Inter-comparison on multi-feature bar calibration for determining machine-tool geometric errors

International audienceTo improve the accuracy of manufactured mechanical parts, the geometric errors of a machine-tool should be evaluated and compensated in order to better master the deviations between the actual and nominal tool positioning (volumetric accuracy). Thus, a novel Multi-Feature Bar (MFB) for machine-tool geometric errors' identification was designed and manufactured. The MFB standard is made of Invar material. The proposed design of the MFB allows extracting three intrinsic parameters: one linear positioning and two straightness errors. The calibration of the MFB was performed on an accurate coordinate measuring machine (CMM) when applying the reversal technique, in order to separate the MFB's error forms from the motion errors of the CMM's mechanical guiding systems. Furthermore, an intercomparison was conducted between four National Metrology Institutes (LNE, PTB, CMI, UM) to evaluate the reliability of the proposed calibration methodology. Findings resulting from this intercomparison reveal dimensional stability of the MFB standard for geometric errors identification on CMM and machine-tool. Therefore, the use on machine-tool of the calibrated MFB, regardless of the harsh environment, guarantees its metrology traceability to the SI metre definition of few micrometres (<5 µm)

Numerical and experimental analysis of nonlinear vibrational response due to pressure-dependent interface stiffness

Modelling interface interaction with wave propagation in a medium is a fundamental requirement for several types of application, such as structural diagnostic and quality control. In order to study the influence of a pressure-dependent interface stiffness on the nonlinear response of contact interfaces, two nonlinear contact laws are investigated. The study consists of a complementary numerical and experimental analysis of nonlinear vibrational responses due to the contact interface. The laws investigated here are based on an interface stiffness model, where the stiffness property is described as a nonlinear function of the nominal contact pressure. The results obtained by the proposed laws are compared with experimental results. The nonlinearity introduced by the interface is highlighted by analysing the second harmonic contribution and the vibrational time response. The analysis emphasizes the dependence of the system response, i.e., fundamental and second harmonic amplitudes and frequencies, on the contact parameters and in particular on contact stiffness. The study shows that the stiffness-pressure trend at lower pressures has a major effect on the nonlinear response of systems with contact interfaces

Primary pelvic hydatid cyst with sciatic compression

Hydatid cysts are endemic in certain regions of the world and particulary in North Africa. They are usually located in the liver, lung, and spleen, though many uncommon locations have been reported. This is the first report of a child with primary pelvic hydatid disease causing a sciatic compression

Giant primary adrenal hydatid cyst presenting with arterial hypertension: a case report and review of the literature

<p>Abstract</p> <p>Introduction</p> <p>A primary hydatid cyst of the adrenal gland is still an exceptional localization. The adrenal gland is an uncommon site even in Morocco, where echinococcal disease is endemic.</p> <p>Case presentation</p> <p>We report the case of a 64-year-old Moroccan man who presented with the unusual symptom of arterial hypertension associated with left flank pain. Computed tomography showed a cystic mass of his left adrenal gland with daughter cysts filing the lesion (Type III). Despite his negative serology tests, the diagnosis of a hydatid cyst was confirmed on surgical examination. Our patient underwent surgical excision of his left adrenal gland with normalization of blood pressure. No recurrence has occurred after 36 months of follow-up.</p> <p>Conclusion</p> <p>There are two remarkable characteristics of this case report; the first is the unusual location of the cyst, the second is the association of an adrenal hydatid cyst with arterial hypertension, which has rarely been reported in the literature.</p

Wet deposition of hydrocarbons in the city of Tehran-Iran

Air pollution in the city of Tehran has been a major problem for the past three decades. The direct effects of hydrocarbon contaminants in the air are particularly important such as their carcinogenic, mutagenic, and teratogenic effects which can be transported to other environments via dry and wet deposition. In the present study, rainwater samples were collected and analyzed for 16 polycyclic aromatic hydrocarbons (PAHs), benzene, toluene, ethyl benzene, and xylene (BTEX) as well as fuel fingerprints in two ranges of gasoline (C5–C11) and diesel fuel (C12–C20) using a gas chromatograph equipped with a flame ionization detector (GC/FID). Mean concentrations of ∑16 PAHs varied between 372 and 527 µg/L and for BTEX was between 87 and 188 µg/L with maximum of 36 µg/L for toluene. Both gasoline range hydrocarbons (GRH) and diesel range hydrocarbons (DRH) were also present in the collected rainwater at concentrations of 190 and 950 µg/L, respectively. Hydrocarbon transports from air to soil were determined in this wet deposition. Average hydrocarbon transportation for ∑PAHs, BTEX, GRH, and DRH was 2,747, 627, 1,152, and 5,733 µg/m2, respectively

Exacerbations of chronic obstructive pulmonary disease: when are antibiotics indicated? A systematic review

