1,238 research outputs found
The association of barite veins with acid igneous and metamorphic rocks
It was observed that barite veins are invariably associated with acid igneous rocks whether Plutonic or volcanic and certain metamorphic rocks which tend to be acidic in composition. The present investigation tries to explain on chemical basis why does this association occur in nature. The associated acid igneous and metamorphic rocks like granite, granodiorite, porphyrite and gneiss are all characterised by being rich in potash feldspar and biotite, in other words they are feldspar-mica rocks. These two minerals are known to be enriched in the element Ba. Weathering processes release Ba in solution. Once in solution, Ba migrates veinward to regions of sulfate in order to form the well known barite veins. Another mechanism of forming barite veins depends on the fact that there is considerable Ba mobility and enrichment during metasomatism and granitization. This mobility with the presence of free S04 2 " radical will help in formation of barite veins characteristic of granitized zones. Magmatic hydrothermal fluids are shown here to be deprived from any significant amount of Ba. Thus hydrothermal origin usually attributed to many barite veins ought to be replaced by a mechanism based on either of the two mentioned models
Investigation of the Zinc Oxide Nanoparticles Effect on Thyroid and Testosterone Hormones in Male Rats
Exposure to zinc oxide nanoparticles (ZnO NPs) has been increasing steadily, causing more attention being paid to their potential toxicity, including cytotoxicity and genotoxicity. Hence, this study aimed to investigate the effect of ZnO NPs on thyroid hormone triiodothyronine (T3), thyroxine (T4), and thyroid-stimulating hormone (TSH) as well as testosterone hormone in male adult rats. A total of 54 Sprague-Dawley albino adult male rats were divided into nine groups each of six rats, daily treated intraperitoneal with ZnO NPs two different doses (30 and 60) mg/kg in three different periods of time (7, 14, and 28) days, as following: Control groups (Groups 1, 2, and 3): Respectively received intraperitoneal injection with distilled water for 7, 14, and 28 days, experimental groups (Groups 4, 5, and 6): They were rats, respectively, received intraperitoneal dose (60 mg/kg) of ZnO NPs for (7, 14, and 28) days, and group (7, 8, and 9) experimental groups were rats, respectively, received intraperitoneal dose (30 mg/kg) of ZnO NPs for (7, 14, and 28) days. Data showed high significant decrease (P < 0.01) in level of T3, T4, TSH, and level of testosterone also decrease at high and low dose for 7, 14, and 28 days
Genetic variations between two ecotypes of Egyptian clover by inter-simple sequence repeat (ISSR) techniques
The inter-simple sequence repeat (ISSR) markers have been used in order to determine genetic variation and relationship between two clover ecotypes. Ten (10) primers for ISSR were used in this study but only six were successful in generating reproducible and reliable amplicons for different types of the Egyptian clover. The results reveal the polymorphism level by ISSR primers. HB10 ISSR-primer was higher than the rest of the ISSR primers in polymorphic 100%. The Fahl monocut ecotype had 29 present bands, 3 absent bands in total of 32 bands; among those there were two unique bands. The multicut ecotype were given different pattern of bands, Gemmiza1 (21 present and 11 absent), Giza6 (21 present and 11 absent) and Serw1; (23 present and 9 absent). There were three unique bands appearance in the two ecotypes. Fahl was given two with HB11 and HB13; the Serw1 multicut cultivar had one unique bands with HB08. Similarity indices among the four Egyptian clover cultivars based on ISSR analysis was estimated and the highest value appeared between Fahl and Gemmiza1 as well as Giza6 and Serw1 followed by Fahl and Serw1. The lowest similarity value appeared between Gemmiza1 and Serw1 followed by Gemmiza1 and Giza6.Key words: Egyptian clover, molecular marker, Fahl, Gemmiza1, Giza6, Serw1
Exact Traveling Wave Solutions of Nonlinear PDEs in Mathematical Physics Using the Modified Simple Equation Method
In this article, we apply the modified simple equation method to find the exact solutions with parameters of the (1+1)-dimensional nonlinear Burgers-Huxley equation, the (2+1) dimensional cubic nonlinear Klein-Gordon equation and the (2+1)-dimensional nonlinear Kadomtsev- Petviashvili-Benjamin-Bona-Mahony (KP-BBM) equation. The new exact solutions of these three equations are obtained. When these parameters are given special values, the solitary solutions are obtained
FORMULATION AND EVALUATION OF FLURBIPROFEN SUSTAINED RELEASE MATRIX TABLETS USING AN ALTERNATIVE TECHNIQUE AS POTENTIAL ECONOMIC APPROACH
Objective: Development of sustained released tablets of flurbiprofen (FP) using an alternative technique to the traditional method of wet granulation process aiming to lower labor cost of the granulation process and formulating tablets with better characteristics.
