355 research outputs found
M-GEAR: Gateway-Based Energy-Aware Multi-Hop Routing Protocol for WSNs
In this research work, we advise gateway based energy-efficient routing
protocol (M-GEAR) for Wireless Sensor Networks (WSNs). We divide the sensor
nodes into four logical regions on the basis of their location in the sensing
field. We install Base Station (BS) out of the sensing area and a gateway node
at the centre of the sensing area. If the distance of a sensor node from BS or
gateway is less than predefined distance threshold, the node uses direct
communication. We divide the rest of nodes into two equal regions whose
distance is beyond the threshold distance. We select cluster heads (CHs)in each
region which are independent of the other region. These CHs are selected on the
basis of a probability. We compare performance of our protocol with LEACH (Low
Energy Adaptive Clustering Hierarchy). Performance analysis and compared
statistic results show that our proposed protocol perform well in terms of
energy consumption and network lifetime.Comment: IEEE 8th International Conference on Broadband and Wireless
Computing, Communication and Applications (BWCCA'13), Compiegne, Franc
Oxidative stress contributes to cobalt oxide nanoparticles-induced cytotoxicity and DNA damage in human hepatocarcinoma cells.
BackgroundCobalt oxide nanoparticles (Co(3)O(4)NPs) are increasingly recognized for their utility in biological applications, magnetic resonance imaging, and drug delivery. However, little is known about the toxicity of Co(3)O(4)NPs in human cells.MethodsWe investigated the possible mechanisms of genotoxicity induced by Co(3)O(4)NPs in human hepatocarcinoma (HepG2) cells. Cell viability, reactive oxygen species (ROS), glutathione, thiobarbituric acid reactive substance, apoptosis, and DNA damage were assessed in HepG2 cells after Co(3)O(4)NPs and Co(2+) exposure.ResultsCo(3)O(4)NPs elicited a significant (P < 0.01) reduction in glutathione with a concomitant increase in lipid hydroperoxide, ROS generation, superoxide dismutase, and catalase activity after 24- and 48-hour exposure. Co(3)O(4)NPs had a mild cytotoxic effect in HepG2 cells; however, it induced ROS and oxidative stress, leading to DNA damage, a probable mechanism of genotoxicity. The comet assay showed a statistically significant (P < 0.01) dose- and time-related increase in DNA damage for Co(3)O(4)NPs, whereas Co(2+) induced less change than Co(3)O(4)NPs but significantly more than control.ConclusionOur results demonstrated that Co(3)O(4)NPs induced cytotoxicity and genotoxicity in HepG2 cells through ROS and oxidative stress
Integration of fuzzy c-means and artificial neural network for short-term localized rainfall forecast in tropical climate
Why Are Outcomes Different for Registry Patients Enrolled Prospectively and Retrospectively? Insights from the Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF).
Background: Retrospective and prospective observational studies are designed to reflect real-world evidence on clinical practice, but can yield conflicting results. The GARFIELD-AF Registry includes both methods of enrolment and allows analysis of differences in patient characteristics and outcomes that may result. Methods and Results: Patients with atrial fibrillation (AF) and ≥1 risk factor for stroke at diagnosis of AF were recruited either retrospectively (n = 5069) or prospectively (n = 5501) from 19 countries and then followed prospectively. The retrospectively enrolled cohort comprised patients with established AF (for a least 6, and up to 24 months before enrolment), who were identified retrospectively (and baseline and partial follow-up data were collected from the emedical records) and then followed prospectively between 0-18 months (such that the total time of follow-up was 24 months; data collection Dec-2009 and Oct-2010). In the prospectively enrolled cohort, patients with newly diagnosed AF (≤6 weeks after diagnosis) were recruited between Mar-2010 and Oct-2011 and were followed for 24 months after enrolment. Differences between the cohorts were observed in clinical characteristics, including type of AF, stroke prevention strategies, and event rates. More patients in the retrospectively identified cohort received vitamin K antagonists (62.1% vs. 53.2%) and fewer received non-vitamin K oral anticoagulants (1.8% vs . 4.2%). All-cause mortality rates per 100 person-years during the prospective follow-up (starting the first study visit up to 1 year) were significantly lower in the retrospective than prospectively identified cohort (3.04 [95% CI 2.51 to 3.67] vs . 4.05 [95% CI 3.53 to 4.63]; p = 0.016). Conclusions: Interpretations of data from registries that aim to evaluate the characteristics and outcomes of patients with AF must take account of differences in registry design and the impact of recall bias and survivorship bias that is incurred with retrospective enrolment. Clinical Trial Registration: - URL: http://www.clinicaltrials.gov . Unique identifier for GARFIELD-AF (NCT01090362)
