Association between sleep regularity and arterial stiffness among middle-age adults in Southwestern China.

BACKGROUND: Sleep regularity has been linked to a risk of arterial stiffness (AS). However, the association between sleep regularity indicators, which reflect 24-hour sleep variability, and AS has not yet been examined. METHODS: We analyzed data from 516 adults, aged 40-65 years (the median age of 51 years), from the 'Follow-up Study of Sleep Characteristics and Chronic Diseases in the Middle-aged and Elderly Population in Guizhou Province'. Participants underwent assessments of AS (OMRON HBP-8000, baPWV ≥ 1400 cm/s) and sleep (wrist smart band (Honor band 5i) for ≥ 7 days). Logistic regression was utilized to evaluate the odds ratio (OR) and 95% confidence interval (CI) of the association between sleep regularity and AS. RESULTS: A total of 516 people were included in this study, of which 279 (54.07%) were in the AS group. The univariate results showed that the AS group (Median 71.18) had lower SRI compared to the No-AS group (Median 75.00) (p < 0.001). The multifactorial results showed participants with higher SRI scores were more likely to have a lower risk of AS compared to those with lower SRI scores (ORQ4 VS. Q1=0.46, 95%CI: 0.25-0.85, p = 0.013). The SRI effect was more pronounced in male (ORQ4 VS. Q1=0.28, 95%CI: 0.12-0.69, p = 0.005), snoring populations (ORQ4 VS. Q1=0.13, 95%CI: 0.04-0.48, p = 0.002), and non-retired populations (ORQ4 VS. Q1=0.45, 95%CI: 0.22-0.92, p = 0.028). CONCLUSIONS: The present findings indicated that the effect between SRI and AS may be more sensitive than the standard deviation of sleep duration as well as the standard deviation of sleep onset.

MIR31HG polymorphisms are related to steroid-induced osteonecrosis of femoral head among Chinese Han population.

BACKGROUNDS: MIR31 host gene (MIR31HG) polymorphisms play important roles in the occurrence of osteonecrosis. However, the association of MIR31HG polymorphisms with the risk of steroid-induced osteonecrosis of the femoral head (SONFH) remains unclear. In this study, we aimed to investigate the correlation between MIR31HG polymorphisms and SONFH susceptibility in the Chinese Han population. METHODS: A total of 708 volunteers were recruited to detect the effect of seven single nucleotide polymorphisms (SNPs) in the MIR31HG gene on SONFH risk in the Chinese Han population. Genotyping of MIR31HG polymorphisms was performed using the Agena MassARRAY platform. The odds ratio (OR) and 95% confidence interval (95% CI) were used to evaluate the correlation between MIR31HG polymorphisms and SONFH risk using logistic regression model. RESULTS: According to the results of genetic model, rs10965059 in MIR31HG was significantly correlated with the susceptibility to SONFH (OR = 0.56, p = 0.002). Interestingly, the stratified analysis showed that rs10965059 was associated with the reduced risk of SONFH in subjects aged > 40 years (OR = 0.30, p < 0.001) and male populations (OR = 0.35, p < 0 .001). Moreover, rs10965059 was associated with the reduced risk of bilateral SONFH (OR = 0.50, p = 0.002). Finally, multi-factor dimension reduction (MDR) results showed that the combination of rs1332184, rs72703442, rs2025327, rs55683539, rs2181559, rs10965059 and rs10965064 was the best model for predicting SONFH occurrence (p < 0.0001). CONCLUSION: The study indicated that rs10965059 could be involved in SONFH occurrence in the Chinese Han population, which might provide clues for investigating the role of MIR31HG in the pathogenesis of SONFH.

Analysis of Risk Factors of Early Mortality After Pericardiectomy For Constrictive Pericarditis.

