LiMnPO4-olivine deposited on a nanoporous alloy as an additive-free electrode for lithium ion batteries.

A new strategy for the fabrication of binder- and carbon-free electrodes for lithium ion batteries is demonstrated. The strategy is based on the employment of a nanoporous metallic structure as a mechanically stable and conductive scaffold inside of which an active material is directly grown. The porous metallic structures with the pore size on the nanometric scale were obtained by de-alloying microcrystalline Cu60Ag30Al10, applying the method of selective dissolution of the less noble metals from the alloy. The active material of choice is LiMnPO4-olivine, which displays higher energy density in comparison with the well-known LiFePO4 (701 W h kg-1versus 586 W h kg-1). The improved electrode capacity can be explained by the enhanced diffusion of Li+ into LiMnPO4, achieved by decreasing the size of the phospho-olivine particles, incorporated inside the pores of the metallic structure. This approach enables to us perform the precise engineering of the particle size, which in turn contributes to the improvement of the electrochemical properties of phospho-olivines.

Eco-compatible oxides enabling energy storage via Li+/Mg2+ co-intercalation.

The storage of energy by means of reversible intercalation of bivalent magnesium ions represents, nowadays, the shortest route for doubling the energy density of conventional lithium ion batteries. Contrary to the intercalation of monovalent lithium ions, the intercalation of Mg2+ is a kinetically limited process. Herein we demonstrate a new approach for improving Mg2+ intercalation, which is based on dual intercalation of Li+ and Mg2+ ions with a synergic effect. The concept is proved on the basis of eco-compatible oxides such as magnesium manganate spinels, MgMn2O4, and lithium titanates Li2TiO3 and Li4Ti5O12 with a monoclinic and spinel structure. These two types of oxides are selected since they exhibit high and low potentials of ion intercalation due to the redox couples Mn2,3+/Mn3,4+ and Ti3+/Ti4+, respectively. Through a newly developed method of synthesis, we succeeded in the preparation of well-crystallized nanosized spinels with a specific cationic distribution. The intercalation properties of MgMn2O4, Li2TiO3 and Li4Ti5O12 are first examined in model cells versus the metallic Li anode. The Li+ and Mg2+ intercalation is directed by the kind of the used electrolyte: a lithium electrolyte consisting of 1 M LiPF6 solution in EC : DMC and a magnesium electrolyte consisting of 0.5 Mg(TFSI)2 solution in diglyme. The mechanism of Li+ and Mg2+ co-intercalation is assessed by ex situ X-ray diffraction and high-resolution transmission electron microscopy (HR-TEM). Finally, a new type of hybrid Li-Mg ion cell combining MgMn2O4 and Li4Ti5O12 oxides as electrodes is constructed. The cell configuration allows reaching an operating voltage of around 1.7 V by using an electrolyte containing 0.5 M LiTFSI in diglyme.

Redox properties of alluaudite sodium cobalt manganese sulfates as high-voltage electrodes for rechargeable batteries.

Alluaudite sulfates are predicted to be high-voltage electrodes for lithium- and sodium-ion batteries. Herein, we provide the first experimental evidence for the operation of sodium cobalt-manganese sulfate, Na2+2δ(Co0.63Mn0.37)2-δ(SO4)3, at potentials higher than 4.0 V vs. Li/Li+. This fact comes as a result of the reduced cationic deficiency, redox properties of Co and Mn and stability of the alluaudite structure during alkali ion intercalation.

Combined use of EPR and 23Na MAS NMR spectroscopy for assessing the properties of the mixed cobalt-nickel-manganese layers of P3-NayCo1-2xNixMnxO2.

