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1.
This paper studies topological properties of the lattices of non-crossing partitions of types A and B and of the poset of injective words. Specifically, it is shown that after the removal of the bottom and top elements (if existent) these posets are doubly Cohen-Macaulay. This strengthens the well-known facts that these posets are Cohen-Macaulay. Our results rely on a new poset fiber theorem which turns out to be a useful tool to prove double (homotopy) Cohen- Macaulayness of a poset. Applications to complexes of injective words are also included. 相似文献
2.
Georgakopoulou S van Grondelle R van der Zwan G 《The journal of physical chemistry. B》2006,110(7):3344-3353
In this work, we investigate the origin and characteristics of the circular dichroism (CD) spectrum of various light-harvesting 1 (LH1) complexes. The near-infrared (NIR) CD signal of these core antennae is strongly nonconservative, and the nature of this nonconservativity is under examination in this paper. So far, on the basis of the high-resolution structures of LH2, we have been able to model the absorption and CD spectra in the bacteriochlorophyll (BChl) Q(Y) and Q(X) regions of LH2 (Georgakopoulou et al., Biophys. J. 2002, 82, 2184-2197), as well as in the carotenoid region (Georgakopoulou et al., Biophys. J. 2004, 87, 3010-3022). We proceed by applying the same modeling method in order to reproduce the LH1 spectra. We assume a ring of dimers in a perfect circular arrangement with 16-fold symmetry, and account for all excitonic interactions within the ring. Because LH1 complexes exhibit Q(Y) and Q(X) CD signals of very low intensity, higher transitions can easily affect these regions. Therefore, we expand the model and take into account also the Soret and carotenoid transitions. We can now understand the shape of the absorption and CD spectra and contemplate the structure of the LH1 complex. The latter is similar to LH2 in that it is a very symmetric ring dominated by excitonic interactions. The larger number of symmetry and the bigger diameter of LH1, combined with small rotations of the BChl transition dipole moments, are responsible for the display of CD signals that are very low in intensity. The interaction of the Q(Y) with the carotenoid transitions results in complete loss of the conservativity. Interaction energies between all the pigments in the ring are calculated, and their values are in good accordance with what is reported in the literature. 相似文献
3.
4.
Motivated by the relation , holding for the -generalized Catalan numbers of type and , the connection between dominant regions of the -Shi arrangement of type and is investigated. More precisely, it is explicitly shown how copies of the set of dominant regions of the -Shi arrangement of type , biject onto the set of type such regions. This is achieved by exploiting two different viewpoints of the representative alcove of each region: the Shi tableau and the abacus diagram. In the same line of thought, a bijection between copies of the set of -Dyck paths of height
and the set of lattice paths inside an rectangle is provided. 相似文献
5.
Myrto Kyropoulou Stefano DiLeone Angelo Lanzilotto Edwin C. Constable Catherine E. Housecroft Wolfgang P. Meier Cornelia G. Palivan 《Macromolecular bioscience》2020,20(2)
Porphyrins are molecules possessing unique photophysical properties making them suitable for application in photodynamic therapy. The incorporation of porphyrins into natural or synthetic nano‐assemblies such as polymersomes is a strategy to improve and prolong their therapeutic capacities and to overcome their limitations as therapeutic and diagnostic agents. Here, 5,10,15,20‐tetrakis(1‐(6‐ethoxy‐6‐oxohexyl)‐4‐pyridin‐1‐io)‐21H,23H‐porphyrin tetrabromide porphyrin is inserted into polymersomes in order to demonstrate that the encapsulation enhances its ability to generate highly reactive singlet oxygen (1O2) upon irradiation in vitro. The photoactivation of the free and polymersome‐encapsulated porphyrin is evaluated by electron spin resonance and cell viability assays on three different mammalian cell lines. The results indicate that by encapsulating the porphyrin, a controlled ROS delivery within the cells is achieved, at the same time avoiding side effects such as dark toxicity, non‐specific porphyrin release and over time decreased activity in vitro. This work focuses on showing a not‐toxic model system for modern therapeutic nanomedicine, which works under mild irradiation and dosage conditions. 相似文献
6.
