Mechanism of gabapentinoid potentiation of opioid effects on cyclic AMP signaling in neuropathic pain.

Over half of spinal cord injury (SCI) patients develop opioid-resistant chronic neuropathic pain. Safer alternatives to opioids for treatment of neuropathic pain are gabapentinoids (e.g., pregabalin and gabapentin). Clinically, gabapentinoids appear to amplify opioid effects, increasing analgesia and overdose-related adverse outcomes, but in vitro proof of this amplification and its mechanism are lacking. We previously showed that after SCI, sensitivity to opioids is reduced by fourfold to sixfold in rat sensory neurons. Here, we demonstrate that after injury, gabapentinoids restore normal sensitivity of opioid inhibition of cyclic AMP (cAMP) generation, while reducing nociceptor hyperexcitability by inhibiting voltage-gated calcium channels (VGCCs). Increasing intracellular Ca2+ or activation of L-type VGCCs (L-VGCCs) suffices to mimic SCI effects on opioid sensitivity, in a manner dependent on the activity of the Raf1 proto-oncogene, serine/threonine-protein kinase C-Raf, but independent of neuronal depolarization. Together, our results provide a mechanism for potentiation of opioid effects by gabapentinoids after injury, via reduction of calcium influx through L-VGCCs, and suggest that other inhibitors targeting these channels may similarly enhance opioid treatment of neuropathic pain.

Luminescence and Excited-State Reactivity in a Heteroleptic Tricyanido Fe(III) Complex.

Harnessing sunlight via photosensitizing molecules is key for novel optical applications and solar-to-chemical energy conversion. Exploiting abundant metals such as iron is attractive but becomes challenging due to typically fast nonradiative relaxation processes. In this work, we report on the luminescence and excited-state reactivity of the heteroleptic [FeIII(pzTp)(CN)3]- complex (pzTp = tetrakis(pyrazolyl)borate), which incorporates a σ-donating trispyrazolyl chelate ligand and three monodentate σ-donating and π-accepting cyanide ligands. Contrary to the nonemissive [Fe(CN)6]3-, a broad emission band centered at 600 nm at room temperature has been recorded for the heteroleptic analogue attributed to the radiative deactivation from a 2LMCT excited state with a luminescence quantum yield of 0.02% and a lifetime of 80 ps in chloroform at room temperature. Bimolecular reactivity of the 2LMCT excited state was successfully applied to different alcohol photo-oxidation, identifying a cyanide-H bonding as a key reaction intermediate. Finally, this research demonstrated the exciting potential of [Fe(pzTp)(CN)3]- as a photo-oxidant, paving the way for further exploration and development of emissive Fe-based photosensitizers competent for photochemical transformations.

X-ray lens figure errors retrieved by deep learning from several beam intensity images.

The phase problem in the context of focusing synchrotron beams with X-ray lenses is addressed. The feasibility of retrieving the surface error of a lens system by using only the intensity of the propagated beam at several distances is demonstrated. A neural network, trained with a few thousand simulations using random errors, can predict accurately the lens error profile that accounts for all aberrations. It demonstrates the feasibility of routinely measuring the aberrations induced by an X-ray lens, or another optical system, using only a few intensity images.

BEATS: BEAmline for synchrotron X-ray microTomography at SESAME.

The ID10 beamline of the SESAME (Synchrotron-light for Experimental Science and Applications in the Middle East) synchrotron light source in Jordan was inaugurated in June 2023 and is now open to scientific users. The beamline, which was designed and installed within the European Horizon 2020 project BEAmline for Tomography at SESAME (BEATS), provides full-field X-ray radiography and microtomography imaging with monochromatic or polychromatic X-rays up to photon energies of 100 keV. The photon source generated by a 2.9 T wavelength shifter with variable gap, and a double-multilayer monochromator system allow versatile application for experiments requiring either an X-ray beam with high intensity and flux, and/or a partially spatial coherent beam for phase-contrast applications. Sample manipulation and X-ray detection systems are designed to allow scanning samples with different size, weight and material, providing image voxel sizes from 13 µm down to 0.33 µm. A state-of-the-art computing infrastructure for data collection, three-dimensional (3D) image reconstruction and data analysis allows the visualization and exploration of results online within a few seconds from the completion of a scan. Insights from 3D X-ray imaging are key to the investigation of specimens from archaeology and cultural heritage, biology and health sciences, materials science and engineering, earth, environmental sciences and more. Microtomography scans and preliminary results obtained at the beamline demonstrate that the new beamline ID10-BEATS expands significantly the range of scientific applications that can be targeted at SESAME.

