Structure, electronic properties, morphology evolution, and photocatalytic activity in PbMoO4 and Pb1-2xCaxSrxMoO4 (x = 0.1, 0.2, 0.3, 0.4 and 0.5) solid solutions.

In this work PbMoO4 and Pb1-2xCaxSrxMoO4 (x = 0.1, 0.2, 0.3, 0.4 and 0.5) solid solutions have been successfully prepared, for the first time, by a simple co-precipitation method and the as-synthesized samples were subjected to a water-based reflux treatment. Structural characterization of these samples was performed using X-ray diffraction with Rietveld refinement analysis and Raman spectroscopy. Their optical properties were investigated by UV-Vis absorption spectroscopy and PL emissions, and the photocatalytic activity of the as-synthesized samples for the degradation process of Rhodamine B has been demonstrated. The surface structure and morphologies were characterized by field emission scanning electron microscopy. To complement and rationalize the experimental results, the geometry, electronic structures, and morphologies of as-synthesized samples were characterized by first-principles quantum-mechanical calculations at the density functional theory level. By using Wulff construction, based on the values of the surface energies for the (001), (100), (110), (111), (011) and (112) surfaces, a complete map of the available morphologies for PbMoO4 was obtained and a good agreement between the experimental and theoretical predicted morphologies was found. The structural and electronic changes induced by the substitution of Pb by Ca and Sr allow us to find a relationship among morphology, the electron-transfer process at the exposed surfaces, optical properties, and photocatalytic activity. We believe that our results offer new insights regarding the local coordination of superficial Pb/Ca/Sr and Mo cations (i.e., clusters) on each exposed surface of the corresponding morphology, which dictate the photocatalytic activities of the as-synthesized samples, a field that has so far remained unexplored. The present study, which combines multiple experimental methods and first-principles calculations, provides a deep understanding of the local structures, bonding, morphologies, band gaps, and electronic and optical properties, and opens the door to exploit the electrical, optical and photocatalytic activity of this very promising family of materials.

Joint Theoretical and Experimental Study on the La Doping Process in In2O3: Phase Transition and Electrocatalytic Activity.

In2O3 and La3+-doped In2O3 nanostructures were synthesized through a facile and fast chemical route based on the microwave-assisted hydrothermal method combined with rapid thermal treatment in a microwave oven. The presence of the La3+ doping process modifies the size and morphology of the In2O3 nanostructures and also stabilizes the rhombohedral (rh) In2O3 phase with respect to the most stable cubic (bcc) polymorph. X-ray diffraction (XRD) patterns and Rietveld refinements, Raman, UV-vis, and energy dispersive X-ray (EDX) spectroscopies, transmission electron (TEM) and field-emission scanning electron (FE-SEM) microscopies, as well as PL emissions have been performed. To complement and rationalize the experimental results, first-principle calculations, based on density functional theory, are carried out to obtain the formation energies of the In2O3 and bcc- and rh-In2O3-doped phases, their geometry and electronic properties. Theoretical results are able to explain the relative stabilization of the rh-phase with respect to the bcc-phase based on the analysis geometry changes and the electronic redistribution induced by the La3+ doping process. In addition, Wulff construction is employed to match the theoretical and experimental morphologies of the cubic phase. The synthesized samples were applied for the O2 evolution reaction (OER). The La3+-doped In2O3 film presents superior electrocatalytic activity, with an onset potential lower than the undoped In2O3 film that can be associated with the increase in electron density caused by the La3+ doping process. This study provides a versatile strategy for obtaining In2O3 and La3+-doped In2O3 nanostructures for practical applications.

ZnWO4 nanocrystals: synthesis, morphology, photoluminescence and photocatalytic properties.

