Search

In this article, we investigate acid fracturing, a promising method to increase the effectiveness of fractures in high temperature carbonate reservoirs. In order to determine the performance of acid fracturing in carbonate reservoirs, we conducted a lab scaled true triaxial acid fracturing experiment on high temperature carbonate rock. The fracture initiation, propagation behavior, and conductivity under the action of acid solution were analyzed. The 3-D micro computed tomography was applied to illuminate the fracture network patterns; coefficient of stress difference, acid etching time, and acid concentration were also analyzed. Results show acidification exhibits the lowest breakdown pressure compared with no-acidification, reduced by 58%. [ABSTRACT FROM AUTHOR]

The current deep learning-based image fusion methods can not sufficiently learn the features of images in a wide frequency range. Therefore, we proposed IFormerFusion, which is based on the Inception Transformer and cross-domain frequency fusion. To learn features from high- and low-frequency information, we designed the IFormer mixer, which splits the input features through the channel dimension and feeds them into parallel paths for high- and low-frequency mixers to achieve linear computational complexity. The high-frequency mixer adopts a convolution and a max-pooling path, while the low-frequency mixer adopts a criss-cross attention path. Considering that the high-frequency information relates to the texture detail, we designed a cross-domain frequency fusion strategy, which trades high-frequency information between the source images. This structure can sufficiently integrate complementary features and strengthen the capability of texture retaining. Experiments on the TNO, OSU, and Road Scene datasets demonstrate that IFormerFusion outperforms other methods in object and subject evaluations. [ABSTRACT FROM AUTHOR]

Background: GBM astrocytes may adopt fetal astrocyte transcriptomic signatures involved in brain development and migration programs to facilitate diffuse tumor infiltration. Our previous data show that ETS variant 6 (ETV6) is highly expressed in human GBM and fetal astrocytes compared to normal mature astrocytes. We hypothesized that ETV6 played a role in GBM tumor progression. Methods: Expression of ETV6 was first examined in two American and three Chinese tissue microarrays. The correlation between ETV6 staining intensity and patient survival was calculated, followed by validation using public databases—TCGA and REMBRANDT. The effect of ETV6 knockdown on glioma cell proliferation (EdU), viability (AnnexinV labeling), clonogenic growth (colony formation), and migration/invasion (transwell assays) in GBM cells was tested. RNA sequencing and Western blot were performed to elucidate the underlying molecular mechanisms. Results: ETV6 was highly expressed in GBM and associated with an unfavorable prognosis. ETV6 silencing in glioma cells led to increased apoptosis or decreased proliferation, clonogenicity, migration, and invasion. RNA-Seq-based gene expression and pathway analyses revealed that ETV6 knockdown in U251 cells led to the upregulation of genes involved in extracellular matrix organization, NF-κB signaling, TNF-mediated signaling, and the downregulation of genes in the regulation of cell motility, cell proliferation, PI3K-AKT signaling, and the Ras pathway. The downregulation of the PI3K-AKT and Ras-MAPK pathways were further validated by immunoblotting. Conclusion: Our findings suggested that ETV6 was highly expressed in GBM and its high expression correlated with poor survival. ETV6 silencing decreased an aggressive in vitro phenotype probably via the PI3K-AKT and Ras-MAPK pathways. The study encourages further investigation of ETV6 as a potential therapeutic target of GBM. [ABSTRACT FROM AUTHOR]

In recent years, numerous neurosurgical multimodal techniques have been utilized to maximize tumor resection safely and effectively. However, the synergetic effects of neurosurgical multimodalities on the survival of glioblastoma patients remain unclear. This study evaluated the role of intraoperative utilization of multimodalities in glioblastoma patients. Data of 912 adult patients with glioblastoma were obtained from the Huashan Glioma Registry. The utilization of fewer than 2 (multimodality value < 2) intraoperative multimodal techniques was defined as the nonmultimodal group. In contrast, the utilization of 2 or more (multimodality value ≥ 2) intraoperative multimodal techniques was regarded as the multimodal group. The prognosis of the 2 cohorts was compared and further stratified based on the diagnosis date (2010–2014 or 2015–2019) to reveal the role of the application of multimodal techniques. The median overall survival (OS) and progression-free survival of glioblastoma patients were 17.70 months and 12.03 months, respectively. The OS time of the multimodal group was noticeably longer than that of the nonmultimodal group (21.0 months vs. 16.0 months, P < 0.001). Multimodal techniques were more frequently applied in surgery in the 2015–2019 group than in the 2010–2014 group. The popularity of multimodal techniques contributed to significant improvement in the prognosis of glioblastoma patients from 2010–2014 to 2015–2019 (OS, 16.0 months vs. 22.0 months, P < 0.001). This study indicated that the utilization of intraoperative multimodal techniques improved the extent of resection and elevated the survival for adult glioblastoma patients. [ABSTRACT FROM AUTHOR]

Cannabidiol (CBD), a chemical found in the Cannabis sativa plant, is a clinically effective antiepileptic drug whose mechanism of action is unknown. Using a fluorescence- based thallium flux assay, we performed a large- scale screen and found enhancement of flux through heterologously expressed human Kv7.2/7.3 channels by CBD. Patch- clamp recordings showed that CBD acts at submicromolar concentrations to shift the voltage dependence of Kv7.2/7.3 channels in the hyperpolarizing direction, producing a dramatic enhancement of current at voltages near -50 mV. CBD enhanced native M- current in mouse superior cervical ganglion starting at concentrations of 30 nM and also enhanced M- current in rat hippocampal neurons. The potent enhancement of Kv2/7.3 channels by CBD may contribute to its effectiveness as an antiepileptic drug by reducing neuronal hyperexcitability. [ABSTRACT FROM AUTHOR]

This article, titled "[Retracted] Effect of metformin on cell proliferation, apoptosis, migration and invasion in A172 glioma cells and its mechanisms," was published in Molecular Medicine Reports in 2019. However, it has since been retracted by the journal due to concerns about the authenticity of the data presented. A concerned reader pointed out that the data in Figures 2 and 6 were similar to data from other articles by different authors. The authors were asked for an explanation but did not respond. The journal apologizes for any inconvenience caused. [Extracted from the article]

Objectives: Differential expression of microRNAs (miRNAs) has been confirmed to promote hypertrophic scar (HS) formation. However, this mechanism remains to be further elucidated. This paper investigated the effects of microRNA26a on HS of rabbit ears or its mechanism. Methods: The rabbit HS models were established and randomly assigned to either the experimental group (20 rabbits with treatment through triamcinolone acetonide) or the scar group (20 rabbits without treatment). In addition, 10 unmodeled rabbits were served as control group. The expression of microRNA-26a in HS tissues was detected via a stem-loop realtime polymerase chain reaction (RT-PCR). Results: According to RT-PCR, we showed the decreased expression of microRNA-26a in the scar group compared with that in the experimental group, and in the experimental group compared with that in the control group (p < .01). In addition, the expression of microRNA-26a was negatively correlated with scar thickness (STs), number of fibroblasts (NFs), Collagen I (Col I) level, Collagen III (Col III) level, Interleukin-6 (IL-6) level, and Tumor necrosis factor-alpha (TNF-α) level (all p < .01). Conclusions: Our findings revealed that the increase of microRNA-26a expression might alleviate excessive inflammation during the HS formation, inhibit fibroblast proliferation and collagen deposition in HS, and promote the treatment of HS. [ABSTRACT FROM AUTHOR]