BACKGROUND: We aimed to investigate risk factors of early mortality following pericardiectomy. METHODS: This was a retrospective study of patients undergoing pericardiectomy between January 1994 and May 2021 at The People's Hospital of Guangxi Zhuang Autonomous Region, Ruikang Hospital Affiliated to Guangxi University of Chinese Medicine, and The People's Hospital of Liuzhou City. RESULTS: This study included 826 patients, who were divided into two groups: group with operative deaths (N = 66) and group without operative deaths (N = 760). There were 66 operative deaths (66/826, 8.0%). The causes of operative deaths were multiorgan failure (86/826, 10.4%). Preoperative CVP (P < 0.001), chest drainage (P < 0.001), surgical duration (P < 0.001), fluid balance postoperative day D2 (P < 0.001), and tuberculosis pericarditis (P = 0.001) in group with operative deaths were significantly higher than those in group without operative deaths. Univariate and multivariate analyses showed that factors associated with operative deaths include male (P < 0.001), age (P < 0.001), ICU retention time (P < 0.001), postoperative hospitalization time (P < 0.001), preoperative central venous pressure (P = 0.018), postoperative central venous pressure (P < 0.001), D0 fluid balance (P < 0.001), D2 fluid balance (P < 0.001), postoperative chest drainage (P = 0.029), surgical duration (P = 0.003), serum creatinine baseline (P = 0.002), serum creatinine 24h after surgery (P < 0.001), serum creatinine 48h after surgery (P < 0.001), blood lactate (P < 0.001), and tuberculosis pericarditis (P = 0.033). CONCLUSION: In our study, incomplete pericardial dissection, fluid overload, and tuberculosis pericarditis are associated with operative deaths following pericardiectomy.

Incomplete Pericardial Dissection, Fluid Overload, Delayed Diagnosis And Treatment, And Tuberculosis Pericarditis Are Associated With Low Cardiac Output Syndrome Following Pericardiectomy.

BACKGROUND: We aimed to investigate risk factors of LCOS following pericardiectomy. METHODS: This was a retrospective study of patients undergoing pericardiectomy at three hospitals between January 1994 and May 2021. RESULTS: A total of 826 patients were divided into two groups: group with LCOS (N = 126) and group without LCOS (N = 700). The incidence of postoperative LCOS was 15.3%. There were 66 operative deaths (8.0%). Univariable and multivariable analyses showed that factors are associated with LCOS, including postoperative LVEDD (P < 0.001), preoperative LVEDD (P < 0.001), time between symptoms and surgery (P < 0.001), thickness of pericardium (P < 0.001), intubation time (P = 0.002), hospitalized time postoperative (P < 0.001), preoperative central venous pressure (P = 0.016), postoperative central venous pressure (P = 0.034), D0 fluid balance (P = 0.019), D2 fluid balance (P = 0.017), postoperative chest drainage (P < 0.001), surgical duration (P < 0.001), bleeding during operation (P = 0.001), serum creatinine 24h after surgery (P < 0.001), serum creatinine 48h after surgery (P = 0.017), fresh-frozen plasma (P = 0.005), packed red cells (P = 0.006), and tuberculosis pericarditis (P = 0.026). CONCLUSION: In our study, incomplete pericardial dissection, fluid overload, delayed diagnosis and treatment, and tuberculosis pericarditis are associated with LCOS following pericardiectomy.

miR-219a-5p inhibits the pyroptosis in knee osteoarthritis by inactivating the NLRP3 signaling via targeting FBXO3.

