407 research outputs found
Wall-crossing, open BPS counting and matrix models
We consider wall-crossing phenomena associated to the counting of D2-branes
attached to D4-branes wrapping lagrangian cycles in Calabi-Yau manifolds, both
from M-theory and matrix model perspective. Firstly, from M-theory viewpoint,
we review that open BPS generating functions in various chambers are given by a
restriction of the modulus square of the open topological string partition
functions. Secondly, we show that these BPS generating functions can be
identified with integrands of matrix models, which naturally arise in the free
fermion formulation of corresponding crystal models. A parameter specifying a
choice of an open BPS chamber has a natural, geometric interpretation in the
crystal model. These results extend previously known relations between open
topological string amplitudes and matrix models to include chamber dependence.Comment: 25 pages, 8 figures, published versio
Expression of the apoptotic markers in normal breast epithelium, benign mammary dysplasia and in breast cancer
Apoptosis and proliferation are processes associated with the development and
progression of breast cancer. The sensitivity of tumour cells to the induction of
apoptosis depends on the balance between pro- and anti-apoptotic proteins.
The expression of Bak and Bcl-2 was examined using an immunohistochemical
method in 71 primary breast cancers. Furthermore, Bcl-2 and Bak were assessed
in the normal mammary gland as well as in benign mammary dysplasia adjacent
to breast cancer. Positive immunostaining for Bcl-2 was observed in 77.8% of
cases of normal breast epithelium (NBE), 93% of benign dysplasia without intraductal
proliferation (BBD) as well as in 94% of intraductal proliferative lesions of
the breast (BIPL). Expression of Bak was detected in 39% of cases of NBE, 45%
of BBD and in 67% of BIPL. In breast cancer Bcl-2 and Bak expression was found
in 83% and 70% of the cases studied, respectively. Increased Bcl-2 expression in
primary tumours significantly correlated with favourable prognostic factors, namely
pT1, G2 and lack of metastases to the regional lymph nodes (p < 0.01,
p < 0.03, p < 0.02, respectively). There were no relationships between Bak and
the clinicopathological features studied, but our results indicate changes in the
expression of Bak during breast cancer development and progression. It would
appear to be important to assess and compare pro- and anti-apoptotic proteins
between normal mammary gland, benign mammary dysplasia and the primary
tumours of breast cancer. This knowledge should be helpful in understanding
breast cancer development and progression
KnotProt: a database of proteins with knots and slipknots.
The protein topology database KnotProt, http://knotprot.cent.uw.edu.pl/, collects information about protein structures with open polypeptide chains forming knots or slipknots. The knotting complexity of the cataloged proteins is presented in the form of a matrix diagram that shows users the knot type of the entire polypeptide chain and of each of its subchains. The pattern visible in the matrix gives the knotting fingerprint of a given protein and permits users to determine, for example, the minimal length of the knotted regions (knot's core size) or the depth of a knot, i.e. how many amino acids can be removed from either end of the cataloged protein structure before converting it from a knot to a different type of knot. In addition, the database presents extensive information about the biological functions, families and fold types of proteins with non-trivial knotting. As an additional feature, the KnotProt database enables users to submit protein or polymer chains and generate their knotting fingerprints
Oral Direct-Acting Agent Therapy for Hepatitis C Virus Infection: A Systematic Review
Rapid improvements in hepatitis C virus (HCV) therapy have led to the approval of multiple oral direct-acting antiviral (DAA) regimens by the U.S. Food and Drug Administration (FDA) for treatment of chronic HCV infection
Statistical model and BPS D4-D2-D0 counting
We construct a statistical model that correctly reproduces the BPS partition
function of D4-D2-D0 bound states on the resolved conifold. We prove that the
known partition function of the BPS indices is reproduced by the counting
"triangular partitions" problem. The wall-crossing phenomena in our model are
also studied.Comment: 9 pages, 6 figures; v2: typos corrected, minor change
Multiple D4-D2-D0 on the Conifold and Wall-crossing with the Flop
We study the wall-crossing phenomena of D4-D2-D0 bound states with two units
of D4-brane charge on the resolved conifold. We identify the walls of marginal
stability and evaluate the discrete changes of the BPS indices by using the
Kontsevich-Soibelman wall-crossing formula. In particular, we find that the
field theories on D4-branes in two large radius limits are properly connected
by the wall-crossings involving the flop transition of the conifold. We also
find that in one of the large radius limits there are stable bound states of
two D4-D2-D0 fragments.Comment: 24 pages, 4 figures; v2: typos corrected, minor changes, a reference
adde
Evidence for Duality of Conifold from Fundamental String
We study the spectrum of BPS D5-D3-F1 states in type IIB theory, which are
proposed to be dual to D4-D2-D0 states on the resolved conifold in type IIA
theory. We evaluate the BPS partition functions for all values of the moduli
parameter in the type IIB side, and find them completely agree with the results
in the type IIA side which was obtained by using Kontsevich-Soibelman's
wall-crossing formula. Our result is a quite strong evidence for string
dualities on the conifold.Comment: 24 pages, 13 figures, v2: typos corrected, v3: explanations about
wall-crossing improved and figures adde
Rationale, challenges, and participants in a Phase II trial of a botanical product for chronic hepatitis C
Background Chronic hepatitis C is associated with significant morbidity and mortality as a consequence of progression to cirrhosis, hepatocellular carcinoma, and liver failure. Current treatment for chronic hepatitis C with pegylated interferon (IFN) and ribavirin is associated with suboptimal responses and numerous adverse effects. A number of botanical products have been used to treat hepatic disorders. Silymarin, extracted from the milk thistle plant, Silybum marianum (L) Gaertn. (Asteraceae), has been most widely used for various liver disorders, including chronic hepatitis C, B, and alcoholic liver disease. However, the safety and efficacy of silymarin have not been studied systematically in chronic hepatitis C
- …