Quantifying pigment content in crustose coralline algae using hyperspectral imaging: A case study with Tethysphytum antarcticum (Ross Sea, Antarctica).

Crustose coralline algae (CCA) are a highly diverse group of habitat-forming, calcifying red macroalgae (Rhodophyta) with unique adaptations to diverse irradiance regimes. A distinctive CCA phenotype adaptation, which allows them to maximize photosynthetic performance in low light, is their content of a specific group of light-harvesting pigments called phycobilins. In this study, we assessed the potential of noninvasive hyperspectral imaging (HSI) in the visible spectrum (400-800 nm) to describe the phenotypic variability in phycobilin content of an Antarctic coralline, Tethysphytum antarcticum (Hapalidiales), from two distinct locations. We validated our measurements with pigment extractions and spectrophotometry analysis, in addition to DNA barcoding using the psbA marker. Targeted spectral indices were developed and correlated with phycobilin content using linear mixed models (R2 = 0.64-0.7). Once applied to the HSI, the models revealed the distinct phycoerythrin spatial distribution in the two site-specific CCA phenotypes, with thin and thick crusts, respectively. This study advances the capabilities of hyperspectral imaging as a tool to quantitatively study CCA pigmentation in relation to their phenotypic plasticity, which can be applied in laboratory studies and potentially in situ surveys using underwater hyperspectral imaging systems.

Exploring precision-cut liver slices for comparative xenobiotic metabolism profiling in swine and cattle.

In vitro systems are useful tools for unravelling species differences in xenobiotic metabolism.The current work aimed to validate the technique of precision-cut liver slices (PCLS) for comparative studies on xenobiotic metabolism in swine and cattle.PCLS from swine (n = 3) and cattle (n = 3) were produced using a Brendel-VitronTM Tissue Slicer and cultured for 6 h. Tissue viability was preserved throughout the whole culture period.Metabolic viability was evaluated using the anthelmintics albendazole (ABZ) and fenbendazole (FBZ) as model drugs, as well as other substrates of hepatic monooxygenases: benzydamine (BZ) N-oxygenase (FMO-dependent), and the O-dealkylations of 7-ethoxyresorufin (EROD, CYP1A1-dependent) and 7-methoxyresorufin (MROD, CYP1A2-dependent).ABZ S-oxygenation resulted 6-fold (cattle) and 13.6-fold (swine) higher (p = 0.001) compared to FBZ S-oxygenation.Similar BZ N-oxygenation and EROD activities were observed in PCLS cultures from both species. MROD was 2.5-fold higher (p = 0.033) in swine than in cattle. Similarly, ABZ S-oxygenation was 1.7-fold higher (p = 0.0002) in swine than in cattle. Conversely, a 82% higher (p = 0.0003) rate of FBZ S-oxygenation was evidenced in PCLS cultures from cattle compared to those from swine.Overall, this work shows that PCLS cultures are useful to obtain relevant information on species differences in xenobiotic metabolism.

Prediction Accuracy of Soil Chemical Parameters by Field- and Laboratory-Obtained vis-NIR Spectra after External Parameter Orthogonalization.

One challenge in predicting soil parameters using in situ visible and near infrared spectroscopy is the distortion of the spectra due to soil moisture. External parameter orthogonalization (EPO) is a mathematical method to remove unwanted variability from spectra. We created two different EPO correction matrices based on the difference between spectra collected in situ and, respectively, spectra collected from the same soil samples after drying and sieving and after drying, sieving and finely grinding. Spectra from 134 soil samples recorded with two different spectrometers were split into calibration and validation sets and the two EPO corrections were applied. Clay, organic carbon and total nitrogen content were predicted by partial least squares regression for uncorrected and EPO-corrected spectra using models based on the same type of spectra ("within domain") as well as using laboratory-based models to predict in situ collected spectra ("cross-domain"). Our results show that the within-domain prediction of clay is improved with EPO corrections only for the research grade spectrometer, with no improvement for the other parameters. For the cross-domain predictions, there was a positive effect from both EPO corrections on all parameters. Overall, we also found that in situ collected spectra provided an equally successful prediction as laboratory-based spectra.

