165 research outputs found
On the Lyapunov functional of Leslie-Gower predator-prey models with time-delay and Holling's functional responses
The global stability on the dynamical behavior of the Leslie-Gower predator-prey system with delayed prey specific growth is analyzed by constructing the corresponding Lyapunov functional. Three different types of famous Holling's functional responses are considered in the present study. The sufficient conditions for the global stability analysis of the unique positive equilibrium point are derived accordingly. A numerical example is presented to illustrate the effect of different Holling-Type functional responses on the global stability of the Leislie-Gower predator-prey model
Targeting extracellular DNA to deliver IGF-1 to the injured heart.
There is a great need for the development of therapeutic strategies that can target biomolecules to damaged myocardium. Necrosis of myocardium during a myocardial infarction (MI) is characterized by extracellular release of DNA, which can serve as a potential target for ischemic tissue. Hoechst, a histological stain that binds to double-stranded DNA can be conjugated to a variety of molecules. Insulin-like growth factor-1 (IGF-1), a small protein/polypeptide with a short circulating-half life is cardioprotective following MI but its clinical use is limited by poor delivery, as intra-myocardial injections have poor retention and chronic systemic presence has adverse side effects. Here, we present a novel delivery vehicle for IGF-1, via its conjugation to Hoechst for targeting infarcted tissue. Using a mouse model of ischemia-reperfusion, we demonstrate that intravenous delivery of Hoechst-IGF-1 results in activation of Akt, a downstream target of IGF-1 and protects from cardiac fibrosis and dysfunction following MI
Moderate strength (0.23–0.28 T) static magnetic fields (SMF) modulate signaling and differentiation in human embryonic cells
<p>Abstract</p> <p>Background</p> <p>Compelling evidence exists that magnetic fields modulate living systems. To date, however, rigorous studies have focused on identifying the molecular-level biosensor (e.g., radical ion pairs or membranes) or on the behavior of whole animals leaving a gap in understanding how molecular effects are translated into tissue-wide and organism-level responses. This study begins to bridge this gulf by investigating static magnetic fields (SMF) through global mRNA profiling in human embryonic cells coupled with software analysis to identify the affected signaling pathways.</p> <p>Results</p> <p>Software analysis of gene expression in cells exposed to 0.23–0.28 T SMF showed that nine signaling networks responded to SMF; of these, detailed biochemical validation was performed for the network linked to the inflammatory cytokine IL-6. We found the short-term (<24 h) activation of IL-6 involved the coordinate up-regulation of toll-like receptor-4 (TLR4) with complementary changes to NEU3 and ST3GAL5 that reduced ganglioside GM3 in a manner that augmented the activation of TLR4 and IL-6. Loss of GM3 also provided a plausible mechanism for the attenuation of cellular responses to SMF that occurred over longer exposure periods. Finally, SMF-mediated responses were manifest at the cellular level as morphological changes and biochemical markers indicative of pre-oligodendrocyte differentiation.</p> <p>Conclusion</p> <p>This study provides a framework describing how magnetic exposure is transduced from a plausible molecular biosensor (lipid membranes) to cell-level responses that include differentiation toward neural lineages. In addition, SMF provided a stimulus that uncovered new relationships – that exist even in the absence of magnetic fields – between gangliosides, the time-dependent regulation of IL-6 signaling by these glycosphingolipids, and the fate of embryonic cells.</p
On the Lyapunov functional of Leslie-Gower predator-prey models with time-delay and Holling's functional responses
A novel SEPT12 mutation, T96I, is associated with sperm head and annulus defects
Infertility affects around 8%–12% of reproductive-aged couples and is a major health concern. Both genetic and environmental factors influence male infertility. SEPTIN12 is a crucial testis-specific gene essential for the final differentiation of male germ cells and is strongly linked to male infertility due to numerous detected mutations. The present study identified a novel SEPTIN12T96I mutation that causes male infertility. Immunofluorescence staining and transmission electron microscopy (TEM) analysis of T96I sperm revealed co-localization of SEPT12 and SEPT7 in the obliquely positioned annulus. In addition, the sperm carrying the T96I mutation demonstrated large nuclear vacuoles, irregular swelling, and decondensation of the acrosomal cap. The overexpression of SEPT12 T96I in NT2/D1 cells impaired the formation of SEPT7 filaments, emphasizing the significance of SEPT12 filaments for sperm morphology and function. Our results demonstrate the importance of SEPTIN12T96I in male infertility and offer valuable insights for future detection in infertile men
Low peripheral levels of insulin growth factor-1 are associated with high incidence of delirium among elderly patients: A systematic review and meta-analysis