Knowledge on the formation of mixed transition metal layers on lithium and sodium transition metal oxides, Li/Na(Co,Ni,Mn,)O2, determines the ability to control their electrochemical properties as electrode materials in alkaline ion batteries. Taking this into account, herein we combine the EPR and 23Na MAS NMR spectroscopic techniques to gain insights into the structural peculiarities of the mixed cobalt-nickel-manganese layers of NayCo1-2xNixMnxO2 with a three-layer stacking (P3-type) structure. Two types of compositions are examined where diamagnetic Co3+ and paramagnetic Ni3+ and Mn4+ are stabilized: Na2/3Co1/3Ni1/3Mn1/3O2 and Na1/2Ni1/2Mn1/2O2. EPR spectroscopy operating in the X- and Q-band region is applied with an aim to improve the spectra resolution and, on the other hand, to provide straightforward information on the coordination of the transition metal ions inside the layers. The analysis of EPR spectra is based on the reference for the Mn4+ and Ni2+ ions occurring simultaneously in oxides with two layer stacking, P2-Na2/3Ni1/3Mn2/3O2. Complementary to EPR, 23Na MAS NMR spectroscopy at high spinning rates is undertaken to assess the local structure of the Na nucleus in the layered P3-NayCo1-2xNixMnxO2 oxides. All results are discussed taking into account the EPR and NMR data for the well-known lithium analogues O3-LiCo1/3Ni1/3Mn1/3O2 and O3-LiNi1/2Mn1/2O2. Finally, the structure peculiarities of the transition metal layers extracted from the EPR and NMR methods are demonstrated by electrochemical intercalation of Li+ ions into P3-NayCo1-2xNixMnxO2.

Crystal chemistry of Mg substitution in NaMnPO4 olivine: concentration limit and cation distribution.

Metal ion substitution in phospho-olivines is an effective way to improve their performance as electrode materials in lithium ion and alternative sodium ion batteries. In this contribution, we examine in detail the crystal structure of Mg-substituted NaMnPO4. The preferential occupancy of the alkaline M1 position by Mg2+ ions has been found for the first time - a phenomenon which appears to be opposite to the case of Mg-substituted LiMnPO4, where Mg2+ and Mn2+ reside in the M2 position. Mg solubility in NaMnPO4 is limited in the range of 0.10 < Mg/(Mg + Mn) < 0.15 mole part. Mg-substituted NaMnPO4 is prepared at 200 °C by ionic exchange reactions involving the participation of mixed dittmarite salts, KMn1-xMgxPO4·H2O. The structural aspects of Mg substitution in NaMnPO4 are studied by combination of powder X-ray diffraction using the Rietveld analysis with IR and electron paramagnetic resonance spectroscopy. The morphologies of precursors and target olivines are examined by means of SEM and EDS. In order to understand the crystal chemistry of Mg-substituted NaMnPO4, we use solid solutions between LiMnPO4 and LiMgPO4 as references. The reference compositions of LiMn1-xMgxPO4 are prepared using the same KMn1-xMgxPO4·H2O precursors as in the case of Mg-substituted NaMnPO4.

Multiparametric evaluation of preoperative MRI in early stage breast cancer: prognostic impact of peri-tumoral fat

Purpose. Obesity is associated with adverse outcomes in breast cancer patients. Fat-specific cytokines (adipokines) have been proposed as key drivers of breast cancer progression, invasion, and metastasis. We aimed at assessing correlations between peri-tumoral fat, quantified on magnetic resonance imaging (MRI) and pathologic factors potentially impacting therapy recommendations. Methods. We retrospectively reviewed records of 63 patients with early stage breast cancer who underwent preoperative MRI imaging using appropriately weighted series for breast and tumor contouring. Fat volumes were generated through voxel intensity filtering. The peri-tumoral region was defined as the intersection of a 1-cm spherical extension around the tumor and the breast contour. Peri-tumoral fat was defined as the fraction of a fat content in this volume. Surgical pathology records were used to extract clinical data. Statistical analyses were conducted using Pearson and Spearman correlation coefficients. Results. Among reviewed patients, 45 had T1 tumors (1.22 ± 0.85 cm diameter) and 18 had T2 tumors (2.08 ± 1.06 cm). Axillary lymph nodes were dissected in 31 and positive in 17 patients analyzed. Peri-tumoral fat ratio ranged between 25 and 99 %. Peri-tumoral fat ratio significantly correlated with the nodal-positive ratio of positive axillary lymph nodes (r = 0.532). Peri-tumoral fat ratio demonstrated optimally prominent correlation among obese patients upon body mass index categorical stratification. Conclusions. In women with early stage breast cancer, peri-tumoral fat correlates positively with the ratio of pathologically involved axillary nodes. This work highlights a novel method for quantitating peri-tumoral fat content. Preoperative breast MRI may be utilized to predict extent of axillary disease (AU)

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Multiparametric evaluation of preoperative MRI in early stage breast cancer: prognostic impact of peri-tumoral fat.

