13 research outputs found
Mössbauer studies of Soltmany and Shisr 176 meteorites â comparison with other ordinary chondrites
Coexistence of a colon carcinoma with two distinct renal cell carcinomas: a case report
<p>Abstract</p> <p>Introduction</p> <p>We present the case of a patient with two tumors in his left kidney and a synchronous colon cancer. While coexisting tumors have been previously described in the same kidney or the kidney and other organs, or the colon and other organs, to the best of our knowledge no such concurrency of three primary tumors has been reported in the literature to date.</p> <p>Case presentation</p> <p>A 72-year-old man of Greek nationality presenting with pain in the right hypochondrium underwent a series of examinations that revealed gallstones, a tumor in the hepatic flexure of the colon and an additional tumor in the upper pole of the left kidney. He was subjected to a right hemicolectomy, left nephrectomy and cholecystectomy, and his postoperative course was uneventful. Histopathology examinations showed a mucinous colon adenocarcinoma, plus two tumors in the left kidney, a papillary renal cell carcinoma and a chromophobe renal cell carcinoma.</p> <p>Conclusion</p> <p>This case underlines the need to routinely scan patients pre-operatively in order to exclude coexisting tumors, especially asymptomatic renal tumors in patients with colorectal cancer, and additionally to screen concurrent tumors genetically in order to detect putative common genetic alterations.</p
Origin of ferromagnetic response in diluted magnetic semiconductors and oxides
This paper reviews the present understanding of the origin of ferromagnetic
response of diluted magnetic semiconductors and diluted magnetic oxides as well
as in some nominally magnetically undoped materials. It is argued that these
systems can be grouped into four classes. To the first belong composite
materials in which precipitations of a known ferromagnetic, ferrimagnetic or
antiferromagnetic compound account for magnetic characteristics at high
temperatures. The second class forms alloys showing chemical nano-scale phase
separation into the regions with small and large concentrations of the magnetic
constituent. To the third class belong (Ga,Mn)As, heavily doped p-(Zn,Mn)Te,
and related semiconductors. In these solid solutions the theory built on p-d
Zener's model of hole-mediated ferromagnetism and on either the Kohn-Luttinger
kp theory or the multi-orbital tight-binding approach describes qualitatively,
and often quantitatively many relevant properties. Finally, in a number of
carrier-doped DMS and DMO a competition between long-range ferromagnetic and
short-range antiferromagnetic interactions and/or the proximity of the
localisation boundary lead to an electronic nano-scale phase separation.Comment: review, 19 pages, 4 figure
Diverse mechanisms in proton knockout reactions from the Borromean nucleus 17Ne
Nucleon knockout experiments using beryllium or carbon targets reveal a strong dependence of the quenching factors, i.e., the ratio (R s) of theoretical to the experimental spectroscopic factors (C 2S), on the proton-neutron asymmetry in the nucleus under study. However, this dependence is greatly reduced when a hydrogen target is used. To understand this phenomenon, exclusive 1H (17Ne , 2p16F) and inclusive 12C(17Ne,2p16F)X , 12C (17Ne , 16F) X as well as 1H (17Ne , 16F) X (X-denotes undetected reaction products) reactions with 16F in the ground and excited states were analysed. The longitudinal momentum distribution of 16F and the correlations between the detached protons were studied. In the case of the carbon target, there is a significant deviation from the predictions of the eikonal model. The eikonal approximation was used to extract spectroscopic factor values C 2S . The experimental C 2S value obtained with C target is markedly lower than that for H target. This is interpreted as rescattering due to simultaneous nucleon knockout from both reaction partners, 17Ne and 12C
Antiferromagnetic interlayer coupling in ferromagnetic semiconductor
Antiferromagnetic coupling between ferromagnetic layers has been observed
for the first time in an all-semiconductor superlattice structure
\chem{EuS/PbS(001)}, by neutron scattering and magnetization measurements.
Spin-dependent superlattice band structure effects are invoked to explain
the possible origin and the strength of the observed coupling