388 research outputs found

    Introductory Chapter: Overview of ZnO Based Nano Materials and Devices

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    FDG PET and alternative imaging in the management of thyroid carcinoma

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    Differentiated carcinoma of the thyroid are one of rare malignancies that is associated with excellent prognosis. Follow-up with regular thyroglobulin assay and 131I whole-body scan is capable of detecting residual or recurrent disease with great sensitivity and specificity. However, there is overwhelming evidence to suggest that this approach is not fail-safe due to increasing reports of false negative and false positive results, which may result in missed or unwarranted therapy with 131I. This article will review the current management of differentiated carcinoma of the thyroid and the possible causes of the reported inadequacy of thyroglobulin and 131I whole-body scan to detect residual or recurrent disease, and the increasing role of alternative imaging, particularly 18F-FDG PET in the management of this curable malignancy

    Atomistic modeling of grain boundary behavior under shear conditions in magnesium and magnesium-based binary alloys

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    In this study, the structure, the energetic, and the strength of a symmetric tilt grain boundary in magnesium and magnesium binary alloys were analyzed in the framework of (semi-)empirical potentials. Following a systematic investigation of the transferability and accuracy of the interatomic potentials, atomistic calculations of the grain boundary energy, the grain boundary sliding energy, and the grain boundary strength were performed in pure magnesium and in binary MgX alloys (X = Al, Ca, Gd, Li, Sn, Y, Ag, Nd, and Pb). The data gained in this study were analyzed to identify the most critical material parameters controlling the strength of the grain boundary, and their consequence on atomic shuffling motions occurring at the grain boundary. From the methodology perspective, the role of in-plane and out-of plane relaxation on the grain boundary sliding energy curves was investigated. In pure magnesium, the results showed that in-plane relaxation is critical in activating twinning dislocation resulting in grain boundary migration. In the alloy systems, however, grain boundary migration was disabled as a consequence of the pinning of the grain boundary by segregated elements. Finally, while the grain boundary energy, the shape of the grain boundary sliding energy curves, and the grain boundary sliding energy are critical parameters controlling the grain boundary strength in pure magnesium, only the grain boundary energy and the segregation energy of the alloying elements at the grain boundary were identified as critical material parameters in the alloys system

    Skin eruptions following treatment with Iodine-131 for hyperthyroidism. A rare and un-reported early/intermediate side effect

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    BACKGROUND: Iodine-131 (131I) is a well-established method for the treatment of hyperthyroidism. Following such therapy, patients may experience symptoms relating to early or delayed side effects that can be prevented or minimized if necessary measures are taken. We have noticed an unusual side effect of 131I therapy in the form of a skin eruption (iododerma) and aimed at assessing the frequency and severity of this side effect. MATERIAL AND METHODS: Retrospective review of 141 patients treated with 131I between January 1994 to December 2000 (86 F, 55 M; mean age 41.35 ± 11.02 years) was performed. The dose of 131I ranged from 250-500 MBq. Post therapy clinical and biochemical evaluation of thyroid function was done at 6 weeks, 3, 6, and 9 months then annually. RESULTS: Of the 141 treated patients, 3 patients (2.1%) presented with iododerma 4-6 weeks after 131I therapy administration. Lesions were observed at both ankles & lower legs in all 3 cases. All lesions disappeared within 6 months with no residual effect. No other skin lesions were seen thereafter during the follow-up period. CONCLUSION: Iododerma is a rare complication of 131I therapy that has not been reported before. It appears within 4-6 weeks after therapy and is a self-limiting condition

    Ultrafast Excited-State Dynamics of Rhenium(I) Photosensitizers [Re(Cl)(CO)_(3)(N,N)] and [Re(imidazole)(CO)_(3)(N,N)]^+: Diimine Effects

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    Femto- to picosecond excited-state dynamics of the complexes [Re(L)(CO)_(3)(N,N)]^n (N,N = bpy, phen, 4,7-dimethyl-phen (dmp); L = Cl, n = 0; L = imidazole, n = 1+) were investigated using fluorescence up-conversion, transient absorption in the 650−285 nm range (using broad-band UV probe pulses around 300 nm) and picosecond time-resolved IR (TRIR) spectroscopy in the region of CO stretching vibrations. Optically populated singlet charge-transfer (CT) state(s) undergo femtosecond intersystem crossing to at least two hot triplet states with a rate that is faster in Cl (~100 fs)^(−1) than in imidazole (~150 fs)^(−1) complexes but essentially independent of the N,N ligand. TRIR spectra indicate the presence of two long-lived triplet states that are populated simultaneously and equilibrate in a few picoseconds. The minor state accounts for less than 20% of the relaxed excited population. UV−vis transient spectra were assigned using open-shell time-dependent density functional theory calculations on the lowest triplet CT state. Visible excited-state absorption originates mostly from mixed L;N,N^(•−) → Re^(II) ligand-to-metal CT transitions. Excited bpy complexes show the characteristic sharp near-UV band (Cl, 373 nm; imH, 365 nm) due to two predominantly ππ*(bpy^(•−)) transitions. For phen and dmp, the UV excited-state absorption occurs at 305 nm, originating from a series of mixed ππ* and Re → CO;N,N•− MLCT transitions. UV−vis transient absorption features exhibit small intensity- and band-shape changes occurring with several lifetimes in the 1−5 ps range, while TRIR bands show small intensity changes (≤5 ps) and shifts (~1 and 6−10 ps) to higher wavenumbers. These spectral changes are attributable to convoluted electronic and vibrational relaxation steps and equilibration between the two lowest triplets. Still slower changes (≥15 ps), manifested mostly by the excited-state UV band, probably involve local-solvent restructuring. Implications of the observed excited-state behavior for the development and use of Re-based sensitizers and probes are discussed

    Patterns and predictors of smoking by race and medical diagnosis during hospital admission: A latent class analysis

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    Hospital-based tobacco treatment programs provide tobacco cessation for a diverse array of admitted patients. Person-centered approaches to classifying subgroups of individuals within large datasets are useful for evaluating the characteristics of the sample. This study categorized patients who received tobacco treatment while hospitalized and determined whether demographics and smoking-related health conditions were associated with group membership. Chart review data was obtained from 4854 patients admitted to a large hospital in South Carolina, USA, from July 2014 through December 2019 who completed a tobacco treatment visit. Smoking characteristics obtained from the visit interview were dichotomized, and then latent class analysis (LCA) was conducted to categorize patients based on smoking history and interest in stopping smoking. Finally, logistic regressions were used to evaluate demographics and smoking-related health conditions as predictors of class membership. LCA generated 5 classes of patients, differentiated by heaviness of smoking and motivation to quit. Patients who were black/African American were more likely to be lighter smokers compared to white patients. Hospitalized patients with a history of hypertension, diabetes, and congestive heart failure were more likely to be motivated to quit and also were more likely to be lighter smokers at the time of hospitalization. Hospitalized patients who smoke and receive tobacco treatment are heterogeneous in terms of their smoking histories and motivation to quit. Understanding latent categories of patients provides insight for tailoring interventions and potentially improving tobacco treatment outcomes
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