Determination of ochratoxin A in bread: evaluation of microwave-assisted extraction using an orthogonal composite design coupled with response surface methodology

An analytical method using microwave-assisted extraction (MAE) and liquid chromatography (LC) with fluorescence detection (FD) for the determination of ochratoxin A (OTA) in bread samples is described. A 24 orthogonal composite design coupled with response surface methodology was used to study the influence of MAE parameters (extraction time, temperature, solvent volume, and stirring speed) in order to maximize OTA recovery. The optimized MAE conditions were the following: 25 mL of acetonitrile, 10 min of extraction, at 80 °C, and maximum stirring speed. Validation of the overall methodology was performed by spiking assays at five levels (0.1–3.00 ng/g). The quantification limit was 0.005 ng/g. The established method was then applied to 64 bread samples (wheat, maize, and wheat/maize bread) collected in Oporto region (Northern Portugal). OTAwas detected in 84 % of the samples with a maximum value of 2.87 ng/g below the European maximum limit established for OTA in cereal products of 3 ng/g.

Inter-application redundancy elimination in sensor networks with compiler-assisted scheduling

Most current-generation Wireless Sensor Network (WSN) nodes are equipped with multiple sensors of various types, and therefore support for multi-tasking and multiple concurrent applications is becoming increasingly common. This trend has been fostering the design of WSNs allowing several concurrent users to deploy applications with dissimilar requirements. In this paper, we extend the advantages of a holistic programming scheme by designing a novel compiler-assisted scheduling approach (called REIS) able to identify and eliminate redundancies across applications. To achieve this useful high-level optimization, we model each user application as a linear sequence of executable instructions. We show how well-known string-matching algorithms such as the Longest Common Subsequence (LCS) and the Shortest Common Super-sequence (SCS) can be used to produce an optimal merged monolithic sequence of the deployed applications that takes into account embedded scheduling information. We show that our approach can help in achieving about 60% average energy savings in processor usage compared to the normal execution of concurrent applications.

Development of biocompatible and “smart” porous structures using CO2-assisted processes

Dissertação apresentada para a obtenção do grau de Doutor em Engenharia Química, especialidade Engenharia da Reacção Química, pela Universidade Nova de Lisboa, Faculdade de Ciências e Tecnologia

Dinuclear Mn (II,II) complexes: magnetic properties and microwave assisted oxidation of alcohols

A series of six new mixed-ligand dinuclear Mn(II, II) complexes of three different hydrazone Schiff bases (H3L1, H3L2 and H3L3), derived from condensation of the aromatic acid hydrazides benzohydrazide, 2-aminobenzohydrazide or 2-hydroxybenzohydrazide, with 2,3-dihydroxy benzaldehyde, respectively, is reported. Reactions of Mn(NO3)(2) center dot 4H(2)O with the H3L1-3 compounds, in the presence of pyridine (1 : 1 : 1 mole ratio), in methanol at room temperature, yield [Mn(H2L1)(py)(H2O)](2)(NO3)(2) center dot 2H(2)O (1 center dot 2H(2)O), [Mn(H2L2)(py)(CH3OH)](2)(NO3)(2) center dot 4H(2)O (2 center dot 4H(2)O) and [Mn(H2L3)(py)(H2O)](2)(NO3)(2) (3) respectively, whereas the use of excess pyridine yields complexes with two axially coordinated pyridine molecules at each Mn(II) centre, viz. [Mn(H2L1)(py)(2)] 2(NO3)(2) center dot H2O (4 center dot H2O), [Mn(H2L2)(py) H-O (6 center dot 2CH(3)OH), respectively. In all the complexes, the (H2L1-3)-ligand coordinates in the keto form. Complexes 1 center dot 2H(2)O, 2 center dot 4H(2)O, 4 center dot H2O, 5 center dot 2H(2)O and 6 center dot 2CH(3)OH are characterized by single crystal X-ray diffraction analysis. The complexes 1, 2 and 6, having different coordination environments, have been selected for variable temperature magnetic susceptibility measurements to examine the nature of magnetic interaction between magnetically coupled Mn(II) centres and also for exploration of the catalytic activity towards microwave assisted oxidation of alcohols. A yield of 81% (acetophenone) is obtained using a maximum of 0.4% molar ratio of catalyst relative to the substrate in the presence of TEMPO and in aqueous basic solution, under mild conditions.

