2,942 research outputs found
Pramanicin induces apoptosis in Jurkat leukemia cells; a role for JNK, p38 and caspase activation
Pramanicin is a novel anti-fungal drug with a wide range of potential application against human diseases. It has been previously shown that pramanicin induces cell death and increases calcium levels in vascular endothelial cells. In the present study, we showed that pramanicin induced apoptosis in Jurkat T leukemia cells in a dose- and time-dependent manner. Our data reveal that pramanicin induced the release of cytochrome c and caspase-9 and caspase-3 activation, as evidenced by detection of active caspase fragments and fluorometric caspase assays. Pramanicin also activated c-jun N-terminal kinase (JNK), p38 and extracellular signal-regulated kinases (ERK 1/2) with different time and dose kinetics. Treatment of cells with specific MAP kinase and caspase inhibitors further confirmed the mechanistic involvement of these signalling cascades in pramanicin-induced apoptosis. JNK and p38 pathways acted as pro-apoptotic signalling pathways in pramanicin-induced apoptosis, in which they regulated release of cytochrome c and caspase activation. In contrast the ERK 1/2 pathway exerted a protective effect through inhibition of cytochrome c leakage from mitochondria and caspase activation, which were only observed when lower concentrations of pramanicin were used as apoptosis-inducing agent and which were masked by the intense apoptosis induction by higher concentrations of pramanicin. These results suggest pramanicin as a potential apoptosis-inducing small molecule, which acts through a well-defined JNK- and p38-dependent apoptosis signalling pathway in Jurkat T leukemia cells
Self-dual solutions of Yang-Mills theory on Euclidean AdS space
We find non-trivial, time-dependent solutions of the (anti) self-dual
Yang-Mills equations in the four dimensional Euclidean Anti-de Sitter space. In
contrast to the Euclidean flat space, the action depends on the moduli
parameters and the charge can take any non-integer value.Comment: 11 pages, 2 figures; version 2: new references added, to appear in
PR
The role of nailfold capillaroscopy in interstitial lung diseases - Can it differentiate idiopathic cases from collagen tissue disease associated interstitial lung diseases?
Introduction: Nailfold capillaroscopy (NFC) is a non-invasive diagnostic test that is mostly used for early diagnosis of collagen tissue diseases (CTDs). We aimed to evaluate whether NFC findings could be a clue for discriminating idiopathic interstitial lung diseases (ILD) from CTD associated ILDs (CTD-ILD). Additionally it was aimed to determine whether NFC could be helpful in discriminating usual interstitial pneumonia (UIP) pattern from non-specific interstitial pneumonia (NSIP) pattern. Materials and Methods: We grouped patients into three main groups: 15 CTD-ILD, 18 idiopathic ILD, and 17 patients in the control group. The CTD-ILD group was split into two subgroups: 8 patients with Sjögren’s syndrome (SJS)-associated ILD and 7 with rheumatoid arthritis (RA)-associated ILD. The idiopathic-ILD group consisted of 10 idiopathic NSIP and 8 IPF patients. The control group consisted of 10 SJS and 7 RA patients without lung disease. None of the patients were on acute exacerbation at the time of examination, and none had Reynaud’s phenomenon. Results: Mean capillary density was significantly reduced only in the CTD-ILD group as compared to the control group (p= 0.006). In subgroup analysis, it was determined that RA-ILD, IPF, and SJSILD subgroups had more severe capillaroscopic abnormalities. Mean capillary density in patients with the UIP pattern was reduced compared to patients with the NSIP pattern and those in the control group; p values were 0.008 and < 0.001, respectively. Conclusion: This study is to be the first describing and comparing the nailfold capillaroscopic findings of patients with NSIP and UIP patterns. NFC findings can be helpful in discriminating UIP patterns from NSIP patterns. But to show its role in differentiating idiopathic disease, more studies with more patients are needed. © 2015, Ankara University. All rights reserved
Cylindrically symmetric, static strings with a cosmological constant in Brans-Dicke theory
The static, cylindrically symmetric vacuum solutions with a cosmological
constant in the framework of the Brans-Dicke theory are investigated. Some of
these solutions admitting Lorentz boost invariance along the symmetry axis
correspond to local, straight cosmic strings with a cosmological constant. Some
physical properties of such solutions are studied. These strings apply
attractive or repulsive forces on the test particles. A smooth matching is also
performed with a recently introduced interior thick string solution with a
cosmological constant.Comment: 8 pages, Revtex; Published versio
Cylindrically Symmetric Vacuum Solutions in Higher Dimensional Brans-Dicke Theory
Higher dimensional, static, cylindrically symmetric vacuum solutions with and
without a cosmological constant in the Brans-Dicke theory are presented. We
show that, for a negative cosmological constant and for specific values of the
