1,461 research outputs found
Probability of EOSS mission survival evaluation of the impact of artificial-gravity operations on the overall mission reliability Preliminary report
Early Orbital Space Station mission reliability in artificial gravity mod
Deadly Carousel or Difficult Interpretation of New Diagnostic Tools for Whipple's Disease: Case Report and Review of the Literature
Abstract : Whipple's disease is a rare systemic disorder classically presenting with weight loss, arthralgias, and diarrhea, which was first described in 1907. The causative bacterium Tropheryma whipplei, is a fastidious organism not growing on conventional media. Before the introduction of polymerase chain reaction (PCR)-based methods, the diagnostic gold standard was histological detection of diastase-resistant periodic acid Schiff (PAS)-positive macrophages or electron microscopy. As in the present case, contradictory results between the former and new diagnostic methods may obscure the correct diagnosis. We critically summarize the performance of the different diagnostic methods and discuss their impact on the clinical management of patients with suspected Whipple's diseas
Body Image Dissatisfaction Among Third, Fourth, and Fifth Grade Children
Body image dissatisfaction has become increasingly more prevalent among the preadolescent population over recent years. This study examines the level of body image dissatisfaction among 261 third, fourth, and fifth grade girls and boys. A pictorial scale was used to assess how the participants viewed their current body shape, their ideal body shape, and what they believed to be the ideal body shape of the opposite gender. Overall results indicated that 50.6% of the children surveyed were dissatisfied with their current body shape, 41.8% wanted to be thinner, while 8.8% wanted to be larger. Fifty percent of the girls were dissatisfied with their current body shape, with 45.1% wishing to be thinner. Boys showed similar trends, with 48.9% dissatisfied and 38.9% wishing to be thinner. A greater percentage of boys wanted to be larger than their current body shape (12.3%) compared to girls (4.9%). A significant difference was found between genders regarding the difference between scores of their current self and ideal self, where girls selected a smaller ideal body shape than the boys. An encouraging finding was that the level of body dissatisfaction decreased from third grade to fifth grade among both genders. Girls, however, still wished to be thinner over time. Boys, on the other hand, indicated a preference for a somewhat larger body shape over time. These results indicate that body image dissatisfaction exists prior to adolescence among this sample of children. Prevention strategies and education are encouraged among this age group
Reduction of Ketones with LiAlH4 Complexes of Ī±,Ī±,Ī±\u27,Ī±\u27-Tetraaryl-1,3-dioxolane-4,5-dimethanols (TADDOLs) A Combination of Enantioselective Reduction and Clathrate Formation with a Discussion of LAH Reagents Bearing C2-Symmetrical Ligands
A complex prepared from one equivalent each of LiAlH4, EtOH and a TADDOL (Ī±,Ī±,Ī±\u27,Ī±\u27-tetraaryl-1,3-dioxolane-4,5-dimethanol) reduces aryl alkyl ketones to sec. alcohols with enantiomer ratios (er) up to 96 : 4. The chiral LAH derivative is used in two-fold excess in THF solution and at dry ice temperatures. The ability of TADDOLs to form clathrates diastereoselectively can be exploited to increase the er of the initially formed alcohols by a simple modification of the work-up procedure and hence, products of very high en- antiopurity (er 99 : 1) can be isolated. When (7i,/i)-TADDOLs (from (ZiA)-tartrate) are applied in the reaction, the 1-aryl-alkanols formed preferentially have (S) configuration, as for the products obtained with the corresponding (P)-BINOL and (P)-BIPHENOL derivatives. A common mechanistic model is discussed
[(4R,5R)-(2,2-Dimethyl-1,3-dioxolane-4,5-diĀyl)bisĀ(diphenylĀmethanoĀlato)-Īŗ2 O:Oā²]bis(N-methylĀmethanaminĀato)titanium(IV)
In the title four-coordinate complex, [Ti(C2H6N)2(C31H28O4)], two symmetry-independent molĀecules are present in the asymmetric unit. The TiIV atom displays a distorted tetraĀhedral geometry, with TiāO bond lengths ranging from 1.805ā
(3) to 1.830ā
(3)ā
Ć
and OāTiāO ligand bite angles of 100.16ā
(12) and 101.36ā
(12)Ā°. The short TiāN bond distances, ranging from 1.877ā
(4) to 1.905ā
(4)ā
Ć
, indicate strong bonding between the TiIV atom and the dimethylĀamide ligands
An exploration of concepts of community through a case study of UK university web production
