Renal Cell Carcinoma Presenting as Metastasis to Scrotum and Spermatic Cord

Unusual site metastasis as presenting complaint of renal cell carcinoma (RCC) has been reported previously in literature. RCC is a notorious tumor with unpredictable behavior. We present a case of RCC who presented with scrotal mass and on subsequent investigation was found to have metastasis to scrotum and spermatic cord. Both testes were normal with no evidence of metastasis

The Health-Seeking Behavior of Leprosy Patients: An explanatory model

The way people interpret their diseases/illness and its treatment, or the meanings of these, has a direct impact on the way populations at the community and reagional levels deal with their illness as well as the treatments sought and chosen. Our study sets out to assess the socio-demographic profile of leprosy patients and their health-seeking behaviour. We also explore certain cultural factors hallmarking local, traditional remedial choices and as to how this presents an obstacle to effective treatement and consultation. This said, our study further considers how cultural variations lead to interpreting the signs and symptoms of leprosy, that is, to different ways of seeing symptoms and ailments

Giant Electroresistance in Ferroelectric Tunnel Junctions

The interplay between the electron transport in metal/ferroelectric/metal junctions with ultrathin ferroelectric barriers and the polarization state of a barrier is investigated. Using a model which takes into account screening of polarization charges in metallic electrodes and direct quantum tunneling across a ferroelectric barrier we calculate the change in the tunneling conductance associated with the polarization switching. We find the conductance change of a few orders of magnitude for metallic electrodes with significantly different screening lengths. This giant electroresistance effect is the consequence of a different potential profile seen by transport electrons for the two opposite polarization orientations.Comment: 4 page

Ferroelectric Dead Layer Driven by a Polar Interface

Based on first-principles and model calculations we investigate the effect of polar interfaces on the ferroelectric stability of thin-film ferroelectrics. As a representative model, we consider a TiO2-terminated BaTiO3 film with LaO monolayers at the two interfaces that serve as doping layers. We find that the polar interfaces create an intrinsic electric field that is screened by the electron charge leaking into the BaTiO3 layer. The amount of the leaking charge is controlled by the boundary conditions which are different for three heterostructures considered, namely Vacuum/LaO/BaTiO3/LaO, LaO/BaTiO3, and SrRuO3/LaO/BaTiO3/LaO. The intrinsic electric field forces ionic displacements in BaTiO3 to produce the electric polarization directed into the interior of the BaTiO3 layer. This creates a ferroelectric dead layer near the interfaces that is non-switchable and thus detrimental to ferroelectricity. Our first-principles and model calculations demonstrate that the effect is stronger for a larger effective ionic charge at the interface and longer screening length due to a stronger intrinsic electric field that penetrates deeper into the ferroelectric. The predicted mechanism for a ferroelectric dead layer at the interface controls the critical thickness for ferroelectricity in systems with polar interfaces.Comment: 33 Pages, 5 figure

Experimental evidence of strong phonon scattering in isotopical disordered systems: The case of LiH_xD_{1-x} crystals

The observation of the local - mode vibration, the two - mode behavior of the LO phonons at large isotope concentration, as well as large line broadening in LIH - D mixed crystals directly evidence strong additional phonon scattering due to the isotope - induced disorder.Comment: 9 pages, 4 figure

Magnetic Moment Softening and Domain Wall Resistance in Ni Nanowires

Magnetic moments in atomic scale domain walls formed in nanoconstrictions and nanowires are softened which affects dramatically the domain wall resistance. We perform ab initio calculations of the electronic structure and conductance of atomic-size Ni nanowires with domain walls only a few atomic lattice constants wide. We show that the hybridization between noncollinear spin states leads to a reduction of the magnetic moments in the domain wall. This magnetic moment softening strongly enhances the domain wall resistance due to scattering produced by the local perturbation of the electronic potential.Comment: 4 pages, 5 figure

Spin blockade in ferromagnetic nanocontacts

Using a free-electron model and a linear response theory we investigate spin-dependent electronic transport in magnetic nanocontacts in the ballistic regime of conduction. We emphasize the fact that in atomic-size ferromagnetic contacts it is possible to achieve the conductance value of e2/h, which implies a fully spin-polarized electric current. We explore some consequences of this phenomenon. In particular, we show that the presence of a nonmagnetic region in the nanocontact separating two ferromagnetic electrodes can lead to a spin blockade resulting in very large values of magnetoresistance

Factors associated with month 2 smear non-conversion among category 1 tuberculosis patients in Karachi, Pakistan

Predictors of smear non-conversion at baseline can help identify cases at risk for failure of tuberculosis treatment. Retrospective data for smear-positive Category 1 patients in Karachi, Pakistan, was analyzed. Predictors of sputum conversion were determined using multiple logistic regression with sputum conversion as outcome variable and patient demographics, baseline weight, baseline sputum smear grade, case-finding approach as explanatory variables. Age ≥35 years, baseline sputum grade of 3+ were significantly associated with predicting sputum smear positivity at month 2 of treatment. Monitoring compliance to TB treatment should be considered amongst older patients and those with a high sputum grade at baseline

Spin-dependent tunneling from clean and oxidized Co surfaces

Transmission through a sufficiently thick vacuum barrier is factorized in the product of two ‘‘surface transmission functions’’ and a vacuum decay factor. Based on this factorization, we study the spin polarization of the tunneling current from clean and oxidized (1 1 1) FCC Co surfaces through vacuum into Al. The conductance is calculated using the principal-layer Green’s function approach within the tight-binding LMTO scheme. We find that for typical vacuum barrier thicknesses the tunneling current from the clean surface is dominated by minority-spin electrons. A monolayer of oxygen on top of the surface completely changes the shape of kll-resolved transmission and makes the tunneling current almost 100% majority-spin polarized