An Improved Bovine Iris Segmentation Method

In order to improve the performance of bovine iris image segmentation, an improved iris image segmentation algorithm is proposed according to the characteristics of bovine iris image. Firstly, based on mathematical morphology and noise suppression template, the inner and outer edges of bovine iris are detected by dynamic contour tracking and least squares fitting ellipse respectively. Then, the annular iris region is normalized. Finally, the normalized iris image is enhanced with adaptive image enhancement method. The experimental results show that the algorithm can effectively segment iris region, it has good performance of speed and accuracy for iris segmentation, and can eliminate the effects of uneven illumination, iris shrinkage and rotation, it promotes iris feature extraction and matching, which has certain reference significance for iris recognition research and meat food safety management of large livestock

Hypoxic stress induces, but cannot sustain trophoblast stem cell differentiation to labyrinthine placenta due to mitochondrial insufficiency

Dysfunctional stem cell differentiation into placental lineages is associated with gestational diseases. Of the differentiated lineages available to trophoblast stem cells (TSC), elevated O2 and mitochondrial function are necessary to placental lineages at the maternal–placental surface and important in the etiology of preeclampsia. TSC lineage imbalance leads to embryonic failure during uterine implantation. Stress at implantation exacerbates stem cell depletion by decreasing proliferation and increasing differentiation. In an implantation site O2 is normally ~ 2%. In culture, exposure to 2% O2 and fibroblast growth factor 4 (FGF4) enabled the highest mouse TSC multipotency and proliferation. In contrast, hypoxic stress (0.5% O2) initiated the most TSC differentiation after 24 h despite exposure to FGF4. However, hypoxic stress supported differentiation poorly after 4–7 days, despite FGF4 removal. At all tested O2 levels, FGF4 maintained Warburg metabolism; mitochondrial inactivity and aerobic glycolysis. However, hypoxic stress suppressed mitochondrial membrane potential and maintained low mitochondrial cytochrome c oxidase (oxidative phosphorylation/OxPhos), and high pyruvate kinase M2 (glycolysis) despite FGF4 removal. Inhibiting OxPhos inhibited optimum differentiation at 20% O2. Moreover, adding differentiation-inducing hyperosmolar stress failed to induce differentiation during hypoxia. Thus, differentiation depended on OxPhos at 20% O2; hypoxic and hyperosmolar stresses did not induce differentiation at 0.5% O2. Hypoxia-limited differentiation and mitochondrial inhibition and activation suggest that differentiation into two lineages of the labyrinthine placenta requires O2 \u3e 0.5–2% and mitochondrial function. Stress-activated protein kinase increases an early lineage and suppresses later lineages in proportion to the deviation from optimal O2 for multipotency, thus it is the first enzyme reported to prioritize differentiation

Application of stimuli-responsive nanomedicines for the treatment of ischemic stroke

Ischemic stroke (IS) refers to local brain tissue necrosis which is caused by impaired blood supply to the carotid artery or vertebrobasilar artery system. As the second leading cause of death in the world, IS has a high incidence and brings a heavy economic burden to all countries and regions because of its high disability rate. In order to effectively treat IS, a large number of drugs have been designed and developed. However, most drugs with good therapeutic effects confirmed in preclinical experiments have not been successfully applied to clinical treatment due to the low accumulation efficiency of drugs in IS areas after systematic administration. As an emerging strategy for the treatment of IS, stimuli-responsive nanomedicines have made great progress by precisely delivering drugs to the local site of IS. By response to the specific signals, stimuli-responsive nanomedicines change their particle size, shape, surface charge or structural integrity, which enables the enhanced drug delivery and controlled drug release within the IS tissue. This breakthrough approach not only enhances therapeutic efficiency but also mitigates the side effects commonly associated with thrombolytic and neuroprotective drugs. This review aims to comprehensively summarize the recent progress of stimuli-responsive nanomedicines for the treatment of IS. Furthermore, prospect is provided to look forward for the better development of this field

