3D printed bilayer tablet with dual controlled drug release for tuberculosis treatment

In this study Fusion Deposition Modelling (FDM) was employed to design and fabricate a bilayer tablet consisting of isoniazid (INZ) and rifampicin (RFC) for the treatment of tuberculosis. INZ was formulated in hydroxypropyl cellulose (HPC) matrix to allow drug release in the stomach (acidic conditions) and RFC was formulated in hypromellose acetate succinate (HPMC – AS) matrix to allow drug release in the upper intestine (alkaline conditions). This design may offer a better clinical efficacy by minimizing the degradation of RFC in the acidic condition and potentially avoid drug-drug interaction. The bilayer tablet was prepared by fabricating drug containing filaments using hot melt extrusion (HME) coupled with the 3D printing. The HME and 3D printing processes were optimized to avoid drug degradation and assure consistent deposition of drug-containing layers in the tablet. The invitro drug release rate was optimized by varying drug loading, infilling density, and covering layers. Greater than 80% of INZ was released in 45 mins at pH 1.2 and approximately 76% of RFC was releases in 45 mins after the dissolution medium was changed to pH 7.4. The work illustrated the potential application of FDM technology in the development of oral fixed dose combination for personalized clinical treatment

Contributions of mean and shape of blood pressure distribution to worldwide trends and variations in raised blood pressure: A pooled analysis of 1018 population-based measurement studies with 88.6 million participants

© The Author(s) 2018. Background: Change in the prevalence of raised blood pressure could be due to both shifts in the entire distribution of blood pressure (representing the combined effects of public health interventions and secular trends) and changes in its high-blood-pressure tail (representing successful clinical interventions to control blood pressure in the hypertensive population). Our aim was to quantify the contributions of these two phenomena to the worldwide trends in the prevalence of raised blood pressure. Methods: We pooled 1018 population-based studies with blood pressure measurements on 88.6 million participants from 1985 to 2016. We first calculated mean systolic blood pressure (SBP), mean diastolic blood pressure (DBP) and prevalence of raised blood pressure by sex and 10-year age group from 20-29 years to 70-79 years in each study, taking into account complex survey design and survey sample weights, where relevant. We used a linear mixed effect model to quantify the association between (probittransformed) prevalence of raised blood pressure and age-group- and sex-specific mean blood pressure. We calculated the contributions of change in mean SBP and DBP, and of change in the prevalence-mean association, to the change in prevalence of raised blood pressure. Results: In 2005-16, at the same level of population mean SBP and DBP, men and women in South Asia and in Central Asia, the Middle East and North Africa would have the highest prevalence of raised blood pressure, and men and women in the highincome Asia Pacific and high-income Western regions would have the lowest. In most region-sex-age groups where the prevalence of raised blood pressure declined, one half or more of the decline was due to the decline in mean blood pressure. Where prevalence of raised blood pressure has increased, the change was entirely driven by increasing mean blood pressure, offset partly by the change in the prevalence-mean association. Conclusions: Change in mean blood pressure is the main driver of the worldwide change in the prevalence of raised blood pressure, but change in the high-blood-pressure tail of the distribution has also contributed to the change in prevalence, especially in older age groups

Height and body-mass index trajectories of school-aged children and adolescents from 1985 to 2019 in 200 countries and territories: a pooled analysis of 2181 population-based studies with 65 million participants

