河南蜂胶抗菌活性成分的研究

从蜂胶乙醇浸提液中分离到3个具有抗菌活性的结晶,经鉴定分别为芥子酸、异阿魏酸和咖啡酸,其乙醇浸提液中尚分离得到白杨素。

Enhancement of catalytic activity by homo-dispersing S_2O_8^(2–)-Fe_2O_3 nanoparticles on SBA-15 through ultrasonic adsorption

Mesoporous superacids S2O82–-Fe2O3/SBA-15(SFS)with active nanoparticles are prepared by ultrasonic adsorption method.This method is adopted to ensure a homo-dispersed nanoparticle active phase,large specific surface area and many acidic sites.Compared with bulk S2O82–-Fe2O3,Br?nsted acid catalysts and other reported catalysts,SFS with an Fe2O3 loading of 30%(SFS-30)exhibits an outstanding activity in the probe reaction of alcoholysis of styrene oxide by methanol with 100%yield.Moreover,SFS-30 also shows a more excellent catalytic performance than bulk S2O82–-Fe2O3 towards the alcoholysis of other ROHs(R=C2H5-C4H9).Lewis and Bronsted acid sites on the SFS-30 surfaces are confirmed by pyridine adsorbed infrared spectra.The highly efficient catalytic activity of SFS-30 may be attributed to the synergistic effect from the nano-effect of S2O82–-Fe2O3 nanoparticles and the mesostructure of SBA-15.Finally,SFS-30 shows a good catalytic reusability,providing an 84.1%yield after seven catalytic cycles.

Solvent Extraction of Yttrium by Task-specific Ionic Liquids Bearing Carboxylic Group

A new kind of hydrophobic ionic liquids [1-alkyl-3-（1-carboxylpropyl）im][PF6] has been synthesized, and their extraction.properties for Y（III） in the nitric acid medium was also investigated. The effects of extractant concentration, equilibrium pH of aqueous phase, salt concentration, temperature etc. were discussed. The results show that this kind of Task-Specific Ionic Liquid （TSIL） needs to be saponified before being used for the Y（III） extraction, and the extraction is-acid dependent,-and the extraction efficiency increases with the aqueous phase acldity decreasing. Furthermore, the loaded organic phase is easy to be stripped; more than 95% Y（III） could be stripped from the loaded organic phase when the stripping acidity is higher than 0.07 mol-L-1. The slope analysis technique is used to investigate the extraction mechanism, and a possible cation-exchange extraction mechanism is proposed in the oresent extraction system.

Synthesis of Mesoporous Chromium Silicates Molecular Sieves in Strong Acidic Media by Assembly of Preformed CrS1 Precursors with Triblock Copolymer

Chromium-incorporated mesoporous silica materials （MCrS） have been successfully prepared in strong acidic media by assembly of preformed CrSI precursors with triblock copolymer of the Pluronic type （P123） by a two steps procedure. Various techniques including XRD, N2 adsorption, FT-IR spectroscopy, diffuse reflectance UV-vis （DRUV-vis） and EPR were employed for the materials characterization. MCrS materials have a hexagonal structure with uniform mesopores and contain Cr（V） and Cr（VI） under low and high Cr content and that the mesoporous walls contain the MFI structure building units.

IL-23 signaling enhances Th2 polarization and regulates allergic airway inflammation

IL-23/IL-17 axis is an important regulator in various inflammatory diseases. However, the role of IL-23 in allergic airway inflammation is not well understood. In this study, we show that in an allergen-induced asthma model, mice with transgenic overexpression of IL-23R exhibited increased airway infiltration of eosinophils and Th2 cytokine production, whereas those deficient in IL-23 displayed reduced airway inflammation. In vitro, IL-23-IL-23R signaling promoted GATA-3 expression and enhanced Th2 cytokine expression. Conversely, in the absence of this signal, Th2 cell differentiation was partially inhibited. Therefore, IL-23 signaling may regulate allergic asthma through modulation of Th2 cell differentiation.

Structure and stability of Li-Mn-Ni composite oxides as lithium ion sieve precursors in acidic medium

A series of spinel Li-Mn-Ni composite oxides with theoretical chemical formula of LiNixMn2-xO4 （0〈_x〈_1.0） were synthesized by liquid phase method. Their structure and morphology were characterized by X-ray diffractometry （XRD） and scanning electron microscopy （SEM）, respectively. The stability of these Ni-substituted spinel oxides prepared at different temperatures was investigated in acidic medium as well. The results show that Ni can be brought into the spinel framework completely to form well-crystallized product when x〈_0.5 and the optimized synthesis temperature is 800℃. LiNi0.4Mn1.6O4 prepared at 800℃ can maintain the spinel structure and morphology with Li extraction ratio of 30.37%, Mn extraction ratio of 8.78% and Ni extraction ratio of 1,82% during acid treatment. The incorporated Ni not only inhibits the dissolution of Mn, but also reduces the extraction of Li due to the lattice contraction

Comparative study on photocatalytic properties of TiO_2 nanoparticles prepared in acidic medium and basic medium by hydrothermal method

In order to investigate the difference of phtotocatalytic properties of TiO2 samples prepared in different pH conditions, TiO2 nanopartieles were prepared in acidic medium and basic medium by a hydrothermal process, respectively. The samples were characterized using XRD, TEM, BET, XPS, surface photovoltage spectroscopy （SPS） and field-induced surface photovohage spectroscopy （FISPS）. Effects of temperature and pH in the hydrothermal process on particle sizes, specific surface areas, and photoeatalytic properties of the TiO2 nanoerystalline were investigated. The experimental results indicate that the photocatalysis activity of TiO2 nanoparticles prepared in basic medium （ B-TiO2 ） is superior to that in acidic medium （ A-TiO2 ）, which is ascribed to the difference of surface state between A-TiO2 and B-TiO2.

