Feedback Inhibition and Ionizing Radiation. Mechanism of Inactivation of Allosteric Properties of Aspartate Transcarbamylase by X-Rays*

Biochemistry ◽  
1967 ◽  
Vol 6 (11) ◽  
pp. 3497-3502 ◽  
Author(s):  
Kjell Kleppe ◽  
Unni Spaeren
Keyword(s):  
Ionizing Radiation ◽  
Feedback Inhibition ◽  
X Rays ◽  
Aspartate Transcarbamylase ◽  
Radiation Mechanism ◽  
Allosteric Properties

scholarly journals Differential Effects of Gold Nanoparticles and Ionizing Radiation on Cell Motility between Primary Human Colonic and Melanocytic Cells and Their Cancerous Counterparts

2021 ◽  
Vol 22 (3) ◽  
pp. 1418
Author(s):  
Elham Shahhoseini ◽  
Masao Nakayama ◽  
Terrence J. Piva ◽  
Moshi Geso
Keyword(s):  
Gold Nanoparticles ◽  
Ionizing Radiation ◽  
Cancer Cells ◽  
Cell Lines ◽  
Colorectal Adenocarcinoma ◽  
X Rays ◽  
Cell Adherence ◽  
Cancerous Cell ◽  
Primary Colon ◽  
Radiation Induced

This study examined the effects of gold nanoparticles (AuNPs) and/or ionizing radiation (IR) on the viability and motility of human primary colon epithelial (CCD841) and colorectal adenocarcinoma (SW48) cells as well as human primary epidermal melanocytes (HEM) and melanoma (MM418-C1) cells. AuNPs up to 4 mM had no effect on the viability of these cell lines. The viability of the cancer cells was ~60% following exposure to 5 Gy. Exposure to 5 Gy X-rays or 1 mM AuNPs showed the migration of the cancer cells ~85% that of untreated controls, while co-treatment with AuNPs and IR decreased migration to ~60%. In the non-cancerous cell lines gap closure was enhanced by ~15% following 1 mM AuNPs or 5 Gy treatment, while for co-treatment it was ~22% greater than that for the untreated controls. AuNPs had no effect on cell re-adhesion, while IR enhanced only the re-adhesion of the cancer cell lines but not their non-cancerous counterparts. The addition of AuNPs did not enhance cell adherence. This different reaction to AuNPs and IR in the cancer and normal cells can be attributed to radiation-induced adhesiveness and metabolic differences between tumour cells and their non-cancerous counterparts.

HEALTH HAZARDS FROM MOBILE TOWER: A REVIEW

2021 ◽  
pp. 78-79
Author(s):  
Avni KP Skandhan ◽  
Skandhan KP ◽  
Prasad BS
Keyword(s):  
Ionizing Radiation ◽  
Ultraviolet Radiation ◽  
Visible Light ◽  
Mobile Phone ◽  
Gamma Rays ◽  
Health Hazards ◽  
X Rays ◽  
Radio Waves ◽  
Fm Radio ◽  
Smart Tv

Our knowledge on X-rays, gamma rays and ultraviolet radiation is ionising . Non-ionising gadget radiation is from Mobile Phone, Laptop, Tablet Smart TV etc. and harmful radiations is from mobile towers . FM radio waves, Microwaves, Visible light are also other forms of non-ionizing radiation.

Evaluation of Static Performance of Optoelectronic Semiconductor Devices under X-Rays Irradiation

2010 ◽  
Vol 173 ◽  
pp. 1-6 ◽  
Author(s):  
Haider F. Abdul Amir ◽  
Fuei Pien Chee
Keyword(s):  
Ionizing Radiation ◽  
Light Emitting Diode ◽  
Optoelectronic Devices ◽  
Third Party ◽  
Infrared Light ◽  
X Rays ◽  
Total Ionizing Dose ◽  
Light Emitting ◽  
Static Performance ◽  
Current Drives

In this research, optoelectronic devices consisted of an infrared light emitting diode and a phototransistor with no special handling or third party-packaging were irradiated to ionizing radiation utilizing x-rays. It was found that the devices under test (DUTs) undergo performance degradation in their functional parameters during exposure to x-rays. These damaging effects are depending on their current drives and also the Total Ionizing Dose (TID) absorbed. The TID effects by x-rays are cumulative and gradually take place throughout the lifecycle of the devices exposed to radiation.

scholarly journals The effect of low LET (Linear Energy Transfer) ionizing radiation to catalase activity of wistar’s submandibular gland

2016 ◽  
Vol 1 (3) ◽  
pp. 145
Author(s):  
Nevy T. Putri ◽  
Sarianoferni Sarianoferni ◽  
Endah Wahjuningsih
Keyword(s):  
Energy Transfer ◽  
Ionizing Radiation ◽  
Submandibular Gland ◽  
Rattus Norvegicus ◽  
Catalase Activity ◽  
Linear Energy Transfer ◽  
Submandibular Salivary Gland ◽  
X Rays ◽  
X Ray ◽  
Bonferroni Test

