EFFECT OF STONE POWDER ON STONE CHIPPINGS CONCRETE

In this paper, the effect and mechanism of calcareous stone powder with size less than 0.074 mm are investigated in stone chippings concrete. The results show that the stone powder can participate in hydration reaction and acts as crystal nucleus in hydration process, namely, it has hydration activity to an extent. The strength of stone chippings concrete is enhanced and the easy-mixing capacity of the concrete mortar is modified when stone chippings contain a proper amount of stone powder. The stone powder has little effect on the wearability of the concrete.

GPGPU-parallelised hybrid finite-discrete element modelling of rock chipping and fragmentation process in mechanical cutting

Mechanical cutting provides one of the most flexible and environmentally friendly excavation methods.It has attracted numerous efforts to model the rock chipping and fragmentation process,especially using the explicit finite element method(FEM) and bonded particle model(BPM),in order to improve cutting efficiency.This study investigates the application of a general-purpose graphic-processing-unit parallelised hybrid finite-discrete element method(FDEM) which enjoys the advantages of both explicit FEM and BPM,in modelling the rock chipping and fragmentation process in the rock scratch test of mechanical rock cutting.The input parameters of FDEM are determined through a calibration procedure of modelling conventional Brazilian tensile and uniaxial compressive tests of limestone,A series of scratch tests with various cutting velocities,cutter rake angles and cutting depths is then modelled using FDEM with calibrated input parameters.A few cycles of cutter/rock interactions,including their engagement and detachment process,are modelled for each case,which is conducted for the first time to the best knowledge of the authors,thanks to the general purpose graphic processing units(GPGPU) parallelisation.The failure mechanism,cutting force,chipping morphology and effect of various factors on them are discussed on the basis of the modelled results.Finally,it is concluded that GPGPU-parallelised FDEM provides a powerful tool to further study rock cutting and improve cutting efficiencies since it can explicitly capture different fracture mechanisms contributing to the rock chipping as well as chip formation and the separation process in mechanical cutting.Moreover,it is concluded that chipping is mostly owed to the mix-mode Ⅰ-Ⅱ fracture in all cases although mode Ⅱ cracks and mode Ⅰ cracks are the dominant failures in rock cutting with shallow and deep cutting depths,respectively.The chip morphology is found to be a function of cutter velocdty,cutting depth and cutter rake angle.

Hard rock tunnel boring machine penetration test as an indicator of chipping process efficiency

The transition from grinding to chipping can be observed in tunnel boring machine(TBM) penetration test data by plotting the penetration rate(distance/revolution) against the net cutter thrust(force per cutter) over the full range of penetration rates in the test.Correlating penetration test data to the geological and geomechanical characteristics of rock masses through which a penetration test is conducted provides the ability to reveal the efficiency of the chipping process in response to changing geological conditions.Penetration test data can also be used to identify stress-induced tunnel face instability.This research shows that the strength of the rock is an important parameter for controlling how much net cutter thrust is required to transition from grinding to chipping.It also shows that the geological characteristics of a rock will determine how efficient chipping occurs once it has begun.In particular,geological characteristics that lead to efficient fracture propagation,such as fabric and mica contents,will lead to efficient chipping.These findings will enable a better correlation between TBM performance and geological conditions for use in TBM design,as a basis for contractual payments where penetration rate dominates the excavation cycle and in further academic investigations into the TBM excavation process.

超宽带穿墙雷达压缩感知成像中chipping序列的设计

在超宽带穿墙雷达压缩感知成像中，常常使用Rademacher序列作为模拟信息转换器的chipping序列。而这种序列的功率谱类似于高斯白噪声的功率谱，它与回波信号的功率谱不匹配，导致低速采样前信号的信噪比偏低，最终影响了成像效果。文章从低速采样前的平均信噪比最大化入手，构建设计匹配chipping序列的优化算法以导出其成立的条件，给出一种使用马尔科夫链游程长度受限（RLL）序列来设计匹配chipping序列的解决方案。仿真结果表明，使用马尔科夫链RLL序列设计匹配chipping序列的成像结果优于Rademacher序列，其图像的信噪比提高2～3dB。

