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Accumulation of sphingolipids, especially sphingosines, in the lysosomes is attributed to the pathogenesis of several lysosomal storage diseases. In search for a lysosomal protein that mediates the release of sphingosines, we identified SPNS1 which shares the highest homology to SPNS2, a sphingosine-1-phosphate (S1P) transporter. We generated knockout cells and mice forSpns1and employed lipidomics and metabolomics to identify SPNS1 ligands. We found that knockouts ofSpns1resulted in the accumulation of sphingolipids, including sphingosines in embryonic brains and cell lines. These results suggest that deficiency of SPNS1 affects the clearance of sphingolipids in lysosomes. Biochemical assays demonstrated that sphingosines released from lysosomes required SPNS1. Furthermore, by performing a comprehensive analysis of metabolites from livers of postnatalSpns1knockout mice (gSpns1-cKO), we detected a striking accumulation of lysoglycerophospholipids including LPC, LPE, LPG, and lysoplasmalogens. Interestingly, the release of these lysoglycerophospholipids also required SPNS1. Global knockout ofSpns1(gSpns1-KO) resulted in embryonic lethality between E12.5-E13.5 with developmental defects. Postnatal deletion ofSpns1in mice caused lipid accumulation in the lysosomes and pathological conditions reminiscent of lysosomal storage diseases. These results reveal a critical molecular role of SPNS1 as a transporter for lysosphingolipids and lysoglyerophospholipids from the lysosomes and link its physiological functions with lysosomal storage diseases.SignificancePhospholipids, including glycerophospholipids and sphingolipids, are delivered to the lysosomes for recycling. The hydrolysis of these lipids by lysosomal enzymes generates the corresponding lysoglycerophospholipids, such as lysophosphatidylcholine and lysosphingolipids, such as sphingosine, which are believed to be exported out of the lysosomes for recycling in the cytoplasm. However, it is unknown how these lysophospholipids are released from the lysosomes. The current study utilized genetic knockout models in combination with mass spectrometry analysis of complex phospholipids and sphingolipids to characterize the roles of an orphan lysosomal transporter, namely SPNS1. These findings show that deficiency of SPNS1 results in the accumulation of lysophospholipids in cells and animal tissues and that the transporter is required to transport both lysoglycerophospholipids and lysosphingolipids out of the lysosomes. SPNS1 is critical for early development in mice. Ablation of SPNS1 at postnatal life causes pathological conditions reminiscent of lysosomal storage diseases in mice. These findings reveal the molecular functions of SPNS1 as a lysophospholipid transporter and provide a foundation for studying the transport of these lysolipids in lysosomal storage diseases.

β-cell dedifferentiation is important in the pathogenesis of type 2 diabetes, and the relationship between lysosome membrane proteins and pancreatic β-cell dedifferentiation is still unknown. Sidt2 is a lysosomal membrane protein identified in our previous study. After Sidt2 elimination, mice exhibited a diabetic phenotype. In the present study, we found that Sidt2 also can be considered a new insulin granule membrane protein. Sidt2 deficiency resulted in islet dysfunction and inhibited insulin secretion. The absence of Sidt2 also led to increased β cell dedifferentiation in mice. Further experiments showed that defects in insulin secretion caused dedifferentiation in the absence of Sid2. In summary, our study has found a new dedifferentiation regulatory mechanism mediated by a lysosomal membrane protein. This new secretory regulation pathway will enrich our understanding of the regulatory mechanisms involved in β cell dedifferentiation and provide new insights into the pathogenesis of diabetes.

HOCN and HNCO abundance ratio in molecular gas can tell us the information of their formation mechanism. We performed high-sensitivity mapping observations of HOCN, HNCO, and HNC18O lines around Sagittarius B2 (Sgr B2) with the IRAM 30 m telescope at the 3 mm wavelength. HNCO 404–303 and HOCN 404–303 are used to obtain the abundance ratio of HNCO to HOCN. The ratio of HNCO 404–303 to HNC18O 404–303 is used to calculate the optical depth of HNCO 404–303. The abundance ratio of HOCN and HNCO is observed to range from 0.4% to 0.7% toward most positions, which agrees well with the gas-grain model. However, the relative abundance of HOCN is observed to be enhanced toward the direction of Sgr B2 (S), with HOCN to HNCO abundance ratio of ∼0.9%. The reason for that still needs further investigation. Based on the intensity ratio of HNCO and HNC18O lines, we updated the isotopic ratio of 16O/18O to be 296 ± 54 in Sgr B2.

