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Background aims Few human induced pluripotent stem cell (hiPSC) lines are Good Manufacturing Practice (GMP)-compliant, limiting the clinical use of hiPSC-derived products. Here, we addressed this by establishing and validating an in-house platform to produce GMP-compliant hiPSCs that would be appropriate for producing both allogeneic and autologous hiPSC-derived products. Methods Our standard research protocol for hiPSCs production was adapted and translated into a GMP-compliant platform. In addition to the generation of GMP-compliant hiPSC, the platform entails the methodology for donor recruitment, consent and screening, donor material procurement, hiPSCs manufacture, in-process control, specific QC test validation, QC testing, product release, hiPSCs storage and stability testing. For platform validation, one test run and three production runs were performed. Highest-quality lines were selected to establish master cell banks (MCBs). Results Two MCBs were successfully released under GMP conditions. They demonstrated safety (sterility, negative mycoplasma, endotoxins <5.0 EU/mL and negative adventitious agents), cell identity (>75% of cells expressing markers of undifferentiated state, identical STR profile, normal karyotype in >20 metaphases), purity (negative residual vectors and no plasmid integration in the genome) and potency (expression of at least two of the three markers for each of the three germ layers). In addition, directed differentiation to somitoids (skeletal muscle precursors) and six potential clinical products from all three germ layers was achieved: pancreatic islets (endoderm), kidney organoids and cardiomyocytes (mesoderm), and keratinocytes, GABAergic interneurons and inner-ear organoids (ectoderm). Conclusions We successfully developed and validated a platform for generating GMP-compliant hiPSC lines. The two MCBs released were shown to differentiate into clinical products relevant for our o, Background aims: Few human induced pluripotent stem cell (hiPSC) lines are Good Manufacturing Practice (GMP)-compliant, limiting the clinical use of hiPSC-derived products. Here, we addressed this by establishing and validating an in-house platform to produce GMP-compliant hiPSCs that would be appropriate for producing both allogeneic and autologous hiPSC-derived products. Methods: Our standard research protocol for hiPSCs production was adapted and translated into a GMP-compliant platform. In addition to the generation of GMP-compliant hiPSC, the platform entails the methodology for donor recruitment, consent and screening, donor material procurement, hiPSCs manufacture, in-process control, specific QC test validation, QC testing, product release, hiPSCs storage and stability testing. For platform validation, one test run and three production runs were performed. Highest-quality lines were selected to establish master cell banks (MCBs). Results: Two MCBs were successfully released under GMP conditions. They demonstrated safety (sterility, negative mycoplasma, endotoxins <5.0 EU/mL and negative adventitious agents), cell identity (>75% of cells expressing markers of undifferentiated state, identical STR profile, normal karyotype in >20 metaphases), purity (negative residual vectors and no plasmid integration in the genome) and potency (expression of at least two of the three markers for each of the three germ layers). In addition, directed differentiation to somitoids (skeletal muscle precursors) and six potential clinical products from all three germ layers was achieved: pancreatic islets (endoderm), kidney organoids and cardiomyocytes (mesoderm), and keratinocytes, GABAergic interneurons and inner-ear organoids (ectoderm). Conclusions: We successfully developed and validated a platform for generating GMP-compliant hiPSC lines. The two MCBs released were shown to differentiate into clinical products relevant for our own and other regenerative medicine i

