Fouling evolution of extracellular polymeric substances in forward osmosis based microalgae dewatering.

Membrane fouling was still a challenge for the potential application of forward osmosis (FO) in algae dewatering. In this study, the fouling behaviors of Chlorella vulgaris and Scenedesmus obliquus were compared in the FO membrane filtration process, and the roles of their soluble-extracellular polymeric substances (sEPS) and bound-EPS (bEPS) in fouling performance were investigated. The results showed that fouling behaviors could be divided into two stages including a quickly dropped and later a stable process. The bEPS of both species presented the highest flux decline (about 40.0%) by comparison with their sEPS, cells and broth. This performance was consistent with the largest dissolved organic carbon losses in feed solutions, and the highest interfacial free energy analyzed by the extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) theory. The chemical characterizations of algal foulants further showed that the severe fouling performance was also consistent with a proper ratio of carbohydrates and proteins contents in the cake layer, as well as the higher low molecular weight (LMW) components. Compared with the bEPS, the sEPS was crucial for the membrane fouling of S. obliquus, and an evolution of the membrane fouling structure was found in both species at the later filtration stage. This work clearly revealed the fundamental mechanism of FO membrane fouling caused by real microalgal suspension, and it will improve our understanding of the evolutionary fouling performances of algal EPS.

Effects of sand burial depth on Xanthium spinosum seed germination and seedling growth.

In desert habitats, sand burial is an important factor affecting germination of plant seeds and seedling growth. Xanthium spinosum has strong adaptability in arid desert areas, and is a common malignant invasive plant in Xinjiang, China. The effects of different sand burial depths on seed germination, seedling emergence, growth and biomass allocation were studied to provide a scientific basis for further control of X. spinosum. Six sand burial depths (1, 2, 3, 5, 7 and 9 cm) were established to explore the response of X. spinosum seed germination and seedling growth to sand burial. The first emergence time, peak emergence time, emergence rate, seedling growth height, biomass and biomass distribution of X. spinosum seeds was significantly different at sand burial depths (P < 0.05). The X. spinosum seeds had the highest emergence rate (71.5%) at 1 cm sand burial and the maximum seedling height (7.1 cm). As sand burial depth increased, the emergence rate and seedling height gradually decreased. Emergence rate (12.25%) and seedling height (2.9 cm) were lowest at 9 cm sand burial. The root length at 9 cm depth (13.6 cm) was significantly higher than that at other sand depths (P < 0.05). The sand burial depth affected the biomass accumulation and distribution of X. spinosum. As sand burial depth increased, the root biomass and rhizome ratio increased, and the most deeply buried seedlings allocated more biomass for root growth. The optimal sand burial depth for seed germination and seedling growth of X. spinosum was 1-3 cm, and high burial depth (5-9 cm) was not conducive to the germination and growth of X. spinosum seedlings. For prevention and control of X. spinosum, we suggest deeply ploughing crops before sowing to ensure X. spinosum seeds are ploughed into a deep soil layer.

Lidocaine mediates the progression of cerebral ischemia/reperfusion injury in rats via inhibiting the activation of NF-κB p65 and p38 MAPK.

BACKGROUND: Lidocaine is a commonly used local anesthetic, and low-dose lidocaine has neuroprotective effects on cerebral ischemia/reperfusion (CI/R) injury; the mechanism for this, however, is still unclear. The aim of this study was to investigate the role and the possible mechanisms of lidocaine on CI/R injury in rats. METHODS: We constructed a rat (male Sprague-Dawley rats, 6-8 weeks old) model of CI/R injury induced by middle cerebral artery occlusion (MCAO). Histopathology, neuronal apoptosis, oxidative stress, and inflammatory response were evaluated using hematoxylin and eosin (HE) staining, Nissl staining, enzyme-linked immunosorbent assay (ELISA) and western blotting, respectively. In addition, brain water content, infarct volume, neurological deficit score each evaluated. RESULTS: The findings showed that lidocaine improved spatial learning and memory impairment, protected I/R-induced brain injury and attenuated neuronal death and apoptosis. Furthermore, lidocaine also regulated the levels of malondialdehyde (MDA), glutathione (GSH), superoxide dismutase (SOD), IL-6, IL-10, iNOS, and IL-4.Notably, lidocaine markedly inhibited the expression of p65 and p38. CONCLUSIONS: The results indicate that lidocaine protects against cerebral injury induced by I/R in rats via the nuclear factor kappa-B (NF-κB) p65 and p38 mitogen-activated protein kinase (MAPK) signaling pathway, it provided a candidate for the treatment of CI/R-induced injury.

