Dynamic mechanical characteristics of deep Jinping marble in complex stress environments

To reveal the dynamic mechanical characteristics of deep rocks,a series of impact tests under triaxial static stress states corresponding to depths of 300-2400 m were conducted.The results showed that both the strain rates and the stress environments in depth significantly affect the mechanical characteristics of rocks.The sensitivity of strain rate to the dynamic strength and deformation modulus shows a negative correlation with depth,indicating that producing penetrative cracks in deep environments is more difficult when damage occurs.The dynamic strength shows a tendency to decrease and then increase slightly,but decreases sharply finally.Transmissivity demonstrates a similar trend as that of strength,whereas reflectivity indicates the opposite trend.Furthermore,two critical depths with high dynamically induced hazard possibilities based on the China Jinping Underground Laboratory(CJPL)were proposed for deep engineering.The first critical depth is 600-900 m,beyond which the sensitivity of rock dynamic characteristics to the strain rate and restraint of circumferential stress decrease,causing instability of surrounding rocks under axial stress condition.The second one lies at 1500-1800 m,where the wave impedance and dynamic strength of deep surrounding rocks drop sharply,and the dissipation energy presents a negative value.It suggests that the dynamic instability of deep surrounding rocks can be divided into dynamic load dominant and dynamic load induced types,depending on the second critical depth.

Preliminary research and scheme design of deep underground in situ geo-information detection experiment for Geology in Time

The deep earth,deep sea,and deep space are the main parts of the national“three deep”strategy,which is in the forefront of the strategic deployment clearly defined in China’s 14th Five-Year Plan(2021-2025)and the Long-Range Objectives Through the Year 2035.It is important to reveal the evolutionary process and mechanism of deep tectonics to understand the earth’s past,present and future.The academic con-notation of Geology in Time has been given for the first time,which refers to the multi-field evolution response process of geological bodies at different time and spatial scales caused by geological processes inside and outside the Earth.Based on the deep in situ detection space and the unique geological envi-ronment of China Jinping Underground Laboratory,the scientific issue of the correlation mechanism and law between deep internal time-varying and shallow geological response is given attention.Innovative research and frontier exploration on deep underground in situ geo-information detection experiments for Geology in Time are designed to be carried out,which will have the potential to explore the driving force of Geology in Time,reveal essential laws of deep earth science,and explore innovative technologies in deep underground engineering.

A precision-drive hysteresis model with an equal-density weight function for GMA feedforward compensation

Giant magnetostrictive actuators(GMAs) are a widely used type of micro-nano actuator, and they are greatly significant in the field of precision engineering. The accuracy of a GMA often depends on its hysteresis model. However, existing models have some limitations,including the difficulty of identifying their parameters and the tradeoff between the quantity of modeling data required and the level of precision achieved. To solve these problems, in this paper, we propose a Preisach inverse model based on equal-density segmentation of the weight function(E-Preisach). The weight function used to calculate the displacement is first discretized. Then, to obtain a finer weight distribution, the discretized geometric units are uniformly divided by area. This can further minimize the output displacement span, and it produces a higher-precision hysteresis model. The process of parameter identification is made easier by this approach, which also resolves the difficulty of obtaining high precision using a small amount of modeling data. The Preisach and the E-Preisach inverse models were investigated and compared using experiments. At frequencies of 1 and 5 Hz, it was found that the E-Preisach inverse model decreases the maximum error of the feedforward compensation open-loop control to within 1 μm and decreases the root-mean-square error in displacement to within0.5 μm without the need to increase the number of measured hysteresis loops. As a result, the E-Preisach inverse model streamlines the structure of the model and requires fewer parameters for modeling. This provides a high-precision modeling method using a small amount of modeling data;it will have applications in precision engineering fields such as active vibration damping and ultra-precision machining.