parameters, a particular subclass of these solutions include higher dimensional
topological black hole-type solutions with a flat horizon topology. We briefly
extend our discussion to stationary vacuum and vacuum solutions.Comment: V3: Published Versio
Two-Frequency Jahn-Teller Systems in Circuit QED
We investigate the simulation of Jahn-Teller models with two non-degenerate
vibrational modes using a circuit QED architecture. Typical Jahn-Teller systems
are anisotropic and require at least a two-frequency description. The proposed
simulator consists of two superconducting lumped-element resonators interacting
with a common flux qubit in the ultrastrong coupling regime. We translate the
circuit QED model of the system to a two-frequency Jahn-Teller Hamiltonian and
calculate its energy eigenvalues and the emission spectrum of the cavities. It
is shown that the system can be systematically tuned to an effective single
mode Hamiltonian from the two-mode model by varying the coupling strength
between the resonators. The flexibility in manipulating the parameters of the
circuit QED simulator permits isolating the effective single frequency and pure
two-frequency effects in the spectral response of Jahn-Teller systems.Comment: 8 pages, 4 figures, figures revise
Factorization of Joint Probability Mass Functions into Parity Check Interactions
We show that any joint probability mass function (PMF) can be expressed as a
product of parity check factors and factors of degree one with the help of some
auxiliary variables, if the alphabet size is appropriate for defining a parity
check equation. In other words, marginalization of a joint PMF is equivalent to
a soft decoding task as long as a finite field can be constructed over the
alphabet of the PMF. In factor graph terminology this claim means that a factor
graph representing such a joint PMF always has an equivalent Tanner graph. We
provide a systematic method based on the Hilbert space of PMFs and orthogonal
projections for obtaining this factorization.Comment: 5 pages, 1 figures, appeared in the proceedings of ISIT 2009; Changed
content, more recent version than as appeared in the proceeding
Godel-type Metrics in Various Dimensions II: Inclusion of a Dilaton Field
This is the continuation of an earlier work where Godel-type metrics were
defined and used for producing new solutions in various dimensions. Here a
simplifying technical assumption is relaxed which, among other things,
basically amounts to introducing a dilaton field to the models considered. It
is explicitly shown that the conformally transformed Godel-type metrics can be
used in solving a rather general class of Einstein-Maxwell-dilaton-3-form field
theories in D >= 6 dimensions. All field equations can be reduced to a simple
"Maxwell equation" in the relevant (D-1)-dimensional Riemannian background due
to a neat construction that relates the matter fields. These tools are then
used in obtaining exact solutions to the bosonic parts of various supergravity
theories. It is shown that there is a wide range of suitable backgrounds that
can be used in producing solutions. For the specific case of (D-1)-dimensional
trivially flat Riemannian backgrounds, the D-dimensional generalizations of the
well known Majumdar-Papapetrou metrics of general relativity arise naturally.Comment: REVTeX4, 17 pp., no figures, a few clarifying remarks added and
grammatical errors correcte
Lessons from Mission-Critical Spreadsheets
We present eighteen examples of mission-critical spreadsheets used by diverse people and organizations for application software development, financial risk management, executive information systems, sales and marketing business processes, business operations, and complex analytics. We argue the spreadsheet is a Rapid Development Language, an Integrated Development Environment, and a Fourth Generation Language, and has unusual challenges regarding source code protection. We note that intentional spreadsheet applications are largely absent from the error literature. We explain why people might prefer a spreadsheet to an application developed by the IT department, and show how some spreadsheet programmers choose to avoid--or do not have--an IT department. We find that 1) Spreadsheets are widely used for mission-critical functions; 2) Spreadsheets are an effective application development platform; 3) There is diversity of development skill in creators of mission-critical spreadsheets; 4) Sophisticated programmers sometimes choose spreadsheets over other languages; 5) Spreadsheets are amenable to formal development practices, but such practices seem rare; 6) Spreadsheets play a central role in the evolution of business processes and work systems; and 7) Spreadsheets are a source of accidental legacy systems . We provide the Skill-User Programming Paradigm to help interpret and explain our observations. We conclude that spreadsheets are vitally important to business, and merit sustained research to discover techniques to enhance quality, productivity, and maintainability
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