3,797 research outputs found
Homogeneous Gold Catalysis through Relativistic Effects: Addition of Water to Propyne
In the catalytic addition of water to propyne the Au(III) catalyst is not
stable under non-relativistic conditions and dissociates into a Au(I) compound
and Cl2. This implies that one link in the chain of events in the catalytic
cycle is broken and relativity may well be seen as the reason why Au(III)
compounds are effective catalysts.Comment: 12 pages, 3 figures, 1 tabl
Spontaneous Coronary Artery Dissection: A Case Series of 9 Patients With Literature Review.
Spontaneous coronary artery dissection is an increasingly recognized nonatherosclerotic cause of acute coronary syndrome. Reports regarding the prognosis and natural history of this disease are limited. In addition to the diagnostic difficulty, this condition poses a significant therapeutic challenge due to the lack of specific management guidelines. We present here a case series of 9 patients with spontaneous coronary artery dissection. Additionally, this article reviews the incidence, clinical characteristics, risk factors, diagnostic modalities, therapeutic approaches, and patterns of recurrence in patients with spontaneous coronary artery dissection
Maturation trajectories of cortical resting-state networks depend on the mediating frequency band
The functional significance of resting state networks and their abnormal manifestations in psychiatric disorders are firmly established, as is the importance of the cortical rhythms in mediating these networks. Resting state networks are known to undergo substantial reorganization from childhood to adulthood, but whether distinct cortical rhythms, which are generated by separable neural mechanisms and are often manifested abnormally in psychiatric conditions, mediate maturation differentially, remains unknown. Using magnetoencephalography (MEG) to map frequency band specific maturation of resting state networks from age 7 to 29 in 162 participants (31 independent), we found significant changes with age in networks mediated by the beta (13–30 Hz) and gamma (31–80 Hz) bands. More specifically, gamma band mediated networks followed an expected asymptotic trajectory, but beta band mediated networks followed a linear trajectory. Network integration increased with age in gamma band mediated networks, while local segregation increased with age in beta band mediated networks. Spatially, the hubs that changed in importance with age in the beta band mediated networks had relatively little overlap with those that showed the greatest changes in the gamma band mediated networks. These findings are relevant for our understanding of the neural mechanisms of cortical maturation, in both typical and atypical development.This work was supported by grants from the Nancy Lurie Marks Family Foundation (TK, SK, MGK), Autism Speaks (TK), The Simons Foundation (SFARI 239395, TK), The National Institute of Child Health and Development (R01HD073254, TK), National Institute for Biomedical Imaging and Bioengineering (P41EB015896, 5R01EB009048, MSH), and the Cognitive Rhythms Collaborative: A Discovery Network (NFS 1042134, MSH). (Nancy Lurie Marks Family Foundation; Autism Speaks; SFARI 239395 - Simons Foundation; R01HD073254 - National Institute of Child Health and Development; P41EB015896 - National Institute for Biomedical Imaging and Bioengineering; 5R01EB009048 - National Institute for Biomedical Imaging and Bioengineering; NFS 1042134 - Cognitive Rhythms Collaborative: A Discovery Network
A Longitudinal Study of the Reliability of Acupuncture Deqi Sensations in Knee Osteoarthritis
Deqi is one of the core concepts in acupuncture theory and encompasses a range of sensations. In this study, we used the MGH Acupuncture Sensation Scale (MASS) to measure and assess the reliability of the sensations evoked by acupuncture needle stimulation in a longitudinal clinical trial on knee osteoarthritis (OA) patients. The Knee injury and Osteoarthritis Outcome Score (KOOS) was used as the clinical outcome. Thirty OA patients were randomized into one of three groups (high dose, low dose, and sham acupuncture) for 4 weeks. We found that, compared with sham acupuncture, real acupuncture (combining high and low doses) produced significant improvement in knee pain (P = .025) and function in sport (P = .049). Intraclass correlation analysis showed that patients reliably rated 11 of the 12 acupuncture sensations listed on the MASS and that heaviness was rated most consistently. Overall perceived sensation (MASS Index) (P = .014), ratings of soreness (P = .002), and aching (P = .002) differed significantly across acupuncture groups. Compared to sham acupuncture, real acupuncture reliably evoked stronger deqi sensations and led to better clinical outcomes when measured in a chronic pain population. Our findings highlight the MASS as a useful tool for measuring deqi in acupuncture research
The EVerT2 (Effective Verruca Treatments) trial : a randomised controlled trial of needling versus nonsurgical debridement for the treatment of plantar verrucae
Background:
Verrucae are a common foot skin pathology which can in some cases persist for many years. Plantar verrucae can be unsightly and painful. There are a range of treatment options including needling.
