Heteroatom tuning in agarose derived carbon aerogel for enhanced potassium ion multiple energy storage

The incorporation of heteroatoms into carbon aerogels(CAs)can lead to structural distortions and changes in active sites due to their smaller size and electronegativity compared to pure carbon.However,the evolution of the electronic structure from single-atom doping to heteroatom codoping in CAs has not yet been thoroughly investigated,and the impact of codoping on potassium ion(K+)storage and diffusion pathways as electrode material remains unclear.In this study,experimental and theoretical simulations were conducted to demonstrate that heteroatom codoping,composed of multiple heteroatoms(O/N/B)with different properties,has the potential to improve the electrical properties and stability of CAs compared to single-atom doping.Electronic states near the Fermi level have revealed that doping with O/N/B generates a greater number of active centers on adjacent carbon atoms than doping with O and O/N atoms.As a result of synergy with enhanced wetting ability(contact angle of 9.26°)derived from amino groups and hierarchical porous structure,ON-CA has the most optimized adsorption capacity(−1.62 eV)and diffusion barrier(0.12 eV)of K^(+).The optimal pathway of K^(+)in ON-CA is along the carbon ring with N or O doping.As K^(+)storage material for supercapacitors and ion batteries,it shows an outstanding specific capacity and capacitance,electrochemical stability,and rate performance.Especially,the assembled symmetrical K^(+)supercapacitor demonstrates an energy density of 51.8 Wh kg^(−1),an ultrahigh power density of 443Wkg^(−1),and outstanding cycling stability(maintaining 83.3%after 10,000 cycles in 1M KPF6 organic electrolyte).This research provides valuable insights into the design of highperformance potassium ion storage materials.

Comparison between Four Types of Buffers for DNA Agarose Gel Electrophoresis

To detect the genome of viruses (in environmental and clinical samples), we use electrophoresis running buffer after PCR reaction. Also, electrophoresis buffers were used widely to separate any DNA molecule. In this paper, we used four types of previously known electrophoresis buffers to compare which is easy for preparation, simple in structure, low cost and good performance in agarose gel electrophoresis. For this, we used two agarose concentration (1%, 2%) and two types of DNA ladder (100 bp, 1 kb) represent both smaller and larger sizes of molecule for each type of buffers, from the result we found in first level both supper buffer and TAE buffer with good performance and in second level we found bicarbonate buffer also with good performance also. Finally, we found the tang buffer cannot pose any electrophoretic activity on DNA agarose gel electrophoresis.

maltosyl-agarose亲和层析法提取人肺灌洗液中肺表面活性物质结合蛋白A及其鉴定

目的:提取及纯化人肺灌洗液中肺表面活性物质结合蛋白A(SP-A)。方法:由支气管肺泡灌洗液经10000g离心40min获得的沉淀中提取SP-A。沉淀溶解于6M的尿素,SP-A蛋白重新复性后上清过maltosyl-agarose柱进行亲和层析,用梯度EDTA洗脱SP-A,并过surpose6柱纯化。聚丙烯酰胺电泳和Westernblotting鉴定。结果:经亲和层析法可以从人肺灌洗液中提取出高纯度的SP-A,聚丙烯酰胺电泳在36ku和70ku处可见清晰条带,在分子量118ku以上亦可看到3条清晰条带,经Westernblotting鉴定均为特异性SP-A蛋白。结论:采用maltosyl-agarose亲和层析法可以从肺灌洗液中获得高纯度的SP-A。为进一步研究SP-A的功能和制备SP-A单克隆抗体提供了充足的SP-A来源。

