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In the heterogeneous distributed computing systems, efficient task scheduling is necessary for high performance. System reliability and completion time are generally the two important metrics. In this paper, we proposed an algorithm named Merging and Duplication for Makespan and Reliability (MDMR) which combines task merging and task duplication to achieve single-objective constrained optimization of workflow reliability and completion time. The MDMR algorithm is divided into three phases: task merging, entry task duplication and reliability detection with nonentry task duplication. In the task merging phase, two tasks with a sole parent–child relationship are merged into a single task, then this process is iterated until no tasks satisfy the merging condition, thus simplifying the directed acyclic graph. In the entry task duplication phase, the entry task with the lowest reliability is duplicated on the processors, which are available at that moment to increase the reliability while reducing the workflow completion time. In the reliability detection and nonentry task duplication phase, the current workflow scheduling reliability is first calculated, then the result is directly output if the reliability is higher than the target value, otherwise the nonentry task duplication is executed with the aim of increasing the reliability until the value surpasses the target. According to the experimental results, MDMR dominates the compared algorithms and ensures that the entire workflow achieves the target reliability and shortens the workflow makespan as much as possible.

The in situ polymerization of monomers to form a second network within a preexisting network (first network) is a facile and effective strategy to fabricate semi-interpenetrating (semi-IPN) hydrogels with enhanced mechanical strength; while to comprehend the effects of the first polymer network on the polymerization process of the second network is still a challenging project. This paper introduces a simple method of employing dynamic rheological measurement loops to monitor the real time progress of the in situ polymerized acrylamide (AAm) in a chitosan (CS) solution towards the formation of a semi-IPN hydrogel. To identify the effects of the preexisting network on the polymerization gelation process, the concept “Effective Conversion Ratio (ECR)” is introduced to evaluate the first network effects on the requirement for the polymerized conversion ratio of the second network to form a critical gel. The rheological properties before gel point, at gel point, and at post-gel stage are discussed via the obtained real time data, respectively. The experimental results have proved the suitability of utilizing dynamic rheology to obtain the real time details of the semi-IPN gel fabrication process.

In vitro mimics recognized that the propensity of a negatively charged phospholipid, DPPS, monolayers to self-aggregate to three-dimensional (3D) giant folds under overcompression at an air–water interface. Time elapsing microscopical observations confirmed that such giant folds were able to float stably on the air–water interface for weeks or even longer. Ex situ atomic force microscopy (AFM) and transmission electronic microscopy (TEM) characterizations pointed out that such giant folds were composed of compactly stacked lipid layers. Phospholipase A2 (PLA2), a principal bactericide in human and animal tear secretion, was chosen to drive the in situ lipid giant folds disassembly on water and supported substrate surfaces, respectively. Our experimental results confirmed the layer-by-layer structures of the giant folds. It is noteworthy that the defect-rich areas of the giant lipid folds were eliminated quickly by PLA2 while defect-free lipid zones were left untouched, suggesting that PLA2 may serve as a ...

The accurate analysis of circulating tumor cells (CTCs) holds great promise in early diagnosis and prognosis of cancers. However, the extremely low abundance of CTCs in peripheral blood samples limits the practical utility of the traditional methods for CTCs detection. Thus, novel and powerful strategies have been proposed for sensitive detection of CTCs. In particular, nanomaterials with exceptional physical and chemical properties have been used to fabricate cytosensors for amplifying the signal and enhancing the sensitivity. In this review, we summarize the recent development of nanomaterials-based optical and electrochemical analytical techniques for CTCs detection, including fluorescence, colorimetry, surface-enhanced Raman scattering, chemiluminescence, electrochemistry, electrochemiluminescence, photoelectrochemistry and so on.

