橙皮甙生理效应研究进展

橙皮甙是柑橘果皮中的主要功能活性成分,具有治疗心脑血管疾病、协同抗肿瘤、抗菌消炎、抗氧化、防止紫外辐射等多种生理功效和药理作用,引起了国内外的广泛关注。本文中综述了橙皮甙近年来在保健功效和应用方面的研究现状,包括橙皮甙的结构与理化性质,橙皮甙的抗菌消炎作用、对心血管系统的作用、对抗氧化的作用等生理效应。并对其在保健食品、医药、化妆品等方面的应用前景作了展望。     

柠檬水的正确泡法

<正>最好选择鲜柠檬。新鲜柠檬香味浓郁,而干柠檬的香气成分和维生素C都有一定损失。鲜柠檬一定要带皮切薄片。因为皮的部分类横酮物质更高,如橙皮甙、柚皮甙等,它们都是有益健康的成分,柠檬精油也主要在皮里面,而切薄则有利于柠檬皮中的香气成分泡出来。水温60~70℃比较适宜。泡柠檬的水太凉,香味不容易泡出来。如用沸水浸泡,则会有较多的苦味物质     

金柑生物学特性及其栽培技术

金柑Fortunella margarita(lour.)又叫金桔或金弹,系芸香科常绿小乔木。果实皮薄肉厚,可溶性固形物14.5×10~(-2),含糖12.3×10~(-2),含酸0.75×10~(-2);每百毫升果汁含 V—C41.5毫克,还含V_A、V_B、V_P及橙皮甙等;宜生食,味香甜酸醇适口,营养丰富。可入药,有清心开胃、理气散寒之效,民间用于治气管炎、高血压、胃病、产妇腹痛等有良效。加工成罐头、果汁、果酒.提取柠檬酸、制成桔饼、蜜饯等。在全国首届金柑研讨会评比中品质和产量名列第二。誉为“金柑之乡”的管前和八字桥乡,种植已300多年,是福建省主要产区,为全国七大产区之一。现尤溪全县种植面积16940亩(其中管前和八字桥12582亩);年产量从1985年的1850吨发展到3930吨,占全省1/3,总收益达700万元以上。省、市、县科委为充分发展这一拳头产品优势,将“金柑高产优质栽培”列为山区资源开发重点项目之一。1992年曾经省、市、县科委按课题合同要求分三种类型,随机抽样进行现场验收测算:     

观点

《新民周刊》在大雾里呼喊"我在雾里呼喊,我在雾里呼吸。我在雾里活着,不想雾里死去。我在雾里奔波,我在雾里哭泣。我在雾里挣扎,不想雾里窒息"。一曲大雾版《北京北京》,唱出了人们心底的悲怆。蓝天白云,心旷神怡——这是2008的北京留给人们的美好记忆。在重重雾霾笼罩之下,我们多么希望能穿越到那个神清气爽的夏天,     

2009影响家居行业十大事件

仍在持续的国际金融危机让中国家居行业在2009年受到不小的波及。29年,在大浪淘沙之中,中国的家居企业不断寻找生存之机、发展之路,在危机的历练中浴火重生,逐渐羽翼丰满,走向成熟。在21年开端之际,我们回望过去,希望通过对2009年的总结,让中国家居行业在新的一年中发展得更加稳健。     

奇妙的种子旅行

足不出户的种子,常常随着人类的足迹、履痕,同样能够远涉重洋,在陆地上驰骋,跟着迁居到遥远的异乡。车前草,在今天是一种很普通的野草。可是,美洲的印第安人在过去却从未见到过这种草。自从哥伦布发现了美洲以后,才有车前草在美洲落户。     

奇妙的种子旅行

足不出户的种子,常常随着人类的足迹、履痕,同样能够远涉重洋,在陆地上驰骋,跟着迁居到遥远的异乡。车前草,在今天是一种很普通的野草。可是,美洲的印第安人在过去却从未见到过这种草。自从哥伦布发现了美洲以后,才有车前草在美洲落户。     

