277 research outputs found
Fem and analytical modeling of the incipient chip formation for the generation of micro-features
This paper explores the modeling of incipient cutting by Abaqus, LS-Dyna, and Ansys Finite Element Methods (FEMs), by comparing also experimentally the results on different material classes, including common aluminum and steel alloys and an acetal polymer. The target application is the sustainable manufacturing of gecko adhesives by micromachining a durable mold for injection molding. The challenges posed by the mold shape include undercuts and sharp tips, which can be machined by a special diamond blade, which enters the material, forms a chip, and exits. An analytical model to predict the shape of the incipient chip and of the formed grove as a function of the material properties and of the cutting parameters is provided. The main scientific merit of the current work is to approach theoretically, numerically, and experimentally the very early phase of the cutting tool penetration for new sustainable machining and micro-machining processes
Performance of Co-Mo/Al2O3 Nano Catalyst for CAMERE Process in a Batch Reactor
Reverse Water Gas Shift (RWGS) reaction is one of the main reactions that can be used to reduce greenhouse gas emissions. Through this reaction CO2 is converted to CO to produce beneficial chemicals such as methanol. In the present study, Mo/Al2O3
and Co-Mo/Al2O3 catalysts were synthesised using impregnation method. The structures of the catalysts were studied using XRD, XRF and TEM techniques. Activity and selectivity of both catalysts were investigated in a batch reactor and the results indicate that addition of cobalt promoter to Mo/Al2O3 catalyst increased its activity and CO selectivity. Co-Mo/Al2O3 can be a suitable candidate for RWGS reaction in CAMERE (carbon dioxide hydrogenation to form methanol via a reverse-water-gas-shift reaction) process
Policy support for autonomous swarms of drones
In recent years drones have become more widely used in military and non-military applications. Automation of these drones will become more important as their use increases. Individual drones acting autonomously will be able to achieve some tasks, but swarms of autonomous drones working together will be able to achieve much more complex tasks and be able to better adapt to changing environments. In this paper we describe an example scenario involving a swarm of drones from a military coalition and civil/humanitarian organisations that are working collaboratively to monitor areas at risk of flooding. We provide a definition of a swarm and how they can operate by exchanging messages. We define a flexible set of policies that are applicable to our scenario that can be easily extended to other scenarios or policy paradigms. These policies ensure that the swarms of drones behave as expected (e.g., for safety and security). Finally we discuss the challenges and limitations around policies for autonomous swarms and how new research, such as generative policies, can aid in solving these limitations
Antiviral activity of Holothuria sp. a sea cucumber against herpes simplex virus type 1 (HSV-1)
BACKGROUND: Finding the new
bioactive compounds with antiviral activity from
the natural resources are in interest of many drug
discovery scientists. Sea cucumber is among the
marine organisms a traditional food item in Asia
with different applications in traditional medicine.
METHODS: In current study, a cold water extract
of the Holothuria sp, one type Persian Gulf’s
sea cucumber was evaluated for its antiviral effects
against KOS strain of Herpes Simplex Virus
tyoe 1 (HSV-1) in cell culture. The half maximal inhibitory
concentration (IC50) values were calculated
for anti-adsorption activity and intracellular antiviral
activity of the crude extract separately.
RESULTS: The extract exhibited antiviral activity
not only against the virus adsorption to the cells,
but also on virus intracellular replication.The CC50
for sea cucumber extract was 32.57 mg/ml. The
IC50 values for the inhibition of the virus adsorption
to the cells and virus intracellular replication
were 120.2 and 189.9 μg/ml respectively. Selectivity
index (SI) value for anti-adsorption activity was
189 while that value for the extract’s intracellular
antiviral activity was 172.
