941 research outputs found

    Linear-log counting-rate meter uses transconductance characteristics of a silicon planar transistor

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    Counting rate meter compresses a wide range of data values, or decades of current. Silicon planar transistor, operating in the zero collector-base voltage mode, is used as a feedback element in an operational amplifier to obtain the log response

    Effect of HER2 Expression on NUPL2 Protein in Cervical Cancer Cells

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    Recurring cervical cancer patients frequently present overexpressed Human Epidermal Growth Factor Receptor 2 (HER2) protein, which promotes the growth of the cancer. Some HER2-expressing cells and cervical cancer patients have enhanced gene expression of Nucleoporin-like 2 (NUPL2). As part of the nuclear pore complex, the NUPL2 protein serves to selectively export substances from the nucleus to the cytoplasm. In this experiment, HER2 was expressed in cervical cancer cells to examine its effect on NUPL2 protein expression and localization. Interestingly, there was no difference in NUPL2 protein levels between HER2-expressing and non-expressing cells. Importantly, consistent instances of NUPL2 protein localization specific to the nucleus occurred in a large sampling of HER2-expressing cells. This is significant because it suggests a mechanism as to how HER2 promotes excessive cell growth, via changes in NUPL2 localization, potentially impacting its function and ability to selectively export substances that modulate cell growth

    The Technological Development of Minimally Invasive Spine Surgery

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    Minimally invasive spine surgery has its roots in the mid-twentieth century with a few surgeons and a few techniques, but it has now developed into a large field of progressive spinal surgery. A wide range of techniques are now called \ minimally invasive,\ and case reports are submitted constantly with new \ minimally invasive\ approaches to spinal pathology. As minimally invasive spine surgery has become more mainstream over the past ten years, in this paper we discuss its history and development. © 2014 Laura A. Snyder et al

    Análisis criptopaleontológico del lapidario de Teofrastro (s. III a.C.)

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    La obra"Perì líthon" o"Tratado de Piedras" de Teofrasto, es considerado el texto más antiguo conservado sobre minerales y rocas, aunque haya llegado hasta nosotros incompleto. En este trabajo se analiza su contenido comparándolo con el de otros lapidarios antiguos y se concluye que once de las piedras que refiere y que vienen indicadas con nombres geográficos o crípticos son fósiles de plantas, vertebrados o químicos. Por eso, esta obra debe considerarse también como el tratado más antiguo que conocemos sobre paleontología, pues además de los fósiles que menciona, en ella se alude expresamente al proceso de fosilización. Palabras clave: Criptopaleontología
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