以硅胶和Agarose 6B为载体金属螯合亲和层析分离纯化重组人Cu,Zn-SOD

以层析硅胶Agarose 6B ,制备了Cu2 + 螯合亲和载体 ,利用合成的Cu2 + IDA 硅胶亲和柱和Cu2 + IDA Agarose 6B亲和柱分离纯化了重组人Cu ,Zn SOD ,并比较了这两 2亲和载体的纯化效果和性能。硅胶纯化SOD的比活、纯化倍数和回收率分别为 75 86U/mg·protein、6 .5倍和 86 .7% ;而Agarose 6B纯化SOD的比活、纯化倍数和回收率则分别为 6 2 2 3/mg·protein、5 .8倍和 93.0 %。 2种亲和载体 5次使用后 。

Poly-lactic acid and agarose gelatin play an active role in the recovery of spinal cord injury

Objective To investigate the role of poly-lactic acid and agarose gelatin in promoting the functional recovery of the injured spinal cord. Methods Poly-lactic acid （PLA） or agarose was embedded in the space between two stumps of the hemisectioned spinal cord. Immunohistochemistry was used to show astroglia proliferation and the infiltration of RhoA-positive cells. Locomotor activity recovery was evaluated by testing the function of hindlimbs. Results Astroglias and RhoA labeled non-neuronal cells accumulated in the area adjacent to the implant, while the number of RhoA-posirive cells was decreased dramatically in the absence of implant. Animals implanted with agarose gelatin recovered more quickly than those with PLA, concomitant with a higher survival rate of the neurons. Conclusion Both PLA and agarose gelatin benefited the recovery of spinal cord after injury by providing a scaffold for astroglia processes. Modulation of the rigidity, pore size and inner structure of PLA and agarose gelatin might make these biodegradable materials more effective in the regeneration of the central nervous system （CNS）.

Fabrication of agarose hydrogel with patterned silver nanowiresfor motion sensor

In this work, a facile strategy is proposed to construct stretchable electronics based on agarose hydrogels. The hot agarose solution is casted onto a template with patterned Ag nanowires, endowing agarose hydrogel with patterned conductive surface. After further heating treatment, Ag nanowires can be embedded into the agarose hydrogel, which improves the stability of Ag pattern and has no obvious e ffect on the conductivity of hydrogels. The agarose hydrogel with patterned Ag nanowires is certi fied to be an e ffective stretchable electrode to record the motion of joints, which has great potential applications in the field of wearable devices.

DNA recovery from agarose gels with a simple centrifuge-driven sephadex filtration

Conventional methods of DNA recovery from agarose gel generally require expensive equipment, extended elution times, or considerable handling of the sample after elution. We developed a simple protocol for a quick and effective recovery of DNA from agarose gels with good yield and quality. Using a Sephadex resin filled spin column, DNA fragments of 500 bp to 6 kb in an agarose gel slice were easily recovered by a 2 min centrifugation. The recovery efficiencies were over 40% -50% and the eluted DNA can be used directly for downstream application, such as polymerase chain reactions （PCR） and restriction enzyme digestion. This method could also be used to recover large DNA fragment （48 kb） without degradation. The use of Sephadex helps to remove small molecular impurities from agarose and it also reduces the chance of clogging the column filter caused by direct contact with agarose.

Efficient Extraction of Agarose from Red Algae Using Ionic Liquids

We explored the possibility of using ionic liquids (ILs) as medium for efficient extraction of agarose via dissolution of red algae under varying conditions of heating or microwave irradiation. As compared to conventional methods, a very high extraction yield of good quality agarose (as high as 39 wt%) could be achieved depending upon the nature of used IL and applied experimental conditions. Purity of extracted agarose was confirmed from various spectral and analytical techniques, such as 1H and 13C NMR, FTIR, circular dichroism (CD), gel permeation chromatography (GPC) and thermogravimetric analysis (TGA). The physicochemical properties, such as gelling or melting temperature, viscosity and gel strength of extracted agarose hydrogels have been measured and compared with the agarose obtained from similar source reported in the literature. ILs were recovered after the extraction of agarose and were reused for further extraction experiments. % Recycling and extraction ability of recycled ILs in different cycles have been measured. The developed extraction process of utilizing ILs as medium is easy, simple and highly efficient as compared to the conventional methods of agarose extraction from algae.

