Enhanced measurement precision with continuous interrogation during dynamical decoupling

Dynamical decoupling(DD)is normally ineffective when applied to DC measurement.In its straightforward implementation,DD nulls out DC signal as well while suppressing noise.This work proposes a phase relay method that is capable of continuously interrogating the DC signal over many DD cycles.We illustrate its efficacy when applied to the measurement of a weak DC magnetic field with an atomic spinor Bose-Einstein condensate.Sensitivities approaching standard quantum limit or Heisenberg limit are potentially realizable for a coherent spin state or a squeezed spin state of 10000 atoms,respectively,while ambient laboratory level noise is suppressed by DD.Our work offers a practical approach to mitigate the limitations of DD to DC measurement and would find other applications for resorting coherence in quantum sensing and quantum information processing research.

The Satellite’s On-Orbit Attitude System Error Compensation Technique Based on Stereo Models

According to the problem that the low measurement accuracy of TH-1 satellite star sensor, the low frequency and “slow drift” error which cannot be ignored in the attitude determination system, resulting in obvious random error in the horizontal position and elevation direction, and the change of the error with time and latitude, cannot be calibrated by the ground field of the real problem. In this paper, a low frequency detection model is established by using the principle of relative orientation, and the low frequency error is obtained by parallax elimination. Finally, the satellite attitude is compensated and the more accurate exterior orientation elements are obtained, thus improving the positioning accuracy and stability. The experimental results show that: the proposed methods are feasible, and by using the model to dynamically calibrate the exterior orientation angle elements on orbit, the plane and elevation errors of the ground points can be basically eliminated. The global uncontrollable positioning accuracy and stability of the photogrammetry satellite are improved.

昆明轨道交通岩溶专项勘察手段及方法

为解决传统勘察手段及方法很难查明岩溶发育特征的难题,以昆明轨道交通4号线岩溶专项勘察为案例工程,介绍在岩土工程初步勘察、详细勘察的基础上,采用以工程地质钻探及现场物探测试(孔间层析成像(CT)、高密度电法、地质雷达)为主,并结合工程地质测绘、原位测试、钻孔抽水试验和室内土工试验等综合勘察技术手段和方法,查明了线路沿线的岩溶分布、规模及形态等发育特征,并对其做出定量或定性评价,为岩溶专项治理施工图设计、优化设计方案及完善施工组织设计等提供了可靠的地质依据,对类似工程具有一定的指导及参考作用。

Radiomics for the detection of microvascular invasion in hepatocellular carcinoma

Hepatocellular carcinoma(HCC)is the most common primary liver cancer,accounting for about 90%of liver cancer cases.It is currently the fifth most common cancer in the world and the third leading cause of cancer-related mortality.Moreover,recurrence of HCC is common.Microvascular invasion(MVI)is a major factor associated with recurrence in postoperative HCC.It is difficult to evaluate MVI using traditional imaging modalities.Currently,MVI is assessed primarily through pathological and immunohistochemical analyses of postoperative tissue samples.Needle biopsy is the primary method used to confirm MVI diagnosis before surgery.As the puncture specimens represent just a small part of the tumor,and given the heterogeneity of HCC,biopsy samples may yield false-negative results.Radiomics,an emerging,powerful,and non-invasive tool based on various imaging modalities,such as computed tomography,magnetic resonance imaging,ultrasound,and positron emission tomography,can predict the HCC-MVI status preoperatively by delineating the tumor and/or the regions at a certain distance from the surface of the tumor to extract the image features.Although positive results have been reported for radiomics,its drawbacks have limited its clinical translation.This article reviews the application of radiomics,based on various imaging modalities,in preoperative evaluation of HCC-MVI and explores future research directions that facilitate its clinical translation.