Improvement of Abiotic Stress Tolerance in Plants with the Application of Nanoparticles
Plants are under the threat of climatic changes and there is a reduction in productivity and deterioration in quality. The application of nanoparticles is one of the recent approaches to improve plant yield and quality traits. A number of nanoparticles, such as zinc nanoparticles (ZnO NPs), iron nanoparticles (Fe2O3 NPs), silicon nanoparticles (SiO2 NPs), cerium nanoparticles (CeO2 NPs), silver nanoparticles (Ag NPs), titanium dioxide nanoparticles (TiO2 NPs), and carbon nanoparticles (C NPs), have been reported in different plant species to play a role to improve the plant physiology and metabolic pathways under environmental stresses. Crop plants readily absorb the nanoparticles through the cellular machinery of different tissues and organs to take part in metabolic and growth processes. Nanoparticles promote the activity of a range of antioxidant enzymes, including catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD), in plant species, which in turn improve the growth and development under stressful conditions. The present review focuses on the mode of action and signaling of nanoparticles to the plant systems and their positive impact on growth, development, and ROS scavenging potential. The appropriate elucidation on mechanisms of nanoparticles in plants leads to better growth and yields under stress conditions, which will ultimately lead to increased agricultural production
Serum bactericidal activity as indicator of innate immunity in pacu Piaractus mesopotamicus (Holmberg, 1887)
The immune system of teleost fish has mechanisms responsible for the defense against bacteria through protective proteins in several tissues. The protein action can be evaluated by serum bactericidal activity and this is an important tool to analyze the immune system. Pacu, Piaractus mesopotamicus, is one of the most important fish in national aquaculture. However there is a lack of studies on its immune responses. In order to standardize and assess the accuracy of the serum bactericidal activity assay, fish were briefly challenged with Aeromonas hydrophila and sampled one week after the challenge. The bacterial infection increased the concentration of protective proteins, resulting in a decrease of colony-forming unit values expressed as well as an enhanced serum bactericidal activity. The protocol showed a reliable assay, appropriate to determine the serum bactericidal activity of pacu in the present experimental conditions.O sistema imune de peixes teleósteos tem mecanismos responsáveis pela defesa contra bactérias e atua através de proteínas presentes em diversos tecidos. A ação destas proteínas pode ser avaliada pela atividade bactericida do soro, sendo esta uma importante ferramenta para analisar o sistema imune. O pacu, Piaractus mesopotamicus, é um peixe nativo muito importante para aquicultura nacional, entretanto há pouco conhecimento sobre o funcionamento de seu sistema imune. Assim foi realizado experimento para padronizar e avaliar a eficiência do ensaio de atividade bactericida. Resumidamente, peixes foram desafiados por Aeromonas hydrophila e amostradas uma semana após o desafio. A infecção bacteriana promoveu um aumento na concentração de proteínas protetoras, resultando em diminuição dos valores de unidades formadoras de colônias ou expressos também como aumento da atividade bactericida do soro. O protocolo se mostrou confiável, sendo apropriado para determinar a atividade bactericida do soro de pacu nas condições experimentais.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Universidade Estadual PaulistaUniversidade Estadual Paulista Faculdade de ZootecniaUniversidade Estadual PaulistaUniversidade Estadual Paulista Faculdade de Zootecni
Continuum of care in maternal, newborn and child health in Pakistan: analysis of trends and determinants from 2006 to 2012
Iqbal S, Maqsood S, Zakar R, Zakria Zakar M, Fischer F. Continuum of care in maternal, newborn and child health in Pakistan: analysis of trends and determinants from 2006 to 2012. BMC Health Services Research. 2017;17(1): 189.Background
Pakistan, being a developing country, presents the dismal picture of maternal and neonatal mortality and morbidity. The majority of maternal and neonatal deaths could be avoided if Continuum of Care (CoC) is provided in a structured pathway from pregnancy to birth and to the first week of life of the newborn child. This study aimed to analyse the trends of CoC at all three levels (antenatal care, skilled delivery and postpartum care) and to identify various factors affecting the continuation in receiving CoC in Pakistan during 2006 to 2012.
