110 research outputs found
Peri-operative use of synthetic intravenous fluid by peri-operative physicians in South Africa
Background Peri-operative physicians increasingly acknowledge that fluid management influences patient outcome. Studies have attempted to understand the changes in practice following recently published evidence, although none have included significant contributions from South Africa. Methods An observational cohort study using an interactive online survey was conducted. Five underlying questions where highlighted during data analysis and these data were summarized into simplified categories for better comparison. Results Three hundred questionnaires where completed. During resuscitation of an unstable trauma patient, 233/300 (78%) use crystalloids, although 107/300 (36%) prefer blood products if available. Synthetic colloids for trauma patients unresponsive to initial fluid (normal haemoglobin) would be chosen first by 179/300 (60%), and 12/28 (46%) of non-anaesthesia physicians prefer blood products. Of interest, 10/300 (3%) would use either albumin or hypertonic saline when resuscitating a non-responding trauma patient. Concerning was 14/300 (5%) of respondents who would use fluid other than blood products for trauma patients with low haemoglobin. A relatively large proportion 47/300 (16%) would use synthetic colloids to resuscitate haemodynamically unstable septic patients. Conclusion The results presented are largely from anaesthesia practitioners and practice follows international trends. However, synthetic colloids are used in septic patients where evidence suggests otherwise. A lack of access to blood products probably influences practice. Findings suggest the need for continued attempts to translate research into clinical practice
Photonics design tool for advanced CMOS nodes
Recently, the authors have demonstrated large-scale integrated systems with
several million transistors and hundreds of photonic elements. Yielding such
large-scale integrated systems requires a design-for-manufacture rigour that is
embodied in the 10 000 to 50 000 design rules that these designs must comply
within advanced complementary metal-oxide semiconductor manufacturing. Here,
the authors present a photonic design automation tool which allows automatic
generation of layouts without design-rule violations. This tool is written in
SKILL, the native language of the mainstream electric design automation
software, Cadence. This allows seamless integration of photonic and electronic
design in a single environment. The tool leverages intuitive photonic layer
definitions, allowing the designer to focus on the physical properties rather
than on technology-dependent details. For the first time the authors present an
algorithm for removal of design-rule violations from photonic layouts based on
Manhattan discretisation, Boolean and sizing operations. This algorithm is not
limited to the implementation in SKILL, and can in principle be implemented in
any scripting language. Connectivity is achieved with software-defined
waveguide ports and low-level procedures that enable auto-routing of waveguide
connections.Comment: 5 pages, 10 figure
High-speed modulator with interleaved junctions in zero-change CMOS photonics
A microring depletion modulator is demonstrated with T-shaped lateral p-n
junctions used to realize efficient modulation while maximizing the RC limited
bandwidth. The device having a 3 dB bandwidth of 13 GHz has been fabricated in
a standard 45 nm microelectronics CMOS process. The cavity has a linewidth of
17 GHz and an average wavelength-shift of 9 pm/V in reverse-bias conditions.Comment: 7 pages, 3 figure
Biochemical Changes in Whole Blood - Effect of Storage
Background: Storage of whole blood has deleterious effects on the biochemical parameters of RBCs. Aim: To study the changes in biochemical parameters in whole blood upon storage. Materials and Methods: 30 healthy donors were included in this study and effect of storing whole blood was studied on day 0, 3, 7, 14 and 21. Results: Highly significant changes were noted in the levels of blood pH, sodium, potassium, chloride, bicarbonate, aspartate transaminase and lactate dehydrogenase. Conclusion: There are significant changes in the biochemical parameters during storage. The most significant change is the marked increase in potassium levels. In order to reduce the deleterious effects of stored blood in the recipient, it is advisable to check the clinical details of the patient. Care should be taken to issue fresh blood (not more than 7 days old) particularly to patients with renal disorders.
