Uncovering the 3d and 4d Electronic Interactions in Solvated Ru Complexes with 2p3d Resonant Inelastic X-ray Scattering.

The electronic structure and dynamics of ruthenium complexes are widely studied given their use in catalytic and light-harvesting materials. Here we investigate three model Ru complexes, [RuIII(NH3)6]3+, [RuII(bpy)3]2+, and [RuII(CN)6]4-, with L3-edge 2p3d resonant inelastic X-ray scattering (RIXS) to probe unoccupied 4d valence orbitals and occupied 3d orbitals and to gain insight into the interactions between these levels. The 2p3d RIXS maps contain a higher level of spectral information than the L3 X-ray absorption near edge structure (XANES). This study provides a direct measure of the 3d spin-orbit splittings of 4.3, 4.0, and 4.1 eV between the 3d5/2 and 3d3/2 orbitals of the [RuIII(NH3)6]3+, [RuII(bpy)3]2+, and [RuII(CN)6]4- complexes, respectively.

Reproducible, high-dimensional imaging in archival human tissue by multiplexed ion beam imaging by time-of-flight (MIBI-TOF).

Multiplexed ion beam imaging by time-of-flight (MIBI-TOF) is a form of mass spectrometry imaging that uses metal labeled antibodies and secondary ion mass spectrometry to image dozens of proteins simultaneously in the same tissue section. Working with the National Cancer Institute's (NCI) Cancer Immune Monitoring and Analysis Centers (CIMAC), we undertook a validation study, assessing concordance across a dozen serial sections of a tissue microarray of 21 samples that were independently processed and imaged by MIBI-TOF or single-plex immunohistochemistry (IHC) over 12 days. Pixel-level features were highly concordant across all 16 targets assessed in both staining intensity (R2 = 0.94 ± 0.04) and frequency (R2 = 0.95 ± 0.04). Comparison to digitized, single-plex IHC on adjacent serial sections revealed similar concordance (R2 = 0.85 ± 0.08) as well. Lastly, automated segmentation and clustering of eight cell populations found that cell frequencies between serial sections yielded an average correlation of R2 = 0.94 ± 0.05. Taken together, we demonstrate that MIBI-TOF, with well-vetted reagents and automated analysis, can generate consistent and quantitative annotations of clinically relevant cell states in archival human tissue, and more broadly, present a scalable framework for benchmarking multiplexed IHC approaches.

Revealing the bonding of solvated Ru complexes with valence-to-core resonant inelastic X-ray scattering.

Ru-complexes are widely studied because of their use in biological applications and photoconversion technologies. We reveal novel insights into the chemical bonding of a series of Ru(ii)- and Ru(iii)-complexes by leveraging recent advances in high-energy-resolution tender X-ray spectroscopy and theoretical calculations. We perform Ru 2p4d resonant inelastic X-ray scattering (RIXS) to probe the valence excitations in dilute solvated Ru-complexes. Combining these experiments with a newly developed theoretical approach based on time-dependent density functional theory, we assign the spectral features and quantify the metal-ligand bonding interactions. The valence-to-core RIXS features uniquely identify the metal-centered and charge transfer states and allow extracting the ligand-field splitting for all the complexes. The combined experimental and theoretical approach described here is shown to reliably characterize the ground and excited valence states of Ru complexes, and serve as a basis for future investigations of ruthenium, or other 4d metals active sites, in biological and chemical applications.

Sulfur Kß X-ray emission spectroscopy: comparison with sulfur K-edge X-ray absorption spectroscopy for speciation of organosulfur compounds.

Until recently, sulfur was known as a "spectroscopically silent" element because of a paucity of convenient spectroscopic probes suitable for in situ chemical speciation. In recent years the technique of sulfur K-edge X-ray absorption spectroscopy (XAS) has been used extensively in sulfur speciation in a variety of different fields. With an initial focus on reduced forms of organic sulfur, we have explored a complementary X-ray based spectroscopy - sulfur Kß X-ray emission spectroscopy (XES) - as a potential analytical tool for sulfur speciation in complex samples. We compare and contrast the sensitivity of sulfur Kß XES with that of sulfur K-edge XAS, and find differing sensitivities for the two techniques. In some cases an approach involving both sulfur K-edge XAS and sulfur Kß XES may be a powerful combination for deducing sulfur speciation in samples containing complex mixtures.

