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In recent year, carbon materials have attracted an intensive interest for scientists to propel the development of nanotechnology. In this manuscript, using forced-field-based molecular dynamics simulations, the interaction between the carbon nanotubes (CNTs) and silver (Ag) nanowires (NWs) has been investigated. The results show that the Ag NW can induce the self-assembly of the CNTs to form a shell-core structure, and the van der Waals interaction and the offset face-to-face π-π stacking interaction play an important role in this process. Furthermore, the size (diameter) of the CNTs should meet some required conditions to guarantee the shell-core configuration and different surface of Ag NWs exhibits different result. Moreover, different metal nanowires were also discussed.

The influence of microstructure on anti-tarnish ability of silver deposit was studied by computational chemistry and experiments. The influence of microstructure on the anti-tarnish ability of silver deposit was firstly predicted by quantum chemical calculations. Theoretical studies revealed that high-index crystal surfaces of silver deposits were more sensitive to corrosive mediums and were seriously damaged when they were discolored. Based on the prediction of quantum chemical calculations, silver electrodeposition process with crystal surfaces controlled by additives was possible approach to improve the anti-tarnish ability of silver deposit in this work. The anti-tarnish ability of silver deposit influenced by crystal surfaces control was studied by surface discoloration investigation and Tafel plots measurements, as well as X-ray photoelectron spectroscopy (XPS) measurements. The results of these measurements confirmed the conclusions of theoretical studies; silver electrodeposition process with microstructure control can be used to improve the anti-tarnish ability of silver deposit.

The recovery of silver from cyanide-free silver electrodeposition bath to prepare AgCl photocatalyst was studied by quantum chemical calculations and experiment. Quantum chemical calculations were used to predict the coordinated bonds broken mechanism as well as silver recovery and AgCl photocatalyst formation. Based on the prediction, HCl was used in silver recovery and preparation of AgCl. With addition of HCl into silver electrodeposition bath, coordinated bonds between Ag+ and composite complexing agents, 5,5-dimethylhydantoin (DMH) and nicotinic acid (NA), were broken and the Ag+ was recovered as AgCl with high purity. The composition of products was studied byXRD and XPS measurements. The introduced method is effective and economical for silver recovery from investigated bath and wastewaters. The insight view of coordination interaction of complexing agents for metal ions in this manuscript is a great strength to perfect the investigation of novel metal recovery and resources recycling in aspect of technique and mechanism.

The neurotrophin brain-derived neurotrophic factor (BDNF) has been involved in supporting of neuron survival. The observation of reduced level of BDNF in the substantia nigra (SN) of Parkinson’s disease (PD) patients suggests its important role in neuron protection in PD pathogenesis. However, the mechanism underlying the down-regulation of BDNF in PD was largely unknown. In this study, we found that miR-210-3p is involved in the regulation of BDNF production by 1-methyl-4-phenylpyridinium (MPP + ). MPP + inhibits the BDNF production in SH-SY5Y cells through a transcription independent manner. Moreover, miR-210-3p, which targets BDNF mRNA, is up-regulated by MPP + in SH-SY5Y cells. Importantly, inhibition of miR-210-3p prevents the reduction of BDNF production by MPP + and improves the DA neuron survival in 1-methyl-4-phenyl-1,2,3,6-tetra hydropyridine (MPTP) model. Together, we demonstrated up-regulation of miR-210-3p by MPP + reduces the BDNF production and contributes to the DA neuron damage.

The interaction between the carbon nanotubes (CNTs) and platinum (Pt) nanowires (NWs) was investigated using forced field-based molecular dynamics (MD) simulations. Our results display that the Pt ...

MnCo2O4 architectures assembled from well-aligned nanowire or nanosheet arrays have been vertically grown on Ni foam with robust adhesion by in situ hydrothermal growth. Interestingly, the nanostructures of MnCo2O4 can be easily tailored from nanowires to nanosheets by the addition of NH4F at moderate concentrations in a mixed solvent. Further, unique 3D self-supported hierarchical core/shell MnCo2O4@CoS nanowire or nanosheet (MCO-NW@CS or MCO-NS@CS) arrays have been further engineered and synthesized via a subsequent electrodeposition process, which shows that interconnected CoS ultrathin layers as the shell have been uniformly immobilized on the MnCo2O4 arrays to form a novel core/shell structure. The synergic effect of the unique structure and heterogeneity is advantageous to increase the interfacial area, improve the charge accumulation and storage, accelerate the electron and electrolyte ion transfer, and enhance the electrochemical activity of the two components (MnCo2O4 and CoS) when used as an integrated electrode for (asymmetric) supercapacitors. As a result, the MCO-NW@CS or MCO-NS@CS electrodes display greatly improved electrochemical performance including remarkable specific capacitance, outstanding rate capability and good cycling stability. Moreover, the solid-state asymmetric supercapacitor using MCO-NS@CS as the positive active electrode and activated carbon (AC) as the negative active electrode has also achieved high energy density (55.1 W h kg−1 at 477.3 W kg−1). The hierarchical MCO-NW@CS or MCO-NS@CS electrodes with outstanding structural characteristics hold great promise not only in high capacitance applications but also in high energy and power density fields. In addition, to have a deeper understanding of their electrochemical behavior, a combined experimental and density functional theory (DFT) calculation study is also introduced.

