The application of a pulsed compression reactor for the generation of syngas from methane

Existing chemical reactors are approaching their technological limits. In order to make more significant progress in the energy efficiency of bulk chemical production processes, a radical shift in technology is needed.\ud The research was aimed at gaining some fundamental insight in the operation of the Pulsed Compression Reactor (PCR) in general, as well as the specific application for syngas generation from methane. The research can be divided into three parts: an investigation of heat transfer from the hot gas to the reactor walls and piston, an investigation of the chemistry of both partial oxidation of methane as well as steam reforming and the investigation of the stability of the PCR piston reciprocation. \ud To investigate the heat transfer from the hot gas to the reactor walls and piston two approaches were used. This was used to derive an empirical relation between the heat loss from the compressed gas in a single shot reactor and the compression pressure. This relation gives insight into the effect that the reactor walls and piston have on the chemistry occurring in the single shot reactor.\ud In the investigation of syngas generation from methane, the chemistry of both partial oxidation and steam reforming of methane were investigated in a single shot reactor. This was done both experimentally and by simulations of the process using models with detailed chemistry. \ud Lastly, an analysis of the experimental and numerical data obtained yielded a theory that describes the behavior of the PCR in continuous reciprocation with respect to reciprocation stability. It was shown that, if a point exists where the energy release of chemical reactions exactly compensates the energy losses, reciprocation will always converge to this point or cease. This is an important result with respect to the safety issues associated with the PCR operation

Infectieziekten zonder grenzen

Diesoratie uitgesproken door Prof.dr. Meta Roestenberg Professor Humane modellen voor vaccinontwikkelingtijdens de 447ste dies natalis op dinsdag 8 februari 2022 in de PieterskerkLUMC / Geneeskund

Controlled human infection models to evaluate schistosomiasis and hookworm vaccines: where are we now?

Host-parasite interactio

Influence of infection on malaria-specific antibody dynamics in a cohort exposed to intense malaria transmission in northern Uganda.

The role of submicroscopic infections in modulating malaria antibody responses is poorly understood and requires longitudinal studies. A cohort of 249 children ≤5 years of age, 126 children between 6 and 10 years and 134 adults ≥20 years was recruited in an area of intense malaria transmission in Apac, Uganda and treated with artemether/lumefantrine at enrolment. Parasite carriage was determined at enrolment and after 6 and 16 weeks using microscopy and PCR. Antibody prevalence and titres to circumsporozoite protein, apical membrane antigen-1 (AMA-1), merozoite surface protein-1 (MSP-119 ), merozoite surface protein-2 (MSP-2) and Anopheles gambiae salivary gland protein 6 (gSG6) were determined by ELISA. Plasmodium falciparum infections were detected in 38·1% (194/509) of the individuals by microscopy and in 57·1% (284/493) of the individuals by PCR at enrolment. Antibody prevalence and titre against AMA-1, MSP-119 , MSP-2 and gSG6 were related to concurrent (sub-)microscopic parasitaemia. Responses were stable in children who were continuously infected with malaria parasites but declined in children who were never parasitaemic during the study or were not re-infected after treatment. These findings indicate that continued malaria infections are required to maintain antibody titres in an area of intense malaria transmission

A genetically attenuated malaria vaccine candidate based on P. falciparum b9/slarp gene-deficient sporozoites

A highly efficacious pre-erythrocytic stage vaccine would be an important tool for the control and elimination of malaria but is currently unavailable. High-level protection in humans can be achieved by experimental immunization with Plasmodium falciparum sporozoites attenuated by radiation or under anti-malarial drug coverage. Immunization with genetically attenuated parasites (GAP) would be an attractive alternative approach. Here we present data on safety and protective efficacy using sporozoites with deletions of two genes i.e. the newly identified b9 and slarp, which govern independent and critical processes for successful liver-stage development. In the rodent malaria model, Pb Delta b9 Delta slarpGAP was completely attenuated showing no breakthrough infections while efficiently inducing high level protection. The human Pf Delta b9 Delta slarpGAP generated without drug-resistance markers were infective to human hepatocytes in vitro and to humanized mice engrafted with human hepatocytes in vivo but completely aborted development after infection. These findings support the clinical development of a Pf Delta b9 Delta slarpSPZ vaccine

Assessment of risks associated with severe acute respiratory syndrome Coronavirus 2 experimental human infection studies

Controlled human infection (CHI) models for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been proposed as a tool to accelerate the development of vaccines and drugs. Such models carry inherent risks. Participants may develop severe disease or complications after deliberate infection. Prolonged isolation may negatively impact their well-being. Through secondary infection of study personnel or participant household contacts, the experimental virus strain may cause a community outbreak. We identified risks associated with such a SARS-CoV-2 CHI model and assessed their likelihood and impact and propose strategies that mitigate these risks. In this report, we show that risks can be minimized with proper risk mitigation strategies; the residual risk, however, should be weighed carefully against the scientific and social values of such a CHI model.Clinical epidemiolog

Corrigendum: Controlled Human Infections As a Tool to Reduce Uncertainty in Clinical Vaccine Development

Host-parasite interactio

Cardiac complication after experimental human malaria infection: a case report

A 20 year-old healthy female volunteer participated in a clinical Phase I and IIa safety and efficacy trial with candidate malaria vaccine PfLSA-3-rec adjuvanted with aluminium hydroxide. Eleven weeks after the third and last immunization she was experimentally infected by bites of Plasmodium falciparum-infected mosquitoes. When the thick blood smear became positive, at day 11, she was treated with artemether/lumefantrine according to protocol. On day 16 post-infection i.e. two days after completion of treatment, she woke up with retrosternal chest pain. She was diagnosed as acute coronary syndrome and treated accordingly. She recovered quickly and her follow-up was uneventful. Whether the event was related to the study procedures such as the preceding vaccinations, malaria infection or antimalarial drugs remains elusive. However, the relation in time with the experimental malaria infection and apparent absence of an underlying condition makes the infection the most probable trigger. This is in striking contrast, however, with the millions of malaria cases each year and the fact that such complication has never been reported in the literature. The rare occurrence of cardiac events with any of the preceding study procedures may even support a coincidental finding