Fuchs endothelial corneal dystrophy: an updated review.

PURPOSE: The present review will summarize FECD-associated genes and pathophysiology, diagnosis, current  therapeutic approaches, and future treatment perspectives. METHODS: Literature review. RESULTS: Fuchs' endothelial corneal dystrophy (FECD) is the most common bilateral corneal dystrophy and accounts for one-third of all corneal transplants performed in the US. FECD is caused by a combination of genetic and non-heritable factors, and there are two types: early-onset FECD, which affects individuals from an early age and is usually more severe, and late-onset FECD, which is more common and typically manifests around the age of 40. The hallmark findings of FECD include progressive loss of corneal endothelial cells and the formation of focal excrescences (guttae) on the Descemet membrane. These pathophysiological changes result in progressive endothelial dysfunction, leading to a decrease in visual acuity and blindness in later stages. The present review will summarize FECD-associated genes and pathophysiology, diagnosis, current therapeutic approaches, and future treatment perspectives. CONCLUSION: With the characterization and understanding of FECD-related genes and ongoing research into regenerative therapies for corneal endothelium, we can hope to see more significant improvements in the future in the management and care of the disease.

Surgical and functional outcomes of Retzius-sparing robotic-assisted radical prostatectomy versus conventional robotic-assisted radical prostatectomy in patients with biopsy-confirmed prostate cancer. Are outcomes worth it? Systematic review and meta-analysis.

BACKGROUND: Radical prostatectomy is the standard of care for prostate cancer. Retzius-sparing robotic-assisted radical prostatectomy (RS-RARP) is being widely adopted due to positive functional outcomes compared to conventional robotic-assisted radical prostatectomy (c-RARP). Concerns regarding potency, oncological outcomes, and learning curve are still a matter of debate. METHODS: Following Preferred Instrument for Systematic Reviews and Meta-Analysis guidelines and PROSPERO registration CRD42023398724, a systematic review was performed in February 2023 on RS-RARP compared to conventional c-RARP. Outcomes of interest were continence recovery, potency, positive surgical margins (PSM), biochemical recurrence (BCR), estimated blood loss (EBL), length of stay (LOS), operation time and complications. Data were analyzed using R version 4.2.2. RESULTS: A total of 17 studies were included, totaling 2751 patients, out of which 1221 underwent RS-RARP and 1530 underwent c-RARP. Continence was analyzed using two definitions: zero pad and one safety pad. Cumulative analysis showed with both definitions statistical difference in terms of continence recovery at 1 month (0 pad odds ratio [OR] = 4.57; 95% confidence interval [CI] = [1.32-15.77]; Safety pad OR = 13.19; 95% CI = [8.92-19.49]), as well as at 3 months (0 pad OR, 2.93; 95% CI = [1.57-5.46]; Safety pad OR = 5.31; 95% CI = [1.33-21.13]). Continence recovery at 12 months was higher in the one safety pad group after RS-RARP (OR = 4.37; 95% CI = [1.97-9.73]). The meta-analysis revealed that overall PSM rates without pathologic stage classification were not different following RS-RARP (OR = 1.13; 95% CI = [0.96-1.33]. Analysis according to the tumor stage revealed PSM rates in pT2 and pT3 tumors are not different following RS-RARP compared to c-RARP (OR = 1.46; 95% CI = [0.84-2.55]) and (OR = 1.41; 95% CI = [0.93-2.13]), respectively. No difference in potency at 12 months (OR = 0.98; 95% CI = [0.69-1.41], BCR at 12 months (OR = 0.99; 95% CI = [0.46-2.16]), EBL (standardized mean difference [SMD] = -0.01; 95% CI = [-0.31 to 0.29]), LOS (SMD = -0.01; 95% CI = [-0.48 to 0.45]), operation time (SMD = -0.14; 95% CI = [-0.41 to 0.12]) or complications (OR = 0.9; 95% CI = [0.62-1.29]) were observed. CONCLUSIONS: Our analysis suggests that RS-RARP is safe and feasible. Faster continence recovery rate is seen after RS-RARP. Potency outcomes appear to be similar. PSM rates are not different following RS-RARP regardless of pathologic stage. Further quality studies are needed to confirm these findings.

