Unusual Lymphomas Developing in Chronic Lymphocytic Leukemia

We report three patients with chronic lymphocytic leukemia (CLL) who developed malignant lymphomas of unusual character and modes of presentation. Two of the patients had received low doses of chlorambucil for several years before they developed malignant lymphoma, diffuse, large cell type (LCL). In one of these patients LCL manifested as a grossly evident osteolytic lesion. In the second patient LCL developed initially as a localized lesion in the iliac bone. Both patients died within a few weeks after LCL was diagnosed. The third patient, who was found to have CLL during a routine examination, did not receive any therapy for the leukemia. Within six months the patient developed diffuse malignant lymphoma, mixed small and large cell type, with total extinction of the leukemic component. The disease responded favorably to chemotherapy for lymphoma, and the patient is alive with minimal residual disease at this time. Immunohistochemical studies in all three patients suggested transformation or dedifferentiation of the original neoplastic lymphoid clone rather than de novo appearance of another neoplasm

Primary Fibrinolysis in Acute Monocytic Leukemia

We present the case of a young man with acute monocytic leukemia (French-American-British classification:M5) and systemic hyperfibrinolysis with severe bleeding. Although fibrinolysis is usually mild and secorulary to disseminated intravascular coagulation, its role as a primary and dominant factor in rare cases of leukemia warrants that its presence be sought as a cause of abnormal bleeding. Decreased serum plasminogen and increased serum plasmin determined by synthetic substrate assay and a negative protamine paracoagulation test are crucial findings. Use of high-dose epsilon-aminocaproic acid was effective in treating this complication. A transient increase in fibrinolytic activity coincident with the early effect of antileukemic treatment suggested that plasminogen activator and/or fibrinolytic protease substances were released from leukemic cells. Fibrinolytic activity subsequently disappeared with reduction in the population of leukemic cells

Altered Platelet Function in Patients with Severe Congestive Heart Failure

Platelet function was assessed in 15 patients with severe congestive heart failure (CHF) and in 26 control subjects of similar ages. The platelet count (mm3), surface reactivity, aggregometry studies, release factors, and circulating aggregates were investigated. The mean number of circulating platelets was normal, but a hyperactive platelet response was found in 53% of the CHF patients. CHF patients had a 42% mean for the spread type platelet, and the average number of aggregates was 64: control subjects had a 12% mean for the spread type platelet, and the average number of aggregates was 40 (p \u3c 0.05). Aggregation with all of the inducers was normal, although 27% of CHF patients showed spontaneous aggregation. The mean plasma levels of both platelet factor 4 and betathromboglobulin were abnormally elevated. No circulating platelet aggregates were detected. Our studies indicate that platelet function is abnormal in patients with CHF. The abnormal platelet reactivity found might contribute to the increased incidence of thromboembolic events observed in CHF patients

Thermal oxidation of Ti6Al4V alloy: Microstructural and electrochemical characterization

Thermal oxidation (TO) of Ti6Al4V alloy was performed at 500, 650 and 800 ◦C for 8, 16, 24 and 48 h in air. The morphological features, structural characteristics, microhardness and corrosion resistance in Ringer’s solution of TO Ti6Al4V alloy were evaluated and compared with those of the untreated one. The surface morphological features reveal that the oxide film formed on Ti6Al4V alloy is adherent to the substrate at 500 and 650 ◦C irrespective of the oxidation time whereas it spalls off when the alloy is oxidized at 800◦C for more than 8 h. X-ray diffraction (XRD) measurement reveals the presence of Ti(O) and -Ti phases on alloy oxidized at 500 and 650◦C, with Ti(O) as the dominant phase at 650◦C whereas the alloy oxidized at 800◦C exhibits only the rutile phase. Almost a threefold increase in hardness is observed for the alloy oxidized at 650 ◦C for 48 h when compared to that of the untreated one. Thermally oxidized Ti6Al4V alloy offers excellent corrosion resistance in Ringer’s solution when compared to that of the untreated alloy

Influence of localized surface plasmons on Pauli blocking and optical limiting in graphene under femtosecond pumping

The Pauli blocking limit and optical limiting threshold have been found to be modified following silver-nanoparticle decoration of functionalized hydrogen induced exfoliated graphene. Femtosecond Z-scan experiments have been used to measure the Pauli blocking range, optical limiting threshold, and the third order nonlinear susceptibility (χ(3)) values. The observed results have been explained by modified band structure of graphene in the presence of silver nanoparticles and their localized surface plasmon resonances

Dangerous Face of the Sun

19-22Are we going to be roasted alive by killer solar storms that may arrive during the next solar maximum in 2012? Why and how do these solar flares occur and how do they affect the earth? Read on to find out

Effect of electropolishing on the room-temperature low-cycle fatigue behaviour of AISI 304LN stainless steel

The surfaces of specimens of AISI 304LN stainless steel were given different levels of finish by means of electropolishing and mechanical polishing with emery papers of different grit sizes. They were subjected to total strain-controlled low-cycle fatigue (LCF) deformation at room temperature. The cyclic stress response and the strain-life plots were recorded. As opposed to the mechanically polished specimens, the electropolished specimens displayed secondary hardening in the later stages of deformation even at low strain amplitudes. This behaviour could be attributed to increased martensite formation in the latter case because of the enhanced life. The effect of electropolishing in enhancing the LCF life was more pronounced at the lower strain amplitudes

A comparison of the room-temperature behaviour of AISI 304LN stainless steel and Nimonic 90 under strain cycling

The influence of room-temperature low-cycle fatigue (LCF) deformation on the microstructure and the consequent modification of the LCF behaviour were examined in the case of AISI 304LN stainless steel and the superalloy Nimonic 90. Secondary hardening due to martensite formation in AISI 304LN enhanced its resistance to plastic flow. On the other hand, in Nimonic 90 shearing of γ' particles led to cyclic softening. A change in the number of operating slip systems as well as the fracture mode was responsible for the observed two-slope behaviour in the Coffin-Manson, the cyclic stress-strain and the energy-life plots in Nimonic 90. While Nimonic 90 resisted the applied strain elastically on the basis of its strength, AISI 304LN resisted the strain plastically on the basis of its ductility. Nimonic 90 had a much higher plastic strain energy absorption capacity than AISI 304LN

Room-temperature low-cycle fatigue behaviour of a Ni-base superalloy

A nickel-base superalloy, Nimonic 90, was subjected to room-temperature low-cycle fatigue under constant total strain control. Cyclic stress response was investigated as a function of the total strain range. Hardening was attributed to slip band formation and softening to the shearing of γ' precipitates Slip band spacing decreased with increasing strain range. Two-slope behaviour or bilinearity seen in Coffin-Manson and cyclic stress-strain plots has been attributed to a change in the deformation mode with increasing strain range

Influence of martensite formation and grain size on room temperature low cycle fatigue behaviour of AISI 304LN austenitic stainless steel

The effects of strain induced martensite formation and grain size on the room temperature low cycle fatigue behaviour of AISI 304LN austenitic stainless steel were considered. Two grain sizes, namely, 60 and 350 µm, were developed via suitable solution annealing treatments. Microstructural changes before and after low cycle fatigue testing were identified. The martensitic transformation was studied using aferritescope, X-ray diffractometry, and optical microscopy. The mechanical response was correlated with the microstructural changes. Secondary hardening as well as a crossover in the strain-life plots for the two grain sizes resulted from martensite formation. Dislocation configurations depended on the strains imposed