Big Molecular Weight Research Articles

A Review on Suppositories and Application of Vaginal Drug Delivery System

Historically, medications that caused unconsciousness, haemorrhoidal, germicidal, and purgative effects were administered the rectal route as suppository injections. The majority of medicinal drugs on the market today are designed to be administered rectal in order to increase their bioavailability and achieve the necessary therapeutic blood concentration. Historically, only locally acting medications, such as steroids, prostaglandins, spermicidal, antifungal, antibacterial, and antiviral, were allowed during vaginal birth. The capacity to avoid first-pass hepatic processing, accessibility, a healthy blood supply, and permeability to big molecular weight medications, such as peptides and proteins, are the main benefits of this route. Vaginal medicine delivery devices that are frequently utilised include suppositories, creams, gels, pills, and vaginal rings. This message is intended to give the reader an overview of the developments in the area of vaginal medication delivery.

Applications of Polymeric Nanoparticle in Nose to Brain Drug Delivery

The primary goal of developing novel formulations is to effectively deliver the drug the at the target site. A desirable, non-invasive method of enhancing medication penetration or delivering innovative drug or gene carriers into the brain is nose-to-brain administration. The main benefit of intranasal medication administration is that it avoids the blood-brain barrier and targets drug molecules directly to the brain. Due to their difficulty in crossing the blood-brain barrier, big molecular weight and hydrophilic compounds can also be transported to the brain by this drug delivery channel. By speeding the administration of treatments at the target site and preventing systemic adverse effects, intranasal delivery to the brain is helpful in treating many neurological disorders. Potential drug delivery systems, the drug-encapsulated polymeric nanoparticles can convey a sizable amount of medication from the nose to brain. The advantages of polymeric nanoparticles-mediated nose to brain targeting are discussed in this paper. Additionally, it provides an overview of the polymeric nanoparticles studied for the therapy of various brain disorders as well as the process of nanoparticle transport.

Study of the dyeing properties of saffron and ultrafiltrated saffron powders, as colourants for natural and synthetic fibres

AbstractThere is a noticeable growing interest in the use of natural dyes in contemporary textile dyeing, motivated by the requirements imposed, in favour of environmental prosperity. The use of natural dyes reduces significantly both the energy requirements and the environmental impact of the process. In the present work natural and synthetic fibres were dyed with the dyestuff isolated from Crocus sativus L., after aqueous extraction of the dried stigmas of the plant. Additionally, part of the powder was purified by using ultrafiltration technology. The saffron extract and the ultrafiltrated saffron retentate were used to dye cotton, wool, nylon and polyester, in various depths of shade and temperatures. Both saffron and ultrafiltrated saffron successfully dyed not only the natural substrates, but also the synthetic ones, while higher dyeing temperatures produced level dyeing with all substrates used. Ultrafiltrated saffron powder produced brighter and much stronger dyeing to the original saffron powder, due to the elimination of extraction by‐products. Isothermal adsorptions for both colourants were performed on all substrates in order to investigate their adsorption mechanism. It was found that saffron and ultrafiltrated saffron follow a Freundlich‐type adsorption isotherm on cotton, wool and nylon which is a typical mechanism for a planar‐directed dye of big molecular weight. Nernst‐type adsorption was found to occur on polyester which again is typical for the adsorption of disperse dyes on polyester. Thus, saffron can be claimed as a universal dye, able to successfully dye natural and synthetic substrates.

A new method for bio-degumming in less-water environment: Solid-state-fermentation progressive bio-degumming

