674 resultados para Steinernema brazilense Nguyen
Resumo:
Evaluation of: Brown DM, Heier JS, Ciulla T et al. Primary end point results of a Phase II study of vascular endothelial growth factor trap-eye in wet age-related macular degeneration. Ophthalmology 118(6), 1089-1097 (2011); Heier JS, Boyer D, Nguyen QD et al. The 1-year results of CLEAR-IT 2, a Phase 2 study of vascular endothelial growth factor trap-eye dosed as-needed after 12-week fixed dosing. Ophthalmology 118(6), 1098-1106 (2011). Age-related macular degeneration is the most common cause of blindness in older adults in western countries, and is likely to become the largest cause of irreversible sight loss in the developing world. Treatments such as ranibizumab and bevacizumab that inhibit VEGF have improved visual outcomes markedly. Controlled trials and clinical experience have shown that the best outcomes are achieved when monthly treatment has been administered over 2 years. This poses a significant burden on health providers and patients. A novel inhibitor of VEGF, VEGF Trap-Eye, which allows less frequent dosing without loss of efficacy, has emerged as a potential treatment. CLEAR-IT 2 was a prospective randomized Phase II trial designed to assess the safety, tolerability and the anatomic and visual effects of repeated treatments with a range of doses of VEGF Trap-Eye. Impressive anatomic and visual improvements were noted with no safety concerns. © 2011 Expert Reviews Ltd.
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In this paper, the impact of hardware impairments on secrecy performance of cognitive MIMO schemes is investigated. In addition, the relay which helps the source forward the source signal to the destination can operate either half-duplex mode or full-duplex mode. For performance evaluation, we give the expressions of average secrecy rate over Rayleigh fading channel. Monte-Carlo simulations are presented to compare and optimize the performance of the proposed schemes.
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Cognitive radio (CR) with spectrum-sharing has been envisioned as emerging technology for the next generation of mobile and wireless networks by allowing the unlicensed customers simultaneously utilize the licensed radio frequency spectrums. However, the CR has faced some practical challenges due to its deduced system performance as compared to non spectrum-sharing counterpart. In this paper, we therefore consider the potential of incorporating the cooperative communications into CR by introducing the concept of reactive multiple decode-and-forward (DF) relays. In particular, we derive new results for exact and asymptotic expressions for the performance of cognitive relay networks with K-th best relay selection. Our novel results have exhibited the significance of using relay networks to enhance the system performance of CR.
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The aim of this paper is to develop a new generation of extruder control system for recycled materials which has ability to automatically maintain constant a polymer melt viscosity of mixed recycled polymers during extrusion, regardless of variations in the Melt Flow Index (MFI) of recycled mixed grade high density polyethylene (HDPE) feedstock. The variations in MFI are due to differences in the source of the recycled material used. The work describes how melt viscosity for specific extruder/die system is calculated in real time using the rheological properties of the materials, the pressure drop through the extruder die and the actual throughput measurements using a gravimetric loss-in-weight hopper feeder. A closed-loop controller is also developed to automatically regulate screw speed and barrel temperature profile to achieve constant viscosity and enable consistent processing of variable grade recycled HDPE materials. Such a system will improve processability of mixed MFI polymers may also reduce the risk of polymer melt degradation, reduce producing large volumes of scrap/waste and lead to improvement in product quality. The experimental results of real time viscosity measurement and control using a 38 mm single screw extruder with different recycled HDPEs with widely different MFIs are reported in this work.
Resumo:
Melt viscosity is one of the main factors affecting product quality in extrusion processes particularly with regard to recycled polymers. However, due to wide variability in the physical properties of recycled feedstock, it is difficult to maintain the melt viscosity during extrusion of polymer blends and obtain good quality product without generating scrap. This research investigates the application of ultrasound and temperature control in an automatic extruder controller, which has ability to maintain constant melt viscosity from variable recycled polymer feedstock during extrusion processing. An ultrasonic modulation system has been developed and fitted to the extruder prior to the die to convey ultrasonic energy from a high power ultrasonic generator to the polymer melt. Two separate control loops have been developed to run simultaneously in one controller: the first loop controls the ultrasonic energy or temperature to maintain constant die pressure, the second loop is used to control extruder screw speed to maintain constant throughput at the extruder die. Time response and energy consumption of the control methods in real-time experiments are also investigated and reported this paper.
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This paper describes the scientific aims and potentials as well as the preliminary technical design of IRIDE, an innovative tool for multi-disciplinary investigations in a wide field of scientific, technological and industrial applications. IRIDE will be a high intensity "particles factory", based on a combination of high duty cycle radio-frequency superconducting electron linacs and of high energy lasers. Conceived to provide unique research possibilities for particle physics, for condensed matter physics, chemistry and material science, for structural biology and industrial applications, IRIDE will open completely new research possibilities and advance our knowledge in many branches of science and technology. IRIDE is also supposed to be realized in subsequent stages of development depending on the assigned priorities. © 2013 Elsevier B.V.
