Salinity induced anatomical and morphological changes in <i>Chloris gayana</i> Kunth roots

Chloris gayana Kunth is a grass species valuable as forage which was introduced into Argentina to be used as pasture in saline soils of subtropical and warm-temperate zones, given its good adaptability to drought, salinity and mild freezing. However, its tolerance varies according to the cultivar. In tetraploid cultivars, important reductions in yield have been observed. Here, a study of the variations produced on the root and stem system by salinity at different NaCl concentrations (0, 150 y 250 mM) was performed in the Boma cultivar, with the aim of determining the anatomical and morphological alterations produced by the salt excess. Plants cultivated with the highest level of salinity showed, in the whole, significant differences in the measured variables. A diminution in absolute values of the variables and a major reduction in vascular tissue dimensions were observed, which suggests that the lack of tolerance to salt stress could be related to a deficient adaptation to absorb and transport water and nutrients from the roots.     

Applications of Variance Reduction Techniques in Construction Simulation

A technique that can be used to reduce the variance of a stochastic simulation output is reviewed. This technique allows the user to reduce the number of simulation runs without sacrificing the level of confidence of the output. This technique entails inducing an artificial correlation between the various runs. The specific technique presented uses common random numbers (CRN). The use of CRN can be applied to the comparison of alternative systems. Using CRN when comparing alternatives insures that the comparison is properly conducted. A sample simulation is presented in order to illustrate these two applications of CRN.     

KRT4 suppresses oral squamous cell carcinoma development by reducing ATG4B-mediated autophagy

Head and neck squamous cell carcinoma is the sixth most common tumor worldwide, and half of head andneck squamous cell carcinoma patients are with oral squamous cell carcinoma (OSCC). 300,000 new cases of OSCCwere reported annually. Even with multi-modality treatment, the prognosis of OSCC remains unsatisfactory. Thus, itis urgent to discover novel therapeutic targets for OSCC. Some microarray studies have revealed that Keratin 4(KRT4) is downregulated in OSCC, whereas its role in OSCC development remains unknown. The present studyrevealed that KRT4 suppressed OSCC progression by inducing cell apoptosis and inhibiting cell invasion. In addition,KRT4 over-expression inhibited autophagy by blocking the interaction of autophagy-related 4B cysteine peptidase(ATG4B) and microtubule-associated protein 1A/1B light chain 3 (LC3) to regulate apoptosis and invasion of OSCC.In conclusion, KRT4 played an important role in OSCC development through regulating ATG4B-mediated autophagyand may be a novel therapeutic drug target of OSCC.     

Oxidative effects of glyphosate on the lipophobic intracellular environment in the microalgae <i>Chlorella vulgaris</i>

The studied hypothesis is that the herbicide glyphosate (GLY) can affect the oxidative balance in the hydrophobic intracellular medium in non-target Chlorella vulgaris cells. Analytical GLY and RoundUp (RUP) supplementation, affected the growth profile. A significant 42% decrease in the cellular biomass in stationary (St) phase was observed in cultures supplemented with either 5 µM of GLY or RUP, as compared to control cultures. The treatment with 0.3 µM of GLY generated non-significant effects on the oxidation rate of 2’, 7’ dichlorofluorescein diacetate (DCFH-DA), neither in exponential (Exp) nor in St phase of development, as compared to control cultures. However, the treatment with either 5 µM GLY or 0.3 and 5 µM RUP lead to a significant decrease in the DCFH-DA oxidation rate, as compared to control cultures. The lipid radical (LR^●) generation rate, detected by Paramagnetic Resonance Spectroscopy (EPR), was significantly increased in the presence of RUP, in Lag and Exp phase of growth. The non-enzymatic antioxidants, α-Tocopherol (α-T) and β-Carotene (β-C), are aimed to protect membranes against the damage produced by the radical reactions. The content of β-C was not significantly affected, as compared to control cultures, by any of the treatments, in both growth phases of cellular development. The content of α-T was significantly decreased by the supplementation with either 0.3 or 5 µM of RUP or 5 µM GLY. The LR^●/α-T ratio, used as indicator of the oxidative balance in the hydrophobic cellular media, was significantly different between samples obtained from control and RUP-exposed microalgae in both, Exp and St phase of development, with either 0.3 or 5 μM RUP. The data presented here showed evidence that suggested that oxidative balance in the hydrophobic environment was affected by either GLY or RUP.

     

Biomedical overview of melanin. 2. Updating molecular modeling,synthesis mechanism,and supramolecular properties regarding melanoma therapy

Melanins represent one of the most ancient and important group of natural macromolecular pigments. They have multiple biological roles in almost all organisms across the Phyla, examples being photoprotection, anti-oxidative action, radical scavenger activity, and heavy metal removal. From the biomedical point of view, melanocytes are involved in the origin of melanoma tumors, and the main therapeutic advances for their treatment have been revised in Part 1 of this review. The chemical structure of eumelanin is a biological concern of great importance, and therefore, exploring theoretical molecular models and synthesis mechanisms will be here described, as well as molecular orbital features and supramolecular organization, which are responsible for the key properties that make these biological pigments so important, and so fascinating. Ultimately, this updated overview is devoted to describe present structural models and physico-chemical characteristics of eumelanin, in order to explain and utilize melanin properties on which new photothermal and ultrasonic protocols for melanoma treatment can be devised and applied.