Comparison of two types of colectomy in treating slow transit constipation with or without melanosis coli

AIM: To compare the follow-up outcomes of ileosigmoidal anastomosis(ISA) and caecorectal anastomosis(CRA) in patients with slow transit constipation(STC) with or without melanosis coli(MC).METHODS: We collected the clinical data of 48 STC patients with or without MC from May 2002 to May 2007.Twenty-six patients underwent CRA(14 with MC) and 22 cases received ISA(14 with MC).A 3-year postoperative follow-up was conducted.RESULTS: CRA improved the quality of life [evaluated by the gastrointestinal quality of life index(GIQLI)] in patients without MC,but was inferior to ISA in stool frequency and Wexner and GIQLI scores for MC patients.In the CRA group,patients with MC suffered worse outcomes than those without MC.CONCLUSION: CRA is more suitable for STC patients without MC; however,for STC patients with MC,ISA is a better choice.

A Deep Learning System to Screen Novel Coronavirus Disease 2019 Pneumonia

实时逆转录聚合酶链反应(RT-PCR)检测早期新冠病毒肺炎(COVID-19)患者的痰液或鼻咽拭子中的病毒RNA阳性率较低。同时,COVID-19的计算机断层扫描(CT)影像学的临床表现有其自身的特点,不同于甲型流感病毒性肺炎(IAVP)等其他类型的病毒性肺炎。本研究旨在应用深度学习技术,建立COVID-19、IAVP及健康人群肺部CT的早期筛查模型。本研究共采集618份CT样本,其中219份样本来自110例COVID-19患者(平均年龄50岁,其中男性63例,占57.3%),224份样本来自224例IAVP患者(平均年龄61岁,其中男性156例,占69.6%),175份样本来自健康人群(平均年龄39岁,其中男性97例,占55.4%)。所有CT样本均来自浙江省三家COVID-19定点收治医院。我们首先利用胸部CT图像集的三维(3D)深度学习模型分割出候选感染区域,然后利用位置敏感机制深度学习网络将这些分离的图像归类为COVID-19、IAVP以及与感染无关(ITI)的图像,并且输出相应置信度得分。最后,用Noisy-OR贝叶斯函数计算每份CT病例的感染类型及总置信度。测试数据集的实验结果表明,从整体CT病例来看,本研究利用深度学习系统建立的COVID-19患者的早期筛查模型的总体准确率为86.7%。该模型有望成为一线临床医生诊断COVID-19的一种有效的辅助方法。

High flux hemodialysis in elderly patients with chronic kidney failure

BACKGROUND Hemodialysis is an advanced blood purification technique to manage kidney failure.However,for conventional hemodialysis,the high prevalence of dyslipidemia may cause cardiovascular diseases and an increase in mortality.Moreover,toxins accumulating in the body over time may induce some complications.High flux hemodialysis can effectively improve disease indexes and clinical symptoms.AIM To investigate the efficacy of high flux hemodialysis in elderly patients with chronic kidney failure(CKF).METHODS A total of 66 elderly patients with CKF who were admitted to our hospital from October 2017 to October 2018 were included in the study.According to the therapies they received,the patients were divided into a study group and a control group with 33 patients in each group.The study group received high flux hemodialysis and the control group received conventional dialysis treatment.Kidney function,toxin levels in serum,and complications were compared in the two groups.RESULTS Before the treatment,there was no significant difference in kidney function,β2-microglobulin,or blood urea nitrogen between the two groups(P>0.05).In contrast,kidney function was better in the study group than in the control group after the treatment(P<0.05).In addition,the study group had significantly lower parathyroid hormone and serum cystatin C than the control group(P<0.05).The incidence of complications was 8.57%in the study group,which was lower than that of the control group(20.00%;P<0.05).CONCLUSION High flux hemodialysis may improve kidney function and reduce toxin levels in serum and the incidence of complications in elderly patients with CKF.