PURPOSE: This work was to identify the function and mechanism of miR-219a-5p in regulating knee osteoarthritis (KOA). METHODS: Rat fibroblast-like synoviocytes (FLSs) were isolated to construct KOA cell model by lipopolysaccharide and adenosine triphosphate treatment. miR-219a-5p and FBXO3 expression in FLSs was modulated by transfection. Flow cytometry was executed to research FLSs apoptosis. Caspase-1 and IL-1ß expression in FLSs was researched by immunofluorescence. The binding between miR-219a-5p and FBXO3 was identified by dual luciferase reporter gene assay. KOA rat model and miR-219a-5p up-modulation KOA rat model were constructed. Step size of rats was analyzed. Knee joints of rats were experienced Safranin O-fast green staining to evaluate the knee joint injury. FBXO3, pyroptosis-associated proteins, and IL-1ß and IL-18 expression in FLSs and articular cartilage tissues of rats were assessed by Western blot, qRT-PCR and Enzyme-linked immunosorbent assay. RESULTS: KOA cell model had higher apoptosis percentage, expression of pyroptosis-associated proteins, and IL-1ß and IL-18 level. miR-219a-5p up-modulation decreased the above indicators, whereas miR-219a-5p down-modulation increased the above indicators. FBXO3 expression was directly repressed by miR-219a-5p. Loss of FBXO3 suppressed the above indicators. FBXO3 counteracted the suppression of miR-219a-5p on the above indicators. miR-219a-5p agomir attenuated knee joint injury, increased step size of KOA rats, and reduced FBXO3, pyroptosis-associated proteins and level of IL-1ß and IL-18 in the articular cartilage tissues of KOA rats. CONCLUSION: miR-219a-5p suppressed the pyroptosis in KOA by inactivating the NLRP3 signaling via targeting FBXO3, which might be a promising target for ameliorating KOA in the clinic.

[Analysis of chemical constituents in ethyl acetate extract of Taxilli Herba by UPLC-Q-Exactive-MS and screening of potential xanthine oxidase inhibitors].

The present study analyzed and identified the chemical constituents from ethyl acetate(EA) extract of Taxilli Herba with UPLC-Q-Exactive-MS and screened active xanthine oxidase(XO) inhibitors with HPLC. The analysis was performed on an Hypersil GOLD C_(18) reversed-phase column(2.1 mm×50 mm, 1.9 µm), with the mobile phase of water containing 1% formic acid(A) and methanol(B) under gradient elution, the flow rate of 0.3 mL·min~(-1), and the injection volume of 5 µL. ESI source was used for MS and the compounds were collected in positive and negative ion modes. Xcalibur 4.1 was used to analyze the retention time, accurate relative molecular weight, and fragmentation of the compounds. The inhibitory activity of some known compounds on XO was screened by HPLC. Thirty chemical constituents were identified, including phenolic acids and flavonoids by experimental data combined with information of standards, data reported previously, and databases, such as MzCloud and ChemSpider. The activities of 10 chemical components were screened. Gallic acid and naringenin chalcone had strong inhibitory activities on XO with IC_(50) of 57 µg·mL~(-1) and 108 µg·mL~(-1). UPLC-Q-Exactive-MS allows the accurate, rapid, and comprehensive identification of main chemical constituents from Taxilli Herba. Gallic acid and naringenin chalcone may be the active components of XO inhibitors.

[Generation and phenotypic characterization of S100A9 gene knockout mice by CRISPR/Cas9-mediated gene targeting].

S100 calcium binding protein A9 (S100A9) is involved in a variety of biological processes such as inflammation and tumor cell migration and invasion regulation. The purpose of this study was to construct S100A9 gene-edited mice by using CRISPR/Cas9 technology, thereby providing an animal model for exploring the biological functions of this gene. According to the S100A9 gene sequence, the single-stranded small guide RNA (sgRNA) targeting exons 2 and 3 was transcribed in vitro, and a mixture of Cas9 mRNA and candidate sgRNA was injected into mouse fertilized eggs by microinjection. Early embryos were obtained and transferred to surrogate mice, and F0 mice were obtained and identified by PCR identification and gene sequencing. F0 mice were further mated with wild-type C57BL/6 mice to obtain F1 heterozygous mice, and then homozygous offspring were obtained through F1 mice self-crossing. Real-time PCR, Western blot and immunohistochemistry (IHC) were used to verify the expression and distribution of S100A9. In order to observe the pathological changes of mouse lung tissue using HE staining, an allergic asthma model was induced by ovalbumin from chicken egg white (OVA). The results showed that the 2 492 bp of exons 2, 3 of the S100A9 gene was successfully knocked out, and S100A9-/- mice with stable inheritance were obtained. Furthermore, it was found that S100A9 gene was highly expressed in the lung and spleen of wild-type mice. The expression of S100A9 mRNA and protein was not detected in the lung and spleen of S100A9-/- mice. However, compared with wild-type mice, the lungs of S100A9-/- mice showed a significantly worse inflammatory phenotype, and the proportion of eosinophils in bronchoalveolar lavage fluid (BALF) was significantly increased in response to the treatment of OVA. These results suggest we have successfully constructed a new strain of S100A9-/- mice, and preliminarily confirmed that the lack of S100A9 function can aggravate airway inflammation in asthmatic mice, providing a new mouse model for further study of S100A9 gene function.

