Effect of Different Organic Modifiers on the Tensile Properties of PVC/EVA/Montmorillonite Composites

Poly (vinyl chloride)/ethylene-vinyl acetate/montmorillonite (PVC/EVA/OMMT) composites were prepared by melt blending method. Two kinds of montmorillonites were organically modified by trimethyloctadecyl ammonium and dimethyl bis (hydrogenated tallow) ammonium, respectively. The morphology and tensile properties of the resultant composites were discussed in terms of the modifier type and OMMT content. The PVC/EVA/OMMT composites have intercalated structure, which is independent of the polarity of the modifiers, while the tensile properties show strong dependence on the modifier type. The OMMT modified by polar modifier gives higher tensile ductile and strength of PVC/EVA/OMMT composites.

Effect of organic modifiers on the capacity factor in micellar electrokinetic chromatography

Organic modifiers were effective both to extend the migration time window and to improve the separation of very hydrophobic compounds in MEKC. An iteration method was used to determine the migration time of micelles. The quantitative relationship between the capacity factor k' and the concentration of organic modifiers was derived, which was investigated experimentally. The linear solvation energy relationships (LSER) methodology was applied to MEKC, and good linear relationships between lnk' and solvatochromic parameters of 15 solutes were obtained in the presence of organic modifier in different concentrations, which indicated a new access in MEKC to predict k' from the structural parameters of solutes. The effect of column temperature T on k' was also investigated.

Boundary slip and lubrication mechanisms of organic friction modifiers with effect of surface moisture

Surface moisture or humidity impacting the lubrication property is a ubiquitous phenomenon in tribological systems,which is demonstrated by a combination of molecular dynamics(MD)simulation and experiment for the organic friction modifier(OFM)-containing lubricant.The stearic acid and poly-α-olefin 4cSt(PAO4)were chosen as the OFM and base oil molecules,respectively.The physical adsorption indicates that on the moist surface water molecules are preferentially adsorbed on friction surface,and even make OFM adsorption film thoroughly leave surface and mix with base oil.In shear process,the adsorption of water film and desorption OFM film are further enhanced,particularly under higher shear rate.The simulated friction coefficient(that is proportional to shear rate)increases firstly and then decreases with thickening water film,in good agreement with experiments,while the slip length shows a contrary change.The wear increases with humidity due to tribochemistry revealing the continuous formation and removal of Si–O–Si network.The tribological discrepancy of OFM-containing lubricant in dry and humid conditions is attributed to the slip plane’s transformation from the interface between OFM adsorption film and lubricant bulk to the interface between adsorbed water films.This work provides a new thought to understand the boundary lubrication and failure of lubricant in humid environments,likely water is not always harmful in oil lubrication systems.

Evaluation of Average Wall Thickness of Organically Modified Mesoporous Silica

The small angle X-ray scattering of organically modified MSU-X silica prepared by co-condensation of tetraethoxysilane (TEOS) and methyltriethoxysilane (MTES) show negative deviation from Debye’s theory due to the existence of the organic interface layer. By exerting correction of the scattering negative deviation, Debye relation may be recovered, and the average wall thickness of the material may be evaluated.

Molecules with a TEMPO-based head group as high-performance organic friction modifiers

High-performance organic friction modifiers(OFMs)added to lubricating oils are crucial for reducing energy loss and carbon footprint.To establish a new class of OFMs,we measured the friction and wear properties of N-(2,2,6,6-tetramethyl-1-oxyl-4-piperidinyl)dodecaneamide referred to as C12Amide-TEMPO.The effect of its head group chemistry,which is characterized by a rigid six-membered ring sandwiched by an amide group and a terminal free oxygen radical,was also investigated with both experiments and quantum mechanical(QM)calculations.The measurement results show that C12Amide-TEMPO outperforms the conventional OFMs of glyceryl monooleate(GMO)and stearic acid,particularly for load-carrying capacity,wear reduction,and stability of friction over time.The friction and wear reduction effect of C12Amide-TEMPO is also greatly superior to those of C12Ester-TEMPO and C12Amino-TEMPO,in which ester and amino groups replace the amide group,highlighting the critical role of the amide group.The QM calculation results suggest that,in contrast to C12Ester-TEMPO,C12Amino-TEMPO,and the conventional OFMs of GMO and stearic acid,C12Amide-TEMPO can form effective boundary films on iron oxide surfaces with a unique double-layer structure:a strong surface adsorption layer owing to the chemical interactions of the amide oxygen and free radical with iron oxide surfaces,and an upper layer owing to the interlayer hydrogen-bonding between the amide hydrogen and free radical or between the amide hydrogen and oxygen.Moreover,the intralayer hydrogen-bonding in each of the two layers is also possible.We suggest that in addition to strong surface adsorption,the interlayer and intralayer hydrogen-bonding also increases the strength of the boundary films by enhancing the cohesion strength,thereby resulting in the high tribological performance of C12Amide-TEMPO.The findings in this study are expected to provide new hints for the optimal molecular design of OFMs.

