Quantum cellular automata quantum computing with endohedral fullerenes

We present a scheme to perform universal quantum computation using global addressing techniques as applied to a physical system of endohedrally doped fullerenes. The system consists of an ABAB linear array of Group V endohedrally doped fullerenes. Each molecule spin site consists of a nuclear spin coupled via a Hyperfine interaction to an electron spin. The electron spin of each molecule is in a quartet ground state $S=3/2$. Neighboring molecular electron spins are coupled via a magnetic dipole interaction. We find that an all-electron construction of a quantum cellular automata is frustrated due to the degeneracy of the electronic transitions. However, we can construct a quantum celluar automata quantum computing architecture using these molecules by encoding the quantum information on the nuclear spins while using the electron spins as a local bus. We deduce the NMR and ESR pulses required to execute the basic cellular automata operation and obtain a rough figure of merit for the the number of gate operations per decoherence time. We find that this figure of merit compares well with other physical quantum computer proposals. We argue that the proposed architecture meets well the first four DiVincenzo criteria and we outline various routes towards meeting the fifth criteria: qubit readout.Comment: 16 pages, Latex, 5 figures, See http://planck.thphys.may.ie/QIPDDF/ submitted to Phys. Rev.

Transepithelial Transport and Enzymatic Detoxification of Gluten in Gluten-Sensitive Rhesus Macaques

In a previous report, we characterized a condition of gluten sensitivity in juvenile rhesus macaques that is similar in many respects to the human condition of gluten sensitivity, celiac disease. This animal model of gluten sensitivity may therefore be useful toward studying both the pathogenesis and the treatment of celiac disease. Here, we perform two pilot experiments to demonstrate the potential utility of this model for studying intestinal permeability toward an immunotoxic gluten peptide and pharmacological detoxification of gluten in vivo by an oral enzyme drug candidate.Intestinal permeability was investigated in age-matched gluten-sensitive and control macaques by using mass spectrometry to detect and quantify an orally dosed, isotope labeled 33-mer gluten peptide delivered across the intestinal epithelium to the plasma. The protective effect of a therapeutically promising oral protease, EP-B2, was evaluated in a gluten-sensitive macaque by administering a daily gluten challenge with or without EP-B2 supplementation. ELISA-based antibody assays and blinded clinical evaluations of this macaque and of an age-matched control were conducted to assess responses to gluten.Labeled 33-mer peptide was detected in the plasma of a gluten-sensitive macaque, both in remission and during active disease, but not in the plasma of healthy controls. Administration of EP-B2, but not vehicle, prevented clinical relapse in response to a dietary gluten challenge. Unexpectedly, a marked increase in anti-gliadin (IgG and IgA) and anti-transglutaminase (IgG) antibodies was observed during the EP-B2 treatment phase.Gluten-sensitive rhesus macaques may be an attractive resource for investigating important aspects of celiac disease, including enhanced intestinal permeability and pharmacology of oral enzyme drug candidates. Orally dosed EP-B2 exerts a protective effect against ingested gluten. Limited data suggest that enhanced permeability of short gluten peptides generated by gastrically active glutenases may trigger an elevated antibody response, but that these antibodies are not necessarily causative of clinical illness

Tunneling Spectra of Individual Magnetic Endofullerene Molecules

The manipulation of single magnetic molecules may enable new strategies for high-density information storage and quantum-state control. However, progress in these areas depends on developing techniques for addressing individual molecules and controlling their spin. Here we report success in making electrical contact to individual magnetic N@C60 molecules and measuring spin excitations in their electron tunneling spectra. We verify that the molecules remain magnetic by observing a transition as a function of magnetic field which changes the spin quantum number and also the existence of nonequilibrium tunneling originating from low-energy excited states. From the tunneling spectra, we identify the charge and spin states of the molecule. The measured spectra can be reproduced theoretically by accounting for the exchange interaction between the nitrogen spin and electron(s) on the C60 cage.Comment: 7 pages, 4 figures. Typeset in LaTeX, updated text of previous versio

Audit of therapeutic interventions in inpatient children using two scores: are they evidence-based in developing countries?

