THE EFFECT OF THE EXOGENOUS GIBBERELLIC ACID ON TWO SALT STRESSED BARLEY CULTIVARS

An alternative strategy to ameliorate salt stress could be to use exogenous application of plant growth regulators. The present investigation was carried out to study the effect of exogenous application of GA3 on germination, some growth parameters, protein banding pattern, nucleic acids content and some minerals of salt stressed two cultivars of barley. The grains of both cultivars Giza 126 and 123 were individually pre emergence treated with different concentrations of NaCl or mixture of NaCl and GA3 for 7 days. The results of germination percentage revealed that cv. Giza 123 had higher response to the interaction between salinity and GA3 than cv. Giza 126. The morphological characters revealed inhibition in all plant growth parameters by salinity stress and this inhibition was significantly alleviated after treatment with GA3. The protein electrophoresis of seedlings of cv. Giza 123 induced formation of unique newly protein bands including certain units may acting as protein receptors for gibberellins (M.W. 71.41 kDa). In addition, the DNA and RNA content of cv. Giza 123 showed its priority to the interaction between salinity and GA3. Regarding to minerals the data showed that cv. Giza 123 had the ability to discard salts and prevent the accumulation of them in its tissues especially Na+, k+ and Ca+2 elements. cv. Giza 123 seedlings could overcome the inimical effects of salt stress whereas cv. Giza 126 seedlings appeared to have an attenuated potential to do so resulting in an efficient tolerance of cv. Giza 123 seedlings

Experimental investigation of long-term performance of fiber-reinforced epoxy and polyurethane polymer composites

The primary challenge encountered by polymers and their composites when exposed to saline water is their inadequate ability to withstand wear and tear over time. With a potential to replace conventional materials the long-term performance of FRP composites is still a novice area. This manuscript thus, reports an experimental investigation and prediction of the durability of fiber-reinforced polymer composites exposed to seawater at different temperatures. E-glass/epoxy and E-glass/polyurethane samples were exposed to 23 °C, 45 °C and 65 °C seawater for up to 2700 days (90 months). Tensile tests evaluated the mechanical performance of the composite as a function of exposure time, and strength-based technique was used to assess the durability. The experimental results revealed that the tensile strength of E-glass/epoxy composite decreased by 6.3% and 48.9% after 90 months in seawater at 23 and 65 °C, respectively, whereas it declined by 37.6% and 63.6% respectively for E-glass/Polyurethane composite. The prolonged immersion in seawater results in plasticization and swelling in the composite material, which accelerates the fiber/matrix debonding. SEM micrographs indicate fiber/matrix debonding, potholing, fiber pull-out, river line marks, and matrix cracking which showcases deterioration in the tensile properties of both composites

Biodegradable Scaffolds for Gastric Tissue Regeneration

Tissue engineering has been viewed as a valid approach toward the partial or total replacement of defective tissues and organs. Recent advances in nanotechnology have made it possible to develop biocompatible materials at the micro- and nano-scales to be used as scaffolds for cellular growth and regeneration of defective tissues. Gastric mucosal lining is an example of soft tissues that are highly susceptible to damage due to various reasons including cancer or ulcer development. Current therapeutic approaches to these diseases have some limitations. This chapter describes the basis for development of a novel modality combining nanotechnology, stem cells, and tissue engineering for the replacement of defective gastric tissues using synthetic biocompatible scaffolds. These microfibrous scaffolds are seeded with gastric stem cells, which are studied for their proliferation and differentiation into functional gastric mucous cells

Gastrografin in the management of adhesive small bowel obstruction in children: a pilot study

