3,744 research outputs found
Energy harvesting from vehicular traffic over speed bumps: A review
Energy used by vehicles to slow down in areas of limited speed is wasted. A traffic energy-harvesting device (TEHD) is capable of harvesting vehicle energy when passing over a speed bump. This paper presents a classification of the different technologies used in the existing TEHDs. Moreover, an estimation of the energy that could be harvested with the different technologies and their cost has been elaborated. The energy recovered with these devices could be used for marking and lighting of roads in urban areas, making transportation infrastructures more sustainable and environmentally friendly
The influence of wildfires on aerosol size distributions in rural areas
The number of particles and their size distributions were measured in a rural area, during the summer, using a PCASP-X. The aim was to study the influence of wildfires on particle size distributions. The comparative studies carried out reveal an average increase of around ten times in the number of particles in the fine mode, especially in sizes between 0.10 and 0.14 μm, where the increase is of nearly 20 times. An analysis carried out at three different points in time--before, during, and after the passing of the smoke plume from the wildfires--shows that the mean geometric diameter of the fine mode in the measurements affected by the fire is smaller than the one obtained in the measurements carried out immediately before and after (0.14 μm) and presents average values of 0.11 μm.publishe
Desalineación rotacional del implante tibial en artroplastia total de rodilla: estudio con navegación
Objetivo: Estudiar la rotación del implante tibial y el
desajuste rotacional de los implantes femoral y tibial en los 19
casos intervenidos de artroplastia total de rodilla modelo
Natural II, con sistema de navegación Navitrack®
(Zimmer®). Material y Métodos: Estudio prospectivo en una
serie consecutiva de 19 casos de artrosis de rodilla. Se analizaron
las medidas realizadas con un sistema de navegación:
1- el ángulo entre la línea que va desde la inserción del
Ligamento Cruzado Posterior al tercio medio de la tuberosidad
tibial anterior y la línea anteroposterior del implante tibial
para determinar la rotación del mismo; 2- el ángulo de la línea
femoral epicondílea con el bloque de corte que nos dará la
rotación del implante femoral. Resultados: La rotación media
del implante tibial ha sido - 0,011º ± 0,533 (r: -0,800 / 1,000). La
rotación del implante femoral con relación a la línea epicondílea
ha sido -3,174º ± 4,733 (r: -12,300 / 7,700). El ajuste rotacional
femorotibial ha sido -2,963º ± 4,649 (r: -11,500/ 6,700).
Encontramos una alineación rotacional femorotibial en el 63%
de los casos. Conclusiones: El sistema de navegación utilizado
permite colocar el implante tibial con una rotación adecuada
así como evitar un desajuste rotacional entre los
implantes femoral y tibial. Actualmente se consideran de
forma combinada las rotaciones de los implantes, lo que tiene
gran importancia para evitar los problemas rotulianos así
como el desgaste del polietileno.To study the rotational alignment of the tibial implant in 19 patients who underwent total knee arthroplasty by surgical navigation system. Material and Methods: Prospective analysis of 19 consecutive patients with knee osteoarthritis. References obtained by the computerized navigation were: 1- the angle between the line from the insertion of the posterior cruciate ligament to the medial tibial tuberosity and the anteroposterior tibial implant line to study the tibial rotation; 2- the angle between the epicondyle line and the cut piece to study the femoral rotation. Results: The media tibial implant rotation was - 0,011º ± 0,533 (r: -0,800/ 1,000). The femoral implant rotation was -3,174º ± 4,733 (r: -12,300 / 7,700). The mean angle of the rotational mismatch of the components was -2,963º ± 4,649 (r: -11,500/ 6,700). There was a good femorotibial mismatch in 63%. Conclusions: The navigation system helps us to put the tibial implant in a good rotation and so a good femorotibial mismatch. Actually we study the combined rotation of the implants to decrease the patelofemoral problems and the polyethylene damage
Efectos de distintos niveles de materia seca y tratamiento sobre la calidad de ensilado de alfalfa
Los autores analizan la calidad de 250 ensilados de alfalfa sometidos a cinco tratamientos (control, evacuación AIV, ácido fórmico y metabisulfito sódico), con forraje entero o picado. y cinco niveles de materia seca inicial (20. 23. 36, 38 y 42%).La elevación de la tasa de materia seca inicial, mejora la capacidad organoléptica hasta el 36-38% de materia seca. El efecto beneficioso del oreo se registra en todos los tratamientos ensayados, salvo en los silos con metabisulfito sódico, que presentan su máxima calidad en los más bajos niveles de materia seca
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Appraising the quality standard underpinning international clinical practice guidelines for the selection and care of vascular access devices: a systematic review of reviews
OBJECTIVE: Catheter-related bloodstream infections are one of the most important adverse events for patients. Evidence-based practice embraces interventions to prevent and reduce catheter-related bloodstream infections in patients. At present, a growing number of guidelines exist worldwide. The purpose of the study was to assess clinical practice guidelines for peripheral and central venous access device care and prevention of related complications.
