Development of new population-averaged standard templates for spatial normalization and segmentation of MR images for postnatal piglet brains

Propose

To design a set of brain templates for postnatal piglet brains based on high-resolution T1-weighted imaging for voxel-based morphometric analysis.

Materials and methods

Using a 3.0 T magnetic resonance (MR) scanner, a population-based whole brain template was developed by averaging forty T1 images in the brains of postnatal piglets at 38 days of age. The templates for gray and white matter, and cerebrospinal fluid were designed based on the corresponding probability maps by adapting individual data sets using statistical parametric mapping. Anatomical labeling maps were generated from labeling propagation derived from the established Pig Brain Atlas. Differences in the coordinates from four significant structural landmarks in the template, plus an additional 12 normalized images and anatomical labeling maps were measured to validate the accuracy of the registration of the template.

Results

A whole brain template, a set of tissue-specific probability and anatomical labeling maps were developed. The location deviation of the four significant structural landmarks, including the anterior and posterior regions in the corpus callosum, and the left and right caudate nucleus, was found to be < 0.25 cm, validating the sensitivity and resolution of the template.

Conclusion

A whole brain template map and a set of tissue-specific probability and anatomical labeling maps were developed to analyze the morphometric imaging of the postnatal piglet brain, an animal model of the human infant.     

Features of the plasma sputtering of polycrystalline Pb1 − x Sn x S films

The processes of the sputtering and modification of surfaces of polycrystalline films of the ternary solid solution Pb_{1 ? x} Sn _x S (x = 0.9–1.0) in a high-density Ar plasma of high-frequency low-pressure inductive discharge are studied. Films with thicknesses of 1–4 μm are grown on glass substrates using the “hot-wall” method and consist of plate-like crystallites. It is established that the sputtering rate for lead-tin sulfide films does not exceed 2.0 nm/s, which is determined by the presence of oxygen-containing compounds on the surfaces. In the case of plate-like crystallites with nanodimensional thicknesses, the effect of smoothing of the developed surfaces of the polycrystalline Pb_{1 ? x} Sn _x S layers during plasma treatment is observed; this is important for fabricating multilayer device structures.     

Formation of W/HfO2/Si gate structures using in situ magnetron sputtering and rapid thermal annealing

The W(150 nm)/HfO₂(5 nm)/Si(100) structures prepared in a single vacuum cycle by rf magnetron sputtering were subjected to rapid thermal annealing in argon. It is found that at an annealing temperature of 950°C, the tungsten oxide WO _x phase and the hafnium silicate HfSi _x O _y phase grow at the W/HfO₂ and HfO₂/Si(100) interfaces, respectively. Herewith, the total thickness of the oxide layeris 30% larger than that of the initial HfO₂ film. In addition, a decrease in the specific capacitance in accumulation C _max and in the dielectric constant k (from 27 to 23) is observed. At an annealing temperature of 980°C, intensive interaction between tungsten and HfO₂ takes place, causing the formation of a compositionally inhomogeneous Hf _x Si _y W _z O oxide layer and further decrease in C _max. It is shown that a considerable reduction in the leakage currents occurs in the W/HfO₂/X/Si(100) structures, where X is a nitride barrier layer.     

Spin polarons at high temperatures in nonstoichiometric La1 − x Mn1 − y O3 manganites

The magnetic properties of the La_{1 ? x} Mn_{1 ? y} O₃ family of nonstoichiometric lanthanum manganites are studied in the 80 K < T < 640 K temperature range. The Curie temperature varies nonmonotonically with the growth in the density of Mn⁴⁺ ions. In the existence range for the paramagnetic phase, magnetic polarons appear in both the orthorhombic and rhombohedral phases. In the range of paramagnetism, the temperature dependence of the magnetic susceptibility is nonlinear and can be fitted by the Curie law with the temperature-dependent Curie constant.     