有关兰花

4月可能是地球上植物开花最多的季节。无论在乡村还是城市,目光所及,总会有花儿在开放。所谓春光明媚,其实就是草在泛青,树在泛绿,花儿在怒放。难以想象,如果不是植物,不是植物怒放的鲜花,我们看到的是怎样的春光。     

感恩塞罕坝精神

在艰苦创业中奋起,在无私奉献中坚持,在科学求实中发展,在开拓创新中升华,在爱岗敬业中凝聚,凝聚我省林业战线中的精神——伟大的塞罕坝精神。时过五十年,飘荡在坝上的创业豪情声犹在耳。一次艰辛的创业激发人心,照亮了我们内心深处的灵魂。感恩塞罕坝,让我们生长于这个人心高尚、光明照耀的时代;感恩塞罕坝,让我们有幸在燕赵18.88万平方公里土地上,与坝上英雄同一脉搏;     

中国麋鹿 向海而生

麋鹿在这片土地上自由自在地生活着,水草丰茂使麋鹿膘肥体壮。一群群儿女尽显麋鹿大家族的天伦之乐。闲暇时,麋鹿们有时在光裸地上相互追逐,有时在草丛里捉迷藏,有时在树林中漫步,有时在河塘边嬉戏。优美的环境、活泼的鹿群构成一幅温馨甜美的自然风景画。     

Isolation of xanthone and benzophenone derivatives from Cyclopia genistoides (L.) Vent. (honeybush) and their pro-apoptotic activity on synoviocytes from patients with rheumatoid arthritis

A fast and efficient method for the isolation of the C-glucosidated xanthones mangiferin and isomangiferin from the South-African plant Cyclopia genistoides was developed for the first time. The procedure involved extraction, liquid–liquid partitioning with ethyl acetate and subsequent precipitation of mangiferin and isomangiferin from methanol and acetonitrile–water fractions, respectively. Additionally, two benzophenone derivatives: 3-C-β-glucosides of maclurin and iriflophenone, were isolated from C. genistoides extracts using semi-preparative HPLC. Apart from the above, the isolation procedure also yielded hesperidin and small amounts of luteolin. The structures of the compounds were determined by 1D and 2D NMR experiments and/or LC-DAD-ESI–MS. The selected Cyclopia constituents were screened for pro-apoptotic activity on TNF-α-stimulated synovial cells isolated from rheumatoid arthritis patients. The strongest effect, measured as percent of apoptotic cells, was recorded for isomangiferin (75%), followed by iriflophenone 3-C-β-glucoside (71%), hesperidin (67%) and mangiferin (65%). The results are encouraging for further studies on the use of the above compounds in the treatment of rheumatoid arthritis.     

Variance of common flavonoids by brand of grapefruit juice

Nine commercial brands of grapefruit juice were analyzed for their flavonoid content by HPLC to determine if significant brand-to-brand variance in grapefruit juice flavonoid content exists. Flavonoid glycosides narirutin, naringin, hesperidin, neohesperidin, didymin, and poncirin have been identified in all the grapefruit juices examined. The aglycone quercetin was detected in only two brands. All the juices were free from methoxylated flavonoid aglycones. There was a significant difference in the amounts of total flavonoids and individual flavonoids in the nine brands. The concentration of total flavonoids ranged between 19.44 and 84.28 mg/100 ml juice. Naringin was found to be the major flavonoid followed by narirutin and hesperidin. Their concentrations ranged from 14.56 to 63.8; 2.25 to 12.20; and 0.24 to 3.12 mg/100 ml juice, respectively.     

