Abstract
BACKGROUND
Cranioplasty is a ubiquitous neurosurgical procedure consisting of reconstruction of a pre-existing calvarial defect. Many materials are available, including ...polymethylmethacrylate in hand-moulded (hPMMA) and prefabricated (pPMMA) form, hydroxyapatite (HA), polyetheretherketone (PEEK) and titanium (Ti).
OBJECTIVE
To perform a network meta-analysis (NMA) to assess the relationship between materials and complications of cranioplasty.
METHODS
PubMed/MEDLINE, Google Scholar, EMBASE, Scopus, and The Cochrane Library were searched from January 1, 1990 to February 14, 2021. Studies detailing rates of any of infections, implant exposure, or revision surgery were included. A frequentist NMA was performed for each complication. Risk ratios (RRs) with 95% CIs were calculated for each material pair.
RESULTS
A total of 3620 abstracts were screened and 31 full papers were included. Surgical revision was reported in 18 studies and occurred in 316/2032 cases (14%; 95% CI 11-17). PEEK had the lowest risk of re-operation with a rate of 8/157 (5%; 95% CI 0-11) in 5 studies, superior to autografts (RR 0.20; 95% CI 0.07-0.57), hPMMA (RR 0.20; 95% CI 0.07-0.60), Ti (RR 0.39; 95% CI 0.17-0.92), and pPMMA (RR 0.14; 95% CI 0.04-0.51). Revision rate was 131/684 (19%; 95% CI 13-25; 10 studies) in autografts, 61/317 (18%; 95%CI 9-28; 7 studies) in hPMMA, 84/599 (13%; 95% CI 7-19; 11 studies) in Ti, 7/59 (9%; 95% CI 1-23; 3 studies) in pPMMA, and 25/216 (12%; 95% CI 4-24; 4 studies) in HA. Infection occurred in 463/4667 (8%; 95% CI 6-11) and implant exposure in 120/1651 (6%; 95% CI 4-9).
CONCLUSION
PEEK appears to have the lowest risk of cranioplasty revision, but further research is required to determine the optimal material.
Graphical Abstract
Graphical Abstract
Notions of civilization and barbarism were intrinsic to Eugène Delacroix’s artistic practice: he wrote regularly about these concepts in his journal, and the tensions between the two ...were the subject of numerous paintings, including his most ambitious mural project, the ceiling of the Library of the Chamber of Deputies in the Palais Bourbon. Exiled in Modernity delves deeply into these themes, revealing why Delacroix’s disillusionment with modernity increasingly led him to seek spiritual release or epiphany in the sensual qualities of painting.
While civilization implied a degree of control and the constraint of natural impulses for Delacroix, barbarism evoked something uncontrolled and impulsive. Seeing himself as part of a grand tradition extending back to ancient Greece, Delacroix was profoundly aware of the wealth and power that set nineteenth-century Europe apart from the rest of the world. Yet he was fascinated by civilization’s chaotic underbelly. In analyzing Delacroix’s art and prose, David O’Brien illuminates the artist’s effort to reconcile the erudite, tradition-bound aspects of painting with a desire to reach viewers in a more direct, unrestrained manner. Focusing chiefly on Delacroix’s musings about civilization in his famous journal, his major mural projects on the theme of civilization, and the place of civilization in his paintings of North Africa and of animals, O’Brien links Delacroix’s increasingly pessimistic view of modernity to his desire to use his art to provide access to a more fulfilling experience.
With more than one hundred illustrations, this original, astute analysis of Delacroix and his work explains why he became an inspiration for modernist painters over the half-century following his death. Art historians and scholars of modernism especially will find great value in O’Brien’s work.
Extrasolar planet host stars have been found to be enriched in key planet-building elements. These enrichments have the potential to drastically alter the composition of material available for ...terrestrial planet formation. Here, we report on the combination of dynamical models of late-stage terrestrial planet formation within known extrasolar planetary systems with chemical equilibrium models of the composition of solid material within the disk. This allows us to determine the bulk elemental composition of simulated extrasolar terrestrial planets. A wide variety of resulting planetary compositions are found, ranging from those that are essentially 'Earth like', containing metallic Fe and Mg silicates, to those that are dominated by graphite and SiC. This shows that a diverse range of terrestrial planets may exist within extrasolar planetary systems.
Background
Decompressive craniectomy (DC) is a common neurosurgical intervention for severe traumatic brain injury (TBI), as well as malignant stroke, malignancy and infection. DC necessitates ...subsequent cranioplasty. There are significant demographic differences between TBI and non-TBI patients undergoing cranioplasty, which may influence their relative risk profiles for infection, aseptic bone flap resorption (aBFR) and re-operation.
Objective
Perform a meta-analysis to determine the relative infection, aBFR and re-operation risk profiles of TBI patients as compared to other indications for DC.
