Secret sharing-based authentication and key agreement protocol for machine-type communications

[EN] One of the main challenges for the development of the Internet of Things is the authentication of large numbers of devices/sensors, commonly served by massive machine-type communications, which jointly with long-term evolution has been considered one of the main foundations for the continued growth of Internet of Things connectivity and an important issue to be treated in the development of 5G networks. This article describes some protocols for the group-based authentication of devices/sensors in Internet of Things and presents a new group authentication protocol based on Shamir's secret and Lagrange interpolation formula. The new protocol protects privacy, avoids unauthorized access to information, and assists in the prevention of attacks, as replay, distributed denial of service, and man-in-the-middle. A security analysis and comparisons among the 3GPP evolved packet system authentication and key agreement standard protocol and other recent group authentication protocols were performed toward proving the efficiency of the proposed protocol. The comparisons regard security properties and computational and communication costs. The safety of the protocol was formally verified through simulations conducted by automated validation of internet security protocols and applications.Lopes, APG.; Hilgert, LO.; Gondim, PRL.; Lloret, J. (2019). Secret sharing-based authentication and key agreement protocol for machine-type communications. International Journal of Distributed Sensor Networks (Online). 15(4):1-21. https://doi.org/10.1177/1550147719841003S12115

Avaliação não invasiva da pressão venosa central por ecocardiografia em cuidados intensivos : particularidades nos doentes com dilatação do ventrículo direito e exacerbação de doença pulmonar crónica

Copyright © 2006 Sociedade Portuguesa de Pneumologia/SPP. Published by Elsevier España, S.L.Objectives: To determine the possibility of non-invasive estimation of central venous pressure (CVP) through inferior vena cava (IVC) analysis, using transthoracic echocardiography (TTE). Design: A prospective 3-year study. Setting: A 16-bed medical/surgical Intensive Care Unit (ICU). Methods: Patients admitted to the ICU were enrolled. CVP measurement and TTE (determining cardiac chambers dimension and left ventricular shortening fraction) with IVC analysis (maximum dimension and IVC index) were performed simultaneously. Parametric and non-parametric statistical analysis was performed to establish correlations between variables. Results: 560 patients were admitted to the study, including 477 in whom IVC was analysed, aging 62.2 ± 17.3 years, a mean ICU stay 11.9 ± 18.7 days, a APACHE II score 23.9 ± 8.9 and a SAPS II score 55.7 ± 20.4. Through linear regression analysis CVP was influenced by IVC index (p=0.001), IVC maximum dimension (p=0.013) and presence of mechanical ventilation (p=0.002). A statistically significant correlation was found between the following parameters: an IVC index13mmHg; an IVC index and a CVP 26%-50%; an IVC index >51% and CVP 20mm and a CVP >13mmHg; an IVC maximum dimension 7mmHg was observed, and in patients with chronic respiratory failure (who presented a high prevalence of right ventricular enlargement) a lack of agreement between IVC index >50% and CVP 13mmHg; índice da VCI entre 26 e 50% e PVC entre 8 e 12mmHg; índice da VCI> 51% e PVC> 7mmHg; dimensão máxima da VCI> 20mmHg e PVC> 13 mmHg; dimensão máxima da VCI> 10mm e PVC> 7mmHg. Nos doentes com dilatação do ventrículo direito (VD) observou-se uma relação mais fraca entre a PVC 50%. A dimensão máxima da VCI, mas não o seu índice, correlacionou-se com a dilatação do VD e AD. Conclusões: A análise da VCI por ETT revelou-se útil na avaliação qualitativa da PVC em doentes admitidos numa UCIP. Em doentes com dilatação do VD e admitidos por exacerbação de doença pulmonar crónica, os métodos avaliados não foram fidedignos para valores baixos de PVC. A dilatação da VCI traduz melhor a cronicidade da doença, enquanto o índice da VCI reflecte melhor o estado de volemia.info:eu-repo/semantics/publishedVersio

Role of protein kinase R in the killing of Leishmania major by macrophages in response to neutrophil elastase and TLR4 via TNF and IFN

