1,155 research outputs found
Cold heteromolecular dipolar collisions
We present the first experimental observation of cold collisions between two
different species of neutral polar molecules, each prepared in a single
internal quantum state. Combining for the first time the techniques of Stark
deceleration, magnetic trapping, and cryogenic buffer gas cooling allows the
enhancement of molecular interaction time by 10. This has enabled an
absolute measurement of the total trap loss cross sections between OH and
ND at a mean collision energy of 3.6 cm (5 K). Due to the dipolar
interaction, the total cross section increases upon application of an external
polarizing electric field. Cross sections computed from \emph{ab initio}
potential energy surfaces are in excellent agreement with the measured value at
zero external electric field. The theory presented here represents the first
such analysis of collisions between a radical and a closed-shell
polyatomic molecule.Comment: 7 pages, 5 figure
Enhancing breast milk production with Domperidone in mothers of preterm neonates (EMPOWER trial)
BACKGROUND: The use of mother’s own breast milk during initial hospitalization has a positive impact not only in reducing potential serious neonatal morbidities but also contribute to improvements in neurodevelopmental outcomes. Mothers of very preterm infants struggle to maintain a supply of breast milk during their infants’ prolonged hospitalization. Galactogogues are medications that induce lactation by exerting its effects through oxytocin or prolactin enhancement. Domperidone is a potent dopamine D(2) receptor antagonist which stimulates the release of prolactin. Small trials have established its ability in enhancing breast milk production. EMPOWER was designed to determine the safety and efficacy of domperidone in mothers experiencing an inadequate milk supply. METHODS/DESIGN: EMPOWER is a multicenter, double masked, randomized controlled phase-II trial to evaluate the safety and effectiveness of domperidone in those mothers identified as having difficulty in breast milk production. Eligible mothers will be randomized to one of two allocated groups: Group A: domperidone 10 mg orally three times daily for 28 days; and Group B: identical placebo 10 mg orally three times daily for 14 days followed by domperidone 10 mg orally three times daily for 14 days. The primary outcome will be determined at the completion of the first 2-week period; the second 2-week period will facilitate answering the secondary questions regarding timing and duration of treatment. To detect an estimated 30% change between the two groups (from 40% to 28%, corresponding to an odds ratio of 0.6), a total sample size of 488 mothers would be required at 80% power and alpha = 0.05. To account for a 15% dropout, this number is increased to 560 (280 per group). The duration of the trial is expected to be 36–40 months. DISCUSSION: The use of a galactogogue often becomes the measure of choice for mothers in the presence of insufficient breast milk production, particularly when the other techniques are unsuccessful. EMPOWER is designed to provide valuable information in guiding the practices for this high-risk group of infants and mothers. The results of this trial will also inform both mothers and clinicians about the choices available to increase and maintain sufficient breast milk. TRIAL REGISTRATION: Clinical Trials.gov Identifier: NCT0151222
Maternal Obesity in Pregnancy Developmentally Programs Adipose Tissue Inflammation in Young, Lean Male Mice Offspring.
