[Screening for asymptomatic atrial fibrillation in elder community populations in Dalian: a single center study]

Objective: We aimed to determine the epidemiological characteristics of asymptomatic AF in elder community population (≥65 years old) to analyze the detection rate of different screening methods. Methods: The study was a prospective cohort study. The elder (≥65 years old) residents who voluntarily participated in free physical examination in Dalian community were selected. The participants were randomly divided into screening group (including intensive screening group and single screening group) and control group. The control group received interrogation, medical history collection and routine 12-lead electrocardiogram (ECG) examination. Screening group received an additional single-lead ambulatory ECG equipment worn for 5-7 days. Intensive screening group received two equal-length wearings in 2020 and 2021 respectively, while one screening group only wore once in 2020. Results: Finally 3 340 residents ((70.7±5.0) years old) which consisted of 1 488 males (44.55%) were enrolled. There were 1 945 residents in screening group, including 859 in intensive screening group and 1 086 in one-time screening group. The control group included 1 395 people. Detection rate of asymptomatic AF was significantly higher in screening group than control group (79(4.06%) vs. 24(1.72%), P<0.001). Higher detection rate was found in screening group than control group in AF risk factors (1 or 2-3) subgroups and CHA2DS2-VASc score (2-3 or≥4) subgroups (P<0.05). Additionally, no difference was found between intensive screening group and single screening group (42(4.89%) vs. 37(3.41%), P=0.100). Intensive screening increased detection rate (7(6.93%) vs. 1(0.58%), P=0.009) only in residents those with low thrombosis risk (CHA2DS2-VaSc<2). Conclusions: Screening in elderly (≥65 years old) can significantly improve the detection rate of asymptomatic AF by wearing single lead dynamic ECG device. The rate increased significantly with the increase of risk factors associated with AF by single screening. In addition, repeat screening of the same method may only improve detection rates in the group with low risk thrombotic scores and non-combination of AF risk factors.Screening methods that are appropriate for different populations may require further exploration.

[Expression of METTL14 in epithelial ovarian cancer and the effect on cell proliferation, invasion and migration of A2780 and SKOV3 cells]

Objective: To study the expression of methyltransferase-like protein 14 (METTL14) in epithelial ovarian cancer and its clinical significance, and to explore the effect of METTL14 expression on the proliferation, invasion and migration of ovarian cancer cells. Methods: Immunohistochemistry (IHC) was used to detect METTL14 expression in tumor tissue samples, and analyze the relationships among METTL14 expression, clinicopathological factors, and prognosis in ovarian cancer. Lentiviral vectors and small interfering RNA (siRNA) were used to up-regulate and down-regulate the METTL14 expression in ovarian cancer cell lines A2780 and SKOV3, respectively. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was used to detect the N6-methyladenosine (m6A) content in ovarian cancer cells. Cell counting kit-8 (CCK-8), wound healing assay, and transwell assay were used to examine the function of METTL14 expression in the cells. Results: (1) The IHC score of METTL14 protein was 6.2±3.7 in 20 samples of ovarian cancer tissues and 3.3±2.5 in 15 samples of normal ovarian tissues, and the difference was statistically significant (t=-2.64, P=0.012). Among the patients who suffered from ovarian cancer, there were 69 cases with high expression of METTL14 protein (IHC score≥6), accounting for 57.0% (69/121), and the cases with low expression of METTL14 protein (IHC score<6) accounting for 43.0% (52/121). Compared with the patients with low expression of METTL14, the patients with high expression of METTL14 had later stages, higher rates of lymph node metastasis, abdominal metastasis, and more ascite amount. The differences were statistically significant (all P<0.05). The overall survival rate was significantly lower in patients with high METTL14 expression than the low expression (P=0.009). (2) LC-MS/MS data showed that the relative expression of m6A in A2780 and SKOV3 cells in the lentivirus (LV)-METTL14 group were 0.213±0.024 and 0.181±0.018, which were significantly higher than those in the LV-normal control (NC) group (0.109±0.022 and 0.128±0.020; all P<0.05). While the relative expression of m6A in A2780 and SKOV3 cells in the si-METTL14 group were 0.063±0.012 and 0.069±0.015, which were significantly lower than the expression in si-NC group of 0.108±0.014 and 0.121±0.014 (all P<0.05). CCK-8 assay showed that the absorbance values were significantly lower in the si-METTL14 group compared with the si-NC group at 36, 48, 60 hours (all P<0.05); while were significantly increased in the LV-METTL14 group compared with the LV-NC group at 48, 60 hours (all P<0.01). Scratch wound assays showed that the migration rate of the si-METTL14 group was lower than those of the si-NC group, while the LV-METTL14 group were higher than the LV-NC group by 24 hours, the differences were statistically significant (all P<0.01). Cell migration and invasion were detected by transwell migration and invasion assays. After cultivated for 24 hours, the invasion cell number and the migration cell number in the si-METTL14 group were less than those in the si-NC group. While the invasion cell number and the migration cell number in the LV-METTL14 group were more than those in the LV-NC group, respectively. The differences were statistically significant (all P<0.01). Conclusion: Patients with high METTL14 expression have a worse prognosis in ovarian cancer, which may increase the m6A modification of ovarian cancer cells and promote cells proliferation, invasion and migration.

