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排序方式: 共有533条查询结果,搜索用时 15 毫秒
171.
Kutomi O Hori M Ishida M Tominaga T Kamachi H Koll F Cohen J Yamada N Noguchi M 《Eukaryotic cell》2012,11(5):645-653
The individual role of the outer dynein arm light chains in the molecular mechanisms of ciliary movements in response to second messengers, such as Ca(2+) and cyclic nucleotides, is unclear. We examined the role of the gene termed the outer dynein arm light chain 1 (LC1) gene of Paramecium tetraurelia (ODAL1), a homologue of the outer dynein arm LC1 gene of Chlamydomonas reinhardtii, in ciliary movements by RNA interference (RNAi) using a feeding method. The ODAL1-silenced (ODAL1-RNAi) cells swam slowly, and their swimming velocity did not increase in response to membrane-hyperpolarizing stimuli. Ciliary movements on the cortical sheets of ODAL1-RNAi cells revealed that the ciliary beat frequency was significantly lower than that of control cells in the presence of ≥ 1 mM Mg(2+)-ATP. In addition, the ciliary orientation of ODAL1-RNAi cells did not change in response to cyclic AMP (cAMP). A 29-kDa protein phosphorylated in a cAMP-dependent manner in the control cells disappeared in the axoneme of ODAL1-RNAi cells. These results indicate that ODAL1 is essential for controlling the ciliary response by cAMP-dependent phosphorylation. 相似文献
172.
Marco Galaverni Davide Palumbo Elena Fabbri Romolo Caniglia Claudia Greco Ettore Randi 《European Journal of Wildlife Research》2012,58(1):47-58
Monitoring populations of elusive large carnivores like wolves (Canis lupus), which are often distributed at low density in widespread forested areas, is difficult or exceedingly expensive. Aiming to assess the power of two indirect monitoring methods, non-invasive genetic sampling and camera trapping, we designed a small-scale pilot study that was carried out from 2006 to 2008 in and around the Corno alle Scale Regional Park, Bologna, northern Italian Apennine. We collected 103 non-invasive samples (mainly scats) that were genotyped at 12 microsatellite loci and sexed using the ZFX gene. We identified 11 distinct wolf genotypes within the park and four wolf genotypes outside. Spatial locations and kinship analyses showed that the wolves belong to three different packs. The breeding pair of the ‘Park’ pack showed a complete turnover in the two sampling seasons. Two dogs, but no hybrids, were identified in the area. Up to five unbaited camera traps were activated (for 1,250 trapping-nights) close to recent wolf presence marks. We obtained 103 photos of wolves, documenting the reproduction events, the minimum number of adult and young wolves, and phenotype information each year. We obtained information on health conditions detecting probable sarcoptic mange in three individuals. Camera trapping also showed that the presence of wolves in a chase area during wild boar (Sus scrofa) hunting sessions was significantly higher in the nights just after a chase (P?0.01, χ 2 test; P?0.07¸ exact Fisher test). The data obtained from genetics and camera trapping were consistent with one other, and in part complementary. The total cost of the study (c. 28,000 €) was moderate, suggesting that this integrated approach can be successfully used to monitor the structure and dynamics of local wolf packs. 相似文献
173.
The linear hypertrophic scar has become the most common type of pathologic scarring. Silicone-gel sheeting is the first line therapy while intralesional steroid is the second. A light and electron microscopic analysis was carried out to reveal differences in tissue reaction following the two different treatments. Two groups of 12 patients each were treated for 4 months. For the first group, diluted Triamcinolone acetonide was injected until an inactive state was achieved. The other group of patients was treated with silicone-gel sheeting. The scars were examined every two weeks and their appearance documented. After reaching the expected therapeutic response, inactive scars were removed. The excised scars were evaluated through light microscopic histopathology and electron microscopy. The light and electron microscopic observations revealed marked differences following treatments. The activity of fibroblasts and the numbers of collagen fibers forming bundles decreased and the orientation of the collagen fibers was more variable in the treated scars. The amount of elastic fibers increased after both steroid and silicone-gel sheeting treatment. Vascularization was also slightly changed, with more capillaries and fewer pre-capillary arteries detected in the treated scars. Both treatments resulted in the same decrease in score but steroid treatment was more rapid in onset. We suggest that the two different treatments work through different mechanisms, although the final functional outcome is similar. 相似文献
174.