Current advances of biocontainment strategy in synthetic biology

Synthetic biotechnology has led to the widespread application of genetically modified organisms(GMOs)in biochemistry, bioenergy, and therapy. However, the uncontrolled spread of GMOs may lead to genetic contamination by horizontal gene transfer, resulting in unpredictable biosafety risks. To deal with these challenges, many effective methods have been developed for biocontainment. In this article, we summarize and discuss recent advances in biocontainment strategies from three aspects: DNA replication, transcriptional regulation, and protein translation. We also briefly introduce the efforts in the biocontainment convention, such as the recent publication of the Tianjin Biosecurity Guidelines for the Code of Conduct for Scientists.

Construction of the Plasmid Reference Molecule for Detection of Transgenic Soybean MON89788

[Objective] The aim was to construct a plasmid reference molecule (PRM) for detection of transgenic soybean MON89788. [Method] the lectin gene sequence,3'-junction and 5'-junction sequence between host plant DNA integrated DNA of MON89788 soybean were amplified independently,and the three fragments were cloned into the cloning vector pMD18-T in order through molecular manipulation method to construct pMD-LM3M5,the applicability of the constructed novel PRM was tested. [Result] Sequencing confirmation result showed that the PRM was 3 700 bp in length,containing 1 029 bp of recombined DNA fragment. The limits of qualitative detection of the PRM were 10 copies. [Conclusion] The PRM constructed in this study was suitable for the identification of MON89788 event.

Detection of Genetically Modified Crops by Combination of Multiplex PCR and Low-density DNA Microarray

Objective To develop a technique for simultaneous detection of various target genes in Roundup Ready soybean by combining multiplex PCR and low-density DNA microarray. Methods Two sets of the multiplex PCR system were used to amplify the target genes in genetically modified （GM） soybean. Seventeen capture probes （PCR products） and 17 pairs of corresponding primers were designed according to the genetic characteristics of Rroundup Ready soybean （GTS40-3-2）, maize （MonS10, Nk603, GA21）, canola （T45, MS1/RF1）, and rice （SCK） in many identified GM crops. All of the probes were categorized and identified as species-specific probes. One negative probe and one positive control probe were used to assess the efficiency of all reactions, and therefore eliminate any false positive and negative results. After multiplex PCR reaction, amplicons were adulterated with Cy5-dUTP and hybridized with DNA microarray. The array was then scanned to display the specific hybridization signals of target genes. The assay was applied to the analysis of sample of certified transgenic soybean （Roundup Ready GTS40-3-2） and canola （MS1/RF1）. Results A combination technique of multiplex PCR and DNA microarray was successfully developed to identify multi-target genes in Roundup Ready soybean and MS 1/RF1 canola with a great specificity and reliability. Reliable identification of genetic characteristics of Roundup Ready of GM soybean from genetically modified crops was achieved at 0.5% transgenic events, indicating a high sensitivity. Conclusion A combination technique of multiplex PCR and low-density DNA microarray can reliably detect and identify the genetically modified crops.