[Feasibility of radiofrequency ablation for cancer patients with atrial fibrillation]

Objective: To analyze the impact of cancer on the recurrence rate of atrial fibrillation (AF) after AF radiofrequency ablation and further evaluate the feasibility of radiofrequency ablation therapy in cancer patients with AF. Methods: This study was a single-center, retrospective study. Cancer patients with AF undergoing radiofrequency ablation for the first time in the First Affiliated Hospital of Dalian Medical University from May 30, 2008 to September 30, 2018 were included (cancer group). AF patients without cancer undergoing radiofrequency ablation for the first time during the same period served as non-cancer group. Clinical data including age, gender, past history, cancer and AF-related parameters, etc. were analyzed. Patients were followed up after radiofrequency ablation. The primary endpoints were AF recurrence or all-cause death. Kaplan-Meier survival analysis was used to analyze the effect of cancers on the recurrence after AF ablation. The multivariate cox regression analysis was further applied to correct for other confounding factors to analyze whether the impact of cancers on the recurrence of atrial fibrillation was statistically significant. Results: A total of 90 patients were enrolled, there were 30 patients in the cancer group (mean age (64.8±6.6) years, 16 (53.3%) males) and 60 patients in the non-cancer group (mean age (63.6±6.2) years, 32 (53.3%) males). Clinical data, such as age, gender, and cancer treatment, were similar between the two groups. During an average follow-up period of (328.7±110.2) days, there were 6 AF recurrences (recurrence rate 20.0%) in the cancer group, and 17 AF recurrences (recurrence rate 28.3%) in the control group. AF recurrence rate was similar between the two groups (P>0.05). During the follow-up period, there was no all-cause death in the two groups. Kaplan-Meier survival analysis showed that cancer was not related to AF recurrence after radiofrequency ablation (P = 0.383). After adjusting for other confounding factors, the multivariate Cox regression analysis showed that cancer was not an independent predictor of AF recurrence after radiofrequency ablation (HR=0.508, 95%CI: 0.192-1.342, P = 0.172). Conclusions: The combination of cancer has no impact on the recurrence of AF after radiofrequency ablation. For cancer patients with AF, radiofrequency ablation therapy can be considered as a feasible heart rhythm control treatment strategy.

