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171.
The title compound, C12H13ClO4, was prepared from the Vilsmeier–Haack reaction on phloroaceto­phenone. The chloro­vinyl and one of the methoxy substituents are twisted through about 75° with respect to the aromatic plane, whilst the other substituents are almost coplanar with the ring. Intermolecular hydrogen bonding involving C—H⃛O interactions generates one-dimensional chains in the direction of the a axis.  相似文献   
172.
Comparative genome sequence analysis is a powerful technique for gaining insights into any genome of interest. Streptococcus pneumoniae is a human pathogen, which causes life-threatening diseases, such as pneumoniae, bacteremia, meningitis, etc. After the whole genome of two strains of S. pneumoniae, the virulent TIGR4 and non-pathogenic R6 were sequenced; there is a hope that comparing the genomes will allow an identification of the genes responsible for its virulence and thus the development of treatment and control. Many antimicrobial drugs have diminished the risk from pneumococcal disease because of its multi-drug resistance nature. Several pneumococcal proteins are also being investigated, as virulence factors as potential vaccine or drug targets. Structural and biochemical studies of these pneumococcal virulence factors have facilitated the development of novel antibiotics or protein antigen-based vaccines for the treatment of pneumococcal disease. Here we describe the comparison between the genomes of two strains of S. pneumoniae with few existing genomics databases and tools available in the public domain websites. By comparing nucleotide and protein sequences of the two strains, we investigate the existing differences and similarities. Mainly we focus on the virulence factors and its encoding genes in TIGR4 and how do they differ from R6 strain.  相似文献   
173.
Cellular membranes exhibit a variety of controlled curvatures, with filopodia, microvilli, and mitotic cleavage furrows being only a few of many examples. Coupling between local curvature and chemical composition in membranes could provide a means of mechanically controlling the spatial organization of membrane components. Although this concept has surfaced repeatedly over the years, controlled experimental investigations have proven elusive. Here, we introduce an experimental platform, in which microfabricated surfaces impose specific curvature patterns onto lipid bilayers, that allows quantification of mechanochemical couplings in membranes. We find that, beyond a critical curvature value, membrane geometry governs the spatial ordering of phase-separated domain structures in membranes composed of cholesterol and phospholipids. The curvature-controlled ordering, a consequence of the distinct mechanical properties of the lipid phases, makes possible a determination of the bending rigidity difference between cholesterol-rich and cholesterol-poor lipid domains. These observations point to a strong coupling between mechanical bending and chemical organization that should have wide-reaching consequences for biological membranes. Curvature-mediated patterning may also be useful in controlling complex fluids other than biomembranes.  相似文献   
174.
175.
For a single-server retrial queue with state-dependent exponential interarrival, service and inter-retrial times, we study the time-dependent system size probabilities by employing continued fractions and numerical illustrations are presented.  相似文献   
176.
Polyaniline sorbed with microgram quantity of mercury was prepared and its homogeneity and stability with respect to mercury was evaluated over a period of time. The volatilisation loss of mercury during and after neutron irradiation was studied. It was found that polyaniline was homogeneous and stable with respect to mercury. No loss of mercury from polyaniline was observed during and after neutron irradiation. Thus polyaniline sorbed with mercury can serve as a good standard for neutron activation analysis of mercury.  相似文献   
177.
178.
In this paper we consider not necessarily symmetric co-positive as well as semi-monotoneQ-matrices and give a set of sufficient conditions for such matrices to beR 0-matrices. We give several examples to show the sharpness of our results. Construction of these examples is based on the following elementary proposition: IfA is a square matrix of ordern whose first two rows are identical and bothA 11 andA 22 areQ-matrices whereA ii stands for the principal submatrix ofA obtained by deleting rowi and columni fromA, thenA is aQ-matrix.Dedicated to our colleague and friend B. Ramachandran on his sixtieth birthday.Corresponding author.  相似文献   
179.
In this preliminary report, benign (n=8) and malignant (n=5) prostate tissues, in vitro, have been taken through autofluorescence spectroscopy. Employing Stokes' shift spectra and fluorescence emission spectra as tools of analysis, we were able to discriminate the two sets of tissues with sensitivity and specificity in excess of 85%. When the excised prostate chips were scanned with a spatial resolution of 1 mm, the epicenter of malignancy also could be delineated.  相似文献   
180.
The two-step (T 1 and T 2) deformation behaviour of Ni3Al-based single crystals was modelled under the framework of a new constitutive model proposed by Y.S. Choi, D.M. Dimiduk, M.D. Uchic, et al. [Phil. Mag. 87 1939 (2007)]. A new set of formulations and criteria, which identify thermally reversible and irreversible components of the constitutive variables and define the relative significance of those components, was developed and implemented within the new constitutive framework. The simulation results well captured the general qualitative trends of the flow behaviour upon re-straining at T 2 after pre-straining at T 1 for both T 1?>?T 2 and T 1?<?T 2. Modelling results suggested that the dislocation substructures generated at T 1 need to be treated as partially or fully transferable to plastic flow at T 2, at least through the early stage of re-straining, to capture all major pre-strain effects. In particular, the large strengthening effect at T 2 for even a few percent of pre-strain at T 1 was obtainable only by controlling the availability of mobile dislocations and sources at T 2.  相似文献   
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