Near-infrared Fourier transform room-temperature photoluminescence of erbium complexes

A modified Fourier transform (FT) Raman bench spectrometer designed for the detection of weak light emission in the 800–1700 nm wavelength region has been used to demonstrate the advantages of FT spectroscopy for measuring near-infrared photoluminescence spectra of lanthanide complexes with a good resolution and very good sensitivity. This apparatus has been tested with an ultraviolet laser source (325 nm) on three standard erbium complexes. The 4I13/24I15/2 emission of tris-(acetylacetonato) (1,10 phenanthroline) erbium [Er(acac)3(phen)], tris-(4,4,4,-trifluoro-1-(2 thenoyl)-1,3-butenedione) (1,10 phenanthroline) erbium [Er(TTFA)3(phen)] and tris(8-hydroxyquinolinato) erbium [Erq3] has thus been recorded in solution and in the solid state and compared with literature. ©2003 American Institute of Physics

Reliability investigation of a carbon nanotube array thermal interface material

As feature density increases within microelectronics, so does the dissipated power density, which puts an increased demand on thermal management. Thermal interface materials (TIMs) are used at the interface between contacting surfaces to reduce the thermal resistance, and is a critical component within many electronics systems. Arrays of carbon nanotubes (CNTs) have gained significant interest for application as TIMs, due to the high thermal conductivity, no internal thermal contact resistances and an excellent conformability. While studies show excellent thermal performance, there has to date been no investigation into the reliability of CNT array TIMs. In this study, CNT array TIMs bonded with polymer to close a Si-Cu interface were subjected to thermal cycling. Thermal interface resistance measurements showed a large degradation of the thermal performance of the interface within the first 100 cycles. More detailed thermal investigation of the interface components showed that the connection between CNTs and catalyst substrate degrades during thermal cycling even in the absence of thermal expansion mismatch, and the nature of this degradation was further analyzed using X-ray photoelectron spectroscopy. This study indicates that the reliability will be an important consideration for further development and commercialization of CNT array TIMs

Common Genetic Polymorphisms Influence Blood Biomarker Measurements in COPD

Implementing precision medicine for complex diseases such as chronic obstructive lung disease (COPD) will require extensive use of biomarkers and an in-depth understanding of how genetic, epigenetic, and environmental variations contribute to phenotypic diversity and disease progression. A meta-analysis from two large cohorts of current and former smokers with and without COPD [SPIROMICS (N = 750); COPDGene (N = 590)] was used to identify single nucleotide polymorphisms (SNPs) associated with measurement of 88 blood proteins (protein quantitative trait loci; pQTLs). PQTLs consistently replicated between the two cohorts. Features of pQTLs were compared to previously reported expression QTLs (eQTLs). Inference of causal relations of pQTL genotypes, biomarker measurements, and four clinical COPD phenotypes (airflow obstruction, emphysema, exacerbation history, and chronic bronchitis) were explored using conditional independence tests. We identified 527 highly significant (p 10% of measured variation in 13 protein biomarkers, with a single SNP (rs7041; p = 10−392) explaining 71%-75% of the measured variation in vitamin D binding protein (gene = GC). Some of these pQTLs [e.g., pQTLs for VDBP, sRAGE (gene = AGER), surfactant protein D (gene = SFTPD), and TNFRSF10C] have been previously associated with COPD phenotypes. Most pQTLs were local (cis), but distant (trans) pQTL SNPs in the ABO blood group locus were the top pQTL SNPs for five proteins. The inclusion of pQTL SNPs improved the clinical predictive value for the established association of sRAGE and emphysema, and the explanation of variance (R2) for emphysema improved from 0.3 to 0.4 when the pQTL SNP was included in the model along with clinical covariates. Causal modeling provided insight into specific pQTL-disease relationships for airflow obstruction and emphysema. In conclusion, given the frequency of highly significant local pQTLs, the large amount of variance potentially explained by pQTL, and the differences observed between pQTLs and eQTLs SNPs, we recommend that protein biomarker-disease association studies take into account the potential effect of common local SNPs and that pQTLs be integrated along with eQTLs to uncover disease mechanisms. Large-scale blood biomarker studies would also benefit from close attention to the ABO blood group

Electronic relaxation of aniline in argon matrix: A site selective laser spectroscopy

International audienceAbsorption (S1←S0), fluorescence (S1→S0) and phosphorescence (T1→S0) spectra of aniline isolated in argon matrices are presented and analyzed. Upon selective laser excitation, two families of sites are characterized by electronic spectroscopy and excited state dynamics. A strong electron/phonon coupling is observed in the S1↔S0 transition due to a geometry change of the molecule. Phosphorescence spectra exhibit different vibronic intensity distribution for both sites; a1 in plane and b1 out-of-plane modes are observed. A direct estimation of the inversion splitting in the ground state (46 cm−1) is obtained from the presence of an intense doublet assigned to 3A1(0+)→1A1(0+,0−) vibronic transitions

Partie II : analyse comparative des politiques de logement.

