Physicochemical properties and biological activities of polysaccharides from the peel of Dioscorea opposita Thunb.extracted by four different methods

Polysaccharides are the important biologically active components found in the peel of Dioscorea opposita Thunb.(DTTP).The influences of 4 extraction methods,namely hot water extraction(W),acidic extraction(HA),hot-compressed water extraction(HCW)and enzyme-assisted extraction(EAE),on the yields,physicochemical properties,hypoglycemic and antioxidant activities of polysaccharides from DTTP were studied and compared.Among these DTTP polysaccharides,DTTP-HA was outstanding in several respects.DTTP-HA was the most water soluble;it had the highest total carbohydrate content(85.08%),the highest uronic acid(13.20%)and the highest thermal stability.DTTP-HA and DTTP-W possessed a triple-helix structure.These 4 kinds of polysaccharides have the same types of monosaccharides,but in different molar percentages.Extraction method had a significant impact on the microstructures of the extracted polysaccharides.DTT-HA exhibited irregular structure with many holes.Among the 4 extracted methods,the DTTP-HA and DTTP-W initially exhibited higher hypoglycemic and antioxidant activities.The better bioactivities of DTTP-HA may be related to the above factors.The findings indicated that acid extraction is an effective method to extract polysaccharides with high biological activities from DTTP.

The Impact of Different Mining and Releasing Ratios on the Over-Support Pressure of Header Working Face

Through the theoretical analysis of overburden destabilization mechanism, FLAC 3D simplified plane numerical simulation method and field measurement method, we compared the relationship of overburden support pressure at 35 m of workface recovery, and the peak overburden support pressure decreased from 13.85 Mpa to 11.97 Mpa from 1:1 to 1:3. With the increase of mining ratio, the peak over-supporting pressure decreases: with the increase of top coal recovery thickness, the peak over-supporting pressure and the influence range will be further expanded, and the distance between the peak over-supporting pressure and the coal wall of the working face will be further increased and the high stress zone of the peak area will be expanded simultaneously.

Tannins from Acacia mangium Bark as Natural Dyes for Textiles:Characteristics and Applications

Tannins are capable of producing natural dyes with antioxidant and antibacterial propertis,while synthetic dyes are commonly used in the textile industry,causing environmental issues like water pollution.This research aims to utilize waste tannins as natural dyes as an alternative to synthetic dyes.This study examined the effect of the extraction method on tannin properties such as phenolic content,antioxidants,and antibacterial activity.In addition,Pyrolysis Gas Chromatography‒Mass Spectrometry(Py-GCMS)analysis was used to identify the effect of extraction temperature on the chemical elucidation of tannin.The effect of tannin concentration was evaluated against four bacteria that are usually found on human skin:Staphylococcus epidermidis,Bacillus subtilis,Propionibacterium acnes,and Staphylococcus aureus.Extraction temperature significantly influences the chemical composition of tannin,which leads to different antioxidant properties.The maximum antibacterial properties of tannin were obtained at 90℃with the inhibition zone in the range of 0.9–1.0 mm against four bacteria,tannin yield of 26.59%,Gallic Acid Equivalents or total phenolic content(GAE)of 40.30 mg/g,and Radical Scavenging Activity or antioxidant activity(RSA)of 89.88%.Moreover,the concentration of tannin was significantly linear with its antibacterial properties.Tannin was successfully applied to the textile by using alum as a mordanting agent to create an antibacterial textile.The textile’s bacterial structure damage was analyzed under Field Emission Scanning Electron Microscopy(FESEM).After 50 washings,tannin-textiles with alum-modified properties remained stable compared to those without alum,with S.aureus and S.epidermidis being the most vulnerable bacteria,as confirmed by FESEM images.Hence,tannin is a feasible alternative to harmful and nondegradable synthetic dyes and antibacterial agents.

Mutagenicity and Genotoxicity of Organic Extracts from Finished Water with Different Treatment Process

Purification of surface water is widely practiced with conventional water treatment processes like coagulation-flocculation, sedimentation, filtration,and disinfection. Some reports have specified that conventional wastewater purification processes do not effectively remove many chemical contaminants,

Non Ideal Schottky Barrier Diode’s Parameters Extraction and Materials Identification from Dark I-V-T Characteristics

Several parameters of a commercial Si-based Schottky barrier diode (SBD) with unknown metal material and semiconductor-type have been investigated in this work from dark forward and reverse I-V characteristics in the temperature (T) range of [274.5 K - 366.5 K]. Those parameters include the reverse saturation current (Is), the ideality factor (n), the series and the shunt resistances (Rs and Rsh), the effective and the zero bias barrier heights (ΦB and ΦB0), the product of the electrical active area (A) and the effective Richardson constant (A**), the built-in potential (Vbi), together with the semiconductor doping concentration (NA or ND). Some of them have been extracted by using two or three different methods. The main features of each approach have been clearly stated. From one parameter to another, results have been discussed in terms of structure performance, comparison on one another when extracted from different methods, accordance or discordance with data from other works, and parameter’s temperature or voltage dependence. A comparison of results on ΦB, ΦB0, n and NA or ND parameters with some available data in literature for the same parameters, has especially led to clear propositions on the identity of the analyzed SBD’s metal and semiconductor-type.

Studies on in-vitro antioxidant activity of marine edible seaweeds from the east coastal region of Peninsular Malaysia using different extraction methods

Objective:To determine the antioxidant activity of two edible marine seaweeds Eucheumacottonii and Padina sp..Methods:The two extraction methods such as conventional and soxhlet extraction were used to isolate the secondary metabolites using methanol as a solvent medium.Total phenolic content of crude seaweeds extract were analysed by standard FC method.The different antioxidant assays DPPH,ferric reducing antioxidant power and β-carotene bleaching assays confirmed the antioxidant activities.Results:with expressed higher total phenolic content in the seaweeds extract.Also β-carotene bleaching assay lower activity compare with BHT as reference control.Additionally IR spectra showed the phenolic related functional groups are present in the solvent extract.The phenolic related compounds are mainly responsible for higher rate of antioxidant activity.Conclusions:DPPH and ferric reducing antioxidant power assays showed the positive correlation higher phenolic contents than the Eucheuma cottonii.And also the soxhlet extraction showed higher yield and better radical scavenging activity compared to conventional method.Moreover the studies confirmed both seaweeds are an effective candidate for the control the free radical scavenging activity.

Effects of Different Extract of PolygonumMultiflorumon Plasma Lipid，Liver Cholesterol and Blood Viscosity

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Evaluation of antibacterial potential of seaweeds occurring along the coast of Mandapam,India against human pathogenic bacteria

Objective:To investigate the antibacterial activity of six seaweeds against twelve human bacterial pathogens using seven different solvents.Methods:Antibacterial activity was evaluated using the disc diffusion technique on Mueller Hinton agar.Broth dilution assays are standard method used to compare the inhibition efficiency of the antimicrobial agents.Results:Among the six seaweeds tested,the antibacterial activity was higher in the brown seaweeds when compared to red and green seaweeds.Padina gymnospora was found exerting a strong antibacterial activity with a high range inhibition[(6.00±0.82)to(22.67±1.25)mm].Broth dilution assay was conducted against Salmonella sp.with the chloroform extract of Padina gymnospora and the growth inhibition was found in the range of 74.26%to 82.56%.Conclusions:Further research studies are being carried out on other species of seaweeds of different habitats in order to provide complete data of the antimicrobial potential of these algae.It is also essential to study the principle compound present in the seaweeds which is responsible for antimicrobial activity.It can be achieved by using advanced separation techniques.