8,026 research outputs found
Cytokine gene polymorphisms in preterm infants with necrotising enterocolitis: genetic association study
BACKGROUND The inflammatory cytokine cascade is implicated in the pathogenesis of necrotising enterocolitis (NEC). Genetic association studies of cytokine polymorphisms may help to detect molecular mechanisms that are causally related to the disease process. AIM To examine associations between the common genetic variants in candidate inflammatory cytokine genes and NEC in preterm infants. METHODS Multi-centre case-control and genetic association study. DNA samples were collected from 50 preterm infants with NEC and 50 controls matched for gestational age and ethnic group recruited to a multi-centre case-control study. Ten candidate single-nucleotide polymorphisms in cytokines previously associated with infectious or inflammatory diseases were genotyped. The findings were included in random-effects meta-analyses with data from previous genetic association studies. RESULTS All allele distributions were in Hardy-Weinberg equilibrium. None of the studied cytokine polymorphisms was significantly associated with NEC. Four previous genetic association studies of cytokine polymorphisms and NEC in preterm infants were found. Meta-analyses were possible for several single-nucleotide polymorphisms. These increased the precision of the estimates of effect size but did not reveal any significant associations. CONCLUSIONS The available data are not consistent with more than modest associations between these candidate cytokine variant alleles and NEC in preterm infants. Data from future association studies of these polymorphisms may be added to the meta-analyses to obtain more precise estimates of effects sizes.The study was funded by Tenovus (Scotland)
A determination of the weight enumerator of the code of the projective plane of order 5
We determine the weight enumerator of the code of the projective plane of order 5 by hand. The main tools used are a version of Gleason's theorem on the enumerators of self-dual codes and geometric descriptions of codewords of low weight. This paper contains the full details of the companion paper [9] the outlined our results
Ferromagnetic imprinting of spin polarization in a semiconductor
We present a theory of the imprinting of the electron spin coherence and
population in an n-doped semiconductor which forms a junction with a
ferromagnet. The reflection of non-equilibrium semiconductor electrons at the
interface provides a mechanism to manipulate the spin polarization vector. In
the case of unpolarized excitation, this ballistic effect produces spontaneous
electron spin coherence and nuclear polarization in the semiconductor, as
recently observed by time-resolved Faraday rotation experiments. We investigate
the dependence of the spin reflection on the Schottky barrier height and the
doping concentration in the semiconductor and suggest control mechanisms for
possible device applications.Comment: 4 pages with 2 figure
Botulinum toxin: A potential alternative to current treatment of neurogenic and idiopathic urinary incontinence due to detrusor overactivity
Objective: To analyze and report the current data on the treatment of both neurogenic and idiopathic detrusor overactivity with Botulinum toxin.Methods: Literature review using PubâMed and Medline from 1990 until June 30, 2006.Results: Case series of patients with neurogenic detrusor dysfunction (NDD) and idiopathic detrusor overactivity (IDO) range from 15 to 200 patients with follow up from 12 to 36Â weeks postâtreatment. Significant improvements in cystometric bladder capacity, reflex volume at first urge to void, and bladder compliance are seen in nearly all patients. Approximately 50% of NDD patients achieved urinary continence and almost all had improvement in bladder control up to 36Â weeks following treatment. Patients with IDO with urgency alone or with incontinence also had urodynamic as well as symptom improvement. Approximately 75% of patients with IDO and incontinence are dry at 12Â weeks postâtreatment. Urgency disappears on average in two thirds of patients. Quality of life scores also shows significant improvement for all groups.Conclusion: Botulinum toxinâA has emerged as a promising option for the treatment of neurogenic and refractory idiopathic detrusor overactivity. Studies to date have shown that not only is this treatment effective at decreasing urinary symptoms and incontinence, as well as improving potentially dangerous urodynamic measures, but it is also minimally invasive, reversible and safe. Questions over proper dosing and dilution, number of injection sites, and reâinjection rates remain to be answered.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/135676/1/ijgo305.pd
Many-body system with a four-parameter family of point interactions in one dimension
We consider a four-parameter family of point interactions in one dimension.
This family is a generalization of the usual -function potential. We
examine a system consisting of many particles of equal masses that are
interacting pairwise through such a generalized point interaction. We follow
McGuire who obtained exact solutions for the system when the interaction is the
-function potential. We find exact bound states with the four-parameter
family. For the scattering problem, however, we have not been so successful.
This is because, as we point out, the condition of no diffraction that is
crucial in McGuire's method is not satisfied except when the four-parameter
family is essentially reduced to the -function potential.Comment: 8 pages, 4 figure
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