1,011 research outputs found
Synthesis and Characterization of Phase Change Microcapsules Containing Nano-Graphite
This study uses the sol-gel method to modify the phase change microcapsules. The phase change material (PCM) is encapsulated by a polymer shell to reduce the leakage in the solid-liquid transition. Furthermore, the nano-graphite particle (NGP) is introduced into the shell to increase its thermal conductivity. The particle size and enthalpy value of the obtained microcapsules are approximately 3 μm and 150.3 J/g, respectively. The results show that the encapsulation efficiency of PCM in the prepared microcapsules is increased and the crystallization rate of PCM becomes faster when the NGP is added. The obtained microcapsules and wood flour are incorporated into high-density polyethylene (HDPE) to form a wood-plastic composite (WPC). The results indicate that the tensile and impact strengths of the WPC are 24.1 MPa and 48.7 J/m, respectively. Moreover, it is observed that the addition of these phase-change microcapsules can improve the heat dissipation of HDPE and accelerate the speed of thermal diffusion
TCP over geo-routing for high mobility: vehicle grids and airborne swarms
Ad hoc wireless networks have become the architecture of choice for peer to peer communications in areas where the telecommunications infrastructure is inadequate or has failed. A major challenge is the reliable delivery of data when nodes move. The reliable Internet protocol is TCP. However, TCP performs poorly in mobile ad hoc networks, mainly because of route breakage. To overcome this problem, a robust routing protocol must be used. To this effect, Geo-routing has recently received attention in large scale, mobile systems as it does not require end- to-end path establishment and pre-computed packet forwarding routing structure at nodes. These properties make Geo-routing robust to highly dynamic route changes.
For best performance, however, several parameters must be carefully tuned.
In this paper we study the joint optimization of TCP and Geo-routing parame- ters to handle high speeds. We first introduce two highly mobile ad hoc scenarios that require reliable delivery, namely the vehicle urban grid and the airborne swarms.
Then, we study the impact of critical system parameters (e.g., hello message ex- change rate, delay timer in TCP for out-of-order delivery, etc) on the performance of both UDP and TCP. We improve hello message effciency in Geo-routing by using an adaptive hello exchange scheme. Then, we fix the out-of-order problem in TCP by using a receiver-side out-of-order detection and delayed ack strategy. We show that these parameter adjustments are critical for effcient TCP over Geo-routing in highly mobile applications. With these enhancements our TCP with Geo-routing solution easily outperforms TCP over traditional ad hoc routing schemes, such as AODV.1st IFIP International Conference on Ad-Hoc NetWorkingRed de Universidades con Carreras en Informática (RedUNCI
Antioxidant Activity and Hepatoprotective Potential of Polyalthia longifolia and Cassia spectabilis Leaves against Paracetamol-Induced Liver Injury
In the present study, in vitro antioxidant, free radical scavenging capacity, and hepatoprotective activity of methanol extracts from
Polyalthia longifolia and Cassia spectabilis were evaluated using established in vitro models such as ferric-reducing antioxidant
power (FRAP), 2,2-diphenyl-1-picryl-hydrazyl (DPPH•), hydroxyl radical (OH•), nitric oxide radical (NO•) scavenging, metal
chelating, and antilipidperoxidation activities. Interestingly, all the extracts showed considerable in vitro antioxidant and free
radical scavenging activities in a dose-dependent manner when compared to the standard antioxidant which verified the presence
of strong antioxidant compound in leaf extracts tested. Phenolic and flavonoid content of these extracts is significantly correlated
with antioxidant capacity. Since P. longifolia extract was exhibited better in vitro antioxidant activities, it was subjected for in
vivo hepatoprotective activity in paracetamol-intoxicated mice. Therapy of P. longifolia showed the liver protective effect on
biochemical and histopathological alterations. Moreover, histological studies also supported the biochemical finding, that is, the
maximum improvement in the histoarchitecture of the liver. Results revealed that P. longifolia leaf extract could protect the liver
against paracetamol-induced oxidative damage by possibly increasing the antioxidant protection mechanism inmice. Our findings
indicated that P. longifolia and C. spectabilis have potential as good sources of natural antioxidant/antiaging compounds
EVALUATION OF IN VITRO CYTOTOXIC ACTIVITY OF OCIMUM BASILICUM AND MENTHA SPICATA EXTRACTS
Objective: The objective of the current research was to evaluate the cytotoxicity of Ocimum basilicum (OB) and Mentha spicata (MS).Methods: In vitro cytotoxic potential of OB and MS extracts was evaluated against human cancer HL60 cell lines using 3-[4,5-dimethylthiazol-2-yl]-2,5diphenyl tetrazolium bromide assay. The treated cell morphology was observed by light microscope.Results: The OB and MS extracts inhibited proliferation of HL60 cells in concentration dependent manner with IC₅₀ of 45.67 µg/ml and 98.1 µg/mlfor 42 hrs, respectively. The morphology of the HL60 cells treated with OB and MS extracts at high concentrations (200 and 100 µg/ml) indicated cellshrinkage, clumping, and signs of apoptosis.Conclusion: OB and MS extracts induced cell death in HL60 cell lines. Further, in vivo studies and identification of active components from OB extract,and their exact mechanism of action could be useful in designing new anticancer therapeutic agents.Keywords: Cytotoxicity; HL60 cell; apoptosis; medicinal plant