RNA modification, like other epigenetic modifications such as DNA modification and histone modification, is an emerging player in the field of the posttranscriptional regulation of gene expression. More than 160 kinds of RNA modifications have been identified, and they are widely distributed in different types of RNA. Recently, researchers have increasingly used advanced technologies to study modified nucleic acids in order to elucidate their biological functions and expand the understanding of the central laws of epigenetics. In this tutorial review, we comprehensively outline current advanced techniques for decoding RNA modifications, highlighting some of the bottlenecks in existing approaches as well as new opportunities that may lead to innovations. With this review, we expect to provide chemistry and biology students and researchers with ideas for solving some challenging problems, such as how to simultaneously detect multiple types of modifications within the same system. Moreover, some low-coverage modifications that may act as 'candidates' in important transcriptional processes need to be further explored. These novel approaches have the potential to lay a foundation for understanding the nuanced complexities of the biological functions of RNA modification. [ABSTRACT FROM AUTHOR]

Nucleation of water on solid surface can be promoted noticeably when the lattice parameter of a surface matches well with the ice structure. However, the characteristic length of the surface lattice reported is generally less than 0.5 nm and is hardly tunable. In this paper, we show that a surface with nanoscale roughness can also remarkably promote ice nucleation if the characteristic length of the surface structure matches well with the ice crystal. A series of surfaces composed of periodic grooves with same depth but different widths are constructed in molecular dynamics simulations. Water cylinders are placed on the constructed surfaces and frozen at constant undercooling. The nucleation rates of the water cylinders are calculated in the simulation using the mean first-passage time method and then used to measure the nucleation promotion ability of the surfaces. Results suggest that the nucleation behavior of the supercooled water is significantly sensitive to the width of the groove. When the width of the groove matches well with the specific lengths of the ice crystal structure, the nucleation can be promoted remarkably. If the width does not match with the ice crystal, this kind of promotion disappears and the nucleation rate is even smaller than that on the smooth surface. Simulations also indicate that even when water molecules are adsorbed onto the surface structure in high-humidity environment, the solid surface can provide promising anti-icing ability as long as the characteristic length of the surface structure is carefully designed to avoid geometric match. [ABSTRACT FROM AUTHOR]

D. candidum Wall. ex Lindl. (D. candidum) is a traditional Chinese herbal medicine with multiple therapeutic properties. D. candidum was administered to mice with high-fat diet (HFD)-induced nonalcoholic fatty liver disease (NAFLD) and its mechanism of action was elucidated. D. candidum was intragastrically administered to HFD mice for 6 weeks at a dosage of 200 or 400 mg/kg. D. candidum reduced body weight gain and blood glucose levels in HFD mice in a dose-dependent manner, while significantly reducing lipid accumulation in the liver. D. candidum significantly regulated the expression of lipid metabolism-and gluconeogenesis-related genes and inhibited activation of the NLRP3 inflammasome. In summary, D. candidum significantly inhibits fat accumulation, maintains lipid metabolism and glucose homeostasis, and inhibits the inflammatory response in the liver of HFD mice. Our findings suggest that D. candidum may be an effective therapeutic strategy against NAFLD injury. Practical applications: The occurrence and development of fatty liver is closely related to abnormalities in lipid and glucose metabolism. An HFD-induced NAFLD mouse model was used to study the effects of D. candidum. After treatment with D. candidum, lipid and glucose metabolism in the mice was effectively regulated, which reduced liver damage and fat storage with obvious protective effects on the liver. Our results suggest that D. candidum has potential for further clinical application in the treatment of NAFLD. [ABSTRACT FROM AUTHOR]

• The ResCC module can extract richer multi-scale features without down-sampling operations. • The criss-cross attention mechanism can capture contextual information from both horizontal and vertical directions efficiently and effectively. • The spatial attention mechanism can deal with interdependencies within individual feature maps at different spatial locations. We proposed an infrared and visible image fusion method based on the ResCC module and spatial criss-cross attention models. The proposed method adopts an auto-encoder structure consisting of an encoder network, fusion layers, and a decoder network. The encoder network has a convolution layer and three ResCC blocks with dense connections. Each ResCC block can extract multi-scale features from source images without down-sampling operations and retain as many feature details as possible for image fusion. The fusion layer adopts spatial criss-cross attention models, which can capture contextual information in both horizontal and vertical directions. Attention in these two directions can also reduce the calculation of the attention maps. The decoder network consists of four convolution layers designed to reconstruct images from the feature map. Experiments performed on the public datasets demonstrate that the proposed method obtains better fusion performance on objective and subjective evaluations compared to other advanced fusion methods. The code is available at https://github.com/xiongzhangzzz/ResCCFusion. [ABSTRACT FROM AUTHOR]

• CMRFusion is designed to fully use the multi-scale features from the high-resolution visible images to preserve as many texture details as possible. • Cross-domain attention fusion strategy takes one type of image feature as the base and another as a reference. • CMRFusion can train with high-resolution visible images and low-resolution infrared images. Existing multi-resolution infrared and visible image fusion methods suffer from the weak ability of texture detail preservation, which restricts the practical application. In this paper, we proposed a cross-domain multi-resolution infrared and visible image fusion method, CMRFusion, based on auto-encoder networks and a cross-domain attention fusion strategy. Auto-encoder networks are adopted to extract deep multi-scale features with encoder networks and reconstruct images with decoder networks. The cross-domain attention fusion strategy is adopted to promote the preservation of texture detail from one of the source images. In the proposed method, low-resolution infrared images are firstly up-scaled by a simple bicubic strategy to match the resolution of source images. Then, an encoder network is adopted to extract features from infrared and visible images. The extracted features of the infrared image are served as the base and supplemented with details in the extracted features from the visible image through a cross-domain attention fusion strategy to obtain the fused features to reconstruct high-resolution infrared images with the first decoder network. Finally, the encoder network is adopted to extract features from visible and reconstructed infrared images. The extracted features of the visible image are served as the base and supplemented with details in the extracted features from the reconstructed high-resolution infrared image through a cross-domain attention fusion strategy to obtain the fused features to reconstruct the fusion result with the second decoder network. The qualitative and quantitative experiments conducted on the TNO, OSU, and MSRS datasets indicate that CMRFusion can balance the information from source images and well-retain texture detail from the visible image. [ABSTRACT FROM AUTHOR]

