13 research outputs found
Shape-stable and smart polyrotaxane-based phase change materials with enhanced flexibility and fire-safety.
post-print2142 K
Lipoprotein lipase regulates Fc receptor-mediated phagocytosis by macrophages maintained in glucose-deficient medium
During periods of intense activity such as phagocytosis, macrophages are thought to derive most of their energy from glucose metabolism under both aerobic and anaerobic conditions. To determine whether fatty acids released from lipoproteins by macrophage lipoprotein lipase (LPL) could substitute for glucose as a source of energy for phagocytosis, we cultured peritoneal macrophages from normal and LPL knockout (LPL-KO) mice that had been rescued from neonatal demise by expression of human LPL via the muscle creatine kinase promoter. Normal and LPL-KO macrophages were cultured in medium containing normal (5 mM) or low (1 mM) glucose, and were tested for their capacity to phagocytose IgG-opsonized sheep erythrocytes. LPL-KO macrophages maintained in 1 and 5 mM glucose phagocytosed 67 and 79% fewer IgG-opsonized erythrocytes, respectively, than macrophages from normal mice. Addition of VLDL to LPL-expressing macrophages maintained in 1 mM glucose enhanced the macrophages' phagocytosis of IgG-opsonized erythrocytes, but did not stimulate phagocytosis by LPL-KO macrophages. Inhibition of secreted LPL with a monoclonal anti-LPL antibody or with tetrahydrolipstatin blocked the ability of VLDL to enhance phagocytosis by LPL-expressing macrophages maintained in 1 mM glucose. Addition of oleic acid significantly enhanced phagocytosis by both LPL-expressing and LPL-KO macrophages maintained in 1 mM glucose. Moreover, oleic acid stimulated phagocytosis in cells cultured in non-glucose-containing medium, and increased the intracellular stores of creatine phosphate. Inhibition of oxidative phosphorylation, but not of glycolysis, blocked the capacity of oleic acid to stimulate phagocytosis. Receptor-mediated endocytosis of acetyl LDL by macrophages from LPL-expressing and LPL-KO mice was similar whether the cells were maintained in 5 or 1 mM glucose, and was not augmented by VLDL. We postulate that fatty acids derived from macrophage LPL-catalyzed hydrolysis of triglycerides and phospholipids provide energy for macrophages in areas that have limited amounts of ambient glucose, and during periods of intense metabolic activity
Sodium alginate and Chitosan aided design of form-stable Polyrotaxane based phase change materials with ultra-high latent heat.
We prepared a series of highly porous Polyrotaxane/sodium alginate, and Polyrotaxane/Chitosan foam alloys according to a sustainable pathway by using water as the only solvent. The foam alloys were further used as supporter materials for poly (ethylene glycol) (PEG) encapsulation, to fabricate shape-stable bio-based phase change materials (PCMs). The pore morphology and the internal interface between PEG and foam alloys were characterized by scanning electron microscope (SEM). Due to the good compatibility between foam alloys and PEG, the PCM performed perfect anti-leakage properties. The introduction of sodium alginate or Chitosan ensures the shape stability of the PCMs during the phase transition. The PCMs performed good cycle stability and showed ultra-high latent heat (171.6 J g−1–189.5 J g−1). Finally, we compared the typical indicators of this work with those reported in the literature, and the comparison highlighted that the present PCMs have the significant advantages: high melting enthalpy, convenient preparation and outstanding sustainability. Notably, the work provided a sustainable idea for the design of anti-leakage and shape-stable PEG-based PCMs.pre-print1327 K
Surface engineering for cellulose as a boosted Layer-by-Layer assembly: Excellent flame retardancy and improved durability with introduction of bio-based “molecular glue”.