A high-throughput energy-dispersive tender X-ray spectrometer for shot-to-shot sulfur measurements.

An X-ray emission spectrometer that can detect the sulfur Kα emission lines with large throughput and a high energy resolution is presented. The instrument is based on a large d-spacing perfect Bragg analyzer that diffracts the sulfur Kα emission at close to backscattering angles. This facilitates the application of efficient concepts routinely employed in hard X-ray spectrometers towards the tender X-ray regime. The instrument described in this work is based on an energy-dispersive von Hamos geometry that is well suited for photon-in photon-out spectroscopy at X-ray free-electron laser and synchrotron sources. Comparison of its performance with previously used instrumentation is presented through measurements using sulfur-containing species performed at the LCLS. It is shown that the overall signal intensity is increased by a factor of ∼15. Implementation of this approach in the design of a tender X-ray spectroscopy endstation for LCLS-II is also discussed.

Postural stability in Parkinson's disease patients' wives and in elderly women leading different lifestyles.

The study aimed to determine postural stability of Parkinson's disease (PD) patients' wives in comparison with women differing in their lifestyle. (PD) patients' wives (n = 44), homemakers (n = 41), and female students of the University of the Third Age (n = 43) performed balance tests on a stabilometric platform. The PD patients' wives were characterized by significantly (p < 0.001) higher values of mean velocity sway than the homemakers and students (approximately 3.5 and 5 mm/s, respectively) and performed worst in displacement velocity and sway range in both sagittal and frontal plane. The results indicate that the wives of PD patients need support in the area of health training targeted at improving their standing stability.

Biological and Social Determinants of Maximum Oxygen Uptake in Adult Men.

The maximum rate of O2 uptake (V̇O2max) is one of the most important positive indicators of health. While the V̇O2max decreases with age, reducing the capacity for physical effort, it can be considerably upregulated through optimal environmental interventions, including systematic physical activity. This study seeks to determine variations in the cardiorespiratory function, estimated from the level of V̇O2max, in 798 employed men aged 20-59, according to biological (age, physical activity, body mass index (BMI), and limb muscle strength and agility) and social (place of residence, education, occupation, economic status, and smoking) predictors. We found that the variables abovementioned, with the exception of smoking and hand strength, were significant predictors of V̇O2max in univariate logistic regression, with age (OR = 0.52; 95%CI 0.47-0.57) and BMI (OR = 0.91; 95%CI 0.90-0.93) having the greatest effect on V̇O2max. The additional predictors, established in multivariate analysis, were the place of residence, education, and hand and arm strength. The multivariate model was fairly well-fitted (Nagelkerke r 2 = 0.54) and had a satisfactory prognostic value, with over 80% of cases classified correctly. Social variance in the V̇O2max makes it desirable to develop and implement the intervention programs with physical activity dedicated for men, especially men who are over the age of 50 years and have an excessive body mass, as this could reduce the risk of disorders and help improve the quality of life and workplace effectiveness of this group.

Revealing Electronic Signature of Lattice Oxygen Redox in Lithium Ruthenates and Implications for High-Energy Li-ion Battery Material Designs.

