155 research outputs found
On some components of Hilbert schemes of curves
Let I_{d,g,R} be the union of irreducible components of the Hilbert scheme whose general points parametrize smooth, irreducible, curves of degree d, genus g, which are non--degenerate in the projective space P^R. Under some numerical assumptions on d, g and R, we construct irreducible components of I_{d,g,R} other than the so-called distinguished component}, dominating the moduli space Mg of smooth genus--g curves, which are generically smooth and turn out to be of dimension higher than the expected one. The general point of any such a component corresponds to a curve X⊂P^R which is a suitable ramified m--cover of an irrational curve Y⊂P^{R−1}, m⩾2, lying in a surface cone over Y. The paper extends some of the results in previous papers of Y. Choi, H. Iliev, S. Kim (cf. [12,13] in Bibliography)
Cyclooxygenase-2 inhibitors. 1,5-diarylpyrrol-3-acetic esters with enhanced inhibitory activity toward cyclooxygenase-2 and improved cyclooxygenase-2/cyclooxygenase-1 selectivity.
he important role of cyclooxygenase-2 (COX-2) in the pathogenesis of inflammation and side effect limitations of current COX-2 inhibitor drugs illustrates a need for the design of new compounds based on alternative structural templates. We previously reported a set of substituted 1,5-diarylpyrrole derivatives, along with their inhibitory activity toward COX enzymes. Several compounds proved to be highly selective COX-2 inhibitors and their affinity data were rationalized through docking simulations. In this paper, we describe the synthesis of new 1,5-diarylpyrrole derivatives that were assayed for their in vitro inhibitory effects toward COX isozymes. Among them, the ethyl-2-methyl-5-[4-(methylsulfonyl)phenyl]-1-[3-fluorophenyl]-1H-pyrrol-3- acetate (1d), which was the most potent and COX-2 selective compound, also showed a very interesting in vivo anti-inflammatory and analgesic activity, laying the foundations for developing new lead compounds that could be effective agents in the armamentarium for the management of inflammation and pain
Triple canonical covers of varieties of minimal degree.
In this article we study pluriregular varieties X of general type with base-point-free canonical bundle whose canonical morphism has degree 3 and maps X onto a variety of minimal degree Y. We carry out our study from two different perspectives. First we study in Section 2 and Section 3 the canonical ring of X describing completely the degrees of its minimal generators. We apply this to the study of the projective normality of the images of the pluricanonical morphisms of X. Our study of the canonical ring of X also shows that, if the dimension of X is greater than or equal to 3, there does not exist a converse to a theorem of M. Green that bounds the degree of the generators of the canonical ring of X. This is in sharp contrast with the situation in dimension 2 where such converse exists, as proved by the authors in a previous work. Second, we study in Section 4, the structure of the canonical morphism of X. We use this to show among other things the nonexistence of some a priori plausible examples of triple canonical covers of varieties of minimal degree. We also characterize the targets of flat canonical covers of varieties of minimal degree. Some of the results of Section 4 are more general and apply to varieties X which are not necessarily regular, and to targets Y that are scrolls which are not of minimal degree
Neutrophils Driving Unconventional T Cells Mediate Resistance against Murine Sarcomas and Selected Human Tumors
Neutrophils are a component of the tumor microenvironment and have been predominantly associated with cancer progression. Using a genetic approach complemented by adoptive transfer, we found that neutrophils are essential for resistance against primary 3-methylcholantrene-induced carcinogenesis. Neutrophils were essential for the activation of an interferon-γ-dependent pathway of immune resistance, associated with polarization of a subset of CD4- CD8- unconventional αβ T cells (UTCαβ). Bulk and single-cell RNA sequencing (scRNA-seq) analyses unveiled the innate-like features and diversity of UTCαβ associated with neutrophil-dependent anti-sarcoma immunity. In selected human tumors, including undifferentiated pleomorphic sarcoma, CSF3R expression, a neutrophil signature and neutrophil infiltration were associated with a type 1 immune response and better clinical outcome. Thus, neutrophils driving UTCαβ polarization and type 1 immunity are essential for resistance against murine sarcomas and selected human tumors
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