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Alyson M Thibodeau, Leonardo López Luján, David J Killick, Frances F Berdan, Joaquin Ruiz
Archaeologists have long suggested that prehispanic states in Mesoamerica acquired turquoise through long-distance exchange with groups living in what is now the American Southwest and adjacent parts of northern Mexico. To test this hypothesis, we use lead and strontium isotopic ratios to investigate the geologic provenance of 43 Mesoamerican turquoise artifacts, including 38 mosaic tiles from offerings within the Sacred Precinct of Tenochtitlan (the Mexica or Aztec capital) and 5 tiles associated with Mixteca-style mosaics currently held by the Smithsonian's National Museum of the American Indian...
June 2018: Science Advances
Timothy Ferreira, Mark D Smith, Hans-Conrad Zur Loye
The compositions of the general formula Ln11- x Sr x Ir4 O24 (Ln = La, Pr, Nd, Sm; 1.37 ≥ x ≥ 2) belonging to a family of A-site cation-deficient double-perovskite-related oxide iridates were grown as highly faceted single crystals from a molten strontium chloride flux. Their structures were determined by single-crystal X-ray diffraction. On the basis of the single-crystal results, additional compositions, Ln9 Sr2 Ir4 O24 (Ln = La, Pr, Nd, Sm), were prepared as polycrystalline powders via solid-state reactions and structurally characterized by Rietveld refinement...
June 21, 2018: Inorganic Chemistry
Andrés M Baraibar, Ricardo de Pascual, Marcial Camacho, Natalia Domínguez, J David Machado, Luis Gandía, Ricardo Borges
Three divalent cations can elicit secretory responses in most neuroendocrine cells, including chromaffin cells. The extent to which secretion is elicited by the cations in intact depolarized cells was Ba2+  > Sr2+  ≥ Ca2+ , contrasting with that elicited by these cations in permeabilized cells (Ca2+  > Sr2+  > Ba2+ ). Current-clamp recordings show that extracellular Sr2+ and Ba2+ cause membrane depolarization and action potentials, which are not blocked by Cd2+ but that can be mimicked by tetra-ethyl-ammonium...
June 21, 2018: Pflügers Archiv: European Journal of Physiology
T A Rodrigues, A O Freire, B F Bonfim, M S S Cartágenes, J B S Garcia
Considering that osteoarthritis (OA) is the most prevalent joint disease worldwide, multiple pharmacological treatments have been proposed to alter the articular structure with potential benefit in the progression of the disease. The so-called disease-modifying OA drugs have been frequently investigated but conclusive findings are rare. Strontium ranelate (SrRan) is a drug usually prescribed to treat osteoporosis, with proven effects in decreasing the risk of fractures and possible effect in reducing the progression of OA...
2018: Brazilian Journal of Medical and Biological Research, Revista Brasileira de Pesquisas Médicas e Biológicas
Arash Panahifar, L Dean Chapman, Lynn Weber, Nazanin Samadi, David M L Cooper
Bone acts as a reservoir for many trace elements. Understanding the extent and pattern of elemental accumulation in the skeleton is important from diagnostic, therapeutic, and toxicological perspectives. Some elements are simply adsorbed to bone surfaces by electric force and are buried under bone mineral, while others can replace calcium atoms in the hydroxyapatite structure. In this article, we investigated the extent and pattern of skeletal uptake of barium and strontium in two different age groups, growing, and skeletally mature, in healthy rats...
June 19, 2018: Journal of Bone and Mineral Metabolism
Mihaela Badea, Octavio P Luzardo, Ana González-Antuña, Manuel Zumbado, Liliana Rogozea, Laura Floroian, Dana Alexandrescu, Marius Moga, Laura Gaman, Mariana Radoi, Luis D Boada, Luis Alberto Henríquez-Hernández
Smoking is considered an important source for inorganic elements, most of them toxic for human health. During the last years, there has been a significant increase in the use of e-cigarettes, although the role of them as source of inorganic elements has not been well established. A cross-sectional study including a total of 150 subjects from Brasov (Romania), divided into three groups (non-smokers, cigarette smokers and electronic cigarettes smokers) were recruited to disclose the role of smoking on the human exposure to inorganic elements...
June 13, 2018: Environmental Research
Fujian Zhao, Bo Lei, Xian Li, Yunfei Mo, Renxian Wang, Dafu Chen, Xiaofeng Chen
Early vascularization capacity of biomaterials plays an essential role in efficient wound healing and tissue regeneration, especially in large tissue tension implanting position such as bone augmentation. Strontium-contained silica-based bioactive materials have shown the role of promoting angiogenesis by stimulating osteoblasts to secrete angiogenesis related cytokines. However, osteoblasts have little effect on early angiogenesis due to the inflammatory reaction of implantation site. Here, for the first time, we found that the monodispersed strontium-contained bioactive glasses microspheres (SrBGM) could significantly promote the early angiogenesis through regulating macrophage phenotypes...
