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As an emerging pollutant, uranium poses serious concerns to ecological and human health. The kidney has been established as a major deposition site and the most sensitive target organ for uranium poisoning, and the underlying toxicological mechanisms have been associated with oxidative stress and mitochondrial respiration. However, the identities of key molecular targets in uranium-induced toxicity remain elusive. In this study, we comprehensively evaluated the in vitro effects of uranium on ten critical enzymes in the mitochondrial respiration pathway and discovered that respiratory chain complex IV (cytochrome c oxidase) and complex V (ATP synthase) were strongly inhibited. The inhibitory effects were validated with mitochondria from human renal proximal tubule cells—the most affected renal site in uranium poisoning. The IC 50 values (around 1 mg/L) are physiologically relevant, as they are comparable to known kidney accumulation levels in uranium poisoning. In addition, these inhibitory effects could explain the well-documented uranium-induced reactive oxygen species generation and mitochondrial alterations. In conclusion, cytochrome c oxidase and ATP synthase are possibly key molecular targets underlying the toxic effects of uranium. Image 1 • Effects of uranium on mitochondrial respiration are comprehensively evaluated. • Uranium inhibits human mitochondrial cytochrome c oxidase and ATP synthase. • The IC 50 values (around 1 mg/L) are comparable to renal levels in uranium poisoning. Mitochondrial cytochrome c oxidase and ATP synthase are identified as potential molecular targets underlying the nephrotoxicity of uranium. [ABSTRACT FROM AUTHOR]

There have been increasing numbers of reports that anti-osteoporosis drugs cause osteonecrosis. A typical example is medication-related osteonecrosis of the jaws (MRONJ) which can cause massive necrosis and defects of the jaws. Thus, the dosage and effects of anti-osteoporosis drugs should be re-examined. Our hypothesis is that primary moderate osteoporosis itself is beneficial for bones and should not be excessively treated other than vitamin D, calcium supplementation and functional exercises. The self-repair and anti-infection abilities of bone depend on its organic tissues including stem cells, blood vessels, osteoclastic and osteogenic factors in bone, which jointly fight against invading pathogens and repair bone damage. Recent evidence supports age-related changes in mesenchymal stem cell including loss of self-renewal and increases in senescent cell numbers. Thus, the number of MSCs and vessels need to be increased to achieve functions similar to those in young people. This requires dissolving a portion of inorganic materials and providing extra space to hold more cells and blood vessels. In contrast, anti-osteoporosis drugs prevent bone destruction, and increase mineralization that occupies the space of organic materials, reduces bone immunity and self-repair. Moreover, long term use of anti-osteoporosis drugs also have negative effects on long bones and cartilages. Therefore, moderate age-related osteoporosis is natural in humans to protect bones. Excessive treatment of osteoporosis weakens immunity and self-repair. [ABSTRACT FROM AUTHOR]

Summary: Lung cancer continues to be the leading cause of cancer deaths worldwide. Cigarette smoking is the predominant cause of lung cancer. Researchers found that tobacco-induced molecular changes in the oral epithelium are similar to those in the lung epithelium. Furthermore, there has been considerable progress in investigating the tumorigenesis of oral epithelium using molecular markers. These results offer hope that we can predict lung cancer in smokers by oral examination, which is much easier and more practical than lung biopsy. The hypothesis is to collect oral epithelial cells by gently scraping the oral mucosa, and analyze the DNA variation in these cells using molecular biological methods. Therefore, the oral epithelium is serving as a surrogate tissue for assessing smoking-induced molecular damage to the lungs and thus have important implications for early detection of lung cancer. [Copyright &y& Elsevier]

Scintillators with n - γ discrimination property are widely used in the measurement of neutrons. In sub MeV region, the n - γ discrimination property will be greatly deteriorated so that the neutron and γ -ray events can't be accurately discriminated. As a result, the determination of the proportions of neutron and γ -ray events beyond the discrimination threshold is important if scintillators are applied to measure the low energy neutrons. In the present work, a method based on the time-of-flight technique is proposed to calibrate the proportions of neutron and γ -ray events beyond the discrimination threshold. After the calibration, the numbers of the measured neutron and γ -ray events can be separately determined even if the neutron and γ -ray events can't be perfectly discriminated. • A method was proposed to calibrate the proportions of neutron and γ-ray events beyond the discrimination threshold. • The numbers of the neutron and γ-ray events can be separately determined even if they can't be accurately classified. • After the calibration, a lower detection threshold can be adopted to improve the detection efficiency of the scintillators. [ABSTRACT FROM AUTHOR]

For the reconstructed image of transmission computed tomography, the linear attenuation coefficients of the diagnosed object may improve the image quality by adding additional constraint besides the projection data. In the present work, an image reconstruction method with the constraint of the linear attenuation coefficients is developed and two models including a classical numerical Shepp-Logan model and a Monte Carlo model are used to show the corresponding benefits. The results indicate that the number of the projection angles is potentially decreased to 1/3 of itself while the quality of the reconstructed image is not deteriorated. • An image reconstruction method with the constraint of the linear attenuation coefficients is developed. • The method can decrease the number of the projection angles to 1/3 of itself while the image quality is not deteriorated. • The present method can prevent the image quality from decreasing with the increase of loop iteration. [ABSTRACT FROM AUTHOR]

Considering the difficulties of the low signal-to-noise ratio in weak radioactive source detections, this study proposes an abandon Gaussian tails method based on the analysis of the characteristic information denoted by the full-energy peak of the gamma spectrum of a gamma-emitting radioactive source. Based on the study of the signal-to-background ratio and the statistical fluctuations in the signal of the weak radioactive source, a factor ζ, incorporating the statistical fluctuations of signal and background and the signal-to-background ratio, is suggested to characterize the sensitivity of a radioactive source detection. When ζ reaches its maximum value, the optimal counting window around the centroid of the full-energy peak can be obtained. To evaluate the effectiveness of the proposed approach, comparisons between the proposed abandon Gaussian tails, the conventional full-energy counting, and other experiential methods were performed. The results show that the sensitivity can be significantly improved. Further, experiments with different intensity of radiation sources and duplicated experiments were conducted to examine the stability of the proposed method. • A method to enhance the sensitivity for weak radioactive source detection is presented. • A factor, ζ, is suggested for characterizing the sensitivity of the presence of a radioactive source. • The detection sensitivity of the source search can be improved when the factor ζ is at its maximized value. [ABSTRACT FROM AUTHOR]