The present joint experimental and theoretical work provides in-depth understanding on the morphology and structural, electronic, and optical properties of ZnWO4 nanocrystals. Monoclinic ZnWO4 nanocrystals were prepared at three different temperatures (140, 150, and 160 °C) by a microwave hydrothermal method. Then, the samples were investigated by X-ray diffraction with Rietveld refinement analysis, field-emission scanning electron microscopy, transmission electronic microscopy, micro-Raman and Fourier transform infrared spectroscopy, ultraviolet-visible spectroscopy, and photoluminescence measurements. First-principles theoretical calculations within the framework of density functional theory were employed to provide information at the atomic level. The band structure diagram, density of states, Raman and infrared spectra were calculated to understand the effect of structural order-disorder on the properties of ZnWO4. The effects of the synthesis temperature on the above properties were rationalized. The band structure revealed direct allowed transitions between the VB and CB and the experimental results in the ultraviolet-visible region were consistent with the theoretical results. Moreover, the surface calculations allowed the association of the surface energy stabilization with the temperature used in the synthesis of the ZnWO4 nanocrystals. The photoluminescence properties of the ZnWO4 nanocrystals prepared at 140, 150, and 160 °C were attributed to oxygen vacancies in the [WO6] and [ZnO6] clusters, causing a red shift of the spectra. The ZnWO4 nanocrystals obtained at 160 °C exhibited excellent photodegradation of Rhodamine under ultraviolet light irradiation, which was found to be related to the surface energy and the types of clusters formed on the surface of the catalyst.

Radiopaque Three-dimensional Printing: A Method to Create Realistic CT Phantoms.

Purpose To develop a method to create anthropomorphic phantoms of individual patients with high precision of anatomic details and radiation attenuation properties. Materials and Methods Inkjet cartridges were filled with potassium iodide solutions (600 mg/mL) and prints were realized on plain paper (80 g/m2). Stacks of 100 prints resulted in three-dimensional phantoms of 1 cm thickness. In a first step, reproduction of patient anatomy was tested by printing computed tomographic (CT) images of a real patient abdomen scan. In a second step, gray scales, iodine deposition, and Hounsfield units were investigated by printing geometric phantoms with gray scales ranging from 0% (white) to 100% (black). On the basis of these results, a gray-scale-correction procedure was developed to achieve realistic Hounsfield units in the patient phantom. In a third step, reproduction of the real patient's Hounsfield units was verified by printing the initial patient CT scan again after application of the gray-scale-correction procedure. Data were analyzed by using Pearson correlation, linear regression, and nonlinear regression. Results The first abdomen phantom showed a detailed reproduction of the patient anatomy and demonstrated feasibility of the concept. However, individual-organ Hounsfield units deviated from the real patient CT scan. Analysis of the geometric phantoms revealed an exponential correlation between template gray scales and printer deposition. Application of a correction procedure to the template gray scales allowed for a linear correlation (r = 0.9946; 95% confidence interval: 0.9916, 0.9966). After the same correction procedure was applied to the abdomen phantom, linear correlation of phantom and patient Hounsfield units was confirmed (r = 0.9925; 95% confidence interval: 0.9635, 0.9985). Conclusion The method presented in this work can realize realistic and customizable phantoms for diagnostic and therapeutic radiology, including the reproduction of individual patients. © RSNA, 2016.

Management of Chronic Spontaneous Urticaria in Routine Clinical Practice Following the EAACI/GA(2)LEN/EDF/WAO Guidelines. / Manejo de la urticaria crónica espontánea en la práctica clínica diaria siguiendo las indicaciones de la guía EAACI/GA(2)LEN/EDF/WAO.

INTRODUCTION: Chronic spontaneous urticaria is a prevalent and difficult-to-treat condition that has a very negative impact on patient quality of life. OBJECTIVE: To describe the epidemiological and clinical characteristics of patients presenting with chronic spontaneous urticaria and the response to treatment administered according to the EAACI/GA(2)LEN/EDF/WAO consensus guideline. MATERIAL AND METHOD: Descriptive cross-sectional study of all the patients with chronic spontaneous urticaria who consulted a skin allergy unit in the dermatology department of a tertiary hospital in Spain between July 2011 and July 2015. RESULTS: The study included 100 patients with chronic spontaneous urticaria; inducible urticaria was present in 43% of cases, and angioedema in 40%. On diagnosis, 53% of patients were taking nonsteroidal anti-inflammatory drugs. All patients were treated with second generation H1-antihistamines, but the standard dose was sufficient in only 18% of cases. Higher doses (up to 4 times the standard dose) achieved control of the urticaria in 74% of the patients studied. Higher doses of second generation H1-antihistamines were required to control the condition in patients with angioedema, and the presence of angioedema was associated with a lack of response to treatment with these drugs (OR, 6.1%; P<.001). One in 4 patients failed to respond to second generation H1-antihistamines and required treatment with omalizumab or ciclosporin to control their condition. CONCLUSIONS: Doses of H1-antihistamines higher than the standard dose are required in most cases to achieve control of chronic spontaneous urticaria. Angioedema is associated with failure to respond to treatment with antihistamines. In refractory cases, control of the condition can be achieved with omalizumab or ciclosporin. Patients with chronic spontaneous urticaria do not generally avoid the use of nonsteroidal anti-inflammatory agents.

