837 research outputs found
33714 Palisaded neutrophilic and granulomatous dermatitis in the setting of SRSF2-mutated chronic myelomonocytic leukemia: Case report and review of the literature
Palisaded neutrophilic and granulomatous dermatitis (PNGD) is a rare cutaneous histopathologic reaction pattern associated with several underlying disorders. Few cases of PNGD have been associated with hematologic malignancies, in particular with chronic myelomonocytic leukemia (CMML), a malignant hematopoietic disorder with features of myeloproliferative neoplasm and myelodysplastic syndrome. CMML is characterized by peripheral blood monocytosis and bone marrow dysplasia, and can be supported by an acquired clonal cytogenetic abnormality most commonly in TET2, SRSF2, ASXL1, RUNX1, NRAS, and CBL. We present a patient with a papulosquamous rash on the neck, chest, and shoulders with histomorphological features on the spectrum of PNGD. Subsequent lab workup demonstrated a persistent mild monocytosis, raising concern for CMML. The patient was referred to hematology-oncology for a bone marrow biopsy, which ultimately led to her diagnosis. Cytogenic studies of the bone marrow biopsy demonstrated mutations in SRSF2, IDH2, and ASXL1, which were strongly supportive of this diagnosis. After discussion at a multidisciplinary tumor board, treatment directed at the skin eruption alone was recommended. She was started on prednisone taper and demonstrated marked clinical improvement. PNGD in the context of CMML has been scarcely reported, with only 4 prior reports in the literature. Our patient is the fifth reported case, and the fourth case with confirmed underlying SRSF2 mutation. This is likely a novel and reproducible clinical-histopathologic-molecular subtype of reactive granulomatous disease. The findings in this case strengthen the previously made association between PNGD and SRSF2-mutated CMML, and may help better define a unique recognizable subtype for dermatopathologists
The soft X-ray properties of quasars in the Sloan Digital Sky Survey
We use the ROSAT All Sky Survey (RASS) to study the soft X-ray properties of
a homogeneous sample of 46,420 quasars selected from the third data release of
the Sloan Digital Sky Survey (SDSS). Optical luminosities, both at rest-frame
2500\AA () and in [OIII] () span more than three
orders of magnitude, while redshifts range over . We detect 3366
quasars directly in the observed 0.1--2.4 keV band. Sub-samples of radio-loud
and radio-quiet objects (RLQs and RQQs) are obtained by cross-matching with the
FIRST catalogue. We study the distribution of X-ray luminosity as a function of
optical luminosity, redshift and radio power using both individual detections
and stacks of complete sets of similar quasars. At every optical luminosity and
redshift \log L_{2\kev} is, to a good approximation, normally distributed
with dispersion , at least brightwards of the median X-ray
luminosity. This median X-ray luminosity of quasars is a power law of optical
luminosity with index for and for
. RLQs are systematically brighter than RQQs by about a factor
of 2 at given optical luminosity. The zero-points of these relations increase
systematically with redshift, possibly in different ways for RLQs and RQQs.