DESIGN: Systematic review of clinical practice guidelines: We conducted a search of the literature published from 2005 to 2018 using Medline/PubMed, Embase, CINAHL, Ovid, ScienceDirect, Scopus and Web of Science. We also evaluated grey literature sources and websites of organisations that compiled or produced guidelines. Guideline quality was assessed with the Appraisal of Guidelines for Research and Evaluation, Second Edition tool by three independent reviewers. Cohen's kappa coefficient was used to evaluate the concordance between reviewers.
RESULTS: We included seven guidelines in the evaluation. The concordance between observers was substantial, K=0.6364 (95% CI 0.0247 to 1.2259). We identified seven international guidelines, which scored poorly on crucial domains such as applicability (medium 39%), stakeholder involvement (medium 65%) and methodological rigour (medium 67%). Guidelines by Spanish Health Ministry and UK National Institute for Health and Care Excellence presented the highest quality.
CONCLUSIONS: It is crucial to critically evaluate the validity and reliability of clinical practice guidelines so the best, most context-specific document is selected. Such choice is a necessary prior step to encourage and support health organisations to transfer research results to clinical practice. The gaps identified in our study may explain the suboptimal clinical impact of guidelines. Such low adoption may be mitigated with the use of implementation guides accompanying clinical documents
A new case of autosomal recessive agammaglobulinaemia with impaired pre-B cell differentiation due to a large deletion of the IGH locus
Males with X-linked agammaglobulinaemia (XLA) due to mutations in the Bruton tyrosine kinase gene constitute the major group of congenital hypogammaglobulinaemia with absence of peripheral B cells. In these cases, blockages between the pro-B and pre-B cell stage in the bone marrow are found. The remaining male and female cases clinically similar to XLA represent a genotypically heterogeneous group of diseases. In these patients, various autosomal recessive disorders have been identified such as mutations affecting IGHM, CD79A, IGLL1 genes involved in the composition of the pre-B cell receptor (pre-BCR) or the BLNK gene implicated in pre-BCR signal transduction. In this paper, we report on a young female patient characterised by a severe non-XLA agammaglobulinaemia that represents a new case of Igmu defect. We show that the B cell blockage at the pro-B to pre-B cell transition is due to a large homologous deletion in the IGH locus encompassing the IGHM gene leading to the inability to form a functional pre-BCR. The deletion extends from the beginning of the diversity (D) region to the IGHG2 gene, with all JH segments and IGHM, IGHD, IGHG3 and IGHG1 genes missing.
CONCLUSION:
alteration in Igmu expression seems to be relatively frequent and could account for most of the reported cases of autosomal recessive agammaglobulinaemia
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Determinants of the optimal selection of vascular access devices: a systematic review underpinned by the COM-B behavioral model
......This research received no specific grant from any funding agency in the public, commercial or not-for-profit sectors
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Care of peripheral intravenous catheters in three hospitals in Spain: Mapping clinical outcomes and implementation of clinical practice guidelines
BACKGROUND: Peripheral intravenous catheters (PIVCs) are the most widely used invasive devices worldwide. Up to 42% of PIVCs are prematurely removed during intravenous therapy due to failure. To date, there have been few systematic attempts in European hospitals to measure adherence to recommendations to mitigate PIVC failures.
AIM: To analyse the clinical outcomes from clinical practice guideline recommendations for PIVC care on different hospital types and environments.
