134 research outputs found
Beyond Clinical Examination: Utilizing MRI Surveillance to Detect Recurrence of Soft Tissue Sarcomas and Differentiate from Posttherapeutic Changes
Background: Early detection of soft tissue sarcoma (STS) recurrence is essential; however, the role and timeline of Magnetic resonance imaging (MRI) surveillance are still under debate. The aim of this study was to determine whether local recurrence (LR) could be identified via clinical examination alone and to assess the MRI morphology of primary STS and LR. Methods: This retrospective study included all patients with STS recurrence after surveillance for at least five years from the tumor database of the Medical University of Vienna from 2000 until December 2023. The characteristics of primary STS and LR and the time interval to recurrence and clinical detectability were assessed. The MRIs of LR and posttherapeutic changes (PTC) were compared with the initial MRIs. Results: A total of 57 patients (60% male; mean age 58.5 ± 18.0 years) with STS and histologically confirmed LR were included. The mean time interval to LR was 2.3 ± 1.8 years (range 108 to 3037 days). The clinically detectable recurrences were significantly larger than the inapparent ones (71.9 cm3 vs. 7.0 cm3; p < 0.01). The MRI morphology of all LRs (26/26) closely resembled the initial STS. For comparison, nine patients were included with clinically suspected LRs, which were histologically proven to be PTC. None of these resembled the primary STS. Conclusion: Based on clinical symptoms alone, especially small and early recurrences can be missed, which supports the importance of MRI surveillance
Femoroazetabuläres Impingement beim Jugendlichen und Adoleszenten
Femoroacetabular impingement syndrome (FAIS) is caused by a repetitive mechanical conflict between the acetabulum and the proximal femur, occurring in flexion and internal rotation. In cam impingement, bony prominences of the femoral head-neck junction induce chondrolabral damage. The acetabular type of FAIS, termed pincer FAIS, may be either due to focal or global retroversion and/or acetabular overcoverage. Combinations of cam and pincer morphology are common. Pathological femoral torsion may aggravate or decrease the mechanical conflict in FAI but can also occur in isolation. Of note, a high percentage of adolescents with FAI-like shape changes remain asymptomatic. The diagnosis of FAIS is therefore made clinically, whereas imaging reveals the underlying morphology. X‑rays in two planes remain the primary imaging modality, the exact evaluation of the osseous deformities of the femur and chondrolabral damage is assessed by magnetic resonance imaging (MRI). Acetabular coverage and version are primarily assessed on radiographs. Evaluation of the entire circumference of the proximal femur warrants MRI which is further used in the assessment of chondrolabral lesions, and also bone marrow and adjacent soft tissue abnormalities. The MRI protocol should routinely include measurements of femoral torsion. Fluid-sensitive sequences should be acquired to rule out degenerative or inflammatory extra-articular changes.Das femoroazetabuläre Impingement-Syndrom (FAIS) wird durch einen repetitiven mechanischen