Methylation of PTCH1a gene in a subset of gastric cancers

AIM： To establish if PTCHla transcriptional regulation region （TRR） is methylated in gastric cancer and its influence in gastric tumorigenesis.METHODS： The CpG islands in PTCHla TRR were analyzed by Methyl Primer Express v1.0 software. The region from -643 to -355 bp （the transcription initiation site of PTCHla was designated as 0） that contained 19 CpG sites was chosen for bisulfitesequencing PCR （BSP） and methylation-specific PCR （MSP） detection. The gastric cancer cell line AGS was treated with 5-aza-2′-deoxycytidine （5-Aza-dC; 1 μmol/L） for 3 d. Alterations in PTCHla TRR methylation in treated AGS cells was measured through BSP clone sequences, and their PTCH1 expression was measured by quantitative RT-PCR. The cell cycle and apoptosis were observed with flow cytometry through propidium iodide （PI） staining or annexin V/PI double staining. The prevalence of PTCHla TRR methylation was investigated in 170 gastric cancer tissue samples and the adjacent normal tissues by MSP. The correlation of PTCH1a TRR methylation with PTCH1 expression or with patients＇ clinical features was analyzed.RESULTS： Methylation of PTCHla TRR was observed in AGS ceils and a subset of gastric cancer tissues （32%, 55/170）, while no methylation amplification products were observed in any normal tissues by MSP. The methylation of PTCH1α TRR was correlated negatively with PTCH1 expression （Spearman＇s r = -0.380, P = 0.000）. However, methylation of PTCHla TRR was not related to the gastric cancer patients＇ clinical features, such as sex, age of onset, clinical stage, lymph node metastasis or histological grade. The methylation of PTCHla TRR in AGS cells was almost converted to non-methylation after 5-Aza-dC treatment, which increased PTCH1 expression （5.3 ± 2.5 times; n = 3） and apoptosis rate （3.0 ± 0.26 times; P 〈 0.05; n = 3）.CONCLUSION： Methylation of PTCH1α TRR is present in a subset of gastric cancers and correlated negatively with PTCH1 expression. This may be an early event in gastric tumorigenesis and a new treatment target.

PINPOINT SOURCE LOCALIZATION FOR OCULAR NONSELECTIVE ATTENTION WITH COMBINATION OF ERP AND fNIRI MEASUREMENTS

Compared with event-related potential(ERP)which is widely used in psychology research,functional near-infrared imaging(fNIRI)is a new technique providing hemodynamic information related to brain activity,except for electrophysiological signals.Here,we use both these techniques to study ocular attention.We conducted a series of experiments with a classic paradigm of ocular nonselective attention,and monitored responses with fNIRI and ERP respectively.The results showed that fNIRI measured brain activations in the left prefrontal lobe,while ERPs showed activation in frontal lobe.More importantly,only with the combination measurements of fNIRI and ERP,we were then able to find the pinpoint source of ocular nonselective attention,which is in the left and upper corner in Brodmann area 10.These results demonstrated that fNIRI is a reliable technique in psychology,and the combination of fNIRI and ERP can be promising to reveal more information in the research of brain mechanism.

Helium extraction from natural gas using DD3R zeolite membranes

Helium(He)is commercially produced from natural gas by low-temperature condensation.The process is energy extensive because of the extremely low He concentration(<0.3%)and the operation at cryogenic temperature.Herein we demonstrated DD3R zeolite membrane was efficient to extract He from natural gas at atmosphere temperature.The membrane performance was evaluated in terms of temperature,pressure and molar fractions.The overall membrane performance was dominated by the diffusivity selectivity.The single He permeance and ideal He/CH_(4) selectivity were 5.8×10^(-9)mol·m^(-2)·s^(-1)·Pa^(-1)and 79 under a feed pressure of 1.3 MPa.Even though He concentration was as low as 0.22%,the He permeance and He/CH_(4) mixture selectivity were 3.0×10^(-9)mol·m^(-2)·s^(-1)·Pa^(-1)and 44 at 0.7 MPa.During the longterm operation(~130 h)the membrane performance was stable even the feed mixture containing3.6%ethane as contaminations.The results approved the feasibility of DD3R zeolite membranes for He extraction from natural gas.

