An approach for determination of lateral limit angle in kinematic planar sliding analysis for rock slopes

Planar sliding is one of the frequently observed types of failure in rock slopes.Kinematic analysis is a classic and widely used method to examine the potential failure modes in rock masses.The accuracy of planar sliding kinematic analysis is significantly influenced by the value assigned to the lateral limit angleγlim.However,the assignment ofγlim is currently used generally based on an empirical criterion.This study aims to propose an approach for determining the value ofγlim in deterministic and probabilistic kinematic planar sliding analysis.A new perspective is presented to reveal thatγlim essentially influences the probability of forming a potential planar sliding block.The procedure to calculate this probability is introduced using the block theory method.It is found that the probability is correlated with the number of discontinuity sets presented in rock masses.Thus,different values ofγlim for rock masses with different sets of discontinuities are recommended in both probabilistic and deterministic planar sliding kinematic analyses;whereas a fixed value ofγlim is commonly assigned to different types of rock masses in traditional method.Finally,an engineering case was used to compare the proposed and traditional kinematic analysis methods.The error rates of the traditional method vary from 45%to 119%,while that of the proposed method ranges between 1%and 17%.Therefore,it is likely that the proposed method is superior to the traditional one.

Spatial variability of soil organic carbon in the forestlands of northeast China

Soil organic carbon （SOC） is an effective indicator of soil fertility and productivity, and it varies spatially and temporally in relation to other soil properties. Spatial variability of SOC in the forestlands of northeast China was characterized using geostatistics. Soil samples at the depths of 0-20 era, 20-40 cm and 40-60 cm were collected from six- ty-three temporary plots to evaluate SOC concentration and density （SOCD） and other soil properties. We analyzed correlations between SOC and soil properties. Soil organic carbon concentrations were high. The total amount of C stored in soil （0-60 cm） was 16.23 kg·m-2 with the highest SOCD of 7.98 kg·m-2 in topsoil. Soil properties in most cases differed by horizon, suggesting different processes and effects in each horizon. Soil organic carbon had positive relationships with total N, P and K as well as readily available K, but did not show a significant posi- tive correlation with available P. Spatial factors including elevation, slope and aspect affected SOC distribution. Soil organic carbon at 0-60 cm had strong spatial autocorrelation with nugget/sill ratio of 5.7%, and moderate structured dependence was found at 0-20 cm, which indicated the existence of a highly developed spatial structure. Spatial distributionsof SOC concentration and SOCD were estimated using regres- sion-kriging, with higher prediction accuracy than ordinary kriging. The fractal dimension of SOC indicated the preferential pattern of SOC dis- tribution, with the greatest spatial heterogeneity and strongest spatial dependence in the northeast-southwest direction.

Accuracy of preoperative serum CA19-9 levels in predicting the resectability of patients with pancreatic adenocarcinoma

Objective To assess the accuracy of preoperative serum CA19-9 levels in predicting the resectability of pancreatic adenocarcinoma.Methods Patients with biopsy-proven pancreatic adenocarcinoma who had preoperative serum CA19-9 level data were enrolled in the present retrospective analysis. Receiver operating characteristics(ROC) curve analysis was used to determine the optimal cut-off value of CA19-9. The sensitivity, specificity, positive predictive value, and negative predictive value were calculated at this cut-off point.Results Seventy-six patients with pancreatic adenocarcinoma that was considered potentially resectable according to radiological imaging were included. Of all 76 patients, 44 received complete resection of the pancreatic adenocarcinoma. The preoperative serum CA19-9 level was significantly higher in the unresectable tumor group than in the resectable tumor group(P = 0.0036). The area under the ROC curve was 0.749(95% confidence interval [CI]: 0.637–0.842). When the cut-off value of CA19-9 was set to 359.1 U/m L, the sensitivity, specificity, positive and negative predictive values were 71.9%(95% CI: 53.3%–86.3%), 70.5%(95% CI: 54.8%–83.2%), 63.9%(95% CI: 46.0%–79.4%), and 77.5%(95% CI: 61.5%–89.2%), respectively.Conclusion The preoperative serum CA19-9 level is useful for predicting the resectability of pancreatic adenocarcinoma.

