Enhanced Detection Precision of the Taiji Program by Frequency Setting Strategy Based on a Hierarchical Optimization Algorithm.

For space-based gravitational wave detection, a laser interferometric measurement system composed of a three-spacecraft formation offers the most rewarding bandwidth of astrophysical sources. There are no oscillators available that are stable enough so that each spacecraft could use its own reference frequency. The conversion between reference frequencies and their distribution between all spacecrafts for the synchronization of the different metrology systems is the job of the inter-spacecraft frequency setting strategy, which is important for continuously acquiring scientific data and suppressing measurement noise. We propose a hierarchical optimization algorithm to solve the frequency setting strategy. The optimization objectives are minimum total readout displacement noise and maximum beat-note frequency feasible range. Multiple feasible parameter combinations were obtained for the Taiji program. These optimized parameters include lower and upper bounds of the beat note, sampling frequency, pilot tone signal frequency, ultrastable clock frequencies, and modulation depth. Among the 20 Pareto optimal solutions, the minimum total readout displacement noise was 4.12 pm/Hz, and the maximum feasible beat-note frequency range was 23 MHz. By adjusting the upper bound of beat-note frequency and laser power transmitted by the telescope, we explored the effects of these parameters on the minimum total readout displacement noise and optimal local laser power in greater depth. Our results may serve as a reference for the optimal design of laser interferometry system instrument parameters and may ultimately improve the detection performance and continuous detection time of the Taiji program.

Advanced inter-spacecraft offset frequency setting strategy for the Taiji program based on a two-stage optimization algorithm.

For space-based gravitational wave (GW) detection, the continuity of detection data acquisition is crucial to the inversion of wave sources and the realization of scientific goals. To control the inter-spacecraft beat-note frequency in an appropriate range for continuous gravitational wave detection and to reduce the upper bound of the beat-note frequency for improving the detection capability, a two-stage optimization algorithm is proposed to solve the offset frequency setting strategy in the Taiji program. The optimization objectives are the maximum offset frequency duration and minimum upper bound of the beat-note frequency. Considering all feasible phase-locked schemes, Doppler frequency shift, and the bandwidth of the phasemeter, a series of offset frequency setting strategies satisfying the conditions was obtained. The solution results show that the upper bound can be reduced to 16 MHz and, in this case, the offset frequency changes nine times with a minimum and maximum offset frequency duration of 90 days and 713 days, respectively. If the Doppler frequency shift is constrained, the minimum upper bound can be reduced to 14 MHz. When the minimum duration is increased, the minimum upper bound is increased. These results show that, by varying the offset frequency a limited number of times, the data continuity requirements of the Taiji program can be satisfied, and the phasemeter development difficulty and detection capability can be balanced, and may provide a reference for the phasemeter design, the setting of phase-locking schemes, and inter-spacecraft offset frequency in the Taiji program.

Inter-spacecraft offset frequency setting strategy in the Taiji program.

For controlling the beat frequency of heterodyne interferometry so that the Taiji program can detect gravitational waves in space, an offset frequency setting strategy based on a linear programming algorithm is proposed. Considering factors such as Doppler frequency shift, phase-locking scheme, laser relative intensity noise, and phase detector bandwidth, inter-spacecraft offset frequency setting results suitable for the Taiji program are obtained. During the six years of running the detection process, the use of frequency bounds in the range of [5 MHz, 25 MHz] showed that offset frequencies will remain unchanged for a maximum of 1931 days. If the upper and lower bounds are adjusted, and the relative motion between spacecraft is further constrained, the offset frequencies do not need to change during the time of the mission. These results may provide insights into selecting the phase detector and designing operation parameters such as orbit and laser modulation frequency in the Taiji program.

Design, green synthesis, antioxidant activity screening, and evaluation of protective effect on cerebral ischemia reperfusion injury of novel monoenone monocarbonyl curcumin analogs.

Antioxidants with high efficacy and low toxicity have the potential to treat cerebral ischemia reperfusion injury (CIRI). Dienone monocarbonyl curcumin analogs (DMCA) capable of overcoming the instability and pharmacokinetic defects of curcumin possess notable antioxidant activity but are found to be significantly toxic. In this study, a novel skeleton of the monoenone monocarbonyl curcumin analogue sAc possessing reduced toxicity and improved stability was designed on the basis of the DMCA skeleton. Moreover, 32 sAc analogs were obtained by applying a green, simple, and economical synthetic method. Multiple sAc analogs with an antioxidant protective effect in PC12 cells were screened using an H2O2-induced oxidative stress damage model, and quantitative evaluation of structure-activity relationship (QSAR) model with regression coefficient of R2 = 0.918921 was built through random forest algorithm (RF). Among these compounds, the optimally active compound sAc15 elicited a potent protective effect on cell growth of PC12 cells by effectively eliminating ROS generation in response to oxidative stress injury by activating the Nrf2/HO-1 antioxidant signaling pathway. In addition, sAc15 exhibited good protection against CIRI in the mice middle cerebral artery occlusion (MCAO) model. In this paper, we provide a novel class of antioxidants and a potential compound for stroke treatment.

