keyword
MENU ▼
Read by QxMD icon Read
search

Rheology

keyword
https://www.readbyqxmd.com/read/28535343/tuning-adsorption-duration-to-control-the-diffusion-of-a-nanoparticle-in-adsorbing-polymers
#1
Xuezheng Cao, Holger Merlitz, Chen-Xu Wu
Controlling the nanoparticle (NP) diffusion in polymers is a prerequisite to obtain polymer nanocomposites (PNCs) with desired dynamical and rheological properties, and to achieve targeted delivery of nanomedicine in biological systems. Here we determinate the suppression mechanism of direct NP-polymer attraction to hamper the NP mobility in adsorbing polymers, and then quantify the dependence of the effective viscosity \eta_{eff} felt by the NP on the adsorption duration \tau_{ads} of polymers on the NP, using scaling theory analysis and molecular dynamics (MD) simulations...
May 23, 2017: Journal of Physical Chemistry Letters
https://www.readbyqxmd.com/read/28535125/preparation-and-characterization-of-adefovir-dipivoxil-stearic-acid-cocrystal-with-enhanced-physicochemical-properties
#2
Jeong-Woong Seo, Kyu-Min Hwang, Sung-Hoon Lee, Dong-Wook Kim, Eun-Seok Park
The objectives of this study were to prepare cocrystal composed of adefovir dipivoxil (AD) and stearic acid (SA) and to investigate the enhanced properties of the cocrystal. The cocrystal was prepared by antisolvent precipitation and characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), X-ray powder diffraction (XRPD), and differential scanning calorimetry (DSC). The enhanced properties were evaluated by dissolution testing, permeability studies, and powder rheology analysis...
May 23, 2017: Pharmaceutical Development and Technology
https://www.readbyqxmd.com/read/28535094/rheological-and-physical-parameters-correlations-in-formulations-with-pinh%C3%A3-o-derivatives-stability-study-building-up-an-analytical-route
#3
Renata Moschini Daudt, Nilo Sergio Medeiros Cardozo, Ligia Damasceno Ferreira Marczak, Irene Clemes Külkamp Guerreiro
This study focuses on the correlations investigation between rheological and physical parameters and how it can contribute to optimize the topical formulations development. A gel and an emulgel containing pinhão derivatives, and their respective controls, were analyzed along six months of storage. A flowchart of analyses was proposed to use in topical formulation development when a benchmark is the goal or when it is necessary to change some raw material. All formulations were stable over the storage time and the formulations containing pinhão starch and coat extract presented similar properties to those of the control formulations...
May 23, 2017: Pharmaceutical Development and Technology
https://www.readbyqxmd.com/read/28534835/emulsion-based-intradermal-delivery-of-melittin-in-rats
#4
Sang Mi Han, Se Gun Kim, Sok Cheon Pak
Bee venom (BV) has long been used as a traditional medicine. The aim of the present study was to formulate a BV emulsion with good rheological properties for dermal application and investigate the effect of formulation on the permeation of melittin through dermatomed rat skin. A formulated emulsion containing 1% (w/v) BV was prepared. The emulsion was compared with distilled water (DW) and 25% (w/v) N-methyl-2-pyrrolidone (NMP) in DW. Permeation of melittin from aqueous solution through the dermatomed murine skin was evaluated using the Franz diffusion cells...
May 19, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/28533551/ionic-liquids-evidence-of-the-viscosity-scale-dependence
#5
Quentin Berrod, Filippo Ferdeghini, Jean-Marc Zanotti, Patrick Judeinstein, Didier Lairez, Victoria García Sakai, Orsolya Czakkel, Peter Fouquet, Doru Constantin
Ionic Liquids (ILs) are a specific class of molecular electrolytes characterized by the total absence of co-solvent. Due to their remarkable chemical and electrochemical stability, they are prime candidates for the development of safe and sustainable energy storage systems. The competition between electrostatic and van der Waals interactions leads to a property original for pure liquids: they self-organize in fluctuating nanometric aggregates. So far, this transient structuration has escaped to direct clear-cut experimental assessment...