Background aims Few human induced pluripotent stem cell (hiPSC) lines are Good Manufacturing Practice (GMP)-compliant, limiting the clinical use of hiPSC-derived products. Here, we addressed this by establishing and validating an in-house platform to produce GMP-compliant hiPSCs that would be appropriate for producing both allogeneic and autologous hiPSC-derived products. Methods Our standard research protocol for hiPSCs production was adapted and translated into a GMP-compliant platform. In addition to the generation of GMP-compliant hiPSC, the platform entails the methodology for donor recruitment, consent and screening, donor material procurement, hiPSCs manufacture, in-process control, specific QC test validation, QC testing, product release, hiPSCs storage and stability testing. For platform validation, one test run and three production runs were performed. Highest-quality lines were selected to establish master cell banks (MCBs). Results Two MCBs were successfully released under GMP conditions. They demonstrated safety (sterility, negative mycoplasma, endotoxins <5.0 EU/mL and negative adventitious agents), cell identity (>75% of cells expressing markers of undifferentiated state, identical STR profile, normal karyotype in >20 metaphases), purity (negative residual vectors and no plasmid integration in the genome) and potency (expression of at least two of the three markers for each of the three germ layers). In addition, directed differentiation to somitoids (skeletal muscle precursors) and six potential clinical products from all three germ layers was achieved: pancreatic islets (endoderm), kidney organoids and cardiomyocytes (mesoderm), and keratinocytes, GABAergic interneurons and inner-ear organoids (ectoderm). Conclusions We successfully developed and validated a platform for generating GMP-compliant hiPSC lines. The two MCBs released were shown to differentiate into clinical products relevant for our o, Background aims: Few human induced pluripotent stem cell (hiPSC) lines are Good Manufacturing Practice (GMP)-compliant, limiting the clinical use of hiPSC-derived products. Here, we addressed this by establishing and validating an in-house platform to produce GMP-compliant hiPSCs that would be appropriate for producing both allogeneic and autologous hiPSC-derived products. Methods: Our standard research protocol for hiPSCs production was adapted and translated into a GMP-compliant platform. In addition to the generation of GMP-compliant hiPSC, the platform entails the methodology for donor recruitment, consent and screening, donor material procurement, hiPSCs manufacture, in-process control, specific QC test validation, QC testing, product release, hiPSCs storage and stability testing. For platform validation, one test run and three production runs were performed. Highest-quality lines were selected to establish master cell banks (MCBs). Results: Two MCBs were successfully released under GMP conditions. They demonstrated safety (sterility, negative mycoplasma, endotoxins <5.0 EU/mL and negative adventitious agents), cell identity (>75% of cells expressing markers of undifferentiated state, identical STR profile, normal karyotype in >20 metaphases), purity (negative residual vectors and no plasmid integration in the genome) and potency (expression of at least two of the three markers for each of the three germ layers). In addition, directed differentiation to somitoids (skeletal muscle precursors) and six potential clinical products from all three germ layers was achieved: pancreatic islets (endoderm), kidney organoids and cardiomyocytes (mesoderm), and keratinocytes, GABAergic interneurons and inner-ear organoids (ectoderm). Conclusions: We successfully developed and validated a platform for generating GMP-compliant hiPSC lines. The two MCBs released were shown to differentiate into clinical products relevant for our own and other regenerative medicine i

Since February 2020, our everyday habits have undergone a process of radical change. Initial news stories from China about the COVID-19 outbreak seemed far removed, and this perception of distance made us feel safe. However, as time went on, the situation evolved into an unstoppable crescendo that has ultimately impacted all aspects of billions of lives. Everything came to a halt: work, school, culture ... to be progressively restored via the only viable strategy available: the deployment of distance modes of delivery. As the emergency escalated, governments around the world identified different levels of response. Social isolation arrangements meant that people would be confined to their homes for an unquantifiable length of time. Many parts of the cultural sector were particularly and severely a!ected by the lockdown, given that they are usually perceived as the places of encounter and exchange par excellence. Some workers were offered temporary unemployment relief, while others had their contracts put on hold. Cultural institutions began to redefine themselves and reprogramme the immediate future, choosing between suspending their activities while waiting, and working to identify the most appropriate means by which they could remain active at a distance. They set out to invisibly heal a breach perceived as irreparable, via a process that saw each individual cultural operator seeking to establish new expressions of the notion of sustainability, as evoked in Agenda 2030.2 This document, produced by the United Nations in 2015,3 called for all actors, collective and individual, to pursue change in the form of 17 sustainable development goals. It o!ered a guide to determining what was truly sustainable, necessary and meaningful at this time of uncertainty, as well as to revisiting existing prospects and plans – Agenda 2030 suddenly took on new relevance. Cultural institutions were now faced with a novel challenge to their priority status as public services. The extrao