Risk assessment of trace metal-polluted coastal sediments on Hainan Island: A full-scale set of 474 geographical locations covering the entire island

Hainan Island is the second largest island and one of the most famous tourist destinations in China, but sediment contamination by trace metals in coastal areas is a major issue. However, full-scale risk assessments of trace metal-polluted coastal sediments are lacking. In this study, coastal surface sediments from 474 geographical locations covering almost the entire island were collected to identify risk-related variables. Controlling factors and possible sources of trace metals were identified, and the toxicity effects were carefully evaluated. Our results suggest that trace-metal pollution in coastal sediments, which was mainly caused by Pb, Zn and Cu emissions, has primarily resulted from industrial sewage and shipping activities and has threatened the offshore ecosystem of Hainan Island and warrants extensive consideration. This is the first study that has systematically investigated trace metal-polluted coastal sediments throughout the entirety of Hainan Island and provides solid evidence for sustainable marine management in the region.

[Association of RTN4 gene rs2864052 and rs6545468 with the susceptibility of nasopharyngeal carcinoma in Guangxi Zhuang population]

Objective:To study the relationship of the polymorphism of RTN4 gene rs2864052 and rs6545468 and haplotype with the susceptibility of nasopharyngeal carcinoma in Guangxi Zhuang population. Method:The polymorphism of Nogo gene (rs2864052,rs6545468) and haplotype were analyzed using the method of single-base extension PCR and DNA sequencing in 282 cases of nasopharyngeal carcinoma (NPC) and 199 healthy persons (control group) in Guangxi Zhuang Autonomous Region. Result:There were no differences between the NPC's patients and controls in the genotype and allele frequencies of RTN4 gene rs2864052 site,or rs6545468 site. The frequency of AG haplotype in the NPC's patients was significantly lower than in the controls(P=0.004, OR=0.14,95%CI=0.31-0.68). Conclusion:The haplotype AG of RTN4 gene rs2864052 and rs6545468 sites may reduce the risk of nasopharyngeal carcinoma in Guangxi Zhuang population.

Ischemia-reperfusion injury in an aortic dissection patient

Aortic dissection is a life-threatening emergency. Well-established risk factors include systemic hypertension, hereditary connective tissue diseases (Marfan syndrome and Ehlers-Danlos syndrome), coarctation of the aorta, bicuspid aortic valve, aortitis, and arch hypoplasia. Ischemia of the viscera, the kidneys, the spinal cord, or the lower extremities due to malperfusion constitutes life-threatening complications that have to be considered in the treatment strategy.We report a rare case of symptomatic ischemia of the lower extremities due to aortic dissection. This case demonstrates that the treating physician needs to be vigilant for ischemia reperfusion injuries such as osteofascial compartment syndrome and acute renal failure in aortic dissection.

Decoupling free-carriers contributions from oxygen-vacancy and cation-substitution in extrinsic conducting oxides

The intrinsic oxygen-vacancies and the extrinsic dopants are two major fundamental free-carrier sources for the extrinsic conducting oxides, such as Sn-doped In(2)O(3). Yet, the individual contributions of the above two free-carrier sources to the total carrier concentrations have never been unraveled. A carrier-concentration separation model is derived in this work, which can define the individual contributions to the total carrier concentration from the intrinsic oxygen-vacancies and the extrinsic dopants, separately. The individual contributions obtained from the present carrier-concentration separation model are verified by the two-state trapping model, photoluminescence, and positron annihilation lifetime (PAL) spectroscopy. In addition, the oxygen-vacancy formation energy of the Sn:In(2)O(3) thin film is determined to be 0.25 eV by PAL spectroscopy.