Study on disc cutter chipping of TBM based on field data and particle flow code simulation

Using tunnel boring machines to excavate high-strength intact rock masses is becoming more common.Due to the interactions between disc cutters and rocks,abnormal wear of disc cutters,especially cutter chipping,has become a common phenomenon.Existing research has mainly focused on normal wear of disc cutters without addressing abnormal wear cases.This study used the disc cutter consumption data of a tunnel project in China to investigate the abovementioned problem based on field research.According to the fail-ure patterns and fracture surface characteristics,the cutter chipping patterns were mainly categorized into four types:granule chipping,patch chipping,primary collapse,and secondary collapse.To further simulate the evolution of disc cutter chipping,based on the linear plastic bond model,a new contact model called the modified plastic bond(MPB)model was proposed to solve the metal simulation prob-lem in Particle Flow Code software.To this end,a set of uniaxial tensile and compressive tests were initially conducted to verify the applicability of the MPB model.Then,a series of three-dimensional rock-cutting simulation tests were conducted to reflect the evolu-tionary processes involved in each type of cutter chipping.The cutter chipping mechanism and morphological characteristics were clas-sified and summarized in detail.The results revealed that the cutting speed and penetration growth led to a rising trend in the probability and intensity of the cutter chipping.The presence of initial defects also induced an adverse effect on the service life of the cutter.The results indicated suitable working conditions for the cutter and suggested ways to control tunneling parameters and avoid frequent cutter chipping cases.

CHIP相关基因与MPN患者心脑血管事件的风险分析

目的:分析骨髓增殖性肿瘤(MPN)患者不确定潜能的克隆性造血(CHIP)相关基因突变谱和临床特征,探讨CHIP相关基因与其心脑血管事件(CCE)的相关性及可能作用机制。方法:回顾性分析2019年8月-2022年7月首都医科大学附属北京安贞医院血液科收治的73例MPN患者的临床资料和二代测序结果,采用Logistic回归分析CHIP相关基因、炎症细胞因子对MPN患者CCE的影响。结果:55例(75.3%)MPN患者检出CHIP相关基因,原发性血小板增多症(ET)和真性红细胞增多症(PV)患者CHIP相关基因各突变频率差异无统计学意义。CHIP相关基因突变以单基因形式为主,检出率从高至低依次为JAK2V617F(63.0%,46/73)、ASXL1(16.4%,12/73)、TET2(11.0%,8/73)、DNMT3A(9.6%,7/73)、SRSF2(6.9%,5/73)、SF3B1(4.1%,3/73)、TP53(1.4%,1/73)和PPMID(1.4%,1/73)。年龄>60岁患者CHIP相关基因检出率明显高于≤60岁者[91.7%(33/36)vs 59.5%(22/37)]。27例(37.0%)MPN患者伴CCE(MPN/CCE),2次CCE者5例,均为动脉事件。CCE组患者年龄(62.8±12.8 vs 53.9±15.8岁,P=0.015)、IL-1β水平(17.7±26.0vs 4.3±8.6,P=0.012)、IL-8水平(360.7±598.6 vs 108.3±317.0,P=0.045)、血栓形成史(29.6%vs 2.2%,P=0.020)和CHIP相关基因检出率(88.9%vs 67.4%,P=0.040)高于无CCE组。多因素Logistic回归分析结果显示,年龄(OR=0.917,95%CI:0.843-0.999,P=0.047)、血栓形成史(OR=34.148,95%CI:2.392-487.535,P=0.009)、任何1个CHIP相关基因突变(OR=16.065,95%CI:1.217-212.024,P=0.035)和IL-1β水平升高(OR=0.929,95%CI:0.870-0.992,P=0.027)均是MPN/CCE的独立危险因素;CHIP相关单基因突变与MPN/CCE无关,但DNMT3A(OR=88.717,95%CI:2.690-292.482,P=0.012)、ASXL1(OR=7.941,95%CI:1.045-60.353,P=0.045)突变是PV/CCE的独立危险因素。结论:MPN患者CHIP相关基因突变率高,尤其是60岁以上患者;高龄、血栓形成史、CHIP相关基因突变和IL-1β水平升高是MPN发生CCE的独立危险因素。DNMT3A、ASXL1单基因突变是PV患者CCE的独立危险因素。CHIP相关基因突变及炎症细胞因子IL-1β升高是MPN新的CCE危险因素。

