Cocrystallisation of high-energy oxidant ammonium dinitramide with triaminoguanidine nitrate for reduced hygroscopicity

In this work,we utilize a cocrystallization technique to solve the problem of high hygroscopicity of the high-energy oxidant ammonium dinitramide(ADN).For this purpose,a non-hygroscopic oxidant,triaminoguanidine nitrate(TAGN),is selected as the cocrystallization ligand.The ADN/TAGN system is simulated by using Material Studio 5.5 software,and the DFT of ADN and TAGN molecules are calculated by Gaussian09 software.The most stable molar ratio of the ADN/TAGN cocrystallization is determined to be 1:1,and the hydrogen bonding between the H atom of ADN and the O atom in the TAGN is the driving force for the formation of cocrystals in this system.Moreover,the electrostatic potential interaction pairing energy difference(ΔEpair)<0 kJ·mol^(-1)(-12.71 kJ·mol^(-1))for nADN:nTAGN=1:1 again indicates cocrystallization at this molar ratio.The crystal structure and crystal morphology is predicted.And the hygroscopicity of ADN/TAGN cocrystal at 20℃and 40%relative humidity is calculated to be only 0.45%.The mechanism of hygroscopicity is investigated by examining the roughness of each crystal surface.Overall,the more hygroscopic it is in terms of surface roughness,with the roughest crystal surface(012)having a hygroscopicity of 1.78,which corresponds to a saturated hygroscopicity of 0.61%.The results show that the(001)crystal surface has the smallest band gap(1.06 eV)and the largest sensitivity.Finally,the oxygen equilibrium value for the ADN/TAGN system is calculated to be-8.2%.

A Reliability Evaluation Method for Intermittent Jointed Rock Slope Based on Evolutionary Support Vector Machine

The randomness of rock joint development is an important factor in the uncertainty of geotechnical engineering stability.In this study,a method is proposed to evaluate the reliability of intermittent jointed rock slope.The least squares support vector machine(LSSVM)evolved by a bacterial foraging optimization algorithm(BFOA)is used to establish a response surface model to express the mapping relationship between the intermittent joint parameters and the slope safety factor.The training samples are obtained from the numerical calculation based on the joint finite element method during this process.Considering the randomness of the intermittent joint parameters in the actual project,each parameter is evaluated at different locations on the site,and its distribution characteristics are counted.According to these statistical results,a large number of parameter combinations are obtained through Monte Carlo sampling.The trained machine learning mapping model is used to obtain the slope safety factor corresponding to each group,and these results are then used to obtain the slope reliability.When the research results were applied to slope disaster treatment along the Yalu River in China’s Jilin Province,it was found that the joint length and joint inclination angle both play key roles in rock slope stability,which should receive more attention in the slope treatment.In summary,this study establishes a method for evaluating the reliability of intermittent jointed rock slope based on an evolutionary SVM model,and its feasibility is verified by engineering application.

Parameters Identification of Tunnel Jointed Surrounding Rock Based on Gaussian Process Regression Optimized by Difference Evolution Algorithm

Due to the geological body uncertainty,the identification of the surrounding rock parameters in the tunnel construction process is of great significance to the calculation of tunnel stability.The ubiquitous-joint model and three-dimensional numerical simulation have advantages in the parameter identification of surrounding rock with weak planes,but conventional methods have certain problems,such as a large number of parameters and large time consumption.To solve the problems,this study combines the orthogonal design,Gaussian process(GP)regression,and difference evolution(DE)optimization,and it constructs the parameters identification method of the jointed surrounding rock.The calculation process of parameters identification of a tunnel jointed surrounding rock based on the GP optimized by the DE includes the following steps.First,a three-dimensional numerical simulation based on the ubiquitous-joint model is conducted according to the orthogonal and uniform design parameters combing schemes,where the model input consists of jointed rock parameters and model output is the information on the surrounding rock displacement and stress.Then,the GP regress model optimized by DE is trained by the data samples.Finally,the GP model is integrated into the DE algorithm,and the absolute differences in the displacement and stress between calculated and monitored values are used as the objective function,while the parameters of the jointed surrounding rock are used as variables and identified.The proposed method is verified by the experiments with a joint rock surface in the Dadongshan tunnel,which is located in Dalian,China.The obtained calculation and analysis results are as follows:CR=0.9,F=0.6,NP=100,and the difference strategy DE/Best/1 is recommended.The results of the back analysis are compared with the field monitored values,and the relative error is 4.58%,which is satisfactory.The algorithm influencing factors are also discussed,and it is found that the local correlation coefficientσf and noise standard deviationσn affected the prediction accuracy of the GP model.The results show that the proposed method is feasible and can achieve high identification precision.The study provides an effective reference for parameter identification of jointed surrounding rock in a tunnel.