CONCLUSIONS: The results showed that
Holothuria sp, water extract has remarkable antiviral
effect against HSV-1 in cell culture and it
is crucial to investigate the mechanism(s) of action
of extract. Moreover, identification of the effective
compound(s) within the extract would be
necessary for future studies towards developing
the new natural antiviral agent against HSV-1
Replacement of salamon with shotor diluent and egg yolk with low density lipoprotein for chilled storage of ram semen
Summary The present study investigated the possibility of replacing salamon with modified shotor diluent (MSD) and egg yolk (EY) with low density lipoprotein (LDL) for chilled storage of ram semen. Good quality semen (>80% progressive forward motility (PFM) of sperm) from 3 fertile rams was collected using an artificial vagina and pooled for each experiment. Low density lipoprotein was extracted from fresh EY. In experiment 1, semen was divided into 2 fractions and extended in MSD or salamon. In experiment 2, semen was assigned into 5 fractions and extended in MSD supplemented with 12 and 15% EY or 3, 5 and 8% LDL. In experiment 3, semen was divided into 2 fractions and extended in MSD supplemented with 12% EY or 5% LDL. Viability of sperm was assessed at times 0 (immediately after semen dilution), 2 or 4 (at 4°C) and up to 72 h after semen dilution. Data was analyzed using General Linear Model (GLM) procedure, including repeated measures. In experiment 1, the viability of sperm was similar in two diluents (P>0.05). In experiment 2, PFM of sperm was similar among groups at the time of dilution (P>0.05); but remained elevated in 5 and 8% LDL compared to other groups afterward (P<0.05). In experiment 3, PFM of sperm was superior at 48 and 72 h after dilution in 5% LDL compared to 12% EY (P<0.05). In conclusion, MSD supplemented with 5% LDL is a suitable diluent for ram fresh semen preserved at 4°C for 72 h
A novel method for RNA extraction from FFPE samples reveals significant differences in biomarker expression between orthotopic and subcutaneous pancreatic cancer patient-derived xenografts.
Next-generation sequencing (NGS) can identify and validate new biomarkers of cancer onset, progression and therapy resistance. Substantial archives of formalin-fixed, paraffin-embedded (FFPE) cancer samples from patients represent a rich resource for linking molecular signatures to clinical data. However, performing NGS on FFPE samples is limited by poor RNA purification methods. To address this hurdle, we developed an improved methodology for extracting high-quality RNA from FFPE samples. By briefly integrating a newly-designed micro-homogenizing (mH) tool with commercially available FFPE RNA extraction protocols, RNA recovery is increased by approximately 3-fold while maintaining standard A260/A280 ratios and RNA quality index (RQI) values. Furthermore, we demonstrate that the mH-purified FFPE RNAs are longer and of higher integrity. Previous studies have suggested that pancreatic ductal adenocarcinoma (PDAC) gene expression signatures vary significantly under in vitro versus in vivo and in vivo subcutaneous versus orthotopic conditions. By using our improved mH-based method, we were able to preserve established expression patterns of KRas-dependency genes within these three unique microenvironments. Finally, expression analysis of novel biomarkers in KRas mutant PDAC samples revealed that PEAK1 decreases and MST1R increases by over 100-fold in orthotopic versus subcutaneous microenvironments. Interestingly, however, only PEAK1 levels remain elevated in orthotopically grown KRas wild-type PDAC cells. These results demonstrate the critical nature of the orthotopic tumor microenvironment when evaluating the clinical relevance of new biomarkers in cells or patient-derived samples. Furthermore, this new mH-based FFPE RNA extraction method has the potential to enhance and expand future FFPE-RNA-NGS cancer biomarker studies
An in vitro Comparative study upon the Hemolytic, Thrombogenic, Coagulation parameters and Stability properties of the Hemiscorpius lepturus Venom
Hemiscorpius lepturus belonging to Hemiscorpiidae family is the most venomous of all types of scorpion existing in south west of Iran causing hemoglobinuria and dermal lesions by envenomation. We compare the hemolytic pattern upon time in different domestic animals upon time according to their different sphingomyelin contents. In addition other in vitro hematologic parameters, platelet lysis, coagulation changes and finally preservative factors (temperature, pH, protases) are discussed. The hemolytic activity was inhibited significantly by heating at 100 °C for 60 minutes (26%) and reached 38% via incubation with papain (10U/ml) while retained over a pH range of 4-11. Horses and sheep have the lower (61%) and upper (100%) rate of hemolysis. Calcium and magnesium ions could increase rate of hemolysis and EDTA solution had significantly decresing effect. The venom significantly changed in vitro coagulation factors (PT and APTT) from base line levels and had no effect on platelet lysis. It seems that our venom belongs to metalloproteinases due to potentiation effects of bivalent cations (calcium and magnesium) and ghost cell formation in our study indicatiing hemoglobin efflux
Quality study of wastewater treated by waste Water Treatment plant (WWTP) in the city of Sana'a (Yemen) used for agriculture.
