The
Insight
-Hard X-ray Modulation Telescope (
Insight
-HXMT) is a broadband X-ray and γ-ray (1-3000 keV) astronomy satellite. One of its three main telescopes is the High Energy X-ray telescope ...(HE). The main detector plane of HE comprises 18 NaI(Tl)/CsI(Na) phoswich detectors, where NaI(Tl) is used as the primary detector to measure ~ 20–250 keV photons incident from the field of view (FOV) defined by collimators, and CsI(Na) is used as the active shielding detector to NaI(Tl) by pulse shape discrimination. Additionally, CsI(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 approximately 5.7°×5.7°. Each HE detector has a diameter of 190 mm resulting in a total geometrical area of approximately 5100 cm
2
, and the energy resolution is ~15% at 60 keV. For each recorded X-ray event by HE, the timing accuracy is less than 10 μs and the dead-time is less than 10 μs. HE is used for observing spectra and temporal variability of X-ray sources in the 20–250 keV 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 MeV band. This paper not only presents the design and performance of HE instruments but also reports results of the on-ground calibration experiments.
Diabetes nephropathy (DN) is the leading cause of end-stage renal disease (ESRD) worldwide, and podocyte injury is the central contributor to the progression of DN. Despite the emerging evidence that ...has established the importance of podocyte endoplasmic reticulum (ER) stress in the pathogenesis of DN, abnormal protein O-GlcNAcylation is also augmented. Currently, the mechanism associating these two hyperglycemia-induced disorders remains poorly understood. This study intended to elucidate whether ER stress drives hyper-protein O-GlcNAcylation to cause podocyte injury in DN. We used both type 1 and type 2 DN models to confirm the occurrence of ER stress and excessive protein O-GlcNAcylation, and then podocyte purification was also conducted for further investigation. Nephroseq V5 data were mined and in vitro studies were applied to reveal the involvement of ER stress and hyper-O-GlcNAcylation in podocyte injury. Our results indicated that ER stress was induced in both type 1 and type 2 DN, and the human RNA-seq data from Nephroseq V5 showed that O-GlcNAcylation-related genes were significantly upregulated in the DN patients. We further demonstrated that ER stress occurred prior to hyper-O-GlcNAc modification and that pharmacologically inhibited protein O-GlcNAcylation can help decrease the podocyte apoptosis induced by hyperglycemia. Together, these discoveries will aid in uncovering the activation of the ER stress-O-GlcNAcylation axis in podocyte injury under DN, which will help open up new therapeutic approaches for preventing DN progression.
The Getang is a representative Carlin-type gold deposit in Southwest China. It has a proven reserve of about 30 tonnes at an average grade of 5.1 g/t Au. The orebodies occur as strat-abound lenses, ...and are structurally controlled by shallow NWW- and NE-trending fold-fault systems and the unconformity between the Upper and Middle Permian. In this study, the regional- and deposit-scale structural investigations, joints and finite strain measurements, and stress and dynamic analysis were conducted with an aim to reveal the structural process of the Getang gold deposit and clarify the relationship between the gold mineralization and structures. Three phases of deformation were identified in the deposit: (1) paleokarst was generated by a crustal uplift when the Youjiang Basin experienced extension at the end of the Middle Permian, laying the foundation for the unconformity; (2) the NW-trending structures were formed under a NNE-SSW compression during the Indochina-South China collision (Indosinian orogeny) in Triassic; (3) the NE-trending structures were generated or reactivated under a NW-SE-oriented compression during the Yanshanian intracontinental orogeny. The unconformity recorded two episodes of tectonic evolution in the NNE-SSW and NW-SE directions. Structural analyses and geochronology data suggest that the Getang gold deposit was formed as a result of tectonic transition from compression to extension during the Yanshanian intracontinental orogeny.
Recently published international guidelines recommend the clinical use of noninvasive prenatal test (NIPT) for aneuploidy screening only among pregnant women whose fetuses are deemed at high risk. ...The applicability of NIPT to aneuploidy screening among average risk pregnancies requires additional supportive evidence. A key determinant of the reliability of aneuploidy NIPT is the fetal DNA fraction in maternal plasma. In this report, we investigated if differences in fetal DNA fractions existed between different pregnancy risk groups. One hundred and ninety-five singleton pregnancies with male fetuses divided into 3 groups according to first trimester screening parameters were examined for fetal DNA percentage by counting Y chromosome DNA sequences using massively parallel sequencing. Fetal DNA fractions were compared between risk groups and assessed for correlations with first trimester screening parameters. There was no statistically significant difference in fetal DNA fractions across the high, intermediate and low risk groups. Fetal DNA fraction showed a strong negative correlation with maternal weight. Fetal DNA fraction also showed weak but significant correlations with gestational age, crown-rump length, multiple of medians of free β-subunit of human chorionic gonadotropin and pregnancy-associated plasma protein A. Similar fetal DNA fractions in maternal plasma between high, intermediate and low risk pregnant women is a precondition for uniform performance of the aneuploidy NIPTs for the general population. This study thus shows that the aneuploidy screening by NIPT is likely to offer similar analytical reliability without respect to the a priori fetal aneuploidy risk.
