An overview of additively manufactured metal matrix composites:preparation,performance,and challenge

Metal matrix composites(MMCs)are frequently employed in various advanced industries due to their high modulus and strength,favorable wear and corrosion resistance,and other good properties at elevated temperatures.In recent decades,additive manufacturing(AM)technology has garnered attention as a potential way for fabricating MMCs.This article provides a comprehensive review of recent endeavors and progress in AM of MMCs,encompassing available AM technologies,types of reinforcements,feedstock preparation,synthesis principles during the AM process,typical AM-produced MMCs,strengthening mechanisms,challenges,and future interests.Compared to conventionally manufactured MMCs,AM-produced MMCs exhibit more uniformly distributed reinforcements and refined microstructure,resulting in comparable or even better mechanical properties.In addition,AM technology can produce bulk MMCs with significantly low porosity and fabricate geometrically complex MMC components and MMC lattice structures.As reviewed,many AM-produced MMCs,such as Al matrix composites,Ti matrix composites,nickel matrix composites,Fe matrix composites,etc,have been successfully produced.The types and contents of reinforcements strongly influence the properties of AM-produced MMCs,the choice of AM technology,and the applied processing parameters.In these MMCs,four primary strengthening mechanisms have been identified:Hall–Petch strengthening,dislocation strengthening,load transfer strengthening,and Orowan strengthening.AM technologies offer advantages that enhance the properties of MMCs when compared with traditional fabrication methods.Despite the advantages above,further challenges of AM-produced MMCs are still faced,such as new methods and new technologies for investigating AM-produced MMCs,the intrinsic nature of MMCs coupled with AM technologies,and challenges in the AM processes.Therefore,the article concludes by discussing the challenges and future interests of AM of MMCs.

PdCu alloy anchored defective titania for photocatalytic conversion of carbon dioxide into methane with 100% selectivity

The photoreduction of CO_(2)into CH_(4)with simultaneous high activity and selectivity is a promising strategy to increase energy supply and alleviate global warming.However,the absence of the active sites that is responsible for the adsorption and activation of CO_(2)and the generation of CO and H2via side reactions often lead to poor efficiency and low selectivity of the catalyst.Herein,Cu,Pd,and PdCu metal clusters cocatalyst-anchored defective TiO_(2)nanotubes(Cu/TiO_(2)-SBO,Pd/TiO_(2)-SBO,and Pd1Cu1/TiO_(2)-SBO)were designed via a simple solution impregnation reduction and applied for photocatalytic conversion of CO_(2)to CH_(4).The Pd1Cu1/TiO_(2)-SBO photocatalyst exhibits excellent catalytic performance among the other catalysts for photoreduction of CO_(2)into CH_(4).More interestingly,the product selectivity of CH_(4)reaches up to 100%with a rate of 25μmol g^(-1)h^(-1).In-situ diffuse reflectance infrared Fourier transform spectroscopy(DRIFTS)and density functional theory(DFT)simulations indicate that the main reasons for the high selectivity of CH_(4)are attributed to the PdCu alloy and oxygen vacancies,which jointly enhance the photoinduced carrier separation and lower energy barriers of key intermediates.Moreover,due to the tunable d-band center of the Cu site in the PdCu alloy,the generated intermediates can be well prevented from poisoning and promoted to participate in further reactions.Hopefully,the current study will provide insight into the development of new,highly selective photocatalysts for the visible light-catalytic reduction of CO_(2)into CH_(4).

