On the effect of thermodiffusion on solute segregation during the growth of semiconductor materials by the vertical Bridgman method

The effect of thermodiffusion on dopant distribution in the melt and in the grown crystal is investigated numerically for a vertical Bridgman configuration for situations of pure thermal convection corresponding to dilute alloys. The dopant distribution is shown to be significantly affected by the Soret parameter value. The sensitivity of the system to a variety of parameters, including the Grashof number and the so-called furnace residence time, i.e. the time during which the crucible is maintained in the furnace before initiating the solidification process, is assessed by means of parametric simulations. Moreover, the results indicate that variations in the sign of the Soret parameter can lead to diametrically opposite behaviours, while an increase in the intensity of the thermal convection generally leads to a mitigation of the effects induced by thermodiffusion. On the basis of the numerical results some useful criteria are drawn which could help crystal growers to discern the complex interrelations among the various parameters under one’s control (that are not independent of one another) and to elaborate rational guidelines relating to strategies to be used to improve the quality of the resulting crystals

Effet d'un champ magnétique uniforme sur les instabilités de Rayleigh–Bénard avec effet Soret. Influence of a magnetic field on the stability of a binary fluid with Soret effect

L’effet de l’intensité et de l’orientation d’un champ magnétique uniforme sur la transition critique au sein d’une couche fluide binaire, électriquement conductrice, stratifiée en température et en concentration, en prenant en considération l’effet Soret, est étudié numériquement. Pour une telle configuration, les résultats ont mis en évidence que les seuils critiques correspondant à un champ magnétique de direction quelconque peuvent se déduire de ceux obtenus pour un champ magnétique vertical et que les axes des rouleaux marginaux des modes instables sont désormais alignés avec la composante horizontale du champ magnétique. Par ailleurs, une étude analytique est menée pour étudier l’impact du champ magnétique sur les instabilités monocellulaires. L’effet du champ magnétique sur de telles instabilités a mis en évidence un phénomène inédit consistant à modifier profondément la nature des modes instables, qui perdent leur caractère monocellulaire pour retrouver leur aspect à plusieurs rouleaux qui les caractérisaient sans champ magnétique pour ψψ0, la valeur du nombre de Hartmann Ha(ψ, Le)correspondant à cette transition responsable d’une modification significative des transferts de masse et de chaleur peut être déterminée à partir des relations analytiques établies dans le cadre de ce travail

Intraperitoneal drain placement and outcomes after elective colorectal surgery: international matched, prospective, cohort study

Despite current guidelines, intraperitoneal drain placement after elective colorectal surgery remains widespread. Drains were not associated with earlier detection of intraperitoneal collections, but were associated with prolonged hospital stay and increased risk of surgical-site infections.Background Many surgeons routinely place intraperitoneal drains after elective colorectal surgery. However, enhanced recovery after surgery guidelines recommend against their routine use owing to a lack of clear clinical benefit. This study aimed to describe international variation in intraperitoneal drain placement and the safety of this practice. Methods COMPASS (COMPlicAted intra-abdominal collectionS after colorectal Surgery) was a prospective, international, cohort study which enrolled consecutive adults undergoing elective colorectal surgery (February to March 2020). The primary outcome was the rate of intraperitoneal drain placement. Secondary outcomes included: rate and time to diagnosis of postoperative intraperitoneal collections; rate of surgical site infections (SSIs); time to discharge; and 30-day major postoperative complications (Clavien-Dindo grade at least III). After propensity score matching, multivariable logistic regression and Cox proportional hazards regression were used to estimate the independent association of the secondary outcomes with drain placement. Results Overall, 1805 patients from 22 countries were included (798 women, 44.2 per cent; median age 67.0 years). The drain insertion rate was 51.9 per cent (937 patients). After matching, drains were not associated with reduced rates (odds ratio (OR) 1.33, 95 per cent c.i. 0.79 to 2.23; P = 0.287) or earlier detection (hazard ratio (HR) 0.87, 0.33 to 2.31; P = 0.780) of collections. Although not associated with worse major postoperative complications (OR 1.09, 0.68 to 1.75; P = 0.709), drains were associated with delayed hospital discharge (HR 0.58, 0.52 to 0.66; P < 0.001) and an increased risk of SSIs (OR 2.47, 1.50 to 4.05; P < 0.001). Conclusion Intraperitoneal drain placement after elective colorectal surgery is not associated with earlier detection of postoperative collections, but prolongs hospital stay and increases SSI risk

Adrenal neuroblastoma in three year old boy, mistaken for pancreatic tumor: A case report

