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The site symmetry and magnitude of the crystal field splitting of metal atoms trapped in rare gas matrices may be determined by a combination of the temperature and magnetic field dependence of magnetic circular dichroism (MCD) and magnetic linear dichroism (MLD). General theoretical expressions are derived for the MCD and MLD considering the Zeeman effect and the matrix (i.e., crystal field) as perturbations on the free atom |JMJ> states. These expressions are applied to the observed MCD and MLD T- and B-saturation curves for Fe atoms isolated in krypton and xenon matrices in the range 0–1.5 T and 2.3–22 K. An octahedral crystal field model accounts well for all four independent sets of data (MCD vs B, MCD vs 1/T, MLD vs B2, and MLD vs 1/T2) for two different, isolated electronic transitions. A crystal field parameter of +0.06±0.05 cm-1 has been determined, corresponding to an overall electronic ground-state splitting of 3.2±2.5 cm-1. This splitting is less than the optical bandwidth and is shown to be consistent with previous studies of rare gas matrix-isolated Fe atoms by Mössbauer and laser-excited emission spectroscopies. [ABSTRACT FROM AUTHOR]

BackgroundFear conditioning involves the amygdala as the main neural structure for learning fear responses whereas fear extinction mainly activates the inhibitory prefrontal cortex (PFC). In this study we investigated whether individual differences in trait anxiety affect amygdala and dorsal anterior cingulate cortex (dACC) activation during fear conditioning and extinction.MethodThirty-two healthy subjects were investigated by functional magnetic resonance imaging (fMRI) at 3 T while performing a cued fear-conditioning task. All participants completed the trait version of the State-Trait Anxiety Inventory (STAI-T). Activations of the amygdala and the dACC were examined with respect to the effects of trait anxiety.ResultsAnalysis of the fMRI data demonstrated enhanced activation in fear-related brain areas, such as the insula and the ACC, during both fear conditioning and extinction. Activation of the amygdala appeared only during the late acquisition phase whereas deactivation was observed during extinction. Regression analyses revealed that highly trait-anxious subjects exhibited sustained amygdala activation and reduced dACC involvement during the extinction of conditioned responses.ConclusionsThis study reveals that high levels of trait anxiety are associated with both increased amygdala activation and reduced dACC recruitment during the extinction of conditioned fear. This hyper-responsitivity of the amygdala and the deficient cognitive control during the extinction of conditioned fear in anxious subjects reflect an increased resistance to extinct fear responses and may thereby enhance the vulnerability to developing anxiety disorders. [ABSTRACT FROM PUBLISHER]

Abstract Background Maturation inhibitors such as Bevirimat are a new class of antiretroviral drugs that hamper the cleavage of HIV-1 proteins into their functional active forms. They bind to these preproteins and inhibit their cleavage by the HIV-1 protease, resulting in non-functional virus particles. Nevertheless, there exist mutations in this region leading to resistance against Bevirimat. Highly specific and accurate tools to predict resistance to maturation inhibitors can help to identify patients, who might benefit from the usage of these new drugs. Results We tested several methods to improve Bevirimat resistance prediction in HIV-1. It turned out that combining structural and sequence-based information in classifier ensembles led to accurate and reliable predictions. Moreover, we were able to identify the most crucial regions for Bevirimat resistance computationally, which are in line with experimental results from other studies. Conclusions Our analysis demonstrated the use of machine learning techniques to predict HIV-1 resistance against maturation inhibitors such as Bevirimat. New maturation inhibitors are already under development and might enlarge the arsenal of antiretroviral drugs in the future. Thus, accurate prediction tools are very useful to enable a personalized therapy.

Abstract Background DNA watermarks can be applied to identify the unauthorized use of genetically modified organisms. It has been shown that coding regions can be used to encrypt information into living organisms by using the DNA-Crypt algorithm. Yet, if the sequence of interest presents a non-coding DNA sequence, either the function of a resulting functional RNA molecule or a regulatory sequence, such as a promoter, could be affected. For our studies we used the small cytoplasmic RNA 1 in yeast and the lac promoter region of Escherichia coli. Findings The lac promoter was deactivated by the integrated watermark. In addition, the RNA molecules displayed altered configurations after introducing a watermark, but surprisingly were functionally intact, which has been verified by analyzing the growth characteristics of both wild type and watermarked scR1 transformed yeast cells. In a third approach we introduced a second overlapping watermark into the lac promoter, which did not affect the promoter activity. Conclusion Even though the watermarked RNA and one of the watermarked promoters did not show any significant differences compared to the wild type RNA and wild type promoter region, respectively, it cannot be generalized that other RNA molecules or regulatory sequences behave accordingly. Therefore, we do not recommend integrating watermark sequences into regulatory regions.

Abstract: The influence of neodymium doping on YVO4 single crystals has been studied. The crystals were grown by the Czochralski method. One of them was pure YVO4 and the others were doped with neodymium (YVO4:Nd) at various concentrations of Nd=0.3–3.0 at.%. The changes of the lattice parameters were determined by the Bond''s method [W.L. Bond, Acta Cryst. 13 (1960) 814]. The thermal diffusivity and the velocity of ultrasound using the photothermal method with mirage effect and the pulse echo method [J. Bodzenta, M. Pyka, J. Phys. IV France 137 (2006) 259] were measured. In the examined crystals, it was found that the lattice parameters increase while the thermal diffusivity decreases with increasing concentration of Nd atoms. [Copyright &y& Elsevier]

Objectives: Uterine fibroids (UF) are the most common benign tumors of the female reproductive organ. It is crucial to recognize that the appropriate treatment of UFs requires an individualized approach. The present paper aimed at the presentation of the five-year experience of our center in the treatment of UFs with the use of magnetic resonance-guided high-intensity ultrasound (MR-HIFU) therapy., Material and Methods: The study enrolled a total of 1284 patients with symptomatic UFs. The Sonalleve MR-HIFU system (Philips Ingenia 3.0T System) was used for magnetic resonance imaging (MRI) qualification and treatment., Results: The group of patients qualified for thermal ablation included 356 (28%) women. No significant differences were observed between the group undergoing thermal ablation and patients who were disqualified. A complete procedure was performed in 22.6% of patients who presented at the center. Non-perfused volume (NPV) is one of the most important parameters assessed during MR-HIFU procedures. The mean NPV value in the present study was 71%. The average UF volumes decreased by 27% at three-month follow-up ultrasound, by 34% after six months and by 39% as shown by MRI measurements performed 6 months post-treatment., Conclusions: According to our data, MR-HIFU therapy is associated with good clinical outcomes in patients with symptomatic UFs. The method facilitates a marked symptom reduction and, in many cases, diminishing tumor volume. The presented five-year outcomes as regards our experience in the MR-HIFU therapy of patients with symptomatic UFs indicate that the method offers an attractive alternative to the traditional methods of UF treatment in selected cases.