1990-2019年中国霍奇金淋巴瘤流行趋势和疾病负担分析

目的分析1990—2019年中国霍奇金淋巴瘤的流行趋势和疾病负担。方法利用2019年全球疾病负担研究(Global Burden of Disease 2019,GBD 2019)数据,采用发病率、死亡率、伤残调整寿命年(disability-adjusted life year,DALY)、早死所致的寿命损失年(years of life lost,YLL)、伤残所致的健康寿命损失年(years lived with disability,YLD)及其标化率,对1990—2019年中国霍奇金淋巴瘤的流行趋势和疾病负担进行分析。结果1990—2019年中国霍奇金淋巴瘤新发病例数由0.66万上升至0.95万,增幅达42.68%,总体上标化发病率由0.65/10万降至0.57/10万,降幅达11.12%,但自2006年起有所反弹;死亡例数与标化死亡率呈下降趋势,降幅分别达45.30%、72.00%;除YLD标化率增加66.77%外,DALY标化率、YLL标化率均呈下降趋势,降幅分别为73.31%、74.82%。不同性别人群发病率、死亡率和DALY率随年龄增长均呈上升趋势,但男性发病率、死亡率和DALY率均高于女性。结论1990—2019年,我国霍奇金淋巴瘤发病率先下降后上升,死亡率和DALY率呈不断下降趋势,男性和老年人是霍奇金淋巴瘤疾病负担的高危人群。

First complete genome sequence in Arborophila and comparative genomics reveals the evolutionary adaptation of Hainan Partridge(Arborophila ardens)

Background:The Hainan Partridge(Arborophila ardens,Phasianidae,Galliformes) is an endemic species of Hainan Island,China,and it is classified as globally vulnerable species.There are at least 16 species in genus Arborophila and no genome sequence is available.Methods:The whole genome of Hainan Partridge was de novo sequenced(with shotgun approach on the Illumina 2000 platform) and assembled.Results:The genome size of Arborophila ardens is about 1.05 Gb with a high N50 scaffold length of 8.28 Mb and it is the first high quality genome announced in Arborophila genus.About 9.19% of the genome was identified as repeat sequences and about 5.88 million heterozygous SNPs were detected.A total of 17,376 protein-coding genes were predicted and their functions were annotated.The genome comparison between Hainan Partridge and Red Junglefowl(Gallus gallus) demonstrated a conserved genome structure.The phylogenetic analysis indicated that the Hainan Partridge possessed a basal phylogenetic position in Phasianidae and it was most likely derived from a common ancestor approximately 36.8 million years ago(Mya).We found that the Hainan Partridge population had experienced bottleneck and its effective population decreased from about 1,040,000 individuals 1.5 Mya to about 200,000 individuals 0.2 Mya,and then recovered to about 460,000 individuals.The number of 1:1 orthologous genes that were predicted to have undergone positive selection in the Hainan Partridge was 504 and some environmental adaptation related categories,such as response to ultraviolet radiation were represented in GO distribution analysis.Conclusions:We announced the first high quality genome in Arborophila genus and it will be a valuable genomic resource for the further studies such as evolution,adaption,conservation,not only on Hainan Partridge but also on Arborophila or Phasianidae species.

