705 research outputs found
124I PET: Pretherapeutic Staging, Detection of Recurrent Thyroid Cancer and Dosimetry
Radioiodine therapy (RIT) is an integral component in the treatment of differentiated thyroid cancer (DTC). Patients usually undergo RIT as initial therapy or later in the case of recurrent or persistent disease. The most important requirement for a successful RIT is the ability of metastases and thyroid (remnant) tissue to accumulate radioiodine. In order to calculate the achievable absorbed radiation dose for a lesion, volume and iodine kinetics in the lesion need to be determined. Pretherapeutic imaging and dosimetry with 124I PET provide the methodology to answer these questions
The Age Distribution of Stellar Orbit Space Clumps
The orbit distribution of young stars in the Galactic disk is highly
structured, from well-defined clusters to streams of stars that may be widely
dispersed across the sky, but are compact in orbital action-angle space. The
age distribution of such groups can constrain the timescales over which
co-natal groups of stars disperse into the `field'. Gaia data have proven
powerful to identify such groups in action-angle space, but the resulting
member samples are often too small and have too narrow a CMD coverage to allow
robust age determinations. Here, we develop and illustrate a new approach that
can estimate robust stellar population ages for such groups of stars. This
first entails projecting the predetermined action-angle distribution into the
5D space of positions, parallaxes and proper motions, where much larger samples
of likely members can be identified over a much wider range of the CMD. It then
entails isochrone fitting that accounts for a) widely varying distances and
reddenings; b) outliers and binaries; c) sparsely populated main sequence
turn-offs, by incorporating the age information of the low-mass main sequence;
and d) the possible presence of an intrinsic age spread in the stellar
population. When we apply this approach to 92 nearby stellar groups identified
in 6D orbit space, we find that they are predominately young (
Gyr), mono-age populations. Many groups are established (known) localized
clusters with possible tidal tails, others tend to be widely dispersed and
manifestly unbound. This new age-dating tool offers a stringent approach to
understanding on which orbits stars form in the solar neighborhood and how
quickly they disperse into the field.Comment: Accepted for publication in Ap
Significance of a new fluorodeoxyglucose-positive lesion on restaging positron emission tomography/computed tomography after induction therapy for non-small-cell lung cancer †
OBJECTIVES Restaging of patients with locally advanced non-small-cell lung cancer (NSCLC) is of paramount importance, since only patients with down-staging after induction therapy will benefit from surgery. In this study, we assessed the aetiology of new 18fluoro-2-deoxy-d-glucose (FDG)-positive focal abnormalities on restaging positron emission tomography/computed tomography (PET/CT) in patients with a good response after induction chemotherapy in the primary tumour and lymph nodes. METHODS Between 2004 and 2008, 31 patients with histological proven stage III NSCLC had a PET/CT prior and after induction chemotherapy. Their medical charts were retrospectively reviewed. RESULTS Restaging PET/CT revealed a new FDG-positive lesion in 6 of 31 (20%) patients. The initial clinical stage of the disease was IIIA N2 in four and IIIB T4 in two patients. The maximal standard uptake value in the primary tumour (P=0.043) and in the initially involved mediastinal nodes (P=0.068) decreased after induction treatment in all patients. The new PET/CT findings were located in an ipsilateral cervical lymph node in two patients, a contralateral mediastinal in one patient and an ipsilateral mammary internal lymph node in one patient. Two other patients had a lesion on the contralateral lung. Malignant lymph node infiltrations were excluded following fine-needle puncture, intraoperative biopsy or follow-up PET/CT. Contralateral pulmonary lesions were diagnosed as benign following mini thoracotomy and pulmonary wedge resection. CONCLUSIONS New solitary FDG-positive lesions on restaging PET/CT after induction chemotherapy for NSCLC are not rare in good responders to chemotherapy. In our experience, all these lesions were not associated with malignanc
Regulation of Gram-Positive Conjugation
