while its inhibition promoted HCV replication. miR-185-5p induced accumulation of NS3 and NS5A in the cells. Dual-luciferase reporter gene assay verified the targeted relationship between miR-185-5p and GALNT8. In addition, the effects of overexpressing or knocking down miR-185-5p on HCV replication could be correspondingly eliminated by the overexpression or knockdown of GALNT8. miR-185-5p may target GALNT8 in JFH1-infected Huh7.5 cells and then inhibit HCV replication. miR-185-5p may be a potential target for treating HCV.

Association between urinary per- and poly-fluoroalkyl substances and COVID-19 susceptibility.

BACKGROUND AND OBJECTIVE: The growing impact of the COVID-19 pandemic has heightened the urgency of identifying individuals most at risk of infection. Per- and poly-fluoroalkyl substances (PFASs) are manufactured fluorinated chemicals widely used in many industrial and household products. The objective of this case-control study was to assess the association between PFASs exposure and COVID-19 susceptibility and to elucidate the metabolic dysregulation associated with PFASs exposure in COVID-19 patients. METHODS: Total 160 subjects (80 COVID-19 patients and 80 symptom-free controls) were recruited from Shanxi and Shandong provinces, two regions heavily polluted by PFASs in China. Twelve common PFASs were quantified in both urine and serum. Urine metabolome profiling was performed by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). RESULTS: In unadjusted models, the risk of COVID-19 infection was positively associated with urinary levels of perfluorooctanesulfonic acid (PFOS) (Odds ratio: 2.29 [95% CI: 1.52-3.22]), perfluorooctanoic acid (PFOA) (2.91, [1.95-4.83], and total PFASs (∑ (12) PFASs) (3.31, [2.05-4.65]). After controlling for age, sex, body mass index (BMI), comorbidities, and urine albumin-to-creatinine ratio (UACR), the associations remained statistically significant (Adjusted odds ratio of 1.94 [95% CI: 1.39-2.96] for PFOS, 2.73 [1.71-4.55] for PFOA, and 2.82 [1.97-3.51] for ∑ (12) PFASs). Urine metabolome-PFASs association analysis revealed that 59% of PFASs-associated urinary endogenous metabolites in COVID-19 patients were identified to be produced or largely regulated by mitochondrial function. In addition, the increase of PFASs exposure was associated with the accumulation of key metabolites in kynurenine metabolism, which are involved in immune responses (Combined ß coefficient of 0.60 [95% CI: 0.25-0.95, P = 0.001]). Moreover, alternations in PFASs-associated metabolites in mitochondrial and kynurenine metabolism were also correlated with clinical lab biomarkers for mitochondrial function (serum growth/differentiation factor-15) and immune activity (lymphocyte percentage), respectively. CONCLUSION: Elevated exposure to PFASs was independently associated with an increased risk of COVID-19 infection. PFASs-associated metabolites were implicated in mitochondrial function and immune activity. Larger studies are needed to confirm our findings and further understand the underlying mechanisms of PFASs exposure in the pathogenesis of SARS-CoV2 infection.

Impact of nanopore morphology on cell viability on mesoporous polymer and carbon surfaces.

Topography at the nanoscale can lead to dramatic changes in the adhesion of cells to surfaces and their subsequent viability. For biological applications, including tissue engineering and cell-based sensing, the large internal surface area of ordered mesoporous carbons provides an opportunity for enhanced sensitivity and performance, but the mesostructure also affects the topography of the material. In this work, we probe the viability and adhesion of osteoblasts on ordered mesoporous materials with different morphologies and matrix chemistries. FDU-15 (hexagonal) and FDU-16 (cubic) films were processed at either 350 degrees C (polymeric) or 800 degrees C (carbon) to provide these different materials. For the films processed at 350 degrees C, the cell adhesion was markedly improved on the mesoporous films in comparison to a dense film analog, consistent with many reports in the literature that nanostructuring of surfaces improves the viability and adhesion of osteoblasts. Conversely, osteoblast adhesion was reduced on the carbonized surfaces processed at 800 degrees C when ordered mesopores were introduced, particularly for the cubic mesostructure (FDU-16). We attribute the decrease in cell adhesion to the propensity of the ordered mesoporous carbon films to sorb organics from aqueous solution, which could lead to removal of adhesion-promoting compounds at the film surface. These results suggest that cell viability on mesoporous polymer and carbon films can be controlled through simple changes in the pyrolysis temperature.

