689 research outputs found
Profile of a cell test database and a corresponding reliability database
The development of computerized control, and data retrieval for aerospace cell testing affords an excellent opportunity to incorporate three specific concepts to both manage the test area and to track product performance on a real-time basis. The adoption and incorporation of precepts fostered by this total quality management (TQM) initiative are critical to us for retaining control of our business while substantially reducing the separate quality control inspection activity. Test discrepancies are all 'equally bad' in cell acceptance testing because, for example, we presently do not discriminate between 1 or 25 mV for an overvoltage condition. We must take leadership in classifying such discrepancies in order to expedite their clearance and redirect our resources for prevention activities. The development and use of engineering alerts (or guardbanding) which more closely match our product capabilities and are toleranced tighter than the required customer specification are paramount to managing the test unit in order to remain both quality and cost effective
Formaldehyde in the industrial environment
Consideration has been given to the toxicity of formaldehyde in the industrial environment. The available literature has been reviewed critically against a background of technological awareness of the usefulness of the material and the factors which influence the assessment of absorption by the body fluids following exposure are examined. Data from experimental work carried out in a number of factory locations has been analysed in an attempt to establish the relationships between somatic absorption and levels of formaldehyde found in ambient air. [Continues.]</div
Clasts in the CM2 carbonaceous chondrite Lonewolf Nunataks 94101: evidence for aqueous alteration prior to complex mixing
Clasts in the CM2 carbonaceous chondrite Lonewolf Nunataks (LON) 94101 have been characterized using scanning and transmission electron microscopy and electron microprobe analysis to determine their degrees of aqueous alteration, and the timing of alteration relative to incorporation of clasts into the host. The provenance of the clasts, and the mechanism by which they were incorporated and mixed with their host material are also considered. Results show that at least five distinct types of clasts occur in LON 94101, of which four have been aqueously altered to various degrees and one is largely anhydrous. The fact that they have had different alteration histories implies that the main part of aqueous activity occurred prior to the mixing and assimilation of the clasts with their host. Further, the presence of such a variety of clasts suggests complex mixing in a dynamic environment involving material from various sources. Two of the clasts, one containing approximately 46 vol% carbonate and the other featuring crystals of pyrrhotite up to approximately 1Ā mm in size, are examples of unusual lithologies and indicate concentration of chemical elements in discrete areas of the parent body(ies), possibly by flow of aqueous solutions
Cephalosporinases associated with outer membrane vesicles released by Bacteroides spp. protect gut pathogens and commensals against beta-lactam antibiotics
Objectives: To identify Ī²-lactamase genes in gut commensal Bacteroides species and to assess the impact of these enzymes, when carried by outer membrane vesicles (OMVs), in protecting enteric pathogens and commensals. Methods: A deletion mutant of the putative class A Ī²-lactamase gene (locus tag BT_4507) found in the genome of the human commensal Bacteroides thetaiotaomicron was constructed and a phenotypic analysis performed. A phylogenetic tree was built from an alignment of nine Bacteroides cephalosporinase protein sequences, using the maximum likelihood method. The rate of cefotaxime degradation after incubation with OMVs produced by different Bacteroides species was quantified using a disc susceptibility test. The resistance of Salmonella Typhimurium and Bifidobacterium breve to cefotaxime in liquid culture in the presence of B. thetaiotaomicron OMVs was evaluated by measuring bacterial growth. Results: The B. thetaiotaomicron BT_4507 gene encodes a Ī²-lactamase related to the CepA cephalosporinase of Bacteroides fragilis. OMVs produced by B. thetaiotaomicron and several other Bacteroides species, except Bacteroides ovatus, carried surface-associated Ī²-lactamases that could degrade cefotaxime. Ī²-Lactamase-harbouring OMVs from B. thetaiotaomicron protected Salmonella Typhimurium and B. breve from an otherwise lethal dose of cefotaxime. Conclusions: The production of membrane vesicles carrying surface-associated Ī²-lactamases by Bacteroides species, which constitute a major part of the human colonic microbiota, may protect commensal bacteria and enteric pathogens, such as Salmonella Typhimurium, against Ī²-lactam antibiotics
Metamorphism on Ordinary Chondrite Parent Bodies: The Role of Fluids.
ē¬¬3åꄵåē§å¦ć·ć³ććøć¦ć /ē¬¬35ååꄵéē³ć·ć³ććøć¦ć 11ę30ę„ļ¼éļ¼ å½ē«å½čŖē ē©¶ę 2éč¬
What is the contribution of physician associates in hospital care in England? A mixed methods, multiple case study.
