1,433 research outputs found
Primary cervical malignant teratoma with a rib metastasis in an adult: Five-year survival after surgery and chemotherapy: A case report with a review of the literature
We report a case of a man presenting with a cervical malignant teratoma and a chondrosarcomatous rib metastasis. He was alive and free of recurrence five years and 10 months (= 70 months) after resection of the primary mass, followed by chemotherapy and subsequent resection of the rib tumor. This is the 35th patient reported in the literature and the first description in which an ‘adjuvant' or primary chemotherapy was used. Previous patients with a cervical malignant teratoma, reported after lethal outcome, had survivals of one to 22 months (median nine months). In all patients with a preoperative clinical impression of an aggressive, differentiated or undifferentiated malignancy, the definite diagnosis of teratoma could only be made histologically. By analogy to germ cell tumors, the prognosis of malignant teratoma might be improved if complete excision is combined with new, adjuvant chemotherapy protocols for germ cell tumors. Lessons learned from this case are placed in the context of germ cell tumors in general and of non-gonadal malignant teratomas in particula
Spectroscopy of stripe order in La1.8Sr0.2NiO4 using resonant soft x-ray diffraction
Strong resonant enhancements of the charge-order and spin-order
superstructure-diffraction intensities in La1.8Sr0.2NiO4 are observed when
x-ray energies in the vicinity of the Ni L2,3 absorption edges are used. The
pronounced photon-energy and polarization dependences of these diffraction
intensities allow for a critical determination of the local symmetry of the
ordered spin and charge carriers. We found that not only the antiferromagnetic
order but also the charge-order superstructure resides within the NiO2 layers;
the holes are mainly located on in-plane oxygens surrounding a Ni2+ site with
the spins coupled antiparallel in close analogy to Zhang-Rice singlets in the
cuprates.Comment: 4 pages, 3 figure
Critical Behaviour of Structure Factors at a Quantum Phase Transition
We review the theoretical behaviour of the total and one-particle structure
factors at a quantum phase transition for temperature T=0. The predictions are
compared with exact or numerical results for the transverse Ising model, the
alternating Heisenberg chain, and the bilayer Heisenberg model. At the critical
wavevector, the results are generally in accord with theoretical expectations.
Away from the critical wavevector, however, different models display quite
different behaviours for the one-particle residues and structure factors.Comment: 17 pp, 10 figure
High (but Not Low) Urinary Iodine Excretion Is Predicted by Iodine Excretion Levels from Five Years Ago
Background: It has not been investigated whether there are associations between urinary iodine (UI) excretion measurements some years apart, nor whether such an association remains after adjustment for nutritional habits. The aim of the present study was to investigate the relation between iodine-creatinine ratio (ICR) at two measuring points 5 years apart. Methods: Data from 2,659 individuals from the Study of Health in Pomerania were analyzed. Analysis of covariance and Poisson regressions were used to associate baseline with follow-up ICR. Results: Baseline ICR was associated with follow-up ICR. Particularly, baseline ICR >300 mu g/g was related to an ICR >300 mu g/g at follow-up (relative risk, RR: 2.20; p < 0.001). The association was stronger in males (RR: 2.64; p < 0.001) than in females (RR: 1.64; p = 0.007). In contrast, baseline ICR <100 mu g/g was only associated with an ICR <100 mu g/g at follow-up in males when considering unadjusted ICR. Conclusions: We detected only a weak correlation with respect to low ICR. Studies assessing iodine status in a population should take into account that an individual with a low UI excretion in one measurement is not necessarily permanently iodine deficient. On the other hand, current high ICR could have been predicted by high ICR 5 years ago. Copyright (C) 2011 S. Karger AG, Base
Soft X-ray resonant scattering study of single-crystal LaSrMnO
Soft X-ray resonant scattering studies at the Mn - and
the La - edges of single-crystal LaSrMnO are
reported. At low temperatures, below K, energy scans
with a fixed momentum transfer at the \emph{A}-type antiferromagnetic (0 0 1)
reflection around the Mn -edges with incident linear
and polarizations show strong resonant enhancements. The
splitting of the energy spectra around the Mn -edges may
indicate the presence of a mixed valence state, e.g., Mn/Mn. The
relative intensities of the resonance and the clear shoulder-feature as well as
the strong incident and polarization dependences strongly
indicate its complex electronic origin. Unexpected enhancement of the charge
Bragg (0 0 2) reflection at the La -edges with
polarization has been observed up to 300 K, with an anomaly appearing around
the orbital-ordering transition temperature, K,
suggesting a strong coupling (competition) between them.Comment: Accepted by European Physical Journal
Simulations of a single membrane between two walls using a Monte Carlo method
Quantitative theory of interbilayer interactions is essential to interpret
x-ray scattering data and to elucidate these interactions for biologically
relevant systems. For this purpose Monte Carlo simulations have been performed
to obtain pressure P and positional fluctuations sigma. A new method, called
