Segmentation of Bacteria Image Based on Level Set Method

In biology ferment engineering, accurate statistics of the quantity of bacteria is one of the most important subjects. In this paper, the quantity of bacteria which was observed traditionally manuauy can be detected automatically. Image acquisition and processing system is designed to accomplish image preprocessing, image segmentation and statistics of the quantity of bacteria. Segmentation of bacteria images is successfully realized by means of a region-based level set method and then the quantity of bacteria is computed precisely, which plays an important role in optimizing the growth conditions of bacteria.     

Transport and uptake characteristics of a new derivative of berberine(CPU-86017) by human intestinal epithelial cell line: Caco-2

AIM: The characteristics of transepithelial transport and uptake of CPU-86017 {[7-(4-chlorbenzyl)-7,8,13,13α-tetrahydroberberine chloride, CTHB]}, a new antiarrhythmia agent and a new derivative of berberine, were investigated on epithelial cell line (Caco-2) to further understand the absorption mechanism of berberine and its derivatives. METHODS: Caco-2 cell was used. RESULTS: 1) The permeability coefficient from the apical (AP) to basolateral (BL) of CPU-86017 was approximately 5 times higher than that from BL-to-AP transport. The effects of a P-glycoprotein (P-gp) inhibitor-cyclosporin A, some surfactants, and lower pH on the transepithelial transport of CPU-86017 were also observed. Cyclosporine A at 7.5 mg/L had no effect on the transepithelial electrical resistance (TEER); an about 4-fold enhancement on the transepithlial transport of CPU-86017 was observed. Some surfactants (sodium citrate, sodium deoxycholate, and sodium dodecyl sulfate) at 100 μmol/L and low pH (pH=6.0) induced a reversible d     

Puerarin blocks Na~+ current in rat ventricular myocytes

AIM: To study the effect of puerarin (Pue) on Na~+ channel in rat ventricular myocytes. METHODS: Whole-cell patch-clamp technique was applied on isolated cardiomyocytes from rats. RESULTS: Pue inhibited cardiac I_(Na) in a positive rate-dependent and dose-dependent manner, with an IC_(50) of 349 μmol/L. The kinetics of blockage of cardiac sodium channel by Pue resembled the ClassIa/Ic of antiarrhythmic agents. Pue 300 μmol/L did not alter the shape of the I-V curve of I_(Na), but markedly shifted the steady-state inactivation curve of I_(Na) towards more negative potential by 15.9 mV, and postponed the recovery of I_(Na) inactivation state from (21.9±1.6) ms to (54.4±3.4) ms (P<0.01 ). It demonstrated that the steady state of inactivation was affected by Pue significantly. CONCLUSION: Pue protected ventricular myocytes against cardiac damage and arrhythmias by inhibiting recovery from inactivation of cardiac Na~+ channels.     

Preparation and study of the flame retardant properties of C60/PMMA microspheres

In this paper, highly flame retardant C₆₀/PMMA composites were prepared using an in situ polymerization method by introducing fullerene (C₆₀) into polymethyl methacrylate (PMMA) to improve its combustion characteristics. The apparent morphologies of PMMA and C₆₀/PMMA microspheres were observed by scanning electron microscopy (SEM), and the structure was characterized by infrared spectroscopy (FT-IR). The thermal stability and flame retardancy were characterized using a synchronous thermal analyzer, a cone calorimeter and an oxygen index tester. The results show that the maximum initial decomposition temperature of C₆₀/PMMA-2 (prepared using C₆₀ with a concentration of 2 mg mL⁻¹) is 234.89 °C, which is about 59.89 °C higher than that of PMMA, and the thermal stability is the best. The limiting oxygen index of the C₆₀/PMMA-2 composite is 21.8, which is 28.2% higher than that of pure PMMA. In addition, the peak heat release rate (PHRR) of C₆₀/PMMA is reduced by 630.4 kW m⁻² when compared with pure PMMA, which means that the flame retardant property is improved. Meanwhile, the mechanical properties of the PMMA are also improved by adding C₆₀.

In this paper, highly flame retardant C₆₀/PMMA composites were prepared using an in situ polymerization method by introducing fullerene (C₆₀) into polymethyl methacrylate (PMMA) to improve its combustion characteristics.     