It is a great challenge to finely tune the morphology of iron oxides for energy storage. In this work, we introduced a facile hydrothermal method to obtain single crystalline hematite (α-Fe2O3) nano-coffee beans (NCBs) with the assistance of acetic acid. Interestingly, α-Fe2O3 nanostructures with this special morphology were formed under the effect of Ostwald ripening and oriented etching of H+ ions along [001] direction, which could be proved by the scanning electron microscope /transmission electron microscope and X-ray diffraction. After calcination at high temperature, the as-prepared α-Fe2O3 NCBs were used as potential anode materials, showing a very high reversible capacity of 810 mA h g−1 (0.2 C), excellent cycling stability, and high-rate performance for lithium storage. Hence, in virtue of the good performances, the structural design of nanomaterials would be promoted in the fabrication of electrode materials for lithium-ion batteries.

It is a challenge to prepare organic electrodes for sodium-ion batteries with long cycle life and high capacity. The highly reactive radical intermediates generated during the sodiation/desodiation process could be a critical issue because of undesired side reactions. Here we present durable electrodes with a stabilized α-C radical intermediate. Through the resonance effect as well as steric effects, the excessive reactivity of the unpaired electron is successfully suppressed, thus developing an electrode with stable cycling for over 2,000 cycles with 96.8% capacity retention. In addition, the α-radical demonstrates reversible transformation between three states: C=C; α-C·radical; and α-C− anion. Such transformation provides additional Na+ storage equal to more than 0.83 Na+ insertion per α-C radical for the electrodes. The strategy of intermediate radical stabilization could be enlightening in the design of organic electrodes with enhanced cycling life and energy storage capability., Reactive radical intermediates can be a problem leading to fast degradation of organic electrodes in sodium-ion batteries. Here, the authors show a stabilized α-C radical displaying reversible transformations between C=C, α-C radical and α-C anionic states to facilitate long cycling and improved capacity.

Self-assembling natural drug hydrogels formed without structural modification and able to act as carriers are of interest for biomedical applications. A lack of knowledge about natural drug gels limits there current application. Here, we report on rhein, a herbal natural product, which is directly self-assembled into hydrogels through noncovalent interactions. This hydrogel shows excellent stability, sustained release and reversible stimuli-responses. The hydrogel consists of a three-dimensional nanofiber network that prevents premature degradation. Moreover, it easily enters cells and binds to toll-like receptor 4. This enables rhein hydrogels to significantly dephosphorylate IκBα, inhibiting the nuclear translocation of p65 at the NFκB signalling pathway in lipopolysaccharide-induced BV2 microglia. Subsequently, rhein hydrogels alleviate neuroinflammation with a long-lasting effect and little cytotoxicity compared to the equivalent free-drug in vitro. This study highlights a direct self-assembly hydrogel from natural small molecule as a promising neuroinflammatory therapy., There is interest in the development of drug-based hydrogels for responsive sustained drug release. Here, the authors report on the self-assembly of natural small molecule, rhein, into hydrogels and the application of the hydrogels as stable controlled release agents for neuro-inflammatory therapy

Self-assembling natural drug hydrogels formed without structural modification and able to act as carriers are of interest for biomedical applications. A lack of knowledge about natural drug gels limits there current application. Here, we report on rhein, a herbal natural product, which is directly self-assembled into hydrogels through noncovalent interactions. This hydrogel shows excellent stability, sustained release and reversible stimuli-responses. The hydrogel consists of a three-dimensional nanofiber network that prevents premature degradation. Moreover, it easily enters cells and binds to toll-like receptor 4. This enables rhein hydrogels to significantly dephosphorylate IκBα, inhibiting the nuclear translocation of p65 at the NFκB signalling pathway in lipopolysaccharide-induced BV2 microglia. Subsequently, rhein hydrogels alleviate neuroinflammation with a long-lasting effect and little cytotoxicity compared to the equivalent free-drug in vitro. This study highlights a direct self-assembly hydrogel from natural small molecule as a promising neuroinflammatory therapy.

