Considering explosive charge shape and embedded depth in the design of concrete shelter thickness

Cost and safety are important considerations when designing the thickness of a protective reinforced concrete shelter.The blast perforation limit(BPL)is the minimum concrete shelter thickness that resists perforation under blast loading.To investigate the influence of the depth of embedment(DOE)and length-to-diameter ratio(L/D)of an explosive charge on the BPL,the results of an explosion test using a slender explosive partially embedded in a reinforced concrete slab were used to validate a refined finite element model.This model was then applied to conduct more than 300 simulations with strictly controlled variables,obtaining the BPLs for various concrete slabs subjected to charge DOEs ranging from0 to∞and L/D values ranging from 0.89 to 6.87.The numerical results were compared with the experimental results from published literature,further verifying the reliability of the simulation.The findings indicate that for the same explosive charge mass and L/D,the greater the DOE,the larger the critical residual thickness(Rc,defined as the difference between the BPL and DOE)up to a certain constant value;for the same explosive charge mass and DOE,the greater the L/D,the smaller the Rc.Thus,corresponding DOE and shape coefficients were introduced to derive a new equation for the BPL,providing a theoretical approach to the design and safety assessment of protective structures.

基于深度学习的卷烟高架库可视化盘点设备的研发

为了建设智慧物流,提高烟草企业高架库卷烟盘点效率,文中通过将3D体积测量技术与深度学习图像识别技术结合起来,研发了可视化盘点设备。该设备平均单件卷烟的盘点时长为1.6秒,相比传统盘点方式,盘点效率提升了650%,并且具有相当可观的经济效益,同时极大地提升了盘点工作的安全性。

一种利用大衍数列构造多码率原模图QC-LDPC码的方法

针对准循环低密度奇偶校验(Quasi-Cyclic Low-Density Parity-Check,QC-LDPC)码存在码长码率不能灵活选择的问题,提出了一种基于大衍数列构造多码率的原模图QC-LDPC码的新颖方法,该方法利用计算机搜索算法得到原模图基矩阵,然后基于大衍数列的循环移位矩阵对原模图基矩阵进行循环扩展,以此得到校验矩阵。该方法构造的校验矩阵围长至少为6,只需要简单的移位寄存器就可以实现编码,并且具有良好的纠错性能。仿真结果表明,在误码率(Bit Error Rate,BER)为10^(-6)时,所构造的码率为0.5的P-DY-QC-LDPC(4000,2000)码和码率为0.75的P-DY-QC-LDPC(4000,3000)码与同码率近似码长的其他码型相比较,其净编码增益均有一定提高。

不同火土灰用量对烟苗生长发育的影响

为明确火土灰对烟苗生长发育的影响,采用漂浮育苗的方式,研究不同含量火土灰育苗基质对烟苗叶绿素含量、根系构型、根系活力及硝酸还原酶活性的影响。结果表明,随育苗基质中火土灰比例升高烟苗叶绿素含量、总根长、根总表面积、根平均直径、根体积和根系活力呈现先升高后降低趋势,在50%火土灰+50%常规育苗基质处理条件下达到峰值;根系硝酸还原酶活性随基质中火土灰用量增加呈增加趋势;育苗基质中火土灰用量在50%以内时,火土灰用量与总根长、根总表面积极显著正相关,与根总体积显著正相关。可见,50%的火土灰和50%的常规育苗基质配比最有助于促进烟苗生长发育。

Dynamic responses of reinforced concrete beams under double-endinitiated close-in explosion

