进展期胃癌腹腔镜切除术后炎性反应和疼痛因子研究

目的 探讨腹腔镜切除术对进展期胃癌患者术后炎性反应和疼痛因子的影响。方法 选择2019年3月-2021年3月该院进展期胃癌患者82例,依据随机数表法分为观察组(n=41)和对照组(n=41)。对照组实施开腹胃癌根治术,观察组实施腹腔镜下胃癌根治术。比较两组患者手术指标和术后并发症,观察术前、术后3和7 d血清炎性因子[肿瘤坏死因子-α (TNF-α)、白细胞介素-6 (IL-6)和C反应蛋白(CRP)]和疼痛因子[去甲肾上腺素(NE)、P物质(SP)和5-羟色胺(5-HT)]的变化。结果观察组手术时间长于对照组,而肛门排气时间、下床活动时间和住院时间均短于对照组,术中出血量少于对照组(P <0.05)。观察组术后并发症发生率低于对照组(P <0.05)。两组患者术后3和7 d血清TNF-α、IL-6和CRP水平较术前升高(P <0.05),观察组术后3和7 d血清TNF-α、IL-6和CRP水平低于对照组(P <0.05)。两组患者术后3和7 d血清NE、SP和5-HT水平较术前升高(P <0.05),观察组术后3和7 d血清NE、SP和5-HT水平低于对照组(P <0.05)。结论 腹腔镜下胃癌根治术治疗进展期胃癌,术后并发症发生率低,且对炎性反应和疼痛因子影响小,值得临床推广应用。

The first data release(DR1) of the LAMOST regular survey

The Large sky Area Multi-Object Fiber Spectroscopic Telescope（LAMOST） general survey is a spectroscopic survey that will eventually cover approximately half of the celestial sphere and collect 10 million spectra of stars, galaxies and QSOs. Objects in both the pilot survey and the first year regular survey are included in the LAMOST DR1. The pilot survey started in October 2011 and ended in June 2012, and the data have been released to the public as the LAMOST Pilot Data Release in August 2012. The regular survey started in September 2012, and completed its first year of operation in June 2013. The LAMOST DR1 includes a total of 1202 plates containing 2 955 336 spectra, of which 1 790 879 spectra have observed signalto-noise ratio（SNR） ≥ 10. All data with SNR ≥ 2 are formally released as LAMOST DR1 under the LAMOST data policy. This data release contains a total of 2 204 696 spectra, of which 1 944 329 are stellar spectra, 12 082 are galaxy spectra and 5017 are quasars. The DR1 not only includes spectra, but also three stellar catalogs with measured parameters： late A,FGK-type stars with high quality spectra（1 061 918 entries）, A-type stars（100 073 entries）, and M-type stars（121 522 entries）. This paper introduces the survey design, the observational and instrumental limitations, data reduction and analysis, and some caveats. A description of the FITS structure of spectral files and parameter catalogs is also provided.

Test area of the SAGE survey

Sky surveys represent one of the most important efforts to improve developments in astrophysics,especially when using new photometric bands. We are performing the Stellar Abundance and Galactic Evolution(SAGE) survey with a self-designed SAGE photometric system, which is composed of eight photometric bands. The project mainly aims to study the stellar atmospheric parameters of ～0.5 billion stars in ～12 000 deg2 of the northern sky, which mainly focuses on Galactic astronomy, as well as some aspects of extragalactic astronomy. This work introduces the detailed data reduction process of the test field NGC 6791, including the data reduction of single-exposure images and stacked multi-exposure images, and properties of the final catalog.

Data release of the LAMOST pilot survey

This paper describes the data release of the LAMOST pilot survey, which includes data reduction, calibration, spectral analysis, data products and data access. The accuracy of the released data and the information about the FITS headers of spectra are also introduced. The released data set includes 319 000 spectra and a catalog of these objects.

The SAGE photometric survey: technical description

To investigate a huge sample of data related to the Stellar Abundance and Galactic Evolution(SAGE) survey in more detail, we are performing a northern sky photometric survey named SAGES with the SAGE photometric system.This system consists of eight filters: Str?mgren-u, SAGE-v, SDSS g, r, i, DDO-51, Hαwideand Hαnarrow, including three Sloan broadband filters, three intermediateband filters, two narrow-band filters and one newly-designed narrow-band filter.SAGES covers～12 000 square degrees of the northern sky with δ >-5°, excluding the Galactic disk(|b| < 10°) and the sky area 12 h <RA <18 h.The photometric detection limit depth at signal-to-noise ratio 5σ can be as deep as V～20 mag.SAGES will produce a photometric catalog with uniform depth for～500 million stars with atmospheric parameters including effective temperature Teff, surface gravity log g and metallicity[Fe/H], as well as interstellar extinction to each individual target.In this work, we will briefly introduce the SAGE photometric system, the SAGE survey and a preliminary test field of the open cluster NGC 6791 and its surroundings.