Summary Background Comparable global data on health and nutrition of school-aged children and adolescents are scarce. We aimed to estimate age trajectories and time trends in mean height and mean body-mass index (BMI), which measures weight gain beyond what is expected from height gain, for school-aged children and adolescents. Methods For this pooled analysis, we used a database of cardiometabolic risk factors collated by the Non-Communicable Disease Risk Factor Collaboration. We applied a Bayesian hierarchical model to estimate trends from 1985 to 2019 in mean height and mean BMI in 1-year age groups for ages 5–19 years. The model allowed for non-linear changes over time in mean height and mean BMI and for non-linear changes with age of children and adolescents, including periods of rapid growth during adolescence. Findings We pooled data from 2181 population-based studies, with measurements of height and weight in 65 million participants in 200 countries and territories. In 2019, we estimated a difference of 20 cm or higher in mean height of 19-year-old adolescents between countries with the tallest populations (the Netherlands, Montenegro, Estonia, and Bosnia and Herzegovina for boys; and the Netherlands, Montenegro, Denmark, and Iceland for girls) and those with the shortest populations (Timor-Leste, Laos, Solomon Islands, and Papua New Guinea for boys; and Guatemala, Bangladesh, Nepal, and Timor-Leste for girls). In the same year, the difference between the highest mean BMI (in Pacific island countries, Kuwait, Bahrain, The Bahamas, Chile, the USA, and New Zealand for both boys and girls and in South Africa for girls) and lowest mean BMI (in India, Bangladesh, Timor-Leste, Ethiopia, and Chad for boys and girls; and in Japan and Romania for girls) was approximately 9–10 kg/m2. In some countries, children aged 5 years started with healthier height or BMI than the global median and, in some cases, as healthy as the best performing countries, but they became progressively less healthy compared with their comparators as they grew older by not growing as tall (eg, boys in Austria and Barbados, and girls in Belgium and Puerto Rico) or gaining too much weight for their height (eg, girls and boys in Kuwait, Bahrain, Fiji, Jamaica, and Mexico; and girls in South Africa and New Zealand). In other countries, growing children overtook the height of their comparators (eg, Latvia, Czech Republic, Morocco, and Iran) or curbed their weight gain (eg, Italy, France, and Croatia) in late childhood and adolescence. When changes in both height and BMI were considered, girls in South Korea, Vietnam, Saudi Arabia, Turkey, and some central Asian countries (eg, Armenia and Azerbaijan), and boys in central and western Europe (eg, Portugal, Denmark, Poland, and Montenegro) had the healthiest changes in anthropometric status over the past 3·5 decades because, compared with children and adolescents in other countries, they had a much larger gain in height than they did in BMI. The unhealthiest changes—gaining too little height, too much weight for their height compared with children in other countries, or both—occurred in many countries in sub-Saharan Africa, New Zealand, and the USA for boys and girls; in Malaysia and some Pacific island nations for boys; and in Mexico for girls. Interpretation The height and BMI trajectories over age and time of school-aged children and adolescents are highly variable across countries, which indicates heterogeneous nutritional quality and lifelong health advantages and risks

Rising rural body-mass index is the main driver of the global obesity epidemic in adults

Body-mass index (BMI) has increased steadily in most countries in parallel with a rise in the proportion of the population who live in cities(.)(1,2) This has led to a widely reported view that urbanization is one of the most important drivers of the global rise in obesity(3-6). Here we use 2,009 population-based studies, with measurements of height and weight in more than 112 million adults, to report national, regional and global trends in mean BMI segregated by place of residence (a rural or urban area) from 1985 to 2017. We show that, contrary to the dominant paradigm, more than 55% of the global rise in mean BMI from 1985 to 2017-and more than 80% in some low- and middle-income regions-was due to increases in BMI in rural areas. This large contribution stems from the fact that, with the exception of women in sub-Saharan Africa, BMI is increasing at the same rate or faster in rural areas than in cities in low- and middle-income regions. These trends have in turn resulted in a closing-and in some countries reversal-of the gap in BMI between urban and rural areas in low- and middle-income countries, especially for women. In high-income and industrialized countries, we noted a persistently higher rural BMI, especially for women. There is an urgent need for an integrated approach to rural nutrition that enhances financial and physical access to healthy foods, to avoid replacing the rural undernutrition disadvantage in poor countries with a more general malnutrition disadvantage that entails excessive consumption of low-quality calories.Peer reviewe

Heterogeneous contributions of change in population distribution of body mass index to change in obesity and underweight NCD Risk Factor Collaboration (NCD-RisC)

From 1985 to 2016, the prevalence of underweight decreased, and that of obesity and severe obesity increased, in most regions, with significant variation in the magnitude of these changes across regions. We investigated how much change in mean body mass index (BMI) explains changes in the prevalence of underweight, obesity, and severe obesity in different regions using data from 2896 population-based studies with 187 million participants. Changes in the prevalence of underweight and total obesity, and to a lesser extent severe obesity, are largely driven by shifts in the distribution of BMI, with smaller contributions from changes in the shape of the distribution. In East and Southeast Asia and sub-Saharan Africa, the underweight tail of the BMI distribution was left behind as the distribution shifted. There is a need for policies that address all forms of malnutrition by making healthy foods accessible and affordable, while restricting unhealthy foods through fiscal and regulatory restrictions

Design and modeling of circularly polarized conical beam antennas for space missions

