Anti-anxiety effect of Valeriana jatamansi Jones extract via regulation of the hypothalamus-pituitary-adrenal axis

BACKGROUND： Hypothalamus-pituitary-adrenal （HPA） axis dysfunction has been closely linked to anxiety. Previous studies have shown that Valeriana jatamansi Jones extract exhibits clear anxiolytic effects, but it is unclear about the mechanism underlying regulation of the HPA axis dysfunction in these anxiolytic effects. OBJECTIVE： To observe the effects of Valeriana jatamansi Jones （Zhizhu Xiang） extract on HPA axis function in a rat model of anxiety, and to compare these effects with positive control estazolam. DESIGN, TIME AND SETTING： Randomized, controlled, animal experiment was performed at Chengdu University of Traditional Chinese Medicine, China, between February and September in 2006. MATERIALS： Estazolam was purchased from Shanghai Jiufu Pharmaceutical, China; Valeriana jatamansiJones was purchased from the Lotus Pond Market for Chinese Herbal Medicine in Chengdu. It consisted of iridoids and flavonoid components. METHODS： A total of 72 Sprague Dawley rats, aged 2 months, were randomly assigned to 6 groups low-, medium-, and high-dose Valerianajatamansi Jones groups intragastrically injected with 0.3, 0.6, and 0.9 g/kg per day Valerianajatamansi Jones extract, respectively; estazolam group intragastrically injected with 1.5 mg/kg per day estazolam; model and normal groups administered 5 mL physiological saline. Anxiety was established in all groups, except the normal group, through the use of elevated plus-maze test at 7 days following drug administration. MAIN OUTCOME MEASURES： Blood β-endorphin and corticosterone levels were determined using enzyme-linked immunosorbent assay following treatment with ValerianajatamansiJones extract. Expressions of HPA axis-related genes were measured by cDNA microarray. RESULTS： Blood β-endorphin and corticosterone levels were significantly greater in the model group than in the normal group. Compared with the model group, levels decreased with Valeriana jatamansi Jones extract or estazolam treatment, particularly in the low-dose Valeriana jatamansi Jones group （P〈 0.01）. cDNA microarray results demonstrated that corticotropin-releasing hormone and Orexin, which are associated with HPA axis function, were differentially expressed; expression increased in the model group, but decreased in rats treated with Valerianajatamansi Jones extract. CONCLUSION： Valerianajatamansi Jones extract plays a role in regulating HPA axis function in a rat model of anxiety, and this effect was superior to estazolam.

In Situ Synthesis of Cuprous Oxide/Cellulose Nanofibers Gel and Antibacterial Properties

Cellulose nanofibers were synthesized by acetobacter xylinum(xylinum 1.1812).The cellulose nanofibers with 30-90 nm width constructed three-dimension network gel,which could be used as a wound dressing since it can provide moist environment to a wound.However,cellulose nanofibers have no antimicrobial activity to prevent wound infection.To achieve antimicrobial activity,the cellulose nanofibers can load cuprous oxide(Cu2O)particles on the surface.The cuprous oxide is a kind of safe antibacterial material.The copper ions can be reduced into cuprous oxides by reducing agents such as glucose,N2H4 and sodium hypophosphite.The cellulose nanofibers network gel was soaked in CuSO4 solution and filled with copper ions.The cuprous oxide nanoparticles were in situ synthesized by glucose and embedded in cellulose nanofibers network.The morphologies and structure of the composite gel were analyzed by FESEM,FTIR,WAXRD and inductively coupled plasma(ICP).The sizes of Cu2O embedded in cellulose nanofibers network are 200-500 nm wide.The peak at 605 cm−1 attributed to Cu(I)-O vibration of Cu2O shits to 611 cm−1 in the Cu2O/cellulose composite.The Cu2O/cellulose nanofibers composite reveals the obvious characteristic XRD pattern of Cu2O and the results of ICP show that the content of Cu2O in the composite is 13.1%.The antibacterial tests prove that the Cu2O/cellulose nanofibers composite has the high antibacterial activities which is higher against S.aureus than against E.coli.

