dose dependence
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Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 193
Author(s):  
Renata Majgier ◽  
Kordian Chamerski ◽  
Arkadiusz Mandowski

In this work, the optically stimulated luminescence (OSL) properties of camera lens protectors and their potential use in emergency dosimetry were investigated. Camera lens protectors can be attached to mobile phones, which are commonly carried by individuals and may be useful in estimating an emergency dose. The presented results confirm the great potential of this type of glass material for dose determination. The glass protectors exhibit advantageous properties, such as linear dose dependence in the range of at least 0.6–10 Gy, minimum detectable dose at the level of tens of mGy, and good measurement repeatability for samples of the same type. Significant fading during the first day after exposure is an undesirable feature of tested glass. Nevertheless, the application of the correction for fading shows promising results in the dose recovery process.


2021 ◽  
Vol 11 (11) ◽  
pp. 1217
Author(s):  
Kuan-Yu Chu ◽  
Yin-Lin Wang ◽  
Yu-Ren Chou ◽  
Jung-Tsu Chen ◽  
Yi-Ping Wang ◽  
...  

Familial tooth agenesis (FTA), distinguished by developmental failure of selected teeth, is one of the most prevalent craniofacial anomalies in humans. Mutations in genes involved in WNT/β-catenin signaling, including AXIN2 WNT10A, WNT10B, LRP6, and KREMEN1, are known to cause FTA. However, mutational interactions among these genes have not been fully explored. In this study, we characterized four FTA kindreds with LRP6 pathogenic mutations: p.(Gln1252*), p.(Met168Arg), p.(Ala754Pro), and p.(Asn1075Ser). The three missense mutations were predicted to cause structural destabilization of the LRP6 protein. Two probands carrying both an LRP6 mutant allele and a WNT10A variant exhibited more severe phenotypes, suggesting mutational synergism or digenic inheritance. Biallelic LRP6 mutations in a patient with many missing teeth further supported the dose-dependence of LRP6-associated FTA. Analysis of 21 FTA cases with 15 different LRP6 loss-of-function mutations revealed high heterogeneity of disease severity and a distinctive pattern of missing teeth, with maxillary canines being frequently affected. We hypothesized that various combinations of sequence variants in WNT-related genes can modulate WNT signaling activities during tooth development and cause a wide spectrum of tooth agenesis severity, which highlights the importance of exome/genome analysis for the genetic diagnosis of FTA in this era of precision medicine.


2021 ◽  
pp. 114386
Author(s):  
Cheylene R. Tanimoto ◽  
Abby R. Thurm ◽  
Devin S. Brandt ◽  
Charles M. Knobler ◽  
William M. Gelbart

NAR Cancer ◽  
2021 ◽  
Vol 3 (4) ◽  
Author(s):  
Sébastien Penninckx ◽  
Eloise Pariset ◽  
Egle Cekanaviciute ◽  
Sylvain V Costes

Abstract Radiation-induced foci (RIF) are nuclear puncta visualized by immunostaining of proteins that regulate DNA double-strand break (DSB) repair after exposure to ionizing radiation. RIF are a standard metric for measuring DSB formation and repair in clinical, environmental and space radiobiology. The time course and dose dependence of their formation has great potential to predict in vivo responses to ionizing radiation, predisposition to cancer and probability of adverse reactions to radiotherapy. However, increasing complexity of experimentally and therapeutically setups (charged particle, FLASH …) is associated with several confounding factors that must be taken into account when interpreting RIF values. In this review, we discuss the spatiotemporal characteristics of RIF development after irradiation, addressing the common confounding factors, including cell proliferation and foci merging. We also describe the relevant endpoints and mathematical models that enable accurate biological interpretation of RIF formation and resolution. Finally, we discuss the use of RIF as a biomarker for quantification and prediction of in vivo radiation responses, including important caveats relating to the choice of the biological endpoint and the detection method. This review intends to help scientific community design radiobiology experiments using RIF as a key metric and to provide suggestions for their biological interpretation.


