Transport Properties of Li-TFSI Water-in-Salt Electrolytes.

Water-in-salts are a new family of electrolytes that may allow the development of aqueous Li-ion batteries. They have a structure that is reminiscent of ionic liquids, and they are characterized by a high concentration of ionic species. In this work, we study their transport properties and how they evolve with concentration by using molecular dynamic simulations. We first focus on the choice of the force field. By comparing the simulated viscosities and self-diffusion coefficients with experimental measurements, we select a set of parameters that reproduces well the transport properties. We then use the selected force field to study in detail the variations of the self and collective diffusivities of all the species as well as the transport number of the lithium ion. We show that correlations between ions and water play an important role over the whole concentration range. In the water-in-salt regime, the anions form a percolating network that reduces the cation-anion correlations and leads to rather large values for the transport number compared to other standard electrolytes.

Magnetic Resonance Imaging of Brain Involvement in Dogs Using Paramagnetic Contrast Enhancement with Mn(II)-DCTA P.

Experimental study of a new paramagnetic complex Mn-DCTA is carried out. The complex (0.5 M manganese(II) solution with trans-1,2-diamine cyclohexane-N,N,N',N'-tetraacetic acid; Cyclomang) was used for contrast magnetic resonance imaging visualization of CNS involvement in dogs with severe forms of Babesia canis infection. CNS injuries were visualized in all cases, with highly intense contrasting at the expense of Mn-DCTA accumulation at the periphery of the damaged zone. Quantitative evaluation of the paramagnetic accumulation in the focus showed that the amplification index wa s 1.19±0.11 for the central areas and 1.47±0.17 for the peripheral ones. The pituitary (1.18±0.05) and vascular plexuses of the lateral ventricles (1.12±0.09) were also contrasted. Injection of the paramagnetic to dogs was not associated with any kinds of pathological or physiological reactions. Mn-DCTA complex allowed contrast visualization of the focal injuries to the CNS and could be regarded as a paramagnetic contrast agent for magnetic resonance imaging of brain injuries in dogs.

[Simultaneous magnetic resonance angiographic and tomographic assessment of atherosclerotic plaques of carotid arteries with paramagnetic contrasting by cyclomang].

The authors studied a possibility of simultaneously performing magnetic resonance (MR) angiography of carotid arteries and contrast-enhanced MR tomography of atherosclerotic plaques of carotid arteries. We examined a total of 16 patients presenting with disseminated atherosclerosis and 8 patients of the control group. Quadrature coils for examination of the head were used in order to sequentially perform MR tomography of the brain, MR angiography of carotid arteries and MR tomography of atherosclerotic plaques of carotid arteries with contrasting by 0.5M cyclomang. Angiography was carried out by means of the technique of 3D GR FFE of rapid gradient echo (TR/TE/FA/ST=10 ms/2.7 ms/20°/1.5 mm). MR tomography of the carotid arteries bifurcation was performed in the T1-weighted spin-echo mode: TR=500-900 ms, TE=10 ms, slice sickness 1-3 mm into the matrix 256x256 voxels, with the voxel size measuring 0.2x0.2x2 mm. The average time of passing of the paramagnetic through the blood vessels of the cerebral hemispheres in the control group amounted to 4.23±0.14 s for the left hemisphere and to 4.27±0.15 s for the right one. The mean time of bolus passing in patients with predominantly unilateral stenosis of the internal carotid artery amounted to 4.89±0.23 on the affected side, equalling 4.56±0.19 s on the unaffected side (p>0.05). In bilateral lesions these indices for the left and right hemispheres amounted to 4.98±0.21 s and 5.01±0.16 s (p>0.05), respectively. Contrast-enhanced MR angiography with cyclomang made it possible in all cases to visualize the localization and character of stenosis. The index of stenosis degree calculated for MR-angiogram highly significantly correlated with the indices of the ultrasonographic examination performed according to the ECST technique both for cases of unilateral (r=0.87, p<0.05) and cases of bilateral stenotic lesion (r=0.85, p<0.05). Inhomogeneous soft plaques with high content of lipids had high values of the enhancement index on contrasting--1.26±0.07, whereas hard fibrous avascular plaques--1.09±0.04 (p<0.05). The total time of the examination amounted to 41±5 min while performing time-fly MR-angiography and to 29±5 min without it. A conclusion was made that simultaneous MR angiography and contrast-enhanced (with Mn-paramagnetic) MR tomography of carotid arteries is possible and appropriate within the framework of a single study using quadratic coil for the head.

Advancing a distributed multi-scale computing framework for large-scale high-throughput discovery in materials science.

We describe the development of a large-scale high-throughput application for discovery in materials science. Our point of departure is a computational framework for distributed multi-scale computation. We augment the original framework with a specialized module whose role is to route evaluation requests needed by the high-throughput application to a collection of available computational resources. We evaluate the feasibility and performance of the resulting high-throughput computational framework by carrying out a high-throughput study of battery solvents. Our results indicate that distributed multi-scale computing, by virtue of its adaptive nature, is particularly well-suited for building high-throughput applications.

[Severe Wegener's granulomatosis successfully treated with rituximab].

The paper discusses the problems of the diagnosis and treatment of Wegener's granulomatosis, the most common anti-neutrophil cytoplasmic antibody-associated systemic vasculitis. It describes a clinical case in which the administration of rituximab could achieve remission of severe Wegener's granulomatosis in a young man having numerous adverse reactions associated with the long-term use of high- and average-dose glucocorticoids and nonselective immunosuppressive agents. A place of rituximab in current drug therapy for Wegener's granulomatosis is shown.

Newly diagnosed thyrotoxicosis in hospitalized patients: clinical characteristics.

