Metallo-Supramolecular Polymerization: A Route to Easy-To-Process Organic/Inorganic Hybrid Materials

The self-assembly polymerization of ditopic macromolecules via metal–ligand binding is a facile route for the preparation of metallo-supramolecular polymers (MSPs). We herein review our recent work focused on the synthesis and investigation of metallo-supramolecular polymers based on 2,6-bis(1′-methylbenzimidazolyl)pyridine endcapped poly(p-phenylene ethynylene) and poly(p-xylene) macromonomers. These materials are readily solution-processable and display appreciable mechanical properties as well as other attractive properties such as specific opto/electrical functions or high thermal stability. Our work illustrates that metallosupramolecular polymerization offers an attractive approach to assemble high-molecular-weight macromolecules from well-defined, easy to process precursors. Variation of the ditopic ligands and metal ions allows one to easily tailor the desired properties. This paper is dedicated to Professor Ian Manners and his scientific accomplishments.     

Photocatalytic study of polymorphic titania synthesized by ambient condition sol process

Nanocrystalline titania of different phases were produced by ambient condition sol process with phase control originating from alterations in experimental variables. The produced titania photocatalysts were characterized by use of x-ray diffraction, BET surface area, transmission electron microscopy and related to methyl orange degradation. The results showed that the photocatalytic activity of brookite and anatase phase titania samples to be greater than that of Degussa P-25 and rutile phase titania sample. In addition, brookite, due to surface area considerations, appears to be the most photocatalytically active phase of titania.     

A POLE Splice Site Deletion Detected in a Patient with Biclonal CLL and Prostate Cancer: A Case Report

Chronic lymphocytic leukemia (CLL) is considered a clonal B cell malignancy. Sporadically, CLL cases with multiple productive heavy and light-chain rearrangements were detected, thus leading to a bi- or oligoclonal CLL disease with leukemic cells originating either from different B cells or otherwise descending from secondary immunoglobulin rearrangement events. This suggests a potential role of clonal hematopoiesis or germline predisposition in these cases. During the screening of 75 CLL cases for kappa and lambda light-chain rearrangements, we could detect a single case with CLL cells expressing two distinct kappa and lambda light chains paired with two separate immunoglobulin heavy-chain variable regions. Furthermore, this patient also developed a prostate carcinoma. Targeted genome sequencing of highly purified light-chain specific CLL clones from this patient and from the prostate carcinoma revealed the presence of a rare germline polymorphism in the POLE gene. Hence, our data suggest that the detected SNP may predispose for cancer, particularly for CLL.     

Spurenstoffabtrennung mit keramischen Nanofiltrationsmembranen als Rotationsscheibenfilter

Reducing micropollutant pollution of water bodies is an important objective of water management and an integral part of environmental policy. Ceramic nanofiltration membranes were developed as multichannel membranes of increased membrane area and rotating disk filters. The membranes developed show retention of over 80 % for PEG 400. The membranes are currently being tested for the separation of micropollutants from wastewater contaminated with pharmaceuticals. With the help of a downstream oxidative process, the trace substances remaining in the permeate are degraded.     

Impact of mass balance calculations on adsorption capacities in microporous shale gas reservoirs

Determination of the adsorbed reservoir capacity of gas shales by adsorption analyses as done routinely by mass balance maybe in significant error if the effects of pore-size dependent void volume (porosity) is not considered. It is shown here that with increasing pressure, helium, which is invariably used to measure void volume, can access pores that are not available for adsorption to gases with larger kinetic diameters as highlighted by experiments with zeolites of known pore-size distribution. Helium can diffuse and/or adsorb in restricted pores of the microporous samples, as indicated by a larger void volume with pressure. The error in adsorption calculations due to helium void volume calibrations for high pressure methane isotherms is most significant with low organic-carbon content, moisture-equilibrated shales and mudrocks in which the overall adsorptive capacity is low. In such samples negative adsorption can be calculated due to the void volume of helium used in the mass balance calculations exceeding the void volume to methane – a reflection of greater pore-space accessibility of the smaller helium molecule than methane. The amount of the error introduced by using helium void volume in mass balance calculations is pore-size and pore-size distribution dependent. Organic-rich shales and mudrocks or coals which do not show negative methane adsorption also maybe in error but the error is masked by their larger adsorbed gas capacities. Such findings underline the importance of analysis gas-type as kinetic diameter size will influence the penetrability/diffusion of the gas through the sample and hence the calculated adsorbed gas capacities.     