Nicotine protects against DSS colitis through regulating microRNA-124 and STAT3

OBJECTIVE Although it is generally believed that nicotine accounts for the beneficial effect of smoking on ulcerative colitis,the underlying mechanisms remain not well understood.Our previous finding that nicotine inhibits inflammatory responses through inducing miRNA-124 prompted us to ask whether the miRNA is involved in the protective action of nicotine on UC.METHODS MiR-124 expres.sion in colon tissues and cells was determined by q-PCR and in situ hybridization.The effect of miR-124 on protective role of nicotine in ulcerative colitis was evaluated in DSS-treated mice and IL-6-treated Caco-2 colon epithelial cells.Expression of p-STAT3/STAT3 was detected by immunohistochemistry and Western-blot analysis.RESULTS miR-124 expression is upregulated in colon tissues from UC patients and DSS-induced colitis mice.Nicotine treatment further elevated miR-124 level in lympho.cytes isolated from human ulcerative colonic mucosa and ulcerative colon tissues from DSS mice,both in infiltrated lymphocytes and epithelial cells.Administration of nicotine also reduced weight loss,improved DAI and decreased HE score in DSS-induced colitis mice.Moreover,knockdown of miR-124 in vivo significantly diminished the beneficial effect of nicotine on murine colitis,and in vitro on IL-6-treated Caco-2 colon epithelial cells.Further analysis indicated that nicotine inhibited STAT3 activation in vivo and in IL-6-treated Caco-2 colon epithelial cells and Jurkat human T lymphocytes,in which miR-124 knockdown led to increased activation of STAT3.Blocking STAT3 activity alone is beneficial for DSS colitis and also abolished nicotine′s protective effect in this model.CONCLUSION These data indicated that nicotine exerts its protective action in UC through inducing miR-124 and its effect on STAT3,and suggest that the miR-124/STAT3 system is a potential target for the therapeutic intervention of UC.

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.

Dynamics Behaviors of a Reaction-Diffusion Predator-Prey System with Beddington-DeAngelis Functional Response and Delay

This paper is concerned with the existence of traveling wave solutions in a reaction-diffusion predator-prey system with Beddington-DeAngelis functional response and a discrete time delay. By introducing a partial quasi-monotonicity condition and constructing a pair of upper-lower solutions, we establish the existence of traveling wave solutions. Moreover, a numerical simulation is carried out to illustrate the theoretical results.

一类渔业生态扩散系统的动力性分析

本文研究一类带有病毒的捕食与被捕食渔业扩散生物经济收获模型,得到了非负平衡点的局部渐近稳定性的一些结果,并且通过构建适当的Lyapunov函数,得到了唯一正平衡点的全局稳定性的充分条件,并通过数值模拟验证了所得到结果的正确性。最后,利用上下解方法,证明了连接两个平衡点的行波解的存在性。

Comparative Study on Population Ageing Between China and Other Asian Countries

Compared with developed countries, the main characteristics of population ageing in China have been regarded as a rapid ageing society. However, China and other Asian countries have been experiencing the demographic transition simultaneously, it is better to understand the characteristics of population ageing in China when compared with other Asian countries. Using the latest UN data, this paper compares the percentage of elderly population, the speed of ageing and the size of aged population among China and other Asian countries. The result indicates that China has a relatively high percentage of aged population, relatively rapid ageing population and will keep the largest size of aged population of the world in the next 60 years.

The Significant Contribution of LINC00673 Rs11655237 C>T Polymorphism to Cancer Susceptibility in Chinese Population:A Meta-analysis of The Current Literature

Objective Considerable studies exploring the relation of rs11655237 C>T polymorphism in the LINC00673 gene with cancer susceptibility have obtained debatable results.This meta-analysis aims to accurately assess this association.Methods Relevant studies with an updated date of April 20,2021,were extensively searched from Embase,PubMed,Web of Science,Google Scholar,Medline,CNKI,and Chinese Wanfang databases.The strength of association was estimated by odds ratios(ORs)and 95%confidence intervals(CIs).Results A total of 8 articles involving 7,893 cases and 12,446 controls were ultimately selected in this analysis.Summary results revealed a significantly enhanced risk of cancer was related to LINC00673 rs11655237 C>T polymorphism for the allele model(OR=1.22,95%CI=1.09-1.36),homozygote model(OR=1.47,95%CI=1.30-1.67),heterozygote model(OR=1.21,95%CI=1.14-1.29),dominant model(OR=1.25,95%CI=1.18-1.32),and recessive model(OR=1.26,95%CI=1.12-1.43).Moreover,subgroup analysis by cancer type showed LINC00673 rs11655237 C>T polymorphism contributed to the increased risk of neuroblastoma in the heterozygote,homozygote,dominant and recessive models.Conclusion The present meta-analysis indicates that LINC00673 rs11655237 C>T polymorphism is related to increased cancer susceptibility in the Chinese population.It may be a potential predictive biomarker of cancer risk.

