Muros Diafragmas en Edificios de Concreto Reforzado Comportamiento ante Cargas Paralelas y Perpendiculares al Plano.

Durante las últimas cuatro décadas una significativa cantidad de investigaciónes teóricas y experimentales sobre el análisis, diseño y comportamiento de muros diafragmas han sido llevadas a cabo. Sin embargo, relativamente pocas de ellas han considerado la respuesta dinámica de estas estructuras al verse sometidas a movimientos sísmicos paralelos y perpendiculares al plano del muro. Además, el efecto del daño en el muro, debido a cargas previas, sobre la resistencia a cargas perpendiculares a su plano, no ha sido suficientemente estudiado. En este informe se presenta, en primer lugar, un estudio experimental reciente en el cual se llevó a cabo una extensa serie de ensayos dinámicos de mesa vibratoria sobre muros diafragmas, sometidos a movimientos sísmicos paralelos y perpendiculares al plano, realizada por el «U.S. Army Construction Engineering Research Laboratories» (USACERL). Seguidamente, se presentan los resultados de un estudio teórico, llevado a cabo en la Universidad de Texas en Austin, en el cual la respuesta experimental obtenida por USACERL es reproducida analiticamente usando modelos de computador. Además, expresiones simplificadas de diseño existentes, para muros diafragmas sometidos a cargas en su plano, son evaluadas y modificadas de acuerdo con los resultados experimentales y analíticos.  De otra parte, una nueva expresión para la resistencia de los paneles fuera del plano, desarrollada con base en una analogía con la teoría de lineas de fluencia para placas, es evaluada y algunas recomendaciones de diseño son sugeridas. Finalmente, implicaciones para el diseño práctico de muros diafragmas e indicaciones para la investigación futura son presentadas

Antioxidant Potential of Spirulina platensis

The present study aimed to examine the protective role of Spirulina platensis (S. platensis) against arsenic-induced testicular oxidative damage in rats. Arsenic (in the form of NaAsO2 at a dose of 6.3 mg/kg body weight for 8 weeks) caused a significant accumulation of arsenic in testicular tissues as well as a decrease in the levels of testicular superoxide dismutase (SOD), catalase (CAT), reduced glutathione, and zinc. Moreover, it significantly decreased plasma testosterone, luteinizing hormone (LH), triiodothyronine (T3), and thyroxine (T4) levels and reduced sperm motility and sperm count. Arsenic (AS) led to a significant increase in testicular malondialdehyde (MDA), tumour necrosis factor alpha (TNF-α), nitric oxide (NO), and sperm abnormalities. S. platensis at a dose of 300 mg/kg was found to attenuate As-induced oxidative stress, testicular damage, and sperm abnormalities by its potent antioxidant activity. S. platensis may represent a potential therapeutic option to protect the testicular tissue from arsenic intoxication

Role of Goldenberry (Fruits with Husk) Extract in Ameliorating the Architecture and Osmotic Fragility of Red Blood Cells in Obese Rats

Goldenberry (GB) is a promising fruit that can be a constituent in many possible nourishments. No notifications were obtained regarding the impact of exposure to goldenberry extract in the viewpoint of blood rheological properties as well as erythrocyte osmotic fragility of red blood cells (RBCs) in obese rats. A substantial reduction in plasma triglyceride, total cholesterol, and LDL, with a considerable increment in HDL levels relative to the obese group (p≤0.05), was observed in rats receiving low and high doses of GB, accompanied by restoration of SOD activity and GSH levels. Rheological parameters of rats' blood have been studied over a wide range of shear rates (225-1875 s-1). A significant decrease in blood viscosity in rats who received low and high doses of GB extract was compatible with every shear rate compared to the control group. The shear stress values of the obese rats reduced appreciably (p≤0.05) in all values of shear rate (from 75 to 500 s-1) proportional to the control group, while in the groups that received low and high doses of GB extract, shear stress was restored to the control values. Finally, administration of GB extract significantly decreased yield stress and indices of whole blood aggregation, with an extremely substantial increment in flow rate, in rats given low or high doses of GB compared to obese ones. The result also showed a decrease in both the average raised osmotic fragility and the hemolysis rate in rats after supplementation with low and high doses of GB extract