Anion redox in lithium transition metal oxides such as Li2RuO3 and Li2MnO3, has catalyzed intensive research efforts to find transition metal oxides with anion redox that may boost the energy density of lithium-ion batteries. The physical origin of observed anion redox remains debated, and more direct experimental evidence is needed. In this work, we have shown electronic signatures of oxygen-oxygen coupling, direct evidence central to lattice oxygen redox (O2-/(O2)n-), in charged Li2-xRuO3 after Ru oxidation (Ru4+/Ru5+) upon first-electron removal with lithium de-intercalation. Experimental Ru L3-edge high-energy-resolution fluorescence detected X-ray absorption spectra (HERFD-XAS), supported by ab-initio simulations, revealed that the increased intensity in the high-energy shoulder upon lithium de-intercalation resulted from increased O-O coupling, inducing (O-O) σ*-like states with π overlap with Ru d-manifolds, in agreement with O K-edge XAS spectra. Experimental and simulated O K-edge X-ray emission spectra (XES) further supported this observation with the broadening of the oxygen non-bonding feature upon charging, also originated from (O-O) σ* states. This lattice oxygen redox of Li2-xRuO3 was accompanied by a small amount of O2 evolution in the first charge from differential electrochemistry mass spectrometry (DEMS) but diminished in the subsequent cycles, in agreement with the more reduced states of Ru in later cycles from Ru L3-edge HERFD-XAS. These observations indicated that Ru redox contributed more to discharge capacities after the first cycle. This study has pinpointed the key spectral fingerprints related to lattice oxygen redox from a molecular level and constructed a transferrable framework to rationally interpret the spectroscopic features by combining advanced experiments and theoretical calculations to design materials for Li-ion batteries and electrocatalysis applications.

Determination of copper nanoparticle size distributions with total reflection X-ray fluorescence spectroscopy.

Total reflection X-ray fluorescence (TXRF) analysis is extensively used by the semiconductor industry for measuring trace metal contamination on silicon surfaces. In addition to determining the quantity of impurities on a surface, TXRF can reveal information about the vertical distribution of contaminants by measuring the fluorescence signal as a function of the angle of incidence. In this study, two samples were intentionally contaminated with copper in non-deoxygenated and deoxygenated ultrapure water (UPW) resulting in impurity profiles that were either atomically dispersed in a thin film or particle-like, respectively. The concentration profile of the samples immersed into deoxygenated UPW was calculated using a theoretical concentration profile representative of particles, yielding a mean particle height of 16.1 nm. However, the resulting theoretical profile suggested that a distribution of particle heights exists on the surface. The fit of the angular distribution data was further refined by minimizing the residual error of a least-squares fit employing a model with a Gaussian distribution of particle heights about the mean height. The presence of a height distribution was also confirmed with atomic force microscopy measurements.

Impact of Controlled Induced Hypotension on Cognitive Functions of Patients Undergoing Functional Endoscopic Sinus Surgery.

BACKGROUND: Controlled induced hypotension guarantees less blood loss and better visibility of the surgical site. The impact of hypotension on post-operative cognitive functions is still being discussed. The objective of this study was to evaluate the effects of controlled induced hypotension on the cognitive functions of patients undergoing functional endoscopic sinus surgery (FESS). MATERIAL/METHODS: We allocated 47 patients with a good grade of preoperative cognitive functions evaluated with the Mini-Mental State Examination to 3 groups (1 - mild hypotension, 2 - intermediate hypotension, 3 - severe hypotension) according to the degree of mean intraoperative arterial pressure compared with preoperative blood pressure. Cognitive functions were evaluated preoperatively, 6 h, and 30 h postoperatively with standardized tests: the Stroop Test, Trail Making Test (TMT), and Verbal Fluency Test (VFT). A decrease in the test results and increase in the number of mistakes made were considered an impairment of cognitive functions. RESULTS: A total of 47 patients (group 1 - mild hypotension - 15, group 2 - intermediate hypotension - 19, group 3 - severe hypotension - 13) were included in the study. A significant decrease was observed in all the 3 groups after Stroop A test 6h postoperatively but it improved 30h postoperatively, without differences between the groups. Neither a significant decrease in the test results nor an increase in the number of mistakes was noted for Stroop B tests, TMT A&B tests and VFT. CONCLUSIONS: The degree of controlled intraoperative hypotension during FESS did not influence the results of psychometric tests.

Ten years of experience in endovascular treatment of ruptured aneurysms of the posterior inferior cerebellar artery.

