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Poisson-Boltzmann electrostatics is a well established model in biophysics; however, its application to large-scale biomolecular processes such as protein-protein encounter is still limited by the efficiency and memory constraints of existing numerical techniques. In this article, we present an efficient and accurate scheme that incorporates recently developed numerical techniques to enhance our computational ability. In particular, a boundary integral equation approach is applied to discretize the linearized Poisson-Boltzmann equation; the resulting integral formulas are well conditioned and are extended to systems with arbitrary numbers of biomolecules. The solution process is accelerated by Krylov subspace methods and a new version of the fast multipole method. In addition to the electrostatic energy, fast calculations of the forces and torques are made possible by using an interpolation procedure. Numerical experiments show that the implemented algorithm is asymptotically optimal O(N) in both CPU time and required memory, and application to the acetylcholinesterase-fasciculin complex is illustrated.

Background/Objectives: Epidemiological results on the association between tea consumption and oral cancer remain controversial. We aimed to evaluate the exact relationship between tea consumption and oral cancer in Chinese population. Subjects/Methods: A large-scale case-control study was conducted on 586 oral cancer patients and 1024 controls frequency-matched by age and gender. Epidemiological data were collected through face-to-face interviews with a structure questionnaire. Unconditional logistic regression model was used to assess the effect of tea consumption on oral cancer stratified by smoking, alcohol drinking and demographics. Quantity of tea consumed (ml/day) was categorized into five subgroups based on quartiles and then its interactions was evaluated with tobacco smoking and alcohol drinking at each subgroup. Results: Tea consumption showed an inverse association with oral cancer for non-smokers or non-alcohol drinkers (the odds ratios (ORs) were 0.610 (95% confidence interval (CI): 0.425-0.876) and 0.686 (95% CI: 0.503-0.934), respectively). For smokers or alcohol drinkers, decreased risk was only observed in those who consumed >800 ml/day. Furthermore, oolong tea consumption was associated with decreased risk of oral cancer in smokers or alcohol drinkers but not in non-smokers or non-alcohol drinkers. Tea consumption combined with smoking or/and alcohol drinking had a greater risk than tea consumption alone, but the risk was roughly reduced from zero to Q4 (>800 ml/day). Additionally, when stratified by demographics, the protective effect of tea was especially evident in females, urban residents, normal body mass index population (18.5-23.9), farmers, office workers and those aged Conclusions: Tea consumption protects against oral cancer in non-smokers or non-alcohol drinkers, but this effect may be obscured in smokers or alcohol drinkers. Additionally, demographics may modify the association between tea consumption and oral cancer., Author(s): F Chen [sup.1] , B-C He [sup.1] , L-J Yan [sup.1] , F-P Liu [sup.1] , J-F Huang [sup.1] , Z-J Hu [sup.1] , Z Lin [sup.1] , X-Y [...]

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DyF3/Bi2O3 nanowires with orthorhombic DyF3 and triclinic Bi2O3 phases were synthesized via a facile hydrothermal route using sodium dodecyl sulfate (SDS). The composite nanowires were characterized by X-ray diffraction, electron microscopy, X-ray photoelectron spectroscopy and electrochemical impedance spectroscopy. The obtained composite nanowires have the length of longer than 10 μm and diameter of about 20–100 nm. X-ray photoelectron spectroscopy confirms the composition of Dy, F, Bi and O in the composite nanowires. The formation process of the DyF3/Bi2O3 nanowires was analyzed based on the morphological and structural evolution of the products from different growth conditions. The cyclic voltammetry (CV) measurement demonstrates good electro-catalytic activity of the composite nanowires towards L-cysteine. Two pairs of CV peaks at +0.08 V, −0.43 V and −0.48 V, −0.78 V, respectively are observed at the DyF3/Bi2O3 nanowires modified glassy carbon electrode. DyF3/Bi2O3 nanowires modified glassy carbon electrode detects L-cysteine linearly over a concentration range from 0.001 to 2 mM with a detection limit of 0.25 μM. Moreover, the results show good selectivity, reproducibility and stability of the DyF3/Bi2O3 nanowires as a promising candidate for L-cysteine determination. [ABSTRACT FROM AUTHOR]

1. The following study provides the first data on the detection and types of Listeria monocytogenes isolated from broiler chickens during processing and from six Taiwanese abattoir environments. 2. Listeria monocytogenes was not detected in any cloacal (n = 120) or environmental (n = 256) samples collected before and during processing, indicating that faecal material and the environment of abattoirs were not important sources of L. monocytogenes for poultry carcases. However, 28 of 246 (11.4%; 95% CI: 7.7–16.0) rinse samples collected from carcases post-evisceration from three abattoirs were positive for L. monocytogenes. 3. The only serotypes detected were 1/2a (82.1%; 95% CI: 63.1–93.9) and 1/2b (14.3%; 95% CI: 4.0–32.7), with 3.6% (95% CI: 0.1–18.3) non-typable isolates. 4. Characterisation by Pulsed Field Gel Electrophoresis (PFGE) identified five PFGE types, confirming cross-contamination with L. monocytogenes during evisceration, chilling and post-chilling. 5. These findings highlight the potential for cross-contamination to occur through direct contact between carcases, especially whilst in chilling tanks. [ABSTRACT FROM AUTHOR]