103 research outputs found
The effect of selective ultrasound screening on the incidence of late presentation of developmental hip dysplasia—a meta-analysis
Different screening strategies for developmental dysplasia of the hip (DDH) exist. Despite screening efforts, cases of late presentation continue to occur, often necessitating surgery. This systematic review and meta-analysis assess the effect of newborn selective ultrasound screening for DDH on the incidence of late presentation in infants and children, compared to a universal ultrasound strategy. A systematic search across Medline and EMBASE databases was performed between January 1950 and February 2021. A consensus-based evaluation of abstracts led to retrieval of relevant full text, original articles or systematic reviews in English only. These were assessed according to agreed eligibility criteria, and their reference lists were reviewed to identify additional eligible publications. Following final consensus on included publications, data was extracted, analysed and reported as per PRISMA and Prospero (CRD42021241957) guidelines. The 16 eligible studies consisted of 2 randomised controlled trials and 14 cohort studies, published between 1989 and 2014, with a total of 511,403 participants. In total, 121,470 (23.8%) received a neonatal hip ultrasound, of whom 58,086 and 63,384 were part of a selective or a universal ultrasound screening strategy, respectively. The difference in the proportion of late presentation between the universal and selective strategies was 0.0904 per 1,000 (P = 0.047). The time effect, i.e. the difference between early and late presentation defined respectively, as less than and more than 3 months of age, regardless of screening strategy, was not significant (P = 0.272). Although there was variability in study design and reporting, the quality of the evidence, based on the critical appraisal skills programme appraisal tools, was generally good. Compared to universal ultrasound screening for DDH, selective screening resulted in a slightly higher rate of late presentation. Uniformity in design and reporting of DDH studies and a cost-effectiveness analysis are needed
Mycobacterium tuberculosis Lipolytic Enzymes as Potential Biomarkers for the Diagnosis of Active Tuberculosis
BACKGROUND: New diagnosis tests are urgently needed to address the global tuberculosis (TB) burden and to improve control programs especially in resource-limited settings. An effective in vitro diagnostic of TB based on serological methods would be regarded as an attractive progress because immunoassays are simple, rapid, inexpensive, and may offer the possibility to detect cases missed by standard sputum smear microscopy. However, currently available serology tests for TB are highly variable in sensitivity and specificity. Lipolytic enzymes have recently emerged as key factors in lipid metabolization during dormancy and/or exit of the non-replicating growth phase, a prerequisite step of TB reactivation. The focus of this study was to analyze and compare the potential of four Mycobacterium tuberculosis lipolytic enzymes (LipY, Rv0183, Rv1984c and Rv3452) as new markers in the serodiagnosis of active TB. METHODS: Recombinant proteins were produced and used in optimized ELISA aimed to detect IgG and IgM serum antibodies against the four lipolytic enzymes. The capacity of the assays to identify infection was evaluated in patients with either active TB or latent TB and compared with two distinct control groups consisting of BCG-vaccinated blood donors and hospitalized non-TB individuals. RESULTS: A robust humoral response was detected in patients with active TB whereas antibodies against lipolytic enzymes were infrequently detected in either uninfected groups or in subjects with latent infection. High specifity levels, ranging from 93.9% to 97.5%, were obtained for all four antigens with sensitivity values ranging from 73.4% to 90.5%, with Rv3452 displaying the highest performances. Patients with active TB usually exhibited strong IgG responses but poor IgM responses. CONCLUSION: These results clearly indicate that the lipolytic enzymes tested are strongly immunogenic allowing to distinguish active from latent TB infections. They appear as potent biomarkers providing high sensitivity and specificity levels for the immunodiagnosis of active TB
Oral HPV infection and MHC class II deficiency (A study of two cases with atypical outcome)
<p>Abstract</p> <p>Background</p> <p>Major histocompatibility complex class II deficiency, also referred to as bare lymphocyte syndrome is a rare primary Immunodeficiency disorder characterized by a profondly deficient human leukocyte antigen class II expression and a lack of cellular and humoral immune responses to foreign antigens. Clinical manifestations include extreme susceptibility to viral, bacterial, and fungal infections. The infections begin in the first year of life and involve usually the respiratory system and the gastrointestinal tract. Severe malabsorption with failure to thrive ensues, often leading to death in early childhood. Bone marrow transplantation is the curative treatment.</p> <p>Case reports</p> <p>Here we report two cases with a late outcome MHC class II deficiency. They had a long term history of recurrent bronchopulmonary and gastrointestinal infections. Bone marrow transplantation could not be performed because no compatible donor had been identified. At the age of 12 years, they developed oral papillomatous lesions related to HPV (human papillomavirus). The diagnosis of HPV infection was done by histological examination. HPV typing performed on the tissue obtained at biopsy showed HPV type 6. The lesions were partially removed after two months of laser treatment.</p> <p>Conclusions</p> <p>Viral infections are common in patients with MHC class II and remain the main cause of death. Besides warts caused by HPV infection do not exhibit a propensity for malignant transformation; they can cause great psychosocial morbidity.</p
