Digitization of Astronomical Photographic Plates of China and Astrometric Measurement of Single-exposure Plates

From the mid-19th century to the end of the 20th century, photographic plates served as the primary detectors for astronomical observations. Astronomical photographic observations in China began in 1901, and over a century, a total of approximately 30,000 astronomical photographic plates were captured. These historical plates play an irreplaceable role in conducting long-term, time-domain astronomical research. To preserve and explore these valuable original astronomical observational data, Shanghai Astronomical Observatory has organized the transportation of plates, taken during nighttime observations from various stations across the country, to the Sheshan Plate Archive for centralized preservation. For the first time, plate information statistics were calculated. On this basis, the plates were cleaned and digitally scanned, and finally digitized images were acquired for 29,314 plates. In this study, using Gaia DR2 as the reference star catalog, astrometric processing was carried out successfully on 15,696 single-exposure plates, including object extraction, stellar identification,and plate model computation. As a result, for long focal length telescopes, such as the 40 cm double-tube refractor telescope, the 1.56 m reflector telescope at Shanghai Astronomical Observatory, and the 1m reflecting telescope at Yunnan Astronomical Observatory, the astrometric accuracy obtained for their plates is approximately 0."1–0."3. The distribution of astrometric accuracy for medium and short focal length telescopes ranges from 0."3 to 1."0. The relevant data of this batch of plates, including digitized images and a stellar catalog of the plates, are archived and released by the National Astronomical Data Center. Users can access and download plate data based on keywords such as station, telescope, observation year, and observed celestial coordinates.

Potential role of microRNA-503 in Icariin-mediated prevention of high glucose-induced endoplasmic reticulum stress

BACKGROUND Dysregulated microRNA(miRNA)is crucial in the progression of diabetic nephropathy(DN).AIM To investigate the potential molecular mechanism of Icariin(ICA)in regulating endoplasmic reticulum(ER)stress-mediated apoptosis in high glucose(HG)-induced primary rat kidney cells(PRKs),with emphasis on the role of miR-503 and sirtuin 4(SIRT4)in this process.METHODS Single intraperitoneal injection of streptozotocin(65 mg/kg)in Sprague-Dawley rats induce DN in the in vivo hyperglycemic model.Glucose-treated PRKs were used as an in vitro HG model.An immunofluorescence assay identified isolated PRKs.Cell Counting Kit-8 and flow cytometry analyzed the effect of ICA treatment on cell viability and apoptosis,respectively.Real-time quantitative polymerase chain reaction and western blot analyzed the levels of ER stressrelated proteins.Dual luciferase analysis of miR-503 binding to downstream SIRT4 was performed.RESULTS ICA treatment alleviated the upregulated miR-503 expression in vivo(DN)and in vitro(HG).Mechanistically,ICA reduced HG-induced miR-503 overexpression,thereby counteracting its function in downregulating SIRT4 levels.ICA regulated the miR-503/SIRT4 axis and subsequent ER stress to alleviate HG-induced PRKs injury.CONCLUSION ICA reduced HG-mediated inhibition of cell viability,promotion of apoptosis,and ER stress in PRKs.These effects involved regulation of the miR-503/SIRT4 axis.These findings indicate the potential of ICA to treat DN,and implicate miR-503 as a viable target for therapeutic interventions in DN.

Four-stage cascaded variable optical attenuator with large attenuation range for quantum key distribution

A four-stage cascaded variable optical attenuator(VOA)with a large attenuation range is presented.The VOA is based on a Mach–Zehnder interferometer(MZI)and fabricated in a silica-based planar lightwave circuit(PLC)platform.The thermo-optic effect is used to achieve intensity modulation.The measured maximum attenuation of the four-stage cascaded VOA is 88.38 d B.The chip is also tested in a quantum key distribution(QKD)system to generate signal and decoy states.The mean photon number after attenuation of the four-stage cascaded VOA is less than 0.1,which can meet the requirement of QKD.

Temperature characterizations of silica asymmetric Mach–Zehnder interferometer chip for quantum key distribution

Quantum key distribution(QKD)system based on passive silica planar lightwave circuit(PLC)asymmetric Mach–Zehnder interferometers(AMZI)is characterized with thermal stability,low loss and sufficient integration scalability.However,waveguide stresses,both intrinsic and temperature-induced stresses,have significant impacts on the stable operation of the system.We have designed silica AMZI chips of 400 ps delay,with bend waveguides length equalized for both long and short arms to balance the stresses thereof.The temperature characteristics of the silica PLC AMZI chip are studied.The interference visibility at the single photon level is kept higher than 95%over a wide temperature range of 12℃.The delay time change is 0.321 ps within a temperature change of 40℃.The spectral shift is 0.0011 nm/0.1℃.Temperature-induced delay time and peak wavelength variations do not affect the interference visibility.The experiment results demonstrate the advantage of being tolerant to chip temperature fluctuations.

