糙米为主要原料的灵芝深层发酵条件优化

对以糙米浆、麦芽汁和黄豆芽汁为培养基组成的灵芝深层发酵条件进行优化,结果表明：灵芝深层发酵的起始pH5．5、接种量10％、装液量40mL和接种菌龄5d时可以获得最大灵芝菌丝干重。方差分析表明装液量和接种菌龄对灵芝生长有显著影响。在优化发酵工艺条件下,发酵第7d胞外多糖产量达到5．7g／L。     

灵芝发酵液体种子培养条件研究

以菌丝体生物量为主要指标,结合发酵液多糖含量,研究灵芝发酵液体种子培养的营养因子和非营养因素.结果表明,适宜灵芝G5760菌株发酵液体种子的培养基配方为麦麸粉5%,黄豆饼粉3%,KH2PO40.10%,MgSO40.09%;而优化发酵条件为初始pH5.5,装液量32%,菌种种龄6d,接种量10%,培养时间8～9d.     

茯苓菌丝体液体培养条件的研究

通过正交试验,筛选出培养茯苓菌丝体的适宜培养基配方:葡萄糖25g,玉米浆10mL,KH2PO41.5g,MgSO40.75g,VB15mg,水1000mL。确定了摇瓶培养茯苓菌丝体适宜的接种量为10%,装液量为50mL/150mL的三角瓶。测定了发酵过程中菌丝体生物量、pH值、胞外多糖及胞内多糖含量的变化曲线。     

铆钉菇菌丝体液体培养产胞外多糖条件的研究

对铆钉菇菌丝体液体培养产胞外多糖的条件进行了研究;结果表明：铆钉菇的菌丝体深层发酵产胞外多糖的适宜培养基组成为：蔗糖20g/L,豆饼粉3g/L,K2HPO4 1．5g/L,KH2PO4 0．8g/L,MnSO4 0．01g/L;适宜温度28℃。pH7．0,装液量250mL三角瓶150mL,接种量15％。铆钉菇菌丝体液体培养7d,胞外多糖产量为4．54g/L,比初始产胞外多糖1．28g／L,提高了2．55倍。     

灵芝胞内多糖高产菌株G7深层发酵工艺的研究

通过摇瓶培养实验从 2 2个广泛栽培的灵芝菌株中筛选出了胞内多糖产量最高的菌株 ,并以胞内多糖产量为指标通过单因子及正交实验优化了该菌株深层发酵所需的营养因子及非营养因子条件 ,包括碳源、氮源、初始pH、接种量、装液量、培养时间等。研究发现G7的最佳培养条件及目标产物不同 ,所需的培养时间也不同。G7在对数期内大量形成胞内多糖 ,在 6 0h胞内多糖产量最高达 5 33mg/mL培养液     

阿魏菇多糖高产菌PFPH-2的发酵过程优化研究

以阿魏菇多糖高产菌PFPH-2为试验菌株,采用营养因子正交优化及发酵过程动态培养方法,研究营养因子对PFPH-2菌丝体多糖产量的影响以及动态发酵过程PFPH-2菌丝体生物量与发酵液pH值的相关性。结果表明:正交优化组合对PFPH-2菌丝体胞内多糖积累有协同效应,在最佳组合的发酵体系中PFPH-2菌丝体胞内多糖产量达到(903.73±1.23)mg/L的最高水平;发酵体系中PFPH-2菌丝体生物量与发酵液pH值有一定相关性,以发酵液pH值降到低点且趋于稳定的时间终止发酵其菌丝体生物量最大。     

白灵菇多糖液体发酵工艺的优化

以胞外多糖为指标,通过摇瓶培养的方式对白灵菇液体发酵培养基及培养条件进行了研究。结果表明,白灵菇液体发酵产胞外多糖的最佳培养基组合为：葡萄糖2%、蛋白胨0.75%、CaCl20.2%;白灵菇液体发酵产胞外多糖的最佳发酵条件为：起始pH值7.0,接种量20%,装液量120mL,培养天数6d。     

红栓菌多糖对无机硒的生物转化

本论文进行了红栓菌对硒的耐受力及其菌丝体多糖对硒富集作用的研究。结果表明，红栓菌具有较强的富硒能力，在发酵培养基中添加硒浓度达到20μg／mL时，对菌丝体生长的抑制率最小，菌丝体干重和多糖含量达到最大值，分别为4.3mg／mL和29．8mg／g同时进行了红栓菌多糖富硒的发酵务件优化：pH5．5，接种量10％，装液量80mL／500mL三角瓶，28℃，200rpm培养3d，在发酵起始加入硒溶液，菌丝体多糖及多糖中硒含量分别达到27．3mg／g和816．7μg／g，多糖对无机硒的转化率为34．2％。     

香菇液体菌种深层发酵工艺探索

在香菇菌种液体发酵培养基筛选、50 L发酵罐工艺试验的基础上,探索500 L发酵罐发酵工艺。发酵30h时p H开始降低;38 h时溶氧开始下降;120 h菌丝球固形物体积达92.16%;76 h~120 h流加碱(饱和Na_2CO_3溶液)频率最高;168 h发酵菌丝体接种栽培袋的菌丝体活力明显下降;192 h在显微镜下可观测到大量菌丝体片段;接种量在5 mL和10 mL时菌丝萌发最好。运用无菌培养接种罐接种(已申请专利),可有效降低接种环节培养基被污染的风险;香菇液体菌种深层发酵在24℃,p H4.5,溶氧量90%~98%,搅拌速率180 r·min-1条件下进行比较适宜;最佳接种时间为96 h~144 h,接种量为每个接种孔5 mL~10 mL。     

桑黄菌液体发酵培养基及发酵条件研究

研究了桑黄菌在发酵过程中菌丝体及胞内外多糖产量变化趋势,碳源、氮源以及接种量、摇床转速、温度和pH值等因素对桑黄菌液体深层发酵菌丝产量的影响。结果表明:玉米粉为最佳碳源,豆饼粉为最佳氮源,优化培养基配方为:玉米粉4.0%、豆饼0.5%、KH2PO40.1%、MgSO4.7H2O0.05%;最适菌丝体生长的液体发酵条件:培养温度26℃,摇瓶转速130rpm,pH值6.5,接种量15%￣20%,培养时间7d。     

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.     

