汉(大)麻与其它纤维素纤维染色性能研究

本文在汉麻纤维化学组分分析的基础上，利用中温活性染料，对多种纤维素纤维的染色性能进行了测定。研究了不同组成成分对汉麻纤维染色性能的影响，比较了汉麻纤维与其它纤维素纤维的上染百分率和上染速率的差异。结果表明，果胶和木质素的含量对汉麻纤维的染色性能均有不同程度的影响，但果胶的影响较木质素更为明显，汉麻纤维的染色性能与苎麻接近，但比棉纤维要差。更低于再生纤维素纤维。     

汉(大)麻与其它纤维素纤维染色性能研究

本文在汉麻纤维化学组分分析的基础上,利用中温活性染料,对多种纤维素纤维的染色性能进行了测定。研究了不同组成成分对汉麻纤维染色性能的影响,比较了汉麻纤维与其它纤维素纤维的上染百分率和上染速率的差异。结果表明,果胶和木质素的含量对汉麻纤维的染色性能均有不同程度的影响,但果胶的影响较木质素更为明显,汉麻纤维的染色性能与苎麻接近,但比棉纤维要差,更低于再生纤维素纤维。     

Synthesis and Characterization of a Novel Preceramic Polymer for SiBNC Ceramic Fibers

A new approach for the synthesis of polymer precursor for quaternary SiBNC fibers is presented. The inexpensive, commercially available reactants n-propylamine (C₃H₇NH₂), trichlorosilane (SiHCl₃) and boron trichloride (BCl₃) were used in a simple one-step reaction. The reaction mainly involved the co-polymerization between Si-Cl, B-Cl and N-CH₂CH₂CH₃ with C₃H₇NH₂ evaporation. Characterization of synthesized polymer was performed by FT-IR and NMR. The polymer has a relatively linear-chain chemical structure, and could be easily converted into flexible green fibers by melt-spun with diameter of 24 μm. After pyrolysis process at 1000 °C under nitrogen atmosphere, SiBNC ceramic fibers were obtained with a diameter of about 19 μm. Those fibers showed average tensile strength of 1.05 GPa and it remained in the amorphous state up to 1600 °C, which made them as the promising candidates for reinforcements in ceramic matrix composites for hightemperature application.     

Design,Synthesis and Biological Evaluation of Tasiamide Analogues as Tumor Inhibitors

Eighteen analogues of the marine cytotoxic linear peptide tasiamide were designed, synthesized and screened for their inhibitory activities against the growth of human nasopharyngeal carcinoma (KB) and human non-small cell lung tumor (A549) cell lines. The results indicated that minor modifications of the C-terminuswith aromatic groups were tolerated, with the IC₅₀ values between 1.29 and 12.88 μM against these two cancer cell lines. Truncation, minor modifications at the N-terminus or elimination of the N-methyl groups in N-Me-d-Gln and/or N-Me-d-Phe residues resulted in inactive analogues.     

Synthesis and Biological Evaluation of Carbocyclic Analogues of Pachastrissamine

A series of carbocyclic analogues of naturally-occurring marine sphingolipid pachastrissamine were prepared and biologically evaluated. The analogues were efficiently synthesized via a tandem enyne/diene-ene metathesis reaction as a key step. We found that the analogue 4b exhibited comparable cytotoxicity and more potent inhibitory activity against sphingosine kinases, compared to pachastrissamine. Molecular modeling studies were conducted to provide more detailed insight into the binding mode of 4b in sphingosine kinase. In our docking model, pachastrissamine and 4b were able to effectively bind to the binding pocket of sphingosine kinase 1 as co-crystalized sphingosine. However, 4b showed a hydrophobic interaction with Phe192, which suggests that it contributes to its increased inhibitory activity against sphingosine kinase 1.     

