Modification of a high Reynolds number turbulent boundary layer with the addition of drag-reducing polymer solution

Polymer drag reduction (PDR) is an active flow control technique that has drawn significant scientific examination and industrial interest for over 70 years (e.g. fluid transport in oil pipelines, surface ships, safer fuels, drug delivery). While it is well known that trace amounts of polymer solutions can reduce drag by up to 80%, the fluid mechanism of how the polymers reduce the drag remains elusive. Recent findings have shown that polymer properties influence how PDR modifies the near-wall mean velocity profile, which is in contrast to the classical view. Consequently, the current study uses a novel technique to create a developing turbulent boundary layer within a homogeneous polymer solution (i.e. polymer ocean), in which polymer properties are sensitive to polymer concentration. This has never been attempted before due to known issues with polymer degradation, which this study includes an assessment of the impact of mechanical degradation on polymer drag reduction performance. The degradation study showed that degradation effects can have an impact on the performance, but these can be mitigated with sufficiently large residence times. The modifications to the velocity distribution are analyzed using particle image velocimetry. Analysis included comparisons between mean and fluctuating velocity profiles and proper orthogonal decomposition (POD). In addition, modifications to coherent structures were studying via two-point correlations between the fluctuating velocity components to reveal modifications to the intermittency of the near-wall events. Results show that for the controlled range of Reynolds number (80040%). A linear relationship was identified between structure inclination angle, a, (in the TBL log-region), and drag reduction (DR), a=-0.563DR+46.9. Faster convergence of cumulative turbulent kinetic energy (TKE) of the POD modes was observed in polymeric cases, which signifies a smaller number of structures containing the total TKE compared to Newtonian flow. This further suggests that polymers are involved in severely mitigating the spatiotemporal evolution of vortical structure in the TBL near-wall region, a process that significantly contributes to the production of skin-friction drag

Black holes”, “Genome fluidity”, and Evolution of Bacterial Species

The formation of the massive deletion of genes called “black holes,” which are detrimental to a pathogenic lifestyle, provides a bacterial evolutionary route that permits a pathogen to augment virulence and host-adaptability. For example, cadaverine substrate has inhibitory effects on the enterotoxin activity of the Shigella species. Therefore, the encoding gene of the lysine decarboxylase enzyme (CadA gene) as an anti-virulence gene is deleted from the genome of the Shigella. This and other similar cases in bacteria can be used for antitoxin therapy. Hence, identification of the role of black holes in the pathogenic evolution of bacteria output could possibly lead to novel treatments of infectious diseases in human beings. Here, we reviewed different types of pathoadaptation mutations among pathogens. Cases of black holes among the important human bacterial pathogens included Shigella, Rickettsiae, Mycobacterium leprae, Burkholderia, Bordetella, and Chlamydia. We found that the most prevalent pathoadaptive pathway among bacteria was the gene inactivation or deletion route

Epidemiological and Clinical Features of Pediatric Open Globe Injuries: A Report from Southern Iran

Purpose: To evaluate the epidemiological features of open globe injury (OGI) in a tertiary ophthalmic center in the south of Iran. Methods: The medical files of pediatric patients diagnosed with OGI between March 2014 and March 2019 were reviewed retrospectively. Demographic data, laterality, time of injury, cause of trauma, location and mechanisms, complications, and the involved tissues, visual acuity, type of operation, and antibiotic therapy were all analyzed. Data were processed using the SPSS. Results: In total, 110 eyes of 108 patients were included. Ages <7 years comprised 49.1%, 7–12 years 26.4%, and 13–18 years 24.5% of cases. Of the 108 patients, 76 (70.3%) were males. No significant difference between right versus left eyes was seen. The incidence of OGI was lowest in winter and highest in spring, and it had more prevalence on the weekends. Sharp objects were the most common cause of OGI in ages <7 years, while blunt objects, accidents and falls, and guns and fireworks were more prevalent in older children. Home was the most common place of injury overall. The most common type of injury was penetrating trauma. Upon arrival, most of the children had a visual acuity <0.1 decimal. Primary wound closure was the most prevalent type of surgery done predominantly within 24 hr from admission time. Conclusion: Ages <7 years and male gender were the most common age and sex of pediatric OGI, respectively, and sharp objects were the predominant etiology. Early management and primary repair are essential for prevention of complications such as endophthalmitis and amblyopia