Layer-by-Layer (LbL) assembly was attractive as a versatile tool to address the flammability of cotton, while the washing fastness of LbL coating stayed an issue. Aiming to tackle this issue, LbL layers consisted of phenylphosphonic acid (PHA) and 3-aminopropyltriethoxysilane (APTES) was deposited on polydopamine (PDA)-coated cotton. The prepared cotton reached 31.4% of limiting oxygen index (LOI), and extinguished immediately after removing the ignitor. Peak of heat release rate (pHRR) attenuated around 36 % compared with pure cotton. A combined barrier and quenching mechanisms were proposed. Moreover, enhanced washing durability (24.1% of LOI) was achieved even after 50 detergent laundering cycles. A facile, boosted LbL approach with proposed π − π stacking interactions between PDA abundant aromatic structures and benzene ring in PHA from LbL layers, is first to put forward to construct durable efficient flame retardant (FR) cotton. This work attempted to enlighten more thoughts and design for durable FR cotton fabrics.pre-print2453 K
Population dynamics of diamondback moth, Plutella xylostella (L.) in northern China: the effect of migration, cropping patterns and climate
The diamondback moth, Plutella xylostella (L.) is the most widely distributed pest of Brassica vegetables. Control of P. xylostella has relied on insecticides and it has developed resistance to most insecticides. Although research has clarified the resistance status and mechanisms in northern China, little work has been conducted on long-term population dynamics in the regions' key vegetable growing areas.We reviewed and summarized the history of P. xylostella field management practices in northern China (Haidian, Changping, Xuanhua and Zhangbei). Moths were caught in pheromone traps throughout the cropping season and P. xylostella phenology and the general trends in abundance was analyzed using DYMEX modelling software. The initial input in the spring determined population size in all years. The seasonal phenology and variation in abundance in most years and sites was simulated suggesting that the suitable climate creates the conditions for population outbreaks, and growers' actual management level (spraying and crop hygiene) influenced population abundance.Based on temperatures and using the timing of the initial peak in pheromone trap captures as a biofix, the timing of emergence of the next generation can be forecast, and more scouting and effective regional management strategies against this pest can be developed
First Discovering of Nanoscale Tectonics in Western of Qiongnan Paleo-Tethyan Suture Zone in North Margin of South China Sea and Its Geotectonic Significance
The western part of Qiongnan Paleo-Tethyan Suture Zone in the northern margin of the South China Sea is commonly known as the Jiusuo-Lingshui fault zone. At first, it was deduced as a near EW-direction tectonic boundary zone based on the data of geophysical field. Due to the lack of direct evidence of tectonic deformation, the existence and geological significance of the boundary zone have been controversial for a long time. Through field observation, indoor polarizing microscope and SEM (scanning electron microscope) tests on the basement rocks exposed along the near NS-direction profile of Xiaomei riverbed, Duzong reservoir, Junchang bridge, and Lipen reservoir, and Hainan Island, the authors discovered ductile shear structure in the boundary zone, crystalline quartz schist, granitic gneiss, meta-quartz sandstone, and porphyritic quartz rock. The sha = ear structures were formed by regional dynamic-thermal metamorphism and are the most common ductile deformation metamorphic rock in general orogenic belt. Furthermore, the microstructure and nano structure, which often developed in the ductile shear zone, were found through microscope and SEM. Moreover, the authors discussed nanoscale characteristics of Xiaomei ductile shear zone in Hainan Island. The study results showed that the three rocks of granite, quartz schist and granitic gneiss have many kinds of nano textures and structures. Based on field actual situation of the development degree of nano particles in this shear zone, it is known that these nano textures and structures are related to shearing action. Their formation mechanism may be as follows: one is thermal decomposition of layered silicate under shearing action, the other is brittle fracture after particle plastic deformation and grinding through shearing action. Based on analysis of the Xiaomei ductile shear zone, and after comparison of SEM test results carried out to the rock samples of ductile shear zone of Taroko deep fault zone in Taiwan, we found that the characteristics of the nano particles and ones in Xiaomei ductile shear zone are comparable. According to their relations with the regional deep fault, it could be speculated that Xiaomei ductile shear zone may be closely correlated with Jiusuo-Lingshui deep fault zone in the regional tectonic belonging. These study results can provide important evidence for determination of the tectonic property and spatial position of Jiusuo-Lingshui fault zone
Inhibition of Tumor Growth by Endohedral Metallofullerenol Nanoparticles Optimized as Reactive Oxygen Species Scavenger
ABSTRACT Intraperitoneal injection of [Gd@C 82 (OH) 22 ] n nanoparticles decreased activities of enzymes associated with the metabolism of reactive oxygen species (ROS) in the tumor-bearing mice. Several physiologically relevant ROS were directly scavenged by nanoparticles, and lipid peroxidation was inhibited in this study. [Gd@C 82 (OH) 22 ] n nanoparticles significantly reduced the electron spin resonance (ESR) signal of the stable 2,2-diphenyl-1-picryhydrazyl radical measured by ESR spectroscopy. Likewise, studies using ESR with spin-trapping demonstrated efficient scavenging of superoxide radical anion, hydroxyl radical, and singlet oxygen ( 1 O 2 ) by [Gd@C 82 (OH) 22 ] n nanoparticles. In vitro studies using liposomes prepared from bovine liver phosphatidylcholine revealed that nanoparticles also had a strong inhibitory effect on lipid peroxidation. Consistent with their ability to scavenge ROS and inhibit lipid peroxidation, we determined that [Gd@C 82 (OH) The endohedral metallofullerenes recently attracted significant attention because of their special biomedical effect as chemotherapeutic medicine