Fracture and crack growth in orthotropic laminates

A mathematical model based on the classical shear-lag assumptions is used to study the residual strength and fracture behavior of composite laminates with symmetrically placed buffer strips. The laminate is loaded by a uniform remote longitudinal tensile strain and has initial damage in the form of a transverse crack in the parent laminate between buffer strips. The crack growth behavior as a function of material properties, number of buffer-strip plies, spacing, width of buffer strips, longitudinal matrix splitting, and debonding at the interface is studied. Buffer-strip laminates are shown to arrest fracture and increase the residual strengths significantly over those of one material laminates, with S-glass being a more effective buffer strip material than Kevlar in increasing the damage tolerance of graphite/epoxy panels. For a typical graphite/epoxy laminate with S-glass buffer-strips, the residual strength is about 2.4 times the residual strength of an all graphite/epoxy panel with the same crack length. Approximately 50% of this increase is due to the S-glass/epoxy buffer-strips, 40% due to longitudinal splitting of the buffer strip interface and 10% due to bonding

Validation of an automated enzyme immunoassay for interleukin-6 for routine clinical use

Serum levels of Interleukin-6 (IL-6), a proinflammatory cytokine, are increased in early stages of inflammatory diseases such as infection and sepsis. Assay systems which permit its measurement within a few hours and as a single measurement have not been reported so far. We therefore evaluated a now commercially available automated method for IL-6 measurement on the Cobas Core(R) immunological analyzer (Roche Diagnostic Systems) which enables single IL-6 measurement within about 1 hour. The automated assay correlates well with an established, manual microtiter plate assay (Biosource GmbH) which uses the same antibodies and reagents (r=0.98). Accuracy of the automated method was established by adding known amounts of IL-6 international reference preparation. Recovery of the international standard was in the range of 92-104%. The automated assay had a precision of singletons below 6% and was linear up to 2800 pg/ml. This automated assay provides a suitable, convenient and time saving method for measurement of IL-6 serum levels in the routine clinical laboratory

Haben die Konzentrationen von Interleukin 6, Procalcitonin und CRP bei Intensivpatienten während des ersten Fieberanstieges eine prognostische Bedeutung?

Serum levels of interleukin 6 (IL-6), procalcitonin (PCT), and C-reactive protein (CRP) were measured in 38 critically ill patients immediately after an increase in body temperature above 38.3 degrees C. Ten healthy controls were also included for comparison. The onset of fever was accompanied by elevated circulating levels of all the 3 markers in comparison to healthy control subjects. However, only IL-6 levels were significantly higher (p<0.05) in nonsurvivors compared with survivors. Sensitivity, specificity, positive, and negative predictive values for survival were higher for IL-6 in comparison to levels of PCT and CRP. Areas under receiver characteristic operating curves revealed the highest area under the curve for IL-6 compared to PCT and CRP. These data suggest that IL-6 rather than PCT or CRP may be an early predictor of prognosis and mortality in patients with the onset of fever

Pharmacokinetic study of saquinavir hard gel caps/ritonavir in HIV-1-infected patients: 1600/100 mg once-daily compared with 2000/100 mg once-daily and 1000/100 mg twice-daily

Objectives: A pharmacokinetic comparison of three dosing regimens of saquinavir/ritonavir was carried out: 1600/100 mg once-daily with 1000/100 mg twice-daily, and 1600/100 mg once-daily with 2000/100 mg once-daily. Methods: Twenty patients on saquinavir hard gel caps/ritonavir 1600/100 mg once-daily in combination with two nucleoside reverse transcriptase inhibitors for at least 4 weeks were enrolled and randomized to either saquinavir hard gel caps/ritonavir 1000/100 mg twice-daily or 2000/100 mg once-daily. Two pharmacokinetic curves were plotted, at baseline (day 0) and 7 days after the switch. Plasma concentrations were measured at 0, 2, 4, 6, 8, 10, 12 (and 24 for once-daily dosing) hours after drug intake by validated high-performance liquid chromatographic assay (HPLC). The area under the plasma concentration-time curve (AUC0-24 or AUC0-12), maximum and minimum concentration (Cmax and Cmin) and elimination half-life were calculated using a non-compartmental model. Results: Compared with saquinavir/ritonavir 1600/100 mg once-daily dosing, the saquinavir AUC and Cmin improved significantly when dosed as 1000/100 mg twice-daily (53% and 299%, respectively), and as 2000/100 mg once-daily (71% and 65%, respectively). Low Cmin in three subjects at baseline was corrected after switch to the other dosages. Saquinavir/ritonavir 2000/100 mg once-daily was also associated with a significant increase in saquinavir Cmax (52%) compared with saquinavir/ritonavir 1600/100 mg once-daily. Conclusions: Saquinavir/ritonavir when dosed as 2000/100 mg once-daily or 1000/100 mg twice-daily achieves higher saquinavir plasma levels compared with saquinavir/ritonavir 1600/100 mg once-daily. Taking the convenience of once-daily dosing into consideration, dosage of 2000/100 mg once-daily may be preferre

An electrocardiagram/ electromyogram with an opto-coupler circuit as a protection

An Electrocardiogram (ECG or EKG) is an important feature in the medical environment, for instance in a hospital. Since this equipment is critical to the physician looking after the patient, the price of an ECG machine is high. When dealing with healthcare, one important aspect is the safety for both, the physician and the patient. The goal of this project is to produce a substitute, which is a cheaper version of the ECG circuit. Also treating the ECG as an Electromyography (EMG), experiment would be done to verify if the former could serve as a dual purpose circuit. Operational amplifiers (op-amps) are very useful in electronics and is the reason why they are present in almost all the major industries such as automotive and medical. This project will explore some of the qualities that op-amps can offer to meet the demand of this project. In addition, a safety circuit will be executed to ensure that the safety of the device as well as the operator is respected in all aspects. Murdoch University has an EKG sensor from Vernier, which can be used to demonstrate whether the results achieved through the amplifiers circuit’s, matches the readings from Vernier’s sensor. Finally modelling is magic as it opens the creativity mind of people, allowing them to think freely. Using this boon some modelling of muscle types have been done as it is really hard to take the EMG of two muscle types

National Politics in the Fiction of Rohinton Mistry

Representation of contemporary politics and human problems is a major theme for contemporary litterateurs and social thinkers. A number of prolific and eminent novelists such as Rohinton Mistry, Salman Rushdie, Vikram Seth, Khushwant Singh, Nayantara Sahgal, Shashi Tharoor, Amitav Ghosh, Arundhti Roy, Kiran Desai and many more have tried to explore the hidden truth and treacherous activities carried out over Indian citizens by their elected political representative on the name of different government schemes. Rohinton Mistry, an Indian of Parsi in origin presently living in Canada, represented contemporary Indian politics in his novels by subverting the conscious or unconscious cultural categorisations associated with the forms of novels focussing on the human condition located in time and space. He tried to show us how politics is used by politicians of all parties to remain in power for fulfilling their vested interest. Present paper is an effort to describe and discuss how political upheavals have an impact on the psyche of common man. It would discuss the theme of politics in the fiction of Rohinton Mistry

Atherothrombosis in cardiovascular disease

In this thesis, atherothrombosis in acute myocardial infarction and ischemic stroke is studied. We have found that this is a multifactorial process that may impact patient care