Using Zeolite-Zirconia-Copper Nanocomposites as a New Asphaltene Inhibitor for Improving Permeability Reduction during CO 2 Flooding

Using nanoparticles for adsorbing asphaltene was known as an efficient method among researchers for crude oil upgrading and in this study, Zeolite-zirconia-copper nanocomposites (NCs) has been synthesized and characterized with SEM, XRD, BET, and EDX for asphaltene precipitation inhibition in the static phase and solving asphaltene deposition problems of dynamic CO2 flooding in low permeability carbonate reservoir. CO2-oil IFT tests, isotherm models, natural depletion tests at static phase were performed in the presence of NCs and the results were compared with zeolite nanoparticles. Then, CO2 core flooding tests at dynamic phase were designed in the presence of NCs at obtained static conditions for surveying permeability/porosity reduction in porous media. After adding NCs and zeolite nanoparticles, the 2nd to 1st slope ratio in CO2-oil IFT tests increased from 19.697 % to 20.895 % and 29.851 %, respectively which shows NCs adsorbed more asphaltene in comparison to zeolite nanoparticles which confirmed UV-Vis results. NCs was decreased asphaltene precipitation more than zeolite at same points during natural depletion tests and it was selected for dynamic CO2 tests. After adding NCs, asphaltene depositions which occurs after CO2 injection was decreased and permeability/porosity reduction parameters were improved.

The Playful Role of the Girl in Empedocles’ B100

Empedocles’ B100 contains an analogy between a girl handling a clepsydra and respiration. This article argues that proposals to establish Love (Bollack 1965, Gheerbrant 2017) or Persephone (Rashed 2008) as the girl’s respiratory equivalent are rendered unlikely by differences between their respective causal roles. Rather than her gender, this article emphasises the importance of the girl’s age: Empedocles required a playful child to handle the clepsydra. This child’s play results in the extra phase of submerging the clepsydra while the upper vent is open, which Empedocles needed to form a parallel for the first static phase of respiration.

Identifikasi Isolat Ekstrak Etanol Kulit Batang Rhizophora apiculata Blume dan Rhizophora mucronata Lam Serta Sitotoksisitasnya Terhadap Sel MCF-7 dan T47D

Mangrove plants as traditional medicine have long been used by the society for the therapy of anticancer diseases. So far, the potency of mangrove plants as anticancer has not been studied intensively. The methanol extract of R. mucronata stem bark has cytotoxic activity on myeloma cells. This study aims to determine the isolates of the ethyl acetate fraction of the methanol extract of the stem bark of R. mucronata and R. apiculata, and to examine the potency of cytotoxic activity against MCF-7 and T47D cells. The powder of the stem bark of R. mucronata and R. apiculata were extracted with methanol by maceration, and then the methanol extract was fractionated consecutively using n-hexane, ethyl acetate, and methanol. Ethyl acetate fraction was then purified by column chromatography with a diameter of 2 cm and a height of 30 cm with a static phase in the form of silica gel 60 (0.063-0.2 mm) Merck 7734 and eluent n-hexane:ethyl acetate (6: 4, 5: 5, 6: 4, 7: 3, 8: 2, 9: 1) and n-hexane: methanol (9,5: 0,5) 10 ml each. The eluates that produce the same number and pattern of stains were combined into one isolate. Then the eluate was evaporated at room temperature. Then the purification results of the extract R. mucronata were isolated using preparative TLC with 0.25 mm GF254 silica gel as static phase and n-hexane mobile phase: ethyl acetate (6: 4), while the apiculata extract with n-hexane mobile phase: ethyl acetate (5: 5). The results of the stain separation of the compound were scraped off and separated from the static phase using a solvent. The purity of isolates compound was examined using TLC in the static phase of silica gel GF254 0.25 mm. The qualitative test results of the ethyl acetate fraction of R. apiculata stem bark with an NMR spectrophotometer showed a composition of cis-3- (3,5-dihydroxyphenyl) acrylic acid, while the ethyl acetate fraction of R. mucronata stem bark contained n-hexan-3-ol compounds. The cytotoxicity test of ethanol extract, n-hexane fraction, ethyl acetate fraction and ethanol extract was carried out on MCF-7 and T47D cells using the MTT method. The results proved that the ethanol extract, n-hexane fraction, ethyl acetate fraction and ethanol fraction from the ethanol extract of R. mucronata and R. apiculata stem bark, based on cytotoxic activity, were inactive against MCF-7 and T47D cells.

Detection of poststroke oropharyngeal dysphagia with swallowing screening by ultrasonography

There are currently no standard evaluation tools for poststroke neurogenic oropharyngeal dysphagia. We previously suggested calculating the relative movements of the hyoid bone and larynx by ultrasonography to evaluate swallowing movement. Swallowing movement is altered in neurogenic oropharyngeal dysphagia. Therefore, the present study aimed to verify whether an ultrasonographic evaluation of swallowing movement facilitates the detection of neurogenic oropharyngeal dysphagia. Eighteen healthy male elderly participants (the healthy group) and 18 male stroke patients diagnosed with neurogenic oropharyngeal dysphagia (the dysphagia group) were enrolled. Participants swallowed 5 mL of liquid and water with an adjusted viscosity and the movements of the hyoid bone and larynx were visualized by ultrasonography. The results obtained revealed significant differences in laryngeal duration (static phase), laryngeal displacement (elevation phase), and the hyoid bone–laryngeal motion ratio (HL motion ratio) between the two groups. A multiple regression analysis was performed to adjust for confounding factors, and laryngeal duration (static phase) and the HL motion ratios were identified as factors affecting dysphagia. In the receiver operation characteristic curve of the two variations, the area under the curve for laryngeal duration (static phase) was 0.744 and the cut-off was 0.26 sec with 72.2% sensitivity and 88.9% specificity; the area under the curve for the HL motion ratio was 0.951 and the cut-off was 0.56 with 88.9% sensitivity and 88.9% specificity. Therefore, the objective evaluation of hyoid bone and larynx movements during swallowing by ultrasonography facilitated the detection of neurogenic oropharyngeal dysphagia.