Fiber-specific increase of carotenoid content promotes cotton fiber elongation by increasing abscisic acid and ethylene biosynthesis

Cotton fiber is a raw material for the global textile industry and fiber quality is essential to its industrial application.Carotenoids are plant secondary metabolites that may serve as dietary components,regulate light harvesting,and scavenge reactive oxygen species.Although carotenoids accumulate predominantly in rapidly elongating cotton fibers,their roles in cotton fiber development remain poorly understood.In this study,a fiber-specific promoter proSCFP was applied to drive the expression of GhOR1Del,a positive regulator of carotenoid accumulation,to upregulate the carotenoid level in cotton fiber in planta.Fiber length,strength,and fineness were increased in proSCFP:GhOR1Del transgenic cotton and abscisic acid(ABA)and ethylene contents were increased in elongating fibers.The ABA downstream regulator GhbZIP27a stimulated the expression of the ethylene synthase gene GhACO3 by binding to its promoter,suggesting that ABA promoted fiber elongation by increasing ethylene production.These findings suggest the involvement of carotenoids and ABA signaling in promoting cotton fiber elongation and provide a strategy for improving cotton fiber quality.

Study of Thermal,Phase Morphological and Mechanical Properties of Poly(L-lactide)-b-Poly(ethylene glycol)-b-Poly(L-lactide)/Poly(ethylene glycol)Blend Bioplastics

A poly(L-lactide)-b-poly(ethylene glycol)-b-poly(L-lactide)(PLLA-PEG-PLLA)block copolymer has great potential for use as a flexible bioplastic.Highly flexible bioplastics are required for flexible packaging applications.In this work,a PEG was incorporated into block copolymer as a plasticizer by solvent casting.PLLA-PEG-PLLA/PEG blends with different blend ratios were prepared,and the plasticizing effect and miscibility of PEG in block copolymer were intensively investigated compared to PLLA/PEG blends.The results indicated that the PEG was an effective plasticizer for the block copolymer.The blending of PEG decreased glass-transition temperature and accelerated the crystallization of both the PLLA and PLLA-PEG-PLLA matrices.The PEG was completely miscible when blended with block copolymer and it improved thermal stability of the block copolymer matrix but not of the PLLA matrix.Film extensibility of PLLA-PEG-PLLA/PEG blends steadily increased as the PEG ratio increased.These non-toxic and highly flexible PLLA-PEG-PLLA/PEG bioplastics are promising candidates for several applications such as biomedical devices,tissue scaffolds and packaging materials.

Synthesis and Hydrophilic Performance of Poly(Lactic Acid)-Poly(Ethylene Glycol) Block Copolymers

Lactide was synthesized using lactic acid and stannous octoate as raw material and catalyst, respectively. Poly(lactic acid)-poly(ethylene glycol) (PLA-PEG) was prepared by lactide and poly (ethylene glycol) (PEG) via ring-opening polymerization. The most appropriate technological conditions of synthesis of lactide were researched in the paper. The copolymers were measured by Infrared spectroscopy (IR) and 1H nuclear magnetic resonance (1H NMR). The results proved that the lactide and PLA-PEG were synthesized successfully. Hydrophilic performance of the copolymer was measured by a water contact angle tester after prepared into a flat membrane. The water contact angle changed from 81.5? to 71.6?, which proved that the hydrophily of PLA-PEG was better than PLA.

De novo transcriptome assembly of Aureobasidium melanogenum CGMCC18996 to analyze theβ-poly(L-malic acid)biosynthesis pathway under the CaCO_(3) addition

β-Poly(L-malic acid)(PMLA)is a water-soluble biopolymer used in food,medicine and other industries.To date,the biosynthesis pathway of PMLA has not been fully elucidated.In this study,we sequenced the transcriptom e of strain Aureobasidium melanogenum under 20 g/L CaCO_(3) addition.The resulting sequencing reads were assembled and annotated for the differentially expressed genes(DEGs)analysis and novel transcripts identification.The result indicated that with the CaCO_(3) addition,the tricarboxylic cycle(TCA)cycle and glyoxylate pathway were up-regulated,and it also found that a non-ribosomal peptide synthetase(NRPS)like protein was highly expressed.The DEGs analysis showed a high expression level of malate dehydrogenase(MDHC)and phosphoenolpyruvate carboxykinase(PCKA)in the CaCO_(3) group,which indicated a cytosolic malate activity.We speculated that the malate should be transported to or synthesized in the cytoplasm,which was then polymerized to PMLA by the NRPS-like protein,accompanied by the up-regulated TCA cycle providing ATP for the polymerization.Depending on the analysis,we assumed that an NRPS-like protein,the TCA cycle,and the cytosolic malate together are contributing to the PMLA biosynthesis.