The reinforced concrete(RC) structural component might suffer a great damage under close-in explosion.Different from distant explosions, blast loads generated by the close-in explosion are non-uniformly distributed on the structural component and may cause both local and structural failure. In this study,an experimental study was conducted to investigate the dynamic responses of RC beams under doubleend-initiated close-in explosions. The experimental results show that the distribution of blast loads generated by the double-end-initiated explosion is much more non-uniform than those generated by single-point detonation, which is caused by the self-Mach-reflection effects. A 3 D finite element model was developed and validated in LS-DYNA by employing the modified K&C model. Intensive numerical calculations were conducted to study the influences of the initiation way, scaled distance and longitudinal reinforcement ratio on the dynamic responses and failure modes of RC beams. Numerical results show that the RC beam suffers greater damage as the cylindrical explosive is detonated at its double ends than the scenario in which the cylindrical explosive is detonated at its central point. RC beams mainly suffer flexural failure and flexure-shear failure under the double-end close-in explosion, and the failure modes of RC beams change from the flexural damage to flexure-shear damage as the scaled distance or the longitudinal reinforcement ratio decreases. The direct shear failure mode is not usually observed in the double-end-initiated explosion, since the intense blast loads is basically concentrated in the midspan of RC beam, which is due to self-Mach-reflection enhancement.

LIN28 expression and prognostic value in hepatocellular carcinoma patients who meet the Milan criteria and undergo hepatectomy

Stem cell marker LIN28,related closely with SOX2 and OCT4,has been studied as a biomarker for the maintainance of pluripotent cells in several malignancies.Our previous study showed that SOX2 and OCT4 were negative predictors for hepatocellular carcinoma(HCC).However,the predictive value of LIN28 in HCC outcome is still undetermined.We hypothesized that LIN28 may also play a role as a biomarker for HCC.To test this hypothesis,we examined the expression of LIN28 in 129 radically resected HCC tissues using reverse transcription-polymerase chain reaction and analyzed the association of LIN28 expression with clinicopathologic features and prognosis.Our study showed that LIN28 was expressed at a higher frequency in tumor tissues than in non-HCC tissues(45.0% vs.21.7%,P = 0.020).Moreover,LIN28 expression was significantly increased in cases with large tumor size(P = 0.010).Univariate analysis did not reveal a significant correlation between LIN28 expression and overall survival or recurrence-free survival.For HCC patients who met the Milan criteria,stratified analysis revealed shorter overall survival(P = 0.007) and recurrence-free survival(P < 0.001) in those with detectable LIN28 expression compared to those with no detectable LIN28 expression.Furthermore,multivariate analysis revealed that LIN28 was a negative independent predictor for both overall survival(hazard ratio= 7.093,P = 0.017) and recurrence-free survival(hazard ratio=5.518,P = 0.004) in patients who met the Milan criteria.Taken together,our results suggest that LIN28 identifies low-risk and high-risk subsets of HCC patients meeting the Milan criteria who undergo hepatectomy.

Numerical investigation on free air blast loads generated from center-initiated cylindrical charges with varied aspect ratio in arbitrary orientation

In current guidelines, the free air blast loads(overpressure and impulse) are determined by spherical charges, although most of ordnance devices are more nearly cylindrical than spherical in geometry. This may result in a great underestimation of blast loads in the near field and lead to an unsafe design.However, there is still a lack of systematic quantitative analysis of the blast loads generated from cylindrical charges. In this study, a numerical model is developed by using the hydrocode AUTODYN to investigate the influences of aspect ratio and orientation on the free air blast loads generated from center-initiated cylindrical charges. This is done by examining the pressure contours, the peak overpressures and impulses for various aspect ratios ranged from 1 to 8 and arbitrary orientation monitored along every azimuth angle with an interval of 5°. To characterize the distribution patterns of blast loads,three regions, i.e., the axial region, the vertex region and the radial region are identified, and the propagation of blast waves in each region is analyzed in detail. The complexity of blast loads of cylindrical charges is found to result from the bridge wave and its interaction with primary waves. Several empirical formulas are presented based on curve-fitting the numerical data, including the orientation where the maximum peak overpressure emerges, the critical scaled distance beyond which the charge shape effect could be neglected and blast loads with varied aspect ratio in arbitrary orientation, all of which are useful for blast-resistant design.

