We present an XMM-Newton X-ray observation of TRAPPIST-1, which is an ultracool dwarf star recently discovered to host three transiting and temperate Earth-sized planets. We find the star is a relatively strong and variable coronal X-ray source with an X-ray luminosity similar to that of the quiet Sun, despite its much lower bolometric luminosity. We find LX/Lbol = 2 − 4 × 10−4, with the total ...

We examined the delayed induction of telomere instability in hTERT-immortalized normal human fibroblast (BJ1-hTERT) cells exposed to X-rays. BJ1-hTERT cells were irradiated with 2 Gy of X-rays, and chromosome aberrations were analyzed 24 hours after irradiation and in the surviving cells 14 days after X-ray exposure. We found that the X-ray-surviving cells showed an increased frequency of chrom...

in this work, mg-doped zno nanostructures were prepared in water under ultrasonic irradiation for 60 min without using any organic compounds or post preparation treatments. the prepared samples were characterized by x-ray diffraction (xrd), scanning electron microscopy (sem), transmission electron microscopy (tem), energy dispersive analysis of x-ray (edx), diffuse reflectance spectroscopy (drs...

A number of studies have demonstrated that a room temperature proton irradiation may not be sufficient to provide an accurate estimation of the impact of the space radiation environment on detector performance. This is a result of the relationship between defect mobility and temperature, causing the performance to vary subject to the temperature history of the device from the point at which it ...

An appropriate radiation source is essential in studies of tissue response in animal models. This paper reports on the evaluation and commissioning of a new irradiator suitable for studies using small animals or cell culture. The Faxitron is a 160-kVp x-ray machine that was adapted from an x-ray imaging unit through modifications to facilitate experimental irradiation. The x-ray unit is housed ...

C-ion radiotherapy is associated with improved local control and survival in several types of tumors. Although C-ion irradiation is widely reported to effectively induce DNA damage in tumor cells, the effects of irradiation on proteins, such as protein stability or degradation in response to radiation stress, remain unknown. We aimed to compare the effects of C-ion and X-ray irradiation focusin...

We studied X-ray-induced delayed cell death, delayed giant cell formation and delayed chromosome aberrations in normal human embryo cells to explore the relationship between initial radiation damage and delayed effect appeared at 14 to 55 population doubling numbers (PDNs) after X-irradiation. The delayed effect was induced in the progeny of X-ray survivors in a dose-dependent manner and recove...

zno and mn-zno nano powders were prepared by the sol-gel auto combustion method. the products were characterized by x-ray diffraction (xrd), energy dispersive analysis of x-ray (edx) and scanning electron microscopy (sem). structural and morphological properties of nano particles were investigated and the average crystalline size of zno and mn-doped zno was obtained 44 and 51 nm, respectively. ...

A challenge of X-ray radiation therapy is that high dose X-ray under therapeutic conditions damages normal cells. This paper describes a nanoparticle-based method to enhance X-ray radiation therapy by delivering radio-sensitizing gold nanoparticles into cancer cells. The nanoparticles have been modified with cationic polyelectrolytes to allow internalization. Upon X-ray irradiation of nanoparti...