Optimization of a Novel Rectenna for RF Energy Harvesting at 2.45 GHz

In this work, the different elements of a rectenna were optimized for the energy harvesting from Wi-Fi at 2.45 GHz, using the particle swarm optimization method with real or hybrid dimensions depending on the element. The antenna was optimized in different steps and for each one the effect on its performance was determined. For the rectifier, several commercial diodes were compared for evaluating the best selection for this application. Additionally, a low pass filter and an impedance matching of L-section were implemented as coupling elements. The antenna from the novel rectenna had a gain equal to 4.42 dBi due to the incorporation of a pixeled metasurface structure in the ground layer, and a maximum conversion efficiency of 73% with the diode SMS-7630. In this sense, the optimized rectenna presented a better performance than others from the literature for RF energy harvesting at 2.45 GHz. Therefore, the proposed rectenna can be a good alternative as a power supply in nodes of wireless sensor networks with the addition of the DC–DC boost converter LTC3105.

     

Exploring New Potential Anticancer Activities of the G-Quadruplexes Formed by [(GTG2T(G3T)3] and Its Derivatives with an Abasic Site Replacing Single Thymidine

In this paper, we report our investigations on five {"type":"entrez-nucleotide","attrs":{"text":"T30175","term_id":"612273"}}T30175 analogues, prepared by replacing sequence thymidines with abasic sites (S) one at a time, in comparison to their natural counterpart in order to evaluate their antiproliferative potential and the involvement of the residues not belonging to the central core of stacked guanosines in biological activity. The collected NMR (Nuclear Magnetic Resonance), CD (Circular Dichroism), and PAGE (Polyacrylamide Gel Electrophoresis) data strongly suggest that all of them adopt G-quadruplex (G4) structures strictly similar to that of the parent aptamer with the ability to fold into a dimeric structure composed of two identical G-quadruplexes, each characterized by parallel strands, three all-anti-G-tetrads and four one-thymidine loops (one bulge and three propeller loops). Furthermore, their antiproliferative (MTT assay) and anti-motility (wound healing assay) properties against lung and colorectal cancer cells were tested. Although all of the oligodeoxynucleotides (ODNs) investigated here exhibited anti-proliferative activity, the unmodified {"type":"entrez-nucleotide","attrs":{"text":"T30175","term_id":"612273"}}T30175 aptamer showed the greatest effect on cell growth, suggesting that both its characteristic folding in dimeric form and its presence in the sequence of all thymidines are crucial elements for antiproliferative activity. This straightforward approach is suitable for understanding the critical requirements of the G-quadruplex structures that affect antiproliferative potential and suggests its application as a starting point to facilitate the reasonable development of G-quadruplexes with improved anticancer properties.     

The evaluation of online courses

Abstract Given the special characteristics of online courses, their quantitative/qualitative evaluation calls for the adoption of specific procedures to assess both the learning process and the participant performance. This paper seeks to shed light on the aspects and issues involved in the evaluation of online courses, focusing on the peculiarities that distinguish such evaluation from that of traditional distance education. Subsequently, a methodological approach will be proposed that was developed and tested during evaluation of online courses for in‐service teacher training and for training of staff in small and medium‐sized enterprises.     

H2S photodegradation by TiO2/M-MCM-41 (M = Cr or Ce): Deactivation and by-product generation under UV-A and visible light

M-MCM-41 molecular sieves (M = Ce or Cr) were prepared by a hydrothermal method and impregnated with TiO₂. The materials were characterized by XRD, N₂ adsorption–desorption, DRS and XPS. Their potential application to photooxidize H₂S in a wet gas stream was tested in a continuous flow reactor operating at a flow rate of 110 mL min⁻¹ at 50% relative humidity and using 30 ppm_v of the pollutant. The photocatalytic efficiency using UV-A and visible light was compared to the activity of TiO₂/MCM-41 without heteroatoms incorporated into the MCM-41 structure. It was found that the incorporation of Ce did not improve the performance of TiO₂/MCM-41, but Cr-containing samples presented higher initial efficiency and were able to photooxidize H₂S without formation of SO₂ as a by-product, in contrast to the other prepared samples and to Degussa P-25 TiO₂. Moreover, no other gaseous by-product was detected. The isomorphic incorporation of Cr into the structure of MCM-41 followed by TiO₂ incorporation produced photocatalysts that presented good adsorption capacity and were much more active under visible light than under UV-light. This performance represents an important advantage for solar applications. Their photoactivity depended on the concentration of chromium; the highest efficiency was attained with samples with a Si/Cr ratio of 50. Finally, deactivation was observed as a consequence of sulfate accumulation on the surface of the catalyst and reduction of Cr⁶⁺.     

