Built defects of homogeneous junction to enhance the lithium storage capacity of niobium pentoxide materials

Niobium pentoxide(Nb_(2)O_(5))is deemed one of the promising anode materials for lithium-ion batteries(LIBs)for its outstanding intrinsic fast Li-(de)intercalation kinetics.The specific capacity,however,is still limited,because the(de)intercalation of excessive Li-ions brings the undesired stress to damage Nb_(2)O_(5) crystals.To increase the capacity of Nb_(2)O_(5) and alleviate the lattice distortion caused by stress,numerous homogeneous H-and M-phases junction interfaces were proposed to produce coercive stress within theNb_(2)O_(5)crystals.Such interfaces bring about rich oxygen vacancies with structural shrinkage tendency,which pre-generate coercive stress to resist the expansion stress caused by excessive Li-ions intercalation.Therefore,the synthesized Nb_(2)O_(5) achieves the highest lithium storage capacity of 315 mA h g−1 to date,and exhibits high-rate performance(118 mA h g^(-1) at 20 C)as well as excellent cycling stability(138 mA h g^(-1) at 10 C after 600 cycles).

乙炔氢氯化反应用无汞铜基催化剂的研究现状

阐述了铜基催化剂的研究现状,包括催化反应机理、失活和再生、单组分铜基催化剂、铜基多金属催化剂及催化剂载体,并对铜基催化剂的工业化应用进行了展望。

PVC塑料改性用氯化聚乙烯生产工艺及结构性能

本文通过对PVC塑改性氯化聚乙烯生产工艺及结构性能研究现状进行分析,为PVC塑改性氯化聚乙烯未来发展方向及关键参数控制提供了参考。

Visible light triggered exfoliation of COF micro/nanomotors for efficient photocatalysis

We report a new facile light-induced strategy to disperse micron-sized aggregated bulk covalent organic frameworks(COFs)into isolated COFs nanoparticles.This was achieved by a series of metal-coordinated COFs,namely COF-909-Cu,-Co or-Fe,where for the first time the diffusio-phoretic propulsion was utilized to design COF-based micro/nanomotors.The mechanism studies revealed that the metal ions decorated in the COF-909 backbone could promote the separation of electron and holes and trigger the production of sufficient ionic and reactive oxygen species under visible light irradiation.In this way,strong light-induced self-diffusiophoretic effect is achieved,resulting in good dispersion of COFs.Among them,COF-909-Fe showed the highest dispersion performance,along with a drastic decrease in particle size from 5μm to500 nm,within only 30 min light irradiation,which is inaccessible by using traditional magnetic stirring or ultrasonication methods.More importantly,benefiting from the outstanding dispersion efficiency,COF-909-Fe micro/nanomotors were demonstrated to be efficient in photocatalytic degradation of tetracycline,about 8 times faster than using traditional magnetic stirring method.This work opens up a new avenue to prepare isolated nanosized COFs in a high-fast,simple,and green manner.

Simulation of gas–liquid two-phase flow in a flow-focusing microchannel with the lattice Boltzmann method

A lattice Boltzmann method for gas–liquid two-phase flow involving non-Newtonian fluids is developed. Bubble formation in a flow-focusing microchannel is simulated by the method. The influences of flow rate ratio, surface tension,wetting properties, and rheological characteristics of the fluid on the two-phase flow are analyzed. The results indicate that the flow pattern transfers from slug flow to dry-plug flow with a sufficiently small capillary number. Due to the presence of three-phase contact lines, the contact angle has a more significant effect on the dry-plug flow pattern than on the slug flow pattern. The deformation of the front and rear meniscus of a bubble in the shear-thinning fluid can be explained by the variation of the capillary number. The reduced viscosity and increased contact angle are beneficial for the drag reduction in a microchannel. It also demonstrates the effectiveness of the current method to simulate the gas–liquid two-phase flow in a microchannel.

Establishment of a non-lethal model of antibody-dependent enhancement of infection in A129 mice based on a non-mouse-adapted dengue virus strain

DEAR EDITOR,Dengue fever(DF),caused by dengue virus(DENV)infection,is a highly prevalent mosquito-borne infectious disease.The development of antiviral drugs and vaccines relies on the clinical utility of dengue infection models,particularly those involving antibody-dependent enhancement(ADE).

