Read by QxMD icon Read

Physical Chemistry

Florent Calvo, Ersin Yurtsever, Adem Tekin
The interaction between hydrogen and carbonaceous nanostructures is of fundamental interest in various areas of physical chemistry. In this contribution we have revisited the physisorption of hydrogen molecules and H2 clusters on fullerenes, following a first-principles approach in which the interaction is quantitatively evaluated for the C20 system using high-level electronic structure methods. Relative to coupled cluster data at the level of single, double, and perturbative triple excitations [CCSD(T)] taken as benchmark, the results for rotationally averaged physisorbed H2 show a good performance of MP2 variants and symmetry-adapted perturbation theory (SAPT), but significant deviations and basis set convergence issues are found for dispersion-corrected density functional theory (DFT)...
February 16, 2018: Journal of Physical Chemistry. A
Denis S Grebenkov, Liubov Tupikina
We introduce a heterogeneous continuous-time random walk (HCTRW) model as a versatile analytical formalism for studying and modeling diffusion processes in heterogeneous structures, such as porous or disordered media, multiscale or crowded environments, weighted graphs or networks. We derive the exact form of the propagator and investigate the effects of spatiotemporal heterogeneities onto the diffusive dynamics via the spectral properties of the generalized transition matrix. In particular, we show how the distribution of first-passage times changes due to local and global heterogeneities of the medium...
January 2018: Physical Review. E
Fernando M Lisboa, Josefredo R Pliego
Prediction of liquid-liquid phase equilibria is an important goal in the physical chemistry of solutions. Quantum chemistry methods, combined with a dielectric continuum description of the solvent, has received attention as a first principle approach. In this work, the performance of the continuum solvation model based on density (SMD) for prediction of γ ∞ in binary liquid mixtures, using 46 values of γ ∞ , was evaluated. We found the mean uncertainty of RTln γ ∞ to be 0.92 kcal mol -1 . Based on the calculated γ ∞ and the two parameters of the Redlich-Kister expansion, we calculated the liquid-liquid phase equilibria...
February 14, 2018: Journal of Molecular Modeling
Bernard J Moxham, Odile Plaisant, Baptiste Lignier, Feisal Brahim
BACKGROUND AND PURPOSE: Admission procedures for recruiting students to medical school vary considerably across the world. Notwithstanding such variability, it is important to know what skills and attributes are required of the students by their teachers on entering medical school. PROCEDURES: Anatomists are often the teachers who first meet the students as they enter medical school and this report analyses, by means of a questionnaire, the putative skills required of their medical students by anatomists from the U...
February 11, 2018: Annals of Anatomy, Anatomischer Anzeiger: Official Organ of the Anatomische Gesellschaft
Pieter Samyn, Leo Vonck, Dirk Stanssens, Henk Van den Abbeele
The encapsulation of vegetable oils within an aqueous dispersion of polymer nanoparticles provides an alternative route to create functional paper coatings from renewable resources, by combining the presentation of hydrophobic moieties together with variations in roughness at the paper surface. The effects of two selected vegetable oil types, i.e., castor oil and hydrogenated castor oil (wax), are compared in terms of nanoparticle synthesis, coating hydrophobicity and surface gloss. The nanoparticles were synthesized by adding 50 wt...
May 1, 2018: Journal of Nanoscience and Nanotechnology
David Botero, Camilo Alvarado, Adriana Bernal, Giovanna Danies, Silvia Restrepo
Even in the age of big data in Biology, studying the connections between the biological processes and the molecular mechanisms behind them is a challenging task. Systems biology arose as a transversal discipline between biology, chemistry, computer science, mathematics, and physics to facilitate the elucidation of such connections. A scenario, where the application of systems biology constitutes a very powerful tool, is the study of interactions between hosts and pathogens using network approaches. Interactions between pathogenic bacteria and their hosts, both in agricultural and human health contexts are of great interest to researchers worldwide...
2018: Frontiers in Microbiology
Arturo Casadevall, Carolina Coelho, Radames J B Cordero, Quigly Dragotakes, Eric Jung, Raghav Vij, Maggie P Wear
The capsule of Cryptococcus neoformans is its dominant virulence factor and plays a key role in the biology of this fungus. In this essay, we focus on the capsule as a cellular structure and note the limitations inherent in the current methodologies available for its study. Given that no single method can provide the structure of the capsule, our notions of what is the cryptococcal capsule must be arrived at by synthesizing information gathered from very different methodological approaches including microscopy, polysaccharide chemistry and physical chemistry of macromolecules...