Two-dimensional (2D) N,S co-doped porous carbon nanosheets are prepared in the presence of graphene oxide (GO) from expired wheat flour. It is found that GO can effectively direct the morphologies of the activated products, resulting in unique 2D structures. The as-obtained 2D N,S co-doped porous carbon nanosheets as electrodes for supercapacitors exhibit a high specific capacitance of 291 F g−1 at a current density of 0.5 A g−1 and good rate capability with a capacitance retention of 70% at a high current density of 30 A g−1. The 2D N,S co-doped porous carbon nanosheet electrodes also exhibit good cycling performance, possessing a high capacitance retention of over 93% after 5000 charge–discharge cycles at a current density of 5 A g−1. Experimental and theoretical results reveal that the synergistic effect of the N and S species can improve the electrochemical performance. The peculiar 2D structural characteristics featuring a short ion transport distance and abundant porous channels also can increase the specific capacitance.

In-suit grown composite materials have received much attention on scientific communities in recent years owing to their unique physicochemical properties for applications such as energy storage devices. Herein, we report freestanding in-situ grown Ni(OH)2 nanosheets on Ni foam by a facile one-step hydrothermal approach using aqueous nickel nitrate as precursor solution without any additives. The influence of concentration of nickel nitrate on morphology and electrochemical properties of the synthesized Ni(OH)2/Ni foam (NHNF) was investigated. Binder-free 0.12-NHNF electrode material exhibited a high gravimetric capacity of 340 mAh g−1 at a current density of 1 A g−1, excellent cycling stability (81.1% capacity retention after 3000 cycles) and good flexibility (89.2% capacity retention after folding in a roll). A hybrid supercapacitor (HSC) based on the synthesized 0.12-NHNF as positive electrode and commercial active carbon as negative electrode delivered a high energy density of 39.2 Wh kg−1 at a power density of 598 W kg−1 at a working voltage of 1.6 V. Long-term cycling stability test shows that the capacity retention of 84.3% was achieved with the HSC after 3000 cycles. The excellent electrochemical performance of the NHNF material indicates that it can be an appealing candidate electrode material in energy storage devices.

SnS/graphene nanocomposites have been prepared through a facile solvothermal reaction with Sn/graphene as the precursor. SnS particles are homogeneously sandwiched between graphene nanosheets. The electrochemical performances of the materials have been evaluated by cyclic voltammetry and galvanostatic discharge/charge cycling. Results show that the nanocomposites exhibit superior reversible lithium storage performance. The strategy presented in this work may provide an easy way for the fabrication of other metal sulfide/graphene nanocomposites.

In this manuscript, a molecular dynamics simulation is used to study the fish-like structure formed through polyacetylene induced by multiple fullerence C70s. The results display that the multiple linearly arranged fullerence C70s becomes a cluster structure located on the head of the “fish” and the polyacetylene is bent into a “fish” shape. The whole formation process experiences three stages which are agglomeration, slippage and torsion. Both the van der Waals potential well and the π–π stacking interaction between the polyacetylene and fullerence C70s play a vital role in the formation of fish-like nanostructures. Furthermore, some factors such as the number of fullerence C70, the length of polymer influence the final configuration of composite. Moreover, the simulation temperature that is too high or too low is not conducive to form the fish-like nanostructures. The new geometrical structures between polyacetylene and fullerence C70s may provide valuable theoretical support for designing and fabricating hybrid structures in the fields of advanced composite materials and functional devices.

The undesired energy level alignment and charge recombination at the perovskite/carbon electrode interface limit the application of carbon-based perovskite solar cells (C-PSCs). The incorporation of hole transport materials, CuSCN, is an effective strategy to solve this issue. However, the mismatched crystal structure and lattice between the perovskite layer (cubic crystal) and CuSCN layer (hexagonal crystal) lead to a charge transport barrier due to the gaps at the heterogeneous interface. Herein, the interfacial engineering designed on CuSCN has been carried out, which not only improves the quality of perovskite film but also reduces the defects, enhances the interfacial connection, and ensures rapid charge extraction and transfer. After key parameter adjustment, both high efficiency (15.81%) and good stability of C-PSCs have been obtained. After storage for 2,000 h at ambient air environment, devices without any encapsulation could maintain 93% of their initial efficiency. The thermal stability test shows that the encapsulated devices retain 83% of their initial efficiency after storage for 300 h in dry air at 85 °C. Deep insight and mechanisms have been proposed in this interfacial engineering design for improving the efficiency and stability of C-PSCs.