EUD-MARS: End-User Development of Model-Driven Adaptive Robotics Software Systems
Empowering end-users to program robots is becoming more significant. Introducing software engineering principles into end-user programming could improve the quality of the developed software applications. For example, model-driven development improves technology independence and adaptive systems act upon changes in their context of use. However, end-users need to apply such principles in a non-daunting manner and without incurring a steep learning curve. This paper presents EUD-MARS that aims to provide end-users with a simple approach for developing model-driven adaptive robotics software. End-users include people like hobbyists and students who are not professional programmers but are interested in programming robots. EUD-MARS supports robots like hobby drones and educational humanoids that are available for end-users. It offers a tool for software developers and another one for end-users. We evaluated EUD-MARS from three perspectives. First, we used EUD-MARS to program different types of robots and assessed its visual programming language against existing design principles. Second, we asked software developers to use EUD-MARS to configure robots and obtained their feedback on strengths and points for improvement. Third, we observed how end-users explain and develop EUD-MARS programs, and obtained their feedback mainly on understandability, ease of programming, and desirability. These evaluations yielded positive indications of EUD-MARS
Joint modified block replacement and production/inventory control policy for a failure-prone manufacturing cell
This paper considers a joint preventive maintenance (PM) and production/inventory control policy of an unreliable single machine, mono-product manufacturing cell with stochastic non-negligible corrective and preventive delays. The production/inventory control policy, which is based on the hedging point policy (HPP), consists in building and maintaining a safety stock of finished products in order to respond to demand and to avoid shortages during maintenance actions. Without considering the impact of preventive and corrective actions on the overall performance of the production system, most authors working in the reliability and maintainability domains confirm that the age-based preventive maintenance policy (ARP) outperforms the classical block-replacement policy (BRP). In order to reduce wastage incurred by the classical BRP, we consider a modified block replacement policy (MBRP), which consists in canceling a preventive maintenance action if the time elapsed since the last maintenance action exceeds a specified time threshold. The main objective of this paper is to determine the joint optimal policy that minimizes the overall cost, which is composed of corrective and preventive maintenance costs as well as inventory holding and backlog costs. A simulation model mimicking the dynamic and stochastic behavior of the manufacturing cell, based on more realistic considerations of the real behavior of industrial manufacturing cells, is proposed. Based on simulation results, the joint optimal MBRP/HPP parameters are obtained through a numerical approach that combines design of experiment, analysis of variance and response surface methodologies. The joint optimal MBRP/HPP policy is compared to classical joint ARP/HPP and BRP/HPP optimal policies, and the results show that the proposed MBRP/HPP outperforms the latter. Sensitivity analyses are also carried out in order to confirm the superiority of the proposed MBRP/HPP, and it is observed that for practitioners, the proposed joint MBRP/HPP offers not only cost savings, but is also easy to manage, as compared to the ARP/HPP policy.Production/inventory control Block/age replacement policies Modified block replacement policy Simulation modeling Response surface methodology
Throughput assessment of mixed-model flexible transfer lines with unreliable machines
Most of the research that has been carried out to date to analyse transfer line performance is so far limited to the mono-product systems due to the complexity associated with multi-product considerations. In this paper, we consider mixed-model flexible transfer lines manufacturing several product types. The flexible transfer line workstations are arranged in a serial configuration, interconnected by an automatic transfer mechanism, and subject to operation-dependent failures. The throughput is an important tool for measuring the performance of transfer lines, and this paper establishes a method for assessing this throughput. A general simulation model is proposed, allowing a comparison of the performance of the proposed method with those of approximate existing techniques. Numerical computations show that the proposed formulae are robust to estimate the throughput of multi-product transfer lines, and that the results are very satisfactory.Mixed model Transfer lines Throughput Homogenization Operation-dependent failures Simulation modeling
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