Evaluation of appendicitis risk prediction models in adults with suspected appendicitis

Background Appendicitis is the most common general surgical emergency worldwide, but its diagnosis remains challenging. The aim of this study was to determine whether existing risk prediction models can reliably identify patients presenting to hospital in the UK with acute right iliac fossa (RIF) pain who are at low risk of appendicitis. Methods A systematic search was completed to identify all existing appendicitis risk prediction models. Models were validated using UK data from an international prospective cohort study that captured consecutive patients aged 16–45 years presenting to hospital with acute RIF in March to June 2017. The main outcome was best achievable model specificity (proportion of patients who did not have appendicitis correctly classified as low risk) whilst maintaining a failure rate below 5 per cent (proportion of patients identified as low risk who actually had appendicitis). Results Some 5345 patients across 154 UK hospitals were identified, of which two‐thirds (3613 of 5345, 67·6 per cent) were women. Women were more than twice as likely to undergo surgery with removal of a histologically normal appendix (272 of 964, 28·2 per cent) than men (120 of 993, 12·1 per cent) (relative risk 2·33, 95 per cent c.i. 1·92 to 2·84; P < 0·001). Of 15 validated risk prediction models, the Adult Appendicitis Score performed best (cut‐off score 8 or less, specificity 63·1 per cent, failure rate 3·7 per cent). The Appendicitis Inflammatory Response Score performed best for men (cut‐off score 2 or less, specificity 24·7 per cent, failure rate 2·4 per cent). Conclusion Women in the UK had a disproportionate risk of admission without surgical intervention and had high rates of normal appendicectomy. Risk prediction models to support shared decision‐making by identifying adults in the UK at low risk of appendicitis were identified

Deposition of SiOx layer by plasma-enhanced chemical vapor deposition for the protection of silver (Ag) surfaces

Silver surfaces have been treated with plasma-enhanced chemical vapor deposition to produce SiO2-like coatings for possible applications in the jewelry industry. Different experimental conditions have been tested in order to optimize the protective effectiveness of the deposited layers. Samples were analyzed with optical and scanning electron microscopy and energy-dispersive spectrometry

Laser-induced forward transfer (LIFT) of material using ablation of thin films

We show the controlled transfer of thin films of different metallic materials to a receiving substrate. Single pulses from a mode locked (40ps pulse), frequency-doubled Nd:YAG laser (energy flux approximate to 13J/cm2 at 532nm) were used. Receiving substrates (metals, semiconductors or crystals) were placed parallel, at a close proximity to the thin film. Optical and scanning electron microscopy (SEM) as well as EDAX analysis were performed, showing evidence of the production of micrometric scale patterns. In particular, we studied the transfer of precious metal to metal/crystals for possible application in the jewellery industry

Laser induced forward transfer (LIFT) of materials using 40 ps pulses-experimental and quantitative modelisation study

In this paper we report the results of experiments on LIFT performed using single pulses from a mode locked (40ps pulses), frequency doubled Nd:YAG laser (energy flux approximate to 13J/cm(2) at lambda = 532 nm). We studied the controlled transfer of thin films of different metallic materials to a receiving substrate. Optical and scanning electron microscopy (SEM) as well as Energy-dispersive X-ray spectroscopy (EDAX) analysis were performed, showing evidence of the production of micrometric scale patterns. One of our objectives is to investigate and develop possible applications of LIFT in jewellery industry. In order to understand the experimental results we developed a simple analytical model based on the Rankine-Hugoniot relations. Comparison between experimental and simulated results is presented

Influence of consecutive picosecond pulses at 532 nm wavelength on laser ablation of human teeth

The interaction of 40 ps pulse duration laser emitting at 532 nm wavelength with human dental tissue (enamel, dentin, and dentin-enamel junction) has been investigated. The crater profile and the surface morphology have been studied by using a confocal auto-fluorescence microscope (working in reflection mode) and a scanning electron microscope. Crater profile and crater morphology were studied after applying consecutive laser pulses and it was found that the ablation depth increases with the number of consecutive pulses, leaving the crater diameter unchanged. We found that the thermal damage is reduced by using short duration laser pulses, which implies an increased retention of restorative material. We observe carbonization of the irradiated samples, which does not imply changes in the chemical composition. Finally, the use of 40 ps pulse duration laser may become a state of art in conservative dentistry