February 13, 2018: Virulence
Houk Jang, Krishna P Dhakal, Kyung-Il Joo, Won Seok Yun, Sachin M Shinde, Xiang Chen, Soon Moon Jeong, Suk Woo Lee, Zonghoon Lee, JaeDong Lee, Jong-Hyun Ahn, Hyunmin Kim
Understanding the collaborative behaviors of the excitons and phonons that result from light-matter interactions is important for interpreting and optimizing the underlying fundamental physics at work in devices made from atomically thin materials. In this study, the generation of exciton-coupled phonon vibration from molybdenum disulfide (MoS2 ) nanosheets in a pre-excitonic resonance condition is reported. A strong rise-to-decay profile for the transient second-harmonic generation (TSHG) of the probe pulse is achieved by applying substantial (20%) beam polarization normal to the nanosheet plane, and tuning the wavelength of the pump beam to the absorption of the A-exciton...
February 13, 2018: Advanced Materials
Julia Schacht, Nicola Gaston
The synthesis of cluster based materials poses an exciting challenge for experimental chemistry. The main advantage of these materials compared to conventional bulk compounds is the simple tunability of the chemical and physical characteristics of individual clusters. As a consequence, cluster assemblies can theoretically be used for the creation of designer materials exhibiting specifically desired properties. Since superatoms reveal a large intrinsic thermodynamic stability and often very interesting tunable electronic characteristics, they seem to be an excellent choice as building blocks for the bulk...
February 12, 2018: Physical Chemistry Chemical Physics: PCCP
Sampsa Vierros, Maria Sammalkorpi
The micelles of the non-ionic C12E10 surfactant and 1-hexanol as an aqueous solution additives are studied toward the purpose of understanding the role of alcohol additives in tuning the characteristics of alkyl-ethoxylate micellar systems. Our dynamic light scattering and cloud point experiments show that the addition of hexanol induces a response similar to an increase of temperature. We associate the change with increased attraction between the micelles at low to moderate hexanol loadings and a potential increase of the aggregate size at a high hexanol-to-surfactant ratio...
February 12, 2018: Physical Chemistry Chemical Physics: PCCP
Y Wang, J Li
Corneal refractive surgery, as one of the common visual correction methods, has been increasingly accepted in China. There are a large number of people in China who undergo the corneal refractive surgery due to the high incidence of myopia in the country. It is essential that the safest and most effective surgery should be used to correct refractive errors in the cases involved with relatively normal eyes and corneas. In recent years, corneal refractive surgery has been rapidly developing with new technologies and techniques emerging all the time, such as SMILE (small incision lenticule extraction) surgery, which has been extensively applied in China since five years ago when it was approved by FDA...
January 11, 2018: [Zhonghua Yan Ke za Zhi] Chinese Journal of Ophthalmology
Mohamed Baalousha, Serge Stoll, Mikaël Motelica-Heino, Nathalie Guigues, Gilles Braibant, Frédéric Huneau, Philippe Le Coustumer
This study investigates the spatiotemporal variability of major and trace elements, dissolved organic carbon (DOC), total dissolved solids (TDS), and suspended particulate matter (SPM) in surface waters of several hydrosystems of the Loire River watershed in France. In particular, this study aims to delineate the impact of the abovementioned water physicochemical parameters on natural iron and manganese physical speciation (homoaggregation/heteroaggregation) among fine colloidal and dissolved (< 10 nm), colloidal (10-450 nm) and particulate (> 450 nm) phases in Loire River watershed...
February 10, 2018: Environmental Science and Pollution Research International
Asuka A Orr, Arul Jayaraman, Phanourios Tamamis
Docking algorithms have been widely used to elucidate ligand:receptor interactions that are important in biological function. Here, we introduce an in-house developed docking-refinement protocol that combines the following innovative features. (1) The use of multiple short molecular dynamics (MD) docking simulations, with residues within the binding pocket of the receptor unconstrained, so that the binding modes of the ligand in the binding pocket may be exhaustively examined. (2) The initial positioning of the ligand within the binding pocket based on complementary shape, and the use of both harmonic and quartic spherical potentials to constrain the ligand in the binding pocket during multiple short docking simulations...
