Paramylon from Euglena gracilis Prevents Lipopolysaccharide-Induced Acute Liver Injury

Acute liver injury (ALI) is a life-threatening syndrome with high mortality and lacks effective therapies. Rodents under LPS (lipopolysaccharide)/D-Gal (D-galactosamine) stress mimic ALI by presenting dramatically increased inflammation and cell death in the liver. Euglena gracilis, functioning like dietary fiber, is commonly used as a paramylon (Pa)-rich nutritional supplement that has various biological effects such as regulating immune system, anti-obesity, and anti-tumor. Here, we found that Pa or sonicated and alkalized paramylon (SA-Pa) alleviated the LPS/D-Gal-induced hepatic histopathological abnormalities in mice. Compared with Pa, SA-Pa had lower molecular weights/sizes and showed better efficacy in alleviating injury-induced hepatic functions, as well as the transcriptional levels of inflammatory cytokines. Moreover, SA-Pa treatment promoted M2 macrophage activation that enhanced the anti-inflammatory function in the liver, and downregulated STAT3 target genes, such as Fos, Jun, and Socs3 upon the injury. Meanwhile, SA-Pa treatment also alleviated apoptosis and necroptosis caused by the injury. Our results demonstrated that SA-Pa efficiently protected the liver from LPS/D-Gal-induced ALI by alleviating inflammation and cell death.

A smart and responsive crystalline porous organic cage membrane with switchable pore apertures for graded molecular sieving

Membranes with high selectivity offer an attractive route to molecular separations, where technologies such as distillation and chromatography are energy intensive. However, it remains challenging to fine tune the structure and porosity in membranes, particularly to separate molecules of similar size. Here, we report a process for producing composite membranes that comprise crystalline porous organic cage films fabricated by interfacial synthesis on a polyacrylonitrile support. These membranes exhibit ultrafast solvent permeance and high rejection of organic dyes with molecular weights over 600 g mol−1. The crystalline cage film is dynamic, and its pore aperture can be switched in methanol to generate larger pores that provide increased methanol permeance and higher molecular weight cut-offs (1,400 g mol−1). By varying the water/methanol ratio, the film can be switched between two phases that have different selectivities, such that a single, ‘smart’ crystalline membrane can perform graded molecular sieving. We exemplify this by separating three organic dyes in a single-stage, single-membrane process.

Efficient room temperature catalytic synthesis of alternating conjugated copolymers via C-S bond activation

Structural defects in conjugated copolymers are severely detrimental to the optoelectronic properties and the performance of the resulting electronic devices fabricated from them. Therefore, the much-desired precision synthesis of conjugated copolymers with highly regular repeat units is important, but presents a significant challenge to synthetic materials chemists. To this end, aryl sulfides are naturally abundant substances and offer unrealized potential in cross-coupling reactions. Here we report an efficient room temperature polycondensation protocol which implements aryl disulfide C-S activation to produce defect-minimized semiconducting conjugated copolymers with broad scope and applicability. Thus, a broad series of arylstannanes and thioethers are employed via the present protocol to afford copolymers with number-average molecular weights (Mns) of 10.0–45.0 kDa. MALDI and NMR analysis of selected copolymers reveals minimal structural defects. Moreover, the polymer trap density here is smaller and the field effect mobility higher than that in the analogous polymer synthesized through thermal-activation Stille coupling.

The Elaboration of Effective Coatings for Photonic Crystal Chips in Optical Biosensors

Here, we propose and study several types of quartz surface coatings designed for the high-performance sorption of biomolecules and their subsequent detection by a photonic crystal surface mode (PC SM) biosensor. The deposition and sorption of biomolecules are revealed by analyzing changes in the propagation parameters of optical modes on the surface of a photonic crystal (PC). The method makes it possible to measure molecular and cellular affinity interactions in real time by independently recording the values of the angle of total internal reflection and the angle of excitation of the surface wave on the surface of the PC. A series of dextrans with various anchor groups (aldehyde, carboxy, epoxy) suitable for binding with bioligands have been studied. We have carried out comparative experiments with dextrans with other molecular weights. The results confirmed that dextran with a Mw of 500 kDa and anchor epoxy groups have a promising potential as a matrix for the detection of proteins in optical biosensors. The proposed approach would make it possible to enhance the sensitivity of the PC SM biosensor and also permit studying the binding process of low molecular weight molecules in real time.