Microwave-assisted and solvent-free peroxidative oxidation of 1-phenylethanol to acetophenone with a CuII-TEMPO catalytic system

The water-soluble copper(II) complex [Cu(H2R)(HL)]center dot H2O (1) was prepared by reaction of copper(II) nitrate hydrate with (E)-2-(((1-hydroxynaphthalen-2-yl)methylene)amino) benzenesulfonic acid (H2L) and diethanolamine (H3R). It was characterized by IR and ESI-MS spectroscopies, elemental and X-ray crystal structural analyses. 1 shows a high catalytic activity for the solvent-free microwave (MW) assisted oxidation of 1-phenylethanol with tert-butylhydroperoxide, leading, in the presence of TEMPO, to yields up to 85% (TON = 850) in a remarkably short reaction time (15 min, with the corresponding TOE value of 3.40 x 10(3) h(-1)) under low power (25W) MW irradiation. Crown Copyright (C) 2014 Published by Elsevier B.V. All rights reserved.

InOx thin films deposited by plasma assisted evaporation: application in light shutters

An integration of undoped InOx and commercial ITO thin films into laboratory assembled light shutter devices is made. Accordingly, undoped transparent conductive InOx thin films, about 100 nm thick, are deposited by radiofrequency plasma enhanced reactive thermal evaporation (rf-PERTE) of indium teardrops with no intentional heating of the glass substrates. The process of deposition occurs at very low deposition rates (0.1-0.3 nm/s) to establish an optimized reaction between the oxygen plasma and the metal vapor. These films show the following main characteristics: transparency of 87% (wavelength, lambda = 632.8 nm) and sheet resistance of 52 Omega/sq; while on commercial ITO films the transparency was of 92% and sheet resistance of 83 Omega/sq. The InOx thin film surface characterized by AFM shows a uniform grain texture with a root mean square surface roughness of Rq similar to 2.276 nm. In contrast, commercial ITO topography is characterized by two regions: one smoother with Rq similar to 0.973 nm and one with big grains (Rq similar to 3.617 nm). For the shutters assembled using commercial ITO, the light transmission coefficient (Tr) reaches the highest value (Tr-max) of 89% and the lowest (Tr-min) of 1.3% [13], while for the InOx shutters these values are 80.1% and 3.2%, respectively. Regarding the electric field required to achieve 90% of the maximum transmission in the ON state (E-on), the one presented by the devices assembled with commercial ITO coated glasses is 2.41 V/mu m while the one presented by the devices assembled with InOx coated glasses is smaller, 1.77 V/mu m. These results corroborate the device quality that depends on the base materials and fabrication process used. (C) 2014 Elsevier Ltd. All rights reserved.

Oxidovanadium complexes with tridentate aroylhydrazone as catalyst precursors for solvent-free microwave-assisted oxidation of alcohols

Aroylhydrazone oxidovanadium compounds, viz, the oxidoethoxidovanadium(V) [VO(OEt)L1] (1) (H2L =salicylaldehyde-2-hydroxybenzoylhydrazone), the salt like dioxidovanadium(V) (NH3CH2CH2OH)(+) [VO2L](-) (2), the mixed-ligand oxidovanadium(V) [VO(hq)L](Hhq = 8-hydroxyquinoline) (3) and the vanadium(IV) [VO(phen)L] (phen=1,10-phenanthroline) (4) complexes (3 and 4 obtained by the first time), have been tested as catalysts for solvent-free microwave-assisted oxidation of aromatic and alicyclic secondary alcohols with tert-butylhydroperoxide. A facile, efficient and selective solvent-free synthesis of ketones was achieved with yields up to 99% (TON= 497, TOF= 993 h(-1) for 3) and 58% (TON =291, TOF= 581 h(-1) for 2) for acetophenone and cyclohexanone, respectively, after 30 min under low power (25W) microwave irradiation. (C) 2015 Elsevier B.V. All rights reserved.