Novel three-dimensional (3D) concentration-gradient Ni-Co hydroxide nanostructures (3DCGNC) have been directly grown on nickel foam by a facile stepwise electrochemical deposition method and intensively investigated as binder- and conductor-free electrode for supercapacitors. Based on a three-electrode electrochemical characterization technique, the obtained 3DCGNC electrodes demonstrated a high specific capacitance of 1,760 F·g−1 and a remarkable rate capability whereby more than 62.5% capacitance was retained when the current density was raised from 1 to 100 A·g−1. More importantly, asymmetric supercapacitors were assembled by using the obtained 3DCGNC as the cathode and Ketjenblack as a conventional activated carbon anode. The fabricated asymmetric supercapacitors exhibited very promising electrochemical performances with an excellent combination of high energy density of 103.0 Wh·kg−1 at a power density of 3.0 kW·kg−1, and excellent rate capability—energy densities of about 70.4 and 26.0 Wh·kg−1 were achieved when the average power densities were increased to 26.2 and 133.4 kW·kg−1, respectively. Moreover, an extremely stable cycling life with only 2.7% capacitance loss after 20,000 cycles at a current density of 5 A·g−1 was achieved, which compares very well with the traditional doublelayer supercapacitors.

Mothers against decapentaplegic homolog 7 (SMAD7) rs12953717 polymorphism has been implicated to alter the risk of colorectal cancer (CRC), but the results are controversial. The objective of this study was to quantitatively evaluate the association between SMAD7 rs12953717 polymorphism and CRC susceptibility. A comprehensive search was conducted to identify all eligible studies of SMAD7 rs12953717 polymorphism and CRC risk. Pooled odds ratio and 95 % confidence interval were calculated using a fixed or random effects model. Statistical analysis was performed with Review Manager 5.0 and Stata 11. A total of 11 case–control studies, including 12,058 cases and 11,444 controls, were identified. The combined results based on all studies suggested that rs12953717 was associated with CRC risk under all genetic models. When stratifying for race, the data showed that the rs12953717 was associated with a significantly increased CRC risk under all genetic models in Caucasians. Statistically significant association was found in all genetic models except in recessive model comparison in the subgroup of Asians. After stratifying the studies by study design, there was a significant association between rs12953717 polymorphism and CRC risk under all genetic models in the subgroup of population-based studies. Our study suggests that rs12953717 polymorphism is associated with an increased CRC risk.

A simple and novel supramolecular hydrogel was prepared from ferrocene (Fc) modified amino acid phenylalanine (F) and utilized as electrochemical immunosensing platform for the detection of human IgG. Scanning electron microscopy (SEM) characterization indicated that the hydrogel is composed of fibrils with diameter around 50-100 nm and length extend to 1mm. When the prepared hydrogel was reacted with H2O2, the Fc moieties on the amino acid was oxidized, leading to the disruption of the hydrogel structure and the decrease of its redox signal, which was characterized in detail by SEM and the electrochemical method. Regarding the redox current decrease upon the reaction of the hydrogel with H2O2, the hydrogel modified electrode was utilized as immunosensing interface. After the construction of the immunosensor based on the traditional sandwich protocol with glucose oxidase (GOx) functionalized carbon nanotube (CNT) as detection antibody label, the GOx attached onto electrode surface would catalyze glucose reaction to produce H2O2 and cause the decrease of redox current of the electrode. The current change is proportional to the concentration of IgG detected in the range from 0.1 to 100 pg/mL. The high sensitivity, wide linear range and good reproducibility of the immunosensor indicate this immunosensing platform can be easily extended to the detection of other protein biomarkers.