Relative flux calibration for the Guoshoujing Telescope (LAMOST)

This paper presents a relative flux calibration method for the Guoshoujing Telescope （LAMOST）, which may be applied to connect a blue spectrum to a red spectrum to build the whole spectrum across the total wavelength range （3700 ～ 9000 A）. In each spectrograph, we estimate the effective temperatures of selected stars using a grid of spectral line indices in the blue spectral range and a comparison with stellar atmosphere models. For each spectrograph, stars of types A and F are selected as pseudo-standard stars, and the theoretical spectra are used to calibrate both the blue （3700 ～ 5900 A） and red spectrograph arms （5700 ～ 9000 A）. Then the spectral response function for these pseudo-standard stars could be used to correct the raw spectra provided by the other fibers of the spectrograph, after a fiber efficiency function has been derived from twilight flat-field exposures. A key problem in this method is the fitting of a pseudo stellar continuum, so we also give a detailed description of this step. The method is tested by comparing a small sample of LAMOST spectra calibrated in this way on stars also observed by the Sloan Digital Sky Survey. The result shows that the T eff estimation and relative flux calibration method are adequate.

Radial velocity measurements from LAMOST medium-resolution spectroscopic observations: a pointing towards the Kepler field

Radial velocity is one of the key measurements in understanding the fundamental properties of stars, stellar clusters and the Galaxy. A plate of stars in the Kepler field was observed in May of 2018 with the medium-resolution spectrographs of LAMOST, aiming to test the performance of this new system which is the upgraded equipment of LAMOST after the first five-year regular survey. We present our analysis on the radial velocity measurements(RVs) derived from these data. The results show that slight and significant systematic errors exist among the RVs obtained from the spectra collected by different spectrographs and exposures, respectively. After correcting the systematic errors with different techniques, the precision of RVs reaches ～1.3,～1.0,～0.5 and ～0.3 km s^(-1) at S/Nr = 10, 20, 50 and 100, respectively. Comparing with the RVs of standard stars from the APOGEE survey, our RVs are calibrated with a zero-point shift of～7 km s^(-1). The results indicate that the LAMOST medium-resolution spectroscopic system may provide RVs with a reasonable accuracy and precision for the selected targets.

M Dwarf catalog of LAMOST general survey data release one

We present a spectroscopic catalog of 93 619 M dwarfs from the first data release of the Large Sky Area Multi-Object Fiber Spectroscopic Telescope（LAMOST）general survey. During sample selection, M giant contamination was eliminated using2 MASS photometry and Ca H/TiO molecular indices. For each spectrum, the spectral subtype and values are provided including radial velocity, Hα equivalent width, a series of prominent molecular band indices, and the metal–sensitive parameter ζ, as well as distances and the space motions for high S/N objects. In addition, Hα emission lines are measured to examine the magnetic activity properties of M dwarfs and 7179 active ones are found. In particular, a subsample with significant variation in magnetic activity is revealed through observations from different epochs. Finally, statistical analysis for this sample is performed, including the metallicity classification, the distribution of molecular band indices and their errors.

LAMOST Time-Domain survey:first results of four K2 plates

From Oct.2019 to Apr.2020,LAMOST performed a time-domain(TD)spectroscopic survey of four K2 plates with both low-and medium-resolution observations.The low-resolution spectroscopic survey acquired 282 exposures(≈46.6 h)over 25 nights,yielding a total of about 767000 spectra,and the medium-resolution survey took 177 exposures(≈49.1 h)over 27 nights,collecting about 478000 spectra.More than 70%/50%of low-resolution/medium-resolution spectra have signal-to-noise ratio higher than 10.We determine stellar parameters(e.g.,Teff,log g,[Fe/H])and radial velocity(RV)with different methods,including LASP,DD-Payne and SLAM.In general,these parameter estimations from different methods show good agreement,and the stellar parameter values are consistent with those of APOGEE.We use the Gaia DR2 RV values to calculate a median RV zero point(RVZP)for each spectrograph exposure by exposure,and the RVZP-corrected RVs agree well with the APOGEE data.The stellar evolutionary and spectroscopic masses are estimated based on the stellar parameters,multi-band magnitudes,distances and extinction values.Finally,we construct a binary catalog including about 2700 candidates by analyzing their light curves,fitting the RV data,calculating the binarity parameters from medium-resolution spectra and cross-matching the spatially resolved binary catalog from Gaia EDR3.The LAMOST TD survey is expected to represent a breakthrough in various scientific topics,such as binary systems,stellar activity,stellar pulsation,etc.

