24 research outputs found
Ptychographic X-ray tomography reveals additive zoning in nanocomposite single crystals
Single crystals containing nanoparticles represent a unique class of nanocomposites whose properties are defined by both their compositions and the structural organization of the dispersed phase in the crystalline host. Yet, there is still a poor understanding of the relationship between the synthesis conditions and the structures of these materials. Here ptychographic X-ray computed tomography is used to visualize the three-dimensional structures of two nanocomposite crystals â single crystals of calcite occluding diblock copolymer worms and vesicles. This provides unique information about the distribution of the copolymer nano-objects within entire, micron-sized crystals with nanometer spatial resolution and reveals how occlusion is governed by factors including the supersaturation and calcium concentration. Both nanocomposite crystals are seen to exhibit zoning effects that are governed by the solution composition and interactions of the additives with specific steps on the crystal surface. Additionally, the size and shape of the occluded vesicles varies according to their location within the crystal, and therefore the solution composition at the time of occlusion. This work contributes to our understanding of the factors that govern nanoparticle occlusion within crystalline materials, where this will ultimately inform the design of next generation nanocomposite materials with specific structure/property relationships
Diagnostic and prognostic value of noninvasive long-term video-electroencephalographic monitoring in epilepsy surgery: A systematic review and meta-analysis from the E-PILEPSY consortium
OBJECTIVE:
The European Unionâfunded EâPILEPSY network (now continuing within the European Reference Network for rare and complex epilepsies [EpiCARE]) aims to harmonize and optimize presurgical diagnostic procedures by creating and implementing evidenceâbased guidelines across Europe. The present study evaluates the current evidence on the diagnostic accuracy of longâterm videoâelectroencephalographic monitoring (LTM) in identifying the epileptogenic zone in epilepsy surgery candidates.
METHODS:
MEDLINE, Embase, CENTRAL, and ClinicalTrials.gov were searched for relevant articles. First, we used randomâeffects metaâanalytical models to calculate pooled estimates of sensitivity and specificity with respect to postsurgical seizure freedom. In a second phase, we analyzed individual patient data in an exploratory fashion, assessing diagnostic accuracy within lesional and nonlesional temporal lobe epilepsy (TLE) and extratemporal lobe epilepsy (ETLE) patients. We also evaluated seizure freedom rate in the presence of âlocalizingâ or ânonlocalizingâ LTM within each group. The quality of evidence was assessed using the QUADASâ2 tool and the GRADE approach.
RESULTS:
Ninetyâfour studies were eligible. Fortyâfour were included in sensitivity metaâanalysis and 34 in specificity metaâanalysis. Pooled sensitivity was 0.70 (95% confidence interval [CI] = 0.60â0.80) and specificity was 0.40 (95% CI = 0.27â0.54). Subgroup analysis was based on individual data of 534 patients (41% men). In lesional TLE patients, sensitivity was 0.85 (95% CI = 0.81â0.89) and specificity was â0.19 (95% CI = 0.13â0.28). In lesional ETLE patients, a sensitivity of 0.47 (95% CI = 0.36â0.58) and specificity of 0.35 (95% CI = 0.21â0.53) were observed. In lesional TLE, if LTM was localizing and concordant with resection site, the seizure freedom rate was 247 of 333 (74%), whereas in lesional ETLE it was 34 of 56 (61%). The quality of evidence was assigned as âvery low.â
SIGNIFICANCE:
Longâterm videoâelectroencephalographic monitoring is associated with moderate sensitivity and low specificity in identification of the epileptogenic zone. Sensitivity is remarkably higher in lesional TLE compared to lesional ETLE. Substantial heterogeneity across the studies indicates the need for improved design and quality of reporting
Tentative evidence for inequity aversion to unequal work-effort but not to unequal reward distribution in Goffin's cockatoos
Funktionelle Ergebnisse nach transmandibulärer Resektion und primärer Radiochemotherapie bei fortgeschrittenen Kopf-Hals-Plattenepithelkarzinomen
Objective!#!The aim of this study was to assess the functional outcome after transmandibular resection and reconstruction via a radial forearm flap (TMR+RFF) compared to primary chemoradiotherapy (pCRT) in advanced oropharyngeal squamous cell carcinoma (OPSCC).!##!Methods!#!The study compared 50 OPSCC patients treated with TMR+RFF to 50 OPSCC patients receiving pCRT. The time taken to swallow water served as the primary endpoint. The Saxon test, maxillomandibular distance, Mallampati score, ratio of height to weight, nasal penetration, tracheostomy/gastral tube requirement, and four validated questionnaires (visual analog scale for xerostomia, Sicca VAS; MD Anderson Dysphagia Inventory, MDADI; Voice Handicap Index, VHI; European Organization for Research and Treatment of Cancer Quality of Life Questionnaire, Head and Neck Cancer, 35 items, QLQ-H&N35) were applied to access functionality and quality of life.!##!Results!#!Patients after TMR+RFF showed an increased rate of nasal penetration (pâŻ<â0.0001), which was associated with a longer water swallowing time (pâŻ<â0.05). A modified reconstruction of the soft palate significantly decreased the rate of nasal penetration in comparison to classical reconstruction (pâŻ=â0.0001). Patients with pCRT suffered significantly more xerostomia (Saxon test) than patients with TMR+RFF and adjuvant therapy. None of the subjective questionnaires revealed significant differences between the groups.!##!Conclusion!#!TMR+RFF with modified reconstruction and adjuvant treatment and pCRT showed comparable functional outcomes
High-acceptance versatile microfocus module based on elliptical Fresnel zone plates for small-angle X-ray scattering
High-efficiency microfocusing of multi-keV X-rays at synchrotron sources is highly profitable for spatially resolved structural analysis of many kinds. Because radiation from synchrotron sources is typically elongated along the horizontal dimension, generating a microbeam that is isotropic in size requires a carefully designed optics system. Here we report on using a combination of a horizontally tunable slit downstream of the undulator source with elliptical diffractive Fresnel zone plates. We demonstrate the arrangement in context of small-angle X-ray scattering experiments, obtaining a microbeam of 2.2 Îźm Ă1.8 Îźm (X Ă Y) with a flux of 1.2 Ă 1010 photons/s at an energy of 11.2 keV at the sample position