Resumo:
CCAAT enhancer binding protein α (C/EBPα) plays an essential role in cellular differentiation, growth, and energy metabolism. Here, we investigate the correlation between C/EBPα and hepatocellular carcinoma (HCC) patient outcomes and how C/EBPα protects cells against energy starvation. Expression of C/EBPα protein was increased in the majority of HCCs examined (191 pairs) compared with adjacent nontumor liver tissues in HCC tissue microarrays. Its upregulation was correlated significantly with poorer overall patient survival in both Kaplan-Meier survival (P = 0.017) and multivariate Cox regression (P = 0.028) analyses. Stable C/EBPα-silenced cells failed to establish xenograft tumors in nude mice due to extensive necrosis, consistent with increased necrosis in human C/EBPα-deficient HCC nodules. Expression of C/EBPα protected HCC cells in vitro from glucose and glutamine starvation-induced cell death through autophagy-involved lipid catabolism. Firstly, C/EBPα promoted lipid catabolism during starvation, while inhibition of fatty acid beta-oxidation significantly sensitized cell death. Secondly, autophagy was activated in C/EBPα-expressing cells, and the inhibition of autophagy by ATG7 knockdown or chloroquine treatment attenuated lipid catabolism and subsequently sensitized cell death. Finally, we identified TMEM166 as a key player in C/EBPα-mediated autophagy induction and protection against starvation.
CONCLUSION: The C/EBPα gene is important in that it links HCC carcinogenesis to autophagy-mediated lipid metabolism and resistance to energy starvation; its expression in HCC predicts poorer patient prognosis.
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Objectives: To develop and manufacture both immediate and sustained release vaginal tablets containing the anticancer drug disulfiram, which has the potential to be used as a non-invasive treatment for cervical cancer.
Methods: Disulfiram-loaded vaginal tablets were manufactured at pilot scale using the direct compression method. These tablets were tested in accordance with the European Pharmacopeia testing of solid dosage form guidelines. They were also tested using a biorelevant dissolution method as well as a dual-chambered release model designed to better mimic the dynamic nature of the vaginal vault.
Key findings: We have developed both immediate and sustained release vaginal tablets, which when manufactured at pilot scale are within the limits set by the European Pharmacopeia for the testing of solid dosage forms. Furthermore, these tablets are capable of releasing disulfiram in vitro using the dual-chambered release model at levels 25 000 times and 35 000 times greater than its IC50 concentration for the HeLa cervical cancer cell line.
Conclusions: The successful pilot manufacture and testing of both the immediate and sustained release disulfiram-loaded vaginal tablets warrant further investigation, using an in-vivo model, to assess their potential for use as a non-invasive treatment option for cervical cancer.
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Human respiratory syncytial virus (HRSV) is the most important viral cause of severe respiratory tract disease in infants. Two subgroups (A and B) have been identified, which cocirculate during, or alternate between, yearly epidemics and cause indistinguishable disease. Existing in vitro and in vivo models of HRSV focus almost exclusively on subgroup A viruses. Here, a recombinant (r) subgroup B virus (rHRSV(B05)) was generated based on a consensus genome sequence obtained directly from an unpassaged clinical specimen from a hospitalized infant. An additional transcription unit containing the gene encoding enhanced green fluorescent protein (EGFP) was introduced between the phosphoprotein and matrix genes (position 5) of the genome to generate rHRSV(B05)EGFP(5). The recombinant viruses replicated efficiently in both HEp-2 cells and in well-differentiated normal human bronchial cells grown at air-liquid interface. Intranasal infection of cotton rats (Sigmodon hispidus) resulted in high numbers of EGFP(+) cells in epithelia of the nasal septum and conchae. When administered in a relatively large inoculum volume, the virus also replicated efficiently in bronchiolar epithelial cells and spread extensively in both the upper and lower respiratory tracts. Virus replication was not observed in ciliated epithelial cells of the trachea. This is the first virulent rHRSV strain with the genetic composition of a currently circulating wild-type virus. In vivo tracking of infected cells by means of EGFP fluorescence in the absence of cytopathic changes increases the sensitivity of virus detection in HRSV pathogenesis studies.
IMPORTANCE
Virology as a discipline has depended on monitoring cytopathic effects following virus culture in vitro. However, wild-type viruses isolated from patients often do not cause significant changes to infected cells, necessitating blind passage. This can lead to genetic and phenotypic changes and the generation of high-titer, laboratory-adapted viruses with diminished virulence in animal models of disease. To address this, we determined the genome sequence of an unpassaged human respiratory syncytial virus from a sample obtained directly from an infected infant, assembled a molecular clone, and recovered a wild-type recombinant virus. Addition of a gene encoding enhanced green fluorescent protein allowed this wild-type virus to be tracked in primary human cells and living animals in the absence of significant cytopathic effects. Imaging of fluorescent cells proved to be a highly valuable tool for monitoring the spread of virus and may help improve assays for evaluating novel intervention strategies.