[PM2.5 exposure-caused damage to male reproductive function: Progress in research].

Particulate matter 2.5 (PM2.5) is considered to be a major harmful constitutent of air pollution. Animal experiments and epidemiological studies at home and abroad have shown that exposure to PM2.5 causes damage to male reproductive function in addition to direct impacts on the respiratory and cardiovascular systems. This review summarizes the results of animal experiments at home and abroad and population epidemiological investigations relating PM2.5-induced damage to male reproductive function as well as the mechanisms of PM2.5 causing the damage.

GmWRKY54 improves drought tolerance through activating genes in abscisic acid and Ca2+ signaling pathways in transgenic soybean.

WRKY transcription factors play important roles in response to various abiotic stresses. Previous study have proved that soybean GmWRKY54 can improve stress tolerance in transgenic Arabidopsis. Here, we generated soybean transgenic plants and further investigated roles and biological mechanisms of GmWRKY54 in response to drought stress. We demonstrated that expression of GmWRKY54, driven by either a constitutive promoter (pCm) or a drought-induced promoter (RD29a), confers drought tolerance. GmWRKY54 is a transcriptional activator and affects a large number of stress-related genes as revealed by RNA sequencing. Gene ontology (GO) enrichment and co-expression network analysis, together with measurement of physiological parameters, supported the idea that GmWRKY54 enhances stomatal closure to reduce water loss, and therefore confers drought tolerance in soybean. GmWRKY54 directly binds to the promoter regions of genes including PYL8, SRK2A, CIPK11 and CPK3 and activates them. Therefore GmWRKY54 achieves its function through abscisic acid (ABA) and Ca2+ signaling pathways. It is valuable that GmWRKY54 activates an ABA receptor and an SnRK2 kinase in the upstream position, unlike other WRKY proteins that regulate downstream genes in the ABA pathway. Our study revealed the role of GmWRKY54 in drought tolerance and further manipulation of this gene should improve growth and production in soybean and other legumes/crops under unfavorable conditions.

Structural determination and in vitro tumor cytotoxicity evaluation of five new cycloartane glycosides from Asplenium ruprechtii Sa. Kurata.

Five new cycloartane glycosides, named aspleniumside A - E, were discovered and characterized by re-investigated the remaining extracts of the whole plant of Asplenium ruprechtii Sa. Kurata, a famous folk medicine for treating thromboangitis obliterans in China, Japan, and Korea. Compounds 3-5 possessed the 9,19-seco-cycloartane-9,11-en triterpene aglycone with 3,7(or 23),24,25,30-highly oxidized methylene, methylene or quaternary carbons, that was found in this species for the first time. The stereo-chemistry of all new compounds were fully discussed by extensive analysis of the 1D and 2D NMR data, and comparisons with those data of known compounds. 24R configuration was determined here which indicated the different growing areas of the same species could influence the secondary metabolic behavior, leading to the differences in chemical composition. All glycoside groups were determined as ß-d-glucopyranosyl by 1H coupling constant of anomeric protons and co-TLC of the acid hydrolysate with d-glucose. All the cycloartane glycosides were evaluated against HL-60 and HepG2 cells for cytotoxicity, compounds 1-3, showed potential cytotoxicity with the IC50 in range of 18-60 µM, while the standard sorafenib showed IC50 value of 10.61 ± 0.43 and 13.43 ± 1.12 µM against HL-60 and HepG2, respectively. The results attained in this study indicated that cycloartane glycosides should be the cytotoxicity substance in A. ruprechtii Sa. Kurata, and had the potential to be developed as tumor cytotoxicity agent applied in clinic.