Adsorption of Graphene Oxide onto Synthetic Fibers: Experimental Conditions

Comparative studies on the adsorption capacity of two synthetic fibers, polyamide (PA 66) and polyester (PET) pre-treated with N-cetylpyridinium chloride (PET-NCPCl), towards graphene oxide (GO) have been carried out. The fiber samples were characterized by scanning electron microscopy (FE-SEM) and Raman spectroscopy. The results of adsorption isotherms, kinetics, and zeta potential determinations as a function of the GO concentration, pH, and temperature show that at a low pH of 2.5 and a high temperature of 323 K, almost 99 % of the 75 mg/l GO solution is adsorbed onto PA 66 and 70 % onto the PET-NCPCl fibers. The interaction should be first attributed to electrostatic forces, also the adsorption data exhibited a good fit to the Freundlich isotherm model and the free energy value of 10 kJ/mol was in the range of physical adsorption, which could suggest that the interaction is driven mainly by physical forces. Due to the increasing development of wastewater treatments based on the GO reactivity with metals and cationic contaminants, synthetic fibers coated with GO could be considered an adsorbent for environmental applications.     

Cyanobacterial Metabolite Calothrixins: Recent Advances in Synthesis and Biological Evaluation

The marine environment is host to unparalleled biological and chemical diversity, making it an attractive resource for the discovery of new therapeutics for a plethora of diseases. Compounds that are extracted from cyanobacteria are of special interest due to their unique structural scaffolds and capacity to produce potent pharmaceutical and biotechnological traits. Calothrixins A and B are two cyanobacterial metabolites with a structural assembly of quinoline, quinone, and indole pharmacophores. This review surveys recent advances in the synthesis and evaluation of the biological activities of calothrixins. Due to the low isolation yields from the marine source and the promise this scaffold holds for anticancer and antimicrobial drugs, organic and medicinal chemists around the world have embarked on developing efficient synthetic routes to produce calothrixins. Since the first review appeared in 2009, 11 novel syntheses of calothrixins have been published in the efforts to develop methods that contain fewer steps and higher-yielding reactions. Calothrixins have shown their potential as topoisomerase I poisons for their cytotoxicity in cancer. They have also been observed to target various aspects of RNA synthesis in bacteria. Further investigation into the exact mechanism for their bioactivity is still required for many of its analogs.     

Preparation,Characterization and Properties of High-salt-tolerance Sodium Alginate/Krill Protein Composite Fibers

Sodium alginate (SA) and krill protein (AKP) were blended to obtain composite solution, and functional SA/AKP composite fibers were prepared via wet spinning. To further improve the salt tolerance, SA/AKP composite fibers were modified with copper sulfate aqueous solution as secondary coagulation bath because of the strong adsorption to copper ions. The CSA/AKP composite fibers with high salt tolerance have been successfully prepared. The intermolecular interaction of SA/AKP composite system and the two-order structure of protein in the composite system were characterized by Fourier transform infrared spectroscopy (FT-IR). Besides, the crystallinity, morphology, mechanical properties, salt tolerance and water resistance and thermal stability of SA/AKP composites were investigated respectively. The results showed that the adsorption rate and the adsorption capacity of the composite solution to copper ion were significantly higher than those to calcium ion. Under the effect of secondary solidification by copper sulfate, the β-sheet chain of the composite fibers increased from 41.48 % to 49.21 %, the intramolecular hydrogen bond increased from 38.18 % to 44.26 %, the intermolecular hydrogen bond decreased from 59.84 % to 54.70 % and free hydroxyl slightly decreased. The water resistance of the modified composite fibers was improved by about 22 %; when the swelling time was 25 min, the salt resistance increased by about 150 %; the number of grooves on the surface of the composite fibers obviously increased, and the grooves on the surface of CSA/AKP composite fibers and the fiber section structure were much denser; Meanwhile, copper sulfate had some influence on the crystallization, thermal stability and mechanical properties of the composite fibers.     

