木质素作为抗氧化剂的应用研究

研究了木质素潜在的抗氧化作用.对来源于甘蔗、木质素磺酸盐和橘子等工业用木质素局部施用可能引起的眼刺激和皮肤刺激进行了探讨.试验表明,所研究的木质素对眼和皮肤均无害.针对木质素的高抗氧化性研究,以及相应的对眼和皮肤的安全性研究,为木质素在化妆品配方中的应用开拓了新的方向.     

Knockdown of ephrin-A5 expression by 40% does not affect motor axon growth or migration into the chick hindlimb

Bidirectional signaling between Eph receptor tyrosine kinases and their cell-surface protein signals, the ephrins, comprises one mechanism for guiding motor axons to their proper targets. During projection of motor axons from the lateral motor column (LMC) motor neurons of the spinal cord to the hindlimb muscles in chick embryos, ephrin-A5 has been shown to be expressed in the LMC motor axons until they reach the base of the limb bud and initiate sorting into their presumptive dorsal and ventral nerve trunks, at which point expression is extinguished. We tested the hypothesis that this dynamic pattern of ephrin-A5 expression in LMC motor axons is important for the growth and guidance of the axons to, and into, the hindlimb by knocking down endogenous ephrin-A5 expression in the motor neurons and their axons. No perturbation of LMC motor axon projections was observed in response to this treatment, suggesting that ephrin-A5 is not needed for LMC motor axon growth or guidance.     

Dietary induction of cholesterol gallstones in hamsters from three different sources

Cholesterol gallstones were produced in young male, golden Syrian hamsters, obtained from three different suppliers, by administering a nutritionally adequate, semipurified diet for periods of either 5 or 10 weeks. The major components of the lithogenic diet were casein, cornstarch, butterfat, corn oil and 0.3% cholesterol. The hamsters were obtained from Sesco, Harlan Sprague-Dawley (Engle hamster) and Charles River (Lakeview hamster). There were profound differences among the three groups with respect to gallstone formation and cholesterol metabolism: The highest incidence of gallstones occurred in Sesco hamsters, 44.4% and 63.6% after 5 and 10 weeks on the lithogenic diet, respectively. In the Engle hamster, after a 5-week feeding, cholesterol crystals and gallstones were absent. When the feeding period was extended to 10 weeks, cholesterol gallstones were present in 45.5% of the animals. In the Lakeview hamsters, neither gallstones nor cholesterol crystals were found in the gallbladder after a 5-week period. After 10 weeks, cholesterol gallstones were found in only a single hamster. In all groups, the lithogenic diet produced large increases of liver, serum and biliary cholesterol concentrations and increased liver weights. When the animals were fed for 5 weeks, only the bile of Sesco hamsters became supersaturated. Supersaturated bile was induced in all groups after a 10-week feeding of the lithogenic diet with cholesterol saturation ranging from 1.47 to 1.97. These data indicate that it is possible to induce cholesterol gallstones in hamsters by means of a nutritionally adequate, semipurified diet of moderate cholesterol content. The source of the animals appears to be an important variable, because there were significant differences among the hamsters of differing origins, in cholesterol metabolism and rates of gallstone formation.     

Different food sources affect the gustatory response of Anaphes iole,an egg parasitoid of Lygus Spp

The gustatory response of female Anaphes iole wasps to naturally occurring carbohydrates, a commercial food source, and host (Lygus lineolaris) frass was determined. Wasps responded to all 14 of the sugars at the highest concentration tested (2 M). At this concentration, sucrose, glucose, maltose, melezitose, fructose, and erlose all elicited <90% acceptance. The lowest concentration that evoked a response (=acceptance threshold) for these sugars was >1/256 M, with the exception of glucose, which was 1/16 M. Raffinose, trehalose, mannose, galactose, melibiose, rhamnose, stachyose, and lactose led to >50% gustatory response by the wasps at 2 M, and were categorized as moderately stimulatory sugars. The acceptance threshold for these sugars was <1/4 M, with the exception of raffinose, which was 1/256 M. In trials with moderately stimulatory sugars combined with either sucrose or maltose, only the rhamnose+maltose mixture significantly inhibited the gustatory response of A. iole. Food and water deprived parasitoids readily accepted the moderately stimulatory sugars. Eliminade^TM, a commercial food supplement, was readily accepted (92%) by A. iole. Conversely, the wasps did not feed on host frass. Chemical analysis of L. lineolaris frass demonstrated the presence of glucose, sucrose, fructose, trehalulose, and melezitose, apparently at concentrations below those perceived by A. iole. The latter two compounds were previously known only from homopteran honeydew (trehalulose and melezitose) and bacteria (trehalulose). With respect to gustatory response to nectar and honeydew sugars, A. iole differs markedly from other hymenopterans that have been studied in that this parasitoid accepted all the naturally occurring sugars with which it was tested. Moreover, this parasitoid had lower acceptance thresholds than other hymenopterans for many of the sugars. This broad and sensitive range of gustatory perception might be helpful in the development of a food source for the wasp that is not exploited by the host.     