The air-entraining capabilities of polycarboxylate superplasticisers (PCEs) with different functional groups were systematically analysed. Using different molecular PCEs, the evolution process from bubbles in fresh cement mortar to pores in hardened cement mortar was investigated, considering their effects on mortar workability and mechanical performance. The results showed that PCEs with various functional groups have different air-entraining capabilities. PCEs with ester groups decreased the surface tension and significantly promoted the air-entraining capability, resulting in a notable increase of air content in fresh cement mortar. PCEs with sulfonic acid groups increased the surface tension and remarkably decreased the air content in the fresh cement mortar. A higher air-entraining capability benefits the dispersing properties of PCEs and therefore the PCEs with ester groups performed better in dispersibility in comparison with the PCEs with sulfonic acid groups. The stability of bubbles entrained in fresh cement mortar leads to differences in the pore structure of hardened cement mortar. The PCEs with ester groups diminished the size of large bubbles, leading to significantly decreased porosity of the hardened mortar. PCEs with sulfonic acid groups in the backbone barely optimised the pore structure, with a large amount of large pores remaining in the hardened mortar. Decreased porosity and pore size hence led to higher compressive strength of the hardened cement mortar. [ABSTRACT FROM AUTHOR]

Myocardial ischemia/reperfusion (MI/R) triggers a complicated chain of inflammatory reactions. Dexmedetomidine (Dex) has been reported to be important in myocardial disorders. We evaluated the role of Dex in MI/R injury via the silent information regulator factor 2-related enzyme 1 (SIRT1)/mammalian target of rapamycin (mTOR) signaling pathway. First, Dex was immediately injected into rat models of MI/R injury during reperfusion. After Evans Blue-triphenyl tetrazolium chloride (TTC) and Hematoxylin--Eosin (H-E) staining, MI/R injury was observed. The extracted serum and myocardial tissues were used to detect oxidative stress and the inflammatory response. Western blot analysiswas performed to evaluateMI/R autophagy and the levels of proteins associated with the SIRT1/mTOR axis. The effects of the combination of Dex and SIRT1 inhibitor EX527 on MI/R injury and autophagy were evaluated. Finally, the mechanism of Dex was tested, and autophagy levels and the levels of proteins associated with the SIRT1/mTOR signaling pathway were assessed in MI/R rats. The results of the present study suggested that Dex relieved MI/R injury, reduced cardiomyocyte apoptosis, oxidative stress and inflammatory reactions, up-regulated the SIRT1/mTOR axis and decreased overautophagy in MI/R rats. SIRT1 inhibitor EX527 attenuated the protective effects of Dex. Our study demonstrated that Dex alleviated MI/R injury by activating the SIRT1/mTOR axis. This investigation may offer new insight into the treatment of MI/R injury. [ABSTRACT FROM AUTHOR]

The purpose of the present study was to determine the effects of metformin on the inhibition of proliferation, apoptosis, invasion and migration of A172 human glioma cells in vitro and determine the underlying mechanism. The effects of metformin at different concentrations (0, 0.1, 1 and 10 mmol/l) on the inhibition of A172 cell proliferation were detected using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Cell apoptosis was detected by flow cytometry. Caspase-3 activity was analyzed by spectrophotometry. The invasion and migration of cells were detected by Transwell assays. The levels of Bcl-2-associated X protein (Bax), B-cell lymphoma 2 (Bcl-2), AMP-activated protein kinase (AMPK), phosphorylated-(p)AMPK and mechanistic target of rapamycin (mTOR) protein expression were detected by western blot analysis, and changes in the malondialdehyde (MDA) content and activity of superoxide dismutase (SOD) were determined. Compared with the control group, metformin significantly increased the inhibition of proliferation and apoptosis, and significantly reduced the invasion and migration of A172 cells in dose- and time-dependent manners (P<0.05). In addition, compared with the control group, metformin significantly enhanced the activity of caspase-3, increased the expression of AMPK/pAMPK/Bax proteins and reduced the expression of mTOR/Bcl-2 proteins (P<0.05). Metformin increased the MDA content and reduced the activity of SOD in a dose-dependent manner (P<0.05). Metformin may inhibit glioma cell proliferation, migration and invasion, and promote its apoptosis; the effects may be associated with the AMPK/mTOR signaling pathway and oxidative stress. [ABSTRACT FROM AUTHOR]

In quantitative analysis by laser-induced breakdown spectroscopy (LIBS), it is necessary to take account of self-absorption effects on emission line intensity. In this work, a fiber laser ablation LIBS (FLA-LIBS) system was developed to reduce the self-absorption effects and improve the quality of quantitative analysis. The self-absorption degree was estimated for Mg and Ca lines, and a comparison of the calibration curves using LIBS and FLA-LIBS was carried out. The coefficients of determination (R2s) of linear calibration curves of Mg and Ca increased from 0.841 and 0.847 in conventional LIBS to 0.954 and 0.859 in FLA-LIBS, respectively. The self-absorption coefficients of Mg and Ca in FLA-LIBS were larger than those in conventional LIBS. And the ratios of Mg and Ca doublet intensity in FLA-LIBS were closer to theoretical values. These results show the great potential of FLA-LIBS in reducing self-absorption effects, especially for high concentration elements. [ABSTRACT FROM AUTHOR]

The field of mechanical manufacturing is becoming more and more demanding on machining accuracy. It is essential to monitor and compensate the deformation of structural parts of a heavy-duty machine tool. The deformation of the base of a heavy-duty machine tool is an important factor that affects machining accuracy. The base is statically indeterminate and complex in load. It is difficult to reconstruct deformation by traditional methods. A reconstruction algorithm for determining bending deformation of the base of a heavy-duty machine tool using inverse Finite Element Method (iFEM) is presented. The base is equivalent to a multi-span beam which is divided into beam elements with support points as nodes. The deflection polynomial order of each element is analysed. According to the boundary conditions, the deformation compatibility conditions and the strain data measured by Fiber Bragg Grating (FBG), the deflection polynomial coefficients of a beam element are determined. Using the coordinate transformation, the deflection equation of the base is obtained. Both numerical verification and experiment were carried out. The deflection obtained by the reconstruction algorithm using iFEM and the actual deflection measured by laser displacement sensors were compared. The accuracy of the reconstruction algorithm is verified. [ABSTRACT FROM AUTHOR]

Panax japonicus is the dried rhizome of Panax japonicus C.A. Mey. (Araliaceae). Saponins from Panax japonicus (SPJ) exhibit anti-oxidative and anti-aging effects. We evaluated the neuroprotective effects of SPJ on aging rats. Sprague-Dawley rats (18-months-old) were randomly divided into aging and SPJ groups (n = 8). Five-month-old rats were taken as the adult control (n = 8). The rats were fed a normal chow diet or the SPJ-containing diet (10 or 30 mg/kg) for 4 months. An in vitro model was established by d-galactose (d-Gal) in the SH-SY5Y cell line and pretreated with SPJ (25 and 50 µg/mL). The neuroprotection of SPJ was evaluated via Nissl staining, flow cytometry, transmission electron microscopy and Western blotting in vivo and in vitro. SPJ improved the neuronal degeneration and mitochondrial morphology that are associated with aging. Meanwhile, SPJ up-regulated the protein levels of mitofusin 2 (Mfn2) and optic atrophy 1 (Opa1) and down-regulated the protein level of dynamin-like protein 1 (Drp1) in the hippocampus of aging rats (p < 0.05 or p < 0.01 vs. 22 M). The in vitro studies also demonstrated that SPJ attenuated d-Gal-induced cell senescence concomitant with the improvement in mitochondrial function; SPJ, also up-regulated the Mfn2 and Opa1 protein levels, whereas the Drp1 protein level (p < 0.05 or p < 0.01 vs. d-Gal group) was down-regulated. Further research on the elderly population will contribute to the development and utilization of SPJ for the treatment of neurodegenerative disorders. [ABSTRACT FROM AUTHOR]

