منابع مشابه
X-ray Absorption in Radio-quiet Qsos
Major flows of ionized gas are thought to be present in the nuclei of most luminous QSOs, and absorption by these flows often has a significant effect upon the observed X-ray continuum from the black hole region. We briefly discuss X-ray studies of this gas and attempts to determine its geometry, dynamics, and ionization physics. Our focus is on X-ray warm absorber QSOs, Broad Absorption Line Q...
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Dosage compensation is a chromosome-wide regulatory process that balances X-chromosome gene expression between males and females that have different complements. Recent advances have clarified the molecular nature of the Caenorhabditis elegans sex-determination signal, which tallies X-chromosome number relative to the ploidy and controls both the choice of sexual fate and the process of dosage ...
متن کاملDeleted X chromosomes in patients with the fragile X syndrome.
It is now well recognised that the fragile X chromosome anomaly is associated with certain cases of X linked mental retardation.'-3 The fragile site is usually seen as an isochromatid gap at the interface of the long arm bands Xq27 and Xq28. However, we have observed that the fragile X is also frequently manifested as a deleted X chromosome with loss of the distal long arm band, q28 (figure). T...
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Historically, it was thought that the number of X chromosomes plays little role in causing sex differences in traits. Recently, selected mouse models have been used increasingly to compare mice with the same type of gonad but with one versus two copies of the X chromosome. Study of these models demonstrates that mice with one X chromosome can be strikingly different from those with two X chromo...
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Introduction: Not being to get pregnant, after one year of unprotected sex is called infertility. In the post, infertility was mainly a female problem, but the role of male factors in infertility has denotation, although a greater percentage of this infertility is related to the deficiencies of semen. Methods: This case-control study was performed on sperm samples from 30 infertile oligoterato...
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ژورنال
عنوان ژورنال: Nature Reviews Molecular Cell Biology
سال: 2016
ISSN: 1471-0072,1471-0080
DOI: 10.1038/nrm.2016.112