Clinical evaluation of bioactive glass in the treatment of periodontal osseous defects in humans

The purpose of this study was to compare the use of bioactive glass to demineralized freeze-dried bone allograft (DFDBA) in the treatment of human periodontal osseous defects. Fifteen systemically healthy patients (6 males and 9 females, aged 30 to 63) with moderate to advanced adult periodontitis were selected for the study. All patients underwent initial therapy, which included scaling and root planing, oral hygiene instruction, and an occlusal adjustment when indicated, followed by re-evaluation 4 to 6 weeks later. Paired osseous defects in each subject were randomly selected to receive grafts of bioactive glass or DFDBA. Both soft and hard tissue measurements were taken the day of surgery (baseline) and at the 6-month re-entry surgery. The clinical examiner was calibrated and blinded to the surgical procedures, while the surgeon was masked to the clinical measurements. Statistical analysis was performed by using the paired Student's t test. The results indicated that probing depths were reduced by 3.07 +/- 0.80 mm with the bioactive glass and 2.60 +/- 1.40 mm with DFDBA. Sites grafted with bioactive glass resulted in 2.27 +/- 0.88 mm attachment level gain, while sites grafted with DFDBA had a 1.93 +/- 1.33 mm gain in attachment. Bioactive glass sites displayed 0.53 +/- 0.64 mm of crestal resorption and 2.73 mm bone fill. DFDBA-grafted sites experienced 0.80 +/- 0.56 mm of crestal resorption and 2.80 mm defect fill. The use of bioactive glass resulted in 61.8% bone fill and 73.33% defect resolution. DFDBA-grafted defects showed similar results, with 62.5% bone fill and 80.87% defect resolution. Both treatments provided soft and hard tissue improvements when compared to baseline (P < or = 0.0001). No statistical difference was found when comparing bioactive glass to DFDBA; however, studies with larger sample sizes may reveal true differences between the materials. This study suggests that bioactive glass is capable of producing results in the short term (6 months) similar to that of DFDBA when used in moderate to deep intrabony periodontal defects.     

The effects of timing jitter and tracking on the performance of impulse radio

Impulse radio (IR) is a promising ultra-wideband technique for tactical military communications. A key feature of time-hopping IR are the very narrow pulses used to convey information. Analysis of such time-hopping schemes under a variety of assumptions have been reported in the literature. However, none of these studies to date consider the effects of timing jitter and tracking on time-hopping in a ultra-wideband (UWB) setting. We consider the effects of timing jitter and tracking on the performance of binary and 4-ary UWB communications. We find that the performance of IR is very sensitive to timing jitter and tracking, at least in part due to the very narrow pulses. We also find that in the presence of timing jitter and tracking, orthogonal 4-ary pulse position modulation (PPM) out performs binary offset PPM at all jitter levels in thermal and pulse noise. Simulation results are presented that quantify the sensitivity of binary and 4-ary IR to timing jitter and tracking error.     

Verbal-discrimination learning: Varied familiarization on correct and incorrect items.

80 Ss in 4 groups were given 12 trials on a 30-pair verbal-discrimination (VD) list of very low-frequency words. The groups received different familiarization training prior to the VD task. Differential familiarization, given on correct and incorrect items, was initially beneficial, but more so when the correct item received the greater familiarization. More familiarization of incorrect than correct items resulted in a slower rate of improvement across trials than occurred when equal familiarization was given on correct and incorrect items, or when Ss received irrelevant familiarization. Equal familiarization of correct and incorrect items led to faster VD acquisition than irrelevant familiarization. (French summary) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Characterizing pathological imperfections in macromolecular crystals: lattice disorders and modulations

Macromolecular crystal structure determination can be complicated or brought to a halt by crystal imperfections. These issues motivated us to write up what we affectionately call ‘The Definitive Hitchhiker’s Guide to Pathological Macromolecular Crystals: Lattice Disorders and Modulations’. Perhaps the most challenging imperfections are lattice order–disorder phenomena and positional modulations. Many of these types of crystals have been solved, and progress has been made on the more challenging forms. Diagnostic tools and how to solve many of these problem crystal structures are reviewed. New avenues are provided for approaching the solution of incommensurately modulated crystals. There are a good number of case studies in the literature of lattice order–disorder phenomena and crystallographic modulations that make it timely to write a review. This review concludes with a projected pathway for solving incommensurately modulated crystals, personal views of future directions and needs of the crystallographic community.     

Decomposition of peracids and their salts with activated carbon

Activated carbon-mediated reductive decomposition of several commonly used peracids, peracid salts, and alkyl hydroperoxides was investigated, and oxygen release was measured. Environmentally unfriendly reagents such as dimethyl sulfide, trimethyl phosphite, and triphenyl phosphine were ineffective in reducing the peracid salts. However, the environmentally friendly and waste-minimizing activated carbon proved an effective, simple, and safe method for the decomposition of peracids, peracid salts, and alkyl hydroperoxides.     

Lower confidence limits for process capability indices Cp and Cpk when data are autocorrelated

Many organizations use a single estimate of C_p and/or C_pk for process benchmarking, without considering the sampling variability of the estimators and how that impacts the probability of meeting minimum index requirements. Lower confidence limits have previously been determined for the C_p and C_pk indices under the standard assumption of independent data, which are based on the sampling distributions of the index estimators. In this paper, lower 100(1‐α)% confidence limits for C_p and C_pk were developed for autocorrelated processes. Simulation was used to generate the empirical sampling distribution of each estimator for various combinations of sample size (n), autoregressive parameter (?), true index value (C_p or C_pk), and confidence level. In addition, the minimum values of the estimators required in order to meet quality requirements with 100(1‐α)% certainty were also determined from these empirical sampling distributions. These tables may be used by practitioners to set minimum capability requirements for index estimators, rather than true values, for the autocorrelated case. The implications of these results for practitioners will be discussed. Copyright © 2008 John Wiley & Sons, Ltd.     

Estimation of the fungal toxins,zearalenone and aflatoxin,contaminating opaque maize beer in Zambia

The concentration of zearalenone and aflatoxin was estimated in Zambian homebrewed and commercial opaque maize beer. Levels of aflatoxin were negligible. Zearalenone was present up to 4.6 mg/litre with a mean concentration of 0.92 mg/litre. Zearalenone was detected in the maize and maize malt used in beer preparation and it was found to dissolve preferentially in the liquid fraction of the beer. The concentration was related to the district of maize growth.     

Predicting trademark effectiveness.

The effectiveness of 7 competing trademarks was studied. 166 male Ss were tested. "Effectiveness is defined in terms of salience, meaning, and memory-value of the trademark. The three characteristics were found to be positively related." Taking memory-value to be the major dependent variable, through a combination of salience and meaning measures, memory-value was predicted "with a high degree of success." (PsycINFO Database Record (c) 2010 APA, all rights reserved)