A three-dimensional network of graphene/silicon/graphene sandwich sheets as anode for Li-ion battery

Abstract(#br)A freestanding porous three-dimensional (3D) network composed of graphene/silicon/graphene sandwich sheets is proposed to prevent the expansion induced pulverization for Si-based anode in a lithium-ion battery. The architecture ensures the attachment of Si active material, improves the conductivity, and absorbs the Si volume expansions. The 3D Graphene and Si in this architecture work synergistically to contribute to the capacity, while the nanoscale of Si lowers the expansion during lithiation. And the 3D graphene with an interconnected skeleton, in addition to active material, also acts as the current collector as well as a stable support for Si

Deregulation of DUX4 and ERG in acute lymphoblastic leukemia

Chromosomal rearrangements deregulating hematopoietic transcription factors are common in acute lymphoblastic leukemia (ALL).1,2 Here, we show that deregulation of the homeobox transcription factor gene DUX4 and the ETS transcription factor gene ERG are hallmarks of a subtype of B-progenitor ALL that comprises up to 7% of B-ALL. DUX4 rearrangement and overexpression was present in all cases, and was accompanied by transcriptional deregulation of ERG, expression of a novel ERG isoform, ERGalt, and frequent ERG deletion. ERGalt utilizes a non-canonical first exon whose transcription was initiated by DUX4 binding. ERGalt retains the DNA-binding and transactivating domains of ERG, but inhibits wild-type ERG transcriptional activity and is transforming. These results illustrate a unique paradigm of transcription factor deregulation in leukemia, in which DUX4 deregulation results in loss-of-function of ERG, either by deletion or induction of expression of an isoform that is a dominant negative inhibitor of wild type ERG function

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Omecamtiv mecarbil in chronic heart failure with reduced ejection fraction, GALACTIC‐HF: baseline characteristics and comparison with contemporary clinical trials

Aims: The safety and efficacy of the novel selective cardiac myosin activator, omecamtiv mecarbil, in patients with heart failure with reduced ejection fraction (HFrEF) is tested in the Global Approach to Lowering Adverse Cardiac outcomes Through Improving Contractility in Heart Failure (GALACTIC‐HF) trial. Here we describe the baseline characteristics of participants in GALACTIC‐HF and how these compare with other contemporary trials. Methods and Results: Adults with established HFrEF, New York Heart Association functional class (NYHA) ≥ II, EF ≤35%, elevated natriuretic peptides and either current hospitalization for HF or history of hospitalization/ emergency department visit for HF within a year were randomized to either placebo or omecamtiv mecarbil (pharmacokinetic‐guided dosing: 25, 37.5 or 50 mg bid). 8256 patients [male (79%), non‐white (22%), mean age 65 years] were enrolled with a mean EF 27%, ischemic etiology in 54%, NYHA II 53% and III/IV 47%, and median NT‐proBNP 1971 pg/mL. HF therapies at baseline were among the most effectively employed in contemporary HF trials. GALACTIC‐HF randomized patients representative of recent HF registries and trials with substantial numbers of patients also having characteristics understudied in previous trials including more from North America (n = 1386), enrolled as inpatients (n = 2084), systolic blood pressure < 100 mmHg (n = 1127), estimated glomerular filtration rate < 30 mL/min/1.73 m2 (n = 528), and treated with sacubitril‐valsartan at baseline (n = 1594). Conclusions: GALACTIC‐HF enrolled a well‐treated, high‐risk population from both inpatient and outpatient settings, which will provide a definitive evaluation of the efficacy and safety of this novel therapy, as well as informing its potential future implementation

Seismic analysis of gravity dam-reservoir-foundation systems using scaled boundary finite element method

