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https://www.readbyqxmd.com/read/28538937/-mother-child-relationship-and-associated-factors-hierarchical-analysis-of-the-population-base-in-a-brazilian-state-capital-brisa-study
#1
Milady Cutrim Vieira Cavalcante, Fernando Lamy, Ana Karina Teixeira da Cunha França, Zeni Carvalho Lamy
Several factors can interfere in the mother-child relationship. Studies about different maternal characteristics and this relationship are scarce; they mainly evaluate women with psychopathology and use simultaneous regression models with adjustment for multiple confounders. This study aimed to assess factors associated with losses in the mother-child relationship through a cohort of 3,215 mothers of children between 15 and 36 months of age. Losses in the mother-child relationship, assessed by the Postpartum Bonding Questionnaire, was the outcome variable and the explanatory variables were demographic, socioeconomic, reproductive health and mental health of mothers as well as the conditions of the birth of children...
May 2017: Ciência & Saúde Coletiva
https://www.readbyqxmd.com/read/28538656/recent-advances-in-c-c-and-c-n-bond-forming-reactions-catalysed-by-polystyrene-supported-copper-complexes
#2
REVIEW
Pavel Drabina, Jan Svoboda, Miloš Sedlák
This present mini-review covers recently published results on Cu(I) and Cu(II) complexes immobilized on polystyrene carriers, which are used as heterogeneous, eco-friendly reusable catalysts applied for carbon-carbon and carbon-nitrogen forming reactions. Recent advances and trends in this area are demonstrated in the examples of oxidative homocoupling of terminal alkynes, the synthesis of propargylamines, nitroaldolization reactions, azide alkyne cycloaddition, N-arylation of nitrogen containing compounds, aza-Michael additions, asymmetric Friedel-Crafts reactions, asymmetric Mukaiyama aldol reactions, and asymmetric 1,3-dipolar cycloaddition of azomethine ylides...
May 24, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/28538206/spectroscopic-far-or-terahertz-mid-infrared-and-raman-investigation-thermal-analysis-and-biological-activity-of-piplartine
#3
Anubha Srivastava, T Karthick, B D Joshi, Rashmi Mishra, Poonam Tandon, A P Ayala, Javier Ellena
Research in the field of medicinal plants including Piper species like long pepper (Piper longum L.- Piperaceae) is increasing all over the world due to its use in traditional and Ayurvedic medicine. Piplartine (piperlongumine, 5,6-dihydro-1-[(2E)-1-oxo-3-(3,4,5-trimethoxyphenyl)-2-propenyl]-2(1H)-pyridinone), a biologically active alkaloid/amide was isolated from the phytochemical investigations of Piper species, as long pepper. This alkaloid has cytotoxic, anti-fungal, anti-diabetic, anti-platelet aggregation, anti-tumoral, anxiolytic, anti-depressant, anti-leishmanial, and genotoxic activities, but, its anticancer property is the most promising and has been widely explored...
May 5, 2017: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
https://www.readbyqxmd.com/read/28538154/effect-of-ca-2-to-sphingomyelin-investigated-by-sum-frequency-generation-vibrational-spectroscopy
#4
Rong-Juan Feng, Lu Lin, Yi-Yi Li, Ming-Hua Liu, Yuan Guo, Zhen Zhang
The interactions between Ca(2+) ions and sphingomyelin play crucial roles in a wide range of cellular activities. However, little is known about the molecular details of the interactions at interfaces. In this work, we investigated the interactions between Ca(2+) ions and egg sphingomyelin (ESM) Langmuir monolayers at the air/water interface by subwavenumber high-resolution broadband sum frequency generation vibrational spectroscopy (HR-BB-SFG-VS). We show that Ca(2+) ions can induce ordering of the acyl chains in the ESM monolayer...
May 23, 2017: Biophysical Journal
https://www.readbyqxmd.com/read/28538148/active-site-pka-determination-for-photoactive-yellow-protein-rationalizes-slow-ground-state-recovery
#5
Nur Alia Oktaviani, Trijntje J Pool, Yuichi Yoshimura, Hironari Kamikubo, Ruud M Scheek, Mikio Kataoka, Frans A A Mulder
The ability to avoid blue-light radiation is crucial for bacteria to survive. In Halorhodospira halophila, the putative receptor for this response is known as photoactive yellow protein (PYP). Its response to blue light is mediated by changes in the optical properties of the chromophore para-coumaric acid (pCA) in the protein active site. PYP displays photocycle kinetics with a strong pH dependence for ground-state recovery, which has remained enigmatic. To resolve this problem, a comprehensive pKa determination of the active-site residues of PYP is required...
