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We report on the synthesis and characterization of new a nano-wire-like material with chemical formula Mo6S4.5I4.5. The material can be synthesized in a single step reaction from elements in bulk quantities. The material has a fur-like appearance and is composed of nanowires that are weakly bound in bundles. Bundles itself can be dispersed using an ultrasonic bath in various organic solvents and water. Elemental analysis, X-ray diffraction, thermal analysis (TG, DTA), and electron microscopy were used to characterize the new material in the shape of nanowires. Due to their monodisperse and metallic nature, molybdenum-sulphur-iodine nanowires are an interesting alternative to carbon nanotubes for some applications.

The process of organogenesis depends on genetic and environmental factors. Besides genetic background, congenital anomalies can also be influenced by micro environmental changes, which are related to maternal-foetal interactions followed by the production of cytokines, hormones, neurotransmitters, growth factors and biochemical mediators, and stress proteins. Pre-natal maternal stress, including infections, psychological stress and other teratogens, can influence a disregulation of maternal immune, endocrine and nervous systems, during pregnancy. This is a crucial condition for the abnormal growth and development of the foetus. Activated maternal immune system can alter the cytokine network and make it inadequate for normal embryogenesis and organogenesis. Heat-shock proteins play an important role in stress physiology repairing DNA errors or activating pro-inflammatory response. Regarded from this aspect, the altered cytokine network suggests aetiopathogenetic basis of congenital anomalies in neonates. It is our wish to point out our potentially harmful conditions in the development of congenital anomalies, as well as their control by using pre-natal and pre-conceptional diagnostics and treatment.

Superconducting state dynamics following excitation of a superconductor with a femtosecond optical pulse is studied in terms of a phenomenological Rothwarf and Taylor model. Analytical solutions for various limiting cases are obtained. The model is found to account for the intensity and temperature dependence of both photoinduced quasiparticle density, as well as pair-breaking and superconducting state recovery dynamics in conventional as well as cuprate superconductors.

Time-resolved optical experiments can give unique information on the characteristic length scales of dynamic charge inhomogeneity on femtosecond time scales. From data on the effective quasiparticle relaxation time tau(r) in La(2-x)SrxCuO4 and Nd(2-x)Ce(x)CuO4, we derive the temperature and doping dependence of the intrinsic phonon escape length l(e), which can be a direct measure of charge inhomogeneity. Remarkably, a common feature of both p- and n-type cuprates is that, as T --> Tc, l(e) approaches the superconducting coherence length l(e) --> xi(s)0. In the normal state l(e) is found to be in excellent agreement with the mean free path l(m) obtained from the resistivity data and structural coherence lengths l(s) from neutron scattering experiments, implying the existence of complex intrinsic textures on different length scales which may have a profound effect on the functional properties of these materials.

Due to their ease of fabrication and monodisperse, metallic nature, molybdenum-sulfur-iodine nanowires are an interesting alternative to carbon nanotubes for some applications. However very little is known about the solubility of these materials. In this work we have investigated the solubility of Mo(6)S(4.5)I(4.5) nanowire soot in a range of common solvents by performing sedimentation studies and microscopic and spectroscopic characterization. A sedimentation equation was derived showing that the concentration of any insoluble dispersed phase decreases exponentially with time. We find that in all solvents, Mo(6)S(4.5)I(4.5) nanowire soot contains three phases, two of which are insoluble with one stable phase. Microscopy and spectroscopy show that the first insoluble phase is associated mainly with spherical impurities and sediments rapidly out of solution resulting in purification. The second phase appears to consist of insoluble nanowire bundles and sediments more slowly, eventually leaving a stable dispersion of nanowire bundles. The stably dispersed bundles tend to be smaller than their insoluble counterparts. The best solvents studied were 2-propanol and dimethylformamide. Microscopy studies showed that, in the case of 2-propanol, sonication significantly reduced the bundle size relative to the unsonicated bulk. However, during sedimentation, large quantities of bundles were observed to reaggregate to form larger bundles which subsequently sedimented out of solution. In general, the sedimentation properties of the various phases did not vary significantly with concentration indicating that the insoluble nanowires are intrinsically insoluble. However, the diameter of the stably dispersed bundles decreased with concentration, until very small bundles consisting of only two or three nanowires were observed at concentrations below 0.003 mg/mL. In addition, stable composite dispersions were produced by mixing the nanowires with poly(vinylpyrrolidone) in 2-propanol opening the way for the formation of polymer/inorganic nanowire composites.