The temperature fluctuation process on localized shear band is an important foundation of the chip formation mechanism in mesoscopic scale of time (700-70ms) and dimension (65-500um). An accurate transient temperature fluctuation modeling of localized shear band is proposed by using the classic method of moving heat source and thermal convection in mesoscopic scale. Where, chip geometry, time coefficient of the coupling effect from relative chip segment, temperature rise from different heat sources and thermal convection model for chip segmentation process are developed, respectively. A novel measuring method are applied for thermal distribution in shear band and its evolution in chip generation progression. The given experimental and numerical results can show that the proposed temperature model can get the efficient predictions of temperature and physical phenomena at various chip segmentation stage. Physical phenomena in chip formation process, such as instable chip flow, crack generated and propagation, from the viewpoint of temperature fluctuation and its instable evolution, and cutting force are addressed and analyzed. The innovative model can determine the temperature fluctuation and evolution, area of maximum temperature of shear band in chip segmentation process in mesoscale of time and dimension.

In this manuscript, the structure liking a Chinese food “hemp flowers” is formed through polyphenyl which is induced by C70. The whole formation process is tracked by the molecular dynamics simulation. The results exhibited that C70 induced polyphenyl to form a “hemp flowers” structure experiencing four stages which are transfer, wrap, maintain and twist. Both the van der Waals potential well and the π–π stacking interaction between the polyphenyl and C70 play the major role in the formation of helical nanostructures. The position of C70 makes the configuration different from the “hemp flowers”. Furthermore, the final configuration of polymer is also depended on the number of C70, the length of polymer and the simulation temperature. The new geometrical structures between polyphenyl and C70 may supply more theoretical foundation in chemical functionalization and helical polymer synthesis, which may be helpful insight for fabricating nanoscale devices.

A general strategy is demonstrated to achieve superior lithium storage properties by constructing Sn/graphene nanocomposite architecture. The synergistic lithium storage performance of Sn/graphene is initially investigated by quantum chemical calculations based on density functional theory. Results show that the electronic conductivity of Sn/graphene is superior to that of Sn metal. Subsequently, a facile precipitation method is designed to fabricate Sn/graphene composites. SEM and TEM analysis reveals that Sn nanoparticles (40–80 nm) are homogenously sandwiched between graphene nanosheets. Cyclic voltammetry and galvanostatic charge/discharge measurements show that Sn/graphene composites exhibit superior lithium storage capability as compared to bare Sn. The enhanced performance is further investigated by electrochemical impedance spectroscopy. Results suggest that the addition of graphene in the nanocomposites significantly improves the electron transfer, which is consistent with the quantum chemical calculations.

The interfacial interaction between polypropylene (PE) and single walled carbon nanotube (SWCNT) was studied using molecular dynamics (MD) simulations. The result showed that the PE chain could stabilize the SWCNT and then extended along the direction of SWCNT. The mechanism of interfacial interaction between PE and SWCNT was also discussed. Furthermore, the interfacial interaction between more PE and SWCNT was also investigated and the position also deeply influenced the interaction. This will be beneficial to understanding the interfacial interaction between polymer and CNT in solution, and also guiding the fabrication of high performance polymer/CNT nanocomposites.

Binocular-like carbon structure was successfully fabricated using forced-field-based molecular dynamics simulations. The mechanism for the self-scrolling of graphene sheet using carbon nanotubes as...