May 22, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28533135/enhanced-local-disorder-in-a-clinically-elusive-von-willebrand-factor-provokes-high-affinity-platelet-clumping
#6
Alexander Tischer, Venkata R Machha, Juan P Frontroth, Maria A Brehm, Tobias Obser, Reinhard Schneppenheim, Leland Mayne, S Walter Englander, Matthew Auton
Mutation of the cysteines forming the disulfide loop of the platelet GPIbα adhesive A1 domain of von Willebrand factor causes quantitative VWF deficiencies in the blood and von Willebrand disease. We report two cases of transient severe thrombocytopenia induced by DDAVP-treatment. Cys1272Trp and Cys1458Tyr mutations identified by genetic sequencing implicate an abnormal gain-of-function phenotype, evidenced by thrombocytopenia, that quickly relapses back to normal platelet counts and deficient plasma VWF. Using surface plasmon resonance, analytical rheology, and hydrogen-deuterium exchange mass spectrometry (HXMS), we decipher mechanisms of A1-GPIbα mediated platelet adhesion and resolve dynamic secondary structure elements that regulate the binding pathway...
May 19, 2017: Journal of Molecular Biology
https://www.readbyqxmd.com/read/28532677/predicting-melt-rheology-for-hot-melt-extrusion-by-means-of-a-simple-tg-measurement
#7
Esther S Bochmann, Elgin E Üstüner, Andreas Gryczke, Karl G Wagner
The feasibility of predicting melt rheology by using the glass transition temperature (Tg) of a desired amorphous solid dispersion (ASD) for hot-melt extrusion (HME) and other melt based processes is presented. Three groups of three different active pharmaceutical ingredients (APIs) or plasticizer/copovidone mixtures, with identical glass transition in rheological testing, were used. Their rheological behavior as a function of temperature and frequency were analyzed by means of small amplitude oscillatory shear (SAOS) on an oscillatory rheometer...
May 19, 2017: European Journal of Pharmaceutics and Biopharmaceutics
https://www.readbyqxmd.com/read/28532266/soft-chewable-gelatin-based-pharmaceutical-oral-formulations-a-technical-approach
#8
Morten J Dille, Magnus N Hattrem, Kurt I Draget
OBJECTIVE: Hard tablets and capsules for oral drug delivery cause problems for people experiencing dysphagia. The present work describes the formulation and properties of a gelatin based, self-preserved and soft chewable tablet as an alternative and novel drug delivery format. MATERIALS AND METHODS: Gelatin (8.8-10% in 24.7-29% water) constituted the matrix of the soft, semi-solid tablets. Three different pharmaceuticals (Ibuprofen 10%, Acetaminophen 15%, Meloxicam 1...
May 22, 2017: Pharmaceutical Development and Technology
https://www.readbyqxmd.com/read/28532176/synthesis-of-n-alkylated-chitosan-and-its-interactions-with-blood
#9
Yuchen Huang, Yi Zhang, Longbao Feng, Liumin He, Rui Guo, Wei Xue
When hydrophobically modified chitosan (HM-CHI) comes into contact with red blood cells (RBCs), it can cause agglomeration. This property leads HM-CHI to be a potential agent to form a rapid haemostatic plug to stop bleeding at wound sites. In this study, we investigated the properties of the HM-CHI biopolymer to act as an agent that rapidly clots blood. We have examined the synthesis and structural characteristics of HM-CHI - blood substances using X-ray diffraction, infrared spectroscopy and elemental analysis...
May 22, 2017: Artificial Cells, Nanomedicine, and Biotechnology
https://www.readbyqxmd.com/read/28530832/neutron-reflectometry-of-an-anionic-surfactant-at-the-solid-liquid-interface-under-shear
#10
Rebecca J L Welbourn, Felicity Bartholomew, Philipp Gutfreund, Stuart Matthew Clarke
Neutron reflectometry with in-situ rheology is used to measure the shear response of an adsorbed anionic surfactant (sodium bis(2-ethylhexyl)sulfosuccinate - AOT) at the alumina-water interface. A low surfactant concentration is measured where a single bilayer adsorbs at the interface as well as a higher concentration where a multi-lamellar structure forms. The low concentration structure does not change with the imposed shear (oscillatory or steady). However the lamellar phase shows a loss of structure under both steady and oscillatory shear...