绝经后出血妇女性激素水平变化的研究

目的：探讨绝经后出血与性激素的关系。方法：对63例绝经后出的病人进行垂体卵巢性激素水平测定。结果：39例绝经后出血的病人伴有雌二醇（E2）升高,促卵泡素（FSH）,促黄体素（LH）下降,占61．9％,结论：提示绝经后出血与雌激素明显增高有关。     

Isoproterenol disperses distribution of NADPH oxidase,MMP-9, and pPKCε in the heart,which are mitigated by endothelin receptor antagonist CPU0213

Aim： Spatial dispersion of bioactive substances in the myocardium could serve as pathological basis for arrhythmogenesis and cardiac impairment by β-adrenoceptor stimulation. We hypothesized that dispersed NADPH oxidase, protein kinase Cε （PKCε）, early response gene （ERG）, and matrix metalloproteinase 9 （MMP-9） across the heart by isoproterenol （ISO） medication might be mediated by the endothelin （ET） - ROS pathway. We aimed to verify if ISO induced spatially heterogeneous distribution of pPKCε, NAPDH oxidase, MMP-9 and ERG could be mitigated by either an ET receptor antagonist CPU0213 or iNOS inhibitor aminoguanidine. Methods：Rats were treated with ISO （1 mg/kg sc） for 10 days, and drug interventions （mg/kg） either CPU0213 （30 sc） or aminoguanidine （100 ip） were administered on days 8-10. Expression of NADPH oxidase, MMP-9, ERG, and PKCε in the left and right ventricle （LV, RV） and septum （S） were measured separately. Results： Ventricular hypertrophy was found in the LV, S, and RV, in association with dispersed QTc and oxidative stress in ISO-treated rats. mRNA and protein expression of MMP-9, PKCε, NADPH oxidase and ERG in the LV, S, and RV were obviously dispersed, with augmented expression mainly in the LV and S. Dispersed parameters were re-harmonized by either CPU0213, or aminoguanidine. Conclusion： We found at the first time that ISO-induced dispersed distribution of pPKCε, NADPH oxidase, MMP-9, and ERG in the LV, S, and RV of the heart, which were suppressed by either CPU0213 or aminoguanidine. It indicates that the ET-ROS pathway plays a role in the dispersed distribution of bioactive substances following sustained β-receptor stimulation.     

抗生素后效应产生机制与临床合理用药的研究近况

近年来大量的实验证明,大多数抗生素均有其相应的抗生素后效应(post antibiotic effect,PAE)。结合PAE现象制定的用药方案具有重要意义,它既能提高抗菌药物的疗效,又能减少药物费用和药物不良反应。本文综述了各类PAE的产生机制与PAE的意义,以及延长PAE的方法,为抗生素的合理使用提供重要的理论依据。     

基质金属蛋白酶和肿瘤坏死因子释放酶选择性多肽抑制剂HQ1～HQ4对内毒素休克的保护作用的研究

基质金属蛋白酶和肿瘤坏死因子释放酶在内毒素休克中都扮演重要角色。前期研究发现,同时抑制这两种酶的多肽抑制剂可保护内毒素休克小鼠。该研究合成多肽文库,筛选出了对基质金属蛋白酶和肿瘤坏死因子释放酶有选择性抑制活力的多肽抑制剂。在此基础上,建立了体外检测酶活力的模型,并比较了多肽抑制剂HQ 1～HQ4对中性粒细胞颗粒释放物中基质金属蛋白酶-9活力的抑制作用,发现5μmol/L的4种多肽抑制剂对基质金属蛋白酶-9酶活力的抑制率分别是79%,80%,43%和63%。同时建立了内毒素休克模型并考察了几种多肽抑制剂的体内活性,发现注射HQ1和HQ4组小鼠的生存率分别为50%和58.3%,而注射HQ2和HQ3组小鼠生存率仅为16.7%。这些结果证明了在该模型中,抑制基质金属蛋白酶具有更好的保护作用。这些工作使我们对内毒素休克模型的发病机理的认识又深入了一步。     

模式动物线虫的学习与学习抉择行为

线虫因为其简单的体系和对于诸如接触、味道、气味和温度等外界刺激的敏感反映能力,日益成为受人瞩目的研究行为可塑性的模式动物。目前认为,线虫中的学习包括非联想与联想学习两大类,且存在至少6种形式化学趋向性介导的联想学习。同时,三种研究体系已经被开发出来用于学习抉择的研究。本文讨论了线虫中学习与学习抉择的形式、研究模型及其遗传与分子调控机制。