Effects of Anacetrapib in Patients with Atherosclerotic Vascular Disease

BACKGROUND: Patients with atherosclerotic vascular disease remain at high risk for cardiovascular events despite effective statin-based treatment of low-density lipoprotein (LDL) cholesterol levels. The inhibition of cholesteryl ester transfer protein (CETP) by anacetrapib reduces LDL cholesterol levels and increases high-density lipoprotein (HDL) cholesterol levels. However, trials of other CETP inhibitors have shown neutral or adverse effects on cardiovascular outcomes. METHODS: We conducted a randomized, double-blind, placebo-controlled trial involving 30,449 adults with atherosclerotic vascular disease who were receiving intensive atorvastatin therapy and who had a mean LDL cholesterol level of 61 mg per deciliter (1.58 mmol per liter), a mean non-HDL cholesterol level of 92 mg per deciliter (2.38 mmol per liter), and a mean HDL cholesterol level of 40 mg per deciliter (1.03 mmol per liter). The patients were assigned to receive either 100 mg of anacetrapib once daily (15,225 patients) or matching placebo (15,224 patients). The primary outcome was the first major coronary event, a composite of coronary death, myocardial infarction, or coronary revascularization. RESULTS: During the median follow-up period of 4.1 years, the primary outcome occurred in significantly fewer patients in the anacetrapib group than in the placebo group (1640 of 15,225 patients [10.8%] vs. 1803 of 15,224 patients [11.8%]; rate ratio, 0.91; 95% confidence interval, 0.85 to 0.97; P=0.004). The relative difference in risk was similar across multiple prespecified subgroups. At the trial midpoint, the mean level of HDL cholesterol was higher by 43 mg per deciliter (1.12 mmol per liter) in the anacetrapib group than in the placebo group (a relative difference of 104%), and the mean level of non-HDL cholesterol was lower by 17 mg per deciliter (0.44 mmol per liter), a relative difference of -18%. There were no significant between-group differences in the risk of death, cancer, or other serious adverse events. CONCLUSIONS: Among patients with atherosclerotic vascular disease who were receiving intensive statin therapy, the use of anacetrapib resulted in a lower incidence of major coronary events than the use of placebo. (Funded by Merck and others; Current Controlled Trials number, ISRCTN48678192 ; ClinicalTrials.gov number, NCT01252953 ; and EudraCT number, 2010-023467-18 .)

Influence of Combustion Modifiers on the Cure Kinetics of Glycidyl Azide Polymer Based Propellant-Evaluated through Rheo-Kinetic Approach

To investigate the influence of combustion modifiers on the curing of glycidyl azide polymer spherical propellants (GAPSPs), the curing process of the GAPSPs was explored using an isothermal rheological measurement method. The parameters of cure kinetics were solved to further establish a kinetic model for the curing reaction of GAPSPs. The results showed that the curing process of GAPSPs under isothermal conditions conformed to the Kamal and LSK (Lu–Shim–Kim) models. The model data indicated significant agreement with the experimental data. The influence of four kinds of combustion performance modifiers on the curing process was explored and the results demonstrated that lead phthalate had a catalytic effect on the curing reaction of GAPSPs, whilst oxides of lead and copper, and copper adipate had no influence on the curing reaction

ADSORPTION OF Ca(II) FROM AQUEOUS SOLUTION ONTO CELLULOSIC FIBERS AND ITS IMPACT ON THE PAPERMAKING PROCESS

Calcium(II) is one of the most common metal ions in papermaking systems. However, the effect of Ca2+ on papermaking processes has not drawn much attention. The adsorption of Ca2+ from aqueous solutions onto bleached Eucalyptus globulus kraft pulp fibers was investigated. Thermodynamic results indicate that the adsorption of Ca2+ onto bleached E. globulus kraft pulp fibers was exothermic, reversible, and spontaneous. The equilibrium data followed Langmuir isotherms. The adsorption basically agrees with the ionic reaction model between carboxyl groups of fibers and Ca2+ in which the molar ratio of carboxyl to Ca2+ is close to 2:1. The binding capacity with carboxyl groups is so strong that the anionic charge of the adsorption sites in fibers can be screened, leading to decreased performance of cationic polyacrylamide for retention and drainage, Alkyl Ketene Dimer (AKD) for sizing, and cationic starch for dry strength. The precipitation effect of Ca2+ with three kinds of dissolved and colloidal substances (sodium rosinate, sodium stearate, sodium oxalate) also was investigated. The results showed that deposits formed by Ca2+ and dissolved and colloidal substances, which could adsorb to the surfaces of fibers, would affect drainage and retention abilities of cationic polyacrylamide

Structure and band gap tuning of transparent (Ba

(Ba1-xSrx)SnO3 (x=0–1) (BSSO) films were epitaxially grown on MgO substrates by pulsed laser deposition. X-ray diffraction, atomic force microcopy, and optical transmittance investigations reveal that the lattice and band structure properties of the BSSO films can be modified significantly by changing the Sr content. With increasing Sr content from 0 to 1 in films, the lattice parameters decrease from 4.123 to 4.037 Å gradually, while the optical band gaps energy increases from 3.50 to 4.27 eV linearly, which was attributed to the octahedral tilting distortion pushing up the minimum of conduction band. This large structure and band gap tuning of BSSO films are promising for desired applications in the thin-film architecture

Theoretical Study on the Dynamic Characteristics of Marine Stern Bearing Considering Cavitation and Bending Deformation Effects of the Shaft

When the ship runs, owing to the superposition of the gravity of the shaft and resistance of water, with the increment in rotational speeds, the shaft will produce different degrees of bending deformation, which immensely reduces the power transmission efficiency. Based on the aforementioned problem, the present study focuses on the influences of bending deformation of the shaft with a cavitation effect on the dynamic characteristics of the stern bearing. The mixed lubrication model with bending deformation and cavitation effect is established. At present, the deflection curve equation is employed, the finite perturbation method is applied to calculate the dynamic coefficient, and the cavitation pressure is determined by the numerical method. According to the analysis, the variation laws of equivalent stiffness and natural frequency are exhibited. It is shown that the equivalent stiffness is more affected by the speeds, especially at low speeds; There is a critical speed between 130 rpm and 150 rpm, which makes the natural frequency strike the maximum value. Finally, the research results provide a theoretical basis for the ships to avoid large vibration during navigation