Low-dose eicosapentaenoic or docosahexaenoic acid administration modifies fatty acid composition and does not affect susceptibility to oxidative stress in rat erythrocytes and tissues

In view of the promising future for use of n-3 polyunsaturated fatty acids (PUFA) in the prevention of cancer and cardiovascular diseases, it is necessary to ensure that their consumption does not result in detrimental oxidative effects. The aim of the present work was to test a hypothesis that low doses of eicosapentaenoic acid (EPA) or docosahexaenoic acid (DHA) do not induce harmful modifications of oxidative cell metabolism, as modifications of membrane fatty acid composition occur. Wistar rats received by gavage oleic acid, EPA, or DHA (360 mg/kg body weight/day) for a period of 1 or 4 wk. Fatty acid composition and α-tocopherol content were determined for plasma, red blood cell (RBC) membranes, and liver, kidney, lung, and heart microsomal membranes. Susceptibility to oxidative stress induced by tert-butylhydroperoxide was measured in RBC. EPA treatment increased EPA and docosapentaenoic acid (DPA) content in plasma and in all the membranes studied. DHA treatment mainly increased DHA content. Both treatments decreased arachidonic acid content and n-6/n-3 PUFA ratio in the membranes, without modifying the Unsaturation Index. No changes in tissue α-tocopherol content and in RBC susceptibility to oxidative stress were induced by either EPA or DHA treatment. The data suggest that EPA and DHA treatments can substantially modify membrane fatty acids, with-out increasing susceptibility to oxidative stress, when administered at low doses. This opens the possibility for use of low doses of n-3 PUFA for chemoprevention without risk of detrimental secondary effects.     

Synthesis of a mesoporous material from two natural sources

Mesoporous materials were obtained from two natural silica sources, diatomite and pumicite, under hydrothermal conditions, autogenic pressure and in presence of the surfactant cetyltrimethylammonium bromide (CTAB) as the template. Using diatomite, a temperature of 383 K and the following molar ratios in the initial reaction gel: SiO₂/Al₂O₃ = 8.86; CTAB/SiO₂ = 0.1; Na₂O/SiO₂ = 0.10–0.25 and H₂O/Na₂O = 250–300, the mesoporous material MCM‐41 was obtained in a reaction time of 48 h. When pumicite was used, a mesoporous material was obtained in a reaction time of 96 h, a reaction temperature of 423 K and an initial reaction gel with the following molar ratios: SiO₂/Al₂O₃ = 8.86; CTAB/SiO₂ = 0.1; Na₂O/SiO₂ = 0.25 and H₂O/Na₂O = 330. Copyright © 2006 Society of Chemical Industry     

Lycopene content and lipophilic antioxidant capacity of by-products from Psidium guajava fruits produced during puree production industry

The comparison of lycopene content and lipophilic antioxidant capacity was explored among pink guava fruit and by-products of its puree production industry namely refiner, siever and decanter. Lycopene content was measured using both UV-vis spectrophotometer and high performance liquid chromatography (HPLC) methods. Atmospheric pressure chemical ionization liquid chromatography-mass spectrometry (APCI-LC-MS) was applied in confirming the studied compound. Two assays were employed to determine the lipophilic antioxidant capacities namely lycopene equivalent antioxidant capacity (LEAC) and β-carotene bleaching assays. Lycopene content and antioxidant capacity were in the order of fruits > decanter > siever > refiner. Decanter exhibited the highest lycopene content and antioxidant among the studied by-products. It also gave a significant higher (p < 0.05) lycopene content than pink guava fruit based on the wet basis. There was a significant correlation between lycopene content and LEAC. All samples had a good antioxidant activity in β-carotene bleaching assay but negatively correlated to lycopene content. Decanter was found to be the highest in lycopene content (17 mg/100 g dry basis) and antioxidant capacity (22 μmol LE/100 g dry basis) among the by-products. This by-product of pink guava puree industry can be a potential source of lycopene and antioxidant compounds.     