Methods
A systematic review and meta-analysis was performed in accordance with the PRISMA guidelines. PubMed, MEDLINE, EMBASE and Google Scholar were searched until 26/11/2020. Studies detailing rates of infection, re-operation and/or aBFR in specific materials and the post-TBI population were included, while studies in paediatrics or craniosynostosis repair were excluded.
Results
Twenty-six studies were included. There was no difference in relative risk of infection between TBI and non-TBI cohorts (RR 0.81, 95% CI 0.57–1.17), with insignificant heterogeneity (
I
2
= 33%). TBI was a risk factor for aBFR (RR 1.54, 95% CI 1.25–1.89), with no significant heterogeneity (
I
2
= 13%). TBI was a risk factor for re-operation in the autologous sub-group (RR 1.49, 95% CI 1.05–2.11) but not in the alloplastic sub-group (RR = 0.86, 95% CI 0.34–2.18). Heterogeneity was insignificant (
I
2
= 11%).
Conclusion
TBI is a risk factor for aBFR and re-operation following cranioplasty. Use of an alloplastic graft for primary cranioplasty in these patients may partially mitigate this increased risk.
•Sufficient water is delivered to terrestrial planets in the Grand Tack scenario.•Radial distribution and dynamical excitation are comparable to the Solar System.•Late giant impacts are relatively ...rare with current set of initial conditions.
A new model for terrestrial planet formation (Hansen 2009. Astrophys. J., 703, 1131–1140; Walsh, K.J., et al. 2011. Nature, 2011, 206–209) has explored accretion in a truncated protoplanetary disk, and found that such a configuration is able to reproduce the distribution of mass among the planets in the Solar System, especially the Earth/Mars mass ratio, which earlier simulations have generally not been able to match. Walsh et al. (Walsh, K.J., et al. 2011. Nature, 2011, 206–209) tested a possible mechanism to truncate the disk—a two-stage, inward-then-outward migration of Jupiter and Saturn, as found in numerous hydrodynamical simulations of giant planet formation. In addition to truncating the disk and producing a more realistic Earth/Mars mass ratio, the migration of the giant planets also populates the asteroid belt with two distinct populations of bodies—the inner belt is filled by bodies originating inside of 3AU, and the outer belt is filled with bodies originating from between and beyond the giant planets (which are hereafter referred to as ‘primitive’ bodies).
One implication of the truncation mechanism proposed in Walsh et al. (Walsh, K.J., et al. 2011. Nature, 2011, 206–209) is the scattering of primitive planetesimals onto planet-crossing orbits during the formation of the planets. We find here that the planets will accrete on order 1–2% of their total mass from these bodies. For an assumed value of 10% for the water mass fraction of the primitive planetesimals, this model delivers a total amount of water comparable to that estimated to be on the Earth today. The radial distribution of the planetary masses and the dynamical excitation of their orbits are a good match to the observed system. However, we find that a truncated disk leads to formation timescales more rapid than suggested by radiometric chronometers. In particular, the last giant impact is typically earlier than 20Myr, and a substantial amount of mass is accreted after that event. This is at odds with the dating of the Moon-forming impact and the estimated amount of mass accreted by Earth following that event. However, 5 of the 27 planets larger than half an Earth mass formed in all simulations do experience large late impacts and subsequent accretion consistent with those constraints.
Recent advances have substantially increased the number of genes that are statistically associated with complex genetic disorders of the CNS such as autism and schizophrenia. It is now clear that ...there will likely be hundreds of distinct loci contributing to these disorders, underscoring a remarkable genetic heterogeneity. It is unclear whether this genetic heterogeneity indicates an equal heterogeneity of cellular mechanisms for these diseases. The commonality of symptoms across patients suggests there could be a functional convergence downstream of these loci upon a limited number of cell types or circuits that mediate the affected behaviors. One possible mechanism for this convergence would be the selective expression of at least a subset of these genes in the cell types that comprise these circuits. Using profiling data from mice and humans, we have developed and validated an approach, cell type-specific expression analysis, for identifying candidate cell populations likely to be disrupted across sets of patients with distinct genetic lesions. Using human genetics data and postmortem gene expression data, our approach can correctly identify the cell types for disorders of known cellular etiology, including narcolepsy and retinopathies. Applying this approach to autism, a disease where the cellular mechanism is unclear, indicates there may be multiple cellular routes to this disorder. Our approach may be useful for identifying common cellular mechanisms arising from distinct genetic lesions.
