511 research outputs found
Exhaustive Suzuki-Miyaura Reactions of Polyhalogenated Heteroarenes with Alkyl Boronic Pinacol Esters
A novel Suzuki-Miyaura protocol is described that enables the exhaustive alkylation of polychlorinated pyridines. This method facilitates a formal synthesis of normuscopyridine and the rapid assembly of a dumbbell shaped portion of a [2]rotaxane
Terapias complementarias y alternativas para el síndrome de Down
Los padres de hijos con síndrome de Down, en su papel de defensores comprometidos de sus hijos, han indagado siempre por terapias alternativas, sobre todo para mejorar su función cognitiva, pero también para mejorar su aspecto. Las terapias complementarias y alternativas más frecuentemente utilizadas han sido los suplementos de tipo nutritivo. Se ha usado la terapia celular, la cirugía plástica, la terapia hormonal y un conjunto de otras estrategias como puede ser el masaje. Carecemos de estudios científicos bien diseñados sobre el empleo de las terapias alternativas en las personas con síndrome de Down. Los productos antioxidantes ofrecen una perspectiva terapéutica para el tratamiento de los problemas de tipo cognitivo, inmunitario, neoplástico y de envejecimiento precoz, asociados al síndrome de Down que están en fase de estudio. Los medicamentos para el tratamiento de la enfermedad de Alzheimer pueden también beneficiar a la población con síndrome de Down
22q11.2 Deletion Syndrome: Are Motor Deficits More Than Expected for IQ Level?
To examine motor function in children with 22q11.2 deletion syndrome (22q11.2) and a Full Scale IQ (FSIQ) comparable control group. This study was part of a prospective study of neuropsychological function in children 9 to 15 years of age with 22q11.2 and community control subjects and included children from these two populations with comparable FSIQs. Verbal IQs on the WISC-R for 40 children with 22q11.2 (88.4) and 24 community control subjects (87.2) were not different (P=.563). However, the performance IQs were (22q11.2; 81.1 vs community controls; 89.3;
Velo-Cardio-Facial Syndrome
Purpose of review: Velo-cardio-facial syndrome has emerged from obscurity to become one of the most researched disorders this past decade. It is one of the most common genetic syndromes in humans, the most common contiguous gene syndrome in humans, the most common syndrome of cleft palate, and the most common syndrome of conotruncal heart malformations. Velo-cardio-facial syndrome has an expansive phenotype, a factor reflected in the wide range of studies that cover both clinical features and molecular genetics. In this review, we cover multiple areas of research during the past year, including psychiatric disorders, neuroimaging, and the delineation of clinical features. Recent findings: The identification of candidate genes for heart anomalies, mental illness, and other clinical phenotypes has been reported in the past year with a focus on TBX1 for cardiac and craniofacial phenotypes and COMT and PRODH for psychiatric disorders. The expansive phenotype of velo-cardio-facial syndrome continues to grow with new behavioral and structural anomalies reported. Treatment issues are beginning to draw attention, although most authors continue to focus on diagnostic issues. Summary: Its high population prevalence, estimated to be as common as 1:2000 has sparked a large amount of research, as has the model the syndrome serves for identifying the causes of mental illness and learning disabilities, but it is obvious that more information is needed. Intensive scrutiny of velo-cardio-facial syndrome will undoubtedly continue for many years to come with the hope that researchers will turn more of their attention to treatment and treatment outcomes
Capturing Fleeting Intermediates in a Catalytic C-H Amination Reaction Cycle
We have applied an ambient ionization technique, desorption electrospray ionization MS, to identify transient reactive species of an archetypal C–H amination reaction catalyzed by a dirhodium tetracarboxylate complex. Using this analytical method, we have detected previously proposed short-lived reaction intermediates, including two nitrenoid complexes that differ in oxidation state. Our findings suggest that an Rh-nitrene oxidant can react with hydrocarbon substrates through a hydrogen atom abstraction pathway and raise the intriguing possibility that two catalytic C–H amination pathways may be operative in a typical bulk solution reaction. As highlighted by these results, desorption electrospray ionization MS should have broad applicability for the mechanistic study of catalytic processes
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Speech production in children with Down's syndrome: The effects of reading, naming and imitation