// Kaishu Li 1, 2, 5, * , Leping Ouyang 1, * , Mingliang He 1, 2, * , Ming Luo 2, 3 , Wangqing Cai 1 , Yalin Tu 4 , Rongbiao Pi 4 , Anmin Liu 1, 2 1 Department of Neurosurgery, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou 510120, PR China 2 Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Sun Yat-sen Memorial Hospital of Sun Yat-sen University, Guangzhou 510120, PR China 3 Department of Oncology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou 510120, PR China 4 Department of Pharmacology & Toxicology, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510080, PR China 5 Department of Neurosurgery, The Sixth Affiliated Hospital of Guangzhou Medical University, Qingyuan 511500, PR China * These authors have contributed equally to this work Correspondence to: Anmin Liu, email: liuanmin@mail.sysu.edu.cn Ming Luo, email: luoming2@mail.sysu.edu.cn Keywords: IDH1, Nrf2, NQO1, temozolomide, chemotherapy Received: October 12, 2016 Accepted: February 13, 2017 Published: March 03, 2017 ABSTRACT Purpose: Numerous studies have reported that glioma patients with isocitrate dehydrogenase 1(IDH1) R132H mutation are sensitive to temozolomide treatment. However, the mechanism of IDH1 mutations on the chemosensitivity of glioma remains unclear. In this study, we investigated the role and the potential mechanism of Nrf2 in IDH1 R132H-mediated drug resistance. Methods: Wild type IDH1 (R132H-WT) and mutant IDH1 (R132H) plasmids were constructed. Stable U87 cells and U251 cells overexpressing IDH1 were generated. Phenotypic differences between IDH1-WT and IDH1 R132H overexpressing cells were evaluated using MTT, cell colony formation assay, scratch test assay and flow cytometry. Expression of IDH1 and its associated targets, nuclear factor-erythroid 2-related factor 2 (Nrf2), NAD(P)H quinine oxidoreductase 1 (NQO1), multidrug resistant protein 1 (MRP1) and p53 were analyzed. Results: The IDH1 R132H overexpressing cells were more sensitive to temozolomide than WT and the control, and Nrf2 was significantly decreased in IDH1 R132H overexpressing cells. We found that knocking down Nrf2 could decrease resistance to temozolomide. The nuclear translocation of Nrf2 in IDH1 R132H overexpressing cells was lower than the WT and the control groups after temozolomide treatment. When compared with WT cells, NQO1 expression was reduced in IDH1 R132H cells, especially after temozolomide treatment. P53 was involved in the resistance mechanism of temozolomide mediated by Nrf2 and NQO1. Conclusions: Nrf2 played an important role in IDH1 R132H-mediated drug resistance. The present study provides new insight for glioma chemotherapy with temozolomide.

The influence of composite additives, 2,2′-bipyridine (BPY) and potassium antimonyl tartrate (PAT), on the electrochemical behavior of a 5,5-dimethylhydantoin (DMH)-based cyanide-free silver plating bath was investigated by experiments and quantum chemical calculations. The cathodic discharge process of the cyanide-free silver plating bath was studied by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) measurements. CVs with different sweep rates and cathodic polarization measurements performed on a glassy carbon rotating disk electrode (GC-RDE) were employed to investigate the influence of composite additives on kinetic features of the discharge process of electroactive species. Without and with additives, the nucleation processes of silver deposition from these two electrolytes both exhibit three-dimensional progressive nucleation according to the chronoamperometry (I–t) measurements. In order to reveal the relevance between the inhibitive influence of additives and their molecular structures, the electronic properties of BPY and PAT were studied by quantum chemical calculations. The adsorption behaviors of BPY and PAT on the silver surface were further investigated by theoretical calculations and X-ray photoelectron spectroscopy (XPS). The results are in good agreement with each other, which confirms that BPY and PAT are effective additives for DMH based silver plating baths due to their ability to strongly adsorb on silver surfaces.

Summary Recurrence and diffuse infiltration challenge traditional therapeutic strategies for malignant glioma. Immunotherapy appears to be a promising approach to obtain long-term survival. Dendritic cells (DCs), the most specialized and potent antigen-presenting cells (APCs), play an important part in initiating and amplifying both the innate and adaptive immune responses against cancer cells. However, cancer cells can escape from immune surveillance by inhibiting maturation of DCs. Until the present, molecular mechanisms of maturation inhibition of DCs in the tumor microenvironment (TME) have not been fully revealed. Our study showed that pretreatment with tumor-conditioned medium (TCM) collected from supernatant of primary glioma cells significantly suppressed the maturation of DCs. TCM pretreatment significantly changed the morphology of DCs, TCM decreased the expression levels of CD80, CD83, CD86 and interleukin (IL)-12p70, while it increased the expression levels of IL-10, transforming growth factor (TGF)-β and IL-6. RNA-Seq showed that TCM pretreatment significantly increased the gene expression level of suppressor of cytokine signaling 1 (SOCS1) in DCs. suppressor of cytokine signaling 1 (SOCS1) knock-down significantly antagonized the maturation inhibition of DCs by TCM, which was demonstrated by the restoration of maturation markers. TCM pretreatment also significantly suppressed T cell viability and T helper type 1 (Th1) response, and SOCS1 knock-down significantly antagonized this suppressive effect. Further, TCM pretreatment significantly suppressed p65 nuclear translocation and transcriptional activity in DCs, and SOCS1 knock-down significantly attenuated this suppressive effect. In conclusion, our research demonstrates that TCM up-regulate SOCS1 to suppress the maturation of DCs via the nuclear factor-kappa signaling pathway.