Age and sex disparities in Latin-American adults with gliomas: a systematic review and meta-analysis.

OBJECTIVE: This study aimed to identify if there are ethnic differences in the age and sex distribution of gliomas in the Latino adult population. METHODS: A systematic review and meta-analysis were conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 recommendations. Databases used were MEDLINE, LILACS, Web of Science, and Scopus. Studies were included if they reported the age and/or sex distribution of gliomas in Latin adults, published in English or Spanish from January 1st, 1985, to December 1st, 2022. The quality of the studies was assessed using the Newcastle-Ottawa Quality Assessment Scale and the NIH Quality Assessment Tool. RESULTS: From 1096 articles, fifteen studies with information on 6,815 patients were selected for the systematic review, and thirteen were selected for the meta-analysis. The mean ages of diagnosis of glioma and glioblastoma were 50.9, 95\%\ CI [47.8-53.9] years and 53.33 years, 95 \% CI [51-55.6], respectively. The male-to-female incidence rate ratio of gliomas was 1.39. CONCLUSION: Our study found mean ages of glioma and glioblastoma were 6 and 10 years lower than those reported in the CBTRUS. Our study suggests disparities in the age and sex distribution of gliomas in Latin America compared to other regions. PROSPERO REGISTRATION NUMBER: CRD42021274423.

Insights into the composition of ancient Egyptian red and black inks on papyri achieved by synchrotron-based microanalyses.

A hitherto unknown composition is highlighted in the red and black inks preserved on ancient Egyptian papyri from the Roman period (circa 100 to 200 CE). Synchrotron-based macro-X-ray fluorescence (XRF) mapping brings to light the presence of iron (Fe) and lead (Pb) compounds in the majority of the red inks inscribed on 12 papyrus fragments from the Tebtunis temple library. The iron-based compounds in the inks can be assigned to ocher, notably due to the colocalization of Fe with aluminum, and the detection of hematite (Fe2O3) by micro-X-ray diffraction. Using the same techniques together with micro-Fourier transform infrared spectroscopy, Pb is shown to be associated with fatty acid phosphate, sulfate, chloride, and carboxylate ions. Moreover, micro-XRF maps reveal a peculiar distribution and colocalization of Pb, phosphorus (P), and sulfur (S), which are present at the micrometric scale resembling diffused "coffee rings" surrounding the ocher particles imbedded in the red letters, and at the submicrometric scale concentrated in the papyrus cell walls. A similar Pb, P, and S composition was found in three black inks, suggesting that the same lead components were employed in the manufacture of carbon-based inks. Bearing in mind that pigments such as red lead (Pb3O4) and lead white (hydrocerussite [Pb3(CO3)2(OH)2] and/or cerussite [PbCO3]) were not detected, the results presented here suggest that the lead compound in the ink was used as a drier rather than as a pigment. Accordingly, the study calls for a reassessment of the composition of lead-based components in ancient Mediterranean pigments.

Current knowledge about the processes of luteolysis and maternal recognition of pregnancy in camelids.