Konflikt zwischen Azetabulum und proximalem Femur insbesondere bei Flexion und Innenrotation hervorgerufen. Beim femoroazetabulären Impingement (FAI) vom Cam-Typ bewirkt eine Asphärizität am femoralen Kopf-Hals-Übergang die Induktion von Scherkräften am Azetabulum. Beim Pincer-Typ kann eine Retroversion der Pfanne und/oder eine vermehrte Überdachung vorliegen. Ein wichtiger mechanischer Einflussfaktor, welcher ein Impingement oder auch Hüftinstabilität verstärken oder kompensieren kann, ist die Femurtorsion. Meistens treten Torsionsstörungen kombiniert mit anderen ossären Deformitäten auf. Zu beachten ist, dass ein hoher Prozentsatz der Adoleszenten mit knöchernen FAI-Morphologien asymptomatisch bleibt. Die Diagnose des FAIS wird daher klinisch gestellt, die Bildgebung zeigt die zugrundeliegende Morphologie. Primäre Bildgebung ist das Röntgenbild in 2 Ebenen zur Beurteilung der Hüftgelenküberdachung und der azetabulären Version. Die vollständige Zirkumferenz des Femurs ist jedoch nur in der Magnetresonanztomographie (MRT) beurteilbar, ebenso Läsionen des Labrums und Knorpels sowie des Knochenmarks und der umgebenden Weichteile. Das MRT-Protokoll sollte routinemäßig eine Bestimmung der Rotation des Femurs beinhalten. Zudem sollten flüssigkeitssensitive Sequenzen des Beckens zum groben Ausschluss degenerativer oder entzündlicher extraartikulärer Veränderungen akquiriert werden
Removing krypton from xenon by cryogenic distillation to the ppq level
The XENON1T experiment aims for the direct detection of dark matter in a
cryostat filled with 3.3 tons of liquid xenon. In order to achieve the desired
sensitivity, the background induced by radioactive decays inside the detector
has to be sufficiently low. One major contributor is the -emitter
Kr which is an intrinsic contamination of the xenon. For the XENON1T
experiment a concentration of natural krypton in xenon Kr/Xe < 200
ppq (parts per quadrillion, 1 ppq = 10 mol/mol) is required. In this
work, the design of a novel cryogenic distillation column using the common
McCabe-Thiele approach is described. The system demonstrated a krypton
reduction factor of 6.410 with thermodynamic stability at process
speeds above 3 kg/h. The resulting concentration of Kr/Xe < 26 ppq
is the lowest ever achieved, almost one order of magnitude below the
requirements for XENON1T and even sufficient for future dark matter experiments
using liquid xenon, such as XENONnT and DARWIN
Rh-POP Pincer Xantphos Complexes for C-S and C-H Activation. Implications for Carbothiolation Catalysis
The neutral Rh(I)–Xantphos
complex [Rh(κ<sup>3</sup>-<sub>P,O,P</sub>-Xantphos)Cl]<sub><i>n</i></sub>, <b>4</b>, and cationic Rh(III) [Rh(κ<sup>3</sup>-<sub>P,O,P</sub>-Xantphos)(H)<sub>2</sub>][BAr<sup>F</sup><sub>4</sub>], <b>2a</b>, and [Rh(κ<sup>3</sup>-<sub>P,O,P</sub>-Xantphos-3,5-C<sub>6</sub>H<sub>3</sub>(CF<sub>3</sub>)<sub>2</sub>)(H)<sub>2</sub>][BAr<sup>F</sup><sub>4</sub>], <b>2b</b>, are described [Ar<sup>F</sup> = 3,5-(CF<sub>3</sub>)<sub>2</sub>C<sub>6</sub>H<sub>3</sub>; Xantphos
= 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene; Xantphos-3,5-C<sub>6</sub>H<sub>3</sub>(CF<sub>3</sub>)<sub>2</sub> = 9,9-dimethylxanthene-4,5-bis(bis(3,5-bis(trifluoromethyl)phenyl)phosphine].