Three New Zn(Ⅱ)/Cd(Ⅱ) Coordination Polymers Constructed with 2-Mercaptonicotinic Acid and 1,2-Di(4-pyridyl)ethylene: Syntheses and Structure Analysis

Three new Zn（Ⅱ）/Cd（Ⅱ） coordination polymers based on 2-mercaptonicotinic acid （H2mna） with 1,2-di（4-pyridyl）ethylene （dpe） introduced as a bridging ligand have been synthesized via hydrothermal method and structurally characterized by single-crystal X-ray diffraction as well as elemental analysis and IR. As reported in this paper, [Zn2（dpe）0.5（mna）2] （1） can be classified as a two-dimensional layer structure in which the 1D chain composed of Zn（Ⅱ） and mna ligands is bridged by dpe ligands, while the complex named [Zn4（dpe）4（mna）4] （2） is a tetra-nuclear cluster compound. These two compounds are further extended to three-dimensional structures by hydrogen bonds along with C–H…π and π…π interactions. Compound 3 with general formular [Cd2（dpe）0.5（mna）2]·H2O belongs to a three-dimensional porous structure in which the 2D metal layers formed by the coordination of Cd（Ⅱ） and mna ligands are connected with the bridging of dpe ligands.

Synthesis of Acetic Acid on Pd-H_4SiW_(12)O_(40)-Based Catalysts by Direct Oxidation of Ethylene

Synthesis of acetic acid by direct oxidation of ethylene on Pd-H4SiW12O40-based catalysts was studied in a fixed-bed integral reactor and a pulse differential reactor. From the performance of the catalysts with different compositions and configurations, it is proposed that acetic acid is predominantly produced via an intermediate of acetaldehyde. This can be easily confirmed by comparing the product distributions in the integral and the differential reactors. The active sites for acetic acid formation are considered to exist mainly at the boundaries between the H4SiW12O40 and the Pd particles. The Pd-based catalysts reduced by H2/N2 have higher activities than those reduced by hydrazine, as explained by the degree of Pd dispersion obtained from the characteristics of hydrogen chemical adsorption. It was found that the Pd-Se-SiW12/SiO2 catalyst with selenium tetrachloride as a precursor was more active than that with potassium selenite, and that the acetic acid yield can be greatly increased by adding a suitable amount of dichloroethane (C2H4C12/C2H4 mole ratio=0.03) to the reactants.

Extend ethylene aromatization single-event kinetic modeling with physical and chemical descriptor based on ZSM-5 catalyst

The ethylene aromatization is critical for the methanol to aromatics and light alkane dehydroaromatization process.The single-event microkinetic(SEMK)model combining the linear free energy theory and solid acid distribution concept were established and extend for the ethylene aromatization process,which can reduce the kinetic parameters and simplify the reaction network by comparison with the SEMK model including subtype elementary steps based on the type of carbenium ions.Further introducing deactivation parametersφinto the model and applying the linear free energy model to the deactivation experimental data,the obtained deactivation parametersφindicate that the carbon deposition precursors have the greatest impact on reducing the reaction rate of single-molecular reactions and the smallest impact on the hydrogen transfer reaction.Meanwhile,according to the change of reaction enthalpy,effect of carbenium ion structure on methylation,ethylation,cyclization and endo-βscission was investigated by introducing linear free energy concept into the SEMK model.The effect of different acid strengths on elementary steps was investigated based on the acid strength distribution model,it was found that the methylation and oligomerization reactions,the ali-βscission reaction,endo-βscission reaction and the cyclization reaction were more sensitive to strong acidity sites.The physisorption and chemisorption heat are separated from the protonation heat in the linear free energy kinetic model and the acid strength distribution kinetic model,and the absolute values of the obtained physisorption and chemisorption heat increase with the carbon number of carbenium ions.Furthermore,the parameters of the acid strength distribution kinetic model were applied to propane dehydroaromatization on H-ZSM-5 and the ethane dehydroaromatization on Zn/ZSM-5 to confirm the independence of parameters in the SEMK model with the similar reaction network.