CRYSTAL is a periodic ab initio code that uses a Gaussian-Type basis set to express crystalline orbitals (i.e., Bloch functions). The use of atomcentered basis functions allows treating 3D (crystals), 2D (slabs), 1D (polymers), and 0D (molecules) systems on the same grounds. In turn, all-electron calculations are inherently permitted along with pseudopotential strategies. A variety of density functionals are implemented, including global and range-separated hybrids of various natures and, as an extreme case, Hartree Fock (HF). The cost for HF or hybrids is only about 3 5 times higher than when using the local density approximation or the generalized gradient approximation. Symmetry is fully exploited at all steps of the calculation. Many tools are available to modify the structure as given in input and simplify the construction of complicated objects, such as slabs, nanotubes, molecules, and clusters. Many tensorial properties can be evaluated by using a single input keyword: elastic, piezoelectric, photoelastic, dielectric, first and second hyperpolarizabilities, etc. The calculation of infrared and Raman spectra is available, and the intensities are computed analytically. Automated tools are available for the generation of the relevant configurations of solid solutions and/or disordered systems. Three versions of the code exist: serial, parallel, and massive-parallel. In the second one, the most relevant matrices are duplicated on each core, whereas in the third one, the Fock matrix is distributed for diagonalization. All the relevant vectors are dynamically allocated and deallocated after use, making the code very agile. CRYSTAL can be used efficiently on high performance computing machines up to thousands of cores.

Author Posting. © American Chemical Society, 2019. This is an open access article published under an ACS AuthorChoice License. The definitive version was published in Environmental Science and Technology 53(14), (2019):8244-8251, doi:10.1021/acs.est.9b02344., Perylene is a frequently abundant, and sometimes the only polycyclic aromatic hydrocarbon (PAH) in aquatic sediments, but its origin has been subject of a longstanding debate in geochemical research and pollutant forensics because its historical record differs markedly from typical anthropogenic PAHs. Here we investigate whether perylene serves as a source-specific molecular marker of fungal activity in forest soils. We use a well-characterized sedimentary record (1735 to 1999) from the anoxic-bottom waters of the Pettaquamscutt River basin, RI, USA to examine mass accumulation rates and isotope records of perylene, and compare them with total organic carbon and the anthropogenic PAH fluoranthene. We support our arguments with radiocarbon (14C) data of higher plant leaf-wax n-alkanoic acids. Isotope-mass balance calculations of perylene and n-alkanoic acids indicate that ~40 % of sedimentary organic matter is of terrestrial origin. Further, both terrestrial markers are pre-aged on millennial time-scales prior to burial in sediments and insensitive to elevated 14C concentrations following nuclear weapons testing in the mid-20th Century. Instead, changes coincide with enhanced erosional flux during urban sprawl. These findings suggest that perylene is definitely a product of soil derived fungi, and a powerful chemical tracer to study spatial and temporal connectivity between terrestrial and aquatic environments., We thank John King, Sean Sylva, Brad Hubeny, Peter Sauer, and Jim Broda for their help in sampling; Carl Johnson and Daniel Montluçon for their incessant help with analyses; as well as Mark Yunker for critical discussion on the perils of perylene. Professor Phil Meyers and two anonymous reviewers provided comments that improved the quality of the manuscript. U.M.H. acknowledges the Swiss National Science Foundation for his postdoctoral fellowship and T.I.E. and K.A.H. acknowledges the NSF for research grants CHE-0089172 and OCE-9708478., 2020-06-19

Perylene is a frequently abundant, and sometimes the only polycyclic aromatic hydrocarbon (PAH) in aquatic sediments, but its origin has been subject of a longstanding debate in geochemical research and pollutant forensics because its historical record differs markedly from typical anthropogenic PAHs. Here we investigate whether perylene serves as a source-specific molecular marker of fungal activity in forest soils. We use a well-characterized sedimentary record (1735 to 1999) from the anoxic-bottom waters of the Pettaquamscutt River basin, RI, USA to examine mass accumulation rates and isotope records of perylene, and compare them with total organic carbon and the anthropogenic PAH fluoranthene. We support our arguments with radiocarbon (14C) data of higher plant leaf-wax n-alkanoic acids. Isotope-mass balance calculations of perylene and n-alkanoic acids indicate that ~40 % of sedimentary organic matter is of terrestrial origin. Further, both terrestrial markers are pre-aged on millennial time-scales prior to burial in sediments and insensitive to elevated 14C concentrations following nuclear weapons testing in the mid-20th Century. Instead, changes coincide with enhanced erosional flux during urban sprawl. These findings suggest that perylene is definitely a product of soil derived fungi, and a powerful chemical tracer to study spatial and temporal connectivity between terrestrial and aquatic environments.