Has clinical activity in paediatric neurology changed in the past 11 years? / ¿Ha cambiado la actividad asistencial de la neurología pediátrica en 11 años?

INTRODUCTION: We believe that the demand for paediatric neurology (PN) care has increased over the past decade, and that reasons for requesting consultations have also changed. The objective of this study is to complete a registry study to profile the demand for PN care in 2013 and compare results to those from a study performed in 2002. METHODS: A prospective registry of PN healthcare activities was completed at Hospital Universitario de Getafe in 2013. Results were compared with those from a prospective registry study conducted in 2002. RESULTS: The number of visits increased from 1,300 in 2002 to 1,982 in 2013 (a 52.46% increase), and from 32.6 visits per 1,000 children to 57.48 (a 76.32% increase). Outpatient consultations accounted for 92.2% of all PN consultations in 2013. Currently, attention deficit-hyperactivity disorder (ADHD) is the most frequent diagnosis (27.6% in 2013 vs. 8.1% in 2002). Although the percentage of headache consultations has decreased (19% in 2013 vs. 22% in 2002), headache was still the most common reason for an initial visit in 2013 (32.1%), followed by ADHD (19.1%). Epilepsy remains the most frequent diagnosis in hospitalised patients (30.3% in 2013 vs. 36.7% in 2002). CONCLUSIONS: PN is fundamentally an outpatient activity that has increased considerably in recent years. This increase is mainly due to neurodevelopmental disorders, especially ADHD. We might state that the role of ADHD in PN is comparable to that of dementia in general neurology.

Educational and skills-based interventions for preventing relationship and dating violence in adolescents and young adults.

BACKGROUND: Educational and skills-based interventions are often used to prevent relationship and dating violence among young people. OBJECTIVES: To assess the efficacy of educational and skills-based interventions designed to prevent relationship and dating violence in adolescents and young adults. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, CINAHL, PsycINFO, six other databases and a trials register on 7 May 2012. We handsearched the references lists of key articles and two journals (Journal of Interpersonal Violence and Child Abuse and Neglect). We also contacted researchers in the field. SELECTION CRITERIA: Randomised, cluster-randomised and quasi-randomised studies comparing an educational or skills-based intervention to prevent relationship or dating violence among adolescents and young adults with a control. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed study eligibility and risk of bias. For each study included in the meta-analysis, data were extracted independently by GF and one other review author (either CH, JN, SH or DS). We conducted meta-analyses for the following outcomes: episodes of relationship violence, behaviours, attitudes, knowledge and skills. MAIN RESULTS: We included 38 studies (15,903 participants) in this review, 18 of which were cluster-randomised trials (11,995 participants) and two were quasi-randomised trials (399 participants). We included 33 studies in the meta-analyses. We included eight studies (3405 participants) in the meta-analysis assessing episodes of relationship violence. There was substantial heterogeneity (I(2) = 57%) for this outcome. The risk ratio was 0.77 (95% confidence interval (CI) 0.53 to 1.13). We included 22 studies (5256 participants) in the meta-analysis assessing attitudes towards relationship violence. The standardised mean difference (SMD) was 0.06 (95% CI -0.01 to 0.15). We included four studies (887 participants) in the meta-analysis assessing behaviour related to relationship violence; the SMD was -0.07 (95% CI -0.31 to 0.16). We included 10 studies (6206 participants) in the meta-analysis assessing knowledge related to relationship violence; the results showed an increase in knowledge in favour of the intervention (SMD 0.44, 95% CI 0.28 to 0.60) but there was substantial heterogeneity (I(2) = 52%). We included seven studies (1369 participants) in the meta-analysis assessing skills related to relationship violence. The SMD was 0.03 (95% CI -0.11 to 0.17). None of the included studies assessed physical health, psychosocial health or adverse outcomes. Subgroup analyses showed no statistically significant differences by intervention setting or type of participants. The quality of evidence for all outcomes included in our meta-analysis was moderate due to an unclear risk of selection and detection bias and a high risk of performance bias in most studies. AUTHORS' CONCLUSIONS: Studies included in this review showed no evidence of effectiveness of interventions on episodes of relationship violence or on attitudes, behaviours and skills related to relationship violence. We found a small increase in knowledge but there was evidence of substantial heterogeneity among studies. Further studies with longer-term follow-up are required, and study authors should use standardised and validated measurement instruments to maximise comparability of results.