May 22, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/28530586/characterization-of-textural-rheological-thermal-microstructural-and-water-mobility-in-wheat-flour-dough-and-bread-affected-by-trehalose
#11
Bo Peng, Youqian Li, Shiyong Ding, Jun Yang
The study aims to elucidate the effects of trehalose on the mechanical, thermal, and rheological properties of wheat flour dough and water distribution in bread. Texture profile analysis, DSC, farinograph, extensograph, and frequency sweep were applied in dough. The results from SEM revealed that the gluten film became less notable with the presence of trehalose. The kinetics of staling process, low-field (1)H NMR, and water-binding capacity were employed to characterize physicochemical properties of bread...
October 15, 2017: Food Chemistry
https://www.readbyqxmd.com/read/28530539/preparation-optimization-and-physicochemical-characterization-of-aripiprazole-loaded-nano-porous-in-situ-forming-implant
#12
Ashkan Hedayati, Sina Ghafurzadeh Yazdi, Pouya Dehghankelishadi, Nika Bahari Javan, Hamid Akbari, Farid A Dorkoosh
BACKGROUND: Multiple applications of antipsychotic agents are the main obstacle upon treatment of schizophrenia. Due to behavioral abnormalities, low compliance is observed in the most of psychotic patients. Designing of new drug delivery systems to overcome compliance problem seems to be necessary. In situ forming implants are a suitable choice for delivery of antipsychotic agents due to easy administration process and sustained release kinetics. OBJECTIVE: In this study, a novel poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) based nano-porous in situ implant system is developed for delivery of aripiprazole...
May 22, 2017: Pharmaceutical Nanotechnology
https://www.readbyqxmd.com/read/28530145/bioengineered-liposome-scaffold-composites-as-therapeutic-delivery-systems
#13
Claudia Zylberberg, Sandro Matosevic
The therapeutic potential of liposomes can be amplified when combined with biomaterial scaffolds. Such configurations overcome the convergent demands of therapies by enabling enhanced delivery, environmental responsiveness and potency. Liposomes benefit from the increased physical and mechanical strength, favorable rheological properties and natural environment conducive to improved tissue formation that scaffolds provide, while enabling biocompatible delivery of hydrophilic and lipophilic compounds that can be further functionalized to achieve targeted delivery...
June 2017: Therapeutic Delivery
https://www.readbyqxmd.com/read/28529037/diabetes-development-increased-concentrations-of-the-conjugated-bile-acid-taurocholic-acid-in-serum-while-treatment-with-microencapsulated-taurocholic-acid-exerted-no-hypoglycaemic-effects
#14
Sangeetha Mathavan, Momir Mikov, Svetlana Golocorbin-Kon, Hani Al-Salami
CONTEXT: The bile acid taurocholic acid (TCA) is endogenously produced, and has shown formulation-stabilising effects when incorporated into microcapsules containing potential antidiabetic drugs. This study aimed to develop and characterise TCA-microcapsules, and test their antidiabetic effects, in an animal model of Type 1 diabetes (T1D). METHODS: Using the polymer sodium alginate (SA), SA-microcapsules (control) and TCA-microcapsules (test) were prepared, and assessed for morphology, surface composition, chemical and thermal stability, swelling, buoyancy, mechanical, release and rheological properties...
May 18, 2017: European Journal of Pharmaceutical Sciences
https://www.readbyqxmd.com/read/28528851/microstructure-evaluation-of-dermally-applicable-liquid-crystals-as-a-function-of-water-content-and-temperature-can-electron-paramagnetic-resonance-provide-complementary-data
#15
Mirjam Gosenca Matjaž, Janez Mravljak, Marija Bešter Rogač, Marjeta Šentjurc, Mirjana Gašperlin, Alenka Zvonar Pobirk
Insight into the microstructure of lyotropic liquid crystals (LCs) is of crucial importance for development of novel dermal delivery systems. Our aim was to evaluate the phase behaviour of dermally applicable LCs composed of isopropyl myristate/Tween 80/lecithin/water, along the dilution line, where phase transitions are predominantly driven by increased water content. Additionally, identification of LC temperature dependence is of great importance for skin application. Selected LCs were evaluated using electron paramagnetic resonance (EPR) plus conventionally used methods of polarization microscopy, small-angle X-ray scattering, differential scanning calorimetry, and rheological measurements...