Thermal Characterization of Alkali Treated Kenaf Fibers and Kenaf-Epoxy Composites

Chemical treatment of natural fibers is a well-defined means of mechanical property improvement in natural fiberreinforced composites. An understanding of mechanical and thermal properties in these media is essential for evaluating heat transfer, thermal degradation, and overall performance of these composites over their product lifetime. However, very little information is available illustrating the effect of such treatment on the thermal properties of kenaf composites. Also, no study to date has reported the thermal conductivity of individual kenaf fibers. This study reports the effects of fiber treatment (in 6 % NaOH) on thermal transport in unidirectionally oriented kenaf-epoxy composites and individual kenaf fibers. The effective thermal conductivities and thermal diffusivities of chemically treated fiber composites show a general increase over untreated fiber composites (0.210 to 0.232 W/m/K at 28 °C, 0.206 to 0.234 W/m/K at 200 °C). This improvement may be attributed to improved interfacial contact between the fibers and epoxy matrix shown in microstructural images after chemical treatment. The thermal conductivity of individual fibers was evaluated at room temperature using two techniques. Results from both techniques showed slight increases after chemical treatment (0.58±0.53 to 1.0±0.13 W/m/K and 1.2±0.54 to 1.6±0.28 W/m/K) but lacked statistical significance. Any improvement in surface crystallinity after chemical treatment does not appear to affect overall fiber thermal conductivity. A better understanding of thermal transport in kenaf fibers and composites enables better estimation of the performance of these composites in different applications. Moreover, the thermal conductivities of individual fibers are useful in understanding the fiber’s contribution to conduction in different fiber reinforcement configurations.     

麻纤维厌氧生物脱胶系统的脱胶特性研究

基于具有自主知识产权的麻纤维厌氧生物脱胶系统,对苎麻、剑麻、大麻和棕榈麻进行厌氧脱胶处理。结果表明:该系统运行过程中pH值稳定在7.2左右,化学需氧量(COD)在327 mg/L以下,氨氮质量浓度在5.2 mg/L以下,能实现近零排放;试验参数条件下苎麻脱胶效果优于剑麻、大麻和棕榈麻:苎麻纤维残胶率可达1.32%(低于化学脱胶),剑麻、大麻和棕榈麻残胶率分别为16.03%、20.13%、35.49%;各纤维强力指标能够达到传统化学脱胶法水平,其中苎麻的各项指标满足《苎麻精干麻》(GB/T 20793-2015)的一等水平。     

Synthesis,Characterization, and Dyeing Performance of Thiadiazole Derivatives

N⁴-(5-methyl-1,3,4-thiadiazol-2-yl)thiazole-2,4-diamine derivatives have been synthesized by the reaction of 2-amino-5-methyl-1,3,4-thiadiazole and chloroaecetylchloride with suitable solvent, then cyclized with thiourea at reflux temperature in methanol to yield N⁴-(5-methyl-1,3,4-thiadiazol-2-yl)thiazole-2,4-diamine which was diazotized and coupled with various naphthalene acid couplers to give new series of acid dyes (AD₁-AD₁₃). All the compounds were characterized by their percentage yield, melting point, elemental analysis, UV spectra, IR spectra, and NMR spectra and dyeing performance on nylon fabric has been assessed.     

Synthesis,Characterization, and Antibacterial Activity of Cross-Linked Chitosan-Glutaraldehyde

This present study deals with synthesis, characterization and antibacterial activity of cross-linked chitosan-glutaraldehyde. Results from this study indicated that cross-linked chitosan-glutaraldehyde markedly inhibited the growth of antibiotic-resistant Burkholderia cepacia complex regardless of bacterial species and incubation time while bacterial growth was unaffected by solid chitosan. Furthermore, high temperature treated cross-linked chitosan-glutaraldehyde showed strong antibacterial activity against the selected strain 0901 although the inhibitory effects varied with different temperatures. In addition, physical-chemical and structural characterization revealed that the cross-linking of chitosan with glutaraldehyde resulted in a rougher surface morphology, a characteristic Fourier transform infrared (FTIR) band at 1559 cm⁻¹, a specific X-ray diffraction peak centered at 2θ = 15°, a lower contents of carbon, hydrogen and nitrogen, and a higher stability of glucose units compared to chitosan based on scanning electron microscopic observation, FTIR spectra, X-ray diffraction pattern, as well as elemental and thermo gravimetric analysis. Overall, this study indicated that cross-linked chitosan-glutaraldehyde is promising to be developed as a new antibacterial drug.     