Fourier Monte-Carlo (FMC), that is based on a Fourier representation of the
displacement field, is developed and its superiority over the standard method
is demonstrated. The FMC method is applied to simulating a single membrane
between two hard walls, which models a stack of lipid bilayer membranes with
non-harmonic interactions. Finite size scaling is demonstrated and used to
obtain accurate values for P and sigma in the limit of a large continuous
membrane. The results are compared with perturbation theory approximations, and
numerical differences are found in the non-harmonic case. Therefore, the FMC
method, rather than the approximations, should be used for establishing the
connection between model potentials and observable quantities, as well as for
pure modeling purposes.Comment: 10 pages, 10 figure
Urinary iodine concentration during pregnancy in an area of unstable dietary iodine intake in Switzerland
We prospectively investigated urinary iodine concentration (UIC) in pregnant women and in female, non-pregnant controls in the canton of Berne, Switzerland, in 1992. Mean UIC of pregnant women [205±151 μg iodine/g creatinine (μg I/g Cr); no.=153] steadily decreased from the first (236±180 μg I/g Cr; no.=31) to the third trimester (183±111 μg I/g Cr, p<0.0001; no.=66) and differed significantly from that of the control group (91±37 μg I/g Cr, p<0.0001; no.=119). UIC increased 2.6-fold from levels indicating mild iodine deficiency in controls to the first trimester, demonstrating that high UIC during early gestation does not necessarily reflect a sufficient iodine supply to the overall population. Pregnancy is accompanied by important alterations in the regulation of thyroid function and iodine metabolism. Increased renal iodine clearance during pregnancy may explain increased UIC during early gestation, whereas increased thyroidal iodine clearance as well as the iodine shift from the maternal circulation to the growing fetal-placental unit, which both tend to lower the circulating serum levels of inorganic iodide, probably are the causes of the continuous decrease of UIC over the course of pregnancy. Mean UIC in our control group, as well as in one parallel and several consecutive investigations in the same region in the 1990s, was found to be below the actually recommended threshold, indicating a new tendency towards mild to moderate iodine deficiency. As salt is the main source of dietary iodine in Switzerland, its iodine concentration was therefore increased nationwide in 1998 for the fourth time, following increases in 1922, 1965 and 198
Universal Window for Two Dimensional Critical Exponents
Two dimensional condensed matter is realised in increasingly diverse forms
that are accessible to experiment and of potential technological value. The
properties of these systems are influenced by many length scales and reflect
both generic physics and chemical detail. To unify their physical description
is therefore a complex and important challenge. Here we investigate the
distribution of experimentally estimated critical exponents, , that
characterize the evolution of the order parameter through the ordering
transition. The distribution is found to be bimodal and bounded within a window
, facts that are only in partial agreement with
the established theory of critical phenomena. In particular, the bounded nature
of the distribution is impossible to reconcile with existing theory for one of
the major universality classes of two dimensional behaviour - the XY model with
four fold crystal field - which predicts a spectrum of non-universal exponents
bounded only from below. Through a combination of numerical and renormalization
group arguments we resolve the contradiction between theory and experiment and
demonstrate how the "universal window" for critical exponents observed in
experiment arises from a competition between marginal operators.Comment: 26 pages, 5 figures and 6 tables. Uses longtable packag
A resource of genome-wide single-nucleotide polymorphisms generated by RAD tag sequencing in the critically endangered European eel
Reduced representation genome sequencing such as restriction-site-associated DNA (RAD) sequencing is finding increased use to identify and genotype large numbers of single-nucleotide polymorphisms (SNPs) in model and nonmodel species. We generated a unique resource of novel SNP markers for the European eel using the RAD sequencing approach that was simultaneously identified and scored in a genome-wide scan of 30 individuals. Whereas genomic resources are increasingly becoming available for this species, including the recent release of a draft genome, no genome-wide set of SNP markers was available until now. The generated SNPs were widely distributed across the eel genome, aligning to 4779 different contigs and 19 703 different scaffolds. Significant variation was identified, with an average nucleotide diversity of 0.00529 across individuals. Results varied widely across the genome, ranging from 0.00048 to 0.00737 per locus. Based on the average nucleotide diversity across all loci, long-term effective population size was estimated to range between 132 000 and 1 320 000, which is much higher than previous estimates based on microsatellite loci. The generated SNP resource consisting of 82 425 loci and 376 918 associated SNPs provides a valuable tool for future population genetics and genomics studies and allows for targeting specific genes and particularly interesting regions of the eel genome
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