Preparation and characterization of agar, agarose,and agaropectin from the red alga Ahnfeltia plicata

Agar,agarose,and agaropectin were extracted from the red alga Ahnfeltia plicata,and their properties and structures were characterized.Agar was extracted by a comparatively low alkaline consumption of 1.2%.It exhibited a gel strength of 1 152.50±74.25 g/cm^2 and a sulfate content of 0.55%±0.08%.The yield of agar from A.plicata was 24.53%,which is higher than those of other agarophytes commonly used in China.Three kinds of the method were compared for the purification of agarose,and the physicochemical properties of agarose that was prepared under the optimal condition were identical to those of commercially available agarose.Furthermore,agaropectin was purified from A.plicata and characterized by GC,HPLC,UV-spectrum,and FI-IR to understand its composition and structure.It was the first time to comprehensively study the agar and its fractions from the red alga of A.plicata.This research provided an eco-friendly agar extraction method from A.plicata and revealed its potential application for the production of agar,agarose,and agaropectin.

Searching for the best agarose candidate from genus Gracilaria, Eucheuma,Gelidium and local brands

Objective: To explore the potential of local agar of genus Gracilaria, Eucheuma,Gelidium and local brands as an alternative for imported agarose for DNA electrophoresis, and to examine their ability related to separation and migration of DNA fragments in DNA electrophoresis.Methods: Their performance at various concentrations were compared via an experimental study with a specific brand of imported commercial agarose used in molecular biology research. The measured variables were separation and migration during electrophoresis of a DNA fragment.Results: The local agar genus Gracilaria gigas, Gelidium, brand “B” and brand “S”could separate DNA fragments at a concentration between 1% and 2%, with an optimum concentration of 2% w/v, as good as a specific brand of imported commercial agarose.Conclusions: Their performance were very close to that of commercial agarose and can still be improved by further agar purification as well as by p H and sulfur control.

AFFINITY CHROMATOGRAPHY PURIFICATION OF UROKINASE WITH EPICHLOROHYDRIN ACTIVATED AGAROSE MATRIX

1 INTRODUCTIONIn literature,most matrices of affinity chromatography for urokinase(EC 3.4.99.26)purification were prepared by cyanogen bromide activation.However,theseadsorbents usually suffered from the drawback of leakage of the ligand,particularly inalkaline medium,because of the instability of the isourea linkage between the ligandand the spacer or agarose.Moreover,the positively charged imido group of theN-substituted isourea derivative and the hydrophobicity of the spacers might promotenonspecific adsorption.On the contrary,the adsorbents prepared by the method

Applying Both Chemical Liquefaction and Enzymatic Catalysis Can Increase Production of Agaro-Oligosaccharides from Agarose

Red algae represents an important marine bioresource.One high-value utilization of red algae is the production of agarooligosaccharides which have many positive biological effects.However,the lack of an efficient production route seriously limits the application of agaro-oligosaccharides.In this study,we established a green route that combines chemical liquefaction and enzymatic catalysis for the efficient production of agaro-oligosaccharides,and we used the production of neoagarotetraose(NA4)as an example.Agarose(150 g L^−1)liquefaction by citric acid was controlled with respect to two targets:a 100%liquefaction rate and a high average degree of polymerization(>4)of the liquesced agaro-oligosaccharides,which were then catalyzed byβ-agarase into an oligosaccharides mixture with a high concentration of NA4(30.8 g L^−1)in a 1-L reaction volume.After purification,we obtained 25.5 g of NA4 with a purity of 92%.This work establishes an easy route for the efficient production of pure agaro-oligosaccharides from agarose.