Disseminated tumor cells in bone marrow as predictive classifiers for small cell lung cancer patients

Background: Small cell lung cancer (SCLC) is a highly aggressive disease characterized by early metastasis. Ane- uploid CD31- disseminated tumor cells (DTCs) and CD31+ disseminated tumor endothelial cells (DTECs) residing in the bone marrow are generally considered as the initiators of metastatic process. However, the clinical signifi- cance of DTCs and DTECs in SCLC remains poorly understood. The aim of this study is to investigate the clinical implications of diverse subtypes of highly heterogeneous DTCs and DTECs in SCLC patients. Methods: Subtraction enrichment and immunostaining-fluorescence in situ hybridization (SE-iFISH) was applied to enrich and perform comprehensive morphologic, karyotypic, and phenotypic characterization of aneuploid DTCs and DTECs in 30 patients. Additionally, co-detection of circulating tumor cells (CTCs) and circulating tumor endothelial cells (CTECs) was conducted on 24 of the enrolled patients. Proof-of-concept of the whole exon sequencings (WES) on precisely selected different subtypes of CTCs or DTCs, longitudinally detected from a representative case with pathologically confirmed bone marrow metastasis, was validated to feasibly reveal genetic mutations in these cells. Results: DTCs, DTECs and their subtypes were readily detectable in SCLC patients. Comparative analysis re- vealed that the number of DTCs and DTECs was significantly higher than that of their corresponding CTCs and CTECs ( P < 0.001 for both). Positive detection of disseminated tumor microemboli (DTM) or disseminated tumor endothelial microemboli (DTEM) was associated with inferior survival outcomes ( P = 0.046 and P = 0.048). Pa- tients with EpCAM+ DTCs detectable displayed significantly lower disease control rate (DCR) (16.67% vs 73.33%, P = 0.019), reduced median progression-free survival (mPFS) and median overall survival (mOS) compared with those with EpCAM- DTCs ( P = 0.028 and P = 0.002, respectively). WES analysis indicated that post-treatment DTCs isolated from bone marrow at the time of disease progression shared more homologous somatic gene mu- tations with pre-treatment CTCs compared with post-treatment CTCs. Conclusions: Our findings suggest that bone marrow sampling and characterization of DTC subtypes provided a valuable tool for predicting treatment response and the prognosis in SCLC. Moreover, DTCs inherit a greater amount of homologous somatic information from pre-treatment CTCs, indicating their potential role in disease progression and treatment resistance.

Breeding and Cultivation Techniques of Zhangzagu No.24

[Objectives]This study was conducted to further enhance the disease resistance of summer-sown hybrid millet varieties and improve the quality of millet.[Methods]Zhangzagu No.24 was bred by Zhangjiakou Academy of Agricultural Sciences with sterile line A2 as the female parent and"5170"as the male parent.[Results]The growth period for summer sowing of Zhangzagu No.24 is 88 d.The seedlings are green and have green leaf sheaths.The plant height is 110 cm.The panicles are 26 cm in length,in a stick panicle type,and moderate in tightness.The single panicle weight is 15.3 g,and the grain weight per panicle is 12.9 g.The grain yield is 84.2%,and the milled rice rate is 78.2%.The 1000-grain weight is 3.11 g.Zhangzagu No.24 shows yellow grains and yellow rice.There is one or two tillers per plant.Zhangzagu No.24 is resistant to herbicide sethoxydim.It obtained the registration certificate for non-main crop varieties,registration number:GPD millet(2018)130194.[Conclusions]This study will contribute to the development of water-saving,high-efficiency and green industrialization of hybrid millet in summer sowing areas in China.

The Breeding and Cultivation Techniques of Zhangzagu No.22

Zhangzagu No.22 was a new high-quality millet cultivar adapted to the climate characteristics of the summer sowing areas,which was selected by the Zhangjiakou Academy of Agricultural Sciences with sterile line A2 as the female parent and‘32×ISE375×Xia1 father’as the male parent.Zhangzagu No.22 has a growth period of 88 d in summer,and exhibits green seedlings,spindle-shaped panicles,a plant height of 135-145 cm,a panicle length of 23-28 cm,a grain weight per panicle of 18-22 g,a 1000-grain weight of 2.90 g,yellow rice,and resistance to herbicide Nabujing.In 2018,it passed the registration of non-major crop varieties by the Ministry of Agriculture,with the registration number:GPD Millet(2018)130193.This study introduced the breeding process,variety characteristics and related cultivation techniques of Zhangzagu No.22.

