We report the results of a study aiming to detect signs of astrometricmicrolensing caused by an intermediate-mass black hole (IMBH) in the center ofglobular cluster M 22 (NGC 6656). We used archival data from the Hubble SpaceTelescope (HST) taken between 1995 and 2014, to derive long-baselineastrometric time series for stars near the center of the cluster, usingstate-of-the-art software to extract high-precision astrometry from images. Wethen modelled these time-series data, and compared microlensing model fits tosimple linear proper-motion fits for each selected star. We find no evidencefor astrometric microlensing in M 22, in particular for Bulge stars, which aremuch more likely to be lensed than cluster stars, due to the geometry ofmicrolensing events. Although it is in principle possible to derive mass limitsfrom such non-detections, we find that no useful mass limits can be derived forM 22 with available data, mostly due to a 10-year gap in coverage. This is aresult from difficulties with deriving precise enough astrometry from WideField Planetary Camera 2 (WFPC2) observations, for stars that do not fall onthe PC chip. However, this study shows that, for other HST instruments, we areable to reach precisions at which astrometric microlensing signals caused byIMBH in globular clusters could be detected, and that this technique is apromising tool to make a first unambiguous detection of an IMBH.
Rice bran oil is characterized by its unique composition of unsaponifiable matter such as oryzanol, squalene, sterols, tocopherols and fatty alcohols. Rice bran oil fatty acid distillate (RBOFAD) is an important by-product of physical refining plants. In the present study, an appropriate fractionation methodology is proposed for isolating the unsaponifiable matter into two fractions, squalene, phytosterols and fatty alcohols as fraction 1; tocopherols and γ- oryzanol as fraction 2. The two fractions together constitute the total unsaponifiable matter in the RBOFAD. The individual unsaponifiable matter components (γ-oryzanol 1.78g/100g, squalene 209.63 mg/100g, tocopherol 2.45mg/100g, total phytosterols 3.79g/100g and fatty alcohols 94.23g/100g) were isolated from RBOFAD by combining a chemical esterification process and liquid-liquid extraction process with 95% ethanol which extracted tocopherol, γ-oryzanol, sterols, squalene, FFA, monoglycerides; later with hexane extraction of the alkaline phase to remove squalene, sterols and fatty alcohols. The alkaline salts of tocopherols and γ-oryzanol are decomposed by the acidification and extraction of the unsaponifiable matter with n-hexane.
Platelet-activating factor (PAF) stimulates numerous cell types via activation of the G protein-coupled PAF receptor (PAFR). PAFR activation not only induces acute proinflammatory responses, but it also induces delayed systemic immunosuppressive effects by modulating host immunity. Although enzymatic synthesis and degradation of PAF are tightly regulated, oxidative stressors, such as UVB, chemotherapy, and cigarette smoke, can generate PAF and PAF-like molecules in an unregulated fashion via the oxidation of membrane phospholipids. Recent studies have demonstrated the relevance of the mast cell (MC) PAFR in PAFR-induced systemic immunosuppression. The current study was designed to determine the exact mechanisms and mediators involved in MC PAFR-mediated systemic immunosuppression. By using a contact hypersensitivity model, the MC PAFR was not only found to be necessary, but also sufficient to mediate the immunosuppressive effects of systemic PAF. Furthermore, activation of the MC PAFR induces MC-derived histamine and PGE 2 release. Importantly, PAFR-mediated systemic immunosuppression was defective in mice that lacked MCs, or in MC-deficient mice transplanted with histidine decarboxylase- or cyclooxygenase-2-deficient MCs. Lastly, it was found that PGs could modulate MC migration to draining lymph nodes. These results support the hypothesis that MC PAFR activation promotes the immunosuppressive effects of PAF in part through histamine- and PGE 2 -dependent mechanisms.
The egg and banana sign can be seen on chest computed tomography (CT) in patients with severe pulmonary arterial hypertension (PAH). It is identified by the presence of the pulmonary artery (PA) lateral to the aortic arch with the aortic arch being described as the banana and the PA as the egg.
Dysraphic lesions in adults, presenting clinically as tethered cord syndrome (TCS), are relatively rare, and their optimal management remains controversial.
The Ewing sarcoma peripheral PNET (ES-pPNET) is very rare small round cell tumour that involves the CNS as either a primary dural neoplasm or by direct extension from contiguous bone or soft tissue.