De novo transcriptomic analysis of the venomous glands from the scorpion Heterometrus spinifer revealed unique and extremely high diversity of the venom peptides.

Scorpion, as an ancient species, has been widely used on dozens of human diseases in traditional Chinese Medicine. Although the scorpion venom from the Buthidae family with the potent toxicity attracts more interests, toxins from the non-Buthidae family draw great attention as well because of its abundance and complexity even without harm to mammals. Moreover, several toxic components of scorpion venom have been identified as valuable scaffolds for the drug design and development. Using the Next Generation Sequencing (NGS) technique, here we reported the transcriptome of the venomous glands of Heterometrus spinifer, a non-Buthidae scorpion that only a few toxic and complete components have been identified known-to-date. The total mRNA extracted from the venomous glands of H. spinifer was subjected to illumina sequencing with a strategy of de novo assembly, and a total of 54 189 transcripts were unigenes from a total of 88 311 600 determined reads. We annotated 18 567 (34.26%) unigenes from NR database, 12 258 (22.62%) from SWISSPROT database, 11 161 (20.60%) from GO database, 10 159 (18.75%) from COG database and 5059 (9.34%) from KEGG database, respectively. 2843 unigenes were further selected against the toxin-related sub-database of SWISSPROT. After removing the redundancy, 13 common toxin-related subfamilies with 62 unigenes were manually confirmed, including 8 K-toxins, 1 calcin, 3 Imperatoxin I-like, 2 La1-like, 1 scorpin-like, 3 antimicrobial peptides, two types of protease inhibitors such as 8 Kunitz-type protease inhibitors and 3 Ascaris-type protease inhibitors, and 33 proteases including 16 serine proteinases, 7 phospholipases, 5 metalloproteases, 3 hyaluronidases and 2 phosphatases. Our report is the first transcriptomic analyses of venomous glands from the scorpion H. spinifer, serving as a public information platform for the development of novel bio-therapeutics.

Chinese Herbal Medicine for Osteoporosis: A Meta-analysis of Randomized Controlled Trials.

Osteoporosis is a major public health problem in the elderly population. Several studies have suggested that Chinese herbal medicine has antiosteoporotic activities that might be beneficial for osteoporosis. This study aimed to assess the effectiveness of Chinese herbal medicine in osteoporosis patients. We comprehensively searched for randomized controlled trials (until December 2016) that compared Chinese herbal medicine with Western medicine in adults with osteoporosis and reported bone mineral densities (BMDs). A total of 10 randomized controlled trials were included. The pooled results suggested that the increased spine BMD was lower but not significant in the Chinese herbal medicine group than in the Western drug group (standard mean difference [SMD] = -0.11, 95% confidence interval [CI]: -0.62 to 0.39, p > 0.05). In the subgroup analysis, in postmenopausal women, Chinese herbal medicine also showed a insignificantly higher increment in BMD than the control group (SMD = 0.22, 95% CI: -0.00 to 0.43, p = 0.05). For different treatment durations, subgroups over 6 mo (SMD = 0.09, 95% CI: -0.24 to 0.41, p > 0.05) and less than 6 mo (SMD = -0.25, 95% CI: -1.14 to 0.64, p > 0.05) showed comparable BMDs between the 2 therapies. Our study demonstrated that Chinese herbal medicine alone did not significantly increase lumbar spine BMD. Further studies with better adherence to the intervention are needed to confirm the results of this meta-analysis.

Increased frequency of self-fertile isolates in Phytophthora infestans may attribute to their higher fitness relative to the A1 isolates.

Knowledge of population dynamics of mating types is important for better understanding pathogen's evolutionary potential and sustainable management of natural and chemical resources such as host resistances and fungicides. In this study, 2250 Phytophthora infestans isolates sampled from 61 fields across China were assayed for spatiotemporal dynamics of mating type frequency. Self-fertile isolates dominated in ~50% of populations and all but one cropping region with an average frequency of 0.64 while no A2 isolates were detected. Analyses of 140 genotypes consisting of 82 self-fertile and 58 A1 isolates indicated that on average self-fertile isolates grew faster, demonstrated higher aggressiveness and were more tolerant to fungicides than A1 isolates; Furthermore, pattern of association between virulence complexity (defined as the number of differential cultivars on which an isolate can induce disease) and frequency was different in the two mating types. In A1 isolates, virulence complexity was negatively correlated (r = -0.515, p = 0.043) with frequency but this correlation was positive (r = 0.532, p = 0.037) in self-fertile isolates. Our results indicate a quick increase of self-fertile isolates possibly attributable to their higher fitness relative to A1 mating type counterpart in the field populations of P. infestans in China.