564 research outputs found
Integrating computational methods to predict mutagenicity of aromatic azo compounds
Azo dyes have several industrial uses. However, these azo dyes and their degradation products showed mutagenicity, inducing damage in environmental and human systems. Computational methods are proposed as cheap and rapid alternatives to predict the toxicity of azo dyes. A benchmark dataset of Ames data for 354 azo dyes was employed to develop three classification strategies using knowledge-based methods and docking simulations. Results were compared and integrated with three models from the literature, developing a series of consensus strategies. The good results confirm the usefulness of in silico methods as a support for experimental methods to predict the mutagenicity of azo compounds
Optimization of organotypic cultures of mouse spleen for staining and functional assays
By preserving cell viability and three-dimensional localization, organotypic culture stands out among the newest frontiers of cell culture. It has been successfully employed for the study of diseases among which neoplasias, where tumoral cells take advantage of the surrounding stroma to promote their own proliferation and survival. Organotypic culture acquires major importance in the context of the immune system, whose cells cross-talk in a complex and dynamic fashion to elicit productive responses. However, organotypic culture has been as yet poorly developed for and applied to primary and secondary lymphoid organs. Here we describe in detail the development of a protocol suitable for the efficient cutting of mouse spleen, which overcomes technical difficulties related to the peculiar organ texture, and for optimized organotypic culture of spleen slices. Moreover, we used microscopy, immunofluorescence, flow cytometry and qRT-PCR to demonstrate that the majority of cells residing in spleen slices remain alive and maintain their original location in the organ architecture for several days after cutting. The development of this protocol represents a significant technical improvement in the study of the lymphoid microenvironment in both physiological and pathological conditions involving the immune system
Investigation of the quasifission process by theoretical analysis of experimental data of fissionlike reaction products
The fusion excitation function is the important quantity in planning
experiments for the synthesis of superheavy elements. Its values seem to be
determined by the experimental study of the hindrance to complete fusion by the
observation of mass, angular and energy distributions of the fissionlike
fragments. There is ambiguity in establishment of the reaction mechanism
leading to the observed binary fissionlike fragments. The fissionlike fragments
can be produced in the quasifission, fast fission, and fusion-fission processes
which have overlapping in the mass (angular, kinetic energy) distributions of
fragments. The branching ratio between quasifission and complete fusion
strongly depends on the characteristics of the entrance channel. In this paper
we consider a wide set of reactions (with different mass asymmetry and mass
symmetry parameters) with the aim to explain the role played by many quantities
on the reaction mechanisms. We also present the results of study of the
Ca+Bk reaction used to synthesize superheavy nuclei with Z = 117
by the determination of the evaporation residue cross sections and the
effective fission barriers of excited nuclei formed along the
de-excitation cascade of the compound nucleus.Comment: 21 pages, 15 figures, 2 table
MRI of female genital tract congenital anomalies: European Society of Urogenital Radiology (ESUR) guidelines
OBJECTIVE: To develop imaging guidelines for the MR work-up of female genital tract congenital anomalies (FGTCA). METHODS: These guidelines were prepared based on a questionnaire sent to all members of the European Society of Urogenital Radiology (ESUR) Female Pelvic Imaging Working Group (FPI-WG), critical review of the literature and expert consensus decision. RESULTS: The returned questionnaires from 17 different institutions have shown reasonable homogeneity of practice. Recommendations with focus on patient preparation and MR protocol are proposed, as these are key to optimised examinations. Details on MR sequences and planning of uterus-orientated sequences are provided. CONCLUSIONS: The multiplanar capabilities and soft tissue resolution of MRI provide superb characterisation of the wide spectrum of findings in FGTCA. A standardised imaging protocol and method of reporting ensures that the salient features are recognised, contributing to a correct diagnosis and classification of FGTCA, associated anomalies and complications. These imaging guidelines are based on current practice among expert radiologists in the field and incorporate up to date information regarding MR protocols and essentials of recently published classification systems. KEY POINTS: * MRI allows comprehensive evaluation of female genital tract congenital anomalies, in a single examination. * A dedicated MRI protocol comprises uterus-orientated sequences and vaginal and renal evaluation. * Integration of classification systems and structured reporting helps in successful communication of the imaging findings
European society of urogenital radiology (ESUR) guidelines: MR imaging of pelvic endometriosis
Endometriosis is a common gynaecological condition of unknown
aetiology that primarily affects women of reproductive
age. The accepted first-line imaging modality is pelvic ultrasound.
However, magnetic resonance imaging (MRI) is increasingly
performed as an additional investigation in complex cases and for surgical planning. There is currently
no international consensus regarding patient preparation, MRI
protocols or reporting criteria. Our aim was to develop clinical
guidelines for MRI evaluation of pelvic endometriosis based
on literature evidence and consensus expert opinion. This
work was performed by a group of radiologists from the European Society of Urogenital Radiology (ESUR), experts in
gynaecological imaging and a gynaecologist expert in methodology.
The group discussed indications for MRI, technical
requirements, patient preparation, MRI protocols and criteria
for the diagnosis of pelvic endometriosis on MRI. The expert
panel proposed a final recommendation for each criterion
using Oxford Centre for Evidence Based Medicine
(OCEBM) 2011 levels of evidence.info:eu-repo/semantics/publishedVersio
Nonisospectral integrable nonlinear equations with external potentials and their GBDT solutions
Auxiliary systems for matrix nonisospectral equations, including coupled NLS
with external potential and KdV with variable coefficients, were introduced.
Explicit solutions of nonisospectral equations were constructed using the GBDT
version of the B\"acklund-Darboux transformation
A new limit on the light speed isotropy from the GRAAL experiment at the ESRF
When the electrons stored in the ring of the European Synchrotron Radiation
Facility (ESRF, Grenoble) scatter on a laser beam (Compton scattering in
flight) the lower energy of the scattered electron spectra, the Compton Edge
(CE), is given by the two body photon-electron relativistic kinematics and
depends on the velocity of light. A precision measurement of the position of
this CE as a function of the daily variations of the direction of the electron
beam in an absolute reference frame provides a one-way test of Relativistic
Kinematics and the isotropy of the velocity of light. The results of GRAAL-ESRF
measurements improve the previously existing one-way limits, thus showing the
efficiency of this method and the interest of further studies in this
direction.Comment: Proceed. MG12 meeting, Paris, July, 200
Limits on light-speed anisotropies from Compton scattering of high-energy electrons
The possibility of anisotropies in the speed of light relative to the
limiting speed of electrons is considered. The absence of sidereal variations
in the energy of Compton-edge photons at the ESRF's GRAAL facility constrains
such anisotropies representing the first non-threshold collision-kinematics
study of Lorentz violation. When interpreted within the minimal Standard-Model
Extension, this result yields the two-sided limit of 1.6 x 10^{-14} at 95%
confidence level on a combination of the parity-violating photon and electron
coefficients kappa_{o+} and c. This new constraint provides an improvement over
previous bounds by one order of magnitude.Comment: 4 pages, 4 figure
Preliminary tests of innovative thin silicon detectors for beam monitoring in particle therapy.
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