Bilingual’s Advantages of not Using Mutual Exclusivity

It is a known fact that monolingual children will take advantage of the principle of mutual exclusivity(ME)in the process of early word learning,i.e.,the names of two different objects are mutually exclusive(one label for one referent).With the help of ME,they can expand their vocabulary effectively with a rapid speed.However,for bilingual children,it seems this principle is not that friendly to them,since they are exposed to two languages at the same time,so there could be at least two labels for the same referent.Hence bilingual children may be confused and encounter difficulties in learning words,which will slower their word learning process.This paper tries to,based on earlier research,probe into the question that how bilingual children acquire words without the help of ME,and explore whether there are advantages of not using ME in word learning for bilingual children.

Genetic lineage tracing identifies adaptive mechanisms of pancreatic islet β cells in various mouse models of diabetes with distinct age of initiation

During the pathogenesis of type 1 diabetes(T1D) and type 2 diabetes(T2D), pancreatic islets, especially the β cells, face significant challenges. These insulin-producing cells adopt a regeneration strategy to compensate for the shortage of insulin, but the exact mechanism needs to be defined. High-fat diet(HFD) and streptozotocin(STZ) treatment are well-established models to study islet damage in T2D and T1D respectively. Therefore, we applied these two diabetic mouse models, triggered at different ages, to pursue the cell fate transition of isletβ cells. Cre-LoxP systems were used to generate islet cell type-specific(α, β, or δ) green fluorescent protein(GFP)-labeled mice for genetic lineage tracing, thereinto β-cell GFP-labeled mice were tamoxifen induced. Single-cell RNA sequencing(scRNA-seq) was used to investigate the evolutionary trajectories and molecular mechanisms of the GFP-labeled β cells in STZ-treated mice. STZ-induced diabetes caused extensive dedifferentiation of β cells and some of which transdifferentiated into α or δ cells in both youth-and adulthood-initiated mice while this phenomenon was barely observed in HFD models. β cells in HFD mice were expanded via self-replication rather than via transdifferentiation from α or δ cells, in contrast, α or δ cells were induced to transdifferentiate into β cells in STZ-treated mice(both youthand adulthood-initiated). In addition to the re-dedifferentiation of β cells, it is also highly likely that these “α or δ” cells transdifferentiated from pre-existing β cells could also re-trans-differentiate into insulin-producing β cells and be beneficial to islet recovery. The analysis of ScRNA-seq revealed that several pathways including mitochondrial function, chromatin modification, and remodeling are crucial in the dynamic transition of β cells. Our findings shed light on how islet β cells overcome the deficit of insulin and the molecular mechanism of islet recovery in T1D and T2D pathogenesis.

强化玉米饮食对小鼠肠道菌群结构和功能的影响

【目的】采用高通量测序方法研究强化玉米饮食对小鼠肠道菌群结构的影响以及可提高宿主糖代谢相关菌群功能基因的分析。【方法】分别给予两组小鼠(各10只)常规饮食和强化玉米饮食(1/4的玉米粉加3/4的常规饮食成分),喂养10周,之后采集小鼠粪便样本,提取DNA,使用高通量测序仪进行宏基因组测序分析,比较两组小鼠肠道菌群和功能基因的差异。【结果】两组小鼠的终末体重没有明显差异。各样本DNA的测序有效率足够,肠道菌群的多样性存在一定差异。属放线菌门(Actinobacteria)的双歧杆菌(Bifidobacteriales)-B.pseudolongum分支和Coriobacteriia-Collinsella/Enterorhabdus分支的丰度在强化玉米饮食组的小鼠中显著升高,相应的宏基因组中涉及糖酵解和胆汁酸合成的一些酶和功能单元的含量也在强化玉米饮食组显著升高。【结论】强化玉米饮食可以提高肠道菌群中双歧杆菌等益生菌的丰度,增加宏基因组糖脂代谢相关基因和通路的含量,从而可能促进宿主的糖代谢功能。

Deep learning applied to two-dimensional color Doppler flow imaging ultrasound images significantly improves diagnostic performance in the classification of breast masses:a multicenter study