锁定钢板结合外展架治疗肱骨近端骨折的专项护理体会

肱骨近端骨折包括肱骨、肱骨颈及其以上部位的骨折,多由暴力导致,发生概率约占骨折的6%。而肱骨近端锁定钢板(locking proximal humeral,LPHP)作为AO/ASIF设计的具有全新理念的新一代接骨板系统在临床中广泛用于肱骨近端骨折患者。2016年1月~2019年12月,笔者采用LPHP结合外展架治疗68例肱骨近段骨折患者,期间严密观察病情,制定专项护理措施,做好体位护理,舒适护理,结合外展架的科学护理及功能锻炼指导,取得良好的效果和满意度,现报道如下。

Construction of miRNA-mRNA network reveals crucial miRNAs and genes in acute myocardial infarction

Acute myocardial infarction(AMI)is a severe cardiovascular disease.This study aimed to identify crucial microRNAs(miRNAs)and mRNAs in AMI by establishing a miRNA-mRNA network.The microarray datasets GSE31568,GSE148153,and GSE66360 were downloaded from the Gene Expression Omnibus(GEO)database.We identified differentially expressed miRNAs(DE-miRNAs)and mRNAs(DE-mRNAs)in AMI samples compared with normal control samples.The consistently changing miRNAs in both GSE31568 and GSE148153 datasets were selected as candidate DE-miRNAs.The interactions between the candidate DE-miRNAs and DE-mRNAs were analyzed,and a miRNA-mRNA network and a protein-protein interaction network were constructed,along with functional enrichment and pathway analyses.A total of 209 DE-miRNAs in the GSE31568 dataset,857 DE-miRNAs in the GSE148153 dataset,and 351 DE-mRNAs in the GSE66360 dataset were identified.Eighteen candidate DE-miRNAs were selected from both the GSE31568 and GSE148153 datasets.Furthermore,miR-646,miR-127-5p,miR-509-5p,miR-509-3-5p,and miR-767-5p were shown to have a higher degree in the miRNA-mRNA network.THBS-1 as well as FOS was a hub gene in the miRNA-mRNA network and the protein-protein interaction(PPI)network,respectively.CDKN1A was important in both miRNA-mRNA network and PPI network.We established a miRNA-mRNA network in AMI and identified five miRNAs and three genes,which might be used as biomarkers and potential therapeutic targets for patients with AMI.

Bio-compatibility and cytotoxicity studies of water-soluble CuInS_2-ZnS-AFP fluorescence probe in liver cancer cells

BACKGROUND： The oncogenesis of hepatocellular carcinoma（HCC） is not clear. The current methods of the pertinent studies are not precise and sensitive. The present study was to use liver cancer cell line to explore the bio-compatibility and cytotoxicity of ternary quantum dots（QDs） probe and to evaluate the possible application of QDs in HCC.METHODS： CuInS_2-ZnS-AFP fluorescence probe was designed and synthesized to label the liver cancer cell HepG 2. The cytotoxicity of CuInS_2-ZnS-AFP probe was evaluated by MTT experiments and flow cytometry. RESULTS： The labeling experiments indicated that CuInS_2-ZnS QDs conjugated with AFP antibody could enter HepG 2 cells effectively and emit intensive yellow fluorescence by ultraviolet excitation without changing cellular morphology. Toxicity tests suggested that the cytotoxicity of CuInS_2-ZnS-AFP probe was significantly lower than that of CdT e-ZnS-AFP probe（t test, F=0.8, T=-69.326, P〈0.001）. For CuInS_2-ZnS-AFP probe, timeeffect relationship was presented in intermediate concentration（〉20%） groups（P〈0.05） and dose-effect relationship was presented in almost all of the groups（P〈0.05）. CONCLUSION： CuInS_2-ZnS-AFP QDs probe had better biocompatibility and lower cytotoxicity compared with CdT e-ZnS-AFP probe, and could be used for imaging the living cells in vitro.