Diabetic retinopathy(DR)is the major microvascular disease in diabetic patients,and it is also one of the main blinding eye diseases in the current population.The typical pathological change of DR in the eyes is vascular endothelial growth factor(VEGF)-mediated neovascularization induced by retinal ischemic stimulation.Therefore,anti-VEGF drugs have gradually become one of the mainstream methods to treat DR and DR-induced diseases such as diabetic macular edema.Recent studies have proved that anti-VEGF drugs have certain effects on ocular blood vessels and blood flow in patients with DR,while the specific mechanism has not been fully elucidated.This article summarizes the research progress on the effects of intravitreal injection of anti-VEGF drugs on the ocular blood vessels and blood flow in patients with DR.

We report a survey of excited-state hydroxyl (ex-OH) masers at the 4.7 and 6.0 GHz transitions toward a sample consisting of 3348 massive star-forming region candidates selected from the all-sky Wide-field Infrared Survey Explorer point-source catalog. The survey was conducted with the Shanghai Tianma Radio Telescope. In total, 6, 9, and 30 sources were detected with the ex-OH masers at the 4766, 6031, and 6035 MHz transitions, respectively. Among them, one 4766 MHz, one 6031 MHz, and five 6035 MHz ex-OH maser sources are newly identified. A series of statistical analyses derived that the ex-OH masers were detected efficiently toward the subsamples associated with both the 6.7 GHz CH3OH maser and radio recombination lines (RRLs), whereas compared to the CH3OH masers, the ex-OH masers are more likely to be produced toward the sources with stronger 22 μm band emission. A significant luminosity correlation is found between the ex-OH masers and RRLs. In addition, we found that the magnetic field strength of most sources with the 6.7 GHz CH3OH maser was stronger relative to that of sources without the CH3OH maser. Combined with these, it demonstrates that the ex-OH maser is associated with more evolved star-forming regions, likely associated with thicker dust envelopes. Meanwhile, the ex-OH masers might be a potential tracer for measuring the Galactic magnetic field information on the large-scale views using their Zeeman pairs.

Reactions of polycarboxylic acid ligands (H3cpa = 3-(4-carboxy-2-methoxyphenoxy) phthalic acid, H3cmp = 4-(4-carboxy-2-methoxyphenoxy) phthalic acid), N-containing ligand (bimp = 1,4-di(1H-imidazol-1-yl) benzene), with cobalt and cadmium salts under diverse reaction conditions have afforded two novel metal-organic frameworks: [Co3(cpa)2(bimp)2]n (1), [Cd2(cmp)(bimp)2]n (2). The V-shape organic polycarboxylic acid ligands play vital roles in determining the final structure and properties of the complexes. Complex 1 has a 3D structure constructed via bimp ligand connecting adjacent 2D layers and complex 2 has a 3D network with right-handed screw. Magnetic susceptibility measurements (χM) for complex 1 has been performed, and revealed predominant antiferromagnetic behavior. Complex 2 has been employed as a type of fluorescent probe to monitor different metal ions, and showed the obviously selective response to Fe3+ ion through luminescence quenching.

Background Microcirculatory disturbance is closely associated with multiple diseases such as ischemic and septic stroke. Luteolin (3,4,5,7-tetrahydroxyflavone) is a vascular protective flavonoid present in several dietary foods. However, how luteolin plays a role in microcirculatory disturbance is still unknown. The purpose of this study was to find out the influence of luteolin on the lipopolysaccharide (LPS)-induced microcirculatory disturbance, focusing on its effect on leukocyte adhesion and the underlying mechanism of this effect. Methods After injecting LPS into rats, we used an inverted intravital microscope to observe the velocity of red blood cells in venules, numbers of leukocytes adherent to and emigrated across the venular wall, hydrogen peroxide production in venular walls and mast cell degranulation. Intestinal microcirculation blood flow was measured by High-resolution Laser Doppler Perfusion Imaging. Histological changes of small intestine and mesenteric arteries were evaluated. Additionally, cell adhesion stimulated by LPS was tested on EA.hy926 and THP-1 cells. The production of pro-inflammatory cytokines, adhesion molecules and the activation of TLR4/Myd88/NF-κB signaling pathway were determined. Results The results showed luteolin significantly inhibited LPS-induced leukocyte adhesion, hydrogen peroxide production and mast cell degranulation, and increased intestinal microcirculation blood flow and ameliorated pathological changes in the mesenteric artery and the small intestine. Furthermore, luteolin inhibited the release of pro-inflammatory cytokines, the expression of TLR4, Myd88, ICAM-1, and VCAM-1, the phosphorylation of IκB-α and NF-κB/p65 in LPS stimulated EA.hy926. Conclusions Our findings revealed that it is likely that luteolin can ameliorate microcirculatory disturbance. The inhibitory effects of luteolin on the leukocyte adhesion stimulated by LPS, which participates in the development of microcirculatory disturbance, are mediated through the regulation of the TLR4/Myd88/NF-κB signaling pathway.