Camelids have many unique reproductive features that considerably differ from those of other domestic species. Females are induced ovulators with subsequent development of a corpus luteum (CL) with a short lifespan. Plasma progesterone concentration starts to increase on day 4, peaks on day 8-9 and, in non-pregnant animals, basal concentration is reached around day 10-11 post-induction of ovulation. Luteolytic pulses of prostaglandin F2α (PGF2α ) are firstly detected on day 7 or 8 (approximately on day 5-6 after ovulation), with maximal luteolytic peaks observed between days 9 and 11 post-mating, in coincidence with a high endometrial expression of cyclooxygenase 2, a limiting enzyme in prostaglandins synthesis. Unlike other species, oxytocin seems not to be involved in the luteolytic process in these species. The CL is the main source of progesterone secretion, and its function is required to support pregnancy. Despite constant research efforts, aspects of reproduction and maternal recognition of pregnancy in camelids remain not fully understood. A transient decrease and subsequent recovery in plasma progesterone concentration are observed after day 9 post-mating in pregnant animals in association with a pulsatile release of PGF2α and a transitory decrease in CL vascularization. Thus, embryo recognition should occur between days 8 and 12 post-mating. In camels, conceptus tissues exhibit aromatizing activity with the capacity to synthesize large amounts of oestradiol. Similarly, llama blastocysts secrete oestradiol-17ß during the preimplantation stage, with a higher production during the elongation period. An increase in the endometrial expression of oestrogen receptor α is also observed on day 12 post-mating. All these evidences suggest that oestrogen could be the signal released by the embryo at the time of its recognition in camelids. Besides, nearly 98% of pregnancies are carried out in the left horn. A decrease in the endometrial expression of mucin 1 and 16 genes has been reported, suggesting that these changes are crucial for successful embryo implantation; however, no differences have been observed between horns. Thus, maternal recognition of pregnancy in camelids is a particularly complex process that must occur in a concise time to allow the rescue of the CL and embryo survival.

Recurrence rate and survival implications of surgical margins in patients with acral melanoma. Is a wide margin necessary?

INTRODUCTION: Appropriate size of resection margins in acral melanoma is not clearly established. OBJECTIVE: To investigate whether narrow-margin excision is appropriate for thick acral melanoma. METHODS: Three-hundred and six patients with acral melanoma were examined. Factors associated with recurrence and survival were analyzed according to surgical margin size (1 to 2 cm and > 2 cm). RESULTS: Out of 306 patients, 183 were women (59.8%). Median Breslow thickness was 6 mm; 224 cases (73.2%) were ulcerated, 154 patients (50.3%) had clinical stage III disease, while 137 were at stage II (44.8%) and 15 at stage IV (4.9%). All cases had negative margins, with a median of 31.5 mm. A Breslow thickness of 7 mm (p = 0.001) and clinical stage III (p = 0.031) were associated with recurrence; the factors associated with survival were Breslow index (p = 0.047), ulceration (p = 0.003), advanced clinical stage (p < 0.001), and use of adjuvant therapy (p = 0.003). CONCLUSION: A resection margin of 1 to 2 cm did not affect tumor recurrence or survival in patients with acral melanoma.

INTRODUCCIÓN: La extensión apropiada de los márgenes de resección en el melanoma acral no está claramente establecida. OBJETIVO: Investigar si la escisión con margen estrecho es adecuada en el melanoma acral grueso. MÉTODOS: Se estudiaron 306 pacientes con melanoma acral. Conforme a la extensión del margen quirúrgico (de 1 a 2 cm y > 2 cm), se analizaron los factores asociados a la recurrencia y la supervivencia. RESULTADOS: De 306 pacientes, 183 fueron mujeres (59.8 %). La mediana del grosor de Breslow fue 6 mm; 224 casos (73.2 %) fueron de tipo ulcerados, 154 pacientes (50.3 %) tenían enfermedad en estadio clínico III, 137 en II (44.8 %) y 15 en IV (4.9 %). Todos los casos presentaron margen negativo, con una mediana de 31.5 mm. Un grosor de Breslow de 7 mm (p = 0.001) y la etapa clínica III (p = 0.031) se asociaron a recurrencia; los factores asociados a la supervivencia fueron el índice de Breslow (p = 0.047), la ulceración (p = 0.003), la etapa clínica avanzada (p < 0.001) y el uso de adyuvancia (p = 0.003). CONCLUSIÓN: Un margen de resección de 1 a 2 cm no afectó la recurrencia tumoral ni la supervivencia en los pacientes con melanoma acral.

The Ravages of Enforced Disappearance: A Psychoanalytic Perspective of Traumatic Events and Encrypted Mourning.