Molecular mechanisms of citrus flavanones on hepatic gluconeogenesis

It is well known that hyperglycaemia is the initiating cause of tissue damage associated with type 2 diabetes mellitus and that enhanced hepatic gluconeogenesis may account for the increase in blood glucose levels. The purpose of this work was to investigate the possible actions and mechanisms of three related citrus flavanones, namely hesperidin, hesperetin and naringenin, on hepatic gluconeogenesis and related parameters using isolated perfused rat liver. Hesperetin and naringenin (but not hesperidin) inhibited gluconeogenesis from lactate plus pyruvate, alanine and dihydroxyacetone. The inhibitory effects of these flavanones on gluconeogenesis from lactate and pyruvate (hesperetin IC₅₀ 75.6 μM; naringenin IC₅₀ 85.5 μM) as well as from alanine were considerably more pronounced than those from dihydroxyacetone. The main cause of gluconeogenesis inhibition is the reduction of pyruvate carboxylation by hesperetin (IC₅₀ 134.2 μM) and naringenin (IC₅₀ 143.5 μM) via inhibition of pyruvate transport into the mitochondria. Secondary causes are likely inhibition of energy metabolism, diversion of glucose 6-phosphate for glucuronidation reactions and oxidation of NADH by flavanone phenoxyl radicals. The influence of the structural differences between hesperetin and naringenin on their metabolic effects was negligible. Analytical evidence indicated that the presence of a rutinoside moiety in hesperidin noticeably decreases its metabolic effects, confirming that hesperetin and naringenin interact with intracellular enzymes and mitochondrial or cellular membranes better than hesperidin. Thus, the inhibition of the gluconeogenic pathway by citrus flavanones, which was similar to that of the drug metformin, may represent an attractive novel treatment strategy for type 2 diabetes.     

FRW阻燃胶合板的DMA分析

目前世界范围内木材资源短缺的情况日益加剧,发展人造板工业已成为世界各国解决木材资源严重不足的重要途径.其中,胶合板作为室内装饰的主要材料,其产量和需求量都在急剧增长.我国胶合板产量从1980年的33.00万m3增长到2004年的2 098.62万m3,呈现大幅度增长的趋势(张文标等,2000).但由于普通胶合板具有易燃性,在许多领域的应用上受到限制.因为一旦发生火灾,不仅造成重大的经济损失,而且往往会发生人员伤亡.1950-2003年全国共发生火灾4 177 730起,直接经济损失2 434.525 1亿元,因火灾死亡174 855人,受伤329 352人.     

Effects of soil temperature on biomass and carbohydrate allocation in Scots pine (Pinus sylvestris) seedlings at the beginning of the growing season

We studied effects of soil temperature on shoot and root extension growth and biomass and carbohydrate allocation in Scots pine (Pinus sylvestris L.) seedlings at the beginning of the growing season. One-year-old Scots pine seedlings were grown for 9 weeks at soil temperatures of 5, 9, 13 and 17 degrees C and an air temperature of 17 degrees C. Date of bud burst, and the elongation of shoots and roots were monitored. Biomass of current and previous season roots, stem and needles was determined at 3-week intervals. Starch, sucrose, glucose, fructose, sorbitol and inositol concentrations were determined in all plant parts except new roots. The timing of both bud burst and the onset of root elongation were unaffected by soil temperature. At Week 9, height growth was reduced and root extension growth was much less at a soil temperature of 5 degrees C than at higher soil temperatures. Total seedling biomass was lowest in the 5 degrees C soil temperature treatment and highest in the 13 degrees C treatment, but there was no statistically significant difference in total biomass between seedlings grown at 13 and 17 degrees C. In response to increasing soil temperature, below-ground biomass increased markedly, resulting in a slightly higher allocation of biomass to below-ground parts. Among treatments, root length was greatest at a soil temperature of 17 degrees C. The sugar content of old roots was unaffected by soil temperature, but the sugar content of new needles increased with increasing soil temperature. The starch content of all seedling parts was lowest in seedlings grown at 17 degrees C. Otherwise, soil temperature had no effect on seedling starch content.     

家具甲醛释放量气候箱(1m~3)测定法影响因素分析

通过对气候箱法(1m3)的影响因子进行正交试验分析,研究试验温度、承载率、试验时间、空气置换率对家具甲醛释放量的影响.结果表明:试验温度为最显著影响因子,对家具甲醛释放的影响最大,增加温度有效地加快了甲醛的释放速度.     

