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排序方式: 共有190条查询结果,搜索用时 93 毫秒
101.
Ashwin Kumar Myakalwar Narahara Chari Dingari Ramachandra Rao Dasari Ishan Barman Manoj Kumar Gundawar 《PloS one》2014,9(8)
We demonstrate the application of non-gated laser induced breakdown spectroscopy (LIBS) for characterization and classification of organic materials with similar chemical composition. While use of such a system introduces substantive continuum background in the spectral dataset, we show that appropriate treatment of the continuum and characteristic emission results in accurate discrimination of pharmaceutical formulations of similar stoichiometry. Specifically, our results suggest that near-perfect classification can be obtained by employing suitable multivariate analysis on the acquired spectra, without prior removal of the continuum background. Indeed, we conjecture that pre-processing in the form of background removal may introduce spurious features in the signal. Our findings in this report significantly advance the prior results in time-integrated LIBS application and suggest the possibility of a portable, non-gated LIBS system as a process analytical tool, given its simple instrumentation needs, real-time capability and lack of sample preparation requirements. 相似文献
102.
Lakshmi Subramanian Ryan Remedios Ashwin Shetty Shubha Tole 《Seminars in cell & developmental biology》2009,20(6):712-718
The early cortical primordium develops from a sheet of neuroepithelium that is flanked by distinct signaling centers. Of these, the hem and the antihem are positioned as longitudinal stripes, running rostro-caudally along the medial and lateral faces, respectively, of each telencepahlic hemisphere. In this review we examine the similarities and differences in how these two signaling centers arise, their roles in patterning adjacent tissues, and the cells and structures they contribute to. Since both the hem and the antihem have been identified across many vertebrate phyla, they appear to be part of an evolutionary conserved set of mechanisms that play fundamental roles in forebrain development. 相似文献
103.
The endoplasmic reticulum (ER) in live cells is a highly mobile network whose structure dynamically changes on a number of timescales. The role of such drastic changes in any system is unclear, although there are correlations with ER function. A better understanding of the fundamental biophysical constraints on the system will allow biologists to determine the effects of molecular factors on ER dynamics. Previous studies have identified potential static elements that the ER may remodel around. Here, we use these structural elements to assess biophysical principles behind the network dynamics. By analyzing imaging data of tobacco leaf epidermal cells under two different conditions, i.e., native state (control) and latrunculin B (treated), we show that the geometric structure and dynamics of ER networks can be understood in terms of minimal networks. Our results show that the ER network is well modeled as a locally minimal-length network between the static elements that potentially anchor the ER to the cell cortex over longer timescales; this network is perturbed by a mixture of random and deterministic forces. The network need not have globally minimum length; we observe cases where the local topology may change dynamically between different Euclidean Steiner network topologies. The networks in the treated cells are easier to quantify, because they are less dynamic (the treatment suppresses actin dynamics), but the same general features are found in control cells. Using a Langevin approach, we model the dynamics of the nonpersistent nodes and use this to show that the images can be used to estimate both local viscoelastic behavior of the cytoplasm and filament tension in the ER network. This means we can explain several aspects of the ER geometry in terms of biophysical principles. 相似文献
104.
Huang X Su J Rao AU Tang H Zhou W Zhu X Chen X Liu Z Huang Y Degrado S Xiao D Qin J Aslanian R McKittrick BA Greenfeder S Heek Mv Chintala M Palani A 《Bioorganic & medicinal chemistry letters》2012,22(2):854-858
Based on in house screening lead compound 1 for the NAR project, SAR studies have been focused on the modification of the C2 ethers of the pyrimidinedione core structure. In this effort, an unpredictable SAR trend was overcome in the alkyl ether and arylalkyl ether series to identify compound 24 with improved in vitro activity compared to nicotinic acid. More consistent and predictable SAR was achieved in the propargyl ether series. Lead compound 41 was identified with good in vitro and in vivo activity in rat, and much improved rat PK profile. 相似文献
105.
106.
