The High Energy X-ray telescope (HE) onboard the Insight-HXMT astronomy satellite

The Insight-Hard X-ray Modulation Telescope(Insight-HXMT) is a broadband X-ray and γ-ray(1-3000 ke V) astronomy satellite. One of its three main telescopes is the High Energy X-ray telescope(HE). The main detector plane of HE comprises 18 Na I(Tl)/Cs I(Na) phoswich detectors, where Na I(Tl) is used as the primary detector to measure ~ 20-250 ke V photons incident from the field of view(FOV) defined by collimators, and Cs I(Na) is used as the active shielding detector to Na I(Tl) by pulse shape discrimination. Additionally, Cs I(Na) is used as an omnidirectional γ-ray monitor. The HE collimators have a diverse FOV,i.e. 1.1°×5.7°(15 units), 5.7°×5.7°(2 units), and blocked(1 unit). Therefore, the combined FOV of HE is approximately5.7°×5.7°. Each HE detector has a diameter of 190 mm resulting in a total geometrical area of approximately 5100 cm2, and the energy resolution is ~15% at 60 ke V. For each recorded X-ray event by HE, the timing accuracy is less than 10 μs and the deadtime is less than 10 μs. HE is used for observing spectra and temporal variability of X-ray sources in the 20-250 ke V band either by pointing observations for known sources or scanning observations to unveil new sources. Additionally, HE is used for monitoring the γ-ray burst in 0.2-3 Me V band. This paper not only presents the design and performance of HE instruments but also reports results of the on-ground calibration experiments.     

Melatonin stimulates aromatase expression and estradiol production in human granulosa-lutein cells: relevance for high serum estradiol levels in patients with ovarian hyperstimulation syndrome

Ovarian hyperstimulation syndrome (OHSS) is one of the most life-threatening and potentially fatal complications associated with controlled ovarian hyperstimulation (COH) during in vitro fertilization (IVF) treatment. Although the pathogenesis of OHSS remains unclear, elevated serum estradiol (E2) levels before human chorionic gonadotropin (hCG) administration are associated with the risk of OHSS. The pineal hormone melatonin and its receptors are expressed in human granulosa cells and have been shown to stimulate E2 production. However, the effect of melatonin on the expression of aromatase, an enzyme responsible for a key step in the biosynthesis of E2, in human granulosa cells remains to be determined. Here, we demonstrate that melatonin upregulates aromatase expression in primary cultured human granulosa-lutein (hGL) cells through the melatonin receptor-mediated PKA-CREB pathway. Using a mouse model of OHSS, we demonstrate that administration of the melatonin receptor inhibitor luzindole inhibits the development of OHSS. In addition, the expression of ovarian aromatase and serum E2 levels are upregulated in OHSS mice compared to control mice, but this upregulation is attenuated by inhibition of the function of melatonin. Moreover, clinical results reveal that aromatase expression levels are upregulated in hGL cells from OHSS patients. Melatonin and E2 levels in the follicular fluid are significantly higher in OHSS patients than in non-OHSS patients. Furthermore, melatonin levels are positively correlated with E2 levels in follicular fluid. This study helps to elucidate the mechanisms mediating the expression of aromatase in hGL cells and provides a potential mechanism explaining the high E2 levels in patients with OHSS.Subject terms: Endocrine reproductive disorders, Endocrine reproductive disorders     

Analysis of the human breast milk microbiome and bacterial extracellular vesicles in healthy mothers

The microbiota of human breast milk (HBM) contribute to infant gut colonization; however, whether bacterial extracellular vesicles (EVs) are present in HBM or might contribute to this process remains unknown. In this study, we characterized the HBM microbiota of healthy Korean mothers and measured the key bacteria likely affecting infant gut colonization by analyzing both the microbiota and bacterial EVs. A total of 22 HBM samples were collected from lactating mothers. The DNA of bacteria and bacteria-derived EVs was extracted from each sample. In alpha-diversity analyses, bacterial samples showed higher richness and evenness than bacterial EV samples, and beta-diversity analyses showed significant differences between bacteria and bacterial EVs within identical individual samples. Firmicutes accounted for the largest proportion among the phyla, followed by Proteobacteria, Bacteroidetes, and Actinobacteria, in both bacteria and bacterial EV samples. At the genus level, Streptococcus (25.1%) and Staphylococcus (10.7%) were predominant in bacterial samples, whereas Bacteroides (9.1%), Acinetobacter (6.9%), and Lactobacillaceae(f) (5.5%) were prevalent in bacterial EV samples. Several genera, including Bifidobacterium, were significantly positively correlated between the two samples. This study revealed the diverse bacterial communities in the HBM of healthy lactating mothers, and found that gut-associated genera accounted for a high proportion in bacterial EV samples. Our findings suggest the existence of key bacteria with metabolic activity that are independent of the major bacterial populations that inhabit HBM, and the possibility that EVs derived from these bacteria are involved in the vertical transfer of gut microbiota.Subject terms: Immunogenetics, Immunization     