AB035. Lactate receptor GPR81 modulates epigenetic modification in the subretina

Background:Retinal pigment epithelium(RPE)is vital for the homeostasis of the subretina including photoreceptors and choroid.Interestingly,our previous results suggested that the recently discovered lactate receptor GPR81 is abundantly expressed in RPE.To date,only one previous study has shown that activating GPR81 could enhance DNA repair by activating HDAC1.Consequently,we investigated whether GPR81 exhibits epigenetic modification in the subretina by using GPR81−/−mice.Methods:GPR81−/−mice and wide type littermates were generated on a background of C57BL/6J mice.The thicknesses of their choroid were evaluated by immunohistochemistry.Meanwhile,Q-PCR,western blot and choroid sprout assay were performed.In vitro,primary retinal pigment epithelium(pRPE)cells were isolated from mice,and cultured for treatments.Results:The thickness of choroid was reduced in GPR81−/−mice compared to GPR81+/+mice,suggesting that GPR81 is important for the integrity of choroid.In the choroid sprout assay,lactate treated RPE/choroid complex showed a significant increase in angiogenesis compared to controls while lactate treated KO RPE/choroid complex showed no difference compared to their controls.For Q-PCR,most of the genes screened elevated their expression in GPR81−/−mice compared to WT mice,suggesting epigenetic modification may exist,which were confirmed by histone acetylation and HDACs activity assay.Conclusions:Taking together,the lactate receptor GPR81 in RPE is very important for maintaining homeostasis of the subretina.This novel discovery sheds new light on the relationship between metabolism and epigenetic modification.

利润表研发费用列示方式改进与投资者投资判断——一项实验研究

为了提高会计信息质量,我国会计准则制定机构对利润表的格式进行了改进,其中一个重要的改变就是将研发费用从管理费用项目中分离出来单独列示。基于心理学的信息加工理论和实验研究方法,本文检验了研发费用列示方式、金额对投资者投资判断的影响。研究发现,在利润表单独列示研发费用的情况下,与低研发费用相比,在高研发费用的情况下,投资者判断的投资吸引力更大。研究还发现,当研发费用(金额)高时,与利润表中研发费用并入管理费用项目列示相比,研发费用单独列示情况下投资者判断的投资吸引力更大;当研发费用(金额)低时,与利润表中研发费用并入管理费用项目列示相比,研发费用单独列示的情况下投资者判断的投资吸引力更小。此外,研发费用列示方式对投资者判断的投资吸引力的影响,为投资者感知的研发费用信息明晰度和投资者感知的公司发展潜力所中介。

整合子系统介导沙门菌耐药性的研究进展

沙门菌(Salmonella spp.)是公共卫生学上具有重要意义的人畜共患病病原菌。人、畜感染沙门菌后会引起伤寒、副伤寒、胃肠炎、败血症和肠外局灶性感染等疾病。抗生素是治疗沙门菌严重感染的有效手段,随着临床和畜牧业中抗生素的大量使用,使得沙门菌的耐药情况日益严重。整合子是普遍存在于细菌中的一种可移动基因元件,可有效捕获外源基因确保其表达,并复合于转座子、质粒等,使多种耐药基因在细菌种内或者种间进行传播。在过去的二十年中,随着新基因盒和复杂整合子的不断出现,导致整合子系统迅速进化。整合子在沙门菌耐药性传播过程中具有非常重要的作用,因此,本文对整合子系统的分子结构、分类、作用机制,以及沙门菌中存在的Ⅰ、Ⅱ、Ⅲ类整合子介导的耐药性及现有检测方法的研究进展进行综述,以期为沙门菌耐药性研究提供参考。

基于“时间窗”的中西药注射剂序贯用药风险防控新策略

中药和西药联合使用在我国非常普遍,若不合理联用有可能引发严重不良反应,特别是中、西药注射剂联用是导致临床严重不良反应的重要因素之一.中、西药注射剂序贯使用时,是否要考虑用药间隔,是否可以通过建立安全用药“时间窗”避免中西药物相互作用,从而降低不良反应发生风险,值得深入研究.为此,本文以临床上不良反应报道较多的药物联用组合双黄连和利巴韦林注射剂为例,提出基于“时间窗”的中西药注射剂序贯用药风险防控的新设想.研究结果表明,给实验动物同时注射上述两种注射剂,可引起由补体系统成分C5介导的类过敏反应,而二者单独使用时类过敏反应均不明显.进一步对此药物组合不同时间间隔给药方案的考察表明,在4 h以内的不同时间间隔进行序贯给药,仍会引起明显的类过敏反应;而给药间隔超过6 h后类过敏反应则较不明显.进一步基于血清代谢组学分析,也证实了双黄连和利巴韦林注射剂的安全用药“时间窗上述研究结果提示,中、西药序贯使用所导致的药物不良反应确实存在“时间窗”现象,在“时间窗”之后间隔用药可显著降低不良反应发生风险,为提高中药和西药联合使用的安全用药水平提供了新的视角和思路.