Nearby M subdwarfs from LAMOST data release 2

We identify 108 M subdwarfs（sd Ms） out of more than two hundred thousand M type spectra from the second data release（DR2） of the LAMOST regular survey. This sample, among which 58 members are identified for the first time, includes 33 extreme subdwarfs（esd Ms） and 11 ultra subdwarfs（usd Ms）.The selection is based on the usual ratio of absorption depth of Ca H2, Ca H3 and TiO 5 band systems.We also emphasize the use of the Ca H1 band. We provide estimates of spectral subtype（SPT）, L′epine metallicity index ζ, effective temperature and [Fe/H]. Both ζ–[Fe/H] and SPT–Teff figures show reasonable consistency; compared to PHOENIX model spectra, average rounded values of [Fe/H] for sd Ms, esd Ms and usd Ms are respectively –0.5, –1 and –1.5. The photometric distances are estimated, indicating that most sources are located within 500 pc of the Sun and 350 pc of the Galactic disk. Velocities and 3D Galactic motions are also briefly discussed. Among the 108 subdwarfs, seven stars appear to be active with a significant Hα emission line. The source LAMOST J104521.52＋482823.3 is a white dwarf- M subdwarf binary, while LAMOST J123045.52＋410943.8, also active, exhibits carbon features in red.

LASPM:the LAMOST stellar parameter pipeline for M-type stars and application to the sixth and seventh data release(DR6 and DR7)

The molecular-rich atmospheres of M type stars complicate our understanding to their atmospheric properties.Recently,great progress has been made in atmospheric modeling of M-type stars,and we take advantage of the updated BT-Settl model grid to develop a pipeline LAS PM to measure atmospheric parameters(Teff,log g,[M/H]) of M-type stars from low-resolution spectra.The pipeline was applied to the sixth and seventh data release(DR6 & DR7) of Large Sky Area Multi-Object Fiber Spectroscopic Telescope(LAMOST),which released atmospheric parameters for 610419 and 680 185 Mtype spectra,respectively.The key algorithm is to find the best-matching for templates in the synthetic spectral library for an observed spectrum,and then minimizing χ^(2) through a linear combination of five best-matching templates.The intrinsic precisions of the parameters were estimated by using the multiple epoch observations for the same stars,which are 118 K,0.20 dex,0.29 dex for Teff,log g,and [M/H]respectively.The Teff and log g are consistent with the spectral and luminosity classifications by LAMOST 1D pipeline,and the loci of giants and dwarfs both on spectral index and color-magnitude diagrams show the validity.The metallicities of LASPM are also checked with the selected members of four open clusters(NGC 2632,Melotte 22,ASCC16,and ASCC19),which are consistent without any bias.Comparing the results between LASPM and the APOGEE Stellar Parameter and Chemical Abundance Pipeline(ASPCAP),there is a scatter of 73 K,0.22 dex,0.21 dex for Teff,log g,and [M/H],respectively.

TPE-H2MWD:an exact thumbnail preserving encryption scheme with hidden Markov model and weighted diffusion

With the substantial increase in image transmission,the demand for image security is increasing.Noise-like images can be obtained by conventional encryption schemes,and although the security of the images can be guaranteed,the noise-like images cannot be directly previewed and retrieved.Based on the rank-then-encipher method,some researchers have designed a three-pixel exact thumbnail preserving encryption(TPE2)scheme,which can be applied to balance the security and availability of images,but this scheme has low encryption efficiency.In this paper,we introduce an efficient exact thumbnail preserving encryption scheme.First,blocking and bit-plane decomposition operations are performed on the plaintext image.The zigzag scrambling model is used to change the bit positions in the lower four bit planes.Subsequently,an operation is devised to permute the higher four bit planes,which is an extended application of the hidden Markov model.Finally,according to the difference in bit weights in each bit plane,a bit-level weighted diffusion rule is established to generate an encrypted image and still maintain the same sum of pixels within the block.Simulation results show that the proposed scheme improves the encryption efficiency and can guarantee the availability of images while protecting their privacy.

Fast synthesis of dopamine-coated Fe_3O_4 nanoparticles through ligand-exchange method

A fast approach was described for the synthesis of water-dispersible monodisperse dopamine-coated Fe304 nanoparticles （DA- Fe304） with uniform size and shape via ligand-exchange of oleic acid on Fe304 using only 2 min. The prepared DA-Fe304 nanoparticles were characterized by transmission electron microscopy, Fourier transform infrared spectrometry, and vibrating sample magnetometer. The results indicated that the resulting DA-Fe304 nanoparticles had an average diameter of about 19.2 nm. The magnetic saturation value of the prepared DA-Fe304 nanoparticles was determined to be 72.87 emu/g, which indicating a well- established superparamagnetic property.

Use of liquid crystal to study the interactions of alkyl polyglycosides with gelatin and bovine serum albumin

In this study, liquid crystal（LC） was used to study the interactions of alkyl polyglycosides（APG） with gelatin and bovine serum albumin（BSA） at the LC-aqueous interface. The LC easily undergo an orientational transition from a homeotropic to a planar state after proteins were in contact to the LCaqueous interface decorated with APG, thus inducing an optical change from dark to bright. The optical image analysis reveals that the rearrangement rate of APG monolayer is tightly dependent on the concentration and chemical structure of the protein of interest. For example, the rearrangement rate of APG monolayer increases with an increasing gelatin concentration. We also find that the chemical structure of the proteins has a significant impact on the difference in the growth behavior of bright domains in LC.