Logarithmic Corrections in the 2D XY Model

Using two sets of high-precision Monte Carlo data for the two-dimensional XY model in the Villain formulation on square $L \times L$ lattices, the scaling behavior of the susceptibility $\chi$ and correlation length $\xi$ at the Kosterlitz-Thouless phase transition is analyzed with emphasis on multiplicative logarithmic corrections $(ln L)^{-2r}$ in the finite-size scaling region and $(ln \xi)^{-2r}$ in the high-temperature phase near criticality, respectively. By analyzing the susceptibility at criticality on lattices of size up to $512^2$ we obtain $r = -0.0270(10)$, in agreement with recent work of Kenna and Irving on the the finite-size scaling of Lee-Yang zeros in the cosine formulation of the XY model. By studying susceptibilities and correlation lengths up to $\xi \approx 140$ in the high-temperature phase, however, we arrive at quite a different estimate of $r = 0.0560(17)$, which is in good agreement with recent analyses of thermodynamic Monte Carlo data and high-temperature series expansions of the cosine formulation.Comment: 13 pages, LaTeX + 8 postscript figures. See also http://www.cond-mat.physik.uni-mainz.de/~janke/doc/home_janke.htm

P450-Mediated Non-natural Cyclopropanation of Dehydroalanine-Containing Thiopeptides

Thiopeptides are a growing class of ribosomally synthesized and post-translationally modified peptide (RiPP) natural products. Many biosynthetic enzymes for RiPPs, especially thiopeptides, are promiscuous and can accept a wide range of peptide substrates with different amino acid sequences; thus, these enzymes have been used as tools to generate new natural product derivatives. Here, we explore an alternative route to molecular complexity by engineering thiopeptide tailoring enzymes to do new or non-native chemistry. We explore cytochrome P450 enzymes as biocatalysts for cyclopropanation of dehydroalanines, chemical motifs found widely in thiopeptides and other RiPP-based natural products. We find that P450TbtJ1 and P450TbtJ2 selectively cyclopropanate dehydroalanines in a number of complex thiopeptide-based substrates and convert them into 1-amino-2-cyclopropane carboxylic acids (ACCAs), which are important pharmacophores. This chemistry takes advantage of the innate affinity of these biosynthetic enzymes for their substrates and enables incorporation of new pharmacophores into thiopeptide architectures. This work also presents a strategy for diversification of natural products through rationally repurposing biosynthetic enzymes as non-natural biocatalysts

Oral Fluid–Based Biomarkers of Alveolar Bone Loss in Periodontitis

Periodontal disease is a bacteria-induced chronic inflammatory disease affecting the soft and hard supporting structures encompassing the teeth. When left untreated, the ultimate outcome is alveolar bone loss and exfoliation of the involved teeth. Traditional periodontal diagnostic methods include assessment of clinical parameters and radiographs. Though efficient, these conventional techniques are inherently limited in that only a historical perspective, not current appraisal, of disease status can be determined. Advances in the use of oral fluids as possible biological samples for objective measures of current disease state, treatment monitoring, and prognostic indicators have boosted saliva and other oral-based fluids to the forefront of technology. Oral fluids contain locally and systemically derived mediators of periodontal disease, including microbial, host-response, and bone-specific resorptive markers. Although most biomarkers in oral fluids represent inflammatory mediators, several specific collagen degradation and bone turnover-related molecules have emerged as possible measures of periodontal disease activity. Pyridinoline cross-linked carboxyterminal telopeptide (ICTP), for example, has been highly correlated with clinical features of the disease and decreases in response to intervention therapies, and has been shown to possess predictive properties for possible future disease activity. One foreseeable benefit of an oral fluid–based periodontal diagnostic would be identification of highly susceptible individuals prior to overt disease. Timely detection and diagnosis of disease may significantly affect the clinical management of periodontal patients by offering earlier, less invasive, and more cost-effective treatment therapies.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73247/1/annals.1384.028.pd

Risk profiles and one-year outcomes of patients with newly diagnosed atrial fibrillation in India: Insights from the GARFIELD-AF Registry.