Transparent,Ultra-Stretching,Tough,Adhesive Carboxyethyl Chitin/Polyacrylamide Hydrogel Toward High-Performance Soft Electronics

To date,hydrogels have gained increasing attentions as a flexible conductive material in fabricating soft electronics.However,it remains a big challenge to integrate multiple functions into one gel that can be used widely under various conditions.Herein,a kind of multifunc-tional hydrogel with a combination of desirable characteristics,including remarkable transparency,high conductivity,ultra-stretchability,tough-ness,good fatigue resistance,and strong adhesive ability is presented,which was facilely fabricated through multiple noncovalent crosslinking strategy.The resultant versatile sensors are able to detect both weak and large deformations,which owns a low detection limit of 0.1%strain,high stretchability up to 1586%,ultrahigh sensitivity with a gauge factor up to 18.54,as well as wide pressure sensing range(0-600 kPa).Meanwhile,the fabrication of conductive hydrogel-based sensors is demonstrated for various soft electronic devices,including a flexible human-machine interactive system,the soft tactile switch,an integrated electronic skin for unprecedented nonplanar visualized pressure sensing,and the stretchable triboelectric nanogenerators with excellent biomechanical energy harvesting ability.This work opens up a simple route for multifunctional hydrogel and promises the practical application of soft and self-powered wearable electronics in various complex scenes.

EVA-g-MAH聚合物降凝剂的制备及性能

为减少原油运输的能耗,结合大庆高蜡原油的特点,以偶氮二异丁腈(AIBN)为引发剂,采用溶液接枝方法将马来酸酐(MAH)接枝到乙烯-醋酸乙烯酯共聚物(EVA)上,制备出EVA-g-MAH(EVAM)聚合物降凝剂,探究了不同条件下合成的EVAM聚合物降凝剂对模拟油凝点和黏度的影响。研究结果表明,选用VA质量分数为33%的EVA,AIBN含量为单体质量的0.3%,m_(EVA):m_(MAH)=1:5,反应温度在60℃,反应时间为5.5 h时,模拟油凝点可以从34℃降至17℃,32℃时黏度由2399 mPa·s降至4.8 m Pa·s;20℃时,添加600 mg/kg EVAM的模拟油黏度仅为837.4 mPa·s,相较于添加相同剂量EVA(w_(VA)=33%)的模拟油黏度进一步降低了67.86%。结合偏光显微镜分析表明,EVAM降凝剂的添加干扰了模拟油中蜡晶的生长方向,进一步提高了蜡晶之间的分散性,使其不易形成三维网状结构,改善了模拟油在低温的时流动性。

小细胞肺癌肿瘤组织及血清CD44表达及临床预后意义

背景与目的小细胞肺癌(small cell lung cancer,SCLC)是一种以增殖迅速、易早期远处转移和获得性治疗耐药为特征的高侵袭性恶性肿瘤,临床预后极差。研究发现干细胞标志物CD44与肿瘤复发转移及治疗抵抗有关,而有关CD44在SCLC患者中的表达及其临床预后意义研究不多。本研究拟通过检测SCLC患者肿瘤组织和血清中CD44的表达水平,初步探索其与患者临床特征的关系并评估其判断预后的临床价值。方法将本院47例初治SCLC患者肿瘤组织和血清标本配对,分别应用免疫组化法(immunohistochemistry,IHC)和酶联免疫吸附试验方法(enzyme-linked immunosorbent assay,ELISA)对CD44进行检测,分析其与患者临床特征及预后的关系。结果SCLC患者肿瘤组织和血清中均可检测到干细胞标志物CD44的表达,体能状态(performance status,PS)2分的患者肿瘤组织CD44阳性率明显高于PS 0分-1分的患者(85.71%vs 30%,P=0.017),根据化疗疗效对患者进行分组,疾病进展组肿瘤组织CD44免疫组化得分及血清CD44浓度均明显高于疾病控制组且差异均达到统计学意义(P=0.006,P=0.034),单因素分析肿瘤组织CD44阳性患者无进展生存期(progression-free survival,PFS)较CD44阴性患者PFS明显缩短(5.23个月vs 9.03个月,P=0.036)。结论初治SCLC患者肿瘤组织中CD44的表达水平与PFS相关,CD44在SCLC中的临床意义值得进一步深入研究。