Evolution is particularly strong at low redshift and if the optical luminosity
is characterised by . At low redshift and at given
the soft X-ray emission from type II AGN is more than 100
times weaker than that from type I AGN.Comment: 16 pages, 15 figures, 3 tables, replaced with final version accepted
by MNRA
Prophylactic antibiotics for burns patients: systematic review and meta-analysis
Objective To assess the evidence for prophylactic treatment with systemic antibiotics in burns patients
The first joint ESGAR/ ESPR consensus statement on the technical performance of cross-sectional small bowel and colonic imaging
Objectives: To develop guidelines describing a standardised approach to patient preparation and acquisition protocols for magnetic resonance imaging (MRI), computed tomography (CT) and ultrasound (US) of the small bowel and colon, with an emphasis on imaging inflammatory bowel disease. Methods: An expert consensus committee of 13 members from the European Society of Gastrointestinal and Abdominal Radiology (ESGAR) and European Society of Paediatric Radiology (ESPR) undertook a six-stage modified Delphi process, including a detailed literature review, to create a series of consensus statements concerning patient preparation, imaging hardware and image acquisition protocols. Results: One hundred and fifty-seven statements were scored for agreement by the panel of which 129 statements (82 %) achieved immediate consensus with a further 19 (12 %) achieving consensus after appropriate modification. Nine (6 %) statements were rejected as consensus could not be reached. Conclusions: These expert consensus recommendations can be used to help guide cross-sectional radiological practice for imaging the small bowel and colon. Key points: âą Cross-sectional imaging is increasingly used to evaluate the bowel âą Image quality is paramount to achieving high diagnostic accuracy âą Guidelines concerning patient preparation and image acquisition protocols are provided
Boson Stars as Gravitational Lenses
We discuss boson stars as possible gravitational lenses and study the lensing
effect by these objects made of scalar particles. The mass and the size of a
boson star may vary from an individual Newtonian object similar to the Sun to
the general relativistic size and mass of a galaxy close to its Schwarzschild
radius. We assume boson stars to be transparent which allows the light to pass
through them though the light is gravitationally deflected. We assume boson
stars of the mass to be on non-cosmological distance from
the observer. We discuss the lens equation for these stars as well as the
details of magnification. We find that there are typically three images of a
star but the deflection angles may vary from arcseconds to even degrees. There
is one tangential critical curve (Einstein ring) and one radial critical curve
for tangential and radial magnification, respectively. Moreover, the deflection
angles for the light passing in the gravitational field of boson stars can be
very large (even of the order of degrees) which reflects the fact they are very
strong relativistic objects. We also propose a suitable formula for the lens
equation for such large deflection angles, and with the reservation that large
deflection angle images are highly demagnified but in the area of the
tangential critical curve, their existence may help in observational detection
of suitable lenses possessing characteristic features of boson stars which
could also serve as a direct evidence for scalar fields in the universe.Comment: accepted by Astrophys. J., 31 pages, AASTeX, 6 figure
Corneal Healing after Uncomplicated LASIK and Its Relationship to Refractive Changes: A Six-Month Prospective Confocal Study
PURPOSE. To investigate corneal healing and the factor(s) possibly responsible for refractive changes after laser in situ keratomileusis (LASIK). METHODS. Twenty eyes of 10 patients who underwent LASIK for myopia were examined clinically and by real-time confocal microscopy for 6 months. Epithelial and posterior stromal thicknesses and the thickness of the keratocyte activation zone were measured, and refractive changes were compared with these values. Keratocyte morphology, flap thickness, and subbasal nerve fiber bundle morphology after LASIK were also investigated. RESULTS. No significant change was detected over time in epithelial thickness after LASIK treatment; however, the posterior stromal thickness was found to be significantly higher 1 month after surgery. A slight but statistically significant negative correlation was detected between the thickness of the keratocyte activation zone and the spheroequivalent refraction after LASIK. The subbasal nerve fiber bundle's morphology returned to its preoperative appearance 6 months after LASIK, but in the