Pro-Resolving Lipid Mediator Resolvin E1 Mitigates the Progress of Diethylnitrosamine-Induced Liver Fibrosis in Sprague-Dawley Rats by Attenuating Fibrogenesis and Restricting Proliferation

Liver fibrosis is a complex process associated to most types of chronic liver disease, which is characterized by a disturbance of hepatic tissue architecture and the excessive accumulation of extracellular matrix. Resolvin E1 (RvE1) is a representative member of the eicosapentaenoic omega-3 lipid derivatives, and is a drug candidate of the growing family of endogenous resolvins. Considering the aforementioned, the main objective of this study was to analyze the hepatoprotective effect of RvE1 in a rat model of liver fibrosis. Male Sprague-Dawley rats received diethylnitrosamine (DEN, 70 mg/mg body weight intraperitoneally (i.p)) as an inductor of liver fibrosis once weekly and RvE1(100 ng/body weight i.p) twice weekly for four weeks. RvE1 suppressed the alterations induced by DEN, normalizing the levels of alanine aminotransferase (ALT), albumin, and lactate dehydrogenase (LDH), and ameliorated DEN injury by decreasing the architecture distortion, inflammatory infiltration, necrotic areas, and microsteatosis. RvE1 also limited DEN-induced proliferation through a decrease in Ki67-positive cells and cyclin D1 protein expression, which is related to an increase of the levels of cleaved caspase-3. Interestingly, we found that RvE1 promotes higher nuclear translocation of nuclear factor κB (NF-κB)p65 than DEN. RvE1 also increased the levels of nuclear the nuclear factor erythroid 2–related factor 2 (Nrf2), but with no antioxidant effect, measured as an increase in glutathione disulfide (GSSG) and a decrease in the ratio of glutathione (GSH)/GSSG. Taken together, these results suggest that RvE1 modulates the fibrogenesis, steatosis, and cell proliferation in a model of DEN induced fibrosis.     

Low-Temperature Crystallization for Separating Monoacetylated Long-Chain Sophorolipids: Characterization of Their Surface-Active and Antimicrobial Properties

Pseudohyphozyma (formerly Rhodotorula) bogoriensis synthesizes long-chain-length (22-carbon chain) sophorolipids (22:0-SL) that are variously acetylated at the 6′- or/and 6″-carbons of the sophorose unit. In this paper, we describe a low-temperature crystallization protocol that preferentially separates the 6′-monoacetylated 22:0-SL (6′-Ac₁-22:0-SL) from a parental mixture of 22:0-SL containing a majority (64.7%) of the 6′,6″-diacetylated moiety (6′,6″-Ac₂-22:0-SL), as deduced from high-pressure-liquid-chromatography evaporative-light-scattering-detection (HPLC-ELSD) and LC/Q-TOF-MS analyses. Tensiometry measurements using the Wilhelmy plate method yielded minimum-surface-tension (SFT_min) and critical-micelle-concentration (CMC) values of 34.6 ± 1.0 mN m⁻¹ and 0.014 mM, respectively, for 6′-Ac₁-22:0-SL (CRYSTAL) fraction and 34.9 ± 1.0 mM m⁻¹ (SFT_min) and 0.018 (CMC) for the hexane precipitate (Hx-PRCP) fraction containing a high concentration (89.2%) of the diacetylated 6′,6″-Ac₂-22:0-SL after crystal removal. In contrast, the SFT_min and CMC of the well-studied 16-18 carbon (C_16-18)-SL of Starmerella bombicola were 35–37.2 mN m⁻¹ and 0.05-(>0.3) mM, respectively. Individually, the purified CRYSTAL and Hx-PRCP fractions exhibited a similar degree of strong growth-inhibition activity against Cutibacterium (formerly Propionibacterium) acnes as determined by an agar-plate zone of inhibition assay. Study on the growth inhibition of oral health-related bacteria, i.e., Streptococcus mutans and Lactobacillus acidophilus, showed that, depending on the bacteria and strains tested, the CRYSTAL fraction was either slightly better than or equally effective as the Hx-PRCP fraction in inhibiting cell growth.     