PURPOSE: Obesity is associated with adverse outcomes in breast cancer patients. Fat-specific cytokines (adipokines) have been proposed as key drivers of breast cancer progression, invasion, and metastasis. We aimed at assessing correlations between peri-tumoral fat, quantified on magnetic resonance imaging (MRI) and pathologic factors potentially impacting therapy recommendations. METHODS: We retrospectively reviewed records of 63 patients with early stage breast cancer who underwent preoperative MRI imaging using appropriately weighted series for breast and tumor contouring. Fat volumes were generated through voxel intensity filtering. The peri-tumoral region was defined as the intersection of a 1-cm spherical extension around the tumor and the breast contour. Peri-tumoral fat was defined as the fraction of a fat content in this volume. Surgical pathology records were used to extract clinical data. Statistical analyses were conducted using Pearson and Spearman correlation coefficients. RESULTS: Among reviewed patients, 45 had T1 tumors (1.22 ± 0.85 cm diameter) and 18 had T2 tumors (2.08 ± 1.06 cm). Axillary lymph nodes were dissected in 31 and positive in 17 patients analyzed. Peri-tumoral fat ratio ranged between 25 and 99 %. Peri-tumoral fat ratio significantly correlated with the nodal-positive ratio of positive axillary lymph nodes (r = 0.532). Peri-tumoral fat ratio demonstrated optimally prominent correlation among obese patients upon body mass index categorical stratification. CONCLUSIONS: In women with early stage breast cancer, peri-tumoral fat correlates positively with the ratio of pathologically involved axillary nodes. This work highlights a novel method for quantitating peri-tumoral fat content. Preoperative breast MRI may be utilized to predict extent of axillary disease.

Assessment of the Personal Losses Suffered by Correctional Officers due to Burnout Syndrome.

BACKGROUND: Professional burnout is defined as a state of depletion and loss of motivation accompanied by different mental and physical symptoms. OBJECTIVE: To assess personal losses suffered by correctional officers due to burnout. METHODS: This cross-sectional study conducted between June and December 2012 included 201 correctional officers in two Bulgarian prisons. The mean age of the whole group was 41.2 (SD 8.0) years. The respondents was mostly male (56.7%), married (72.6%), had a secondary educational level (61.7%), and 76.1% of them had been in current prison work over 5 years. RESULTS: The demographic characteristics had no influence on the occurrence of burnout but there was a correlation between level of burnout and the number of sick-leaves, the need for medical help, and the expenses spent on medications. Officers affected by burnout took more sick-leaves and this affected adversely their remuneration as they lost 3.1% of their annual wages. Their expenses spent on user fees for medical services were 3 times higher. Their monthly expenses spent on medications were 3.14 times higher than those of people without the burnout syndrome. CONCLUSION: The high level of burnout has a negative personal economic effect on the prison employees.

Mapping of glycine distributions in gliomas.

BACKGROUND AND PURPOSE: Increased glycine concentration in the brain is associated with altered metabolism in cancer and can be detected by using in vivo MR spectroscopy. This has been proposed as a marker for grade IV gliomas; however, little is known about the potential significance and frequency of in vivo glycine observation. The purpose of this study was to examine the rate of occurrence and spatial distribution of glycine observation with respect to other MR imaging parameters. MATERIALS AND METHODS: Data from volumetric whole-brain MR spectroscopic imaging of 59 subjects with glioma were analyzed with glycine included in the spectral model. The associations of the signal amplitude and spatial distributions of glycine with findings from contrast-enhanced T1, perfusion, and diffusion MR imaging were then examined. RESULTS: Glycine was detected in 24% of all studies, though with a wide range of signal amplitude and extent of the spatial distributions. While more commonly seen in grade IV tumors (42% of studies), relatively large concentrations were also detected in grade II and III gliomas. Coanalysis with other metabolites indicated a strong association with choline and that glycine was frequently seen to be overlapping with, and adjacent to, areas of high lactate concentration. Increased glycine was always associated with contrast enhancement and areas of increased cerebral blood flow, but without any clear association with other image parameters. CONCLUSIONS: Detection of increased glycine in gliomas appears to identify a subgroup of tumors and areas of increased proliferation.