Georgakopoulou S van der Zwan G Olsen JD Hunter CN Niederman RA van Grondelle R 《The journal of physical chemistry. B》2006,110(7):3354-3361
Absorption and circular dichroism (CD) spectra of light-harvesting (LH)1 complexes from the purple bacteria Rhodobacter (Rba.) sphaeroides and Rhodospirillum (Rsp.) rubrum are presented. The complexes exhibit very low intensity, highly nonconservative, near-infrared (NIR) CD spectra. Absorption and CD spectra from several mutant and reconstituted LH1 complexes, with the carotenoid neurosporene and the precursor phytoene replacing the wild-type (WT) carotenoids, are also examined. The experiments show that the position of the carotenoid bands as well as the bacteriochlorophyll (BChl)/carotenoid ratio affect the NIR CD spectra: bluer bands and larger ratios make the NIR CD signal more conservative. Modeling results that support this finding are presented. This study, combined with the theoretical approach of the companion paper, where modeling of such complexes is presented and discussed in detail, provide a complete explanation of the origin of the nonconservative NIR CD spectra of LH1 and B820. 相似文献
7.
Afroditi Papasavva Antonio Shegani Christos Kiritsis Ioanna Roupa Myrto Ischyropoulou Konstantina Makrypidi Irineos Pilatis George Loudos Maria Pelecanou Minas Papadopoulos Ioannis Pirmettis 《Molecules (Basel, Switzerland)》2021,26(16)
Sentinel lymph node detection (SLND) is rapidly entering common practice in the management of patients with tumors. The introduction of mannose molecules to 99mTc-labeled dextrans, so far, showed that the sentinel node could trap these agents due to their recognition by the mannose receptors of lymph node macrophages. The current study aimed to synthesize, characterize, and biologically evaluate a series of mannosylated dextran derivatives labeled with 99mTc for potential use in SLND. The compounds were designed to have a dextran with a molecular weight of 10–500 kDa as a backbone, S-derivatized cysteines, efficient SNO chelators, and mannose moieties for binding to mannose receptors. They were successfully synthesized, thoroughly characterized using NMR techniques, and labeled with the fac-[99mTc(CO)3]+ synthon. Labeling with high yields and radiochemical purities was achieved with all derivatives. In vivo biodistribution and imaging studies demonstrated high uptake in the first lymph node and low uptakes in the following node and confirmed the ability to visualize the SLN. Among the compounds studied, 99mTc-D75CM demonstrated the most attractive biological features, and in combination with the high radiochemical yield and stability of the compound, its further evaluation as a new radiopharmaceutical for sentinel lymph node detection was justified. 相似文献
8.
Myrto Manolaki 《Journal of Mathematical Analysis and Applications》2012,391(2):480-488
Ostrowski showed that there are intimate connections between the gap structure of a Taylor series and the behaviour of its partial sums outside the disk of convergence. This paper investigates the corresponding problem for the homogeneous polynomial expansion of a harmonic function. The results for harmonic functions display new features in the case of higher dimensions. 相似文献
9.
Myrto Manolaki 《Potential Analysis》2013,38(3):985-1000
Let Ω be a domain in ? N such that $\left(\mathbb{R}^{N}\cup\lbrace\infty\rbrace\right)\setminus\Omega$ is connected. It is known that, for each w?∈?Ω, there exist harmonic functions on Ω that are universal at w, in the sense that partial sums of their homogeneous polynomial expansion about w approximate all plausibly approximable functions in the complement of Ω. Under the assumption that Ω omits an infinite cone, it is shown that the connectedness hypothesis on $\left(\mathbb{R}^{N}\cup\lbrace\infty\rbrace\right)\setminus\Omega$ is essential, and that a harmonic function which is universal at one point is actually universal at all points of Ω. 相似文献
10.
Myrto? SauvageotEmail author 《NoDEA : Nonlinear Differential Equations and Applications》2003,10(4):375-397
Generalizing previous results of M. Comte and P. Mironescu, it
is shown that for degree d large enough
(such that
), there
is a bifurcation branch in the set of the solutions of the Ginzburg-Landau
equation, emanating from the branch of radial solutions at the critical value
d of the parameter. Moreover, the solutions on the bifurcation branch admit
exactly d zeroes, and the energy on the bifurcation branch is strictly smaller
than the energy on the radial branch. 相似文献