flap stroma the nerve fiber bundle morphology remained abnormal at 6 months after LASIK surgery. CONCLUSIONS. A weak but significant negative correlation between the thickness of the keratocyte activation zone and spheroequivalent refraction was found after LASIK. The different refractive properties of activated keratocytes may be responsible for the myopic shift after LASIK. Further studies are needed to clarify this hypothesis. (Invest Ophthalmol Vis Sci. 2004;45:1334 -1339) DOI:10.1167/iovs.03-1025 L aser in situ keratomileusis (LASIK) is a relatively new technique for correction of myopia. A hinged flap (consisting of epithelium, Bowman's layer, and anterior stroma) is created first, and the exposed stroma is photoablated after the flap is folded back. Although many studies have been published on the clinical outcome after LASIK, 1-4 relatively few reports address the biological changes associated with the procedure. 10,11 Keratocyte activation was strongest at 1 to 2 weeks and persisted until 3 months after LASIK surgery. 10,13 Neither LASIK nor PRK has been shown superior in efficacy outcomes 14 -16 A recent confocal microscopic study revealed that keratocyte-mediated regrowth of the photoablated stroma was a key biological factor responsible for post-PRK refractive instability in humans treated with PRK. The purpose of this study was to investigate the factor(s) responsible for the refractive changes after LASIK. For this purpose, epithelial thickness, posterior stromal thickness, and the thickness of the keratocyte activation zone were measured by confocal microscopy, and we sought to establish a correlation between refractive changes and these measurements. We also investigated keratocyte morphology, flap thickness, and subbasal nerve fiber bundle morphology after LASIK. METHODS Design This prospective, interventional cohort study was begun after approval was obtained from the LSU Health Sciences Center institutional review board. Each patient gave written informed consent, and the research followed the tenets of the Declaration of Helsinki. Patients Twenty eyes of 10 patients who underwent LASIK for myopia were included in the study. All eyes had normal anterior ocular segments, intraocular pressure (Ïœ20 mm Hg), and fundi. Contact lens wear was discontinued 2 weeks (soft lenses) or 3 weeks (hard lenses) before the LASIK operation. There were six women and four men (mean age, 35.4 Ïź 8.7 years). All patients were 21years of age or older and had stable refractive errors at least 1 year before the laser procedure. Patients who had undergone reoperation, those with diabetes mellitus or glaucoma, or those using any topical ophthalmic medication were excluded. Patients with corneas thinner than 500 m centrally and/or with a severe systemic disorder that could cause them to miss examinations were also excluded. The average preoperative spheroequivalent refraction was ÏȘ5.87 Ïź 3.45 D (range, ÏȘ1.75-11.00 D) and the planned ablation depth was 59.8 Ïź 27.1 m (range, 16 -110 m). Each patient was examined in the pre-and postoperative period. Preoperative examinaFrom th
No apparent accretion mode changes detected in Cen X-3
The presence of two distinct spectral states has previously been reported for
Cen X-3 on the basis of RXTE/ASM observations. Triggered by this result, we
investigated the spectral properties of the source using the larger amount of
X-ray data now available with the aim to clarify and interpret the reported
behavior. To check the reported results we used the same data set and followed
the same analysis procedures as in the work reporting the two spectral states.
Additionally, we repeated the analysis using the enlarged data sample including
the newest RXTE/ASM observations as well as the data from the MAXI monitor and
from the INTEGRAL/JEM-X and ISGRI instruments. We could not confirm the
reported presence of the two spectral states in Cen X-3 either inComment: 4 pages, 6 figures, article is accepted for Astronomy & Astrophysic
Analysis of in Vivo Plant Stem Impedance Variations in Relation with External Conditions Daily Cycle
World population growth and desertification are the most severe issue to agricultural food production. Smart agriculture is a promising solution to ensure food security. The use of sensors to monitor crop production can help farmers improve the yield and reduce water consumption. Here we propose a study where the electrical impedance of green plants' stem is analyzed in vivo, along with environmental conditions. In particular, the variations associated with the daily cycle are highlighted. These analyses lead to the possibility of understanding plant status directly from stem impedance
Sediment source and mixing and the cycle of sediment transport: an example from NE Negev Desert, Israel.