替普瑞酮通过E3泛素连接酶CHIP减轻LPS引起的心肌炎症反应和心功能障碍

目的:探究替普瑞酮又称香叶基香叶基丙酮,GGA)对脂多糖(LPS)诱导的心功能障碍的治疗作用及机制。方法:(1)取8周龄C57BL/6雄性野生型小鼠和热休克蛋白70(HSP70)羧基末端相互作用蛋白(CHIP)基因敲除小鼠,随机分为对照组、LPS组、LPS+GGA组和GGA组,每组8只。用腹腔注射LPS(25 mg/kg)的方法建立模型,于LPS刺激后1 h给予小鼠腹腔注射GGA(100 mg/kg)。利用小动物超声系统评估小鼠心脏功能;采集各组小鼠血清,检测血清肌酸激酶同工酶(CK-MB)和乳酸脱氢酶(LDH)水平;HE染色观察病理学改变;ELISA检测心脏组织中炎症因子肿瘤坏死因子α(TNF-α)和白细胞介素6(IL-6)的水平;Western blot检测各组心脏组织HSP70、CHIP、核转运蛋白α2(KPNA2)、髓过氧化物酶(MPO)、血管细胞黏附分子(VCAM)和细胞间黏附分子(ICAM)的蛋白表达以及细胞核NF-κB的水平。(2)利用小鼠心肌细胞HL-1,建立LPS刺激的离体细胞炎症模型。ELISA检测细胞上清中TNF-α和IL-6的水平;Western blot检测心肌细胞中HSP70、CHIP和KPNA2蛋白表达;免疫荧光染色观察细胞核NF-κB的表达。结果:(1)GGA有效改善LPS刺激小鼠的心脏功能,显著提高射血分数和左室短轴缩短率(P<0.01),减少血清CK-MB和LDH含量(P<0.01),减轻心肌损伤。(2)GGA显著减少LPS引起的TNF-α和IL-6炎症因子的释放(P<0.01),以及NF-κB的入核,降低心肌组织中KPNA2、MPO、VCAM和ICAM蛋白表达,增加心肌组织和细胞HSP70的水平(P<0.01)。(3)在CHIP基因敲除的心肌细胞和小鼠中,GGA不能抑制LPS引起的炎症反应,失去了改善LPS刺激小鼠心脏功能的作用。结论:GGA能够减轻LPS引起的心功能障碍,其作用机制与升高HSP70的表达,促进CHIP的活化,减少NF-κB的入核,抑制炎症因子的释放有关。CHIP的敲除使GGA丧失了减轻LPS诱导的炎症反应和心肌损伤的作用。

湖羊lncRNA-269的鉴定及转录调控分析

[目的]本文旨在研究湖羊长链非编码RNA-269(long no-coding RNA-269,lncRNA-269)序列特征、表达模式和转录调控,为后续开展lncRNA-269的功能研究提供理论基础。[方法]以湖羊为研究对象,采用5′/3′RACE结合PCR扩增方法获得其序列全长,利用RT-qPCR方法鉴定其在湖羊组织中的表达模式,并利用PCR方法扩增其启动子区,鉴定其启动子区特征,分析其转录调控情况。[结果]湖羊lncRNA-269全长3 146 bp,组织表达谱显示其在湖羊各组织中广泛表达,且在健康卵泡中显著高表达,其表达水平与NR5A1 mRNA水平和血清中雌二醇(E_(2))水平呈正相关。荧光素酶活性分析发现在lncRNA-269启动子区的-359~-17 nt有1个转录激活基序,在-1 485~-942 nt有1个转录抑制基序。JASPAR软件预测发现在lncRNA-269转录抑制启动子区域存在FOXO3、PDX1等转录因子结合位点,在转录激活区域有SMAD4、YY1等转录因子结合位点。过表达SMAD4可显著提升lncRNA-269启动子区荧光素酶活性,染色质免疫沉淀(ChIP)-PCR试验进一步确认了SMAD4特异性与lncRNA-269启动子区结合。[结论]湖羊lncRNA-269在健康卵泡中显著高表达,其启动子区存在一个转录激活区域和一个转录抑制区域,转录因子SMAD4可通过与lncRNA-269启动子区结合显著上调lncRNA-269的启动子活性。

