999 research outputs found
An algorithmic proof for the completeness of two-dimensional Ising model
We show that the two dimensional Ising model is complete, in the sense that
the partition function of any lattice model on any graph is equal to the
partition function of the 2D Ising model with complex coupling. The latter
model has all its spin-spin coupling equal to i\pi/4 and all the parameters of
the original model are contained in the local magnetic fields of the Ising
model. This result has already been derived by using techniques from quantum
information theory and by exploiting the universality of cluster states. Here
we do not use the quantum formalism and hence make the completeness result
accessible to a wide audience. Furthermore our method has the advantage of
being algorithmic in nature so that by following a set of simple graphical
transformations, one is able to transform any discrete lattice model to an
Ising model defined on a (polynomially) larger 2D lattice.Comment: 18 pages, 15 figures, Accepted for publication in Physical Review
Minimal Uncertainty in Momentum: The Effects of IR Gravity on Quantum Mechanics
The effects of the IR aspects of gravity on quantum mechanics is
investigated. At large distances where due to gravity the space-time is curved,
there appears nonzero minimal uncertainty in the momentum of a
quantum mechanical particle. We apply the minimal uncertainty momentum to some
quantum mechanical interferometry examples and show that the phase shift
depends on the area surrounded by the path of the test particle . We also put
some limits on the related parameters. This prediction may be tested through
future experiments. The assumption of minimal uncertainty in momentum can also
explain the anomalous excess of the mass of the Cooper pair in a rotating thin
superconductor ring.Comment: 8 pages, revised version accepted by PR
Metabolic Dependencies in Pancreatic Cancer.
Pancreatic ductal adenocarcinoma (PDA) is a highly lethal cancer with a long-term survival rate under 10%. Available cytotoxic chemotherapies have significant side effects, and only marginal therapeutic efficacy. FDA approved drugs currently used against PDA target DNA metabolism and DNA integrity. However, alternative metabolic targets beyond DNA may prove to be much more effective. PDA cells are forced to live within a particularly severe microenvironment characterized by relative hypovascularity, hypoxia, and nutrient deprivation. Thus, PDA cells must possess biochemical flexibility in order to adapt to austere conditions. A better understanding of the metabolic dependencies required by PDA to survive and thrive within a harsh metabolic milieu could reveal specific metabolic vulnerabilities. These molecular requirements can then be targeted therapeutically, and would likely be associated with a clinically significant therapeutic window since the normal tissue is so well-perfused with an abundant nutrient supply. Recent work has uncovered a number of promising therapeutic targets in the metabolic domain, and clinicians are already translating some of these discoveries to the clinic. In this review, we highlight mitochondria metabolism, non-canonical nutrient acquisition pathways (macropinocytosis and use of pancreatic stellate cell-derived alanine), and redox homeostasis as compelling therapeutic opportunities in the metabolic domain
Detection of human papillomavirus DNA sequences in oral lesions using polymerase chain reaction
The purpose of the present study was to estimate the frequency of HPV DNA in four groups of oral lesions, including oral squamous cell carcinoma. Sixty paraffin-embedded oral tissue samples were examined for the presence of HPV DNAs using the PCR technique. These specimens were obtained from patients with oral squamous cell carcinoma (OSCC), leukoplakia, oral lichen planus (OLP), and pyogenic granuloma (PG). Consensus primers for L1 region (MY09 and MY11) and specific primers were used for detection of HPV DNA sequences in this study. we detected HPV DNA in 60% (9 out of 15) of OSCCs, 26.7% (4 out of 15) of leukoplakia, 13.3% (2 out of 15) of OLPs, and 6.7% (1 out of 15) of PGs. Statistical analysis showed that the prevalence of HPV in OSCC was significantly higher than other groups (P < 0.05). The frequency of HPV-16 and 18 detection in OSCC samples were 40% and 20%, respectively. The prevalence of these high risk HPVs was significantly higher in OSCC group (P < 0.05). The results of the present study show a successive increase of detection rate of HPV-16 and 18 DNAs from low level in samples of pyogenic granuloma and non-premalignant or questionably premalignant lesions of OLP to premalignant leukoplakia and to OSCC. © 2007 Tehran University of Medical Sciences. All rights reserved
The food safety impact of salt and sodium reduction initiatives
Excessive or high salt or sodium intake is known to cause hypertension and other diseases. Within the United Kingdom voluntary targets for salt reduction have been set and laid out in the Secretary of State responsibility deal. This review considers the options available to food manufacturers to enable them to reduce salt and the potential food safety risks associated with those options. Gaps in research and knowledge within the areas of information supplied to food manufacturers, alternative solutions for salt replacement and the food safety impact of salt reduction are discussed
Generation of circular polarization of the CMB
According to the standard cosmology, near the last scattering surface, the
photons scattered via Compton scattering are just linearly polarized and then
the primordial circular polarization of the CMB photons is zero. In this work
we show that CMB polarization acquires a small degree of circular polarization
when a background magnetic field is considered or the quantum electrodynamic
sector of standard model is extended by Lorentz-noninvariant operators as well
as noncommutativity. The existence of circular polarization for the CMB
radiation may be verified during future observation programs and it represents
a possible new channel for investigating new physics effects.Comment: 28 pages, v3, Phys. Rev. D 81, 084035 (2010
A survey of patient safety culture: A tool for improving patient safety in healthcare providers service organizations
Background and aims: Patient safety is one of the main factors in quality of services provided by a health system. Patient safety culture plays a key role in improvement of patient safety, reduction of medical errors, and prevention of adverse events in health care organizations. Thereby, the present study is aimed to survey patient safety culture in hospitals of Neyshabur University of Medical Sciences. Methods: This research was a cross sectional study that conducted on all qualified staff of hospitals affiliated with Neyshabur University of Medical Sciences in 2013. Hospital Survey of Patient Safety Culture (HSOPSC) questionnaire was used to assess patient safety culture. The collected data were analyzed in SPSS (16), using Chi-Square test and logistic regression model. Results: Total score average of patient safety culture was 25.50±9.52. The results showed that among the twelve dimensions the highest and lowest scores were obtained by the supervisor/ manager expectations & actions promoting patient safety (score rate 45) and the reporting frequency of adverse events (score rate 15) respectively According to logistic regression model there was also significant relationship between the patient safety culture and direct contact with the patient, employment duration in hospital, and current unit (p<0.05). Conclusion: Total average of patient safety culture and scores of all twelve dimensions were lower than the acceptable criteria. Patient safety culture in the studied hospitals urgently needs enhancement and improvement. So, creating policies to institutionalize and enhance patient safety culture among the staffs are recommended
- …