Meta-Analysis of the Effect of the Escape Room Teaching Method on Nursing Education

Objectives:A meta-analysis was conducted to systematically evaluate the effect of the escape room teaching method on nursing education.Methods:We searched PubMed,Medline,Web of Science,CNKI,VIP,and Wanfang databases,with a search time frame from the first day of database establishment to October 2022.Two researchers evaluated the quality of the obtained literature and extracted the data.The RevMan5.4 software was used for meta-analysis.Results:A total of 7 studies involving 1487 nursing students were included.Compared with the control group,the escape room teaching method improved the professional performance of nursing students[standardized mean difference(SMD)=0.98,95%confidence interval(CI;0.38,1.59),P<0.0001].The critical thinking ability of nursing students was enhanced[mean difference(MD)=12.64,95%CI(7.91,17.37),P<0.0001],and the investment level of nursing students in learning was improved[MD=4.18,95%CI(1.74,6.62),P<0.0001].Conclusion:The escape room teaching method can improve nursing students’professional performance,critical thinking ability,and learning engagement level.There is no significant difference in the impact of nursing teaching satisfaction,and there is still a lack of data support.This paper is limited by the quality and quantity of included literature,and more high-quality studies are still needed to further demonstrate the above conclusions.

化学变脸之神奇的超浸润——推荐一个化学科普实验

自然界中有一类神奇的超浸润,如荷叶上水珠和水黾轻功“水上漂”等,这是材料表面特异的微纳超级结构和活性物质所致。效法自然,合成了两种超浸润界面剂和一种开关型的Cu(OH)2@ZIF-8纳米网膜。从自然植物–日常应用–科技发展,由浅入深,全方位地科普了神奇而又不乏科学趣味的自然现象(化学变脸),以激发青少年对于自然、科学的兴趣。

Identification of the anomaly component using BEMD combined with PCA from element concentrations in the Tengchong tin belt, SW China

Concentration of elements or element groups in a geological body is the result of multiple stages of rockforming and ore-forming geological processes.An ore-forming element group can be identified by PCA(principal component analysis)and be separated into two components using BEMD(bi-dimensional empirical mode decomposition):(1)a high background component which represents the ore-forming background developed in rocks through various geological processes favorable for mineralization(i.e.magmatism,sedimentation and/or metamorphism);(2)the anomaly component which reflects the oreforming anomaly that is overprinted on the high background component developed during mineralization.Anomaly components are used to identify ore-finding targets more effectively than ore-forming element groups.Three steps of data analytical procedures are described in this paper;firstly,the application of PCA to establish the ore-forming element group;secondly,using BEMD on the o re-forming element group to identify the anomaly components created by different types of mineralization processes;and finally,identifying ore-finding targets based on the anomaly components.This method is applied to the Tengchong tin-polymetallic belt to delineate ore-finding targets,where four targets for Sn(W)and three targets for Pb-Zn-Ag-Fe polymetallic mineralization are identified and defined as new areas for further prospecting.It is shown that BEMD combined with PCA can be applied not only in extracting the anomaly component for delineating the ore-finding target,but also in extracting the residual component for identifying its high background zone favorable for mineralization from its oreforming element group.