June 8, 2018: Biomaterials
Alamuddin Bakhit, Nobuyuki Kawashima, Kentaro Hashimoto, Sonoko Noda, Keisuke Nara, Masashi Kuramoto, Kento Tazawa, Takashi Okiji
This study examined the effects and mechanisms of strontium ranelate (SrRn)-a drug used to treat osteoporosis-on the proliferation and differentiation/mineralization of cloned dental pulp-like cells (mouse dental papillae cells; MDPs). It also determined whether topical application of SrRn to exposed dental pulp tissue promotes the formation of mineralized tissue in vivo. The MDPs were cultured with or without SrRn, and cell proliferation, odonto-/osteoblastic gene expression, mineralized nodule formation, and Akt phosphorylation were evaluated...
June 15, 2018: Scientific Reports
Mangesh I Chaudhari, Susan B Rempe
Ion hydration structure and free energy establish criteria for understanding selective ion binding in potassium (K+ ) ion channels and may be significant to understanding blocking mechanisms as well. Recently, we investigated the hydration properties of Ba2+ , the most potent blocker of K+ channels among the simple metal ions. Here, we use a similar method of combining ab initio molecular dynamics simulations, statistical mechanical theory, and electronic structure calculations to probe the fundamental hydration properties of Sr2+ , which does not block bacterial K+ channels...
June 14, 2018: Journal of Chemical Physics
Alvaro J Leite, Ana I Gonçalves, Marcia T Rodrigues, Manuela E Gomes, João F Mano
The present work explores bioactive glass nanoparticles (BGNPs) and developed strontium-doped nanoparticles (BGNPsSr), envisioning orthopedic strategies compatible with vascularization. The nanoparticles were synthesized by sol-gel, achieving a diameter of 55 nm for BGNPs and of 75 nm for BGNPsSr, and the inclusion of strontium caused none structural alteration. The nanoparticles exhibited high cytocompatibility for HUVECs and SaOS-2. Additionally, the incorporation of strontium emphasized the tubule networking behavior of HUVECs...
June 15, 2018: ACS Applied Materials & Interfaces
Tianxiang Geng, Xi Chen, Mengxue Zheng, Haochen Yu, Shuai Zhang, Shouxuan Sun, Haohui Guo, Qunhua Jin
Aseptic loosening and menopause‑induced osteoporosis are caused by an imbalance between bone formation and osteolysis. With an aging population, the probability of simultaneous occurrence of such conditions in an elderly individual is increasing. Strontium ranelate (SR) is an anti‑osteoporosis drug that promotes bone formation and inhibits osteolysis. The present study compared the effects of SR with those of the traditional anti‑osteoporosis drug alendronate (ALN) using an ovariectomized mouse model of osteolysis...
June 5, 2018: Molecular Medicine Reports
Wilfredo Gustavo Escalante-Otárola, Gabriela Mariana Castro-Núñez, Keren Cristina Fagundes Jordão-Basso, Bruno Martini Guimarães, Regina Guenka Palma-Dibb, Milton Carlos Kuga
OBJECTIVES: To evaluate the effect of desensitizing agent containing calcium phosphate nanoparticles on the bond strength ofetch-and-rinse adhesive system (Scotchbond Multi-Purpose), presence of precipitate, dentinal tubule obliteration and hybrid layer formation in dentin in comparison with potassium nitrate plus sodium fluoride or strontium chloride compounds. METHODS: 150 bovine incisors were treated with (n = 10): G1, Desensibilize Nano P (Ca3 (PO4 )2 +5%KNO3 +0...
June 9, 2018: Journal of Dentistry
Florian Lackner, Wolfgang E Ernst
Besides the use as cold matrix for spectroscopic studies, superfluid helium droplets have served as cold environment for the synthesis of molecules and clusters. Since vibrational frequencies of molecules in helium droplets exhibit almost no shift compared to the free molecule values, one could assume the solvated particles move frictionless and undergo a reaction as soon as their paths cross. There have been a few unexplained observations that seemed to indicate cases of two species on one droplet not forming bonds but remaining isolated...
June 12, 2018: Journal of Physical Chemistry Letters
Elisa Martín-Merino, Amaia Calderón-Larrañaga, Samuel Hawley, Beatriz Poblador-Plou, Ana Llorente-García, Irene Petersen, Daniel Prieto-Alhambra
Background: Missing data are often an issue in electronic medical records (EMRs) research. However, there are many ways that people deal with missing data in drug safety studies. Aim: To compare the risk estimates resulting from different strategies for the handling of missing data in the study of venous thromboembolism (VTE) risk associated with antiosteoporotic medications (AOM). Methods: New users of AOM (alendronic acid, other bisphosphonates, strontium ranelate, selective estrogen receptor modulators, teriparatide, or denosumab) aged ≥50 years during 1998-2014 were identified in two Spanish (the Base de datos para la Investigación Farmacoepidemiológica en Atención Primaria [BIFAP] and EpiChron cohort) and one UK (Clinical Practice Research Datalink [CPRD]) EMR...