The wastewater treated by the PWTS Sanaa (Yemen), are discharged into Wadi Bani Houat to be used for irrigation of agricultural fields (cereals and "qat"). The quality of water discharged by the station is affected by neo-contamination part of untreated water diverted through bypass and also untreated effluent intake of a river that flows into the canal about 15 Km from the station. The various measurements show that the levels of contaminants studied, decrease at the exit of the station but undergo severe degradation after canal-branch river. Similarly, we noted illegal contributions at this place made of waste thrown into the canal by the surrounding population. The salinity is classified C4S2, C3S3, C4S3 and C4S4 in RICHARDS diagram, leading to poor quality water for irrigation. The ratio COD / BOD5 reaching a value of 2 after treatment and self purification of water, up to a value of 4, at a distance of 12 km along the canal before dropping to a value below 2 at the areas of retention dams located north of the study area, showing a self-purification capacity. NO2- (nitrite ions) appear downstream canal in the dams, highlighting the impact of agricultural activity on water quality. Minors cations and traces show different concentrations varying spatially and temporally along the canal during the dry and wet seasons. Overruns by FAO and Yemen standards were observed for some components such as phenol, organic micropolluant showing levels higher than standard along the canal in all seasons. The principal component analysis showed the correlation between the measured quantities and the vulnerability of sampling sites to different pollutants.
Split Learning for Distributed Collaborative Training of Deep Learning Models in Health Informatics
Deep learning continues to rapidly evolve and is now demonstrating remarkable
potential for numerous medical prediction tasks. However, realizing deep
learning models that generalize across healthcare organizations is challenging.
This is due, in part, to the inherent siloed nature of these organizations and
patient privacy requirements. To address this problem, we illustrate how split
learning can enable collaborative training of deep learning models across
disparate and privately maintained health datasets, while keeping the original
records and model parameters private. We introduce a new privacy-preserving
distributed learning framework that offers a higher level of privacy compared
to conventional federated learning. We use several biomedical imaging and
electronic health record (EHR) datasets to show that deep learning models
trained via split learning can achieve highly similar performance to their
centralized and federated counterparts while greatly improving computational
efficiency and reducing privacy risks
Cost-Effectiveness of Wound Care: A concept analysis
This review aimed to analyse the concept of cost-effectiveness within the context of chronic wound care using Walker and Avant’s approach. The Cumulative Index to Nursing and Allied Health Literature® (EBSCO Information Services, Ipswich, Massachusetts, USA), MEDLINE® (National Library of Medicine, Bethesda, Maryland, USA) and Nursing & Allied Health® (ProQuest LLC, Ann Arbor, Michigan, USA) databases were searched using a combination of keywords. A total of 18 peer-reviewed articles were identified. In wound care, defining attributes for the concept of cost-effectiveness encompassed treatments which were both effective and economical. Four antecedents were identified, including the type of wound, care setting, type of dressing and patient-related characteristics. The consequences of cost-effective wound care were patient prognosis, quality of life, the economic burden on the patient and healthcare system and cost-savings. These findings will hopefully help to standardise cost-effectiveness terminology among nursing professionals in various healthcare settings.
Keywords: Cost Effectiveness; Wounds and Injuries; Healthcare Costs; Nursing; Concept Formation
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