People with DS are known to have difficulties with expressive language, and often have difficulties with intelligibility. They often have stronger visual than verbal short-term memory skills and, therefore, reading has often been suggested as an intervention for speech and language in this population. However, there is as yet no firm evidence that reading can improve speech outcomes. This study aimed to compare reading, picture naming and repetition for the same 10 words, to identify if the speech of eight children with DS (aged 11-14 years) was more accurate, consistent and intelligible when reading. Results show that children were slightly, yet significantly, more accurate and intelligible when they read words compared with when they produced those words in naming or imitation conditions although the reduction in inconsistency was non-significant. The results of this small-scale study provide tentative support for previous claims about the benefits of reading for children with DS. The mechanisms behind a facilitatory effect of reading are considered, and directions are identified for future research
Hadron Production and Phase Changes in Relativistic Heavy Ion Collisions
We study soft hadron production in relativistic heavy ion collisions in a
wide range of reaction energy, 4.8 GeV <sqrt{s_ NN}<200 GeV, and make
predictions about yields of particles using the statistical hadronization
model. In fits to experimental data, we obtain both statistical parameters as
well as physical properties of the hadron source. We identify the properties of
the fireball at the critical energy threshold, 6.26 GeV < sqrt{s_NN}^cr} <7.61
GeV, delineating for higher energies hadronization of an entropy rich phase. In
terms of the chemical composition, one sees a phase which at low energy is
chemically under-saturated, and which turns into a chemically over-saturated
state persisting up to the maximum accessible energy. Assuming that there is no
change in physical mechanisms in the energy range 15>sqrt{s_NN} \ge 200 GeV, we
use continuity of particle yields and statistical parameters to predict the
hadron production at sqrt{s_NN}=62.4 GeV, and obtain total yields of hadrons at
sqrt{s_NN}=130 GeV. We consider, in depth, the pattern we uncover within the
hadronization condition, and discuss possible mechanisms associated with the
identified rapid change in system properties at sqrt{s_NN ^cr}. We propose that
the chemically over-saturated 2+1 flavor hadron matter system undergoes a 1st
order phase transition.Comment: 23 pages; a) we correct an entropy yield error which the early SHARE
release contained; this changes tables and figures comprising physical
properties involving entropy, the data fits are unaffected. b) we
incorporated the latest strange hadron yields of NA49 and c) this version is
in press in EPJ
Down syndrome and postoperative complications after paediatric cardiac surgery: a propensity-matched analysis
OBJECTIVESThe incidence of congenital heart disease is approximately 50%, mostly related to endocardial cushion defects. The aim of our study was to investigate the postoperative complications that occur after paediatric cardiac surgery.METHODSOur perioperative data were analysed in paediatric patients with Down syndrome undergoing cardiac surgery. We retrospectively analysed the data from 2063 consecutive paediatric patients between January 2003 and December 2008. After excluding the patients who died or had missing data, the analysed database (before propensity matching) contained 129 Down patients and 1667 non-Down patients. After propensity matching, the study population comprised 222 patients and 111 patients had Down syndrome.RESULTSBefore propensity matching, the occurrences of low output syndrome (21.2 vs 32.6%, P = 0.003), pulmonary complication (14 vs 28.7%, P < 0.001) and severe infection (11.9 vs 22.5%, P = 0.001) were higher in the Down group. Down patients were more likely to have prolonged mechanical ventilation [median (interquartile range) 22 (9-72) h vs 49 (24-117) h, P = 0.007]. The total intensive care unit length of stay [6.9 (4.2-12.4) days vs 8.3 (5.3-13.2) days, P = 0.04] and the total hospital length of stay [17.3 (13.3-23.2) days vs 18.3 (15.1-23.6) days, P = 0.05] of the Down patients were also longer. Mortality was similar in the two groups before (3.58 vs 3.88%, P = 0.86) and after (5.4 vs 4.5%, P = 1.00) propensity matching. After propensity matching, there was no difference in the occurrence of adverse events.CONCLUSIONSAfter propensity matching Down syndrome was not associated with increased mortality or complication rate following congenital cardiac surgery
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