基于区块链技术的可信电子文件长期保存策略探析

可信电子文件蕴含大量有价值的信息,国家对于可信电子文件长期保存的需求日益迫切,区块链技术为满足这一需求提供了新技术手段。本文通过分析可信电子文件长期保存价值,介绍区块链技术并分析其对于可信电子文件长期保存中的作用,提出在以区块链技术为轴心基础上,从人才、法律、观念、管理、政策维度出发,构建国家可信电子文件长期保存体系。

Potential roles of vitamin D binding protein in attenuating liver injury in sepsis

Background:In sepsis,vitamin D binding protein(VDBP)has been shown to be low-expressed.The current study examined the relationship between serum VDBP level and liver injury in sepsis patients,as well as in a mouse model for sepsis and in cultured liver epithelial cell line exposed to lipopolysaccharide(LPS).Methods:The human study included 78 sepsis patients and 50 healthy volunteers.Sepsis patients were categorized into sepsis survivor group(n=43)and sepsis non-survivor group(n=35)based on 28-day mortality for data analysis.Adult male C57BL/6 mice were subjected to cecal ligation and puncture(CLP).Serum samples were collected on day 1,3,5 and 7 to determine the levels of VDBP,25-hydroxyvitamin D[25(OH)D_(3)],1,25-dihydroxyvitamin D[1,25(OH)_(2)D_(3)],interleukin-6(IL-6)and tumor necrosis factor alpha(TNF-α).Potential protective effects of VDBP overexpression against LPS-induced liver damage were examined in cultured THLE2 cells.Results:Serum levels of VDBP,25(OH)D_(3),and 1,25(OH)_(2)D_(3)were significantly lower in sepsis patients vs.the healthy control(P<0.001),as well as in the sepsis non-survivor group vs.the sepsis survivor group(P<0.001,P=0.0338,or P=0.0013,respectively).Lower serum VDBP level was associated with higher Acute Physiology and Chronic Health Evaluation(APACHE)II score(r=−0.2565,P=0.0234)and Sequential Organ Failure Assessment score(r=−0.3522,P=0.0016),but lower serum albumin(ALB,r=0.4628,P<0.001)and total protein(TP,r=0.263,P=0.02).In CLP mice,there was a 5-day period of serum VDBP reduction,followed by return towards the baseline on day 7.VDBP was also decreased in LPS-treated THLE2 cells(P<0.001).VDBP overexpression reduced LPS-induced THLE2 damage.Reduced damage was associated with decreased oxidative stress and inactivation of the c-Jun N-terminal kinase signaling pathway.Conclusion:VDBP may be protective against sepsis-induced liver injury.

An Energy Sharing EH-DAS Model and its Power Allocation Among RAUs

For the energy sharing problem of distributed antenna system(DAS)with energy harvesting(EH),a distributed antenna system model capable of sharing collected energy among the components in system is proposed.Compared with the existing model in literatures,the proposed model connects with smart grid through a unified interface and facilitates energy management and scheduling.Based on the proposed model,three kinds of energy sharing methods including the partial energy sharing method,the complete energy sharing method and the self-sustaining energy sharing method are analyzed.Under various energy sharing methods,the corresponding optimization problems of power allocation among the remote antenna units(RAUs)are described,formed and solved.As a result,the corresponding power allocation algorithm to each method has been concluded.Simulation results show that the proposed model is more efficient in terms of the channel capacity and energy efficiency,compared to the existing model.

Nomogram prediction model called“ADPLCP”for predictinglinezolid-associated thrombocytopenia in elderly individuals

