121 research outputs found
Persistence and stability properties of powers of ideals
We introduce the concept of strong persistence and show that it implies
persistence regarding the associated prime ideals of the powers of an ideal. We
also show that strong persistence is equivalent to a condition on power of
ideals studied by Ratliff. Furthermore, we give an upper bound for the depth of
powers of monomial ideals in terms of their linear relation graph, and apply
this to show that the index of depth stability and the index of stability for
the associated prime ideals of polymatroidal ideals is bounded by their
analytic spread.Comment: 15 pages, 1 figur
Assessment of a novel biomarker panel for the earlier prediction of acute kidney injury in patients with diabetes mellitus undergoing coronary angiography and intervention
PhDDiabetes mellitus triples the risk of developing coronary heart disease (CHD).
The manifestations of CHD are more severe in patients with diabetes with both
more extensive and more diffuse disease. Outcomes in patients with diabetes
are significantly worse both in terms of Major Adverse Cardiovascular Events
(MACE) overall and specifically following revascularisation procedures such as
percutaneous coronary intervention (PCI). Furthermore patients with chronic
kidney disease (CKD) are excluded from the vast majority of cardiology trials and
therefore there is a lack of data for these patients. Contrast induced acute kidney
injury (AKI) is an important complication following procedures in the cardiac
catheterisation laboratory and patients with diabetes are at particular risk.
Patients with diabetes and CKD are a particular challenge. They have an
extremely high incidence of co-morbidities such as CHD and peripheral vascular
disease (PVD). When renal function is already impaired by other pathological
processes, the kidney is much less capable of tolerating the stress of excreting a
contrast load. If AKI develops, there is a risk of further loss of nephron units and
irreversible reduction in residual renal function. Earlier identification of patients
as risk of developing AKI will allow earlier therapeutic intervention which might
translate into improved clinical outcomes for these patients.
The study aimed to evaluate the incidence of contrast induced AKI in a high risk
population (diabetes and CKD) undergoing coronary angiography and PCI.
From a literature review Neutrophil Gelatinase Associated Lipocalin (NGAL) and
Interleukin-18 (IL-18) were identified as promising candidates for inclusion in a
‘renal injury’ biomarker panel for development of AKI early post coronary
angiography or PCI. It was then determined if concentrations of these markers
changed significantly at various time intervals post procedure. The aim was to
establish a panel of markers with the best predictive ability for identifying
development of AKI.
208 patients with a known diagnosis of diabetes mellitus and CKD (eGFR < 60
ml/min) were recruited over a one year period at The London Chest Hospital. 39
patients (18.8%) developed contrast induced AKI. There were no significant
differences between patients who did/did not develop AKI with respect to
baseline demographics, cardiac risk factors and co-morbidities. There was a
significant trend towards patients in the AKI group having a higher NYHA Class
(p=0.048) and this was further supported by echocardiogram and other imaging
data. Additional reinforcement came from the higher rate of loop diuretic
prescription (59% vs 26.9%) in the AKI group, p=0.012.
59 patients underwent renal angiography at the time of their coronary procedure.
There was no association between presence of structural renal disease and
development of AKI. 7 patients (12.5%) had moderate or severe renal artery
stenosis with 1 patient requiring further renal angioplasty due to the presence of
a critical lesion
Regularity of joint-meet ideals of distributive lattices
Let be a distributive lattice and the associated Hibi ring. We
compute \reg R(L) when is a planar lattice and give a lower bound for
\reg R(L) when is non-planar, in terms of the combinatorial data of
As a consequence, we characterize the distributive lattices for which the
associated Hibi ring has a linear resolution
Gr\"obner bases of balanced polyominoes
We introduce balanced polyominoes and show that their ideal of inner minors
is a prime ideal and has a quadratic Gr\"obner basis with respect to any
monomial order, and we show that any row or column convex and any tree-like
polyomino is simple and balanced
Polarization of Koszul cycles with applications to powers of edge ideals of whisker graphs
In this paper, we introduced the polarization of Koszul cycles and use it to
study the depth function of powers of edge ideals of whisker graphs
- …