Long-term evaluation of cantilevered versus fixed–fixed resin-bonded fixed partial dentures for missing maxillary incisors

© 2016 Elsevier LtdObjectives To evaluate the long-term longevity and patient-reported outcomes of two-unit cantilevered (CL2) and three-unit fixed–fixed (FF3) resin-bonded fixed partial dentures (RBFPDs) for the replacement of a maxillary permanent incisor. Materials and methods Twenty-eight subjects were randomly assigned to receive either a CL2 or FF3 RBFPD placed by one operator. Prosthesis longevity was determined by clinical examination and history. Success was defined as absence of complications requiring intervention and survival as retention of the original prosthesis in mouth. Subjects’ satisfaction was assessed using visual analogue scale (VAS) and oral health-related quality of life (OHRQoL) using Oral Health Impact Profile (OHIP-49). Outcomes were analysed with t-test/Mann–Whitney U test, chi-square and log-rank test at significance level α = 0.05. Results Twenty-two subjects were reviewed. Thirteen of fifteen CL2 and ten of fourteen FF3 RBFPDs were examined (79.3 percent response rate) with a mean service life of 216.5 ± 20.8 months. All CL2 RBFPDs survived with no complications while only 10 percent of FF3 experienced no complications and only 50 percent of them survived (both P = 0.000). CL2 had a significantly better success and survival rate than FF3 (P = 0.000 and P = 0.009, respectively). There was no significant difference in subjects’ satisfaction and OHRQoL apart from CL2 group subjects had a higher satisfaction in cleaning of the prosthesis (84.1 ± 13.6) than FF3 group (72.6 ± 11.7) (P = 0.05). Conclusions Two-unit cantilevered RBFPDs were observed to have a significantly better success and survival than the FF3 design for the replacement of a maxillary incisor. Good patient-reported outcomes have been found for RBFPDs in single-tooth replacement in aesthetic zone.postprin

Surveillance of emerging drugs of abuse in Hong Kong: Validation of an analytical tool

© 2015, Hong Kong Academy of Medicine Press. All rights reserved. Objective: To validate a locally developed chromatography-based method to monitor emerging drugs of abuse whilst performing regular drug testing in abusers. Design: Cross-sectional study. Setting: Eleven regional hospitals, seven social service units, and a tertiary level clinical toxicology laboratory in Hong Kong. Participants: A total of 972 drug abusers and high-risk individuals were recruited from acute, rehabilitation, and high-risk settings between 1 November 2011 and 31 July 2013. A subset of the participants was of South Asian ethnicity. In total, 2000 urine or hair specimens were collected. Main outcome measures: Proof of concept that surveillance of emerging drugs of abuse can be performed whilst conducting routine drug of abuse testing in patients. Results: The method was successfully applied to 2000 samples with three emerging drugs of abuse detected in five samples: PMMA (paramethoxymethamphetamine), TFMPP [1-(3-trifluoromethylphenyl)piperazine], and methcathinone. The method also detected conventional drugs of abuse, with codeine, methadone, heroin, methamphetamine, and ketamine being the most frequently detected drugs. Other findings included the observation that South Asians had significantly higher rates of using opiates such as heroin, methadone, and codeine; and that ketamine and cocaine had significantly higher detection rates in acute subjects compared with the rehabilitation population. Conclusions: This locally developed analytical method is a valid tool for simultaneous surveillance of emerging drugs of abuse and routine drug monitoring of patients at minimal additional cost and effort. Continued, proactive surveillance and early identification of emerging drugs will facilitate prompt clinical, social, and legislative management.Link_to_subscribed_fulltex

Frontal traumatic brain injury in rats causes long-lasting impairments in impulse control that are differentially sensitive to pharmacotherapeutics and associated with chronic neuroinflammation.