Background:Linezolid-associated thrombocytopenia(LAT)leads to drug withdrawal associated with a poor prognosis.Some risk factors for LAT have been identified;however,the sample size of previous studies was small,data from elderly individuals are limited,and a simple risk score scale was not established to predict LAT at anearly stage,making it difficult to identify and intervene in LAT at an early stage.Methods:In this single-center retrospective case-control study,we enrolled elderly patients treated with linezolidin the intensive care unit from January 2015 to December 2020.All the data of enrolled patients,includingdemographic information and laboratory findings at baseline,were collected.We analyzed the incidence andrisk factors for LAT and established a nomogram risk prediction model for LAT in the elderly population.Results:A total of 428 elderly patients were enrolled,and the incidence of LAT was 35.5%(152/428).Age≥80 years old(OR=1.980;95%CI:1.179–3.325;P=0.010),duration of linezolid≥10 days(OR=1.100;95%CI:1.050–1.152;P<0.0001),platelet count at baseline(100–149×10^(9)/L vs.≥200×10^(9)/L,OR=8.205,95%CI:4.419–15.232,P<0.0001;150–199×10^(9)/L vs.≥200×10^(9)/L,OR=3.067,95%CI:1.676–5.612,P<0.001),leukocytecount at baseline≥16×10^(9)/L(OR=2.580;95%CI:1.523–4.373;P<0.0001),creatinine clearance<50 mL/min(OR=2.323;95%CI:1.388–3.890;P=0.001),and total protein<60 g/L(OR=1.741;95%CI:1.039–2.919;P=0.035)were associated with LAT.The nomogram prediction model called“ADPLCP”(age,duration,platelet,leukocyte,creatinine clearance,protein)was established based on logistic regression.The area under the curve(AUC)of ADPLCP was 0.802(95%CI:0.748–0.856;P<0.0001),with 78.9%sensitivity and 69.2%specificity(cut-off was 108).Risk stratification for LAT was performed based on“ADPLCP.”Total points of<100 were defined as low risk,and the possibility of LAT was<32.0%.Total points of 100–150 were defined as medium risk,and the possibility of LAT was 32.0–67.5%.A total point>150 was defined as high risk,and the probability ofLAT was>67.5%.Conclusions:We created the ADPLCP risk score scale to predict the occurrence of LAT in elderly individuals.ADPLCP is simple and feasible and is helpful for the early determination of LAT to guide drug withdrawal orearly intervention.

Metatranscriptome of human lung microbial communities in a cohort of mechanically ventilated COVID-19 Omicron patients

The Omicron variant of the severe acute respiratory syndrome coronavirus 2(SARS‑CoV‑2)infected a substantial proportion of Chinese population,and understanding the factors underlying the severity of the disease and fatality is valuable for future prevention and clinical treatment.We recruited 64 patients with invasive ventilation for COVID-19 and performed metatranscriptomic sequencing to profile host transcriptomic profiles,plus viral,bacterial,and fungal content,as well as virulence factors and examined their relationships to 28-day mortality were examined.In addition,the bronchoalveolar lavage fluid(BALF)samples from invasive ventilated hospital/community-acquired pneumonia patients(HAP/CAP)sampled in 2019 were included for comparison.Genomic analysis revealed that all Omicron strains belong to BA.5 and BF.7 sub-lineages,with no difference in 28-day mortality between them.Compared to HAP/CAP cohort,invasive ventilated COVID-19 patients have distinct host transcriptomic and microbial signatures in the lower respiratory tract;and in the COVID-19 non-survivors,we found significantly lower gene expressions in pathways related viral processes and positive regulation of protein localization to plasma membrane,higher abundance of opportunistic pathogens including bacterial Alloprevotella,Caulobacter,Escherichia-Shigella,Ralstonia and fungal Aspergillus sydowii and Penicillium rubens.Correlational analysis further revealed significant associations between host immune responses and microbial compositions,besides synergy within viral,bacterial,and fungal pathogens.Our study presents the relationships of lower respiratory tract microbiome and transcriptome in invasive ventilated COVID-19 patients,providing the basis for future clinical treatment and reduction of fatality.

一株多环芳烃降解菌及其在多种强化体系中降解菲的潜力

多环芳烃是一类普遍的环境污染物,因其潜在的环境暴露和对人类健康的危害而备受关注。从石化品污染土壤样品中分离到一株以菲为唯一碳源和能源的中温菌(15-37℃,最佳30℃)菌株CFP312。经菌落和菌体形态观察、生理生化测试和16S rRNA同源性分析鉴定属于莫拉氏菌Moraxella sp.。这是Moraxella属中多环芳烃降解菌种的首次报道。研究表明,当菲浓度为400 mg/L时,在48 h和60 h时,菲的去除率分别为84%和90%,降解速率达到1.21、1.29 mg/(L·h)。在菲的降解过程中,检测到3,4-二氢-3,4-二羟基菲为中间产物。据此推断降解菌通过在菲的3,4位进行双加氧完成其生物降解的第一个关键步骤。在水-有机溶剂两相分配体系、胶束水溶液体系和浊点体系中检测了降解菌对不同的菲强化降解体系的适应性。结果表明,降解菌对不同降解体系都表现出了良好的适应性。另外,降解菌可在泥浆-水体系中快速降解污染土壤中的多环芳烃菲,表明其在环境修复方面具有很大的应用潜力。