The deformation of the gantry structure in heavy-duty machine tools is an important factor that affects machining accuracy. In order to realize real-time monitoring of the deformation of the gantry structure, which is statically indeterminate and complex in shape, the reconstruction algorithm based on inverse Finite Element Method (iFEM) is proposed and fiber Bragg grating (FBG) sensors are used to measure strain data. The elements of the gantry structure are divided and the displacement functions of each element are determined. The shape function is obtained by substituting degree of freedoms (DOF) of element nodes into displacement functions. Through a differential method, the relation between strain and DOF of element nodes is established by the strain matrices. Subsequently, the DOF of element nodes are obtained by minimizing an error functional defined as the least-squares error between the analytic strain data and the corresponding experimental strains. Considering coordinate transformation and problem-specific displacement boundary conditions, the total deformation of the gantry structure is obtained. Following this, the experiment was carried out. The deformation simulated by ANSYS was used to replace the experimentally measured deformation and then compared with the deformation reconstructed by iFEM under the same loading condition. The accuracy of iFEM for reconstructing deformation of the gantry structure in heavy-duty machine tools is verified. It provides a new view for improving the machining precision of heavy-duty machine tools. [ABSTRACT FROM AUTHOR]

The dynamic process of gas-solid chlorination of high-density polyethylene (HDPE) was revealed using a vibrated-bed reactor, where a UV-Vis measurement system was used to record the kinetics of chlorination online. Thermal and UV-enhanced chlorination at fixed temperature below the melting point (Tm) of HDPE were firstly investigated. It was observed that UV irradiation could accelerate the reaction rate. However, all of the prepared chlorinated polyethylene (CPE) products had unchlorinated crystal structures and a limitation of chlorine content. Multi-stage chlorination was hence designed for more homogeneous chlorination and decreasing the residual crystallinity. The differential scanning calorimetry (DSC) results showed effective decrease of the melting enthalpy (ΔHm) while the final reaction temperature was beyond Tm. Meanwhile, the presence of -CH = CH- bonds in the polymer chain revealed by solid-state nuclear magnetic resonance (S-NMR) indicated that the final reaction temperature should not be higher than 150 °C. [ABSTRACT FROM AUTHOR]

Kurtogram can adaptively select the resonant frequency band, and then the characteristic fault frequency can be obtained by analyzing the selected band. However, the kurtogram is easily affected by random impulses and noise. In recent years, improvements to kurtogram have been concentrated on two aspects: (a) the decomposition method of the frequency band; and (b) the selection index of the optimal frequency band. In this article, a new method called Teager Energy Entropy Ratio Gram (TEERgram) is proposed. The TEER algorithm takes the wavelet packet transform (WPT) as the signal frequency band decomposition method, which can adaptively segment the frequency band and control the noise. At the same time, Teager Energy Entropy Ratio (TEER) is proposed as a computing index for wavelet packet subbands. WPT has better decomposition properties than traditional finite impulse response (FIR) filtering and Fourier decomposition in the kurtogram algorithm. At the same time, TEER has better performance than the envelope spectrum or even the square envelope spectrum. Therefore, the TEERgram method can accurately identify the resonant frequency band under strong background noise. The effectiveness of the proposed method is verified by simulation and experimental analysis. [ABSTRACT FROM AUTHOR]

The resilient modulus of a base course granular material is an important input parameter for pavement design and analysis. In recent decades, numerous studies have been performed to characterize and model the resilient behavior of base course materials under unfrozen conditions. In cold regions, frost heaving and subsequent thawing significantly affect the resilient behavior of base course materials. Due to the complex nature of the problem, relatively less effort was dedicated to characterize and model the resilient behavior of base course materials after seasonal freeze-thaw cycles. Among the limited studies, very often the soil specimens were prepared in an open system with free water access to simulate the frost heave, which represented the worst-case scenario in terms of stiffness reduction during thawing. Sometimes omni-directional freeze tests were performed to simplify the testing procedures. In reality, soils in the field often experience one-dimensional freeze and thaw. When the permeability of the soil is very low, the groundwater table is far from the freezing front, or the freezing temperature gradient is high, the freezing process can be considered to be in a closed system (i.e., limited or no water exchange). The closed system represented the best-case scenario in terms of stiffness reduction during thawing, which has rarely been investigated. Hence, an in-depth understanding of the seasonal resilient behavior of base course materials in a closed system is essential for cold region pavement design and analysis. In this study, repeated loading triaxial tests were performed to investigate the effects of nonplastic fines content, moisture content, temperature, thermal gradient, and freeze-thaw cycling on the resilient modulus of unbound granular base course materials under seasonal frost conditions. Soil specimens were prepared in the laboratory using a one-dimensional frost heave chamber with temperature--thermal gradient control. Specimens were subjected to a closed-system freezing (undrained) condition. Test results were analyzed and discussed, and models were developed to predict granular materials' resilient moduli as a function of the state of stress, temperature, moisture, and fines content to complement the previous study. [ABSTRACT FROM AUTHOR]

The ternary transitional metal oxide NiCo2O4 is a promising anode material for sodium ion batteries due to its high theoretical capacity and superior electrical conductivity. However, its sodium storage capability is severely limited by the sluggish sodiation/desodiation reaction kinetics. Herein, NiCo2O4 double-shelled hollow spheres were synthesized via a microwave-assisted, fast solvothermal synthetic procedure in a mixture of isopropanol and glycerol, followed by annealing. Isopropanol played a vital role in the precipitation of nickel and cobalt, and the shrinkage of the glycerol quasi-emulsion under heat treatment was responsible for the formation of the double-shelled nanostructure. The as-synthesized product was tested as an anode material in a sodium ion battery, was found to exhibit a high reversible specific capacity of 511 mAh g-1 at 100 mA g-1, and deliver high capacity retention after 100 cycles. [ABSTRACT FROM AUTHOR]

Ring-contraction of 2,4,6,8-tetrasubstituted 1,5-diazacyclooctatetraenes was highly efficiently promoted by Lewis acid such as TiCl4, affording 2,4,6-trisubstituted pyridines in excellent yields, along with release of a nitrile. A reaction mechanism involving a 6π electrocyclic ring-closing followed by a retro [2 + 2] cyclization of an 1-azetine moiety was supported by both experimental observations and density functional theory calculation. [ABSTRACT FROM AUTHOR]