A solid-state structure of <b>2b</b> isolated from C<sub>6</sub>H<sub>5</sub>Cl solution shows a κ<sup>1</sup>-chlorobenzene
adduct, [Rh(κ<sup>3</sup>-<sub>P,O,P</sub>-Xantphos-3,5-C<sub>6</sub>H<sub>3</sub>(CF<sub>3</sub>)<sub>2</sub>)(H)<sub>2</sub>(κ<sup>1</sup>-ClC<sub>6</sub>H<sub>5</sub>)][BAr<sup>F</sup><sub>4</sub>], <b>3</b>. Addition of H<sub>2</sub> to <b>4</b> affords,
crystallographically characterized, [Rh(κ<sup>3</sup>-<sub>P,O,P</sub>-Xantphos)(H)<sub>2</sub>Cl], <b>5</b>. Addition of diphenyl
acetylene to <b>2a</b> results in the formation of the C–H
activated metallacyclopentadiene [Rh(κ<sup>3</sup>-<sub>P,O,P</sub>-Xantphos)(ClCH<sub>2</sub>Cl)(σ,σ-(C<sub>6</sub>H<sub>4</sub>)C(H)CPh)][BAr<sup>F</sup><sub>4</sub>], <b>7</b>, a rare example of a crystallographically characterized Rh–dichloromethane
complex, alongside the Rh(I) complex <i>mer</i>-[Rh(κ<sup>3</sup>-<sub>P,O,P</sub>-Xantphos)(η<sup>2</sup>-PhCCPh)][BAr<sup>F</sup><sub>4</sub>], <b>6</b>. Halide abstraction from [Rh(κ<sup>3</sup>-<sub>P,O,P</sub>-Xantphos)Cl]<sub><i>n</i></sub> in the presence of diphenylacetylene affords <b>6</b> as the
only product, which in the solid state shows that the alkyne binds
perpendicular to the κ<sup>3</sup>-POP Xantphos ligand plane.
This complex acts as a latent source of the [Rh(κ<sup>3</sup>-<sub>P,O,P</sub>-Xantphos)]<sup>+</sup> fragment and facilitates
<i>ortho</i>-directed C–S activation in a number
of 2-arylsulfides to give <i>mer</i>-[Rh(κ<sup>3</sup>-<sub>P,O,P</sub>-Xantphos)(σ,κ<sup>1</sup>-Ar)(SMe)][BAr<sup>F</sup><sub>4</sub>] (Ar = C<sub>6</sub>H<sub>4</sub>COMe, <b>8</b>; C<sub>6</sub>H<sub>4</sub>(CO)OMe, <b>9</b>; C<sub>6</sub>H<sub>4</sub>NO<sub>2</sub>, <b>10</b>; C<sub>6</sub>H<sub>4</sub>CNCH<sub>2</sub>CH<sub>2</sub>O, <b>11</b>; C<sub>6</sub>H<sub>4</sub>C<sub>5</sub>H<sub>4</sub>N, <b>12</b>).
Similar C–S bond cleavage is observed with allyl sulfide,
to give <i>fac</i>-[Rh(κ<sup>3</sup>-<sub>P,O,P</sub>-Xantphos)(η<sup>3</sup>-C<sub>3</sub>H<sub>5</sub>)(SPh)][BAr<sup>F</sup><sub>4</sub>], <b>13</b>. These products of C–S
activation have been crystallographically characterized. For <b>8</b> in situ monitoring of the reaction by NMR spectroscopy reveals
the initial formation of <i>fac</i>-κ<sup>3</sup>-<b>8</b>, which then proceeds to isomerize to the <i>mer</i>-isomer. With the <i>para</i>-ketone aryl sulfide, 4-SMeC <sub>6</sub>H<sub>4</sub>COMe, C–H activation <i>ortho</i> to the ketone occurs to give <i>mer</i>-[Rh(κ<sup>3</sup>-<sub>P,O,P</sub>-Xantphos)(σ,κ<sup>1</sup>-4-(COMe)C<sub>6</sub>H<sub>3</sub>SMe)(H)][BAr<sup>F</sup><sub>4</sub>], <b>14</b>. The temporal evolution of carbothiolation catalysis using <i>mer</i>-κ<sup>3</sup>-<b>8</b>, and phenyl acetylene
and 2-(methylthio)acetophenone substrates shows initial fast catalysis
and then a considerably slower evolution of the product. We suggest
that the initially formed <i>fac</i>-isomer of the C–S
activation product is considerably more active than the <i>mer</i>-isomer (i.e., <i>mer</i>-<b>8</b>), the latter of
which is formed rapidly by isomerization, and this accounts for the
observed difference in rates. A likely mechanism is proposed based
upon these data
Influence of taste disorders on dietary behaviors in cancer patients under chemotherapy