In cutaneous leishmaniasis, Leishmania amazonensis activates macrophage double-stranded, RNA-activated protein kinase R (PKR) to promote parasite growth. In our study, Leishmania major grew normally in RAW cells, RAW-expressing dominant-negative PKR (PKR-DN) cells, and macrophages of PKR-knockout mice, revealing that PKR is dispensable for L. major growth in macrophages. PKR activation in infected macrophages with poly I:C resulted in parasite death. Fifty percent of L. major-knockout lines for the ecotin-like serine peptidase inhibitor (ISP2; Δisp2/isp3), an inhibitor of neutrophil elastase (NE), died in RAW cells or macrophages from 129Sv mice, as a result of PKR activation. Inhibition of PKR or NE or neutralization of Toll-like receptor 4 or 2(TLR4 or TLR2) prevented the death of Δisp2/isp3. Δisp2/isp3 grew normally in RAW-PKR-DN cells or macrophages from 129Sv pkr−/−, tlr2−/−, trif−/−, and myd88−/− mice, associating NE activity, PKR, and TLR responses with parasite death. Δisp2/isp3 increased the expression of mRNA for TNF-α by 2-fold and of interferon β (IFNβ) in a PKR-dependent manner. Antibodies to TNF-α reversed the 95% killing by Δisp2/isp3, whereas they grew normally in macrophages from IFN receptor–knockout mice. We propose that ISP2 prevents the activation of PKR via an NE-TLR4-TLR2 axis to control innate responses that contribute to the killing of L. major.—Faria, M. S., Calegari-Silva, T. C., de Carvalho Vivarini, A., Mottram, J. C., Lopes, U. G., Lima, A. P. C. A. Role of protein kinase R in the killing of Leishmania major by macrophages in response to neutrophil elastase and TLR4 via TNFα and IFNβ

Evaluation of efficacy and safety of itraconazole oral solution for the treatment of oropharyngeal candidiasis in AIDS patients

This study was a non-comparative multicenter clinical trial to evaluate the efficacy and tolerability of itraconazole oral solution 200 mg/day (100 mg twice a day in the fasting state) for the treatment of oropharyngeal candidiasis in AIDS patients. We included 50 patients who were treated and followed for up to 3 weeks after ending therapy in the analysis. Mycological cures at the end of therapy occurred in 20/50 patients (40%), but colonization by Candida sp. was recorded in 42/50 (84%) by the end of follow-up. A high rate of clinical response was observed in 46/50 (92%), and the response was sustained for up to 21 days after stopping therapy in 24/46 patients (52%). Clinical relapses were documented among 22 patients, but all causative fungal organisms associated with a relapse were susceptible to itraconazole. There were many patients with persistence or recurrence of Candida, but without mucositis. Relapse of Candida mucositis was significantly related to low levels of CD4 lymphocytes exhibited by symptomatic patients. The drug was well tolerated by all but 1 patient. We conclude that itraconazole oral solution (100 mg bid for 7-14 days) is a well tolerated and effective treatment for suppressing the symptoms of oropharyngeal candidiasis in AIDS patients. Patients with severe immunosuppression may relapse and require frequent cycles of treatment or longterm suppressive therapy.Federal University of Paraná Clinical HospitalAliança HospitalFederal University of São Paulo DIPA Special Mycology LaboratoryJanssen-Cilag Farmacêutica do BrasilUNIFESP, DIPA Special Mycology LaboratorySciEL

Ocorrência de microrganismos em ração animal preparada artesanalmente a partir do licuri (Syagrus coronata)

