The energy E(G) of a graph G is the sum of the absolute values of the eigenvalues of the adjacency matrix of G. Wong et al. (2018) 11 proved that E(G)≥2ν(G) where ν(G) denotes the matching number of ...G. We settle the equality case that was left open from that paper. We also show that for connected graphs without perfect matching, E(G)≥2ν(G)+1, except for complete bipartite graphs of the form Kr,r+1. Further, for graphs with vertex-disjoint cycles, we prove that E(G)≥2ν(G)+co(G), where co(G) denotes the number of odd cycles of G with length at least 5. This improves another result of Wong et al.
Let
be a simple graph and
be the signless Laplacian matrix of
. Let
be the sum of the
th powers of the nonzero eigenvalues of
. We disprove two conjectures by You and Yang on the extremal values of
...among bipartite graphs and among graphs with bounded connectivity.
Let
G
be an
n
-vertex graph. If
λ
1
,
λ
2
,
…
,
λ
n
and
μ
1
,
μ
2
,
…
,
μ
n
are the ordinary (adjacency) eigenvalues and the Laplacian eigenvalues of
G
, respectively, then the Estrada index and the ...Laplacian Estrada index of
G
are defined as
EE
(
G
)
=
∑
i
=
1
n
e
λ
i
and
LEE
(
G
)
=
∑
i
=
1
n
e
μ
i
, respectively. Some new lower bounds for
EE
and
LEE
are obtained and shown to be the best possible.
Let
be a symmetric matrix, or equivalently, a weighted graph
whose edge ij has the weight
. The eigenvalues of
are the eigenvalues of M. We denote by
the principal submatrix of M obtained by deleting ...from M both the ith row and the ith column. If μ is an eigenvalue of M, and thus of
, of multiplicity
, then vertex i of
is a downer, or a neutral, or a Parter vertex, depending whether the multiplicity of μ in
or, equivalently, in
, is k−1, k, or k+1, respectively. In this paper, for a fixed μ, we consider vertex types according to the above classification in graphs which are generalized lexicographic products of an arbitrary graph over cliques and co-cliques, or connected regular graphs. In addition, we add some comments on constructions of large families of cospectral and integral graphs.
The aim of the present study was to investigate the effect of linagliptin on microalbuminuria in patients with diabetic nephropathy (DN). The present double-blind randomized placebo-controlled ...clinical trial was performed on 92 patients with DN who were divided into two groups. The intervention and control groups received linagliptin 5 mg and placebo for 24 weeks, respectively. Blood pressure, lipid profile, liver enzymes, fasting plasma glucose (FPG), and urine albumin-creatinine ratio (UACR) were assessed and recorded before, 12 weeks, and 24 weeks after the beginning of the intervention. The mean value of UACR decrease was significant over time in both groups, with higher decrease in linagliptin group, however, the differences between two groups were not, statistically significant (P > 0.05). However, the percentage of improvement in microalbuminuria (UACR < 30 mg/g) in the linagliptin group was significantly higher than that of the control group during 24 weeks of intervention (68.3% vs. 25%; P-value < 0.001). There was no statistically significant difference in the mean value of the UACR and other parameters between linagliptin treated and placebo treated patients with diabetic nephropathy. Further studies, with longer periods of follow-up are suggested to examine these patients' renal outcomes.
Background
One of the main causes of diabetic nephropathy is oxidative stress induced by hyperglycemia. Apelin inhibits insulin secretion. Besides, renal expression of TGF-β is increased in diabetes ...mellitus (DM). The preventive effect of quercetin (Q) against renal functional disorders and tissue damage developed by DM in rats was assessed.
Methods
Forty male Wistar rats were grouped into normal control (NC), normal + quercetin (NQ: quercetin, 50 mg/kg/day by gavage), diabetic control (DC: streptozotocin, 65 mg/kg, i.p.), diabetic + quercetin pretreatment (D + Qpre), and diabetic + quercetin post-treatment (D + Qpost). All samples (24-hour urine, plasma, pancreatic, and renal tissues) were obtained at the terminal of the experiment.
Results
Compared to NC and NQ groups, DM ended in elevated plasma and glucose levels, decreased plasma insulin level, kidney dysfunction, augmented levels of malondialdehyde, decreased level of reduced glutathione, reduced enzymatic activities of superoxide dismutase and catalase, elevated gene expression levels of apelin and TGF-β, also renal and pancreatic histological damages. Quercetin administration diminished entire the changes. However, the measure of improvement in the D + Qpre group was higher than that of the D + Qpost group.
Conclusion
Quercetin prevents renal dysfunction induced by DM, which might be related to the diminution of lipid peroxidation, strengthening of antioxidant systems, and prevention of the apelin/ TGF-β signaling pathway.