白内障术后黄斑囊样水肿的OCTA研究

目的:使用光学相干断层扫描血管造影术(Optical Coherence Tomography Angiography, OCTA)对白内障术后黄斑囊样水肿患者的黄斑区视网膜厚度及血流情况进行研究。材料:本研究为前瞻性研究,收集2017年4月到2018年2月期间就诊于青岛大学附属医院眼科的白内障术后黄斑囊样水肿患者20例20只眼,正常白内障术后患者20例20只眼,利用OCTA测量白内障术后黄斑囊样水肿患者治疗前后、正常白内障术后患者的黄斑区视网膜厚度,黄斑的灌注、血管密度并进行分析。结果:正常组黄斑血管密度为19.23 &#177;1.88,灌注密度为0.429 &#177;0.039,黄斑区视网膜厚度为254.12 &#177;22.02 μm,白内障术后黄斑囊样水肿组黄斑血管密度为18.66 &#177;2.911,灌注密度为0.408 &#177;0.045,黄斑区视网膜厚度为482.15 &#177;19.23 μm,黄斑囊样水肿组黄斑血管、灌注密度较正常组减少(P <0.05),黄斑区视网膜厚度增加(P <0.01)。经过曲安奈德治疗后,白内障术后黄斑囊样水肿组黄斑血管密度为19.06 &#177;2.911,灌注密度为0.418 &#177;0.031,黄斑区视网膜厚度为268.34 &#177;17.14 μm,较治疗前血管密度、灌注密度增加(P <0.05),黄斑区视网膜厚度减少(P <0.01)。结论:白内障术后黄斑水肿患者黄斑区视网膜厚度增加,血流密度及灌注密度减少。经曲安奈德治疗后,白内障术后黄斑水肿患者黄斑区视网膜厚度较治疗前减少,血管密度及灌注密度较治疗前增加。

A radiomic nomogram based on an apparent diffusion coefficient map for differential diagnosis of suspicious breast findings

Objective： To develop and validate a radiomic nomogram based on an apparent diffusion coefficient （ADC） mapfor differentiating benign and malignant lesions in suspicious breast findings classified as Breast Imaging Reportingand Data System （BI-RADS） category 4 on breast magnetic resonance imaging （MR2）.Methods： Eighty-eight patients diagnosed with BI-RADS 4 findings on breast MRI in the First AffiliatedHospital of China Medical University from December 2014 to December 2015 were retrospectively analyzed inthis study. Sixty-three were randomized electronically to establish forecasting models, and the other 25 were usedfor validation. Radiomic features based on the ADC map were generated automatically by Artificial Intelligence Kitsoftware （A.K. software; GE Healthcare, China）. Feature reduction was conducted using the Mann-Whitney testand Spearman correlation after pre-treatment. A prediction model of ADC radiomics was established by logisticlinear regression and cross-validation. A nomogram was established based on ADC radiomic features,pharmacokinetics and clinical features, including the morphology and ADC value for breast BI-RADS 4 lesionson MRI.Results： A total of 396 radiomic features were extracted automatically by the A.K. software. Five features wereselected after pre-processing, Mann-Whitney tests and Spearman correlation analysis. The area under the ROCcurve of the prediction model comprising ADC radiomie features was 0.79 when the cutoffvalue was 0.45, and theaccuracy, sensitivity and specificity were 80.0%, 0.813 and 0.778, respectively. A visualized differential nomogrambased on the radiomic score, pharmacokinetics and clinical features was established. The decision curve showedgood consistency.Conclusions： ADC radiomie features could provide an important reference for differential diagnosis betweenbenign and malignant lesions in suspicious BI-RADS 4 lesions. The visualized nomogram based on ADC radiomicfeatures, pharmaeokinetics and clinical features may have good prospects for clinical application.