Neuroblastoma is the most common extracranial solid tumor in children, often manifests in the retroperitoneal region. We present a case of a 3-year-old boy with no previous medical history, presented for abdominal distension. Physical examination revealed a distinct, mobile, solid mass situated in the left lumbar region. Abdominal magnetic resonance imaging displayed a well delimited, well-encapsulated mass attached to the tail of the pancreas. Urinary catecholamine metabolite levels were negative. Surgical exploration revealed that the tumor was primitively related to the left adrenal gland, and a complete resection was performed. The postoperative recovery was uncomplicated. NMYC oncogene was non-amplified

Influence of Conservation Agriculture on Durum Wheat Grain, Dough Texture Profile and Pasta Quality in a Mediterranean Region

There is a growing interest in the Mediterranean regions to switch to conservation agriculture (CA) to address climate change and soil deterioration issues. The novelty of this study lies in the quality of the supply chain, from the raw material (durum wheat grain) to the ready-to-sell product (spaghetti), under long-term CA, and using two varieties over two years of study. This study aims to investigate the impact of two soil management systems (SM) (CA after 10/11 (since 2009–2010) years switching vs. conventional tillage (CT)) on grain quality, dough texture profile, and pasta quality of two Tunisian durum wheat varieties (Karim and Monastir) in a 2-year-long experiment (2019 and 2020). The results showed that the SM had a significant impact on the grain quality in both years in terms of protein content and wet gluten, which were, respectively, lower under CA (11.92% vs. 11.15% for protein content) and (18.75% vs. 17.68% for wet gluten) in the wet year. These parameters increased in the dry year but they were higher under CA (15.70% vs. 14.42 ± 0.94% for protein content) and (26.00% vs. 23.20% for wet gluten). These results have, in turn, affected the dough quality (springiness, chewiness, and cohesiveness) and pasta cooking time and decreased the pasta cooking loss and water absorption index. In terms of the variety (V) factor, “Karim” variety in the dry year had a higher protein content and better dough quality than “Monastir” variety, and it reduced the pasta cooking time. In addition, the pasta yellow index (b*) from grains grown under CA was always higher than those in the CT system (23.99 vs. 19.72% and 25.24 vs. 22.19% in 2019 and 2020, respectively). The interaction between SM and V was significant in both years only for the dough hardness and pasta b* parameters. In conclusion, long-term CA may be a crucial solution in the dry season to promote food quality and achieve sustainable agriculture goals

Molecular epidemiology of poliovirus infection in Tunisia

International audienceThis report is an overview of poliomyelitis surveillance in Tunisia from 1991 to 1996. In all, 2088 stool specimens, collected from 152 acute flaccid paralysis (AFP) cases and from 1747 of their healthy contacts were investigated. Virus isolation was done systematically in RD and HEp-2C cell lines and isolated viruses were typed by sero-neutralisation as polioviruses or non-polio enteroviruses. Poliovirus isolates were analysed systematically for their wild or vaccine-related origin by two methods-one based on antigenic differences and one on genetic differences between strains. All type 2 polioviruses were vaccine-related and most wild viruses belonged to polio serotype 3. Wild polio type 3 viruses were detected in 1991 and 1992 in six cases of paralytic polio. A silent circulation of wild polio 1 and wild polio 3 was detected in 1994. No wild virus was detected in Tunisia from 1995 onwards. Wild polioviruses were sequenced and compared with Tunisian wild strains isolated during the 1980s, as well as other genotypes from the international database. These investigations revealed a single Tunisian polio 3 genotype that has been circulating from 1985 to 1994 and two different polio 1 genotypes. These results reflect effective control strategies within the country and contribute to the improvement of the polio eradication programme effectiveness at national and global levels

The LRR and RING domain protein LRSAM1 is an E3 ligase crucial for ubiquitin-dependent autophagy of intracellular salmonella typhimurium

Several species of pathogenic bacteria replicate within an intracellular vacuolar niche. Bacteria that escape into the cytosol are captured by the autophagic pathway and targeted for lysosomal degradation, representing a defense against bacterial exploitation of the host cytosol. Autophagic capture of Salmonella Typhimurium occurs predominantly via generation of a polyubiquitin signal around cytosolic bacteria, binding of adaptor proteins, and recruitment of autophagic machinery. However, the components mediating bacterial target selection and ubiquitination remain obscure. We identify LRSAM1 as the E3 ligase responsible for anti-Salmonella autophagy-associated ubiquitination. LRSAM1 localizes to several intracellular bacterial pathogens and generates the bacteria-associated ubiquitin signal; these functions require LRSAM1's leucine-rich repeat and RING domains, respectively. Using cells from LRSAM1-deficient individuals, we confirm that LRSAM1 is required for ubiquitination associated with intracellular bacteria but dispensable for ubiquitination of aggregated proteins. LRSAM1 is therefore a bacterial recognition protein and ubiquitin ligase that defends the cytoplasm from invasive pathogens