Background:The current deep learning diagnosis of breast masses is mainly reflected by the diagnosis of benign and malignant lesions.In China,breast masses are divided into four categories according to the treatment method:inflammatory masses,adenosis,benign tumors,and malignant tumors.These categorizations are important for guiding clinical treatment.In this study,we aimed to develop a convolutional neural network(CNN)for classification of these four breast mass types using ultrasound(US)images.Methods:Taking breast biopsy or pathological examinations as the reference standard,CNNs were used to establish models for the four-way classification of 3623 breast cancer patients from 13 centers.The patients were randomly divided into training and test groups(n=1810 vs.n=1813).Separate models were created for two-dimensional(2D)images only,2D and color Doppler flow imaging(2D-CDFI),and 2D-CDFI and pulsed wave Doppler(2D-CDFI-PW)images.The performance of these three models was compared using sensitivity,specificity,area under receiver operating characteristic curve(AUC),positive(PPV)and negative predictive values(NPV),positive(LR+)and negative likelihood ratios(LR-),and the performance of the 2D model was further compared between masses of different sizes with above statistical indicators,between images from different hospitals with AUC,and with the performance of 37 radiologists.Results:The accuracies of the 2D,2D-CDFI,and 2D-CDFI-PW models on the test set were 87.9%,89.2%,and 88.7%,respectively.The AUCs for classification of benign tumors,malignant tumors,inflammatory masses,and adenosis were 0.90,0.91,0.90,and 0.89,respectively(95%confidence intervals[CIs],0.87-0.91,0.89-0.92,0.87-0.91,and 0.86-0.90).The 2D-CDFI model showed better accuracy(89.2%)on the test set than the 2D(87.9%)and 2D-CDFI-PW(88.7%)models.The 2D model showed accuracy of 81.7%on breast masses≤1 cm and 82.3%on breast masses>1 cm;there was a significant difference between the two groups(P<0.001).The accuracy of the CNN classifications for the test set(89.2%)was significantly higher than that of all the radiologists(30%).Conclusions:The CNN may have high accuracy for classification of US images of breast masses and perform significantly better than human radiologists.Trial registration:Chictr.org,ChiCTR1900021375;http://www.chictr.org.cn/showproj.aspx?proj=33139.

The heterogeneity of islet autoantibodies and the progression of islet failure in type 1 diabetic patients

Type 1 diabetes mellitus is heterogeneous in many facets. The patients suffered from type 1 diabetes present several levels of islet function as well as variable number and type of islet-specific autoantibodies. This study was to investigate prevalence and heterogeneity of the islet autoantibodies and clinical phenotypes of type 1 diabetes mellitus; and also discussed the process of islet failure and its risk factors in Chinese type 1 diabetic patients. A total of 1,291 type 1 diabetic patients were enrolled in this study. Demographic information was collected. Laboratory tests including mixed-meal tolerance test, human leukocyte antigen alleles, hemoglobin A1 c, lipids, thyroid function and islet autoantibodies were conducted. The frequency of islet-specific autoantibody in newly diagnosed T1 DM patients(duration shorter than half year) was 73% in East China. According to binary logistic regressions, autoantibody positivity, longer duration and lower Body Mass Index were the risk factors of islet failure. As the disease developed, autoantibodies against glutamic acid decarboxylase declined as well as the other two autoantibodies against zinc transporter 8 and islet antigen 2. The decrease of autoantibodies was positively correlated with aggressive beta cell destruction. Autoantibodies can facilitate the identification of classic T1 DM from other subtypes and predict the progression of islet failure. As there were obvious heterogeneity in autoantibodies and clinical manifestation in different phenotypes of the disease, we should take more factors into consideration when identifying type 1 diabetes mellitus.

TwoMADS-boxgenes regulate vascularcambium activity and secondary growth by modulating auxin homeostasis in Populus

In trees,stem secondary growth depends on vascular cambium proliferation activity and subsequent cell differentiation,in which an auxin concentration gradient across the cambium area plays a crucial role in regulating the process.However,the underlying molecular mechanismfor the establishment of auxin concentration is not fully understood.In this study,we identified two function-unknown MADS-box genes,VCM1 and VCM2,which are expressed specifically in the vascular cambium and modulate the subcellular homeostasis of auxin.Simultaneous knockdown of both VCM1 and VCM2 enhanced vascular cambium proliferation activity and subsequent xylem differentiation.Overexpression of VCM1 suppressed vascular cambium activity and wood formation by regulating PIN5 expression,which tuned the soluble auxin concentration in the vascular cambium area.This study reveals the role of VCM1 and VCM2 in regulating the proliferation activity of the vascular cambium and secondary growth by modulating the subcellular auxin homeostasis in Populus.