May 23, 2017: Biophysical Journal
https://www.readbyqxmd.com/read/28538145/nmr-analysis-of-amide-hydrogen-exchange-rates-in-a-pentapeptide-repeat-protein-from-a-%C3%A2-thaliana
#6
Shenyuan Xu, Shuisong Ni, Michael A Kennedy
At2g44920 from Arabidopsis thaliana is a pentapeptide-repeat protein (PRP) composed of 25 repeats capped by N- and C-terminal α-helices. PRP structures are dominated by four-sided right-handed β-helices typically consisting of mixtures of type II and type IV β-turns. PRPs adopt repeated five-residue (Rfr) folds with an Rfr consensus sequence (STAV)(D/N)(L/F)(S/T/R)(X). Unlike other PRPs, At2g44920 consists exclusively of type II β-turns. At2g44920 is predicted to be located in the thylakoid lumen although its biochemical function remains unknown...
May 23, 2017: Biophysical Journal
https://www.readbyqxmd.com/read/28538102/effects-of-wet-blending-on-detection-of-melamine-in-spray-dried-lactose
#7
Betsy Jean Yakes, Marti M Bergana, Peter F Scholl, Magdi M Mossoba, Sanjeewa R Karunathilaka, Luke K Ackerman, Jason D Holton, Boyan Gao, Jeffrey C Moore
During the development of rapid screening methods to detect economic adulteration, spray-dried milk powders prepared by dissolving melamine in liquid milk exhibited an unexpected loss of characteristic melamine features in the NIR and Raman spectra. To further characterize this "wet-blending" phenomenon, spray-dried melamine and lactose samples were produced as a simplified model and investigated by near-infrared spectroscopy, Raman spectroscopy, 1H NMR, and DART-FTMS. In contrast to dry-blended samples, characteristic melamine bands in NIR and Raman spectra disappeared or shifted in wet-blended lactose-melamine samples...
May 24, 2017: Journal of Agricultural and Food Chemistry
https://www.readbyqxmd.com/read/28537746/classical-dynamics-simulations-of-dissociation-of-protonated-tryptophan-in-the-gas-phase
#8
Yogeshwaran Krishnan, Nishant Sharma, Upakarasamy Lourderaj, Manikandan Paranjothy
Gas phase decomposition of protonated amino acids are of great interest due to their role in understanding protein and peptide chemistry. Several experimental and theoretical studies have been reported in the literature on this subject. In the present work, decomposition of the aromatic amino acid protonated tryptophan was studied by on-the-fly classical chemical dynamics simulations using density functional theory. Mass spectrometry and electronic structure theory studies have shown multiple dissociation pathways for this biologically relevant molecule...
May 24, 2017: Journal of Physical Chemistry. A
https://www.readbyqxmd.com/read/28537743/er-3-photoluminescence-in-er2-c82-and-er2c2-c82-metallofullerenes-elucidated-by-density-functional-theory
#9
Jian Wang, Yuan-Yuan Zhao, Po-Heng Lee, Stephan Irle
Metallofullerenes with two erbium atoms encapsulated in IPR C82 cage isomers Cs-6 (I), C2v-9 (II), and C3v-8 (III) were investigated using density functional theory. The calculations suggest that erbium atoms assume a trivalent state with Er (4f(11)) valence electronic configuration in Er2@C82 and Er2C2@C82, where two electrons (6s(2)) per Er atom are transferred to the cage carrying four negative charges (C82(4-)), while the third electron is promoted from the 4f to the 5d shell, becoming involved in covalent bonding to near atoms...
