517 research outputs found

    Classical bifurcations and entanglement in smooth Hamiltonian system

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    We study entanglement in two coupled quartic oscillators. It is shown that the entanglement, as measured by the von Neumann entropy, increases with the classical chaos parameter for generic chaotic eigenstates. We consider certain isolated periodic orbits whose bifurcation sequence affects a class of quantum eigenstates, called the channel localized states. For these states, the entanglement is a local minima in the vicinity of a pitchfork bifurcation but is a local maxima near a anti-pitchfork bifurcation. We place these results in the context of the close connections that may exist between entanglement measures and conventional measures of localization that have been much studied in quantum chaos and elsewhere. We also point to an interesting near-degeneracy that arises in the spectrum of reduced density matrices of certain states as an interplay of localization and symmetry.Comment: 7 pages, 6 figure

    Coronary artery disease in females

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    INTRODUCTION : Coronary heart disease has been defined as “impairment of heart function due to inadequate blood flow to the heart compared to its needs, caused by obstructive changes in the coronary circulation to the heart”. Coronary heart disease is assuming serious dimension in developing countries. It is expected to be the single most important cause of death in India by the year 2015. Coronary artery disease is the leading cause of death among women, regardless of race or ethnicity and causing the deaths of 1 in 3 women than from stroke, lung cancer, chronic obstructive lung disease, and breast cancer combined. Women with coronary artery disease present differently than men, have different pathophysiologies and risks profiles and are often significantly older and thus often have poorer outcomes. Experts in industrialized societies have long recognized that the first presentation with coronary heart disease occurs approximately 10 years later among women than men, most commonly after menopause. Although coronary artery disease in general manifests earlier in less well-developed countries, the approximate 8 to 10 years age gap in time of onset between men and women is universal. Despite this delay in onset, mortality from coronary heart disease is increasing more rapidly among women than men from both developed and developing world. AIM OF STUDY : 1. This study is to find the various modes of presentation and clinical profile of coronary artery disease in females. 2. To study the associated risk factors, there is an urgent need to recognize all these conditions so as to reduce the burden associated with it in terms of increased morbidity and mortality. OBJECTIVE : 1. To find the various modes of presentation and clinical profile of coronary artery disease in females 2. To study the associated risk factopors METHODOLOGY : Design: Prospective cross sectional study. Place: Coimbatore Medical College Hospital, Coimbatore, Tertiary Care Hospital. Period of study: September 2010 to June 2011. Inclusion criteria : 1. Patients above 40 years, 2. Hypertension, 3. Diabete mellitus, 4. Dyslipidemia. Exclusion criteria: 1. Congenital heart disease, 2. Rheumatic heart disease, 3. Structural heart disease, 4. Electrical abnormalities. Subjects: 100 female patients admitted with symptoms, signs and ECG changes suggestive of CAD with biochemical markers taken as cases. RESULTS : In this study, 33% were among age group between 60 - 70 years. Coronary artery disease mortality among women gradually increases with age and increase in the risk of coronary artery disease is related to a higher incidence of hypertension, diabetes, obesity, and dyslipidemia. CONCLUSION : 1. The most common presentation is chest pain. 2. Waist-hip ratio associated with obesity and overweight increases the risk of myocardial infarction in female populations. 3. Most common presentation is STEMI. 4. Systemic hypertension, diabetes mellitus also associated with increased trisk of MI

    Record statistics in random vectors and quantum chaos

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    The record statistics of complex random states are analytically calculated, and shown that the probability of a record intensity is a Bernoulli process. The correlation due to normalization leads to a probability distribution of the records that is non-universal but tends to the Gumbel distribution asymptotically. The quantum standard map is used to study these statistics for the effect of correlations apart from normalization. It is seen that in the mixed phase space regime the number of intensity records is a power law in the dimensionality of the state as opposed to the logarithmic growth for random states.Comment: figures redrawn, discussion adde

    Enhanced magnetic properties of polymer-magnetic nanostructures synthesized by ultrasonication

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    Polymer based nickel (Ni) and cobalt (Co) co-doped ferrites were prepared by adept ultrasonication route. Different concentrations of polymer [polyvinyl alcohol (PVA)] (0.2 g and 0.5 g) was added as a surfactant to the magnetic particles. The phase purity of Ni-Co ferrites (spinel structure) was confirmed by X-ray diffraction (XRD). Enhanced saturation magnetization of polymer based magnetic nanoparticles due to shape anisotropy and size. 0.2 wt% doped ferrite showed superparamagnetic characteristics with blocking temperature above room temperature. Hence, ultrasonication route is a rapid and effective technique for tailoring size and morphology of magnetic nanostructure that could be useful in magnetic-sensor applications