The preparation of low electroendosmosis agarose and its physico-chemical property

Studies on Gelidium amansii agar fractionations were carried out in this paper. Gelidium amansii agar was fractionated on DEAE-Cellulose, and four fractions were obtained sequentially. The fractions were analyzed on physical and chemical properties, and IR and 13C-NMR spectroscopy applied for elucidating the chemical structure. Among the four fractions obtained, water fraction measured up to the standard of low EEO agarose. The sulfate content, ash content, electroendosmosis and gel strength (1%) of water fraction were 0.16%, 0.34%, 0.12 and 1 130g/cm2 respectively, similar to those of the Sigma products.

Effects of agarose concentration and addition on the properties of gel-cast 3Y-ZrO2 green and sintered bodies

Using agarose as a gel agent to prepare ceramics is a suitable non-toxic gel-casting method. The effects of agarose concentration and addition amount on gel-cast 3Y-ZrO2 green and sintered bodies were investigated. Green bodies were prepared by gel-casting using an agarose solution of a different agarose mass fraction including 3.0%, 3.5%, 4.0%, 4.5%, 5.0% and 5.5% with an added amount of agarose in the green body at a mass fraction of 0.7%, and using the agarose solution of a mass fraction of 4.5% with a different amount of added agarose including 0.6%, 0.7%, 0.8%, 0.9%, and 1.0% in terms of mass fraction. The green bodies were sintered at I 600 ~C for 4 h. The relative density, linear shrinkage, and bending strength of the green bodies, and L^e density, microstructure, bending strength, and fracture toughness of sintered samples were characterized and analyzed. Results show that comprehensive properties of green bodies made with 4.5% （in terms of mass fraction） agarose solution added to an mass fraction of agarose in the slurry at 0.6% were the best, of which the bending strength was 3.14 MPa, the linear shrinkage was below 4.3%, and the relative density is 57.3%. For sintered bodies, the best fracture toughness was 5.63 MPa m1/2, and the optimal density was 5.88 gcm-3.

A Rapid Electrophoresis Method on Agarose Gel to Characterise Dairy Protein Aggregates

Heat treatment of milk may cause whey proteins and caseins to form aggregates. These soluble and micellar aggregates and their other properties (size, composition, shape, etc.) can affect the techno-functionalities to the milk, conferring interesting or negative features depending on the application in dairy industries. In this study, we propose a new approach to characterise those protein aggregates. SDS-agarose electrophoresis is followed by the calculation of a retention factor (Rf) for each protein spot. Rf allows milk aggregates to be compared qualitatively under the same conditions. This method could be transposed to the dairy industry for a better knowledge of the milk subsequent to heat treatment.

Agarose hydrogel doped with soluble Se-chitosan for Se-enriched cultivation of sprouts

Se-chitosan with a high Se content of 139 mg/g was successfully synthesized using the glacial acetic acid-sodium selenite(HAc-Na2SeO3)method.The chemical structure of Se-chitosan was characterized by FTIR,XRD,TGA,UV–vis and 13C NMR,confirming that selenite acid was introduced into chitosan via the esterification reaction of the hydroxyl group at C6 and the electrostatic interaction of the amino group at C2 of chitosan.Agarose hydrogels were designed as an efficient carrier of Se-chitosan for Se-enriched cultivation of sprouts.The hydrogels exhibited a porous structure,which is beneficial for Se diffusion in hydrogels.The growth indexes of sprouts grown in Agar/Se-chitosan composite hydrogels with different Se concentrations,including plant weight,plant height and Se content,were investigated.The results showed that in the Se-enriched cultivation of sprouts,Se-chitosan possessed an excellent Se enrichment effect.As the Se concentration in Agar/Se-chitosan composite hydrogels increases from 0 to 1600μg/L,the Se content of the sprouts will also increase from 0.92 mg/kg to 6.79 mg/kg accordingly.Moreover,it is necessary to control the amount of Se-chitosan added to the hydrogels;otherwise,the growth of sprouts will be inhibited.This research provided a simple and effective method for the fabrication of Secontaining hydrogels for Se-enriched cultivation of sprouts.