Atractylodin Induces Myosin Light Chain Phosphorylation and Promotes Gastric Emptying through Ghrelin Receptor.

Atractylodin is one of the main constituents in the rhizomes of Atractylodes lancea Thunb., being capable of treating cancer cachexia-anorexia and age-related diseases as an agonist of growth hormone secretagogue receptor (GHSR). GHSR was herein expressed in human gastric smooth muscle cells (HGSMCs) and activated by ghrelin receptor agonist L-692,585. Like L-692,585, atractylodin also increased Ca2+ and enhanced the phosphorylation of myosin light chain (MLC) through GHSR in HGSMCs. In addition, atractylodin promoted gastric emptying and MLC phosphorylation in the gastric antrum of mice also through GHSR. Collectively, atractylodin can activate GHSR in gastric smooth muscle, as a potential target in clinical practice.

Three novel isomeric zinc metal-organic frameworks from a tetracarboxylate linker.

Three porous supramolecular isomers (IZE-1, IZE-2, and IZE-3) with the same framework component [Zn(2)(EBTC)(H(2)O)(2)] (EBTC = 1,1'-ethynebenzene-3,3',5,5'-tetracarboxylate) were successfully constructed by finely tuning the reaction condition. Although both IZE-1 and IZE-2 are constructed from the linear EBTC subunits and one kind of regular [Zn(2)(CO(2))(4)] paddlewheels, their frameworks exhibit two different (3,4)-c net of fof (sqc1575) and sqc1572, respectively, resulting in cavities with different size and shape. However, as for isomer IZE-3, the EBTC ligands are bent and one-half of the [Zn(2)(CO(2))(4)] paddlewheels are distorted, leading to a novel (3,4,4)-c hyx net with point symbol (6.7(2))(4)(6(2).8(2).10(2))(7(2).8(2).11(2)) and vertex symbol (6.7.7)(4)(7(2).7(2).8.8.12.12)(6.6.8.8.10(2).10(2)). Quantum chemical calculations by DFT indicate that the three isomers have very close thermodynamic stabilities, which may explain that subtle condition change leads to variation of the frameworks. Further theoretical semiempirical investigation on the interactions between solvent molecules and compounds shows different hydrogen binding patterns in good agreement with the experimental observations. Furthermore, they exhibit good solid-state luminescence properties with long lifetime.

catena-Poly[[[triaqua-cobalt(II)]-µ-10-methyl-phenothia-zine-3,7-dicarboxyl-ato] monohydrate].

The polymeric title compound, {[Co(C(15)H(9)NO(4)S)(H(2)O)(3)]·H(2)O}(n), consists of chains along [001] made up from Co(2+) ions bridged by 10-methyl-phenothia-zine-3,7-dicarboxyl-ate anions. The Co(2+) ion, coordinated by three O atoms from two different carboxyl-ate groups and three water mol-ecules, displays a distorted octa-hedral environment. In the crystal, π-π inter-chain inter-actions, with centroid-centroid distances of 3.656 (2) and 3.669 (2) Šbetween the benzene rings of the ligands, assemble the chains into sheets parallel to (100). O-H⋯O hydrogen-bonding inter-actions between the coordinating water mol-ecules and carboxyl-ate O atoms link the sheets into a three-dimensional network.

Phenothiazine-anthraquinone donor-acceptor molecules: synthesis, electronic properties and DFT-TDDFT computational study.

Two donor-acceptor molecules with different pi-electron conjugative units, 1-((10-methyl-10H-phenothiazin-3-yl)ethynyl)anthracene-9,10-dione (AqMp) and 1,1'-(10-methyl-10H-phenothiazine-3,7-diyl)bis(ethyne-2,1-diyl)dianthracene-9,10-dione (Aq2Mp), have been synthesized and investigated for their photochemical and electrochemical properties. Density functional theory (DFT) calculations provide insights into their molecular geometry, electronic structures, and properties. These studies satisfactorily explain the electrochemistry of the two compounds and indicate that larger conjugative effect leads to smaller HOMO-LUMO gap (Eg) in Aq2Mp. Both compounds show ICT and pi --> pi* transitions in the UV-visible range in solution, and Aq2Mp has a bathochromic shift and shows higher oscillator strength of the absorption, which has been verified by time-dependent DFT (TDDFT) calculations. The differences between AqMp and Aq2Mp indicate that the structural and conjugative effects have great influence on the electronic properties of the molecules.