    Parallel screening of FDA-approved antineoplastic drugs for identifying sensitizers of TRAIL-induced apoptosis in cancer cells

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    <p>Abstract</p> <p>Background</p> <p>Tumor Necrosis Factor-α Related Apoptosis Inducing Ligand (TRAIL) and agonistic antibodies to death receptor 4 and 5 are promising candidates for cancer therapy due to their ability to induce apoptosis selectively in a variety of human cancer cells, while demonstrating little cytotoxicity in normal cells. Although TRAIL and agonistic antibodies to DR4 and DR5 are considered safe and promising candidates in cancer therapy, many malignant cells are resistant to DR-mediated, TRAIL-induced apoptosis. In the current work, we screened a small library of fifty-five FDA and foreign-approved anti-neoplastic drugs in order to identify candidates that sensitized resistant prostate and pancreatic cancer cells to TRAIL-induced apoptosis.</p> <p>Methods</p> <p>FDA-approved drugs were screened for their ability to sensitize TRAIL resistant prostate cancer cells to TRAIL using an MTT assay for cell viability. Analysis of variance was used to identify drugs that exhibited synergy with TRAIL. Drugs demonstrating the highest synergy were selected as leads and tested in different prostate and pancreatic cancer cell lines, and one immortalized human pancreatic epithelial cell line. Sequential and simultaneous dosing modalities were investigated and the annexin V/propidium iodide assay, in concert with fluorescence microscopy, was employed to visualize cells undergoing apoptosis.</p> <p>Results</p> <p>Fourteen drugs were identified as having synergy with TRAIL, including those whose TRAIL sensitization activities were previously unknown in either prostate or pancreatic cancer cells or both. Five leads were tested in additional cancer cell lines of which, doxorubicin, mitoxantrone, and mithramycin demonstrated synergy in all lines. In particular, mitoxantrone and mithramycin demonstrated significant synergy with TRAIL and led to reduction of cancer cell viability at concentrations lower than 1 μM. At these low concentrations, mitoxantrone demonstrated selectivity toward malignant cells over normal pancreatic epithelial cells.</p> <p>Conclusions</p> <p>The identification of a number of FDA-approved drugs as TRAIL sensitizers can expand chemotherapeutic options for combination treatments in prostate and pancreatic cancer diseases.</p

    Entanglement between two subsystems, the Wigner semicircle and extreme value statistics

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    The entanglement between two arbitrary subsystems of random pure states is studied via properties of the density matrix's partial transpose, ρ12T2\rho_{12}^{T_2}. The density of states of ρ12T2\rho_{12}^{T_2} is close to the semicircle law when both subsystems have dimensions which are not too small and are of the same order. A simple random matrix model for the partial transpose is found to capture the entanglement properties well, including a transition across a critical dimension. Log-negativity is used to quantify entanglement between subsystems and analytic formulas for this are derived based on the simple model. The skewness of the eigenvalue density of ρ12T2\rho_{12}^{T_2} is derived analytically, using the average of the third moment over the ensemble of random pure states. The third moment after partial transpose is also shown to be related to a generalization of the Kempe invariant. The smallest eigenvalue after partial transpose is found to follow the extreme value statistics of random matrices, namely the Tracy-Widom distribution. This distribution, with relevant parameters obtained from the model, is found to be useful in calculating the fraction of entangled states at critical dimensions. These results are tested in a quantum dynamical system of three coupled standard maps, where one finds that if the parameters represent a strongly chaotic system, the results are close to those of random states, although there are some systematic deviations at critical dimensions.Comment: Substantially improved version (now 43 pages, 10 figures) that is accepted for publication in Phys. Rev.

    Molecular Screening for Terahertz Detection with Machine-Learning-Based Methods

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    The molecular requirements are explored for achieving efficient signal up-conversion in a recently developed technique for terahertz (THz) detection based on molecular optomechanics. We discuss which molecular and spectroscopic properties are most important for predicting efficient THz detection and outline a computational approach based on quantum-chemistry and machine-learning methods for calculating these properties. We validate this approach by bulk and surface-enhanced Raman scattering and infrared absorption measurements. We develop a virtual screening methodology performed on databases of millions of commercially available compounds. Quantum-chemistry calculations for about 3000 compounds are complemented by machine-learning methods to predict applicability of 93 000 organic molecules for detection. Training is performed on vibrational spectroscopic properties based on absorption and Raman scattering intensities. Our top molecules have conversion intensity two orders of magnitude higher than an average molecule from the database. We also discuss how other properties like molecular shape and self-assembling properties influence the detection efficiency. We identify molecular moieties whose presence in the molecules indicates high activity for THz detection and show an example where a simple modification of a frequently used self-assembling compound can enhance activity 85-fold. The capabilities of our screening method are demonstrated on narrow-band and broadband detection examples, and its possible applications in surface-enhanced spectroscopy are also discussed

    miRConnect 2.0: identification of oncogenic, antagonistic miRNA families in three human cancers