May 24, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28537725/the-color-of-cation-%C3%AF-interactions-subtleties-of-amine-tryptophan-interaction-energetics-allow-for-radical-like-visible-absorbance-and-fluorescence
#10
Laura J Juszczak, Azaria S Eisenberg
Several peptides and a protein with an inter- or intramolecular cation-π interaction between tryptophan (Trp) and an amine cation are shown to absorb and fluoresce in the visible region of the spectrum. Titration of indole with sodium hydroxide or ammonium hydroxide yields an increasing visible fluorescence as well. Visible absorption and multi-peaked fluorescence excitation spectra correlate with experimental absorption spectra and the vibrational modes of calculated absorption spectra for the neutral Trp radical...
May 24, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28537713/site-occupancy-preference-and-antithermal-quenching-of-the-bi-2-deep-red-emission-in-%C3%AE-ca2p2o7-bi-2
#11
Liyi Li, Jiangkun Cao, Bruno Viana, Shanhui Xu, Mingying Peng
The resistance to thermal quenching is an essential factor in evaluating the performance of luminescent materials for application in white light emitting diodes (WLEDs). In this work, we studied the site occupancy preference and thermal quenching of luminescence in β-Ca2P2O7:Bi(2+) red phosphor at low (10-300 K) and high temperatures (303-573 K). In β-Ca2P2O7, the host lattice has four different calcium sites, at which Bi(2+)dopant can be located. After comparing the change of bond energy when the Bi(2+) ions are incorporated into the four calcium sites, we found out that Bi(2+) would preferentially occupy the smaller energy variation sites Ci(2) and Ci(1) in this compound, which can be assigned to Bi(2) and Bi(1), respectively...
May 24, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28535488/ftir-analysis-on-aging-characteristics-of-abs-pc-blend-under-uv-irradiation-in-air
#12
Jiarong Li, Fu Chen, Long Yang, Long Jiang, Yi Dan
Fourier Transform Infrared Spectroscopy (FTIR) is adopted to study the aging characteristics of poly(acrylonitrile-butadiene-styrene)/polycarbonate (ABS/PC) blend under UV-irradiation in air by analyzing the variation of the three main absorbance at about 967cm(-1), 1720cm(-1) and 3420cm(-1) associated with carbon-hydrogen bonds belonging to 1,4 butadiene, carbonyl and hydroxyl groups, respectively. Results indicate that, under UV-irradiation in air, the photo-oxidation of the blend is not a simple combination of the photo-oxidation of corresponding ABS and PC themselves and takes place predominantly at the ABS component...
April 29, 2017: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
https://www.readbyqxmd.com/read/28535460/a-synchrotron-infrared-absorption-study-of-pressure-induced-polymerization-of-acrylamide
#13
Himal Bhatt, M N Deo
The hydrogen bonded dimeric structure of the model amide based molecular crystal acrylamide has been investigated under pressure using micro-spectroscopy, employing synchrotron infrared radiation up to 24GPa at room temperature. The high pressure spectra indicate systematic evolution of new features above 4GPa, which have been identified to be due to the emergence of a polymeric phase. The polymerization gets completed up to 16.8GPa and the observed changes are found to be irreversible upon the release of pressure...
May 1, 2017: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
https://www.readbyqxmd.com/read/28535459/spectra-structure-correlations-of-saturated-and-unsaturated-medium-chain-fatty-acids-near-infrared-and-anharmonic-dft-study-of-hexanoic-acid-and-sorbic-acid
#14
Justyna Grabska, Krzysztof B Beć, Mika Ishigaki, Marek J Wójcik, Yukihiro Ozaki
Quantum chemical reproduction of entire NIR spectra is a new trend, enabled by contemporary advances in the anharmonic approaches. At the same time, recent increase of the importance of NIR spectroscopy of biological samples raises high demand for gaining deeper understanding of NIR spectra of biomolecules, i.e. fatty acids. In this work we investigate saturated and unsaturated medium-chain fatty acids, hexanoic acid and sorbic acid, in the near-infrared region. By employing fully anharmonic density functional theory (DFT) calculations we reproduce the experimental NIR spectra of these systems, including the highly specific spectral features corresponding to the dimerization of fatty acids...
