Statistical steady state in turbulent droplet condensation

Motivated by systems in which droplets grow and shrink in a turbulence-driven supersaturation field, we investigate the problem of turbulent condensation in a general manner. Using direct numerical simulations we show that the turbulent fluctuations of the supersaturation field offer different conditions for the growth of droplets which evolve in time due to turbulent transport and mixing. Based on that, we propose a Lagrangian stochastic model for condensation and evaporation of small droplets in turbulent flows. It consists of a set of stochastic integro-differential equations for the joint evolution of the squared radius and the supersaturation along the droplet trajectories. The model has two parameters fixed by the total amount of water and the thermodynamic properties, as well as the Lagrangian integral timescale of the turbulent supersaturation. The model reproduces very well the droplet size distributions obtained from direct numerical simulations and their time evolution. A noticeable result is that, after a stage where the squared radius simply diffuses, the system converges exponentially fast to a statistical steady state independent of the initial conditions. The main mechanism involved in this convergence is a loss of memory induced by a significant number of droplets undergoing a complete evaporation before growing again. The statistical steady state is characterised by an exponential tail in the droplet mass distribution. These results reconcile those of earlier numerical studies, once these various regimes are considered.Comment: 24 pages, 12 figure

Adaptive immune defense prevents Bartonella persistence upon trans-placental transmission

Vertical transmission of Bartonella infection has been reported for several mammalian species including mice and humans. Accordingly, it is commonly held that acquired immunological tolerance contributes critically to the high prevalence of Bartonellae in wild-ranging rodent populations. Here we studied an experimental model of Bartonella infection in mice to assess the impact of maternal and newborn immune defense on vertical transmission and bacterial persistence in the offspring, respectively. Congenital infection was frequently observed in B cell-deficient mothers but not in immunocompetent dams, which correlated with a rapid onset of an antibacterial antibody response in infected WT animals. Intriguingly, B cell-deficient offspring with congenital infection exhibited long-term bacteremia whereas B cell-sufficient offspring cleared bacteremia within a few weeks after birth. Clearance of congenital Bartonella infection resulted in immunity against bacterial rechallenge, with the animals mounting Bartonella-neutralizing antibody responses of normal magnitude. These observations reveal a key role for humoral immune defense by the mother and offspring in preventing and eliminating vertical transmission. Moreover, congenital Bartonella infection does not induce humoral immune tolerance but results in anti-bacterial immunity, questioning the contribution of neonatal tolerance to Bartonella prevalence in wild-ranging rodents

Identification of the; Bartonella; autotransporter CFA as a protective antigen and hypervariable target of neutralizing antibodies in mice

The bacterial genus; Bartonella; comprises numerous emerging pathogens that cause a broad spectrum of disease manifestations in humans. The targets and mechanisms of the anti-; Bartonella; immune defense are ill-defined and bacterial immune evasion strategies remain elusive. We found that experimentally infected mice resolved; Bartonella; infection by mounting antibody responses that neutralized the bacteria, preventing their attachment to erythrocytes and suppressing bacteremia independent of complement or Fc receptors.; Bartonella; -neutralizing antibody responses were rapidly induced and depended on CD40 signaling but not on affinity maturation. We cloned neutralizing monoclonal antibodies (mAbs) and by mass spectrometry identified the bacterial autotransporter CFA (CAMP-like factor autotransporter) as a neutralizing antibody target. Vaccination against CFA suppressed; Bartonella; bacteremia, validating CFA as a protective antigen. We mapped; Bartonella; -neutralizing mAb binding to a domain in CFA that we found is hypervariable in both human and mouse pathogenic strains, indicating mutational antibody evasion at the; Bartonella; subspecies level. These insights into; Bartonella; immunity and immune evasion provide a conceptual framework for vaccine development, identifying important challenges in this endeavor

Деловая карьера и ее развитие в Государственном профессиональном образовательном учреждении "Яшкинский техникум технологий и механизации" (пгт. Яшкино)