On Riesz Means of Eigenvalues

In this article we prove the equivalence of certain inequalities for Riesz means of eigenvalues of the Dirichlet Laplacian with a classical inequality of Kac. Connections are made via integral transforms including those of Laplace, Legendre, Weyl, and Mellin, and the Riemann–Liouville fractional transform. We also prove new universal eigenvalue inequalities and monotonicity principles for Dirichlet Laplacians as well as certain Schrödinger operators. At the heart of these inequalities are calculations of commutators of operators, sum rules, and monotonic properties of Riesz means. In the course of developing these inequalities we prove new bounds for the partition function and the spectral zeta function (cf. Corollaries 3.5–3.7) and conjecture about additional bounds.     

Arithmetical and semihereditary semigroup rings

In this paper conditions on the commutative ring R (with identity) and the commutative semigroup ring S (with identity) are found which characterize those semigroup rings R[S] which are reduced or have weak global dimension at most one. Likewise, those semigroup rings R[S] which are semihereditary are completely determined in terms of R and S.     

New trans-[Re6S8(CN)4L2] n− Rhenium Cluster Complexes: Syntheses, Crystal Structures and Properties

Reaction of polymeric compound Cs₄[Re₆S₈(CN)₄S_2/2] with aqueous solution of KOH led to formation of trans-[Re₆S₈(CN)₄(OH)₂]⁴⁻ anion which was crystallized in ordered Cs_1.68K_2.32[Re₆S₈(CN)₄(OH)₂] · 2H₂O (1a) and disordered Cs_1.83K_2.17[Re₆S₈(CN)₄(OH)₂] · 2H₂O (1b) modifications. The presence of two types of apical ligands, inert cyanides and labile hydroxides, opened a way to other trans-[Re₆S₈(CN)₄L₂] ⁿ⁻ rhenium cluster complexes: trans-[Re₆S₈(CN)₄Cl₂]⁴⁻, trans-[Re₆S₈(CN)₄(H₂O)Br]³⁻, and trans-[Re₆S₈(CN)₄Br₂]⁴⁻, crystallized as Cs_1.84K_1.16(H)[Re₆S₈(CN)₄Cl₂] (2), Cs_1.68K_1.32[Re₆S₈(CN)₄(H₂O)Br] (3), (Me₄N)₃(H₅O₂)[Re₆S₈(CN)₄Br₂] (4), and CsK{Cu(H₂O)₂[Re₆S₈(CN)₄Cl₂]} · 4H₂O (5) salts.     

Vacuum‐UV Irradiation‐Based Formation of Methyl‐Si‐O‐Si Networks from Poly(1,1‐Dimethylsilazane‐co‐1‐methylsilazane)

The vacuum‐UV (VUV)‐induced conversion of commercially available poly(1,1‐dimethylsilazane‐co‐1‐methylsilazane) into methyl‐Si‐O‐Si networks was studied using UV sources at wavelengths around 172, 185, and 222 nm, respectively. Time‐of‐flight secondary ion mass spectroscopy (TOF‐SIMS), X‐ray photo electron spectroscopy (XPS), and Fourier transform infrared (FTIR) measurements, as well as kinetic investigations, were carried out to elucidate the degradation process. First‐order kinetics were found for the photolytically induced decomposition of the Si? NH‐Si network, the subsequent formation of the methyl‐Si‐O‐Si network and the concomitant degradation of the Si? CH₃ bond, which were additionally independent of the photon energy above a threshold of about 5.5 eV (225 nm). The kinetics of these processes were, however, dependent on the dose actually absorbed by the layer and, in the case of Si‐O‐Si formation, additionally on the oxygen concentration. The release of ammonia and methane accompanied the conversion process. Quantum‐chemical calculations on methyl substituted cyclotetrasilazanes as model compounds substantiate the suggested reaction scheme. Layers <100 nm in thickness based on mixtures of poly(1,1‐dimethylsilazane‐co‐1‐methylsilazane) and perhydropolysilazane (PHPS) were coated onto polyethylene terephthalate (PET) foils by a continuous roll to roll process and cured by VUV irradiation by using wavelengths <200 nm and investigated for their O₂ and water vapor‐barrier properties. It was found that the resulting layers displayed oxygen and water vapor transmission rates (OTR and WVTR, respectively) of <1 cm³ m^?2 d^?1 bar^?1 and <4 g m^?2 d^?1, respectively.