Water saving and environmental protection is the key objective for material process. Bast fiber like flax and ramie was considered as sustainable resource for fiber. Degumming was the first and necessary process for abstracting fiber. Although bio-degumming was seen as energy saving and environmentally friendly method compared with conventional chemical process, considerable amount of water can be consumed and convert to waste water in traditional bio-degumming of bast fiber. In this investigation, the approach of bio-degumming was improved by combining of solid-state fermentation (SSF) method with deconstructing biomass recalcitrance, and a novel degumming method of solid-state-fermentation progressive bio-degumming (SPB) process was constructed for abstracting bast fiber with less water. The bio-recalcitrance of flax bast was break using cryogenic treatment and then the gum in flax bast was degraded with solid-state fermentation. Compared with conventional chemical degumming, more than 95% of Chemicals and 55% of water can be save in process of flax fiber with SPB method. Moreover, high quality flax fiber can be obtained in this SPB process and the degummed fiber have higher breaking strength (1.22 Mpa) and bigger molecular weight (105.7 kg/mol) than that obtained by chemical method (0.99 Mpa and 86.1 kg/mol). This SPB method also have obviously advantage that traditional bio-degumming base on liquid fermentation in consumption of water and production of waste water. Considering the mild temperature, the approach of SPB may provide a low-carbon and energy-saving technology for extracting fiber from bast plant. Thus, the SPB method presented in this study propose a novel strategy for process bast fiber in more green and sustainable way.

Transdermal Penetrating Peptide Conjugated Liposomes as Drug Delivery Carrier Comprising Macromolecules

: The aim of the study was to investigate a system using liposomes and cell penetrating peptides (CPP) for optimal transdermal delivery of macromolecules. Typical DOPE liposomes were prepared with lipid mixture (DOPE:PC:Chol = 1.5:1.5:2.0, molar ratio) and active materials (Rhodamine B; MW ~480 and Dextran-RITC; MW ~10,000). CPP-conjugated DOPE liposomescontaining active materials were prepared by conjugating the peptide to DOPE liposomes (DOPE:PC:Chol:DSPE-PEG-Mal = 1.5:1.1:2.0:0.2 or 0.4, molar ratio). Physical properties of both liposomes were evaluated, including particle size and zeta potential. The particle sizes of typical liposome and CPP-DOPE liposome were approximately 100 nm, and the zeta potential values of both liposomes were approximately -25mV and over +11mV respectively. Moreover, cellular uptake efficiency was assessed by flow cytometry (FACS). CPP-conjugated liposomes resulted higher cellular uptake efficiency compared to typical DOPE liposomes, showing higher fluorescent intensity in CPP-DOPE liposomes. In confocal laser scanning microscope (CLSM) studies, both cellular uptake and skin permeation were visually estimated. In the case of Rhodamine B, having a relatively small molecular weight,absorption into the cell was successful, and showed the highest rate of cellular uptake with CPP-DOPE liposomes. Dextran-RITC, a macromolecule with a relatively bigger molecular weight, showed similar results to Rhodamine B. In terms of skin permeation, CPP-DOPE liposomes containing Rhodamine B showed noticeable skin absorption after 4 and 18 hours, and the permeation range was wider and thicker than that with typical liposomes. For Dextran-RITC, with typical DOPE liposome, it was hardly permeable through the skin, but with CPP-DOPE liposomes, on the other hand, the skin permeations after 4 and 18 hours were remarkable. The improved cellular uptake and skin permeation of the CPP-conjugated liposomes are due to the cationic arginine-rich peptide. In vivo studies also proved that the CPP-conjugated liposomes are superior in depigmentation and anti-wrinkle studies than typical liposomes. These results demonstrate that the CPP-conjugated liposomes could also be effective for transdermal drug delivery of antioxidant and anti-aging therapeutics.

Physicochemical, functional and structural properties of the major protein fractions extracted from Cordyceps militaris fruit body

The physicochemical and functional as well as structural properties of major protein fractions (albumin, globulin, glutelin) sequentially extracted in water, salt, alkaline solution respectively from Cordyceps militaris Minfu20 fruit body were investigated. The glutelin (43.11%, w/w) was the predominant protein component of C. militaris fruit body followed by albumin (36.47%) and globulin (17.94%). The three proteins extracted from different solvents showed different characteristics, which were related to the alternation of amino acid composition, surface hydrophobicity, and structural feature. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) showed that the albumin and globulin mainly consisted of polypeptides with size < 20 kDa. The glutelin showed serious staining on the lane which may have a relatively bigger molecular weight. Intrinsic fluorescence intensity (FI) suggested glutelin contained more unfolding conformations (highest FI) which were probably resulted in a better foaming capacity of 151% and emulsion formation with the smallest size oil droplets (10.410 µm). The protein fractions showed great nutritional quality since they satisfied all recommended essential amino acid allowances for adults of Food & Agriculture Organization (FAO)/World Health Organization (WHO). Therefore, Cordyceps militaris Minfu20 fruit body proteins have potential alternative renewable edible fungi (mushroom) protein and could be used effectively as a food ingredient to improve food nutrition and product diversification compared with plant proteins.