     

Isolation of epithelial cells,villi and crypts from small intestine of pigeons (<i>Columba livia</i>)

The isolation of viable enterocytes, villi and crypts from the small intestine of a feral bird (Columba livia) is important for performing physiological experiments in ecologically relevant processes of membrane transport. The effectiveness of mechanical disruption, enzymatic digestion and chelating agents were compared. The objectives were to isolate enterocytes, villi and crypts from the small intestine of young pigeons; to evaluate the viability of the isolated intestinal epithelial cells isolated; and to verify the integrity of enterocytes by biochemical features. Enzymatic and mechanical methods yielded both elongated columnar and spherical cells. With the chelating method villi and crypts were obtained. All methods produced a high yield of intestinal epithelial cells with about 50 % viability. Brush border enzymes (sucrase-isomaltase and alkaline phosphatase) activities were high and, as reported in chickens, they did not differ along the intestinal villus-crypt axis. Although the three methods have good viabilities, the enzymatic technique gives the best yield in cell number, while the chelating method provides the highest populations of morphologically distinctive villi and crypts.     

埋地管道夏季泄漏土壤温度场及原油分布数值计算

基于分布式温度光纤传感技术检测管道泄漏机理,研究了埋地管道泄漏传热特点,并采用有限容积法建立了管道泄漏多孔介质流固耦合换热控制方程,针对夏季埋地热油管道不同位置泄漏前后大地温度场的变化及原油在土壤中的分布规律进行数值计算,得出了管道正上/下方穿孔泄露后土壤温度场及原油分布随时间的变化关系.研究表明:夏季泄漏初期管道周围土壤温度场变化剧烈,泄漏位置对土壤温度场分布影响较大,检测管道发生泄漏可以使用分布式温度传感技术.     

THE USE OF OZONATION TO REDUCE THE POTENTIAL FOR FORMING TRIHALOMETHANE COMPOUNDS IN CHLORINATING RESORCINOL,PHLOROGLUCINOL AND 1,3 CYCLOHEXANEDIONE

This study concerns the ozonation of Resorcinol, Phloroglucinol and 1,3 Cyclohexanedione in the presence of bromide ion in a bubble column, prior to chlorination. Preozonation in aqueous solutions reduces the potential for forming chlorinated trihalomethane compounds. At organic concentrations greater than 10^?4?M a short ozonation time increases the potential for forming trihalo compounds. At longer ozonation times the reverse is true. Finally the influence of mass transfer and chemical reaction on the ozone absorption rate have been evaluated following the film theory.     

Examination of camptothecin and 10-hydroxycamptothecin in <i>Camptotheca acuminata</i> plant and cell culture,and the affected yields under several cell culture treatments

Camptothecin and its derivatives are monoterpenoid indole alkaloids exhibiting significant anti-tumor actions. With the aim of improving the production of these pharmaceuticals, the contents of camptothecin and 10-hydroxycamptothecin in different tissues including roots, stems, leaves, young flower buds, opening flowers, fading flowers and seeds from Camptotheca acuminata, were investigated. The young flower buds had the highest alkaloid concentrations (camptothecin, 2.46 mg/g of dry weight; 10- hydroxycamptothecin, 1.41 mg/g of dry weight). Callus showed lower concentrations but it should also be considered as a potential source of these pharmaceuticals. In the present study, the growth rate of Camptotheca acuminata cells in culture did not correlate with contents of camptothecin and 10-hydroxycamptothecin. Alkaloid accumulation by cells under various treatments (heavy metal ions, UV-B), methyl-jasmonate, abscisic acid, salicylic acid and hydrogen peroxide was examined, and the most notable effects appeared in the cells induced by UV-B light (which showed an 11-fold increase in camptothecin concentration) and by salicylic acid (which showed a 25-fold increase in 10-hydroxycamptothecin concentration). These results are significant in the context of the production of both pharmaceuticals.     

Effect of morphological heterogeneity of somatic embryos of Melia azedarach on conversion into plants

Embryogenic cultures were initiated from immature Melia azedarach (Meliaceae) zigotic embryos. Explants were induced on Murashige and Skoog (1962) medium with 4.54 μM thidiazuron or 0.45 μM dichlorophenoxyacetic acid. After 6 weeks of culture on induction medium, somatic embryos were categorized in four morphological classes based on the presence of single or fused embryos and if they remained united or not to the original explant; that were evaluated histologically. The somatic embryos of every category were transferred, in groups or individually, on a 1/4 MS medium. Bipolar embryos, the more typically normal ones, had well defined shoot and root apical meristems and produced single plants; subcultured individually their conversion was 28%, and subcultured in groups the conversion declined to 6.8%. Fused embryos subcultured in groups had only a 2.1% conversion and produced plants with fused stems. None conversion rate in the others classes was associated to poorly developed shoot and root meristematic areas or with their absence. The converted plants were acclimatized and transferred, in a mist, to soil, with an independent of the class 95% survival rate.