The 8×10 GHz Receiver Optical Subassembly Based on Silica Hybrid Integration Technology for Data Center Interconnection

An 8×10 GHz receiver optical sub-assembly （ROSA） consisting of an 8-channel arrayed waveguide grating （AWG） and an 8-channel PIN photodetector （PD） array is designed and fabricated based on silica hybrid integration technology. Multimode output waveguides in the silica AWG with 2% refractive index difference are used to obtain fiat-top spectra. The output waveguide facet is polished to 45° bevel to change the light propagation direction into the mesa-type PIN PD, which simplifies the packaging process. The experimentM results show that the single channel I dB bandwidth of AWG ranges from 2.12nm to 3.06nm, the ROSA responsivity ranges from 0.097 A/W to 0.158A/W, and the 3dB bandwidth is up to 11 GHz. It is promising to be applied in the eight-lane WDM transmission system in data center interconnection.

Copy Number Aberrations of Multiple Genes Identified as Prognostic Markers for Extrahepatic Metastasis-free Survival of Patients with Hepatocellular Carcinoma

Extrahepatic metastasis confers unfavorable patient prognosis in patients with hepatocellular carcinoma(HCC),however,reliable markers allowing prediction of extrahepatic metastasis at the time of initial diagnosis are still lacking.This study was to identify gene-level copy number aberrations(CNAs)related to extrahepatic metastasis-free survival of HCC patients,and further examine the associations between CNAs and gene expression.Array comparative genomic hybridization(aCGH)and expression array were used to analyze gene CNAs and expression levels,respectively.The associations between CNAs of a panel of 20 genes and extrahepatic metastasis-free survival were analyzed in 66 patients with follow-up period of 1.6-90.5 months.The gene expression levels between HCCs with and without gene CNA were compared in 109 patients with HCC.We observed that gains at MDM4 and BCL2L1,and losses at APC and FBXW7 were independent prognostic markers for extrahepatic metastasis-free survival of HCC patients.Integration analysis of aCGH and expression data showed that MDM4 and BCL2L1 were significantly upregulated in HCCs with gene gain,while APC and FBXW7 were significantly downregulated in HCCs with gene loss.We concluded that gene gains at MDM4 and BCL2L1,and losses at APC and FBXW7,with concordant expression changes,were associated with extrahepatic metastasis-free survival of HCC patients and have potential to act as novel prognostic markers.

Effect of magnesium addition on inclusions in H13 die steel

The effect of magnesium addition on the number, morphology, composition, size, and density of inclusions in H13 die steel was studied. The results show that the total oxygen content in the steel can be significantly decreased to 0.0008wt%. Al2O3 and Mn S inclusions are changed into nearly spherical Mg O·Al2O3 spinel and spherical Mg O·Mg S inclusions, respectively. The number of inclusions larger than 1 μm decreases and the number of inclusions smaller than 1 μm increases with increasing magnesium content. V（N,C） precipitates around Mg O·Al2O3 and Mg O·Mg S inclusions during solidification of liquid steel. The densities of Mg O·Al2O3 spinel inclusions are lower than that of alumina inclusions. With increasing magnesium content in the Mg-containing inclusions, the density of inclusions decreases, leading to the improvement of inclusion removal efficiency.

High efficiency,small size,and large bandwidth vertical interlayer waveguide coupler

Since the advent of three-dimensional photonic integrated circuits,the realization of efficient and compact optical interconnection between layers has become an important development direction.A vertical interlayer coupler between two silicon layers is presented in this paper.The coupling principle of the directional coupler is analyzed,and the traditional method of using a pair of vertically overlapping inverse taper structures is improved.For the coupling of two rectangular waveguide layers,a pair of nonlinear tapers with offset along the transmission direction is demonstrated.For the coupling of two ridge waveguide layers,a nonlinear taper in each layer is used to achieve high coupling efficiency.The simulation results show that the coupling efficiency of the two structures can reach more than 90%in a wavelength range from 1500 nm to 1650 nm.Moreover,the crosstalk is reduced to less than-50 d B by using multimode waveguides at intersections.The vertical interlayer coupler with a nonlinear taper is expected to realize the miniaturization and dense integration of photonic integrated chips.

