Flow Cytometry: From Experimental Design to Its Application in the Diagnosis and Monitoring of Respiratory Diseases

Recent advances in the field of flow cytometry (FCM) have highlighted the importance of incorporating it as a basic analysis tool in laboratories. FCM not only allows the identification of cell subpopulations by detecting the expression of molecules in the cell membrane or cytoplasm, but it can also quantify and identify soluble molecules. The proper functioning of the FCM requires six fundamental systems, from those related to the transport of events to the systems dedicated to the analysis of information. In this review, we have identified the main considerations that every FCM user must know for an optimal antibody panel design, the quality systems that must govern the FCM protocols to guarantee reproducible results in research or clinical laboratories. Finally, we have introduced the current evidence that highlights the relevance of FCM in the investigation and clinical diagnosis of respiratory diseases, establishing important advances in the basic and clinical study of diseases as old as Tuberculosis along with the recent proposals for the monitoring and classification of patients infected with the new SARS-CoV2 virus.     

Modeling segregation of polydisperse granular materials in developing and transient free-surface flows

Predicting segregation and mixing of polydisperse granular materials in industrial processes remains a challenging problem. Here, we extend the application of a general predictive continuum model that captures the effects of segregation, diffusion, and advection in two ways. First, we consider polydisperse segregating flow in developing steady segregation and in developing unsteady segregation. In both cases, several terms in the model that were zero in the previously examined case of fully developed streamwise-periodic steady segregation in a chute are now non-zero, which makes application of the model substantially more challenging. Second, we apply the polydisperse approach to density polydisperse materials with the same particle size. Predictions of the model agree quantitatively with experimentally validated discrete element method (DEM) simulations of both size polydisperse and density polydisperse mixtures having uniform, triangular, and log-normal distributions. © 2018 American Institute of Chemical Engineers AIChE J, 65: 882–893, 2019     

Secondary Metabolites in Ramalina terebrata Detected by UHPLC/ESI/MS/MS and Identification of Parietin as Tau Protein Inhibitor

Liquid chromatography coupled with mass spectrometry is an outstanding methodology for fast analysis of phenolic compounds in biological samples. Twenty two compounds were quickly and accurately identified in the methanolic extract of the Antarctic lichen Ramalina terebrata for the first time using ultra high pressure liquid chromatography coupled with photodiode array detector and high resolution mass spectrometry (UHPLC-PDA-Q/Orbitrap/MS/MS). In addition, the extract and the four compounds isolated from this species were tested for the inhibitory activity of tau protein aggregation, which is a protein involved in Alzheimer’s disease (AD). All compounds showed null activity with the exception of parietin, which it was able to inhibit aggregation process of tau in a concentration range between 3 µg/mL (10 µM) to 28 µg/mL (100 µM). In addition, we show how parietin interact with tau ³⁰⁶VQIVYK³¹¹ hexapeptide inside of the microtubule binding domain (4R) with the help of molecular docking experiments. Finally, the constituents present in the methanolic extract could possibly contribute to the established anti-aggregation activity for this extract and this in-depth analysis of the chemical composition of R. terebrata could guide further research into its medicinal properties and potential uses.     

Nanoparticles of 4,7-dichloro-2-quinolinemethylacrylate-based copolymers and their potential cytotoxic activity on human breast carcinoma cells

In this article, an improved synthesis strategy of the potent anticancer compound 4,7-dichloro-2-quinolinemethanol (QM) and its acrylate ester 4,7-dichloro-2-quinolinemethylacrylate (AQM) are described. AQM is copolymerized using free-radical polymerization with N-vinyl-2-pyrrolidone (VP) and the copolymers obtained from different molar ratios of monomers are subjected to nanoprecipitation to produce suspensions of nanoparticles (NPs) in phosphate buffered saline (PBS). The smallest and stable NPs are prepared with the AQM-VP copolymers 45:55 and 40:60 (118.9 and 128.7 nm in diameter, respectively) at 1 mg mL⁻¹, and along with AQM and QM, are evaluated for their cytotoxic activity on MDA-MB-453 breast carcinoma cells using MTT bioassay. AQM and QM are highly cytotoxic (IC₅₀: 19 and 41 μM, respectively); however, the NPs are not cytotoxic in the range of the assayed concentrations. These results contribute to the search for new polymeric NPs with potential application as QM delivery systems for the treatment of cancer or other diseases treatable with QM. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47545.     