Jupiter and Saturn formed in a few million years (ref. 1) from a gas-dominated protoplanetary disk, and were susceptible to gas-driven migration of their orbits on timescales of only ∼100,000 years ...(ref. 2). Hydrodynamic simulations show that these giant planets can undergo a two-stage, inward-then-outward, migration. The terrestrial planets finished accreting much later, and their characteristics, including Mars' small mass, are best reproduced by starting from a planetesimal disk with an outer edge at about one astronomical unit from the Sun (1 au is the Earth-Sun distance). Here we report simulations of the early Solar System that show how the inward migration of Jupiter to 1.5 au, and its subsequent outward migration, lead to a planetesimal disk truncated at 1 au; the terrestrial planets then form from this disk over the next 30-50 million years, with an Earth/Mars mass ratio consistent with observations. Scattering by Jupiter initially empties but then repopulates the asteroid belt, with inner-belt bodies originating between 1 and 3 au and outer-belt bodies originating between and beyond the giant planets. This explains the significant compositional differences across the asteroid belt. The key aspect missing from previous models of terrestrial planet formation is the substantial radial migration of the giant planets, which suggests that their behaviour is more similar to that inferred for extrasolar planets than previously thought.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Notions of civilization and barbarism were intrinsic to Eugène
Delacroix's artistic practice: he wrote regularly about these
concepts in his journal, and the tensions between the two were the
subject ...of numerous paintings, including his most ambitious mural
project, the ceiling of the Library of the Chamber of Deputies in
the Palais Bourbon. Exiled in Modernity delves deeply into
these themes, revealing why Delacroix's disillusionment with
modernity increasingly led him to seek spiritual release or
epiphany in the sensual qualities of painting.
While civilization implied a degree of control and the
constraint of natural impulses for Delacroix, barbarism evoked
something uncontrolled and impulsive. Seeing himself as part of a
grand tradition extending back to ancient Greece, Delacroix was
profoundly aware of the wealth and power that set
nineteenth-century Europe apart from the rest of the world. Yet he
was fascinated by civilization's chaotic underbelly. In analyzing
Delacroix's art and prose, David O'Brien illuminates the artist's
effort to reconcile the erudite, tradition-bound aspects of
painting with a desire to reach viewers in a more direct,
unrestrained manner. Focusing chiefly on Delacroix's musings about
civilization in his famous journal, his major mural projects on the
theme of civilization, and the place of civilization in his
paintings of North Africa and of animals, O'Brien links Delacroix's
increasingly pessimistic view of modernity to his desire to use his
art to provide access to a more fulfilling experience.
With more than one hundred illustrations, this original, astute
analysis of Delacroix and his work explains why he became an
inspiration for modernist painters over the half-century following
his death. Art historians and scholars of modernism especially will
find great value in O'Brien's work.
The Ru–Mo isotopic compositions of inner Solar System bodies may reflect the provenance of accreted material and how it evolved with time, both of which are controlled by the accretion scenario these ...bodies experienced. Here we use a total of 116 N-body simulations of terrestrial planet accretion, run in the Eccentric Jupiter and Saturn (EJS), Circular Jupiter and Saturn (CJS), and Grand Tack scenarios, to model the Ru–Mo anomalies of Earth, Mars, and Theia analogues. This model starts by applying an initial step function in Ru–Mo isotopic composition, with compositions reflecting those in meteorites, and traces compositional evolution as planets accrete. The mass-weighted provenance of the resulting planets reveals more radial mixing in Grand Tack simulations than in EJS/CJS simulations, and more efficient mixing among late-accreted material than during the main phase of accretion in EJS/CJS simulations. We find that an extensive homogeneous inner disk region is required to reproduce Earth's observed Ru–Mo composition. EJS/CJS simulations require a homogeneous reservoir in the inner disk extending to ≥3–4 AU (≥74–98% of initial mass) to reproduce Earth's composition, while Grand Tack simulations require a homogeneous reservoir extending to ≥3–10 AU (≥97–99% of initial mass), and likely to ≥6–10 AU. In the Grand Tack model, Jupiter's initial location (the most likely location for a discontinuity in isotopic composition) is ∼3.5 AU; however, this step location has only a 33% likelihood of producing an Earth with the correct Ru–Mo isotopic signature for the most plausible model conditions. Our results give the testable predictions that Mars has zero Ru anomaly and small or zero Mo anomaly, and the Moon has zero Mo anomaly. These predictions are insensitive to wide variations in parameter choices.
•Model can reproduce Earth's zero Ru–Mo anomaly for EJS, CJS, and Grand Tack.•Inner disk constrained to have near-zero Ru–Mo anomaly.•Grand Tack implies more Solar System mass in homogeneous inner disk than EJS/CJS do.•Mars's Ru–Mo anomaly is likely small (and dominated by Mo) or zero.•Theia, and therefore the Moon, likely has no Mo anomaly.
Musée de Picardie, Amiens O’Brien, David
Nineteenth-Century Art Worldwide,
10/2022, Letnik:
21, Številka:
3
Journal Article, Book Review
Recenzirano
Odprti dostop
Works by Constance Charpentier, Gustave Courbet, and Pierre Puvis de Chavannes amongst others are at the Musee de Picardie in Amiens, France. Partially closed since 2008, and wholly from 2017 to ...2020, the renovated museum has now been open for two years, with its collection reinstalled under the direction of Laure Dalon. The stunning result makes obligatory the short trip from Paris to Amiens, at least for true dix-neuvièmistes. The museum possesses excellent collections in several areas, but a variety of circumstances contributed to its special strength in nineteenth-century French art.
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