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# Hydration

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#1
Madhusmita Tripathy, Sunil Kumar P B, Abhijit P Deshpande
The extent of phase separation and water percolation in sulfonated membranes are the key to their performance in fuel cells. Toward this, the effect of hydration on the morphology and transport characteristics of sulfonated poly(ether ether ketone), sPEEK, membrane is investigated using atomistic molecular dynamics simulation at various hydration levels($\lambda$: number of water molecules per sulfonate group). The evolution of local morphology is investigated using structural correlations and minimum pair distances...
April 21, 2017: Journal of Physical Chemistry. B
#2
Fabio Novelli, Saeideh Ostovar Pour, Jonathan O Tollerud, Ashkan Roozbeh, Dominique R T Appadoo, Ewan W Blanch, Jeffrey A Davis
Here we reveal details of the interaction between human lysozyme proteins, both native and fibrils, and their water environment by intense terahertz time domain spectroscopy. With the aid of a rigorous dielectric model, we determine the amplitude and phase of the oscillating dipole induced by the THz field in the volume containing the protein and its hydration water. At low concentrations, the amplitude of this induced dipolar response decreases with increasing concentration. Beyond a certain threshold, marking the onset of the interactions between the extended hydration shells, the amplitude remains fixed but the phase of the induced dipolar response, which is initially in phase with the applied THz field, begins to change...
April 21, 2017: Journal of Physical Chemistry. B
#3
Takuya Shiba, Hiroshi Tsuneoka
PURPOSE: To describe a technique for intraocular lens (IOL) implantation that lessens the degree of surgical invasiveness by implanting a tightly rolled IOL through a small incision without touching the eye with the cartridge tip. METHODS: An IOL was inserted through an incision by first allowing the leading haptic to protrude slightly from the cartridge tip. It was then injected through the incision without allowing any part of the cartridge to touch the eye during IOL implantation...
April 7, 2017: European Journal of Ophthalmology
#4
Andrés Aguirre, Erena Gil-Quintana, Marisa Fenaux, Sandra Erdozain, Itziar Sarria
Collagens and hyaluronic acid have long been used in pharmaceuticals and food supplements for the improvement of skin elasticity and hydration. These compounds provide the building blocks of the skin. Ovoderm is an oral supplement obtained from eggshells that contains naturally occurring collagen and glycosaminoglycans, such as hyaluronic acid. We evaluated the efficacy of Ovoderm on skin biophysical parameters related to cutaneous aging such as elasticity, hydration, and pigmentation. Two pilot studies were run to assess the effect of daily oral supplementation with 300 mg Ovoderm on skin parameters...
April 21, 2017: Journal of Dietary Supplements
#5
Eva Pluharova, Damien Laage, Pavel Jungwirth
Long-range ordering of water around solutes has been invoked repeatedly in the literature as the key to understanding its biological function. Recently, it has been shown that in a dilute 8 mM aqueous NaCl solution the orientational correlation between water molecules extends beyond 8 nanometers. This was interpreted as arising from a long-range effect induced by the ions on the water collective hydrogen-bond interactions. Within this interpretation, each ion was supposed to affect tens of thousands or more water molecules in its surroundings, invoking a picture of ordered domains extending to several nanometers...
April 21, 2017: Journal of Physical Chemistry Letters
#6
Shigeyoshi Nakamura, Tomonori Saotome, Akiko Nakazawa, Masao Fukuda, Yutaka Kuroda, Shun-Ichi Kidokoro
In this study, we performed differential scanning calorimetry (DSC) and pressure perturbation calorimetry (PPC) analysis of the thermal transition of cytochrome c from an acidic molten globule (MG) state with the protein concentrations of 0.5-18.2 mg/mL. DSC profiles were highly reversible and showed clear protein-concentration dependence, indicating that reversible oligomerization occurred accompanying the thermal transition from the MG state. The DSC and PPC data required at least a six-state model including three new oligomeric states: dimer (I2), trimer (I3), and tetramer (I4) in addition to the three monomeric states previously characterized...