Mesoporous silica SBA-15 functionalized with phosphonate and amino groups for uranium uptake

Mesoporous silicas have a very attractive ability of sorption and enrichment of metal ions due to their huge surface area and facile functionalization by organic ligands. In this work, phosphonate-amino hifunctionalized mesoporous silica SBA-15 （PA-SBA-15） as U（VI） sorbent was fabricated through post-grafting method. The obtained mesoporous silica was character- ized by SEM, XRD, NMR and nitrogen sorption/desorption experiments, which revealed the existence of ordered mesoporous structure with uniform pore diameter and large surface area. The adsorptivity of PA-SBA-15 for U（VI） from aqueous solution was investigated using batch sorption technique under different experimental conditions. The preliminary results show that the U（VI） sorption by PA-SBA-15 is very quick with equilibrium time of less than 1 h, and the U（VI） uptake is as large as 373 mg/g at pH 5.5 under 95℃. The sorption isotherm has been successfully modeled by the Langmuir isotherm, suggesting a monolayer homogeneous sorption of U（VI） in PA-SBA-15. The sorption is pH-dependent due to the pH-dependent charge of sorbent in the aqueous solution. The thermodynamics research shows that the sorption is a feasible and endothermic process. Based on these results, PA-SBA-15 could be a promising solid phase sorbent for highly-efficient removal of U（VI） ions from waste water and enrichment of U（VI） from a solution at a very low level.

An above-room-temperature switchable molecular dielectric with a large dielectric change between high and low dielectric states

Dielectric anisotropy of anilinium perchlorate is investigated at various temperatures. Crystal structures at different temperatures reveal that significant dielectric change between low and high dielectric states is closely related to the disorder of the anilinium cation and perchlorate anion at high dielectric state; meanwhile, the conductivity after phase transition also contributes a lot to the high dielectric state.

Effect of electroacupuncture on NF-κB and NLRP3 inflammasome in uterine tissues of rats with primary dysmenorrhea

Objective: To observe the effect of electroacupuncture (EA) on nuclear factor kappa B (NF-κB) and nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) inflammasome in uterine tissues of rats with primary dysmenorrhea (PD), thus to explore the possible mechanism of EA for PD. Methods: Fifty female Sprague-Dawley (SD) rats were randomly divided into a normal group, a model group, an EA at non-acupoint group, an EA at acupoint group and a Western medicine group, with 10 rats in each group. Except for the normal group, rats in the other four groups were treated with estradiol benzoate combined with oxytocin for 11 d to establish PD rat models. From day 1 of the modeling, rats in the normal group and the model group were only properly grasped without any intervention;Guanyuan (CV 4) and Sanyinjiao (SP 6) were selected for EA treatment in the EA at acupoint group;rats in the EA at non-acupoint group were treated with EA at 5 mm away from the acupoints selected above;rats in the Western medicine group were treated with ibuprofen via gavage. Rats in each group were treated for 10-day successively. On the 11th day, except for the normal group, rats in the other groups were intraperitoneally injected with oxytocin (2 U/rat), and the writhing number within 30 min in each group was compared;the pathological changes in rat uteruses were observed by hematoxylin-eosin (HE) staining, and the pathological damage scores were evaluated. Protein expression levels of NF-κB p65, phospho-NF-κB p65, NLRP3, cysteine aspastic acid-specific protease 1 (caspase-1), interleukin (IL)-1β and IL-18 were detected by Western blot. Results: Compared with the normal group, the writhing number increased significantly (P<0.05), and the extensive exfoliation of the endometrium, severe edema, and histopathological score all increased significantly in the model group (P<0.05) as well as the protein levels of NLRP3, caspase-1, IL-1β and IL-18, and the ratio of phospho-NF-κB p65/NF-κB p65 in rat uterine tissues (all P<0.05);compared with the model group, the numbers of writhing reaction decreased within 30 min (P<0.05), the endometrial exfoliation was rare, the edema degree was mild, and the histopathological scores decreased significantly (all P<0.05) in the EA at acupoint group and the Western medicine group;compared with the model group, the phospho-NF-κB p65/NF-κB p65 ratio and the NLRP3, caspase-1, IL-1β and IL-18 protein levels of rat uterine tissues in the EA at acupoint group were significantly lower (P<0.05);compared with the model group, the caspase-1, IL-1β and IL-18 protein levels of the rat uterine tissues decreased significantly (all P<0.05), and the differences in the NLRP3 and phospho-NF-κB p65/NF-κB p65 levels were statistically insignificant (all P>0.05) in the Western medicine group;compared with the Western medicine group, the phospho-NF-κB p65/NF-κB p65 ratio, also the NLRP3, IL-1β and IL-18 protein levels of the uterine tissues decreased significantly in the EA at acupoint group (all P<0.05), while the difference in the caspase-1 level was statistically insignificant (P>0.05);there were no significant differences between the EA at non-acupoint group and the model group in any indicators (all P>0.05). Conclusion: EA at acupoints significantly improves the pain and pathological damages of PD rats. The mechanism may be related to the reduced uterine inflammation via inhibiting NF-κB phosphorylation and NLRP3 activation in uteruses of PD rats.