Optical Properties and van der Waals–London Dispersion Interactions in Berlinite Aluminum Phosphate from Vacuum Ultraviolet Spectroscopy

The interband optical properties of single‐crystal berlinite AlPO₄ have been investigated in the vacuum ultraviolet (VUV) range using VUV spectroscopy and spectroscopic ellipsometry. The complex optical properties were directly determined from 0.8 to 45 eV. Band gap energies, index of refraction and complex dielectric functions, oscillator index sum rule, and energy loss functions were calculated through Kramers–Kronig transformation. Direct and indirect band gap energies of AlPO₄ over the absorption coefficient range of 33–11 000 cm^?1 are 8.06 and 7.89 eV, respectively. The index of refraction at 2 eV, n_vis, is 1.51. The interband transition features at 10.4, 11.4, 14.2, 16.2, 17.3, 21, 22.5, 24.5, and 31 eV were indexed and correlated with the electronic structure of AlPO₄. Strong similarities were observed between AlPO₄ and its structural isomorph SiO₂ in the exciton and interband transitions, resulting from the similarity of their constituent tetrahedra and the strong electron localization therein. The London dispersion spectrum for AlPO₄ was calculated, and the Hamaker coefficients for AlPO₄ with various interlayers were calculated using the Lifshitz method. These results elucidate the role of phosphate complex anions on the electronic structure and van der Waals forces in important organic and inorganic systems.     

Physical,mechanical, and biological properties of electrophoretically deposited lithium-doped calcium phosphates

In the present work, the preparation of sintered lithium-doped tricalcium phosphates was studied, along with their physical, mechanical, and biological properties. Calcium phosphates were shaped via the use of electrophoretic deposition (EPD), using colloidally milled dispersions of hydroxyapatite (HAp) particles. The dispersions were stabilised with monochloroacetic acid. Lithium was incorporated into the structure via an addition of lithium chloride, which also served to optimise the deposition process. The dispersions were milled colloidally for periods of 0–48 h. The colloidal milling resulted in two effects: i) disintegration of the commercial HAp powder (10 µm) agglomerates, ii) unimodal distribution of the HAp particles (~ 170 nm). The fine particles of the milled HAp dispersions accelerated the deposition rate, and increased the mass of the deposit. The reduced size of the initial particles, owed to the milling, led to the superior arrangement of the particles during deposition and to reduced porosity after sintering (1050–1250 °C). The HAp decomposed into tricalcium phosphate phases during sintering. At a sintering temperature of 1250 °C, grain growth occurred, which consequently resulted in a slight degradation of the mechanical properties (reduction in hardness and Young's modulus). In contrast, the hardness and Young's modulus increased as the dispersion milling time increased (smaller grain size after sintering); however, the fracture toughness did not change. The results of the biological testing confirmed the bioactivity of the material through the growth of the apatite layer in the simulated body fluid (SBF), and the biodegradation of the prepared materials in the Tris-HCl solution. With regard to the preparation of compact lithium-doped tricalcium phosphates, the best results were obtained in the case of the sample that utilised the dispersion that was milled for 48 h, and was sintered at 1050 °C.