2021 ◽  
Author(s):  
Suzan Farhang-Sardroodi ◽  
Michael A. La Croix ◽  
Kathleen P. Wilkie

AbstractAlthough chemotherapy is a standard treatment for cancer, it comes with significant side effects. In particular, certain agents can induce severe muscle loss, known as cachexia, worsening patient quality of life and treatment outcomes. 5-fluorouracil, an anti-cancer agent used to treat several cancers, has been shown to cause muscle loss. Experimental data indicates a non-linear dose-dependence for muscle loss in mice treated with daily or week-day schedules. We present a mathematical model of chemotherapy-induced muscle wasting that captures this non-linear dose-dependence. Area-under-the-curve metrics are proposed to quantify the treatment’s effects on lean mass and tumour control. Model simulations are used to explore alternate dosing schedules, aging effects, and morphine use in chemotherapy treatment with the aim of better protecting lean mass while actively targeting the tumour, ultimately leading to improved personalization of treatment planning and improved patient quality of life.Author SummaryIn this paper we present a novel mathematical model for muscle loss due to cancer chemotherapy treatment. Loss of muscle mass relates to increased drug toxicity and side-effects, and to decreased patient quality of life and survival rates. With our model, we examine the therapeutic efficacy of various dosing schedules with the aim of controlling a growing tumour while also preserving lean mass. Preservation of body composition, in addition to consideration of inflammation and immune interactions, the gut microbiome, and other systemic health measures, may lead to improved patient-specific treatment plans that improve patient quality of life.


Author(s):  
Pham Thi Bich ◽  
Vu Thi Thu

Aim: This study was carried to evaluates of Cobalt chloride (CoCl2) on cardiac mitochondrial function. Methods: H9C2 cardiomyocytes were cultured in medium containing different concentrations of CoCl2. Cell viability, cardiolipin content, mitochondrial function, and mitochondrial oxidative stress were assessed by using Cell Counting Kit-8 and suitable fluorescence kits. Results: The obtained data showed that CoCl2 (200÷400 µM) induced cell death and decreased mitochondrial function of H9C2 cardiomyocytes in dose dependence. Especially, CoCl2 at dose of 300 µM significantly altered values of mitochondrial membrane potential, H2O2 and O2- to 63.79±2.15%, 145.81±5.83% and 143.10±3.07% (of 100% control), respectively. Conclusion: CoCl2 strongly induced cardiomyocyte death via altering mitochondrial function in a dose-dependent manner.


Author(s):  
David Yakubu Bot ◽  
Odachi Helen Agbo ◽  
Abigail John Ajiji ◽  
Abraham Adoniyi Ahmed ◽  
Adaobi Ifeoma Ekwenpu ◽  
...  

Background: Diabetes Mellitus is a debilitating metabolic disease characterized by hyperglycemia due to insufficient insulin or inability of insulin receptors to respond positively to circulating insulin. Prevalence of the disease is on the global increase annually with tendency to rise from 380 to over 592 million by 2035 in developing countries. Toxicity of some Orthodox drugs in use has led to searches for alternative sources for treatment and management of the disease. Aim: This work was aimed at investigating the effect of methanolic extract of Albizia lebbeck leaf on Alloxan monohydrate induced diabetic albino rats. Materials and Methods: Qualitative Phytochemical analysis of the plant extract was carried out in Biochemistry Division of National Veterinary Research Institute Vom, Plateau State, Nigeria. Forty female Wistar albino rats were used for the study, divided into five groups (A-E) in two replicates. Group A- negative control (non-induced, not treated) and group B- positive control (induced with Alloxan - 120mg/kg body weight (b.w), administered intra-peritoneally but not treated). Groups C- and D- induced and treated with 100 and 200mg/kg b.w extract respectively. Group E- non-induced but treated with 100mg/kg b.w of extract. Diabetes was established on day 3 after induction. Blood samples were collected through retro-orbital plexus into Fluoride oxalate bottles on days 0, 3, 5 and 9. Glucose was estimated by Glucose Oxidase method. Results/Conclusion: Phytochemical analysis of the extract showed the presence of saponins, tannins, steroids, cardiac glycosides, flavonoids, alkaloids and terpenes. Glucose analysis results showed dose dependence and statistically significant reduction (p<0.05) in blood glucose from 3rd, 5th and 9th days post induction following treatment with Albizia lebbeck in group C- 14.5±3.5, 10.4±4.6 and 8.4±3.7; in group D- 14.0±4.7, 10.2±3.3 and 6.5±2.5; and in group E- 5.0±0.6, 3.7±0.5 and 3.5±0.5 respectively. We conclude that methanolic leaf extract of the plant Albezia lebbeck (L.) Benth, possesses anti-diabetic properties effective on both normal and Alloxan-induced diabetic rats.


Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5283
Author(s):  
Sunseng Pyon ◽  
Soichi Taya ◽  
Yuto Kobayashi ◽  
Ayumu Takahashi ◽  
Wenjie Li ◽  
...  

We report the critical current density (Jc) and vortex pinning properties in single crystals of a novel iron-based superconductor (IBS) KCa2Fe4As4F2 with large Jc in the pristine state, before and after introduction of artificial defects by swift-particle irradiation. The effects of 2.6 GeV U and 3 MeV proton irradiations in KCa2Fe4As4F2 single crystals on transition temperature Tc and Jc, including its dose dependence, are systematically studied. Jc~8 MA/cm2 under a self-field at 2 K in the pristine crystal is strongly enhanced up to 19.4 and 17.5 MA/cm2 by irradiation of 2.6 GeV U-ions and 3 MeV protons, respectively. Suppression of Tc and dose dependence of Jc in KCa2Fe4As4F2 is different from that in a representative IBS of (Ba,K)Fe2As2, which can be explained by considering the presence of embedded defects in pristine KCa2Fe4As4F2. The vortex dynamics in the pristine and proton irradiated KCa2Fe4As4F2 single crystals are also investigated from the analyses of the field dependence of Jc and the normalized magnetic relaxation rate. In addition to the contribution of embedded defects, weak collective pinning is considered for comprehensive analyses. Vortex dynamics in KCa2Fe4As4F2 is similar to those in (Ba,K)Fe2As2 to some extent, and different from that in anisotropic Li0.8Fe0.2OHFeSe. Large anisotropy, due to the presence of insulating blocking layers in KCa2Fe4As4F2, which leads to much lower irreversibility field (Hirr) compared with 122-type IBSs, strongly affect the vortex dynamics.


2021 ◽  
Vol 9 (09) ◽  
pp. 23-27
Author(s):  
Rajan Kamble S

There has a wide interest in stability of different types of ion exchange resins against ionizing radiations. The irradiation damage and stability of polystyrendigni benzene and phenolformaldehide sulphonic acid ion exchange resins was investigated by determination of the radiolytic gases. The gas analysis showed a very good linear dose dependence of the evolved hydrogen and carbon monoxide. The linearity of carbon dioxide was good for Dowex 50 WX 10 but less pronounce for zeo-carb 215. Sulphur dioxide was at least partially produced by direct action and was consumed by secondary reaction during irradiation. Kuzin  et al [1] analysed radiolytic gases evolved from a carboxylic acid exchange resin. Wiely et al [2] investigated gamma radiation induce degradation of sulphonetic styrle resin cross link with 4 and 8 % m / p dinyl benzene isomer or mixtures thereof including commercial divenyle benzene have been shown loss in capacity 5-12. 8% at the radiation intensities of 290 R/hr and total dose 0.91 – 1.0 x 10-8 rad in presence of water.


2021 ◽  
Vol 28 (5) ◽  
pp. 1284-1295 ◽  
Author(s):  
Seiki Baba ◽  
Hiroaki Matsuura ◽  
Takashi Kawamura ◽  
Naoki Sakai ◽  
Yuki Nakamura ◽  
...  

Intense micro-focus X-ray beamlines available at synchrotron facilities have achieved high-quality data collection even from the microcrystals of membrane proteins. The automatic data collection system developed at SPring-8, named ZOO, has contributed to many structure determinations of membrane proteins using small-wedge synchrotron crystallography (SWSX) datasets. The `small-wedge' (5–20°) datasets are collected from multiple crystals and then merged to obtain the final structure factors. To our knowledge, no systematic investigation on the dose dependence of data accuracy has so far been reported for SWSX, which is between `serial crystallography' and `rotation crystallography'. Thus, herein, we investigated the optimal dose conditions for experimental phasing with SWSX. Phase determination using anomalous scattering signals was found to be more difficult at higher doses. Furthermore, merging more homogeneous datasets grouped by hierarchical clustering with controlled doses mildly reduced the negative factors in data collection, such as `lack of signal' and `radiation damage'. In turn, as more datasets were merged, more probable phases could be obtained across a wider range of doses. Therefore, our findings show that it is essential to choose a lower dose than 10 MGy for de novo structure determination by SWSX. In particular, data collection using a dose of 5 MGy proved to be optimal in balancing the amount of signal available while reducing the amount of damage as much as possible.


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