With a rapid improvement of smartphone hardware and software, especially complementary metal oxide semiconductor (CMOS) cameras, many optical biosensors based on smartphone platforms have been presented, which have pushed the development of the point-of-care testing (POCT). Imaging-based and spectrometry-based detection techniques have been widely explored via different approaches. Combined with the smartphone, imaging-based and spectrometry-based methods are currently used to investigate a wide range of molecular properties in chemical and biological science for biosensing and diagnostics. Imaging techniques based on smartphone-based microscopes are utilized to capture microscale analysts, while spectrometry-based techniques are used to probe reactions or changes of molecules. Here, we critically review the most recent progress in imaging-based and spectrometry-based smartphone-integrated platforms that have been developed for chemical experiments and biological diagnosis. We focus on the analytical performance and the complexity for implementation of the platforms. [ABSTRACT FROM AUTHOR]

An intermittent aerobic process has been developed to effectively remove nitrogen from polluted rivers. In addition, a chemometric model was developed to achieve simultaneous rapid analysis of total nitrogen, ammonia nitrogen, and nitrite nitrogen based on near-infrared spectroscopy data combined with a support vector machine. An intermittent aeration process showed that total nitrogen decreased from 54.25 mg·L-1 to 0.64 mg·L-1. Ammonia nitrogen decreased significantly in the aeration stage, but increased in the non-aeration stage. Eventually, ammonia nitrogen decreased from 45.04 mg·L-1 to 0.57 mg·L-1. Nitrite nitrogen and nitrate nitrogen increased in the aeration stage, but decreased in the non-aeration stage. The concentration ranges of nitrite nitrogen and nitrate nitrogen were, respectively, 0.05∼31.40 mg·L-1 and 0∼0.38 mg·L-1. The 138 water samples were collected during the intermittent aeration process, of which 116 samples were used as the calibration set and the remaining 22 samples were used as a test set in modeling. The actual concentration values and the near-infrared spectroscopy data were used as input of the models. Then the corresponding calibration values and predication values were output by the models. All the samples were scanned with near-infrared spectroscopy from 4,000∼12,500 cm-1 and measured by chemical methods. Principal component analysis of raw near-infrared spectral data showed that the matrix dimension of spectral data was significantly reduced, which decreased from 2,203×106 to 6×106. Support vector machine models of total nitrogen, ammonia nitrogen, and nitrite nitrogen showed that the calibration correlation coefficient (R2) of calibration values and actual values were, respectively, 0.9561, 0.9661, and 0.9702, with the root mean square error of cross validation (RMSECV) being 0.09372, 0.04749, and 0.03187. The test results of support vector machine models of total nitrogen, ammonia nitrogen, and nitrite nitrogen showed that the predication correlation coefficient (R2) of prediction values and actual values were, respectively, 0.9616, 0.9410, and 0.9284, with the root mean square error of prediction (RMSEP) being 0.09420, 0.08227, and 0.06770. This study indicated that nitrogen in a polluted river can be removed through the intermittent aerobic process. Moreover, simultaneous rapid determination of total nitrogen, ammonia nitrogen, and nitrite nitrogen may be achieved with near-infrared spectroscopy and a support vector machine. The results showed that the proposed methods provided effective treatment and detection technology for a polluted river. [ABSTRACT FROM AUTHOR]

With 4′-amino-N,N-diethylaniline and aniline as starting materials, methylene violet 3RAX 1 and its derivatives 2-5 were synthesised. The five compounds were characterised by IR, UV-vis, and ¹H NMR spectroscopy and mass spectrometry. The binding mode between the synthesised compounds and DNA were investigated. The results show that both compounds 1 and 5 bind to DNA by an intercalative mode, while compounds 2-4 interact with DNA through a mixed binding mode involving groove binding and electrostatic interactions. The photocleavage ability of the five compounds to DNA were calculated to be 38, 40, 30, 20, and 13%, respectively, when their concentration was adjusted to 400 μM. The singlet oxygen production of compounds measured by the 1,3-diphenylisobenzofuran method was consistent with the trend ofDNAphotocleavage ability. TheDNAstudies suggest that the binding mode between methylene violet 3RAX and DNA, the ability of methylene violet 3RAX to generate singlet oxygen, and the DNA photocleavage activity could be adjusted through modification of the amino group on methylene violet 3RAX. [ABSTRACT FROM AUTHOR]

The present study attempted to identify potential key genes and pathways of peri-implantitis, and to investigate the possible mechanisms associated with it. An array data of GSE57631 was downloaded, including six samples of peri-implantitis tissue and two samples of normal tissue from the Gene Expression Omnibus (GEO) database. The differentially expressed genes (DEGs) in the peri-implantitis samples compared with normal ones were analyzed with the limma package. Moreover, Gene Ontology annotation and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses for DEGs were performed by DAVID. A protein-protein interaction (PPI) network was established using Cytoscape software, and significant modules were analyzed using Molecular Complex Detection. A total of 819 DEGs (759 upregulated and 60 downregulated) were identified in the peri-implantitis samples compared with normal ones. Moreover, the PPI network was constructed with 413 nodes and 1,114 protein pairs. Heat shock protein HSP90AA1 (90 kDa α, member 1), a hub node with higher node degrees in module 4, was significantly enriched in antigen processing, in the presentation pathway and nucleotide-binding oligomerization domain (NOD)-like receptor-signaling pathway. In addition, nuclear factor-κ-B1 (NFKB1) was enriched in the NOD-like receptor-signaling pathway in KEGG pathway enrichment analysis for upregulated genes. The proteasome is the most significant pathway in module 1 with the highest P-value. Therefore, the results of the present study suggested that HSP90AA1 and NFKB1 may be potential key genes, and the NOD-like receptor signaling pathway and proteasome may be potential pathways associated with peri-implantitis development. [ABSTRACT FROM AUTHOR]

Low-infrared-emissivity coatings were prepared using metallic particles (including Cu, Al, Ni, Ag, etc.) and an ethylene-propylene-diene monomer (EPDM) binder. The effects of size, shape, morphology, and content of metallic particles on infrared emissivity of the coatings were systematically investigated. The principles of the low-infrared-emissivity and low-solar-reflectance coatings are discussed in terms of reflection, emissions, and chemical structure. The thermal insulation performance of composite coatings is studied via a simulation model. Mechanical properties of composite coatings are studied by using circle-cut test and impact strength test. The composite coatings are also tested for corrosion behavior with potentiodynamic polarization. The results indicate that when the Cu particles and Al particles are flaky and high-leafing, they have the minimum coating emissivity, exhibiting infrared emissivity values of 0.33–0.40 and solar reflectance values of 0.38–0.53. The formation of low-infrared-emissivity coatings depends highly on the size and shape of the metallic particles. A simulation model is proposed to account for thermal insulation properties of the coatings, which indicates that an EPDM/Cu-powder coating achieves good thermal insulation performance, with a 4°C relative temperature drop. The low-infrared-emissivity composite coatings also show excellent corrosion resistance and mechanical performance. [ABSTRACT FROM AUTHOR]

