Physical properties of dry-heated octenyl succinylated waxy corn starches and its application in fat-reduced muffin

Waxy corn starch was modified by dry heating (130 °C, 2 h) in the presence of octenyl succinic acid (OSA) at different pHs (4, 6, and 8), and the physicochemical properties of the modified starch were evaluated. The dry-heated octenyl succinylated (DH-OS) starch was also evaluated as a partial fat substitute in a muffin. Dry heating of starch under a more acidic condition resulted in lower degree of polymerization (DP_n) but lower degree of substitution (DS). The pasting viscosity of the DH-OS starch prepared under basic conditions was higher than that of the unheated counterparts, whereas that under acidic conditions was lower. It was because the substitution favored basic conditions, and thermal degradation was accelerated by acids. The gelatinization characteristic was not significantly altered by OSA substitution and dry heating. The muffin containing the DH-OS starch had a higher specific volume and a softer texture than the muffin containing maltodextrin. Among the DH-OS starches tested, the starch prepared under acidic conditions produced muffins that had a greater volume, which was most likely due to its low molecular size. The muffin prepared with DH-OS starch at pH 6 was the softest in texture and had characteristics that were relatively close to the full-fat muffin.     

Preparation and radiopaque properties of chitosan/BaSO4 composite fibers

Chitin and chitosan have been extensively investigated as a matrix of organic/inorganic composite. Barium, one of the radiopaque inorganic materials, can provide chitosan with radiopaque property by blending of chitosan and BaSO₄. The filtered and deaerated chitosan/BaCl₂ solutions were extruded into NaOH and Na₂SO₄ coagulation bath through a nozzle by gear pump. BaSO₄ was synthesized by the reaction between BaCl₂ and Na₂SO₄ in the coagulation bath, in which acidic chitosan solution was also solidified at the same time. In XRD, the introduction of BaSO₄ into chitosan fibers reduced the inherent peak of chitosan fibers. In angiographic observation, chitosan/BaSO₄ hybrid fibers exhibited the clear contrast images which become clear with an increase in BaSO₄ content.     

Selective cationic surfactant detection in aqueous solution by polyurethane copolymer linked with metal ion indicator

Polyurethane (PU) copolymer is laterally linked with three kinds of metal ion indicator (calcein, calmagite, or eriochrome black T), with which free metal ion in aqueous solution is intended to be detected by PU color change. Metal ion detection by the indicator-PU fails due to the poor permeation of hydrophilic metal ion into hydrophobic PU layer. Instead, three surfactants with different ionic head groups, aerosol OT (AOT), cetyltrimethylammonium bromide (CTAB), and sodium dodecylsulfate (SDS), are tested for metal ion. Cationic CTAB exhibits an instant PU color change, but anionic AOT and SDS do not respond at all. Reason for the selective detection of cationic surfactant is the complex formation between cationic surfactant and indicator. Molecular interactions between PUs are affected by the laterally linked indicators based on the results by infrared spectra and differential thermal analysis. UV-vis spectra reveal that extra peak arising from the linked indicator appears compared to plain PU. The lateral linking of indicator to PU demonstrates, as well as the selective surfactant detection, a 454 % increase in tensile strength and reproducible shape recovery as high as 99 % compared to plain PU.     

白蛾黑棒啮小蜂人工复壮技术研究

白蛾黑棒啮小蜂是美国白蛾等多种鳞翅目食叶害虫蛹期的重要寄生性天敌,但采取同一寄主连续繁蜂多代,往往会降低整个种群的雌雄比及寄生率,影响其对美国白蛾的生物防治效果。该文从对小蜂补充营养及转寄主寄生2个方面对白蛾黑棒啮小蜂进行复壮技术方面的研究,以期为解决人工繁育过程中蜂种退化问题提供理论基础与技术方面的支持。     

农业科研机构科技软实力分析——以中国热带农业科学院为例

针对中国热带农业科学院14个科研单位进行问卷调查,并用SPSS软件进行频数、相关性和回归分析发现：单位风气、团队协作、科学作风、人文环境和鼓励创新等科技软实力相互间呈低度至中度相关。说明单位风气、团队协作、科学作风、人文环境和鼓励创新相互间密切联系,相互影响。只有协调好单位风气、团队协作、科学作风、人文环境和鼓励创新相互间的关系,才能做大做强做优农业科研机构,促进农业科研产业安全、科学发展,为实现农业增效农民增收作出更大贡献。     

Effect of glycerol cross-linking and PDI on the shape memory effect and mechanical properties of polyurethane

A series of shape memory polyurethane (PU) copolymers synthesized from 1,4-phenyldiisocyanate (PDI), poly(tetramethyleneglycol) (PTMG), 1,4-butanediol (BD) as a chain extender, and glycerol as a cross-linking agent were tested for the mechanical properties and the shape memory effect at the temperature 20 °C above melting temperature (T _m), and were compared with other PUs synthesized from 4,4′-methylene-bis-phenyldiisocyanate (MDI), PTMG, and BD. Mechanical properties and shape memory effect were improved substantially by adopting both PDI and glycerol. Interestingly, enthalpy of melting and T _m were not affected by the glycerol content. Vibration and shock absorption ability was investigated by measuring both loss tan δ and storage modulus with dynamic mechanical analyzer (DMA).     

红心火龙果品质及产量对稻壳有机肥施用量的响应

本研究通过探索红心火龙果营养品质和产量对稻壳有机肥施用量的响应,旨在为红心火龙果的施肥管理提供参考.以5年生'台农二号'红心火龙果为供试材料,设置3个稻壳有机肥施用水平(低施肥量L:22500 kg/hm2;中施肥量M:45000 kg/hm2;高施肥量H:90000 kg/hm2),调查火龙果全年各批次果实的还原糖、...     

橡胶树死皮病的分子生物学研究进展

橡胶树死皮（tapping panel dryness,TPD）是一种复杂的生理综合症,其发生和发展机理十分复杂。随着分子生物学的快速发展。从分子角度来研究死皮病已有一些报道。本文归纳总结近些年来橡胶树死皮病在分子生物学方面的研究工作．为进一步开展死皮研究及揭示死皮发生的分子机制提供理论参考。     

Molecular Characterization of the Von Willebrand Factor Type D Domain of Vitellogenin from Takifugu flavidus

The von Willebrand factor type D (VWD) domain in vitellogenin has recently been found to bind tetrodotoxin. The way in which this protein domain associates with tetrodotoxin and participates in transporting tetrodotoxin in vivo remains unclear. A cDNA fragment of the vitellogenin gene containing the VWD domain from pufferfish (Takifugu flavidus) (TfVWD) was cloned. Using in silico structural and docking analyses of the predicted protein, we determined that key amino acids (namely, Val¹¹⁵, ASP¹¹⁶, Val¹¹⁷, and Lys¹²²) in TfVWD mediate its binding to tetrodotoxin, which was supported by in vitro surface plasmon resonance analysis. Moreover, incubating recombinant rTfVWD together with tetrodotoxin attenuated its toxicity in vivo, further supporting protein–toxin binding and indicating associated toxicity-neutralizing effects. Finally, the expression profiling of TfVWD across different tissues and developmental stages indicated that its distribution patterns mirrored those of tetrodotoxin, suggesting that TfVWD may be involved in tetrodotoxin transport in pufferfish. For the first time, this study reveals the amino acids that mediate the binding of TfVWD to tetrodotoxin and provides a basis for further exploration of the molecular mechanisms underlying the enrichment and transfer of tetrodotoxin in pufferfish.