Purification and Characterization of Strong Simultaneous Enzyme Production of Protease and α-Amylase from an Extremophile-Bacillus sp. FW2 and Its Possibility in Food Waste Degradation

Microbial enzymes such as protease and amylase are valuable enzymes with various applications, widely investigated for their applications in degradation of organic waste, biofuel industries, agricultural, pharmaceuticals, chemistry, and biotechnology. In particular, extremophiles play an important role in biorefinery due to their novel metabolic products such as high value catalytic enzymes that are active even under harsh environmental conditions. Due to their potentials and very broad activities, this study isolated, investigated, and characterized the protease- and amylase-producing bacterial strain FW2 that was isolated from food waste. Strain FW2 belongs to the genus Bacillus and was found to be closest to Bacillus amyloliquefaciens DSM 7T with a similarity of 99.86%. This strain was able to degrade organic compounds at temperatures from −6 °C to 75 °C (but weak at 80 °C) under a wide pH range (4.5–12) and high-salinity conditions up to 35% NaCl. Maximum enzyme production was obtained at 1200 ± 23.4 U/mL for protease and 2400 ± 45.8 U/mL for amylase for 4 days at pH 7–7.5, 40–45 °C, and 0–10% NaCl. SDS-PAGE analysis showed that the molecular weights of purified protease were 28 kDa and 44 kDa, corresponding to alkaline protease (AprM) and neutral protease (NprM), respectively, and molecular weight of α-amylase was 55 kDa. Degradation food waste was determined after 15 days, observing a 69% of volume decrease. A potential commercial extremozyme-producing bacteria such as strain FW2 may be a promising contributor to waste degradation under extreme environmental conditions.

High-efficiency casing perforation oil and gas wells

The energetic capabilities of a high-speed jet of an aqueous solution of polyethylene oxide (PEO) with varying concentration and different outflow pressures from a jetforming nozzle were investigated using the length of the forming channel in the model of the casing of an oil and gas well, cement sheath and rock layer, as well as impact of the jet force on a metal plate fixed on a physical pendulum. The experimental data made it possible to obtain a calculated dependence in a dimensionless form to determine the quality (initial sections) of jets of aqueous solutions with different concentrations and molecular weights of PEO, considering the real parameters of the jet-forming nozzles of the hydroperforator. A comprehensive study of the perforation process made it possible to substantiate the mechanism of the high destructive capacity of a high-speed jet of polymer solution. It has been established that the mechanism of the high destructive capacity of the polymer water jet is not due to the Toms effect, but caused by the destructive action of the dynamic pressure of the polymer water jet «reinforced» by strongly unfolded macromolecular chains under the action of a tensile flow in the inlet area of the jet forming nozzle of the hydroperforator. Keywords: perforator; jet nozzle; jet quality; casing; cement sheath; rock; Toms effect.

Molecular-mass distribution of humus acids of taiga soils

Purpose of the study: to reveal the influence of hydromorphism and agricultural use on the molecular-mass distribution (MMD) of humic (HAs) and fulvic acids (FAs) isolated from the soils of the European northeast of Russia. To assess the influence of the acidity of the medium on the MWD of FAs. Place and time of the event. The studies were carried out on the territory of the middle taiga (Maksimovsky station of the Institute of Biology of the Federal Research Center of the KSC UB RAS, located 8 km west of the city of Syktyvkar and the field of the Syktyvkar state farm, 5 km south-west of Syktyvkar, on the watershed of the Sysola and Vazhel-yu rivers) and northern taiga (3 km west of the Troitsko-Pechorsk station). The objects of the study were humic substances isolated from typical podzolic (Eutric Albic Retisol (Loamic)), gleypodzolic (Eutric Albic Stagnic Retisol (Loamic)), peaty-podzolic surface-gleyed (Eutric Albic Stagnic Histic) Retisol (Loamic Eutric Albic Retisol (Loamic)) soils. The soil sampling period is from 1 to 30 August 2014. Methodology. Quantitative analysis of the MMD of HA and FA preparations was performed using liquid size exclusion chromatography (gel chromatography) on Sephadex G-25 and G-100 gels with continuous automatic registration of the optical density of the eluate (λ = 280 nm) in a quartz flow cell, K 9 × 60 cm column (Pharmacia, Sweden). Distilled water, 0.05 M NaOH solution, and Tris-HCl buffer with pH = 8.2 were used as the eluent. Main results. Studies of the MMD of humic substances have been carried out. It was found that HAs contain three fractions with different molecular weights: ≥ 150 kDa, 73–80 kDa, and 13–23 kDa; FAs – two fractions: ≥ 5 kDa, 1–2 kDa. The low molecular weight of FAs, together with a large amount of oxygen-containing functional groups, contributes to their better solubility and migration ability in soils. The HAs of automorphic soils are characterized by a high content of low molecular weight fractions, and the proportion of the high molecular weight fraction in the HAs of the litter is 1.5–2.0 times higher than in the HAs of the podzolic horizon, which may be due to the migration of the low molecular weight fraction down the profile. The high proportion of the acidic low molecular weight fraction in the podzolic horizon promotes the decomposition of soil minerals and their leaching into the illuvial horizon. The influence of agricultural use of soils on the fractional composition of humic compounds is estimated. A sharp increase in the share of the high molecular weight fraction in the preparations of HAs of arable podzolic soil by 2–4 times compared with the HAs of virgin podzolic soils was noted, which is due to the cultivation of the arable horizon, the nature of the incoming plant residues and the increased microbiological activity of the developed soils. The effect of acidity of the medium on the character of chromatograms of FA preparations isolated from the main types of soils of the Komi Republic was studied. It has been shown that in the region of high pH values of the eluent 9–13, the absence of fractionation is associated with the association of FAs, a change in their conformation, and the effect of “over-exclusion”. Elution with distilled water (pH = 6.5) allows the separation of FAs into two fractions with molecular weights ≥ 5 kDa and 1–2 kDa.

