789 research outputs found
Bentonite functionalized with propyl sulfonic acid groups used as catalyst in esterification reactions
AbstractThe main objective of this work is the functionalization of bentonite from the Amazon (region) by the grafting of propyl sulfonic acid groups to catalyze the esterification reaction of acetic acid and 1-propanol. Functionalization was accomplished by anchoring, oxidation and acid activation of (3-mercaptopropyl)trimethoxysilane, (MTPS). The procedure gave acid properties to the raw bentonite. This material, acting as a catalyst, increased the reaction speed and improved the yield by about 12% compared to the uncatalyzed reaction. The functionalized bentonite was characterized by XRD, TG/DTA, FTIR, N2 adsorption/desorption at 77K and XRF, and the surface acidity was determined by titration
Behavioral Analysis Of Malicious Code Through Network Traffic And System Call Monitoring
Malicious code (malware) that spreads through the Internet-such as viruses, worms and trojans-is a major threat to information security nowadays and a profitable business for criminals. There are several approaches to analyze malware by monitoring its actions while it is running in a controlled environment, which helps to identify malicious behaviors. In this article we propose a tool to analyze malware behavior in a non-intrusive and effective way, extending the analysis possibilities to cover malware samples that bypass current approaches and also fixes some issues with these approaches. © 2011 SPIE.8059The Society of Photo-Optical Instrumentation Engineers (SPIE)Balzarotti, D., Cova, M., Karlberger, C., Kruegel, C., Kirda, E., Vigna, G., Efficient detection of split personalities in malware (2010) 17th Annual Network and Distributed System Security SymposiumBayer, U., Habibi, I., Balzarotti, D., Kirda, E., Kruegel, C., A view on current malware behaviors (2009) Usenix Workshop on Large-scale Exploits and Emergent Threats (LEET)Bayer, U., Kruegel, C., Kirda, E., TTanalyze: A tool for analyzing malware (2006) Proc. 15th Ann. Conf. European Inst. for Computer Antivirus Research (EICAR), pp. 180-192Bellard, F., QEMU, a fast and portable dynamic translator (2005) Proc. of the Annual Conference on USENIX Annual Technical Conference, pp. 41-41. , USENIX AssociationBinsalleeh, H., Ormerod, T., Boukhtouta, A., Sinha, P., Youssef, A., Debbabi, M., Wang, L., On the analysis of the zeus botnet crimeware toolkit (2010) Proc. of the Eighth Annual Conference on Privacy, Security and Trust, PST'2010Blunden, B., (2009) The Rootkit Arsenal: Escape and Evasion in the Dark Corners of the System, , Jones and Bartlett Publishers, Inc, 1th editionChoi, Y., Kim, I., Oh, J., Ryou, J., PE file header analysis-based packed pe file detection technique (PHAD) (2008) Proc of the International Symposium on Computer Science and Its Applications, pp. 28-31Dinaburg, A., Royal, P., Sharif, M., Lee, W., Ether: Malware analysis via hardware virtualization extensions (2008) Proc. Proceedings of the 15th ACM Conference on Computer and Communications Security (CCS 2008), , OctoberFather, H., Hooking windows API-technics of hooking API functions on windows (2004) CodeBreakers J., 1 (2)Franklin, J., Paxson, V., Perrig, A., Savage, S., An inquiry into the nature and causes of the wealth of internet miscreants (2007) Conference on Computer and Communications Security (CCS)Garfinkel, T., Rosenblum, M., A virtual machine introspection based architecture for intrusion detection (2003) Proc. Network and Distributed Systems Security Symposium, pp. 191-206Hoglund, G., Butler, J., (2005) Rootkits: Subverting the Windows Kernel, , Addison- Wesley Professional, 1th editionHolz, T., Engelberth, M., Freiling, F., Learning more about the underground economy: A case-study of keyloggers and dropzones (2008) Reihe Informatik TR-2008-006, , University of Mannheimhttp://www.joebox.org/Kang, M.G., Poosankam, P., Yin, H., Renovo: A hidden code extractor for packed exe-cutables (2007) Proc. of the 2007 ACM Workshop on Recurring Malcode (WORM 2007)Kong, J., (2007) Designing BSD Rootkits, , No Starch Press, 1th editionLeder, F., Werner, T., Know your enemy: Containing conficker (2009) The Honeynet Project & Research AllianceMartignoni, L., Christodorescu, M., Jha, S., Omniunpack: Fast, generic, and safe unpack-ing of malware (2007) Proc. of the Annual Computer Security Applications Conference (ACSAC)http://download.microsoft.com/download/9/c/5/9c5b2167-8017-4bae-9fde- d599bac8184a/pecoff_v8.docxMoser, A., Kruegel, C., Kirda, E., Limits of static analysis