A black phosphorus (BP)/Ti

Visual signal (i.e., images and videos) coding is to compress digital visual data to be as small in size as possible in order to make use of limited bandwidth of networks and cater for compact storage, by exploring various data redundancy. It exploits the redundancy in signal itself (statistical redundancy, i.e., spatial-temporal redundancy and spectral/color redundancy). Since the human visual system (HVS) is the ultimate receiver and appreciator of most processed visual signal, we should also consider the redundancy due to the human vision properties (i.e., perceptual/psycho-visual redundancy) in the course of coding. The effectiveness of image and video coding methods is traditionally evaluated with their rate-distortion (RD) performance where rate is the number of bits required for the compressed visual signal (or its variants such as bits per pixel (bpp) and bits per second) and distortion is usually measured as peak signal to noise ratio (PSNR). However, it has been found that PSNR is not always in accordance with the human judgment and therefore the measurement for perceptual distortion is an active research area. Firstly, in this work, we discuss the statistical redundancy of video and then propose a novel optimal compression plane (OCP) based video coding scheme. In the sense of data structure, video is nothing more than a three dimensional data matrix, and the distinction among X (a spatial dimension), Y (the other spatial dimension), and T (the temporal dimension) is not absolutely necessary. We ignore the physical meaning of X, Y, and T axes for a video during the video coding process; frames are allowed to be formed in the TX (or TY) plane rather than the traditional XY plane to exploit the redundancy more effectively, and therefore better coder performance is achieved. Secondly, the model reflecting the masking characteristics of the HVS is studied as it is fundamental for perceptual redundancy exploring and visual distortion (quality) measurement. Just noticeable difference (JND) accounts for various masking effects of the HVS. We improve the pixel domain JND model by better contrast masking (CM) evaluation and appropriately accounting for the difference of CM for textural and edge regions. We also investigate into the application of the perceptual models (i.e., visual attention model and JND model) in the context of adaptive sampling based low-bit-rate image coding and JND based histogram adjustment for visually lossless image coding. Lastly, an effective and efficient metric of visual quality/distortion evaluation is proposed. The metric is based on the similarity between the gradient profiles of the reference and distorted signals which accounts for both the high level premise of the HVS (i.e., high sensitivity to image edges and structure) and the masking property. This new metric is with simple calculation and high accuracy (verified with extensive cross-database tests); it is robust to various distortion types and can be easily embedded in coding systems (as well as other visual signal processing algorithms). DOCTOR OF PHILOSOPHY (SCE)

Background:\ud External devices are used to manage musculoskeletal pathologies by altering loading of the foot, which could result in altered muscle activity that could have therapeutic benefits.\ud \ud Objectives:\ud To establish if evidence exists that footwear, foot orthoses and taping alter lower limb muscle activity during walking and running.\ud \ud Study design:\ud Systematic literature review.\ud \ud Methods:\ud CINAHL, MEDLINE, ScienceDirect, SPORTDiscus and Web of Science databases were searched. Quality assessment was performed using guidelines for assessing healthcare interventions and electromyography methodology.\ud \ud Results:\ud Thirty-one studies were included: 22 related to footwear, eight foot orthoses and one taping. In walking, (1) rocker footwear apparently decreases tibialis anterior activity and increases triceps surae activity, (2) orthoses could decrease activity of tibialis posterior and increase activity of peroneus longus and (3) other footwear and taping effects are unclear.\ud \ud Conclusion:\ud Modifications in shoe or orthosis design in the sagittal or frontal plane can alter activation in walking of muscles acting primarily in these planes. Adequately powered research with kinematic and kinetic data is needed to explain the presence/absence of changes in muscle activation with external devices.\ud \ud Clinical relevance:\ud This review provides some evidence that foot orthoses can reduce tibialis posterior activity, potentially benefitting specific musculoskeletal pathologies.

The mechanical properties of an extruded 6013-T4 alloy were tested at a temperature range from 25 to 400 &deg, C and strain rate range from 1 &times, 103 to 5 &times, 103 s&minus, 1. The results demonstrate that the stress level is sensitive to strain rate and temperature. The stress level increases slightly with increasing strain rate and decreases remarkably with increasing temperature. The dislocation and precipitate undergo great changes. When deformed at 25 &deg, C, the density of the dislocation increases with strain and strain rate, which leads to a higher stress level. A great number of needle-like precipitates were observed at samples deformed at 200 &deg, C. It is clear that the density of dislocation increases with strain and strain rate. When impacted at 400 &deg, C, the coarser precipitates were found in the specimen, the density of the dislocation increases with strain and strain rate.

All-inorganic perovskites are attracting increasing attention due to their superior thermal stability than that of the traditional CH

Ultrathin 2D nitrogen-doped carbon nanosheets with a thickness of about 5 nm have been facilely synthesized from potato starch by using graphene oxides (GO) as the structure-directing agent. The pore structures and surface properties can be feasibly and rationally tailored by addition of a certain amount of GO in the precursor. The addition of GO to the potato starch can increase the surface areas and the pyridinic-N and pyrrolic-N ratios of the as-prepared 2D carbon nanosheets. The as-obtained ultrathin nitrogen-doped carbon nanosheets with the optimized amount of GO in potato starch (3 wt%) possess a unique 2D structure, a high N content, and high ratios of pyridinic-N and pyrrolic-N, exhibiting a high capacitance of 301 F g−1 at 0.5 A g−1, superior rate capability of 81% at 50 A g−1, and good cycling stability in 6 M KOH electrolyte. Experimental and theoretical results show that high pyridinic-N and pyrrolic-N ratios in the NCNSs are beneficial for improving the electrochemical performance. This work may provide helpful guidance for understanding the effect of the addition of GO to biomass precursors on the electrochemical performance of the 2D nitrogen-doped carbon electrodes for supercapacitors.