Design,Synthesis and Biological Evaluation of Novel Bromophenol Derivatives Incorporating Indolin-2-One Moiety as Potential Anticancer Agents

A series of bromophenol derivatives containing indolin-2-one moiety were designed and evaluated that for their anticancer activities against A549, Bel7402, HepG2, HeLa and HCT116 cancer cell lines using MTT assay in vitro. Among them, seven compounds (4g–4i, 5h, 6d, 7a, 7b) showed potent activity against the tested five human cancer cell lines. Wound-healing assay demonstrated that compound 4g can be used as a potent compound for inactivating invasion and metastasis by inhibiting the migration of cancer cells. The structure–activity relationships (SARs) of bromophenol derivatives had been discussed, which were useful for exploring and developing bromophenol derivatives as novel anticancer drugs.     

Studies toward the Total Synthesis of Itralamide B and Biological Evaluation of Its Structural Analogs

Itralamides A and B were isolated from the lipophilic extract of Lyngbya majuscula collected from the eastern Caribbean. Itralamide B (1) showed cytotoxic activity towards human embryonic kidney cells (HEK293, IC₅₀ = 6 μM). Preliminary studies disapproved the proposed stereochemistry of itralamide. In this paper, we will provide a full account of the total synthesis of four stereoisomers of itralamide B and the results derived from biological tests of these structural congeners.     

Recyclable One-Step Extraction and Characterization of Intact Melanin from Alpaca Fibers

Melanin, a ubiquitous natural pigment, has attracted much attention in energy and nanotechnology areas in recent years. With the increasing demand for high-quality melanin materials and sustainable experimental environment, this study was conducted to achieve melanin with intact structure through recyclable extraction method using ionic liquid (IL). Melanin extracted from base dissolution and acid isolation (BA) method and acid hydrolysis (AH) method were also used for comparison. SEM and ¹³C-NMR characterizations indicated that IL treatment has retained the original structure of melanin while other methods caused particle damage to various degrees. In addition, the recycled IL (up to five times) showed good reproducibility, and the performance of extracted melanin at the 5th cycle was well-maintained.     

Synthesis and Biological Evaluation of Novel 3-Alkylpyridine Marine Alkaloid Analogs with Promising Anticancer Activity

Cancer continues to be one of the most important health problems worldwide, and the identification of novel drugs and treatments to address this disease is urgent. During recent years, marine organisms have proven to be a promising source of new compounds with action against tumoral cell lines. Here, we describe the synthesis and anticancer activity of eight new 3-alkylpyridine alkaloid (3-APA) analogs in four steps and with good yields. The key step for the synthesis of these compounds is a Williamson etherification under phase-transfer conditions. We investigated the influence of the length of the alkyl chain attached to position 3 of the pyridine ring on the cytotoxicity of these compounds. Biological assays demonstrated that compounds with an alkyl chain of ten carbon atoms (4c and 5c) were the most active against two tumoral cell lines: RKO-AS-45-1 and HeLa. Micronucleus and TUNEL assays showed that both compounds are mutagenic and induce apoptosis. In addition, Compound 5c altered the cellular actin cytoskeleton in RKO-AS-45-1 cells. The results suggest that Compounds 4c and 5c may be novel prototype anticancer agents.     

