Моделирование струйного размыва донных отложений в нефтяных резервуарах

Объект исследования: электромеханическое устройство для размыва донных отложений в резервуарах вертикальных стальных. Предмет исследования – размыв донных отложений в резервуарах хранения нефти. Цель работы – Анализ существующих методов борьбы с донными отложениями. Моделирование гидродинамических процессов размыва донных отложений в резервуарах вертикальных стальных.Object of research: an electromechanical device for washing bottom sediments in vertical steel tanks. The subject of research is the erosion of bottom sediments in oil storage tanks. Purpose of the work - Analysis of existing methods for dealing with bottom sediments. Simulation of hydrodynamic processes of erosion of bottom sediments in vertical steel tanks

The Natural Cytotoxicity Receptor 1 Contribution to Early Clearance of Streptococcus pneumoniae and to Natural Killer-Macrophage Cross Talk

Natural killer (NK) cells serve as a crucial first line of defense against tumors, viral and bacterial infections. We studied the involvement of a principal activating natural killer cell receptor, natural cytotoxicity receptor 1 (NCR1), in the innate immune response to S. pneumoniae infection. Our results demonstrate that the presence of the NCR1 receptor is imperative for the early clearance of S. pneumoniae. We tied the ends in vivo by showing that deficiency in NCR1 resulted in reduced lung NK cell activation and lung IFNγ production at the early stages of S. pneumoniae infection. NCR1 did not mediate direct recognition of S. pneumoniae. Therefore, we studied the involvement of lung macrophages and dendritic cells (DC) as the mediators of NK-expressed NCR1 involvement in response to S. pneumoniae. In vitro, wild type BM-derived macrophages and DC expressed ligands to NCR1 and co-incubation of S. pneumoniae-infected macrophages/DC with NCR1-deficient NK cells resulted in significantly lesser IFNγ levels compared to NCR1-expressing NK cells. In vivo, ablation of lung macrophages and DC was detrimental to the early clearance of S. pneumoniae. NCR1-expressing mice had more potent alveolar macrophages as compared to NCR1-deficient mice. This result correlated with the higher fraction of NCR1-ligandhigh lung macrophages, in NCR1-expressing mice, that had better phagocytic activity compared to NCR1-liganddull macrophages. Overall, our results point to the essential contribution of NK-expressed NCR1 in early response to S. pneumoniae infection and to NCR1-mediated interaction of NK and S. pneumoniae infected-macrophages and -DC

Caractérisation de la capture du VIH-1 (du récepteur DC-SIGN aux extensions trans-épithéliales des cellules dendritiques)

En tant que sentinelles du système immunitaire, les CD expriment une lectine, le DC-SIGN, présentant une forte affinité pour de nombreux pathogènes, incluant le VIH-1. L objectif premier de cette étude est d utiliser cette lectine comme outil de screening d enveloppes issues d isolats primaires de primo-infection afin d identifier une enveloppe d intérêt comme immunogène bloquant l interaction avec le DC-SIGN. Nous avons ainsi pu identifier deux mutations dans la gp41 susceptibles d amplifier l interaction DC-SIGN /gp120. Enfin, nous avons étudié la capacité de prise en charge locale et spécifique d Aspergillus fumigatus par des extensions trans-épithéliales formées par les CD au niveau des villosités de l iléon terminal murin. Notre étude souligne le rôle primordial du DC-SIGN au niveau des muqueuses monostratifiées que ce soit pour la voie de contamination homosexuelle du VIH-1 ou pour l efficacité de capture de pathogènes par les dendrites trans-épithéliales des CDAs the sentinels of the immune system, DC express a lectin DC-SIGN known to bind with high affinity a wide range of pathogens, including HIV-1. The first aim of this study is to use this lectin as a screening tool for envelopes from acute HIV-1 primary isolates in order to identify an envelope of interest that could be used as an immunogen to block the interaction with DC-SIGN. We have identified two point mutations in the gp41 susceptible to increase the DC-SIGN/gp120 interaction. At last, we have studied the local and specific uptake of Aspergillus fumigatus by trans-epithelial dendrites formed by DC in villi of the murine terminal ileum. Our study highlights the crucial role of DC-SIGN in monolayered mucosa, as suggested by the predominance of HIV-1 homosexual contamination or the efficiency of DC trans-epithelial dendrites to capture pathogensLYON1-BU.Sciences (692662101) / SudocSudocFranceF

NCR1 involvement in NK cells activation following infection of BMMQ/ BMDC with <i>S. pneumoniae.</i>

<p>(A-D) Six-day culture of BMMQ and BMDC grown from <i>Ncr1</i>^+/+ BM cells (C57BL/6) were stained with mNCR1-Ig, mNKG2D-Ig and LIR1-Ig fusion proteins. Shown are representative overlays of F4/80⁺CD115⁺ BMMQ (A, C) and CD11c⁺ BMDC (B, D) demonstrating staining with mNCR1-Ig (solid line, A-D), mNKG2D-Ig (dotted line, C–D), LIR1-Ig (dashed line, A–B) and with goat anti-human IgG (grey-filled, A–D). Shown is one representative experiment out of four to five independent experiments. In some experiments, NKG2D-Ig staining was higher compared to NCR1-Ig staining. (E–F) Six-day culture- BMMQ (E) and -BMDC (F) grown from <i>Ncr1</i>^+/+ BM cells (C57BL/6) were infected with 1 MOI of <i>S. pneumoniae</i> for 1.5 h, then bacteria were removed and antibiotics were added. In parallel, NK cells were isolated from splenocytes of <i>Ncr1</i>^+/+ (‘NK WT’) and <i>Ncr1</i>^gfp/gfp (‘NK KO’) C57BL/6 mice. Isolated NK were incubated with uninfected BMMQ or BMDC, or with <i>S. pneumoniae</i>-infected BMMQ or BMDC (‘BMMQ+SP’, ‘BMDC+SP’) after removal of bacteria for additional 18 hours. NK-BMMQ ratio was 1∶4 and NK-BMDC ration was 1∶10. IFNγ concentration levels in the co-culture supernatants were determined by ELISA. Results are from one representative experiment out of two. ** p<0.01 compared with IFNγ levels of NK WT incubated with infected BMMQ/BMDC, ± SD (ANOVA test).</p