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Fluid kinetics

Tarek Aboul-Fadl, Soliman S Al-Hamad, Ehab A Fouad
Naproxen (nap) is belonging to Non-steriodal anti-inflammatory drugs (NSAIDs) group of drugs that characterized by their free carboxylic group. The therapeutic activity of nap is usually accompanied by GI untoward side effects. Recently synthesized naproxen amides of some amino acid esters prodrugs to mask the free carboxylic group were reported. Those prodrugs showed a promising colorectal cancer chemopreventive activity. The current study aims to investigate the fate and hydrolysis of the prodrugs kinetically in different pH conditions, simulated gastric and intestinal fluids with pHs of 1...
December 2, 2017: Bioorganic Chemistry
Alberto Leonardi, Laura Penta, Marta Cofini, Lucia Lanciotti, Nicola Principi, Susanna Esposito
Background: Hashimoto thyroiditis (HT) is the most frequent cause of acquired hypothyroidism in paediatrics. HT is usually diagnosed in older children and adolescents, mainly in females and is rare in infants and toddlers with cardiac involvement, including pericardial effusion, that can be found in 10% to 30% of adult HT cases. In this paper, a child with HT and pericardial effusion as the most important sign of HT is described. Case presentation: A four-year-old male child suffering for a few months from recurrent abdominal pain sometimes associated with vomiting underwent an abdominal ultrasound scan outside the hospital...
December 14, 2017: International Journal of Environmental Research and Public Health
Kristoffer E Johansson, Jakob Plum, Majid Mosleh, Cecilie M Madsen, Thomas Rades, Anette Müllertz
The hydrodynamics of a miniaturized dissolution apparatus was characterized using computational fluid dynamics (CFD) simulations and analyzed in relation to the biorelevance and robustness of measurements of drug dissolution and precipitation kinetics from supersaturated drug solutions. The effect of using three different agitator geometries operated at 50, 100, 150 and 200 RPM as well as different positioning of an UV probe in the vessel was systematically evaluated. The CFD simulations were validated using a particle streak velocimetry experiment...
December 9, 2017: Journal of Pharmaceutical Sciences
Mudassar Mumtaz Virk, Erik Reimhult
Hybrid vesicles, comprising blends of amphiphilic block copolymers and phospholipids, have attracted significant attention recently due to their unique combination of chemical and physical properties. We report a method to make unilanellar hybrid vesicles with diameters of 100 nm by mixing polybutadiene-block-poly(ethylene oxide) and phosphocholine lipids using a combination of solvent inversion and sonication. We show that homogeneous hybrid vesicles are formed when one component is a minor fraction. At compositions with balanced mass fractions, separate populations of similarly sized pure liposomes and hybrid vesicles were observed...
December 12, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
Marcel Oliver
This paper revisits the derivation of the Lagrangian averaged Euler (LAE), or Euler-α equations in the light of an intrinsic definition of the averaged flow map as the geodesic mean on the volume-preserving diffeomorphism group. Under the additional assumption that first-order fluctuations are statistically isotropic and transported by the mean flow as a vector field, averaging of the kinetic energy Lagrangian of an ideal fluid yields the LAE Lagrangian. The derivation presented here assumes a Euclidean spatial domain without boundaries...
November 2017: Proceedings. Mathematical, Physical, and Engineering Sciences
Wafaa A Zaghary, Shereen Mowaka, Mostafa A Hassan, Bassam M Ayoub
Multifaceted comparative analytical methods for trelagliptin (TRL) were investigated, applied to ZAFATEK tablets and HPLC-UV was selected for a degradation kinetic study. UPLC-MS/MS (Method I), UPLC-UV (Method II), HPLC-UV (Method III), UHPLC-UV (Method IV) and direct UV (Method V) methods were developed. Methods (I-V) showed satisfactory results using TRL concentration ranges of 50-800 ng/mL, 2.5-80 μg/mL, 5-100 μg/mL, 5-100 μg/mL and 5-50 μg/mL, respectively. Multiple Reaction Monitoring (MRM) of the transition pairs of m/z 358...
December 8, 2017: Scientific Reports
Brendan P Lucey, Terry J Hicks, Jennifer S McLeland, Cristina D Toedebusch, Jill Boyd, Donald L Elbert, Bruce W Patterson, Jack Baty, John C Morris, Vitaliy Ovod, Kwasi G Mawuenyega, Randall J Bateman
Sleep disturbances are associated with future risk of Alzheimer's disease. Disrupted sleep increases soluble amyloid-β, suggesting a mechanism for sleep disturbances to increase Alzheimer's disease risk. We tested this response in humans using indwelling lumbar catheters to serially sample cerebrospinal fluid while participants were sleep-deprived, treated with sodium oxybate, or allowed to sleep normally. All participants were infused with 13 C6 -leucine to measure amyloid-β kinetics. We found that sleep deprivation increased overnight amyloid-β-38, amyloid-β-40, and amyloid-β-42 levels by 25-30% via increased overnight amyloid-β production relative to sleeping controls...
