1,208 research outputs found
High-spin low-spin transition
Temperature dependent nuclear inelastic-scattering (NIS) of synchrotron
radiation was applied to investigate both spin states of the spin-crossover
complex [Fe(tpa)(NCS)(2)] (tpa = tris(2-pyridylmethyl)amine). A remarkable
increase of the iron-ligand bond stretching upon spin crossover has
unambiguously been identified by comparing the measured NIS spectra with
theoretical simulations based on density-functional calculations
Pressure-induced changes of the vibrational modes of spin-crossover complexes studied by nuclear resonance scattering of synchrotron radiation
Nuclear inelastic scattering (NIS) spectra were recorded for the
spin-crossover complexes STP and ETP (STP =
[Fe(1,1,1-trisf[N-(2-pyridylmethyl)-N-methylamino]methylg- ethane)](ClO4)2 and
ETP =
[Fe(1,1,1-trisf[N-(2-pyridylmethyl)-N-methylamino]methylg-butane)](ClO4)2) at
30 K and at room temperature and also at ambient pressure and applied pressure
(up to 2.6 GPa). Spin transition from the high-spin (HS) to the low-spin (LS)
state was observed by lowering temperature and also by applying pressure at
room temperature and has been assigned to the hardening of iron-bond stretching
modes due to the smaller volume in the LS isomer
Sarcopenia Is a Negative Prognostic Factor in Patients Undergoing Transarterial Chemoembolization (TACE) for Hepatic Malignancies
Background and Aims: While transarterial chemoembolization (TACE) represents a
standard of therapy for intermediate-stage hepatocellular carcinoma (HCC) and is also routinely
performed in patients with liver metastases, it is still debated which patients represent the ideal
candidates for TACE therapy in terms of overall survival. Sarcopenia, the degenerative loss of skeletal
muscle mass and strength, has been associated with an adverse outcome for various malignancies,
but its role in the context of TACE has largely remained unknown. Here, we evaluated the role of
sarcopenia on the outcome of patients undergoing TACE for primary and secondary liver cancer.
Methods: The patients’ psoas muscle size was measured on axial computed tomography (CT)
scans and normalized for the patients’ height squared. This value was referred to as the psoas
muscle index (PMI). The PMI was correlated with clinical and laboratory markers. Results: While
pre-interventional sarcopenia had no impact on the direct tumor response to TACE, sarcopenic patients
with a pre-interventional PMI below our ideal cut-o value of 13.39 mm/m2 had a significantly
impaired long-term outcome with a median overall survival of 491 days compared to 1291 days
for patients with a high PMI. This finding was confirmed by uni- and multivariate Cox-regression
analyses. Moreover, a progressive rapid decline in muscle mass after TACE was a predictor for
an unfavorable prognosis. Conclusion: Our data suggest that sarcopenia represents a previously
unrecognized prognostic factor for patients undergoing TACE therapy which might yield important
information on the patients’ post-interventional outcome and should therefore be implemented into
clinical stratification algorithms
Density functional theory calculations and vibrational spectroscopy on iron spin-crossover compounds
Iron complexes with a suitable ligand field undergo spin-crossover (SCO),
which can be induced reversibly by temperature, pressure or even light.
Therefore, these compounds are highly interesting candidates for optical
information storage, for display devices and pressure sensors. The SCO
phenomenon can be conveniently studied by spectroscopic techniques like Raman
and infrared spectroscopy as well as nuclear inelastic scattering, a technique
which makes use of the M\"ossbauer effect. This review covers new developments
which have evolved during the last years like, e.g. picosecond infrared
spectroscopy and thin film studies but also gives an overviewon newtechniques
for the theoretical calculation of spin transition phenomena and vibrational
spectroscopic data of SCO complexes
Introduction to the special issue devoted to the 2018 ESHET conference at Madrid
The 22nd Annual ESHET Conference was held at the Faculty of Economic Sciences and Business of the Complutense University of Madrid from 7 to 9 June 2018.Depto. de Economía Aplicada, Estructura e HistoriaFac. de Ciencias Económicas y EmpresarialesTRUEpu
A Combined Score of Circulating miRNAs Allows Outcome Prediction in Critically Ill Patients
Background and aims: Identification of patients with increased risk of mortality represents an important prerequisite for an adapted adequate and individualized treatment of critically ill patients. Circulating micro-RNA (miRNA) levels have been suggested as potential biomarkers at the intensive care unit (ICU), but none of the investigated miRNAs displayed a sufficient sensitivity or specificity to be routinely employed as a single marker in clinical practice. Methods and results: We recently described alterations in serum levels of 7 miRNAs (miR-122, miR-133a, miR-143, miR-150, miR-155, miR-192, and miR-223) in critically ill patients at a medical ICU. In this study, we re-analyzed these previously published data and performed a combined analysis of these markers to unravel their potential as a prognostic scoring system in the context of critical illness. Based on the Youden’s index method, cut-off values were systematically defined for dysregulated miRNAs, and a “miRNA survival score” was calculated. Patients with high scores displayed a dramatically impaired prognosis compared to patients with low values. Additionally, the predictive power of our score could be further increased when the patient’s age was additionally incorporated into this score. Conclusions: We describe the first miRNA-based biomarker score for prediction of medical patients’ outcome during and after ICU treatment. Adding the patients’ age into this score was associated with a further increase in its predictive power. Further studies are needed to validate the clinical utility of this score in risk-stratifying critically ill patients
DFT Calculations as a Tool to Analyse Quadrupole Splittings of Spin Crossover Fe(II) complexes
Density functional methods have been applied to calculate the quadrupole
splitting of a series of iron(II) spin crossover complexes. Experimental and
calculated values are in reasonable agreement. In one case spin-orbit coupling
is necessary to explain the very small quadrupole splitting value of 0.77 mm/s
at 293 K for a high-spin isomer
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