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Outflow and clogging of shape-anisotropic grains in hoppers with small apertures
No full textOutflow of granular material through a small orifice is a fundamental process in many industrial fields,
for example in silo discharge, and in everyday’s life. Most experimental studies of the dynamics have
been performed so far with monodisperse disks in two-dimensional (2D) hoppers or spherical grains in
3D. We investigate this process for shape-anisotropic grains in 3D hoppers and discuss the role of size
and shape parameters on avalanche statistics, clogging states, and mean flow velocities. It is shown that
an increasing aspect ratio of the grains leads to lower flow rates and higher clogging probabilities
compared to spherical grains. On the other hand, the number of grains forming the clog is larger for
elongated grains of comparable volumes, and the long axis of these blocking grains is preferentially
aligned towards the center of the orifice. We find a qualitative transition in the hopper discharge
behavior for aspect ratios larger than E6. At still higher aspect ratios 48–12, the outflowing material
leaves long vertical holes in the hopper that penetrate the complete granular bed. This changes the discharge
characteristics qualitatively
Chemometrics Tools in Detection and Quantitation of the Main Impurities Present in Aspirin/Dipyridamole Extended-Release Capsules
No full text
PARP-1 inhibition alleviates diabetic cardiac complications in experimental animals
No full textCardiovascular complications are the major causes of mortality among diabetic population. Poly(ADP-ribose) polymerase-1 enzyme (PARP-1) is activated by oxidative stress leading to cellular damage. We investigated the implication of PARP-1 in diabetic cardiac complications. Type 2 diabetes was induced in rats by high fructose-high fat diet and low streptozotocin dose. PARP inhibitor 4-aminobenzamide (4-AB) was administered daily for ten weeks after diabetes induction. At the end of study, surface ECG, blood pressure and vascular reactivity were studied. PARP-1 activity, reduced glutathione (GSH) and nitrite contents were assessed in heart muscle. Fasting glucose, fructosamine, insulin, and tumor necrosis factor alpha (TNF-α) levels were measured in serum. Finally, histological examination and collagen deposition detection in rat ventricular and aortic sections were carried out.
Hearts isolated from diabetic animals showed increased PARP-1 enzyme activity compared to control animals while significantly reduced by 4-AB administration. PARP-1 inhibition by 4-AB alleviated cardiac ischemia in diabetic animals as indicated by ECG changes. PARP-1 inhibition also reduced cardiac inflammation in diabetic animals as evidenced by histopathological changes. In addition, 4-AB administration improved the elevated blood pressure and the associated exaggerated vascular contractility, endothelial destruction and vascular inflammation seen in diabetic animals. Moreover, PARP-1 inhibition decreased serum levels of TNF-α and cardiac nitrite but increased cardiac GSH contents in diabetic animals. However, PARP-1 inhibition did not significantly affect the developed hyperglycemia.
Our findings prove that PARP-1 enzyme plays an important role in diabetic cardiac complications through combining inflammation, oxidative stress, and fibrosis mechanisms
Complete field design
No full textOne of the most important and emerging challenges for any petroleum engineer is to improve the evaluation of a reservoir or in another way to describe it with all of its’ parameters and characteristics to find the most efficient applications to improve production, which will help then to increase the profitability of the discovery
Expansion of Mandibular Knife-Edge Ridge and Simultaneous Implant Placement to Retain Overdentures: One-Year Clinical and Radiographic Results of a Prospective Study
No full textPurpose: The aim of this study was to evaluate and compare the clinical and radiographic outcomes of two implants placed in expanded mandibular knife-edge ridge and implants placed in unexpanded ridges to retain overdentures. Materials and methods: Fifteen completely edentulous patients with knife-edge ridges at canine areas of the mandible received two implants using the ridge expansion technique (study group, SG). Expansion was performed using piezoelectric corticotomy, and self-threading expanders. The control group (CG) comprised patients who received two-implant at canine areas without ridge expansion but were all case matched to SG and served as historical cohort. In both groups, mandibular overdentures were connected to the implants with Locator attachments 3 months after implant placement. Clinical (Plaque index; PI, Gingival index; GI, Probing depth; PD, and implant stability; ISQ) and radiographic (Vertical bone loss; VBL) parameters were recorded at time of overdenture insertion (base line, T0), 6 months (T6), and 12 months (T12) after insertion.Results: The cumulative success rates were 100% and 96.4% for CG and SG, respectively, without significant difference between groups. All tested parameters increased significantly with advance of time in both groups. There was no significant difference in PI, GI, PD, and ISQ between groups. However, SG recorded significant higher VBL than CG at T6 and T12.Conclusion: Expansion of mandibular knife edge ridge and simultaneous placement of implants to retain overdentures is associated with clinic and radiographic outcomes comparable to implants placed in unexpanded ridges after 1 year. However, long term randomized controlled trials with sufficient sample size are still needed to ensure the findings of the present study