Background/purpose Adhesive small bowel obstruction (ASBO) is a common emergency problem in children with previous abdominal surgery. Management protocols usually start with a conservative approach that may be successful in some cases, whereas in others it will end eventually by laparotomy with its associated morbidity and mortality. Our aim was to assess the role of water-soluble contrast, gastrografin, in the conservative management of ASBO. Patients and methods During the period January 2009 to July 2010, 33 patients with ASBO were presented at the Pediatric Surgery Unit at the Ain Shams University Hospitals. Patients who failed to improve after 48 h of conservative management in the absence of signs of strangulation were subjected to gastrografin administration. Patients were evaluated clinically and radiologically to determine the resolution of the adhesive attack, with estimation of hospital stay time. Results An oral administration of gastrografin successfully completed the conservative management in eight of 12 patients (66.6%), thus avoiding surgery and subsequently reducing hospital stay. Conclusion Gastrografin may have a valuable role in the management of ASBO, whether diagnostic or therapeutic, but a randomized controlled trial is needed to prove its effectiveness in reducing surgical intervention rate and hospital stay time.Keywords: adhesive, bowel obstruction, gastrografi

Thiosemicarbazide as an Inhibitor in the Corrosion of Aluminium & Zinc

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Surface modification of starch based blends using potassium permanganate-nitric acid system and its effect on the adherence and proliferation of osteoblastic-like cells

The surface modification of three starch based polymeric biomaterials, using a KMnO4/NHO3 oxidizing system, and the effect of that modification on the osteoblastic cell adhesion has been investigated. The rationale of this work is as follows—starch based polymers have been proposed for use as tissue engineering scaffolds in several publications. It is known that in biodegradable systems it is quite difficult to have both cell adhesion and proliferation. Starch based polymers have shown to perform better than poly-lactic acid based materials but there is still room for improvement. This particular work is aimed at enhancing cell adhesion and proliferation on the surface of several starch based polymer blends that are being proposed as tissue engineering scaffolds. The surface of the polymeric biomaterials was chemically modified using a KMnO4/HNO3 system. This treatment resulted in more hydrophilic surfaces, which was confirmed by contact angle measurements. The effect of the treatment on the bioactivity of the surface modified biomaterials was also studied. The bioactivity tests, performed in simulated body fluid after biomimetic coating, showed that a dense film of calcium phosphate was formed after 30 days. Finally, human osteoblast-like cells were cultured on unmodified (control) and modified materials in order to observe the effect of the presence of higher numbers of polar groups on the adhesion and proliferation of those cells. Two of the modified polymers presented changes in the adhesion behavior and a significant increase in the proliferation rate kinetics when compared to the unmodified controls.FCT (Portugal) for providing the postdoctoral grant (BPD/8491/2002)

Simultano UV-spektrofotometrijsko određivanje ramiprila, acetilsalicilne kiseline i atorvastatin kalcija u kapsulama primjenom kemometrijskih metoda