Solvent-free microwave-assisted peroxidative oxidation of alcohols catalyzed by Iron(III)-TEMPO catalytic systems

The iron(III) complexes [H(EtOH)][FeCl2(L)(2)] (1), [H(2)bipy](1/2)[FeCl2(L)(2)].DMF (2) and [FeCl2(L)(2,2'-bipy)] (3) (L = 3-amino-2-pyrazinecarboxylate; H(2)bipy = doubly protonated 4,4'-bipyridine; 2,2'-bipy = 2,2'-bipyridine, DMF = dimethylformamide) have been synthesized and fully characterized by IR, elemental and single-crystal X-ray diffraction analyses, as well as by electrochemical methods. Complexes 1 and 2 have similar mononuclear structures containing different guest molecules (protonated ethanol for 1 and doubly protonated 4,4'-bipyridine for 2) in their lattices, whereas the complex 3 has one 3-amino-2-pyrazinecarboxylate and a 2,2'-bipyridine ligand. They show a high catalytic activity for the low power (10 W) solvent-free microwave assisted peroxidative oxidation of 1-phenylethanol, leading, in the presence of TEMPO, to quantitative yields of acetophenone [TOFs up to 8.1 x 10(3) h(-1), (3)] after 1 h. Moreover, the catalysts are of easy recovery and reused, at least for four consecutive cycles, maintaining 83 % of the initial activity and concomitant rather high selectivity. 3-Amino-2-pyrazinecarboxylic acid is used to synthesize three new iron(III) complexes which act as heterogeneous catalysts for the solvent-free microwave-assisted peroxidative oxidation of 1-phenylethanol.

Cloud-assisted Wireless Body Area Networks

Wireless Body Area Networks (WBANs) have emerged as a promising technology for medical and non-medical applications. WBANs consist of a number of miniaturized, portable, and autonomous sensor nodes that are used for long-term health monitoring of patients. These sensor nodes continuously collect information of patients, which are used for ubiquitous health monitoring. In addition, WBANs may be used for managing catastrophic events and increasing the effectiveness and performance of rescue forces. The huge amount of data collected by WBAN nodes demands scalable, on-demand, powerful, and secure storage and processing infrastructure. Cloud computing is expected to play a significant role in achieving the aforementioned objectives. The cloud computing environment links different devices ranging from miniaturized sensor nodes to high-performance supercomputers for delivering people-centric and context-centric services to the individuals and industries. The possible integration of WBANs with cloud computing (WBAN-cloud) will introduce viable and hybrid platform that must be able to process the huge amount of data collected from multiple WBANs. This WBAN-cloud will enable users (including physicians and nurses) to globally access the processing and storage infrastructure at competitive costs. Because WBANs forward useful and life-critical information to the cloud – which may operate in distributed and hostile environments, novel security mechanisms are required to prevent malicious interactions to the storage infrastructure. Both the cloud providers and the users must take strong security measures to protect the storage infrastructure.