METHODS: We conducted an observational study in three hospitals in Spain from December 2017 to April 2018. The adherence to recommendations was monitored via visual inspection in situ evaluations of all PIVCs inserted in adults admitted. Context and clinical characteristics were collected by an evaluation tool, analysing data descriptively.
RESULTS: 646 PIVCs inserted in 624 patients were monitored, which only 52.7% knew about their PIVC. Regarding PIVC insertion, 3.4% (22/646) patients had at least 2 PIVCs simultaneously. The majority of PIVCs were 20G (319/646; 49.4%) and were secured with transparent polyurethane dressing (605/646; 93.7%). Most PIVCs (357/646; 55.3%) had a free insertion site during the visual inspection at first sight. We identified 342/646 (53%) transparent dressings in optimal conditions (clean, dry, and intact dressing). PIVC dressings in medical wards were much more likely to be in intact conditions than those in surgical wards (234/399, 58.7% vs. 108/247, 43.7%). We identified 55/646 (8.5%) PIVCs without infusion in the last 24 hours and 58/646 (9.0%) PIVCs without infusion for more than 24 hours. Regarding PIVC failure, 74 (11.5%) adverse events were identified, all of them reflecting clinical manifestation of phlebitis.
CONCLUSIONS: Our findings indicate that the clinical outcome indicators from CPG for PIVC care were moderate, highlighting differences between hospital environments and types. Also, we observed that nearly 50% of patients did not know what a PIVC is
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Defining risk factors associated with difficult peripheral venous Cannulation: A systematic review and meta-analysis
Peripheral venous catheterization is a common technique in hospitals which is not always successful, resulting in multiple punctures and degradation of the vessels. This scenario, which we have termed 'difficult peripheral venous access', is associated to delays in care, obtention of samples or diagnosis, as well as a higher use of central catheters. This study intends to identify risk factors associated to the incidence of 'difficult peripheral venous access' in adults at hospital. We designed a systematic review of published studies (protocol PROSPERO 2018 CRD42018089160). We conducted structured electronic searches using key words and specific vocabulary, as well as directed searches in several databases. After validity analysis, we selected 7 studies with observational methodology. We found great variability in the definition of 'difficult peripheral venous access' and in the variables proposed as risk factors. Statistically significant factors through studies include demographic and anthropometric variables (gender, Body Mass Index), as well as medical and health conditions (diabetes, renal insufficiency, parenteral drug abuse, cancer chemotherapy), together with variables related to the vein or vascular access (vein visibility and palpability, vessel diameter, previous history of difficulty). Some studies have also considered variables related to the professional performing the technique. Meta-analyses were carried out for gender and obesity as potential risk factors. Only obesity appeared as a statistically significant risk factor with OR of 1.48; 95% CI (1.03 to 1.93; p = 0.016). Methodological heterogeneity prevented the development of further meta-analyses. It is essential to design future studies with diverse hospital populations, in which a wide selection of potential risk factors can be studied in a unique analysis. Our work identifies the most relevant variables that should be included in those studies
Spectroscopic study of solvent effects on the electronic absorption spectra of flavone and 7-hydroxyflavone in neat and binary solvent mixtures
The solvatochromic characteristics of flavone and 7-hydroxyflavone were investigated in neat and binary solvent mixtures. The spectral shifts of these solutes were correlated with the Kamlet and Taft parameters (α, β and π*) using linear solvation energy relationships. The multiparametric analysis indicates that both specific hydrogen bond donor ability and non-specific dipolar interactions of the solvents play an important role in absorption maxima of flavone in pure solvents. The hydrogen bond acceptor ability of the solvent was the main parameter affecting the absorption maxima of 7-hydroxyflavone. The simulated absorption spectra using a TD-DFT method were in good agreement with the experimental ones for both flavones. Index of preferential solvation was calculated as a function of solvent composition. Preferential solvation by ethanol was detected in cyclohexane-ethanol and acetonitrile-ethanol mixtures for flavone and in acetonitrile-ethanol mixtures for 7-hydroxyflavone. These results indicate that intermolecular hydrogen bonds between solute and solvent are responsible for the non-linear variation of the solvatochromic shifts on the mole fraction of ethanol in the analyzed binary mixtures.Facultad de Ciencias Exacta
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