Influence of structural factors on the tribological performance of organic friction modifiers

The influence of structural factors on the lubrication performance of organic friction modifiers(OFMs)formulated in Group V(polyol ester oil)base oil was studied using a ball-on-disk tribometer.The results show that OFMs can mitigate friction under heavy loads,low sliding speeds,and high temperatures.These conditions are commonly encountered in internal-combustion engines between cylinder liners and piston rings.The reduction in friction is ascribed to the boundary lubrication film containing the OFM.The chemical composition analysis of the metal disk surface using energy dispersive X-ray spectroscopy(EDS)confirmed the presence of a protective film of OFM on the wear track,albeit inconsistently deposited.Although the adsorption of the OFM on the metal surface was observed to be dependent on the chemical reactivity of the functional groups,levels of unsaturation,and hydrocarbon chain length of the OFM,the frictional performance was not always directly correlated with the surface coverage and tribofilm thickness.This implies that the friction reduction mechanism can involve other localized processes at the interface between the metal surface and lubricant oil.The occasional variation in friction observed for these OFMs can be attributed to the stability and durability of the boundary film formed during the rubbing phase.

Constructing the barley model for genetic transformation in Triticeae

Barley（Hordeum vulgare L.） is one of the oldest domesticated crops, showing dramatic adaptation to various climate and environmental conditions. As a major cereal crop, barley ranks the 4th after wheat, maize and rice in terms of planting area and production all over the world. Due to its diploid nature, the cultivated barley is considered as an ideal model to study the polyploid wheat and other Triticeae species. Here, we reviewed the development, optimization, and application of transgenic approaches in barley. The most efficient and robust genetic transformation has been built on the Agrobacterium-mediated transfer in conjunction with the immature embryo-based regeneration. We then discussed future considerations of using more practical technologies in barley transformation, such as the T-DNA/transposon tagging and the genome editing. As a cereal crop amenable to genetic transformation, barley will serve as the most valuable carrier for global functional genomics in Triticeae and is becoming the most practical model for generating value-added products.

Luminescence Quenching Behavior of Oxygen Sensing ORMOSIL Films Based on Ruthenium Complex

An organically modified silicate(ORMOSIL) based optical sensor response to gaseous O2 or O2 dissolved in water is presented. The oxygen sensing film mechanism is based on the principle of fluorescence quenching of tris(4,7-diphenyl-l , 10-phenanthroline) ruthenium ( ) ([Ru(dpp)3]2+), which has been entrapped in a porous ORMOSIL film. In order to establish optimum film-processing parameters, comprehensive investigations, including the effects of the polarity and the hydrophobicity of the sensing film on oxygen quenching response and response time, were carried out. The film hydrophobicity increased as a function of dimethyl-dimethoxysilane (DiMe-DMOS) content, which is correlated with enhanced oxygen sensor performance. The sensor developed in the present work exhibits the advantages of fast response time and good reversibility. The detection limits are 0. 5 % and 0. 3 g/mL for O2 in the gaseous and the aqueous phases, respectively.

Evaluation of genetically modified rice detection methods 2011/884/EU and 2008/289/EC proposed by the European Union

Increases in the number of cases of identified genetically modified （GM） rice contamination can be traced back to the first Rapid Alert System for Food and Feed （RASFF） in 2006. In response to the lack of reliable detection methods, Decision 2011/884/EU proposed that new screening methods replace Decision 2008/289/EC, to identify all possible GM rice products originating in China. However, the synergy brands （SYBR） Green real-time PCR assay proposed by Decision 2011/884/EU has been shown to lack conformity with other TaqMan methods currently in use. To evaluate the specificity and repeatability of the methods recommended in Decision 2011/884/EU and Decision 2008/289/EC, we collected 74 rice products originating from six countries or districts. The 74 rice samples were tested using the Decision 2011/884/EU and Decision 2008/289/ EC methods. The parallel use of different instruments and reagents were used for testing in parallel, and the results were analyzed statistically. To avoid the limitations of specific laboratories, eight GM organism detection laboratories in China participated in a collaborative trial. In our tests, 24.3% （18/74） of the samples tested were positive with the SYBR Green real-time PCR assay using the Decision 2011/884/EU method, but were negative with the TaqMan real-time PCR assay using the Decision 2011/884/EU and Decision 2008/289/EC methods. Sequencing the PCR-amplified CrylA（b/c） genes in three samples （6, 30 and 43） showed that the products consisted of primer dimers rather than the targeted sequence. The combined experimental results showed that testing for the nopaline synthase gene （NOS） of Agrobacterium tumefasciens terminator and CrylA（b/c） produced false-positive results when the Decision 2011/884/EU method was used. Because of the high rate of false-positive results, the Decision 2011/884/EU SYBR Green method to detect GM rice requires improvement.