Introduction Delirium, a serious condition observed in critically ill patients, clinically presents with impaired cognition and consciousness. The relationship between delirium and peripheral levels of insulin growth factor-1 (IGF-1) is unclear. Thus we conducted a meta-analysis to address this issue. Methods Seven major electronic databases were searched from inception until October 2, 2017 to obtain relevant clinical variables to compare the difference in IGF-1 levels between delirious and non-delirious elderly in-patients. A random effects meta-analysis was conducted. Results We studies 10 articles involving 294 delirious patients (mean age 73.0 years) and 604 non-delirious patients (mean age 76.9 years). We found that peripheral levels of IGF-1 in patients with delirium were significantly lower than in those without delirium (Hedges‘ g = −0.209, 95% confidence interval [CI] = −0.393 to −0.026, p = 0.025). Meta-regression analyses found that no variables such as percentage of cognitive impairment, mean age, and female proportion contribute to heterogeneity in terms of the entire population. Conclusions Our data suggests that lower peripheral levels of IGF-1 could be associated with a higher incidence of delirium among elderly patients. Further prospective studies with larger sample sizes are needed to investigate the association between peripheral levels of IGF-1 and delirium
Mortality associated with the use of non-vitamin K antagonist oral anticoagulants in cancer patients:Dabigatran versus rivaroxaban
Abstract Objective This study assesses the mortality outcomes of non‐vitamin K antagonist oral anticoagulants (NOACs) in cancer patients with venous thromboembolism (VTE) and atrial fibrillation (AF). Methods Medical records of cancer patients receiving NOACs for VTE or AF between January 1, 2011, and December 31, 2016, were retrieved from Taiwan's National Health Institute Research Database. NOACs were compared using the inverse probability of treatment weighting (IPTW) method. The primary outcome was cancer‐related death. Secondary outcomes were all‐cause mortality, major bleeding, and gastrointestinal (GI) bleeding. Results Among 202,754 patients who received anticoagulants, 3591 patients (dabigatran: 907; rivaroxaban: 2684) with active cancers were studied. Patients who received dabigatran were associated with lower risks of cancer‐related death at one year (HR = 0.71, 95% CI = 0.54–0.93) and at the end of follow‐ups (HR = 0.79, 95% CI = 0.64–0.98) compared with rivaroxaban. Patients who received dabigatran were also associated with lower risks of all‐cause mortality (HR = 0.81, 95% CI = 0.67–0.97), major bleeding (HR = 0.64, 95% CI = 0.47–0.88), and GI bleeding (HR = 0.57, 95% CI = 0.39–0.84) at the end of follow‐ups compared with rivaroxaban. Conclusion Compared with rivaroxaban, the use of dabigatran may be associated with a lower risk of cancer‐related death and all‐cause mortality
Atomistic nucleation sites of Pt nanoparticles on N-doped carbon nanotubes
[[abstract]]The atomistic nucleation sites of Pt nanoparticles (Pt NPs) on N-doped carbon nanotubes (N-CNTs) were investigated using C and N K-edge and Pt L3-edge X-ray absorption near-edge structure (XANES)/extended X-ray absorption fine structure (EXAFS) spectroscopy. Transmission electron microscopy and XANES/EXAFS results revealed that the self-organized Pt NPs on N-CNTs are uniformly distributed because of the relatively high binding energies of the adsorbed Pt atoms at the imperfect sites. During the atomistic nucleation process of Pt NPs on N-CNTs, stable Pt–C and Pt–N bonds are presumably formed, and charge transfer occurs at the surface/interface of the N-CNTs. The findings in this study were consistent with density functional theory calculations performed using cluster models for the undoped, substitutional-N-doped and pyridine-like-N-doped CNTs.[[journaltype]]國外[[incitationindex]]SCI[[booktype]]紙本[[countrycodes]]GB
The effectiveness of adjunct mindfulness-based intervention in treatment of bipolar disorder: A systematic review and meta-analysis
BACKGROUND: Mindfulness-based interventions (MBIs) have been increasingly used as an adjunctive treatment to pharmacotherapy for a few psychiatric disorders. However, few studies have investigated the efficacy of MBIs in bipolar disorder (BD). METHODS: We performed a systematic review and meta-analysis to evaluate the efficacy of MBIs as an adjunctive treatment in BD. Major electronic databases were independently searched by two authors for controlled and uncontrolled studies which examined the effects of MBIs on psychiatric symptoms in subjects with BD. Data from original studies were synthesized by using a random effects model. RESULTS: Twelve trials were eligible for inclusion into current meta-analysis, including three controlled studies (n=132) and nine uncontrolled studies (n=142). In within-group analysis, MBIs significantly reduced depressive (7 studies, n=100, Hedges' g=0.58, p<0.001) and anxiety (4 studies, n=68, Hedges' g=0.34, p=0.043) symptoms, but not manic symptoms (6 studies, n=89, Hedges' g=0.09, p=0.488) and cognition (3 studies, n=43, Hedges' g=0.35, p=0.171), compared to baseline. In between-group analysis (intervention group versus waiting list group, all patients with BD), MBIs did not reduce depressive (3 studies, n=132, Hedges' g=0.46, p=0.315) or anxiety (3 studies, n=132, Hedges' g=0.33, p=0.578) symptoms. LIMITATIONS: Only three controlled trials compared MBIs to control conditions. CONCLUSIONS: Our meta-analysis showed significantly beneficial effects on depressive and anxiety symptoms of BD patients in within-group analysis. However, this significance was not observed in comparison with the control groups. Further clinical trials are warranted to investigate the differences in the benefits of MBIs between treatment and control subjects
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