A gravity dam is designed to retain water by using its self-weight to resist hydro-pressure of the reservoir. When an earthquake occurs, the energy emanated from the earthquake source may reach the dam site and cause the dam to vibrate. The earthquake action at the site is often the most critical loading case in the design of gravity dams. The estimation of the dynamic responses of gravity dams to earthquakes is necessary for achieving optimal upgrades and maintenance, and for improving our confidence in knowing that a dam will survive the impact of an earthquake of a specified magnitude. This thesis develops an efficient approach to the seismic analysis of gravity dam-reservoir-foundation systems with an emphasis on the seismic input modelling and adaptive damage simulation of dams. The whole system is divided into a bounded domain including the dam body and adjacent parts of reservoir and foundation, and an unbounded domain of reservoir and an unbounded domain of foundation. The dynamic properties of the unbounded domains are simulated by artificial boundaries formulated in the framework of Scaled Boundary Finite Element Method (SBFEM). The seismic waves are considered as plane waves in both two-dimensional and three-dimensional media. The seismic waves are inputted to the bounded domains by means of the Domain Reduction Method (DRM) through a single layer of elements adjacent to the interface between the bounded domain and the unbounded domain of foundation. The fully automatic quadtree/octree mesh technique is employed to discretize the complex geometry of the bounded domain including the dam and geological features in the foundation. The scaled boundary finite element method is applied in the bounded domain and overcomes the issue of hanging node faced by standard finite elements. The continuum damage mechanics is applied to model concrete and rocks as quasi-brittle materials. An h-adaptive strategy is developed for damage analysis to improve the computational efficiency. A progressive damage process is simulated through a series of optimal meshes. The proposed strategy simplifies the implementation of the adaptive analysis in automatic mesh refinement and data transfer. As the final outcome of this thesis, an automatic and efficient SBFEM formulation for seismic analysis of gravity dam-reservoir-foundation interaction systems has been developed. Case studies of gravity dams are performed

Research Progress on Calcium Ion in Gametophytic Self-Incompatibility

Calcium ions are involved in plant self-incompatibility response as important signaling substances in cells. In the sporophytic self-incompatibility response, Ca2+ enters the stigma papilla cells and plays a key role in inhibiting incompatible pollen tube growth. In the gametophytic self-incompatibility reaction of Papaveraceae, the female determinants in the style (PrsS) and the male determinants in the pollen (PrpS) recognize each other, promote extracellular Ca2+ influx into the incompatible pollen tube, destroy the calcium ion gradient at the tip of the pollen tube, and inhibit the pollen tube growth. In the S-RNase-based Rosaceae game-tophytic self-incompatibility response, it is still unclear how the S-RNase interacts with the male determinant and how the S-RNase specifically degrades the RNA in the pollen tube. Therefore, we reviewed the research progress on the role of Ca2+ in self-incompatibility and, based on our research results, proposed a role model of Ca2+ as a signal substance in the gametophyte self-incompatibility response in Rosaceae

Insights into cell classification based on combination of multiple cellular mechanical phenotypes by using machine learning algorithm

Although cellular elastic property (CEP, also known as cellular elastic modulus) has been frequently reported as a biomarker to distinguish some cancerous cells from their benign counterparts, it cannot be adopted as a universal hallmark to be applied to every kind cell. In the present study, we report that insignificant difference is observed between normal gastric cell and its cancer counterpart which is one of the common human malignancies, in terms of CEP statistical distribution. In this regard, we propose multiple cellular mechanical phenotypes (CMPs) to differentiate the above two cell types, which is realized by machine learning algorithm (MLA). The results show that the cellular classification effect proves better with more CMPs adopted, regardless of the exact MLA employed. Moreover, the MLA-based method remains effective if we add two more cell lines to the above two cell categories. Our study indicates that MLA-based cellular classification can potentially serve as an efficient and objective means to assist or even validate cancer prognostics

Molecular cloning and expression analysis of annexin A2 gene in sika deer antler tip