In silico discovery of antigenic proteins and epitopes of SARS-CoV-2 for the development of a vaccine or a diagnostic approach for COVID-19

In the genome of SARS-CoV-2, the 5′-terminus encodes a polyprotein, which is further cleaved into 15 non-structural proteins whereas the 3′ terminus encodes four structural proteins and eight accessory proteins. Among these 27 proteins, the present study aimed to discover likely antigenic proteins and epitopes to be used for the development of a vaccine or serodiagnostic assay using an in silico approach. For this purpose, after the full genome analysis of SARS-CoV-2 Wuhan isolate and variant proteins that are detected frequently, surface proteins including spike, envelope, and membrane proteins as well as proteins with signal peptide were determined as probable vaccine candidates whereas the remaining were considered as possible antigens to be used during the development of serodiagnostic assays. According to results obtained, among 27 proteins, 26 of them were predicted as probable antigen. In 26 proteins, spike protein was selected as the best vaccine candidate because of having a signal peptide, negative GRAVY value, one transmembrane helix, moderate aliphatic index, a big molecular weight, a long-estimated half-life, beta wrap motifs as well as having stable, soluble and non-allergic features. In addition, orf7a, orf8, and nsp-10 proteins with signal peptide were considered as potential vaccine candidates. Nucleocapsid protein and a highly antigenic GGDGKMKD epitope were identified as ideal antigens to be used in the development of serodiagnostic assays. Moreover, considering MHC-I alleles, highly antigenic KLNDLCFTNV and ITLCFTLKRK epitopes can be used to develop an epitope-based peptide vaccine.

Experimental research on the characteristics of drag reduction and mechanical degradation of polyethylene oxide solution

ABSTRACT Polymer drag reduction agents are easy to degrade during application. The drag reduction and mechanical degradation characteristics of polyethylene oxide were investigated in this research. A rotating disk apparatus evaluated the influence of molecular weight, concentration, temperature, mechanical degradation, and ultrasonic degradation. The experimental results showed that drag reduction property was influenced by the molecular formation, flow regime, and concentration. Rotating disk apparatus is similar to test circular system regarding reduction rate measurement for polyethylene oxide, where the rotating velocity was affected by the Reynolds number. The increase in temperature is not favorable for the drag reduction of polyethylene oxide, because of the more cluster formation caused by molecular motion strengthening. Simultaneously, polyethylene oxide with bigger molecular weight and hydraulic volume would show lower optimum concentration than smaller molecular weight. Also, the mechanical and ultrasonic degradation of polyethylene oxide solution were investigated. Due to the external transfer induced by free radical reaction energy, the polyethylene oxide with bigger molecular weight and longer chains are more likely to degrade, showing bad drag reduction effect.

Organic acid-assisted preparation of highly dispersed Co/ZrO2 catalysts with superior activity for CO2 methanation

Various organic acids were investigated for preparing the highly dispersed cobalt catalysts on zirconia support, Co/ZrO2, by an acid-assisted incipient wetness impregnation. The organic acid-assisted preparation results in highly dispersed Co/ZrO2 catalysts which demonstrate superior catalytic activity with only 2 wt.% Co loading for CO2 methanation. Among the acids, the carboxylic acids with bigger molecular weight, more carboxyl groups and hydroxyl groups are more effective. Furthermore, the amino acids can also change the charge property of ZrO2 surface through controlling the solution pH and increase the metal dispersion through strong electrostatic adsorption. It is worth mentioning that, among the numerous organic acids, citric acid-assisted preparation gives Co/ZrO2 catalyst with superior catalytic activity and increased the CO2 conversion from 38% to 85% with highest turnover frequency. The linear relationship between metal dispersion and TOF with the molar ratio of acid to cobalt nCA/Co ranging from 0 to 2 demonstrates the importance of well dispersed metal particles in the enhanced activity. However, when the nCA/Co value exceeds 2 and the metal particle size further decreases, but no further enhancement is observed and the CO2 conversion even slightly decreased at the nCA/Co value of 5. The organic acids-assisted strategy can lead to increased metal dispersion and higher TOF for Co/ZrO2 catalysts; the appropriate metal dispersion corresponds to the suitable Co-ZrO2 interaction with oxygen vacancy which leads to more catalytically active sites for CO2 adsorption and catalytic hydrogenation. The organic acid-assisted strategy provides a new design approach for highly dispersed and active catalysts.

