香菇子实体多糖分步酶解法提取研究

首先采用正交试验优化纤维素酶﹑果胶酶和木瓜蛋白酶对香菇(Lentinula edodes)子实体多糖酶解提取的工艺参数,然后在优化酶解条件下,依次采用纤维素酶﹑果胶酶和木瓜蛋白酶分步处理香菇子实体以提取香菇多糖,并与单一酶解提取法和传统热水浸提法进行对比.结果表明,纤维素酶﹑果胶酶﹑木瓜蛋白酶的最佳提取工艺参数依次为加酶量0.8%、温度45 ℃、pH 4.5、提取时间1 h,加酶量1.0%、温度45 ℃、pH 3.5、提取时间2.0 h和加酶量1.0%、温度45 ℃、pH 4.0、提取时间1.5 h;在优化提取条件下,分步酶解法提取香菇粗多糖的提取率可达14.17%,比传统热水浸提法提高128.2%,比单独采用纤维素酶﹑果胶酶﹑木瓜蛋白酶酶解提取分别提高了43.71%、46.99%和23.11%.紫外光谱分析表明,分步酶解法提取的香菇多糖纯度明显高于热水浸提法提取的香菇多糖.-     

枸骨叶抑菌物质的提取及抑菌作用研究

采用正交试验法探讨枸骨叶抑菌物质的最佳提取条件,以杯碟法对枸骨叶提取物进行体外抗菌作用以及pH、温度、时间因素对其抗菌活性的影响。结果表明:枸骨叶抑菌物质的最佳提取条件为:以乙酸乙酯为溶剂,提取温度为40℃,料液比为1∶10,浸提时间为2.5 h;枸骨叶提取物对金色葡萄球菌、枯草杆菌、大肠杆菌都有明显的抑菌效果,最低抑菌浓度分别为0.0625、0.50、.5 mg/mL;最小杀菌浓度为0.1251、0、.5 mg/mL。该物质抑菌pH范围为7~9,热稳定性较差,最佳抑菌时间为24 h。     

混合酶提法提取铁皮石斛中石斛多糖的优化工艺研究

以铁皮石斛为试材,采用纤维素酶与果胶酶的等量混合提取法,通过单因素试验与正交实验,研究了pH值、酶浓度、酶解时间、酶解温度等因素对石斛多糖提取效率的影响。结果表明:铁皮石斛多糖提取最佳工艺为pH 6.5、1%浓度的纤维素酶和果胶酶1∶1等量混合、50℃下提取135min,在此条件下石斛多糖提取率为41.33%;说明该工艺是可行的,且具有较高的提取率。     

籽瓜总皂苷的提取工艺研究

以籽瓜为试材,通过乙醇回流法、超声法、超声纤维素酶法、超声果胶酶法提取籽瓜总皂苷,并采用4因素3水平正交实验设计对超声纤维素酶法提取工艺进行优选,以籽瓜提取液中总皂苷的含量和提取物得率为指标,优选最佳提取工艺。结果表明:纤维素酶用量为10U/g,pH 4.5,酶解温度为45℃,酶反应时间为120min为籽瓜总皂苷提取的最佳工艺条件。籽瓜提取物得率为61.32%,籽瓜总皂苷的含量为5.03%,该试验操作简单,工艺条件稳定。     

纤维素酶果胶酶辅助提取西瓜番茄红素工艺优化

本试验以质量比为4:1的纤维素酶、果胶酶组成的复合酶辅助提取西瓜番茄红素,分析了纤维素酶、果胶酶的最佳提取条件,分析了纤维素酶、果胶酶的最佳作用条件,采用正交试验优化了纤维素酶、果胶酶辅助提取西瓜番茄红素的工艺。结果得出,提取西瓜番茄红素最佳工艺为添加复合酶(维素酶:果胶酶=4:1)至西瓜糊(0.60%,w/w),调节体系pH值为4.5,55℃下酶解2.0 h;采用乙酸乙酯-丙酮混合溶剂(7:1,V/V)提取,提取率91%,提取效果较好。     

纤维素酶解复合碱提酸沉法提取杏鲍菇蛋白质

为提高杏鲍菇(Pleurotus eryngii)蛋白质的提取率,本试验采用纤维素酶解复合碱提酸沉法进行提取,以料液比、酶的添加量、反应时间和温度为因素进行单因素试验,蛋白质提取率为响应值,利用Box-Behnken进行响应面优化纤维素酶解条件,与单一碱提酸沉法提取蛋白质后的提取率进行比较。试验结果表明,纤维素酶解最佳工艺条件为:料液比1:55,温度40℃,时间100 min,酶的添加量1.5%,复合碱提酸沉后蛋白质提取率为51.36%,显著高于碱提酸沉法的45.89%。因此,纤维素酶复合碱提酸沉法提取杏鲍菇蛋白质优于碱提酸沉法。     