Effects of different carbon sources on the removal of ciprofloxacin and pollutants by activated sludge:Mechanism and biodegradation

This research investigated the effects of ciprofloxacin(CIP)(0.5,5,and 20 mg/L)on SBR systems under different carbon source conditions.Microbial community abundance and structure were determined by quantitative PCR and high-throughput sequencing,respectively.The biodegradation production of CIP and possible degradation mechanism were also studied.Results showed that CIP had adverse effects on the nutrient removal from wastewater.Compared with sodium acetate,glucose could be more effectively used by microorganisms,thus eliminating the negative effects of CIP.Glucose stimulated the microbial abundance and increased the removal rate of CIP by 18%–24%.The mechanism research indicated that Proteobacteria and Acidobacteria had a high tolerance for CIP.With sodium acetate as a carbon source,the abundance of nitrite-oxidizing bacterial communities decreased under CIP,resulting in the accumulation of nitrite and nitrate.Rhodanobacter and Microbacterium played a major role in nitrification and denitrification when using sodium acetate and glucose as carbon sources.Dyella and Microbacterium played positive roles in the degradation process of CIP and eliminated the negative effect of CIP on SBR,which was consistent with the improved removal efficiency of pollutants.

Observations and modeling of flat subduction and its geological effects

Flat subduction refers to low-angle(<10°) or sub-horizontal subduction of oceanic slabs. Flat subduction is only recognized in ~10% of present-day subduction zones, but its impact on the behavior of the overriding plate is particularly strong.For example, flat subduction zones are typically associated with stronger earthquakes. The deformation caused by typical flat subduction will transfer from the trench to the overriding continental interior and form a broad magma belt. The formation mechanism of flat subduction has been linked to the relative buoyancy of subducted oceanic plateaus, overthrusting of the overriding plate, hydrodynamic suction, and trench retreat. However, these mechanisms remain debated. This paper systematically analyzes and summarizes previous studies on flat subduction, and outlines the possible geological effects of flat subduction, such as intracontinental orogeny and magmatism. Using examples from numerical modeling, we discuss the possible formation mechanisms. The most important factors that control the formation of flat subduction are associated with overthrusting of the overriding plate and the arrival of an oceanic plateau at the subduction zone. In addition, trench retreat is necessary to enable flat subduction. Hydrodynamic suction contributes to the reduction of the slab dip angle, but is insufficient to form flat subduction. Future numerical modeling of flat subduction should carry out three-dimensional high-resolution thermo-mechanical simulation, considering the influence of crustal eclogitization(negative buoyancy) and mantle serpentinization(positive buoyancy) of oceanic lithosphere, in combination with geological and geophysical data.

微塑料在土壤中的赋存特征、吸附和迁移机制

塑料污染已成为备受关注的全球环境问题,土壤是塑料的主要汇集地之一,进入到土壤中的塑料会经过物理、化学和生物老化过程降解为微塑料.由于微塑料具有粒径小、难降解等特点,容易吸附土壤环境中共存的污染物,如有机污染物和重金属等,进而发生共迁移.本文总结了微塑料在全球不同地区土壤中的赋存特征,并探讨了土壤中微塑料的可能来源(农业地膜、工业活动、污水污泥等);归纳了土壤中微塑料对共存有机污染物和重金属的吸附机制以及影响因素(微塑料的理化性质和环境条件),微塑料吸附有机污染物和重金属的机制均包括孔隙填充作用、范德华力、静电力和阳离子-π键.除此之外,微塑料吸附有机污染物的机制还包括疏水作用、分配作用、氢键、π-π键、卤素键、负电荷辅助氢键和CH/π键;而络合(螯合)作用和离子交换在微塑料吸附重金属过程中起到了重要作用.综述了微塑料在土壤中的迁移机制(物理截留、静电力、疏水作用、氢键和络合作用等)以及影响因素;并进一步讨论了微塑料吸附和迁移行为对土壤理化性质及其生态毒性的影响.最后,对土壤中微塑料环境行为研究进行了展望.本文对于客观评价微塑料在土壤中的归趋和生态风险具有重要意义.