The Synchronization Transceiver Design and Experimental Verification for the LuTan-1 SAR Satellite.

The deviation between the two oscillators in BiSAR systems will cause a residual modulation of echo signal. Therefore, the phase synchronization is an important issue that must be addressed for BiSAR systems. An advanced non-interrupted phase synchronization scheme is used for the LuTan-1 SAR satellite. The synchronization transceiver (STR) is designed for transmitting and receiving synchronization signals. In addition, STR mainly consists of master and auxiliary transceivers and switch module. Furthermore, the function and working principle of STR are introduced, and the detailed design of each part is described. The measured results are also evaluated to prove the performance of the STR. In addition, the phase synchronization accuracy is also demonstrated to verify the effectiveness of the non-interrupted synchronization scheme. The standard deviation (STD) of the residual phase is less than 0.3 degrees. The results have guiding significance for the synchronization unit design of LuTan-1 and the future BiSAR system.

Implementation of a Phase Synchronization Scheme Based on Pulsed Signal at Carrier Frequency for Bistatic SAR.

Phase synchronization is one of the key technical challenges and prerequisites for the bistatic synthetic aperture radar (SAR) system, which can form a single-pass interferometry system to perform topographic mapping. In this paper, an advanced phase synchronization scheme based on a pulsed signal at carrier frequency is proposed for a bistatic SAR system and it is verified by a ground validation system. In the proposed phase synchronization scheme, the pulsed signal at carrier frequency is used for phase synchronization link, and it is exchanged by virtue of a time slot between radar signals. The feasibility of the scheme is proven by theoretical analysis of various factors affecting the performance of phase synchronization, and the reliability of the scheme is verified by the test results of the ground validation system.

[Impacts of Bisphenol A exposure on spermatogenesis in men: Advances in studies].

Bisphenol A (BPA), a common endocrine disrupting chemical, is becoming a focus of studies and receiving increasing attention. Because of its wide use in food packaging materials, receipt paper, dental sealant and other products, people contact it through the skin, respiratory tract, digestive system and other routes. A large number of studies at home and abroad have shown that BPA exposure can adversely affect male reproductive function, including semen quality, spermatogenesis, sperm epigenetic inheritance, etc. Its action mechanisms, however, remain unclear and require more studies. This review focuses on the impacts of BPA exposure on spermatogenesis in males.

Metal trabecular bone reconstruction system better improves clinical efficacy and biomechanical repair of osteonecrosis of the femoral head than free vascularized fibular graft: A case-control study.

In this study, we aim to compare and analyze the biomechanical repair and clinical efficacy of osteonecrosis of the femoral head (ONFH) with the use of metal trabecular bone reconstruction system and free vascularized fibular graft. The study enrolled 66 adult patients from medical records of nontraumatic ARCO 2A-3B stage ONFH. A simple ONFH model without surgical treatment was established in 13 cases, 29 cases were treated with metal trabecular bone reconstruction system, and 24 cases were treated with free vascularized fibular graft. Computer-recognized and extracted femur outlines were imported, and three-dimensional reconstructions were performed. The stress concentration and stress peak value were analyzed, and the Harris score, visual analog scale pain score, and operation status of the above patients were compared. Finally, quality of life assessment was performed using SF-36 scale. Metal trabecular bone reconstruction system provided less operation time, blood loss, and the total length of postoperative hospital stay than free vascularized fibular graft. Metal trabecular bone reconstruction system promoted bone reconstruction, increased bone mineral density and Harris score. The total clinical effective rate of young patients (20-40 years) was higher than that of older patients (41-60 years). Metal trabecular bone reconstruction system provided higher physical component summary, mental component summary, and role/social component summary than free vascularized fibular graft. This study demonstrates that both metal trabecular bone reconstruction system and free vascularized fibular graft can prevent or delay the progression of ONFH, while metal trabecular bone reconstruction system is a better choice because of better short-term clinical efficacy.