Ultrafast Infrared Spectroscopic Study of Microscopic Structural Dynamics in pH Stimulus-Responsive Hydrogels

Hydrogels show versatile properties and are of great interest in the fields of bioelectronics and tissue engineering.Understanding the dynamics of the water molecules trapped in the three-dimensional polymeric networks of the hydrogels is crucial to elucidate their mechanical and swelling properties at the molecular level.In this report,the poly(DMAEMA-co-AA)hydrogels were synthesized and characterized by the macroscopic swelling measurements under different pH conditions.Furthermore,the microscopic structural dynamics of pH stimulus-responsive hydrogels were studied using FTIR and ultrafast IR spectroscopies from the viewpoint of the SCN-anionic solute as the local vibrational reporter.Ultrafast IR spectroscopic measurements showed the time constants of the vibrational population decay of SCN-were increased from 14±1 ps to 20±1 ps when the pH of the hydrogels varied from2.0 to 12.0.Rotational anisotropy measurements further revealed that the rotation of SCNanionic probe was restricted by the three-dimensional network formed in the hydrogels and the rotation of SCN-anionic probe cannot decay to zero especially at the pH of 7.0.These results are expected to provide a molecular-level understanding of the microscopic structure of the cross-linked polymeric network in the pH stimulus-responsive hydrogels.

Metabolome profiling of stratified seeds provides insight into the regulation of dormancy in Davidia involucrata

Dove tree(Davidia involucrata),a tertiary vestige species,is well-adapted to cool conditions.Dormancy in D.involucrata seed lasts for an extremely long period of time,typically between 3 and 4 years,and this characteristic makes the species an excellent model for studying the mechanisms of seed dormancy.The molecular mechanisms governing germination control in D.involucrata are still unknown.Seed stratification have been reported to enhance germination in recalcitrant seeds.We performed a widely targeted metabolome profiling to identify metabolites and associated pathways in D.involucrata seeds from six different moist sand stratification durations(0-30 months) using the ultra-high-performance liquid chromatography-Q Exactive Orbitrap-Mass spectrometry.There was an increasing germination rate with prolonged stratification durations(12-30 months).Furthermore,we detected 10,008 metabolites in the stratified seeds.We also detected 48 differentially accumulated metabolites(DAMs) between all stratification periods in the seeds,with 10 highly conserved metabolites.Most of the differentially accumulated metabolites between unstratified and stratified seeds were enriched in purine metabolism,pyrimidine metabolism,flavone and flavonol biosynthesis,phenylpropanoid biosynthesis,and arginine biosynthesis pathways.Key phytohormones,abscisic acid,indole-3 acetic acid,and sinapic acid were differentially accumulated in the seeds and are predicted to regulate dormancy in D.involucrata.We have provided extensive metabolic information useful for future works on dove tree germination study.

Ⅰ期≤20 mm微小结节肺腺癌患者术后长期生存分析

目的:回顾性分析手术切除的直径≤20 mm的Ⅰ期微小结节肺腺癌患者的5年生存率,以及5年生存率与患者临床特征、影像学特点和干预方法间的关系。方法:收集2007年6月—2015年5月就诊的404例有高分辨CT(high resolutionCT,HRCT)图像、直径≤20mm、手术切除肺微小结节的肺癌患者进行研究。其中311例为Ⅰ期肺腺癌,直径≤10 mm的微结节患者102例,直径为11～20mm的小结节患者209例。分析患者的5年生存率与影像特点、临床特征和治疗方法的关系。结果:微小结节肺腺癌患者的5年生存率为97.7%,微结节和小结节肺腺癌患者的5年生存率分别为99.0%和97.2%。女性微小结节肺腺癌患者的5年生存率明显高于男性(98.4%vs 96.4%,P=0.042),吸烟微小结节肺腺癌患者的5年生存率低于不吸烟患者(92.3%vs 98.5%,P=0.019)。肺腺癌病理亚型、手术范围、有无淋巴结清扫和是否胸腔镜手术与患者的5年生存率无明显关系(P值均> 0.05)。结论:直径≤20 mm的Ⅰ期微小结节肺腺癌患者预后良好,男性和吸烟可能增加了患者的死亡风险。

2-强Gorenstein半单环上模的结构及其应用

研究了局部2-强Gorenstein半单环上任一模M的结构,证明了M可以唯一分解为不可分解模的直和。利用模M的直和分解,引入了有限生成模M的秩rank(M)的概念,证明了在有限局部2-强Gorenstein半单环上这样定义的秩就是线性码的信息位数。