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Over the course of the past two decades there has been growing research interest in the site formation processes of shell middens. This stands along-side and is being used to inform cultural, dietary and palaeo-environmental reconstructions. Just as midden site formation processes have turned out to be many and varied, however, the kinds of shell-bearing sites that past human communities created are likely to have been no less diverse. Subsuming such sites under a single category - shell middens - normalises that variation and may lead to the misinterpretation of site function. The greater part of research in this field also continues to focus on coastal shell middens; comparatively little attention has been paid to middens containing freshwater and especially terrestrial molluscs from hinterland locations. As a result, much of the current understanding about shell-midden sites carries a spatial as well as a functional bias. This paper hopes to contribute towards discussion on both fronts. It presents a detailed examination of the formation processes that went into the creation of a land snail-dominated late- to post-glacial midden from northern Vietnam, and considers the role that it may have played in the early settlement of this area. The data presented comes from ongoing archaeological excavations at Hang Boi, a cave located in the sub-coastal karstic uplands of Trang An park, in the Vietnamese Province of Ninh Binh. (C) 2010 Elsevier Ltd and INQUA. All rights reserved.
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Human settlement of Oceania marked the culmination of a global colonization process that began when humans first left Africa at least 90,000 years ago. The precise origins and dispersal routes of the Austronesian peoples and the associated Lapita culture remain contentious, and numerous disparate models of dispersal (based primarily on linguistic, genetic, and archeological data) have been proposed. Here, through the use of mtDNA from 781 modern and ancient Sus specimens, we provide evidence for an early human-mediated translocation of the Sulawesi warty pig (Sus celebensis) to Flores and Timor and two later separate human-mediated dispersals of domestic pig (Sus scrofa) through Island Southeast Asia into Oceania. Of the later dispersal routes, one is unequivocally associated with the Neolithic (Lapita) and later Polynesian migrations and links modern and archeological Javan, Sumatran, Wallacean, and Oceanic pigs with mainland Southeast Asian S. scrofa. Archeological and genetic evidence shows these pigs were certainly introduced to islands east of the Wallace Line, including New Guinea, and that so-called "wild" pigs within this region are most likely feral descendants of domestic pigs introduced by early agriculturalists. The other later pig dispersal links mainland East Asian pigs to western Micronesia, Taiwan, and the Philippines. These results provide important data with which to test current models for human dispersal in the region. © 2007 by The National Academy of Sciences of the USA.
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Background: The steady increase in the number of people living and dying with dementia, coupled with the recent focus on quality of care, has highlighted the importance of dementia training for health care professionals. This exploratory study aimed to discover which skills health care students felt were important in providing quality end-of-life care to dementia patients.
Methods: Ninety-four medicine, nursing, and pharmacy students participated in a larger study using open-ended and closed questions to explore attitudes related to caring for dementia patients at the end of life. This study looks at the student responses to an open-ended question regarding the skills and knowledge they believe are needed to provide end-of-life care to dementia patients. Individual responses were reviewed by the researchers, coded into key issues, and tabulated for frequency of occurrences and group differences.
Results: Several common issues emerged: knowledge, patience, empathy, understanding, family involvement, compassion, medication knowledge, respect/patient autonomy, communication, quality of life, and patient education. Significant differences were observed among the participant groups on the following issues: Patience and understanding (pharmacy students mentioned these issues less frequently than medical and nursing students), compassion (medical students mentioned this issue more frequently than pharmacy students), and medication knowledge (pharmacy students mentioned this issue more frequently than medical and nursing students).
Conclusions: Different health care disciplines (in-training) value different skill sets for the provision of dementia care at the end-of-life. As health care education for dementia patients at the end of life is expanded, it will be important to understand which skills both patients and health care students value.
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Organic Rankine Cycle (ORC) is the most commonly used method for recovering energy from small sources of heat. The investigation of the ORC in supercritical condition is a new research area as it has a potential to generate high power and thermal efficiency in a waste heat recovery system. This paper presents a steady state ORC model in supercritical condition and its simulations with a real engine’s exhaust data. The key component of ORC, evaporator, is modelled using finite volume method, modelling of all other components of the waste heat recovery system such as pump, expander and condenser are also presented. The aim of this paper is to investigate the effects of mass flow rate and evaporator outlet temperature on the efficiency of the waste heat recovery process. Additionally, the necessity of maintaining an optimum evaporator outlet temperature is also investigated. Simulation results show that modification of mass flow rate is the key to changing the operating temperature at the evaporator outlet.