Fused tricyclic indoles as S1P₁ agonists with robust efficacy in animal models of autoimmune disease
Buzard DJ Han S Lopez L Kawasaki A Moody J Thoresen L Ullman B Lehmann J Calderon I Zhu X Gharbaoui T Sengupta D Krishnan A Gao Y Edwards J Barden J Morgan M Usmani K Chen C Sadeque A Thatte J Solomon M Fu L Whelan K Liu L Al-Shamma H Gatlin J Le M Xing C Espinola S Jones RM 《Bioorganic & medicinal chemistry letters》2012,22(13):4404-4409
Two series of fused tricyclic indoles were identified as potent and selective S1P(1) agonists. In vivo these agonists produced a significant reduction in circulating lymphocytes which translated into robust efficacy in several rodent models of autoimmune disease. Importantly, these agonists were devoid of any activity at the S1P(3) receptor in vitro, and correspondingly did not produce S1P(3) mediated bradycardia in telemeterized rat. 相似文献
107.
doi: 10.1111/j.1741‐2358.2011.00496.x Understanding the psychology of geriatric edentulous patients Objective: This article focuses on understanding our older patients who require complete prosthodontic care. By breaking down the patient psychology to its component parts, it is easier to obtain a clear picture of this special cohort of patients. Considering the increase in number of geriatric edentulous patients, this knowledge will help the dentist serve the geriatric population better. Background: The role of psychology and personality in complete denture treatment is well documented. The geriatric patient who needs complete dentures has a psychological aspect that needs consideration. Although significant, these aspects may sometimes be ignored or considered irrelevant. Materials and methods: A review of relevant literature was carried out to obtain data on the psychology and personality of geriatric, complete denture patients and their behavioural changes. The obtained data was filtered and condensed to provide a short but comprehensive look at the geriatric edentulous patient’s psychology. Conclusion: When handling geriatric edentulous patients, the dentist must be confident of addressing and managing the psychology of these patients. A thorough understanding of the geriatric mental state thus becomes important and significant for the clinician. 相似文献
108.
A Kumar R Kumar V Beniwal SN Kala A Mishra AA Raut PK Naik V Chhokar 《Bioinformation》2012,8(13):600-606
Peroxysome proliferator activated receptor coactivator-1 gene (PPARGC1A) is a positional and functional candidate gene for milk fat yield. It has key role in energy, fat and glucose metabolism. Single nucleotide polymorphisms (SNPs) in Exon-8 of PPARGC1A are reported to be associated with milk fat yield in dairy cattle. In the present investigation PPARGC1A was partially amplified (around 767bp) by designing gene specific primer and confirm by sequencing the amplicon and its comparison with the PPARGC1A gene of bovine. Comparative study of PPARGC1A among different breeds of buffaloes reveals different level of mutations with respect to its gene sequence 0.013-1.69% and protein sequence 0.42% to 2.99%, Similarly the protein structures modeled from their sequences were compared by structural superposition that shows variations (RMSD) from 0.736 to 1.507. Furthermore, the sequences were used to generate a dendrogram. It reveals that Murrah and reference are very close to each other, similarly Toda, Bhadawari and Surti are closely related, whereas Pandharpuri is separated from both the cluster. Especially the variations are more at the binding site of this protein that may be the cause that different breeds have different percentage of milk fat. Further study is underway to detect polymorphism and associate them with milk fat related traits in buffalo. 相似文献
109.
110.
Developmental pattern formation allows cells within a tissue or organ to coordinate their development and establish cell types in relationship to one another. To better characterize the developmental patterning events within one organ, the C. elegans hindgut, we have analyzed the expression pattern of several genes using green fluorescent protein-based reporter transgenes. In wild-type animals, these genes are expressed in subsets of hindgut cells rather than in individual cell types. In mutant animals, we find that some, but not all, genes expressed in cells with altered development exhibit a corresponding alteration of gene expression. The results are consistent with a model where a combination of factors contribute to each cell's fate, and address how developmental information converges to specify cell types. 相似文献