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.     

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.     

Effect of L-Arg on plasma content of endothelin and expression of c-fos mRNA in the left ventricle of rats with renovascular hypertensive hypertrophy

AIM:To study the effect of L-Arg on plasma content of endothelin (ET) and the expression of proto-oncogene c-fos mRNA in the left ventricle of rats with renovascular hypertensive hypertrophy. METHODS: The level of c-fos mRNA were measured by in situ hybridization. The ET in plasma were measured by radioimmunoassay. RESULTS:After eight weeks of treatment with L-Arg, the expression of c-fos decreased markedly (P＜0.01). The ET content in plasma also decreased significantly by L-Arg(P＜0.01).CONCLUSION: Plasma ET content and the expression of c-fos in the left ventricle of rats with renovascular hypertensive hypertrophy could be decreased by L-Arg administration.     

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.     

Compositional and Functional Properties of Saskatoon Berry and Blueberry

Abstract

Saskatoon berry (Amelanchier alnifolia Nutt., Rosaceae) and blueberry (Vaccinium corymbosum L., Ericaceae) are substantially equivalent in all characteristics that are important to the consumer, including fruit color, shape, size, nutrition, texture, and uses. In addition, both fruits are native to North America and they have practically identical historical uses and known health benefits. Their composition, processing, nutritional value and metabolism, intended uses, and levels of undesirable substances are compared.     

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.     

Relationships of landscape,prey and agronomic variables to the abundance of generalist predators in cotton (<Emphasis Type="Italic">Gossypium hirsutum</Emphasis>) fields

A two-year field study investigated the possible effects of grain sorghum (Sorghum bicolor [L.] Moench) and uncultivated areas on the abundance of generalist predators in commercially-managed cotton (Gossypium hirsutum L.) fields in Texas, USA. From 63 to 70 fields were sampled for pests and predators over nine consecutive weeks during early stages of cotton development. Additional data on agronomic practices and landscape composition at three spatial scales were also collected for each field. Stepwise regression analyses were used to determine the relationships of landscape, agronomic and prey variables to the abundance of generalist predators. Because the variables most closely linked to predator levels could vary over time, separate regressions were conducted for three time periods corresponding to stages of grain sorghum growth (half-bloom, hard-dough, maturity) in each year. Significant relationships between predator abundance and agricultural landscape composition appear in both years and in all three time periods, but the specific relationships of landscape variables to cotton predator levels differed between and within years. At maturity in 2001, predator levels rose as the amount of uncultivated land from 1.6 to 3.2 km distant and the perimeter shared with grain sorghum increased. During 2002, the area of grain sorghum (half-bloom) and uncultivated land (hard-dough) within 1.6 km of cotton fields were both positively related to predator numbers. Cotton planting dates and the abundance of cotton fleahoppers (Pseudatomoscelis seriatus [Reuter]) were also strongly linked to predator numbers during both years. Results suggest that the total amount of grain sorghum or uncultivated land in an area is more important than the presence of these habitats adjacent to cotton fields, and that landscape composition may sometimes be the most important factor in determining predator abundance.     

Cryopreservation of shoot apices of hawthorn in vitro cultures originating from East Asia

The objective of this study was to establish a cryopreservation protocol for hawthorn shoot apices (Crataegus pinnatifida Bge.). Cryopreservation was carried out via encapsulation–dehydration, vitrification, and encapsulation–vitrification on shoot apices excised from in vitro cultures. We began by showing that cold-acclimation enhanced the regrowth of cryopreserved apices from 10.0 to 65.5% in encapsulation–dehydration. We then decided that the encapsulation–dehydration method was an optimal cryopreservation method for hawthorn shoot apices in terms of its high recovery after cryopreservation as well as its ease of use compared with vitrification and encapsulation–vitrification. In encapsulation–dehydration, the protocol leading to optimal regrowth was as follows: after cold-acclimation at 5 °C in the dark for 2 weeks, excised shoot tips were pretreated for 24 h at 25 °C on hormone-free Murashige and Skoog [Murashige, T., Skoog, F., 1962. A revised medium for rapid growth and bioassays with tobacco tissue culture. Physiol. Plant. 15, 473–497] (MS) basal medium with 0.4 mol/L sucrose, then encapsulated and precultured in liquid MS medium with 0.8 mol/L sucrose for 16 h at 25 °C. Precultured beads were dehydrated for 6 h at 25 °C in the dessicator containing 50 g silica gel to a moisture content of 15.3% (fresh-weight basis) before cryostorage for 1 h. In addition, we examined the effect of adding glycerol to both the alginate beads and loading solution to enhance regrowth after cryopreservation in encapsulation–dehydration. In the present study, it was shown that adding 0.5 mol/L glycerol resulted in high regrowth percentages (82.5–90.0%) in four Crataegus species.