BACKGROUND: The Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF) is an ongoing prospective noninterventional registry, which is providing important information on the baseline characteristics, treatment patterns, and 1-year outcomes in patients with newly diagnosed non-valvular atrial fibrillation (NVAF). This report describes data from Indian patients recruited in this registry. METHODS AND RESULTS: A total of 52,014 patients with newly diagnosed AF were enrolled globally; of these, 1388 patients were recruited from 26 sites within India (2012-2016). In India, the mean age was 65.8 years at diagnosis of NVAF. Hypertension was the most prevalent risk factor for AF, present in 68.5% of patients from India and in 76.3% of patients globally (P < 0.001). Diabetes and coronary artery disease (CAD) were prevalent in 36.2% and 28.1% of patients as compared with global prevalence of 22.2% and 21.6%, respectively (P < 0.001 for both). Antiplatelet therapy was the most common antithrombotic treatment in India. With increasing stroke risk, however, patients were more likely to receive oral anticoagulant therapy [mainly vitamin K antagonist (VKA)], but average international normalized ratio (INR) was lower among Indian patients [median INR value 1.6 (interquartile range {IQR}: 1.3-2.3) versus 2.3 (IQR 1.8-2.8) (P < 0.001)]. Compared with other countries, patients from India had markedly higher rates of all-cause mortality [7.68 per 100 person-years (95% confidence interval 6.32-9.35) vs 4.34 (4.16-4.53), P < 0.0001], while rates of stroke/systemic embolism and major bleeding were lower after 1 year of follow-up. CONCLUSION: Compared to previously published registries from India, the GARFIELD-AF registry describes clinical profiles and outcomes in Indian patients with AF of a different etiology. The registry data show that compared to the rest of the world, Indian AF patients are younger in age and have more diabetes and CAD. Patients with a higher stroke risk are more likely to receive anticoagulation therapy with VKA but are underdosed compared with the global average in the GARFIELD-AF. CLINICAL TRIAL REGISTRATION-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01090362

TWO PRACTICAL MAGNETIC THERMOMETERS FOR USE BELOW 30 K

Nous avons mesuré la susceptibilité magnétique de Gd (PO3)3(GP) et de Nd (C2H5SO4)3. 9H2O (NES) dans le domaine de température allant de 2 à 27 K et nous avons trouvé que ces sels sont de bons thermomètres magnétiques, bien que le NES ne soit pas convenable pour des mesures précises dans la totalité du domaine considéré. En ajustant les données magnétiques aux températures récemment déterminées par des mesures acoustiques de Plumb et Cataland, nous avons développé une échelle magnétique de température ; et nous avons comparé cette échelle avec d'autres.We have measured the magnetic susceptibility of Gd (PO3)3(GP) and of Nd (C2H5SO4)3. 9H2O (NES) over the range 2 to 27 K and found these salts to be good magnetic thermometers, although NES is less suitable for accurate work over this entire range. By fitting the magnetic data to recently calculated temperatures (Tac) determined acoustically by Plumb and Catalan, a magnetic temperature scale is developed and it is compared to other scales

Anti-drug efforts ‘undermined by bureaucracy’.

The bureaucratic obsession with management objectives is undermining efforts to combat drug misuse, according to the head of the Southern Regional Drug Task Force. Chairman Peadar King said this zeal has spawned its own "management speak", peppered with words such as "organisational outputs, performance indicators, service users", etc. He made the comments in the task force’s report for 2011, which said alcohol, cannabis, and benzodiazepines were the "major presenting issues" last year. The report warned of emerging issues during the year, including oxycontin, a prescription painkiller, in Killarney, and a rise in the use of "powders" in Tralee. The report also found a rise in the use of illegal drugs, namely cannabis, as well as anti-depressants...