Comparison of Alleles at Gli-2 Loci of Common Wheat by Means of Two-Dimensional Electrophoresis of Gliadin

Electrophoretic mobility (EM) and molecular weight (MW) of some allelic variants of α- and β-gliadins contrlled by Gli-2 loci were compared by means of two-dimensional (APAGE × SDS) electrophoresis. Comparison of α-gliadins of the alleles Gli-A2b and Gli-A2p, of β-gliadins of the Gli-B2b and Gli-B2c, and of β-gliadins of the Gli-D2b, Gli-D2c, Gli-D2j, and Gli-D2r indicated that a gliadin with lower EM had, as a rule, bigger MW which is known to depend on the length of the polyglutamine domain of gliadin of α-type. However, allelic variants of the α-gliadin encoded by Gli-D2b and Gli-D2e differ in EM but not in apparent MW. It might be caused by a substitution of some charged/uncharged aminoacids in the polypeptide of gliadin. Allele Gli-B2o which is very frequent in up-to-date common wheat germplasm originated probably by means of unequal crossingover. Some alleles at Gli-A2 is found to control completely different blocks of gliadins and therefore might come to common wheat from different genotypes of the polymorphic diploid donor of the A genome. The results indicate that the reason of the known more vast polymorphism of gliadins controlled by Gli-2 loci as compared with Gli-1 loci is the considerable difference of the structure, first, of Gli-1 and Gli-2 loci (Gli-2 loci have more expressed genes per locus) and, second, of genes encoding gliadins of α- and γ-types (α-gliadins are shown to contain a long polyglutamine sequences highly variable in their length).

Hydrogen-Bonded Polymer Complex Thin Film of Poly(2-oxazoline) and Poly(acrylic acid).

The hydrogen-bonded polymer complex thin film of poly(2-ethyl-2-oxazoline) (PEOX) and poly(acrylic acid) (PAA) was fabricated with layer-by-layer (LbL) assembly. The film shows exponential growth at early stage and transfers to linear growth after 10 assembling cycles, and the stable thickness increment per assembling cycle in the linear region could be higher than 100 nm. The film growth should be related with polymer chain diffusion during LbL assembly. The effects of assembling time, rinsing time, temperature, pH value, concentration and molecular weight on the thin film growth were investigated. Increasing the assembly time, the temperature and the concentration is favorable to produce the thick film. Prolonging rinsing time is good for preparing smooth film. The film can be constructed below pH 4.5 while the prepared film will not completely dissolve until pH value elevates to 7.0. Molecular weight has a subtle effect on the PEOX/PAA film growth. The PEOX-PAA pair that has a big molecular weight contrast shows fast film growth in the linear region.

DETERMINATION OF SOME PHYSICAL AND CHEMICAL PROPERTIES OF PECTIN SUBSTANCES FROM THE SOLVENT CAKE OF TAGETES PATULA L. INFLORESCENCES

