Determination of Non-Recrystallization Temperature for Niobium Microalloyed Steel

In the present investigation, the non-recrystallization temperature (T_NR) of niobium-microalloyed steel is determined to plan rolling schedules for obtaining the desired properties of steel. The value of T_NR is based on both alloying elements and deformation parameters. In the literature, T_NR equations have been developed and utilized. However, each equation has certain limitations which constrain its applicability. This study was completed using laboratory-grade low-carbon Nb-microalloyed steels designed to meet the API X-70 specification. Nb- microalloyed steel is processed by the melting and casting process, and the composition is found by optical emission spectroscopy (OES). Multiple-hit deformation tests were carried out on a Gleeble^® 3500 system in the standard pocket-jaw configuration to determine T_NR. Cuboidal specimens (10 (L) × 20 (W) × 20 (T) mm³) were taken for compression test (multiple-hit deformation tests) in gleeble. Microstructure evolutions were carried out by using OM (optical microscopy) and SEM (scanning electron microscopy). The value of T_NR determined for 0.1 wt.% niobium bearing microalloyed steel is ~ 951 °C. Nb- microalloyed steel rolled at T_NR produce partially recrystallized grain with ferrite nucleation. Hence, to verify the TNR value, a rolling process is applied with the finishing rolling temperature near TNR (~951 °C). The microstructure is also revealed in the pancake shape, which confirms T_NR.     

Response of acromegaly to long term bromocriptine therapy: a biochemical and clinical assessment.

The long term effects of bromocriptine in 12 acromegalics treated for a mean duration of 10.2 months are reported. Seven showed a significant (P less than 0.05) and sustained fall in serum immunoreactive growth hormone (GH) levels throughout 24 h, 6 of whom had a 50% or greater reduction in mean circulating GH during glucose tolerance testing. Only one patient had mean serum GH levels throughout the day suppressed to normal (less than 5 mIU/l) but 3 had suppression of mean serum GH during GTT to normal or very near normal (less than 10 mIU/l). The effective dose was 20 mg daily. Only 4 patients reported any improvement in soft tissue swelling and acral features, which was unrelated to the GH response. Possible reasons for the discrepancy between clinical and biochemical responses are discussed. In 9 of the 12 patients bromocriptine was discontinued and pituitary ablative therapy offered. Three out of 4 patients who underwent trans-sphenoidal hypophysectomy had mean GH levels during GTT reduced to less than 7 mIU/l. In the three who continued bromocriptine treatment GH suppression was maintained at less than 10 mIU/l for up to 3 years but with little change in acral features. Although bromocriptine is safe and was well tolerated it is not as effective as existing forms of pituitary ablative therapy and should be reserved for those cases where ablation is contraindicated or unsuccessful.     

COVID-19: mobilising CT as a frontline management tool

As the COVID-19 pandemic has spread across the globe, questions have arisen about the approach healthcare systems should adopt in order to optimally manage patient influx. With a focus on the impact of COVID-19 on the NHS, we describe the frontline experience of a severely affected hospital in close proximity to London. We highlight a protocol-driven approach, incorporating the use of CT in the rapid triage, assessment and cohorting of patients, in an environment where there was a lack of readily available, onsite RT-PCR testing facilities. Furthermore, the effects of the protocol on the effective streamlining of patient flow within the hospital are discussed, as are the resultant improvements in clinical management decisions within the acute care service. This model may help other healthcare systems in managing this pandemic whilst assessing their own needs and resources.