Mn-II and Cu-II complexes with arylhydrazones of active methylene compounds as effective heterogeneous catalysts for solvent- and additive-free microwave-assisted peroxidative oxidation of alcohols

A one-pot template reaction of sodium 2-(2-(dicyanomethylene) hydrazinyl) benzenesulfonate (NaHL1) with water and manganese(II) acetate tetrahydrate led to the mononuclear complex [Mn(H2O)(6)](HL1a)(2)center dot 4H(2)O (1), where (HL1a) -= 2-(SO3-)C6H4(NH)=N=C(C N) (CONH2) is the carboxamide species derived from nucleophilic attack of water on a cyano group of (HL1) . The copper tetramer [Cu-4(H2O)(10)(-) (1 kappa N: kappa O-2: kappa O, 2 kappa N: k(O)-L-2)(2)]center dot 2H(2)O (2) was obtained from reaction of Cu(NO3)(2)center dot 2.5H(2)O with sodium 5-(2( 4,4-dimethyl-2,6-dioxocyclohexylidene) hydrazinyl)-4-hydroxybenzene-1,3-disulfonate (Na2H2L2). Both complexes were characterized by elemental analysis, IR spectroscopy, ESI-MS and single crystal X-ray diffraction. They exhibit a high catalytic activity for the solvent-and additive-free microwave (MW) assisted oxidation of primary and secondary alcohols with tert-butylhydroperoxide, leading to yields of the oxidized products up to 85.5% and TOFs up to 1.90 x 103 h(-1) after 1 h under low power (5-10 W) MW irradiation. Moreover, the heterogeneous catalysts are easily recovered and reused, at least for three consecutive cycles, maintaining 89% of the initial activity and a high selectivity.

Vision-Based Assisted Teleoperation for Inspection Tasks with a Small ROV

It is well-known that ROVs require human intervention to guarantee the success of their assignment, as well as the equipment safety. However, as its teleoperation is quite complex to perform, there is a need for assisted teleoperation. This study aims to take on this challenge by developing vision-based assisted teleoperation maneuvers, since a standard camera is present in any ROV. The proposed approach is a visual servoing solution, that allows the user to select between several standard image processing methods and is applied to a 3-DOF ROV. The most interesting characteristic of the presented system is the exclusive use of the camera data to improve the teleoperation of an underactuated ROV. It is demonstrated through the comparison and evaluation of standard implementations of different vision methods and the execution of simple maneuvers to acquire experimental results, that the teleoperation of a small ROV can be drastically improved without the need to install additional sensors.

Bioelectrochemically-assisted reductive dechlorination of 1,2-dichloroethane by a Dehalococcoides-enriched microbial culture

The aim of this study was to verify the possibility to use a polarized graphite electrode as an electron donor for the reductive dechlorination of 1,2-dichloroethane, an ubiquitous groundwater contaminant. The rate of 1,2-DCA dechlorination almost linearly increased by decreasing the set cathode potential over a broad range of set cathode potentials (i.e., from −300 mV to −900 mV vs. the standard hydrogen electrode). This process was primarily dependent on electrolytic H2 generation. On the other hand, reductive dechlorination proceeded (although quite slowly) with a very high Coulombic efficiency (near 70%) at a set cathode potential of −300 mV, where no H2 production occurred. Under this condition, reductive dechlorination was likely driven by direct electron uptake from the surface of the polarized electrode. Taken as a whole, this study further extends the range of chlorinated contaminants which can be treated with bioelectrochemical systems.

Biosynthesis-Assisted Structural Elucidation of the Bartolosides, Chlorinated Aromatic Glycolipids from Cyanobacteria

The isolation of the bartolosides, unprecedented cyanobacterial glycolipids featuring aliphatic chains with chlorine substituents and C-glycosyl moieties, is reported. Their chlorinated dialkylresorcinol (DAR) core presented a major structural-elucidation challenge. To overcome this, we discovered the bartoloside (brt) biosynthetic gene cluster and linked it to the natural products through in vitro characterization of the DAR-forming ketosynthase and aromatase. Bioinformatic analysis also revealed a novel potential halogenase. Knowledge of the bartoloside biosynthesis constrained the DAR core structure by defining key pathway intermediates, ultimately allowing us to determine the full structures of the bartolosides. This work illustrates the power of genomics to enable the use of biosynthetic information for structure elucidation.