Big molecular weight conditions are responsible for some properties, which are absent in low molecular compounds. Therefore, its determination allows revealing of some physical and technological properties of biopolymers and prediction of the possibility of their practical application. The aim of this work was to determine an average molar weight, to study the superficial properties at the border of “solution-air” phases, and to establish an isoelectric spot of water solutions of pectin substances (PS), isolated from a solvent cake of Tagetes patula inflorescences. Materials and methods. Polysaccharide complexes were isolated from the solvent cake of Tagetes patula inflorescences of Carmen species which was left after a raw material extraction with ethanol 40% with the method of Kochetkov and M. Sinnera. The time of water and PS solutions flow out was measured by the use of a capillary Ostwald viscosimeter; different types of viscosity were calculated. The density of solutions was determined by using a picnometric method, however due to the closeness of density of the analyzed solutions and water, they were not considered in the calculation of the relative viscosity. Series of solutions with 0.01 to 0.5% concentrations were prepared from 1% PS water solutions to determine a surface activity. Monometric liquid tension variations were set in Rehbinder’s apparatus in the moment of an air bubble appearance on the surface of PS solution. Isoelectric spot (IES) of PS was determined in acetate buffer solution with pH within 3.2 to 6.2 by using the viscometer method. Results and discussion. Fractioning of the obtained polysaccharide complexes showed that efficiency of the pectin substances amounted to 2.2%. Calculation shows that an average molar weight of PS amounted to 45272 g/mol. About the degree of interaction between macromolecules of polymer and solvent, structural properties of macromolecule, the degree of its branching can be judged by the value of Huggins test. The value was found to be 1.46, which proves the low solubility of PS in water. Apparently, a biopolymer chain has been branched which worsen the solubility of macromolecules and further may promote the formation of gel condition. PS, isolated from the solvent cake of Tagetes patula, belong to the group of the surface active substances. Due to a big cross section of a molecule (S) and the high average molar weight, (45272 g/mol) molecules occupy a big volume at the surface of phase separation. We have established that macromolecule is in the isoelectric state at pH = 4.7. Conclusion. In the result of the studies using viscometer method, we have determined a molar weight of PS equal to 45272 g/mol. Huggins constant (1.46) which is connected to a low solubility of PS in water has been determined. We have established that PS, isolated from the solvent cake of Tagetes patula, are surface active. We have shown that PS macromolecule is in the state of polyamphion at pH = 4.7.

Establishment of Magnetic Microparticles-Assisted Time-Resolved Fluoroimmunoassay for Determinating Biomarker Models in Human Serum.

In order to early screen and detect suspected biomarkers from pathogens and the human body itself, tracers or reaction strategies that can act as signal enhancers have been proposed forth at purpose. In this paper, we discussed the applicability of magnetic microparticles-assisted time-resolved fluoroimmunoassay (MMPs-TRFIA) for sensitive determination of potential analytes. Hepatitis B e antigen, antibody to hepatitis B surface antigen and free triiodothyronine were used as biomarker models to explore the reliability of the method. By coupling with bioprobes, MMPs were used as immunoassay carriers to capture target molecules. Under optimal condition, assay performance, including accuracy, precision and specificity, was outstanding and demonstrated satisfactory. To further evaluate the performance of the MMPs-TRFIA in patients, a total of 728 serum samples from hospital were analyzed for three biomarkers in parallel with the proposed method and chemiluminescence immunoassay kit commercially available. Fairly good agreements are obtained between the two methods via data analysis. Not only that but the reliability of MMPs-TRFIA has also been illustrated by three different reaction models. It is confirmed that the novel method modified with MMPs has been established and showed great potential applications in both biological detection and clinical diagnosis, including big molecule protein and low molecular weight haptens.

Auto-adaptive Air Distribution and Structure Optimization of Ejector Burner for Biomass Alcohol Fuels

A plenty of studies on the utilization of biomass alcohol fuels have been conducted, but combustion efficiency and stability of this fuels still need to be improved. Based on biomass alcohol fuels (bio-methanol and bio-ethanol), this paper studied auto-adaptive air distribution characteristics and optimum structure parameters of an ejector burner by numerical simulation method. Also, an experiment was conducted to verify the numerical results. The results show that the mole air entrainment ratio (MAER) keeps almost constant when the ejector fuel nozzle exit locates at the segment between the ejector throat and the suction chamber entrance, but a bigger ratio α would lead to a higher MAER till the α is bigger than 8.5 for bio-methanol and 11.5 for bio-ethanol. The bio-ethanol fuel is more beneficial for air carrying role because of its big molecular weight. Operation pressure (Pw) has a little impact on MAER of the two fuels, but the rise of back pressure (Pb) would lead to rapid decrease of MAER for the two fuels. For the optimum structure burners, the MAER can be maintained at the value of theoretical complete combustion. Its changing rate is less than 2.3% for bio-methanol and 2.5% for bio-ethanol when the burner load changes from 30% to 120%, which is highly consistent with the experimental results. The optimum burner can distribute air supply automatically with the changing of burner load.