Traumatic brain injury (TBI) affects millions yearly, and is increasingly associated with chronic neuropsychiatric symptoms. We assessed the long-term effects of different bilateral frontal controlled cortical impact injury severities (mild, moderate, severe) on the five-choice serial reaction time task, a paradigm with relatively independent measurements of attention, motor impulsivity and motivation. Moderately- and severely-injured animals exhibited impairments across all cognitive domains that were still evident 14 weeks post-injury, while mild-injured animals only demonstrated persistent deficits in impulse control. However, recovery of function varied considerably between subjects such that some showed no impairment (“TBI-resilient”), some demonstrated initial deficits that recovered (“TBI-vulnerable”) and some never recovered (“chronically-impaired”). Three clinically-relevant treatments for impulsecontrol or TBI, amphetamine, atomoxetine, and amantadine, were assessed for efficacy in treating injury-induced deficits. Susceptibility to TBI affected the response to pharmacological challenge with amphetamine. Whereas sham and TBI-resilient animals showed characteristic impairments in impulse control at higher doses, amphetamine had the opposite effect in chronically-impaired rats, improving task performance. In contrast, atomoxetine and amantadine reduced premature responding but increased omissions, suggesting psychomotor slowing. Analysis of brain tissue revealed that generalized neuroinflammation was associated with impulsivity even when accounting for the degree of brain damage. This is one of the first studies to characterize psychiatric-like symptoms in experimental TBI. Our data highlight the importance of testing pharmacotherapies in TBI models in order to predict efficacy, and suggest that neuroinflammation may represent a treatment target for impulse control problems following injury

Multiloop Calculations in the String-Inspired Formalism: The Single Spinor-Loop in QED

We use the worldline path-integral approach to the Bern-Kosower formalism for developing a new algorithm for calculation of the sum of all diagrams with one spinor loop and fixed numbers of external and internal photons. The method is based on worldline supersymmetry, and on the construction of generalized worldline Green functions. The two-loop QED $\beta$ -- function is calculated as an example.Comment: uuencoded ps-file, 20 pages, 2 figures, final revised version to appear in Phys. Rev.

Dynamical response of a pinned two-dimensional Wigner crystal

We re-examine a long-standing problem of a finite-frequency conductivity of a weakly pinned two-dimensional classical Wigner crystal. In this system an inhomogeneously broadened absorption line (pinning mode) centered at disorder and magnetic field dependent frequency $\omega_p$ is known to appear. We show that the relative linewidth $\Delta \omega_p / \omega_p$ of the pinning mode is of the order of one in weak magnetic fields, exhibits a power-law decrease in intermediate fields, and eventually saturates at a small value in strong magnetic fields. The linewidth narrowing is due to a peculiar mechanism of mixing between the stiffer longitudinal and the softer transverse components of the collective excitations. The width of the high-field resonance proves to be related to the density of states in the low-frequency tail of the zero-field phonon spectrum. We find a qualitative agreement with recent experiments and point out differences from the previous theoretical work on the subject.Comment: 19 pages, 11 figures. Supersedes cond-mat/990424

Amenability of groups and GG-sets

This text surveys classical and recent results in the field of amenability of groups, from a combinatorial standpoint. It has served as the support of courses at the University of G\"ottingen and the \'Ecole Normale Sup\'erieure. The goals of the text are (1) to be as self-contained as possible, so as to serve as a good introduction for newcomers to the field; (2) to stress the use of combinatorial tools, in collaboration with functional analysis, probability etc., with discrete groups in focus; (3) to consider from the beginning the more general notion of amenable actions; (4) to describe recent classes of examples, and in particular groups acting on Cantor sets and topological full groups

Microtubules gate tau condensation to spatially regulate microtubule functions.

Tau is an abundant microtubule-associated protein in neurons. Tau aggregation into insoluble fibrils is a hallmark of Alzheimer's disease and other types of dementia1, yet the physiological state of tau molecules within cells remains unclear. Using single-molecule imaging, we directly observe that the microtubule lattice regulates reversible tau self-association, leading to localized, dynamic condensation of tau molecules on the microtubule surface. Tau condensates form selectively permissible barriers, spatially regulating the activity of microtubule-severing enzymes and the movement of molecular motors through their boundaries. We propose that reversible self-association of tau molecules, gated by the microtubule lattice, is an important mechanism of the biological functions of tau, and that oligomerization of tau is a common property shared between the physiological and disease-associated forms of the molecule

Study on Biodegradation of Polyunclear Aromatic Hydrocarbons with Molecular Luminescence Spectroscopy

建立了用荧光法研究有序介质影响生物降解水中多环芳烃(PAHs) 的方法. 实验结果表明, 有序介质的增溶作用可加速PAHs 的降解. 该方法的优点是快速、简单.福建省自然科学基金资助项目(D9910008