Type IV Secretion Systems (T4SSs) are membrane-spanning multiprotein complexes dedicated to protein secretion or conjugative DNA transport (conjugation systems) in bacteria. The prototype and best-characterized T4SS is that of the Gram-negative soil bacterium Agrobacterium tumefaciens. For Gram-positive bacteria, only conjugative T4SSs have been characterized in some biochemical, structural, and mechanistic details. These conjugation systems are predominantly encoded by self-transmissible plasmids but are also increasingly detected on integrative and conjugative elements (ICEs) and transposons. Here, we report regulatory details of conjugation systems from Enterococcus model plasmids pIP501 and pCF10, Bacillus plasmid pLS1, Clostridium plasmid pCW3, and staphylococcal plasmid pSK41. In addition, regulation of conjugative processes of ICEs (ICEBs1, ICESt1, ICESt3) by master regulators belonging to diverse repressor families will be discussed. A special focus of this review lies on the comparison of regulatory mechanisms executed by proteins belonging to the RRNPP family. These regulators share a common fold and govern several essential bacterial processes, including conjugative transfer
Therapeutische Intervention bei Scheidungsfamilien
Ausgehend von einer Beschreibung der spezifischen Probleme, die eine Scheidung für Eltern und Kinder mit sich bringt, werden auch Chancen und die Möglichkeit einer positiven Veränderung im Rahmen von Scheidungen erörtert. Es wird deutlich gemacht, wie diese Chancen mit Hilfe professioneller therapeutischer Unterstützung genutzt werden können
Longitudinal increase in the detection rate of Mycobacterium chimaera in heater-cooler device-derived water samples
Colonization with Mycobacterium chimaera and other nontuberculous mycobacteria (NTM) has been reported for heater-cooler devices (HCD) produced by several manufacturers. Up to now, exclusively LivaNova (London, UK) HCDs have been associated with M. chimaera infections after cardiac surgery. The vast majority of studies on HCD colonization were cross-sectional. We were interested in longitudinal dynamics of mycobacterial growth in HCD water samples and analyzed data of a prospective mycobacterial surveillance of five LivaNova 3T HCDs. Nontuberculous mycobacteria were isolated in 319 (48.0%, 21 water samples grew more than one mycobacterial species) of a total of 665 water samples. The most frequently detected species were M. chimaera (N= 247/319, 77.4%), Mycobacterium gordonae (46/319, 14.4%) and Mycobacterium paragordonae (34/319, 10.7%). Detection rates increased longitudinally for any NTM (odds ratio (OR) per year in use: 1.60, 95% CI 1.17-2.24, P<0.001) and for M. chimaera (OR per year in use: 1.67, 95% CI 1.11-2.57, P<0.01)
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Multiband Wavelet Age Modeling for a ∼293 m (∼600 kyr) Sediment Core From Chew Bahir Basin, Southern Ethiopian Rift
The use of cyclostratigraphy to reconstruct the timing of deposition of lacustrine deposits requires sophisticated tuning techniques that can accommodate continuous long-term changes in sedimentation rates. However, most tuning methods use stationary filters that are unable to take into account such long-term variations in accumulation rates. To overcome this problem we present herein a new multiband wavelet age modeling (MUBAWA) technique that is particularly suitable for such situations and demonstrate its use on a 293 m composite core from the Chew Bahir basin, southern Ethiopian rift. In contrast to traditional tuning methods, which use a single, defined bandpass filter, the new method uses an adaptive bandpass filter that adapts to changes in continuous spatial frequency evolution paths in a wavelet power spectrum, within which the wavelength varies considerably along the length of the core due to continuous changes in long-term sedimentation rates. We first applied the MUBAWA technique to a synthetic data set before then using it to establish an age model for the approximately 293 m long composite core from the Chew Bahir basin. For this we used the 2nd principal component of color reflectance values from the sediment, which showed distinct cycles with wavelengths of 10–15 and of ∼40 m that were probably a result of the influence of orbital cycles. We used six independent 40Ar/39Ar ages from volcanic ash layers within the core to determine an approximate spatial frequency range for the orbital signal. Our results demonstrate that the new wavelet-based age modeling technique can significantly increase the accuracy of tuned age models
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