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    Abstract Background Based on their function in cancer micro(mi)RNAs are often grouped as either tumor suppressors or oncogenes. However, miRNAs regulate multiple tumor relevant signaling pathways raising the question whether two oncogenic miRNAs could be functional antagonists by promoting different steps in tumor progression. We recently developed a method to connect miRNAs to biological function by comparing miRNA and gene array expression data from the NCI60 cell lines without using miRNA target predictions (miRConnect). Results We have now extended this analysis to three primary human cancers (ovarian cancer, glioblastoma multiforme, and kidney renal clear cell carcinoma) available at the Cancer Genome Atlas (TCGA), and have correlated the expression of the clustered miRNAs with 158 oncogenic signatures (miRConnect 2.0). We have identified functionally antagonistic groups of miRNAs. One group (the agonists), which contains many of the members of the miR-17 family, correlated with c-Myc induced genes and E2F gene signatures. A group that was directly antagonistic to the agonists in all three primary cancers contains miR-221 and miR-222. Since both miR-17 ~ 92 and miR-221/222 are considered to be oncogenic this points to a functional antagonism of different oncogenic miRNAs. Analysis of patient data revealed that in certain patients agonistic miRNAs predominated, whereas in other patients antagonists predominated. In glioblastoma a high ratio of miR-17 to miR-221/222 was predictive of better overall survival suggesting that high miR-221/222 expression is more adverse for patients than high miR-17 expression. Conclusion miRConnect 2.0 is useful for identifying activities of miRNAs that are relevant to primary cancers. The new correlation data on miRNAs and mRNAs deregulated in three primary cancers are available at miRConnect.orghttp://deepblue.lib.umich.edu/bitstream/2027.42/112974/1/12864_2013_Article_4929.pd

    Entanglement, avoided crossings and quantum chaos in an Ising model with a tilted magnetic field

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    We study a one-dimensional Ising model with a magnetic field and show that tilting the field induces a transition to quantum chaos. We explore the stationary states of this Hamiltonian to show the intimate connection between entanglement and avoided crossings. In general entanglement gets exchanged between the states undergoing an avoided crossing with an overall enhancement of multipartite entanglement at the closest point of approach, simultaneously accompanied by diminishing two-body entanglement as measured by concurrence. We find that both for stationary as well as nonstationary states, nonintegrability leads to a destruction of two-body correlations and distributes entanglement more globally.Comment: Corrections in two figure captions and one new reference. To appear in Phys. Rev.

    Correlation between cribriform/intraductal prostatic adenocarcinoma and percent Gleason pattern 4 to a 22‐gene genomic classifier

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    BackgroundThe Decipher test measures expression of 22 RNA biomarkers associated with aggressive prostate cancer used to improve risk stratification of patients to help guide management. To date, Decipher’s genomic classification has not been extensively correlated with specific histologic growth patterns in prostatic adenocarcinoma. With a growing understanding of the clinical aggressiveness associated with cribriform growth pattern (CF), intraductal carcinoma (IDC), and percent Gleason pattern 4 (G4%), we sought to determine if their presence was associated with an increased genomic risk as measured by the Decipher assay.DesignClinical use of the Decipher assay was performed on the highest Gleason score (GS) tumor nodule of prostatectomy specimens from a prospective cohort of 48 patients, with GS varying from 7 through 9 to help guide clinical risk stratification. The tumors were reviewed for CF, IDC, and G4%, which were then compared to the Decipher score (0‐1) and risk stratification (high vs not high).ResultsThe presence of CF/IDC was significantly associated with Decipher risk score (P = .007), with a high‐risk Decipher score in 22% vs 56% of patients without or with CF/IDC. On binary logistic regression analysis, G4% (odds ratio [OR] 1.04 per percent increase [95% confidence interval [CI], 1.02‐1.06]; P = .0004) and CF predominant (OR, 9.60 [95%CI, 1.48‐62.16]; P = .02) were significantly associated with a high‐risk GC score. IDC did not reach significance (OR, 1.92 [95%CI, 0.65‐5.67]; P = .24).ConclusionsOur findings add to an expanding knowledge base that supports G4% and CF/IDC as molecularly unique and clinically relevant features in prostatic adenocarcinoma. These histologic features should be standardly reported as they are associated with more aggressive prostate cancer. Future work should determine the independent information of these histologic findings that are relative to genomic assessment on long‐term outcomes.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/153011/1/pros23926.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/153011/2/pros23926_am.pd
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