During the dry season in the Brazilian Caatinga region when sources of food are very scanty, many farmers use alternative forms to feed their livestock. One of these alternative forms is the feed made with the fruits of licuri palm (Syagrus coronata), produced by hand by farmers or associations without any microbial control, until the present study. The control of the microbial growth in feeds, used in the animal feeding, aims mainly to decrease risks in the health of the meat consumers, by increasing sanitation and hygienic quality of the feed. Therefore, this work aimed to carry out a microbiological analysis (presence of salmonela, counting of mesophilic microorganisms, and contamination by filamentous fungi and yeasts) of the ration of licuri prepared by an association of agricultural producers from the town of Valente, Bahia. The microbiological quality in the analyzed samples was good in accordance with standardized microbiological norms from The Netherlands, without salmonela, low counting of mesophilic microorganisms, and low contamination by filamentous fungi and yeasts in all analyses that were conducted. This is the first work published that describes the microbiological quality of the licuri feed produced by hand.Durante a época de seca na região da Caatinga brasileira, quando a oferta de alimento é escassa, muitos produtores utilizam formas alternativas para alimentar seu rebanho. Uma delas é a ração à base de frutos de licurizeiro (Syagrus coronata), processada artesanalmente pelos próprios produtores rurais ou associações, sem nenhum controle microbiano, feito até o presente estudo. O controle do desenvolvimento microbiano em rações utilizadas na alimentação animal visa principalmente diminuir os riscos à saúde dos consumidores de carnes, melhorando a qualidade higiênica e sanitária da ração. Por isso, este trabalho objetivou a análise microbiológica (presença de salmonelas, contagem de microsganismos mesófilos e contaminação por fungos e leveduras) da ração à base de licuri preparada por uma associação de produtores rurais do município de Valente, Bahia. A qualidade microbiológica encontrada nas amostras analisadas foi boa quando comparada com as normas microbiológicas para ração padronizadas da Holanda, ocorrendo ausência de salmonelas, baixa contagem de microrganismos mesófilos e baixa contaminação por fungos filamentosos e leveduras em todas as análises realizadas. Este é o primeiro trabalho na literatura que descreve a qualidade microbiológica da ração à base de licuri produzida artesanalmente

Methylene blue associated with maghemite nanoparticles has antitumor activity in breast and ovarian carcinoma cell lines

Background: Cancer constitutes group of diseases responsible for the second largest cause of global death, and it is currently considered one of the main public health concerns nowadays. Early diagnosis associated with the best choice of therapeutic strategy, is essential to achieve success in cancer treatment. In women, breast cancer is the second most common type, whereas ovarian cancer has the highest lethality when compared to other neoplasms of the female genital system. The present work, therefore, proposes the association of methylene blue with citrate-coated maghemite nanoparticles (MAGCIT–MB) as a nanocomplex for the treatment of breast and ovarian cancer. Results: In vitro studies showed that T-47D and A2780 cancer cell lines underwent a significant reduction in cell viability after treatment with MAGCIT–MB, an event not observed in non-tumor (HNTMC and HUVEC) cells and MDA-MB-231, a triple-negative breast cancer cell line. Flow cytometry experiments suggest that the main mechanism of endocytosis involved in the interiorization of MAGCIT–MB is the clathrin pathway, whereas both late apoptosis and necrosis are the main types of cell death caused by the nanocomplex. Scanning electron microscopy and light microscopy reveal significant changes in the cell morphology. Quantification of reactive oxygen species confirmed the MAGCIT–MB cytotoxic mechanism and its importance for the treatment of tumor cells. The lower cytotoxicity of individual solution of maghemite nanoparticles with citrate (MAGCIT) and free methylene blue (MB) shows that their association in the nanocomplex is responsible for its enhanced therapeutic potential in the treatment of breast and ovarian cancer in vitro. Conclusions: Treatment with MAGCIT–MB induces the death of cancer cells but not normal cells. These results highlight the importance of the maghemite core for drug delivery and for increasing methylene blue activity, aiming at the treatment of breast and ovarian cancer

Starch-based films doped with porphyrinoid photosensitizers for active skin wound healing