Raoultella Infections from Clinical to Laboratory- Update & Literature review

The genus Raoultella is still understudied compared to other Enterobacteriaceae members. However, there are numerous published case reports on Raoultella infections. The genetic closeness of Raoultella spp. and Klebsiella spp. may lead to misidentification using conventional microbiology methods. The prevalence of this bacterium in clinical settings can vary geographically. Our knowledge of its resistome evolution contributing to Raoultella antibiotic resistance is also limited to a few characterized genes. This review summarises the current knowledge on Raoultella genetic and microbiology aspects, its identification methods, virulence factors, clinical manifestations, and so on. This combined information highlights the gaps in our understanding of Raoultella pathogenesis, resistome, and vaccine suggesting future research directions. The diversity and plasticity of the antibiotic resistance plane of Raoultella species have determined the early and precise identification of Raoultella infection is very important to improve the prognosis of the clinical infections and to control the spread of this bacterium. According to our literature review results, patients with multiple congenital abnormalities are susceptible to Raoultella infection. Tumours, immune deficiency, and invasive operations increase the risk of infection

Antibacterial activity of Mangifera indica seed extracts combined with common antibiotics against multidrug-resistant Pseudomonas aeruginosa and Acinetobacter baumannii isolates

In this project, we employed ethanolic (EMI) and aqueous (AMI) extracts of mango (Mangifera indica L., Anacardiaceae) fruit seeds as a modulator of antibiotic resistance against multidrug-resistant (MDR) Pseudomonas aeruginosa and Acinetobacter baumannii to evaluate natural compounds isolated from by-products or waste of edible plants. We also investigated the effect of these extracts alone and in combination with standard classes of antibiotics in the desired strains. M. indica seeds were processed and exploited using ethanol and water. The minimum inhibitory concentrations (MICs) of clinical isolates were examined against EMI and AMI extracts, followed by seven antibiotics of ceftazidime, ciprofloxacin, penicillin, amikacin, meropenem, ampicillin, and colistin. The checkerboard method evaluated the synergistic action between mango kernel extract (EMI) and seven antibiotics. EMI extract significantly revealed antimicrobial properties against MDR A. baumannii and P. aeruginosa with synergistic effects with the applied antibiotics. The considerable antibacterial efficacy of ethanolic extract of M. indica seeds can have great curative value as antibacterial drugs against infections caused by MDR P.aeruginosa and A. baumannii

”I ett LVU så kan man känna sig ganska liten” : En inblick i socialsekreterares resonemang kring LVU-handläggning.

Tvångsvård är ett omdiskuterat ämne i dagens samhälle och Sverige. Många debatter råder där betoningen ligger på de tvivelaktiga omhändertaganden där barn och unga far illa. I denna studie undersöker vi hur socialsekreterare resonerar kring LVU med fokus på handlingsutrymme, makt samt överväganden och osäkerheter i LVUhandläggning i syfte att undersöka socialsekreterarnas egna tankar och upplevelser vilket är ett perspektiv som i nuvarande forskningsfält är svagt behandlat. Med utgångspunkt i Lipskys teori om gräsrotsbyråkrati har vi utfört semistruktureradeintervjuer med åtta socialsekreterare vid fyra barnenheter och två ungdomsenheter. Vi fann att socialsekreterarna i vår studie beskrev en komplex bild av deras arbete. Stundom upplever de att de har makt och handlingsutrymme, och stundom inte. Detta kunde bero på LVU-handläggningens utformande, samt hur mycket ansvar den enskilde socialsekreteraren fick från sin organisation. Deras arbete genomsyras även av flera genomgående osäkerheter som uppstår i svåra överväganden i LVUhandläggning. Vi såg även att makt hade en stor roll i socialsekreterarnas arbete,framför allt när det kommer till samarbete med familj och hur mötet med barn och unga struktureras. Samtidigt beskrev socialsekreterarna hur LVU-handläggning ibland följs av en känsla av maktlöshet när det inte går som planerat