© 2019, American College of Rheumatology Objective: Lateral wedge shoe insoles decrease medial knee loading, but trials have shown no effect on pain in medial knee osteoarthritis (OA). However, loading effects of insoles are inconsistent, and they can increase patellofemoral loading. We undertook this study to investigate the hypothesis that insoles would reduce pain in preselected patients. Methods: Among patients with painful medial knee OA, we excluded those with patellofemoral OA and those with a pain rating of

Backward slope walking was considered as a practical rehabilitation and training skill. However, its gait stability has been hardly studied, resulting in its limited application as a rehabilitation tool. In this study, the effect of walking direction and slope grade were investigated on the local dynamic stability of the motion of lower extremity joints and trunk segment during backward and forward upslope walking (BUW/FUW). The local divergence exponents (λS) of 16 adults were calculated during their BUW and FUW at grades of 0%, 5%, 10%, and 15%. Mean standard deviation over strides (MeanSD) was analyzed as their gait variability. Backward walking showed larger λS for the abduction-adduction and rotational angles of knee and ankle on inclined surface than forward walking, while λS for hip flexion-extension angle at steeper grades was opposite. No grade effect for any joint existed during BUW, while λS increased with the increasing grade during FUW. As to the trunk, walking direction did little impact on λS. Still, significant larger λS for its medial-lateral and vertical motion were found at the steeper grades during both FUW and BUW. Results indicate that during BUW, the backward direction may influence the stability of joint motions, while the trunk stability was challenged by the increasing grades. Therefore, BUW may be a training tool for the stability of both upper and lower body motion during gait.

The conjugate bridge plays an important role in the D–π–A sensitizers, which affects the optical properties, energy levels and electron transfer from donor to acceptor unit. The transfer and securing abilities of conjugate bridge is a necessary conditions to raise the red-shift absorption band, light harvesting ability. In this paper, the effect of conjugate bridge in the D–π–A sensitizers, such as benzene, thiophene, bithiophene, 4-(thiophen-2-yl)benzo[c] [1,2,5]thiadiazole, 4-(thiophen-2-yl)benzo[c] [1,2,5]thiadiazole, terthiophene and so on, which were studied to predict the photoelectric properties of molecules. The ground-state structure and excited-state properties of the dyes and dyes/TiO2 were calculated using density functional theory (DFT) and time-dependent density functional theory (TD-DFT). The short circuit density (J sc), open-circuit voltage (V oc), fill factor (FF), and photo-to-electric conversion efficiency (η) are critical factors for dye-sensitized solar cells (DSSCs). Then, this method not only considered the relationship between macroscopic phenomena and macroscopic properties but also reasonably selected the dye molecules suitable for dye batteries.

In this manuscript, a molecular dynamics simulation was used to investigate the formation process of multiple helical nanostructures which was induced by the boron nitride nanotubes. The results displayed that three chains of polyacetylene changed to helical nanostructures in the boron nitride nanotube through self-assemble process. The combined action of the van der Waals potential well and the π–π stacking interaction between the polyacetylene and the inner surface of boron nitride nanotubes results in the formation of helical nanostructures. The chain number of polyacetylene influences the final configuration of polymer. Furthermore, some other influence factors such as the diameter of boron nitride nanotube and the length of polymer were also displayed. The new geometrical structures between polyacetylene and boron nitride nanotubes may attract more attention in chemical functionalization and helical polymer synthesis, which may be helpful for fabricating nanoscale devices.

In this manuscript, helical polyphenyl (PP) nanostructures were formed on single-wall carbon nanotubes (SWCNT) through self-assemble process which was investigated by a molecular dynamics simulation. The results displayed that the linear polyphenyl changed into helical structure and finally a core–shell structure was formed. The formation mechanism of whole process was also exhibited. Furthermore, some influence factors such as the initial angle between polyphenyl chain and nanotube axis, the diameter of carbon nanotube were also displayed. Moreover, the interactions between different halogenated benzene polymer and carbon nanotube were also studied. The new geometrical structures between polyphenyl and single-wall carbon nanotubes may attract more attention in chemical functionalization and helical polymer synthesis, which may be helpful for fabricating nanoscale devices.

