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排序方式: 共有191条查询结果,搜索用时 15 毫秒
71.
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Summary A novel nickel resistant, hyperaccumulatingN.crassa nir-2 mutant, isolated by us, sequestered 90% of Ni2+ from medium with 120 mg/l Ni2+. The parent wild strain showed comparable efficiency only at much lower concentrations (<10mg/l). The initial rapid rate and efficiency of Ni2+ removal could be maintained beyond 2 h by fresh addition of mycelial biomass. The results have been discussed from the stand point of the utility of metal resistant fungi in the control of environmental pollution. 相似文献
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Towards the mechanism of cellulose synthesis 总被引:9,自引:0,他引:9
Recent research has provided insights into how plants make cellulose - the major structural material of their cell walls and the basis of the cotton and wood fibre industries. Arabidopsis thaliana mutants impaired in cellulose production are defective in genes encoding membrane-bound glycosyltransferases, an endo-1,4-beta-glucanase and several enzymes involved in the N-glycosylation and quality-control pathways of the endoplasmic reticulum. The glycosyltransferases form the rosette terminal complexes seen in plasma membranes making cellulose. Synthesis might start by making lipoglucans, which, in turn, might form the substrate for the endo-1,4-beta-glucanase, before being elongated to form the long, crystalline microfibrils that assemble in the cell wall. 相似文献
76.
Chuti Laowtammathron Eric CH Cheng Pei-Hsun Cheng Brooke R Snyder Shang-Hsun Yang Zach Johnson Chanchao Lorthongpanich Hung-Chih Kuo Rangsun Parnpai Anthony WS Chan 《BMC cell biology》2010,11(1):12
Background
Pluripotent stem cells that are capable of differentiating into different cell types and develop robust hallmark cellular features are useful tools for clarifying the impact of developmental events on neurodegenerative diseases such as Huntington's disease. Additionally, a Huntington's cell model that develops robust pathological features of Huntington's disease would be valuable for drug discovery research. 相似文献77.
Cynthia CH Khoo Joseph Piper Irma Sanchez-Vargas Ken E Olson Alexander WE Franz 《BMC microbiology》2010,10(1):130
Background
The RNA interference (RNAi) pathway acts as an innate antiviral immune response in Aedes aegypti, modulating arbovirus infection of mosquitoes. Sindbis virus (SINV; family: Togaviridae, genus: Alphavirus) is an arbovirus that infects Ae. aegypti in the laboratory. SINV strain TR339 encounters a midgut escape barrier (MEB) during infection of Ae. aegypti. The nature of this barrier is not well understood. To investigate the role of the midgut as the central organ determining vector competence for arboviruses, we generated transgenic mosquitoes in which the RNAi pathway was impaired in midgut tissue of bloodfed females. We used these mosquitoes to reveal effects of RNAi impairment in the midgut on SINV replication, midgut infection and dissemination efficiencies, and mosquito longevity. 相似文献78.