The properties of a system of charged particles on a 2D lattice, subject to an anisotropic Jahn-Teller-type interaction and 3D Coulomb repulsion, are investigated. In the mean-field approximation without Coulomb interaction, the system displays a phase transition of first order. When the long-range Coulomb interaction is included, Monte Carlo simulations show that the system displays very diverse mesoscopic textures, ranging from spatially disordered pairs to ordered arrays of stripes, or charged clusters, depending only on the ratio of the two interactions (and the particle density). Remarkably, charged objects with an even number of particles are more stable than with an odd number of particles. We suggest that the diverse functional behavior-including superconductivity-observed in oxides can be thought to arise from the self-organization of this type.

We report on a study of the interactions between holes and molecular vibrations on dry DNA using photoinduced infrared absorption spectroscopy. Laser photoexcited holes are found to have a room-temperature lifetime in excess of tau > 1 ms, clearly indicating the presence of localization. However, from a quantitative model analysis of the frequency shifts of vibrational modes caused by the holes, we find the hole-vibrational coupling constant to be relatively small, lambda approximately 0.2. This interaction leads to a change in the conformational energy of DeltaE0 approximately 0.015 eV, which is too small to cause self-trapping at room temperature. We conclude that, at least in the dry (A) form, DNA is best understood in terms of a double chain of coupled quantum dots arising from the pseudorandom chain sequence of base pairs, in which Anderson localization prevents the formation of a metallic state.

Objective: To estimate nuclear size and integrated optical density of parenchymal cells from various organs in patients with Down syndrome and a control group., Study Design: During the years 1988-2000, 14 cases of Down syndrome were found (8 male and 6 female). Ten infants without congenital anomalies died of respiratory distress syndrome and were used as a control group. Five nuclear variables were estimated: area, equivalent diameter, volume of equivalent sphere, roundness and total optical density (TOD)., Results: Mean nuclear volume and TOD of thyroid follicular cells were significantly lower in patients with Down syndrome (43.82 +/- 8.95 and 173.81 +/- 32.85 microns 3, respectively) than in the control group (65.46 +/- 15.31 and 234.58 +/- 32.85 microns 3, respectively) (P < .01). Mean hepatocite nuclear volume and TOD were significantly higher in the control group (165.54 +/- 55.42 and 220.84 +/- 51.75 microns 3, respectively) than in trisomy 21 (110.39 +/- 32.97 and 176.58 +/- 28.53 microns 3, respectively) (P < .05)., Conclusion: The present results suggest altered gene expression in excessive genetic material, especially in thyroid follicular cells.

We report on the very peculiar magnetic properties of an ensemble of very weakly coupled lithium-doped MoS2 nanotubes. The magnetic susceptibility chi of the system is nearly 3 orders of magnitude greater than in typical Pauli metals, yet there is no evidence for any instability which would alleviate this highly frustrated state. Instead, the material exhibits peculiar paramagnetic stability down to very low temperatures, with no evidence of a quantum critical point as T-->0 in spite of clear evidence for strongly correlated electron behavior. The exceptionally weak intertube interactions appear to lead to a realization of a near-ideal one-dimensional state in which fluctuations prevent the system from reordering magnetically or structurally.

Objective: To perform a quantitative analysis to identify which of 7 nuclear morphometry-related variables are of diagnostic value in distinguishing benign from malignant melanocytic skin lesions., Study Design: At the Institute of Pathology, University of Nis, formalin-fixed, paraffin-embedded skin biopsies from 23 cases of benign nevi (18 intradermal and 5 junctional) and 25 cases of primary nodular malignant melanomas were retrieved. Specimens were routinely stained with hematoxylin and eosin and analyzed using a computer-assisted interactive image analysis system. Nuclear area, equivalent diameter, volume of equivalent sphere, perimeter, mean chord, circularity and integrated optical density were estimated after manual editing of binary images., Results: In univariate analysis, 6 features were found to be significantly different between the benign and malignant groups (P < .0001); all measured nuclear variables (except circularity) were higher in malignant melanomas. No significant differences were found among lesions with respect to nuclear shape. Using discriminant function analysis, a correct diagnosis was achieved in 95.8% of benign nevi cases and 84.0% of malignant melanoma cases. The best discriminant variable was nuclear area., Conclusion: Image analysis is diagnostically relevant to the evaluation of melanocytic lesions of the skin. The area of the nucleus appeared to have potential for differentiating benign from malignant tumors and can be estimated in the course of routine histology.

Critical exponents at the ferromagnetic transition were measured for the first time in an organic ferromagnetic material tetrakis(dimethylamino)ethylene fullerene[60] (TDAE- C(60)). From a complete magnetization-temperature-field data set near T(c) = 16.1+/-0.05, we determine the susceptibility and magnetization critical exponents gamma = 1.22+/-0.02 and beta = 0.75+/-0.03, respectively, and the field vs magnetization exponent at T(c) of delta = 2.28+/-0.14. Hyperscaling is found to be violated by Omega identical with d(')-d approximately -1/4, suggesting that the onset of ferromagnetism can be related to percolation of a particular contact configuration of C(60) molecular orientations.

