Critical review: Injectability of calcium phosphate pastes and cements

Calcium phosphate cements (CPC) have seen clinical success in many dental and orthopaedic applications in recent years. The properties of CPC essential for clinical success are reviewed in this article, which includes properties of the set cement (e.g. bioresorbability, biocompatibility, porosity and mechanical properties) and unset cement (e.g. setting time, cohesion, flow properties and ease of delivery to the surgical site). Emphasis is on the delivery of calcium phosphate (CaP) pastes and CPC, in particular the occurrence of separation of the liquid and solid components of the pastes and cements during injection; and established methods to reduce this phase separation. In addition a review of phase separation mechanisms observed during the extrusion of other biphasic paste systems and the theoretical models used to describe these mechanisms are discussed

The age of data-driven proteomics : how machine learning enables novel workflows

A lot of energy in the field of proteomics is dedicated to the application of challenging experimental workflows, which include metaproteomics, proteogenomics, data independent acquisition (DIA), non-specific proteolysis, immunopeptidomics, and open modification searches. These workflows are all challenging because of ambiguity in the identification stage; they either expand the search space and thus increase the ambiguity of identifications, or, in the case of DIA, they generate data that is inherently more ambiguous. In this context, machine learning-based predictive models are now generating considerable excitement in the field of proteomics because these predictive models hold great potential to drastically reduce the ambiguity in the identification process of the above-mentioned workflows. Indeed, the field has already produced classical machine learning and deep learning models to predict almost every aspect of a liquid chromatography-mass spectrometry (LC-MS) experiment. Yet despite all the excitement, thorough integration of predictive models in these challenging LC-MS workflows is still limited, and further improvements to the modeling and validation procedures can still be made. In this viewpoint we therefore point out highly promising recent machine learning developments in proteomics, alongside some of the remaining challenges

Modification of Experimental Protocols for a Space Shuttle Flight and Applications for the Analysis of Cytoskeletal Structures During Fertilization, Cell Division , and Development in Sea Urchin Embryos

To explore the role of microgravity on cytoskeletal organization and skeletal calcium deposition during fertilization, cell division, and early development, the sea urchin was chosen as a model developmental system. Methods were developed to employ light, immunofluorescence, and electron microscopy on cultures being prepared for flight on the Space Shuttle. For analysis of microfilaments, microtubules, centrosomes, and calcium-requiring events, our standard laboratory protocols had to be modified substantially for experimentation on the Space Shuttle. All manipulations were carried out in a closed culture chamber containing 35 ml artificial sea water as a culture fluid. Unfertilized eggs stored for 24 hours in these chambers were fertilized with sperm diluted in sea water and fixed with concentrated fixatives for final fixation in formaldehyde, taxol, EGTA, and MgCl2(exp -6)H2O for 1 cell to 16 cell stages to preserve cytoskeletal structures for simultaneous analysis with light, immunofluorescence, and electron microscopy, and 1.5 percent glutaraldehyde and 0.4 percent formaldehyde for blastula and plueus stages. The fixed samples wre maintained in chambers without degradation for up to two weeks after which the specimens were processed and analyzed with routine methods. Since complex manipulations are not possible in the closed chambers, the fertilization coat was removed from fixation using 0.5 percent freshly prepared sodium thioglycolate solution at pH 10.0 which provided reliable immunofluorescence staining for microtubules. Sperm/egg fusion, mitosis, cytokinesis, and calcium deposition during spicule formatin in early embryogenesis were found to be without artificial alterations when compared to cells fixed fresh and processed with conventional methods

Interpenetrated Magnesium–Tricalcium Phosphate Composite: Manufacture, Characterization and In Vitro Degradation Test