Nicoline BM Voet Gijs Bleijenberg George W Padberg Baziel GM van Engelen Alexander CH Geurts 《BMC neurology》2010,10(1):56
Background
In facioscapulohumeral dystrophy (FSHD) muscle function is impaired and declines over time. Currently there is no effective treatment available to slow down this decline. We have previously reported that loss of muscle strength contributes to chronic fatigue through a decreased level of physical activity, while fatigue and physical inactivity both determine loss of societal participation. To decrease chronic fatigue, two distinctly different therapeutic approaches can be proposed: aerobic exercise training (AET) to improve physical capacity and cognitive behavioural therapy (CBT) to stimulate an active life-style yet avoiding excessive physical strain. The primary aim of the FACTS-2-FSHD (acronym for Fitness And Cognitive behavioural TherapieS/for Fatigue and ACTivitieS in FSHD) trial is to study the effect of AET and CBT on the reduction of chronic fatigue as assessed with the Checklist Individual Strength subscale fatigue (CIS-fatigue) in patients with FSHD. Additionally, possible working mechanisms and the effects on various secondary outcome measures at all levels of the International Classification of Functioning, Disability and Health (ICF) are evaluated.Methods/Design
A multi-centre, assessor-blinded, randomized controlled trial is conducted. A sample of 75 FSHD patients with severe chronic fatigue (CIS-fatigue ≥ 35) will be recruited and randomized to one of three groups: (1) AET + usual care, (2) CBT + usual care or (3) usual care alone, which consists of no therapy at all or occasional (conventional) physical therapy. After an intervention period of 16 weeks and a follow-up of 3 months, the third (control) group will as yet be randomized to either AET or CBT (approximately 7 months after inclusion). Outcomes will be assessed at baseline, immediately post intervention and at 3 and 6 months follow up.Discussion
The FACTS-2-FSHD study is the first theory-based randomized clinical trial which evaluates the effect and the maintenance of effects of AET and CBT on the reduction of chronic fatigue in patients with FSHD. The interventions are based on a theoretical model of chronic fatigue in patients with FSHD. The study will provide a unique set of data with which the relationships between outcome measures at all levels of the ICF could be assessed.Trial registration
Dutch Trial Register, NTR1447.79.
The Medicago truncatula small protein proteome and peptidome 总被引:1,自引:0,他引:1
The small protein and native peptide component of plant tissues is a neglected area of proteomic studies. We have used fractionation techniques for denatured and nondenatured protein preparations combined with 2-D LC tandem mass spectrometry to examine the sequences of small proteins and peptides in four tissues of the model legume, Medicago truncatula: the root tip and root of germinating seedlings, nitrogen fixing nodules, and young leaves. The isolation and fractionation strategies successfully enriched the small protein and native peptide content of the samples. Eighty-one small M. truncatula proteins and native peptides were identified. Most samples were dominated by ribosomal and histone proteins, and leaf samples possessed photosynthesis-related proteins. Secreted proteins such as lipid transfer proteins were common to several tissues. Twenty-four hours after germination, the roots and root tip tissues possessed several "seed-specific" and late-embryogenesis proteins. We conclude that these proteins are present in cells prior to germination and that they are subsequently used as a nutritional source for the young tissues. Native UV absorbing peptides were detected in very low molecular weight fractions and sequenced. Each peptide shared C-terminal residues and showed homology to the seed storage protein legumin. The strategies used here would be suitable for combining bioassays and mass spectrometry to identify bioactive peptides in the M. truncatula peptidome. 相似文献
80.
FABIOLA LANGO-REYNOSO JORGE CHÁVEZ-VILLABA MARCEL LE PENNEC 《Invertebrate reproduction & development.》2013,57(1-2):41-50
Summary In France, national management programs focus research on understanding reproductive factors in Crassostrea gigas to confront problems of the oyster industry. However, little information has been documented in which reproductive patterns include sexual changes. The reproductive cycle of oysters at three sites of the Atlantic coast of France was examined from 1996 to 1998, and the seasonal variations in oocyte size-frequencies, and sex ratio were described. The results showed a synchronism within the population concerning reproductive behavior. Young oocytes are generated after spawning and show no apparent changes during winter. Growth of oocytes begins in spring and cells reach maturity in April-May and are ready for a single spawning season in June-July. Oocytes that were not released during spawning are reabsorbed within the gonad. The significant difference between sites is that spawning occurred 1 month later in the southern area. A modal analysis showed that oocyte populations in the sample individuals are primordially bimodal, but with polymodal occurrences in June-July, in some cases. Irregular alternative sexuality was detected at all sites, and hermaphrodites appear to be a transition phase that allows changes from male to female during early spring. Previous observations, together with the study of the development of oocyte cohorts over time, permit a hypothetical model concerning the kinetics of gametogenesis in C. gigas. The model suggests that primary oocytes are generated from energy supplied from degenerating, as well as young oocytes that do not reach the mature stage within the gonad during autumn-winter. It seems that, during vitellogenesis, there is disintegration of smaller cells coupled with transfer of energy to the larger oocytes, which continue to grow and mature. 相似文献