Advanced in solubilization methods of water-insoluble natural drugs

With the development of natural products, the research activities on the solubilization methods of water-insoluble natural products have been carried out worldwide. Big molecular weight and poor solubility of most natural active ingredients lead to a very poor oral absorption and low bioavailability, which has extremely limited their development in pharmaceutical fields and clinical application. As a result, it is necessary to find out a suitable technique to improve the solubility and enhance the oral bioavailability of insoluble natural drugs. Based on the related references published in these years, this review introduced some new techniques to improve the solubility and bioavailability of natural drugs, including prodrugs, inclusion complex, solid dispersion, cocrystals, osmotic pump, liquisolid compacts, micronization, self-microemulsifying, nanosuspensions, lipsomes, polymeric micelles and so on, and summarized the theory, characteristics, application range, application examples, problems and development direction of each technique.

Tripeptidic BACE1 inhibitors devised by in-silico conformational structure-based design

Previously reported pentapeptidic BACE1 inhibitors, designed using a substrate-based approach, were used as lead compounds for the further design of non-peptidic BACE1 inhibitors. Although these peptidic and non-peptidic inhibitors, with a hydroxymethylcarbonyl isostere as a substrate transition-state mimic, exhibited potent BACE1 inhibitory activities, their molecular-sizes appeared a little too big (molecular weight of >600daltons) for developing practical anti-Alzheimer's disease drugs. To develop lower weight BACE1 inhibitors, a series of tripeptidic BACE1 inhibitors were devised using a design approach based on the conformation of a virtual inhibitor bound to the BACE1 active site, also called 'in-silico conformational structure-based design'. Although these tripeptidic BACE1 inhibitors contained some natural amino acid residues, they are expected to be useful as lead compounds for developing the next generation BACE1 inhibitors, due to their low molecular size and unique structural features compared with previously reported inhibitors.

Research on the Application of Recycled PE in High Modulus Asphalt Mixture

In this paper, recycled PE was added directly to the asphalt mixture to prepare high modulus asphalt mixture. To study the influence of the dosage and molecular weight of recycled PE on the performance of asphalt mixture, three kinds of recycled PE with different molecular weight and three asphalt binders (Conventional, SBS Modified and PE Modified) were used to prepare eight kinds of asphalt mixture. Various tests, including dynamic modulus, wheel tracking and Lottman test, were conducted to evaluate the performance of them. The results showed that 1) the dynamic modulus of asphalt mixture modified by recycled PE is higher than the normal mixture and mixture prepared with SBS modified asphalt binder; 2) adding recycled PE directly into the asphalt mixture during mixing is more effective than preparing asphalt mixture with PE modified asphalt binder in making high modulus asphalt mixture; 3) the recycled PE used to produce high modulus asphalt mixture should have certain big molecular weight, more than 27,000, and the dosage of recycled PE should be no less than 0.4% of the total weight of asphalt mixture. The performance tests indicted the good high temperature deformation resistance property of asphalt mixture modified by recycled PE.

Effect of Molecular Weight of Long-Side-Chain of Polycarboxylic Acid Type Water-Reducer on Hydration of C&lt;sub&gt;3&lt;/sub&gt;A

Several polycarboxylic acid type water-reducing agents (PCs) with different side-chain structure have been synthesized. The effect of side-chain structure of PCs on hydration of C3A has been investigated by XRD, TG-DSC and SEM. The results show that PCs restrain hydration of C3A as a whole, but accelerate the transformation from C2AH8 to Al (OH) 3 and C3AH6; for structure of the PCs, the bigger molecular weight of long-side-chain of PCs is advantage to restrain hydration of C3A. And it also is better to formation of six-party flake hydrated products. But the little molecular weight of long-side-chain of PCs tends to form the cube-shaped hydrated products.