Radiomic features from computed tomography to differentiate invasive pulmonary adenocarcinomas from non-invasive pulmonary adenocarcinomas appearing as part-solid groundglass nodules

Objective:We aim to investigate radiomic imaging features extracted in computed tomography(CT)images to differentiate invasive pulmonary adenocarcinomas(IPAs)from non-IPAs appearing as part-solid ground-glass nodules(GGNs),and to incorporate significant radiomic features with other clinically-assessed features to develop a diagnostic nomogram model for IPAs.Methods:This retrospective study was performed,with Institutional Review Board approval,on 88 patients with a total of 100 part-solid nodules(56 IPAs and 44 non-IPAs)that were surgically confirmed between February 2014and November 2016 in the First Affiliated Hospital of China Medical University.Quantitative radiomic features were computed automatically on 3D nodule volume segmented from arterial-phase contrast-enhanced CT images.A set of regular risk factors and visually-assessed qualitative CT imaging features were compared with the radiomic features using logistic regression analysis.Three diagnostic models,i.e.,a basis model using the clinical factors and qualitative CT features,a radiomics model using significant radiomic features,and a nomogram model combining all significant features,were built and compared in terms of receiver operating characteristic(ROC)curves.Decision curve analysis was performed for the nomogram model to explore its potential clinical benefit.Results:In addition to three visually-assessed qualitative imaging features,another three quantitative features selected from hundreds of radiomic features were found to be significantly(all P<0.05)associated with IPAs.The diagnostic nomogram model showed a significantly higher performance[area under the ROC curve(AUC)=0.903]in differentiating IPAs from non-IPAs than either the basis model(AUC=0.853,P=0.0009)or the radiomics model(AUC=0.769,P<0.0001).Decision curve analysis indicates a potential benefit of using such a nomogram model in clinical diagnosis.Conclusions:Quantitative radiomic features provide additional information over clinically-assessed qualitative features for differentiating IPAs from non-IPAs appearing as GGNs,and a diagnostic nomogram model including all these significant features may be clinically useful in preoperative strategy planning.

Edema and neuronal apoptosis in the hippocampus and cortex of elderly rats following transient cerebral ischemia/reperfusion injury

BACKGROUND： Previous studies of cerebral ischemia have used young animals, with an ischemic time greater than 5 minutes （safe time limit）. Despite an increased understanding of neuronal apoptosis, it remains uncertain whether brief cerebral ischemic events of 5 minutes or less damage brain tissue in elderly rodents. OBJECTIVE： To investigate the effects of transient cerebral ischemia （5 minutes）/reperfusion injury on brain cortical and hippocampal edema, aquaporin-4 （AQP-4） expression, and neuronal apoptosis in aged rats, and to compare ischemic sensitivity between cortex and hippocampus. DESIGN, TIME AND SETTING： A randomized, controlled, animal experiment was performed at the Institute of Cerebrovascular Disease, Qingdao University Medical School from April 2008 to March 2009. MATERIALS： Rabbit anti-AQP-4 polyclonal antibody, TUNEL kit, and SABC immunohistochemistry kit were purchased from Wuhan Boster Bioengineering, China. METHODS： A total of 160 healthy, male, aged 19-21 months, Wistar rats were randomly assigned to 4 groups： sham-surgery, and ischemia 1-, 3-, and 5-minute groups, with 40 rats in each group. The global cerebral ischemia model was established using the Pusinelli four-vessel occlusion, and the three cerebral ischemia groups were subdivided into reperfusion 12-hour, 1-, 2-, 3-, and 7-day subgroups, with 8 rats in each subgroup. The sham-surgery group was subjected to exposure of the first cervical bilateral alar foramina and bilateral common carotid arteries. MAIN OUTCOME MEASURES： The dry-wet weight assay was used to measure brain water content and histopathology of the cortex and hippocampus was observed following hematoxylin-eosin staining. In addition, cortical and hippocampal AQP-4 expression was detected by streptavidin-biotin complex immunohistochemistry, and neuronal apoptosis was detected by the TUNEL method. RESULTS： There was no significant difference in brain water content or AQP-4 expression in the cortex and hippocampus between ischemia 1- and 3-minute groups and the sham-surgery group or brain water content or AQP-4 expression in the cortex between ischemia 5-minute group and sham-surgery group （P 〉 0.05）. However, brain water content and AQP-4 expression in the hippocampus after 5 minutes of cerebral ischemia were significantly increased compared with the sham-surgery group （P 〈 0.05 or P 〈 0.01）. Several TUNEL-positive cells were observed in the cortex and hippocampus of the sham-surgery group and ischemia 1-minute group, as well as in the cortex of the ischemia 3-minute group. In addition, the number of apoptotic neurons in the hippocampus of ischemia 3-minute group and in the cortex and hippocampus of ischemia 5-minute group was significantly increased （P 〈 0.05 or P 〈 0.01 ）. Neuronal apoptosis was increased after 12 hours of ischemia/reperfusion, and it reached a peak by 2 days （P 〈 0.01）. CONCLUSION： Transient cerebral ischemia （5 minutes） resulted in increased hippocampal edema, AQP-4 expression, and neuronal apoptosis. Moreover, cerebral ischemia had a greater effect on neuronal apoptosis than brain edema or AQP-4 expression, and the hippocampus was more sensitive than the cortex.

