109 research outputs found
Bone mineral mass and bone turnover parameters in osteoporosis
In the past decades osteoporosis has been recognized as an important public health problem.
Several causes for this problem can be pointed out. The most probable cause for the
development of osteoporosis is the loss of ovarian function in women and the increasing age
of people, thereby increasing the incidence of osteoporosis. Other causes or risk factors for
the development of osteoporosis are immobilization and dietary deficiencies. Finally, the
outcome of osteoporosis is an increased risk for the development of fractures (chapter 1.3).
The terminology associated with osteoporosis was developed in the nineteenth century by
German pathologists to distinguish diseases of bone. Pommer stated in 1926 that in
osteoporosis the formation of bone by osteoblasts was not able to replace the bone resorbed
by osteoclasts. Pommer performed extensive histomorphometric analysis of bone, thereby
distinguishing various forms of osteoporosis (senile, immobility), osteomalacia and osteitis
fibrosa cystica
Koopmotieven de Grachten, Uitwellingerga:onderzoeksrapport
SDDM-research heeft onderzoek gedaan naar de koopmotieven van de bewoners uit project ‘De Grachten’ te Uitwellingerga. Wat waren de beweegredenen voor de bewoners om specifiek dit project te kiezen en wat maakt dit project nu zo speciaal? Door middel van gedegen onderzoek is het gelukt de koopmotieven van de bewoners duidelijk in kaart te brengen. Studentenonderzoek in het kader van het thema Werklandschappe
Puzzled by GRB 060218
We study the optical-UV/X-ray spectral energy distribution of GRB 060218
during the prompt phase and during what seems to be the afterglow phase. The
results are puzzling, since if the opt-UV and the X-ray emission belong to a
single backbody (BB), then its luminosity is too large, and this BB cannot be
interpreted as the signature of the shock breakout of the supernova. There are
also serious problems in associating the emission expected by the supernova
shock breakout with either the opt-UV or the X-ray emission. In the former case
we derive too small ejecta velocities; in the latter case, on the contrary, the
required velocity is too large, corresponding to the large radius of a BB
required to peak close to the UV band. We then present what we think is the
most conservative alternative explanation, namely a synchrotron spectrum,
self-absorbed in the opt-UV and extending up to the X-ray band, where we
observe the emission of the most energetic electrons, which are responsible for
the exponential roll-over of the spectrum. The obtained fit can explain the
entire spectrum except the BB observed in the X-rays, which must be a separate
component. The puzzling feature of this interpretation is that the same model
is required to explain the spectrum also at later times, up to 1e5 s, because
the opt-UV emission remains constant in shape and also (approximately) in
normalisation. In this case the observed X-ray flux is produced by self-Compton
emission. Thus the prompt emission phase should last for ~1e5 s or more.
Finally, we show that the BB observed in X-rays, up to 7000 seconds, can be
photospheric emission from the cocoon or stellar material, energized by the GRB
jet at radii comparable to the stellar radius (i.e. 1e10-1e11 cm), not very far
from where this material becomes transparent (e.g. 1e12 cm).Comment: revised version accepted for publication in MNRAS (Letters
Differences in presentation between paediatric- and adult-onset primary Sjögren's syndrome patients
OBJECTIVES: Primary Sjögren's syndrome (pSS) is a rare disease in paediatric patients. Presenting symptoms differ from those in adult patients. The aim of this study was to evaluate presenting symptoms, classification criteria and clinical assessments, including salivary gland ultrasonography (SGUS), at disease onset in paediatric and adult patients with pSS. METHODS: Data of 23 paediatric- and 33 adult-onset patients with pSS were obtained from our standardised multidisciplinary REpSULT and RESULT cohorts, respectively. Clinical, patient-reported, serological, functional, biopsy and SGUS parameters were compared. RESULTS: In paediatric-onset pSS (pedSS) patients, recurrent parotid gland swelling (91% vs. 49%, p<0.001) and fever (30% vs. 3%, p=0.006) were more often present than in adult-onset patients. In contrast, sicca symptoms of mouth (52% vs. 79%, p=0.046) and eyes (26% vs. 73%, p<0.001) were less common in pedSS patients. In paediatric patients, the entry criteria of the ACR/EULAR classification were most often met due to activity in the glandular domain of the ESSDAI. When applying the ACR/EULAR classification criteria, only 78% of pedSS fulfilled these criteria compared to 100% of adult patients. Abnormal glandular function tests had a greater contribution to fulfilling the criteria in adults, while the biopsy had a greater contribution in paediatric patients. Anti-SSA/Ro serology had similar contribution for both cohorts. SGUS Hocevar score was significantly higher in paediatric compared to adult patients (median 25 vs. 18, p=0.004). CONCLUSION: PedSS has a different presentation than adult-onset pSS. Recurrent parotid gland swelling in paediatric patients should alert clinicians to the potential presence of pSS
Differences in presentation between paediatric- and adult-onset primary Sjögren's syndrome patients
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