BACKGROUND: Thyrotoxicosis is often diagnosed in an outpatient setting. The most common symptoms include irritability, heat intolerance, palpitations and weakness. Sometimes, however, thyrotoxicosis is first diagnosed in the hospital setting. The prevalent symptoms in hospitalized patients with newly diagnosed thyrotoxicosis have not been fully characterized. AIM: To determine the clinical characteristics of patients with thyrotoxicosis newly diagnosed during hospitalization. DESIGN: A retrospective computer-based search was undertaken to detect patients that were hospitalized in our medical centre during 1999-2006, and discharged with thyrotoxicosis or thyroiditis as the primary diagnosis. RESULTS: Fifty-eight patients (36F/22M; mean age 52.1 +/- 17.5 years) were identified. Weakness, weight loss and palpitations were the most common manifestations (50, 40 and 35%, respectively) and were predominantly present in patients with hyperthyroidism. Sore throat was present in 41% of patients with thyroiditis. Sinus tachycardia and atrial fibrillation occurred in 65.5 and 15.5% of the patients, more common in those with hyperthyroidism. The diagnoses on discharge were Graves' disease, subacute thyroiditis and multinodular goiter in 39.7, 34.5 and 8.9%, respectively. CONCLUSION: Weakness, weight loss and palpitations were the main symptoms in patients diagnosed with thyrotoxicosis during hospitalization. Thyrotoxicosis should be included in the differential diagnosis when patients are admitted to the hospital with those symptoms.

[Preclinical investigation of Mn(II)-diethylenetriaminepentaacetate (Mangapentetate) as paramagnetic contrast agent for magnetic resonance tomography].

The preclinical evaluation of 0.5 M solution of a manganese(II)-DTPA complex (Mangapentetate, Pentamang) has been carried out in order to test the ability of manganese to be used as substitute for potentially toxic gadolinium in paramagnetic contrast agents in the MRI clinical routines. The toxicologic tests of the Mn(II) - DTPA were carried out in mice, rats, and rabbits. Liquid phantoms served for direct comparison of the ability of Mn(II) - DTPA to increase the intensity of T1-weighted SE-images to the contrast properties of the Gd(III) - DTPA (Magnevist). Normal healthy rabbits (n = 12) were used for quantification of the imaging ability of Mn(II) - DTPA. The value of LD50 in rabbits was above 10 ml/kg, rather close to that one of Gd(III) - DTPA. An increase in intensity of the T1-weighted images induced by addition of Mn(II) - DTPA in phantom tests did not differ significantly from the values obtained with Gadopentetate. Mn(II) - DTPA delivered prominent enhancement of normal kidneys in healthy rabbits as well as chest tumors in dogs.

[Estimation of cardiac output from dynamic contrast multispiral tomographic data].

OBJECTIVE: To describe and apply a method for programmatically calculating central hemodynamic parameters from the data of dynamic contrast X-ray computed tomography (CT). MATERIAL AND METHODS: A procedure is proposed to calculate cardiac output (CO) on the basis of the tracer dilution method as a ratio of the injected dose of a contrast agent (Urografin, Shering AG, Austria) to the area under the concentration-time curve derived for one of the cardiac chambers: [see text]. The blood concentration of the agent was estimated from the blood iodine (I) concentration-X-ray density (XD) regression dependence: [XD] = 0.49+22.07 x [I]. Thirty-three patients were studied on a multispiral X-ray Somatom Sensation 4 computed tomograph (Siemens), by injecting 15-20 ml of Urografin. The calculating method was realized as a software package for processing dynamic contrast CT data. RESULTS: The proposed method could exactly determine the values of cardiac output: the correlation with the results of the reference technique (Doppler echo measurement) was highly significant (r = 0.95; p < 0.001) in the whole range of values. Moreover, the data on XD could accurately determine the blood concentration of both iodine (I): [XD] = 0.49+22.07 x [I] and gadolinium as a component of the contrast paramagnetic Gd-DTPA for which the solution concentration-XR dependence was as follows: XD 1.2+33.6 x [Gd]. CONCLUSIONS: Thus, dynamic spiral CT may be also used for the estimation of cardiac output by the tracer dilution method.

[Evaluation of endothelial permeability in brain tumors by dynamic magnetic resonance tomography with magnevist contrast imaging on low-field MR-tomograph]. / Otsenka endotelial'noi pronitsaemosti opukholei mozga metodom dinamicheskoi magnitno-rezonansnoi tomografii s kontrastirovaniem Magnevistom na nizkopol'nom MR-tomografe..

In order to study the endothelial permeability to hydrophilic macromolecules in brain tumors we have developed a technique based on Gjedde-Rutland-Patlak approach to dynamic MRI study with Gd-DTPA injected intravenously, performed with low-field MRI tomograph Magnetom Open (Siemens medical). 27 patients with various brain tumors were referred for the study. The indices of Gd-DTPA transport to tumor tissue (KGd-DTPA) vary substantially, depending on the degree of malignancy and deliver essential information on microvascular permeability of tumor capillary bed.

Molecular dynamics simulation study of hydrogen bonding in aqueous poly(ethylene oxide) solutions.

A molecular dynamics simulation study of hydrogen bonding in poly(ethylene oxide) (PEO)/water solutions was performed. PEO-water and water-water hydrogen bonding manifested complex dependence on both composition and temperature. Strong water clustering in concentrated solutions was seen. Saturation of hydrogen bonding at w(p) approximately equal to 0.5 and a dramatic decrease in PEO-water hydrogen bonding with increasing temperature, consistent with experimentally observed closed-loop phase behavior, were observed. Little tendency toward intermolecular bridging of PEO chains by water molecules was seen.