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It is not easy to estimate self-mixing interferometry parameters, namely, the optical feedback factor and the linewidth enhancement factor from the self-mixing signals (SMSs) affected by noise such as speckle. These SMSs call for normalization, which is not only difficult, but also apt to distort the intrinsic information of the signals, thereby resulting in incorrect estimation of the parameters and the displacement reconstruction. In this paper, we present what we believe is a novel normalization method we call "local normalization," which enables more exact and simpler estimation and displacement retrieval compared to previous methods, for it is based on an analytic relation instead of approximation. The method is very noise-proof, and especially speckle-noise-proof as well. The method proposed can be applied to moderate and strong feedback regimes. The simplicity and accuracy of the method will provide a fine tool for a low-cost self-mixing displacement sensor with a high resolution of about 40 nm.

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Objective:To investigate the correlation between lumbar bone mineral density (BMD), musculoskeletal perfusion andmuscle mass.Methods:From May 2019 to August 2020, totally 91 patients who applied for CT perfusion (CTP) examination of abdomen (the scan range included the vertebral body of L1－L3) in Shanghai Tenth People′s Hospital of Tongji University were retrospectively analyzed. The mean BMD of L1－L3 vertebral body was measured by quantitative CT (QCT) at the same time of CT plain scan. According to BMD, the subjects were divided into normal BMD group ( n=33), osteopenia group ( n=41) and osteoporosis (OP) group ( n=17). The L3 level perivertebral muscle mass index and fat fraction were calculated based on QCT examination. The lumbar vertebral and perivertebral muscle perfusion parameters were measured based on CTP images. The parameters of QCT and CTP among three groups were analyzed by Kruskal-Wallis H test or one-way ANOVA. The correlation analysis was conducted between these parameters using Pearson or Spearman analysis. Results:The differences of the perivertebral muscle mass index and fat fraction among three groups were statistically significant ( P<0.05). The differences of the lumbar vertebral perfusion parameters including blood flow (BF), blood volume (BV) and flow extraction product (FE) among three groups were statistically significant ( P<0.05), and BF, BV and FE were positively correlated with BMD ( r=0.444, 0.312 and 0.266 respectively, all P<0.05; adjusted for age and gender r=0.437, 0.340 and 0.337 respectively, all P<0.05). There was no statistically significant difference in perivertebral muscle perfusion parameters among three groups ( P>0.05). Perivertebral muscle mass index was negatively correlated with fat fraction ( r=-0.599, P<0.001; adjusted for age and gender r=-0.404, P<0.001), and there was no correlation between perivertebral muscle mass index and muscle perfusion parameters, as well as perivertebral muscle fat fraction and muscle perfusion parameters. Conclusions:With the changes of BMD, bone mass and perivertebral muscle mass at L3 level are synchronous. Decreased vertebral bone mass is accompanied with reduced perivertebral muscle mass, increased muscle fat and decreased bone perfusion. The changes of vertebral perfusion and perivertebral muscle perfusion at L3 level are asynchronous, which implies that reduced perfusion in OP patients may be confined to the bone.

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The aim of the present study was to investigate the mechanism underlying the antitumor effects of ent-11α-hydroxy-15-oxo-kaur-16-en-19-oic-acid (5F) in colorectal cancer (CRC). 5F was isolated and used to treat C26 murine colon carcinoma cells, a xenograft tumor mouse model (induced by C26 cells) and a CRC mouse model [induced by 1,2-dimethylhydrazine (DMH)/dextran sodium sulfate (DSS)]. C26 cell growth was inhibited by 5F in a dose- and time-dependent manner in vitro. In addition, 5F induced cell apoptosis and cell cycle arrest in the G2 phase, increased the activity of caspase-3 and caspase-9, but did not affect the activity of cascase­8, suggesting that 5F induced apoptosis via activation of the mitochondrial signaling pathway rather than the death­receptor signaling pathway. Furthermore, treatment of C26 cells with 5F resulted in upregulation of cyclin­dependent kinase inhibitor 1A (p21, Cip1), Bcl­2­associated X protein, nuclear factor of κ light polypeptide gene enhancer in B­cells inhibitor, α and downregulation of B­cell lymphoma 2, nuclear factor κ­light­chain enhancer of activated B cells and survivin. In vivo animal models demonstrated that 5F treatment protected mice from carcinogenesis induced by DMH/DSS and markedly decreased the xenograft tumor weight with minimal side effects. Therefore, 5F may have potential as an anti-CRC therapeutic agent for use in the clinical setting.

