Quantum Simulation of the Universal Features of the Polyakov Loop.

Lattice gauge theories are fundamental to our understanding of high-energy physics. Nevertheless, the search for suitable platforms for their quantum simulation has proven difficult. We show that the Abelian Higgs model in 1+1 dimensions is a prime candidate for an experimental quantum simulation of a lattice gauge theory. To this end, we use a discrete tensor reformulation to smoothly connect the space-time isotropic version used in most numerical lattice simulations to the continuous-time limit corresponding to the Hamiltonian formulation. The eigenstates of the Hamiltonian are neutral for periodic boundary conditions, but we probe the nonzero charge sectors by introducing either a Polyakov loop or an external electric field. In both cases we obtain universal functions relating the mass gap, the gauge coupling, and the spatial size, which are invariant under the deformation of the temporal lattice spacing. We propose to use a physical multileg ladder of atoms trapped in optical lattices and interacting with Rydberg-dressed interactions to quantum simulate the model and check the universal features. Our results provide a path to the analog quantum simulation of lattice gauge theories with atoms in optical lattices.

Indoor air quality in hairdressing salons in Taipei.

To improve indoor air quality and to protect public health, Taiwan has enacted the "Indoor Air Quality Act (IAQ Act)" in 2012. For the general public, the indoor air quality in hair salons is important because it is a popular location that people will often visit for hair treatments. However, only a few exposure assessments regarding air pollutants have previously been performed in hair salons. To assess the air quality of hairdressing environments in Taipei, ten hairdressing salons were included for a walk-through survey in this study. In addition, the airborne concentrations of formaldehyde, volatile organic compounds (VOCs), CO2 , and phthalate esters were also determined in 5 salons. Charcoal, XAD-2, and OVS-Tenax tubes were used for the air sampling, while the samples were analyzed with gas chromatography/mass spectrometer. It was found that the products used in hair salons contained various chemicals. In fact, from the walk-through survey, a total of 387 different ingredients were found on 129 hair product labels. The hair salons were not well ventilated, with CO2 levels of 600 to 3576 ppm. The formaldehyde concentrations determined in this study ranged from 12.40 to 1.04 × 103  µg m-3 , and the maximum level was above the permissible exposure limit (PEL) of US Occupational Safety and Health Administration (US OSHA). Additionally, 83% of the samples were with levels higher than the standard regulated by Taiwan's IAQ Act. The concentrations of VOCs and phthalate esters were below the occupational exposure limits (OELs), but higher than what was found in general residential environments. The hair products were considered as the major source of air pollutants because significantly higher concentrations were found around the working areas. The number of perming treatments, the number of workers, and the frequency of using formaldehyde releasing products, were found to be associated with the levels of formaldehyde. This study indicates that efforts are needed to improve the indoor air quality in hairdressing salons in Taipei.

New applications of the renormalization group method in physics: a brief introduction.

The renormalization group (RG) method developed by Ken Wilson more than four decades ago has revolutionized the way we think about problems involving a broad range of energy scales such as phase transitions, turbulence, continuum limits and bifurcations in dynamical systems. The Theme Issue provides articles reviewing recent progress made using the RG method in atomic, condensed matter, nuclear and particle physics. In the following, we introduce these articles in a way that emphasizes common themes and the universal aspects of the method.

The association between lumican gene polymorphisms and high myopia.

PURPOSES: Lumican (LUM) is one of the major extracellular matrix components of the sclera. Increasing evidence suggests that changes in the structure and composition of the sclera are major factors in regulating scleral integrity and axial elongation of the eye, as in myopia. PATIENTS AND METHODS: Patients (n=182; age range, 17-24 years) were with a myopic spherical equivalent (SE)>6.5 diopters (D) and the control group comprised individuals (n=78; age range, 17-25 years) were with a myopic SE<0.5 D. The DNA fragments were separated by horizontal electrophoresis on 3% agarose gels. The forward primer was labelled with a 5' FAM and the reaction products were detected using a 3100 Genetic Analyzer. RESULTS: The polymorphisms detected in this study were LUMc.601, LUM-59, LUM-628, and LUM-1554. Moreover, the haplotype distributions of Ht1 (C/A/CC/T), Ht2 (C/A/--/T), Ht3 (T/A/CC/C), Ht4 (T/--/CC/T), Ht5 (T/--/CC/C), and Ht6 (T/--/--/C) of these polymorphisms were compared between the two groups. The haplotype frequencies of Ht1, Ht2, Ht5, and Ht6 differed significantly between the two groups (P=2.08x10(-5), odds ratio (OR): 2.19, 95% confidence interval (CI): 1.52-3.15; P=2.2x10(-5), OR: 0.39, 95% CI: 0.25-0.61; P=2.7x10(-5), OR: 0.36, 95% CI: 0.22-0.59; P=3.7x10(-5), OR: 4.71, 95% CI: 2.12-10.5, respectively). CONCLUSIONS: These observations suggest that the four polymorphisms of the LUM promoter contribute to the pathogenesis of high myopia. Understanding the functions of LUM in myopia helps us design new methods in treating and preventing myopia.

Theory of scanning tunneling spectroscopy of magnetic adatoms in graphene.

We examine theoretically the signatures of magnetic adatoms in graphene probed by scanning tunneling spectroscopy (STS). When the adatom hybridizes equally with the two graphene sublattices, the broadening of the local adatom level is anomalous and can scale with the cube of the energy. In contrast to ordinary metal surfaces, the adatom local moment can be suppressed by the proximity of the probing scanning tip. We propose that the dependence of the tunneling conductance on the distance between the tip and the adatom can provide a clear signature for the presence of local magnetic moments. We also show that tunneling conductance can distinguish whether the adatom is located on top of a carbon atom or in the center of a honeycomb hexagon.

