466 research outputs found
A 10-Year Prospective Evaluation of Balloon Tube Tamponade and Emergency Injection Sclerotherapy for Actively Bleeding Oesophageal Varices
During a 10 year study period 234 patients were admitted on 371 occasions with a total of 566 acute variceal
bleeding episodes. Of these, 173 patients had 343 variceal bleeds which required balloon tamponade to
achieve initial control of bleeding during 229 admissions and were then referred for emergency injection
sclerotherapy. Sixty-eight percent of these patients had alcoholic cirrhosis and 42% were poor risk Grade
C patients. Injection sclerotherapy was performed initially using the rigid Negus oesophagoscope under
general anaesthesia and later using the fibreoptic endoscope under light sedation. Definitive control of
variceal bleeding was achieved with sclerotherapy during 197 hospital admissions (92%). Of the 17
failures of emergency sclerotherapy, 4 patients died from uncontrolled bleeding and 13 patients
underwent major surgical intervention. Definitive control of variceal bleeding was achieved with a single
injection treatment in 138 hospital admissions (70%). Complications were mostly of a minor nature and
occurred at a rate of 6% per injection treatment. The overall hospital admission mortality was 36%. The
majority of patients died due to liver failure. The mortality in patients who required 4 injection treatments
to control variceal bleeding was 71%. Injection sclerotherapy is proposed as the emergency treatment of
choice for patients whose variceal bleeding continues or recurs after initial conservative management.
Patients whose variceal bleeding is not controlled by 2 injection treatments require more major
emergency surgery
Modified polysaccharide-based particles for strengthening paper
Thesis (PhD (Process Engineering))--University of Stellenbosch, 2010.ENGLISH ABSTRACT: The ongoing trend in papermaking industries is to lower production costs by increasing
the low cost filler content in the sheets. However, the disruption of inter-fibre bonding is
accompanied by a deterioration of paper stiffness and mechanical properties if filler content
exceeds 18 wt%. Polysaccharide solutions, such as starch, are often used as a low cost
biodegradable additive to improve internal sheet strength when added to the wet-end of
production. The amount of starch that can be added is however limited as only a small percentage
will be retained in the paper web.
A dual additive multifunctional polysaccharide system was developed to allow higher
filler loading levels without detrimental deterioration in paper properties. In order to achieve a
larger surface area for fibre/filler interaction and to reduce drainage losses, at least one of these
additives was in particulate form. Anionic, cationic, and unsaturated derivatives were prepared
using sodium monochloroacetate, 3-chloro-2-hydroxypropyltrimethylammonium chloride, and
allyl bromide, respectively. The degree of substitution was determined by 1H-NMR spectroscopy
and back titration methods and the interaction of the ionic modified derivatives with paper
components was determined using fluorescence microscopy.
Anionic modified polysaccharide particles were prepared using techniques such as
macrogel ultrasonification, water-in-water emulsification, and in-situ cross-linking and
carboxymethylation of granular starch. A process of adding sequential layers of oppositely
charged polyelectrolyte layers onto the filler particles was also investigated. A novel approach of
preparing modified particles with tailored size and distribution using microfluidics was studied
and modelled using response surface methodology.
Hand sheets were prepared using the dual additive system and improvements in stiffness,
tear resistance, breaking length, and folding endurance were observed. The modified granular
maize starch particles had a pre-eminent effect on improving stiffness at higher filler loadings
(14% improvement at 30 wt% filler loading), while bulky particles prepared using microfluidics
showed a more consistent improvement (between 6% and 10%) across the loading range.