SEM in-situ investigation on fatigue cracking behavior of P/M Rene95 alloy with surface inclusions

The low-cycle fatigue behavior of powder metallurgy Rene95 alloy containing surface inclusions was investigated by in-situ observation with scanning electron microscopy （SEM）. The process of fatigue crack initiation and early stage of propagation behavior indicates that fatigue crack mainly occurs at the interface between the inclusion and the matrix. The effect of inclusion on the fatigue crack initiation and the early stage of crack growth was very obvious. The fatigue crack growth path in the matrix is similar to the shape of inclusion made on the basis of fatigue fracture image analysis. The empiric relation between the surface and inside crack growth length, near a surface inclusion, can be expressed. Therefore, the fatigue crack growth rate or life of P/M Rene95 alloy including the inclusions can be evaluated on the basis of the measurable surface crack length parameter. In addition, the effect of two inclusions on the fatigue crack initiation behavior was investigated by the in-situ observation with SEM.

Formation mechanism of methane during coal evolution:A density functional theory study

The formation mechanism of methane （CH4） during coal evolution has been investigated by density functional theory （DFT） of quantum chemistry. Thermogenic gas, which is generated during the thermal evolution of medium rank coal, is the main source of coalbed methane （CBM）. Ethylbenzene （A） and 6,7-dimethyl-5,6,7,8-tetrahydro-1-hydroxynaphthalene （B） have been used as model compounds to study the pyrolysis mechanism of highly volatile bituminous coal （R）, according to the similarity of bond orders and bond lengths. All possible paths are designed for each model. It can be concluded that the activation energies for H-assisted paths are lower than others in the process of methane formation; an H radical attacking on β-C to yield CH4 is the dominant path for the formation of CH4 from highly volatile bituminous coal. In addition, the calculated results also reveal that the positions on which H radical attacks and to which intramolecular H migrates have effects on methyl cleavage.

Variational Assimilation of Satellite Cloud Water/Ice Path and Microphysics Scheme Sensitivity to the Assimilation of a Rainfall Case

Hydrometeor variables （cloud water and cloud ice mixing ratios） are added into the WRF three-dimensional variational assimilation system as additional control variables to directly analyze hydrometeors by assimilating cloud observations. In addition, the background error covariance matrix of hydrometeors is modeled through a control variable transform, and its characteristics discussed in detail. A suite of experiments using four microphysics schemes （LIN, SBU-YLIN, WDM6 and WSM6） are performed with and without assimilating satellite cloud liquid/ice water path. We find analysis of hydrometeors with cloud assimilation to be significantly improved, and the increment and distribution of hydrometeors are consistent with the characteristics of background error covariance. Diagnostic results suggest that the forecast with cloud assimilation represents a significant improvement, especially the ability to forecast precipitation in the first seven hours. It is also found that the largest improvement occurs in the experiment using the WDM6 scheme, since the assimilated cloud information can sustain for longer in this scheme. The least improvement, meanwhile, appears in the experiment using the SBU-YLIN scheme.