Relationships of Ethylene Evolution Rate and 1-Aminocylopropane-1-Carboxylic Acid Concentration in Grains during Filling Period with Appearance Quality of Rice

To elucidate the relationship between ethylene evolution from the grains and the appearance quality of rice, ten different rice genotypes were used to determine the ethylene evolution rate, 1-aminocylopropane-1-carboxylic acid （ACC） concentration in grains during grain filling and the appearance quality of rice, and the effects of chemical regulators on concentrations of ethylene and ACC in the grains during grain filling were also investigated to verify the roles of ethylene in the rice quality formation. The ethylene evolution rates and ACC concentrations in grains during the mid and late grain filling stages were very significantly and positively correlated with chalky kernel percentage and chalkiness. The cultivars with a low ACC concentration in grains exhibited a close amyloplast arrangement and small space between starch granules, whereas those with a high ACC concentration in grains showed a loose arrangement and wide space between the granules. Application of 1 μmol/L ACC to panicles at mid and late grain filling stages significantly loosened amyloplast arrangement and increased chalky kernel percentage, chalky area and chalkiness, and the results were reversed when 1 μmol/L amino-ethoxyvinylglycine, an inhibitor of ACC synthesis enzyme, was applied to panicles. A practice of moderate dry-wet alternate irrigation reduced ethylene evolution and ACC concentration in grains and thereby reduced chalkiness. The results suggested that ethylene and ACC in grains play an important role in the endosperm structure and appearance quality of rice, and the appearance quality would be improved by reducing ethylene evolution and ACC in grains through either variety breeding and selection, or chemical regulations or cultivation techniques.

Effects of acidity and mesoporosity development in ZSM-5 on biomass-derived ethylene oligomerization for liquid fuel synthesis

The acidities of different Si O2/Al2O3 ratio ZSM-5 zeolites, CBV3024 E, CBV5524 G and CBV8014 were investigated with temperature-programmed desorption of ammonia and diffuse reflectance infrared Fourier transform spectroscopy, and their catalytic performances were evaluated to screen the optimal CBV8014 catalyst for ethylene oligomerization. The mesoporosity development in CBV8014 zeolite was conducted by desilication in alkaline medium. The porous characteristics, structural properties and acidic properties of parent and alkali-treated CBV8014 zeolites were studied, and their catalytic performances were evaluated, indicating that CBV8014 treated by 0.2 mol/L NaO H solution has an appropriate mesoporosity development, well preservation of catalyst acidity and crystallinity, good catalytic activity and stability, and high liquid fuel yield for ethylene oligomerization. The effect of reaction pressure on ethylene oligomerization over 0.2HZ catalyst was also investigated, and JP-8 likely hydrocarbon jet fuel was obtained by using 0.2HZ catalyst at 0.344 75 MPa with a high catalyst stability and high liquid yield.

SYNTHESIS OF NOVEL BLOCK COPOLYMERS OF POLY(3-HYDROXYBUTYRIC ACID)WITH POLY(ETHYLENE GLYCOL)THROUGH ANIONIC POLYMERISATION

A novel kind of copolymer with ABA-type block structure was synthesized by anionic ring-opening polymerization of beta-butyrolactone (beta-BL) in the presence of a PEG-based dicarboxylates as macroinitiators which were prepared by the esterification of aliphatic cyclic anhydride and poly(ethylene glycol) (PEG) oligomers (M-n = 2000, 4000 and 6000) and conversion of potassium dicarboxylates. The resultant copolymers as well as the intermediates were characterized by IR, H-1-NMR and GPC.

Photodegradation Behavior of Polycaprolactone-Poly(ethylene glycol)Block Copolymer

The biodegradation behavior in vitro and in vivo of polycaprolactone-poly (ethylene glycol) block copolymer (PCE) was reported in detail. In this paper, photodegradation test of PCE was performed by exposure to UV light. The mechanical properties and the inherent viscosity of PCE samples which are subjected to photodegradation were determined. The experimental results indicated that poly (ethylene glycol) (PEO) segment in PCE copolymer is photosensitive. The photodegra-dation rate of the PCE was increased with increasing poly (ethylene glycol) content.