Objectives:
The EVerT2 trial aimed to evaluate the clinical and cost effectiveness of the needling procedure for the treatment of plantar verrucae, relative to callus debridement.
Methods:
This single centre randomised controlled trial recruited 60 participants (aged 18 years and over with a plantar verruca). Participants were randomised 1:1 to the intervention group (needling) or the control group (debridement of the overlying callus). The primary outcome was clearance of the index verruca at 12 weeks after randomisation. Secondary outcomes include recurrence of the verruca; clearance of all verrucae; number of verrucae; size of the index verruca; pain; and participant satisfaction at 12 and 24 weeks. A cost-effectiveness analysis was carried out from the NHS perspective over 12 weeks.
Results:
Sixty eligible patients were randomised (needling group n=29, 48.3%; debridement group n=31, 51.7%) and 53 were included in the primary analysis (needling n=28, 96.6%; debridement n=25, 80.7%). Clearance of the index verruca occurred in 8 (15.1%) participants (needling n=4, 14.3%; debridement n=4, 16.0%, p=0.86). The needling intervention costs were on average £14.33 (95% CI 5.32 to 23.35) more per patient than debridement.
Conclusions:
There is no evidence that the needling technique is more clinically or cost effective than callus debridement. The results show a significant improvement in pain outcomes after needling compared to the debridement treatment alone.
Trial registration number: Current Controlled Trials ISRCTN1642944
Reactivity of Gold Hydrides: O2 Insertion into the Au–H Bond
Dioxygen reacts with the gold(I) hydride (IPr)AuH under insertion to give the hydroperoxide, (IPr)AuOOH, a long-postulated reaction in gold catalysis and the first demonstration of O2 activation by Au-H in a well-defined system. Subsequent condensation gave the peroxide (IPr)Au-OO-Au(IPr) (IPr = 1,3-bis(2,6-diisopropylphenyl)imidazole-2-ylidene). The reaction kinetics are reported, as well as the reactivity of Au(I) hydrides with radical scavengers
Living on the edge: Biofilms developing in oscillating environmental conditions
For the first time, the densities and diversity of microorganisms developed on ocean gliders were investigated using flow cytometry and Illumina MiSeq sequencing of 16S and 18S rRNA genes. Ocean gliders are autonomous buoyancy-driven underwater vehicles, equipped with sensors continuously recording physical, chemical, and biological parameters. Microbial biofilms were investigated on unprotected parts of the glider and surfaces coated with base, biocidal and chitosan paints. Biofilms on the glider were exposed to periodical oscillations of salinity, oxygen, temperature, pressure, depth and light, due to periodic ascending and descending of the vehicle. Among the unprotected surfaces, the highest microbial abundance was observed on the bottom of the glider’s body, while the lowest density was recorded on the glider’s nose. Antifouling paints had the lowest densities of microorganisms. Multidimensional analysis showed that the microbial communities formed on unprotected parts of the glider were significantly different from those on biocidal paint and in seawater
Vascular responses of the extremities to transdermal application of vasoactive agents in Caucasian and African descent individuals
This is an accepted manuscript of an article published by Springer in European Journal of Applied Physiology on 04/04/2015, available online: https://doi.org/10.1007/s00421-015-3164-2
The accepted version of the publication may differ from the final published version.© 2015, Springer-Verlag Berlin Heidelberg. Purpose: Individuals of African descent (AFD) are more susceptible to non-freezing cold injury than Caucasians (CAU) which may be due, in part, to differences in the control of skin blood flow. We investigated the skin blood flow responses to transdermal application of vasoactive agents. Methods: Twenty-four young males (12 CAU and 12 AFD) undertook three tests in which iontophoresis was used to apply acetylcholine (ACh 1 w/v %), sodium nitroprusside (SNP 0.01 w/v %) and noradrenaline (NA 0.5 mM) to the skin. The skin sites tested were: volar forearm, non-glabrous finger and toe, and glabrous finger (pad) and toe (pad). Results: In response to SNP on the forearm, AFD had less vasodilatation for a given current application than CAU (P = 0.027–0.004). ACh evoked less vasodilatation in AFD for a given application current in the non-glabrous finger and toe compared with CAU (P = 0.043–0.014) with a lower maximum vasodilatation in the non-glabrous finger (median [interquartile], AFD n = 11, 41[234] %, CAU n = 12, 351[451] %, P = 0.011) and non-glabrous toe (median [interquartile], AFD n = 9, 116[318] %, CAU n = 12, 484[720] %, P = 0.018). ACh and SNP did not elicit vasodilatation in the glabrous skin sites of either group. There were no ethnic differences in response to NA. Conclusion: AFD have an attenuated endothelium-dependent vasodilatation in non-glabrous sites of the fingers and toes compared with CAU. This may contribute to lower skin temperature following cold exposure and the increased risk of cold injuries experienced by AFD.Published versio