OBJECTIVES: To investigate the deployment of physician associates (PAs); the factors supporting and inhibiting their employment and their contribution and impact on patients' experience and outcomes and the organisation of services. DESIGN: Mixed methods within a case study design, using interviews, observations, work diaries and documentary analysis. SETTING: Six acute care hospitals in three regions of England in 2016-2017. PARTICIPANTS: 43 PAs, 77 other health professionals, 28 managers, 28 patients and relatives. RESULTS: A key influencing factor supporting the employment of PAs in all settings was a shortage of doctors. PAs were found to be acceptable, appropriate and safe members of the medical/surgical teams by the majority of doctors, managers and nurses. They were mainly deployed to undertake inpatient ward work in the medical/surgical team during core weekday hours. They were reported to positively contribute to: continuity within their medical/surgical team, patient experience and flow, inducting new junior doctors, supporting the medical/surgical teams' workload, which released doctors for more complex patients and their training. The lack of regulation and attendant lack of authority to prescribe was seen as a problem in many but not all specialties. The contribution of PAs to productivity and patient outcomes was not quantifiable separately from other members of the team and wider service organisation. Patients and relatives described PAs positively but most did not understand who and what a PA was, often mistaking them for doctors. CONCLUSIONS: This study offers new insights concerning the deployment and contribution of PAs in medical and surgical specialties in English hospitals. PAs provided a flexible addition to the secondary care workforce without drawing from existing professions. Their utility in the hospital setting is unlikely to be completely realised without the appropriate level of regulation and authority to prescribe medicines and order ionising radiation within their scope of practice
Learning from people with long-term conditions: new insights for governance in primary health care
Internationally, system-wide changes to the structures and systems governing health care aim to improve outcomes for patients, quality of care and access to services. The introduction of top-down centrally driven solutions to governance of health care, at the same time as increasing policy emphasis on greater ābottom upā patient and public involvement in all aspects of health care, has set up complex tensions for policy implementation and health care practice. This paper explores the interplay of these agendas in the context of changes in primary health care services provided by the National Health Service (NHS) in England. Specifically, it looks at an example of service user involvement in a study (the PEGI study) of professional response to changes in the governance and incentives in the care of people with long-term conditions. This qualitative study was conducted in three Primary Care Trust sites in England. Service users influenced and guided the study throughout. In-depth interviews with 56 health and social care professionals engaged in the development of local policies and the delivery of care for people with complex long-term illness drew on vignettes developed by 32 members from three Service User Reference Groups (SURG). Themes generated by the cross case analysis were validated through these SURG groups. The findings presented here focus on four themes about risk and comparison of professionalsā/service usersā perspectives of the issues: managing risks/consistent support, the risks of letting go/feeling in control, professionalism/helping people to help themselves, and managing expectations/professionals losing out. Service user involvement added value by: validating understandings of governance, framing debates to focus on what matters at the point of care, and enabling perspective sharing and interaction. We suggest that more collaborative forms of governance in health care, that take account of service user perspectives and enable interaction with professional groups, could help to validate processes of quality assurance and provide motivation for continuous quality improvement. We offer a model for āopening upā collaborative projects to evaluation and appraisal and a process for critical reflection of the interrelationships between the PEGI study context, researcher issues, methods/approach and outcomes/impact of service user involvement
Stacking Defects in Synthetic and Meteoritic Hibonites: Implications for High-Temperature Processes in the Solar Nebula
Hibonite (CaAl12O19) is a primary, highly refractory phase occurring in many Ca-Al-rich inclusions (CAIs) from different chondrite groups, except CI chondrites. Hibonite is predicted to be one of the earliest minerals to condense during cooling of the solar nebula at higher temperatures than any other major CAI mineral. Therefore, hibonite has great potential to reveal the processes and conditions of the very early, high-temperature stages of the solar nebular evolution. Previous microstructural studies of hibonite in CAIs and their Wark-Lovering (WL) rims showed the presence of numerous stacking defects in hibonite. These defects are interpreted as the modification of the stacking sequences of spinel and Ca-containing blocks within the ideal hexagonal hibonite structure, as shown by experimental studies of reaction-sintered ceramic CaO-Al2O3 compounds. We performed preliminary experiments in the CaO-Al2O3-MgO system to understand the formation processes and conditions of defect-structured hibonite found in meteorites
- ā¦