Laparoscopic Assisted Vaginal Hysterectomy Versus Vaginal Hysterectomy

Introduction: Hysterectomy is the commonest gynecologic operation, performed for malignant and benign conditions. There are many approaches to hysterectomy for benign disease. Studies comparing the techniques have showed that vaginal hysterectomy has benefits in terms of reduced hospital stay, faster recovery and less operating time. Objective: The purpose of this study is to compare the surgical and immediate postoperative outcomes of Laparoscopic Assisted Vaginal Hysterectomy (LAVH) with those of Vaginal Hysterectomy (VH). Methods: Retrospective descriptive study, comparing two groups of women who underwent LAVH or VH in our department during a 24 months period, from January 2009 to December 2010. The two groups were compared regarding age, vaginal deliveries, previous abdominal surgery, uterine and adnexal pathology, intra-operative and post-operative complications, uterus weight, blood loss and number of days until discharge. Results: In our study 42 LAVH and 99 VH were included, with a patient mean age of 47 and 59, respectively. The most frequent indication for hysterectomy was fibroids (80%) for LAVH and POP(58.6%) for HV. In LAVH group 47.6% of patients had previous abdominal surgery, vs 28.2% in VH group. The medium operative time was 167 minutes for LAVH vs 99 minutes for HV. The intra-operative complications were one case (2%) of accidental incision of rectum in LAVH, and one bladder incision in the VH (1%). There were 3 conversions to laparotomy for difficult technique (7%) in LAVH group. There were no significant post-operative complications for LAVH. In VH group there were 2 cases of haemoperitoneum (2%) and 1 case requiring blood transfusion (1%). The mean time for discharge was 4.23 days for LAVH and 4.46 days for VH. Conclusions: In our study, the main advantage for VH was the reduced operative time. In terms of time to discharge there was no difference between the 2 groups. The main intra-operative complication of LAVH was the risk of conversion to laparotomy, but post-operatively this procedure had fewer complications than VH. In conclusion, LAVH is a safe option for women requiring hysterectomy in cases where VH is anticipated to be technically difficult.

Web-assisted tobacco intervention in Portuguese : intentions to make behavioural changes and behavioural changes