Genomic-Bioinformatic Analysis of Transcripts Enriched in the Third-Stage Larva of the Parasitic Nematode Ascaris suum
Differential transcription in Ascaris suum was investigated using a genomic-bioinformatic approach. A cDNA archive enriched for molecules in the infective third-stage larva (L3) of A. suum was constructed by suppressive-subtractive hybridization (SSH), and a subset of cDNAs from 3075 clones subjected to microarray analysis using cDNA probes derived from RNA from different developmental stages of A. suum. The cDNAs (n = 498) shown by microarray analysis to be enriched in the L3 were sequenced and subjected to bioinformatic analyses using a semi-automated pipeline (ESTExplorer). Using gene ontology (GO), 235 of these molecules were assigned to ‘biological process’ (n = 68), ‘cellular component’ (n = 50), or ‘molecular function’ (n = 117). Of the 91 clusters assembled, 56 molecules (61.5%) had homologues/orthologues in the free-living nematodes Caenorhabditis elegans and C. briggsae and/or other organisms, whereas 35 (38.5%) had no significant similarity to any sequences available in current gene databases. Transcripts encoding protein kinases, protein phosphatases (and their precursors), and enolases were abundantly represented in the L3 of A. suum, as were molecules involved in cellular processes, such as ubiquitination and proteasome function, gene transcription, protein–protein interactions, and function. In silico analyses inferred the C. elegans orthologues/homologues (n = 50) to be involved in apoptosis and insulin signaling (2%), ATP synthesis (2%), carbon metabolism (6%), fatty acid biosynthesis (2%), gap junction (2%), glucose metabolism (6%), or porphyrin metabolism (2%), although 34 (68%) of them could not be mapped to a specific metabolic pathway. Small numbers of these 50 molecules were predicted to be secreted (10%), anchored (2%), and/or transmembrane (12%) proteins. Functionally, 17 (34%) of them were predicted to be associated with (non-wild-type) RNAi phenotypes in C. elegans, the majority being embryonic lethality (Emb) (13 types; 58.8%), larval arrest (Lva) (23.5%) and larval lethality (Lvl) (47%). A genetic interaction network was predicted for these 17 C. elegans orthologues, revealing highly significant interactions for nine molecules associated with embryonic and larval development (66.9%), information storage and processing (5.1%), cellular processing and signaling (15.2%), metabolism (6.1%), and unknown function (6.7%). The potential roles of these molecules in development are discussed in relation to the known roles of their homologues/orthologues in C. elegans and some other nematodes. The results of the present study provide a basis for future functional genomic studies to elucidate molecular aspects governing larval developmental processes in A. suum and/or the transition to parasitism
The Immune-related role of BRAF in melanoma
Background: The existence of a dichotomy between immunologically active and quiescent, tumor phenotypes has been recently recognized in several types of cancer. The activation of a Th1 type of immune signature has been shown to confer better prognosis and likelihood to respond to immunotherapy. However, whether such dichotomy depends on the genetic make-up of individual cancers is not known yet. BRAF and NRAS mutations are commonly acquired during melanoma progression. Here we explored the role of BRAF
and NRAS mutations in influencing the immune phenotype based on a classification previously identified by our group.
Methods: One-hundred-thirteen melanoma metastases underwent microarray analysis and
BRAF and NRAS genotyping. Allele-specific PCR was also performed in order to exclude low-frequency mutations.
Results: Comparison between BRAF and NRAS mutant versus wild type samples identified mostly constituents or regulators of MAPK and related pathways. When testing gene lists discriminative of BRAF, NRAS and MAPK alterations, we found that 112 BRAF-specific transcripts were able to distinguish the two immune-related phenotypes already described in melanoma, with the poor phenotype associated mostly with BRAF mutation. Noteworthy, such association was stronger in samples displaying low BRAF mRNA expression. However, when testing NRAS mutations, we were not able to find the same association.
Conclusion: This study suggests that BRAF mutation-related specific transcripts associate
with a poor phenotype in melanoma and provide a nest for further investigation.</br
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