Synthesis and characterization of novel thermo- and salt-sensitive amphoteric terpolymers based on acrylamide derivatives

A novel linear amphoteric terpolymers based on neutral monomer — N-isopropylacrylamide (NIPAM), ani- onic monomer — 2-acrylamido-2-methyl-1-propanesulfonic acid sodium salt (AMPS), and cationic mono- mer — (3-acrylamidopropyl) trimethylammonium chloride (APTAC) were synthesized by free-radical polymerization in aqueous solution and characterized by methods of 1H NMR and FTIR spectroscopy, TGA, GPC, Dynamic light scattering (DLS) and zeta-potential. The thermal and salt sensitivity of amphoteric ternary polymers of various compositions, particularly, [NIPAM]:[AMPS]:[APTAC] = 90:2.5:7.5; 90:5:5; 90:7.5:2.5 mol.% were studied in aqueous and aqueous-salt solutions in the temperature range from 25 to 60 C and at the NaCl ionic strength  interval from 10–3 to 1M. It was found that due to hydrophobic/hydrophilic balance, the temperature dependent conformational and phase change of macromolecular chains becomes sensitive to salt addition and allows the fine-tuning of the phase transition. In aqueous and aqueous-salt solutions, the average hydrodynamic size of amphoteric terpolymers is varied from 8 to 300 nm exhibiting bimodal distribution at room temperature. The number average (Mn) and weight average (Mw) molecular weights, polydispersity index (PDI), and zeta-potentials of amphoteric terpolymers in aqueous solu- tions were determined

Polymer Functionalized Nanoparticles in Blue Phase LC: Effect of Particle Shape

Ethylene oxide oligomers and polymers, free and tethered to gold nanoparticles, were dispersed in blue phase liquid crystals (BPLC). Gold nanospheres (AuNPs) and nanorods (AuNRs) were functionalized with thiolated ethylene oxide ligands with molecular weights ranging from 200 to 5000 g/mol. The BPLC mixture (ΔTBP ~6 °C) was based on the mesogenic acid heterodimers, n-hexylbenzoic acid (6BA) and n-trans-butylcyclohexylcarboxylic acid (4-BCHA) with the chiral dopant (R)-2-octyl 4-[4-(hexyloxy)benzoyloxy]benzoate. The lowest molecular weight oligomer lowered and widened the BP range but adding AuNPs functionalized with the same ligand had little effect. Higher concentrations or molecular weights of the ligands, free or tethered to the AuNPs, completely destabilized the BP. Mini-AuNRs functionalized with the same ligands lowered and widened the BP temperature range with longer mini-AuNRs having a larger effect. In contrast to the AuNPs, the mini-AuNRs with the higher molecular weight ligands widened rather than destabilized the BP, though the lowest MW ligand yielded the largest BP range, (ΔTBP > 13 °C). The different effects on the BP may be due to the AuNPs accumulating at singular defect sites whereas the mini-AuNRs, with diameters smaller than that of the disclination lines, can more efficiently fill in the BP defects.