2018: Methods in Molecular Biology
Yong-Chao Jiang, Hong-Li Jiao, Ming-Song Lee, To Wang, Lih-Sheng Turng, Qian Li, Wan-Ju Li
During the process of tissue regeneration facilitated by stem cells, physical properties of a scaffold affect behavior and activities of the cell. To enhance differentiation of human mesenchymal stem cells (MSCs) into endothelial-like cells (ELCs), we used electrospun fibrous substrates with different stiffness to enhance the differentiation. A simple method of annealing with different lengths of treatment time was employed to modulate stiffness of electrospun fibrous substrates without changing their chemistry...
February 10, 2018: Journal of Biomedical Materials Research. Part A
Jeroen Vangindertael, Rafael Camacho, Wouter Sempels, Hideaki Mizuno, Peter Dedecker, Kris Pieter Frans P F Janssen
Ever since the inception of light microscopy, the laws of physics have seemingly thwarted every attempt to visualize the processes of life at its most fundamental, sub- cellular, level. The diffraction limit has restricted our view to length scales well above 250 nm and in doing so, severely compromised our ability to gain true insights into many biological systems. Fortunately, continuous advancements in optics, electronics and mathematics have since provided the means to once again make physics work to our advantage...
February 9, 2018: Methods and Applications in Fluorescence
Tiantian Li, Fu Liu, Haibo Lin, Zhu Xiong, Hui Wang, Yun Zhong, Lingchao Xiang, Aiguo Wu
Herein we provide an "outside-in" interface segregation strategy to modify polyvinylidene fluoride (PVDF) membranes with anti-fouling, anti-bacterial and non-clotting performances for the first time. The coagulation bath composed of DMAc, water and synthesized copolymer was used to solidify and modify membrane during phase inversion process. The functional polymer e.g. poly(vinylpyrrolidone-vinyltriethoxysilane) (PVP-VTES), poly(dimethylamino ethyl methacrylate-vinyltriethoxysilane) (PDMAEMA-VTES), poly(acrylic acid-sodium p-styrene sulfonate-vinyltriethoxysilane) (PAA-SSNa-VTES) was segregated into membrane interface from outside coagulation bath...
February 2, 2018: Journal of Colloid and Interface Science
Han Lin, Yu Chen, Jianlin Shi
Tumour chemotherapy employs highly cytotoxic chemodrugs, which kill both cancer and normal cells by cellular apoptosis or necrosis non-selectively. Catalysing/triggering the specific chemical reactions only inside tumour tissues can generate abundant and special chemicals and products locally to initiate a series of unique biological and pathologic effects, which may enable tumour-specific theranostic effects to combat cancer without bringing about significant side effects on normal tissues. Nevertheless, chemical reaction-initiated selective tumour therapy strongly depends on the advances in chemistry, materials science, nanotechnology and biomedicine...
February 8, 2018: Chemical Society Reviews
Yunxiang Gao
Magnetic resonance imaging (MRI) is the most powerful tool for deep penetration and high-quality 3D imaging of tissues with anatomical details. However, the sensitivity of the MRI technique is not as good as that of the radioactive or optical imaging methods. Carbon-based nanomaterials have attracted significant attention in biomaterial research in recent decades due to their unique physical properties, versatile functionalization chemistry, as well as excellent biological compatibility. Researchers have employed various carbon nano-allotropes to develop hybrid MRI contrast agents for improved sensitivity...
February 6, 2018: Journal of Functional Biomaterials
Tiina Nypelö, Hassan Amer, Johannes Konnerth, Antje Potthast, Thomas Rosenau
Nanocellulose-based self-standing films are becoming a substrate for flexible electronics, diagnostics and sensors. Strength and surface chemistry are vital variables for these film-based endeavors, the former that is one of the assets of nanocellulose. To contribute to the later, nanocellulose films are tuned with a side-specific functionalization, having an aldehyde and a carboxyl side. The functionalities were obtained combining premodification of the film components by periodate oxidation with ozone post-treatment...
February 7, 2018: Biomacromolecules
Gary T Ferguson, Anthony J Hickey, Sarvajna Dwivedi
Technologies for long-term delivery of aerosol medications in asthma and chronic obstructive pulmonary disease have improved over the past 2 decades with advancements in our understanding of the physical chemistry of aerosol formulations, device engineering, aerosol physics, and pulmonary biology. However, substantial challenges remain when a patient is required to use multiple inhaler types, multiple medications, and/or combinations of medications. Combining multiple drugs into a single inhaler while retaining appropriate dosing of the individual agents in the combination may enhance patient adherence to therapy and reduce device errors that occur when patients are using multiple inhalers...
January 2018: Respiratory Medicine
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"