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91.
《Journal of biological education》2012,46(4):186-189
The method for extracting and separating hydrophobic photosynthetic pigments proposed by Katayama et al. (Japanese Journal of Phycology, 42, 71-77, 1994) has been improved to introduce it to student laboratories at the senior high school level. Silica gel powder was used for removing water from fresh materials prior to extracting pigments by a mixture of organic solvents that was also used for chromatographic separation of the pigments. A small silica gel thin-layer plate or a paper strip was used for separating the pigments. The improved method may be applicable to all kinds of plant materials including algae, is easier than most other methods, and can lead to more successful results in separating these pigments by both thin-layer chromatography and paper chromatography. The method has been carried out in student laboratories in some senior high schools and universities in Japan. The results indicate that this laboratory exercise is effective for students to recognise the unity and diversity of plants. Therefore, this laboratory seems to be useful for teaching plant systematics as well as for teaching photosynthesis. 相似文献
92.
《Journal of biological education》2012,46(1):58-66
An interactive computer program written in Fortran is described which provides an exercise in the identification of bacteria. The program, IDEN, provides a novel way of enhancing a student's approach to systematic bacteriology and numerical identification procedures. An unknown bacterium is assigned to a student who is provided with a list of possible species and a list of tests which may be carried out. The student's objective is the correct identification of the unknown in the most economical manner. An indication is given concerning the way in which this program can be used to enhance theoretical instruction and practical investigation. 相似文献
93.
《Process Biochemistry》2014,49(5):751-757
The biosynthesis of L-phenylalanine (Phe) is one of the most complicated amino acid synthesis pathways. In this study, the engineering of Phe producer was carried out to illustrate the effectiveness of systems level engineering: (1) inactivated glucose specific phosphoenolpyruvate-carbohydrate phosphotransferase (PTS) system by inactivation of crr to moderate the glucose uptake rate to reduce overflow metabolism; (2) genetic switch on or off the expression of phefbr, aroG15, ydiB, aroK, and tyrB to increase the supply of precursors; (3) employed a tyrA mutant strain to reduce carbon diversion and to result in non-growing cells; (4) enhanced the efflux of Phe by overexpressing yddG to shift equilibrium towards Phe synthesis and to release the feedback regulation in Phe synthesis. The mutants in PTS were firstly compared and a crr− mutant was firstly screened. The mutant AroG15 was demonstrated to a thermostable mutant. The strains expressing yddG excreted Phe into the medium at higher rate and less intracellular Phe accumulated. By systems level engineering, an engineered Phe producer achieved 47.0 g/L Phe with a yield of 0.252 g/g which was the highest under the non-optimized fermentation condition. 相似文献
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95.
《Molecular & cellular proteomics : MCP》2020,19(3):456-466
Highlights
- •Urinary proteomes of patients with recurrent UTI, renal scarring, and VUR.
- •80 proteins differentially expressed, compared to healthy controls.
- •62 proteins may be indicative of susceptibility for UTI.
- •Altered acute phase response, extracellular matrix and carbohydrate metabolism.
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猪支原体肺炎是由猪肺炎支原体(Mycoplasma hyopneumoniae,Mhp)引起的一种存在于世界各地的严重危害养猪业的疾病,严重影响饲料报酬,造成巨大的经济损失。准确、敏感、快速的Mhp检测方法有助于了解Mhp在猪群的流行情况,进而采取相应的预防、治疗和综合防控措施。对国内外Mhp病原学、分子生物学和免疫学检测方法进行了综述,为科技工作者全面了解Mhp检测方法提供参考资料。 相似文献
100.
Jeremy M. Cohen Taegan A. McMahon Chloe Ramsay Elizabeth A. Roznik Erin L. Sauer Scott Bessler David J. Civitello Bryan K. Delius Neal Halstead Sarah A. Knutie Karena H. Nguyen Nicole Ortega Brittany Sears Matthew D. Venesky Suzanne Young Jason R. Rohr 《Ecology letters》2019,22(5):817-825
Global climate change is increasing the frequency of unpredictable weather conditions; however, it remains unclear how species‐level and geographic factors, including body size and latitude, moderate impacts of unusually warm or cool temperatures on disease. Because larger and lower‐latitude hosts generally have slower acclimation times than smaller and higher‐latitude hosts, we hypothesised that their disease susceptibility increases under ‘thermal mismatches’ or differences between baseline climate and the temperature during surveying for disease. Here, we examined how thermal mismatches interact with body size, life stage, habitat, latitude, elevation, phylogeny and International Union for Conservation of Nature (IUCN) conservation status to predict infection prevalence of the chytrid fungus Batrachochytrium dendrobatidis (Bd) in a global analysis of 32 291 amphibian hosts. As hypothesised, we found that the susceptibility of larger hosts and hosts from lower latitudes to Bd was influenced by thermal mismatches. Furthermore, hosts of conservation concern were more susceptible than others following thermal mismatches, suggesting that thermal mismatches might have contributed to recent amphibian declines. 相似文献