Space missions present antenna designers with a unique set of requirements. Not only does the antenna need to perform optimally from the electromagnetic radiation point of view, but also need to survive launch conditions, perform optimally at extreme temperatures, deter ionizing radiation, and provide electrostatic protection. Furthermore, without any prospect of repair, such antennas need to be robust enough to withstand the harsh environment on its own. This thesis work touches upon such multi-physics approach to antenna design. More specifically, the antennas concern the ones for the Lander Radioscience (LaRa) instrument intended for the surface platform of the ExoMars 2020 mission to Mars. The antennas would allow direct communication with Earth irrespective of the orientation of the surface platform when it lands, and allow observation throughout the year. This is possible through the conical radiation patterns, which have uniform elevation pattern over the azimuthal plane along the surface platform. For space communications, it is a necessity to have circular polarization as well. Therefore, the thesis proposes different topologies of circularly polarized conical beam antennas ideal for space communications, from planar antennas to 3D metallic antenna. Concerning the planar antenna technology, a circular slot array and a circular patch antenna were developed. The multi-layered PCB structure requires a careful design given the need for space qualification, due to the thermoelastic effect. Metallic antennas are deemed more appropriate to counter such effect, since the homogeneous material properties of the metallic antennas ensure better performance under the thermoelastic stress. To that end, a novel 3D metallic antenna is proposed which is based on gamma-shaped vertical posts surrounding a centrally radiating monopole. Moreover, a numerical method to analyze the near-field performance of the antenna has also been proposed. Especially in the case of space antennas, whose level of detail requires a dense mesh, the proposed method is effective. The method aims to improve the near-interactions in the well known Method of Moments (MoM) by making the integrals separable with respect to source and observation coordinates. This approach opens new avenues for fast electromagnetic analysis of complex structures.(FSA - Sciences de l'ingénieur) -- UCL, 201

CubeCat-1: Sistema de Comunicacions de un Nano-satèl·lit

[ANGLÈS] The CubeSat program provides a cost-effective solution to the educational institutions and private firms, around the world, willing to put their satellites in orbit, which are no bigger than a 10 cm cube, and weigh less than 1.33 kg. Benefitting from such program is a CubeSat from Universitat Politècnica de Catalunya, 3Cat-1, which aims to test various scientific payloads in a space environment. Like most of the satellites, a CubeSat requires a harmonious interactions among different subsystems to function properly. The thesis focuses on one such subsystem, the communications subsystem, which is responsible for establishing a communication link between the CubeSat and the ground stations. The communication can take different form, from transmitting only the status of the satellite to transferring payloads data to earth or responding to the tele-commands uploaded from the ground station. The report emphasises on the detailed design and test of the communications subsys- tem consisting of the RF front-end, the antenna and the electronic hardware. It also focuses on different experiments conducted to optimise the design. Furthermore, the work outlined in this thesis can be extended to future CubeSat projects.[CASTELLÀ] La iniciativa CubeSat ha abierto el acceso al espacio a organismos educacionales y empresas privadas que necesitan poner en órbita pequeñas cargas útiles, que puedan caber en un cubo de 10cm de lado con un peso inferior a 1.33kg. Dentro de esta iniciativa, la Universitat Politècnica de Catalunya ha puesto en marcha el 3Cat−1, con la intención de probar distintas cargas útiles diseñadas en distintos departamentos en el espacio. Como cualquier otro satélite, un CubeSat necesita un correcto funcionamiento de los distintos subsistemas para poder funcionar. Esta tesis se focaliza en el subsistema de comunicaciones, que es el responsable de establecer la comunicación entre el satélite y la estación de seguimiento terrestre. La comunicación entre la Tierra y el satélite puede ir desde una transmisión del estado del satélite hasta el envío de los datos de los experimentos embarcados, o bien responder a los telecomandos que se envían desde la estación terrestre. El trabajo presentado enfatiza el diseño y test del subsistema de comunicaciones, que consiste en una interfície RF, la antena y el hardware electrónico. Igualmente, el documento presta especial atención a los tests realizados para validar y optimizar el diseño del subsistema. Finalmente, se prevé que el material presentado en esta Tesi pueda ser reutilizado en las próximas misiones de satélites de la UPC.[CATALÀ] La iniciativa CubeSat ha permès obrir l’accés a l’espai a organismes educacionals i em- preses privades, que necessiten posar en òrbita petites càrregues útils, que puguin cabre en un cub de 10cm i un pes inferior a 1.33kg. Emmarcat en aquesta iniciativa, la Universitat Politècnica de Catalunya ha posat en marxa el 3Cat − 1, amb la intenció de provar diferents càrregues útils dissenyades per diferents departaments a l’espai. Com qualsevol altre satèl·lit, un CubeSat necessita un bon funcionament dels diferents subsitemes per poder funcionar. Aquesta tesis es focalitza en el subsistema de comunicacions, que és el responsable d’establir comunicació entre el satèl·lit i la estació de seguiment terrestre. La comunicació entre els dos pot anar des de transmetre únicament l’estat del satèl·lit fins a transmetre les dades dels experiments, o bé respondre als telecomandaments enviats des de l’estació terrestre. El treball presentat emfatitza el disseny i test del subsistema de comunicacions, que con- sisteix en una interfície RF, l’antena i el hardware electrònic. Igualment, el document para especial atenció als tests realitzats per a validar i optimitzar el disseny del subsiste- ma. Finalment, es preveu que el material presentat en aquesta Tesi pugui ser reutilitzat en futures missions de satèl·lits a la UPC