PaPYL9 is involved in the regulation of apricot fruit ripening through ABA signaling pathway

Abscisic acid(ABA)is a major regulator of non-climacteric fruit ripening;however,the role of ABA in the ripening of climacteric fruit is not clear.Here,as a typical climacteric fruit,apricots were used to investigate the role of ABA in fruit ripening.Based on weighted gene coexpression network analysis(WGCNA)of our previous transcriptome data,we treated‘Danxing’fruit with exogenous ABA and obtained ABA receptor genes,genes related to ABA biosynthesis and signal transduction,and analyzed the response of these candidate genes to exogenous ABA during fruit ripening.Subsequently,the full length of candidate PYLs genes were cloned,and their putative function were analyzed by phylogenetic analysis and protein structure domain analysis.And then the function of one candidate gene PaPYL9 was verified by using transgenic tomato.Furthermore,the response genes in transgenic tomato were screened by transcriptome sequencing,and ultimately the related regulatory network was proposed.The results showed that the injection of exogenous 1.89 mmol·L^(-1) ABA remarkably promoted fruit coloration,and increased the color index for red grapes(CIRG)and the total soluble solids(TSS)content,but significantly decreased the firmness and titratable acid(TA)content(p<0.01).Nordihydroguaiaretic acid(NDGA),the inhibitor of ABA,appeared to have the converse role in TA,TSS,CIRG and firmness,during the ripening process.One NCED(9-cis-epoxycarotenoiddioxygenase)and five ABA receptor genes related to signal transduction were mined from the transcriptome data of apricot fruit through WGCNA.Compared with the control,the expression levels of NCED1,PYL9(PYR/PYL/RCAR),SnRK2(SUCROSE NON-FERMENTING1(SNF1)-RELATED PROTEIN KINASE 2S),and ABF2(ABRE-binding bZIP transcription)were induced dramatically by ABA treatment(p<0.01),while NDGA treatment significantly inhibited their expression.Based on gene expression and protein domain analysis,we inferred that PaPYL9 is putatively involved in apricot fruit ripening.Overexpression of PaPYL9 in Micro-TOM tomatoes resulted in the promotion of early ripening.Simultaneously,the expression levels of genes related ethylene biosynthesis,chlorophyll degradation,fruit softening,flavor formation,pigment synthesis,and metabolism were all significantly induced in overexpression of PaPYL9 tomatoes.This indicates the central role of ABA in climacteric fruit ripening.A regulatory network was tentatively proposed,laying the foundation to unveil the molecular mechanism of the regulatory role of PaPYL9 in fruit ripening.

Nutrient Composition of Different Foxtail Millet Seeds

Ten millet cultivars from China and abroad were analyzed for their crude fat, amylose and amylopectin, crude protein and amino acid content. A wide variation was observed in amylopectin contain, ranging from 54.47% to 69.26%, while amylose content ranged from 11.26% to 23.22%. The average crude fat in all cultivates was 3.46%, and most cultivates ranged from 3.1% to 3.7%. Protein contents ranged from 8.61% to 15.54% with a mean value of 11.94%. For amino acid composition, the ten cultivates were particularly rich in leucine, and the mean was 34.57 mg/g. The millet cultivars were also high in glycine, glutamic acid and cysteine. Millet was known to be limiting in the essential amino lysine, and the mean was 5.18 mg/g. Other amino acids, tyrosine, histidine and arginine were also very low in the ten cultivars. In general, significant nutrient composition differences were observed between the different millet cultivars, and A2 （a kind of mother line of the hybrid millet） and hybrid millet registered a higher level of protein and amino acid composition which would be useful in millet breeding.