Extreme gradient boosting algorithm based urban daily traffic index prediction model:a case study of Beijing,China

The exhaust emissions and frequent traffic incidents caused by traffic congestion have affected the operation and development of urban transport systems.Monitoring and accurately forecasting urban traffic operation is a critical task to formulate pertinent strategies to alleviate traffic congestion.Compared with traditional short-time traffic prediction,this study proposes a machine learning algorithm-based traffic forecasting model for daily-level peak hour traffic operation status prediction by using abundant historical data of urban traffic performance index(TPI).The study also constructed a multi-dimensional influencing factor set to further investigate the relationship between different factors on the quality of road network operation,including day of week,time period,public holiday,car usage restriction policy,special events,etc.Based on long-term historical TPI data,this research proposed a daily dimensional road network TPI prediction model by using an extreme gradient boosting algorithm(XGBoost).The model validation results show that the model prediction accuracy can reach higher than 90%.Compared with other prediction models,including Bayesian Ridge,Linear Regression,ElatsicNet,SVR,the XGBoost model has a better performance,and proves its superiority in large high-dimensional data sets.The daily dimensional prediction model proposed in this paper has an important application value for predicting traffic status and improving the operation quality of urban road networks.

OBE教育理念下应用化学专业综合实验课程的创新实践

针对应用化学综合实验课程内容陈旧、教学模式不利于学生创新能力的培养,及其自主学习能力发挥、教学评价方式单一等问题,基于OBE (Outcome-based education)教育理念对该课程进行了系统的教学设计:采取将科研成果与教学内容相融合的方式设计创新型实验项目,提高实验内容的前沿性、创新性及科学性;课堂教学增加设计性、探索性及挑战性环节,激发学生的学习兴趣及自主学习意识,培养学生的创新能力及科学精神;建立以成果为导向的教学评价模式,强化过程考核,完成课程目标达成度评价。根据课程目标达成度评价结果及持续改进的原则优化教学方案,推动实验教学向能力导向培养模式发展。

Experimental infection of tree shrews(Tupaia belangeri) with Coxsackie virus A16

Coxsackie virus A16(CA16) is commonly recognized as one of the main human pathogens of hand-foot-mouth disease(HFMD). The clinical manifestations of HFMD include vesicles of hand, foot and mouth in young children and severe inflammatory CNS lesions. In this study, experimentally CA16 infected tree shrews(Tupaia belangeri) were used to investigate CA16 pathogenesis. The results showed that both the body temperature and the percentages of blood neutrophilic granulocytes / monocytes of CA16 infected tree shrews increased at 4-7 days post infection. Dynamic distributions of CA16 in different tissues and stools were found at different infection stages. Moreover, the pathological changes in CNS and other organs were also observed. These findings indicate that tree shrews can be used as a viable animal model to study CA16 infection.

Value of radiofrequency ablation in the treatment of hepatocellular carcinoma

Hepatocellular carcinoma(HCC)is a malignant disease that substantially affects public health worldwide.It is especially prevalent in east Asia and sub-Saharan Africa,where the main etiology is the endemic status of chronic hepatitis B.Effective treatments with curative intent for early HCC include liver transplantation,liver resection(LR),and radiofrequency ablation(RFA).RFA has become the most widely used local thermal ablation method in recent years because of its technical ease,safety,satisfactory local tumor control,and minimally invasive nature.This technique has also emerged as an important treatment strategy for HCC in recent years.RFA,liver transplantation,and hepatectomy can be complementary to one another in the treatment of HCC,and the outcome benefits have been demonstrated by numerous clinical studies.As a pretransplantation bridge therapy,RFA extends the average waiting time without increasing the risk of dropout or death.In contrast to LR,RFA causes almost no intraabdominal adhesion,thus producing favorable conditions for subsequent liver transplantation.Many studieshave demonstrated mutual interactions between RFA and hepatectomy,effectively expanding the operative indications for patients with HCC and enhancing the efficacy of these approaches.However,treated tumor tissue remains within the body after RFA,and residual tumors or satellite nodules can limit the effectiveness of this treatment.Therefore,future research should focus on this issue.