Myeloid-derived Suppressor Cells Activate Liver Natural Killer Cells in a Murine Model in Uveal Melanoma

Objective Elevated myeloid-derived suppressor cells(MDSCs)in many malignancies are associated with the increased risk for metastases and poor prognosis.Therefore,a mouse model of intraocular melanoma was established to explore how MDSCs influence liver metastases.Methods In this study,murine B16LS melanoma cells were transplanted into the posterior compartment(PC)of the eye of C57BL/6 mice.Leucocytes from the liver of naive mice and mice bearing melanoma liver metastasis were isolated using isotonic Percoll centrifugation,examined by flow cytometry for their expression of Gr1,CD11b,F4/80,RAE-1,and Mult-1,and further isolated for MDSCs and natural killer(NK)cells.The effects of MDSCs on NK cells were tested by coculturing and assessing the ability of NK cells to produce interferon-gamma(IFN-γ)by ELISA and NK cell cytotoxicity by 3H-thymidine incorporation assay.The impact of IFN-γon liver metastases was examined via selectively depleting IFN-γin vivo.Results The results showed that mice with liver metastases had increased levels of CD11b+Gr1+F4/80+as well as CD11b+Gr1+F4/80−MDSCs.MDSCs significantly enhanced the generation of IFN-γtogether with the cytotoxicity of the NK cells.Furthermore,these effects were cell-cell contact-dependent.Although IFN-γwas not of a toxic nature to the melanoma cells,it profoundly inhibited B16LS cell proliferation.Depleting IFN-γin vivo led to increased liver metastases.Conclusion All these findings first revealed that MDSCs accumulated in liver metastasis of intraocular melanoma could activate the NK cells to produce an effective anti-tumor immune response.Thus,the MDSCs’performance in different tumor models would need more investigation to boost current immunotherapy modalities.

Quantum key distribution transmitter chip based on hybrid-integration of silica and lithium niobates

A quantum key distribution transmitter chip based on hybrid-integration of silica planar light-wave circuit(PLC)and lithium niobates(LN)modulator PLC is presented.The silica part consists of a tunable directional coupler and 400-ps delay line,and the LN part is made up of a Y-branch,with electro-optic modulators on both arms.The two parts are facet-coupled to form an asymmetric Mach-Zehnder interferometer.We successfully encode and decode four BB84 states at 156.25-MHz repetition rate.Fast phase-encoding of 0 orπis achieved,with interference fringe visibilities 78.53%and 82.68%for states|+〉and|-〉,respectively.With the aid of an extra off-chip LN intensity modulator,two time-bin states are prepared and the extinction ratios are 18.65 dB and 15.46 dB for states|0〉and|1〉,respectively.

A new pattern of the tectonic units and metallogenic belts in Africa continent in terms of lithosphere

Based on the comprehensive study of geology and geophysics in African continent,three types of lithosphere(craton-type,orogenic-type and rift-type)can be identified.Considering lithosphere discontinuities as the boundary,two first-order tectonic units(mainly cratonic-type in the west and rift-type in the east)are proposed.Different types of lithosphere can be divided into secondary-order and third-order structural units,and the blocks within lithosphere can be further divided into fourth-order structural units.The geological history,the formation process and significance of different types of lithosphere in African continent are briefly discussed.

Switching On/Off of Guide RNA by Photoinduced Strand Displacement for Functional Control of CRISPR/Cas9

Functional control of CRISPR/Cas9 is essential for precise gene manipulation.Chemical engineering of guide RNA(gRNA)provides diverse approaches for conditional control of CRISPR/Cas9 function with a variety of chemical reactive groups.However,previous investigations into chemically engineering gRNA only unidirectionally regulated the CRISPR/Cas9 function via stimuli-induced caging/decaging processes.Herein,we propose a combinatory strategy to engineer the dynamics of gRNA in which photocontrolled strand-displacement reactions coupled with sequence designs of gRNA can achieve lightinduced switching-on/off control of CRISPR/Cas9 function.Biochemical analysis and cellular gene regulation indicate this approach is capable of both activating and deactivating CRISPR/Cas9 activities using light irradiation.Moreover,photocontrolled multiplex modulations of gene expression for opposite regulatory effects have also been achieved simultaneously under the same cellular context.This work establishes an essential principle for construction of stimuli-induced switching-on/off modulations of gRNA that can greatly enrich the versatility of conditional control for a variety of CRISPR/Cas9-based applications.