EPIDEMIOLOGICAL REGISTRY OF NEUROENDOCRINE TUMORS IN BULGARIA--A PILOT SURVEY.

The National registry of patients with neuroendocrine tumors (NET) in Bulgaria was established in 2013 as a joint initiative of the Bulgarian Surgical Society and the Institute for Rare Diseases. The register aims to explore the epidemiology of NET in Bulgaria, as well as the different diagnostic and treatment approaches for the disease throughout the country. This the first of its kind retrospective study of NET in the country is covering the period January 2012 - January 2013. A total of 127 patients with NET were identified. At the time of the survey the average age of patients with NET was 58.61 ± 15.59 years. The data show almost equal distribution between the genders with a slight predominance of women. The largest relative part of NET is those of NET located in the gastrointestinal tract (54.10 ± 4.51%), followed by those located in the pancreas (12.30 ± 2.97%) and in the lungs (10.66 ± 2.79%). In 72.44 ± 3.96% of the patients a immunohistochemical diagnosis was performed. The study confirmed the leading role of the surgery method of the NET management. In 65.83 ± 4.33% of the patients a radical removal of the tumor was conducted, while the relative part of the undertaken partial resection was 7.50 ± 2.40%. A statistically significant association between the type of surgical treatment and during the follow-up of patients was found. An update of the information in the register will allow a more precise determining of the distribution and management of NET in Bulgaria.

Gaussian mixture model-based classification of dynamic contrast enhanced MRI data for identifying diverse tumor microenvironments: preliminary results.

Tumor hypoxia develops heterogeneously, affects radiation sensitivity and the development of metastases. Prognostic information derived from the in vivo characterization of the spatial distribution of hypoxic areas in solid tumors can be of value for radiation therapy planning and for monitoring the early treatment response. Tumor hypoxia is caused by an imbalance between the supply and consumption of oxygen. The tumor oxygen supply is inherently linked to its vasculature and perfusion which can be evaluated by dynamic contrast enhanced (DCE-) MRI using the contrast agent Gd-DTPA. Thus, we hypothesize that DCE-MRI data may provide surrogate information regarding tumor hypoxia. In this study, DCE-MRI data from a rat prostate tumor model were analysed with a Gaussian mixture model (GMM)-based classification to identify perfused, hypoxic and necrotic areas for a total of ten tumor slices from six rats, of which one slice was used as training data for GMM classifications. The results of pattern recognition analyzes were validated by comparison to corresponding Akep maps defining the perfused area (0.84 ± 0.09 overlap), hematoxylin and eosin (H&E)-stained tissue sections defining necrosis (0.64 ± 0.15 overlap) and pimonidazole-stained sections defining hypoxia (0.72 ± 0.17 overlap), respectively. Our preliminary data indicate the feasibility of a GMM-based classification to identify tumor hypoxia, necrosis and perfusion/permeability from non-invasively acquired, in vivo DCE-MRI data alone, possibly obviating the need for invasive procedures, such as biopsies, or exposure to radioactivity, such as positron emission tomography (PET) exams.

The P2-Na(2/3)Co(2/3)Mn(1/3)O2 phase: structure, physical properties and electrochemical behavior as positive electrode in sodium battery.

Manganese substituted sodium cobaltate, Na(2/3)Co(2/3)Mn(1/3)O(2), with a layered hexagonal structure (P2-type) was obtained by a co-precipitation method followed by a heat treatment at 950 °C. Powder X-ray diffraction analysis revealed that the phase is pure in the absence of long-range ordering of Co and Mn ions in the slab or Na(+) and vacancy in the interslab space. The oxidation states of the transition metal ions were studied by magnetic susceptibility measurements, electron paramagnetic resonance (ESR) and (23)Na magic angle spinning nuclear magnetic resonance (MAS NMR) spectroscopy. The charge compensation is achieved by the stabilization of low-spin Co(3+) and Mn(4+) ions. The capability of Na(2/3)Co(2/3)Mn(1/3)O(2) to intercalate and deintercalate Na(+) reversibly was tested in electrochemical sodium cells. It appears that the P2 structure is maintained during cycling, the cell parameter evolution versus the sodium amount is given. From the features of the cycling curve the formation of an ordered phase for the Na(0.5)Co(2/3)Mn(1/3)O(2) composition is expected.