Inhibition of dental erosion by casein and casein-derived proteins.

The application of milk-derived proteins such as casein as anti-erosion agents in oral healthcare products is of current interest. The aim of this study was to investigate the potential of 3 commercially available, milk-derived proteins as agents to inhibit enamel erosion. Aqueous solutions of 0.5% w/v casein, casein phosphopeptide (CPP) or glycomacropeptide (GMP) with and without 300 ppm fluoride (F, as NaF) were investigated with regard to enamel softening and tissue loss, in comparison with a deionised water (DIW) negative control and 300 ppm F positive control. Casein and F reduced enamel surface softening compared to DIW, but CPP and GMP did not (DIW: 58.2% reduction in hardness; F: 13.3%; casein: 21.8%; CPP: 50.8%; GMP: 62.4%). Similar results were obtained with solutions containing protein and F, and the effects were statistically indistinguishable from protein alone (casein + F: 19.1%; CPP + F: 48.2%; GMP + F: 66.1%). By contrast, all protein solutions and F significantly reduced tissue loss (p < 0.050; DIW: 25.8 µm tissue loss; F: 21.6 µm; casein: 20.3 µm; CPP: 20.5 µm; GMP: 20.0 µm). Solutions containing protein and F reduced erosion more than protein alone, but this difference was only significant from protein alone for casein (casein + F: 12.2 µm; CPP + F: 17.3 µm; GMP + F: 18.2 µm). Casein and casein-derived proteins may therefore have the potential to act as agents to reduce or prevent enamel erosion. Furthermore, the erosion-reducing efficacy is not reduced by F, and is in some cases enhanced.

A new approach for initial callus growth during fracture healing in long bones.

The incidence of bone fracture has become a major clinical problem on a worldwide scale. In the past two decades there has been an increase in the use of computational tools to analyse the bone fracture problem. In several works, various study cases have been analysed to compare human and animal bone fracture healing. Unfortunately, there are not many publications about computational advances in this field and the existing approaches to the problem are usually similar. In this context, the objective of this work is the application of a diffusion problem in the model of the bone fragments resulting from fracture, working together with a mesh-growing algorithm that allows free growth of the callus depending on the established conditions, without a pre-meshed domain. The diffusion problem concerns the different biological magnitudes controlling the callus growth, among which Mesenchymal Stem Cells and chondrocytes concentrations were chosen, together with Tumour Necrosis Factor α and Bone Morphogenetic Protein as the factors influencing the velocity in the callus formation. A Finite Element approach was used to solve the corresponding diffusion problems, obtaining the concentration values along the entire domain and allowing detecting the zones in which biological magnitudes reach the necessary thresholds for callus growth. The callus growth is guided by a geometrical algorithm which performs an additional mesh generation process (self-added mesh) at each step of the iterative procedure until complete callus formation. The proposed approach was applied to different types of diaphyseal femoral fractures treated by means of intramedullary nailing. Axisymmetric models based on triangular quadratic elements were used, obtaining results in good agreement with clinical evidence of these kinds of fractures. The algorithm proposed has the advantage of a natural callus growth, without the existence of a previous mesh that may affect the conditions and direction of growth. The approach is intended for the initial phase of callus growth. Future work will address the implementation of the corresponding formulations for tissue transformation and bone remodelling in order to achieve complete fracture healing.

Are the unreamed nails indicated in diaphyseal fractures of the lower extremity? A biomechanical study.