Starch is a biodegradable and biocompatible carbohydrate that, when combined with bioactive molecules, can be processed as biomimetic platforms with enhanced performance, allowing its use as active wound dressing materials. Porphyrinoid photosensitizers can tune the physicochemical/functional profile of biomacromolecules, allowing their use in anti-infective strategies. In this work, the feasibility of using the cationic 5,10,15,20-tetrakis(1-methylpyridinium-4-yl)porphyrin tetraiodide (TMPyP) to enhance the physicochemical, mechanical, antimicrobial performance, and wound healing ability of casted starch-based films was studied. TMPyP conferred a reddish coloration to the films, maintaining their pristine transparency. It increased by 87 % the films hydrophobicity and, depending on the TMPyP used, conferred mobility to the starch polymeric chains. Starch/TMPyP-based films effectively photoinactivated Escherichia coli (>99.99 %) and favored the wound healing process, even in the absence of light. Therefore, the incorporation of TMPyP into starch-based formulations revealed to be a promising strategy to tune the films compaction degree while giving rise to water tolerant and photosensitive biomaterials that can act as multitarget antimicrobial medical dressings and glycocarriers of active compounds relevant for effective skin wound healing.The authors thank to University of Aveiro and FCT/MCT for the financial support provided to CICECO (UIDB/50011/2020, UIDP/50011/2020, LA/P/0006/2020), LAQV-REQUIMTE (UIDB/50006/2020 and UIDP/50006/2020), CESAM (UIDP/50017/2020, UIDB/50017/2020, LA/P/0094/2020), CEB (UIDB/04469/2020), LABBELS (LA/P/0029/2020), and to projects PORP2PS (EXPL/QUI-QOR/0586/2021) and PREVINE (FCT-PTDC/ASP-PES/29576/2017), through national funds (OE) and where applicable co-financed by the FEDER - Operational Thematic Program for Competitiveness and Internationalization - COMPETE 2020, within the PT2020 Partnership Agreement. Thanks are also due to the Portuguese NMR and Mass Networks. FCT also funded ASMJ PhD grant (2021.06854.BD), Investigator FCT program (PF, IF/00300/2015), and the Scientific Employment Stimulus program (IG, CEECIND/00430/2017; AR, 2021.02803.CEECIND). NMMM thanks FCT for funding through program DL 57/2016 (CDL-CTTRI-048-88-ARH/2018). The authors also acknowledge to POTATOPLASTIC project (POCI-01-0247-FEDER-017938), financed by FEDER through POCI, to Isolago – Indústria de Plásticos, S. A., the project leader, and to A Saloinha, Lda. company for providing the starch-rich potato washing slurries.info:eu-repo/semantics/publishedVersio

Exploring and developing a shared understanding of the issues surrounding engineering mathematics

Abstract: - Although Mathematics is a pillar which many of the subjects of any Engineering degree are based on, and in spite of being used as a tool in almost all of such subjects, it is sometimes difficult for students to assimilate the mathematical concepts. Since this relationship between Engineering and Mathematics is unavoidable, a consortium of universities from different countries is working on a project, EngiMath, to, on the one hand, make it easier for teachers to teach Mathematics in the first years of Engineering degrees; and, on the other hand, to promote study from a “student-centric” point of view. As a previous step to the development of educational material that fulfills these purposes, a study of the students' feelings about Mathematics and their experience in studying them has been carried out.info:eu-repo/semantics/publishedVersio

Diversity and patterns of marine non-native species in the archipelagos of Macaronesia

Tiago Marques and Carolina Marques thank partial support by CEAUL (funded by FCT through the project UIDB/00006/2020).Aims The present study is the first attempt to grasp the scale and richness of marine biological invasions in Macaronesia. We pioneered a comprehensive non-native species (NNS), inventory in the region to determine their diversity patterns and native distribution origins. NNS were defined here as the result of both introductions and range expansions. We also used statistical modelling to examine relationships among NNS richness, anthropogenic activities, demographic and geographical variables across Macaronesia. Location Macaronesia. Methods A comprehensive literature search was conducted for marine NNS records in Macaronesia, registering the first record's location and year from 1884 to 2020. We used univariate and multivariate analyses to evaluate differences and similarities in community composition. By applying a Generalized Linear Model (GLM), we tested hypotheses regarding NNS richness as a function of anthropogenic activities, demographic and geographical variables. Results A total of 144 marine non-native species (NNS) were recorded for the whole of Macaronesia. The highest NNS richness was registered in the Canary Islands (76 NNS), followed by the Azores (66 NNS), Madeira (59 NNS) and finally Cabo Verde (18 NNS). Some differences amongst archipelagos were observed, such as the high number of non-native macroalgae in the Azores, fishes in the Canary Islands and tunicates in Cabo Verde. Overall, macroalgae, tunicates and bryozoans were the predominant taxonomic groups in the Macaronesian archipelagos. Madeira and Canary Islands were the archipelagos with more similarity in marine NNS, and Cabo Verde the most divergent. Finally, GLM suggested that non-native richness patterns across Macaronesia were dependent on the considered archipelago and strongly affected by (1) minimum distance to the mainland, (2) the total number of ports and marinas and (3) total marinas area (km2). Conclusions The model results and NNS listing in the present study will likely raise the awareness and response regarding marine NNS in the whole Macaronesia region, serving as a baseline for future research as well as implementing and enforcing regulations related to the introduction of marine NNS in oceanic islands.Publisher PDFPeer reviewe