AcWRKY28 mediated activation of AcCPK genes confers salt tolerance in pineapple(Ananas comosus)

Unfavorable environmental cues severely affect crop productivity resulting in significant economic losses to farmers. In plants, multiple regulatory genes, such as the WRKY transcription factor (TF) family, modulate the expression of defense genes. However, the role of the pineapple WRKY genes is poorly understood. Here, we studied the pineapple WRKY gene, AcWRKY28, by generating AcWRKY28 over-expressing transgenic pineapple plants. Overexpression of AcWRKY28 enhanced the salt stress resistance in transgenic pineapple lines. Comparative transcriptome analysis of transgenic and wild-type pineapple plants showed that “plant-pathogen interaction” pathway genes, including 9calcium-dependent protein kinases (CPKs), were up-regulated in AcWRKY28 over-expressing plants. Furthermore, chromatin immunoprecipitation and yeast one-hybrid assays revealed AcCPK12, AcCPK3, AcCPK8, AcCPK1, and AcCPK15 as direct targets of AcWRKY28. Consistently, the study of AcCPK12 over-expressing Arabidopsis lines showed that AcCPK12 enhances salt, drought, and disease resistance. This study shows that AcWRKY28 plays a crucial role in promoting salt stress resistance by activating the expression of AcCPK genes.

Simplified quantitative analysis method and its application in the insitu synthesized copper-based azide chips

Copper-based azide(Cu(N_(3))2 or CuN_(3),CA)chips synthesized by in-situ azide reaction and utilized in miniaturized explosive systems has become a hot research topic in recent years.However,the advantages of in-situ synthesis method,including small size and low dosage,bring about difficulties in quantitative analysis and differences in ignition capabilities of CA chips.The aim of present work is to develop a simplified quantitative analysis method for accurate and safe analysis of components in CA chips to evaluate and investigate the corresponding ignition ability.In this work,Cu(N_(3))2 and CuN_(3)components in CA chips were separated through dissolution and distillation by utilizing the difference in solubility and corresponding content was obtained by measuring N_(3)-concentration through spectrophotometry.The spectrophotometry method was optimized by studying influencing factors and the recovery rate of different separation methods was studied,ensuring the accuracy and reproducibility of test results.The optimized method is linear in range from 1.0-25.0 mg/L,with a correlation coefficient R^(2)=0.9998,which meets the requirements of CA chips with a milligram-level content test.Compared with the existing ICP method,component analysis results of CA chips obtained by spectrophotometry are closer to real component content in samples and have satisfactory accuracy.Moreover,as its application in miniaturized explosive systems,the ignition ability of CA chips with different component contents for direct ink writing CL-20 and the corresponding mechanism was studied.This study provided a basis and idea for the design and performance evaluation of CA chips in miniaturized explosive systems.

A novel integrated microfluidic chip for on-demand electrostatic droplet charging and sorting

