LAMOST medium-resolution spectroscopic survey of binarity and exotic star(LAMOST-MRS-B):Observation strategy and target selection

LAMOST-MRS-B is one of the sub-surveys of LAMOST medium-resolution(R~7500)spectroscopic survey.It aims at studying the statistical properties(e.g.,binary fraction,orbital period distribution,mass ratio distribution)of binary stars and exotic stars.We intend to observe about 30000 stars(10 mag≤G<14.5 mag)with at least 10 visits in five years.We first planned to observe 25 plates around the galactic plane in 2018.Then the plates were reduced to 12 in 2019 because of the limitation of observation.At the same time,two new plates located at the high galactic latitude were added to explore binary properties influenced by the different environments.In this survey project,we set the identified exotic and low-metallicity stars with the highest observation priorities.For the rest of the selected stars,we gave the higher priority to the relatively brighter stars in order to obtain high quality spectra as many as possible.Spectra of49129 stars have been obtained in LAMOST-MRS-B field and released in DR8,of which 28828 and 3375 stars have been visited more than twice and ten times with SNR≥10,respectively.Most of the sources are B-,A-,and F-type stars with-0.6<[Fe/H]<0.4 dex.We also obtain 347 identified variable and exotic stars and about 250 stars with[Fe/H]<-1 dex.We measure radial velocities(RVs)by using 892233 spectra of the stars.The uncertainties of RV achieve about 1 km·s^(-1)and 10 km·s^(-1)for 95%of late-and early-type stars,respectively.The datasets presented in this paper are available at http://www.doi.org/10.57760/sciencedb.j00113.00035.

Mesh erosion into the colon following repair of parastomal hernia: A case report

BACKGROUND In recent years,mesh has become a standard repair method for parastomal hernia surgery due to its low recurrence rate and low postoperative pain.However,using mesh to repair parastomal hernias also carries potential dangers.One of these dangers is mesh erosion,a rare but serious complication following hernia surgery,particularly parastomal hernia surgery,and has attracted the attention of surgeons in recent years.CASE SUMMARY Herein,we report the case of a 67-year-old woman with mesh erosion after parastomal hernia surgery.The patient,who underwent parastomal hernia repair surgery 3 years prior,presented to the surgery clinic with a complaint of chronic abdominal pain upon resuming defecation through the anus.Three months later,a portion of the mesh was excreted from the patient’s anus and was removed by a doctor.Imaging revealed that the patient’s colon had formed a t-branch tube structure,which was formed by the mesh erosion.The surgery reconstructed the structure of the colon and eliminated potential bowel perforation.CONCLUSION Surgeons should consider mesh erosion since it has an insidious development and is difficult to diagnose at the early stage.

Potential protective effects of Clostridium butyricum on experimental gastric ulcers in mice

AIM: To investigate the effects of Clostridium butyricum(C. butyricum) on experimental gastric ulcers(GUs) induced by alcohol, restraint cold stress, or pyloric ligation in mice, respectively.METHODS: One hundred and twenty mice were randomly allocated into three types of gastric ulcer models(n = 40 each), induced by alcohol, restraint cold stress, or pyloric ligation. In each GU model, 40 mice were allocated into four groups(n = 10 each): the sham control group; model group(GU induction without pretreatment); C. butyricum group(GU induction with C. butyricum pretreatment); and Omeprazole group(GU induction with Omeprazole pretreatment). Theeffects of C. butyricum were evaluated by examining the histological changes in the gastric mucosal erosion area, the activities of superoxide dismutase(SOD) and catalase(CAT), the level of malondialdehyde(MDA), and the contents of interleukin(IL)-1b, tumor necrosis factor(TNF)-α, leukotriene B4(LTB4) and 6-keto-PGF-1α(degradation product of PGI2) in the gastric tissue.RESULTS: Our data showed that C. butyricum significantly reduced the gastric mucosal injury area and ameliorated the pathological conditions of the gastric mucosa. C. butyricum not only minimized the decreases in activity of SOD and CAT, but also reduced the level of MDA in all three GU models used in this study. The accumulation of IL1-b, TNF-α and LBT4 decreased, while 6-keto-PGF-1α increased with pretreatment by C. butyricum in all three GU models.CONCLUSION: Our data demonstrated the protective effects of pretreatment with C. butyricum on antioxidation and anti-inflammation in different types of GU models in mice. Further studies are needed to explore its potential clinical benefits.