Alignment and efficiency-monitoring method of high-power fiber-to-fiber coupling

High-power fiber-to-fiber coupling is extensively used in fiber laser applications,and its performance is determined by coupling efficiency.We demonstrate a novel method for alignment and monitoring efficiency by detecting backscattering power at the fiber end cap.The relationship between alignment error and backscattering power is determined by simulations and experiments.Through this method,a state-of-the-art kW-level fiberto-fiber optic switch is developed(transmission efficiency>97%).It performs well for longer than 60 min.To the best of our knowledge,it is the first time to establish the mathematical model based on this method.Our results can provide guidance in high-power fiber-to-fiber coupling.     

Click and count: specific detection of acid ceramidase activity in live cells

The use of intact cells in medical research offers a number of advantages over employing cell-free systems. In diagnostics, cells isolated from liquid biopsies can be directly used, speeding up the time of analysis and diminishing the risk of protein degradation by sample manipulation. In drug discovery, studies in live cells take into account aspects neglected in cell-free systems, such as uptake, metabolization, and subcellular concentration by compartmentalization of potential drug candidates. Therefore, probes for studies in cellulo are of paramount importance. Acid ceramidase (AC) is a lysosomal enzyme that hydrolyses ceramides into sphingoid bases and fatty acids. The essential role of this enzyme in the outburst and progress of several diseases, some of them still incurable, is well sustained. Despite the great clinical relevance of AC as a biomarker and therapeutic target, the specific monitoring of AC activity in live cells has remained elusive due to the concomitant existence of neutral and alkaline ceramidases. In this work, we report that 1-deoxydihydroceramides are exclusively hydrolysed by AC. Using N-octanoyl-18-azidodeoxysphinganine as a probe and a BODIPY-substituted bicyclononyne, we show the click-reliant predominant staining of lysosomes, with extra-lysosomal labeling also occurring in some cells. Importantly, using pharmacological and genetic tools together with high resolution mass spectrometry, we demonstrate that both lysosomal and extra-lysosomal staining are AC-dependent. These findings are translated into the specific flow cytometry monitoring of AC activity in intact cells, which fills an important gap in the field of diseases linked to altered AC activity.

The use of intact cells in medical research offers a number of advantages over employing cell-free systems.     

Light-intensity switch enabled nonsynchronous growth of fluorinated raspberry-like nanoparticles

Raspberry-like (RB) nanoparticles hold potential for diverse applications due to their hierarchical morphology. Here we developed a novel tandem synthetic approach of nonsynchronous growth based on photo-mediated reversible-deactivation radical polymerization, enabling simple, efficient and bottom-up synthesis of RB nanoparticles of uniform sizes at quantitative conversions of fluorinated monomers. Chain transfer agents of different chain lengths, concentrations and chemical compositions were varied to tune the diameter of RB particles. Importantly, fluorinated RB nanoparticles obtained with this method allow facile post modifications via both covalent bond formation and intermolecular physical interactions without disrupting the RB morphology. The facile nature of this method and versatility of the obtained fluorinated RB materials open new opportunities for the development of functional materials using nanoparticles.

Nonsynchronous growth of raspberry-like (RB) nanoparticles in a one-pot and bottom-up fashion, enabling simple post-modification of RB colloids through both covalent bond formation and supramolecular interaction.     

Construction of Generalized Diffusion Processes: the Resolvent Approach

In this paper, we define the generalized diffusion operator ■ for two suitable measures on the line, which includes the generators of the birth-death processes, the one-dimensional diffusion and the gap diffusion among others. Via the standard resolvent approach, the associated generalized diffusion processes are constructed.     

基于近似解析法的超导储能磁体设计

降低超导储能磁体的研制成本一直是控制超导磁储能系统(Superconducting Magnetic Energy Storage, SMES) 总成本的重要手段之一. 本文考虑在一定磁体结构参数范围内, 磁体产生的最大磁场值可以采用级数进行 表示, 磁体的电感值可以采用线性函数表示, 给出了超导储能磁体磁场能量的近似解析表达式, 提出了一种基于近 似解析法的超导储能磁体设计方法. 该方法以储能磁体的线材用量最小作为设计目标, 在给定超导线材参数和临界电流特性曲线, 以及磁体储能总量要求的情况下, 依据此方法可快速的得到成本最优时所对应的磁体结构参数.将近似解析法优化和采用传统的有限元软件 Ansys 仿真优化进行对比分析, 结果表明采用近似解析法进行磁体优化更加方便快捷, 节省了大量计算时间.