酶解工艺对籽瓜浓缩汁出汁率的影响

以籽瓜为试验材料,利用果胶酶和纤维素酶进行酶解。通过单因素和正交试验确定籽瓜的最佳酶解工艺:果胶酶0.1%,纤维素酶0.05%,酶解温度45℃,酶解时间2h,酶解p H=4.5。在此最佳酶解条件下,出汁率达86.3%。     

双酶法提取角瓜籽仁蛋白质的工艺研究

以角瓜籽为试材,采用超声波进行预处理,选取纤维素酶和Alcalase碱性蛋白酶以2∶1比例复配为复合酶制剂,研究了双酶法提取角瓜籽仁蛋白质的最佳工艺条件。结果表明:角瓜籽仁蛋白质的最佳提取工艺为:料液比1∶20g/mL、总加酶量7%、酶解温度55℃、酶解时间120min,酶解pH 7.5,在此条件下角瓜籽仁蛋白质的提取率最高,为74.2%。     

酶法提取刺玫果总黄酮工艺研究

以刺玫果为试材,采用酶法辅助提取刺玫果总黄酮,研究各因素对刺玫果总黄酮提取率的影响。结果表明:纤维素酶辅助提取刺玫果总黄酮的最佳工艺条件为提取溶剂为50%乙醇、温度控制在50℃、料液比1∶15g/mL、纤维素酶加入量为40mg/g、控制提取液于pH 5.5条件下,酶解提取2次,每次140min,在最佳条件下进行3次验证试验,其总黄酮提取率平均为95.94mg/g。     

酶法提取云南萝芙木中阿吗碱的研究

研究3种纤维素酶法提取云南萝芙木中阿吗碱的最佳工艺。结果表明:酶解最适条件为:pH 5.0,酶用量5 mg/5g,时间2 h,温度50℃;酶解处理后的阿吗碱提取率比直接用甲醇提取提高了29.3%;说明酶解处理更有利于阿吗碱的提取。     

Effects of radiation from 188Re on smooth muscle cell proliferation

AIM: Although endovascular radiotherapy inhibits neointimal hyperplasia, the exact alterations induced by β-particles irradiation remain to be elucidated. The objective of this study was to investigate the ability and the cellular mechanism of local β^-particles emission from ¹⁸⁸Re to inhibit vascular smooth muscle cells (SMCs). METHODS: The SMCs in vitro were irradiated by ¹⁸⁸Re with single doses of 2.6 Gy-25.8 Gy. The effects of β-particles on SMCs, such as effective irradiate doses, the period of inhibition for SMCs proliferation, the changes of cell proliferation rate and DNA synthesis rate, cell cycle progression and related gene expression, were investigated by cell count, [³H]-TdR incorporation, cell cycle progression analysis, cell viability and immunocytochemistry, respectivecy. RESULTS: β-particles irradiation with dose of 5.2 Gy could inhibit significantly SMCs proliferation. At dose of 20.6 Gy DNA synthesis inhibitory rate was 92%, SMCs proliferation rate was only 3%. Renoval of ¹⁸⁸Re did not abolish the inhibitory effects of β-particles on SMCs proliferation. The expression of P53 was up regulation and PCNA was down regulation after irradiation. CONCLUSION: β-particles from ¹⁸⁸ Re was significantly effective and permanent in inhibiting SMCs proliferation, and inhibitory effect was in dose-dependet manner ED50was 5 Gy, the best dose to inhibit SMCs proliferation was 20 Gy. β-particles irradiation induced SMCs to occur G₀/G₁ arrest, damaged the ability of SMCs reproliferation and led to cell clonogenic death. P53 and PCNA had regulatiory effects on SMCs proliferation after β-particles irradiation.     

Relationship between renal hypertension and cardiac α1-adrenoceptor autoantibodies in rats

AIM: To examine the autoantibody against α₁-adrenoceptor and its biologic activities during the development of renal hypertension. METHODS: Renal hypertension of rat was achieved by clipped renal artery, the titre of autoantibody to α₁-adrenoceptor was detected using ELISA immunoassay. Furthermore, the biological offects of these autoantibodies on cultured cardiomyocytes were also examined. RESULTS: After two weeks of clipping renal arteries, both the frequency of occurrence and the titre of autoantibodies to cardiac α₁-adrenergic receptor were significantly increased as compared with the control of pre-treatment. The increased autoantibodies lasted for several weeks and then automatically decreased gradually to the pre-clipping level at 12 weeks. The biological effects of these autoantibodies displayed an "agonistic-like" activities on the beating frequency of cultured neonatal cardiomyocytes. CONCLUSION: Autoantibodies against α₁-adrenoceptor may play a role in the elevation of peripheral vascular resistance and in the development of cardiac hypertrophy in rats with renal hypertension.     