In the context of violence and enforced disappearance in Mexico, the concept of mourning is recontextualized from a psychoanalytic perspective. Two themes of the psychoanalytic theory of mourning are considered: 1) the impossibility to confirm the death of the missing person and 2) the availability and purpose of symbolic resources (rites, community activities). The private and public aspects of mourning are reviewed in relation to the afflictions of the relatives of the missing. Without a body to mourn, the rites that are performed around the disappeared have a different function than funeral rites. Nuanced by repetition, these rites attempt to work through the traumatic loss. The role of search groups in working through the pain of loss is also explored. The notions of intrapsychic crypt and endocryptic identification are reviewed, to better understand the encrypted mourning -the particular state of prolonged grief- endured by the relatives of the disappeared.

A fast and lightweight tool for partially coherent beamline simulations in fourth-generation storage rings based on coherent mode decomposition.

A new algorithm to perform coherent mode decomposition of undulator radiation is proposed. It is based on separating the horizontal and vertical directions, reducing the problem by working with one-dimension wavefronts. The validity conditions of this approximation are discussed. Simulations require low computer resources and run interactively on a laptop. The focusing with lenses of the radiation emitted by an undulator in a fourth-generation storage ring (EBS-ESRF) is studied. Results are compared against multiple optics packages implementing a variety of methods for dealing with partial coherence: full two-dimension coherent mode decomposition, Monte Carlo combination of wavefronts from electrons entering the undulator with different initial conditions, and hybrid ray-tracing correcting geometrical optics with wave optics.

The Nutrition in Early Life and Asthma (NELA) birth cohort study: Rationale, design, and methods.

BACKGROUND: Primary prevention strategies for asthma are lacking. Its inception probably starts in utero and/or during the early postnatal period as the developmental origins of health and disease (DOHaD) paradigm suggests. OBJECTIVES: The main objective of Nutrition in Early Life and Asthma (NELA) cohort study is to unravel whether the following factors contribute causally to the developmental origins of asthma: (1) maternal obesity/adiposity and foetal growth; (2) maternal and child nutrition; (3) outdoor air pollution; (4) endocrine disruptors; and (5) maternal psychological stress. Maternal and offspring biological samples are used to assess changes in offspring microbiome, immune system, epigenome and volatilome as potential mechanisms influencing disease susceptibility. POPULATION: Randomly selected pregnant women from three health areas of Murcia, a south-eastern Mediterranean region of Spain, who fulfilled the inclusion criteria were invited to participate at the time of the follow-up visit for routine foetal anatomy scan at 19-22 weeks of gestation, at the Maternal-Fetal Medicine Unit of the "Virgen de la Arrixaca" University Clinical Hospital over a 36-month period, from March 2015 to April 2018. DESIGN: Prospective, population-based, maternal-child, birth cohort study. METHODS: Questionnaires on exposures and outcome variables were administered to mothers at 20-24 gestation week; 32-36 gestation week; and delivery. Children were surveyed at birth, 3 and 18 months of age and currently at 5 years. Furthermore, physical examinations were performed; and different measurements and biological samples were obtained at these time points. PRELIMINARY RESULTS: Among the 1350 women invited to participate, 738 (54%) were finally enrolled in the study and 720 of their children were eligible at birth. The adherence was high with 612 children (83%) attending the 3 months' visit and 532 children (72%) attending the 18 months' visit. CONCLUSION: The NELA cohort will add original and unique knowledge to the developmental origins of asthma.

Components of case management in caring for patients with dementia: a mixed-methods study.

BACKGROUND: Case management has shown improvements in some health outcomes for dementia patients and their families. However, despite its benefits the components of case management in order to provide effective patient and family care remain unknown at present. Thus, the aim of this study is to identify the specific components of case management in caring for patients with dementia and to determine the necessary intensity of its deployment to enhance outcomes for these patients and their caregivers. METHODS: Mixed-methods study with a qualitative phase to characterise forms of service provision, according to the case management components involved, followed by a quantitative phase to analyse the correlations between different patterns of service provision, adverse events in patients and caregiver overload. This study will be based on the variables described in the RANGE.COM register. DISCUSSION: This research is expected to achieve a reproducible, evaluable set of interventions that can be modelled to optimise case management effectiveness for patients with dementia. Interactions between patients with dementia, their family caregivers and case management healthcare services, the components of these interactions and their association with the conditions of the individuals concerned are issues of great interest in the field of case management, which is constantly evolving.