Intraoral periapical radiograph examination is the additional examination which is the most widely used in Dentistry. This radiograph examination using an x-ray ionizing radiation with low LET (Linear Energy Transfer), and may affect submandibular salivary gland. Ionizing radiation exposure can cause damage by inducing a series of changes at the molecular and cellular level. This study aimed to prove the effects of x-ray ionizing radiation with low LET towards the catalase activity of Rattus norvegicus strain Wistar’s submandibular gland. The subjects were 28 male Wistar rats and divided into 4 groups (n=7). Three groups were exposed 4, 8 and 14 times to radiation with 0.002 µSv for each exposure. The catalase activity of each rat was examined by a spectrophotometer. Data were analyzed using one-way ANOVA followed by Bonferroni test. The results showed the average of catalase activity on Wistar rat’s submandibular gland, respectively for: 0.150±0.0895 (KK), 0.1405±0.0607 (K1), 0.1228±0.0290 (K2), 0.1227±0.0556 (K3). Data showed significant differences of catalase activity between test groups, but showed not significant differences of catalase activity between each groups of Rattus norvegicus strain Wistar’s submandibular gland. In this study concluded decreased catalase activity of Rattus norvegicus strain Wistar’s submandibular gland resulting from x-rays ionizing radiation by 4 times, 8 times and 14 times exposures.

scholarly journals Evaluation the Safety and Security Procedures used In X-ray Clinics in Al-Harthiya-Baghdad

2021 ◽  
Vol 2114 (1) ◽  
pp. 012009
Author(s):  
Thuraya A. Abdul Hussian ◽  
Anwar kh. Farman
Keyword(s):  
Ionizing Radiation ◽  
X Rays ◽  
X Ray ◽  
Beta Particles ◽  
Medical Clinics ◽  
Γ Rays ◽  
Health Laws ◽  
Different Sources ◽  
Α Particles ◽  
Security Procedures

Abstract Radiation is a form of energy, its emitted either in the form of particles such as α-particles and β-particles (beta particles including the electron and the positron) or waves such as sunlight, X-rays and γ-rays. Radiation found everywhere around us and it comes from many different sources naturally or man-made sources. In this study a questionnaire was distributed to people working in the field of X-rays that used for a medical imaging (X-ray and CT-scan) to evaluate the extent of awareness and knowledge in estimate the damage of ionizing radiation as a result of wrong use. The questionnaire was distributed to medical clinics in Al-Harithiya in Baghdad, which it’s considered as one of the important areas in Iraq to attract and treat patients. It’s found that most of the commitment of radiography clinics by safety and security procedures. Most of the radiology clinics abide by most of the Iraqi Ministry of Health laws. However, some clinics did not implement some of the security and safety conditions

scholarly journals An in vitro of radiation dose enhancement using gold nanorods and plasmonic photothermal therapy

2021 ◽  
Author(s):  
Daniel DiCenzo DiCenzo
Keyword(s):  
Radiation Dose ◽  
Ionizing Radiation ◽  
Gold Nanorods ◽  
Near Infrared ◽  
Infrared Light ◽  
Nuclear Localization Sequence ◽  
X Rays ◽  
Dose Enhancement ◽  
Near Infrared Light ◽  
Pc3 Cells

Gold nanoparticles (GNP) have been shown to highly absorb ionizing radiation compared to tissue. GNPs have also been shown to be high absorbers of non-ionizing radiation with a peak absorbance at a wavelength dependent on their shape and size. This study investigated radiation dose enhancement in PC3 cells when in the presence of gold nanorods (NR) and near infrared light (IR). The PC3 cells were incubated with either PEGylated NRs (PNR) or anti prostate stem cell antigen antibody with nuclear localization sequence peptide conjugated NRs (AbNR). They were exposed to near infrared light at a wavelength of 810 nm to achieve a temperature of 42 ºC to 43 ºC for 60 minutes. They were also exposed to 160 kVp x-rays. It was found that both targeted and non-targeted GNPs when exposed to radiation and near infrared light synergistically enhanced radiation dose. It was also found that AbNRs provide greater dose enhancement than PNRs.

Safety in pediatric imaging: an update

2013 ◽  
Vol 54 (9) ◽  
pp. 983-990 ◽  
Author(s):  
Owen John Arthurs ◽  
Alvhild Alette Bj⊘rkum
Keyword(s):  
Ionizing Radiation ◽  
Knowledge Base ◽  
Low Dose ◽  
Imaging Modality ◽  
Scientific Data ◽  
X Rays ◽  
Pediatric Imaging ◽  
Medical Exposure ◽  
Ct And Mri

Many assumptions are made when imaging children. In particular a judgement is made regarding how safe or unsafe each imaging modality is, using relatively arbitrary definitions and distinctions, due to the lack of robust scientific data. Here, the latest evidence is reviewed, particularly regarding the medical exposure to ionizing radiation (X-rays and CT) and MRI in childhood. The best evidence currently available suggests a small but convincing risk of cumulative low-dose ionizing radiation in children. Given our predictions for the children imaged today, it seems reasonable to pursue non-ionizing-based techniques wherever possible, although there is emerging evidence that MRI and ultrasound may have hitherto unknown effects. As our knowledge base expands, we must continually review our practice in light of the latest scientific data.

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