Faster Base64 Encoding and Decoding Using AVX2 Instructions

Web developers use base64 formats to include images, fonts, sounds and other resources directly inside HTML, JavaScript, JSON and XML files. We estimate that billions of base64 messages are decoded every day. We are motivated to improve the efficiency of base64 encoding and decoding. Compared to state-of-the-art implementations, we multiply the speeds of both the encoding (~10x) and the decoding (~7x). We achieve these good results by using the single-instruction-multiple-data (SIMD) instructions available on recent Intel processors (AVX2). Our accelerated software abides by the specification and reports errors when encountering characters outside of the base64 set. It is available online as free software under a liberal license.Comment: software at https://github.com/lemire/fastbase6

From the Cochrane library: Ginkgo biloba for intermittent claudication

Background: Patients with intermittent claudication suffer from pain in the muscles of the legs during exercise that is relieved by a short rest. Ginkgo biloba extract is a vasoactive agent used for symptomatic relief in intermittent claudication. In this article a meta-analysis is discussed that assessed the effect of Ginkgo biloba on walking capacity in patients with intermittent claudication. Patients and methods: The Cochrane Peripheral Vascular Diseases Group searched their Trials Register and the Cochrane Central Register of Controlled Trials in The Cochrane Library. Furthermore MEDLINE/PUBMED (until May 2008) and EMBASE (until May 2008) were searched and manufacturers of Ginkgo biloba extract were contacted. Randomized controlled trials of Ginkgo biloba extract versus placebo in people with intermittent claudication were included. Two authors independently assessed trials for selection, assessed study quality and extracted data. To standardize walking distance or time, caloric expenditures were used to correct for the different treadmill protocols. Results: Eleven trials involving 477 participants compared Ginkgo biloba with placebo and assessed the absolute claudication distance (maximal walking distance). At the end of the study the absolute claudication distance increased with an overall effect size of 3.57 kilocalories ( p = 0.06), for treatment with Ginkgo biloba, compared to placebo. This translates to an increase of 64.5 meters (confidence interval -1.8 to 130.7) on a flat treadmill with an average speed of 3.2 km/h. Conclusions: There is no evidence that Ginkgo biloba has a clinically significant benefit for patients with intermittent claudication

De restauratieve verzorgingsgraad bij de jeugd 1. Patiëntgebonden factoren

In 2007 a study was undertaken of the restorative care index of the teeth of children under the age of 18. The aim of this study was to gain insight into the factors associated with the restorative care index in children. Factors investigated were (post-) brushing, inspection frequency, sweets-consumption frequency, socio-economic status and treatment or lack thereof by a general practitioner or dentist who works in a clinic for child health care. This study made use of statistics assembled for an earlier study of children formerly covered by public health insurance in the municipality of The Hague and research carried out at child dental clinics. Socio-economic status and the level of oral care were correlated with dental quality. No patient-bound factors were significantly correlated with the level of care. There was however a positive correlation between the'type' of dentist (family dentist or dentist associated with a clinic for child dental care) and the chance of curative treatment (in the case of developing caries)

Short-term anti-plaque effect of two chlorhexidine varnishes

Background: Chlorhexidine (CHX) varnishes have been mainly used for the prevention of caries in high-risk populations. Reports regarding their anti-plaque effect on a clinical level are limited to non-existing as opposed to their microbiological impact on plaque formation. Aim: The aim of this preliminary investigation was to evaluate the anti-plaque effect of two CHX varnishes applied on sound enamel in relation to a positive control, a negative control and to one another. Methods: Sixteen healthy subjects volunteered for this randomized-controlled, single-blind, four-treatment-four-period crossover-designed clinical trial. A 3-day plaque re-growth model was used to determine de novo plaque accumulation following CHX rinsing, Cervitec (R) application, EC40 (R) application and no therapy. The amount of plaque was measured using the Quigley and Hein plaque index and "automatic image analysis'' (AIA). Results and Conclusions: Varnish treatment resulted in significantly higher plaque levels than CHX rinsing irrespective of the varnish that was used (p <= 0.002), implying that the latter is likely to remain the gold standard as an anti-plaque agent. However, highly significant differences were also found in favour of both varnish systems when compared with no therapy (p < 0.001), which indicates that varnish treatment is an effective means of inhibiting plaque formation in a short time span. Cervitec (R) exhibited slightly, yet significantly, higher plaque levels in comparison with EC40 (R) as determined by AIA (p=0.006). Large-scale trials with a longer observation period are necessary to substantiate these results

Effects of high-fluoride dentifrice (5,000-ppm) on caries-related plaque and salivary variables

Objectives The aim of the present study was to measure the effects of a 5,000-ppm F toothpaste on caries-related factors in dental plaque and saliva. Materials and methods A 6-week clinical trial was designed with a total of 34 participants, of which 26 completed the study. The participants were assessed on four visits, 2 weeks apart. Sampling of approximal fluid for fluoride analysis and approximal plaque for organic acid analysis was performed. Chair-side tests were performed to register the lactic acid production rate on the tongue using Clinpro™ Cario L-Pop™, approximal plaque pH using the pH "strip method" and salivary buffer capacity and counts of cariogenic microorganisms using CRT Buffer® and CRT Bacteria®. Results Six weeks’ use of 5,000-ppm fluoridated (F) toothpaste significantly increased the approximal fluid F concentration (p < 0.05). There was a significant decrease in lactic acid production rate on the tongue assessed by Clinpro™ (p < 0.05). This was accompanied by changes in interproximal plaque acidogenicity, including significant reductions in AUC5.7, AUC6.2 and maximum pH fall and an increase in minimum pH (p < 0.05). A significant increase in the salivary buffer capacity and a reduction in the salivary mutans streptococci were observed (p < 0.05). Conclusion The present study demonstrates the ability of 5,000-ppm F toothpaste to modify caries-related factors in dental plaque and saliva. Clinical relevance The 5,000-ppm F toothpaste could be regarded as a possible effective regimen against caries in the near future