An elderly female patient with ROS1 rearrangement primary lung adenocarcinoma and breast carcinoma:a rare case report and review of the literature

We report the case of a 90-year-old female patient who was suffering from c-ros oncogene 1(ros-1)rearrangement adenocarcinoma and breast cancer.After about 14 months of a reduced dose of crizotinib treatment,she had a stable disease according to the Response Evaluation Criteria in Solid Tumors version 1.1(RECIST 1.1).This patient’s case demonstrates that ros-1 rearrangements are not limited to patients of young age.In addition,this case indicates that crizotinib,as second-line,or even first-line,treatment may be effective and manageable in elderly patients.Furthermore,for elderly patients carrying a ros1 fusion,a reduced dose of crizotinib may be efficacious rather than a resistance factor.Based on our findings,we recommend that elderly patients with advanced lung adenocarcinoma should be considered for inclusion in molecular screening for ros-1 translocation,especially for never-smokers negative for epidermal growth factor receptor(egfr)mutation and the fusion between echinoderm microtubule associated protein-like 4(EML4)and anaplastic lymphoma kinase(ALK).This deserves attention because the population is aging,with increasing incidence and morbidity of multiple primary malignant tumors.Neglect of breast nodules at the onset is one of the limitations of our case,as combination of primary lung cancer with breast cancer is common.Above all,use of antiestrogens before and after the diagnosis of non-small-cell lung cancer is related to a reduced risk of lung cancer mortality.Therefore,careful attention should always be paid to these cases.

A CD44-biosensor for evaluating metastatic potential of breast cancer cells based on quartz crystal microbalance

A sensitive CD44-biosensor based on quartz crystal microbalance(QCM) was proposed for evaluating metastatic potential of breast cancer cells by using hyaluronan(HA) functionalized substrate film,polydopamine and polyethyleneimine composite film,for the purpose of capturing CD44-positive cancer cells through specific binding of HA to CD44.Two differently CD44-expressed breast cancer cell lines(MDAMB-231 cells and MCF-7 cells) were put to use as targets for quantitative analysis as well as evaluation of metastatic potential of the cells.The limit of detection for MDA-MB-231(M231) cells and MCF-7 cells were 300 and 1,000 cells mL ~1 respectively.The expression level of CD44 on M231 cells exhibited two times higher than that of MCF-7 cells,indicating of a higher metastatic potential.Moreover,poly-Llysine modified QCM sensor was applied to monitor the stiffness of breast cancer cells that can reflect metastatic potential of cells.The results revealed that the MCF-7 cells were stiffer than M231 cells,implying that the M231 cells possessed higher metastatic potential.The proposed protocol is simple and rapid to evaluate the metastatic potential of cancer cells,in addition to offering a promising diagnostic tool for metastatic cancer.

Disclosure of Critical Audit Matters,Audit Risk and Audit Opinion

We explore the association between the number of critical audit matters and auditing opinion based on the Chinese capital market data.In addition,we investigate the effect of audit risk on the relationship between the number of critical audit matters and auditing opinion.Using 6,662 firm-year observations listed in the Chinese capital market from 2017–2019,we find that the number of critical audit matters has significantly positive association with clear audit opinion.Specially,the greater the number of critical audit matters,the more likely getting clear audit opinion.We also find that the audit risk restricts the effect of the critical audit matters on the audit opinion.Lastly,we find that Big4 accounting firms are less likely to be influenced by the number of critical audit matters;the audit complexity restricts the effect of the critical audit matters on the audit opinion;the more board members,the less effect of the number of critical audit matters on the audit opinion.We also use several robustness tests to strengthen the conclusion.Our research may contribute to the understanding of the new audit standard.