Effects of elevated CO(2) and temperature on cold hardiness and spring bud burst and growth in Douglas-fir (Pseudotsuga menziesii)

We examined effects of elevated CO(2) and temperature on cold hardiness and bud burst of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) seedlings. Two-year-old seedlings were grown for 2.5 years in semi-closed, sunlit chambers at either ambient or elevated (ambient + ~ 4 degrees C) air temperature in the presence of an ambient or elevated (ambient + ~ 200 ppm) CO(2) concentration. The elevated temperature treatment delayed needle cold hardening in the autumn and slowed dehardening in the spring. At maximum hardiness, trees in the elevated temperature treatment were less hardy by about 7 degrees C than trees in the ambient temperature treatment. In general, trees exposed to elevated CO(2) were slightly less hardy during hardening and dehardening than trees exposed to ambient CO(2). For trees in the elevated temperature treatments, date to 30% burst of branch terminal buds was advanced by about 6 and 15 days in the presence of elevated CO(2) and ambient CO(2), respectively. After bud burst started, however, the rate of increase in % bud burst was slower in the elevated temperature treatments than in the ambient temperature treatments. Time of bud burst was more synchronous and bud burst was completed within a shorter period in trees at ambient temperature (with and without elevated CO(2)) than in trees at elevated temperature. Exposure to elevated temperature reduced final % bud burst of both leader and branch terminal buds and reduced growth of the leader shoot. We conclude that climatic warming will influence the physiological processes of dormancy and cold hardiness development in Douglas-fir growing in the relatively mild temperate region of western Oregon, reducing bud burst and shoot growth.     

环境因子对喙尾琵甲卵孵化的影响

研究了温度、光照和基质含水量对喙尾琵甲(Blaps rhynchopetera Fairmaire)卵孵化的影响。结果表明:12 - 28 ℃ 6个恒温条件下卵均可孵化,随着温度的升高卵的发育历期缩短(32.92 - 5.83 d),发育速率加快(0.03 - 0.172/d)。12 - 25 ℃下孵化率较高,平均孵化率70%,8 ℃和31 ℃未见卵孵化。喙尾琵甲卵的发育起点温度为(10.08±0.93) ℃,有效积温为(99.91±8.11)日·度。在0 - 8 000 lx光照条件下,随着光照度的增加,孵化率呈下降趋势,光照度≥8 000 lx,卵不孵化。基质含水量和温度共同影响试验中,基质含水量、温度以及二者的交互作用均对卵的孵化有显著影响,多重比较分析后筛选出了适宜卵孵化的温度含水量组合;并对云南地区限制喙尾琵甲卵孵化的气候因素进行了探讨。     

温湿度对昆嵛山腮扁叶蜂的影响

[目的]通过研究温度、降水量、温湿度系数与昆嵛山腮扁叶蜂种群动态变化的关系,探索气象因子对昆嵛山腮扁叶蜂发生的影响。[方法]在昆嵛山区选取7块标准样地,调查昆嵛山腮扁叶蜂发育期内的温度、降水量和相对湿度以及越冬蛹数量,然后统计分析温度、降水量、温湿度系数与昆嵛山腮扁叶蜂种群动态变化的关系。[结果]昆嵛山腮扁叶蜂在生活史的不同阶段所需的温度不同。6、7月份较高的降水量有助于昆嵛山腮扁叶蜂产卵和孵化,较低的降水量有利于其下树入土。同一样地的昆嵛山腮扁叶蜂越冬蛹的数量在不同年份中差异极显著(P<0.001);且所有样地的越冬蛹总量和虫口密度也均达到极显著水平(P<0.001)。昆嵛山腮扁叶蜂的虫口密度与发育期降水量和温湿度系数的年份变化趋势一致,但与温度的年份变化趋势不一致。2011年较低的温度、较高的降水量和温湿度系数造成了昆嵛山腮扁叶蜂的越冬蛹数量增多。[结论]低温高湿环境适合昆嵛山腮扁叶峰越冬蛹的生活。气象因子在调控昆翕山腮扁叶蜂的发生方面起着重要的作用,其为森林有害生物生态调控机制的重要组成部分。