With the consumption of fossil fuels, energy and environmental problems have become increasingly prominent. Finding new energy to replace traditional fossil fuels is one of the most promising approaches to solve current energy shortages and environmental problems. Fuel cells are not restricted to Carnot cycles when chemical energy is converted to electrical energy. It has the advantages of high energy conversion efficiency, cleanliness and environmental friendliness, and occupies an important position in the fields of new energy. However, slow cathode kinetics is an important reason which has limited development of fuel cells. The traditional Pt-based catalysts with poor stability, CO poisoning, high price and other shortcomings have been unable to meet the demands for serving as fuel cell catalysts. In recent years, the non-precious metal catalysts have been widely recognized for their higher stability and resistance to CO poisoning, which are cheaper than Pt-based catalysts. Scientists have made many efforts in research of non-precious metal catalysts. This review summarizes the research progress of non-precious metal catalysts in the field of fuel cells in recent years, mainly including non-metal doped carbon materials, metal and non-metal co-doped carbon materials, and the catalytic mechanism of various catalysts.

Metal corrosion is an important technical problem often encountered in industrial production in various fields. One of the efficient and economical methods to effectively block corrosion is to add a corrosion inhibitor, which forms a protective film on the metal surface. Accordingly, environmentally friendly organic corrosion inhibitors have become research hotspots in recent years. Among them, polyorganic substances have been proved to be effective corrosion inhibitors; however, research on this topic is still scarce. In this study, (poly) ethylene glycol and (poly) acrylamide are investigated as polyorganic inhibitors by density functional theory and molecular dynamic simulation, and the effect of the degree of polymerization (DP) on the adsorption behavior on metal surfaces is theoretically analyzed. On the basis of a comprehensive evaluation of their stability and adsorption energy, the optimal DPs of these two inhibitors are determined. This work may provide a theoretical basis and guidance for further research of corrosion inhibitor.

The decent power conversion efficiency (~20%), ultra-low cost, and 1-year stability make carbon-based perovskite solar cells (C-PSCs) one of the most promising candidates for commercialization in the field of perovskite photovoltaics. However, the stability of C-PSCs still lags behind that of the commercialized silicon and thin-film photovoltaics. Although there have been many reviews of the long-term stability of perovskite solar cells (PSCs), none has specifically focused on the long-term stability of C-PSCs. Herein, we summarize the environmental risks and strategies for ensuring the long-term stability of C-PSCs, highlighting also the various contributions of our research group. The most important factors affecting long-term stability are analyzed according to the environmental risks (i.e. moisture, oxygen, light, and thermal stress) of device degradation. The proposed strategies chiefly center around improving the intrinsic stability and strengthening encapsulation. In our conclusions, we also present an outlook on future work concerning stability improvement and commercial development of C-PSCs. Our work provides a clear guideline for future research on C-PSCs.

Metal-free catalysts for the CO2 reduction reaction (CO2RR) is a research hotspot to enhance CO2 utilization as a way to counteract global warming. Nitrogen-doped graphene attracts attention because of the abundance of nitrogen and promising catalytic performance of graphene. In this work, we investigated various N-doped configurations and their corresponding catalytic abilities for CO2RR to ethanol via spin-polarized density functional theory (DFT) computations. The final results indicate that site 43 of binary-N-doped graphene had high CO2RR activity, stable adsorption of reactants, and good activation of CO2. The catalysis process demonstrated features of low free energy barriers in the rising stage and obvious facilitation of the potential-limiting step. Compared with a catalyst-free process, it can effectively improve the reaction activity. The results provide theoretical guidance for the design and preparation of high-performance CO2RR catalysts.

The anodic methanol oxidation reaction (MOR) generates a toxic intermediate CO in direct methanol fuel cell (DMFC), where the Pt catalyst is easily deactivated and the catalytic activity will be inevitably lowered. Alloying modification is an important approach to improve the anti-CO ability of Pt catalyst. In this work, MOR mechanism on PtNi catalyst is theoretically studied on four crystal planes doped with one-to-three Ni atoms. The main path of CO poisoning on the catalyst surface: CH3OH → CH2OH → CHOH → CHO → CO was studied. Meanwhile, the adsorption of PtNi catalyst on the reaction intermediate was carried out. Based on the relative energy ΔE, the four optimal catalysts were compared for MOR. Building on the above comprehensive evaluations the appropriate catalysts were finally selected by the activation effect. It is proved by calculation that the selected 1,2,3Ni-Pt (2 0 0) reduces the relative energy of the overall reaction path, possessing good catalytic effect on MOR with certain anti-CO toxicity.

Correction for ‘Complexing agent study via computational chemistry for environmentally friendly silver electrodeposition and the application of a silver deposit’ by Anmin Liu et al., RSC Adv., 2014, 4, 40930–40940, DOI: 10.1039/C4RA05869K.