•Human endometriosis organoids represent attenuated response to progesterone.•Eutopic endometriosis organoids represent hypermethylation for progesterone receptor.•Ectopic endometriosis organoids ...don't show progesterone receptor hypermethylation.
Do human endometriosis organoids recapitulate aberrant progesterone signalling in the disease to serve as advanced experimental models for uncovering epigenetic mechanisms involved in attenuated progesterone response in endometriosis?
Initially, the organoids were established from acquired biopsies (women with and without endometriosis) and characterized by morphological, histological and immunostaining analyses. Results: A panel of endometriosis-related genes showed a pattern of expressions in cytochrome c oxidase subunit II (COX2), matrix metalloproteinase 2 (MMP2), MMP9, tissue inhibitor of metalloproteinase-3 (TIMP3), transforming growth factor beta 1 (TGF-β1), and zinc finger E-box binding homeobox 1 (ZEB1), and a contradictory expression pattern for cadherin (CDH1), POU class 5 homeobox 1 (POU5F1; also known as OCT4), and Nanog homeobox (NANOG) in the endometriosis organoids that is concordant with published research. These endometriosis organoids failed to upregulate 17β-Hydroxysteroid dehydrogenase 2 (17HSDβ2), progestogen associated endometrial protein (PAEP), secreted phosphoprotein 1 (SPP1), and leukaemia inhibitory factor (LIF) in response to progesterone at the level observed in control endometrium organoids. Progesterone receptor B (PRB) gene expression significantly decreased in both eutopic and ectopic organoids compared with control endometrium organoids. DNA hypermethylation, as an epigenetic mechanism for suppression of transcription, was detected at the PRB promoter in the eutopic, but not ectopic, organoids. Therefore, other epigenetic mechanisms, such as histone modifications and microRNAs, may be responsible for PRB downregulation in ectopic organoids.
Endometriosis organoids are powerful preclinical models that can be used to investigate the molecular mechanisms involved in endometriosis-associated progesterone resistance.
This study was designed to evaluate the incidence of uterine pathologies in infertile women with a history of two implantation failures after in vitro fertilization (IVF) and estimate the effect of ...hysteroscopic correction on achieving a pregnancy in these patients.
The retrospective study population included 238 infertile women attended the outpatient infertility clinic between November 2007 and December 2008. Patients with at least two previous IVF failures were eligible for this study. All patients had normal findings on hysterosalpingography performed prior their first attempt for IVF. Standard transvaginal ultrasonography and diagnostic hysteroscopy were performed in patients before the subsequent IVF attempt.
Out of 238 patients with previous IVF failure who underwent hysteroscopic evaluation, 158 patients (66.4%) showed normal uterine cavity. Abnormal cavity was found in 80 patients (33.6%). We found polyp as the most common abnormality (19.7%) in the patients with previous history of IVF failure. The pregnancy rate was similar between IVF failure patients who treated by hysteroscopy for a detected uterine abnormality (24.6%) and similar patients with normal uterine cavity (21.2%) in hysteroscopic examinations.
The intrauterine lesions diagnosed by hysteroscopy in patients with previous IVF failure ranges from 0.8%-19.7%. Correction of abnormalities such as myoma and polyp showed good outcome, similar to that achieved in patients with a normal hysteroscopy.
Oxidized low density lipoprotein (ox-LDL) is a product of oxidative stress. In this cross-sectional study, we compared the ox-LDL concentrations in diabetic patients with normoalbuminuria (n=28), ...microalbuminuria (n=28), and macroalbuminuria (n=28) with their first degree relatives (n=28) and healthy control people (n=31). They were selected by consecutive patient selection method. The ox-LDL level was assayed using ELISA. We measured blood pressure, lipid profile, fasting plasma glucose (FPG), and HbA1c in all groups. There was no significant difference in ox-LDL concentrations among normoalbuminuric, microalbuminuric, and macroalbuminuric diabetic groups. In diabetic patients with micro- and macroalbuminuria, ox-LDL concentration was higher than their first degree relatives (P=0.04 and P=0.03) and control group (P=0.001 and P=0.03, resp.). In normoalbuminuric diabetic persons, ox-LDL concentration was just higher than that of healthy people (P=0.02). There was no statistically significant difference in ox-LDL levels between normoalbuminuric diabetic patients and their first degree relatives. In conclusion, the presence and progression of albuminuria in diabetic patients are not related to ox-LDL concentration and genetic predisposition influences the plasma OX-LDL level. Larger sample size is needed to confirm this conclusion in future studies.
Coexistence of a viable fetus with a hydatidiform mole is a rare condition and the diagnosis is very important because of the risk of developing severe complications in pregnancy. The management of ...these pregnancies is optional, although accurate and great care is required to find early signs of maternal or fetal complications.Hereby we report a case of dizygotic twin pregnancy with a complete mole and coexisting fetus that resulted in a live neonate.
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