Alluvial terraces represent the end product of sedimentary cycles; each includes sediment generation, transport, accumulation, and the ultimate incision that forms abandoned alluvial surfaces. We examine the middle Pleistocene to recent drainage system evolution in Makhtesh Hazera, Negev Desert, southern Israel and compare the characteristics of erosion and sediment transport in the present system with those expressed by the alluvial
terraces. The Hazera drainage basin lies at the margins of the arid to hyper-arid Dead Sea rift (DSR). Makhtesh (crater) Hazera is a deeply incised erosional structure (5X7 km) that has been excavated since the early Pliocene into the crest of the Hazera asymmetric anticline. The Makhtesh floor is surrounded by cliffs rising more than
400 meters high. The cliffs are built of Upper Cretaceous hard carbonates caprocks overlying Lower Cretaceous friable quartz sandstones. Bedrock knickpoints isolate the drainage basin in the Makhtesh and above it from a direct influence of the terminal base level of the DSR. Thus, the accumulation of sediment and abandonment of terraces are controlled by climate and bedrock barriers located at the Makhtesh outlet. We use cosmogenic isotope concentrations to determine bedrock denudation rates, ages of alluvial terraces, and basin wide erosion rates in different channels throughout the basin. The use of cosmogenic isotopes enables us to determine sediment sources
and reconstruct sedimentary cycles. OSL dating was used to determine the accumulation ages of alluvial sediment
in alluvial terraces. These two methods enable quantitative evaluation of fluvial processes. Bedrock erosion rates suggest a strong dependence of erosion on lithology. While the Lower Cretaceous sandstone
erodes at >100 mm ky-1, the overlying hard carbonate caprock yielded cosmogenic isotope concentrations that correspond to erosion rates of 1-3 mm ky-1. This significant difference in erosion rates maintains the dramatic relief of the Hazera drainage basin. We find that the quartz sediment in the present fluvial system of Makhtesh
Hazera originates from two predominant sources. One is the Lower Cretaceous sandstone that crops out along the base of the Makhtesh cliffs. The second source are un consolidated Miocene sands that fill the syncline which is located north west of the Makhtesh and is drained into it. 10Be concentrations in successive samples indicate
that the Miocene sand is gradually diluted by Lower Cretaceous sand as it flows down stream and the mixing of sediment from both sources is good. Alluvial terraces and bedrock units exposed inside the Makhtesh do not contribute a significant amount of sediment to the present drainage system.
Three major alluvial terrace levels were identified. The highest terrace level (MKT0) was abandoned at 279±19 ky. This level probably covered most of the Makhtesh surface. The deposition of the two lower levels, MKT1 and MKT2 (which were abandoned at 160±6 and 47±9 ky, respectively), was confined to the present drainage system. Analysis of cosmogenic depth profiles from the terraces suggests significant recycling of sediment within the Mekhtesh. This is in contrast to the present system that lacks recycled sediment. We explain this difference by the fact that the terraces are the final product of a sedimentary cycle while the present drainage system presents
a âsnapshotâ in time which does not represent the entire cycle only the present state of the system which is expressed by rapid incision and very little lateral migration.European Geosciences Unio
Systematic review of early warning signs of relapse and behavioural antecedents of symptom worsening in people living with schizophrenia spectrum disorders
Background Identification of the early warning signs (EWS) of relapse is key to relapse prevention in schizophrenia spectrum disorders, however, limitations to their precision have been reported. Substantial methodological innovations have recently been applied to the prediction of psychotic relapse and to individual psychotic symptoms. However, there has been no systematic review that has integrated findings across these two related outcomes and no systematic review of EWS of relapse for a decade.
Method We conducted a systematic review of EWS of psychotic relapse and the behavioural antecedents of worsening psychotic symptoms. Traditional EWS and ecological momentary assessment/intervention studies were included. We completed meta-analyses of the pooled sensitivity and specificity of EWS in predicting relapse, and for the prediction of relapse from individual symptoms.
Results Seventy two studies were identified including 6903 participants. Sleep, mood, and suspiciousness, emerged as predictors of worsening symptoms. Pooled sensitivity and specificity of EWS in predicting psychotic relapse was 71% and 64% (AUC value = 0.72). There was a large pooled-effect size for the model predicting relapse from individual symptom which did not reach statistical significance (d = 0.81, 95%CIs = â0.01, 1.63).
Conclusions Important methodological advancements in the prediction of psychotic relapse in schizophrenia spectrum disorders are evident with improvements in the precision of prediction. Further efforts are required to translate these advances into effective clinical innovations
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