May 18, 2017: International Journal of Pharmaceutics
https://www.readbyqxmd.com/read/28528095/structural-and-mechanical-properties-of-organogels-role-of-oil-and-gelator-molecular-structure
#16
Miguel A Cerqueira, Luiz H Fasolin, Carolina S F Picone, Lorenzo M Pastrana, Rosiane L Cunha, António A Vicente
This work aims at evaluating the influence of oil and gelator structure on organogels' properties through rheological measurements, polarized microscopy and small-angle X-ray scattering (SAXS). Four different food-grade gelators (glyceryl tristearate - GT; sorbitan tristearate - ST; sorbitan monostearate - SM and glyceryl monostearate - GM) were tested in medium-chain triglyceride and high oleic sunflower (MCT and LCT, respectively) oil phases. Organogels were prepared by mixing the oil phase and gelator at different concentrations (5, 10, 15, 20 and 25%) at 80°C during 30min...
June 2017: Food Research International
https://www.readbyqxmd.com/read/28528092/structural-strength-analysis-of-amorphous-trehalose-maltodextrin-systems
#17
V A Maidannyk, B Nurhadi, Y H Roos
Fundamental knowledge of physical state of materials gives practically important information for food, biological and pharmaceutical industry. Based on Williams-Landel-Ferry (WLF) equation, the strength concept was introduced. This concept provides a simple parameter, S, to express resistance of solids to flow above the glass transition temperature. To develop this approach, miscible trehalose-maltodextrin (0:100; 20:80; 40:60; 60:40; 80:20 and 100:0) systems with different ratios of components were used in the present study...
June 2017: Food Research International
https://www.readbyqxmd.com/read/28527299/role-of-pickering-stabilization-and-bulk-gelation-for-the-preparation-and-properties-of-solid-silica-foams
#18
I Lesov, S Tcholakova, M Kovadjieva, T Saison, M Lamblet, N Denkov
Foaming of particulate suspensions, followed by foam drying, is developed as an efficient method for production of highly porous materials with various applications. A key factor for success is the appropriate choice of surfactants which both modify the particle surface and stabilize the foam. Here we compare the efficiency of this method for silica suspensions containing two surfactants which lead to very different types of foam stabilization. Cationic TTAB leads to particle-stabilized foams (Pickering stabilization) whereas zwitterionic CAPB - to surfactant-stabilized foams...
May 12, 2017: Journal of Colloid and Interface Science
https://www.readbyqxmd.com/read/28527296/performances-and-working-mechanism-of-a-novel-polycarboxylate-superplasticizer-synthesized-through-changing-molecular-topological-structure
#19
Xiao Liu, Jianan Guan, Guanghong Lai, Ziming Wang, Jie Zhu, Suping Cui, Mingzhang Lan, Huiqun Li
A novel star-shaped polycarboxylate superplasticizer (SPCE) was synthesized through a simple two-step method. (1)H Nuclear Magnetic Resonance ((1)H NMR) and Infrared Spectroscopy (IR) measurements were used for structural characterization. SPCE and comb-shaped polycarboxylate superplasticizer (CPCE) with same molecular weights were designed and synthesized. The cement paste containing SPCE exhibited better fluidity, fluidity retention, water reduction, 25% lower saturated dosage of PCE, 10% longer setting time, lower hydration heat, more delayed hydration heat evolution and lower amount of hydration products at early ages...
May 10, 2017: Journal of Colloid and Interface Science
https://www.readbyqxmd.com/read/28526627/dynamic-fatigue-measurement-of-human-erythrocytes-using-dielectrophoresis
#20
Yuhao Qiang, Jia Liu, E Du
Erythrocytes must undergo severe deformation to pass through narrow capillaries and submicronic splenic slits for several hundred thousand times in their normal lifespan. Studies of erythrocyte biomechanics have been mainly focused on cell deformability and rheology measured from a single application of stress and mostly under a static or quasi-static state using classical biomechanical techniques, such as optical tweezers and micropipette aspiration. Dynamic behavior of erythrocytes in response to cyclic stresses that contributes to the membrane failure in blood circulation is not fully understood...
May 16, 2017: Acta Biomaterialia
keyword
keyword
69174
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"