The genome sequence of celery(Apium graveolens L.),an important leaf vegetable crop rich in apigenin in the Apiaceae family

Celery(Apium graveolens L.)is a vegetable crop in the Apiaceae family that is widely cultivated and consumed because it contains necessary nutrients and multiple biologically active ingredients,such as apigenin and terpenoids.Here,we report the genome sequence of celery based on the use of HiSeq 2000 sequencing technology to obtain 600.8 Gb of data,achieving~189-fold genome coverage,from 68 sequencing libraries with different insert sizes ranging from 180 bp to 10 kb in length.The assembled genome has a total sequence length of 2.21 Gb and consists of 34,277 predicted genes.Repetitive DNA sequences represent 68.88%of the genome sequences,and LTR retrotransposons are the main components of the repetitive sequences.Evolutionary analysis showed that a recent whole-genome duplication event may have occurred in celery,which could have contributed to its large genome size.The genome sequence of celery allowed us to identify agronomically important genes involved in disease resistance,flavonoid biosynthesis,terpenoid metabolism,and other important cellular processes.The comparative analysis of apigenin biosynthesis genes among species might explain the high apigenin content of celery.The whole-genome sequences of celery have been deposited at CeleryDB(http://apiaceae.njau.edu.cn/celerydb).The availability of the celery genome data advances our knowledge of the genetic evolution of celery and will contribute to further biological research and breeding in celery as well as other Apiaceae plants.

Atropine 0.01% eye drops slow myopia progression: a systematic review and Meta-analysis

AIM: To evaluate the effects of atropine 0.01% on slowing myopia progression. METHODS: We searched for relevant studies in the Cochrane Library, PubMed, Embase, Ovid, CBM, CNKI, VIP and Wan Fang Data in Chinese. A supplementary search was conducted in OpenGrey(System for Information on Grey Literature in Europe), the ISRCTN registry, Clinical Trials.gov, and the WHO International Clinical Trials Registry Platform(ICTRP) from the dates of inception to June 30, 2018. RESULTS: Seven randomized controlled trials(RCTs) with a total of 1079 subjects were included(505 in the atropine 0.01% group and 574 in the control group). The results showed that the atropine 0.01% group exhibited significantly greater control of axial growth than the control group (MD=-0.12, 95%CI(-0.19,-0.06))There was also a statistically significant difference between the atropine 0.01% and control groups in the changes in axial length [MD=-0.14, 95%CI(-0.25,-0.03)], but the quality of evidence was low. There were no significant differences between the atropine 0.01% and control groups in the overall effect with respect to diopter value, change in diopter, distance vision and intraocular pressure (MD=0.08, 95%CI(-0.27, 0.42);MD=0.09, 95%CI(-0.17, 0.36);MD=-0.01, 95%CI(-0.02, 0.00);MD=0.08, 95%CI(-0.56,0.40))The sensitivity analysis showed that the conclusion of the Meta-analysis is relatively stable. With respect to adverse events, there were significant differences between the atropine 0.01% and control groups (OR=0.26, 95%CI(0.11, 0.61))CONCLUSION: Based on the available evidence, atropine 0.01% eye drops offer benefits in controlling axial growth and safety without causing significant differences in diopter values, distance vision and intraocular pressure.

In-situ/operando techniques to identify active sites for thermochemical conversion of CO_(2) over heterogeneous catalysts

The catalytic conversion of CO_(2) to fuels or chemicals is considered to be an effective pathway to mitigate the greenhouse effect. To develop new types of efficient and durable catalysts, it is critical to identify the catalytic active sites, surface intermediates, and reaction mechanisms to reveal the relationship between the active sites and catalytic performance. However, the structure of a heterogeneous catalyst usually dynamically changes during reaction, bringing a great challenge for the identification of catalytic active sites and reaction pathways. Therefore, in-situ/operando techniques have been employed to real-time monitor the dynamic evolution of the structure of active sites under actual reaction conditions to precisely build the structure–function relationship. Here, we review the recent progress in the application of various in-situ/operando techniques in identifying active sites for catalytic conversion of CO_(2) over heterogeneous catalysts. We systematically summarize the applications of various optical and X-ray spectroscopy techniques, including Raman spectroscopy, Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and X-ray absorption spectroscopy (XAS), in identifying active sites and determining reaction mechanisms of the CO_(2) thermochemical conversion with hydrogen and light alkanes over heterogeneous catalysts. Finally, we discuss challenges and opportunities for the development of in-situ characterization in the future to further enlarge the capability of these powerful techniques.