Author Posting. © American Chemical Society, 2019. This is an open access article published under an ACS AuthorChoice License. The definitive version was published in Environmental Science and Technology 53(14), (2019):8244-8251, doi:10.1021/acs.est.9b02344., Perylene is a frequently abundant, and sometimes the only polycyclic aromatic hydrocarbon (PAH) in aquatic sediments, but its origin has been subject of a longstanding debate in geochemical research and pollutant forensics because its historical record differs markedly from typical anthropogenic PAHs. Here we investigate whether perylene serves as a source-specific molecular marker of fungal activity in forest soils. We use a well-characterized sedimentary record (1735 to 1999) from the anoxic-bottom waters of the Pettaquamscutt River basin, RI, USA to examine mass accumulation rates and isotope records of perylene, and compare them with total organic carbon and the anthropogenic PAH fluoranthene. We support our arguments with radiocarbon (14C) data of higher plant leaf-wax n-alkanoic acids. Isotope-mass balance calculations of perylene and n-alkanoic acids indicate that ~40 % of sedimentary organic matter is of terrestrial origin. Further, both terrestrial markers are pre-aged on millennial time-scales prior to burial in sediments and insensitive to elevated 14C concentrations following nuclear weapons testing in the mid-20th Century. Instead, changes coincide with enhanced erosional flux during urban sprawl. These findings suggest that perylene is definitely a product of soil derived fungi, and a powerful chemical tracer to study spatial and temporal connectivity between terrestrial and aquatic environments., We thank John King, Sean Sylva, Brad Hubeny, Peter Sauer, and Jim Broda for their help in sampling; Carl Johnson and Daniel Montluçon for their incessant help with analyses; as well as Mark Yunker for critical discussion on the perils of perylene. Professor Phil Meyers and two anonymous reviewers provided comments that improved the quality of the manuscript. U.M.H. acknowledges the Swiss National Science Foundation for his postdoctoral fellowship and T.I.E. and K.A.H. acknowledges the NSF for research grants CHE-0089172 and OCE-9708478., 2020-06-19

No abstract, Negli ultimi due decenni, l'identificazione delle proprietà biologiche del Fibroblast Growth Factor 23 (FGF23) ha notevolmente ampliato le conoscenze sulla regolazione endocrina e paracrina dell'omeostasi dei fosfati e sulle relazioni intercorrenti tra asse rene-intestino-tessuto osseo e sistema biologico vitamina D-FTH-calcio-fosfati. Lo studio delle proprietà biologiche di FGF23 ha inoltre aperto interessanti campi di ricerca in ambito clinico e farmacologico.

No abstract, Negli ultimi due decenni, l'identificazione delle proprietà biologiche del Fibroblast Growth Factor 23 (FGF23) ha notevolmente ampliato le conoscenze sulla regolazione endocrina e paracrina dell'omeostasi dei fosfati e sulle relazioni intercorrenti tra asse rene-intestino-tessuto osseo e sistema biologico vitamina D-FTH-calcio-fosfati. Lo studio delle proprietà biologiche di FGF23 ha inoltre aperto interessanti campi di ricerca in ambito clinico e farmacologico.

Metabolic syndrome is a risk factor for nephrolithiasis. This study was performed to evaluate the clinical and biochemical profile of calcium-oxalate nephrolithiasis in stone formers with metabolic syndrome. A total of 526 recurrent stone formers, 184 of them with metabolic syndrome, and 214 controls were examined. Stone formers with metabolic syndrome showed higher sodium excretion [mean (95% confidence interval), 196 (176–218) vs 160 (150–168) mmol/24h; p, La sindrome metabolica è un fattore di rischio per nefrolitiasi. Questo studio è stato effettuato per valutare il profilo clinico e biochimico di pazienti con nefrolitiasi recidivante da ossalato di calcio e sindrome metabolica. Sono stati arruolati un totale di 526 calcolotici, 184 dei quali con sindrome metabolica, e 214 controlli. I calcolotici con sindrome metabolica hanno mostrato un'escrezione di sodio superiore [media (95% intervallo di confidenza), 196 (176-218) vs 160 (150-168) mmol/24h; p

