11 research outputs found
Profiling of external metabolites during production of hantavirus nucleocapsid protein with recombinant Saccharomyces cerevisiae
Recombinant strains of Saccharomyces cerevisiae, producing hantavirus Puumala nucleocapsid protein for diagnostics and as a candidate vaccine were analyzed for uptake and excretion of intermediary metabolites during process optimization studies of fed-batch bioreactor cultures. Concentrations of glucose, maltose, galactose, pyruvate, acetaldehyde, ethanol, acetate, succinate and formaldehyde (used as a selection agent) were measured in the culture medium in order to find a metabolite pattern, indicative for the physiological state of the producer culture. When the inducer galactose was employed as a growth substrate, the metabolite profile of recombinant yeast cells was different from those of the non-recombinant original strain which excreted considerable amounts of metabolites with this substrate. In contrast, galactose-induced heterologous gene expression was indicated by the absence of excreted intermediary metabolites, except succinate. A model strain expressing a GFP fusion of hantavirus nucleocapsid protein differed in the excretion of metabolites from strains without GFP. In addition, the influence of alkali ions, employed for pH control is also demonstrated
Performance and Acceptance of Novel Silver-Impregnated Ceramic Cubes for Drinking Water Treatment in Two Field Sites: Limpopo Province, South Africa and Dodoma Region, Tanzania
Diarrheal disease and environmental enteropathy are serious public health concerns in low-income countries. In an effort to reduce enteric infection, researchers at the University of Virginia developed a new point-of-use (POU) water treatment technology composed of silver-impregnated porous ceramic media. The ceramic is placed in a 15 L plastic container of water in the evening and the water is ready to drink in the morning. The purpose of this study was to assess field performance and local acceptance of technology in two communities in Limpopo Province, South Africa, and one community in Dodoma Region, Tanzania. Performance was determined by coliform testing of treated water. Acceptance was determined using data from 150 household surveys and a nine-day structured observational study at a local primary school. At the primary school, 100% of treated water samples had no detectable levels of total coliform bacteria (TCB) in buckets filled by researchers. For all treated school buckets, 74% of samples achieved less than or equal to 1 CFU/100 mL and 3.2 average log reduction of TCB. Laboratory experiments with highly contaminated water diluted to lower turbidity achieved 4.2 average log reduction of TCB. Turbid water (approximately 10 NTU) only achieved 1.1 average log reduction of TCB; turbidity and organic material may have interfered with disinfection. The Tanzania primary school (deep groundwater source) had less turbid water and achieved 1.4 average log reduction of TCB; however, it did have high chloride levels that may have interfered with silver disinfection. The surveys revealed that the majority of people retrieve, store, and dispense water in ways that are compatible with the new technology. The willingness-to-pay study revealed potential customers would be willing to pay for the technology without subsidies. The results of this study indicate that this novel silver-impregnated ceramic POU water treatment technology is both effective and appropriate for use in the study communities
Relations of Perceived Social Efficacy and Social Goal Pursuit to Self-Efficacy for Academic Work
Successful functioning in a classroom setting requires students to interact effectively and form positive social relationships both with teachers and peers. Self-efficacy for success in schoolwork, therefore, should depend in part on students' perceptions of their social efficacy and on their endorsement of goals to be responsible class members and to form intimate peer relationships. Survey data from 753 fifth-grade students indicated that girls felt more efficacious in their interactions with their teachers and endorsed both responsibility and intimacy goals more strongly than did boys. No gender difference was found for social efficacy with peers. Hierarchical regression analysis indicated that students' perceptions of their social efficacy both with teacher and peers and their endorsement of responsibility goals were related significantly to their academic efficacy after accounting for prior achievement and gender These findings indicated that such social perceptions are important for students'academic progress and that teachers should pay serious attention to students'social relationships in the classroom.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67648/2/10.1177_0272431697017002001.pd
Postoperative Respiratory Complications in SARS-CoV-2 Positive Pediatric Patients Across 20 United States Hospitals: A Cohort Study
IntroductionData examining rates of postoperative complications among SARS-CoV-2 positive children are limited. The purpose of this study was to evaluate the impact of symptomatic and asymptomatic SARS-CoV-2 positive status on postoperative respiratory outcomes for children.MethodsThis retrospective cohort study included SARS-CoV-2 positive pediatric patients across 20 hospitals who underwent general anesthesia from March to October 2020. The primary outcome was frequency of postoperative respiratory complications, including: high-flow nasal cannula/non invasive ventilation, reintubation, pneumonia, Extracorporeal Membrane Oxygenation (ECMO), and 30-day respiratory-related readmissions or emergency department (ED) visits. Univariate analyses were used to evaluate associations between patient and procedure characteristics and stratified analyses by symptoms were performed examining incidence of complications.ResultsOf 266 SARS-CoV-2 positive patients, 163 (61.7%) were male, and the median age was 10 years (interquartile range 4-14). The majority of procedures were emergent or urgent (n = 214, 80.5%). The most common procedures were appendectomies (n = 78, 29.3%) and fracture repairs (n = 40,15.0%). 13 patients (4.9%) had preoperative symptoms including cough or dyspnea. 26 patients (9.8%) had postoperative respiratory complications, including 15 requiring high-flow oxygen, 8 with pneumonia, 4 requiring non invasive ventilation, 3 respiratory ED visits, and 2 respiratory readmissions. Respiratory complications were more common among symptomatic patients than asymptomatic patients (30.8% vs. 8.7%, p = 0.01). Higher ASA class and comorbidities were also associated with postoperative respiratory complications.ConclusionsPostoperative respiratory complications are less common in asymptomatic versus symptomatic SARS-COV-2 positive children. Relaxation of COVID-19-related restrictions for time-sensitive, non urgent procedures in selected asymptomatic patients may be reasonably considered. Additionally, further research is needed to evaluate the costs and benefits of routine testing for asymptomatic patients.Level of evidenceIii, Respiratory complications