BACKGROUND: For decades, there is an unresolved debate about adequate prescription of antibiotics for patients suffering from exacerbations of chronic obstructive pulmonary disease (COPD). The aim of this systematic review was to analyse randomised controlled trials investigating the clinical benefit of antibiotics for COPD exacerbations. METHODS: We conducted a systematic review of randomised, placebo-controlled trials assessing the effects of antibiotics on clinically relevant outcomes in patients with an exacerbation. We searched bibliographic databases, scrutinized reference lists and conference proceedings and asked the pharmaceutical industry for unpublished data. We used fixed-effects models to pool results. The primary outcome was treatment failure of COPD exacerbation treatment. RESULTS: We included 13 trials (1557 patients) of moderate to good quality. For the effects of antibiotics on treatment failure there was much heterogeneity across all trials (I(2 )= 82%). Meta-regression revealed severity of exacerbation as significant explanation for this heterogeneity (p = 0.016): Antibiotics did not reduce treatment failures in outpatients with mild to moderate exacerbations (pooled odds ratio 1.09, 95% CI 0.75–1.59, I(2 )= 18%). Inpatients with severe exacerbations had a substantial benefit on treatment failure rates (pooled odds ratio of 0.25, 95% CI 0.16–0.39, I(2 )= 0%; number-needed to treat of 4, 95% CI 3–5) and on mortality (pooled odds ratio of 0.20, 95% CI 0.06–0.62, I(2 )= 0%; number-needed to treat of 14, 95% CI 12–30). CONCLUSION: Antibiotics effectively reduce treatment failure and mortality rates in COPD patients with severe exacerbations. For patients with mild to moderate exacerbations, antibiotics may not be generally indicated and further research is needed to guide antibiotic prescription in these patients

Value of Lung Ultrasound Sonography B-Lines Quantification as a Marker of Heart Failure in COPD Exacerbation

Fadwa Lajili,1,2 Marwa Toumia,1,2 Adel Sekma,1,2 Khaoula Bel Haj Ali,1,2 Sarra Sassi,1,2 Asma Zorgati,3 Hajer Yaakoubi,3 Rym Youssef,3 Mohamed Habib Grissa,1,2 Kaouther Beltaief,1,2 Zied Mezgar,4 Mariem Khrouf,4 Ikram Chamtouri,5 Wahid Bouida,1,2 Hamdi Boubaker,1,2 Mohamed Amine Msolli,1,2 Zohra Dridi,6 Riadh Boukef,1,3 Semir Nouira1,2 1Research Laboratory LR12SP18, Monastir University, Monastir, 5019, Tunisia; 2Emergency Department, Fattouma Bourguiba University Hospital, Monastir, 5000, Tunisia; 3Emergency Department, Sahloul University Hospital, Sousse, 4011, Tunisia; 4Emergency Department, Farhat Hached University Hospital, Sousse, 4031, Tunisia; 5Department of Cardiology B, Fattouma Bourguiba University Hospital, Monastir, 5000, Tunisia; 6Department of Cardiology A, Fattouma Bourguiba University Hospital, Monastir, 5000, TunisiaCorrespondence: Semir Nouira, Emergency Department and Laboratory Research(LR12SP18), Fattouma Bourguiba University Hospital, Monastir, 5000, Tunisia, Tel +21673106046, Email [email protected]: Identifying heart failure (HF) in acute exacerbation of chronic obstructive pulmonary disease (AECOPD) can be challenging. Lung ultrasound sonography (LUS) B-lines quantification has recently gained a large place in the diagnosis of HF, but its diagnostic performance in AECOPD remains poorly studied.Purpose: This study aimed to assess the contribution of LUS B-lines score (LUS score) in the diagnosis of HF in AECOPD patients.Patients and methods: This is a prospective cross-sectional multicenter cohort study including patients admitted to the emergency department for AECOPD. All included patients underwent LUS. A lung ultrasound score (LUS score) based on B-lines calculation was assessed. A cardiac origin of dyspnea was retained for a LUS score greater than 15. HF diagnosis was based on clinical examination, pro-brain natriuretic peptide levels, and echocardiographic findings. The LUS score diagnostic performance was assessed by receiver operating characteristic (ROC) curve, sensitivity, specificity, and likelihood ratio at the best cutoffs.Results: We included 380 patients, mean age was 68&plusmn; 11.6 years, sex ratio (M/F) 1.96. Patients were divided into two groups: the HF group [n=157 (41.4%)] and the non-HF group [n=223 (58.6%)]. Mean LUS score was higher in the HF group (26.8&plusmn; 8.4 vs 15.3&plusmn; 7.1; p&lt; 0.001). The mean LUS score in the HF patients with reduced LVEF was 29.2&plusmn; 8.7, and was 24.5&plusmn; 7.6 in the HF patients with preserved LVEF. LUS score area under ROC curve for the diagnosis of HF was 0.71 [0.65&ndash; 0.76]. The best sensitivity (89% [85.9&ndash; 92,1]) was observed at the threshold of 5; the best specificity (85% [81.4&ndash; 88.6]) was observed at the threshold of 30. Correlation between LUS score and E/E&rsquo; ratio was good (R=0.46, p=0.0001).Conclusion: Our results suggest that LUS score could be helpful and should be considered in the diagnostic approach of HF in AECOPD patients, at least as a ruling in test.Keywords: chronic obstructive pulmonary disease, COPD, heart failure, dyspnea, lung ultrasound sonograph

Year in review in Intensive Care Medicine 2011: III. ARDS and ECMO, weaning, mechanical ventilation, noninvasive ventilation, pediatrics and miscellanea

SCOPUS: re.jinfo:eu-repo/semantics/publishe