Solar X-ray and EUV imager on board the FY-3E satellite.

The solar X-ray and Extreme Ultraviolet Imager (X-EUVI), developed by the Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences (CIOMP), is the first space-based solar X-ray and Extreme ultraviolet (EUV) imager of China loaded on the Fengyun-3E (FY-3E) satellite supported by the China Meteorological Administration (CMA) for solar observation. Since started work on July 11, 2021, X-EUVI has obtained many solar images. The instrument employs an innovative dual-band design to monitor a much larger temperature range on the Sun, which covers 0.6-8.0 nm in the X-ray region with six channels and 19.5 nm in the EUV region. X-EUVI has a field of view of 42', an angular resolution of 2.5″ per pixel in the EUV band and an angular resolution of 4.1″ per pixel in the X-ray band. The instrument also includes an X-ray and EUV irradiance sensor (X-EUVS) with the same bands as its imaging optics, which measures the solar irradiance and regularly calibrates the solar images. The radiometric calibration of X-EUVS on the ground has been completed, with a calibration accuracy of 12%. X-EUVI is loaded on the FY-3E satellite and rotates relative to the Sun at a uniform rate. Flat-field calibration is conducted by utilizing successive rotation solar images. The agreement between preliminarily processed X-EUVI images and SDO/AIA and Hinode/XRT images indicates that X-EUVI and the data processing algorithm operate properly and that the data from X-EUVI can be applied to the space weather forecast system of CMA and scientific investigations on solar activity.

Hypoxic ucMSC-secreted exosomal miR-125b promotes endothelial cell survival and migration during wound healing by targeting TP53INP1.

A hypoxic microenvironment is a common feature of skin wounds. Our previous study demonstrated that three-dimensional coculture of umbilical cord-derived mesenchymal stem cells (ucMSCs) and endothelial cells facilitates cell communication and host integration in skin tissue engineering. Here, we aimed to identify the mechanism by which ucMSCs affect endothelial cells under hypoxic conditions after skin injury. We demonstrate that hypoxia enhances the exosome-mediated paracrine function of ucMSCs, which increases endothelial cell proliferation and migration. In a mouse full-thickness skin injury model, ucMSC-derived exosomes can be taken up by endothelial cells and accelerate wound healing. Hypoxic exosomes lead to a better outcome than normoxic exosomes by promoting proliferation and inhibiting apoptosis. Mechanistically, microRNA-125b (miR-125b) transcription is induced by hypoxia in ucMSCs. After being packaged into hypoxic exosomes and transported to endothelial cells, miR-125b targets and suppresses the expression of tumor protein p53 inducible nuclear protein 1 (TP53INP1) and alleviates hypoxia-induced cell apoptosis. Inhibition of miR-125b-TP53INP1 interaction attenuates the protective effect of hypoxic exosomes. Moreover, artificial agomiR-125b can accelerate wound healing in vivo. Our findings reveal communication between ucMSCs and endothelial cells via exosomal miR-125b/TP53INP1 signaling in the hypoxic microenvironment and present hypoxic exosomes as a promising therapeutic strategy to enhance cutaneous repair.

Photon Counting Imaging with Low Noise and a Wide Dynamic Range for Aurora Observations.

The radiation intensity of observed auroras in the far-ultraviolet (FUV) band varies dramatically with location for aerospace applications, requiring a photon counting imaging apparatus with a wide dynamic range. However, combining high spatial resolution imaging with high event rates is technically challenging. We developed an FUV photon counting imaging system for aurora observation. Our system mainly consists of a microchannel plate (MCP) stack readout using a wedge strip anode (WSA) with charge induction and high-speed electronics, such as a charge sensitive amplifier (CSA) and pulse shaper. Moreover, we constructed an anode readout model and a time response model for readout circuits to investigate the counting error in high counting rate applications. This system supports global rates of 500 kilo counts, 0.610 dark counts s-1 cm-2 at an ambient temperature of 300 K and 111 µm spatial resolution at 400 kilo counts s-1 (kcps). We demonstrate an obvious photon count loss at incident intensities close to the counting capacity of the system. To preserve image quality, the response time should be improved and some noise performance may be sacrificed. Finally, we also describe the correlation between counting rate and imaging resolution, which further guides the design of space observation instruments.