In this paper, the robust consensus control problem is investigated for a class of nonlinear second-order multi-agent systems against system time-varying state/input-independent uncertainties. By designing adaptive schemes and state-feedback control gains, a distributed controller is constructed to ensure the bounded consensus of agents in the presence of the uncertainties, and nonlinear dynamics. Finally, a multiple coupled nonlinear forced pendulum is used to validate the feasibility of the proposed method.

The technique of carbonated stabilization is an innovative method to improve the engineering performance of soft soils. However, the improvement in the engineering performance of stabilized soils with carbonized steel slag has not been studied. In addition, the effect of clay minerals on carbonation parameters and D-W cycle performance remains unknown. To this end, in this paper, three types of synthetic soils containing different clay minerals were prepared to be stabilized by carbonated steel slag. The strength performance and microstructural evolution of carbonated steel slag stabilized soils were investigated by drying-wetting (D-W) cycle tests, unconfined compression strength (UCS) tests, X-ray diffraction (XRD), thermogravimetry (TG), and scanning electron microscopy (SEM). The results showed that the compressive strength after and resistance to D-W cycles of carbonated steel slag stabilized soils were significantly improved due to carbonation treatment. The presence of clay minerals in stabilized soils led to the high values of optimum moisture content for carbonation (C-OMC). The C-OMC value of stabilized soils containing montmorillonite was higher than that of stabilized soils containing kaolinite. Montmorillonite had a higher negative effect on the D-W cycle performance of soils compared to kaolinite. This fact could be reflected by the fluctuation of UCS and mass change ratio (Rm). The main carbonation product by three types of carbonated steel slag stabilized soils was calcite, which remained stable after D-W cycles. After carbonation for 18 h, the generated calcite and carbonation degrees for three types of stabilized soils were obtained. In the microstructures of carbonated steel slag stabilized soils, the spindle-like clusters of the generated calcite appeared, which adhered to the surface of mineral particles. The aggregated degrees of the generated calcite in stabilized soils containing clay minerals tended to decrease after D-W cycles. In this work, a new type of carbonated steel slag stabilized soil was studied. The results indicated that the effect of clay minerals on the engineering characteristics of soil should be considered.

Pulsar's position, proper motion and parallax are important parameters in timing equations. It is a really challenging work to fit astrometric parameters accurately through pulsar timing, especially for pulsars that show irregular timing properties. As the fast development of related techniques, it is possible to measure astrometric parameters of more and more pulsars in a model$\textrm{-}$independent manner with the Very Long Baseline Interferometry (VLBI). In this work, we select 16 normal pulsars, whose parallax and proper motion have not been successfully fitted with timing observations or show obvious differences with corresponding latest VLBI solutions, and do further studies on their timing properties. After updating astrometric parameters in pulsar ephemerides with the latest VLBI measurements, we derive the latest rotation solutions of these pulsars with observation data at S and C$\textrm{-}$band obtained from the Shanghai Tian Ma Radio Telescope (TMRT). Compared with spin frequency $\nu$ inferred from previous rotation solutions, the newly$\textrm{-}$fitted $\nu$ show differences larger than 10$^{-9}$ Hz for most pulsars. The contribution of the Shklovsky effect to period derivative $\dot{P}$ can be properly removed taking advantages of accurate proper motion and distance of target pulsars measured by VLBI astrometry. This further leads to a precise estimate of intrinsic characteristic age $\tau_{\rm c}$. Differences between the newly$\textrm{-}$measured $\tau_{\rm c}$ and corresponding previous results are as large as 2% for some pulsars. VLBI astrometric parameter solutions also lead to better measurements of timing irregularities. For PSR B0154$+$61, the glitch epoch (MJD 58279.5) measured with previous ephemeris is about 13 d later than the result (MJD 58266.4) obtained with VLBI astrometric parameter solutions.