Fueling Open‐Source Drug Discovery: 177 Small‐Molecule Leads against Tuberculosis

With the aim of fuelling open‐source, translational, early‐stage drug discovery activities, the results of the recently completed antimycobacterial phenotypic screening campaign against Mycobacterium bovis BCG with hit confirmation in M. tuberculosis H37Rv were made publicly accessible. A set of 177 potent non‐cytotoxic H37Rv hits was identified and will be made available to maximize the potential impact of the compounds toward a chemical genetics/proteomics exercise, while at the same time providing a plethora of potential starting points for new synthetic lead‐generation activities. Two additional drug‐discovery‐relevant datasets are included: a) a drug‐like property analysis reflecting the latest lead‐like guidelines and b) an early lead‐generation package of the most promising hits within the clusters identified.     

Performance Evaluation of FSO and MMW for the Uruguayan Weather Conditions

In this work the free space optics (FSO) and the millimeter waves (MMW) links are studied for the Uruguayan weather conditions. FSO availability is affected by fog significantly, while MMW availability is mainly affected by rains. Considering visibility and rain intensity data, these availabilities are estimated for the Uruguayan weather conditions. The results are extensible to other areas with similar weather. Finally the use of both links simultaneously, one as a backup of the other, is discussed.     

SOLAR PHOTOCATALYTIC DEGRADATION OF WATER AND AIR POLLUTANTS: CHALLENGES AND PERSPECTIVES

Solar photocatalytic oxidation processes (PCO) for degradation of water and air pollutants have recently received increasing attention. Some field-scale experiments have demonstrated the feasibility of using a semiconductor (TiO₂) in solar collectors and concentrators to completely mineralize organic contaminants in water and air. Although successful pre-industrial solar tests have been carried out, there are still discrepancies and doubt concerning process fundamentals such as the roles of active components, appropriate modelling of reaction kinetics or quantification of photoefficiency. Challenges to development are catalyst deactivation, slow kinetics, low photoefficiency and unpredictable mechanisms. The development of specific non-concentrating collectors for detoxification and the use of additives such as peroxydisulfate have made competitive use of solar PCO possible. The challenges and perspectives of solar driven PCO as illustrated in the literature and our own results in large solar field loops at the Plataforma Solar de Almeria and CIEMAT laboratories are described.     

Protein Corona Gold Nanoparticles Fingerprinting Reveals a Profile of Blood Coagulation Proteins in the Serum of HER2-Overexpressing Breast Cancer Patients

Breast cancer (BC) is a molecularly heterogeneous disease that encompasses five major molecular subtypes (luminal A (LA), luminal B HER2 negative (LB-), luminal B HER2 positive (LB+), HER2 positive (HER2+) and triple negative breast cancer (TNBC)). BC treatment mainly depends on the identification of the specific subtype. Despite the correct identification, therapies could fail in some patients. Thus, further insights into the genetic and molecular status of the different BC subtypes could be very useful to improve the response of BC patients to the range of available therapies. In this way, we used gold nanoparticles (AuNPs, 12.96 ± 0.72 nm) as a scavenging tool in combination with Sequential Window Acquisition of All Theoretical Mass Spectra (SWATH-MS) to quantitatively analyze the serum proteome alterations in the different breast cancer intrinsic subtypes. The differentially regulated proteins specific of each subtype were further analyzed with the bioinformatic tools STRING and PANTHER to identify the major molecular function, biological processes, cellular origin, protein class and biological pathways altered due to the heterogeneity in proteome of the different BC subtypes. Importantly, a profile of blood coagulation proteins was identified in the serum of HER2-overexpressing BC patients.     

Substituted Aminoacetamides as Novel Leads for Malaria Treatment

Herein we describe the optimization of a phenotypic hit against Plasmodium falciparum based on an aminoacetamide scaffold. This led to N-(3-chloro-4-fluorophenyl)-2-methyl-2-{[4-methyl-3-(morpholinosulfonyl)phenyl]amino}propanamide (compound 28 ) with low-nanomolar activity against the intraerythrocytic stages of the malaria parasite, and which was found to be inactive in a mammalian cell counter-screen up to 25 μm . Inhibition of gametes in the dual gamete activation assay suggests that this family of compounds may also have transmission blocking capabilities. Whilst we were unable to optimize the aqueous solubility and microsomal stability to a point at which the aminoacetamides would be suitable for in vivo pharmacokinetic and efficacy studies, compound 28 displayed excellent antimalarial potency and selectivity; it could therefore serve as a suitable chemical tool for drug target identification.