INTRODUCTION: Intramedullary nailing is generally accepted as the first choice for the treatment of diaphyseal fractures of femur and tibia, with a gradual incease in the use of unreamed nails. Different studies during last years show controversial outcomes. Some authors strongly favor unreamed nailing, but most of the authors conclude that reamed nailing have proved to be more successful. MATERIAL AND METHODS: This study simulates unreamed intramedullary nailing of four femoral and three tibial fracture types by means of Finite Element (FE) models, at early postoperative stages with a fraction of physiological loads, in order to determine whether sufficient stability is achieved, and if the extent of movements and strains at the fracture site may preclude proper consolidation. RESULTS: The behavior observed in the different fracture models is very diverse. In the new biomechanical situation, loads are only transmitted through the intramedullary nail. Mean relative displacement values of fractures in the femoral bone range from 0.30 mm to 0.82 mm, depending on the fracture type. Mean relative displacement values of the tibial fractures lie between 0.18 and 0.62 mm, depending on the type of fracture. Concerning mean strains, for femoral fractures the maximum strains ranged between 12.7% and 42.3%. For tibial fractures the maximum strains ranged between 10.9% and 40.8%. CONCLUSIONS: The results showed that unreamed nailing provides a very limited mechanical stability, taking into account that analyzed fracture patterns correspond to simple fracture without comminution. Therefore, unreamed nailing is not a correct indication in femoral fractures and should be an exceptional indication in open tibial fractures produced by high-energy mechanism.

Density functional theory study of the oxidation of methanol to formaldehyde on a hydrated vanadia cluster.

Density functional theory was used to study the mechanism for the oxidation of methanol to formaldehyde. A vanadium oxide cluster O=V(OH)(3) has been utilized to represent the catalytic system under hydrated conditions, i.e., in the presence of V-OH hydroxyl groups. Two types of methoxy-intermediates have been considered: a penta-coordinate methoxy-intermediate (OH)(4)V(OCH(3)) and a tetrahedral methoxy-intermediate (OH)(2)VO(OCH(3))(H(2)O). The most plausible reaction pathway corresponds to the process involving first the formation of the tetrahedral methoxide, and a subsequent rate-limiting step where hydrogen is transferred from the methoxy groups toward the oxygen atom of the vanadyl V=O site. The reaction mechanism is a typical two-state reactivity process due to a change of the multiplicity (reactive singlet --> product triplet) along the reaction coordinate accompanied by a reduction of the vanadium center from V(V) (d(0)) to V(III) (d(2)). Minimum energy crossing points were localized and possible spin inversion processes are discussed by means of the intrinsic reaction coordinate approach to find the most favorable reaction pathways. The hydration effect is found to be mainly the destabilization of the methoxy intermediates. An alternative reaction pathway with a lower apparent barrier is presented.

A comparative study of hyperelastic constitutive models for colonic tissue fitted to multiaxial experimental testing.

For colonic stents design, the interaction with colonic tissue is essential in order to characterize the appropriate radial stiffness which provides a minimum lumen for intestinal transit to be maintained. It is therefore important to develop suitable constitutive models allowing the mechanical behavior of the colon tissue to be characterized. The present work investigates the biomechanical behavior of colonic tissue by means of biaxial tests carried out on different parts of the colonic tract taken from several porcine specimens. Samples from the colonic tract were quasi-statically tensioned using a load-controlled protocol with different tension ratios between the circumferential and the axial directions. Fitting techniques were then used to adjust specific hyperelastic models accounting for the multilayered conformation of the colonic wall and the fiber-reinforced configuration of the corresponding tissues. It was found that the porcine colon changed from a more isotropic to a more anisotropic tissue and became progressively more flexible and compliant in circumferential direction depending on the position along the duct as it approaches the rectum. The best predictive capability of mechanical behavior corresponds to the Four Fiber Family model showing mean values of coefficient of determination R2=0.97, and a normalized root mean square error of εNRMS=0.0814 for proximal spiral samples, and R2=0.89 , ÎµNRMS=0.1600 and R2=0.94 , ÎµNRMS=0.1227 for distal spiral and descending colon samples, respectively. The other analyzed models provide good results for proximal spiral colon specimens, which have a lower degree of anisotropy. The analyzed models with the fitted elastic parameters can be used for more realistic and reliable FE simulations, providing the appropriate framework for the design of optimal devices for the treatment of colonic diseases.

Biomechanical analysis of the stability of anterograde reamed intramedullary nails in femoral spiral fractures.

