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排序方式: 共有173条查询结果,搜索用时 187 毫秒
101.
Lena Rimsten Tove Stenberg Roger Andersson Annica Andersson Per man 《Cereal Chemistry》2003,80(4):485-490
A high‐performance size‐exclusion chromatography system (HPSEC) was set up with detection based on the specific binding of Calcofluor to β‐glucan for determination of amount and molecular weight of β‐glucan in different cereal extracts. To calibrate the HPSEC system, a purified β‐glucan was fractionated into narrow molecular weight ranges and the average molecular weight was determined before analysis on the HPSEC system. The detector response was similar for β‐glucans from oats and barley and appeared to be independent of molecular weight. Four different methods for extraction of β‐glucan from different cereal products were tested: two alkaline, one with hot water and added α‐amylase, and one with water and added xylanase. Inactivation of endogenous β‐glucanase was crucial for the stability of the extracts, even when extracting at high temperature or pH. Yields varied widely between the different extraction methods but average molecular weight and molecular weight distribution were similar. Extraction with sodium hydroxide generally gave a higher yield and molecular weight of β‐glucan in the extracts. 相似文献
102.
Vondráková Zuzana Pešek Bedřich Malbeck Jiří Bezděčková Lena Vondrák Tomáš Fischerová Lucie Eliášová Kateřina 《New Forests》2020,51(4):671-688
New Forests - Seed dormancy is an adaptive mechanism that allows seed germination under suitable environmental conditions. Germination of stored dormant seeds proceeds after dormancy breaking... 相似文献
103.
Julia Ohmes Lena Marie Saure Fabian Schütt Marie Trenkel Andreas Seekamp Regina Scherließ Rainer Adelung Sabine Fuchs 《Marine drugs》2022,20(6)
Fucoidans, sulfated polysaccharides from brown algae, possess multiple bioactivities in regard to osteogenesis, angiogenesis, and inflammation, all representing key molecular processes for successful bone regeneration. To utilize fucoidans in regenerative medicine, a delivery system is needed which temporarily immobilizes the polysaccharide at the injured site. Hydrogels have become increasingly interesting biomaterials for the support of bone regeneration. Their structural resemblance with the extracellular matrix, their flexible shape, and capacity to deliver bioactive compounds or stem cells into the affected tissue make them promising materials for the support of healing processes. Especially injectable hydrogels stand out due to their minimal invasive application. In the current study, we developed an injectable thermosensitive hydrogel for the delivery of fucoidan based on chitosan, collagen, and β-glycerophosphate (β-GP). Physicochemical parameters such as gelation time, gelation temperature, swelling capacity, pH, and internal microstructure were studied. Further, human bone-derived mesenchymal stem cells (MSC) and human outgrowth endothelial cells (OEC) were cultured on top (2D) or inside the hydrogels (3D) to assess the biocompatibility. We found that the sol-gel transition occurred after approximately 1 min at 37 °C. Fucoidan integration into the hydrogel had no or only a minor impact on the mentioned physicochemical parameters compared to hydrogels which did not contain fucoidan. Release assays showed that 60% and 80% of the fucoidan was released from the hydrogel after two and six days, respectively. The hydrogel was biocompatible with MSC and OEC with a limitation for OEC encapsulation. This study demonstrates the potential of thermosensitive chitosan-collagen hydrogels as a delivery system for fucoidan and MSC for the use in regenerative medicine. 相似文献
104.
El-Sayed NM Myler PJ Bartholomeu DC Nilsson D Aggarwal G Tran AN Ghedin E Worthey EA Delcher AL Blandin G Westenberger SJ Caler E Cerqueira GC Branche C Haas B Anupama A Arner E Aslund L Attipoe P Bontempi E Bringaud F Burton P Cadag E Campbell DA Carrington M Crabtree J Darban H da Silveira JF de Jong P Edwards K Englund PT Fazelina G Feldblyum T Ferella M Frasch AC Gull K Horn D Hou L Huang Y Kindlund E Klingbeil M Kluge S Koo H Lacerda D Levin MJ Lorenzi H Louie T Machado CR McCulloch R 《Science (New York, N.Y.)》2005,309(5733):409-415
Whole-genome sequencing of the protozoan pathogen Trypanosoma cruzi revealed that the diploid genome contains a predicted 22,570 proteins encoded by genes, of which 12,570 represent allelic pairs. Over 50% of the genome consists of repeated sequences, such as retrotransposons and genes for large families of surface molecules, which include trans-sialidases, mucins, gp63s, and a large novel family (>1300 copies) of mucin-associated surface protein (MASP) genes. Analyses of the T. cruzi, T. brucei, and Leishmania major (Tritryp) genomes imply differences from other eukaryotes in DNA repair and initiation of replication and reflect their unusual mitochondrial DNA. Although the Tritryp lack several classes of signaling molecules, their kinomes contain a large and diverse set of protein kinases and phosphatases; their size and diversity imply previously unknown interactions and regulatory processes, which may be targets for intervention. 相似文献
105.
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107.
Jinghua Fan Zhenli He Lena Q. Ma Peter J. Stoffella 《Journal of Soils and Sediments》2011,11(4):639-648
Purpose
Copper is a trace element of environmental concern. Repeated applications of Cu-containing fungicides have resulted in a large scale of Cu contamination in agricultural soils. However, limited information is available regarding Cu accumulation and availability in soils under citrus production in the Indian River Area, South Florida, which has received increasing amounts of Cu fungicides to control canker and other diseases. The purpose of this study was to investigate Cu transformation, availability, and mobility in soils as affected by external Cu loading and soil properties. 相似文献108.
109.
- During this study, the effects of epiphytic filamentous algae on the survival of demersal spawned fish eggs were investigated in one of the most important spawning grounds of herring in the western Baltic Sea, which is subject to intense and ongoing eutrophication.
- In coastal marine ecosystems all over the world, eutrophication is a primary water quality issue, often resulting in mass developments of bloom‐forming algae. Macro‐algal blooms have immense ecological effects, as they alter the structure and the function of an ecosystem. Numerous fish species are affected, as they depend on those coastal areas for spawning and as juvenile habitats.
- A comparison of the survival of herring eggs on two natural spawning beds re‐vealed an immense impact of a filamentous algal bloom. The mortality rate reached nearly 100% in the area with massive occurrence of filamentous brown algae.
- Hypothesizing that the presence of filamentous algae facilitates herring egg mortality, field and laboratory experiments were conducted and revealed particular effects of distinct algal species. The survival rate of artificially spawned eggs on algal substrates and control substrates was compared. Whereas filamentous forms of the green alga Ulva intestinalis induced no immediate effect, significantly higher egg mortality was documented in experiments with the filamentous brown alga Pylaiella littoralis.
- Considering the ecological and economical importance of herring and other coastal spawners on the one hand and the persisting and increasing effects of eutrophication and climate change on the other hand, the results of our study clearly underpin the necessity to increase global efforts to reduce nutrient loads in coastal waters.
110.
Anette Krogen?s Vibeke Rootwelt Stig Larsen Lena Renstr?m Wenche Farstad Arve Lund 《Acta veterinaria Scandinavica》2014,56(1):19