Comparative Sorption of Methylene Blue onto Hydrophobic Clays

Chemical modifications of clay to remove methylene blue (MB) from aqueous solutions at room temperature were compared. Natural bentonite (NC) was modified by cation exchange with hexadecyltrimethylammonium chloride (HC), bencyltriethylammonium chloride (BC), and tetramethylammonium chloride (TC) to reverse the surface polarity of the hydrophilic bentonite. The adsorption of MB was studied and fitted by the adsorption theories of Langmuir, Freundlich, Dubinin-Radushkevich, and Temkin. Equilibrium parameters were calculated, indicating that chemical modification did not improve the adsorption, due to the electrostatic adsorption mechanism. Specific surface area was determined, reporting the following trend: NC \u3e TC \u3e BC \u3e HC. Isotherms show that TC is the best modified clay for the adsorption of MB with a capacity of 217 mg/g. Adsorbents were characterized by SEM and the determination of their point zero charge, indicating a charge reversal at pH 9.5 and a heterogeneous surface that is optimum for the adsorption of molecules and ions onto their surfaces

Ordinal regression methods: survey and experimental study

Abstract—Ordinal regression problems are those machine learning problems where the objective is to classify patterns using a categorical scale which shows a natural order between the labels. Many real-world applications present this labelling structure and that has increased the number of methods and algorithms developed over the last years in this field. Although ordinal regression can be faced using standard nominal classification techniques, there are several algorithms which can specifically benefit from the ordering information. Therefore, this paper is aimed at reviewing the state of the art on these techniques and proposing a taxonomy based on how the models are constructed to take the order into account. Furthermore, a thorough experimental study is proposed to check if the use of the order information improves the performance of the models obtained, considering some of the approaches within the taxonomy. The results confirm that ordering information benefits ordinal models improving their accuracy and the closeness of the predictions to actual targets in the ordinal scal

Electronic properties of Naphthalimide derivatives

Molecular systems have proven to be efficient active materials in electronics, making then suitable substitutes of the inorganic semiconductors used nowadays in electronic devices. For this reason, organic electronics has emerged as a research field with great potential and interest. In this project we have studied, both experimentally and theoretically, two ladder-type compounds functionalized with naphthalimides (Figure 1). The two molecular systems have been implemented in organic field effect transistors (OFETs), to assess their potential as active materials in organic electronics. Both compounds show p-type type mobility, moreover, NDI-TP-Ph-TP material also displays low n-type mobility, presenting a certain ambipolar character. The nature and stability of the charged species involved in the charge transport process have also been studied by spectroelectrochemical experiments.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Electronic Properties of Naphthalimide-based Ladder-type Systems

The tuneable electronic and structural properties of organic semiconductors together with their flexibility, light weight, high solution processing and low costs in comparison with inorganic semiconductors are some of the key points for the current interest in the development of π-conjugated small molecules and polymers for a variety of applications. In this project, a combined experimental and theoretical study of two ladder-type compounds functionalized with naphthalimides1 (Figure 1) is performed with the aim to explore the impact of the structure on the optical and charge-transport properties. Compound NDI-TP-Ph-TP has an imidazole group as a spacer ring and NIP-TP-Ph-TP has a spacer ring of pyrazine type. The two molecular systems have been implemented in organic field effect transistors2 (OFETs), to assess their potential as active materials in organic electronics. Both compounds show p-type mobility, moreover, NDI-TP-Ph-TP material also displays low n-type mobility, presenting a certain ambipolar character.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

The Poor Survival among Pulmonary Tuberculosis Patients in Chiapas, Mexico: The Case of Los Altos Region

Objective. To analyse survival in patients with pulmonary tuberculosis (PTB) and factors associated with such survival. Design. Study of a cohort of patients aged over 14 years diagnosed with PTB from January 1, 1998 to July 31, 2005. During 2004–2006 a home visit was made to each patient and, during 2008-2009, they were visited again. During these visits a follow-up interview was administered; when the patient had died, a verbal autopsy was conducted with family members. Statistical analysis consisted of survival tests, Kaplan-Meier log-rank test and Cox regression. Results. Of 305 studied patients, 68 had died due to PTB by the time of the first evaluation, 237 were followed-up for a second evaluation, and 10 of them had died of PTB. According to the Cox regression, age (over 45 years) and treatment duration (under six months) were associated with a poorer survival. When treatment duration was excluded, the association between poorer survival with age persisted, whereas with having been treated via DOTS strategy, was barely significant. Conclusions. In the studied area it is necessary that patients receive a complete treatment scheme, and to give priority to patients aged over 45 years

Fractura de Maisonneuve abierta: una entidad infrecuente: a propósito de un caso y revisión de la literatura