Determination of chlorogenic acid in traditional Chinese prescription Shuanghuanglian capsule using quantitative nuclear magnetic resonance spectroscopy in combination with solid phase extraction

The determination method of chlorogenic acid in traditional Chinese prescription Shuanghuanglian capsule was established by using quantitative nuclear magnetic resonance spectroscopy(q NMR) in combination with solid phase extraction(SPE). As the capsule’s main active component, chlorogenic acid comes from the extraction of Chinese herb medicine Flos Lonicerae. The chlorogenic acid in capsule was ultrasonically extracted at room temperature using pure water as solvent. The extracting solution was enriched and cleaned using HC-C18 SPE cartridge. The effect of ultrasonic extraction, sample pretreatment conditions via SPE and q NMR experimental conditions were investigated. The q NMR experiment conditions were selected using deuterated DMSO as solvent, calibrated 1,4-phthalaldehyde as internal standard, and P1(pulse width) = 14.4 μs, d1(pulse delay time) = 1 s, NS(number of scan) = 512. The 1 H NMR peaks of δ 6.138–6.182(H-8’, d, 1 H) of chlorogenic acid was chosen as the quantitative peaks. Method validation was performed, including precision(the intra-day RSD = 1.2% and the inter-day RSD = 1.5%), linearity(correlation coefficient r>0.9999), LOD(0.0017 mg/g) and LOQ(0.079 mg/g). The recovery of the SPE-q NMR was within the range of 100.2%–103.2%. The result showed that the method was stable, accurate and reliabile. Determined by the method, the chlorogenic acid in a real Shuanghuanglian capsule was within the range of 9.68–10.35 mg/g.

Expert consensus on clinical standardized application of high-flow nasal cannula oxygen therapy in adults

High-flow nasal cannula oxygen therapy(HFNC)is a novel respiratory support technology and has been extensively applied in clinics in recent years.This therapeutic equipment mainly includes an air-oxygen blender,an active humidifier,a high-flow nasal cannula,and a connecting inspiratory circuit.It provides patients a humidified high-flow gas(8-80 L/min)with relatively stable oxygen concentration(21-100%),temperature(31-37℃)and performs oxygen therapy via a nasal cannula,which is very comfortable.

An attempt to treat Hoffa fractures under arthroscopy： A case report

We treated a 15-year-old female patient with fracture of the post-lateral femoral condyle and the bone shifted in front of the knee. Considering that the traditional surgical approach has the shortcomings of significant trauma and poor prognosis, we designed an arthroscopic procedure, which achieved satis- factory short-term efficacy, effectively reduced and fixed the fractures, avoided damage to vascular nerves, and maximally reduced the trauma caused by surgery itself.

Advances in mesenchymal stem cell-mediated tissue repair of lung injury

The repair of lung injury has always been a fundamental problem in the treatment of acute and chronic lung diseases,and more effective treatment approaches have been sought.Regenerative medicine,which gradually repairs impaired tissue and improves lung function,has been increasingly applied in the field of acute and chronic respiratory diseases.

A new method of deliverability prediction by steady point in gas wells

Calculating the absolute open flow potential timely and investigating production capacity so as to adjust working system of production wells is one of main means to effectively recovery gas reservoirs during intermediate and late development stage.In order to obtain the open flow potential of gas wells accurately,a new method which utilized a single steady point was proposed in this research,which was based on deliverability formula of a gas well in pseudo-steady state flow with pseudo-pressure form.The influence on factor B in binomial productivity equation caused by the changed permeability was taken into consideration.According to the stable production data,reservoir permeability K can be determined by iterative method firstly,and the coefficient A,B in binomial productivity equation can be calculated with the open flow potential subsequently.It illustrated clearly by a practical example that the new method was suitable for gas wells especially when the producing pressure drop is large.Additionally,the error between the open flow potential value and interpretation result from the multi-point test was small,which proved it to be more simple,economic and effective than the common one.