CubeCat-1: Sistema de Comunicacions de un Nano-satèl·lit

[ANGLÈS] The CubeSat program provides a cost-effective solution to the educational institutions and private firms, around the world, willing to put their satellites in orbit, which are no bigger than a 10 cm cube, and weigh less than 1.33 kg. Benefitting from such program is a CubeSat from Universitat Politècnica de Catalunya, 3Cat-1, which aims to test various scientific payloads in a space environment. Like most of the satellites, a CubeSat requires a harmonious interactions among different subsystems to function properly. The thesis focuses on one such subsystem, the communications subsystem, which is responsible for establishing a communication link between the CubeSat and the ground stations. The communication can take different form, from transmitting only the status of the satellite to transferring payloads data to earth or responding to the tele-commands uploaded from the ground station. The report emphasises on the detailed design and test of the communications subsys- tem consisting of the RF front-end, the antenna and the electronic hardware. It also focuses on different experiments conducted to optimise the design. Furthermore, the work outlined in this thesis can be extended to future CubeSat projects.[CASTELLÀ] La iniciativa CubeSat ha abierto el acceso al espacio a organismos educacionales y empresas privadas que necesitan poner en órbita pequeñas cargas útiles, que puedan caber en un cubo de 10cm de lado con un peso inferior a 1.33kg. Dentro de esta iniciativa, la Universitat Politècnica de Catalunya ha puesto en marcha el 3Cat−1, con la intención de probar distintas cargas útiles diseñadas en distintos departamentos en el espacio. Como cualquier otro satélite, un CubeSat necesita un correcto funcionamiento de los distintos subsistemas para poder funcionar. Esta tesis se focaliza en el subsistema de comunicaciones, que es el responsable de establecer la comunicación entre el satélite y la estación de seguimiento terrestre. La comunicación entre la Tierra y el satélite puede ir desde una transmisión del estado del satélite hasta el envío de los datos de los experimentos embarcados, o bien responder a los telecomandos que se envían desde la estación terrestre. El trabajo presentado enfatiza el diseño y test del subsistema de comunicaciones, que consiste en una interfície RF, la antena y el hardware electrónico. Igualmente, el documento presta especial atención a los tests realizados para validar y optimizar el diseño del subsistema. Finalmente, se prevé que el material presentado en esta Tesi pueda ser reutilizado en las próximas misiones de satélites de la UPC.[CATALÀ] La iniciativa CubeSat ha permès obrir l’accés a l’espai a organismes educacionals i em- preses privades, que necessiten posar en òrbita petites càrregues útils, que puguin cabre en un cub de 10cm i un pes inferior a 1.33kg. Emmarcat en aquesta iniciativa, la Universitat Politècnica de Catalunya ha posat en marxa el 3Cat − 1, amb la intenció de provar diferents càrregues útils dissenyades per diferents departaments a l’espai. Com qualsevol altre satèl·lit, un CubeSat necessita un bon funcionament dels diferents subsitemes per poder funcionar. Aquesta tesis es focalitza en el subsistema de comunicacions, que és el responsable d’establir comunicació entre el satèl·lit i la estació de seguiment terrestre. La comunicació entre els dos pot anar des de transmetre únicament l’estat del satèl·lit fins a transmetre les dades dels experiments, o bé respondre als telecomandaments enviats des de l’estació terrestre. El treball presentat emfatitza el disseny i test del subsistema de comunicacions, que con- sisteix en una interfície RF, l’antena i el hardware electrònic. Igualment, el document para especial atenció als tests realitzats per a validar i optimitzar el disseny del subsiste- ma. Finalment, es preveu que el material presentat en aquesta Tesi pugui ser reutilitzat en futures missions de satèl·lits a la UPC