A protocol for a randomized trial measuring flowmetry in risk areas for pressure ulcer: Hyperoxygenated fatty acids vs olive oil.

BACKGROUND: Pressure ulcers are a common adverse event in healthcare. To date, no flowmetry studies have been conducted to compare hyperoxygenated fatty acids (HFA) vs. extra-virgin olive oil (EVOO) in alleviating this condition. AIMS: To determine and evaluate the effect of the application of HFA vs. EVOO on tissue oxygenation and perfusion in heels under pressure, in healthy persons and in hospitalised patients. DESIGN: Two-phase experimental study. METHODS: Phase 1 will be conducted with healthy subjects, using a randomised, open study design, evaluating an intrasubject control group. Phase 2 will focus on hospitalised subjects, with a randomised, open study group vs. a control group. DISCUSSION: This Project is undertaken to identify the mechanisms that intervene in the genesis of pressure ulcers and to determine whether there are differences in outcomes between the application of HFA vs. EVOO as a preventive measure The results of this study are of economic importance (due to the price difference between the products used) and will also impact on usual clinical practice for patients with impaired mobility and liable to suffer from pressure ulcers, by considering an alternative to established preventive measures.

Design simulations of a horizontally deflecting high-heat-load monochromator.

The performance of a liquid-nitrogen-cooled high-heat-load monochromator with a horizontal scattering plane has been analysed, aiming to preserve the high quality of the X-ray beam in the vertical plane for downstream optics. Using finite-element analysis, height profiles of the crystal surface for various heat loads and the corresponding slope errors in the meridional and sagittal planes were calculated. Then the angular distortions of the reflected beam in both meridional and sagittal planes were calculated analytically and also modelled by ray tracing, revealing a good agreement of the two approaches. The results show that with increasing heat load in the crystal the slope errors of the crystal surface reach their smallest values first in the sagittal and then in the meridional plane. For the considered case of interest at a photon energy of 14.412 keV and the Si(111) reflection with a Bragg angle of 7.88°, the angular distortions of the reflected beam in the sagittal plane are an order of magnitude smaller than in the meridional one. Furthermore, they are smaller than the typical angular size of the beam source at the monochromator position. For a high-heat-load monochromator operating in the horizontal scattering plane, the sagittal angular distortions of the reflected beam appear in the vertical plane. Thus, such an instrument perfectly preserves the high quality of the X-ray beam in the vertical plane for downstream optics. Compared with vertical scattering, the throughput of the monochromatic beam with the horizontal scattering plane is reduced by only 3.3% for the new EBS source, instead of 34.3% for the old ESRF-1 machine. This identifies the horizontal-scattering high-heat-load monochromator as a device essentially free of the heat-load effects in the vertical plane and without significant loss in terms of throughput.

Thermal optimization of a high-heat-load double-multilayer monochromator.

Finite-element analysis is used to study the thermal deformation of a multilayer mirror due to the heat load from the undulator beam at a low-emittance synchrotron source, specifically the ESRF-EBS upgrade beamline EBSL-2. The energy bandwidth of the double-multilayer monochromator is larger than that of the relevant undulator harmonic, such that a considerable portion of the heat load is reflected. Consequently, the absorbed power is non-uniformly distributed on the surface. The geometry of the multilayer substrate is optimized to minimize thermally induced slope errors. We distinguish between thermal bending with constant curvature that leads to astigmatic focusing or defocusing and residual slope errors. For the EBSL-2 system with grazing angles θ between 0.2 and 0.4°, meridional and sagittal focal lengths down to 100 m and 2000 m, respectively, are found. Whereas the thermal bending can be tuned by varying the depth of the `smart cut', it is found that the geometry has little effect on the residual slope errors. In both planes they are 0.1-0.25 µrad. In the sagittal direction, however, the effect on the beam is drastically reduced by the `foregiveness factor', sin(θ). Optimization without considering the reflected heat load yields an incorrect depth of the `smart cut'. The resulting meridional curvature in turn leads to parasitic focal lengths of the order of 100 m.