Obesity during pregnancy has a long-term effect on the health of the offspring including risk of developing the metabolic syndrome. Using a mouse model of maternal diet-induced obesity, we employed a genome-wide approach to investigate the microRNA (miRNA) and miRNA transcription profile in adipose tissue to understand mechanisms through which this occurs. Male offspring of diet-induced obese mothers, fed a control diet from weaning, showed no differences in body weight or adiposity at 8 weeks of age. However, offspring from the obese dams had up-regulated cytokine (Tnfα; P < .05) and chemokine (Ccl2 and Ccl7; P < .05) signaling in their adipose tissue. This was accompanied by reduced expression of miR-706, which we showed can directly regulate translation of the inflammatory proteins IL-33 (41% up-regulated; P < .05) and calcium/calmodulin-dependent protein kinase 1D (30% up-regulated; P < .01). We conclude that exposure to obesity during development primes an inflammatory environment in adipose tissue that is independent of offspring adiposity. Programming of adipose tissue miRNAs that regulate expression of inflammatory signaling molecules may be a contributing mechanism.This work was supported by Funding sources: National Council for the Improvement of Higher Education (CAPES - Brazil - BEX 10 594/13–2); National Counsel of Technological and Scientific Development (CNPq – Brazil – PDE/204416/ 2014–0); Medical Research Council (MC UU 12012/4 and MC UU12012/5), BBSRC (BB/M001636/1) and the Wellcome Trust (089940/Z/09/Z).This is the final version of the article. It first appeared from the Endocrine Society via http://dx.doi.org/10.1210/en.2016-131
Histologic and phenotypic factors and MC1R status associated with BRAF(V600E), BRAF(V600K), and NRAS mutations in a community-based sample of 414 cutaneous melanomas
Cutaneous melanomas arise through causal pathways involving interplay between exposure to UV radiation and host factors, resulting in characteristic patterns of driver mutations in BRAF, NRAS, and other genes. To gain clearer insights into the factors contributing to somatic mutation genotypes in melanoma, we collected clinical and epidemiologic data, performed skin examinations, and collected saliva and tumor samples from a community-based series of 414 patients aged 18 to 79, newly diagnosed with cutaneous melanoma. We assessed constitutional DNA for nine common polymorphisms in melanocortin-1 receptor gene (MC1R). Tumor DNA was assessed for somatic mutations in 25 different genes. We observed mutually exclusive mutations in BRAF (26%), BRAF (8%), BRAF (5%), and NRAS (9%). Compared to patients with BRAF wild-type melanomas, those with BRAF mutants were significantly younger, had more nevi but fewer actinic keratoses, were more likely to report a family history of melanoma, and had tumors that were more likely to harbor neval remnants. BRAF mutations were also associated with high nevus counts. Both BRAF and NRAS mutants were associated with older age but not with high sun exposure. We also found no association between MC1R status and any somatic mutations in this community sample of cutaneous melanomas, contrary to earlier reports
Sepsis-associated microvascular dysfunction measured by peripheral arterial tonometry: an observational study
INTRODUCTION: Sepsis has a high mortality despite advances in management. Microcirculatory and endothelial dysfunction contribute to organ failure, and better tools are needed to assess microcirculatory responses to adjunctive therapies. We hypothesised that peripheral arterial tonometry (PAT), a novel user-independent measure of endothelium-dependent microvascular reactivity, would be impaired in proportion to sepsis severity and related to endothelial activation and plasma arginine concentrations. METHODS: Observational cohort study in a 350-bed teaching hospital in tropical Australia. Bedside microvascular reactivity was measured in 85 adults with sepsis and 45 controls at baseline and 2-4 days later by peripheral arterial tonometry. Microvascular reactivity was related to measures of disease severity, plasma concentrations of L-arginine (the substrate for nitric oxide synthase), and biomarkers of endothelial activation. RESULTS: Baseline reactive hyperaemia index (RH-PAT index), measuring endothelium-dependent microvascular reactivity; (mean [95% CI]) was lowest in severe sepsis (1.57 [1.43-1.70]), intermediate in sepsis without organ failure (1.85 [1.67-2.03]) and highest in controls (2.05 [1.91-2.19]); P < 0.00001. Independent predictors of baseline RH-PAT index in sepsis were APACHE II score and mean arterial pressure, but not plasma L-arginine or markers of endothelial activation. Low baseline RH-PAT index was significantly correlated with an increase in SOFA score over the first 2-4 days (r = -0.37, P = 0.02). CONCLUSIONS: Endothelium-dependent microvascular reactivity is impaired in proportion to sepsis severity and suggests decreased endothelial nitric oxide bioavailability in sepsis. Peripheral arterial tonometry may have a role as a user-independent method of monitoring responses to novel adjunctive therapies targeting endothelial dysfunction in sepsis