ABSTRACT - The problem of how to support “intentions to make behavioural changes” (IBC) and “behaviour changes” (BC) in smoking cessation when there is a scarcity of resources is a pressing issue in public health terms. The present research focuses on the use of information and communications technologies and their role in smoking cessation. It is developed in Portugal after the ratification of WHO Framework Convention on Tobacco Control (on 8 November 2005). The prevalence of smokers over fifteen years of age within the population stood at 20.9% (30.9% for men and 11.8% for women). While the strategy of helping people to quit smoking has been emphasised at National Health Service (NHS) level, the uptake of cessation assistance has exceeded the capacity of the service. This induced the search of new theoretical and practical venues to offer alternative options to people willing to stop smoking. Among these, the National Health Plan (NHP) of Portugal (2004-2010), identifies the use of information technologies in smoking cessation. eHealth and the importance of health literacy as a means of empowering people to make behavioural changes is recurrently considered an option worth investigating. The overall objective of this research is to understand, in the Portuguese context, the use of the Internet to help people to stop smoking. Research questions consider factors that may contribute to “intentions to make behavioural changes” (IBC) and “behavioural changes” (BC) while using a Web-Assisted Tobacco Intervention Probe (WATIP). Also consideration is given to the trade-off on the use of the Web as a tool for smoking cessation: can it reach a vast number of people for a small cost (efficiency) demonstrating to work in the domain of smoking cessation (efficacy)”? In addition to the introduction, there is a second chapter in which the use of tobacco is discussed as a public health menace. The health gains achieved by stopping smoking and the means of quitting are also examined, as is the use of the Internet in smoking cessation. Then, several research issues are introduced. These include background theory and the theoretical framework for the Sense of Coherence. The research model is also discussed. A presentation of the methods, materials and of the Web-Assisted Tobacco Intervention Probe (WATIP) follows. In chapter four the results of the use of the Web-Assisted Tobacco Intervention Probe (WATIP) are presented. This study is divided into two sections. The first describes results related to quality control in relation to the Web-Assisted Tobacco Intervention Probe (WATIP) and gives an overview of its users. Of these, 3,150 answered initial eligibility questions. In the end, 1,463 met all eligibility requirements, completed intake, decided on a day to quit smoking (Dday) and declared their “intentions to make behavioural changes” (IBC) while a second targeted group of 650 did not decide on a Dday. With two quit attempts made before joining the platform, most of the participants had experienced past failures while wanting to stop. The smoking rate averaged 21 cigarettes per day. With a mean age of 35, of the participants 55% were males. Among several other considerations, gender and the Sense of Coherence (SOC) influenced the success of participants in their IBC and endeavour to set quit dates. The results of comparing males and females showed that, for current smokers, establishing a Dday was related to gender differences, not favouring males (OR=0.76, p<0.005). Belonging to higher Socio-economic strata (SES) was associated with the intention to consider IBC (when compared to lower SES condition) (OR=1.57, p<0.001) and higher number of school years (OR=0.70, p<0.005) favoured the decision to smoking cessation. Those who demonstrated higher confidence in their likelihood of success in stopping in the shortest time had a higher rate of setting a Dday (OR=0.51, p<0.001). There were differences between groups in IBC reflecting the high and low levels of the SOC score (OR=1.43, p=0.006), as those who considered setting a Dday had higher levels of SOC. After adjusting for all variables, stages of readiness to change and SOC were kept in the model. This is the first Arm of this research where the focus is a discussion of the system’s implications for the participants’ “intentions to make behavioural changes” (IBC). Moreover, a second section of this study (second Arm) offers input collected from 77 in-depth interviews with the Web-Assisted Tobacco Intervention Probe (WATIP) users. Here, “Behaviour Change” (BC) and the usability of the platform are explored a year after IBC was declared. A percentage of 32.9% of self-reported, 12-month quitters in continuous abstinence from smoking from Dday to the 12-month follow- up point of the use of the Web-Assisted Tobacco Intervention Probe (WATIP) has been assessed. Comparing the Sense of Coherence (SOC) scores of participants by their respective means, according to the two groups, there was a significant difference in these scores of non smokers (BC) (M=144,66, SD=22,52) and Sense of Coherence (SOC) of smokers (noBC) (M=131,51, SD=21,43) p=0.014. This WATIP strategy and its contents benefit from the strengthening of the smoker’s sense of coherence (SOC), so that the person’s progress towards a life without tobacco may be experienced as comprehensible, manageable and meaningful. In this sample the sense of coherence (SOC) effect is moderate although it is associated with the day to quit smoking (Dday). Some of the limitations of this research have to do with self-selection bias, sample size (power) and self-reporting (no biochemical validation). The enrolment of participants was therefore not representative of the smoking population. It is not possible to verify the Web-Assisted Tobacco Intervention Probe (WATIP) evaluation of external validity; consequently, the results obtained cannot be applied generalized. No participation bias is provided. Another limitation of this study is the associated limitations of interviews. Interviewees’ perception that fabricating answers could benefit them more than telling the simple truth in response to questions is a risk that is not evaluated (with no external validation like measuring participants’ carbon monoxide levels). What emerges in this analysis is the relevance of the process that leads to the establishment of the quit day (Dday) to stop using tobacco. In addition, technological issues, when tailoring is the focus, are key elements for scrutiny. The high number of dropouts of users of the web platform mandates future research that should concentrate on the matters of the user-centred design of portals. The focus on gains in health through patient-centred care needs more research, so that technology usability be considered within the context of best practices in smoking cessation.