December 8, 2017: Annals of Neurology
Damiano Caprioli, Dennis T Yi, Anatoly Spitkovsky
We study the thermalization, injection, and acceleration of ions with different mass/charge ratios, A/Z, in nonrelativistic collisionless shocks via hybrid (kinetic ions-fluid electrons) simulations. In general, ions thermalize to a postshock temperature proportional to A. When diffusive shock acceleration is efficient, ions develop a nonthermal tail whose extent scales with Z and whose normalization is enhanced as (A/Z)^{2} so that incompletely ionized heavy ions are preferentially accelerated. We discuss how these findings can explain observed heavy-ion enhancements in Galactic cosmic rays...
October 27, 2017: Physical Review Letters
Laetitia Canini, Michio Imamura, Yoshiiku Kawakami, Susan L Uprichard, Scott J Cotler, Harel Dahari, Kazuaki Chayama
BACKGROUND & AIMS: High cure rates are achieved in HCV genotype-1b patients treated with daclatasvir and asunaprevir, DCV/ASV. Here we analyzed early HCV kinetics in genotype-1b infected Japanese subjects treated with DCV/ASV and retrospectively projected, using mathematical modeling, whether shorter treatment durations might be effective. METHODS: HCV RNA levels were measured frequently during DCV/ASV therapy in 95 consecutively treated patients at a single center in Japan...
2017: PloS One
Maria Antonieta Anaya Castro, Isabelle Alric, Fabien Brouillet, Jérôme Peydecastaing, Sophie Girod Fullana, Vanessa Durrieu
The objective of this work was to evaluate soy protein isolate (SPI) and acylated soy protein (SPA) as spray-drying encapsulation carriers for oral pharmaceutical applications. SPI acylation was performed by the Schotten-Baumann reaction. SPA, with an acylation rate of 41%, displayed a decrease in solubility in acidic conditions, whereas its solubility was unaffected by basic conditions. The drug encapsulation capacities of both SPI and SPA were tested with ibuprofen (IBU) as a model poorly soluble drug. IBU-SPI and IBU-SPA particles were obtained by spray-drying under eco-friendly conditions...
December 6, 2017: AAPS PharmSciTech
Vladimir A Andryushchenko, Sergei F Chekmarev
Recently, when studying folding of a SH3 domain, we discovered that the flows of transitions between protein states can be surprisingly similar to turbulent fluid flows. This similarity was not restricted by a vortex pattern of the flow fields but extended to a spatial correlation of flow fluctuations, resulting, in particular, in the structure functions such as in the Kolmogorov theory of homogeneous and isotropic turbulence. Here, we undertake a detailed analysis of spatial distribution of folding flows and their similarity to turbulent fluid flows...
2017: PloS One
Matteo Amabili, Simone Meloni, Alberto Giacomello, Carlo Massimo Casciola
A liquid in contact with a textured surface can be found in two states, Wenzel and Cassie. In the Wenzel state the liquid completely wets the corrugations while in the Cassie state the liquid is suspended over the corrugations with air or vapor trapped below. The superhydrophobic properties of the Cassie state are exploited for self-cleaning, drag reduction, drug delivery etc., while in the Wenzel state most of these properties are lost; it is therefore of great fundamental and technological interest to investigate the kinetics and mechanism of the Cassie-Wenzel transition...
December 4, 2017: Journal of Physical Chemistry. B
Talin Louder, Eadric Bressel, Clint Nardoni, Dennis Dolny
Researchers have observed physical improvements following the completion of aquatic-based jump training. However, there is a lack of research on the biomechanical specificity of aquatic-based movement. Therefore, the purpose of this investigation was to evaluate the kinetics and kinematics of loaded countermovement jumps performed in water versus land. Twenty young males and twenty-four NCAA division I women's soccer and gymnastics athletes were asked to perform unloaded and loaded countermovement jumps on land and in chest-deep water immersion...
November 29, 2017: Journal of Strength and Conditioning Research
Mohammad Banaei, Jeroen Jegers, Martin van Sint Annaland, Johannes A M Kuipers, Niels G Deen
The hydrodynamics and heat transfer of cylindrical gas-solid fluidized beds for polyolefin production was investigated with the two-fluid model (TFM) based on the kinetic theory of granular flow (KTGF). It was found that the fluidized bed becomes more isothermal with increasing superficial gas velocity. This is mainly due to the increase of solids circulation and improvement in gas solid contact. It was also found that the average Nusselt number weakly depends on the gas velocity. The TFM results were qualitatively compared with simulation results of computational fluid dynamics combined with the discrete element model (CFD-DEM)...
