A 60-year-old Man Presented with Relapsing Polychondritis with Haemophagocytic Lymphohistiocytosis.

Relapsing polychondritis is a rare autoimmune disorder of unknown etiology, which can affect multiple organs. It usually presents with involvement of elastic cartilage of ear and nose and involvement of other organs like kidney and central nervous system. Here, we report a case of 60-year-old man, who initially presented with fever, polyarthritis, erythema nodosum and painful swelling and redness of both external ears admitted in Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh on 13th December 2019. Two days after hospitalization, he developed sudden onset of proptosis with ophthalmoplegia. After evaluation, he was diagnosed as relapsing polychondritis with haemophagocytic lymphohistiocytosis and was treated with high dose prednisolone. His clinical condition and laboratory parameters significantly improved after treating with prednisolone during follow up.

Experimental and theoretical analysis of Dy3+-doped fiber lasers for efficient yellow emission.

We report a detailed experimental and theoretical analysis of the $^4{{\rm F}_{9/2}}$ to $^6{{\rm H}_{13/2}}$ lasing transition of a dysprosium (${{\rm Dy}^{3 +}}$)-doped ZBLAN fiber, a strong candidate for future compact and highly efficient yellow laser emission. Experimentally, we used a gallium nitride laser diode emitting at 447 nm as a pump source and measured yellow laser output generated with a maximum slope efficiency of 33%, which is less than half of the Stokes limit (of ${\sim}78\%$). This result is commensurate with two other reports of yellow emission from ${{\rm Dy}^{3 +}}$. As a result, we developed a numerical model to understand and analyze the improvement potential of this fiber laser system. For reliable spectroscopic data input to the numerical model, we measured the absorption and emission cross sections from ${{\rm Dy}^{3 +}}$-doped ZBLAN glass. We investigated the potential causes of the low experimental slope efficiency and found contributions from the background loss of the fiber and excited-state absorption (ESA) of the intracavity yellow light. We estimated the signal re-absorption cross section using the emission cross section and the McCumber relation, which was subsequently used in our numerical model to compare successfully with our experimental results. We show that the ESA can be reduced for future ${{\rm Dy}^{3 +}}$-doped yellow laser systems by cascade lasing or co-doping with a suitable rare earth ion desensitizer.

A Cost-Effective Alternative for Lateral Femoral Wall Perforation in Anterior Cruciate Ligament (ACL) Reconstruction: A Case Report.

Lateral femoral wall perforation is a rare intra-operative complication in anterior cruciate ligament (ACL) reconstruction surgery. However, it can be challenging to manage if it occurs. We share our experience on lateral femoral wall perforation managed by a large fragment washer. A 25-year-old man with right ACL injury presented with knee instability despite physiotherapy. Anterior drawer test (ADT) and Lachman test were grade 3, glide on pivot shift was positive. During ACL reconstruction, the lateral femoral wall was perforated. Due to unavailability of the rescue endobutton and budget constraint, we passed the endobutton through a washer and allowed it to sit on the washer over the lateral femoral wall. ADT and Lachman test on post-operative 6, 12 and 24 weeks were grade 1, with a negative pivot shift test. Lysholm knee score improved from 69 pre-operatively to 98 post-operatively. Conventionally, lateral femoral wall perforation can be managed by rescue endobutton, or screw and washer post technique. As this complication is rare, the rescue endobutton may not be available at all times, and the cost of the implant is also another important factor to consider. A washer can be used as an alternative technique to manage lateral femoral wall perforation in ACL reconstruction as it is not only cost-effective but also provides stable fixation with good functional outcome.

Three Level Thoracolumbar Spondylectomy for Recurrent Giant Cell Tumour of the Spine: A Case Report.

Giant cell tumour (GCT) is a benign tumour but can be locally aggressive and with the potential to metastasise especially to the lungs. Successful treatments have been reported for long bone lesions; however, optimal surgical and medical treatment for spinal and sacral lesions are not well established. In treating spinal GCTs, the aim is to achieve complete tumour excision, restore spinal stability and decompress the neural tissues. The ideal surgical procedure is an en bloc spondylectomy or vertebrectomy, where all tumour cells are removed as recurrence is closely related to the extent of initial surgical excision. However, such a surgery has a high complication rate, such as dura tear and massive blood loss. We report a patient with a missed pathological fracture of T12 treated initially with a posterior subtraction osteotomy, who had recurrence three years after the index surgery and subsequently underwent a three level vertebrectomy and posterior spinal fusion.

Future climate change impact assessment of watershed scale hydrologic processes in Peninsular Malaysia by a regional climate model coupled with a physically-based hydrology modelo.

Impacts of climate change on the hydrologic processes under future climate change conditions were assessed over Muda and Dungun watersheds of Peninsular Malaysia by means of a coupled regional climate and physically-based hydrology model utilizing an ensemble of future climate change projections. An ensemble of 15 different future climate realizations from coarse resolution global climate models' (GCMs) projections for the 21st century was dynamically downscaled to 6km resolution over Peninsular Malaysia by a regional climate model, which was then coupled with the watershed hydrology model WEHY through the atmospheric boundary layer over Muda and Dungun watersheds. Hydrologic simulations were carried out at hourly increments and at hillslope-scale in order to assess the impacts of climate change on the water balances and flooding conditions in the 21st century. The coupled regional climate and hydrology model was simulated for a duration of 90years for each of the 15 realizations. It is demonstrated that the increase in mean monthly flows due to the impact of expected climate change during 2040-2100 is statistically significant from April to May and from July to October at Muda watershed. Also, the increase in mean monthly flows is shown to be significant in November during 2030-2070 and from November to December during 2070-2100 at Dungun watershed. In other words, the impact of the expected climate change will be significant during the northeast and southwest monsoon seasons at Muda watershed and during the northeast monsoon season at Dungun watershed. Furthermore, the flood frequency analyses for both watersheds indicated an overall increasing trend in the second half of the 21st century.