Knockdown of KDM2A inhibits proliferation associated with TGF-ß expression in HEK293T cell.

Lysine-specific demethylase 2A (KDM2A, also known as JHDM1A or FBXL11) plays an important role in regulating cell proliferation. However, the mechanisms on KDM2A controlling cell proliferation are varied among cell types, even controversial conclusions have been drawn. In order to elucidate the functions and underlying mechanisms for KDM2A controlling cell proliferation and apoptosis, we screened a KDM2A knockout HEK293T cell lines by CRISPR-Cas9 to illustrate the effects of KDM2A on both biological process. The results indicate that knocking down expression of KDM2A can significantly weaken HEK293T cell proliferation. The cell cycle analysis via flow cytometry demonstrate that knockdown expression of KDM2A will lead more cells arrested at G2/M phase. Through the RNA-seq analysis of the differential expressed genes between KDM2A knockdown HEK293T cells and wild type, we screened out that TGF-ß pathway was significantly downregulated in KDM2A knockdown cells, which indicates that TGF-ß signaling pathway might be the downstream target of KDM2A to regulate cell proliferation. When the KDM2A knockdown HEK293T cells were transient-transfected with KDM2A overexpression plasmid or treated by TGF-ß agonist hydrochloride, the cell proliferation levels can be partial or completely rescued. However, the TGF-ß inhibitor LY2109761 can significantly inhibit the KDM2A WT cells proliferation, but not the KDM2A knockdown HEK293T cells. Taken together, these findings suggested that KDM2A might be a key regulator of cell proliferation and cell cycle via impacting TGF-ß signaling pathway.

Using redox-sensitive mitochondrial cytochrome Raman bands for label-free detection of mitochondrial dysfunction.

Mitochondrial activity is a widely used criterion to judge the metabolic condition of a living specimen. Numerous methods have been developed for related analyses, including the detection of O2 consumption, trans-membrane potential, and ATP production. In this study, we demonstrate that the redox state of cytochromes can serve as a sensitive mitochondrial activity indicator in glutamate-stressed neuronal cells. Mitochondrial dysfunction was detected by Raman imaging as early as 30 min after glutamate-stress induction. By comparing this result with other commonly used mitochondrial function assays, we found Raman imaging has a similar sensitivity to ATP production and trans-membrane potential assays. Other viability tests, such as MTT assay and ROS production tests, showed a slower response than our method. A thorough understanding of cytochrome dynamics with our new method will help establish Raman spectroscopy as a competitive clinical diagnosis tool for neurodegenerative diseases involving mitochondrial dysfunction.

Theoretical and experimental research on self-assembly system of molecularly imprinted polymers formed via chloramphenicol and methacrylic acid.

Chloramphenicol was chosen as the imprinting molecule and the methacrylic acid was chosen as the functional monomer to prepare molecularly imprinted polymers. Ethylene glycol dimethacrylate, pentaerythritol triacrylate, and trimethylolpropane trimethylacrylate were used as the cross-linking agents, respectively. The interaction processes between chloramphenicol and methacrylic acid were simulated by using the ωB97XD/6-31G (d,p) method. The self-assembled configuration, bonding sites, binding number, binding energy, and interaction principle of stable complex formed by chloramphenicol and methacrylic acid with different molar ratios have been studied. The selectivity of the most stable complex formed from chloramphenicol and methacrylic acid was discussed with the thiamphenicol and florfenicol as the analogues of chloramphenicol. The results showed that chloramphenicol and methacrylic acid were interacted through the hydrogen bonds. When the molar ratio was 1:10 and pentaerythritol triacrylate as the cross-linking agent, the ordered complex formed by chloramphenicol and methacrylic acid has the largest amount of hydrogen bonds and the lowest binding energy. Scatchard analysis showed that the maximum apparent adsorption capacity was 173.3 mg/g (0.536 mol/g), and the selection factor of florfenicol was the largest. This study provides a reliable theoretical and experimental basis for the design, preparation, and characterization of chloramphenicol molecularly imprinted polymers.