Magnesium and calcium phosphates composites are promising biomaterials to create biodegradable load-bearing implants for bone regeneration. The present investigation is focused on the design of an interpenetrated magnesium–tricalcium phosphate (Mg–TCP) composite and its evaluation under immersion test. In the study, TCP porous preforms were fabricated by robocasting to have a prefect control of porosity and pore size and later infiltrated with pure commercial Mg through current-assisted metal infiltration (CAMI) technique. The microstructure, composition, distribution of phases and degradation of the composite under physiological simulated conditions were analysed by scanning electron microscopy, elemental chemical analysis and X-ray diffraction. The results revealed that robocast TCP preforms were full infiltrated by magnesium through CAMI, even small pores below 2 lm have been filled with Mg, giving to the composite a good interpenetration. The degradation rate of the Mg–TCP composite displays lower value compared to the one of pure Mg during the first 24 h of immersion test.Magnesium and calcium phosphates composites are promising biomaterials to create biodegradable load-bearing implants for bone regeneration. The present investigation is focused on the design of an interpenetrated magnesium–tricalcium phosphate (Mg–TCP) composite and its evaluation under immersion test. In the study, TCP porous preforms were fabricated by robocasting to have a prefect control of porosity and pore size and later infiltrated with pure commercial Mg through current-assisted metal infiltration (CAMI) technique. The microstructure, composition, distribution of phases and degradation of the composite under physiological simulated conditions were analysed by scanning electron microscopy, elemental chemical analysis and X-ray diffraction. The results revealed that robocast TCP preforms were full infiltrated by magnesium through CAMI, even small pores below 2 lm have been filled with Mg, giving to the composite a good interpenetration. The degradation rate of the Mg–TCP composite displays lower value compared to the one of pure Mg during the first 24 h of immersion test

Estatus taxonomico de Oenocarpus bataua (Euterpeae, Arecaceae) inferido por secuencias del ADN cloroplastico

With the aim of testing the evolutionary relationships between Oenocarpus bataua (formerly Jessenia bataua) and other Oenocarpus species (Arecaceae), a phylogenetic study of tribe Euterpeae (Arecaceae) was conducted using 3,6 kb of non-coding chloroplast DNA sequence data. The results of maximum parsimony analysis support the monophyly of Euterpeae and the inclusion of O. bataua within the Oenocarpus clade. Our results show substantial molecular divergence between O. bataua var. bataua and var. oligocarpus suggesting that, according to their original description, these two taxa may indeed represent different species. However, our phylogenies should be considered as tentative due to low statistical support.Las relaciones evolutivas entre la especie Oenocarpus bataua (anteriormente denominada Jessenia bataua) y otras especies del género Oenocarpus fueron estudiadas mediante un análisis filogenético de la tribu Euterpeae (Arecaceae) en base a 3,6 kb de secuencias de espaciadores intergénicos del cloroplasto. Los cladogramas recuperados sugieren: (1) la monofilia de la tribu Euterpeae, (2) la inclusión de los individuos de O. bataua dentro del clado de Oenocarpus, y (3) la divergencia molecular entre O. bataua var. bataua y var. oligocarpus, sugiriendo que estos taxa podrían representar especies distintas, así como fueron descritos originalmente. Sin embargo, los patrones filogenéticos mencionados tuvieron un bajo soporte estadístico, por lo cual las conclusiones derivadas de estos permanecen tentativas

Elaeis oleifera (Kunth) Cortés: A neglected palm from the Ecuadorian Amazon

Ecuador has an outstanding diversity of palm species, some of which have been well studied, certain others remain an enigma, however. A particular case is the American oil palm, Elaeis oleifera (Kunth) Cortés, first recorded in Ecuador in 1986. The genus Elaeis has a trans-Atlantic (Africa-America) distribution, with E. oleifera from the Neotropics, and E. guineensis Jacq. from Africa. It has been hypothesized that E. oleifera derives from populations of E. guineensis, which diverged 15 million years ago. At the local level, the populations of E. oleifera have a disjunct distribution, with isolated populations in Central America, the Amazonia basin, the Guianas, Chocó and the Caribbean Cost of Colombia and Venezuela, frequently associated with human or archaeological settlements. Despite the spatial and historical separation between the two species, there are no reproductive barriers to the generation of fertile hybrids. This important reproductive characteristic has allowed E. oleifera to become a major source of genetic variation for the improvement and adaptability of commercial populations of E. guineensis throughout the tropics. The Ecuadorian populations of E. oleifera from Taisha, with morphological, reproductive and agronomically important biochemical characteristics, have been used for the creation of commercial hybrids, which today are planted in many tropical regions