Three new Coordination Polymers (CPs), namely [Co2(dpb)(dipe)(H2O)2]n (1), [Zn2(dpb)(dipe)(H2O)2]n (2) and {[Co2(dpb)(bib)2(H2O)]·H2O}n (3), where H4dpb = 1-(3,5-dicarboxy-benzyl)-1H-pyrazole-3,5-dicarboxylic acid, dipe = (E)-1,2-di(pyridin-4-yl)ethene, bib = 1,4-di(1H-imidazol-1-yl)benzene, have been synthesized hydrothermally and characterized. Single-crystal XRD data analysis reveals that 1 and 2 are isomorphic, and possessing a (3,4,5)-connected net with a Schlafli symbol of (4·62)(4·65)(42·65·83), Complex 3 presents a (4,4,4)-connected 3-nodal 3D net with {4·62·83}{4·63·82}{64·82}. Also, we systematically examined the fluorescence sensing responses of 2 to small solvent molecules and metal ions. Notably, complex 2 can act as a potential promising fluorescence sensor for sensing acetone and Fe3+ ion with high selectivity and sensitivity. Meanwhile, we have investigated the magnetic behaviors of complexes 1 and 3 with dinuclear Co(II) centers, revealing antiferromagnetic behavior in 1 and 3.

Peptide bonds, as the molecular bridges that connect amino acids, are crucial to the formation of proteins. Searches and studies of molecules with embedded peptide-like bonds are thus important for the understanding of protein formation in space. Here we report the first tentative detection of propionamide (C2H5CONH2), the largest peptide-like molecule detected in space toward Sagittarius B2(N1) at a position called N1E that is slightly offset from the continuum peak. A new laboratory measurements of the propionamide spectrum were carried out in the 9-461 GHz, which provide good opportunity to check directly for the transition frequencies of detected interstellar lines of propionamide. Our observing result indicates that propionamide emission comes from the warm, compact cores in Sagittarius B2, in which massive protostellars are forming. The column density of propionamide toward Sgr B2(N1E) was derived to be 1.5\times 10^{16} cm^-2, which is three fifths of that of acetamide, and one nineteenth of that of formamide. This detection suggests that large peptide-like molecules can form and survive during star-forming process and may form more complex molecules in the interstellar medium. The detection of propionamide bodes well for the presence of polypeptides, as well as other complex prebiotic molecules in the interstellar medium., 49 pages, 13 figures, accepted by ApJ

The purpose of this study is to investigate the digital features of various constituents on granite specimen in the crack initiation and propagation process. The test video image photographed during laboratory uniaxial compression test and digital image processing techniques were used to conduct this study. The video image was first converted into the format easily recognized in programming. A multiple-object tracking technique was then developed to detect the locations of the individual cracks at any time. The initiation of each crack was determined by the occurring instant of the bounding box including the cracks. The length, width and area of each crack at any time were thereafter recorded. The relation of the propagation process with digital features of the constituents in various locations was furthermore investigated. It shows that two cracks propagated respectively along the vertical and horizontal directions as uniaxial compression test was performed; a limit box technique can be used to determinate the initiation instants of the multi cracks on the specimen surfaces; during propagation, the width of the cracks increased quickly just after initiation, and then fluctuated around a magnitude until the completely failure of the specimen; the constituents near the crack would split as the crack initiated; the shape features of biotites, feldspar and quartz changed in different manners during crack's initiation and propagation. The technique presented herein may be referable in investigating the failure mechanism of rock materials.

Two metal–organic frameworks (MOFs), [Ag2(H2L)(4,4′-bipy)(μ3-OH)]n (1) and [Zn3(L)2(bpe)2(H2O)2]n (2) were synthesized under hydrothermal conditions using the tricarboxylate and N-containing ligands (H3L = 3-(3-carboxyphenoxy) phthalic acid, 4,4′-bipy = 4,4′-bipyridine, bpe = 1,2-di(pyridine-4-yl)ethene), and structurally characterized by single-crystal X-ray diffraction analysis, FT-IR spectroscopy, powder X-ray diffraction (PXRD) and thermogravimetric analysis (TGA), furthermore, fluorescent spectra and absorption properties are discussed. Structural analysis reveals that Complex 1 is built from H3L, 4,4′-bipy and trinucleated Ag to form a three-dimensional (3D) network with a (4,4)-connected topology and a symbol of (63.83)4(86). As for 2, a trinucleate secondary building units (SBU), linked by the H3L ligand generated a one-dimensional (1D) chain, then the two adjacent 1D chains are joined together by bpe ligand, yielding a 1D trapezoidal chain. Our successive application studies indicate that complex 1 shows rapid uptake for methyl orange (MO) and iodine (I2), compound 2 is an impressive Zn-MOF based sensor for detecting Fe3+ ions in aqueous solution.