2018: Clinical Epidemiology
Yanbei Zhu, Kazumi Nakano, Yasuyuki Shikamori
A determination of rubidium (Rb) was carried out by isotope dilution (ID) using an inductively coupled plasma tandem quadrupole mass spectrometer (ICP-QMS/QMS) with an octupole reaction-cell (ORC). Spectral interference of 87 Sr with the measurement of 87 Rb was effectively removed by using fluoromethane (CH3 F) as the reaction cell gas at the optimum flow rate. In comparison to the measurement obtained with a mathematical correction, good precision for the analysis of the Rb isotope could be obtained independent of the concentration of Sr without any chemical separation in advance...
2018: Analytical Sciences: the International Journal of the Japan Society for Analytical Chemistry
Blai Casals, Andrea Schiaffino, Arianna Casiraghi, Sampo J Hämäläinen, Diego López González, Sebastiaan van Dijken, Massimiliano Stengel, Gervasi Herranz
Strontium titanate (SrTiO_{3}) is the quintessential material for oxide electronics. One of its hallmark features is the transition, driven by antiferrodistortive (AFD) lattice modes, from a cubic to a ferroelastic low-temperature phase. Here we investigate the evolution of the ferroelastic twin walls upon application of an electric field. Remarkably, we find that the dielectric anisotropy of tetragonal SrTiO_{3}, rather than the intrinsic domain wall polarity, is the main driving force for the motion of the twins...
May 25, 2018: Physical Review Letters
Yi Pei, Ke Zheng, GuanNing Shang, YuMing Wang, Wei Wang, EnDuo Qiu, ShenLong Li, XiaoJing Zhang
The purpose of this study was to determine whether treatment with strontium ranelate (SrR) can restore bone mass and strength at a skeletal site with established osteopenia in chemotherapy-induced rats. Forty-five Sprague-Dawley male rats were randomly assigned to three study groups (n = 15 rats per group): normal rats (control group), osteopenic rats (chemo group), and osteopenic rats with SrR (chemo-SrR group). We chose a male rat model that mimicked a clinical setting by weekly intravenous injection of cyclophosphamide at 20 mg/kg...
June 7, 2018: Biological Trace Element Research
Weixuan Zeng, Yuan Bian, Sheng Cao, Yongjin Ma, Yi Liu, Anquan Zhu, Pengfei Tan, Jun Pan
Tantalum oxynitride-based materials, which possess narrow bandgaps and sufficient band energy potentials, have been of immense interest for water splitting. However, the efficiency of photocatalytic reactions is still low due to the fast electron-hole recombination. Here, a Sr2Ta2O7-xNx/SrTaO2N heterostructured photocatalyst with well-matched band structure was in situ constructed by nitridation of hydrothermal-prepared Sr2Ta2O7 nanosheets. Compared to Sr2Ta2O7-xNx and pure SrTaO2N, the Sr2Ta2O7-xNx/SrTaO2N heterostructured photocatalyst exhibited highest rate of hydrogen evolution, which is ca...
June 7, 2018: ACS Applied Materials & Interfaces
Silvia Panzavolta, Paola Torricelli, Sonia Casolari, Annapaola Parrilli, Milena Fini, Adriana Bigi
Strontium has a beneficial role on bone remodeling and is proposed for the treatment of pathologies associated to excessive bone resorption, such as osteoporosis. Herein, the possibility to utilize a biomimetic scaffold as strontium delivery system is explored. Porous 3D gelatin scaffolds containing about 30% of strontium substituted hydroxyapatite (SrHA) or pure hydroxyapatite (HA) are prepared by freeze-drying. The scaffolds display a very high open porosity, with an interconnectivity of 100%. Reinforcement with further amount of gelatin provokes a modest decrease of the average pore size, without reducing interconnectivity...
June 7, 2018: Macromolecular Bioscience
Iara da C Souza, Hiulana P Arrivabene, Carol-Ann Craig, Andrew J Midwood, Barry Thornton, Silvia T Matsumoto, Michael Elliott, Daniel A Wunderlin, Magdalena V Monferrán, Marisa N Fernandes
Anthropogenic activities including metal contamination create well-known problems in coastal mangrove ecosystems but understanding and linking specific pollution sources to distinct trophic levels within these environments is challenging. This study evaluated anthropogenic impacts on two contrasting mangrove food webs, by using stable isotopes (δ13 C, δ15 N, 87 Sr/86 Sr, 206 Pb/207 Pb and 208 Pb/207 Pb) measured in sediments, mangrove trees (Rhizophora mangle, Laguncularia racemosa, Avicennia schaueriana), plankton, shrimps (Macrobranchium sp...
June 1, 2018: Science of the Total Environment
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