51 research outputs found
Magnetic ground state and spin fluctuations in MnGe chiral magnet as studied by Muon Spin Rotation
We have studied by muon spin resonance ({\mu}SR) the helical ground state and
fluctuating chiral phase recently observed in the MnGe chiral magnet. At low
temperature, the muon polarization shows double period oscillations at short
time scales. Their analysis, akin to that recently developed for MnSi [A. Amato
et al., Phys. Rev. B 89, 184425 (2014)], provides an estimation of the field
distribution induced by the Mn helical order at the muon site. The refined muon
position agrees nicely with ab initio calculations. With increasing
temperature, an inhomogeneous fluctuating chiral phase sets in, characterized
by two well separated frequency ranges which coexist in the sample. Rapid and
slow fluctuations, respectively associated with short range and long range
ordered helices, coexist in a large temperature range below T = 170 K. We
discuss the results with respect to MnSi, taking the short helical period,
metastable quenched state and peculiar band structure of MnGe into account.Comment: 13 pages, 11 figure
Актуальные вопросы молеку лярной диагностики рака предстательной железы
Prostate cancer (PC) is the second most common cancer and the fifth highest malignancy mortality rate in men worldwide. Although PC is detectable in 15-20% of men during life, its death risk is only about 3%. This means that not all PC cases require the same management tactics. The given review analyzes the current investigations searching for molecular biological markers to predict the course of PC and to choose its treatment policy, including that in the development of resistance to androgen-deprivation therapy.Рак предстательной железы (РПЖ) является 2-м по частоте и 5-м по смертности злокачественным новообразованием у мужчин в мире. Несмотря на то, что рак предстательной железы выявляют в течение жизни у 15–20 % мужчин, риск наступления смерти от РПЖ составляет только около 3 %. Это означает, что не все случаи РПЖ должны иметь одинаковую тактику ведения. Представленный обзор посвящен анализу современных исследований в области поиска молекулярно-биологических маркеров для прогнозирования течения и выбора тактики лечения РПЖ, в том числе и при развитии резистентности к андрогендепривационной терапии
Growth, spectroscopy and first laser operation of monoclinic Ho3+ :MgWO4 crystal
A monoclinic 0.86 at.% Ho3+:MgWO4 crystal is grown by the Top-Seeded-Solution Growth method. Its spectroscopic properties are studied with polarized light for E || a, b, c. The Ho3+ ion transition probabilities are determined within the modified Judd-Ofelt theory (mJ-O) accounting for the configuration interaction. The intensity parameters are Ω2 = 21.09, Ω4 = 4.42, Ω6 = 2.28 [10–20 cm2] and α= 0.053 [10-4cm]. The calculated radiative lifetime of the 5I7 state is 6.18 ms. The Stark splitting of the 5I7 and 5I8 multiplets is determined with low-temperature spectroscopy. The absorption, stimulated-emission (SE) and gain cross-sections for the 5I8↔5I7 transition are derived. Ho3+ :MgWO4 features a large Stark splitting of the ground-state (380 cm-1), high maximumσSE of 1.82 × 10–20 cm2 at 2.083μm, broad gain spectra and high luminescence quantum yield making it suitable for efficient continuous-wave and mode-locked lasers at∼2.1μm. First laser operation of Ho3+:MgWO4 crystal is demonstrated at 2.104μm reaching a slope efficiency of 72%
Non-Invasive Detection of a Small Number of Bioluminescent Cancer Cells In Vivo
Early detection of tumors can significantly improve the outcome of tumor treatment. One of the most frequently asked questions in cancer imaging is how many cells can be detected non-invasively in a live animal. Although many factors limit such detection, increasing the light emission from cells is one of the most effective ways of overcoming these limitations. Here, we describe development and utilization of a lentiviral vector containing enhanced firefly luciferase (luc2) gene. The resulting single cell clones of the mouse mammary gland tumor (4T1-luc2) showed stable light emission in the range of 10,000 photons/sec/cell. In some cases individual 4T1-luc2 cells inserted under the skin of a nu/nu mouse could be detected non-invasively using a cooled CCD camera in some cases. In addition, we showed that only few cells are needed to develop tumors in these mice and tumor progression can be monitored right after the cells are implanted. Significantly higher luciferase activity in these cells allowed us to detect micrometastases in both, syngeneic Balb/c and nu/nu mice
Применение петлевой изотермической амплификации ДНК для диагностики микрометастазов рака предстательной железы в лимфатические узлы
A comparative analysis of the results of diagnosis of cancer metastases in the lymph nodes using a method of one-step nucleic acids amplification (OSNA) and morphological methods was performed. Comparable sensitivity and specificity of OSNA and histological examination of a lymph node were observed. Проведен сравнительный анализ результатов выявления метастазов рака в лимфатических узлах с помощью OSNA и морфологическими методами. Показана сопоставимая чувствительность и специфичность OSNA и гистологического исследования лимфатического узла
The M235T Polymorphism in the AGT Gene and CHD Risk: Evidence of a Hardy-Weinberg Equilibrium Violation and Publication Bias in a Meta-Analysis
BACKGROUND: The M235T polymorphism in the AGT gene has been related to an increased risk of hypertension. This finding may also suggest an increased risk of coronary heart disease (CHD). METHODOLOGY/PRINCIPAL FINDINGS: A case-cohort study was conducted in 1,732 unrelated middle-age women (210 CHD cases and 1,522 controls) from a prospective cohort of 15,236 initially healthy Dutch women. We applied a Cox proportional hazards model to study the association of the polymorphism with acute myocardial infarction (AMI) (n = 71) and CHD. In the case-cohort study, no increased risk for CHD was found under the additive genetic model (hazard ratio [HR] = 1.20; 95% confidence interval [CI], 0.86 to 1.68; P = 0.28). This result was not changed by adjustment (HR = 1.17; 95% CI, 0.83 to 1.64; P = 0.38) nor by using dominant, recessive and pairwise genetic models. Analyses for AMI risk under the additive genetic model also did not show any statistically significant association (crude HR = 1.14; 95% CI, 0.93 to 1.39; P = 0.20). To evaluate the association, a comprehensive systematic review and meta-analysis were undertaken of all studies published up to February 2007 (searched through PubMed/MEDLINE, Web of Science and EMBASE). The meta-analysis (38 studies with 13284 cases and 18722 controls) showed a per-allele odds ratio (OR) of 1.08 (95% CI, 1.01 to 1.15; P = 0.02). Moderate to large levels of heterogeneity were identified between studies. Hardy-Weinberg equilibrium (HWE) violation and the mean age of cases were statistically significant sources of the observed variation. In a stratum of non-HWE violation studies, there was no effect. An asymmetric funnel plot, the Egger's test (P = 0.066), and the Begg-Mazumdar test (P = 0.074) were all suggestive of the presence of publication bias. CONCLUSIONS/SIGNIFICANCE: The pooled OR of the present meta-analysis, including our own data, presented evidence that there is an increase in the risk of CHD conferred by the M235T variant of the AGT gene. However, the relevance of this weakly positive overall association remains uncertain because it may be due to various residual biases, including HWE-violation and publication biases
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