9,869 research outputs found
An Exact Renormalization Group analysis of 3-d Well Developed turbulence
We take advantage of peculiar properties of three dimensional incompressible
turbulence to introduce a nonstandard Exact Renormalization Group method. A
Galilean invariance preserving regularizing procedure is utilized and a field
truncation is adopted to test the method. Results are encouraging: the energy
spectrum E(k) in the inertial range scales with exponent -1.666+/- 0.001 and
the Kolmogorov constant C_K, computed for several (realistic) shapes of the
stirring force correlator, agrees with experimental data.Comment: 12 pg, 2figures, LaTex, To be published on Physics Letters
Facile one-pot synthesis of amoxicillin-coated gold nanoparticles and their antimicrobial activity
Nanomaterials have been the object of intense study due to promising applications in a number of different disciplines. In particular, medicine and biology have seen the potential of these novel materials with their nanoscale properties for use in diverse areas such as imaging, sensing and drug vectorisation. Gold nanoparticles (GNPs) are considered a very useful platform to create a valid and efficient drug delivery/carrier system due to their facile and well-studied synthesis, easy surface functionalization and biocompatibility. In the present study, stable antibiotic conjugated GNPs were synthesised by a one-step reaction using a poorly water soluble antibiotic, amoxicillin. Amoxicillin, a member of the penicillin family, reduces the chloroauric acid to form nanoparticles and at the same time coats them to afford the functionalised nanomaterial. A range of techniques including UV-vis spectroscopy, dynamic light scattering (DLS), transmission electron microscopy (TEM) and thermogravimetric analysis (TGA) were used to ascertain the gold/drug molar ratio and the optimum temperature for synthesis of uniform monodisperse particles in the ca. 30-40 nm size range. Amoxicillin-conjugated gold showed an enhancement of antibacterial activity against Escherichia coli compared to the antibiotic alone
Use of a liquid nicotine delivery product to promote smoking cessation
<p>Abstract</p> <p>Background</p> <p>Despite access to various pharmacotherapies and counseling support to aid cessation, smokers typically demonstrate quit rates below 50%. This report describes the results of a Phase 2a study exploring the efficacy of a liquid nicotine delivery system as an aid to smoking cessation assessed after 12 weeks of therapy.</p> <p>Methods</p> <p>A single-arm Phase 2a study was conducted. Community-based smokers (ages 18+ years, smoking at least 10 cigarettes daily for the past year and interested in making a quit attempt) were recruited and completed clinic visits at 2 week intervals over the 12 week study period where carbon monoxide levels were assessed and the Smoke-Break product was rated on taste and overall satisfaction. Participants were provided with a supply of liquid nicotine cigarettes (e.g., Smoke-Break) at each clinic visit. A total of 69 smokers were enrolled and received the intervention product (intention to treat group, ITT) and 52 smokers verified participation (according to protocol group, ATP).</p> <p>Results</p> <p>The cessation rate at 12 weeks after the baseline visit, assessed as the bioverified point prevalence of abstinence, was 71.1% (95% confidence interval [CI] 58.8%-83.5%) in the ATP group and 53.6% (41.8%-65.4%) in the ITT group. Participants rated the liquid nicotine delivery system highly and also expressed general satisfaction. Few adverse events were identified with no serious adverse events.</p> <p>Conclusions</p> <p>These results support the efficacy of the liquid nicotine delivery system in smoking cessation. If this nicotine delivery product proves to be effective in larger trials, it could represent an inexpensive, readily accessible and well-tolerated agent to promote smoking cessation.</p> <p>Trial Registration</p> <p>This trial is registered at clinicaltrials.gov as study NCT00715871.</p
Prognostic relevance of a T-type calcium channels gene signature in solid tumours: A correlation ready for clinical validation
BackgroundT-type calcium channels (TTCCs) mediate calcium influx across the cell membrane. TTCCs regulate numerous physiological processes including cardiac pacemaking and neuronal activity. In addition, they have been implicated in the proliferation, migration and differentiation of tumour tissues. Although the signalling events downstream of TTCC-mediated calcium influx are not fully elucidated, it is clear that variations in the expression of TTCCs promote tumour formation and hinder response to treatment.MethodsWe examined the expression of TTCC genes (all three subtypes; CACNA-1G, CACNA-1H and CACNA-1I) and their prognostic value in three major solid tumours (i.e. gastric, lung and ovarian cancers) via a publicly accessible database.ResultsIn gastric cancer, expression of all the CACNA genes was associated with overall survival (OS) among stage I-IV patients (all pConclusionsAlterations in CACNA gene expression are linked to tumour prognosis. Gastric cancer represents the most promising setting for further evaluation
Future therapeutic targets in rheumatoid arthritis?
Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by persistent joint inflammation. Without adequate treatment, patients with RA will develop joint deformity and progressive functional impairment. With the implementation of treat-to-target strategies and availability of biologic therapies, the outcomes for patients with RA have significantly improved. However, the unmet need in the treatment of RA remains high as some patients do not respond sufficiently to the currently available agents, remission is not always achieved and refractory disease is not uncommon. With better understanding of the pathophysiology of RA, new therapeutic approaches are emerging. Apart from more selective Janus kinase inhibition, there is a great interest in the granulocyte macrophage-colony stimulating factor pathway, Bruton's tyrosine kinase pathway, phosphoinositide-3-kinase pathway, neural stimulation and dendritic cell-based therapeutics. In this review, we will discuss the therapeutic potential of these novel approaches
Long-lived charged Higgs at LHC as a probe of scalar Dark Matter
We study inert charged Higgs boson production and decays at LHC
experiments in the context of constrained scalar dark matter model (CSDMM). In
the CSDMM the inert doublet and singlet scalar's mass spectrum is predicted
from the GUT scale initial conditions via RGE evolution. We compute the cross
sections of processes at the LHC and show that
for light the first one is dominated by top quark mediated 1-loop
diagram with Higgs boson in s-channel. In a significant fraction of the
parameter space are long-lived because their decays to predominantly
singlet scalar dark matter (DM) and next-to-lightest (NL) scalar, are suppressed by the small singlet-doublet mixing
angle and by the moderate mass difference
The experimentally measurable displaced vertex in decays to leptons
and/or jets and missing energy allows one to discover the signal over
the huge background. We propose benchmark points for studies of this
scenario at the LHC. If, however, are short-lived, the subsequent
decays necessarily produce additional
displaced vertices that allow to reconstruct the full decay chain.Comment: 15 pages, 5 figure
Viral Hepatitis and Rapid Diagnostic Test Based Screening for HBsAg in HIV-infected Patients in Rural Tanzania.
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Co-infection with hepatitis B virus (HBV) is highly prevalent in people living with HIV in Sub-Saharan Africa. Screening for HBV surface antigen (HBsAg) before initiation of combination antiretroviral therapy (cART) is recommended. However, it is not part of diagnostic routines in HIV programs in many resource-limited countries although patients could benefit from optimized antiretroviral therapy covering both infections. Screening could be facilitated by rapid diagnostic tests for HBsAg. Operating experience with these point of care devices in HIV-positive patients in Sub-Saharan Africa is largely lacking. We determined the prevalence of HBV and Hepatitis C virus (HCV) infection as well as the diagnostic accuracy of the rapid test device Determine HBsAg in an HIV cohort in rural Tanzania. Prospectively collected blood samples from adult, HIV-1 positive and antiretroviral treatment-naïve patients in the Kilombero and Ulanga antiretroviral cohort (KIULARCO) in rural Tanzania were analyzed at the point of care with Determine HBsAg, a reference HBsAg EIA and an anti-HCV EIA. Samples of 272 patients were included. Median age was 38 years (interquartile range [IQR] 32-47), 169/272 (63%) subjects were females and median CD4+ count was 250 cells/µL (IQR 97-439). HBsAg was detected in 25/272 (9.2%, 95% confidence interval [CI] 6.2-13.0%) subjects. Of these, 7/25 (28%) were positive for HBeAg. Sensitivity of Determine HBsAg was rated at 96% (95% CI 82.8-99.6%) and specificity at 100% (95% CI, 98.9-100%). Antibodies to HCV (anti-HCV) were found in 10/272 (3.7%, 95% CI 2.0-6.4%) of patients. This study reports a high prevalence of HBV in HIV-positive patients in a rural Tanzanian setting. The rapid diagnostic test Determine HBsAg is an accurate assay for screening for HBsAg in HIV-1 infected patients at the point of care and may further help to guide cART in Sub-Saharan Africa
Retinal glycoprotein enrichment by concanavalin a enabled identification of novel membrane autoantigen synaptotagmin-1 in equine recurrent uveitis.
