Microprocessor based system for the development of control and protection of HVDC convertors.

This project investigates aspects of microprocessor based control and protection schemes for high voltage direct current convertors. To enable this investigation to be carried out, a multiple microprocessor HVDC development system has been assembled. This provides the necessary hardware resources, as well as providing the software development facilities necessary for the implementation of real time control and protection tasks. In order to assess and optimise the performance of the various control and protection systems, considerable interactive monitoring facilities are provided as part of the HVDC development system's software. The development system is used to implement real time control of a small scale convertor model. It is also used to implement a new form of convertor fault detection, which is in turn used as the basis for an implementation of convertor fault development control techniques for the first time on an operating convertor. The operation of the fault development control scheme is examined in some detail, and results are presented showing its operation over a wide variety of fault types and system conditions

Molecular systematics of Campylobacter isolated from the human clinical environment.

Campylobacter jejuni is the major cause of campylobacteriosis in humans. This thesis recorded the distribution of C. jejuni and C. coli isolates in a hospital environment during 1997/98. 105 clinical isolates of Campylobacter were examined using flaA and gmhA PCR-RFLP analysis. Isolates were collected from 84 patients who presented at Christchurch Public Hospital or from the South Canterbury region. Males accounted for 63.1 % of the sample. The largest number of cases was reported in the age group 20-29 years. flaA specific primers were applied to all samples with 83.8 % generating a 1.7 kb amplicon. RFLP analysis using DdeI provided 17 different flaA profiles, with flaA 6 being the most common type identified in this study. 82.9 % of the sample generated a distinguishable profile. This technique provided a D value of 92 % (D = Simpson's index of diversity). gmhA primers were also applied to this sample, with 71.4 % generating either a 900 bp, 1.6 kb or multiple band profile. 62.9 % of the sample provided a distinguishable RFLP profile. gmhA 1 was the most commonly observed profile. This technique provided a D value of 74 %. When combining these two genetic markers, discrimination was increased. 59 % (n=62) of the isolates had provided both flaA and gmhA profiles. These isolates were distributed into 22 different classifications. MLEE analysis was applied to the largest flaA group in an attempt to further assess relationships. This analysis allowed flaA 6 to be subdivided into a further five groups, therefore increasing strain discrimination. PCR-RFLP procedures were highly reproducible, robust, discriminative and rapid to perform. However 17.1 % and 37.1 % were untypeable by flaA and gmhA respectively. 20 environmental (sheep) isolates from Massey University were also examined using flaA and gmhA PCR-RFLP analysis. Four flaA types and two gmhA types were observed amongst these isolates. The flaA and gmhA types had been previously observed in the clinical isolates, therefore suggesting that no strain was specific to a particular environment. However not all isolates were typeable with these two methods

Antimykotische Therapie der invasiven pulmonalen Infektion durch Scedosporium und Pseudallescheria spp. bei Mukoviszidose

Autre titre : Antimykotische Therapie der pulmonalen Infektion durch Scedosporien bei MukoviszidoseInternational audienc

Combined antifungal therapy is superior to monotherapy in pulmonary scedosporiosis in cystic fibrosis

Cystic fibrosis (CF) is characterised by chronic airway infection with bacteria and fungi. Infections caused by Scedosporium/Lomentospora species can occur and are difficult to treat. Moulds belonging to the genus Scedosporium/Lomentospora are detected most frequently in respiratory samples of patients with CF, next to Aspergillus spp. Our aim was to define pulmonary fungal infections due to Scedosporium/Lomentospora in CF and to study the antimycotic treatment. In this multicentre study (12 centres; duration January 2008 to December 2014) 31 patients with a lung infection caused by moulds of the genus Scedosporium/Lomentospora were included. 36 courses of antifungal treatment were documented. Scedosporium apiospermum sensu stricto accounted for 48.4% of cases. In 20/31 patients a therapeutic response under antimycotics (median duration 3.9 months) was achieved. Triple and double therapy was significantly more effective compared to monotherapy regarding FEV1, radiology, and symptoms. This data suggests that combined treatment is superior to monotherapy in patients with CF

Determination of nutrient salts by automatic methods both in seawater and brackish water: the phosphate blank

9 páginas, 2 tablas, 2 figurasThe main inconvenience in determining nutrients in seawater by automatic methods is simply solved: the preparation of a suitable blank which corrects the effect of the refractive index change on the recorded signal. Two procedures are proposed, one physical (a simple equation to estimate the effect) and the other chemical (removal of the dissolved phosphorus with ferric hydroxide).Support for this work came from CICYT (MAR88-0245 project) and Conselleria de Pesca de la Xunta de GaliciaPeer reviewe

Single-cell transcriptomics reveals common epithelial response patterns in human acute kidney injury

BACKGROUND: Acute kidney injury (AKI) occurs frequently in critically ill patients and is associated with adverse outcomes. Cellular mechanisms underlying AKI and kidney cell responses to injury remain incompletely understood. METHODS: We performed single-nuclei transcriptomics, bulk transcriptomics, molecular imaging studies, and conventional histology on kidney tissues from 8 individuals with severe AKI (stage 2 or 3 according to Kidney Disease: Improving Global Outcomes (KDIGO) criteria). Specimens were obtained within 1-2 h after individuals had succumbed to critical illness associated with respiratory infections, with 4 of 8 individuals diagnosed with COVID-19. Control kidney tissues were obtained post-mortem or after nephrectomy from individuals without AKI. RESULTS: High-depth single cell-resolved gene expression data of human kidneys affected by AKI revealed enrichment of novel injury-associated cell states within the major cell types of the tubular epithelium, in particular in proximal tubules, thick ascending limbs, and distal convoluted tubules. Four distinct, hierarchically interconnected injured cell states were distinguishable and characterized by transcriptome patterns associated with oxidative stress, hypoxia, interferon response, and epithelial-to-mesenchymal transition, respectively. Transcriptome differences between individuals with AKI were driven primarily by the cell type-specific abundance of these four injury subtypes rather than by private molecular responses. AKI-associated changes in gene expression between individuals with and without COVID-19 were similar. CONCLUSIONS: The study provides an extensive resource of the cell type-specific transcriptomic responses associated with critical illness-associated AKI in humans, highlighting recurrent disease-associated signatures and inter-individual heterogeneity. Personalized molecular disease assessment in human AKI may foster the development of tailored therapies

Apnea of prematurity: from cause to treatment

Apnea of prematurity (AOP) is a common problem affecting premature infants, likely secondary to a “physiologic” immaturity of respiratory control that may be exacerbated by neonatal disease. These include altered ventilatory responses to hypoxia, hypercapnia, and altered sleep states, while the roles of gastroesophageal reflux and anemia remain controversial. Standard clinical management of the obstructive subtype of AOP includes prone positioning and continuous positive or nasal intermittent positive pressure ventilation to prevent pharyngeal collapse and alveolar atelectasis, while methylxanthine therapy is a mainstay of treatment of central apnea by stimulating the central nervous system and respiratory muscle function. Other therapies, including kangaroo care, red blood cell transfusions, and CO2 inhalation, require further study. The physiology and pathophysiology behind AOP are discussed, including the laryngeal chemoreflex and sensitivity to inhibitory neurotransmitters, as are the mechanisms by which different therapies may work and the potential long-term neurodevelopmental consequences of AOP and its treatment