No abstract, Negli ultimi due decenni, l'identificazione delle proprietà biologiche del Fibroblast Growth Factor 23 (FGF23) ha notevolmente ampliato le conoscenze sulla regolazione endocrina e paracrina dell'omeostasi dei fosfati e sulle relazioni intercorrenti tra asse rene-intestino-tessuto osseo e sistema biologico vitamina D-FTH-calcio-fosfati. Lo studio delle proprietà biologiche di FGF23 ha inoltre aperto interessanti campi di ricerca in ambito clinico e farmacologico.

Metabolic syndrome is a risk factor for nephrolithiasis. This study was performed to evaluate the clinical and biochemical profile of calcium-oxalate nephrolithiasis in stone formers with metabolic syndrome. A total of 526 recurrent stone formers, 184 of them with metabolic syndrome, and 214 controls were examined. Stone formers with metabolic syndrome showed higher sodium excretion [mean (95% confidence interval), 196 (176–218) vs 160 (150–168) mmol/24h; p, La sindrome metabolica è un fattore di rischio per nefrolitiasi. Questo studio è stato effettuato per valutare il profilo clinico e biochimico di pazienti con nefrolitiasi recidivante da ossalato di calcio e sindrome metabolica. Sono stati arruolati un totale di 526 calcolotici, 184 dei quali con sindrome metabolica, e 214 controlli. I calcolotici con sindrome metabolica hanno mostrato un'escrezione di sodio superiore [media (95% intervallo di confidenza), 196 (176-218) vs 160 (150-168) mmol/24h; p

No abstract, Negli ultimi due decenni, l'identificazione delle proprietà biologiche del Fibroblast Growth Factor 23 (FGF23) ha notevolmente ampliato le conoscenze sulla regolazione endocrina e paracrina dell'omeostasi dei fosfati e sulle relazioni intercorrenti tra asse rene-intestino-tessuto osseo e sistema biologico vitamina D-FTH-calcio-fosfati. Lo studio delle proprietà biologiche di FGF23 ha inoltre aperto interessanti campi di ricerca in ambito clinico e farmacologico.

No abstract, Negli ultimi due decenni, l'identificazione delle proprietà biologiche del Fibroblast Growth Factor 23 (FGF23) ha notevolmente ampliato le conoscenze sulla regolazione endocrina e paracrina dell'omeostasi dei fosfati e sulle relazioni intercorrenti tra asse rene-intestino-tessuto osseo e sistema biologico vitamina D-FTH-calcio-fosfati. Lo studio delle proprietà biologiche di FGF23 ha inoltre aperto interessanti campi di ricerca in ambito clinico e farmacologico.

Metabolic syndrome is a risk factor for nephrolithiasis. This study was performed to evaluate the clinical and biochemical profile of calcium-oxalate nephrolithiasis in stone formers with metabolic syndrome. A total of 526 recurrent stone formers, 184 of them with metabolic syndrome, and 214 controls were examined. Stone formers with metabolic syndrome showed higher sodium excretion [mean (95% confidence interval), 196 (176–218) vs 160 (150–168) mmol/24h; p, La sindrome metabolica è un fattore di rischio per nefrolitiasi. Questo studio è stato effettuato per valutare il profilo clinico e biochimico di pazienti con nefrolitiasi recidivante da ossalato di calcio e sindrome metabolica. Sono stati arruolati un totale di 526 calcolotici, 184 dei quali con sindrome metabolica, e 214 controlli. I calcolotici con sindrome metabolica hanno mostrato un'escrezione di sodio superiore [media (95% intervallo di confidenza), 196 (176-218) vs 160 (150-168) mmol/24h; p

Fully hydroxylated surfaces derived from crystalline edingtonite were adopted to model the variety of sites known to exist at the amorphous silica surface, namely isolated, geminal and interacting silanols. Structures, energetics and vibrational features of the surfaces either bare or in contact with water were modelled at DFT level using the B3LYP functional with a GTO basis set of double-zeta polarized quality using the periodic ab-initio CRYSTAL06 code. Simulated infrared spectra of both dry and water wet edingtonite surfaces were in excellent agreement with the experimental ones recorded on amorphous silica. Water interaction energies were compared with microcalorimetric differential heats of adsorption data showing good agreement, albeit computed ones being slightly underestimated due to the lack of dispersive forces in the B3LYP functional

