269 research outputs found
Thermodynamics and Kinetics of Inhibition of Aluminum in Hydrochloric Acid by Date Palm Leaf Extract
The corrosion behavior of commercial aluminum in HCl was investigated
by gravimetric method in absence and presence of date palm leaf extract
(DPLE) as inhibitor. Corrosion rates in absence of extract ranged from
2.4-8.0 mg/cm2/h in the temperature range 20- 50\ubaC but decreased
down to 0.30-2.6 mg/cm2/h in presence of the inhibitor. Hot-water
extract of date palm leaves has shown inhibition efficiency (IE) of 40-
88% at the tested conditions. IE was found to increase with increasing
inhibitor concentration from 0.2 to 0.6 g/L and decrease as temperature
increased. Data showed that Langmuir adsorption isotherm represents
surface coverage versus extract concentration data indicating that
inhibition is due to monolayer adsorption of extract components on
aluminum surface. Low activation energy and enthalpy values support
physical adsorption mechanism. SEM-EDS microanalysis of aluminum
surface supported the inhibitive effect of the extract at the metal
surface
Delay Differential Model for Tumour-Immune Response with Chemoimmunotherapy and Optimal Control
We present a delay differential model with optimal control that describes the interactions
of the tumour cells and immune response cells with external therapy. The intracellular
delay is incorporated into the model to justify the time required to stimulate the effector
cells. The optimal control variables are incorporated to identify the best treatment strategy
with minimum side effects by blocking the production of new tumour cells and keeping the
number of normal cells above 75% of its carrying capacity. Existence of the optimal control
pair and optimality system are established. Pontryagin’s maximum principle is applicable
to characterize the optimal controls. The model displays a tumour-free steady state and up
to three coexisting steady states. The numerical results show that the optimal treatment
strategies reduce the tumour cells load and increase the effector cells after a few days of
therapy. The performance of combination therapy protocol of immunochemotherapy is
better than the standard protocol of chemotherapy alone
Antitumor activity of miR-34a in peritoneal mesothelioma relies on c-MET and AXL inhibition: persistent activation of ERK and AKT signaling as a possible cytoprotective mechanism
Attractivity for a k-dimensional system of fractional functional differential equations and global attractivity for a k-dimensional system of nonlinear fractional differential equations
Burnout among surgeons before and during the SARS-CoV-2 pandemic: an international survey
Background: SARS-CoV-2 pandemic has had many significant impacts within the surgical realm, and surgeons have been obligated to reconsider almost every aspect of daily clinical practice. Methods: This is a cross-sectional study reported in compliance with the CHERRIES guidelines and conducted through an online platform from June 14th to July 15th, 2020. The primary outcome was the burden of burnout during the pandemic indicated by the validated Shirom-Melamed Burnout Measure. Results: Nine hundred fifty-four surgeons completed the survey. The median length of practice was 10 years; 78.2% included were male with a median age of 37 years old, 39.5% were consultants, 68.9% were general surgeons, and 55.7% were affiliated with an academic institution. Overall, there was a significant increase in the mean burnout score during the pandemic; longer years of practice and older age were significantly associated with less burnout. There were significant reductions in the median number of outpatient visits, operated cases, on-call hours, emergency visits, and research work, so, 48.2% of respondents felt that the training resources were insufficient. The majority (81.3%) of respondents reported that their hospitals were included in the management of COVID-19, 66.5% felt their roles had been minimized; 41% were asked to assist in non-surgical medical practices, and 37.6% of respondents were included in COVID-19 management. Conclusions: There was a significant burnout among trainees. Almost all aspects of clinical and research activities were affected with a significant reduction in the volume of research, outpatient clinic visits, surgical procedures, on-call hours, and emergency cases hindering the training. Trial registration: The study was registered on clicaltrials.gov "NCT04433286" on 16/06/2020
Ingestão de cálcio e densidade mineral óssea em mulheres adultas intolerantes à lactose
Discard avoidance by improving fishing gear selectivity: helping the industry help themselves
The provision of fishery information by ices-wgftfb to assessment working groups: use of information and lessons learned
ICES is now asked to provide advice that is more holistic in nature, including information on the influence and effects of human activities on the marine ecosystem. From a fishing-technology perspective, this includes information on how fishers respond and adapt to changes in regulatory frameworks, the impact of technology creep, ecosystem impacts, and changes in fleet dynamics. Recognizing the importance of this, in 2005, the ICES-Food and Agriculture Organization (FAO) Working Group on Fish Technology and Fish Behaviour (WGFTFB) began to collect data and information to support scientific advice on fisheries and ecosystem issues through a questionnaire circulated to its members. The information from the questionnaires was collated by the WGFTFB and submitted in the form of summary documents to various ICES assessment working groups. This paper describes the background to this initiative, the questionnaire structure, the type of information provided, and its utility
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