BACKGROUND: The evidence base of clinical interventions in paediatric hospitals of developing countries has not been formally assessed. We performed this study to determine the proportion of evidence-based therapeutic interventions in a paediatric referral hospital of a developing country METHODS: The medical records of 167 patients admitted in one-month period were revised. Primary diagnosis and primary therapeutic interventions were determined for each patient. A systematic search was performed to assess the level of evidence for each intervention. Therapeutic interventions were classified using the Ellis score and the Oxford Centre for Evidence Based Medicine Levels of Evidence RESULTS: Any dehydration due to diarrhoea (59 cases) and pneumonia (42 cases) were the most frequent diagnoses. Based on Ellis score, level I evidence supported the primary therapeutic intervention in 21%, level II in 73% and level III in 6% cases. Using the Oxford classification 16%, 8%, 1% and 75% therapeutic interventions corresponded to grades A, B, C, and D recommendations, respectively. Overall, according to Ellis score, 94% interventions were evidence based. However, out of the total, 75% interventions were based on expert opinion or basic sciences. Most children with mild to moderate dehydration (52 cases) were inappropriately treated with slow intravenous fluids, and most children with non-complicated community acquired pneumonia (42 cases) received intravenous antibiotics CONCLUSIONS: Most interventions were inappropriate, despite the availability of effective therapy for several of them. Diarrhoeal dehydration and community acquired pneumonia were the most common diagnoses and were inappropriately managed. Existing effective interventions for dehydration and pneumonia need to be put into practice at referral hospitals of developing countries. For the remaining problems, there is the need to conduct appropriate clinical studies. Caution must be taken when assigning the level of evidence supporting therapeutic interventions, as commonly used classifications may be misleadin

Spin resonance clock transition of the endohedral fullerene N15@C60

The endohedral fullerene 15N@C60 has narrow electron paramagnetic resonance lines which have been proposed as the basis for a condensed-matter portable atomic clock. We measure the low-frequency spectrum of this molecule, identifying and characterizing a clock transition at which the frequency becomes insensitive to magnetic field. We infer a linewidth at the clock field of 100 kHz. Using experimental data, we are able to place a bound on the clock’s projected frequency stability. We discuss ways to improve the frequency stability to be competitive with existing miniature clocks

Parallels between Pathogens and Gluten Peptides in Celiac Sprue

Pathogens are exogenous agents capable of causing disease in susceptible organisms. In celiac sprue, a disease triggered by partially hydrolyzed gluten peptides in the small intestine, the offending immunotoxins cannot replicate, but otherwise have many hallmarks of classical pathogens. First, dietary gluten and its peptide metabolites are ubiquitous components of the modern diet, yet only a small, genetically susceptible fraction of the human population contracts celiac sprue. Second, immunotoxic gluten peptides have certain unusual structural features that allow them to survive the harsh proteolytic conditions of the gastrointestinal tract and thereby interact extensively with the mucosal lining of the small intestine. Third, they invade across epithelial barriers intact to access the underlying gut-associated lymphoid tissue. Fourth, they possess recognition sequences for selective modification by an endogenous enzyme, transglutaminase 2, allowing for in situ activation to a more immunotoxic form via host subversion. Fifth, they precipitate a T cell–mediated immune reaction comprising both innate and adaptive responses that causes chronic inflammation of the small intestine. Sixth, complete elimination of immunotoxic gluten peptides from the celiac diet results in remission, whereas reintroduction of gluten in the diet causes relapse. Therefore, in analogy with antibiotics, orally administered proteases that reduce the host's exposure to the immunotoxin by accelerating gluten peptide destruction have considerable therapeutic potential. Last but not least, notwithstanding the power of in vitro methods to reconstitute the essence of the immune response to gluten in a celiac patient, animal models for the disease, while elusive, are likely to yield fundamentally new systems-level insights

Do African-American men need separate prostate cancer screening guidelines?

BACKGROUND: In 2012, the United States Preventative Services Task Force issued new guidelines recommending that male U.S. residents, irrespective of race, no longer be screened for prostate cancer. In African American men, the incidence of prostate cancer is almost 60 % higher and the mortality rate is two to three times greater than in Caucasians. The purpose of this study is to reduce African American men's prostate cancer burden by demonstrating they need separate screening guidelines. METHODS: We performed a PubMed search using the keywords: African American, Prostate cancer, Outcomes, Molecular markers, Prostate-specific Antigen velocity, PSA density, and to derive data relevant to our hypothesis. RESULTS: In our literature review, we identified several aspects of prostate cancer that are different in Caucasian and African American men. These included prostate cancer incidence and outcome, the clinical course of the disease, serum PSA levels, genetic differences, and social barriers. It's also important to note that the USPSTF guidelines were based on two studies, one of which reported that only 4 % of its participants were African American. The other did not report demographic information, but used participants from seven European countries with small African American populations. CONCLUSION: Given the above, we conclude that separate prostate cancer screening guidelines are greatly necessary to help save the lives of African Americans