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<p><b>OBJECTIVE</b>To investigate the effects of sleep deprivation on intelligence development in primary school students.</p><p><b>METHODS</b>Between June 2009 and April 2010, 316 grade 5 students aged 10-11 years were selected from four primary schools in four administrative districts of Changsha, China by stratified random sampling. The intelligence characteristics of children with varying degrees of sleep deprivation were investigated using the Chinese Wechsler Intelligence Scale for Children.</p><p><b>RESULTS</b>A total of 286 valid questionnaires were received, with a response rate of 90.5%. The survey was comprised of a sleep deprivation group (sleep time <8 hours per night; n=180) and a control group (sleep time ≥8 hours per night; n=106). The sleep deprivation group had significantly lower subtest scores, verbal intelligence quotient (IQ) (VIQ), performance IQ (PIQ) and full scale IQ (P<0.05) and significantly lower verbal comprehension factor score and memory/attention factor score compared with the control group (P<0.05). Compared with the control group, the moderate sleep deprivation subgroup had significantly decreased VIQ and full scale IQ as well as verbal comprehension factor score and memory/attention factor score (P<0.05), and the severe sleep deprivation subgroup showed decreases in all scores (P<0.05). The sleep deprivation group and moderate and severe sleep deprivation subgroups had significantly higher proportions of children with VIQ-PIQ imbalance than the control group.</p><p><b>CONCLUSIONS</b>Sleep deprivation adversely affects intelligence development, especially VIQ, in primary school students, and the adverse effects of sleep deprivation are mainly seen in students with moderate and severe sleep deprivation.</p>

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<p><b>OBJECTIVE</b>To investigate the apoptosis-inducing effect of trichloroethylene (TCE) on cultured normal human epidermis keratinocytes (NHEK) in vitro.</p><p><b>METHODS</b>NR(50) values (the concentration of neutral red absorbed is reduced to 50%) of TCE on NHEK were assayed by neutral red uptake (NRU), and the administered dose of TCE was determined. Lipid peroxidation (LPO) and oxidative stress were assessed by measurement of malondialdehyde (MDA) contens and superoxide dismutase (SOD) activity. Transmission electron microscope (TEM) were used to observe morphologic changes, flow cytometer (FCM) was used to measure DNA contents and calculate cell apoptosis rate and proliferation index (PI).</p><p><b>RESULTS</b>NR(50) values of TCE on NHEK was found to be 4.53 mmol/L (95% CI: 3.92-5.13 mmol/L). The increase in MDA content and inhibition of SOD activity in a concentration-dependent manner were shown after NHEK was treated with a series of dose of TCE 4 h later, and typical morphologic changes of apoptosis were also observed by TEM examination. FCM analysis revealed a sub-G(1) peak in the apoptotic cells. The apoptotic rate in TCE 0.125, 0.500, 2.000 mmol/L exposed groups (31.83%, 38.63%, 44.35%, respectively) were significantly higher than that in blank control (18.42%), while PI in TCE 0.125, 0.500, 2.000 mmol/L group (3.26%, 2.48%, 2.07%, respectively) were significantly lower than that in blank control (4.99%).</p><p><b>CONCLUSION</b>TCE may induce apoptosis of cultured NHEK in vitro, and inhibit cell proliferation through lipid peroxidation and oxidative stress.</p>

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