April 21, 2017: Biochemistry
#7
Mariela Arias-Hidalgo, Samer Al-Samir, Natalie Weber, Cornelia Geers-Knörr, Gerolf Gros, Volker Endeward
AIM: We determine here the CO2 permeability (PCO2 ) of plasma membranes of cardiomyocytes. These cells were chosen because heart possesses the highest rate of O2 -consumption/CO2 -production in the body. METHODS: Cardiomyocytes were isolated from rat hearts using the Langendorff technique. Cardiomyocyte suspensions exhibited a vitality of 2-14% and were studied by the previously described mass spectrometric (18) O-exchange-technique deriving PCO2 . We show by mass spectrometry and by carbonic anhydrase (CA)-staining that non-vital cardiomyocytes are free of CA and thus do not contribute to the mass spectrometric signal, which is determined exclusively by the fully functional vital cardiomyocytes...
April 20, 2017: Acta Physiologica
#8
Dalia Ali Farghaly, Ahmed A Aboelwafa, Manal Y Hamza, Magdy I Mohamed
The aim of this study was to investigate the potential of surfactant-based nanovesicular system (spanlastics) for topical delivery of fenoprofen calcium (FPCa) to eliminate its oral gastrointestinal adverse effects. FPCa-loaded spanlastics were prepared by thin film hydration (TFH) technique according to a full factorial design to investigate the influence of formulation variables on the drug entrapment efficiency (%EE), particle size (PS), deformability index (DI), and the % drug released after 24 h through the cellulose membrane (Q24h) using Design-Expert® software...
April 20, 2017: AAPS PharmSciTech
#9
Carboplatin is a chemotherapeutic agent used against various malignancies such as ovarian carcinoma. The aim of this study is to improve the therapeutic efficacy of carboplatin using pegylated liposomal nanocarriers. Nanoparticles were synthesized using thin film hydration technique and characterized for shape morphology, particle size, zeta potential and drug-release properties. In the next step, A2780S and A2780CP ovarian cancer cell lines were used to determine the efficacy of nanodrug by MTT assay. The particle size and zeta potential of nanodrug were measured 244...
June 2017: Indian Journal of Clinical Biochemistry: IJCB
#10
Masashi Nakamura, Takahiro Banzai, Yuto Maehata, Osamu Endo, Hiroo Tajiri, Osami Sakata, Nagahiro Hoshi
Understanding the electrocrystallization mechanisms of metal cations is of importance for many industrial and scientific fields. We have determined the transitional structures during underpotential deposition (upd) of various metal cations on Au(111) electrode using time-resolved surface X-ray diffraction and step-scan IR spectroscopy. At the initial stage of upd, a characteristic intensity transient appears in the time-resolved crystal truncation rod depending on metal cations. Metal cations with relatively high coordination energies of hydration water are deposited in two steps: first, the hydrated metal cations approached the surface and are metastably located at the outer Helmholtz plane, then they are deposited via the destruction of the hydration shell...
April 20, 2017: Scientific Reports
#11
REVIEW
Jean Alric, Xenie Johnson
Photosynthetic reactions proceed along a linear electron transfer chain linking water oxidation at photosystem II (PSII) to CO2 reduction in the Calvin-Benson-Bassham cycle. Alternative pathways poise the electron carriers along the chain in response to changing light, temperature and CO2 inputs, under prolonged hydration stress and during development. We describe recent literature that reports the physiological functions of new molecular players. Such highlights include the flavodiiron proteins and their important role in the green lineage...
April 17, 2017: Current Opinion in Plant Biology
#12
Nancy C Andrés, Noelia L D'Elía, Juan M Ruso, Adrián Esteban Campelo, Virginia L Massheimer, Paula V Messina
Ionic substitution can affect essential physicochemical properties leading to a specific biological behavior upon implantation. Therefore it has been proposed as a tool to increase the biological efficiency of calcium phosphate based materials. In the following study we have evaluated the contribution of an important cation in nature, Mg2+, into the structure of previously studied biocompatible and biodegradable hydroxyapatite (HA) nano-rods and its subsequent effect on its chemical, morphology and bone mimetic articulation...
April 20, 2017: ACS Applied Materials & Interfaces
#13
Catherine M Oikonomou, Grant J Jensen
Electron cryotomography (ECT) provides three-dimensional views of macromolecular complexes inside cells in a native frozen-hydrated state. Over the last two decades, ECT has revealed the ultrastructure of cells in unprecedented detail. It has also allowed us to visualize the structures of macromolecular machines in their native context inside intact cells. In many cases, such machines cannot be purified intact for in vitro study. In other cases, the function of a structure is lost outside the cell, so that the mechanism can be understood only by observation in situ...