В современной России наблюдается разбалансированность рынка педагогического труда. Система образования не испытывает количественной нехватки преподавателей, но существуют трудности с удержанием молодых преподавателей и развитием уже работающих опытных специалистов. Цель работы – выявить особенности карьеры в образовательном учреждении современной России.Объект исследования – система управления деловой карьерой в организации.In modern Russia there is an imbalance of the market of pedagogical work. The education system does not have a quantitative shortage of teachers, but there are difficulties in retaining young teachers and developing experienced professionals who are already working. The purpose of the work is to identify the features of a career in an educational institution of modern Russia.The object of research is the system of business career management in the organization

Examination of macro- and microelements distribution between total extract and fractions for nootropic plant-derived raw material Alfredia cernua

The paper dwells on a quantitative determination of macro- and microelements in the ethanol Alfredia cernua extract and its chloroform, ethyl acetate, and butanol fractions. The distribution of macro- and microelements in the extract and fractions was investigated to further study of the interrelation between chemical composition and nootropic activity Alfredia cernua. It is shown that B, Fe, and Sn is mainly accumulated in butanol and Si, P, Al - in chloroform fraction respectively, but most macro- and microelements remain in the ethanol extract

Development of a biodegradable microstent for minimally invasive treatment of Fallopian tube occlusions

Obstructions of the Fallopian tube represent one of the most common reasons for an unfulfilled desire to have children. Microstent technology opens up new therapeutic possibilities to restore the natural lumen of the Fallopian tube within a single treatment. Within the current work we developed a self-expandable biodegradable microstent for gynecological applications. Based on a novel microstent design, prototypes were manufactured from poly-L-lactide tubing by means of fs-laser cutting. Microstent prototypes were characterized morphologically by means of scanning electron microscopy and biaxial laser scanning. As manufactured, a microstents outside diameter of about 2.3 mm and a strut thickness/width of about 114 µm/103 µm was measured. Mechanical characterization of microstents included bending as well as crimping and release behavior. After crimping to a minimum diameter of 0.8 mm and consecutive release, a microstent recovery to a diameter of 1.8 mm was found. Therefore, proof-of-concept for the self-expandable microstent could be successfully provided. © 2020 by Walter de Gruyter Berlin/Boston 2020

Survival after chemotherapy and/or radiotherapy versus self-expanding metal stent insertion in the setting of inoperable esophageal cancer: a case-control study

<p>Abstract</p> <p>Background</p> <p>Our aim was to compare survival of the various treatment modality groups of chemotherapy and/or radiotherapy in relation to SEMS (self-expanding metal stents) in a retrospective case-control study. We have made the hypothesis that the administration of combined chemoradiotherapy improves survival in inoperable esophageal cancer patients.</p> <p>Methods</p> <p>All patients were confirmed histologically as having surgically non- resectable esophageal carcinoma. Included were patients with squamous cell carcinoma, undifferentiated carcinoma as well as Siewert type I--but not type II - esophagogastric junctional adenocarcinoma. The decision to proceed with palliative treatments was taken within the context of a multidisciplinary team meeting and full expert review based on patient's wish, co-morbid disease, clinical metastases, distant metastases, M1 nodal metastases, T4-tumor airway, aorta, main stem bronchi, cardiac invasion, and peritoneal disease. Patients not fit enough to tolerate a radical course of definitive chemo- and/or radiation therapy were referred for self-expanding metal stent insertion. Our approach to deal with potential confounders was to match subjects according to their clinical characteristics (contraindications for surgery) and tumor stage according to diagnostic work-up in four groups: SEMS group (A), Chemotherapy group (B), Radiotherapy group (C), and Chemoradiotherapy group (D).</p> <p>Results</p> <p>Esophagectomy was contraindicated in 155 (35.5%) out of 437 patients presenting with esophageal cancer to the Department of General and Abdominal Surgery of the University Hospital of Mainz, Germany, between November 1997 and November 2007. There were 133 males and 22 females with a median age of 64.3 (43-88) years. Out of 155 patients, 123 were assigned to four groups: SEMS group (A) n = 26, Chemotherapy group (B) n = 12, Radiotherapy group (C) n = 23 and Chemoradiotherapy group (D) n = 62. Mean patient survival for the 4 groups was as follows: Group A: 6.92 ± 8.4 months; Group B: 7.75 ± 6.6 months; Group C: 8.56 ± 9.5 months, and Group D: 13.53 ± 14.7 months. Significant differences in overall survival were associated with tumor histology (<it>P </it>= 0.027), tumor localization (<it>P </it>= 0.019), and type of therapy (<it>P </it>= 0.005), respectively, in univariate analysis. Treatment modality (<it>P </it>= 0.043) was the only independent predictor of survival in multivariate analysis. The difference in overall survival between Group A and Group D was highly significant (<it>P </it>< 0.01) and in favor of Group D. As concerns Group D versus Group B and Group D versus Group C there was a trend towards a difference in overall survival in favor of Group D (<it>P </it>= 0.069 and <it>P </it>= 0.059, respectively).</p> <p>Conclusions</p> <p>The prognosis of inoperable esophageal cancer seems to be highly dependent on the suitability of the induction of patient-specific therapeutic measures and is significantly better, when chemoradiotherapy is applied.</p