<p>Abstract</p> <p>Objectives</p> <p>To determine the relationship between energy and nutrient consumption with chemosensory changes in cancer patients under chemotherapy.</p> <p>Methods</p> <p>We carried out a cross-sectional study, enrolling 60 subjects. Cases were defined as patients with cancer diagnosis after their second chemotherapy cycle (n = 30), and controls were subjects without cancer (n = 30). Subjective changes of taste during treatment were assessed. Food consumption habits were obtained with a food frequency questionnaire validated for Mexican population. Five different concentrations of three basic flavors --sweet (sucrose), bitter (urea), and a novel basic taste, umami (sodium glutamate)-- were used to measure detection thresholds and recognition thresholds (RT). We determine differences between energy and nutrient consumption in cases and controls and their association with taste DT and RT.</p> <p>Results</p> <p>No demographic differences were found between groups. Cases showed higher sweet DT (6.4 vs. 4.4 μmol/ml; p = 0.03) and a higher bitter RT (100 vs. 95 μmol/ml; <it>p </it>= 0.04) than controls. Cases with sweet DT above the median showed significant lower daily energy (2,043 vs.1,586 kcal; p = 0.02), proteins (81.4 vs. 54 g/day; <it>p </it>= 0.01), carbohydrates (246 vs.192 g/day; <it>p </it>= 0.05), and zinc consumption (19 vs.11 mg/day; <it>p </it>= 0.01) compared to cases without sweet DT alteration. Cases with sweet DT and RT above median were associated with lower completion of energy requirements and consequent weight loss. There was no association between flavors DT or RT and nutrient ingestion in the control group.</p> <p>Conclusion</p> <p>Changes of sweet DT and bitter RT in cancer patients under chemotherapy treatment were associated with lower energy and nutrient ingestion. Taste detection and recognition thresholds disorders could be important factors in malnutrition development on patients with cancer under chemotherapy treatment.</p
New Clathrin-Based Nanoplatforms for Magnetic Resonance Imaging
Background: Magnetic Resonance Imaging (MRI) has high spatial resolution, but low sensitivity for visualization of molecular targets in the central nervous system (CNS). Our goal was to develop a new MRI method with the potential for non-invasive molecular brain imaging. We herein introduce new bio-nanotechnology approaches for designing CNS contrast media based on the ubiquitous clathrin cell protein. Methodology/Principal Findings: The first approach utilizes three-legged clathrin triskelia modified to carry 81 gadolinium chelates. The second approach uses clathrin cages self-assembled from triskelia and designed to carry 432 gadolinium chelates. Clathrin triskelia and cages were characterized by size, structure, protein concentration, and chelate and gadolinium contents. Relaxivity was evaluated at 0.47 T. A series of studies were conducted to ascertain whether fluorescent-tagged clathrin nanoplatforms could cross the blood brain barriers (BBB) unaided following intranasal, intravenous, and intraperitoneal routes of administration. Clathrin nanoparticles can be constituted as triskelia (18.5 nm in size), and as cages assembled from them (55 nm). The mean chelate: clathrin heavy chain molar ratio was 27.0464.8: 1 fo
The XENONnT Dark Matter Experiment
The multi-staged XENON program at INFN Laboratori Nazionali del Gran Sasso
aims to detect dark matter with two-phase liquid xenon time projection chambers
of increasing size and sensitivity. The XENONnT experiment is the latest
detector in the program, planned to be an upgrade of its predecessor XENON1T.
It features an active target of 5.9 tonnes of cryogenic liquid xenon (8.5
tonnes total mass in cryostat). The experiment is expected to extend the
sensitivity to WIMP dark matter by more than an order of magnitude compared to
XENON1T, thanks to the larger active mass and the significantly reduced
background, improved by novel systems such as a radon removal plant and a
neutron veto. This article describes the XENONnT experiment and its sub-systems
in detail and reports on the detector performance during the first science run.Comment: 32 pages, 19 figure
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