CubeCat-1: Sistema de Comunicacions de un Nano-satèl·lit

[ANGLÈS] The CubeSat program provides a cost-effective solution to the educational institutions and private firms, around the world, willing to put their satellites in orbit, which are no bigger than a 10 cm cube, and weigh less than 1.33 kg. Benefitting from such program is a CubeSat from Universitat Politècnica de Catalunya, 3Cat-1, which aims to test various scientific payloads in a space environment. Like most of the satellites, a CubeSat requires a harmonious interactions among different subsystems to function properly. The thesis focuses on one such subsystem, the communications subsystem, which is responsible for establishing a communication link between the CubeSat and the ground stations. The communication can take different form, from transmitting only the status of the satellite to transferring payloads data to earth or responding to the tele-commands uploaded from the ground station. The report emphasises on the detailed design and test of the communications subsys- tem consisting of the RF front-end, the antenna and the electronic hardware. It also focuses on different experiments conducted to optimise the design. Furthermore, the work outlined in this thesis can be extended to future CubeSat projects.[CASTELLÀ] La iniciativa CubeSat ha abierto el acceso al espacio a organismos educacionales y empresas privadas que necesitan poner en órbita pequeñas cargas útiles, que puedan caber en un cubo de 10cm de lado con un peso inferior a 1.33kg. Dentro de esta iniciativa, la Universitat Politècnica de Catalunya ha puesto en marcha el 3Cat−1, con la intención de probar distintas cargas útiles diseñadas en distintos departamentos en el espacio. Como cualquier otro satélite, un CubeSat necesita un correcto funcionamiento de los distintos subsistemas para poder funcionar. Esta tesis se focaliza en el subsistema de comunicaciones, que es el responsable de establecer la comunicación entre el satélite y la estación de seguimiento terrestre. La comunicación entre la Tierra y el satélite puede ir desde una transmisión del estado del satélite hasta el envío de los datos de los experimentos embarcados, o bien responder a los telecomandos que se envían desde la estación terrestre. El trabajo presentado enfatiza el diseño y test del subsistema de comunicaciones, que consiste en una interfície RF, la antena y el hardware electrónico. Igualmente, el documento presta especial atención a los tests realizados para validar y optimizar el diseño del subsistema. Finalmente, se prevé que el material presentado en esta Tesi pueda ser reutilizado en las próximas misiones de satélites de la UPC.[CATALÀ] La iniciativa CubeSat ha permès obrir l’accés a l’espai a organismes educacionals i em- preses privades, que necessiten posar en òrbita petites càrregues útils, que puguin cabre en un cub de 10cm i un pes inferior a 1.33kg. Emmarcat en aquesta iniciativa, la Universitat Politècnica de Catalunya ha posat en marxa el 3Cat − 1, amb la intenció de provar diferents càrregues útils dissenyades per diferents departaments a l’espai. Com qualsevol altre satèl·lit, un CubeSat necessita un bon funcionament dels diferents subsitemes per poder funcionar. Aquesta tesis es focalitza en el subsistema de comunicacions, que és el responsable d’establir comunicació entre el satèl·lit i la estació de seguiment terrestre. La comunicació entre els dos pot anar des de transmetre únicament l’estat del satèl·lit fins a transmetre les dades dels experiments, o bé respondre als telecomandaments enviats des de l’estació terrestre. El treball presentat emfatitza el disseny i test del subsistema de comunicacions, que con- sisteix en una interfície RF, l’antena i el hardware electrònic. Igualment, el document para especial atenció als tests realitzats per a validar i optimitzar el disseny del subsiste- ma. Finalment, es preveu que el material presentat en aquesta Tesi pugui ser reutilitzat en futures missions de satèl·lits a la UPC

Metallic monopole parasitic antenna with circularly polarized conical patterns

In this paper, a new geometry for antenna producing conical patterns with circular polarization is proposed. The symmetrically placed parasitic posts, with different horizontal and vertical segments, around the centrally fed monopole control the circular polarization purity and the angle of maximum gain. The 3-D geometry favors high gain at low elevation angles. A circular ground plane atop a choke ring facilitates easy mounting of a radome and improves gain at lower elevation due to lower backlobe. The all-metal radiator has good mechanical stability and remains impervious to large temperature variations, which is ideal for use in space applications. An application to a Martian transponder at the X-band is also discussed. The measured results of the manufactured antennas show a good agreement with those of the simulated one. Furthermore, the optimization of the antenna design parameters allows the antenna to have high gain and low axial ratio (AR), from high elevation (θ max= 350) to low elevation (θ max= 700) angles