Methods
Secondary data analysis was performed on nationally representative data from the last two iterations of Pakistan Demographic and Health Survey (PDHS), conducted during 2006/07 to 2012/13. The analysis is limited to women of the reproductive age group (15–49 years) who gave birth during the last five years preceding both surveys. This leads to a sample size of 5,724 and 7,461 respondents from PDHS 2006/07 and 2012/13 respectively. The association between CoC and several factors, including individual attributes (reproductive status), family influences, community context, as well as cultural and social values was assessed in bivariate analyses in a first step. Furthermore, odds ratios and adjusted odds ratios with 95% confidence intervals using a binary and multivariable logistic regression were calculated.
Results
Our research presents the trends of a composite measure of CoC including antenatal care, delivery assistance and postpartum care. The largest gap in CoC was observed at antenatal care followed by delivery and postnatal care within 48 h after delivery. Results show that CoC completion rate has increased from 15% to 27% amongst women in Pakistan over time from 2006 to 2012. Women with high age at first birth, having less number of children, with higher education, belonging to richest quintile, living in Sindh province and urban areas, having high autonomy and exposure to mass media were most likely to avail complete CoC.
Conclusions
The findings show that women in Pakistan still lack the CoC. This calls for attention to develop and implement tailored interventions, focusing on the needs of women in Pakistan to provide CoC in an integrated manner, involving both public and private sectors by appropriately addressing the factors hindering CoC completion rates
Absolute Quantification of [11C]docetaxel Kinetics in Lung Cancer Patients Using Positron Emission Tomography
Abstract
Purpose: Tumor resistance to docetaxel may be associated with reduced drug concentrations in tumor tissue. Positron emission tomography (PET) allows for quantification of radiolabeled docetaxel ([11C]docetaxel) kinetics and might be useful for predicting response to therapy. The primary objective was to evaluate the feasibility of quantitative [11C]docetaxel PET scans in lung cancer patients. The secondary objective was to investigate whether [11C]docetaxel kinetics were associated with tumor perfusion, tumor size, and dexamethasone administration.
Experimental Design: Thirty-four lung cancer patients underwent dynamic PET–computed tomography (CT) scans using [11C]docetaxel. Blood flow was measured using oxygen-15 labeled water. The first 24 patients were premedicated with dexamethasone. For quantification of [11C]docetaxel kinetics, the optimal tracer kinetic model was developed and a noninvasive procedure was validated.
Results: Reproducible quantification of [11C]docetaxel kinetics in tumors was possible using a noninvasive approach (image derived input function). Thirty-two lesions (size ≥4 cm3) were identified, having a variable net influx rate of [11C]docetaxel (range, 0.0023–0.0229 mL·cm−3·min−1). [11C]docetaxel uptake was highly related to tumor perfusion (Spearman's ρ = 0.815;P &lt; 0.001), but not to tumor size (Spearman's ρ = −0.140; P = 0.446). Patients pretreated with dexamethasone showed lower [11C]docetaxel uptake in tumors (P = 0.013). Finally, in a subgroup of patients who subsequently received docetaxel therapy, relative high [11C]docetaxel uptake was related with improved tumor response.
Conclusions: Quantification of [11C]docetaxel kinetics in lung cancer was feasible in a clinical setting. Variable [11C]docetaxel kinetics in tumors may reflect differential sensitivity to docetaxel therapy. Our findings warrant further studies investigating the predictive value of [11C]docetaxel uptake and the effects of comedication on [11C]docetaxel kinetics in tumors. Clin Cancer Res; 17(14); 4814–24. ©2011 AACR.</jats:p
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