Complete knowledge of autoantigen spectra is crucial for understanding pathomechanisms of autoimmune diseases like equine recurrent uveitis (ERU), a spontaneous model for human autoimmune uveitis. While several ERU autoantigens were identified previously, no membrane protein was found so far. As there is a great overlap between glycoproteins and membrane proteins, the aim of this study was to test whether pre-enrichment of retinal glycoproteins by ConA affinity is an effective tool to detect autoantigen candidates among membrane proteins. In 1D Western blots, the glycoprotein preparation allowed detection of IgG reactions to low abundant proteins in sera of ERU patients. Synaptotagmin-1, a Ca2+-sensing protein in synaptic vesicles, was identified as autoantigen candidate from the pre-enriched glycoprotein fraction by mass spectrometry and was validated as a highly prevalent autoantigen by enzyme-linked immunosorbent assay. Analysis of Syt1 expression in retinas of ERU cases showed a downregulation in the majority of ERU affected retinas to 24%. Results pointed to a dysregulation of retinal neurotransmitter release in ERU. Identification of synaptotagmin-1, the first cell membrane associated autoantigen in this spontaneous autoimmune disease, demonstrated that examination of tissue fractions can lead to the discovery of previously undetected novel autoantigens. Further experiments will address its role in ERU pathology
Response to novel objects and foraging tasks by common marmoset (Callithrix Jacchus) female Pairs
Many studies have shown that environmental enrichment can significantly improve the psychological well-being of captive primates, increasing the occurrence of explorative behavior and thus reducing boredom. The response of primates to enrichment devices may be affected by many factors such as species, sex, age, personality and social context. Environmental enrichment is particularly important for social primates living in unnatural social groupings (i.e. same-sex pairs or singly housed animals), who have very few, or no, benefits from the presence of social companions in addition to all the problems related to captivity (e.g. increased inactivity). This study analyses the effects of enrichment devices (i.e. novel objects and foraging tasks) on the behavior of common marmoset (Callithrix jacchus) female pairs, a species that usually lives in family groups. It aims to determine which aspects of an enrichment device are more likely to elicit explorative behaviors, and how aggressive and stress-related behaviors are affected by its presence. Overall, the marmosets explored foraging tasks significantly longer than novel objects. The type of object, which varied in size, shape and aural responsiveness (i.e. they made a noise when the monkey touched them), did not affect the response of the monkeys, but they explored objects that were placed higher in the enclosure more than those placed lower down.Younger monkeys were more attracted to the enrichment devices than the older ones. Finally, stress-related behavior (i.e. scratching) significantly decreased when the monkeys were presented with the objects; aggressive behavior as unaffected. This study supports the importance of environmental enrichment for captive primates and shows that in marmosets its effectiveness strongly depends upon the height of the device in the enclosure and the presence of hidden food. The findings can be explained ifone considers the foraging behavior of wild common marmosets. Broader applications for the research findings are suggested in relation to enrichment
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