Mussel-inspired agarose hydrogel scaffolds for skin tissue engineering

Polysaccharide hydrogels are widely used in tissue engineering because of their superior biocompatibility and low immunogenicity.However,many of these hydrogels are unrealistic for practical applications as the cost of raw materials is high,and the fabrication steps are tedious.This study focuses on the facile fabrication and optimization of agarose-polydopamine hydrogel(APG)scaffolds for skin wound healing.The first study objective was to evaluate the effects of polydopamine(PDA)on the mechanical properties,water holding capacity and cell adhesiveness of APG.We observed that APG showed decreased rigidity and increased water content with the addition of PDA.Most importantly,decreased rigidity translated into significant increase in cell adhesiveness.Next,the slow biodegradability and high biocompatibility of APG with the highest PDA content(APG3)was confirmed.In addition,APG3 promoted full-thickness skin defect healing by accelerating collagen deposition and promoting angiogenesis.Altogether,we have developed a straightforward and efficient strategy to construct functional APG scaffold for skin tissue engineering,which has translation potentials in clinical practice.

A Micro Structure POF Relative Humidity Sensor Modified With Agarose Based on Surface Plasmon Resonance and Evanescent Wave Loss

A novel high sensitivity relative humidity(RH)sensor was proposed by using micro structure plastic optical fiber(POF)based on the surface plasmon resonance(SPR)effect and the evanescent wave(EW)loss.The micro structure was fabricated on the POF and coated with a gold layer and agarose,adopting the sputtering and dip-coating technique.These construction effects on the attenuation of power caused by the SPR effect and the EW loss were used to perform RH detections.The agarose9s different refractive indexes(RIs)caused fluctuations in the transmission power when the humidity increased.The demonstrated experimental results showed that the proposed sensor achieved a linear response from 20%RH to 80%RH with a high sensitivity of 0.595μW/%.The proposed sensor had the advantages of fast response and recovery.Furthermore,the temperature dependence and the repeatability test of the sensor were also performed.

Metal chelate affinity to immobilize horseradish peroxidase on functionalized agarose/CNTs composites for the detection of catechol

The paper reports a novel amperometric biosensor for catechol based on immobilization of a highly sensitive horseradish peroxidase by affinity interactions on metal chelate-functionalized agarose/carbon nanotubes composites. Metal chelate affinity takes advantage of the affinity of Ni2＋ ions to bind strongly and reversibly to histidine or cysteine tails found on the surface of the horseradish peroxidase. Thus, enzymes with such residues in their molecules can be easily attached to functionalized aga- rose/carbon nanotubes composites support containing a nickel chelate. Linear sweep voltammograms and amperometry are used to study the proposed electrochemical biosensor. Catechol is determined by direct reduction of biocatalytically liberated quinone species at -0.05 V （vs. SCE）. The effect ofpH, applied electrode potential and the concentration of H2O2 on the sensitivity of the biosensor has been investigated. The performance of the proposed biosensor is tested using four different phenolic compounds, showing very high sensitivity, in particular, the linearity of cateehol is observed from 2.0 × 10-8 to 1.05×10-5 M with a detection limit of 5.0×10-9 M.

A simple method for the detection of hepatitis A virus in the environmental samples by polymerase chain reaction

Hepatitis A virus (HAV) is very persistent in the environment and is especially difficult to detect in the seafoods. In recent years, molecular cloning of the genome of HAV has led to sensitive polymerase chain reaction (PCR) method for the detection of HAV RNA. Here we describe a new and simple procedure to extract RNA from contaminated clams and the PCR method for detection of HAV in environmental samples. The specificity and efficiency of PCR amplification were studied using cDNA and RNA of HAV. Three primer couples gave satisfactory results. Some basic parameters of the PCR were modified to perform a highly specific and sensitive test.