High-gravity technology intensified Knoevenagel condensation-Michael addition polymerization of poly (ethylene glycol)-poly (n-butyl cyanoacrylate) for blood-brain barrier delivery

Poly(ethylene glycol)-poly(n-butyl cyanoacrylate)(PEG-PBCA)is a remarkable drug delivery carrier for permeating blood-brain barrier.In this work,a novel high-gravity procedure was reported to intensify Knoevenagel condensation-Michael addition polymerization of PEG-PBCA.A series of PEG-PBCA containing different block ratios were synthesized with narrow molecular weight distribution of polydispersity indexes less than 1.1.Furthermore,the reaction time reduced 60%compared to conventional stirred tank reactor process.Chemical structures of as-prepared polymers were characterized.In vitro drug delivery performance was evaluated.The cytotoxicity of PEG-PBCA to brain microvessel endothelial cells(BMVEC)decreases with the extension of the PEG chain and the shortening of the PBCA chain.The polymer cellular uptake to BMVECs was better after improving hydrophilicity by PEG block.Results of bloodbrain barrier permeability demonstrated that medium length of PBCA chain and short PEG chain are favorable for hydrophobic Nile red permeation,while long PEG chain and short PBCA chain are beneficial to delivery water-soluble doxorubicin hydrochloride(Dox).The average apparent permeability coeffi-cient increased 1.7 and 0.25 times than that of raw Nile red and Dox,respectively.High-gravity intensi-fied condensation polymerization should have great potential in brain drug delivery system.

Poly Ethylene Glycols as Efficient Media for the Synthesis of <i>β</i>-Nitro Styrenes from <i>α</i>, <i>β</i>-Unsaturated Carboxylic Acids and Metal Nitrates under Conventional and Non-Conventional Conditions

Poly ethylene glycols (PEG-200, 400, 600, 4000 and 6000) supported reactions were conducted with certain α, β-unsaturated acids in presence of metal nitrates under solvent free (solid state) and mineral acid free conditions. The reactants were ground in a mortar with a pestle for about 30 minutes. The aromatic acids underwent nitro decarboxylation and afforded β-nitro styrene derivatives in very good yield while α, β-unsaturated aliphatic carboxylic acids gave corresponding nitro derivatives. Addition of PEG accelerated rate of the reaction enormously. Reaction times substantially decreased from several hours to few minutes followed by highly significant increase in the product yield. Among the several PEGs PEG-300 has been found to be much more effective than other PEGs.

Effect of Water Vapour on the Acidity of ZSM-5 Zeolite Used for Catalytic Cracking of Naphtha to Manufacture Ethylene and Propylene

在它与水蒸汽被对待以后，在 ZSM-5 沸石的酸味的变化被调查，并且它氨吸附上的能力是也在在产品分发上吸附了水蒸汽的水 vapour.The 效果以后学习了在石油的催化裂开期间被学习，在催化剂与都显示的磷 species.These 结果被装载以后，处于吸附能力和 ZSM-5

Ethylenediaminetetraacetic Acid Chelation for Band Keratopathy before Ab Interno Glaucoma Surgery

An 87-year-old woman with primary open-angle glaucoma presented to our hospital. Although the combined cataract and minimally invasive glaucoma surgeries (MIGS) were an appropriate surgical option, the presence of band keratopathy made it difficult to perform ab interno glaucoma surgery in her right eye (OD);therefore, the corneal opacity was removed using ethylenediaminetetraacetic acid (EDTA) chelation procedure. One month after chelation, microhook ab interno trabeculotomy and cataract surgery were performed successfully. Clear intraoperative visualization of the angle structures is critical for the success of these MIGS procedures. In glaucomatous eyes that require MIGS, EDTA chelation is a good neoadjuvant therapy for coexisting band keratopathy.