Effect of Modified Diatomite Addition on Sludge Properties for Membrane Fouling Alleviation in Submerged Membrane Bioreactor

To alleviate the membrane fouling in membrane bioreactor, a kind of modified diatomite was used as anti-fouling agent to examine the effect on sludge properties in submerged membrane bioreactor for synthetic domestic wastewater treatment. Three submerged membrane bioreactor setups were operated under fixed membrane flux 21.9m3/m2·h, meanwhile, modified diatomite was added into each membrane bioreactor with dosage of 0mg/L, 1000mg/L and 2000mg/L respectively. Sludge particle size, extracellular polymeric substances and molecular weight distribution were characterized as the activated sludge properties in this study. The experiment results showed that with the increase of modified diatomite dosage, the number of sludge particle size less than 10μm was declined, however, the number between 10–20μm was increased correspondingly. Total extracellular polymeric substances and big molecular weight substances were decreased remarkably with modified diatomite addition dosage of 1000mg/L. The results indicated that addition of modified diatomite could effect of sludge properties in submerged membrane bioreactor. Therefore, membrane filtration performance could be improved by modified diatomite adding which alleviate membrane fouling directly.

A New Protein Sensor Platform Based on Competitive Protein Adsorption for Thyroglobulin Detection

We report a new sensing technique of proteins using competitive proteins' displacement reaction on a surface, namely Vroman effect. A target protein displaces a pre-adsorbed weak-affinity protein; however a pre-adsorbed strong affinity protein is not displaced by the target protein. In a microfluidic device, we engineer two gold surfaces covered by two known proteins. The sensor allows selective protein detection by being displaced by a target protein on only one of the surfaces. The SPR (Surface Plasmon Resonance) sensorgrams show that three different human serum proteins, immunoglobulin G (IgG), tyroglobulin (Tg) and fibrinogen (Fib) have different adsorption strengths to the surface and the competitive adsorption of individuals controls the exchange sequence. Based on the exchange reaction, we demonstrate that the sensor has a high selectivity for Tg. Immunosensor techniques have become the dominant test methods in diagnostics, therapeutics and protein research, partially due to the highly selective molecular recognition of antibody and antigen. However, they often suffer from cross-reactivity, non-specific adsorption and lack of antibody diversity. Besides these limitations, integrating antibodies on to a transducer is a time-consuming and labor intensive process and often become the bottle neck of high yield sensors. To date, few alternative platforms for the protein detection have been active in biosensor communities. Here, we report a fundamentally different protein detection method that relies on the competitive nature of protein adsorption onto a surface, namely the Vroman effect. The Vroman effect is governed by thermodynamics as it is more thermodynamically stable in nature. By using the technique, we obviate the need to rely on antibodies and their attachment to transducers. Our approach is that one can engineer two surface pre-absorbed by two known proteins; one is a little smaller and the other is a little bigger molecular weight proteins than the target protein. Then, the pair of the surfaces becomes a highly-selective protein sensor since one is displaced an the other is not displaced by the target protein. In its first implementation, we demonstrate that three human serum proteins, IgG, Tg, and Fib, have different adsorption strengths onto a hydrophobic gold surface. The different strengths induce an exchange reaction among them. The displacement strength is ranked in the following order; Fib (340 kDa) &gt; Tg (660 kDa) &gt; IgG (150 kDa). In other words, fibrinogen can displace all other proteins while Tg only can displace IgG. Based on the results, we can identify specific target proteins without using the conventional immunosensor technique. Our results show how to detect Tg using a pair of surfaces pre-adsorbed by two known-size proteins; IgG in channel 1 and Fib in channel 2. Tg displaces IgG in channel 1 but just flows through the fibrinogen-covered surface in channel 2 without any exchange reaction. The differential measurement of the SPR angle change from channel 1 and 2 allows the detection of Tg and the angle change also indicates how many thyroglobulins replace IgG.