Traditional monopulse angle estimations are mainly based on phase comparison and amplitude comparison methods, which are commonly adopted in narrowband radars. In modern radar systems, wideband radars are becoming more and more important, while the angle estimation for wideband signals is little studied in previous works. As noise in wideband radars has larger bandwidth than narrowband radars, the challenge lies in the accumulation of energy from the high resolution range profile (HRRP) of monopulse. In wideband radars, linear frequency modulated (LFM) signals are frequently utilized. In this paper, we investigate the monopulse angle estimation problem for wideband LFM signals. To accumulate the energy of the received echo signals from different scatterers of a target, we propose utilizing a cross-correlation operation, which can achieve a good performance in low signal-to-noise ratio (SNR) conditions. In the proposed algorithm, the problem of angle estimation is converted to estimating the frequency of the cross-correlation function (CCF). Experimental results demonstrate the similar performance of the proposed algorithm compared with the traditional amplitude comparison method. It means that the proposed method for angle estimation can be adopted. When adopting the proposed method, future radars may only need wideband signals for both tracking and imaging, which can greatly increase the data rate and strengthen the capability of anti-jamming. More importantly, the estimated angle will not become ambiguous under an arbitrary angle, which can significantly extend the estimated angle range in wideband radars. [ABSTRACT FROM AUTHOR]

Group decision making (GDM) problems consist of finding the most acceptable solution based on a group of experts' preferences. Sometimes, the experts experience difficulty expressing their preferences using crisp values or making comparisons between each pair of alternatives. Meanwhile, because of their different backgrounds or knowledge concerning a specific problem, the opinions of different experts may carry different weights along the decision process. Thus, a new consensus model is proposed to solve these problems. First, experts are required to express their opinions using fuzzy linguistic preference relations, and then, a new method is proposed for classifying the experts into three different importance levels according to these opinions. Then, consistency measures and proximity measures are used to guide the decision-making process. A new feedback mechanism that generates advice for experts according to their different levels is proposed. The importance degrees of experts are taken into consideration throughout the process, which is one of the main novelties of this model. Finally, a numerical example is conducted to illustrate the utilization and compared results are also presented to check the feasibility of the proposed model. [ABSTRACT FROM AUTHOR]

Background: T-type calcium channels are important contributors to signaling in the primary afferent pain pathway and are thus important targets for the development of analgesics. It has been previously reported that certain piperazine-based compounds such as flunarizine are able to inhibit T-type calcium channels. Thus, we hypothesized that novel piperazine compounds could potentially act as analgesics. Results: Here, we have created a series of 14 compound derivatives around a diphenyl methyl-piperazine core pharmacophore. Testing their effects on transiently expressed Cav3.2 calcium channels revealed one derivative (3-((4-(bis(4-fluorophenyl) methyl)piperazin-1-yl)methyl)-4-(2-methoxyphenyl)-1,2,5-oxadiazole 2-oxide, compound 10e) as a potent blocker. 10e mediate tonic block of these channels with an IC50 of around 4 micromolar. 10e also blocked Cav3.1 and Cav3.3 channels, but only weakly affected high-voltage-activated Cav1.2 and Cav2.2 channels. Intrathecal delivery of 10e mediated relief from formalin and complete Freund's adjuvant induced inflammatory pain that was ablated by genetic knockout of Cav3.2 channels. Conclusions: Altogether, our data identify a novel T-type calcium channel blocker with tight structure activity relationship (SAR) and relevant in vivo efficacy in inflammatory pain conditions. [ABSTRACT FROM AUTHOR]

Selenium is an essential metalloid required for the expression of selenoproteins. While cells are constantly challenged by clastogens of endogenous and exogenous origins, genome integrity is maintained by direct repair of DNA damage, redox balance, and epigenetic regulation. To date, only five selenoproteins are experimentally demonstrated to reside in nucleus, exclusively or partially, including selenoprotein H, methionine-R-sulfoxide reductase 1, glutathione peroxidase-4, thioredoxin reductase-1, and thioredoxin glutathione reductase. All these five selenoproteins have demonstrated or potential roles in redox regulation and genome maintenance. Selenoprotein H is known to transactivate the expression of a couple of genes against oxidative stress. The thioredoxin reductase-1b isoform delivers estrogen receptor-α and -β to the nucleus. Nuclear glutathione peroxidase-4 epigenetically and globally inhibits gene expression through the maintenance of chromatin compactness in testes. Continued studies on how these and additional nuclear selenoproteins regulate genome stability will have profound impact on advancing our understanding in selenium regulation of optimal health. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to investigate the protective effect of curcumin on chronic ethanol-induced liver injury in mice and to explore its underlying mechanisms. Materials and Methods: Ethanol-exposed Balb/c mice were simultaneously treated with curcumin for 6 weeks. Liver injury was evaluated by biochemical and histopathological examination. Lipid peroxidation and anti-oxidant activities were measured by spectrophotometric method. Anti-oxidative genes expression such as NAD(P)H quinone oxidoreductase 1 (NQO1), heme oxygenase-1 (HO-1), and superoxide dismutase (SOD) were determined by real-time polymerase chain reaction. The nuclear factor E2-related factor 2 (Nrf2) and the phosphorylation states of specific proteins central to intracellular signaling cascades were measured by western blotting. Results: Curcumin treatment protected liver from chronic ethanol-induced injury through reducing serum alanine aminotransferase and aspartate aminotransferase activities, improving liver histological architecture, and reversing lipid disorders indicated by decrease of triglyceride, total cholesterol and low-density lipoprotein-cholesterol levels and increase of High-density lipoprotein-cholesterol levels. Meanwhile, curcumin administration attenuated oxidative stress via up-regulating SOD and glutathione peroxidase activities, leading to a reduction of lipid hydroperoxide production. In addition, curcumin increased Nrf2 activation and anti-oxidative genes expressions such as NQO1, HO-1, and SOD through inducing extracellular signal-regulated kinase (ERK) and p38 phosphorylation. Conclusion: Our data suggested that curcumin protected the liver from chronic-ethanol induced injury through attenuating oxidative stress, at least partially, through ERK/p38/Nrf2-mediated anti-oxidant signaling pathways. [ABSTRACT FROM AUTHOR]

Semibullvalene (SBV) and its aza analogue 2,6-diazasemibullvalene(NSBV) are theoretically interesting and experimentally challengingorganic molecules because of four unique features: highly strainedring systems, intramolecular skeletal rearrangement, extremely rapiddegenerate (aza-)Cope rearrangement, and the predicted existence ofneutral homoaromatic delocalized structures. SBV has received muchattention in the past 50 years. In contrast, after NSBV was predictedin 1971 and the first in situ synthesis was realized in 1982, no progresson NSBV chemistry was made until our results in 2012. We have beeninterested in the reaction chemistry of 1,4-dilithio-1,3-butadienes(dilithio reagents for short), especially for their applications inthe synthesis of SBV and NSBV, because (i) the cyclodimerization ofdilithio reagents could provide the potential eight-carbon skeletonof SBV from four-carbon butadiene units and (ii) the insertion reactionof dilithio reagents with CN bonds of two nitriles could providea 6C + 2N skeleton that might be a good precursor for the synthesisof NSBV. Therefore, we initiated a journey into the synthesis andreaction chemistry of SBV and NSBV starting from dilithio reagentsthat has been ongoing since 2006. In this Account, we outline mainlyour recent achievements in the synthesis, structural characterization,reaction chemistry, synthetic application, and theoretical/computationalanalysis of NSBV. [ABSTRACT FROM AUTHOR]

