滇龙胆不同部位裂环烯醚萜类物质含量比较分析

采用高效液相色谱法,对云南临沧云县滇龙胆不同部位龙胆苦苷、獐牙菜苦苷、当药苷含量进行分析.结果显示:(1)龙胆苦苷、獐牙菜苦苷、当药苷在滇龙胆根、茎、叶、花中均有分布;龙胆苦苷、獐牙菜苦苷在根部含量较高,分别为(35.88±5.89)mg/g和(1.35±0.33)mg/g;当药苷在花部含量最高,为(0.97±0.24)mg/g.(2)不同部位有效成分间具有显著(P<0.05)或极显著(P<0.01)的相关性.(3)相同海拔条件下,不同栽培方式下滇龙胆根部龙胆苦苷含量差异不显著(P>0.05),但茎部、叶部獐牙菜苦苷含量差异显著(P<0.05).     

秸秆还田条件下灌水模式对冬小麦产量和水肥利用效率的影响

于2008-2010年,在山西省临汾市尧都区半干旱、半湿润季风气候区,通过大田试验研究了玉米秸秆连续还田条件下灌水模式对冬小麦籽粒产量、干物质转移及水肥利用效率的影响.结果表明:浇越冬水可促进小麦分蘖;浇拔节水可提高分蘖成穗率,增加成穗数;浇孕穗水可促进穗部干物质积累,提高千粒重.浇2水时,推迟第2次浇水时期使叶片干物质转移量和穗粒数增加;浇2水比浇l水的肥料表观利用率高,可促进穗部干物质积累.越冬水灌水量和总灌水量对分蘖、穗部干物质积累的影响较小;拔节期或孕穗期增加灌水量则更有利于养分吸收及干物质积累与转移,提高籽粒水分利用效率,产量构成因素协调,增产效果明显.因此,确保越冬水可实现稳产,在越冬水基础上,拔节期增量灌水(900 m3·hm-2)可满足冬小麦中后期生长发育的需要,提高籽粒水分利用效率,实现节水高产栽培.     

Granulomatous Propionibacterium acnes infection after trauma surgery

We report here a rare case of infection caused by Propionibacterium acnes following trauma surgery: a 36-year-old male, accident victim was admitted to the hospital because of polytrauma. He underwent a long-drawn-out surgical intervention and after a free-muscle transfer using the rectus femoris muscle, signs of inflammation were detected in the affected area. Microbiological examination of the wound revealed the presence of P. acnes as the only etiological agent of this infection. Adequate antibiotic treatment with penicillin had been started right after the positive microbiological result. Our data confirm the pathogenic potential of P. acnes in late post-surgical infections, and suggest a proper therapeutic approach with intravenous antibiotics and surgical removal of the infected tissue.     

Efficient suspension bioreactor expansion of murine embryonic stem cells on microcarriers in serum-free medium

Large numbers of cells will be required for successful embryonic stem cell (ESC)-based cellular therapies or drug discovery, thus raising the need to develop scaled-up bioprocesses for production of ESCs and their derived progeny. Traditionally, ESCs have been propagated in adherent cultures in static flasks on fibroblasts layers in serum-containing medium. Direct translation of two-dimensional flatbed cultures to large-scale production of the quantities of cells required for therapy simply by increasing the number of dishes or flasks is not practical or economical. Here, we describe successful scaled-up production of ESCs on microcarriers in a stirred culture system in a serum-free medium. Cells expanded on CultiSpher S, Cytodex 3, and Collagen microcarriers showed superior cell-fold expansions of 439, 193, and 68, respectively, without excessive agglomeration, compared with 27 in static culture. In addition, the ESCs maintained their pluripotency after long-term culture (28 days) in serum-free medium. This is the first time mESCs have been cultured on microcarriers without prior exposure to serum and/or fibroblasts, while also eliminating the excessive agglomeration plaguing earlier studies. These protocols provide an economical, practical, serum-free means for expanding ESCs in a stirred suspension bioprocess.     

Garden Game: Shifting Cultivation,Indigenous Hunting and Wildlife Ecology in Western Panama

Participatory research documented the hunting yields of 59 households in five neighboring indigenous villages in western Panama. These households captured 2,580 kg of game over 8 months, with 47% of the harvest coming from agricultural areas. The quantity of game captured in anthropogenic habitats is influenced by the hunting strategies employed. Only 25% of game captured during hunting trips was captured in agricultural areas, as opposed to 93% while “awaiting” and 65% using traps. Reliance on different strategies is in turn dependent on age, gender, and access to firearms. I argue that garden hunting is not a response to game depletion, but rather a productive activity that is complementary to broader cultural and economic patterns, and that simultaneously protects crops from animal predation. The creation of heterogeneous habitat mosaics through shifting cultivation has played a key role in the relationship between people and wildlife in the humid neotropics, leading to adjustments in both animal foraging patterns and indigenous hunting practices.     