April 19, 2017: Annual Review of Biochemistry
#14
Dengpan Dong, Justin B Hooper, Dmitry Bedrov
Understanding the behavior of aqueous solutions containing tetra-alkyl ammonium (TAA) cations is of great significance in a number of applications, including polymer membranes for fuel cells. In this work, a polarizable force field has been used to preform atomistic molecular dynamics (MD) simulations of aqueous solutions containing tetra-methyl ammonium (TMA) or tetra-butyl ammonium (TBA) cations and Br counterions. Extensive MD simulations of TMA-Br/water and TBA-Br/water systems were conducted as a function of solution composition (ion pair : water molar ratios of 1:10, 1:20, 1:30, 1:63, 1:500) at atmospheric pressure and 298K...
April 20, 2017: Journal of Physical Chemistry. B
#15
Tapan Kumar Giri, Kaustav Pramanik, Tapan Kumar Barman, Subhasis Maity
Protective effects of capsaicin (CAP) loaded nano-emulsomes (EML) was evaluated against the oxidative stress of rat livers induced through sodium fluoride (NaF). EML was prepared by thin film hydration method that is development of thin lipid film followed by hydration and sonication. EML was characterized by Fourier transform infrared (FT-IR) spectroscopy and X-ray diffraction (XRD) techniques. In vitro drug release study of optimized formulation showed that 50% of CAP was released within 50.21 min while 85% CAP was released in 227...
April 19, 2017: Anti-cancer Agents in Medicinal Chemistry
#16
R S Renslow, M J Marshall, A E Tucker, W B Chrisler, X-Y Yu
Biofilms are comprised of microbial cells and an extracellular polymeric substance (EPS) matrix that supports interactions between community members and with the local environment. The highly hydrated EPS matrix makes the application of many biofilm visualization techniques difficult. Hence, to better visualize how biofilms interact with their environment, there is a need for imaging techniques to monitor hydrated state biofilm dynamics. We employed an in situ dynamic approach to construct label-free images of biofilms...
April 20, 2017: Analyst
#17
REVIEW
Runsheng Jiao, Dan Cui, Stephani C Wang, Dongyang Li, Yu-Feng Wang
Life is maintained in a sea water-like internal environment. The homeostasis of this environment is dependent on osmosensory system translation of hydromineral information into osmotic regulatory machinery at system, tissue and cell levels. In the osmosensation, hydromineral information can be converted into cellular reactions through osmoreceptors, which changes thirst and drinking, secretion of antidiuretic vasopressin (VP), reabsorption of water and salt in the kidneys at systemic level as well as cellular metabolic activity and survival status at tissue level...
2017: Frontiers in Molecular Neuroscience
#18
Luís Monteiro Monteiro Rodrigues, Lídia Palma, Osvaldo Santos, Maria Angélica Almeida, Julia Bujan, Liliana Tavares
BACKGROUND/AIMS: Recently classified as an epidemic by the WHO, obesity (as well as the state of being overweight) clearly affects significant populations across all ages. The relationship between obesity and some diseases (e.g. cardiovascular ones) is known, although many paradoxes remain to be explained. Very little information is available, however, regarding its impact on skin physiology and skin disease. This study aims to examine the influence of excessive weight on epidermal hydration and transepidermal water loss, key variables of skin water balance and skin biomechanics...
April 20, 2017: Skin Pharmacology and Physiology
#19
Mariya Moosajee, Veronica Ferguson
April 19, 2017: Journal of Ocular Pharmacology and Therapeutics
#20
Tatyana V Rodionova, Artem A Sizikov, Vladislav Yu Komarov, Galina V Villevald, Tamara D Karpova, Andrey Yu Manakov
In the present work we studied semiclathrate hydrates in the TBPO ‒ H2O and TBPO ‒ H2O ‒ CH4 systems. The stoichiometry, temperature and enthalpy of dissociation of TBPO semiclathrate hydrate crystals formed in TBPO - H2O binary system were found to be TBPO·33.6±0.9Н2О, 280.0 K, and 253.1±4.7 Jg(-1), respectively. The crystal structure determined by single crystal XRD analysis (150 K) was orthorhombic with space group Pbam and unit cell parameters a =19.9313(8) Å, b =23.4660(7) Å, c =12.1127(5) Å...
April 19, 2017: Journal of Physical Chemistry. B
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