Removal of molybdate and vanadate ions by a copolymer adsorbent in a ultrafiltration system

In this investigation, the removal of Mo and V oxyanions was carried out using the polymer-assisted ultrafiltration technique with a poly(acrylamide-co-diallyldimethylammonium chloride) [P(AAm-DDACl)]. As a result, 100% of the Mo and 80% of the V were removed at pH 9 with a polymer:metal molar ratio of 10:1 and an optimal metal concentration of 60 mg L⁻¹. The presence of competitive ions such as phosphate, sulfate, and chloride affected the retention of Mo, decreasing its retention to 60% in all cases. For the V, all competitive ions behaved in a similar way, producing approximately 50% metal removal. The permeate flux was kept almost constant for all solutions (40 to 80 L hm⁻²), which indicates that the optimal retention conditions are stable over time. In addition, the characterization of the P(AAm-DDACl) was carried out using infrared spectroscopy analysis (FTIR), and the morphology of the membrane before and after use was analyzed using scanning electron microscopy, which showed significant changes in its morphology. The energy-dispersive X-ray spectroscopy analysis indicates the presence of Mo and P(AAm-DDACl) in the membrane after use. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 48184.     

Internet in teachers' professional practice outside the classroom: Examining supportive and management uses in primary and secondary schools

In recent years there has been widespread interest in the implementation of information and communication technologies (ICT) in schools. While most studies primarily focus on the use of ICT in teaching and learning, little attention has been given to their incorporation as a professional tool outside the classroom. Using a digital inequality approach, the aim of this paper is to develop and test a model of the factors that affect teachers' professional use of ICT, particularly the Internet, in primary and secondary schools. One thousand four hundred and five (1405) teachers from a representative sample of 536 primary and 273 secondary schools in Spain were surveyed. The dependent variables include attitudes towards the professional use of ICT and the use of the Internet in professional practice. The explanatory variables are the socio-demographics, school-level information, frequency of Internet access within and outside the school, educational ICT training, digital literacy, and organisational development. Controlling for socio-demographics and school-level information, multiple regression analyses are used to make inferential judgements and test the separate effects of the independent variables. Findings suggest that technological factors and organisational practices are important predictors of ICT appropriation for professional purposes.     

Global robust stabilization of nonlinear systems subject to input constraints

Our main purpose in this paper is to further address the global stabilization problem for affine systems by means of bounded feedback control functions, taking into account a large class of control value sets: p, r ‐weighted balls ??^m _r (p), with 1<p?∞, defined via p, r ‐weighted gauge functions. Observe that p=∞ is allowed, so that m‐dimensional r ‐hyperboxes ??^m _r (∞)?[?r₁^?,r₁⁺]×???×[?r_m^?,r_m⁺], r_j^±>0 are also considered. Working along the line of Artstein–Sontag's approach, we construct an explicit formula for a one‐parameterized family of continuous feedback controls taking values in ?? _r ^m(p) that globally asymptotically stabilize an affine system, provided an appropriate control Lyapunov function is known. The designed family of controls is suboptimal with respect to the robust stability margin for uncertain systems. The problem of achieving disturbance attenuation for persistent disturbances is also considered. Copyright © 2002 John Wiley & Sons, Ltd.     

A framework for avoiding steganography usage over HTTP

Steganographic techniques allow users to covertly transmit information, hiding the existence of the communication itself. These can be used in several scenarios ranging from evading censorship to discreetly extracting sensitive information from an organization. In this paper, we consider the problem of using steganography through a widely used network protocol (i.e. HTTP). We analyze the steganographic possibilities of HTTP, and propose an active warden model to hinder the usage of covert communication channels. Our framework is meant to be useful in many scenarios. It could be employed to ensure that malicious insiders are not able to use steganography to leak information outside an organization. Furthermore, our model could be used by web servers administrators to ensure that their services are not being abused, for example, as anonymous steganographic mailboxes. Our experiments show that steganographic contents can be successfully eliminated, but that dealing with high payload carriers such as large images may introduce notable delays in the communication process.     

LAMED — A PRNG for EPC Class-1 Generation-2 RFID specification

RFID is a relatively heterogenous radio technology, where it is necessary to put an extra effort on security and privacy-related issues. As early as 2004, some authors suggested the use of a PRNG for increasing security. This was later questioned because many thought a PRNG implementation may go well beyond the very limited computational capabilities of low-cost RFID tags. However, its use has been ratified by EPCGlobal (EPC Class-1 Generation-2) and ISO (ISO/IEC 18000-6C). This motivates our proposal of a new PRNG, named LAMED, which is compliant with the standards and successfully passes several batteries of very demanding randomness tests (ENT, DIEHARD, NIST, and SEXTON). A study of its hardware complexity shows that LAMED can be implemented with slightly less than 1.6 K gates, and that pseudo-random numbers can be generated each 1.8 ms. So we can affirm this is a realist proposal both conforming with the EPC-G1C2 standard, and suitable for low-cost RFID tags.