防治烟草靶斑病复配增效配方筛选及田间防效

[目的]为控制湖南郴州烟区烟草靶斑病流行,筛选有效杀菌剂。[方法]通过菌丝生长速率和田间小区试验方法筛选了防治烟草靶斑病的高效配方药剂。[结果]11种化学杀菌剂和9种生物杀菌剂中咯菌腈和丁子香酚对烟草靶斑病菌抑制作用最强,EC_(50)值分别为0.057、1.087 mg/L。选择其中3种单剂复配,发现咯菌腈与丁子香酚复配比为1∶1时,增效效果最优,增效系数为3.06,田间试验发现该复配的相对防效为77.44%,高于单一药剂。[结论]该复配能够有效防治烟草靶斑病,并且减少化学农药用量。

Monoclonal antibody-based serological methods for detecting Citrus tristeza virus in citrus groves

Citrus tristeza virus （CTV） is one of the most economically important citrus viruses and harms the citrus industry worldwide. To develop reliable and effective serological detection assays of CTV, the major capsid protein （CP） gene of CTV was expressed in Escherichia coli BL21 （DE3） using the expression vector pET-28a and purified through Ni＊-NTA affinity chromatography. The recombinant protein was used to immunize BALB/c mice. Four hybridoma cell lines （14B10, 14Hll, 20D5, and 20G12） secreting monoclonal antibodies （MAbs） against CTV were obtained through conventional hybridoma technology. The titers of MAb-containing ascitic fluids secreted by the four hybridoma lines ranged from 10-6 to 10.7 in indirect enzyme-linked immunosorbent assay （ELISA）. Western blots showed that all four MAbs could specifically react with CTV CP. Using the prepared MAbs, dot-ELISA, Tissue print-ELISA, and triple antibody sandwich （TAS）-ELISA were developed to detect CTV in tree nurseries and epidemiological studies. The developed dot-ELISA and TAS-ELISA methods could detect CTV in crude extracts of infected citrus leaves with dilutions of 1：2560 and 1：10, 240 （w/v, g/mL）, respectively. Tissue print-ELISA was particularly useful for large-scale field sample detection, mainly owing to its simplicity and lack of sample preparation requirements. The field survey revealed that CTV is prevalent on citrus trees in the Chongqing Municipality, Jiangxi Province, and Zhejiang Province of China. The coincidence rate of serological and RT-PCR test results reached more than 99.5%. The prepared MAbs against CTV and established sensitive and specific serological assays have a significant role in the detection and prevention and control of CTV in our country.

Monoclonal Antibody-Based Serological Detection of Rice Stripe Mosaic Virus Infection in Rice Plants or Leafhoppers

Rice stripe mosaic virus(RSMV) is a rhabdovirus recently found in southern part of China and can cause severe reduction in rice production. To establish serological methods for RSMV epidemiological studies and to establish a control strategy for this virus, we first purified RSMV virions from infected rice plants and then used them as an immunogen to produce four RSMV-specific monoclonal antibodies(MAbs)(i.e.,1D4, 4A8, 8E4 and 11F11). With these MAbs, we have developed a highly specific and sensitive antigen-coated plate enzyme-linked immunosorbent assay(ACP-ELISA), a Dot-ELISA and a Tissue print-ELISA for rapid detections of RSMV infection in rice plants or in leafhoppers. Our results showed that RSMV can be readily detected in RSMV-infected rice plant tissue crude extracts diluted at 1:20,971,520(w/v, g/m L)through ACP-ELISA or diluted at 1:327,680(w/v, g/m L) through Dot-ELISA. Both ACP-ELISA and Dot-ELISA can also be used to detect RSMV infection in individual RSMV viruliferous leafhopper(Recilia dorsalis) homogenate diluted at 1:307,200 and 1:163,840(individual leafhopper/l L), respectively. Detection of RSMV infection in field-collected rice samples or in RSMV viruliferous leafhoppers indicated that the three serological methods can produce same results with that produced by RT-PCR(19 of the 33 rice samples and 5 of the 16 leafhoppers were RSMV-positive). We consider that the four MAbs produced in this study are very specific and sensitive, and the three new serological methods are very useful for detections of RSMV infection in rice plants or in leafhoppers and the establishment of the disease control strategies.