The paper explores the inter-relation and differences between the concepts of occupational community, community of practice, online community and social network. It uses as a case study illustration the domain of UK university web site production and specifically a listserv for those involved in it. Different latent occupational communities are explored, and the potential for the listserv to help realize these as an active sense of community is considered. The listserv is not (for most participants) a tight knit community of practice, indeed it fails many criteria for an online community. It is perhaps best conceived as a loose knit network of practice, valued for information, implicit support and for the maintenance of weak ties. Through the analysis the case for using strict definitions of the theoretical concepts is made
Bioactivity in silica/poly(Ī³-glutamic acid) solāgel hybrids through calcium chelation
Bioactive glasses and inorganic/organic hybrids have great potential as biomedical implant materials. Solāgel hybrids with interpenetrating networks of silica and biodegradable polymers can combine the bioactive properties of a glass with the toughness of a polymer. However, traditional calcium sources such as calcium nitrate and calcium chloride are unsuitable for hybrids. In this study calcium was incorporated by chelation to the polymer component. The calcium salt form of poly(Ī³-glutamic acid) (Ī³CaPGA) was synthesized for use as both a calcium source and as the biodegradable toughening component of the hybrids. Hybrids of 40 wt.% Ī³CaPGA were successfully formed and had fine scale integration of Ca and Si ions, according to secondary ion mass spectrometry imaging, indicating a homogeneous distribution of organic and inorganic components. 29Si magic angle spinning nuclear magnetic resonance data demonstrated that the network connectivity was unaltered with changing polymer molecular weight, as there was no perturbation to the overall Si speciation and silica network formation. Upon immersion in simulated body fluid a hydroxycarbonate apatite surface layer formed on the hybrids within 1 week. The polymer molecular weight (Mw 30ā120 kDa) affected the mechanical properties of the resulting hybrids, but all hybrids had large strains to failure, >26%, and compressive strengths, in excess of 300 MPa. The large strain to failure values showed that Ī³CaPGA hybrids exhibited non-brittle behaviour whilst also incorporating calcium. Thus calcium incorporation by chelation to the polymer component is justified as a novel approach in hybrids for biomedical materials
Considerations for a European animal welfare standard to evaluate adverse phenotypes in teleost fish
No abstract available
Sarcoidosis - a multisystem disease.
Sarcoidosis is a systemic inflammatory disease, characterised by granuloma formation upon an unknown trigger in genetically predisposed individuals. The inflammation is characterised by an activation of both the innate immune system, with macrophages differentiating into epitheloid cells and dendritic cells, and the adaptive immune system, particularly T helper (Th) 1 and Th17 cells. Since all organs can be affected to varying extents, clinical presentation is often diverse. Most commonly, the lungs, lymph nodes, skin and eyes are involved, whereas cardiac, renal and neurological manifestations are less common but associated with higher morbidity. Depending on the clinical symptoms, a detailed evaluation including thorough clinical examination, imaging and laboratory tests should explore all possible organ involvements. In some patients, fatigue manifests as a para-sarcoidosis symptom impacting quality of life, even if sarcoidosis is in remission. Some acute syndromic presentations, such as Lƶfgren's syndrome, have a good prognosis and are commonly self-limiting. If possible, a topical treatment, for example for cutaneous sarcoidosis or bronchial involvement, should be applied. Treatment of severe cases with persisting disease activity necessitates long-term immunosuppressive drugs, with glucocorticoids as the first-line option. Steroid-sparing and second-line drugs include methotrexate, azathioprine, mycophenolate mofetil and immunomodulators such hydroxychloroquine, with the latter being first-line therapy in cutaneous sarcoidosis. Tumour necrosis factor-alpha inhibitors (particularly adalimumab and infliximab) are used as third-line agents but are administered earlier in cases of persistent disease activity, severe organ-involvement or intolerance to conventional drugs. Treatment decisions should be based on a multidisciplinary approach, depending on organ involvement and treatment tolerability. Para-sarcoidosis manifestations, particularly fatigue, should also be carefully addressed, where the patient could also be enrolled in multidimensional rehabilitation programmes. With various organ involvement and different phenotypes, larger studies including real-world data from registries are necessary to evaluate different sarcoidosis endotypes and preferential treatment pathways
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