By statistically analysing a large sample that includes Fermi-detected blazars (FBs) and non-Fermi-detected blazars (NFBs), we find that there are significant differences between FBs and NFBs in redshift, black hole mass, jet kinetic power from cavity power, broad-line luminosity and the ratio of core luminosity to absolute V-band magnitude (Rv), but not in the ratio of the radio core to extended flux (Rc) and the Eddington ratio. Compared with NFBs, FBs have larger mean jet power, Rc and Rv, while having smaller mean redshift, black hole mass and broad-line luminosity. These results support the fact that the beaming effect is the main reason for differences between FBs and NFBs, and that FBs are likely to have a more powerful jet. For both FBs and NFBs, there are significant correlations between the jet power and the accretion rate (traced by the broad-emission line luminosity), and between the jet power and the black hole mass. For FBs, the black hole mass does not have a significant influence on jet power, while for NFBs, both the accretion rate and black hole mass contribute to the jet power. Our results support the ‘blazar sequence’ and show that the synchrotron peak frequency (νpeak) is associated with the accretion rate but not with the black hole mass. [ABSTRACT FROM AUTHOR]

Catalyticguanylation reactions of amines with carbodiimides havereceived increasing attention because of the atom-economical preparationof guanidines since 2003. To date, more than 40 catalysts includingtransition metals, main-group metals, and rare-earth metals have beendesigned and tested for the guanylation reaction to construct acyclicand cyclic guanidines. In this review, we present a mechanistic considerationon catalytic guanylation reactions of amines with carbodiimides forguanidine synthesis to elucidate its development and importance. Fourdifferent types of reaction mechanisms have been well categorized:[2 + 2]-cycloaddition/protonation, insertion/protonation, activationof carbodiimide/nucleophilic addition/intramolecular protonation,and protonation/nucleophilic addition/disassociation. It is usefulto understand these reaction processes in order to accelerate therapid development in related areas to meet the growing need for guanidines. [ABSTRACT FROM AUTHOR]

Organolithium compounds can behave as reductants but never as oxidants in redox reactions. Reported herein is that 1,4-dilithio-1,3-butadienes reacted with [Ni(cod)2] (cod=1,5-cyclooctadiene) to deliver dilithionickeloles. Single-crystal X-ray structural analysis revealed a coplanar structure of dilithionickeloles with an averaging of bond lengths. XPS data confirmed the oxidation state of Ni in dilithionickeloles was Ni2+. 7Li NMR spectra of dilithionickeloles and theoretical calculations revealed a considerable aromatic character. In this redox reaction, the dilithio dianionic compounds behaved as formal oxidants, thus oxidizing Ni0 into Ni2+. These results demonstrated that organolithium compounds with β-conjugation could be used as oxidants and could continue to accept extra electrons. [ABSTRACT FROM AUTHOR]

Organolithium compounds can behave as reductants but never as oxidants in redox reactions. Reported herein is that 1,4-dilithio-1,3-butadienes reacted with [Ni(cod)2] (cod=1,5-cyclooctadiene) to deliver dilithionickeloles. Single-crystal Xray structural analysis revealed a coplanar structure of dilithionickeloles with an averaging of bond lengths. XPS data confirmed the oxidation state of Ni in dilithionickeloles was Ni2+. 7Li NMR spectra of dilithionickeloles and theoretical calculations revealed a considerable aromatic character. In this redox reaction, the dilithio dianionic compounds behaved as formal oxidants, thus oxidizing Ni0 into Ni2+. These results demonstrated that organolithium compounds with π-conjugation could be used as oxidants and could continue to accept extra electrons. [ABSTRACT FROM AUTHOR]

The developments in nanocoating and nanospray technology have resulted in the increasing importance of the impact of micro-/nanoscale liquid droplets on solid surface. In this paper, the impact of a nanodroplet on a flat solid surface is examined using molecular dynamics simulations. The impact velocity ranges from 58 m/s to 1044 m/s, in accordance with theWeber number ranging from 0.62 to 200.02 and the Reynolds number ranging from 0.89 to 16.14. The obtained maximum spreading factors are compared with previous models in the literature. The predicted results from the previous models largely deviate from our simulation results, with mean relative errors up to 58.12%. The estimated viscous dissipation is refined to present a modified theoretical model, which reduces the mean relative error to 15.12% in predicting the maximum spreading factor for cases of nanodroplet impact. [ABSTRACT FROM AUTHOR]

The single application of high-concentration of capsaicin has been used as an analgesic therapy of persistent pain. However, its effectiveness and underlying mechanisms remain to be further evaluated with experimental approaches. The present study provided evidence showing that the single application of capsaicin dose-dependently alleviated nociceptive hypersensitivity, and reduced the action potential firing in small-diameter neurons of the dorsal root ganglia (DRG) in rats and mice. Pre-treatment with capsaicin reduced formalin-induced acute nocifensive behavior after a brief hyperalgesia in rats and mice. The inhibitory effects of capsaicin were calcium-dependent, and mediated by the capsaicin receptor (transient receptor potential vanilloid type-1). We further found that capsaicin exerted inhibitory effects on the persistent nociceptive hypersensitivity induced by peripheral inflammation and nerve injury. Thus, these results support the long-lasting and inhibitory effects of topical capsaicin on persistent pain, and the clinic use of capsaicin as a pain therapy. [ABSTRACT FROM AUTHOR]

The T42 peptide, generated from two active fragments of tumstatin, has been shown to have anti-tumor activity. The adenoviral vector is the most frequently used vector in research and clinical trials for gene therapy. In the present study, the anti-tumor activity of the T42 peptide and quadruple T42 (4xT42) peptide adenoviral vectors were elucidated for the first time, to the best of our knowledge. Human embryonic kidney 293 cells were infected with plasmid adenovirus (pAd)-enhanced green fluorescent protein (EGFP)-T42 or pAd-EGFP-4xT42 and the expression of the T42 and 4xT42 genes was confirmed by the identification of GFP expression and reverse transcription polymerase chain reaction experiments. The anti-cancer effects of pAd-EGFP-T42 and pAd-EGFP-4xT42 on breast cancer cells in vivo and in vitro were subsequently investigated. The results indicated that the packaging of the recombinant adenoviruses with the viral titer was successful, following purification at 5x109 plaque forming units/ml. The results also revealed that the recombinant adenoviruses promoted apoptosis in MCF-7 breast cancer cells and inhibited cancer growth. Through the analysis of caspase-3, B-cell lymphoma 2 (Bcl-2) and Bcl-2-associated X protein expression, it was demonstrated that the T42/4xT42 peptide may induce apoptosis via the mitochondrial pathway. In addition, mouse xenograft experiments confirmed that the T42 peptide inhibited tumor growth and reduced angiogenesis in vivo. In conclusion, the results of the present study indicated that the T42 and 4xT42 peptide genes, transfected by a recombinant adenovirus, may provide a potential novel strategy for the treatment of breast cancer. [ABSTRACT FROM AUTHOR]

