Energy levels and far-infrared spectroscopy for two electrons in a semiconductor nanoring

The effects of electron-electron interaction of a two-electron nanoring on the energy levels and far-infrared (FIR) spectroscopy have been investigated based on a model calculation which is performed within the exactly numerical diagonalization. It is found that the interaction changes the energy spectra dramatically, and also shows significant influence on the FIR spectroscopy. The crossings between the lowest spin-singlet and triplet states induced by the coulomb interaction are clearly revealed. Our results are related to the experiment recently carried out by A. Lorke et al. [Phys. Rev. Lett. 84, 2223 (2000)].Comment: 17 pages, 6 figures, revised and accepted by Phys. Rev. B (Dec. 15

Circulating metastasis associated in colon cancer 1 transcripts in gastric cancer patient plasma as diagnostic and prognostic biomarker

Aim: To evaluate the diagnostic and prognostic value of circulating Metastasis Associated in Colon Cancer 1 (MACC1) transcripts in plasma of gastric cancer patients. Methods: We provide for the first time a blood-based assay for transcript quantification of the metastasis inducer MACC1 in a prospective study of gastric cancer patient plasma. MACC1 is a strong prognostic biomarker for tumor progression and metastasis in a variety of solid cancers. We conducted a study to define the diagnostic and prognostic power of MACC1 transcripts using 76 plasma samples from gastric cancer patients, either newly diagnosed with gastric cancer, newly diagnosed with metachronous metastasis of gastric cancer, as well as follow-up patients. Findings were controlled by using plasma samples from 54 tumor-free volunteers. Plasma was separated, RNA was isolated, and levels of MACC1 as well as S100A4 transcripts were determined by quantitative RT-PCR. Results: Based on the levels of circulating MACC1 transcripts in plasma we significantly discriminated tumor-free volunteers and gastric cancer patients (P < 0.001). Levels of circulating MACC1 transcripts were increased in gastric cancer patients of each disease stage, compared to tumor-free volunteers: patients with tumors without metastasis (P = 0.005), with synchronous metastasis (P = 0.002), with metachronous metastasis (P = 0.005), and patients during follow-up (P = 0.021). Sensitivity was 0.68 (95%CI: 0.45-0.85) and specificity was 0.89 (95%CI: 0.77-0.95), respectively. Importantly, gastric cancer patients with high circulating MACC1 transcript levels in plasma demonstrated significantly shorter survival when compared with patients demonstrating low MACC1 levels (P = 0.0015). Furthermore, gastric cancer patients with high circulating transcript levels of MACC1 as well as of S100A4 in plasma demonstrated significantly shorter survival when compared with patients demonstrating low levels of both biomarkers or with only one biomarker elevated (P = 0.001). Conclusion: Levels of circulating MACC1 transcripts in plasma of gastric cancer patients are of diagnostic value and are prognostic for patient survival in a prospective study

Circulating MACC1 transcripts in colorectal cancer patient plasma predict metastasis and prognosis

BACKGROUND: Metastasis is the most frequent cause of treatment failure and death in colorectal cancer. Early detection of tumors and metastases is crucial for improving treatment strategies and patient outcome. Development of reliable biomarkers and simple tests routinely applicable in the clinic for detection, prognostication, and therapy monitoring is of special interest. We recently identified the novel gene Metastasis-Associated in Colon Cancer 1 (MACC1), a key regulator of the HGF/Met-pathway. MACC1 is a strong prognostic biomarker for colon cancer metastasis and allows identification of high-risk subjects in early stages, when determined in patients' primary tumors. To overcome the limitation of a restricted number of molecular analyses in tumor tissue, the establishment of a non-invasive blood test for early identification of high-risk cancer patients, for monitoring disease course and therapy response is strongly needed. METHODOLOGY/PRINCIPAL FINDINGS: For the first time, we describe a non-invasive assay for quantification of circulating MACC1 transcripts in blood of more than 300 colorectal cancer patients. MACC1 transcript levels are increased in all disease stages of the cancer patients compared to tumor-free volunteers. Highest MACC1 levels were determined in individuals with metastases (all P<0.05). Importantly, high MACC1 levels correlate with unfavorable survival (P<.0001). Combining MACC1 with circulating transcripts of the metastasis gene S100A4, a transcriptional target of the Wnt/beta-catenin-pathway, improves survival prediction for newly diagnosed cancer patients. CONCLUSION/SIGNIFICANCE: This blood-based assay for circulating MACC1 transcripts, which can be quantitated on a routine basis, is clinically applicable for diagnosis, prognosis, and therapeutic monitoring of cancer patients. Here we demonstrate the diagnostic and prognostic value of circulating MACC1 transcripts in patient plasma for metastasis and survival. Since MACC1 represents a promising target for anti-metastatic therapies, circulating MACC1 transcripts may prove to be an ideal read-out for monitoring therapeutic response of future interventions targeting MACC1-induced metastasis in cancer patients

Theoretical calculations of the primary defects induced by pions and protons in SiC

In the present work, the bulk degradation of SiC in hadron (pion and proton) fields, in the energy range between 100 MeV and 10 GeV, is characterised theoretically by means of the concentration of primary defects per unit fluence. The results are compared to the similar ones corresponding to diamond, silicon and GaAs.Comment: 9 pages, 2 figures, in press to Nuclear Instruments and Methods in Physics Research A v2 - modified title, and major revision

Review: Short-term sea-level changes in a greenhouse world - A view from the Cretaceous

© 2015. This review provides a synopsis of ongoing research and our understanding of the fundamentals of sea-level change today and in the geologic record, especially as illustrated by conditions and processes during the Cretaceous greenhouse climate episode. We give an overview of the state of the art of our understanding on eustatic (global) versus relative (regional) sea level, as well as long-term versus short-term fluctuations and their drivers. In the context of the focus of UNESCO-IUGS/IGCP project 609 on Cretaceous eustatic, short-term sea-level and climate changes, we evaluate the possible evidence for glacio-eustasy versus alternative or additional mechanisms for continental water storage and release for the Cretaceous greenhouse and hothouse phases during which the presence of larger continental ice shields is considered unlikely. Increasing evidence in the literature suggests a correlation between long-period orbital cycles and depositional cycles that reflect sea-level fluctuations, implying a globally synchronized forcing of (eustatic) sea level. Fourth-order depositional sequences seem to be related to a ~. 405. ka periodicity, which most likely represents long-period orbital eccentricity control on sea level and depositional cycles. Third-order cyclicity, expressed as time-synchronous sea level falls of ~. 20 to 110. m on ~. 0.5 to 3.0. Ma timescales in the Cretaceous, are increasingly recognized as connected to climate cycles triggered by long-term astronomical cycles that have periodicity ranging from ~. 1.0 to 2.4. Ma. Future perspectives of research on greenhouse sea-level changes comprise a high-precision time-scale for sequence stratigraphy and eustatic sea-level changes and high-resolution marine to non-marine stratigraphic correlation

Magneto infra-red absorption in high electronic density GaAs quantum wells

Magneto infra-red absorption measurements have been performed in a highly doped GaAs quantum well which has been lifted off and bonded to a silicon substrate, in order to study the resonant polaron interaction. It is found that the pinning of the cyclotron energy occurs at an energy close to that of the transverse optical phonon of GaAs. This unexpected result is explained by a model taking into account the full dielectric constant of the quantum well.Comment: 4 pages, 4 figures, to be published in Phys. Rev. Let