Wide-field auroral imager onboard the Fengyun satellite.

The newly launched Fengyun-3D (FY-3D) satellite carried a wide-field auroral imager (WAI) that was developed by Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences (CIOMP), which will provide a large field of view (FOV), high spatial resolution, and broadband ultraviolet images of the aurora and the ionosphere by imaging the N2 LBH bands of emissions. The WAI consists of two identical cameras, each with an FOV of 68° in the along-track direction and 10° in the cross-track direction. The two cameras are tilted relative to each other to cover a fan-shaped field of size 130° × 10°. Each camera consists of an unobstructed four-mirror anastigmatic optical system, a BaF2 filter, and a photon-counting imaging detector. The spatial resolution of WAI is ~10 km at the nadir point at a reference height of 110 km above the Earth's surface. The sensitivity is >0.01 counts s-1 Rayleigh-1 pixel-1 (140-180 nm) for both cameras, which is sufficient for mapping the boundaries and the fine structures of the auroral oval during storms/substorms. Based on the tests and calibrations that were conducted prior to launch, the data processing algorithm includes photon signal decoding, geometric distortion correction, photometric correction, flat-field correction, line-of-sight projection and correction, and normalization between the two cameras. Preliminarily processed images are compared with DMSP SSUSI images. The agreement between the images that were captured by two instruments demonstrates that the WAI and the data processing algorithm operate normally and can provide high-quality scientific data for future studies on auroral dynamics.

Yin-yang and Zheng: Exported from Chinese medicine.

Chinese medicine (CM) basic theory differs substantially from modern medicine in methodology. CM views the healthy human body as an entity in yinyang equilibrium. CM practitioners typically diagnose patients with "Zheng (CM syndrome)"-yin-yang status of specific organs, and the ultimate goal of treatment in CM is to restore the yin-yang balance. This concept might seem strange to Western perceptions; however, CM philosophy and methodology have been gradually accepted and used in the West. There is growing evidence from prestigious worldwide journals like Nature, Science and Cell indicating that CM theory is becoming an important component in dealing with health issues in the West.

Anti-tumor efficacy of a transcriptional replication-competent adenovirus, Ad-OC-E1a, for osteosarcoma pulmonary metastasis.

BACKGROUND: Osteosarcoma (OSA) is the most frequent type of primary malignant bone tumor and is apt to occur in children and young adults. Pulmonary metastasis (OSPM) is the major reason for its fatal outcome. Osteocalcin (OC) is a major noncollagenous bone protein whose expression is limited almost exclusively to bone marrow and osteotropic tumors. OC is also known to express in cell lines with bone metastasis feathers. Gene therapy strategies with the OC promoter directing the replication of adenovirus in a tumor-specific manner are a potential modality for OSPM therapy. METHODS: We detected OC mRNA expression by RNA in situ hybridization in OSA and OSPM samples from patients, and tested OC promoter transcriptional activity in OSA and non-OSA cell lines. Then we used a transcriptional replication-competent adenovirus, Ad-OC-E1a, to treat OSPM, and evaluated its tumor-specific replication and killing activities in vitro as well as anti-OSPM efficacy in vivo via systemic delivery. RESULTS: OC mRNA was detected in all types of OSA tissues, including OSPM tissues. The transcriptional activity of the OC promoter was much higher in a OSPM cell line SAOS-2LM7 and primary OSA cell line MG63 than in non-OSA cell lines, including cell lines from breast cancer, colon cancer, and liver cancer. Ad-OC-E1a expressed E1a protein only in MG63 and SAOS-2LM7, which indicated that adenovirus E1a was under strict control by the OC promoter. Ad-OC-E1a demonstrated killing and viral replication activity close to wild-type adenovirus levels in MG63 and SAOS-2LM7, but the killing and viral replication activities were attenuated significantly in cells expressing low OC transcriptional activity. To test whether Ad-OC-E1a could be used to target human OSPM in vivo, SAOS-2LM7 pulmonary metastasis models in nude mice were induced and treated by tail-vein injection with Ad-OC-E1a. Compared to tumor nodules in the lung in groups treated with PBS or control virus, the quantity of metastasized tumor nodules decreased significantly. Adenovirus-infected cells were stained immunohistochemically only inside and around the OSPM nodules but spared normal lung tissue and other organs. CONCLUSIONS: These data demonstrated that OC promoter could direct adenovirus replication by controlling the E1a gene to target human OSPM in a tumor-specific manner, providing an efficient tool to develop a feasible therapeutic modality for OSPM.

