Observation and comparison of tower vibration and underwater noise from offshore operational wind turbines in the East China Sea Bridge of Shanghai.

Underwater operational turbine noise emitted by China's first offshore wind farm in the East China Sea Bridge of Shanghai was measured and analyzed in this study. Two sensors were used in the measurement: a hydrophone recording the underwater sound and an accelerometer placed in the turbine tower detecting the tower vibrations. Measurements were performed at two different types of wind turbines: a Sinovel 3 MW SL3000 turbine and a Shanghai Electric 3.6 MW W3600 turbine. The two turbines show similar tower vibration characteristics, characterized by a number of tonal components, mainly in the low-frequency domain (30-500 Hz). The peak vibration frequencies changed with the wind speed until the turbine approached its nominal power rating. Spectral analysis of the underwater acoustic data showed that the amplitude spectra had a strong correlation with the spectra of the turbine vibration intensity level, indicating that the measured underwater noise was generated by the tower mechanical vibration.

Comparing baseline VAF in circulating tumor DNA and tumor tissues predicting prognosis of patients with colorectal cancer liver metastases after curative resection.

INTRODUCTION: The prognostic value of baseline variant allele frequency (VAF) in circulating tumor DNA (ctDNA) of colorectal cancer liver metastases (CRLM) patients after curative resection was rarely investigated. METHODS: A single-center prospective study was performed to investigate the prognostic impact of baseline VAF in ctDNA and matched tumor tissues of CRLM patients after curative resection between May 2019 and May 2021 by the Illumina NovoSeq 6000 platform. The relationship of the tumor burden score (TBS) and the VAF in ctDNA and matched tumor tissues was evaluated by the Pearson correlation method. The survival curves of recurrence-free survival (RFS) and overall survival (OS) were plotted. Factors associated with RFS were calculated using Cox regression analysis, and an integrated prognostic model using significant baseline variables was proposed. RESULTS: There were 121 patients with baseline ctDNA and matched tumor tissues enrolled in the study. A total of 417 mutations spanning 20 genes were identified in baseline tumor tissues of 119/121 (98.3 %) cases. The overall mutations in tumor tissues were completely covered by ctDNA in 52 of 121(43.0 %) patients. Baseline VAF in ctDNA but not in tumor tissues was significantly correlated to TBS of CRLM (R = 0.36, p < 0.001). Significantly longer RFS but not OS was observed in patients with lower VAF in ctDNA compared to those with higher one (p < 0.001 and p = 0.33 respectively). Multivariate Cox regression analysis showed higher VAF in baseline ctDNA was an independent risk factor for RFS. An integrated prognostic model including baseline metastasis location and VAF in ctDNA outperformed the traditional CRS model in predicting RFS. CONCLUSION: Baseline VAF in ctDNA but not in tumor tissues influenced RFS of CRLM patients after curative resection.

Controllable acoustic deterrent based on the warning signals generated by nonel detonators.

Acoustic deterrents are a practical strategy to mitigate the impact of underwater noise on marine mammals. However, their safety and effectiveness are still debatable. This study proposes a controllable acoustic deterrence method to protect marine mammals threatened by underwater blasting noise. The method creates strong-randomness warning signals using nonel detonators and establishes an escape time for animals protected. Combining the BELLHOP ray-based acoustic model with the marine environmental parameters and animals' auditory characteristics, we built a prediction model to establish a link between the acoustic fields and the adjustable source parameters, and provide a Risk zone and Deterrent zone for animals. The simulation and experimental results demonstrated that the root mean squared error between the simulated and measured sound pressure spectral density levels did not exceed 4.5 dB and the coefficient of determination remained at approximately 0.8, indicating that the new deterrent is an effective method with good controllable performances.

Steroids from the gorgonian Isis hippuris.

Six new polyoxygenated steroids, hippuristerones J-L (1-3), hippuristerols E-F (4, 5), and a novel gorgosteroid, 1alpha,3beta,5beta,11alpha-tetrahydroxygorgostan-6-one (6), were isolated from the gorgonian Isis hippuris. The structures of these metabolites were elucidated by extensive spectroscopic analyses and comparison of the NMR data with those of related steroids.

Polyoxygenated steroids from the gorgonian Isis hippuris.

Eleven new hippuristanols (1-4, 7-9, and 11-14), along with eight known metabolites (5, 6, 10, and 15-19), have been isolated from the gorgonian coral Isis hippuris. Single-crystal X-ray diffraction analyses supported the structure elucidation of known steroids 5 and 10. The absolute structures of hippuristanols were established by application of modified Mosher's method on 19. Compounds 14-19 have been found to exhibit significant cytotoxicity against several cancer cell lines.

Hippuristerones E-I, new polyoxygenated steroids from the gorgonian coral Isis hippuris.

Five novel (22R,23S,24S)-steroids, hippuristerones E-I (1-5), have been isolated from the gorgonian coral Isis hippuris. The structures of steroids 1-5 were deduced by extensive 1D and 2D NMR studies ((1)H, (13)C, (1)H-(1)H COSY, HMQC, HMBC, and NOESY experiments). The structure of 1 was further supported by molecular mechanics calculations.