Introducción. La fractura de Maisonneuve representa aproximadamente el 5% de todas las fracturas de tobillo tratadas quirúrgicamente. Debido a que suelen ser fracturas cerradas, presentamos el caso de una fractura de Maisonneuve abierta por su infrecuencia. Caso Clínico. Varón de 63 años que acudió a urgencias tras traumatismo de miembro inferior derecho. En la exploración se evidenció una solución de continuidad de la piel en cara medial de tobillo con exposición de maléolo tibial. La radiografía mostró una apertura de la mortaja tibio-peronea y una fractura espiroidea en el tercio proximal del peroné. Se realizó osteosíntesis con dos tornillos canulados. Tras 12 meses de seguimiento, el paciente presenta una puntuación media de 86,8 puntos en la escala AOFAS. Conclusión. Ante una luxación abierta de tobillo, debe sospecharse una fractura de Maisonneuve aunque sea poco frecuente, siendo la osteosíntesis una opción terapéutica eficaz en este tipo de fracturas.Introduction. Maisonneuve fracture represents approximately 5% of all surgically treated ankle fractures. Because these fractures are usually closed, we present the case of a Maisonneuve open fracture owing to its rarity. Case report. A 63-year-old man presented to his emergency department after a right leg trauma. Physical examination revealed a skin solution of continuity above the ankle joint, with a medial tibial malleolus exposure. The radiography showed an opening of the tibiofibular mortise and a spiral fracture of the proximal third of the fibula. Fixation with two cannulated screws was performed. After 12 months of follow up, the patient has an average score of 86.8 points on the AOFAS scale. Conclusion. In the face of an open ankle dislocation, a Maisonneuve open fracture should be suspected in spite of its infrequency, being the osteosynthesis an effective therapeutic option in this type of fracture

A LoRaWAN testbed design for supporting critical situations: prototype and evaluation

The Internet of Things is one of the hottest topics in communications today, with current revenues of $151B, around 7 billion connected devices, and an unprecedented growth expected for next years. A massive number of sensors and actuators are expected to emerge, requiring new wireless technologies that can extend their battery life and can cover large areas. LoRaWAN is one of the most outstanding technologies which fulfill these demands, attracting the attention of both academia and industry. In this paper, the design of a LoRaWAN testbed to support critical situations, such as emergency scenarios or natural disasters, is proposed. This self-healing LoRaWAN network architecture will provide resilience when part of the equipment in the core network may become faulty. This resilience is achieved by virtualizing and properly orchestrating the different network entities. Different options have been designed and implemented as real prototypes. Based on our performance evaluation, we claim that the usage of microservice orchestration with several replicas of the LoRaWAN network entities and a load balancer produces an almost seamless recovery which makes it a proper solution to recover after a system crash caused by any catastrophic event.Postprint (published version

Fabrication and characterization of superficially modified porous dental implants

Stress-shielding and loosening compromise the success of dental implants under real-life service conditions. This work evaluates the mechanical behavior of superficially modified porous titanium dental implants fabricated by two different routes: conventional powder metallurgy and space-holder techniques. A novel, feasible and repetitive protocol of micro-milling of the implant thread (before sintering), as well as surface modification treatments (after sintering) are also implemented. The discussion is conducted in terms of the influence of porosity and surface roughness on the stiffness and yield strength of implants. The macro-pores concentrate stress locally, and, at the same time, they could act as a barrier to the propagation of micro-cracks. Higher rugosity was observed for virgin implants obtained with spacer particles. Concerning superficially modified implants, while bioglass 1393 was the most effective coating due to its greater infiltration and adhesion capacity, chemical etching could improve osteoblast adhesion because modifies the roughness of the implant surface.Ministry of Science and Innovation of Spain PID2019-109371GB-I00Junta de Andalucía–FEDER (Spain) US-125977

Tunable electroactive oligothiophene-naphthalimide semiconductors via end-capped engineering: cumulative effects beyond the linker

Aiming to obtain novel functional semiconducting materials for their use in organic electronics, the combination of strong donor moieties with electron-withdrawing units is one of the most useful strategies to obtain ambipolar semiconductors with tunable properties. Nowadays most of the efforts headed to efficient materials are based on small changes in the alkyl pendant chains or by replacing single atoms. However, a precise design of new functional materials is still challenging. For this reason, in this work we present a new synthetic approach for achieving redox amphoteric organic semiconductors by tuning their opto-electrochemical properties via rational chemical modifications. All these materials present low-lying LUMO levels, lower than −4.00 eV with broad absorption up to 800 nm in the UV-Vis-NIR spectra. In addition, they have been characterized by DFT, absorption and Raman vibrational spectroscopies, while their charge stabilization abilities are studied by means of spectroelectrochemical techniques. The results point out to a quite complex electronic scenario that goes beyond the expected cumulative effects of the independent molecular units constituting the final molecular assembly.Funding for open access charge: Universidad de Málaga / CBU