Challenges in fabrication of mesoporous carbon films with ordered cylindrical pores via phenolic oligomer self-assembly with triblock copolymers.

Mesoporous phenol formaldehyde (PF) polymer resin and carbon films are prepared by a solution self-assembly of PF oligomers with amphiphilic triblock copolymers. After thermopolymerization of the PF to cross-link the network, the films show an ordered morphology as determined by X-ray diffraction and grazing incidence small-angle X-ray scattering (GISAXS). Our results show that the amphiphilic triblock copolymer template greatly influences the stability of the final porous mesostructures. The pyrolysis of the two-dimensional (2-D) hexagonal films with p6mm symmetry templated by Pluronic F127 yields a disordered porous structure following the template removal. Conversely, films templated by Pluronic P123 can exhibit well-ordered cylindrical pores after the template removal, but the solution composition range to yield ordered cylindrical mesopores is significantly reduced (nearly 70%) for thin films in comparison to bulk powders. We propose two dominant difficulties in fabricating well-ordered cylindrical mesopores in films: first, the stress from contraction during the pyrolysis can lead to a collapse of the mesostructure if the wall thickness is insufficient, and second, the surface wetting behavior in thin films leads to a small compositional range.

Additive route to lithographically defined nanoporous silica, polymer, and carbon films.

A facile method was investigated for patterning microporous and mesoporous silica, polymer, and carbon films using a combination of lithography and solid-state chemistry. This process exploits the difference in chemical reactivity between the lithographically exposed and unexposed regions to control the reaction of a target precursor from the vapor phase. A block copolymer film loaded with a photoacid generator is utilized as a preformed template, and tetraethylorthosilicate (TEOS) and furfuryl alcohol (FA) are the silica and carbon precursors, respectively. Following UV exposure and reaction with vaporized precursors, thermal decomposition of the polymeric template yields a mesoporous film in the exposed regions. Dense line-space patterns down to 1.5 microm features were resolved with I-line lithography. Sharper features were formed using FA; this behavior is attributed to the requirement for water in the system during TEOS condensation. Moisture in the system appears to lead to enhanced diffusion of the photoacid and a small decrease in the feature resolution. This methodology provides a simple etch-free route to patterning mesoporous films using commercially available materials.

Templating multiple length scales by combining phase separation, self-assembly and photopatterning in porous films.

Patternable nanoporous silica thin films with pore sizes on multiple length scales are fabricated using preformed block copolymer/homopolymer blend films as templates. Previous work by Tirumala et al. [V.R. Tirumala, R.A. Pai, S. Agarwal, J.J. Testa, G. Bhatnagar, A.H. Romang, C. Chandler, B.P. Gorman, R.L. Jones, E.K. Lin, J.J. Watkins, Adv. Mater. 18 (8) (2008) 1603] has demonstrated that hydrogen bonding between an amphiphilic copolymer and a homopolymer leads to significant enhancements in the long range order of the template self assembly. However if the copolymer template is simply changed from Pluronic F127 to Brij78, a well ordered template is no longer always obtained; the blend phase separates with apparent selective partitioning of the photoacid generator (PAG) at the interface of the polymer phases. UV exposure selectively generates a photoacid, which is utilized to catalyze tetraethylorthosilicate (TEOS) condensation. The large disparity in diffusivity of the photoacid between the glassy poly(hydroxystyrene) (PHOSt) and rubbery Brij78 phases results in selective templating of the Brij mesostructure and limited reaction into the PHOSt. Calcination yields relatively monodisperse mesopores from the Brij phase and macropores from the PHOSt phase. Simple variations in processing parameters allow the macropore morphology to be tuned to create high surface area materials with structures on the order of 1 nm, 100 nm and microms from self assembly, phase separation and lithographic patterning respectively.