Double-Mesopore V-MSU-X Silica and its Pure Siliceous Derivative Prepared by One Synthesis System

Non-ionically templated organo-modified MSU-2 mesoporous silicas have been prepared in neutral medium by co-condensation TEOS and vinyltriexoylsiloxane (VTES) and exhibit highly symmetric bimodal mesopore systems. A bromination reaction of V-MSU-2 provides evidence for attachment of most vinyl groups to the accessible surface within the channels. Further, siliceous MSU-2 materials with double pore size have been obtained from calcination of so-produced organo-modified MSU-2 and demonstrate the immense flexibility of the non-ionic templating system.

An efficient method to extract DNA from refined rapeseed oil

Genetically modified oilseeds were used as processing raw material for edible oils. The protection of consumer rights to information as well as the genetically modified orgamisms （GMO） labe-ling polily required analytical methods to determine whether the oils contained genetically modified ingre-dient or not. Polymerase chain reaction （PCR） - based method was used commonly to determine the presence of GMOs. Adulteration attracted peoples concern also. Thus it was crucial that enough DNA ex-tracts can be obtained successfully from oil samples. For the purpose, three DNA extraction methods （modified emulsification method, the kits Wizard Magnetic DNA purification system for food and Nucleospin Food） ,were applied to 3 different grades of rapeseed oil samples. Those methods were compared by the amplification of Brassica napus reference gene CruA using real - time PCR. The results demonstra-ted that both the modified emulsification and the Nucleospin methods were able to extract enough DNA from refined oils. The modified emulsification method was superior to the kit of Nucleospin food due to smaller volume of required sample.

Comparison of GMO Safety Management Policies in Major Countries and Regions

With the rapid development of genetic technology,the application of genetically modified crops has brought revolutionary changes to the global agricultural production and agricultural trade patterns,and has played an important role in ensuring human health,environmental safety and sustainable agricultural development.In order to strengthen genetically modified organisms(GMO)safety management,countries around the world have formulated GMO safety management policies adapted to their own national conditions with reference to internationally accepted practices.In this study,we carried out comparative studies among the United States,the European Union,Japan and other developed countries or regions and China from the aspects of regulations and management institutions,safety evaluation systems,and label management,so as to provide references for the improvement of China's GMO safety management policies.

Effects of GMO Agricultural Products on Living Things

By obtaining changes on gene sequences of living things with the applied biotechnological methods;The idea of“Genetically Modified Organisms(GMO)”,which aims to bring the living creature in question the original gene combinations with the desired characteristics,came to life in the late twentieth century.Despite the high probability that hunger problems may increase with the increasing world population;It is thought that plant breeding with classical farming methods will be insufficient in solving these problems.With various GMO applications developed all over the world,it aims to produce solutions to these problems.With the presence of GMO,it was possible to increase the shelf life of qualitative and quantitative values of the existing foods.In addition,decreases in agricultural use of pesticides used in agricultural struggle and threatening human health with GMO production are noteworthy.However,some concerns about anomalies that may occur in living things fed GMO products remain on the agenda.Because,in the long term,there is no clear and precise information that GMO will not have negative effects on living things;There are many recorded incidents showing their negative effects.

Isoflavone and Mineral Content in Conventional and Transgenic Soybean Cultivars

The objective of this study was to evaluate the differences in composition among six brands of conventional soybean and six genetically modified cultivars (GM). We focused on the isoflavones profile and mineral content questioning the substantial equivalence between conventional and GM organisms. The statement of compliance label for conventional grains was verified for the presence of genetic modified genes by real time polymerase chain reaction (PCR). We did not detect the presence of the 35S promoter in commercial samples, indicating the absence of transgene insertion. For mineral analysis, we used the method of inductively coupled plasma-optical emission spectrometry (ICP-OES). Isoflavones quantification was performed by high performance liquid chromatography (HPLC). The results showed no statistical difference between the conventional and transgenic soybean groups concerning isoflavone content and mineral composition. The concentration of potassium, the main mineral component of soy, was the highest in conventional soybeans compared to that in GM soy, while GM samples presented the highest concentrations of iron.