Femoral shaft fractures present high morbidity and important complications and consequences, being spiral fractures the most complicated from a biomechanical point of view, being unstable and without possibility of getting a good contact between nail and femoral endosteum. Femoral diaphyseal fractures are treated, usually, by means of intramedullary nailing. So, it is necessary to know the osteosynthesis stability and which locking screws combination is optimal. This work studies the use of reamed locked intramedullary nails in spiral femoral fractures located along zones 2 and 4 of wiss, depending on the spire length, corresponding to 32-A spiral type in AO/OTA classification, which represent a percentage of 23% within the total of diaphyseal fractures. A three-dimensional finite element model of the femur was developed, modeling a spiral fracture with different spiral lengths and gaps. A femoral nail was used, considering two transversal screws both at the proximal and the distal parts. The study was focused on the immediately post-operative stage, verifying the appropriate stability of the osteosynthesis. Reamed intramedullary blocked nails provide appropriate stability of femoral spiral fractures, considering global mobility of femoral head with respect to femoral condyles, relative displacements between fragments at fracture site, stresses at nail and locking screws, and stresses at cortical bone. The obtained results show that the use of blocked reamed nails in spiral femoral fractures can be considered as an appropriate surgical technique, providing sufficient stability in order to obtain an adequate fracture healing.

Comparative analysis of the biomechanical behavior of anterograde/retrograde nailing in supracondylar femoral fractures.

Supracondylar femoral fractures account for a noticeable percentage of the femoral shaft fractures, affecting two etiological groups: high energy trauma in young men, with good bone quality, and older women with osteoporotic femur. Surgical treatment of those kind of fractures remains controversial, with different surgical options such as plate and sliding barrel locking condylar plate, less invasive stabilization system (LISS) or intramedullary nailing, which has emerged as a new fixation choice in the treatment of that type of fractures. The present work performs a comparative study about the biomechanical behavior of anterograde and retrograde nailing in supracondylar femoral fractures type A, in order to determine the best choice of nailing and locking configuration. A three-dimensional finite element model of the femur was developed, modeling femoral supracondylar fracture and different nailing configurations, both for anterograde and retrograde nails. The study was focused on the immediately post-operative stage, verifying the appropriate stability of the osteosynthesis. The obtained results show a better biomechanical behavior for anterograde nails, providing a better stability from the point of view of global movements, lower stresses in screws, and less stress concentration in cortical bone. So, for the analyzed fractures and osteosyntheses types, anterograde nailing has demonstrated to be a better surgical option, being an excellent indication in supracondylar fractures of femur, with clear benefits compared to retrograde nailing, providing a better stabilization which enables for a more satisfactory fracture healing.

Fluoride penetration from toothpastes into incipient enamel erosive lesions investigated using dynamic secondary ion mass spectrometry.

OBJECTIVE: The primary aim of this study was to assess the utility of dynamic secondary ion mass spectrometry (DSIMS) as a convenient and sensitive technique for determining fluoride uptake and distribution into incipient human enamel erosive lesions in vitro. A secondary aim was to correlate the extent of lesion rehardening following treatment with a toothpaste slurry, with relative fluoride uptake determined by DSIMS. The final aim was to compare fluoride uptake by incipient lesions treated with toothpastes containing different sources of fluoride using DSIMS. METHODS: Relative fluoride uptake into the surface and body of enamel erosive lesions was monitored by DSIMS as a function of fluoride concentration in a series of formulation-matched experimental pastes. Fluoride uptake into lesions that had been subjected to treatment with different toothpaste slurries in a single-treatment enamel lesion rehardening model was also determined, and its relationship with regard to the extent of rehardening and also the fluoride source investigated. RESULTS: Fluoride uptake by incipient erosive lesions treated with toothpastes containing NaF was quantitatively compared by DSIMS and found to be directly proportional to the fluoride concentration over the studied range (0-1400 ppm). Lesion repair observed in a single-treatment lesion rehardening model was positively correlated with the extent of fluoride uptake by the treated lesions. DSIMS was also able to show differences between commercial toothpastes containing different sources of fluoride and their ability to deliver the fluoride into the body of the lesion. The detrimental effect of sodium hexametaphosphate (NaHMP) present in Crest Pro-Health formulations previously reported in the single-treatment lesion rehardening model was also evident from the DSIMS elemental line scans obtained from the lesion cross-sections. CONCLUSION: DSIMS has been shown to be a powerful selective technique for quantifying relative fluoride uptake into enamel erosive lesions, and determining the extent and depth of lesion penetration. The relative efficacy of toothpastes containing fluoride from a variety of sources in the single-treatment lesion rehardening study is positively correlated with fluoride uptake and penetration determined by DSIMS.