A novel series of Zn/Cd coordination polymers based on H3L, namely, [Zn2(HL)2(bipy)2(H2O)6]n (1), [Zn(HL)(phen)]n (2), [Cd3L2(bbi)3]n (3), [Zn3L2(bbi)3]n (4) [(H3L =4-[(1-carboxynaphthalen-2-yl)oxy]phthalic acid, bipy =4,4′-bipyridine, phen =1,10-phenanthroline, bbi =1,1′-(1,4-butanediyl)bis(imidazole] have been successfully synthesized by solvothermal reaction. Compound 1 possesses two diverse 1D chains constructed by different bipy coligands, which were further connected to form a 3D supramolecular architecture by hydrogen bonding interactions. Compound 2 possesses a complicated 1D chain based on secondary building unit (SBU) with binuclear Zn cluster. Compounds 3 and 4 exhibit similar 2D→3D framework, which can be rationalized as (3,4,4)-connected 3D net with a Schlafli symbol of (63.8.102)2(63)2(64.8.10). In particular, compound 3 exhibited a high sensitivity for Cr3+ in aqueous solutions, which suggest that compound 3 is a promising luminescent probe for selectively sensing Cr3+.

Ocular myasthenia gravis(OMG)is an autoimmune disease caused by neuromuscular junction transmission disorders and manifested mainly as fluctuating blepharoptosis and diplopia,with the extraocular muscles as the main involveed sites.While the pathogenesis of OMG remains unclear,some antibodies,complements,and cytokines may be the contributing factors.The diagnosis and treatment of OMG have been defined in recent years.This article reviews the pathogenesis,diagnosis,and treatment of OMG.

We report the results of our systematic survey for Galactic 6.7 GHz Class II CH$_3$OH maser emission toward a sample of young stellar objects. The survey was conducted with the Shanghai Tianma Radio Telescope (TMRT). The sample consists of 3348 sources selected from the all-sky \emph{Wide-Field Infrared Survey Explorer (WISE)} point source catalog. We have discussed the selection criteria in detail and the detection results of those at high Galactic latitudes (i.e. $|b|>$ 2$^\circ$) in a previous paper (paper I). Here, we present the results from the survey of those at low Galactic latitudes, i.e. $|b, 46 pages, 9 figures, 6 tables

Objective To analyze the levels of cytokines (IL-2,IFN-γ,IL-6,IL-10) associated with Th1 and Th2 cells in HLA-DQ8 transgenic mice model of ocular experimental autoimmune myasthenia gravis (oEAMG) induced by recombinant H-AChR γ subunit immunization.Methods DQ8 mice were immunized with 20 μg of AChR γ subunit,20 μg of crude E. coli extract (E. coli group),or complete Freund's adjuvant (CFA) only (CFA group). All mice were immunized on days 0,30,and 60. Mice were euthanized 28 days after the third immunization,and draining lymph node cells (LNC) and spleen lymphocytes were cultured in vitro. The supernatant was collected to observe the interleukin(IL)-2,interferon(IFN)-γ,IL-6,IL-10 production by ELISA.Results LNCs and spleen lymphocytes of H-AChR γ subunit-immunized mice exhibited significantly enhanced IFN-γ (F=76.332,P0.001;F=34.865,P0.001) and IL-2 (F=42.835,P0.001;F=38.030,P0.001),which associated with Th1 cells,as compared to E. coli group and CFA group. There were no significant differences in IL-6 (F=1.325,P=0.284;F=1.935,P=0.166) and IL-10 (F=0.908,P=0.417;F=1.189,P=0.322) levels,which secreted by Th2 cells,among these three groups.Conclusion Th1 cytokines play key roles in the pathogenesis of oEAMG,while the mechanism of Th2 cytokines for oEAMG remains unclear.

