Espérance de vie humaine | EPFL Graph Search

thumb|right|400px|Carte indiquant l' espérance de vie à la naissance dans les États membres de l'ONU en 2007. L'espérance de vie humaine est un des indicateurs statistiques les plus utilisés dans le domaine de la prospective et des projections démographiques, et pour évaluer le niveau de développement et l'indice de développement humain d'un État ou d'une région du monde. Elle permet de quantifier les conditions de mortalité à une année donnée : l'espérance de vie à la naissance est égale à la durée de vie moyenne d'une population fictive qui vivrait toute son existence dans les conditions de mortalité de l'année considérée. L'année 2020 a vu sa régression mondiale « pour la première fois depuis la Seconde Guerre mondiale ». Contrairement à ce que le terme « espérance de vie » peut laisser penser, cette statistique n'est pas une prévision des probabilités de décès pour les années ultérieures. Dire par exemple que l'espérance de vie des hommes en 2000 est de soixante-quinze ans sign

Dynamics of Defects in Field-Induced Skyrmion Lattice Melting

Guanghao Li

TP4 project: My work is mainly to achieve the identification, segmentation and tracking of defects and analyze their dynamics. In detail, the positions, the motion tracks, life expectancy, velocity distribution, etc. We will determine these observables among 488 frames while experimentally the field is ramped continuously from about 600 Oe to 1200 Oe.

2019

Evaluation of oxidation-sensitive polymersomes as vaccine nanocarriers to enhance humoral responses against arenavirus envelope glycoproteins

Clara Galan Navarro

Vaccines currently represent one of the most effective means to control and prevent infectious diseases affecting humans and animals and have dramatically improved public health, quality of life, and life expectancy. Over the last years several conceptual and technological advances in the field of bioengineering and immunology have allowed the development of new vaccines designs. Expanding novel domains such as structural biology, human monoclonal antibody isolation, high throughput sequencing, and design of new nanocarrier delivery platforms have changed the landscape of vaccinology. These new vaccine formulations allow the design of tailor-made antigens and particulate vehicles which allow better and fine-tuned protective immune responses against known and newly emerging pathogens. Over the past decades emerging human pathogens with the potential to cause severe epidemics have become a major public health problem. The last Ebola and Zika virus epidemics demonstrated in a dramatic manner that there is an urgent need to develop prophylactic and therapeutic approaches against pathogenic emerging viruses. Most successful vaccines rely on attenuated live microorganisms to induce protective immunity. However, changed demographics and associated safety concerns makes the development of a safer alternative a priority. Subunit vaccines composed of microbial components and proteins have emerged as a suitable alternative, however they are generally less immunogenic. To address this problematic our laboratory works on the development of immunization platforms which allow 1) the development of safe recombinant subunit vaccines and 2) the rapid generation of specific monoclonal antibodies using biosynthetic immunogens without the need for prior isolation and culture of the agent. The approach evaluated in the present studies is based on a novel polymersome (PS) platform serving as nanocarrier for efficient antigen delivery and the induction of humoral immunity. The potential of PS was assessed in the context of two important human emerging pathogens form the arenavirus family that cause severe hemorrhagic fevers and of which there are neither FDA-approved vaccines not prophylactic treatments: Lassa virus (LASV), endemic in Western Africa, and Machupo virus (MACV), the causative agent of Bolivian hemorrhagic fever. In a first part, we evaluated the PS platformâs capacity to enhance humoral immunity against the envelope glycoprotein 1 of LASV, (LASV GP1) that is notorious for its weak immunogenicity and poor antibody response. Immunization of mice with adjuvanted PS (LASV GP1) enhanced the quality of the humoral response to LASV GP1, eliciting antibodies with higher binding affinity to virion GP1, increased levels of polyfunctional anti-viral CD4 T cells, and the frequency of IgG-secreting B cells. PS (LASV GP1) elicited a more diverse epitope repertoire of anti-viral IgG. In a second part, we employed the PS platform in combination with single cell B cell sorting and cloning of recombinant IgG to generate a first set of species-specific mAbs against MACV. These new mAbs show exquisite specificity and negligible cross-reactivity to closely related arenaviruses in relevant techniques making them a unique and powerful tool for research and diagnostics purposes.

EPFL2017

Temperature-Dependent Nucleation and Electrochemical Performance of Zn Metal Anodes

Di Yang, Kangning Zhao

A fundamental understanding of the nucleation and growth behaviors of Zn metal anodes over a wide range of temperatures is of great value for suppressing Zn dendrite growth. However, work focused on the early nucleation and growth behavior of Zn metal at various temperatures is still absent. Here, we study the effect of cycling temperature on Zn nuclei size and areal density and find that low temperature induces a smaller and dense nucleus, which prevents the formation of dendrites. Based on this finding, a cooling-treatment-based self-healing strategy is developed to in situ eliminate dendrites, which effectively prolongs the lifespan of the Zn anode by 520%. This novel self-healing strategy could be employed as a reliable strategy for restoring batteries in situ to reach a longer lifespan.

AMER CHEMICAL SOC2022

Evaluation of oxidation-sensitive polymersomes as vaccine nanocarriers to enhance humoral responses against arenavirus envelope glycoproteins

Clara Galan Navarro

EPFL2017