Fate of nonylphenol polyethoxylates and their metabolites in four Beijing wastewater treatment plants

Four Beijing wastewater treatment plants (WWTPs) were selected to investigate behaviours of nonylphenol polyethoxylates and their metabolites in different wastewater treatment processes. The results showed that the total concentrations of nonylphenolic compounds in the influents of the four WWTPs ranged from 0.115 to 0.347 mumol/L, as well as their removal efficiencies ranging from 75.7% to 90.8%. Both influent concentrations and removal efficiencies of nonylphenol polyethoxylates were correlated to seasons as follows: higher in the summer than in the winter, and influent concentrations were lower during the rain weather. The analysis revealed that 21.8-47.6% of nonylphenol polyethoxylates and their metabolites entering WWTPs were released via effluents and excess sludge, leaving a great part of them for biodegradation. Nonylphenol and short-chain nonylphenol polyethoxylates were disposed to the environment mainly via sewage sludge, while carboxylated nonylphenol polyethoxylates were the most abundant group of nonylphenol polyethoxylates in effluents.

Adjustability of the circadian clock in the cockroaches: a comparative study of two closely related species, Blattella germanica and Blattella bisignata

A single 2h light pulse (250 lux) was given at various times to phase shift the locomotor circadian rhythm of two species of closely related cockroaches, Blattella bisignata and Blatella germanica. The phase-response curve (PRC) of both species showed a similar pattern. Phase delays and advances were induced by light pulse during the early and late subjective night, respectively, while no clear phase shifting was elicited during the subjective day. However, the magnitude of the phase delay (1.89h +/- 0.66h) and advance (0.69h +/- 0.36h) of B. bisignata was significantly larger than that of B. germanica (0.78h +/- 0.38h and 0.35h +/- 0.18h, respectively). This result indicates the superior adjustability of the circadian clock in B. bisignata. The period-response curve (PdRC) was also constructed for both species. Although both species did not show great flexibility in circadian period changes, the phase shifts were significantly correlated with the period changes in the advance zone of B. bisignata (r = 0.72, P < .1). This allowed the circadian clock of B. bisignata to display better entrainability since the phase advance adjustment was significantly more difficult than that of phase delay. The results indicate the overall adjustability of the circadian clock of B. germanica is inferior to that of B. bisignata. The significance of this finding is discussed from an ecological perspective.

Fluorescence quenching of ethidium ion by porphyrin cations and quaternary ammonium surfactants in the presence of DNA

Fluorescence quenching of free and DNA-bound ethidium bromide (EB) by a number of quaternary ammonium and other compounds was studied. For free EB or bound EB at lower DNA concentration the fluorescence quenching follows the Stern-Volmer equation and at higher DNA concentration follows an exponential model. At least at low quencher concentrations the quenching efficiency varies with DNA or NaCl concentrations and is about 100 times greater for bound than free EB. The quenching pathways may involve energy transfer and conformational loosening or distortion of the DNA helix in addition to possible electron transfer.

Inhibitory effect of triptolide on colony formation of breast and stomach cancer cell lines

Triptolide (Tri) is a diterpenoid triepoxide isolated from Tripterygium wilfordii Hook F. The effects of Tri on the colony formation of breast cancer cell lines MCF-7 and BT-20, stomach cancer cell lines MKN-45, MKN-7, and KATO-III, and promyelocytic leukemia cell line HL-60 were reported. Using Hamburger-Salmon's double layer agar technique with certain modifications, cancer cells were cultured in 0.3% agar in a highly humidified atmosphere of 5% CO2 at 37 degrees C for 14-21 d. Colonies were counted on d 14 (occasionally d 21) with the colony analyzer system CA-7A. Of the 5 solid tumor cell lines tested, 4 showed diminished colony formation in soft agar by greater than 70% of control value in Tri 10(-8) mol.L-1 (continuous exposure). The magnitudes of the inhibitory effect of Tri on most breast and stomach cancer cell lines were similar to that on the leukemia cell line HL-60. IC50 were 0.504-1.22 micrograms.L-1. The clinically achievable peak plasma concentration (PPC) of Tri was estimated as 0.15 mg.L-1, being 72-126 times higher than the IC70 of the cancer cell lines except KATO-III. The results suggest that Tri might have a potential therapeutic effect on some types of solid tumors, e.g., breast and stomach cancers.