Ammonia (NH3) is recognized as a chemical substance that is very important for the development of human society. At present, the traditional industrial synthetic ammonia process is Haber-Bosch, which has some shortcomings such as low conversion rate, high energy consumption and greenhouse gas emission. Therefore, the search for new synthetic ammonia methods has attracted the attention of many scientific researchers. In this work, we use density functional theory (DFT) to explore vacancy and heteroatom (N, S) doped defective carbon materials suitable for catalyzing nitrogen reduction reaction (NRR). The introduction of vacancy defect, N or S atom doping graphene can improve the reactivity of graphene. In addition, the high activity sites of defective graphene mainly distribute on the carbon atoms at the upper left edge, the right edge and the lower edge. The research results theoretically determine the effect of different doping methods, doping positions and quantities on material properties, and provide theoretical basis and guidance for exploring new carbon catalysts.

Background: Knee valgus braces are used to reduce knee load and varus deformities in individuals with medial compartment osteoarthritis (OA). The purpose of this study was to determine whether the kinematics and kinetics of the knee are improved when wearing a knee-ankle-foot orthosis (KAFO) compared with knee valgus braces while walking and stair climbing. Materials and Methods: One male individual (with 10° of knee varus) was assessed with a control shoe, custom, and off-the-shelf (OTS) Unloader knee valgus braces, and a custom-made KAFO in situ during walking and stair climbing. Results: The KAFO significantly reduced the knee varus angle compared with the shoe and both knee valgus braces during walking and stair climbing, as well as the first peak of the external knee adduction moment (EKAM) during walking and the knee adduction angular impulse (KAAI) during ascending compared with the shoe. No significant differences were noted between the custom and OTS knee valgus braces in any measures. Conclusions: Knee-ankle-foot orthoses may be recommended for individuals with high knee varus angles.

The electrochemical behaviors of Ga3+ ions in 1-butyl-3-methylimidazolium trifluoromethanesulfonate ([BMIM][TfO]) ionic liquid are investigated by electrochemical methods and SEM. The cyclic voltammetry study reveals that both the temperature and the material of the electrodes have a significant influence on the electrochemical kinetics. The three methods involved rotating disk electrode have been used to obtain the diffusion coefficient (around 5.57 × 10−8 cm2/s) of Ga3+ ions in [BMIM][TfO] ionic liquid at 70 °C. Meanwhile, the diffusion coefficients at 40, 50, 60 °C and the activation energy are obtained by two of the three methods. By analyzing the current transients and the SEM images of the Ga particles formed during the transients, it is found that the nucleation of Ga on both the glass carbon electrode (GCE) and the Mo electrode in [BMIM][TfO] ionic liquid is a 3-D instantaneous process at 70 °C, while a 3-D progressive process on GCE at 25 °C. The compact and smooth Ga layer is electrodeposited on Mo film sputtered on ITO glass at −1.5 V (vs Pt) and 20 °C from the [BMIM][TfO] ionic liquid. Increasing the overpotential of the electrodeposition makes the Ga layer more porous. When the temperature is higher than the melting point of gallium metal, it has no significant influence on the morphology of the Ga deposits.

Electrochemical behaviors of a silver complex in an environmentally friendly silver plating bath with 5,5-dimethylhydantoin (DMH) and nicotinic acid (NA) as complexing agents were investigated in this paper. Like the cyanide based silver electroplating bath, silver deposits with smooth and compact morphologies, as well as high purity could be obtained from the studied DMH and NA based silver electroplating bath. The electrochemical behaviors of the silver complex in this cyanide-free silver electroplating were studied by cyclic voltammetry with different sweep rates to investigate the discharge process of the silver plating bath, the transfer coefficients and diffusion coefficient of the silver complex in this bath. The results of the chronoamperometry on a glass carbon electrode indicate that the nucleation processes of silver from the bath is a three-dimensional progressive nucleation process, and the growth of silver nucleation and the nucleation rate of silver deposit in the DMH and NA based silver plating bath were highly dependent on the applied potential.

Pt-based alloy electrocatalysts, PtNi/CNTs and PtNi, were synthesized through facile chemical reduction reaction for methanol oxidation reaction (MOR). Morphology, structure and composition of the PtNi/CNTs and PtNi electrocatalysts were physical characterized by the means of SEM, EDS, XRD and XPS. The catalytic activity, stability and durability of the obtained electrocatalysts were studied by cyclic voltammetry (CV) and amperrometric i-t cueves (i-t). The PtNi catalysts nanoparticles (NPs) obtained around 20 nm were homogenous distribution of two metal elements, and PtNi were well doped on the carbon nanotubes (CNTs) for PtNi/CNTs catalysts. The incorporation of Ni and high surface area of CNTs make the PtNi/CNTs and PtNi catalysts showing high eletrocatalytic activity for MOR. Furthermore, both PtNi/CNTs and PtNi electrocatalysts exhibit outstanding stability and durability at room temperature in acidic medium. This research provides positive guidance to prepare high performance and excellent stability electrocatalysts for MOR.