Multisubstituted guanidines have received much attention because of important applications in many fields, such as pharmaceutics, organometallic and coordination chemistry, and organic synthesis. Although classical methods are available for the preparation of guanidines, synthetic preparation approaches to guanidines are still in great demand. In this review, we summarize recent developments on synthetic methods via the C-N bond formation. Three aspects are included: transition-metal-catalyzed guanidine synthesis based on classical methods; catalytic guanylation reaction of amines with carbodiimides; and tandem catalytic guanylation/cyclization reactions. [ABSTRACT FROM AUTHOR]

Previous studies show that ice nucleation can be promoted remarkably when the structure of a solid surface matches well with the ice lattice. In this paper, we show that this kind of match needs not to be established directly between the solid surface and the ice. By using molecular dynamics simulation technique, we investigate the electrofreezing of liquid water on polyethylene surfaces. Two kinds of surfaces are modeled with the (1 0 0) and (0 1 0) faces of the polyethylene crystal. As exposed to the electric field, a slice of quasi-ice layer (QIL) consisting of two highly ordered layers of water molecules forms in the vicinity of the polyethylene surface. The results show that the structural difference between the solid surface and the ice lattice can be relaxed through the QIL. If the structural deviation is relatively small, as on (1 0 0) surface, the structural match can be established directly between the QIL and the bulk ice. In this situation, the nucleation is observed to be highly promoted. On the contrary, as on (0 1 0) surface, the structural deviation between the surface and the bulk ice is too large to be relaxed through the QIL, an additional liquid-like layer connecting the bulk ice and the QIL is formed. In this condition, the promotion of ice nucleation is unobservable. [ABSTRACT FROM AUTHOR]

In this work, a facile soft template-assisted water-bath method was adopted to synthesize pure phase single-crystalline β-cobalt hydroxide. Using polyvinyl pyrrolidone (PVP), polyethylene glycol (PEG) and cetyltrimethyl ammonium bromide (CTAB) as soft templates, β-Co(OH)2 with hexagonal, disc-like and flower-like morphologies was successfully fabricated. It was found that all of the nanostructures exhibited preferentially oriented crystal growth along the (001) plane. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) showed that the soft templates had an important role in guiding the crystal growth and determining the final structure of β-Co(OH)2. Cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD) measurements indicated that the flower-like structures had superior electrochemical properties over hexagonal and disc-like ß-Co(OH)2. A four-step growth mecha- nism of β-Co(OH)2 was proposed based on time-dependent morphological evolution results. The results reveal the potentiality of soft templates in fine-tuning the morphology of single crystal β-Co(OH)2 nanomaterials. [ABSTRACT FROM AUTHOR]

Beaver Slide is on the Dalton Highway near 177.8 km (110.5 mi), and it is downhill when heading north. The road gradient is approximately 11% and the road prism is on a side hill. Each year, there are soft spots that usually appear in late April and remain all summer, which are also called "frost boils" by engineers at the Alaska Department of Transportation and Public Facilities (AKDOT&PF). The frost boils have resulted in extremely unsafe driving conditions and frequent accidents. Past repair efforts indicate conventional road construction methods do not work. A new type of geosynthetic wicking fabric has been recently developed that has a high specific surface area (consequently high wettability and high capillary action) and high directional permittivity. Preliminary laboratory tests indicate it has great promise as a cost-effective means to solve the frost heave-related problems on northern road systems. This study verifies the effectiveness of the wicking fabric to mitigate frost boils in Alaskan pavements. A test section was built at the Beaver Slide area of the Dalton Highway with installation of two layers of wicking fabric. The test section was instrumented with moisture and temperature sensors to measure the temperature and moisture variations for two years. Results were analyzed to evaluate the effectiveness of the wicking fabric to mitigate the frost boils in Alaskan pavements. [ABSTRACT FROM AUTHOR]

Near-ultraviolet (UV) InGaN/AlGaN light-emitting diodes (LEDs) are grown by low-pressure metal-organic chemical vapor deposition. The scanning electronic microscope image shows that the p-GaN micro-rods are formed above the interface of p-AlGaN/p-GaN due to the rapid growth rate of p-GaN in the vertical direction. The p-GaN micro-rods greatly increase the escape probability of photons inside the LED structure. Electroluminescence intensities of the 372 nm UV LED lamps with p-GaN micro rods are 88% higher than those of the flat surface LED samples. [ABSTRACT FROM AUTHOR]

Morphology control of carbon-based nanomaterials (nanocarbons) is critical to practical applications because their physical and chemical properties are highly shape-dependent. The discovery of novel shaped nanocarbons stimulates new development in carbon science and technology. Based on direct reaction ofCO2 with Mg metal, we achieved controlled synthesis of several different types of nanocarbons including mesoporous graphene, carbon nanotubes, and hollow carbon nanoboxes. The last one, to our knowledge, has not been previously reported to this date. The method described here allows effective control of the shape and dimensions of nanocarbons through manipulation of reaction temperature. The formation mechanism of nanocarbons is proposed. As a proof of concept, the synthesized nanocarbons are used for electrodes in symmetrical supercapacitors, which exhibit high capacitance and good cycling stability. The reported protocols are instructive to production of nanocarbons with controlled shape and dimensions which are much desirable for many practical applications. [ABSTRACT FROM AUTHOR]

This paper was aimed to study the influence of modification of biochar on the performance of CO 2 adsorption. Biochar, obtained from cotton stalk pyrolysis in a fixed bed reactor, was modified with ammonia and CO 2. The physicochemical properties of biochars were characterized by the Fourier transform infrared spectroscopy and automatic adsorption equipment (Micromeritics, ASAP 2020, USA). CO 2 adsorption of biochar was performed in thermogravimetric analyzer. The results showed that the surface area of char was increased significantly by CO 2 modification, while N-contained compound on char surface was enriched obviously by NH 3 modification. CO 2 adsorption of biochar increased greatly with CO 2 and NH 3 modification. CO 2 adsorption was mainly attributed to physical adsorption at 20 °C, and the adsorption quantity (maximum = 99 mg/g) was proportional to the micropore volume of the char. However, at 120 °C, molecular thermal motion increase, chemical adsorption start to play a dominated role, and the adsorption was directly proportional to the N content of this char. [ABSTRACT FROM AUTHOR]

Evolution of the synthetic strategy that culminated in the first asymmetric total synthesis of the Aspidosperma alkaloid limaspermidine is described. The successful enantioselective route to (-)-limaspermidine proceeds in 10 steps and with the isolation of only six intermediates using a Pd-catalyzed enantioselective decarboxylative allylation we have recently developed. This first enantioselective synthesis of (-)-limaspermidine establishes unambiguously its absolute configuration and allows the first asymmetric formal total synthesis of the Aspidoalbine alkaloid (-)-1-acetylaspidoalbidine. [ABSTRACT FROM AUTHOR]