Botox as an adjunct to lip repositioning for the management of excessive gingival display in the presence of hypermobility of upper lip and vertical maxillary excess
No full textBackground: Excessive gingival display (GD) is a frequent finding that can occur because of various intraoral or extraoral etiologies. This work describes the use of a mucosal repositioned flap for the management of a gummy smile associated with vertical maxillary excess (VME) and hypermobility of the upper lip followed by injection of Botox. Materials and Methods: Seven female patients in the age range of 17–25 years presented with a gummy smile. At full smile, the average GD ranged from 6 to 8 mm. A clinical examination revealed hypermobility of the upper lip. A cephalometric analysis pointed to the presence of VME. The mucosal repositioned flap surgery was conducted followed by injection with botulinum toxin type A (Botox) 2 weeks postsurgically. Results: After 4 weeks, results were definitely observed with a decrease from 8 mm gingival exposure to 3 mm, which was considered as normal GD for an adult during smiling. Conclusion: For patients desiring a less invasive alternative to orthognathic surgery, the mucosal repositioned flap is a viable alternative. Moreover, Botox is a useful adjunct to enhance the esthetics and improve patient satisfaction where surgery alone may prove inadequately in moderate VME
Nameless Field (Bahariya Formation) Western Desert of Egypt
No full textThis report is talking about evaluation and development of an x-field area on Bahariya 1 formation western desert in Egypt with several drilled wells, The development will occur according to the study of geology and the volumetric estimate, offset data of drilled well in the field, formation evaluation, reservoir engineering, and production engineering. The study and the evaluation on the x-field will give a view of next step of reserve calculation and development plans to start water flooding development based on the interpretation of the given items
Evaluation of Wear and Hardness of Zirconia with Different Surface Treatment Protocols a Systematic Review
No full textThe objective of this systematic review is to assess the wear and hardness of surface treated zirconia. Methods: Two automated databases were investigated till July 2015 with no limits. The scientific terms: “Dental enamel”, “Yttria stabilized tetragonal zirconia”, “Tooth wear”, “Enamel wear”, “Hardness”, “Translucent zirconia’ and “Dental restoration wear” were used in this study. Initially screening was performed for the retrieved articles through title and abstract after that, full-text assessment was done to those articles that fulfilled the inclusion criteria. Findings: Sixty-nine potentially eligible studies were retrieved from the data base search; after duplicate removal the studies became sixty-three. Full-text assessment was performed for all titles and abstracts that met the inclusion criteria. Finally, seventeen studies met the inclusion criteria, and so their references were also screened. Applications/Improvements: Although studies applied different wear testing methodologies; wear testing devices, number of cycles, magnitude of force, number of samples, sample preparation for zirconia and enamel antagonist surface, as well as hardness measurement protocol, full con- toured polished zirconia and human enamel (as antagonist) showed high resistance to wear. It was also concluded that zirconia showed high hardness as a surface property. It is recommended to polish the surface of restorations made of full-contour zirconia because this polishing favours the surface properties (wear and hardness) to opposing ename
A Novel Method for Preparing Surface-Modified Fluocinolone Acetonide Loaded PLGA Nanoparticles for Ocular Use: In Vitro and In Vivo Evaluations
No full textOur objective was to prepare nanoparticulate system using a simple yet attractive innovated method as an ophthalmic delivery system for fluocinolone acetonide to improve its ocular bioavailability. Poly(lactic-co-glycolic acid) (PLGA) nanoparticles were prepared by adopting thin film hydration method using PLGA/poloxamer 407 in weight ratios of 1:5 and 1:10. PLGA was used in 75/25 and 50/50 copolymer molar ratio of DL-lactide/glycolide. Results revealed that using PLGA with lower glycolic acid monomer ratio exhibited high particle size (PS), zeta potential (ZP) and drug encapsulation efficiency (EE) values with slow drug release pattern. Also, doubling the drug concentration during nanoparticles preparation ameliorated its EE to reach almost 100%. Furthermore, studies for separating the un-entrapped drug in nanoparticles using centrifugation method at 20,000 rpm for 30 min showed that the separated clear supernatant contained nanoparticles encapsulating an important drug amount. Therefore, separation of un-entrapped drug was carried out by filtrating the preparation using 20-25 μm pore size filter paper to avoid drug loss. Aiming to increase the PLGA nanoparticles mucoadhesion ability, surface modification of selected formulation was done using different amount of stearylamine and chitosan HCl. Nanoparticles coated with 0.1% w/v chitosan HCl attained most suitable results of PS, ZP and EE values as well as high drug release properties. Transmission electron microphotographs illustrated the deposition of chitosan molecules on the nanoparticles surfaces. Pharmacokinetic studies on Albino rabbit's eyes using HPLC indicated that the prepared novel chitosan-coated PLGA nanoparticles subjected to separation by filtration showed rapid and extended drug delivery to the eye