Pairing and density-wave phases in boson-fermion mixtures at fixed filling.

We study a mixture of fermionic and bosonic cold atoms on a two-dimensional optical lattice, where the fermions are prepared in two isospin states and the bosons have Bose-Einstein condensed. Number density fluctuations of the condensate form delocalized bosonic modes which couple to the fermionic atoms similarly to the electron-phonon coupling in crystals. We study the phase diagram for this system at fixed fermion density of one per site. We find that tuning of the lattice parameters and interaction strengths drives the system to undergo antiferromagnetic ordering, s-wave and d-wave pairing superconductivity, or a charge density-wave phase. We use functional renormalization group analysis where retardation effects are fully taken into account. We calculate response functions and also provide estimates of the energy gap associated with the dominant order, and how it depends on different parameters of the problem.

Competing types of order in two-dimensional bose-fermi mixtures.

Using a functional renormalization group approach we study the zero temperature phase diagram of two-dimensional Bose-Fermi mixtures of ultracold atoms in optical lattices, in the limit when the velocity of bosonic condensate fluctuations is much larger than the Fermi velocity. For spin-1/2 fermions we obtain a phase diagram, which shows a competition of pairing phases of various orbital symmetry (s, p, and d) and antiferromagnetic order. We determine the value of the gaps of various phases close to half filling, and identify subdominant orders as well as short-range fluctuations from the renormalization group flow. For spinless fermions we find that p-wave pairing dominates the phase diagram.

Association of tumour necrosis factor alpha -308 gene polymorphism with primary open-angle glaucoma in Chinese.

PURPOSE: Genetic factors are known to play a role in the aetiology of glaucoma, and in particular the role of the immune system is highly suspected. In this study, we evaluated the association between tumour necrosis factor alpha -308 (TNF alpha -308) and primary open-angle glaucoma (POAG). METHODS: A total of sixty POAG patients and 103 healthy volunteers as control group were enrolled in this case-controlled study. Furthermore, we used polymerase chain reaction based analysis to resolve the TNF alpha -308 polymorphism. Statistical analysis for the relative risk of TNF alpha -308 polymorphism was compared by the chi(2) test. RESULTS: There were significant differences in the distribution of the polymorphism between the POAG patients and the control subjects (P = 0.00016; P < 0.05) and it was found that the A(-308) allele occurred more frequently in POAG patients (odds ratio: 2.72; 95% confidence interval: 1.66-4.45). CONCLUSION: The results of our study concluded that the distribution of TNF alpha -308 was significantly higher in the POAG patients than in the control group. Therefore, the A(-308) allele appears to be associated with POAG and, therefore, could be used as a genetic marker for disease mapping. POAG is a complex disease, and a single gene could not be responsible. Understanding the role of genetic polymorphisms, like TNF alpha, could be a prediction of the disease and useful for developing new treatments for POAG.

Distributions of p53 codon 72 polymorphism in primary open angle glaucoma.

BACKGROUND: Glaucomatous neuropathy is a type of cell death by apoptosis. The p53 gene is one of the regulatory genes of apoptosis. Recently, p53 codon 72 polymorphism has been extensively studied to determine the risk factors responsible for many diseases. In the p53 gene, a single base change from G to C causes the alternation of amino acid residue 72 from arginine to proline. In this study the association between p53 codon 72 polymorphism and primary open angle glaucoma (POAG) patients was evaluated. METHODS: 58 POAG patients and 59 healthy volunteers were enrolled in this study. Polymerase chain reaction based analysis was used to resolve the p53 codon 72 polymorphism. RESULTS: There were significant differences in the distribution of the polymorphism between the control subjects and the POAG patients (p = 0.00782) The proline form of p53 gene codon 72 appears to be a significant risk factor in the development of POAG (odds ratio 2.389, 95% confidence interval: 1.14 to 5.01). CONCLUSIONS: Retinal ganglion cells die during POAG by apoptosis. The tumour suppressor protein, p53, is one of the primary regulators steps of apoptosis, and the results of our study are compatible with this concept.

Quantitative analysis of enantioselective enzymatic hydrolysis with non-enantioselective removal of chiral products.

Kinetic resolution of racemic compounds by enzymatic hydrolysis with non-enantioselective separation of enantiomer products via a separator or ion-pair formation has been quantitatively analyzed. Theoretical results indicate that the removal of chiral products has profound effects on improving the conversion and enantiomeric excess for the desired chiral substrate or product. The analysis was confirmed from lipase-catalyzed hydrolysis of racemic methyl 2-chloropropionate in the presence of pyrrolidine in buffer saturated dichloromethane.

Lipase-catalyzed dynamic resolution of naproxen 2,2,2-trifluoroethyl thioester by hydrolysis in isooctane

A lipase-catalyzed enantioselective hydrolysis process under continuous in situ racemization of substrate by using trioctylamine as an organic base was developed for the production of (S)-naproxen from racemic naproxen thioesters in isooctane. Naproxen 2,2, 2-trifluoroethyl thioester and 45 degrees C were selected as the best substrate and temperature, respectively, by comparing the time-course variations for the racemization of (S)-naproxen thioesters containing an electron-withdrawing group. A detailed investigation of the effect of trioctylamine concentration on the kinetic behaviors of the thioester in racemization and enzymatic reaction was conducted, in which more than 70% conversion of the racemate (or 67.2% yield of (S)-naproxen) with eep value higher than 92% was obtained. Copyright 1999 John Wiley & Sons, Inc.