In occasione del cinquecentenario della morte di Raffaello Sanzio (1483-1520) si propone un testo agile e informato per scoprire dipinti e architetture eseguiti a Roma dall\u2019arrivo nell\u2019Urbe nel 1508 alla morte nel 1520. Aggiornate e complete dei dati essenziali, le schede esplicative illustrano l\u2019ampio ventaglio della produzione matura del Raffaello pittore, dagli affreschi alle pale d\u2019altare ai ritratti eseguiti per Roma o oggi l\uec conservati, e permettono di individuare e di comprendere le tracce dell\u2019attivit\ue0 del Raffaello architetto. Si svolge attraverso le opere il racconto dell\u2019appassionante stagione romana dell\u2019artista, impegnato nel continuo rinnovamento del proprio linguaggio di pittore nel dialogo travolgente con Michelangelo, nella gara con Sebastiano del Piombo, nella spinta possente delle sollecitazioni fornite dal repertorio antico della scultura, nel nuovo impegno come caposcuola, alla guida di una bottega che far\ue0 da modello per tutto il secolo e oltre, e si segue il definirsi proprio a Roma dei suoi interessi di architetto e degli obiettivi che egli matura sul fronte dell\u2019architettura moderna su sollecitazione di Bramante e poi di altri, nella sfida costituita dal confronto con i resti degli edifici antichi, in uno scambio costante con gli umanisti, come Pietro Bembo e Fra Giocondo, suoi ferventi interlocutori, committenti, sostenitori. Il testo non trascura di segnalare le opere non accessibili legate all\u2019operato del Sanzio, quali, in Vaticano, le Logge o l\u2019Appartamento del cardinal Bibbiena, o quelle che da architetto egli non pot\ue9 realizzare ma di cui ci restano suoi progetti, o che vennero distrutte (Palazzo Branconio dell\u2019Aquila), e dedica un\u2019attenzione speciale, per la forza del suo rapporto con il presente, alla lettera a Leone X scritta da Raffaello e da Baldassarre Castiglione, riconosciuta come primo documento di una consapevole riflessione sull\u2019urgenza della conservazione dell\u2019architettura e dell\u2019arte del passato alla quale oggi pi\uf9 di allora siamo chiamati a rispondere

Site effects on the electronic relaxation of aromatic molecules in van der Waals solids

International audienceFluorescence and phosphorescence of naphthalene and aniline molecules trapped in cryogenic matrices present site-dependent features. The isolation in solid argon has been especially investigated. Experimental results for naphthalene are summarized and related to the site geometries obtained from molecular dynamics calculations. In the case of aniline, site effects are mainly revealed through the phosphorescence spectra. In particular sites, the measurement of the inversion frequency can be directly extracted

Thermoelectric property analysis of CsSnX3 Materials (X=1, Br, Cl)

International audienceThe thermoelectric properties of CsSnI3 are analysed with the ab initio first-principle density functional theory (DFT). Seebeck coefficient, electrical and thermal conductivities are calculated in order to determine the dimensionless figure ofmerit ZT. Knowing that CsSnI3 is one of the perovskite series of materials that undergo complex phase transitions with temperature, the calculations are performed for different common phases. Several phases of CsSnBr3 and CsSnCl3 are alsoanalysed as comparisons. For the same material, comparison of band structures showed that the band gap increases withphase transition from phase – α to phase – β then to phase – γ. And the ZT values show the same trend as the band gaps.CsSnCl3 exhibits a higher ZT value than CsSnBr3 and CsSnI3 at phase-α

Highly Efficient Thermal Glue for Carbon Nanotubes based on Azide Polymers

International audienceEquilibrium molecular dynamics (EMD) simulations and experimental data show that the thermal contact resistance (TCR) between carbon nanotube (CNT) and azide-functionalized polymer with C-N bond is significantly decreased compared to that with Van der Waals force interaction. EMD simulations indicate that C-N covalent bond between CNT and polymer is the most efficient way to reduce TCR, and we measured the lowest thermal interface resistance of Si/CNT/Polymer/Cu thermal interface material as 1.40 mm2 KW 1 with CNTs of 10 lm length. These results provide useful information for future designs of thermal glue for carbon-based materials with better thermal conduction

Hiponatremia e hipokalemia graves, recientes, asociadas a hidroclorotiazida, enalaprila y citalopram.: Caso clínico

We report a 72 years old hypertensive female, treated with enalapril 10 mg/day and hydrochlorothiazide 25 mg/day during three years. She presented a depressive disorder and cytalopram was prescribed in a dose of 10 mg/day. Two weeks before admission, a serum electrolyte analysis disclosed normal results and the cytalopram dose was increased to 20 mg/day. The patient was admitted with a hyponatremic encephalopathy with a plasma sodium of 100 mEq/L and a plasma potassium of 2.0 mEq/L. Cytalopram, enalapril and hydrochlorothiazide were discontinued, hypertonic NaCl and KCl were administered. The patient had a favorable evolution with a remarkable improvement of her symptoms