Thermal diffusion by Brownian motion induced fluid stress
The Ludwig-Soret effect, the migration of a species due to a temperature
gradient, has been extensively studied without a complete picture of its cause
emerging. Here we investigate the dynamics of DNA and spherical particles sub
jected to a thermal gradient using a combination of Brownian dynamics and the
lattice Boltzmann method. We observe that the DNA molecules will migrate to
colder regions of the channel, an observation also made in the experiments of
Duhr, et al[1]. In fact, the thermal diffusion coefficient found agrees
quantitatively with the experimental value. We also observe that the thermal
diffusion coefficient decreases as the radius of the studied spherical
particles increases. Furthermore, we observe that the thermal
fluctuations-fluid momentum flux coupling induces a gradient in the stress
which leads to thermal migration in both systems.Comment: 6 pages, 5 figue
Wandoo Walk 1
Cervical cancer is a life-threatening complication, appearing as the uncontrolled growth of abnormal cells in the lining of the cervix. Every year, increasing numbers of cervical cancer cases are reported worldwide. Different identification strategies were proposed to detect cervical cancer at the earlier stages using various biomarkers. Squamous cell carcinoma antigen (SCC-Ag) is one of the potential biomarkers for this diagnosis. Nanomaterial-based detection systems were shown to be efficient with different clinical biomarkers. In this study, we have demonstrated strontium oxide-modified interdigitated electrode (IDE) fabrication by the sol-gel method and characterized by scanning electron microscopy and high-power microscopy. Analysis of the bare devices indicated the reproducibility with the fabrication, and further pH scouting on the device revealed that the reliability of the working pH ranges from 3 to 9. The sensing surface was tested to detect SCC-Ag against its specific antibody; the detection limit was found to be 10 pM, and the sensitivity was in the range between 1 and 10 pM as calculated by 3σ. The specificity experiment was carried out using major proteins from human serum, such as albumin and globulin. SCC-Ag was shown to be selectively detected on the strontium oxide-modified IDE surface
Acute and Subchronic Toxicity Study of Euphorbia hirta L. Methanol Extract in Rats
Despite Euphorbia hirta L. ethnomedicinal benefits, very few studies have described the potential toxicity.The aim of the present
study was to evaluate the in vivo toxicity of methanolic extracts of E. hirta.The acute and subchronic oral toxicity of E. hirta was
evaluated in Sprague Dawley rats. The extract at a single dose of 5000mg/kg did not produce treatment related signs of toxicity
or mortality in any of the animals tested during the 14-day observation period. Therefore, the LD 50 of this plant was estimated
to be more than 5000mg/kg. In the repeated dose 90-day oral toxicity study, the administration of 50mg/kg, 250mg/kg, and
1000mg/kg/day of E. hirta extract per body weight revealed no significant difference
Anti-cancer natural products inducing cross-talk between apoptosis and autophagy mutual proteins to regulate cancer cell death: design of future green anticancer therapies
The present letter concerns anti-cancer natural products inducing cross-talk between apoptosis and autophagy mutual proteins to regulate cancer cell death for future cancer green therapeutic approaches. The course of cancer advancement has always been attributed to the defectiveness in cell death mechanisms (Du et al., 2013; Hematulin et al., 2014). These defects act as a shield in protecting tumor cells from drugs and therapies, all at the same time, maintaining a longer life span and prompting their dispersion procedures. Autophagy and apoptosis safeguards cells from cellular damages and maintains proliferation and homeostasis by deporting outgrowth and controlling differentiation of pernicious cells. The autophagic proteins are conventionally found in hindering apoptosis whereas vice versa accounts had been reported for apoptotic-intermediates in preventing autophagic responses
Chemical composition and antioxidant activity of the crude methanolic extracts of Mentha spicata
The chemical constituents and antioxidant activity of the crude extracts of Mentha spicata were investigated. Phytochemical analysis indicated the presence of sugar, flavonoids and alkaloids in the crude extracts of Mentha spicata. GC-TOFMS (Gas Chromatography Time-of-Flight Mass Spectrometry) analysis indicated the presence of fatty acid methyl esters (hexa decane, hepta decane, octa decane) terpenoids, terpenoid alcohol, caryophyllene and glycosides. Total phenolic components of the crude extracts was found to be 27.26±0.62 mg/g gallic acid equivalent which was determined by Folin-Ciocalteu method. The DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity was found to increase with increasing concentrations and was found to be 54.84±0.57% with an IC50 value of 25.2µg/ml. The reported antioxidant activity may be due to the presence of flavonoids and fatty acid methyl esters which has the scavenging potential by reducing the free radicals. Â
Regulating mitochondrial biogenesis : from herbal remedies to phytomedicine for cancer prevention
Mitochondria are well-adapted endosymbiotic intracellular organelles, acting as the energy supplier for survival and proliferation of cells under aerobic conditions. Moreover, cellular proliferation largely depends on the total number of mitochondria, governed by the process of mitochondrial biogenesis (Davila and Zamorano, 2013; Yoboue et al., 2014)
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