On-demand droplet sorting is extensively applied for the efficient manipulation and genome-wide analysis of individual cells.However,state-of-the-art microfluidic chips for droplet sorting still suffer from low sorting speeds,sample loss,and labor-intensive preparation procedures.Here,we demonstrate the development of a novel microfluidic chip that integrates droplet generation,on-demand electrostatic droplet charging,and high-throughput sorting.The charging electrode is a copper wire buried above the nozzle of the microchannel,and the deflecting electrode is the phosphate buffered saline in the microchannel,which greatly simplifies the structure and fabrication process of the chip.Moreover,this chip is capable of high-frequency droplet generation and sorting,with a frequency of 11.757 kHz in the drop state.The chip completes the selective charging process via electrostatic induction during droplet generation.On-demand charged microdroplets can arbitrarilymove to specific exit channels in a three-dimensional(3D)-deflected electric field,which can be controlled according to user requirements,and the flux of droplet deflection is thereby significantly enhanced.Furthermore,a lossless modification strategy is presented to improve the accuracy of droplet deflection or harvest rate from 97.49% to 99.38% by monitoring the frequency of droplet generation in real time and feeding it back to the charging signal.This chip has great potential for quantitative processing and analysis of single cells for elucidating cell-to-cell variations.

Advances in microfluidic-based DNA methylation analysis

DNA methylation has been extensively investigated in recent years,not least because of its known relationship with various diseases.Progress in analytical methods can greatly increase the relevance of DNA methylation studies to both clinical medicine and scientific research.Microflu-idic chips are excellent carriers for molecular analysis,and their use can provide improvements from multiple aspects.On-chip molecular analysis has received extensive attention owing to its advantages of portability,high throughput,low cost,and high efficiency.In recent years,the use of novel microfluidic chips for DNA methylation analysis has been widely reported and has shown obvious superiority to conventional methods.In this review,wefirst focus on DNA methylation and its applications.Then,we discuss advanced microfluidic-based methods for DNA methylation analysis and describe the great progress that has been made in recent years.Finally,we summarize the advantages that microfluidic technology brings to DNA methylation analysis and describe several challenges and perspectives for on-chip DNA methylation analysis.This review should help researchers improve their understanding and make progress in developing microfluidic-based methods for DNA methylation analysis.

Differential expression of plasma cytokines in sepsis patients and their clinical implications

BACKGROUND Sepsis,which is characterized by acute systemic inflammation and is associated with high rates of morbidity and mortality,presents a significant challenge in health care.Some scholars have found that the sequential organ failure assessment(SOFA)and quick SOFA scores are not ideal for predicting severe sepsis and mortality.Microbial culture takes a long time(2-3 d)and provides no information for early diagnosis and treatment.Therefore,new diagnostic methods for sepsis need to be explored.AIM To assess cytokine levels in the plasma of sepsis patients and identify potential biomarkers for diagnosing sepsis.METHODS Ten sepsis patients admitted to the emergency department within 24 h of onset were enrolled as the observation group,whereas ten noninfected patients served as the control group.Of the 10 noninfected patients,9 hypertension combined with cerebral infarction,1 patients with vertiginous syndrome.Plasma Cytokines were measured using the Bio-Plex Pro^(TM)Human Chemokine Panel 40-plex.Differentially expressed cytokines in plasma of sepsis and nonsepsis patients were analyzed using Gene Ontology(GO)functional enrichment and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway analyses.RESULTS Interleukin(IL)-16,granulocyte-macrophage granulocyte-macrophage colony-stimulating factor(GM-CSF),CX3CL1,CXCL9,CXCL16,CCL25,and CCL23 plasma levels were significantly increased in sepsis patients.GO analysis revealed that these cytokines were mainly associated with cellular structures such as intermediates,nuclear plaques,adhesion plaques,lateral plasma membranes,and cell matrix junctions.These genes were involved in various molecular functions,such as cytokine activity,receptor ligand activity,and signal receptor activator activity,contributing to various biological functions,such as leukocyte chemotaxis,migration,and chemotaxis.KEGG analysis indicated involvement in cytokine cytokine receptor interactions,chemokine signaling pathways,virus–protein interactions with cytokines and cytokine receptors,and the tumor necrosis factor signaling pathway.CONCLUSION Elevated serum levels of IL-16,GM-CSF,CX3CL1,CXCL9,CXCL16,CCL25,and CCL23 in sepsis patients suggest their potential as diagnostic biomarkers for sepsis.