Health seeking behavior acceptability of available health facilities and knowledge about tuberculosis in a tribal area
A study was undertaken among the tribals living in Buttayagudem Mandal consisting of 53 villages in West Godavari district of Andhra Pradesh to study their health seeking behaviour, acceptability of available health facilities and knowledge about tuberculosis. Information was also obtained on their practices to get relief from illness and type of health facilities used. In all, 429 households belonging to 34 villages were selected at random and the heads of these households or the next responsible persons were interviewed. A total of 189 (44%) had heard of tuberculosis and of these, 72 (38%) attributed it to tubercle bacilli. A majority of the tribals were in favour of modern medicine and accepted the available health facilities
Sclerostin-Mediated Impaired Osteogenesis by Fibroblast-Like Synoviocytes in the Particle-Induced Osteolysis Model
Engineered biomaterials are envisioned to replace, augment, or interact with living tissues for improving the functional deformities associated with end-stage joint pathologies. Unfortunately, wear debris from implant interfaces is the major factor leading to periprosthetic osteolysis. Fibroblast-like synoviocytes (FLSs) populate the intimal lining of the synovium and are in direct contact with wear debris. This study aimed to elucidate the effect of Ti particles as wear debris on human FLSs and the mechanism by which they might participate in the bone remodeling process during periprosthetic osteolysis. FLSs were isolated from synovial tissue from patients, and the condition medium (CM) was collected after treating FLSs with sterilized Ti particles. The effect of CM was analyzed for the induction of osteoclastogenesis or any effect on osteogenesis and signaling pathways. The results demonstrated that Ti particles could induce activation of the NFκB signaling pathway and induction of COX-2 and inflammatory cytokines in FLSs. The amount of Rankl in the conditioned medium collected from Ti particle–stimulated FLSs (Ti CM) showed the ability to stimulate osteoclast formation. The Ti CM also suppressed the osteogenic initial and terminal differentiation markers for osteoprogenitors, such as alkaline phosphate activity, matrix mineralization, collagen synthesis, and expression levels of Osterix, Runx2, collagen 1α, and bone sialoprotein. Inhibition of the WNT and BMP signaling pathways was observed in osteoprogenitors after the treatment with the Ti CM. In the presence of the Ti CM, exogenous stimulation by WNT and BMP signaling pathways failed to stimulate osteogenic activity in osteoprogenitors. Induced expression of sclerostin (SOST: an antagonist of WNT and BMP signaling) in Ti particle–treated FLSs and secretion of SOST in the Ti CM were detected. Neutralization of SOST in the Ti CM partially restored the suppressed WNT and BMP signaling activity as well as the osteogenic activity in osteoprogenitors. Our results reveal that wear debris–stimulated FLSs might affect bone loss by not only stimulating osteoclastogenesis but also suppressing the bone-forming ability of osteoprogenitors. In the clinical setting, targeting FLSs for the secretion of antagonists like SOST might be a novel therapeutic approach for preventing bone loss during inflammatory osteolysis
A prospective observational study of preoperative natriuretic peptide testing in adult non-cardiac surgical patients in hospitals in Western Cape Province, South Africa
Background. International guidelines recommend risk stratification to identify high-risk non-cardiac surgical patients. It is also recommended that all patients aged ≥45 years with significant cardiovascular disease should have preoperative natriuretic peptide (NP) testing. Abnormal preoperative B-type NPs have a strong association with postoperative cardiac complications. In South African hospitals, it is not known how many patients with significant cardiovascular disease scheduled for intermediate- to high-risk surgery will have raised NPs.Objectives. To determine the prevalence of abnormal (raised) NPs in non-cardiac surgical patients with cardiac clinical risk factors. A secondary objective was to develop a model to identify surgical patients who may benefit from preoperative NP screening.Methods. The inclusion criteria were patients aged ≥45 years presenting for elective, non-obstetric, intermediate- to high-risk non-cardiac surgery with at least one of the following cardiovascular risk factors: a history of ischaemic heart disease or peripheral vascular disease (coronary equivalent); a history of stroke or transient ischaemic attack; a history of congestive cardiac failure; diabetes mellitus currently on an oral hypoglycaemic agent or insulin; and serum creatinine level >175 µmol/L (>2.0 mg/dL). Blood samples for N-terminal-prohormone B-type NP (NT-proBNP) were collected before induction of anaesthesia. The preoperative prognostic threshold for abnormal (raised) NT-proBNP was ≥300 pg/mL. A generalised linear mixed model was used to determine the association between the risk factors and an abnormal NT-proBNP level.Results. Of 172 patients, 63 (37%) had an elevated preoperative NT-proBNP level. The comorbidities independently associated with elevated preoperative NT-proBNP were coronary artery disease or peripheral vascular disease, congestive cardiac failure, diabetes mellitus, and a creatinine level >175 µmol/L.Conclusions. We strongly recommend that non-cardiac surgical patients aged ≥45 years undergoing intermediate- or high-risk non-cardiac surgery with a history of coronary artery disease/peripheral vascular disease, congestive cardiac failure, diabetes mellitus or elevated creatinine have preoperative NP testing as part of risk stratification
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