汇流旋涡临界贯穿条件与Ekman抽吸演化机理（英文）

目的:提出一种自由汇流旋涡形成过程建模求解方法,得到其临界贯穿条件,并揭示其Ekman边界层抽吸演化机理。创新点:1.基于二维Rankine位势涡理论,建立自由汇流旋涡动力学模型,得到其压力、速度分布;2.提出一种基于Helmholtz方程的汇流旋涡贯穿临界条件求解方法;3.成功搭建一种基于双目内窥技术的汇流旋涡观测实验平台,可实现对旋涡贯穿及Ekman抽吸过程的精确观测。方法:1.将汇流旋涡定义为涡核与核外流两部分,并基于Bernoulli方程与Lamb-ΓΡΟΜΕΚΟ方程得到汇流旋涡界面形状及压力、速度分布;2.基于上述动力学模型,结合Helmholtz涡量动力学方程,利用分离变量积分方法,得到旋涡形成轴向速度与深度的解析关系表达式;3.基于粒子图像测速(PIV)方法,结合双目内窥技术,实现对汇流旋涡临界贯穿与边界层抽吸的流动细节特征的实时追踪。结论:1.汇流旋涡临界贯穿条件是一个解集,这是由不同的流场初始扰动条件造成的;2.旋涡抽吸孔最低点的高度由容器的几何参数决定,与初始扰动速度无关;3.若初始扰动增强,旋涡深度与Ekman层厚度增加,但在抽吸过程中的边界层涡量强度有减弱趋势;4.PIV实验验证了上述理论结果的正确性,并观测到旋涡半径边界与涡量集聚现象。

Critical tectonic events and their geological controls on deep buried coalbed methane accumulation in Daning-Jixian Block, eastern Ordos Basin

Commercial exploration and development of deep buried coalbed methane (CBM) in Daning-Jixian Block, eastern margin of Ordos Basin, have rapidly increased in recent decades. Gas content, saturation and well productivity show significant heterogeneity in this area. To better understand the geological controlling mechanism on gas distribution heterogeneity, the burial history, hydrocarbon generation history and tectonic evolution history were studied by numerical simulation and experimental simulation, which could provide guidance for further development of CBM in this area. The burial history of coal reservoir can be classified into six stages, i.e., shallowly buried stage, deeply burial stage, uplifting stage, short-term tectonic subsidence stage, large-scale uplifting stage, sustaining uplifting and structural inversion stage. The organic matter in coal reservoir experienced twice hydrocarbon generation. Primary and secondary hydrocarbon generation processes were formed by the Early and Middle Triassic plutonic metamorphism and Early Cretaceous regional magmatic thermal metamorphism, respectively. Five critical tectonic events of the Indosinian, Yanshanian and Himalayan orogenies affect different stages of the CBM reservoir accumulation process. The Indosinian orogeny mainly controls the primary CBM generation. The Yanshanian Orogeny dominates the second gas generation and migration processes. The Himalayan orogeny mainly affects the gas dissipation process and current CBM distribution heterogeneity.