Spinocerebellar ataxia type 3 (SCA3) is a polyglutamine (polyQ) disorder caused by a CAG repeat expansion in the ataxin-3 (ATXN3) gene resulting in toxic protein aggregation. Inflammation and oxidative stress are considered secondary factors contributing to the progression of this neurodegenerative disease. There is no cure that halts or reverses the progressive neurodegeneration of SCA3. Here we show that overexpression of cystathionine.-lyase, a central enzyme in cysteine metabolism, is protective in a Drosophila model for SCA3. SCA3 flies show eye degeneration, increased oxidative stress, insoluble protein aggregates, reduced levels of protein persulfidation and increased activation of the innate immune response. Overexpression of Drosophila cystathionine.-lyase restores protein persulfidation, decreases oxidative stress, dampens the immune response and improves SCA3-associated tissue degeneration. Levels of insoluble protein aggregates are not altered; therefore, the data implicate a modifying role of cystathionine.-lyase in ameliorating the downstream consequence of protein aggregation leading to protection against SCA3-induced tissue degeneration. The cystathionine.-lyase expression is decreased in affected brain tissue of SCA3 patients, suggesting that enhancers of cystathionine.-lyase expression or activity are attractive candidates for future therapies.

Spinocerebellar ataxia type 3 (SCA3) is a polyglutamine (polyQ) disorder caused by a CAG repeat expansion in the ataxin-3 (ATXN3) gene resulting in toxic protein aggregation. Inflammation and oxidative stress are considered secondary factors contributing to the progression of this neurodegenerative disease. There is no cure that halts or reverses the progressive neurodegeneration of SCA3. Here we show that overexpression of cystathionine.-lyase, a central enzyme in cysteine metabolism, is protective in a Drosophila model for SCA3. SCA3 flies show eye degeneration, increased oxidative stress, insoluble protein aggregates, reduced levels of protein persulfidation and increased activation of the innate immune response. Overexpression of Drosophila cystathionine.-lyase restores protein persulfidation, decreases oxidative stress, dampens the immune response and improves SCA3-associated tissue degeneration. Levels of insoluble protein aggregates are not altered; therefore, the data implicate a modifying role of cystathionine.-lyase in ameliorating the downstream consequence of protein aggregation leading to protection against SCA3-induced tissue degeneration. The cystathionine.-lyase expression is decreased in affected brain tissue of SCA3 patients, suggesting that enhancers of cystathionine.-lyase expression or activity are attractive candidates for future therapies.

The reflectance spectrum of one member of the garnet family, Mn3Al2Si3O12 spessartine, was computed at the ab initio level with an all electron Gaussian type basis set and the B3LYP Hamiltonian. The static high frequency dielectric constant was obtained by applying the Coupled Perturbed Kohn Sham scheme as implemented in the CRYSTAL code; the Hessian matrix was evaluated numerically starting from the analytical gradients of the total energy with respect to the Cartesian coordinates of the atoms; the oscillator strengths were computed from well localized Wannier functions. An excellent agreement was obtained with the corresponding experimental spectrum, the exception being the very low frequency region.

Ocean Sampling Day was initiated by the EU-funded Micro B3 (Marine Microbial Biodiversity, Bioinformatics, Biotechnology) project to obtain a snapshot of the marine microbial biodiversity and function of the world's oceans. It is a simultaneous global mega-sequencing campaign aiming to generate the largest standardized microbial data set in a single day. This will be achievable only through the coordinated efforts of an Ocean Sampling Day Consortium, supportive partnerships and networks between sites. This commentary outlines the establishment, function and aims of the Consortium and describes our vision for a sustainable study of marine microbial communities and their embedded functional traits.

