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To explore the therapeutic effect of metformin combined with single high-dose radiotherapy in mice with non-small cell lung cancer and the mechanism involved. In vitro cell test: the cytotoxicity of metformin under different oxygen and glucose contents was evaluated using cell survival curves. In vivo xenograft tumor test: NSCLC-A549 cells were injected into mice, which were then divided into the following five groups: control group, metformin group, single high-dose radiotherapy group, metformin 1 h before radiotherapy group, and metformin 24 h after radiotherapy group. Growth of the tumor was evaluated in each group, and the blood flow and histology of the tumor tissues were analyzed. According to the in vitro test results, metformin was the most cytotoxic under hypoxic and low-glucose conditions. The in vivo results showed that the tumor volume was the smallest in the mouse groups administered metformin 1 h before high-dose radiotherapy and 24 h after radiotherapy ((0.47±0.12) cm3 and (0.49±0.21) cm3, respectively). Blood flow analysis showed that single high-dose radiotherapy destroyed the micro-vessels of tumor tissue and reduced the perfusion of oxygen and glucose. Histological analysis revealed that cells in hypoxic and hypoglycemic area of the tumor tissue center were preferentially killed by metformin, whereas there were viable cells in the surrounding well perfused areas. Metformin combined with single high-dose radiotherapy enhanced the toxicity by changing tumor cell metabolism. These results provide theoretical and data support for the future use of metformin combined with stereotactic body radiotherapy.

Using stochastic resonance (SR) mechanism, the output signal can be enhanced by adding noise to the nonlinear system. Therefore, an image denoising algorithm based on adaptive bi-dimensional stochastic resonance (ABSR) is proposed in this paper. Firstly, the image is sampled as a bi-dimensional signal, and an adaptive bi-dimensional dynamic nonlinear system model is constructed. The peak signal-to-noise ratio (PSNR) and structural similarity (SSIM) of the output image are used as the double evaluation model of the adaptive system, and the optimal parameters of the model are automatically obtained by adjusting the parameters of the dynamic nonlinear system using the reverse positioning method. Compared with the traditional mean filter, median filter and one-dimensional stochastic resonance, the image restoration effect of dynamic adaptive bi-dimensional stochastic resonance is more closer to the original image, and the histogram, PSNR and SSIM of the output image are also significantly better than the other three methods. The results show that dynamic adaptive bi-dimensional stochastic resonance has better denoising effect and better robustness to the change of noise intensity in image processing. [ABSTRACT FROM AUTHOR]

Background: Depression is one of the most common neuropsychiatric symptoms of Alzheimer's disease (AD) which decreases the life quality of both patients and caregivers. There are currently no effective drugs. It is therefore important to explore the pathogenesis of depression in AD patients., Objective: The present study aimed to investigate the characteristics of the entorhinal cortex (EC) functional connectivity (FC) in the whole brain neural network of AD patients with depression (D-AD)., Methods: Twenty-four D-AD patients, 14 AD patients without depression (nD-AD), and 20 healthy controls underwent resting-state functional magnetic resonance imaging. We set the EC as the seed and used FC analysis. One-way analysis of variance was used to examine FC differences among the three groups., Results: Using the left EC as the seed point, there were FC differences among the three groups in the left EC-inferior occipital gyrus. Using the right EC as the seed point, there were FC differences among the three groups in the right EC-middle frontal gyrus, -superior parietal gyrus, -superior medial frontal gyrus, and -precentral gyrus. Compared with the nD-AD group, the D-AD group had increased FC between the right EC and right postcentral gyrus., Conclusion: Asymmetry of FC in the EC and increased FC between the EC and right postcentral gyrus may be important in the pathogenesis of depression in AD., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Introduction: Long-term exposure to ambient fine particulate matter (PM 2.5 ) has been linked to increases in the incidence of lung cancer. However, more evidence is needed to conclude its effects on lung cancer survival., Objectives: The study aimed to explore the relationship between long-term PM 2.5 exposure and lung cancer survival and evaluated the benefits of clean air actions in Beijing., Methods: A whole-population cohort study was conducted on lung cancer patients diagnosed between 2001 and 2017. An atmospheric chemical transport model was used to estimate exposure under a counterfactual scenario without the policy and then quantified the effect of the policy. Cox regression models were used with the seasonality-adjusted PM 2.5 as the main effect., Results: A 10 μg/m 3 increase in PM 2.5 was estimated to be with a 6.5 % (95 % CI: 4.8 %, 8.2 %) increase in the mortality rates. The association was heterogeneous and modified by individual-level characteristics. The clean air actions were estimated to have prevented 3548 (95 % CI: 3280, 3825) premature deaths and to have prolonged survival time by 4.29 months (95 % CI: 0.01, 25.11)., Conclusion: Our findings suggest that PM 2.5 exposure lowers the survival rate for lung cancer. The clean air actions implemented in Beijing can protect lung cancer patients by increasing their survival time., Synopsis: Long-term exposure to PM 2.5 can lower lung patients' survival rates whereas the clean air actions in Beijing have prolonged these patients' survival time by reducing PM 2.5 level., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 The Authors. Published by Elsevier B.V. All rights reserved.)