Inhibition of enamel erosion and promotion of lesion rehardening by fluoride: a white light interferometry and microindentation study.

OBJECTIVE: The primary aim of the present in vitro studies was to investigate fluoride as an inhibitor of citric acid-mediated demineralization of human enamel and promoter of lesion repair using a combination of white light interferometry, scanning electron microscopy, and microindentation. Secondary aims included investigation of the importance of brushing on bulk tissue loss, and comparison of the relative efficacy of commercially available toothpastes on inhibiting enamel surface softening and rehardening of incipient erosive lesions. METHODS: Resin-mounted polished enamel specimens were prepared from extracted human molars and pre-molars. Mean surface roughness (Sa) and bulk tissue loss following exposure to an erosive challenge, or an erosive challenge plus brushing were investigated using a MicroXAM ADE PhaseShift white light interferometer. Surface morphology was determined using a Zeiss Evo 50 scanning electron microscope (SEM). The utility of fluoride-based treatments to protect against subsequent acid demineralization and to promote remineralization of pre-formed incipient lesions was determined using microindentation-based enamel surface softening and enamel lesion rehardening models. RESULTS: Treating human enamel specimens with Sensodyne Pronamel conferred a clear protective benefit against a subsequent 300-second citric acid challenge as evidenced by the interferometry and SEM data. The increase in Sa and bulk tissue loss caused by an erosive challenge followed by brushing was markedly reduced by pre-treatment with sodium fluoride (NaF) in a concentration-dependent manner. Sensodyne Pronamel statistically outperformed Colgate Sensitive Enamel Protect both in the enamel surface softening model and lesion rehardening model, and conferred statistically superior enamel fluoride uptake. Treatment of erosive lesions with Sensodyne Pronamel resulted in statistically superior rehardening versus two Crest Pro-Health formulations containing stannous fluoride (SnF2) and sodium hexametaphosphate (NaHMP); the latter did not differ significantly from the fluoride-free negative control paste. Sensodyne Pronamel exhibited statistically significant superiority in a human saliva-based lesion rehardening model compared to Zendium Sensitive containing nominally comparable concentrations of NaF, as well as Colgate Sensitive and Colgate Sensitive Multi Protection containing sodium monofluorophosphate (NaMFP). CONCLUSION: The utility of NaF, whether delivered from simple solution or toothpaste, to reduce citric acid-mediated surface roughening and bulk tissue loss has been clearly demonstrated. The effectiveness of Sensodyne Pronamel as an anti-erosion toothpaste has also been demonstrated in various microhardness models. Crest Pro-Health toothpastes containing SnF2 and NaHMP were not statistically differentiable from a fluoride-free control paste in the lesion rehardening model. The latter result indicates that the benefit of fluoride to promote mineral formation is outweighed by the effect of NaHMP as a mineralization inhibitor in this model.

Treatment of animal carcasses in poultry farms using sealed ditches.

Several hen carcass elimination experiments were conducted by isolating corpses in a sealed ditch and adding different doses of lime. The aim was to evaluate the viability of this method as an alternative to other elimination techniques, as required in the European regulation CE 1774/2002 [Reglamento CE 1774/2002, de 3 de octubre por el que se establecen las normas sanitarias aplicables a los subproductos animales no destinados a consumo humano]. The experiments were carried out at a natural scale, in a 200m3 ditch located in a livestock enterprise, using a proportion of 200g of lime/kg of carcass. We observed a high degradation of carcasses after six months, the method being also safe from a microbiological point of view. The material extracted from the ditch had a high calcium content (330.7gkg(-1)), which makes it an ideal product for soil lacking this element, or as an acidity corrector in acid soils due to its basic (pH 8.48) nature. It also contains a significant amount of mineral nutrients (17.0gkg(-1) N, 2.4gkg(-1) P and 4.9gkg(-1) K) and organic matter (101.5gkg(-1)). We also analysed the material extracted from the ditch prior to its renovation for the experiments and followed the processes taking place in the ditch during the first six months, when lime doses of 100, 200 and 300 gkg(-1) of treated carcass were applied. Simultaneously, we carried out laboratory experiments in cylindrical 25L deposits to evaluate the gas release of the three (100, 200 and 300g of lime/kg carcass) doses of lime used. After the tenth week, we observed CO2 concentrations ranging from 5% for the lower lime doses to very low levels for the 300g lime/kg carcass dose. As regards methane, in the three series of experiments, the release was highest during the first weeks, began to decrease in the eighth week and reached its lower value during the fourteenth week. Emissions of NO2 were not observed, and the levels of NH3 and SH2 were usually so high that they exceeded the detection level of the apparatus used to register them.

