Alginate Properties and Heavy Metal Biosorption by Marine Algae

The physical properties of the alginate component in four different brown seaweeds (Sargassumfluitans, Ascophyllum nodosum, Fucus vesiculo-sus, andLaminaria japonica) were characterized using potentiometric titration,¹³C-nuclear magnetic resonance (NMR), chemical analysis, and viscosity measurements. The heavy metal binding capacities of the corresponding seaweeds were directly proportional to their respective total carboxyl group content, and related to the electronegativity of the elements investigated (Ca, Zn, Cd, Cu, and Pb). The uronic acid composition or sequence of the alginate component did not affect the metal uptake properties of the biosorbents studied here. However, the alginate leaching owing to its solubilization by Na ions was observed to decrease with increasing intrinsic viscosity of the extracted alginate, related to its molecular weight, and with increasing apparent acidic dissociation constant, related to the alginate density inside the biomass.     

NAK-12树脂脱除蚕蛹复合氨基酸异味及褐变物质的研究

本文研究了用NAK－12吸附树脂脱除蚕蛹复合氨基酸异味及褐变色素的条件，初步分析了蚕蛹复合氨基酸异味产生的原因，实验结果表明：当流速为3BV／h时，1ml NAK-12吸附树脂能吸附1．75g蚕蛹复合氨基酸中的异味物质；能吸附1．45g蚕蛹复合氨基酸中的褐变物质。甲醇是异味物质和褐变物质的良好洗脱剂，用pH1．0的甲醇以1BV／h流速洗脱，仅用3．5BV的洗脱剂即可完全洗脱异味物质和褐变物质，蚕蛹复合氨基酸异味产生的可能机理是：加热蚕蛹复合氨基酸液时，其苯丙氨酸，蛋氨酸，蛋氨酸，异亮氨酸，亮氨酸，苏氨酸被氧化脱氨，生成挥发性醛，而其褐变则是赖氨酸，精氨酸与还原糖发生Maillard反应生成褐变物质引起的。     

Monitoring of Fe,Mn, Cu,Pb and Cd levels in two brown macroalgae from the Bulgarian Black Sea coast

Heavy metal contents (Fe, Mn, Cu, Pb and Cd) were determined in two brown macroalgal species (Cystoseira crinita and Cystoseira barbata). Samples were collected during six seasons from spring 1996 to summer 2000 from five different sites of the Bulgarian Black Sea coastal zone – Tuzlata, Ravda, Sozopol, Ahtopol and Sinemoretz. The local and seasonal metal distribution and their variations were examined.

The data obtained indicate that the two investigated species demonstrate various degrees of metal accumulation and can be used as indicators for the type and quantity of anthropogenic contamination in marine ecosystems.     

The effect of tourmaline on cell membrane of nitrosomonas europaea and biodegradation of micropollutant

As a kind of ammonia‐oxidizing bacteria, Nitrosomonas europaea (N. europaea) was chosen as a research model to study the alteration of cell membrane in the presence of tourmaline and biodegradation of acetochlor. atomic force microscopy images reveal that the presence of tourmaline substantially changes the structure of the outer membrane of the cell responsible for the cell permeability. SEM images show that the introduction of tourmaline makes the cell lose its ability to resist lysozyme owing to the damages. The fluorescence polarization has shown a significant decrease in membrane fluidity and the increase of permeability of cell membrane. Ca²⁺ and Mg²⁺ was measured using inductively coupled plasma mass spectrometry and was found in the supernatant from the cells treated by tourmaline. Tourmaline can improve the efficiency of biodegradation of acetochlor for N. europaea. It is proposed that the cell permeability is slightly increased, and the absorbability of nutrition from the medium becomes easier. As a result, N. europaea grows faster in the presence of tourmaline than the native cells. Copyright © 2014 John Wiley & Sons, Ltd.     

Histone deacetylase (HDAC) inhibitor curcumin upregulates mitochondrial uncoupling protein1 (UCP1) and mitochondrial function in brown adipocytes,in-silico study and screening natural drug library

Mitochondrial dysfunction has been associated with diverse pathological conditions globally. Specifically, in adipose tissues, mitochondrial dysfunction is the primary cause of obesity and obesity-related illnesses. An existing drugs such as atorvastatin and other lipid-lowering drugs demonstrated adverse effects and initiated other diseases. Thus, we need to explore new methods to prevent and treat obesity. In this study, we used the cell screening method to identify several natural compounds that increase adipocyte UCP1 gene expression. The identified drug Curcumin was evaluated in cell models and the In-silico model. We found curcumin is an active compound of turmeric belonging to Zingiberaceae (ginger family), which activates the Nrf2 mechanism. Curcumin potentially endorses the expression of UCP1 in the brown adipocyte in vitro cellular model. Curcumin plays an important role that modulating mitochondrial function and improving mitochondrial DNA quantification, ATP production, and cell viability. We have established an efficient in vitro cell experiment system to study the metabolic regulation of UCP1. The in-silico model revealed curcumin-UCP1 interaction. Curcumin, via enhancing mitochondrial activity, could be a helpful therapeutic molecule against metabolic disorders or obesity-related diseases. Curcumin will be the subject of more research in both human and murine models, which will provide novel therapeutic pathways for the treatment of metabolic illnesses by modulating the control of mitochondrial function.     

The structure of some virtually free pro- groups

We prove two conjectures on pro- groups made by Herfort, Ribes and Zalesskii. The first says that a finitely generated pro- group which has an open free pro- subgroup of index is a free pro- product , where the are free pro- of finite rank and the are cyclic of order . The second says that if is a free pro- group of finite rank and is a finite -group of automorphisms of , then is a free factor of . The proofs use cohomology, and in particular a ``Brown theorem' for profinite groups.

     

A structural model for the time-dependent recovery of mineral suspensions

A thixotropic recovery model has been developed that is based on consideration of the microstructural interactions that occur between particles within a suspension particle network. The model is based on Smoluchowski coagulation rate theory, utilizing second order kinetics to describe the thixotropic recovery behavior. The model is applied to Na-montmorillonite-based coal tailings suspensions and is also shown to be applicable to brown coal and bauxite residue suspensions. The model describes all the recovery data well, especially at intermediate to large recovery times. The recovery of the montmorillonite suspensions at short times was faster than predicted, indicating the existence of additional factors in early-time structure development. The discrepancy may have also been due to the highly anisotropic nature of the clay platelets. The recovery rate constant, K _r , increases with increasing solids concentration (for constant surface chemical conditions) as would be expected from the basis of the model. Received: 22 September 2000 Accepted: 16 March 2001     

非退化扩散过程的极性与相交性

本文讨论非退化扩散过程的极性，得到了几个较好的充分条件，它可看作[1]的进一步深化，此外，我们将这些结果用来研究两个独立的非退化扩散过程的相交性，得到了一些有意思的结果。     

Hoek–Brown criterion applied to circular tunnel using elastoplasticity and in situ axial stress

Based on the nonlinear Hoek–Brown failure criterion, elastoplastic analytical solutions are developed for the elastoplastic stresses, strains and plastic zones around a circular tunnel subjected to different value of the axial in situ stress. Effects of the transverse in situ stress, the axial in situ stress and the strength parameters of rock masses on the elastoplastic stresses, strains and plastic zones in the surrounding rock masses are investigated. It is found from the numerical results that the stresses, strains, and plastic zones in the surrounding rock depend not only on the transverse in situ stress but also on the axial in situ stress as well as the mechanical parameters of rock masses.