Chemical Profile of Cyperus laevigatus and Its Protective Effects against Thioacetamide-Induced Hepatorenal Toxicity in Rats

Cyperus species represent a group of cosmopolitan plants used in folk medicine to treat several diseases. In the current study, the phytochemical profile of Cyperus laevigatus ethanolic extract (CLEE) was assessed using UPLC-QTOF–MS/MS. The protective effect of CLEE at 50 and 100 mg /kg body weight (b.w.) was evaluated on hepatorenal injuries induced by thioacetamide (100 mg/kg) via investigation of the extract’s effects on oxidative stress, inflammatory markers and histopathological changes in the liver and kidney. UPLC-QTOF–MS/MS analysis of CLEE resulted in the identification of 94 compounds, including organic and phenolic acids, flavones, aurones, and fatty acids. CLEE improved the antioxidant status in the liver and kidney, as manifested by enhancement of reduced glutathione (GSH) and coenzyme Q10 (CoQ10), in addition to the reduction in malondialdehyde (MDA), nitric oxide (NO), and 8-hydroxy-2′-deoxyguanosine (8OHdG). Moreover, CLEE positively affected oxidative stress parameters in plasma and thwarted the depletion of hepatorenal ATP content by thioacetamide (TAA). Furthermore, treatment of rats with CLEE alleviated the significant increase in plasma liver enzymes, kidney function parameters, and inflammatory markers. The protective effect of CLEE was confirmed by a histopathological study of the liver and kidney. Our results proposed that CLEE may reduce TAA-hepatorenal toxicity via its antioxidant and anti-inflammatory properties suppressing oxidative stress

Anthocyanin biosynthesis mystery in gerbera cultivars Estelle and Ivory

Flavonoids in our model ornamental plant Gerbera hybrida, consist of three subgroups, flavones, flavonols and anthocyanins. Anthocyanins accumulate in the adaxial surface of petals and give the different cultivars their different color. Both pelargonidin and cyanidin derivatives are found in gerbera, but none of the cultivars contain delphinidin. The acyanic cultivar Ivory is a sport of the pelargonidin containing pink cultivar Estelle, i.e., it originates from an acyanic branch of Estelle. Ivory is apparently a transposon mutant of Estelle, since revertant sectors are regularly observed (Figure 1). In spite of complete loss of anthocyanin pigmentation, all genes encoding enzymes necessary for pelargonidin biosynthesis (PAL, C4H, 4CL, CHS, CHI, F3H, F3’H, DFR, and ANS) are expressed in Ivory at similar levels as in Estelle. We performed a comprehensive flavonoid analysis using UHPLC MS/MS for Estelle and Ivory, collecting samples from whole ray flower petals and from their isolated adaxial epidermi. Except for pelargonidin derivatives, which are present in Estelle but lack nearly completely from Ivory, we found that both cultivars have similar amounts of flavones and flavonoids (mainly apigenin and kaempherol glycosides). We further analyzed the cultivars using RNA sequencing and produced on average 10 million Illumina reads from two developmental stages of Estelle and Ivory petals. Mapping of the reads to an assembly of gerbera Sanger (1), 454 and Illumina reads confirms that all anthocyanidin biosynthesis genes are expressed similarly in the two samples. Surprisingly, none of the assembled contigs show differential expression between these two cultivars. Although dramatically different to the eye, the difference in Estelle and Ivory at transcript level eludes our attempts of analysis. Pelargonidin biosynthesis is intact at least up to the point of dihydrokaempherol synthesis. In reads mapping to transcripts for DFR and ANS we have not observed anomalies that would be indicative of a transposon insertion. None of the glucosyl transferase encoding transcripts are down regulated or anomalous either. However, we do not have biochemical evidence which one of the contigs would encode the gerbera anthocyanidin 3-O-glucosyltransferas

Washington, DC 20001, USA

The value of herd somatic cell counts (SCC) in evaluating mastitis control programmes is pointed out; in conjunction with DHIA measures, a herd SCC programme should enable farmers to maintain SCC at less than 500 000/ml in 90% of cows. High individual cow SCC are discussed as indicators for culling, early drying-off, and milk culture and antibiotics sensitivity testing, but traditional mastitis therapy based only on high SCC is not recommended.