Palms,Pastures, and Swidden Fields: The Grounded Political Ecology of “Agro-Extractive/Shifting-cultivator Peasants” in Maranhão,Brazil

This article examines transformations associated with changes in resource use and land cover dynamics in the community of São Manoel, Maranhão state, in the eastern Brazilian Amazon. The shifting cultivator peasants in São Manoel integrate swidden fields for annual cropping, the extraction of babassu palm products, and pastures for cattle ranching. Since the early twentieth century, predominant vegetative cover patterns have been altered from species-rich mature forests to secondary succession with babassu dominant to pasture or swidden fields containing palm stands of various densities. A grounded political ecology of resource use in the area suggests that management strategies and the resulting land cover dynamics integrate site-specific decisions of peasant producers. I discuss the trajectory of production strategies in São Manoel since the establishment of the community in the 1920s, and identify the multiple dimensions affecting resource use and environmental outcomes, with an emphasis on the period following land struggles and the recovery of peasant tenure rights in the mid-1980s. The analysis indicates that socionatural trajectories that optimize resource use and address the socioeconomic needs of the community include the maintenance of palm/pastures associations.     

Response Surface Analysis of Solid State Growth of <Emphasis Type="Italic">Pleurotus ostreatus</Emphasis> Mycelia utilizing Whey Permeate

A novel approach to utilizing whey permeate, the cultivation of mycelia of the edible mushroom Pleurotus ostreatus, is introduced. Response surface analysis (RSA) was successfully applied to determine the combination of substrate concentration, temperature and pH that would result in a maximal mycelial extension rate under solid state cultivation. The conditions to maximize the mycelial extension rate were predicted to be 44 g lactose l⁻¹, pH 6.0 and 24.2 °C. Subsequent verification of these levels agreed with model predictions.     

Production of fuculose-1-phosphate aldolase using operator-repressor titration for plasmid maintenance in high cell density Escherichia coli fermentations

We report a novel application for the operator-repressor titration (ORT) plasmid maintenance system. The ability of ORT to maintain a plasmid during production of DNA has been demonstrated previously. In this study, we have used the ORT system to maintain a plasmid during high cell density cultivation and expression of a recombinant protein. No evidence of plasmid loss was seen during protein expression at high cell densities. In addition, the quantity of protein produced using this system was similar to traditional plasmid maintenance systems.     

Orbital shaker technology for the cultivation of mammalian cells in suspension

For large-scale applications in biotechnology, cultivation of mammalian cells in suspension is an essential prerequisite. Typically, suspension cultures are grown in glass spinner flasks filled to less than 50% of the nominal volume. We propose a superior system for suspension cultures of mammalian cells based on orbital shaker technology. We found that "square-shaped" bottles (square bottles) provide an inexpensive but efficient means to grow HEK-293 EBNA and CHO-DG44 cells to high density. Cultures in agitated 1-L square bottles exceeded the performance of cultures in spinner flasks, reaching densities up to 7 x 10(6) cells/mL for HEK-293 EBNA cells and 5 x 10(6) cells/mL for CHO-DG44 cells in comparison to (2.5-4) x 10(6) cells/mL for cultures of the same cells grown in spinner flasks. For 1-L square bottles, optimal cell growth and viability were observed with a filling volume of 30-40% of the nominal volume and an agitation speed of 130 rpm at a rotational diameter of 2.5 cm. Transient reporter gene expression following gene delivery by calcium phosphate-DNA co-precipitation was the same or slightly better for HEK-293 EBNA cells grown in square bottles as compared to spinner flasks. Reductions in cost, simplified handling, and better performance in cell growth and viability make the agitated square bottle a new and very promising tool for the cultivation of mammalian cells in suspension.     

Quantitative analysis of the microbial metabolome by isotope dilution mass spectrometry using uniformly 13C-labeled cell extracts as internal standards

A novel method was developed for the quantitative analysis of the microbial metabolome using a mixture of fully uniformly (U) (13)C-labeled metabolites as internal standard (IS) in the metabolite extraction procedure the subsequent liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) analysis. This mixture of fully U (13)C-labeled metabolites was extracted from biomass of Saccharomyces cerevisiae cultivated in a fed-batch fermentation on fully U (13)C-labeled substrates. The obtained labeled cell extract contained, in principle, the whole yeast metabolome, allowing the quantification of any intracellular metabolite of interest in S. cerevisiae. We have applied the labeled cell extract as IS in the analysis of glycolytic and tricarboxylic acid (TCA) cycle intermediates in S. cerevisiae sampled in both steady-state and transient conditions following a glucose pulse. The use of labeled IS effectively reduced errors due to variations occurring in the analysis and sample processing. As a result, the linearity of calibration lines and the precision of measurements were significantly improved. Coextraction of the labeled cell extract with the samples also eliminates the need to perform elaborate recovery checks for each metabolite to be analyzed. In conclusion, the method presented leads to less workload, more robustness, and a higher precision in metabolome analysis.