Management of symptomatic caliceal diverticular calculi:Minimally invasive percutaneous nephrolithotomy versus flexible ureterorenoscopy

Objective: To retrospectively evaluate appropriate treatment for patients with symptomatic caliceal diverticular calculi, by comparing the therapeutic outcomes for those undergoing minimally invasive percutaneous nephrolithotomy (MPCNL) and flexible ureterorenoscopy (F-URS). Methods: From March 2009 to May 2014, 36 consecutive patients with caliceal diverticular calculi were divided into 2 groups:21 patients underwent MPCNL, and 15 were treated by F-URS. All procedures were performed by one surgical group, which ensured relatively constant parameters. Patient characteristics, operative time, hospital stay after surgery, stone-free rate, symptomatic improvement rate, complications, diverticular obliteration, and stone composition were analyzed retrospectively in the 2 groups. Results: Patient preoperative variables were comparable between the two groups, with no significant difference (P>0.05). Mean operative time was 136.9 ± 22.8 min in the MPCNL group and 117.3 ± 24.3 min in the F-URS group (P ? 0.019). Hospital stay was significantly longer in the MPCNL group than in the F-URS group (9.4 ± 3.1 vs. 6.9 ± 2.1 days, P ? 0.010). The stone-free rates after MPCNL and F-URS were 90.5%(19/21) and 60.0%(9/15), respectively (P ? 0.046). Additionally, 71.4%(15/21) of patients in the MPCNL group and 46.7%(7/15) of patients in the F-URS group had symptomatic improvement at the 6-month follow-up (P ? 0.175);the rates of complications in the 2 groups were 19.0%(4/21) and 13.3%(2/15), respectively (P ? 0.650). Complete diverticular obliteration was achieved in 16 (76.2%) cases in the MPCNL group and 5 (33.3%) cases in the F-URS group (P ? 0.017). The distributions of calcium oxalate and hydroxyapatite in the stones were 66.7% (14/21) and 33.3% (7/21), respectively, in the MPCNL group;however, the distributions in the F-URS group were 46.7%(7/15) and 53.3%(8/15), respec-tively (P ? 0.310). Conclusion: MPCNL is an effective method for the treatment of caliceal diverticular calculi. However, F-URS is an alternative technique in selected patients with a patent infundibulum, despite lower stone-free rates than with MPCNL. Fulguration of the diverticular lining with a high-power holmium laser and permitting the cavity to collapse are useful to increase the chance of diverticular obliteration.

Digitization modeling of a CGEM detector based on Garfield++simulation

Background The Cylindrical Gas ElectronMultiplier Inner Tracker(CGEM-IT)is one of the candidates for the replacement of the current BESIII inner drift chamber,which has developed serious aging effects due to beam-related backgrounds.Purpose To build a full digitization model,it is necessary to understand the electron drift behavior and signal induction.Methods A simulation study based on Garfield++and ANSYS software has been performed.Results Parameters describing the Lorentz angle,diffusion effect,drift time,multiplication,and induction are obtained from the Garfield++simulation.Based on these results,a preliminary digitization model is implemented in the BESIII offline software system.

Low transverse momentum track reconstruction based on the Hough transform for the BESIII drift chamber

Background The multilayer drift chamber(MDC)is one of the key detectors at the BESIII,which is mainly responsible for the precise measurement of charged particles.High reconstruction efficiency of charged particles with a wide range of momentums is a basic requirement for the MDC reconstruction software.Purpose The purpose is to improve the tracking efficiency at the low transverse momentum region.Methods The Hough transform is a mathematical method that can map hits in a detector to parameter space to find tracks globally.In this paper,we have used it as the basis for developing a new tracking algorithm to find tracks in MDC.In addition,the drift distances of hits are considered when implementing Hough transform.Results This tracking algorithm is implemented in the BESIII offline software system,and its performance is checked using both Monte Carlo and data.The results show that this tracking method improves reconstruction efficiency at the low transverse momentum region.Conclusions The tracking algorithm based on Hough transform is proved to be beneficial for the MDC low transverse momentum tracking,and has been used in BESIII offline data reconstruction .

1.3-μm 4×25-Gb/s hybrid integrated TOSA and ROSA

The design and fabrication of a compact and low-cost 4×25-Gb/s transmitter optical sub-assembly(TOSA) and receiver optical sub-assembly(ROSA) using a hybrid integrated technique are reported. TOSA and ROSA are developed without thermoelectric cooler for coarse wavelength division multiplexing applications. Physical dimension of the packaged optical subassembly is limited to 11.5 mm×5.4 mm×5.4 mm. The design of TOSA and ROSA is employed using a silica-based arrayed waveguide grating chip to select the specific channel wavelength at O-band. In TOSA, the wavelength of four 1.3-μm discrete directly modulated laser chips is well controlled based on the reconstruction equivalent chirp technique. In the back-to-back transmission test, bit error rates for all lanes of cascade of the TOSA and ROSA are small. A clear opening eye diagram is obtained.

Derived Born cross sections of e^+e^-annihilation into open charm mesons from CLEO-c measurements

The exclusive Born cross sections of the production of D0, D＋ and Ds＋ mesons in e＋e- annihilation at 13 energy points between 3.970 and 4.260 GeV are obtained by applying corrections for initial state radiation and vacuum polarization to the observed cross sections measured by the CLEO-c experiment. Both the statistical and the systematic uncertainties for the obtained Born cross sections are estimated.