Overall improvements gained by the introduction of multi-layered soluble polymers onto
fillers suggest that the introduction of nanotechnology to the papermaking process should be of
potential benefit to the industry. Furthermore, the dual additive system developed during the
course of this study should also be tested on a continuous pilot plant papermaking process.AFRIKAANSE OPSOMMING: Die papierindustrie neig voortdurend daarna om produksiekostes te verlaag deur die
persentasie lae koste vulstof wat gebruik word te verhoog. Aangesien die vulstof vesel kontak
belemmer, gaan hoër vlakke (> 18 wt%) egter gepaard met ’n verlaging in papier styfheid en
meganiese eienskappe. Polisakkaried oplossings, soos byvoorbeeld stysel, word dikwels gebruik
as lae koste vergaanbare bymiddel om papier intern te versterk wanneer dit voor die
vormingsproses bygevoeg word. Slegs ’n beperkte hoeveelheid stysel word egter behou in die
papier matriks en oormatige oplossings ontsnap tydens dreinering in die afvalwater.
’n Dubbele multi-funksionele polisakkaried bymiddelsisteem was ontwikkel wat
ongewensde verwakking in papiereienskappe verminder tydens vulstof verhogings. Ten minste
een van die bymiddels was in partikelvorm om sodoende ’n groter oppervlak te bied vir
vesel/vulstof interaksie en om dreineringsverliese te verminder. Anioniese, kationiese, sowel as
onversadigde derivate was berei deur onderskeidelik gebruik te maak van natrium
monochloroasetaat, 3-chloro-2-hidroksiepropieltrimetielammonium chloried, en alliel bromied.
Die graad van substitutiese was bepaal met behulp van 1H-KMR spektroskopie sowel as titrasie
tegnieke terwyl die ioniese interaksie van die gemodifiseerde stysels met die papierkomponente
ondersoek was met behulp van fluoressensie mikroskopie.
Anioniese polisakkaried partikels was berei met tegnieke soos makro-jel ultrasonifikasie,
water-in-water emulsifikasie, en in-situ kruisbinding en karboksiemetielasie van stysel granulate.
’n Proses was ook ondersoek waar vulstof partikels omhul was in verskeie lae poliëlektroliet
oplossings. ’n Nuwe benadering was toegepas waar gemodifiseerde partikels met voorafbepaalde
grootte en verspreiding berei is deur gebruik te maak van mikrofluïdika en gemodelleer met
behulp van oppervlakte ontwerp metodeleer.
Papier toetse was uitgevoer met die bymiddelsisteem en algehele verbetering in styfheid,
skeurweerstand, breeklengte, en voulydsaamheid is waargeneem. Die gemodifiseerde stysel
granulate het die grootste verbetering in styfheid by hoë vulstofladings getoon (14% verbetering
by 30 wt% vulstoflading) terwyl die groter mikrofluïdika-bereide partikels algehele verbetering
(tussen 6% en 10%) getoon het oor die hele vulstoflading reeks.
Die verbeteringe in styfheid sowel as meganiese eienskappe van papier voorberei met
poliëlektroliet omhulde vulstof toon dat aanwending van nanotegnologie in hierdie bedryf
potensieel voordelig kan wees. Opskalering van die polisakkaried bymiddels ontwikkel
gedurende hierdie studie behoort uitgevoer te word vir verdere toetse op ’n kontinue papier
loodsaanleg
Statin therapy in critical illness : an international survey of intensive care physicians' opinions, attitudes and practice
Background
Pleotropic effects of statins on inflammation are hypothesised to attenuate the severity of and possibly prevent the occurrence of the host inflammatory response to pathogen and infection-related acute organ failure. We conducted an international survey of intensive care physicians in Australia, New Zealand (ANZ) and United Kingdom (UK). The aims of the survey were to assess the current prescribing practice patterns, attitudes towards prescribing statin therapy in critically ill patients and opinions on the need for an interventional trial of statin therapy in critically ill patients.
Methods
Survey questions were developed through an iterative process. An expert group reviewed the resulting 26 items for face and content validity and clarity. The questions were further refined following pilot testing by ICU physicians from Australia, Canada and the UK. We used the online Smart SurveyTM software to administer the survey.