May 13, 2017: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
https://www.readbyqxmd.com/read/28535442/mining-for-osteogenic-surface-topographies-in-silico-design-to-in%C3%A2-vivo-osseo-integration
#15
Frits F B Hulshof, Bernke Papenburg, Aliaksei Vasilevich, Marc Hulsman, Yiping Zhao, Marloes Levers, Natalie Fekete, Meint de Boer, Huipin Yuan, Shantanu Singh, Nick Beijer, Mark-Anthony Bray, David J Logan, Marcel Reinders, Anne E Carpenter, Clemens van Blitterswijk, Dimitrios Stamatialis, Jan de Boer
Stem cells respond to the physicochemical parameters of the substrate on which they grow. Quantitative material activity relationships - the relationships between substrate parameters and the phenotypes they induce - have so far poorly predicted the success of bioactive implant surfaces. In this report, we screened a library of randomly selected designed surface topographies for those inducing osteogenic differentiation of bone marrow-derived mesenchymal stem cells. Cell shape features, surface design parameters, and osteogenic marker expression were strongly correlated in vitro...
May 12, 2017: Biomaterials
https://www.readbyqxmd.com/read/28535395/a-zinc-chloride-doped-adhesive-facilitates-sealing-at-the-dentin-interface-a-confocal-laser-microscopy-study
#16
Manuel Toledano, Raquel Osorio, Estrella Osorio, Inmaculada Cabello, Manuel Toledano-Osorio, Fátima S Aguilera
The aim of this study was to ascertain the effect of Zn-doping of dental adhesives and mechanical load cycling on the micromorphology of the resin-dentin interdiffusion zone (of sound and caries affected dentin). The investigation considered two different Zn-doped adhesive approaches and evaluated the interface using a doubled dye fluorescent technique and a calcium chelator fluorophore under a confocal laser scanning microscopy. Sound and carious dentin-resin interfaces of unloaded specimens were deficiently resin-hybridized, in general...
May 19, 2017: Journal of the Mechanical Behavior of Biomedical Materials
https://www.readbyqxmd.com/read/28535348/coarse-grained-modeling-of-polyethylene-melts-effect-on-dynamics
#17
Brandon L Peters, K Michael Salerno, Anupriya Agrawal, Dvora Perahia, Gary S Grest
The distinctive viscoelastic behavior of polymers results from a coupled interplay of motion on multiple length and time scales. Capturing the broad time and length scales of polymer motion remains a challenge. Using polyethylene (PE) as a model macromolecule, we construct coarse-grained (CG) models of PE with 3-6 methyl groups per CG bead and probe two critical aspects of the technique: pressure corrections required after iterative Boltzmann inversion (IBI) to generate CG potentials that match the pressure of reference fully-atomistic melt simulations and the transferability of CG potentials across temperatures...
May 23, 2017: Journal of Chemical Theory and Computation
https://www.readbyqxmd.com/read/28535254/invited-commentary-cassel-s-the-contribution-of-the-social-environment-to-host-resistance-a-modern-classic
#18
Sherman A James
John Cassel's 1976 paper "The Contribution of the Social Environment to Host Resistance" (Am J Epidemiol. 1976;104(2):107-123) is widely regarded as a classic in epidemiology. He makes the compelling argument that the quality of a person's social relationships, that is, the degree to which her relationships are more stressful than supportive (or vice versa) influences her susceptibility to disease independent of genetic endowment, diet, physical activity, etc. Cassel's provocative thesis was anchored in a cogent synthesis of findings from animal experiments and observational studies on diverse human populations...
May 23, 2017: American Journal of Epidemiology
https://www.readbyqxmd.com/read/28535125/preparation-and-characterization-of-adefovir-dipivoxil-stearic-acid-cocrystal-with-enhanced-physicochemical-properties
#19
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/28535070/polarity-control-of-heteroepitaxial-gan-nanowires-on-diamond
#20
Martin Hetzl, Max Kraut, Theresa Hoffmann, Martin Stutzmann
Group III-nitride materials such as GaN nanowires are characterized by a spontaneous polarization within the crystal. The sign of the resulting sheet charge at the top and bottom facet of a GaN nanowire is determined by the orientation of the wurtzite bilayer of the different atomic species, called N and Ga polarity. We investigate the polarity distribution of heteroepitaxial GaN nanowires on different substrates and demonstrate polarity control of GaN nanowires on diamond. Kelvin Probe Force Microscopy is used to determine the polarity of individual selective area-grown and self-assembled nanowires over a large scale...
May 23, 2017: Nano Letters
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