Methods: Eight matrix tablets formulae of FP were prepared by the alternative technique. The various characteristics of FP prepared tablets were investigated and comparatively evaluated by FP tablets prepared by the traditional method. The release data was analyzed according to various kinetic equations. The ulcerogenic effects of some FP tablets formulae were evaluated.
Results: FP tablets prepared by the alternative technique displayed the best physical characteristics. All FP prepared tablets displayed good sustained-release patterns. FP tablets prepared by the traditional method showed a progress decrease in drug dissolution by increasing matrix concentration and hence, more matrix agent or multiple granulations was needed which makes granulation process to be difficult and cost. While, FP tablets prepared by the alternative technique displayed dissolution profiles with minimal differences in-between reflecting the low labor cost of granulation process where good sustained patterns could be obtained by a minor of the matrix agent. Histologically, the ulcerogenic effects of FP on the rats were highly reduced by FP tablets prepared by the alternative technique rather than others. The release kinetics of different prepared FP tablets displayed a coupled release pattern between diffusion and dissolution.
Conclusion: This work proved the potential of the alternative technique as an effective economic approach for formulating FP sustained released tablets with better characteristics and low labor cost
Izrada i značajke tankih polikristaliničnih hetero-spojeva n-Cd0.9Zn0.1S/p-CuGa0.3In0.7Se2
CuGa0.3In0.7Se2 polycrystalline thin films were prepared by thermal evaporation under vacuum of about 10-4Pa, with a deposition rate of about 200 nm/min. The selenization of these films at 723 K improves their properties. The activation energy as well as the optical energy gap of the investigated samples decreased with annealing and selenization. Polycrystalline thin film n-Cd0.9Zn0.1S/p-CuGa0.3In0.7Se2 heterojunctions were fabricated and the current density - voltage and capacitance - voltage characteristics of the junction were studied. The heterojunctions were exposed to light, and under illumination of 1000 mWcm-2, the open circuit voltage was 580 mV, the short circuit current density 4.8 mAcm-2, the fill factor 0.682 and the electrical conversion efficiency was 1.898% for cells of active area of 1 cm2.Tanke polikristalinične slojeve CuGa0.3In0.7Se2 pripremali smo naparavanjem u vakuumu oko 10−4 Pa, brzinom polaganja oko 200 nm/min. Seleniranje tih slojeva na 723 K poboljšava im svojstva. Aktivacijska energija i optički energijski procijep smanjuju se opuštanjem i seleniranjem. Pripremali smo i polikristalinične tankoslojne hetero-spojeve n-Cd0.9Zn0.1S/p-CuGa0.3In0.7Se2 i proučavali njihova značajke: gustoća struje – napon i kapacitet – napon. Ćelije ploštine 1 cm2 heterospojeva osvijetlili smo svjetlošću jakosti 1000 mW/cm2 i izmjerili napon otvorenog kruga od 580 mV, gustoću struje kratkog spoja 4.8 mAcm−2 , faktor punjenja 0.682 i učinkovitost pretvorbe 1.898%
Multimodal thrombectomy device for treatment of acute deep venous thrombosis
Deep vein thrombosis (DVT) is a potentially deadly medical condition that is costly to treat and impacts thousands of Americans every year. DVT is characterized by the formation of blood clots within the deep venous system of the body. If a DVT dislodges it can lead to venous thromboembolism (VTE) and pulmonary embolism (PE), both of which can lead to significant morbidity or death. Current treatment options for DVT are limited in both effectiveness and safety, in part because the treatment of the DVT cannot be confined to a defined sequestered treatment zone. We therefore developed and tested a novel thrombectomy device that enables the sequesteration of a DVT to a defined treatment zone during fragmentation and evacuation. We observed that, compared to a predicate thrombectomy device, the sequestered approach reduced distal DVT embolization during ex vivo thrombectomy. The sequestered approach also facilitated isovolumetric infusion and suction that enabled clearance of the sequestered treatment zone without significantly impacting vein wall diameter. Results suggest that our novel device using sequestered therapy holds promise for the treatment of high risk large-volume DVTs
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