The vibrational properties of CaCO3 aragonite have been investigated both theoretically, by using a quantum mechanical approach (all electron Gaussian type basis set and B3LYP HF-DFT hybrid functional, as implemented in the CRYSTAL code) and experimentally, by collecting polarized infrared (IR) reflectance and Raman spectra. The combined use of theory and experiment permits on the one hand to analyze the many subtle features of the measured spectra, on the other hand to evidentiate limits and deficiencies of both approaches. The full set of TO and LO IR active modes, their intensities, the dielectric tensor (in its static and high frequency components), and the optical indices have been determined, as well as the Raman frequencies. Tools such as isotopic substitution and graphical animation of the modes are available, that complement the analysis of the spectrum.

The IR vibrational properties and the corresponding reflectance spectra of the six most common members of the garnet family (pyrope Mg3Al2Si3O12, almandine Fe3Al2Si3O12, spessartine Mn3Al2Si3O12, grossular Ca3Al2Si3O12, uvarovite Ca3Cr2Si3O12, and andradite Ca3Fe2Si3O12) were simulated at the ab initio level with the CRYSTAL09 code by using a large all-electron Gaussian-type basis set and the B3LYP hybrid functional. The 17 IR active F1u transverse optical (TO) and longitudinal optical (LO) frequencies, the oscillator strengths, the high frequency and static dielectric constants, and the reflectance spectrum were computed. The agreement with experiments for the TO and LO peaks is always excellent, the mean absolute difference for the whole set of data (overall 178 peaks) being 5 cm−1. Oscillator strengths, calculated from the mass-weighted effective Born charges, are found in semi-quantitative agreement with the experimental data. The reflectance spectra, simulated through the classical dispersion relation, reproduce the experimental curves extremely well. The availability of the full set of simulated frequencies and intensities, obtained by using uniform computational tools (computer code, variational basis sets, density functional), permits the establishment of correlations between IR wavenumbers and structural features suggested, but only partially documented, in the past.

The structure and vibrational spectrum of boehmite have been in- vestigated at the quantum-mechanical level with the CRYSTAL code, using a Gaussian-type basis set and the B3LYP Hamiltonian. Three space groups are considered in this study: Cmcm, Cmc21, P21/c. Cmcm turns out to corre- spond to a transition state, whereas Cmc21 and P21/c are minimum energy structures. The difference among them is the position of H atoms only, the Al-O frame being essentially the same. Harmonic frequencies at the ?? point have been computed. The comparison between calculated and experimental frequencies shows a good agreement for the Al-O part of the spectrum (under 790 cm-1). For the Al-OH bending modes (800-1300 cm-1) an absolute dif- ferences of 50-100 cm-1 is observed; for the OH stretching modes (3200-3500 cm-1) it increases to 120-200 cm-1: anharmonicity is large because OH groupsare involved in strong hydrogen bonds.

This paper reports about the development and test of a recovery system for small capsules, originally developed for the YES2 satellite launched in 2007, that included a miniature re-entry capsule, Fotino. The system includes a beacon and parachute, an activation system, and a compact spring-based parachute ejection system, initiated by a pyrotechnic device. Design challenges were low mass (few hundred grams), low volume (the ejection system is the size of a shoe-polish box) and (de)installation possible with minimal access. High ejection energy was required (about 15 J) to eject the parachute even reliably from a spinning fast-dropping capsule. The system can be used for recovery of lightweight capsules and probes released from orbit, sounding rockets or high altitude balloons. The overall design approach has been hands-on, goal-oriented and pragmatic, due to time and budget constraints. Pros and cons of this approach are highlighted. The paper reports on design, trade-offs and the successful qualification of the various systems involved and the mechanism in particular. Unfortunately the capsule has not been recovered yet, but analysis of its whereabouts and possible reasons of lack of beacon signal will be discussed. Nevertheless, a reflight is foreseen, as the successful qualification and overall mass and dimensional properties make the recovery system an attractive option for future small capsules and probes., Space Engineering, Aerospace Engineering