We performed a systematic 6.7 GHz Class \uppercase\expandafter{\romannumeral2} methanol maser survey using the Shanghai Tianma Radio Telescope toward targets selected from the all-sky \emph{Wide-Field Infrared Survey Explorer (WISE)} point catalog. In this paper, we report the results from the survey of those at high Galactic latitudes, i.e. $|b|>$ 2$^\circ$. Of 1473 selected \emph{WISE} point sources at high latitude, 17 point positions that were actually associated with 12 sources were detected with maser emission, reflecting the rarity (1$-$2\%) of methanol masers in the region away from the Galactic plane. Out of the 12 sources, 3 are detected for the first time. The spectral energy distribution (SED) at infrared bands shows that these new detected masers occur in the massive star forming regions. Compared to previous detections, the methanol maser changes significantly in both spectral profiles and flux densities. The infrared \emph{WISE} images show that almost all of these masers are located in the positions of the bright \emph{WISE} point sources. Compared with the methanol masers at the Galactic plane, these high-latitude methanol masers provide good tracers for investigating the physics and kinematics around massive young stellar objects, because they are believed to be less affected by the surrounding cluster environment., 27pages, 8 figures, 3 tables. Published in ApJ

Foodborne shrimp allergy events have occurred in recent years. To illustrate the mechanism of high hydrostatic pressure technology to change the allergenicity of shrimp, the major allergen tropomyosin was separated and purified from Litopenaeus vannamei, and indentified with matrix assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF-MS). The effect of temperature factor under high hydrostatic pressure was measured with indirect ELISA method, CD and fluorescence spectrum. The results showed that the antigenicity of TM protein had an increase after being heated at 35 or 45 ℃ when treated at 300 MPa for 15 minutes, while the antigenicity decreased at 55, 65, and 75 ℃. With the increase of heat temperature, the secondary structure of TM also changed. The mutual transformation happened between the alpha-helix and beta-sheet, beta-turn, and the random coil. The tertiary structure of TM was observed dynamic changes from the extended state to the folded state, and then re-extended state to re-folded state. These results suggested that high hydrostatic pressure combined with temperature could influence the antigenicity of TM by the change of conformation which would be useful as theoretical guidance on developing new methods or technologies for producing hypoallergenic shrimp products.

Heavy pollution events frequently occur during fall and winter seasons in northern areas. In order to understand the characteristics and chemical composition of PM

Chang’E-3 spacecraft was orbiting the Moon from December 6–14, 2013, and very long baseline interferometry (VLBI) observations were performed to improve the accuracy of its orbit determination. In the process of recording VLBI raw data, 2 bits quantization was implemented. Interesting phenomenon was that signal-to-noise ratio (SNR) of each VLBI station experienced periodical change and had large variation on amplitude while in the Moon’s orbit, whereas SNR kept in a stable level after Chang’E-3 landed on the Moon. Influence of varying elevation angle on SNR was analyzed and compensation of 2 bits quantization harmonics to SNR calculation was investigated. Most importantly, telescope system noise temperature increase caused by the Moon was computed along the time of Chang’E-3 orbiting the Moon, and well matched SNR changing trend in terms of correlation coefficients.

In this paper, we reported the measured results of the antenna efficiency, sensitivity, and system noise temperature of the TM65m radio telescope. The key parameters describing a radio astronomy receiving system were introduced at first. Then, we discussed the measurement methods and the measuring errors. Finally, the measured results of the antenna efficiency, sensitivity, and system noise temperature performances at the L, S, C, and X bands were given. The results show that the efficiency and SEFD (System Equivalent Flux Density) decrease dramatically at both low and high elevations when the position of the subreflector is fixed. The antenna efficiencies at the C and X bands can be raised to 60% and more in the whole elevation range when the subreflector (servo) model is activated. The system noise temperature is independent to the subreflector model. Among the four wavebands, the C-band sensitivity and system noise temperature are optimal.

Three coordination polymers based on the new ligand oxamide N,N-bis(4-phthalic acid), namely [Zn(L)0.5-(2,2′-bpy)] n (1), [Ni2(2,2′-bpy)4(µ 2-Ox)]L·3H2O (2) and [Cd(L)(1,10-phen)] (3) [L = oxamide N,N-bis(4-phthalic acid)], (2,2′-bpy = 2,2′-bipyridine), (1,10-phen = 1,10-phenanthroline), have been solvothermally synthesized and structurally characterized by single-crystal X-ray diffraction: compound 1 is one-dimensional ladder-like coordination polymer, compound 2 exhibits a three-dimensional structure resulting in extensive hydrogen bonds built with the help of lattice water molecules, compound 3 also exhibits a three-dimensional supramolecular structure. All compounds were also characterized by elemental analysis, IR spectra and thermogravimetric analysis; furthermore, the magnetic measurements for 2 reveal antiferromagnetic coupling between the nickel(II) ions.