Cuff-leak test combined with interventional bronchoscopy benefits early extubation for patients who received tarp surgery.

PURPOSE: This study explored the performance characteristics of a cuff-leak test (CLT) combined with interventional fiberoptic bronchoscopy (FBS) for evaluating whether early nasoendotracheal extubation was possible for patients who had received transoral atlantoaxial reduction plate (TARP) internal fixation surgery. METHODS: 318 patients who underwent surgery were retrospectively analyzed (between January 2006 and December 2012). Extubation was performed by conventional approach (CA group, until December 2008) and improved approach (IA group, from January 2009) including CLT and an interventional FBS procedure. The extubation success within 1-3 days after surgery, incidence of postextubation stridor and tracheal reintubation were examined. RESULTS: More IA-treated patients experienced extubation during the first 2 days than those CA-treated, median extubation time was 3 (2, 3) days in the CA group and 2 (1, 2) days in the IA group (all P < 0.01). The incidence of stridor and reintubation was 5.69 and 0.57 % in IA and 11.98 and 4.93 % in CA, respectively (both P < 0.05). For the CLT-positive patients in the IA group that remained intubated until day 3-4, interventional FBS was applied for safe extubation and achieved 100 % success. CONCLUSION: Early extubation through IA is safe and interventional FBS assists successful extubation for CLT-positive patients who underwent TARP surgery.

The decreased N6-methyladenine DNA modification in cancer cells.

N6-methyladenine (6 mA) is a recently characterized DNA modification in mammalian genomes, although its biological importance remains to be resolved. Using a highly sensitive HPLC/MS/MS approach, here we report regulation of 6 mA modification in mammalian cells. To these aspects, down-regulation of 6 mA modification was first characterized in human cancer cells and tissues, relative to their normal controls. In contrast to the relative stable 5 mC modification, a dramatic decrease of 6 mA modification was found, showing that 6 mA is the most regulated DNA modification in cancers. In addition to the regulation in cancer cells, a hundreds-fold increase of 6 mA modification was found for in vitro cultured human cells, relative to the in vivo cells. This up-regulation was also confirmed with in vitro cultured mouse cells. Taken together, our study revealed distinct 6 mA modification profiles in the cancer and cultured cells. Considering its distinct regulation from that of 5 mC, our study suggests that 6 mA DNA modification may play a crucial role in cell fate transition of mammalian cells.

[The Research on Optic Fiber FBG Corrosion Sensor Based on the Analysis of the Spectral Characteristics].

Aiming at meeting the need of aluminum corrosion monitoring in aerospace field, a pre-load type fiber grating corrosion sensor based on an aluminum thin tube structure is proposed. The corrosion sensor of aluminum alloy structure in-service monitoring mechanism is studied, a theoretical model about the relation of FBG reflection spectral characteristics and aluminum thickness variation is also obtained. Optical fiber grating corrosion monitoring test system based on the capillary structure of aluminum alloy is constructed by acid-base environment. The problem of cross sensitivity of temperature and strain is solved by configuring an optical fiber grating which is not affected by strain and only sensitive to temperature inside the aluminum alloy tube. The results shows that he aluminum tube packaging design not only can sense the effects of corrosion on the mechanical properties, but also can interference shielding effect of corrosion on the tube optical fiber sensing device. With the deepening of the metal tube corrosion and aluminum alloy tube thickness gradually thinning, fiber grating reflective spectrum gradually shift to the short wavelength and the wall thickness and the grating center wavelength offset has a good monotonic relation. These characteristics can provide useful help to further research corrosion online monitoring based on optic fiber sensor.