两种福建产茶叶多酚粗提物具有显著抗氧化活性

对福建安溪铁观音和福建武夷山大红袍采用热水浸提法提取总多酚,运用ABTS和DPPH检测方法评估提取物的抗氧化活性。结果表明,铁观音和大红袍茶叶粗提物总酚含量分别为(17.13±1.35)%和(16.77±2.97)%;相对于阳性标准品Trolox,其抗氧化活性分别为6.85 mmol/g和6.52 mmol/g;氧自由基活性的半数抑制率浓度分别为(0.072±0.004)mg/m L和(0.08±0.002)mg/m L。铁观音和大红袍两种茶叶提取物都具有显著抗氧化活性。     

两种福建产茶叶多酚粗提物具有显著抗氧化活性

对福建安溪铁观音和福建武夷山大红袍采用热水浸提法提取总多酚,运用ABTS和DPPH检测方法评估提取物的抗氧化活性。结果表明,铁观音和大红袍茶叶粗提物总酚含量分别为(17.13±1.35)%和(16.77±2.97)%;相对于阳性标准品Trolox,其抗氧化活性分别为6.85 mmol/g和6.52 mmol/g;氧自由基活性的半数抑制率浓度分别为(0.072±0.004)mg/m L和(0.08±0.002)mg/m L。铁观音和大红袍两种茶叶提取物都具有显著抗氧化活性。     

Docosahexaenoic acid does not affect aggression of normal volunteers under nonstressful conditions. A randomized, placebo-controlled, double-blind study

We previously found that docosahexaenoic acid (DHA) intake prevents aggression enhancement at times of mental stress. In the present study we investigated changes in aggression under nonstressful conditions. Forty-six students of two universities took either DHA-rich fish oil capsules containing 1.5 g DHA (DHA group: 13 males and 9 females) or control oil capsules containing 97% soybean oil plus 3% of another fish oil (control group: 11 males and 13 females) for 3 mon in a double-blind fashion. At the start and end of the study they took an aggression-estimating test (P-F Study) without a stressor component. DHA (5.9 to 8.5%, P<0.001) and eicosapentaenoic acid (0.7 to 1.5%, P<0.001) increased in red blood cell phospholipids in the DHA group, while linoleic acid increased slightly (8.3 to 9.1%, P<0.002) in the soybean oil control group. In the control group, measured aggression levels decreased from 34.8 to 29.4% (P<0.005), whereas they remained stable in the DHA group (33.5 to 33.8%). The intergroup differences (−5.4 vs. 0.3%) were marginally significant (P≤0.05). Aggression levels were stable in the DHA group whether there was stressor (as previously shown) or not. This effect of DHA appears to be interesting, considering the reported association between a low intake of n-3 fatty acids and depression.     

Examining the validity and utility of two secondary sources of food environment data against street audits in England

Background

Secondary data containing the locations of food outlets is increasingly used in nutrition and obesity research and policy. However, evidence evaluating these data is limited. This study validates two sources of secondary food environment data: Ordnance Survey Points of Interest data (POI) and food hygiene data from the Food Standards Agency (FSA), against street audits in England and appraises the utility of these data.

Methods

Audits were conducted across 52 Lower Super Output Areas in England. All streets within each Lower Super Output Area were covered to identify the name and street address of all food outlets therein. Audit-identified outlets were matched to outlets in the POI and FSA data to identify true positives (TP: outlets in both the audits and the POI/FSA data), false positives (FP: outlets in the POI/FSA data only) and false negatives (FN: outlets in the audits only). Agreement was assessed using positive predictive values (PPV: TP/(TP?+?FP)) and sensitivities (TP/(TP?+?FN)). Variations in sensitivities and PPVs across environment and outlet types were assessed using multi-level logistic regression. Proprietary classifications within the POI data were additionally used to classify outlets, and agreement between audit-derived and POI-derived classifications was assessed.

Results

Street audits identified 1172 outlets, compared to 1100 and 1082 for POI and FSA respectively. PPVs were statistically significantly higher for FSA (0.91, CI: 0.89–0.93) than for POI (0.86, CI: 0.84–0.88). However, sensitivity values were not different between the two datasets. Sensitivity and PPVs varied across outlet types for both datasets. Without accounting for this, POI had statistically significantly better PPVs in rural and affluent areas. After accounting for variability across outlet types, FSA had statistically significantly better sensitivity in rural areas and worse sensitivity in rural middle affluence areas (relative to deprived). Audit-derived and POI-derived classifications exhibited substantial agreement (p?<?0.001; Kappa?=?0.66, CI: 0.63–0.70).