LgR5 expression and cancer stem cell hypothesis: clue to define the true origin of esophageal adenocarcinomas with and without Barrett's Esophagus?

<p>Abstract</p> <p>Background</p> <p>Investigation of the expression of an intestinal stem cell marker in esophageal adenocarcinomas (EAC) with and without Barrett's Esophagus (BE), with respect to a cancer stem cell (CSC) hypothesis.</p> <p>Materials and methods</p> <p>Expression of a putative intestinal stem cell marker LgR5 was analyzed in esophageal cancer specimen (n = 70: 41 EAC with BE, 19 EAC without BE, and n = 10 esophageal squamous-cell carcinomas, ESCC) and in the adenocarcinoma cell line OE-33. Ki-67 and Cdx-2 were co-labelled with LgR5 in double staining experiments. Immunhistochemical expression results were confirmed by RT-PCR and correlated with tumor stage and five-year survival rates.</p> <p>Results</p> <p>LgR5was found expressed in 35 of 41 (85%) EAC with BE and in 16 of 19 (81%) EAC without BE. By contrast, LgR5 was not found to be expressed in ESCC. Quantification of immunolabeling showed 15% LgR5+ cells in EAC with BE, 32% LgR5+ cells in adjacent BE and 13% in EAC without BE. Immunofluorescence double staining experiments with LgR5 and Ki-67 revealed a subpopulation (~5%) of proliferating LgR+/Ki-67+ cells. On mRNA-level, expression of LgR5 was higher in BE in comparison to EAC (p = 0.0159). High levels of LgR5 expression in BE associated EAC were associated with poorer survival in univariate analysis.</p> <p>Conclusion</p> <p>The stem cell marker LgR5 is expressed in EAC, irrespective of association with BE, and appears to have negative impact on survival. The subset of proliferating LgR5+ cells (<5%) might resemble rapidly cycling CSCs, which needs to be substantiated in further investigations.</p

A concept for trial institutions focussing on randomised controlled trials in surgery

<p>Abstract</p> <p>Background</p> <p>Although considered the reference standard for generating valid scientific evidence of a treatment's benefits and harms, the number of Randomised Controlled Trials (RCT) comparing surgical techniques remains low. Much effort has been made in order to overcome methodological issues and improve quality of RCTs in surgery. To the present there has been, however, only little emphasis on development and maintenance of institutions for implementation of adequately designed and conducted surgical RCTs.</p> <p>Mehods/Design</p> <p>Description of the developments in surgical RCT infrastructure in Germany between 2001 and 2006. Cross sectional evaluation of completed and ongoing surgical RCTs within the German Surgical Society and the Clinical Study Centre, Department of Surgery, University of Heidelberg.</p> <p>Results</p> <p>Foundation of a national Clinical Trial Centre (CTC) for the organisation of multi-centre RCTs in the surgical setting (Study Center of the German Surgical Society, SDGC). Establishment of a network of CTCs with affiliated Clinical Sites (CSs) to enhance patient recruitment and shorten the duration of RCTs. Since its foundation four surgical RCTs with a total sample size of 1650 patients (1006 of these randomised) have been supervised by the SDGC with 35 CSs involved in patient recruitment. Five further CTCs were set up in 2006. Together with their affiliated CSs a network has been organised providing improved conditions for the conduction of surgical RCTs.</p> <p>Conclusion</p> <p>Improvement of infrastructure substantially facilitates integration of RCTs into routine surgical practice. A network of collaborating CTCs and CSs can provide an adequate infrastructure for the conduction of multi-centre RCTs.</p