Results
Of 239 respondents (62 from ANZ and 177 from UK) 58% worked in teaching hospitals; most (78.2%) practised in ‘closed’ units with a mixed medical and surgical case mix (71.0%). The most frequently prescribed statins were simvastatin (77.6%) in the UK and atorvastatin (66.1%) in ANZ. The main reasons cited to explain the choice of statin were preadmission prescription and pharmacy availability. Most respondents reported never starting statins to prevent (65.3%) or treat (89.1%) organ dysfunction. Only a minority (10%) disagreed with a statement that the risks of major side effects of statins when prescribed in critically ill patients were low. The majority (84.5%) of respondents strongly agreed that a clinical trial of statins for prevention is needed. More than half (56.5%) favoured rates of organ failure as the primary outcome for such a trial, while a minority (40.6%) favoured mortality.
Conclusions
Despite differences in type of statins prescribed, critical care physicians in the UK and ANZ reported similar prescription practices. Respondents from both communities agreed that a trial is needed to test whether statins can prevent the onset of new organ failure in patients with sepsis
Geographic variation and plasticity in climate stress resistance among southern African populations of Ceratitis capitate (Weidemann) (Diptera: Tephritidae)
Traits of thermal sensitivity or performance are typically the focus of species distribution modelling. Among-population trait variation, trait plasticity, population connectedness and the possible climatic covariation thereof are seldom accounted for. Here, we examine multiple climate stress resistance traits, and the plasticity thereof, for a globally invasive agricultural pest insect, the Mediterranean
fruit fly, Ceratitis capitata (Wiedemann) (Diptera: Tephritidae). We also accounted for body size and population genetic connectivity among distinct populations from diverse bioclimatic regions across southern Africa. Desiccation resistance, starvation resistance, and critical thermal minimum (CTmin) and maximum (CTmax) of C. capitata varied between populations. For thermal tolerance traits, patterns of flexibility in response to thermal acclimation were suggestive of beneficial acclimation, but this was not the case for desiccation or starvation resistance. Population differences in measured traits were larger than those associated with acclimation, even though gene flow was high. Desiccation resistance was weakly but positively affected by growing degree-days. There was also a weak positive relationship between CTmin and temperature seasonality, but CTmax was weakly but negatively affected by the same
bioclimatic variable. Our results suggest that the invasive potential of C. capitata may be supported by adaptation of tolerance traits to local bioclimatic conditions
DIE ONTWIKKELING VAN ’N BEMARKINGSTRATEGIE VIR CENTURION GEMEENSKAPSDIENS
Centurion Community Services (CCS), a social service agency situated in Lyttelton,Pretoria, was founded in February 1999. The geographical area where services were rendered over the past four years has been transformed from a once quiet rural scene to a densely populated urban area. The founding of CCS testifies to a pro-active step to address anticipated social problems associated with urbanisation.A qualitative study was launched with the aim to assess the community’s perception concerning CCS and whether this service is able to fulfil the needs and wants of the community with a view of development of guidelines for a consumer-based marketing strategy.A schedule covering the seven critical areas of decision-making in a marketing strategy had been developed and utilised as a data collection instrument to collect data from respondents, who have all been beneficiaries in one way or another of this service.It was found that a strategic planning process should be implemented in order to obtain clarity regarding the vision and mission of the organization; a marketing plan (which includes the strategic analysis, the SWOT analysis, marketing objectives and marketing strategy) should be applied extensively. A number of recommendations regarding critical decision making areas were also formulated
Long-Term Management After Variceal Bleed — The Current Role of Sclerotherapy
While injection sclerotherapy has been accepted as the treatment of choice for acute variceal bleeding,
its role as a definitive long-term treatment modality has not yet been clearly defined. This paper will
critically analyse the current status of this technique, now widely used, and a comparison will be made
with conventional medical management. The review will be based on the 10 years' Cape Town
experience and the published series on this subject. A long-term management strategy will also be
discussed
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