Conclusions

POI and FSA data have good agreement with street audits; although both datasets had geographic biases which may need to be accounted for in analyses. Use of POI proprietary classifications is an accurate method for classifying outlets, providing time savings compared to manual classification of outlets.

     

Effect of isoessential fatty acid lipids from animal and plant sources on cholesterol levels in mature male rats

Isopolyunsaturated lipids isolated from plant and animal sources were included in the diets of mature male rats. Liver and blood serum cholesterol lowering effects were noted only in the lipid from the vegetable source. The authors suggest that the cholesterol lowering effect of vegetable oils is associated with the generally betaunsaturated triglycerides found therein. Journal Article No. 3758, Michigan Agricultural Experiment Station, East Lansing, Mich.     

Porous properties of mesoporous silicas from two silica sources (acid-leached kaolinite and Si-alkoxide)

Two different mesoporous silicas (MesoPS) were synthesized by hydrothermal treatment in NaOH solution of two silica sources. One of these starting silicas was derived from selectively acid leached metakaolinite, and the other was from tetraethylorthosilicate (TEOS). The syntheses used a surfactant, cethyltrimethylammonium bromide (CTABr) and were carried out at different CTABr/Si, NaOH/Si and H₂O/Si ratios. In the MesoPS from kaolinite, the specific surface areas (S _BET) of the products were >1500 m²/g when prepared with 0.2 ≤ CTABr/Si ≤ 0.4, 0.3 ≤ NaOH/Si ≤ 0.6 and H₂O/Si = 150. These S _BET values are higher than those obtained from TEOS (ca. 1300 m²/g). The XRD patterns of these products contain a hexagonal (10-) peak with a lattice parameter a ₀ = 4.2–5.2 nm in the MesoPS derived from kaolinite and a ₀ = 4.0–4.6 nm in the products from TEOS. The regularity of the hexagonal structure is higher in the MesoPS derived from TEOS than from kaolinite. The pore size distributions of the products show a sharp peak at 2.8 nm in the MesoPS from kaolinite and at 2.4–2.5 nm in those from TEOS. The meso-structure is found to be formed during the stirring step of the synthesis and becomes more regular after hydrothermal treatment. The differences in the porous properties of the two MesoPSs from kaolinite and TEOS are attributed to differences in the dissolution rates and silica concentrations in the synthesis solutions. The ²⁹Si MAS NMR spectra show a higher number of Q ³ (Si(OSi)₃OH) units in the MesoPS from kaolinite and this is suggested to be related to the difference in their porous properties.     

Isolation of ricin,ricinine, and the allergenic fraction from castor seed pomace from two different sources

Summary A scheme of separation is described for the extraction of ricin, ricinine, and the allergenic fractions from the same lot of castor seeds, thereby considerably curtailing the hazard associated with the handling of the material. The yield of ricin from the commercially prepared pomace was only one-tenth of that from the laboratory-prepared pomace, which contained approximately 1% of this toxic protein. Likewise the amount of dialyzed allergenic fraction present in commercial pomace is only about one-third of that present in the laboratory sample, which contained 0.22% of this constituent. The laboratory pomace contained five times as much (0.10%) of the alkaloid ricinine as did the commercial pomace. It appears that commercial processing of the pomace is effective in destroying a considerable portion of the toxic and allergenic activity in castor seeds. The pomace remaining from the extraction is nontoxic and may be used to provide a source of protein for feeding stuffs. Published with approval of the director of the Oklahoma Agricultural Experiment Station as Journal Article No. 400.     

Exposure to ambient concentrations of particulate air pollution does not influence vascular function or inflammatory pathways in young healthy individuals

Background  

Particulate air pollution is associated with increased risk of cardiovascular events although the involved mechanisms are poorly understood. The objective of the present study was to investigate the effects of controlled exposure to ambient air fine and ultrafine particles on microvascular function and biomarkers related to inflammation, haemostasis and lipid and protein oxidation.     

一般工业固废源替代燃料制备工艺现状分析

经过近几年的快速发展,替代燃料制备行业迎来了爆发式增长。但发展的过程也产生了因市场原因导致的原料价格不断上升、品质不断下降的问题,以及后端需求量不断上升导致的单一废纺来源已不能满足要求的问题。物料的变化使原有替代燃料制备工艺运行过程投资及运行成本过大、系统故障率升高等问题更加突出。本文分析了原料变化、替代燃料制备工艺流程及设备选型在运行过程中存在的问题,提出了适合我国替代燃料制备行业发展的方向及建议。