This paper reports about the development and test of a recovery system for small capsules, originally developed for the YES2 satellite launched in 2007, that included a miniature re-entry capsule, Fotino. The system includes a beacon and parachute, an activation system, and a compact spring-based parachute ejection system, initiated by a pyrotechnic device. Design challenges were low mass (few hundred grams), low volume (the ejection system is the size of a shoe-polish box) and (de)installation possible with minimal access. High ejection energy was required (about 15 J) to eject the parachute even reliably from a spinning fast-dropping capsule. The system can be used for recovery of lightweight capsules and probes released from orbit, sounding rockets or high altitude balloons. The overall design approach has been hands-on, goal-oriented and pragmatic, due to time and budget constraints. Pros and cons of this approach are highlighted. The paper reports on design, trade-offs and the successful qualification of the various systems involved and the mechanism in particular. Unfortunately the capsule has not been recovered yet, but analysis of its whereabouts and possible reasons of lack of beacon signal will be discussed. Nevertheless, a reflight is foreseen, as the successful qualification and overall mass and dimensional properties make the recovery system an attractive option for future small capsules and probes., Space Engineering, Aerospace Engineering

The OH vibrational frequency of four crystalline compounds ranging from ionic (brucite, Mg(OH)(2), and portlandite, Ca(OH)(2)) to semi-covalent (edingtonite, as representative of free surface OH groups in silica, and acid chabazite, as representative of acid zeolites) has been investigated at quantum mechanical level with the CRYSTAL program using the B3LYP hybrid functional. The OH vibration is calculated in two ways: (i) in the harmonic approximation, by diagonalizing the fully coupled dynamical matrix to yield the harmonic frequency omega(h). (ii) at the anharmonic level, by decoupling the OH stretching mode from the bulk phonons and by numerically solving the one-dimensional Schrodinger equation associated with the OH potential energy to yield the fundamental omega(01) and the first overtone omega(02) frequencies. The harmonic and anharmonic frequencies differ by more than 150 cm(-1). In the cases where direct comparison is possible ( brucite, portlandite and edingtonite), the experimental and calculated frequencies differ by less than 10 cm(-1); the calculated anharmonicity constant, omega(e)x(e) (2 omega(01) - omega(02))/2, is systematically smaller than the experimental value by about 10 cm(-1). The effect of the computational parameters on the computed frequencies is explored, with particular attention to the grid used for the construction of the DFT exchange and correlation contribution to the Hamiltonian and the accuracy in the geometry optimisation

The vibrational spectrum of Ca3Fe2Si3O12 andradite is calculated at the point by using the periodic ab initio CRYSTAL program that adopts an all-electron Gaussian-type basis set and the B3LYP Hamiltonian. The full set of frequencies (17 IR active, 25 Raman active, and 55 inactive modes) is calculated. The effect of the basis set on the calculated frequencies is discussed. The modes are characterized by direct inspection of the eigenvectors and isotopic substitution. The present calculations permit us to clarify some of the assignment problems raised by experiments. The mean absolute differences of the various modes with respect to the available experimental IR and Raman data are as small as 9 and 5 cm-1, respectively.

Ab initio periodic calculations have been performed with the CRYSTAL code, which is based on Gaussian basis sets, to investigate the structure and OH vibrational features (both harmonic and anharmonic) of Mg(OH)(2) and beta-Be(OH)(2) crystals, which represent two extreme situations in which the OH group can be involved. In the latter, it participates in H-bonds of intermediate strength, whereas, in the former, it is essentially free. Hartree-Fock (HF), local density (LDA), gradient-corrected (PW91), and hybrid (B3LYP) density functionals have been used and the results compared with experiment. For Mg(OH)(2) the B3LYP OH frequencies are in very good agreement with experiment, whereas, for beta-Be(OM)(2), they are similar to100 cm(-1) too low. LDA grossly underestimates the OH frequency (330 and 800 cm(-1) for Mg(OH)(2) and beta-Be(OH)(2), respectively), and PW91 moderately does (170 and 400 cm(-1), respectively)

The harmonic frequency spectrum of bulk Mg(OH)(2), brucite, has been computed with the CRYSTAL periodic code, using four different hamiltonians, namely Hartree-Fock (HF), local density (LDA), gradient corrected PW91 and hybrid B3LYP. The anharmonicity of the 011 stretching frequency has also been evaluated, as well as the transverse/longitudinal optical (TO/LO) splitting. Comparison with the frequencies of the single layer shows that the bulk OH stretching splitting is due to interlayer interaction. Agreement with experiment is excellent for B3LYP (less than 10 cm(-1) differences), less so for PW91 and much less satisfactory for both LDA and HF. (C) 2004 Elsevier B.V. All rights reserved