High-frequency electron paramagnetic resonance analysis of the oxidation state and local structure of Ni and Mn ions in Ni,Mn-codoped LiCoO(2).

High-frequency electron paramagnetic resonance (HF-EPR) spectroscopy was employed to examine the oxidation state and local structure of Ni and Mn ions in Ni,Mn-codoped LiCoO(2). The assignment of EPR signals was based on Mg,Mn-codoped LiCoO(2) and Ni-doped LiCoO(2) used as Mn(4+) and low-spin Ni(3+) EPR references. Complementary information on the oxidation state of transition-metal ions was obtained by solid-state (6,7)Li NMR spectroscopy. For slightly doped oxides (LiCo(1-x)Ni(x)Mn(x)O(2) with x < 0.05), nickel and manganese substitute for cobalt in the CoO(2) layers and are stabilized as Ni(3+) and Mn(4+) ions. The local structure of Mn(4+) ions was determined by modeling of the axial zero-field-splitting parameter in the framework of the Newman superposition model. It has been found that the local trigonal distortion around Mn(4+) is smaller in comparison with that of the host site. To achieve a local compensation of Mn(4+) charge, several defect models are discussed. With an increase in the total dopant content (LiCo(1-x)Ni(x)Mn(x)O(2) and 0.05

[Standards for determining the physical development of newborn children of Turkish ethnicity].

The ethnicity, as part of other important factors, which are determinants of children's physical development, has a specific role. The main purpose of this study was to determine the standards, which have to be used in order to assess the physical development of newborn children of Turkish ethnic origin. The primer source of information is the Obstetric Clinic of Medical University, where 265 newborn children of Turkish ethnicity were registered. The Percentile method was used to derive the standards. Referring to the extent of the excerpt the standards of height, body mass and tours of the head evaluation are authentic and statistically reliable. This is the reason why they could be in assistance of obstetrician gynecologists and microbiologists, when assessing the physical development of children in next 8-10 years.

Local coordination of Fe(3+) in layered LiCo(1-y)Al(y)O(2) oxides determined by high-frequency electron paramagnetic resonance spectroscopy.

The local coordination of Fe(3+) spin probes in trigonal LiAl(y)Co(1-y)O(2) was studied using high-frequency electron paramagnetic resonance spectroscopy. This technique allows the determination of Fe(3+) ions in respect to axial and rhombic zero-field splitting parameters (ZFS). After the progressive replacement of Co by Al, the axial D parameter of Fe(3+) increases from +0.0548 to +0.2802 cm(-1). On the same order, the rhombic E parameter decreases. Structural information about the Fe(3+) site in layered LiAl(y)Co(1-y)O(2) oxides was based on modeling of the magnitude of the ZFS parameters by means of the Newman superposition model. It was found that the first metal coordination sphere including Co(3+) and Al(3+) ions gave rise to differentiation of the Fe(3+) dopants in respect to local trigonal and rhombic distortion. The maximum trigonal distortion for the FeO(6) octahedron was achieved when Fe(3+) spin probes were surrounded by Al only, while the Co environment yields a rhombic distortion of the FeO(6) octahedron.

In vivo 31P MR spectral patterns and reproducibility in cancer patients studied in a multi-institutional trial.