BACKGROUND: The aim of this study is to present our 10 years of experience in endovascular treatment of ruptured posterior inferior cerebellar artery (PICA) saccular aneurysms and to compare clinical presentation and outcome after endovascular treatment between patients with PICA aneurysms and patients with aneurysms in different locations. METHODS AND FINDINGS: Out of 932 patients with a ruptured intracranial aneurysm treated endovascularly in our institution, 38 aneurysms were located at the posterior inferior cerebellar artery. Clinical presentation, mean aneurysm diameter and outcome of the therapy in this group were compared with the same for ruptured aneurysms in other locations. Patients discharged with favourable outcomes were checked angiographically in the follow-up period. Thirty-four patients with ruptured PICA aneurysms were treated by selective endovascular coiling. Two patients with wide-necked aneurysms had endovascular stents implanted. In two cases, the parent vessel was occluded due to failure to catheterise the target aneurysm. The evaluated variables did not differ significantly between two groups, but significantly more ruptured aneurysms in the PICA group were under 6 mm in diameter. 29.4% of controlled aneurysms needed additional reembolisation in the follow-up period. CONCLUSIONS: Clinical presentation, extension of subarachnoid haemorrhage and outcome after endovascular treatment did not differ significantly between patients with ruptured aneurysms located on the PICA and patients with aneurysms located elsewhere intracranially. Endovascular treatment is an effective method of therapy in patients with ruptured PICA aneurysms. In our experience, even when sacrificing of the PICA is required, the results of treatment are favourable.

Wnt pathway antagonists, SFRP1, SFRP2, SOX17, and PPP2R2B, are methylated in gliomas and SFRP1 methylation predicts shorter survival.

The deregulation of Wnt signaling is observed in various cancers, including gliomas, and might be related to the methylation of the genes encoding antagonists of this signaling pathway. The aim of the study was to assess the methylation status of the promoter regions of six Wnt negative regulators and to determine their prognostic value in clinical samples of gliomas of different grades. The methylation of SFRP1, SFRP2, PPP2R2B, DKK1, SOX17, and DACH1 was analyzed in 64 glioma samples using methylation-specific polymerase chain reaction (MSP). The results were analyzed in correlation with clinicopathological data. Promoter methylation in at least one of the analyzed genes was found in 81.3 % of the tumors. All benign tumors [grade I according to the World Health Organization (WHO) classification] lacked the methylation of the studied genes, whereas grade II, III, and IV tumors were, in most cases, methylation-positive. The methylation index correlated with the patient's age. The most frequently methylated genes were SFRP1 and SFRP2 (73.4 % and 46.9 %, respectively), followed by SOX17 (20.3 %) and PPP2R2B (10.9 %); DKK1 and DACH1 were basically unmethylated (1.6 %). SFRP1 methylation negatively correlated with patients' survival time, and was significantly more frequent in older patients and those with higher grade tumors. Overall, the results of this study indicate that aberrant promoter methylation of Wnt pathway antagonists is common in gliomas, which may be the possible cause of up-regulation of this signaling pathway often observed in these tumors. Moreover, SFRP1 promoter methylation can be regarded as a potential indicator of glioma patients' survival.

A New Epigenetic Mechanism of Temozolomide Action in Glioma Cells.

Temozolomide (TMZ) is an oral alkylating chemotherapeutic agent that prolongs the survival of patients with glioblastoma (GBM). Despite that high TMZ potential, progression of disease and recurrence are still observed. Therefore a better understanding of the mechanism of action of this drug is necessary and may allow more durable benefit from its anti-glioma properties. Using nucleotide post-labelling method and separation on thin-layer chromatography we measured of global changes of 5-methylcytosine (m5C) in DNA of glioma cells treated with TMZ. Although m5C is not a product of TMZ methylation reaction of DNA, we analysed the effects of the drug action on different glioma cell lines through global changes at the level of the DNA main epigenetic mark. The first effect of TMZ action we observed is DNA hypermethylation followed by global demethylation. Therefore an increase of DNA methylation and down regulation of some genes expression can be ascribed to activation of DNA methyltransferases (DNMTs). On the other hand hypomethylation is induced by oxidative stress and causes uncontrolled expression of pathologic protein genes. The results of brain tumours treatment with TMZ suggest the new mechanism of modulation epigenetic marker in cancer cells. A high TMZ concentration induced a significant increase of m5C content in DNA in the short time, but a low TMZ concentration at longer time hypomethylation is observed for whole range of TMZ concentrations. Therefore TMZ administration with low doses of the drug and short time should be considered as optimal therapy.