The presence of fetal DNA in maternal plasma represents a source of fetal genetic material for noninvasive prenatal diagnosis; however, the coexisting background maternal DNA complicates the analysis ...of aneuploidy in such fetal DNA. Recently, the SERPINB5 gene on chromosome 18 was shown to exhibit different DNA-methylation patterns in the placenta and maternal blood cells, and the allelic ratio for placenta-derived hypomethylated SERPINB5 in maternal plasma was further shown to be useful for noninvasive detection of fetal trisomy 18.
To develop a similar method for the noninvasive detection of trisomy 21, we used methylation-sensitive single nucleotide primer extension and/or bisulfite sequencing to systematically search 114 CpG islands (CGIs)-76% of the 149 CGIs on chromosome 21 identified by bioinformatic criteria-for differentially methylated DNA patterns. The methylation index (MI) of a CpG site was estimated as the proportion of molecules methylated at that site.
We identified 22 CGIs which were shown to contain CpG sites that were either completely unmethylated (MI = 0.00) in maternal blood cells and methylated in the placenta (MI range, 0.22-0.65), or completely methylated (MI = 1.00) in maternal blood cells and hypomethylated in the placenta (MI range, 0.00-0.75). We detected, for the first time, placental DNA-methylation patterns on chromosome 21 in maternal plasma during pregnancy and observed their postpartum clearance.
Twenty-two (19%) of the 114 studied CGIs on chromosome 21 showed epigenetic differences between samples of placenta and maternal blood cells; these CGIs may provide a rich source of markers for noninvasive prenatal diagnosis.
The increasing load of senescent cells is a source of aging, and chronic inflammation plays a pivotal role in cellular senescence. In addition, senescent renal tubular epithelial cells are closely ...associated with renal aging. Lysophosphatidic acid (LPA) is a bioactive lipid mainly produced by the catalytic action of autotaxin (ATX), and its ligation to LPA receptor-1 (LPAR1) is associated with chronic inflammation and renal fibrosis; however, its role in renal aging is unclear. Male 2-, 12-, and 24-month-old C57BL/6 mice and Human renal proximal tubular epithelial cells (HRPTEpiC) were used in the present study. DNA damage and oxidative stress-induced senescence were simulated using doxorubicin (DOXO) and H
O
, respectively. The aged kidney showed decreased renal function, increased fractional mesangial area, and tubulointerstitial fibrosis. Both aged kidney and senescent cells showed increased levels of LPAR1, Nuclear factor κB (NF-κB), and inflammatory cytokines. In addition,
knockdown reduced NF-κB and subsequent inflammatory cytokine induction, and
-knockdown resulted in decreased LPAR1 expression. Our study revealed a positive feedback loop between LPAR1 and NF-κB, which reinforces the role of inflammatory response, suggesting that blocking of aberrantly activated LPAR1 may reduce excessive inflammation, thereby providing a new possible therapeutic strategy to attenuate renal aging.
A novel biomimetic immuno‐magnetosome (IMS) is developed by coating a leukocyte membrane (decorated with anti‐epithelial cell‐adhesion molecule antibody) on a magnetic nanocluster. In addition to the ...good stability and magnetic controllability, the IMS also exhibits satisfactory binding avidity to circulating tumor cells but stealth property to leukocytes. As a result, rare tumor cells can be effectively enriched with undetectable leukocyte background.
A black hole X-ray binary produces hard X-ray radiation from its corona and disk when the accreting matter heats up. During an outburst, the disk and corona co-evolves with each other. However, such ...an evolution is still unclear in both its geometry and dynamics. Here we report the unusual decrease of the reflection fraction in MAXI J1820+070, which is the ratio of the coronal intensity illuminating the disk to the coronal intensity reaching the observer, as the corona is observed to contrast during the decay phase. We postulate a jet-like corona model, in which the corona can be understood as a standing shock where the material flowing through. In this dynamical scenario, the decrease of the reflection fraction is a signature of the corona's bulk velocity. Our findings suggest that as the corona is observed to get closer to the black hole, the coronal material might be outflowing faster.
Positron emission tomography (PET) is typically based on 2-D array of scintillation crystals coupled to photon detector and decoded by the Anger-logic. The decoded result is a pseudo-position of the ...gamma interaction. A crystal position map (CPM) generated from the flood histogram is used as a crystal look-up table (CLT) to assign each pseudo-position to a specific crystal. It is crucial that the accuracy of CPMs affects the detector's spatial resolution. In this paper, we developed a neighborhood standard deviation (NSD) based algorithm for generating CPM. We first calculated the NSD of each pixel in the flood histogram including the x and y directions. NSD maps have strips whose peaks highly correspond to the valley of the flood histogram. The peaks were identified by fitting the profiles of NSD to Gaussian mixture functions using nonlinear least-square method. Using the peaks, the CPM was generated by a scan line algorithm. The proposed algorithm was applied in an animal PET system. 115 of 120 detector blocks can be automatically segmented in ~1000 s. A hot rod phantom experiment was performed, and the reconstruction results showed that the one with CPM generated by NSD based automatic method achieved higher spatial resolution than the one with CPM generated by manual segmentation. We concluded that the proposed method is fast, robust and high accuracy.
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