Endpoint temperature prediction of molten steel in RH using improved case-based reasoning

An improved case-based reasoning （CBR） method was proposed to predict the endpoint temperature of molten steel in Ruhrstahl Heraeus （RH） process. Firstly, production data were analyzed by multiple linear regressions and a pairwise comparison matrix in analytic hierarchy process （AHP） was determined by this linear regression＇s coefficient. The weights of various influencing factors were obtained by AHP. Secondly, the dividable principles of case base including ＂0-1＂ and ＂breakpoint＂ were proposed, and the case base was divided into several homogeneous parts. Finally, the improved CBR was compared with ordinary CBR, which is based on the even weight and the single base. The results show that the improved CBR has a higher hit rate for predicting the endpoint temperature of molten steel in RH.

Integrative genome,transcriptome,microRNA,and degradome analysis of water dropwort(Oenanthe javanica)in response to water stress

Water dropwort(Liyang Baiqin,Oenanthe javanica(BI.)DC.)is an aquatic perennial plant from the Apiaceae family with abundant protein,dietary fiber,vitamins,and minerals.It usually grows in wet soils and can even grow in water.Here,whole-genome sequencing of O.javanica via HiSeq 2000 sequencing technology was reported for the first time.The genome size was 1.28 Gb,including 42,270 genes,of which 93.92%could be functionally annotated.An online database of the whole-genome sequences of water dropwort,Water dropwortDB,was established to share the results and facilitate further research on O.javanica(database homepage:http://apiaceae.njau.edu.cn/waterdropwortdb).Water dropwortDB offers whole-genome and transcriptome sequences and a Basic Local Alignment Search Tool.Comparative analysis with other species showed that the evolutionary relationship between O.javanica and Daucus carota was the closest.Twenty-five gene families of O.javanica were found to be expanded,and some genetic factors(such as genes and miRNAs)related to phenotypic and anatomic differentiation in O.javanica under different water conditions were further investigated.Two miRNA and target gene pairs(miR408 and Oja15472,miR171 and Oja47040)were remarkably regulated by water stress.The obtained reference genome of O.javanica provides important information for future work,thus making in-depth genetic breeding and gene editing possible.The present study also provides a foundation for the understanding of the O.javanica response to water stress,including morphological,anatomical,and genetic differentiation.

高效液相色谱法测定马来酸、丁二酸和富马酸的含量

建立了高效液相色谱法测定马来酸、丁二酸和富马酸的方法。采用Agilent XDB-C18色谱柱(4.6mm×150mm,5μm),流动相为0.1%磷酸水溶液和甲醇混合液(V∶V=88∶12),流速0.5mL·min^(-1),进样量10μL,柱温30℃,检测波长210nm,采用外标法定量。结果表明,3种有机酸的分离度好,线性范围内,各酸的浓度与色谱峰面积的线性关系良好,相关系数为0.9991~0.9999,平均加标回收率为80%~10%,RSD(n=3)在1%以下。该方法简便快速,分离效果好,精密度高,是同时分离测定3种有机酸的有效方法。

Near-field acoustic levitation and applications to bearings:a critical review

The importance to industry of non-contact bearings is growing rapidly as the demand for highspeed and high-precision manufacturing equipment increases.As a recently developed non-contact technology,near-field acoustic levitation(NFAL)has drawn much attention for the advantages it offers,including no requirement for an external pressurized air supply,its compact structure,and its ability to adapt to its environment.In this paper,the working mechanism of NFAL is introduced in detail and compared to all existing non-contact technologies to demonstrate its versatility and potential for practical applications in industry.The fundamental theory of NFAL,including gas film lubrication theory and acoustic radiation pressure theory is presented.Then,the current stateof-the-art of the design and development of squeeze film air bearings based on NFAL is reviewed.Finally,future trends and obstacles to more widespread use are discussed.