We report on the synthesis, structure, and self-assembly of single-wall subnanometer-diameter molybdenum disulfide tubes. The nanotubes are up to hundreds of micrometers long and display diverse self-assembly properties on different length scales, ranging from twisted bundles to regularly shaped "furry" forms. The bundles, which contain interstitial iodine, can be readily disassembled into individual molybdenum disulfide nanotubes. The synthesis was performed using a novel type of catalyzed transport reaction including C(60) as a growth promoter.

Organic ferromagnets, which exhibit exchange interactions between unpaired electrons in pi-orbitals, are rare, and the origin of ferromagnetism in these compounds has so far remained unexplained. Tetrakis(dimethylamino)ethylene-fullerene[60] (TDAE-C60) shows a transition to a ferromagnetic state with fully saturated s = 1/2 molecular spins at the relatively high Curie temperature (for organic materials) of 16 K (ref. 4). It has been suggested that the orientations of the C60 molecules may be important for ferromagnetism in this material, but in the absence of structural data at low temperatures there has been little progress towards understanding these microscopic interactions. Here we report the results of a comparative structural study of two different magnetic forms of TDAE-C60 crystals at low temperatures, correlating the structural properties--in particular, the intermolecular orientations--with the magnetic properties. We find that both ferromagnetism and spin-glass-like ordering are possible in this material, and depend on the orientational state of C60 molecules. This resolves the apparent contradictions posed by different macroscopic measurements, and opens the way to a microscopic understanding of pi-electron ferromagnetic exchange interactions in organic materials.

Renal ischemia as well as oxygen metabolites play an important role in renal injury during myoglobinuric acute renal failure (ARF). On the other hand, flavonoids, a diverse group of constituents naturally occurring in plants, have a strong antioxidative activity, and have been implicated in vascular relaxation. In this study the protective effect of a new bioflavonoid proanthocyanidin-BP1 (BP1), extracted from seeds of grapes, was evaluated in glycerol-induced ARF in rats. Stereological methods were used to quantify changes in renal morphology associated with ARF. Volume density of tubular lumen and intratubular cast formations, nuclear parameters (area, diameter, volume) of epithelial cells in the cortical proximal tubules, and glomerular parameters (surface area, diameter, volume, perimeter) were estimated on kidney sections of rats treated either with 50% glycerol (8 mL/kg i.m.) alone. BP1 (20 mg/kg i.p.) in addition to glycerol, or BP1 alone. It was noted that the volume density of tubular lumen and cast formations were significantly lower (p < 0.001) in kidneys of the rats treated with BP1 in addition to glycerol, compared with those treated with glycerol alone. There were no significant differences in glomerular and nuclear parameters between glycerol treated, and BP1 in addition to glycerol treated rats. Renal function was significantly improved in rats treated with BP1 in addition to glycerol. The results suggest that BP1 is a protective agent in glycerol model of ARF. This effect is probably due to the antioxidative activity of BP1 and reduced toxicity of myoglobin in renal tissue. Moreover, it is possible that the ability of BP1 to protect the kidney is dependent upon renal vascular relaxation. The potential beneficial effects of bioflavonoid-BP1 demonstrated in experimental ARF could be considered in therapy of myoglobinuric ARF.

The prognostic value of histopathological typing of breast carcinomas is relatively good. The determination of cell size has been a common and useful parameter in the diagnosis of various malignancies. With modern stereologic methods it is possible to obtain unbiased estimates of nucleolar volume. The aim of this study was to present our data regarding the nucleolar size in breast carcinoma. Patients treated for breast carcinoma (n = 39) were retrieved and randomly selected from the files of the University Institute of Pathology, Nis. Histological sections (4 microns) were cut from each of the routinely processed, paraffin-embedded tissue blocks and stained with hematoxylin and eosin. A Carl Zeiss NU-1 microscope equipped with a x 100 oil-immersion lens (N.A. = 1.25) and eyepiece graticule was used for stereological measurements. A total magnification of x 1600 was used. A simple grid was used for point sampling of nucleolar intercepts, which were measured in one arbitrary direction. By multiplying the averaged, cubed intercept length by pi/3, an unbiased estimate of volume-weighted nucleolar volume was obtained. The nucleolar volume was significantly larger in invasive ductal carcinoma (12.34 +/- 3.48 microns3) than invasive lobular carcinoma (5.6 +/- 2.73 microns 3) and mucinous (colloid) adenocarcinoma (0.88 +/- 0.42 micron 3). Various histological types of breast cancer exhibit differences with regard to nucleolar volume.