Design,preparation,and characterization of a novel ZnO/CuO/Al energetic diode with dual functionality:Logic and destruction

Self-destructing chips have promising applications for securing data.This paper proposes a new concept of energetic diodes for the first time,which can be used for self-destructive chips.A simple two-step electrochemical deposition method is used to prepare ZnO/CuO/Al energetic diode,in which N-type ZnO and P-type CuO are constricted to a PN junction.This paper comprehensively discusses the material properties,morphology,semiconductor characteristics,and exploding performances of the energetic diode.Experimental results show that the energetic diode has typical rectification with a turn-on voltage of about 1.78 V and a reverse leakage current of about 3×10^(-4)A.When a constant voltage of 70 V loads to the energetic diode in the forward direction for about 0.14 s or 55 V loads in the reverse direction for about 0.17 s,the loaded power can excite the energetic diode exploding and the current rises to about100 A.Due to the unique performance of the energetic diode,it has a double function of rectification and explosion.The energetic diode can be used as a logic element in the normal chip to complete the regular operation,and it can release energy to destroy the chip accurately.

Estimation of cancer cell migration in biomimetic random/oriented collagen fiber microenvironments

Increasing data indicate that cancer cell migration is regulated by extracellular matrixes and their surrounding biochemical microenvironment,playing a crucial role in pathological processes such as tumor invasion and metastasis.However,conventional two-dimensional cell culture and animal models have limitations in studying the influence of tumor microenvironment on cancer cell migration.Fortunately,the further development of microfluidic technology has provided solutions for the study of such questions.We utilize microfluidic chip to build a random collagen fiber microenvironment(RFM)model and an oriented collagen fiber microenvironment(OFM)model that resemble early stage and late stage breast cancer microenvironments,respectively.By combining cell culture,biochemical concentration gradient construction,and microscopic imaging techniques,we investigate the impact of different collagen fiber biochemical microenvironments on the migration of breast cancer MDA-MB-231-RFP cells.The results show that MDA-MB-231-RFP cells migrate further in the OFM model compared to the RFM model,with significant differences observed.Furthermore,we establish concentration gradients of the anticancer drug paclitaxel in both the RFM and OFM models and find that paclitaxel significantly inhibits the migration of MDA-MB-231-RFP cells in the RFM model,with stronger inhibition on the high concentration side compared to the low concentration side.However,the inhibitory effect of paclitaxel on the migration of MDA-MB-231-RFP cells in the OFM model is weak.These findings suggest that the oriented collagen fiber microenvironment resembling the late-stage tumor microenvironment is more favorable for cancer cell migration and that the effectiveness of anticancer drugs is diminished.The RFM and OFM models constructed in this study not only provide a platform for studying the mechanism of cancer development,but also serve as a tool for the initial measurement of drug screening.

LncRNA LOC103694972 promotes fibrosis of NRK-49F cells by regulating STAT3-dependent Smad/CTGF pathway via targeting miR-29c-3p

Background:Renalfibrosis is an important process in the development of chronic kidney disease.Understanding the pathogenesis andfinding effective treatments for renalfibrosis is crucial.This study aims to investigate whether a newly discovered long non-coding RNA(lncRNA)called LOC103694972 could be a potential target for treatingfibrosis of NRK-49F cells.Methods:LncRNA Chip was used to identify differentially expressed lncRNAs between TGF-β1-induced NRK-49F cells and normal cells.The dual-luciferase assay confirmed the binding between miR-29c-3p and signal transducer and activator of transcription(STAT3),as well as between miR-29c-3p and lncRNA LOC103694972.Si-LOC103694972 and miR-29c-3p mimic were then transfected into TGF-β1-induced NRK-49F cells.Results:The study found that LOC103694972 was highly expressed in TGF-β1-induced NRK-49F cells.These cells exhibited increased cell length and activity compared to the control group.The expression levels of Collagen I,α-Smooth muscle actin(α-SMA),and tissue inhibitor of metalloproteinase(TIMP-1)were increased,while matrix Metalloproteinase 2(MMP2)and matrix Metalloproteinase 9(MMP9)expression was decreased.However,transfection with si-LOC103694972 and miR-29c-3p mimics restored cell morphology and reduced cell viability.This led to a decrease in the levels of Collagen I,α-SMA,and TIMP-1,as well as an increase in MMP2 and MMP9 expression.Additionally,TGF-β1-induced NRK-49F cells transfected with miR-29c-3p mimics activated the STAT3-Smad3/CTGF pathway.Conclusion:Based on thesefindings,lncRNA LOC103694972 shows promise as a target for treating renalfibrosis.It negatively regulates miR-29c-3p and activates the STAT3-Smad3/CTGF pathway.