Ethylene and Spermidine in Wheat Grains in Relation to Starch Content and Granule Size Distribution Under Water Deficit

Two wheat cultivars （Triticum aestivum L.） were used to evaluate the effects ofpost-anthesis severe water deficit （SD） on starch content and granule size distribution and their relations with ethylene and spermidine （Spd）. Comparison to the well-watered （WW） treatment, SD led to lower Spd and higher 1-aminocylopropane-l-carboxylic acid （ACC） concentrations and ethylene evolution rate （EER） in grains at the critical stage of forming starch granules. Application of Spd or aminoethoxyvinylglycine （AVG） significantly reduced ACC concentration and EER and increased Spd concentration, while ethephon or methylglyoxal-bis （MGBG） had an opposite impact. The volume and surface area distribution of starch granules showed a bimodal curve, while the number distribution exhibited a unimodal curve. SD caused a marked drop in grain weight, grain number and starch content, also led to a significant reduction in the proportion （both by volume and by surface area） of B-type starch granules （〈10 Ixm）, with an increase in those of A-type starch granules （〉10 ~tm）. Application of Spd or AVG increased the proportion （both by volume and by surface area） of B-type starch granules under SD. Correlation analysis suggested that ethylene and Spd showed an antagonism relation in the formation of B-type granules. These results suggested that it would be good for the formation of B-type starch granules to have the physiological traits of higher Spd and lower ACC concentrations and ethylene emission under SD.

Ethylene Conversion to Higher Hydrocarbon over Copper Loaded BZSM-5 in the Presence of Oxygen

The successful production of higher hydrocarbons from methane depends on the stability or the oxidation rate of the intermediate products. The performances of the BZSM-5 and the modified BZSM-5 catalysts were tested for ethylene conversion into higher hydrocarbons. The catalytic experiments were carried out in a fixed-bed micro reactor at atmospheric pressure. The catalysts were characterized using XRD, NH3-TPD, and IR for their structure and acidity. The result suggests that BZSM-5 is a weak acid. The introduction of copper into BZSM-5 improved the acidity of BZSM-5. The conversion of ethylene toward higher hydrocarbons is dependent on the acidity of the catalyst. Only weaker acid site is required to convert ethylene to higher hydrocarbons. The loading of Cu on BZSM-5 improved the selectivity for higher hydrocarbons especially at low percentage. The reactivity of ethylene is dependent on the amount of acidity as well as the presence of metal on the catalyst surface. Cul%BZSM-5 is capable of converting ethylene to higher hydrocarbons. The balances between the metal and acid sites influence the performance of ethylene conversion and higher hydrocarbon selectivity. Higher loading of Cu leads to the formation of COx.

Characteristics of Titanocene Catalyst Supported on Palygorskite for Ethylene Polymerization

A series of heterogeneous catalysts with Cp2TiCl2 supported on palygorskite were prepared and evaluated by ethylene slurry polymerizations. The so-called direct supported catalyst, for which the pretreatment of palygorskite with MAO or Al（i-Bu）3 was not necessary, gave the highest activity among these supported catalysts and could be more robust than homogeneous Cp2TiCl2. With the direct supported catalyst, no significant activity loss was observed under low Al/Ti molar ratios （Al/Ti=300） and the decay of polymerization rate was slower when compared to the other supported catalysts. It was found that the surface Lewis acidity of palygorskite after thermal treatment played an important role in activation of metallocene compound and resulted in high catalyst activity.

3D打印工艺参数对PLA/PTW共混物力学性能影响的研究

采用3D打印中的熔融沉积成型(FDM)工艺制备了聚乳酸/乙烯-丙烯酸丁酯-甲基丙烯酸缩水甘油酯共聚物(PLA/PTW),通过单因素实验探究了3D打印工艺参数(喷头温度、打印平台温度和打印速度)对PLA/PTW共混物力学性能的影响,并在此基础上设计了三因素三水平正交实验,优化了3D打印的工艺参数。结果表明,共混物的冲击强度和拉伸强度均随喷头温度的增加呈现先上升后下降、均随打印平台温度的增加而增加、均随打印速度的增加出现下降的趋势。各工艺参数对PLA/PTW共混物综合力学性能的影响从大到小依次为:喷头温度、打印速度、打印平台温度,且当喷头温度为210℃、打印平台温度为80℃以及打印速度为40 mm/s时,打印出的PLA/PTW共混物的综合力学性能最佳。