The standardization and reproducibility of techniques required to acquire anatomically localized 31P MR spectra non-invasively while studying tumors in cancer patients in a multi-institutional group at 1.5 T are reported. This initial group of patients was studied from 1995 to 2000 to test the feasibility of acquiring in vivo localized 31P MRS in clinical MR spectrometers. The cancers tested were non-Hodgkin's lymphomas, sarcomas of soft tissue and bone, breast carcinomas and head and neck carcinomas. The best accrual and spectral quality were achieved with the non-Hodgkin's lymphomas. The initial analysis of the spectral values of the sum of phosphoethanolamine plus phosphocholine normalized by the content of nucleotide triphosphates in a homogeneous sample of 32 NHL patients studied by in vivo (31)P MRS showed good reproducibility among different institutions. No statistical differences were found between the institution with the largest number of cases accrued and the rest of the multi-institutional NHL data (2.28 +/- 0.64, mean +/- standard error; n = 17, vs 2.08 +/- 0.14, n = 15). The preliminary data reported demonstrate that the institutions involved in this trial are obtaining reproducible 31P MR spectroscopic data non-invasively from human tumors. This is a fundamental prerequisite for the international cooperative group to be able to demonstrate the clinical value of the normalized determination of phosphoethanolamine plus phosphocholine by 31P MRS as predictor for treatment response in cancer patients.

NMR spectral quantitation by principal component analysis. III. A generalized procedure for determination of lineshape variations.

We present a general procedure for automatic quantitation of a series of spectral peaks based on principal component analysis (PCA). PCA has been previously used for spectral quantitation of a single resonant peak of constant shape but variable amplitude. Here we extend this procedure to estimate all of the peak parameters: amplitude, position (frequency), phase and linewidth. The procedure consists of a series of iterative steps in which the estimates of position and phase from one stage of iteration are used to correct the spectra prior to the next stage. The process is convergent to a stable result, typically in less than 5 iterations. If desired, remaining linewidth variations can then be corrected. Correction of (typically) unwanted variations of these types is important not only for direct peak quantitation, but also as a preprocessing step for spectral data prior to application of pattern recognition/classification techniques. The procedure is demonstrated on simulated data and on a set of 992 (31)P NMR in vivo spectra taken from a kinetic study of rat muscle energetics. The proposed procedure is robust, makes very limited assumptions about the lineshape, and performs well with data of low signal-to-noise ratio.

NMR spectral quantitation by principal component analysis.

The use of principal component analysis (PCA) for simultaneous spectral quantitation of a single resonant peak across a series of spectra has gained popularity among the NMR community. The approach is fast, requires no assumptions regarding the peak lineshape and provides quantitation even for peaks with very low signal-to-noise ratio. PCA produces estimates of all peak parameters: area, frequency, phase and linewidth. If desired, these estimates can be used to correct the original data so that the peak in all spectra has the same lineshape. This ability makes PCA useful not only for direct peak quantitation, but also for processing spectral data prior to application of pattern recognition/classification techniques. This article briefly reviews the theoretical basis of PCA for spectral quantitation, addresses issues of data processing prior to PCA, describes suitable and unsuitable datasets for PCA applications and summarizes the developments and the limitations of the method.

Synthesis and antibacterial activity of 5-nitrofuryl and 3-methoxy-2-nitrophenyl derivatives of 6 beta-aminopenicillanic, 7 beta-aminocephalosporanic and 7 beta-aminodesacetoxy-cephalosporanic acids.

A number of 5-nitrofuryl and 3-methoxy-2-nitrophenyl derivatives of 6 beta-aminopenicillanic (6 beta-APA), 7 beta-aminocephalosporanic (7 beta-ACA) and 7 beta-aminodesacetoxycephalosporanic (7 beta-ADCA) acids were synthesized by the method of mixed anhydrides or via Schiff bases. The chemical structures of the new compounds were confirmed by IR-, 1H-NMR and mass spectral data, obtained by negative ion electrospray ionization. The in vitro testing results indicated that all penicillins and cephalosporins prepared exhibited antibacterial activity equal to or in many cases considerably higher than those of ampicillin (CAS 69-53-4) and cephalexin (CAS 23325-78-2) against the Gram-positive microorganisms, excluding B. subtilis L2, B. subtilis HB2 and S. aureus 1/45 "Oxford". Their activity towards the two strains of Proteus mirabilis was also good being greater than that of cephalexin contrary to the demonstrated lower activity towards all strains of E. coli tested. The most active compounds which simultaneously possessed the broadest spectrum of antibacterial activity proved to be compounds 1 and 8 both bearing as a substituent a 5-nitrofuran group.