Efficient ring opening of steroidal 2,3-epoxides with stoichiometric amount of aromatic amines has been carried out using an ionic liquid ([bmim](+)[BF(4)](-)) both as solvent and catalyst. The reactions were completely regio- and stereoselective in each case. The aminoalcohol products have chair conformations in ring A. The ionic liquid-mediated ring opening can efficiently be carried out with aliphatic amines like morpholine as well. 相似文献
175.
Kunsági-Máté S Szabó K Nikfardjam MP Kollár L 《Journal of biochemical and biophysical methods》2006,69(1-2):113-119
The thermodynamics of the molecular association process between the malvidin-3-O-glucoside and a series of polyphenol derivatives (called 'copigmentation' in food chemistry) were studied in aqueous media. The Gibbs free energy, enthalpy and entropy values were determined by the fluorometric method. A combination of the Job's method with the van't Hoff theory was applied for data evaluation. The results show the exothermic character of the copigmentation process. The change of the enthalpy seems to be the same in every complexation step. However, the decreasing of the entropy term is higher at higher stoichiometries. As a result, the Gibbs free energy changes and, thus, the complex stability decreases quickly with increasing stoichiometry. Quantum-chemical investigation reveals the complexity of molecular interactions between malvidin and polyphenols, which is preferably based on pi-pi and OH-pi interaction moderated by repulsive Coulomb-type interactions. 相似文献
176.
Three years old boy with developmental renal dysplasia was hit as newborn child by attack of cerebral edema with metabolic disturbances (hypoglycemia, hypophosphatemia, ketoacidosis and with hypocoagulation state) and was classified as child at risk in the pediatric evidence. In the third year of the age he went through nephrectomy and after the operation, the similar metabolic disturbances occurred (hypoglycemia, ketoacidosis, derangement of the metabolic situation). Cerebral edema and the metabolic stroke developed. Reye's-like syndrome was considered and serious functional disturbances of basal ganglia and brain-stem structure were observed. 相似文献
177.
Randi E 《Molecular ecology》2008,17(1):285-293
The widespread occurrence of free-ranging domestic or feral carnivores (dogs, cats) or ungulates (pigs, goats), and massive releases of captive-reproduced game stocks (galliforms, waterfowl) is raising fear that introgressive hybridization with wild populations might disrupt local adaptations, leading to population decline and loss of biodiversity. Detecting introgression through hybridization is problematic if the parental populations cannot be sampled (unlike in classical stable hybrid zones), or if hybridization is sporadic. However, the use of hypervariable DNA markers (microsatellites) and new statistical methods (Bayesian models), have dramatically improved the assessment of cryptic population structure, admixture analyses and individual assignment testing. In this paper, I summarize results of projects aimed to identify occurrence and extent of introgressive hybridization in European populations of wolves (Canis lupus), wildcats (Felis silvestris), rock partridges and red-legged partridges (Alectoris graeca and Alectoris rufa), using genetic methods. Results indicate that introgressive hybridization can be locally pervasive, and that conservation plans should be implemented to preserve the integrity of the gene pools of wild populations. Population genetic methods can be fruitfully used to identify introgressed individuals and hybridizing populations, providing data which allow evaluating risks of outbreeding depression. The diffusion in the wild of invasive feral animals, and massive restocking with captive-reproduced game species, should be carefully controlled to avoid loss of genetic diversity and disruption of local adaptations. 相似文献
178.
179.