Fermentation of mung bean milk by Lactococcus lactis:Focus on the physicochemical properties,antioxidant capacities and sensory evaluation

Mung bean,a kind of leguminous crop loved by people,contains high nutritional values as well as medicinal properties.Mung bean fermentation by lactic acid bacteria is a meaningful attempt for development of novel functional foods.In this study,the effects of Lactococcus lactis RQ1066(L.lactis RQ1066)fermentation on physicochemical properties,anti-nutritional factors,antioxidant capacities,amino acids composition,and sensory evaluation of mung bean milk(MBM)were investigated.We found that L.lactis RQ1066 had the potential of utilizing MBM as the fermentation substrate,which can change amino acids composition and sensory characteristics of MBM.The protein hydrolysis degree,solubility and antioxidant capacities increased after fermentation,while the anti-nutritional factor contents were decreased.Moreover,the aroma,taste,and state of organization were higher than those of unfermented MBM.Our results illustrated that L.lactis RQ1066 fermentation can enhance physicochemical and functional properties of MBM,which provided a promising approach for the deep processing of mung bean products and the increase of the added value of mung bean.

Research on the Novel Honeycomb-Like Cabin Based on Computer Simulation

The antiknock capability and thermal protection performance of rescue capsules mainly depend on the structural design of the cabin.By designing a new type of cabin structure,it can resist the impact of explosion shock waves and thermal shocks.In this paper,a new honeycomb-like cabin is proposed;the model has a novel thermal insulation layer design.Then,the antiknock capabilities and thermal protection analysis are carried out by using computer software.The“Autodyn”analysis module in ANSYS Workbench 17.0 has been used to simulate the explosion of TNT with a certain quality in a single room.The pressure map over time and the pressure variation curve at different locations for a single room are obtained.Through the analysis module“Transient Structural,”the stress and deformation of the honeycomb-like cabin under the blast load are simulated.The“Transient Thermal”analysis module in the finite element software is used to conduct a transient thermal analysis on the cabin structure.The temperature map and the temperature rise curve of each layer of the cabin cases are obtained.The analysis results indicate that the honeycomb-like cabin design has a good antiknock capability and thermal protection performance,and it can meet the usage requirements of the rescue capsule under dangerous conditions.

Electron beam pumping improves the conversion efficiency of low-frequency photons radiated by perovskite quantum dots

This research argues that using an electron beam with high kinetic energy to pump perovskite quantum dots can significantly boost the efficiency of the low-frequency photon radiation conversion.Firstly,we measure the random lasing threshold and luminescence threshold of CsPbX_(3)films pumped by an electron beam.Then,we simulate the spatial distribution of the electron beams in CsPbX_(3)films.Combined with the above data,a low-frequency photon radiation conversion model based on the electron pumped perovskite quantum dots is presented.This could be a way to create a terahertz source with a high-power output or to multiply the terahertz power.

Ciprofloxacin stress changes key enzymes and intracellular metabolites of Lactobacillus plantarum DNZ-4

Ciprofloxacin(CIP)is an antibiotic used to treat infections caused by bacteria.In this experiment,key enzymes and intracellular metabolites of Lactobacillus plantarum DNZ-4 was researched under CIP stress.The results showed that the activities of hexokinase,pyruvate kinase,β-galactosidase and Na^(+),K^(+)-ATPase after 1/2 minimum bacteriostatic concentration(MIC)CIP treatment were significantly decreased(P<0.01).Gas chromatography-mass spectrometry was used to analysis the changes of main metabolites in the cells and principal component analysis and partial least square model were constructed.The results indicated that CIP could cause changes in intracellular fatty acids,carbohydrates and amino acids,and the mechanism of amino acid metabolism under CIP stress was significantly inhibited.L.plantarum DNZ-4 made stress response to CIP by regulating the ratio of saturated fatty acids and unsaturated fats.This experiment revealed the changes of growth and metabolism mechanism of L.plantarum DNZ-4 under CIP stress,which help to provide technical means for the development of effective probiotics preparation products.