Cold heteromolecular dipolar collisions
We present the first experimental observation of cold collisions between two
different species of neutral polar molecules, each prepared in a single
internal quantum state. Combining for the first time the techniques of Stark
deceleration, magnetic trapping, and cryogenic buffer gas cooling allows the
enhancement of molecular interaction time by 10. This has enabled an
absolute measurement of the total trap loss cross sections between OH and
ND at a mean collision energy of 3.6 cm (5 K). Due to the dipolar
interaction, the total cross section increases upon application of an external
polarizing electric field. Cross sections computed from \emph{ab initio}
potential energy surfaces are in excellent agreement with the measured value at
zero external electric field. The theory presented here represents the first
such analysis of collisions between a radical and a closed-shell
polyatomic molecule.Comment: 7 pages, 5 figure
Inflammatory Aetiology of Human Myometrial Activation Tested Using Directed Graphs
There are three main hypotheses for the activation of the human uterus at labour: functional progesterone withdrawal, inflammatory stimulation, and oxytocin receptor activation. To test these alternatives we have taken information and data from the literature to develop causal pathway models for the activation of human myometrium. The data provided quantitative RT-PCR results on key genes from samples taken before and during labour. Principal component analysis showed that pre-labour samples form a homogenous group compared to those during labour. We therefore modelled the alternative causal pathways in non-labouring samples using directed graphs and statistically compared the likelihood of the different models using structural equations and D-separation approaches. Using the computer program LISREL, inflammatory activation as a primary event was highly consistent with the data (p = 0.925), progesterone withdrawal, as a primary event, is plausible (p = 0.499), yet comparatively unlikely, oxytocin receptor mediated initiation is less compatible with the data (p = 0.091). DGraph, a software program that creates directed graphs, produced similar results (p = 0.684, p = 0.280, and p = 0.04, respectively). This outcome supports an inflammatory aetiology for human labour. Our results demonstrate the value of directed graphs in determining the likelihood of causal relationships in biology in situations where experiments are not possible
The Role of the Uncinate Margin in Pancreaticoduodenectomy for Pancreatic Ductal Adenocarcinoma: A Survival Analysis
Introduction: Positive margins during pancreaticoduodenectomy for pancreatic cancer portend worse survival, but additional resection of the uncinate margin is typically unfeasible without major vascular reconstruction. The survival benefit of resecting additional neck or bile duct margins in the face of a positive uncinate is also unknown. We examined the impact of re-resection of these margins on survival.
Methods: Patients with pancreatic adenocarcinoma who underwent pancreaticoduodenectomy from 2006-2015. Pancreatic neck, bile duct, uncinate, and duodenal frozen section margins were assessed before and after resection of positive margins. Kaplan-Meier survival curves were compared with log-rank tests. Multivariable Cox regression was used to assess the effect of margin status on overall survival.
Results: Among 508 patients identified, 388 (76.4%) underwent a pylorus-preserving procedure, 435 (85.6%) had T3 tumors, and 379 (74.6%) had nodal involvement. There were 21 instances where an uncinate margin was concurrently positive with a neck or bile duct margin; this additional neck or bile duct margin was resected in 13 cases (61.9%). Resection of additional margins when the uncinate was concurrently positive was not associated with improved survival (p=0.36). Median survival with and without positive uncinate margins was 13.8 vs. 19.7 months (p=0.04). A positive uncinate margin was associated with decreased survival independent of other margins and cancer stage (HR 1.28 [95% CI 1.00-1.65]).
Conclusion: In patients with pancreatic adenocarcinoma, positive uncinate margins are associated with decreased overall survival; resection of additional margins at the neck and bile duct in those with a positive uncinate margin is not warranted
Best practices in data analysis and sharing in neuroimaging using MRI
Given concerns about the reproducibility of scientific findings, neuroimaging must define best practices for data analysis, results reporting, and algorithm and data sharing to promote transparency, reliability and collaboration. We describe insights from developing a set of recommendations on behalf of the Organization for Human Brain Mapping, and identify barriers that impede these practices, including how the discipline must change to fully exploit the potential of the world’s neuroimaging data
Corrigendum: Determination of CSF GFAP, CCN5, and vWF levels enhances the diagnostic accuracy of clinically defined MS from non-MS patients with CSF oligoclonal bands
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