Influence of Mineral Nutrients on Strawberry Fruit Quality and Their Accumulation in Plant Organs

Abstract

This review is based partly on complete articles and partly on abstracts. Three of the 60 articles deal with the total uptake of elements in strawberry plant organs in two different strawberry production systems, both considered as optimal concerning amount and balance of elements. The effect on fruit quality may be dramatic if the level of a particular element is outside this range, but there may also be effects initiated by differences within the optimal range of elements. Most articles refer to product oriented quality, but some focus on consumer oriented quality, as discussed by Shewfelt (1999). The discussion here is on a general basis, so one should keep in mind that there are cultivar differences and that specification of nutrition ideally should mirror the needs of a single cultivar, or a group of cultivars with similar requirements. Also, to get a complete understanding of the subject future reviews should embrace a broader access of information including the effect on plant development of individual elements, such as the role of calcium in fruit firmness and its importance in cell wall structure. However, the intention here is to narrow the information to results that suggest a direct connection between nutrient uptake and fruit quality.     

多效唑对猕猴桃离体试管苗生长及内源激素的影响

多效唑（ＰＰ３３３）处理猕猴桃试管苗，降低了其生长强度；植株体内的ＧＡ３、ＩＡＡ和ＺＴ含量下降，ＡＢＡ的含量上升，乙烯释放率增加；并且能降低外源的ＧＡ３和ＩＡＡ促进生长的作用，而外源的ＧＡ３和ＩＡＡ又能不同程度地逆转多效唑的抑制作用，使植株恢复生长。     

Proteomic analysis between pathological scars and normal skin

AIM: To investigate and screen the sensitive proteins in the formation mechanism of pathological scars by comparing the results of differential proteomic analysis between pathological scars and normal skin.METHODS: Two-dimensional gel electrophoresis was used to detect the protein expression profiles in 8 keloid patients, 8 hypertrophic scar patients and 3 matched normal skin patients.The proteins that showed differential expression of over 4-fold change were cut and analyzed by MALDI-TOF/TOF mass spectrometry.RESULTS: A two-dimensional protein profiling comparison between pathological scars and normal skin was successfully established.On average, 2 978 spots in keloid, 2 975 spots in hypertrophic scar and 3 053 spots in normal skin were identified using gel analysis software.Compared with normal skin, there were totally 36 differentially-expressed proteins in keloid and hypertrophic scar identified from the spots of over 4-fold change, including 16 proteins in both keloid and hypertrophic scar (8 up-regulated and 8 down-regulated), 11 only in keloid (9 up-regulated and 2 down-regulated) and 9 only in hypertrophic scar (4 up-regulated and 5 down-regulated).CONCLUSION: Proteomic analysis can identify the proteins with variance of pathological scars versus normal skin, thus providing probable new clues to reveal the formation mechanism of pathological scars.     

Mixed-severity fire regime in a high-elevation forest of Grand Canyon,Arizona, USA

Fire regime characteristics of high-elevation forests on the North Rim of the Grand Canyon, Arizona, were reconstructed from fire scar analysis, remote sensing, tree age, and forest structure measurements, a first attempt at detailed reconstruction of the transition from surface to stand-replacing fire patterns in the Southwest. Tree densities and fire-/non-fire-initiated groups were highly mixed over the landscape, so distinct fire-created stands could not be delineated from satellite imagery or the oldest available aerial photos. Surface fires were common from 1700 to 1879 in the 4,400 ha site, especially on S and W aspects. Fire dates frequently coincided with fire dates measured at study sites at lower elevation, suggesting that pre-1880 fire sizes may have been very large. Large fires, those scarring 25% or more of the sample trees, were relatively infrequent, averaging 31 years between burns. Four of the five major regional fire years occurred in the 1700s, followed by a 94-year gap until 1879. Fires typically occurred in significantly dry years (Palmer Drought Stress Index), with severe drought in major regional fire years. Currently the forest is predominantly spruce-fir, mixed conifer, and aspen. In contrast, dendroecological reconstruction of past forest structure showed that the forest in 1880 was very open, corresponding closely with historical (1910) accounts of severe fires leaving partially denuded landscapes. Age structure and species composition were used to classify sampling points into fire-initiated and non-fire-initiated groups. Tree groups on nearly 60% of the plots were fire-initiated; the oldest such groups appeared to have originated after severe fires in 1782 or 1785. In 1880, all fire-initiated groups were less than 100 years old and nearly 25% of the groups were less than 20 years old. Non-fire-initiated groups were significantly older (oldest 262 years in 1880), dominated by ponderosa pine, Douglas-fir, or white fir, and occurred preferentially on S and W slopes. The mixed-severity fire regime, transitioning from lower-elevation surface fires to mixed surface and stand-replacing fire at higher elevations, appeared not to have been stable over the temporal and spatial scales of this study. Information about historical fire regime and forest structure is valuable for managers but the information is probably less specific and stable for high-elevation forests than for low-elevation ponderosa pine forests.This revised version was published online in May 2005 with corrections to the Cover Date.     