Five novel coordination polymers (CPs) [Co(pmb)(bibp)]n (1, 2), [Co3(cpa)2(bibp)3·H2O]n (3), [Ni3(cpa)2(bibp)3·4H2O]n (4) and [Cd3(cpa)2(bibp)3]n (5), have been prepared by employing two asymmetric semi-rigid carboxylate organic ligands (H2pmb = 4-(4-carboxyphenoxy)-3-methoxybenzoic acid, H3cpa = 3-(4-carboxy-2-methoxyphenoxy) phthalic acid) and one N-containing ligand (bibp = 4,4′-di(1H-imidazol-1-yl)-1,1′-biphenyl) under hydrothermal conditions. Interestingly, single crystal X-ray analysis reveals that compounds 1 and 2 feature differently structural frameworks despite using the same ligands and metal ion Co(II) but different solvents. Compound 1 has an 8-fold interpenetrated 3D net topology, while compound 2 has a 2D net topology. This study shows a controllable regulation of framework by changing solvent type in isomers CPs. Compounds 3, 4 and 5 are isomorphic, which exhibit uniform 3, 4-connected 3D net topology. The dye adsorption studies of 1 and 2 revealed that rapid uptake for methyl orange (MO) can be attributed to the porous character and charge properties of CPs. In addition, magnetic susceptibility measurements of compounds 1, 2 and 3 reveal predominant antiferromagnetic exchange interactions between central Co(II) ions.

Non-methane hydrocarbons (NMHCs) from four sampling sites in Lanzhou, a petrochemical industrialized city in northwest China, was sampled by stainless steel canisters and measured by gas chromatography&ndash, mass selective detection/flame ionization detection (GC&ndash, MSD/FID) in May and June of 2017. Based on these results, the contributions of NMHCs to the ozone (O3) and secondary organic aerosols (SOA), differences in tracer ratios, and source apportionment by principal component analysis (PCA) were analyzed. The results showed that the total NMHCs concentration in Lanzhou was 48.4 &plusmn, 48.3 ppbv (parts per billion by volume) during the observation and it was higher in May (78.6 ppbv) than in June (37.8 ppbv), the highest NMHCs concentration was observed in industrial areas. Alkanes were the dominant group at all sites in Lanzhou and account for more than 60% of the NMHCs, while isopentane, n-butane n-pentane, propane and ethane were the major compounds. Additionally, the NMHCs in Lanzhou have made great contributions to O3 and SOA generation and the S1 site of the industrial area contributed the most to both of them. Propene, toluene, ethylbenzene and n-pentane were found to be more reactive with relatively high contributions to ozone formation. Aromatics and high carbon alkanes were major contributors to SOA formation potential (SOAp) (i.e., toluene, m,p-xylene, dodecane, undecane, n-tanane, benzene and ethylbenzene) in Lanzhou. Based on the specific volatile organic compounds (VOCs) ratio method and the PCA mode,the observation sites in Lanzhou were greatly affected by the surrounding industrial areas. The sources consisted of petrochemical industry, vehicle emissions, solvent usage and combustion sources, which contributed to 33.9%, 31.6%, 19.2% and 7.9% of the total monitored NMHCs, respectively. From different sites, though the influence of regional transport was not very significant on the whole, it also affected the NMHCs of nonindustrial areas based on the ratio of xylene to ethyl-benzene (X/E), especially the S4 site, vehicle emission was less important compared to sources from petrochemical industries in S1, as characterized by relatively higher toluene to benzene (T/B) ratios. However, vehicle emission has significant influence on NMHCs in S4. Overall, local emissions are the main source of NMHCs in Lanzhou and the petrochemical industry has a great influence on the distribution of NMHCs in the whole region.