Comprehensive analysis of microRNA expression profile in malignant glioma tissues.

Malignant gliomas represent the most devastating group of brain tumors in adults, among which glioblastoma multiforme (GBM) exhibits the highest malignancy rate. Despite combined modality treatment, GBM recurs and is invariably fatal. A further insight into the molecular background of gliomagenesis is required to improve patient outcomes. The primary aim of this study was to gain broad information on the miRNA expression pattern in malignant gliomas, mainly GBM. We investigated the global miRNA profile of malignant glioma tissues with miRNA microarrays, deep sequencing and meta-analysis. We selected miRNAs that were most frequently deregulated in glioblastoma tissues, as well as in peritumoral areas, in comparison with normal human brain. We identified candidate miRNAs associated with the progression from glioma grade III to glioma grade IV. The meta-analysis of miRNA profiling studies in GBM tissues summarizes the past and recent advances in the investigation of the miRNA signature in GBM versus noncancerous human brain and provides a comprehensive overview. We propose a list of 35 miRNAs whose expression is most frequently deregulated in GBM patients and of 30 miRNA candidates recognized as novel GBM biomarkers.

DNA methylation analysis of benign and atypical meningiomas: correlation between RUNX3 methylation and WHO grade.

PURPOSE: Although meningiomas are common central nervous system tumors, the biomarkers allowing early diagnosis and progression are still needed. The aim of this study was to evaluate the methylation status of 12 cancer-related genes, namely ERCC1, hMLH1, ATM, CDKN2B (p15INK4B), p14ARF, CDKN2A (p16INK4A), RASSF1A, RUNX3, GATA6, NDRG2, PTEN, and RARß, in 44 meningioma samples of WHO grade I and II. METHODS: All genes were analyzed using methylation-specific polymerase chain reaction, while pyrosequencing (PSQ) was used to study NDRG2 promoter methylation. RESULTS: The most frequently methylated genes in both types of meningiomas were p14ARF, RASSF1A, and p15INK4B. RUNX3, GATA6, and p16INK4A were methylated to a lesser extent, whereas ATM and RARß were found to be methylated in a marginal number of patients. The ERCC1, hMLH1, NDRG2, and PTEN genes were unmethylated in all cases. Although tumors of the same grade according to WHO criteria had different genes methylated, the number of methylated genes for each individual patient was low. RUNX3 methylation significantly correlated with meningioma WHO grade, therefore, can be considered as a potential indicator of tumor aggressiveness. The sequence of NDRG2 chosen for PSQ analysis was found methylated in the majority of meningiomas; however, the methylation level was only slightly elevated as compared to non-cancerous brain. CONCLUSIONS: Overall, the results of this study confirm that DNA methylation plays an important role in the pathogenesis of meningiomas. Further investigations, particularly concerning RUNX3 methylation, are necessary in order to assess the clinical usefulness of the methylation analysis of the studied genes.

Melatonin and cortisol profiles in patients with pituitary tumors.

The optic tract section at the optic chiasm is expected to disturb the suprachiasmatic nucleus (SCN) rhythm, circadian rhythm and melatonin secretion rhythms in humans, although detailed studies have never been conducted. The aim of this paper was to describe melatonin and cortisol profiles in patients with a pituitary tumor exerting optic chiasm compression. Six patients with pituitary tumors of different size, four of whom had significant optic chiasm compression, were examined. In each brain, MRI, an ophthalmological examination including the vision field and laboratory tests were performed. Melatonin and cortisol concentrations were measured at 22:00 h, 02:00 h, 06:00 h, and 10:00 h in patients lying in a dark, isolated room. One of the four cases with significant optic chiasm compression presented a flattened melatonin rhythm. The melatonin rhythm was also disturbed in one patient without optic chiasm compression. Larger tumors may play a role in the destruction of neurons connecting the retina with the suprachiasmatic nucleus (SCN) and breaking of basic way for inhibiting effect to the SCN from the retina.