Transplantation of human placental chorionic plate-derived mesenchymal stem cells for repair of neurological damage in neonatal hypoxic-ischemic encephalopathy

Neonatal hypoxic-ischemic encephalopathy is often associated with permanent cerebral palsy,neurosensory impairments,and cognitive deficits,and there is no effective treatment for complications related to hypoxic-ischemic encephalopathy.The therapeutic potential of human placental chorionic plate-derived mesenchymal stem cells for various diseases has been explored.However,the potential use of human placental chorionic plate-derived mesenchymal stem cells for the treatment of neonatal hypoxic-ischemic encephalopathy has not yet been investigated.In this study,we injected human placental chorionic plate-derived mesenchymal stem cells into the lateral ventricle of a neonatal hypoxic-ischemic encephalopathy rat model and observed significant improvements in both cognitive and motor function.Protein chip analysis showed that interleukin-3 expression was significantly elevated in neonatal hypoxic-ischemic encephalopathy model rats.Following transplantation of human placental chorionic plate-derived mesenchymal stem cells,interleukin-3 expression was downregulated.To further investigate the role of interleukin-3 in neonatal hypoxic-ischemic encephalopathy,we established an in vitro SH-SY5Y cell model of hypoxic-ischemic injury through oxygen-glucose deprivation and silenced interleukin-3 expression using small interfering RNA.We found that the activity and proliferation of SH-SY5Y cells subjected to oxygen-glucose deprivation were further suppressed by interleukin-3 knockdown.Furthermore,interleukin-3 knockout exacerbated neuronal damage and cognitive and motor function impairment in rat models of hypoxic-ischemic encephalopathy.The findings suggest that transplantation of hpcMSCs ameliorated behavioral impairments in a rat model of hypoxic-ischemic encephalopathy,and this effect was mediated by interleukin-3-dependent neurological function.

Link Budget and Enhanced Communication Distance for Ambient Internet of Things

Backscatter communications will play an important role in connecting everything for beyond 5G(B5G)and 6G systems.One open challenge for backscatter communications is that the signals suffer a round-trip path loss so that the communication distance is short.In this paper,we first calculate the communication distance upper bounds for both uplink and downlink by measuring the tag sensitivity and reflection coefficient.It is found that the activation voltage of the envelope detection diode of the downlink tag is the main factor limiting the back-scatter communication distance.Based on this analysis,we then propose to implement a low-noise amplifier(LNA)module before the envelope detection at the tag to enhance the incident signal strength.Our experimental results on the hardware platform show that our method can increase the downlink communication range by nearly 20 m.

Research on Three-Dimensional Simulation of the Internal Arc Gear Skiving

Aiming at the problems that the simulation accuracy which is reduced due to the simplification of the model,a three-dimensional simulation method based on solid modeling is being proposed.By analyzing the motion relationship and positional relationship between the caries knife and the workpiece,the coordinate system of the caries machining was established.With the MATLAB software,the cutting edge model and the blade sweeping surface model of the boring cutter are sequentially established.Boolean operation is performed on the blade swept surface formed by the tooth cutter teeth with time t and the workpiece tooth geometry as well as the undeformed three-dimensional chip geometry model and the instantaneous cogging geometry model are obtained at different times.Through the compare between gear end face simulation tooth profile and the theoretical inner arc tooth profile,we verified the accuracy and rationality of the proposed method.

Flip Chip技术在集成电路封装中的应用

阐述从集成电路封装发展现状、Flip Chip技术内涵、Flip Chip技术在集成电路封装中的应用剖析、市场发展展望等多个角度,探讨在集成电路封装中,应用Flip Chip技术的必要性和重要性。