Analysis of the correlation between the longitudinal trajectory of SOFA scores and prognosis in patients with sepsis at 72 hour after admission based on group trajectory modeling

Background:To identify the distinct trajectories of the Sequential Organ Failure Assessment(SOFA)scores at 72 h for patients with sepsis in the Medical Information Mart for Intensive Care(MIMIC)-IV database and determine their effects on mortality and adverse clinical outcomes.Methods:A retrospective cohort study was carried out involving patients with sepsis from the MIMIC-IV database.Group-based trajectory modeling(GBTM)was used to identify the distinct trajectory groups for the SOFA scores in patients with sepsis in the intensive care unit(ICU).The Cox proportional hazards regression model was used to investigate the relationship between the longitudinal change trajectory of the SOFA score and mortality and adverse clinical outcomes.Results:A total of 16,743 patients with sepsis were included in the cohort.The median survival age was 66 years(interquartile range:54-76 years).The 7-day and 28-day in-hospital mortality were 6.0%and 17.6%,respectively.Five different trajectories of SOFA scores according to the model fitting standard were determined:group 1(32.8%),group 2(30.0%),group 3(17.6%),group 4(14.0%)and group 5(5.7%).Univariate and multivariate Cox regression analyses showed that,for different clinical outcomes,trajectory group 1 was used as the reference,while trajectory groups 2-5 were all risk factors associated with the outcome(P<0.001).Subgroup analysis revealed an interaction between the two covariates of age and mechanical ventilation and the different trajectory groups of patients’SOFA scores(P<0.05).Conclusion:This approach may help identify various groups of patients with sepsis,who may be at different levels of risk for adverse health outcomes,and provide subgroups with clinical importance.

Geochemical characteristics of produced fluids from CBM wells and their indicative significance for gas accumulation in Daning-Jixian block,Ordos Basin

The Daning-Jixian block,the eastern edge of the Ordos Basin,is one of the most potential areas for CO_(2)geological storage,enhanced coalbed methane recovery(ECBM)exploration and production in China in recent decades.The ionic composition and total dissolved solids(TDS)of the produced water,coal organic matter maturity,molecular composition and carbon isotope characteristics of the produced gas were utilized to analyze the hydrogeological condition,CBM generation and migration characteristics in this area.The CBM enrichment patterns and the geological impacts on gas well production characteristics were revealed.The optimal area for CBM development and CO_(2)geological storage in the study area were also proposed.Dominated by the Xueguan reverse fault zone,the hydraulic unit in this area can be divided into two parts(i.e.,the recharge-runoff zone in the east and the weak runoff-stagnation zone in the west).The thermogenic gas is dominating CBM genesis in this area.Secondary biogenic gas replenishment is only distributed in the eastern margin area,where theδ13C1 value is less than the thermal simulation results as an influence of hydrodynamic fractionation.Finally,two models of CBM formation and accumulation were proposed,1)thermogenic CBM migrated by hydrodynamic and resorbed for preservation at impermeable fault boundaries;2)thermogenic CBM trapped by fault and accumulated by hydrodynamic in slope zone.The gas production performance,generally increased from east to west,is mainly dominated by hydrogeological conditions.Generally,the west side of the fault zone is the enrichment and high-yield area for ECBM development and CO_(2)geological storage in the study area.

Sequence variability analysis on major histocompatibility complex class Ⅱ DRB alleles in three felines

The variation of the exon 2 of the major histo-compatibility complex(MHC)class II gene DRB locus in three feline species were examined on clouded leopard(Neofelis nebulosa),leopard(Panthera pardus)and Amur tiger(Panthera tigris altaica).A pair of degenerated primers was used to amplify DRB locus covering almost the whole exon 2.Exon 2 encodes theβ1 domain which is the most vari-able fragments of the MHC class II molecule.Single-strand conformational polymorphism(SSCP)analysis was applied to detect different MHC class II DRB haplotypes.Fifteen recombinant plasmids for each individual were screened out,isolated,purified and sequenced finally.Totally eight distinct haplotypes of exon 2 were obtained in four individuals.With-in 237 bp nucleotide sequences from four samples,30 vari-able positions were found,and 21 putative peptide-binding positions were disclosed in 79 amino acid residues.The ratio of nonsynonymous substitutions(d_(N))was much higher than that of synonymous substitutions(d_(S)),which indicated that balancing selection probably maintain the variation of exon 2.MEGA neighbor joining(NJ)and PAUP maximum parsimo-ny(MP)methods were used to reconstruct phylogenetic trees among species,respectively.Results displayed a more close relationship between leopard and tiger;however,clouded leopard has a comparatively distant relationship form the other two.