Research on the influences of confining pressure and strain rate on NEPE propellant:Experimental assessment and constitutive model

In order to study the influences of confining pressure and strain rate on the mechanical properties of the Nitrate Ester Plasticized Polyether(NEPE)propellant,uniaxial tensile tests were conducted using the selfmade confining pressure system and material testing machine.The stress-strain responses of the NEPE propellant under different confining pressure conditions and strain rates were obtained and analyzed.The results show that confining pressure and strain rate have a remarkably influence on the mechanical responses of the NEPE propellant.As confining pressure increases(from 0 to 5.4 MPa),the maximum tensile stress and ultimate strain increase gradually.With the coupled effects of confining pressure and strain rate,the value of the maximum tensile stress and ultimate strain at 5.4 MPa and 0.0667 s^(-1)is 2.03 times and 2.19 times of their values under 0 MPa and 0.00333 s^(-1),respectively.Afterwards,the influence mechanism of confining pressure on the NEPE propellant was analyzed.Finally,based on the viscoelastic theory and continuous damage theory,a nonlinear constitutive model considering confining pressure and strain rate was developed.The damage was considered to be rate-dependent and pressuredependent.The constitutive model was validated by comparing experimental data with predictions of the constitutive model.The whole maximum stress errors of the model predictions are lower than 4%and the corresponding strain errors are lower than 7%.The results show that confining pressure can suppress the damage initiation and evolution of the NEPE propellant and the nonlinear constitutive model can describe the mechanical responses of the NEPE propellant under various confining pressure conditions and strain rates.This research can lay a theoretical foundation for analyzing the structural integrity of propellant grain accurately under working pressure loading.

Preparation and performance of 3D-Pb anodes for nonferrous metals electrowinning in H2SO4 aqueous solution

The effects of Pb^2+concentration,current density,deposition time and temperature on Pb deposit structure were investigated.In lower Pb^2+concentration(~0.15 mol/L),carambola-like 3D-Pb structure was constructed,while in higher Pb2+concentration(≥0.30 mol/L),Pb deposits exhibited pyramid-like structure.Furthermore,the oxide layer and anodic potential of carambola-shaped 3D-Pb(Cara-Pb)and pyramid-shaped 3D-Pb(Pyra-Pb)anodes were investigated and compared with those of fresh Pb anode.After 72 h galvanostatic electrolysis(50 mA/cm2)in 160 g/L H2SO4 solution,the oxide layer on Pyra-Pb was much thicker than that on Cara-Pb and Pb anodes,which remarkably relieved intercrystalline corrosion of the metallic substrate.Additionally,the oxide layer on Pyra-Pb anode presented a larger surface area and higher PbO2 content.Hence,Pyra-Pb anode showed a 40 m V lower anodic potential compared to Cara-Pb and Pb anodes.In sum,Pyra-Pb anode had a potential to decrease energy consumption and prolong the life span of traditional Pb anode.

Review and prospects of bioleaching in the Chinese mining industry

As the world’s second largest economy experiencing rapid economic growth,China has a huge demand for metals and energy.In recent years,China ranks first,among all the countries in the world,in the production and consumption of several metals such as copper,gold,and rare earth elements.Bioleaching,which is an approach for mining low grade and refractory ores,has been applied in industrial production,and bioleaching has made great contributions to the development of the Chinese mining industry.The exploration and application of bioleaching in China are reviewed in this study.Production and consumption trends of several metals in China over the past decade are reviewed.Technological processes at key bioleaching operations in China,such as at the Zijinshan Copper Mine and Mianhuakeng Uranium Mine,are presented.Also,the current challenges faced by bioleaching operations in China are introduced.Moreover,prospects such as efficiency improvement and environmental protection are proposed based on the current situation in the Chinese bioleaching industry.

MicroRNAs in tumor immunity:functional regulation in tumor-associated macrophages

Tumor-associated macrophages(TAMs)are the most abundant immune cells in the tumor microenvironment(TME)and are critical for cancer initiation and progression.MicroRNAs(miRNAs)could notably influence the phenotype of TAMs through various targets and signal pathways during cancer progression due to their posttranscriptional regulation.In this review,we discuss mainly the regulatory function of miRNAs on macrophage differentiation,functional polarization,and cellular crosstalk.Firstly,during the generation process,miRNAs take part in the differentiation from myeloid cells to mature macrophages,and this maturation process directly influences their recruitment into the TME,attracted by tumor cells.Secondly,macrophages in the TME can be either tumor-promoting or tumor-suppressing,depending on their functional polarization.Large numbers of miRNAs can influence the polarization of macrophages,which is crucial for tumor progression,including tumor cell invasion,intravasation,extravasation,and premetastatic site formation.Thirdly,crosstalk between tumor cells and macrophages is essential for TME formation and tumor progression,and miRNAs can be the mediator of communication in different forms,especially when encapsulated in microvesicles or exosomes.We also assess the potential value of certain macrophage-related miRNAs(MRMs)as diagnostic and prognostic markers,and discuss the possible development of MRM-based therapies.

I2/K2CO3-promoted ring-opening/cyclization/rearrangement/aromatization sequence：A powerful strategy for the synthesis of polysubstituted furans

An efficient and straightforward synthetic method has been developed for the preparation of 4-cyanofuran-3-carboxylate derivatives via iodine/potassium carbonate-promoted ring-opening/cyclization/rearrangement domino reaction of 1-cyanocyclopropane-1-carboxylates,which are a wide range of structurally interesting and pharmacologically significant compounds.