Regulation of gene-edited plants in Europe:from the valley of tears into the shining sun?

Some 20 years ago,the EU introduced complex regulatory rules for the growth of transgenic crops,which resulted in a de facto ban to grow these plants in fields within most European countries.With the rise of novel genome editing technologies,it has become possible to improve crops genetically in a directed way without the need for incorporation of foreign genes.Unfortunately,in 2018,the European Court of Justice ruled that such gene-edited plants are to be regulated like transgenic plants.Since then,European scientists and breeders have challenged this decision and requested a revision of this outdated law.Finally,after 5 years,the European Commission has now published a proposal on how,in the future,to regulate crops produced by new breeding technologies.The proposal tries to find a balance between the different interest groups in Europe.On one side,genetically modified plants,which cannot be discerned from their natural counterparts,will exclusively be used for food and feed and are-besides a registration step-not to be regulated at all.On the other side,plants expressing herbicide resistance are to be excluded from this regulation,a concession to the strong environmental associations and NGOs in Europe.Moreover,edited crops are to be excluded from organic farming to protect the business interests of the strong organic sector in Europe.Nevertheless,if this law passes European parliament and council,unchanged,it will present a big step forward toward establishing a more sustainable European agricultural system.Thus,it might soon be possible to develop and grow crops that are more adapted to global warming and whose cultivation will require lower amounts of pesticides.However,there is still a long way to go until the law is passed.Too often,the storm of arguments raised by the opponents,based on irrational fears of mutations and a naive understanding of nature,has fallen on fruitful ground in Europe.

Fluorescent AIE dots encapsulated organically modified silica (ORMOSIL) nanoparticles for two-photon cellular imaging

2,3-Bis(4-(phenyl(4-(1,2,2-triphenylvinyl)phenyl)amino)phenyl) fumaronitrile (TPE-TPA-FN or TTF), which possesses aggregation-induced emission (AIE) characteristic, is doped in organically modified silica (ORMOSIL) nanoparticles. By increasing the weight ratio of TTF to the precursor of silica nanoparticles (the quantities of the precursors were kept the same), the fluorescence intensity of nanoparticles increased correspondingly, due to the formation of larger AIE dots in the cores of ORMOSIL nanoparticles. The fluorescent and biocompatible nanoprobes were then utilized for in vitro imaging of HeLa cells. Two-photon fluorescence microscopy clearly illustrated that the nanoparticles have the capacity of nucleus permeability, as well as cytoplasm staining towards tumor cells. Our experimental results may offer a promising method for fast and bright fluorescence imaging, as well as bio-molecule/drug delivery to cell nucleus.

Effect of algal flocculation on dissolved organic matters using cationic starch modified soils

Modified soils（MSs） are being increasingly used as geo-engineering materials for the sedimentation removal of cyanobacterial blooms. Cationic starch（CS） has been tested as an effective soil modifier, but little is known about its potential impacts on the treated water.This study investigated dissolved organic matters in the bloom water after algal removal using cationic starch modified soils（CS-MSs）. Results showed that the dissolved organic carbon（DOC） could be decreased by CS-MS flocculation and the use of higher charge density CS yielded a greater DOC reduction. When CS with the charge density of 0.052, 0.102 and0.293 meq/g were used, DOC was decreased from 3.4 to 3.0, 2.3 and 1.7 mg/L, respectively.The excitation–emission matrix fluorescence spectroscopy and UV254 analysis indicated that CS-MS exhibits an ability to remove some soluble organics, which contributed to the DOC reduction. However, the use of low charge density CS posed a potential risk of DOC increase due to the high CS loading for effective algal removal. When CS with the charge density of 0.044 meq/g was used, DOC was increased from 3.4 to 3.9 mg/L. This study suggested, when CS-MS is used for cyanobacterial bloom removal, the content of dissolved organic matters in the treated water can be controlled by optimizing the charge density of CS. For the settled organic matters, other measures（e.g., capping treatments using oxygen loaded materials） should be jointly applied after algal flocculation.