PREDICTION OF PROJECTILE PENETRATION AND PERFORATION BY FINITE CAVITY EXPANSION METHOD WITH THE FREE-SURFACE EFFECT

With a target treated as the incompressible Tresca and Mohr-Coulomb material, by assuming that cavity expansion produces plastic-elastic and plastic-cracked-elastic response region, the decay function for the free-surface effect is constructed for metal and geological tar- gets, respectively. The forcing function for oblique penetration and perforation is obtained by multiplying the forcing function derived on the basis of infinite target assumption with the de- cay function. Then the projectile is modeled with an explicit transient dynamic finite element code and the target is represented by the forcing function as the pressure boundary condition. This methodology eliminates discretizing the target as well as the need for a complex contact algorithm and is implemented in ABAQUS explicit solver via the user subroutine VDLOAD. It is found that the free-surface effect must be considered in terms of the projectile deformation, residual velocity, projectile trajectory, ricochet limits and critical reverse velocity. The numerical predictions are in good agreement with the available experimental data if the free-surface effect is taken into account.

Development of a colloidal gold-based immunochromatographic strip for rapid detection of Rice stripe virus

Rice stripe virus(RSV) causes dramatic losses in rice production worldwide. In this study, two monoclonal antibodies(MAbs) 16E6 and 11 C1 against RSV and a colloidal gold-based immunochromatographic strip were developed for specific, sensitive, and rapid detection of RSV in rice plant and planthopper samples. The MAb 16E6 was conjugated with colloidal gold and the MAb 11C1 was coated on the test line of the nitrocellulose membrane of the test strip. The specificity of the test strip was confirmed by a positive reaction to RSV-infected rice plants and small brown planthopper(SBPH), and negative reactions to five other rice viruses, healthy rice plants, four other vectors of five rice viruses, and non-viruliferous SBPH. Sensitivity analyses showed that the test strip could detect the virus in RSV-infected rice plant tissue crude extracts diluted to 1:20 480(w/v, g/mL), and in individual viruliferous SBPH homogenate diluted to 1:2560(individual SPBH/μL). The validity of the developed strip was further confirmed by tests using field-collected rice and SBPH samples. This newly developed test strip is a low-cost, fast, and easy-to-use tool for on-site detection of RSV infection during field epidemiological studies and paddy field surveys, and thus can benefit decision-making for RSV management in the field.

Nucleolar GTPase Bms1 displaces Ttf1 from RFB-sites to balance progression of rDNA transcription and replication

18S,5.8S,and 28S ribosomal RNAs(rRNAs)are cotranscribed as a pre-ribosomal RNA(pre-rRNA)from the rDNA by RNA polymerase I whose activity is vigorous during the S-phase,leading to a conflict with rDNA replication.This conflict is resolved partly by replication-fork-barrier(RFB)-sites sequences located downstream of the rDNA and RFB-binding proteins such as Ttf1.However,how Ttf1 is displaced from RFB-sites to allow replication fork progression remains elusive.Here,we reported that loss-of-function of Bms1l,a nucleolar GTPase,upregulates rDNA transcription,causes replication-fork stall,and arrests cell cycle at the S-to-G2 transition;however,the G1-to-S transition is constitutively active characterized by persisting DNA synthesis.Concomitantly,ubf,tif-IA,and taf1b marking rDNA transcription,Chk2,Rad51,and p53 marking DNA-damage response,and Rpa2,PCNA,Fen1,and Ttf1 marking replication fork stall are all highly elevated in bms1l mutants.We found that Bms1 interacts with Ttf1 in addition to Rc1l.Finally,we identified RFB-sites for zebrafish Ttf1 through chromatin immunoprecipitation sequencing and showed that Bms1 disassociates the Ttf1–RFB complex with its GTPase activity.We propose that Bms1 functions to balance rDNA transcription and replication at the S-phase through interaction with Rcl1 and Ttf1,respectively.TTF1 and Bms1 together might impose an S-phase checkpoint at the rDNA loci.