for malware detection (2007) ACSAC, pp. 421-430. , IEEE Computer Societyhttp://www.securelist.com/en/descriptions/old145521http://www.softpanorama.org/Malware/Malware_defense_history/ Malware_gallery/Network_worms/allaple_rahack.shtmlSong, D., Brumley, D., Yin, H., Caballero, J., Jager, I., Kang, M.G., Liang, Z., Saxena, P., BitBlaze: A new approach to computer security via binary analysis (2008) Proc. of the 4th International Conference on Information Systems SecurityWillems, G., Holz, T., Freiling, F., Toward automated dynamic malware analysis using CWSandbox (2007) IEEE Security and Privacy, 5 (2), pp. 32-39. , DOI 10.1109/MSP.2007.45Yegneswaran, V., Saidi, H., Porras, P., Eureka: A framework for enabling static analysis on malware (2008) Technical Report SRI-CSL-08-01 Computer Science Laboratory and College of Computing, , Georgia Institute of Technolog
Use of Cellulosic Materials as Dye Adsorbents — A Prospective Study
Cellulose is the most abundant biopolymer of nature, and it is widely used in the synthesis of new materials as well as in the adsorption of dye. This study reports a literature review (articles) and technology review (patents) about publications and product invention, which contain information on the use of cellulose on the adsorption of dyes in the period 2004–2014. For this work, research database and keywords were used to find articles and patents related to the subject under review. Specific words were used to find articles and patents related to the subject under review. After a demanding research, 1 patent and 23 articles that contain the words “cellulose,” “dye,” and “adsorption or sorption” in their titles were assessed, and annual evolution studies were performed for publications and countries that publish more
Chemical Functionalization of Cellulosic Materials — Main Reactions and Applications in the Contaminants Removal of Aqueous Medium
The cellulose is the most abundant biopolymer in the world and presents a higher chemical variability for presence of several hydroxyl groups. These hydroxyl groups allow surface modification of biomaterials, with insertion of several chemical groups which change cellulose characteristics. This natural biopolymer and its derivatives have been used a lot as adsorbent, from several contaminants of aqueous medium due to biocompatibility, chemical degradability, and variability. Therefore, this chapter has the objective to review the literature about several cellulose surfaces or cellulosic material (incorporation of carboxymethyl, phosphorus, carboxyl, amines, and sulfur), presenting the main characteristics of reactions and showing its adsorption in application of aqueous medium (metals, dyes, and drugs), locating the main interactions between biomaterial/contaminant
Ictiofauna Dos Enclaves De Floresta úmida Nos Planaltos Da Ibiapaba E Do Araripe, Nordeste Do Brasil
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Humid highland forest enclaves are remnants of Atlantic Forest found in tablelands within the Caatinga biome (Northeastern Brazil), which emerged during interglacial periods in the Pleistocene. These ecosystems have a highly diverse and endemic fish fauna. Most earlier surveys have focused on the tableland of Borborema (Pernambuco and Paraíba States). In this study we surveyed the fish fauna of the humid forest enclaves in the tablelands of Ibiapaba and Araripe, based on samples collected in the rainy season (March and April) between 2009 and 2014. The 45 sampling points covered rivers, streams and reservoirs in five river basins belonging to three ecoregions. The species were listed according to drainage divide, and endemism was determined for each ecoregion and for the Caatinga. Our area was more species-rich (n=59) than Borborema (n=27). The samples included five introduced species and 29 species endemic to the Caatinga (49.1% of the sampled species). The distribution of Parotocinclus haroldoi was expanded to the Mid-Northeastern Caatinga ecoregion (Timonha river basin, Ceará State). Our study intends to make a significant contribution to current knowledge of the ichthyofauna in humid highland forest enclaves of semiarid Northeastern Brazil, identified as a priority in the conservation of the biodiversity in the Caatinga. © 2016, Universidade Estadual de Campinas UNICAMP. All rights reserved.164457463/2012-0, CNPq, Conselho Nacional de Desenvolvimento Científico e Tecnológico552009/2011-3, CNPq, Conselho Nacional de Desenvolvimento Científico e Tecnológico552086/2011-8, CNPq, Conselho Nacional de Desenvolvimento Científico e TecnológicoConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq
Hyperpigmentant activity of leaves and flowers extracts of Pyrostegia venusta on murine B16F10 melanoma
AbstractEthnopharmacological relevancePyrostegia venusta is a native Brazilian plant which has a variety of uses in traditional folk medicine including the treatment of vitiligo. However, its effectiveness on melanogenesis is not yet elucidated.Aim of the studyThis study aimed to investigate the melanogenic activity of hydroalcoholic extracts from the leaves and flowers of P. venusta on murine B16F10 melanoma cells.Materials and methodsDifferent concentrations of the hydroalcoholic extracts of flowers and leaves of P. venusta were evaluated in trials of spontaneous melanin content (4 days), and cell viability by the MTT assay in murine B16F10 cells, and in the mushroom tyrosinase activity in vitro.ResultsBoth extracts, leaves (0.1; 0.3; 1 and 3μg/mL) and flowers (0.03 and 0.1μg/mL) increased the melanin content in a concentration dependent manner after 4 days of incubation on melanoma cells. Leaves extract promoted enhancement of melanogenesis with maximum effect of 33.3±3% (3μg/mL), and the flower extract increased in 23.4±3% (0.1μg/mL). The cell viability test using MTT showed that in the same tested concentrations of both extracts no cell death was detected. Actually, either extract was not able to cause any change in the tyrosinase activity. HPLC analysis of P. venusta extracts found 0.09% and 1.08% of allantoin on leaves and flowers extracts, respectively.ConclusionsThe leaves and flowers extracts of P. venusta stimulates B16F10 melanogenesis at very low concentrations. These findings support the folk medicinal use of P. venusta on the treatment of hypopigmentation diseases, such as vitiligo
Two-Photon Doppler cooling of alkaline-earth-metal and ytterbium atoms
A new possibility of laser cooling of alkaline-earth-metal and Ytterbium
atoms using a two-photon transition is analyzed. We consider a -
transition, with excitation in near resonance with the
level. This greatly increases the two-photon transition rate, allowing an
effective transfer of momentum. The experimental implementation of this
technique is discussed and we show that for Calcium, for example, two-photon
cooling can be used to achieve a Doppler limit of 123 microKelvin. The
efficiency of this cooling scheme and the main loss mechanisms are analyzed.Comment: 7 pages, 5 figure
Validation of low anterior resection syndrome score in Brazil with Portuguese
Purpose This study was performed to investigate the convergent validity, discriminative validity, and reliability of the Brazilian version of the low anterior resection syndrome (LARS) score in a population with low educational and socioeconomic levels. Methods The LARS score was translated into the Portuguese language by forward- and back-translation procedures. In total, 127 patients from a public hospital in Brazil completed the questionnaires. The convergent validity was tested by comparing the LARS score with the European Organization for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire Core Module 30 (QLQ-C30) and with patients’ self-reported quality of life. For the discriminative validity, we tested the ability of the score to differentiate among subgroups of patients regarding neoadjuvant radiotherapy, type of surgery, and tumor distance from the anal verge. The test-retest reliability was investigated in a subgroup of 36 patients who responded to the survey twice in 2 weeks. Results The LARS score demonstrated a strong correlation with 5 of 6 items from the EORTC QLQ-C30 (P<0.05) and good concordance with patients’ self-reported quality of life (95.3%), confirming the convergent validity. The score was able to discriminate between subgroups of patients with different clinical characteristics related to LARS (P<0.001). The agreement between the test and retest showed that 86.1% of the patients remained in the same LARS category, and there was no significant difference between the LARS score numerical values (P=0.80), indicating good reliability overall. Conclusion The Brazilian version of the LARS score is a valid and reliable instrument to assess postoperative bowel function in a population with low educational and socioeconomic levels
Efeito do corte da parte aérea na sobrevivência do marmeleiro (Croton Sonderianus Muell.Arg.)
Minimizing inter-genotypic competition effects to predict genetic values and selection in forestry genetic tests
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