Attributional and consequential LCA of milk production 总被引:1,自引:1,他引:0
Marlies A. Thomassen Randi Dalgaard Reinout Heijungs Imke de Boer 《The International Journal of Life Cycle Assessment》2008,13(4):339-349
Background, aim and scope Different ways of performing a life cycle assessment (LCA) are used to assess the environmental burden of milk production.
A strong connection exists between the choice between attributional LCA (ALCA) and consequential LCA (CLCA) and the choice
of how to handle co-products. Insight is needed in the effect of choice on results of environmental analyses of agricultural
products, such as milk. The main goal of this study was to demonstrate and compare ALCA and CLCA of an average conventional
milk production system in The Netherlands.
Materials and methods ALCA describes the pollution and resource flows within a chosen system attributed to the delivery of a specified amount of
the functional unit. CLCA estimates how pollution and resource flows within a system change in response to a change in output
of the functional unit. For an average Dutch conventional milk production system, an ALCA (mass and economic allocation) and
a CLCA (system expansion) were performed. Impact categories included in the analyses were: land use, energy use, climate change,
acidification and eutrophication. The comparison was based on four criteria: hotspot identification, comprehensibility, quality
and availability of data.
Results Total environmental burdens were lower when using CLCA compared with ALCA. Major hotspots for the different impact categories
when using CLCA and ALCA were similar, but other hotspots differed in contributions, order and type. As experienced by the
authors, ALCA and use of co-product allocation are difficult to comprehend for a consequential practitioner, while CLCA and
system expansion are difficult to comprehend for an attributional practitioner. Literature shows concentrates used within
ALCA will be more understandable for a feeding expert than the feed used within CLCA. Outcomes of CLCA are more sensitive
to uncertainties compared with ALCA, due to the inclusion of market prospects. The amount of data required within CLCA is
similar compared with ALCA.
Discussion The main cause of these differences between ALCA and CLCA is the fact that different systems are modelled. The goal of the
study or the research question to be answered defines the system under study. In general, the goal of CLCA is to assess environmental
consequences of a change in demand, whereas the goal of ALCA is to assess the environmental burden of a product, assuming
a status-quo situation. Nowadays, however, most LCA practitioners chose one methodology independent of their research question.
Conclusions This study showed it is possible to perform both ALCA (mass and economic allocation) and CLCA (system expansion) of milk.
Choices of methodology, however, resulted in differences in: total quantitative outcomes, hotspots, degree of understanding
and quality.
Recommendations and perspectives We recommend LCA practitioners to better distinguish between ALCA and CLCA in applied studies to reach a higher degree of
transparency. Furthermore, we recommend LCA practitioners of different research areas to perform similar case studies to address
differences between ALCA and CLCA of the specific products as the outcomes might differ from our study. 相似文献
180.
Pingbo Zhang Min Zhu Yuming Zhao Jiang Qian Craig Dufresne Randi Turner Richard D. Semba Sharon D. Solomon 《Clinical proteomics》2017,14(1):37
Idiopathic macular holes (IMH) are full-thickness defects of retinal tissue that cause severe vision loss due to disruption of the anatomic fovea. Abnormal vitreous traction is involved in the formation of macular holes. Both glial cells and hyalocytes contribute to epiretinal membrane formation in IMH. In order to gain further insight into the pathophysiology of IMH, we conducted a discovery phase investigation of the vitreous proteome in four patients with macular holes and six controls using one-dimensional gel fractionation and liquid chromatography–tandem mass spectrometry analyses on an Orbitrap Elite mass spectrometer. Of a total of 5912 vitreous proteins, 32 proteins had increased and 39 proteins had decreased expression in IMH compared with controls, using a false discovery rate approach with p value < 0.001 and q value < 0.05. IMH was associated with increased expression of proteins in the complement pathway, α-2-macroglobulin, a major inducer of Müller glial cell migration, fibrinogen, and extracellular matrix proteins, and decreased expression of proteins involved in protein folding and actin filament binding. A proteomic approach revealed proteins and biological pathways that may be involved in the pathogenesis of IMH and could be targeted for future studies. 相似文献