580 research outputs found
Research Paper Polyclonal antibodies production against Staphylococcus aureus protein A: ELISA technique optimization for milk quality control
The main aim of this project is to produce polyclonal antibodies directed against the Staphylococcus aureus protein A and their use to appreciate bacteriological analysis of milk quality. In this context, an immunization produce was set up to test and detect in a batch of animals the convenient responder to the injected antigen. Furthermore, to optimize all parameters of retained ELISA test, a cross-table was conceived by using various concentrations of different reagents and has allowed selecting the optimaldilutions as follows: 1) 1/1000 for anti-Staphylococcus aureus protein A mouse antibodies and 1/2000 for anti-Staphylococcus aureus protein A rabbit antibodies. 2) 1/4000 for anti-Staphylococcus aureus treated by heat mouse antibodies and 1/500 for anti-Staphylococcus aureus protein A rabbit antibodies. 3) 1/2000 for anti-Staphylococcus aureus treated by NaClO mouse antibodies and 1/500 for anti-Staphylococcus aureus protein A rabbit antibodies. The application of optimized ELISA test to searchand detect Staphylococcus aureus germs in different samples of milk has shown very satisfying results when compared to those obtained by bacteriological method. Indeed, the sensitiveness and the reproducibility, as well as the possibility to analyze a great number of samples in the same time at a reduced manner make the immunochemical method a best choice of test able to replace recent bacteriological methods
Retrospective study of epidemiological, clinicopathological and biological profils of 62 colorectal cancers cases in Jijel provence (Algeria)
In Algeria, the CRC wing and become the first digestive cancer in both sexes,Ā outperforming stomach cancer. To enrich the Algerian cancer registries, we analyzed the profiles of patients with these cancers in Jijel Willaya. This was a retrospective and descriptive analysis of epidemiological, clinicopathological and biological profiles of 62 CRC cases. We found that the CRC represented the first type of digestive cancers in which the three quarters were colon cancers. The most affected age group was 60-70 years with a male predominance and an average age of 56.20 years. The bleeding and abdominal pain were the majority telltale signs. The combined chemotherapy has been standardized with all patients and the LieberkĆ¼hnien adenocarcinoma was the major histological form. The disease issue and the choice of therapy depended on the K-RAS gene mutations. Our results were often compatible with the available literature and may provide reliable and relevant data on this disease.Key words: Colorectal cancer; Epidemiology; Therapy; Adenocarcinoma; K-RAS gen
Influence of oxygen deficiency on optical and dielectric properties of La0.75Ba0.10Sr0.15FeO2.875-Ī“ compounds
Using the conventional sol-gel process, the series of non-stoichiometric oxygen lanthanum
ferrites with the formula 0.750.100.152.875 ā (Ī“=0.00, 0.125 and 0.25) were
prepared. X-ray diffraction analysis confirmed the formation of the orthorhombic structure
with Pnma space group. In the present work, we confirm the potential of 0.750.100.15
2.875 ā (Ī“=0.00, 0.125 and 0.25) as an efficient dielectric material. All samples show high
absorbance in the visible region with wavelength above 300 nm. The optical band gaps are
found to increase from 3.25 to 4.1 with increasing oxygen vacancy concentration. The
dielectric constant, dielectric loss and loss factor were carried out as a function of oxygen
vacancy concentration and frequency (102
-106 Hz) at room temperature. The variation of
dielectric constant with frequency indicates dispersive behavior and giant dielectric response
(more than 104
) at low frequencies for compounds deficient in oxygen. Such value of makes ā²
these samples an interesting material to be used in applications namely the reduction of
electronic components size. To summarize, incorporating vacancy oxygen enhances the
dielectric properties. Thus, the interesting dielectric constant and weak loss strengthen the use
for potential applications.publishe
Optical properties of an ensemble of G-centers in silicon
We addressed the carrier dynamics in so-called G-centers in silicon
(consisting of substitutional-interstitial carbon pairs interacting with
interstitial silicons) obtained via ion implantation into a
silicon-on-insulator wafer. For this point defect in silicon emitting in the
telecommunication wavelength range, we unravel the recombination dynamics by
time-resolved photoluminescence spectroscopy. More specifically, we performed
detailed photoluminescence experiments as a function of excitation energy,
incident power, irradiation fluence and temperature in order to study the
impact of radiative and non-radiative recombination channels on the spectrum,
yield and lifetime of G-centers. The sharp line emitting at 969 meV (1280
nm) and the broad asymmetric sideband developing at lower energy share the same
recombination dynamics as shown by time-resolved experiments performed
selectively on each spectral component. This feature accounts for the common
origin of the two emission bands which are unambiguously attributed to the
zero-phonon line and to the corresponding phonon sideband. In the framework of
the Huang-Rhys theory with non-perturbative calculations, we reach an
estimation of 1.60.1 \angstrom for the spatial extension of the
electronic wave function in the G-center. The radiative recombination time
measured at low temperature lies in the 6 ns-range. The estimation of both
radiative and non-radiative recombination rates as a function of temperature
further demonstrate a constant radiative lifetime. Finally, although G-centers
are shallow levels in silicon, we find a value of the Debye-Waller factor
comparable to deep levels in wide-bandgap materials. Our results point out the
potential of G-centers as a solid-state light source to be integrated into
opto-electronic devices within a common silicon platform
Accurate Anisotropic Fast Marching for Diffusion-Based Geodesic Tractography
Using geodesics for inferring white matter fibre tracts from diffusion-weighted MR data is an attractive method for at least two reasons: (i) the method optimises a global criterion, and hence is less sensitive to local perturbations such as noise or partial volume effects, and (ii) the method is fast, allowing to infer on a large number of connexions in a reasonable computational time. Here, we propose an improved fast marching algorithm to infer on geodesic paths. Specifically, this procedure is designed to achieve accurate front propagation in an anisotropic elliptic medium, such as DTI data. We evaluate the numerical performance of this approach on simulated datasets, as well as its robustness to local perturbation induced by fiber crossing. On real data, we demonstrate the feasibility of extracting geodesics to connect an extended set of brain regions
Les kystes dermoĆÆdes de la fosse cerebrale postereure
Matériel et Méthode 3 enfants âgés de 18 mois à 8 ans ont été colligés au service entre 2005 et 2010. Résultas 3 patients ont présenté un syndrome d’hypertension intracrânienne, dont un patient a présenté une méningite récidivante. Tous avaient un sinus dermique. L’IRM a été réalisée dans tous les cas. Tous ont bénéficié d’une exérèse chirurgicale totale et d’une dérivation du LCR par ventriculo-cisternostomie première en urgence dans un cas et par dérivation ventriculo-péritonéale en post-opératoire dans deux cas. L’évolution était satisfaisante sans récidive avec un recul moyen de 3 ans. Conclusion Dans notre série, le KD de la fosse cérébrale postérieure est toujours associé à un sinus dermique et à une hydrocéphalie. La prise en charge repose sur l’exérèse chirurgicale et sur la dérivation du liquide cérébro-spinal.Mots clés : kyste dermoïde, sinus dermique, fosse cérébrale postérieure, chirurgie, résonance magnétiqu
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