We have investigated the mode-changing properties of PSR B0329+54 using 31 epochs of simultaneous 13 cm/3 cm single-pulse observations obtained with Shanghai Tian Ma 65 m telescope. The pulsar was found in the abnormal emission mode 17 times, accounting for ~13% of the 41.6 hours total observation time. Single pulse analyses indicate that mode changes took place simultaneously at 13 cm/3 cm within a few rotational periods. We detected occasional bright and narrow pulses whose peak flux densities were 10 times higher than that of the integrated profile in both bands. At 3 cm, about 0.66% and 0.27% of single pulses were bright in the normal mode and abnormal mode respectively, but at 13 cm the occurrence rate was only about 0.007%. We divided the pulsar radiation window into three components (C1, C2 and C3) corresponding to the main peaks of the integrated profile. The bright pulses preferentially occurred at pulse phases corresponding to the peaks of C2 and C3. Fluctuation spectra showed that C2 had excess red noise in the normal mode, but broad quasi-periodic features with central frequencies around 0.12 cycles/period in the abnormal mode. At 3 cm, C3 had a stronger quasi-periodic modulation centered around 0.06 cycles/period in the abnormal mode. Although there were some asymmetries in the two-dimensional fluctuation spectra, we found no clear evidence for systematic subpulse drifting. Consistent with previous low-frequency observations, we found a very low nulling probability for B0329+54 with upper limits of 0.13% and 1.68% at 13 cm/3 cm respectively., Comment: 16 pages, 10 figures, 3 tables

We report the detection of widespread CH$_2$OHCHO and HOCH$_2$CH$_2$OH emission in Galactic center giant molecular cloud Sagittarius B2 using the Shanghai Tianma 65m Radio Telescope. Our observations show for the first time that the spatial distribution of these two important prebiotic molecules extends over 15 arc-minutes, corresponding to a linear size of approximately 36 pc. These two molecules are not just distributed in or near the hot cores. The abundance of these two molecules seems to decrease from the cold outer region to the central region associated with star-formation activity. Results present here suggest that these two molecules are likely to form through a low temperature process. Recent theoretical and experimental studies demonstrated that prebiotic molecules can be efficiently formed in icy grain mantles through several pathways. However, these complex ice features cannot be directly observed, and most constraints on the ice compositions come from millimeter observations of desorbed ice chemistry products. These results, combined with laboratory studies, strongly support the existence of abundant prebiotic molecules in ices., 20 pages, 7 figures, accepted by ApJ

Same-beam very long baseline interferometry observations were performed between the rover and the lander of Chang'E-3 and differential phase delay data were obtained with the minimum random error of about 0.03ps. These data were used to monitor the rover motions, as small as several centimeters, including movement, turning, and attitude adjustment. The relative position between the rover and the lander was precisely measured with an accuracy of 1m, which is an improvement of 10 times compared with that of the Apollo project.

The emission geometries, e.g. the emission region height, the beam shape, and radius-to-frequency mapping, are important predictions of pulsar radiation model. The multi-band radio observations carry such valuable information. In this paper, we study two bright pulsars, (PSRs B0329+54 and B1642-03) and observe them in high frequency (2.5 GHz, 5 GHz, and 8 GHz). The newly acquired data together with historical archive provide an atlas of multi-frequency profiles spanning from 100 MHz to 10 GHz. We study the frequency evolution of pulse profiles and the radiation regions with the these data. We firstly fit the pulse profiles with Gaussian functions to determine the phase of each component, and then calculate the radiation altitudes of different emission components and the radiation regions. We find that the inverse Compton scattering (ICS) model can reproduce the radiation geometry of these two pulsars. But for PSR B0329+54 the radiation can be generated in either annular gap (AG) or core gap (CG), while the radiation of PSR B1642-03 can only be generated in the CG. This difference is caused by the inclination angle and the impact angle of these two pulsars. The relation of beaming angle (the angle between the radiation direction and the magnetic axis) and the radiation altitudes versus frequency is also presented by modelling the beam-frequency evolution in the ICS model. The multi-band pulse profiles of these two pulsars can be described well by the ICS model combined with the CG and AG.

Integrated pulse profiles at 8.6~GHz obtained with the Shanghai Tian Ma Radio Telescope (TMRT) are presented for a sample of 26 pulsars. Mean flux densities and pulse width parameters of these pulsars are estimated. For eleven pulsars these are the first high-frequency observations and for a further four, our observations have a better signal-to-noise ratio than previous observations. For one (PSR J0742-2822) the 8.6~GHz profiles differs from previously observed profiles. A comparison of 19 profiles with those at other frequencies shows that in nine cases the separation between the outmost leading and trailing components decreases with frequency, roughly in agreement with radius-to-frequency mapping, whereas in the other ten the separation is nearly constant. Different spectral indices of profile components lead to the variation of integrated pulse profile shapes with frequency. In seven pulsars with multi-component profiles, the spectral indices of the central components are steeper than those of the outer components. For the 12 pulsars with multi-component profiles in the high-frequency sample, we estimate the core width using gaussian fitting and discuss the width-period relationship., Comment: 33 pages, 49 figures, 5 Tables; accepted by ApJ