Clinical Characteristics of 261 Cases of Hospitalized Patients with Type 1 Diabetes Mellitus

Objective To retrospectively analyze the clinical characteristics of 261 cases of hospitalized patients with type 1 diabetes mellitus(T1DM) in Peking Union Medical College Hospital(PUMCH). Methods Clinical data of 261 cases of hospitalized patients diagnosed with T1DM in the Department of Endocrinology at PUMCH from January 2007 to December 2014 were analyzed retrospectively. All patients were divided into the T1DM antibodies positive group(n=180) and negative group(n=81) according to the results of immunohistochemistry, in which 123 newly diagnosed T1DM patients were divided into the adult onset group(>18 years, n=58) and non-adult onset group(≤18 years, n=65) according to the onset age of T1DM, respectively. The clinical characteristics from different groups were compared. Results In 261 patients, the average age was 26.6±15.4 years, the average disease duration was 49(1-480) months, the positive rate of antibodies to glutamic acid decarboxylase antibody was 58.8%(153/260). The level of 2-hour postprandial C peptide and the positive rate of T1DM antibodies in the non-adult onset group were higher than those in the adult onset group(0.98 vs. 0.52 ng/ml, P=0.002 and 80.4% vs. 62.5%, P=0.048). The age of onset in the T1DM antibodies positive group was smaller than that in the T1DM antibodies negative group(19.7±11.4 vs. 24.7±15.6 years, P=0.04), while the incidence of ketosis in the T1DM antibodies positive group was higher than that in the T1DM antibodies negative group(48.3% vs. 34.2%, P=0.035). With the progress of the disease, the fasting C peptide level of the T1DM antibodies positive group decreased more rapidly. Compared with the single time hospitalized patients, multiplehospitalized patients had a lower incidence of diabetic retinopathy(8.2% vs. 22.4%, P=0.032), a lower hemoglobin A1 c level(8.04%±2.10% vs. 9.56%±2.64%, P<0.001) and fasting blood glucose level(8.7±3.1 vs. 10.9±4.2 mmol/L, P<0.001). Conclusions Compared with the non-adult onset T1DM patients, the islet function of adult onset patients was even worse. In the T1DM antibodies positive patients, the islet β cell function decreased more rapidly, so the antibodies could not only clarify the diagnosis of T1DM and also predict prognosis of the islet β cell function. In the management of T1DM patients, regular hospital revisits contributed to get better glycemic control and reduced the occurrence of diabetic complications.

AgMYB1,an R2R3-MYB factor,plays a role in anthocyanin production and enhancement of antioxidant capacity in celery

Celery is rich in nutrients and cultivated worldwide.Anthocyanins are natural plant pigments with high antioxidant capabilities in the human diet.The accumulation of anthocyanins in celery results in the purple skin color of petioles.Here,an R2R3-MYB transcription factor(TFs),AgMYB1,was cloned from purple-skin celery.Phylogenetic analysis revealed that AgMYB1 belongs to the anthocyanin branch.Sequence alignment showed that AgMYB1 contains multiple anthocyanin-related motifs.Consistent with the activating role in anthocyanin production,AgMYB1 showed higher transcriptions in purple celery compared with non-purple celery.Transient expression of AgMYB1 in tobacco leaves promoted the accumulation of anthocyanins and produced red pigments in leaves.Heterologous expression of AgMYB1 in Arabidopsis activates anthocyanin production and generates dark-purple plants.The enhancement of anthocyanin biosynthetic genes transcripts and glycosylation capacities in transgenic Arabidopsis verified the activating roles of AgMYB1 at the gene and protein level,respectively.The antioxidant capacity of transgenic Arabidopsis was also increased compared to wild type Arabidopsis.Additionally,yeast two-hybrid assay proved that AgMYB1 interacted with bHLH TFs to regulate anthocyanin biosynthesis.Our results show that the overexpression of single R2R3-MYB gene,AgMYB1,without coexpression of other TFs,can improve anthocyanin production and antioxidant capacity in transgenic plants.This study presents new information for anthocyanin regulatory mechanisms in purple celery and provides a strategy for cultivating plants with high levels of anthocyanins.