Coupling past management practice and historic landscape change on John F. Kennedy Space Center,Florida

Historic landcover dynamics in a scrubby flatwoods (Tel-4) and scrub landscape (Happy Creek) on John F. Kennedy Space Center were measured using aerial images from 1943, 1951, 1958, 1969, 1979, and 1989. Landcover categories were mapped, digitized, geometrically registered, and overlaid in ARC/INFO. Both study sites have been influenced by various land use histories, including periods of range management, fire suppression, and fire management. Several analyses were performed to help understand the effects of past land management on the amount and spatial distribution of landcover within the study sites. A chi-squared analysis showed a significant difference between the frequency of landcover occurrence and management period. Markov chain models were used to project observed changes over a 100-year period; these showed current management practices being effective at Tel-4 (restoring historic landscape structure) and much less effective at Happy Creek. Documenting impacts of past management regimes on landcover has provided important insight into current landscape composition and will provide the basis for improving land management on Kennedy Space Center and elsewhere.     

瓜叶绿素降解关键酶基因PPH和PAO cDNA片段的克隆与表达初步分析

 以西双版纳黄瓜和‘华黄5号’黄瓜叶片为试验材料,研究了衰老过程中两种黄瓜叶片叶绿素含量变化及脱镁叶绿素脱镁叶绿酸水解酶基因PPH和脱镁叶绿酸a加氧酶基因PAO的表达。结果表明：随着叶片衰老,叶绿素a和叶绿素b含量显著降低,叶绿素a与叶绿素b的比值在0.5左右,推测叶绿素b的含量可能对黄瓜叶片保绿起到重要作用。荧光定量RT-PCR分析结果显示：PPH和PAO在西双版纳黄瓜叶片生长35 d时表达量最高,分别为5.50和1.86;PPH在‘华黄5号’叶片35 d时表达量最高,为7.14,而PAO在35和45 d表达量都很高,分别为3.90和3.91;PPH和PAO在西双版纳黄瓜叶片中的表达量低于在‘华黄5号’中。     

Effects of simvastatin on PDGF-BB and serum-induced proliferation of vascular smooth muscle cells and on the expression of tumor suppressor gene PTEN

AIM:To observe the effect of simvastatin on the proliferation of vascular smooth muscle cells(VSMCs) induced by serum and growth factor PDGF-BB and the effect of simvastatin on the expression of PTEN,a important regulator of G₁/S cell cycle transition. METHODS:The DNA synthesis was determined by [³H]-TdR incorporation, cell cycle was examined with flow cytometry, the protein level of PTEN was measured by Western blot method. RESULTS: (1)Simvastatin inhibited [³H]-TdR incorporation in a dose dependent manner. (2) Flow cytometric DNA analysis revealed that simvastatin induced significantly enhancement of G₀/G₁ phase and decrease in S phase VSMCs.(3)Simvastatin increased protein level of PTEN and mevalonate, a metabolite of HMG-COA, reversed the effect of simvastatin on PTEN protein expression. CONCLUSION:Simvastatin may inhibit proliferation of VSMCs and retarded cell cycle in G₀/G₁ phase by increasing PTEN expression through inhibiting synthesis of mevalonate.     

XBP-01 accelerated apoptosis induced by oxidized low density lipoprotein in vascular smooth muscle cells

AIM: Previous studies performed with XBP-01 in vitro indicated that XBP-01 could inhibit vascular smooth muscle cells from being transformed into foam cell and could eliminate the atherosclerotic plaque in C57BL/6J mouse. This experiment is to investigate its mechanism of eliminating plaques in vitro. METHODS: The cultured porcine artery smooth muscle cells incubated with XBP-01 of 0.1 mg/L for 24 h after preincubated with oxidized low density lipoprotein of 15 mg/L for 72 h in vitro. The samples were analyzed by fluorescence microscope, confocal microscope system and flow cytometry. RESULTS: Apoptosis was triggered by being incubated with oxidized low density lipoprotein and this process was accelerated additionally by being incubated with XBP-01. CONCLUSION: XBP-01 can be effective in eliminating atherosclerotic plaque by accelerating the process in which oxidized low density lipoprotein induced smooth muscle cell apoptosis.