Probing the initial stages of plasticity with nanoindentation

The probed volumes in nanoindentation can be comparable to the characteristic length scales of some of the defect configurations that control early-stage plastic deformation in metals. Representative examples from work carried out with my collaborators will be reviewed with a view to shedding light on the elementary processes associated with the transition from elastic to plastic deformation. Among the topics to be discussed are: homogeneous versus heterogeneous dislocation nucleation, nucleation versus activation of pre-existing dislocations, effects of source density, pinning by interstitial elements, and influence of crystal structure

Simulation Application for the LHCb Experiment

We describe the LHCb detector simulation application (Gauss) based on the Geant4 toolkit. The application is built using the Gaudi software framework, which is used for all event-processing applications in the LHCb experiment. The existence of an underlying framework allows several common basic services such as persistency, interactivity, as well as detector geometry description or particle data to be shared between simulation, reconstruction and analysis applications. The main benefits of such common services are coherence between different event-processing stages as well as reduced development effort. The interfacing to Geant4 toolkit is realized through a facade (GiGa) which minimizes the coupling to the simulation engine and provides a set of abstract interfaces for configuration and event-by-event communication. The Gauss application is composed of three main blocks, i.e. event generation, detector response simulation and digitization which reflect the different stages performed during the simulation job. We describe the overall design as well as the details of Gauss application with a special emphasis on the configuration and control of the underlying simulation engine. We also briefly mention the validation strategy and the planing for the LHCb experiment simulation.Comment: Talk from the 2003 Computing in High Energy and Nuclear Physics (CHEP03), La Jolla, Ca, USA, March 2003, 6 pages, LaTeX, 9 eps figures. PSN TUMT00

Vitamin B12 Deficiency in a Patient Presenting with Dyspnea: A Case Report

Introduction: Pancytopenia can be caused by underlying disorders such as certain autoimmune conditions, leukemia or even a few nutritional deficiencies such as vitamin B12 deficiency. Vitamin B12 deficiency most commonly presents as megaloblastic anemia but can also be associated with pancytopenia. It can present with a range of symptoms associated with anemia and gastrointestinal or neurological systems. Understanding the etiology of the deficiency is crucial for initiating proper treatments. Case Report: A 19-year-old patient presented with complaints of dyspnea and fever, myalgia and generalized tiredness. Examinations found him to suffer pancytopenia and esophageal candidiasis caused by vitamin B12 deficiency. This deficiency can be associated to inadequate intake and the diet of the patient as a vegetarian. Parenteral B12 treatment led the patient to symptomatically improve. Conclusion: Vitamin B12 deficiency is a reversible cause of bone marrow failure and can be easily treated if diagnosed early enough. Eggs and animal-derived foods constitute the usual source of this vitamin. Vitamin B12 deficiency should therefore be of high index suspicion to a clinician if the patient presents in similar conditions with a vegetarian diet. In the event of the deficiency being caused by inadequate intake or intrinsic factor deficiency, the treatment can be started quickly leading to the dramatic improvement of the patient’s condition

Ultrasound-Guided Emergency Pericardiocentesis of a Patient with Multiple Myeloma in a Resource Limited Setting

Introduction: Cardiac tamponade, a variant of cardiogenic shock, is a medical emergency. A traumatic cardiac tamponade is an expected phenomenon; however, in non-traumatic events such as malignant pathology, it is usually less dramatic and takes several days or weeks to manifest. Occurrence of tamponade physiology due to pericardial effusion in a patient with multiple myeloma is a distinctly unusual entity. The involvement of a serous cavity in multiple myeloma is rare and pericardial effusion in such a case is due to restrictive cardiomyopathy or amyloidosis, a presentation late in the course of the disease that carries a grave prognosis. Case presentation: We present to you a case of a 60-year-old patient with cardiac tamponade due to pericardial effusion secondary to an advanced multiple myeloma. Due to the early diagnosis, she underwent a successful emergency pericardiocentesis with a central venous catheter under ultrasound guidance even in a resource limited emergency department (ED) of a district in southern India. She also showed marked improvement after the procedure and was transferred to the intensive care unit for further management. Conclusion: Cardiac tamponade is not an “all or none” phenomenon, but rather a continuum of findings. A high index of suspicion and timely clinical decision-making is the key for an emergency physician. Although there are several mimics for cardiac tamponade in ED, it is important for an emergency physician to be aware of such varied presentations of a disease spectrum owing to its rarity and clinical importance

Delayed diagnosis of right ventricle perforation after blind needle pericardiocentesis

A case of right ventricle perforation in a 63-year old man after blind needle pericardiocentesis for pericardial effusion is presented, focusing on the delayed diagnosis of this serious complication. During surgical repair, the pigtail catheter was found to enter the right ventricle with its tip resting within the pulmonary artery

Interstitial Nephritis Presenting as Acute Kidney Injury Following Ingestion of Alternative Medicine Containing Lead: A Case Report

Introduction: Some studies have shown that patients consuming alternate medicine can suffer from complications like acute kidney injury (AKI) due to heavy metal poisoning. The use of traditional ayurvedic herbal remedies may be difficult to identify as a source of toxicity, especially if the treating doctor is not aware of this habit, unless a detailed history is taken. In this report, we describe a patient who had consumed ayurvedic supplements for treating fever and abdominal pain and presented to our emergency department (ED) with AKI. Case presentation: A 24-year-old male presented to the ED with complaints of abdominal pain, fever and loose stools. His blood tests revealed AKI and he was started on emergency hemodialysis. His renal function improved after only one cycle of dialysis and he was discharged in a stable condition. Conclusion: Acute lead toxicity should be suspected in patients with abdominal and neurological dysfunction who have a history of chronic ayurvedic medicine intake and thus should be promptly treated. Physicians should rule out potential toxicity from these supplements and have a heightened level of suspicion for lead toxicity in patients presenting with abdominal pain and AKI without any obvious cause

Non-ST-Elevation Myocardial Infarction in a Case of Von Willebrand Disease: a Case Report

Introduction: Studies have shown that patients with Von Willebrand disease (VWD) have decreased prevalence of thrombotic events like myocardial infarction (MI). Here we describe a case of VWD with acute non-ST-elevation MI with ongoing bleeding manifestations. Case presentation: A 37-year-old female patient presented to the emergency department with a complaint of central chest pain since 7 days. She also had a history of hemoptysis since 8 days. Electrocardiogram (ECG) revealed ST-segment depression in leads I, aVL, II, III, aVF, and V4-V6 compatible with diagnosis of Non-ST-Elevation Myocardial Infarction (Non STEMI). She was started on nitroglycerine infusion, angiotensin II receptor blockers, and calcium channel blockers along with trimetazidine. Her chest pain and ECG changes settled after 2 days, and she was discharged in a stable condition. Conclusion: There are limited studies available regarding the management of acute MI in VWD patients with acute bleeding manifestations. Further studies have to be carried out to determine successful ways of managing thrombotic events like MI in this subset of patients