HOXB13 induces growth suppression of prostate cancer cells as a repressor of hormone-activated androgen receptor signaling.

Androgen receptor (AR) signals play a decisive role in regulating the growth and differentiation of both normal and cancerous prostate cells by triggering the regulation of target genes, in a process in which AR cofactors have critical functions. Because of the highly prostate-specific expression pattern of HOXB13, we studied the role of this homeodomain protein in prostate cells. Expression of HOXB13 was limited to AR-expressing prostate cells. Reporter transcription assay demonstrated that HOXB13 significantly suppressed hormone-mediated AR activity in a dose-responsive manner, and suppression was specific to AR with which HOXB13 physically interacts. Overexpression of HOXB13 further down-regulated the androgen-stimulated expression of prostate-specific antigen, and suppression of endogenous HOXB13 stimulated transactivation of AR. Functionally, HOXB13 suppressed growth of LNCaP prostate cancer cells, which could be counteracted by additional hormone-activated AR. On the other hand, the growth-suppressive function of HOXB13 in AR-negative CV-1 cells was not affected by AR. These results suggest that HOXB13 functions as an AR repressor to modulate the complex AR signaling and subsequent growth regulation of prostate cancer cells. In addition to the loss of HOXB13 expression, maintaining AR may be an important step for prostate cancer cells to tolerate the suppressor function of HOXB13. Altogether, our data present a novel mechanism for the HOXB13-mediated repression of AR signaling, which can be interpreted to a growth-suppressive event.

Coordinate increase of telomerase activity and c-Myc expression in Helicobacter pylori-associated gastric diseases.

AIM: To detect the telomerase activity and c-Myc expression in gastric diseases and to examine the relation between these values and Helicobacter pylori (H pylori) as a risk factor for gastric cancer. METHODS: One hundred and seventy-one gastric samples were studied to detect telomerase activity using a telomerase polymerase chain reaction enzyme linked immunosorbent assay (PCR-ELISA), and c-Myc expression using immunohistochemistry. RESULTS: The telomerase activity and c-Myc expression were higher in cancers (87.69% and 61.54%) than in noncancerous tissues. They were higher in chronic atrophic gastritis with severe intestinal metaplasia (52.38% and 47.62%) than in chronic atrophic gastritis with mild intestinal metaplasia (13.33% and 16.67%). In chronic atrophic gastritis with severe intestinal metaplasia, the telomerase activity and c-Myc expression were higher in cases with H pylori infection (67.86% and 67.86%) than in those without infection (21.43% and 7.14%). c-Myc expression was higher in gastric cancer with H pylori infection (77.27%) than in that without infection (28.57%). The telomerase activity and c-Myc expression were coordinately up-regulated in H pylori infected gastric cancer and chronic atrophic gastritis with severe intestinal metaplasia. CONCLUSION: H pylori infection may influence both telomerase activity and c-Myc expression in gastric diseases, especially in chronic atrophic gastritis.