Bacterial Exopolysaccharides from Extreme Marine Habitats: Production,Characterization and Biological Activities

Many marine bacteria produce exopolysaccharides (EPS) as a strategy for growth, adhering to solid surfaces, and to survive adverse conditions. There is growing interest in isolating new EPS producing bacteria from marine environments, particularly from extreme marine environments such as deep-sea hydrothermal vents characterized by high pressure and temperature and heavy metal presence. Marine EPS-producing microorganisms have been also isolated from several extreme niches such as the cold marine environments typically of Arctic and Antarctic sea ice, characterized by low temperature and low nutrient concentration, and the hypersaline marine environment found in a wide variety of aquatic and terrestrial ecosystems such as salt lakes and salterns. Most of their EPSs are heteropolysaccharides containing three or four different monosaccharides arranged in groups of 10 or less to form the repeating units. These polymers are often linear with an average molecular weight ranging from 1 × 10⁵ to 3 × 10⁵ Da. Some EPS are neutral macromolecules, but the majority of them are polyanionic for the presence of uronic acids or ketal-linked pyruvate or inorganic residues such as phosphate or sulfate. EPSs, forming a layer surrounding the cell, provide an effective protection against high or low temperature and salinity, or against possible predators. By examining their structure and chemical-physical characteristics it is possible to gain insight into their commercial application, and they are employed in several industries. Indeed EPSs produced by microorganisms from extreme habitats show biotechnological promise ranging from pharmaceutical industries, for their immunomodulatory and antiviral effects, bone regeneration and cicatrizing capacity, to food-processing industries for their peculiar gelling and thickening properties. Moreover, some EPSs are employed as biosurfactants and in detoxification mechanisms of petrochemical oil-polluted areas. The aim of this paper is to give an overview of current knowledge on EPSs produced by marine bacteria including symbiotic marine EPS-producing bacteria isolated from some marine annelid worms that live in extreme niches.     

咖啡种间嫁接与不嫁接植株主要农艺和品质性状比较

为探明种间嫁接生产应用可行性,以解决连作咖啡园再植植株长势弱、死亡率高的问题,布置了以未嫁接的中粒种咖啡热研3号实生后代为对照,查理种16号为砧木、中粒种咖啡热研3号实生后代为接穗的种间嫁接大田试验。经过5 a的田间性状观测,结果表明：1年生种间嫁接植株株高、茎粗、冠幅、最长一级分枝长度大于未嫁接植株,但差异未达显著,种间嫁接植株一级分枝对数、最长一级分枝节数显著大于未嫁接植株;2015年单节果实数未嫁接植株显著高于嫁接植株,其余年份（2014年、2016年）差异不显著;干鲜比、百粒重、单株鲜果产量两者间差异不显著。虽然嫁接植株2015年单节果实数显著低于未嫁接植株,但种间嫁接促进了中粒种咖啡的生长,增加了单株结果节数,因而嫁接植株单株鲜果产量未显著减少。综上,嫁接不影响中粒种单株鲜果产量和果实的品质性状,该组合的种间嫁接在生产中推广应用是可行的。     

Chemical Bonding of Organic Dye onto Cotton Fibers Using Silane as Coupling Agent (I)

A derivative of an optical brightening agent (organic dye), i.e., 2,6-dibromo-4-flouroaniline (synthesized and reported previously) has been chemically bonded to cotton fabrics through a coupling agent, i.e., 3-(2-aminoethylamino)- propyltrimethoxy silane. These chemically treated cotton fabrics have been characterized by FTIR spectroscopy, color observation, tear properties determination, and UV-DRS analysis. The relevant spectra of FTIR confirm chemical bonding of the silane with cotton on one end and with the dye on the other. Comparison of the various treated and untreated cotton samples before and after washing by visual observations confirms the claim of chemical bonding of the dye with the cotton. The consistent decreasing patterns observed in tear strengths of the treated cloths with increase in concentration of the respective chemical validate modification of the cotton cloths. UV-DRS analysis of the modified cotton cloths show that the reflectance decreases with the use of silane.