Characterization of the high-pressure structures and phase transformations in SnO2. A density functional theory study.

Theoretical investigations concerning the high-pressure polymorphs, the equations of state, and the phase transitions of SnO2 have been performed using density functional theory at the B3LYP level. Total energy calculations and geometry optimizations have been carried out for all phases involved, and the following sequence of structural transitions from the rutile-type (P42/mnm) driven by pressure has been obtained (the transition pressure is in parentheses): --> CaCl2-type, Pnnm (12 GPa) --> alpha-PbO2-type, Pbcn (17 GPa) --> pyrite-type, Pa (17 GPa) --> ZrO2-type orthorhombic phase I, Pbca (18 GPa) --> fluorite-type, Fmm (24 GPa) --> cotunnite-type orthorhombic phase II, Pnam (33 GPa). The highest bulk modulus values, calculated by fitting pressure-volume data to the second-order Birch-Murnaghan equation of state, correspond to the cubic pyrite and the fluorite-type phases with values of 293 and 322 GPa, respectively.

Successful use of lipid emulsion to resuscitate a foal after intravenous lidocaine induced cardiovascular collapse.

BACKGROUND: Lipid emulsion has been reported to be effective for the treatment of local anaesthetic overdoses in rats, dogs and man. OBJECTIVES: To describe the successful treatment of cardiovascular lidocaine toxicity in a foal with intravenous lipid administration. STUDY DESIGN: Observational study: case report. METHODS: An 8-month-old Arabian cross foal was anaesthetised for removal of the right alar fold and nasal plate. Anaesthesia was maintained with isoflurane in oxygen and lidocaine administered with a loading dose followed by a continuous rate infusion (CRI). The anaesthetic period was uneventful and 30 min before expected termination of the procedure lidocaine infusion was stopped. A sudden drop in mean arterial blood pressure was then observed. The ECG signal was lost, the end tidal CO2 tension dropped from 40 to 10 mmHg, corneal reflex was absent and asystole diagnosed. Cardiopulmonary resuscitation manoeuvres were immediately initiated, but epinephrine and atropine were unsuccessfully administered. Lipid emulsion was administered and the heart rate and arterial blood pressure gradually returned to normal. RESULTS: The foal recovered consciousness 3 h later, regained its sternal position, was responsive and 20 h later was able to stand up alone. MAIN LIMITATIONS: It will be necessary to evaluate a greater number of cases to determine the effectiveness of lipids in foals intoxicated with lidocaine. CONCLUSION: Intravenous lipid emulsion may be helpful in the treatment of potentially lethal cardiotoxicity attributable to lidocaine overdose in the foal.

A methodology for the customized design of colonic stents based on a parametric model.

The choice of necessary stent properties depends mainly on the length of the stenosis and degree of occlusion. So a stent design with variable radial stiffness along its longitudinal axis would be a good option. The design proposed corresponds to a tube-based stent with closed diamond-shaped cells made from a NiTi alloy. By acting independently on different geometric factors, variable geometries can be obtained with different radial force reactions. A design adjustment according to specific requirements, in order to get a better fit to ill-duct and reduces complications, is possible. A parametric analysis using finite element has been conducted to determine the influence of slot length, number of circumferential slots, tube thickness and shape-factor on stent mechanical behavior, which allow eliminating the need for extensive experimental work and knowing and quantifying the influence of those factors. The results of finite element simulations have been used, by means of least-squares fit techniques, to obtain analytical expressions for the main mechanical characteristics of the stent (Chronic Expansive Radial Force and Radial Compression Resistance) in terms of the different geometrical factors. This allows the stent geometry to be customized without launching an iterative and costly process of modeling and simulation for each case.