In the present work, three different spectrophotometric methods for simultaneous estimation of ramipril, aspirin and atorvastatin calcium in raw materials and in formulations are described. Overlapped data was quantitatively resolved by using chemometric methods, viz. inverse least squares (ILS), principal component regression (PCR) and partial least squares (PLS). Calibrations were constructed using the absorption data matrix corresponding to the concentration data matrix. The linearity range was found to be 1-5, 10-50 and 2-10 µg mL–1 for ramipril, aspirin and atorvastatin calcium, respectively. The absorbance matrix was obtained by measuring the zero-order absorbance in the wavelength range between 210 and 320 nm. A training set design of the concentration data corresponding to the ramipril, aspirin and atorvastatin calcium mixtures was organized statistically to maximize the information content from the spectra and to minimize the error of multivariate calibrations. By applying the respective algorithms for PLS 1, PCR and ILS to the measured spectra of the calibration set, a suitable model was obtained. This model was selected on the basis of RMSECV and RMSEP values. The same was applied to the prediction set and capsule formulation. Mean recoveries of the commercial formulation set together with other figures of merit (calibration sensitivity, selectivity, limit of detection, limit of quantification and analytical sensitivity) were estimated. Validity of the proposed approaches was successfully assessed for analyses of drugs in the various prepared physical mixtures and formulations.U radu su opisane tri različite spektrofotometrijske metode za određivanje ramiprila, acetilsalicilne kiseline i atorvastatin kalcija u sirovinama i formulacijama. Preklapanje podataka kvantitativno je riješeno pomoću kemometrijskih metoda, tj. metodama inverznih najmanjih kvadrata (ILS), regresije glavnog sastojka (PCR) i djelomičnih najmanjih kvadrata (PLS). Kalibracije su postavljene pomoću matrice podataka za apsorpciju koja odgovara matrici pripadajućih koncentracija. Područje linearnosti za ramipril iznosilo je 1–5, za acetilsalicilnu kiselinu 10–50, a za atorvastatin kalcij 2–10 µg mL–1. Matrica s apsorbancijama dobivena je mjerenjem apsorbancije nultog reda na valnim duljinama između 210 i 320 nm. Set podataka za koncentracije ramiprila, acetilsalicilne kiseline i atorvastatin kalcija u smjesi statistički je tako organiziran da osigura maksimalnu količinu informacije u spektrima i minimalizira grešku multivarijantnih kalibracija. Primjenom odgovarajućih algoritama za PLS, PCR i ILS na snimljene spektre kalibracijskog seta dobiven je dobar model, koji je odabran na temelju RMSECV i RMSEP vrijednosti. Isti model je primijenjen i na set s predviđenim vrijednostima i na kapsule sa smjesom ove tri ljekovite tvari. Određena je srednja vrijednost povrata za komercijalnu formulaciju te ostale analitičke izvedbene značajke (kalibracijska osjetljivost, selektivnost, granica dokazivanja, granica određivanja i analitička osjetljivost). Potvrđena je primjenjljivost predloženih metoda u analizama lijekova u fizičkim smjesama i u gotovim ljekovitim oblicima

SN 2009md: Another faint supernova from a low mass progenitor

We present adaptive optics imaging of the core collapse supernova (SN) 2009md, which we use together with archival \emph{Hubble Space Telescope} data to identify a coincident progenitor candidate. We find the progenitor to have an absolute magnitude of $V = -4.63^{+0.3}_{-0.4}$ mag and a colour of $V-I = 2.29^{+0.25}_{-0.39}$ mag, corresponding to a progenitor luminosity of log $L$/L$_{\odot}$ $\sim4.54\pm0.19$ dex. Using the stellar evolution code STARS, we find this to be consistent with a red supergiant progenitor with $M = 8.5_{-1.5}^{+6.5}$ M$_{\odot}$. The photometric and spectroscopic evolution of SN 2009md is similar to that of the class of sub-luminous Type IIP SNe; in this paper we compare the evolution of SN 2009md primarily to that of the sub-luminous SN 2005cs. We estimate the mass of $^{56}$Ni ejected in the explosion to be $(5.4\pm1.3) \times 10^{-3}$ M$_{\odot}$\ from the luminosity on the radioactive tail, which is in agreement with the low $^{56}$Ni masses estimated for other sub-luminous Type IIP SNe. From the lightcurve and spectra, we show the SN explosion had a lower energy and ejecta mass than the normal Type IIP SN 1999em. We discuss problems with stellar evolutionary models, and the discrepancy between low observed progenitor luminosities (log $L$/L$_{\odot}$ $\sim4.3-5$ dex) and model luminosities after the second-dredge-up for stars in this mass range, and consider an enhanced carbon burning rate as a possible solution. In conclusion, SN 2009md is a faint SN arising from the collapse of a progenitor close to the lower mass limit for core-collapse. This is now the third discovery of a low mass progenitor star producing a low energy explosion and low $^{56}$Ni ejected mass, which indicates that such events arise from the lowest end of the mass range that produces a core-collapse supernova (7-8 M$_{\odot}$).Comment: MNRAS accepted, revised version following referee's comment