August 2, 2017: Industrial & Engineering Chemistry Research
Naohide Shinohara, Guihua Zhang, Yutaka Oshima, Toshio Kobayashi, Nobuya Imatanaka, Makoto Nakai, Takeshi Sasaki, Kenji Kawaguchi, Masashi Gamo
BACKGROUND: The toxicokinetics of nanomaterials are an important factor in toxicity, which may be affected by slow clearance and/or distribution in the body. METHODS: Four types of nickel oxide (NiO) nanoparticles were single-administered intratracheally to male F344 rats at three doses of 0.67-6.0 mg/kg body weight. The rats were sacrificed under anesthesia and the lung, thoracic lymph nodes, bronchoalveolar lavage fluid, liver, and other organs were sampled for Ni burden measurement 3, 28, and 91 days post-administration; Ni excretion was measured 6 and 24 h after administration...
November 28, 2017: Particle and Fibre Toxicology
Nobuyuki Takahashi, Yukinori Take
Tegoprazan, (S)-4-((5,7-difluorochroman-4-yl)oxy)-N,N,2-trimethyl-1H-benzo[d]imidazole-6-carboxamide, a potassium-competitive acid blocker (P-CAB), is a novel potent and highly selective inhibitor of gastric H+/K+-ATPase. Tegoprazan inhibited porcine, canine, and human H+/K+-ATPases in vitro with IC50 values ranging 0.29 ~ 0.52 μM while that for canine kidney Na+/K+-ATPase was more than 100 μM. A kinetic analysis revealed that tegoprazan inhibited H+/K+-ATPase with potassium-competitive manner and the binding was reversible...
November 27, 2017: Journal of Pharmacology and Experimental Therapeutics
Yoon Kyeung Lee, Ki Jun Yu, Yerim Kim, Younghee Yoon, Zhaoqian Xie, Enming Song, Haiwen Luan, Xue Feng, Yonggang Huang, John A Rogers
Flexible electronic systems for bio-implants with long-term (multi-decade) stability and safety in operation require thin, bio-compatible layers that can prevent bio-fluid penetration. Recent work shows that ultrathin films of silicon dioxide thermally grown (TG-SiO2) on device-grade silicon wafers and then released as transferrable barriers offer a remarkable set of attributes in this context. This paper examines the chemical stability of these materials in aqueous solutions with different combinations of chemistries that are present in biofluids...
November 27, 2017: ACS Applied Materials & Interfaces
Mahdiyeh Ebrahimi Rahmani, Mehdi Ansari, Maryam Kazemipour, Mohammadreza Nateghi
The determination of morphine concentration in the blood and urine is necessary for patients and recruitment purposes. Herein, a magnetic molecularly imprinted polymer for selective and efficient extraction of morphine from biological samples was synthesized by using a core-shell method. Fe3 O4 nanoparticles were coated with SiO2 -NH2 . The molecularly imprinted polymer was coated on the Fe3 O4 /SiO2 -NH2 surface by the copolymerization of methacrylic acid and ethylene glycol dimethacrylate in the presence of morphine as the template molecule...
November 27, 2017: Journal of Separation Science
V P Baklaushev, G M Yusubalieva, M S Burenkov, P A Mel'nikov, E A Bozhko, G A Mentyukov, L S Lavrent'eva, M A Sokolov, V P Chekhonin
Permeability of the blood-brain barrier for protein fractions 50-100 kDa (PF50-100) of Cellex Daily preparation labeled with fluorescent tracer FITC and non-conjugated FITC were compared after intranasal administration of the preparations to healthy rats. Fluorimetrical analysis of the serum and cerebrospinal fluid samples showed that Cellex Daily PF50-100-FITC administered intranasally penetrated into the blood and cerebrospinal fluid with maximum accumulation in 2 h after administration and persists in the circulation for 24 h probably due to binding with plasma proteins...
November 27, 2017: Bulletin of Experimental Biology and Medicine
Ji-Yuan Zhang, Xiao-Qian Liu, Li-Xin Yang, Wei-Hong Feng, Zhi-Min Wang, Chun Li
To investigate the stability and degradation kinetics of febrifugine. The results showed that within 24 hours, febrifugine content was decreased by only 1% in mobile phase solvent, but its content was decreased to be 90% of the initial content in the water, methanol, 50% methanol and 10% acetonitrile solution. When the pH value of the solution was between 3 and 7, the retention rate of febrifugine in 24 hours was over 98%, but its content was decreased by about 12% in alkaline solution (pH 9.0). The higher the temperature, the worse the stability of febrifugine...
August 2017: Zhongguo Zhong Yao za Zhi, Zhongguo Zhongyao Zazhi, China Journal of Chinese Materia Medica
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