Objective Molecular cloning and bioinformatics analysis of annexin A2 (ANXA2) gene in sika deer antler tip were conducted. The role of ANXA2 gene in the growth and development of the antler were analyzed initially. Methods The reverse transcriptase polymerase chain reaction (RT-PCR) was used to clone the cDNA sequence of the ANXA2 gene from antler tip of sika deer (Cervus Nippon hortulorum) and the bioinformatics methods were applied to analyze the amino acid sequence of Anxa2 protein. The mRNA expression levels of the ANXA2 gene in different growth stages were examined by real time reverse transcriptase polymerase chain reaction (real time RT-PCR). Results The nucleotide sequence analysis revealed an open reading frame of 1,020 bp encoding 339 amino acids long protein of calculated molecular weight 38.6 kDa and isoelectric point 6.09. Homologous sequence alignment and phylogenetic analysis indicated that the Anxa2 mature protein of sika deer had the closest genetic distance with Cervus elaphus and Bos mutus. Real time RT-PCR results showed that the gene had differential expression levels in different growth stages, and the expression level of the ANXA2 gene was the highest at metaphase (rapid growing period). Conclusion ANXA2 gene may promote the cell proliferation, and the finding suggested Anxa2 as an important candidate for regulating the growth and development of deer antler

Spontaneous Imbibition Characteristics of Slickwater and its Components in Longmaxi Shale

During and after multi-stage hydraulic fracturing, the spontaneous imbibition of water-base fracturing fluid in shale formation is considered as the main mechanism responsible for the retention of large amounts of fracturing fluid. Slickwater is widely applied in Fuling shale gas field, the largest shale gas field in China. To characterize the spontaneous imbibition of slickwater and its four major components, experiments were carried out by using modified imbibition cells. Results show that all of the imbibition curves can be divided into three stages: linear imbibition stage, transition stage and stable imbibition stage. Their imbibition capacities are in the order of cleanup additive, clay stabilizer, slickwater, defoamer and friction reducer from highest to lowest. We have found that the imbibed volume is larger than the initial pore volume. Nuclear Magnetic Resonance (NMR) tests, core images and porosity comparison before and after imbibition all indicate the secondary microfractures were created during the imbibition process. The calculated volume of secondary microfractures which is the difference between the pore volume before and after the imbibition is very close to the imbibed volume, indicating the imbibition mainly through the microfractures. We also found that the imbibition rate of slickwater and its components in the order from highest to lowest is cleanup additive (0.087 cc/d), slickwater (0.058 cc/d), clay stabilizer (0.035 cc/d), defoamer (0.022 cc/d) and friction reducer (0.014 cc/d), indicating the synergy effect of slickwater components on the imbibition process and the role to optimize the cleanup additives during slickwater design

Preparation and Thermoelectric Properties of Semiconducting Single-Walled Carbon Nanotubes/Regioregular Poly(3-dodecylthiophene) Composite Films

Single-walled carbon nanotubes (SWNTs) have been widely used as leading additives for improving the thermoelectric properties of organic materials, due to their unique structure and excellent electronic transport properties. However, the as-synthesized SWNTs are mixtures (mix-SWNT) of semiconducting (sc-SWNT) and metallic (met-SWNT) carbon nanotubes. The significantly different surface character and transport behavior of sc-SWNT and met-SWNT frequently raise the difficulty of modifying microstructures, and tuning transport properties of SWNTs/organic composites, when using mix-SWNTs as dispersion phase. Herein, we prepared high quality sc-SWNTs/rr-P3DDT composite film by presorting pure sc-SWNT from the raw mix-SWNTs using regioregular poly(3-dodecylthiophene) (rr-P3DDT). Both the smoothness and compactness of sc-SWNTs/rr-P3DDT are great improved, as compared with the mix-SWNTs/rr-P3DDT films, and the sc-SWNTs are well-dispersed and uniformly wrapped by rr-P3DDT with diameter less than 50 nm. The significantly enhanced Seebeck coefficients and power factors are obtained in the sc-SWNT/rr-P3DDT samples. As the result, the maximum power factor of 60 μW/mK2 in 50 wt% sc-SWNTs sample is 70% higher than that of mix-SWNTs/P3DDT sample. This work reveals the effectiveness of pure semiconductor SWNTs as fillers to optimize the thermoelectric properties of CNT/polymer nano-composites