A green, energy-efficient and simple route was design to synthesis the hollow structure of precursor electrode materials for high-performance lithium-ion batteries through in situ reduction self-assembly metallic composites in supramolecular hydrogel. By annealing the precursor at the appropriate temperature, we successfully obtained hollow CuO spheres with many self-assembly nanoparticles and highly homogeneous carbon distribution and N dopant as well. The hollow CuO spheres exhibit remarkably enhanced cycling performance and rate performance when being used as anode materials in lithium-ion batteries. This process provides a general route to the synthesis of hollow nanostructures of a large number of compounds for fields such as smart devices and other energy store systems. Figure 1a presents SEM of CuO-500. As can be seen, the microsphere is apparently having a hollow structure. To investigate the compositional distributions of Cu, O, N and C in CuO-500, we carried out elemental mapping using EDS coupled with HAADF/STEM. The images revealed that these components in the hollow sphere, along with the N and C atoms, were distributed uniformly with the Cu and O atoms. The intensity of these elements components was slightly higher at the sphere rims, similarly strong confirmed the formation of a hollow structure. As anodes in Li-ion batteries, Figure 1b, the specific capacity of as-prepared CuO was found to be 750 mAhg−1 after 10 cycles and can retain almost 100% of its original capacity after 100 cycles. The outstanding electrochemical performance of the CuO-500 composite could be attributed to the unique advantageous hollow structure. These can be explained by the following aspects: Firstly, the chitosan was successfully grafted to the Cu/Cu2O particles during the in situ reduction and self-assembly process, this special method formed a highly homogeneous carbon distribution and N dopant after the carbonization of chitosan. These carbon particles not only helped provide good electrical connection to the poor conductive CuO particles and provided channels for fast electron transport, but also hindered the aggregation of CuO nanoparticles. Secondly, the unique hollow structure supplied a large void space which can largely endure the volume expansion of CuO particles without changing the secondary particle size during the lithium insertion. And the carbon around the CuO particles also reinforced strength of the hollow structure and played an important role in preventing the cracking of the electrode during the volume change process. This particular structure can stay the original big-ball morphology even after 138 cycles. Thirdly, the assemble CuO particles lowered the electrode–electrolyte contact area, limited most SEI formation to the outer secondary particle surface instead of on individual nanoparticles, thus increased the stability of the SEI films1 Acknowledgments This work was financially supported by the Shenzhen Peacock Plan (KQCX20140522150815065), the Natural Science Foundation of Shenzhen (JCYJ20150331101823677) and the Science and Technology Innovation Foundation for the Undergraduates of SUSTC (2015x19 and 2015x12). Reference Liu, N. et al. A pomegranate-inspired nanoscale design for large-volume-change lithium battery anodes. Nature nanotechnology 9, 187-192, doi:10.1038/nnano.2014.6 (2014). Figure 1

Sensitive electrochemical immunosensor for the detection of protein biomarker tumor necrosis factor α (TNF-α) was reported that uses ferrocene carboxylic acid (Fc) functionalized self-assembled peptide nanowire (Fc-PNW) as sensor platform and glucose oxidase (GOx) modified gold nanorod (GNR) as label. Greatly enhanced sensitivity is achieved based on a dual signal amplification strategy: first, the synthesized Fc-PNW used as the sensor platform increased the loading of primary anti-TNF-α antibody (Ab(1)) onto electrode surface due to its large surface area. At the same time, the Fc moiety on the nanowire is used as a mediator for GOx to catalyze the glucose reaction. Second, multiple GOx and secondary anti-TNF-α antibody (Ab(2)) molecules are bounded onto each GNR to increase the sensitivity of the immunosensor. After the preparation of the immunosensor based on the traditional sandwich protocol, the response of the immunosensor towards glucose was used as a signal to differentiate various concentrations of TNF-α. The resulting immunosensor has high sensitivity, wide linear range (0.005-10ng/mL) and good selectivity. This immunosensor preparation strategy is a promising platform for clinical screening of protein biomarkers.

This paper introduces the first example of two dimensional (2D) DNA networks that were formed through self-assembly at an air–water interface over time. DNA molecules are highly hydrophilic and have never been reported to exhibit surface activity. Our experimental results confirmed an increase of surface pressure resulting from the formation of a DNA film. We found that upon layer-by-layer Langmuir–Blodgett transformation, 2D DNA molecules preferred to stack on the pre-loaded DNA domains rather than occupy the empty areas on the silicon wafers. We also observed that the fluorescence intensity of DNA films continually increased with incubation time, suggesting that DNA molecules may undertake supra-molecular rearrangements to form well-organized networks. We believe that the success in obtaining well-organized and large scaled DNA 2D and 3D templates may greatly simplify the procedure and decrease the cost for DNA nanotechnologies.