The methylation of a panel of genes differentiates low-grade from high-grade gliomas.

Epigenetic changes play an important role in the pathogenesis of gliomas and have the potential to become clinically useful biomarkers. The aim of this study was the evaluation of the profile of promoter methylation of 13 genes selected based on their anticipated diagnostic and/or prognostic value. Methylation-specific PCR (MSP) was used to assess the methylation status of MGMT, ERCC1, hMLH1, ATM, CDKN2B (p15INK4B), p14ARF, CDKN2A (p16INK4A), RASSF1A, RUNX3, GATA6, NDRG2, PTEN, and RARß in a subset of 95 gliomas of different grades. Additionally, the methylation status of MGMT and NDRG2 was analyzed using pyrosequencing (PSQ). The results revealed that the methylation index of individual glioma patients correlates with World Health Organization (WHO) tumor grade and patient's age. RASSF1A, RUNX3, GATA6, and MGMT were most frequently methylated, whereas the INK4B-ARF-INK4A locus, PTEN, RARß, and ATM were methylated to a lesser extent. ERCC1, hMLH1, and NDRG2 were unmethylated. RUNX3 methylation correlated with WHO tumor grade and patient's age. PSQ confirmed significantly higher methylation levels of MGMT and NDRG2 as compared with normal, non-cancerous brain tissue. To conclude, DNA methylation of a whole panel of selected genes can serve as a tool for glioma aggressiveness prediction.

The degree of global DNA hypomethylation in peripheral blood correlates with that in matched tumor tissues in several neoplasia.

There are no good blood and serum biomarkers for detection, follow up, or prognosis of brain tumors. However, they are needed for more detailed tumor classification, better prognosis estimation and selection of an efficient therapeutic strategy. The aim of this study was to use the epigenetic changes in DNA of peripheral blood samples as a molecular marker to diagnose brain tumors as well as other diseases. We have applied a very precise thin-layer chromatography (TLC) analysis of the global amount of 5-methylcytosine (m(5)C) in DNA from brain tumors, colon and breast cancer tissues and peripheral blood samples of the same patients. The m(5)C level in tissue DNA from different brain tumor types, expressed as R coefficient, changes within the range of 0.2-1.6 and overlaps with R of that of blood samples. It negatively correlates with the WHO malignancy grade. The global DNA hypomethylation quantitative measure in blood, demonstrates a big potential for development of non-invasive applications for detection of a low and a high grade brain tumors. We have also used this approach to analyze patients with breast and colon cancers. In all these cases the m(5)C amount in DNA cancer tissue match with data of blood. This study is the first to demonstrate the potential role of global m(5)C content in blood DNA for early detection of brain tumors and others diseases. So, genomic DNA hypomethylation is a promising marker for prognosis of various neoplasms as well as other pathologies.

Detection of MGMT, RASSF1A, p15INK4B, and p14ARF promoter methylation in circulating tumor-derived DNA of central nervous system cancer patients.

Despite the growing understanding of the mechanisms of carcinogenesis, cancers of the central nervous system are usually associated with unfavorable prognosis. The use of an appropriate molecular marker may improve the treatment outcome by allowing early diagnosis and treatment susceptibility monitoring. Since methylation of tumor-derived DNA can be detected in the serum of cancer patients, this makes DNA methylation-based biomarkers one of the most promising diagnostic strategies. In this study, the methylation profiles of MGMT, RASSF1A, p15INK4B, and p14ARF genes were evaluated in serum free-circulating DNA and the corresponding tumor tissue in a group of 33 primary or metastatic central nervous system cancer patients. Gene promoter methylation was assessed using methylation-specific polymerase chain reaction (PCR). All the tested genes were found to be methylated to a different extent in both serum and tumor samples. In comparison to metastatic brain tumor patients, the patients with glial tumors were characterized by a higher frequency of gene hypermethylation. The hypermethylation of RASSF1A differentiated primary from metastatic brain cancers. Moreover, the gene methylation profiles observed in serum, in most cases, matched the methylation profiles detected in paired tumor samples.