Search

Although recycled aggregate concrete (RAC) has been studied intensively over past two decades, its damping property is still not analyzed sufficiently. In this paper, a nonlinear damping model for RAC prisms subjected to cyclic uniaxial compression are presented. Then with the combination of the compressive strength and damping property of RAC, an optimum recycled concrete aggregates (RCA) content including particle size and replacement percentage are recommended. The cyclic uniaxial compression test was conducted to investigate the dynamic modulus and nonlinear damping property of RAC, meanwhile tests for the RAC’s static compressive strength and modulus of elasticity were also carried out. Then based on the nonlinear damping model and compressive strength, relationships among the compressive strength, damping property, load indicators and RCA content are analyzed to obtain the optimum RCA content. Test results indicate that RAC obtains a higher loss factor than NAC. The loss factor of RAC is an increasing power function of RCA particle size and a decreasing power function of RCA replacement percentage. However, the compressive strength and dynamic modulus of RAC decreases compare with that of natural aggregate concrete. The different choice of cyclic uniaxial compression load indicators (cyclic stress range, stress level or strain range) has significance impact on RAC damping property and optimum RCA content.

Hydrophilic polypyrrole-coated copper nanoneedles (PPy-CuNDs) were synthesized and utilized to construct a superhydrophobic surface on a polyethylene terephthalate fabric (PET) by using the spray-coating technique. The morphology of the as-synthesized PPy-CuNDs can be facilely tuned by changing the concentration of the reducing agent: hydrazine monohydrate. The CuNDs with well-defined nanocrystalline structures and nanoscale thick, rough PPy coating layers were formed simultaneously in one pot. The PPy-CuNDs self-assembled into an entangled, stacking nanocarpet on the surface of the PET fabric, and they eventually formed a reentrant surface texture similar to that of chrysanthemum leaves. The PPy-CuND-PET surface initially showed good superhydrophobic properties, but a fast transition from the superhydrophobic state to the highly adhesive state was observed. The underlying mechanism of this transition and its potential applications were proposed in the context.

Energy consumption and pollutant emissions from buildings have caused serious impacts on the environment. Currently, research on building environmental costs is quite insufficient. Based on life cycle inventory of building materials, fossil fuel and electricity power, a calculating model for environmental costs during different stages is presented. A single-objective optimization model is generated by converting environmental impact into environmental cost, with the same unit with direct cost. Two residential buildings, one located in Beijing and another in Xiamen, China, are taken as the case studies and analyzed to test the proposed model. Moreover, data uncertainty and sensitivity analysis of key parameters, including the discount rate and the unit virtual abatement costs of pollutants, are also conducted. The analysis results show that the environmental cost accounts for about 16% of direct cost. The environmental degradation cost accounts for about 70% of the total environmental cost. According to the probabilistic uncertainty analysis results, the coefficient of variation of material production stage is the largest. The sensitivity analysis results indicate that the unit virtual abatement cost of CO2 has the largest influence on the final environmental cost.

Selenium (Se)-containing polysaccharide, a Se-conjugate macromolecule, generally exhibited higher antitumor activity than its regular polysaccharide. Previously, we extracted Se-containing tea polysaccharides (Se-TPS) from Se-enriched tea, and explored its structure and antioxidant activity. In this study, we investigated antitumor activity of Se-TPS on sarcoma 180 (S-180), and compared with its regular polysaccharides TPS and dietary supplement Se-yeast. In vitro antitumor activity of Se-TPS was evaluated by MTT and LDH assays, and the results indicated that Se-TPS can significantly inhibit the proliferation of S-180 in dose-dependent manner (R2=0.97, p

Benefiting from the integrated functions of cilia and glomeruli in the olfactory system, animals can discriminate various odors even in hostile environments. Inspired by this synergetic system of response and signal processing units, a sensor chip of graphene oxide (GO) and photonic crystals (PCs) is fabricated. The GO aerogel functions like the olfactory cilia, which effectively captures the analytes and generates abundant sensing signals for recognition; and the PCs act as the olfactory glomeruli, whose periodic structure enables selective enhancement of the fluorescent signals to realize further signal processing. Ten biogenic amines and seven drug amines are effectively discriminated. The integrated sensor strategy of response and signal manipulation units will promote enormous pursuits of rapid clinical diagnosis or intractable pathology analysis.

Damping properties have important effects on the dynamic behavior of civil engineering structures. However, the influence of load on the material damping of concrete has not been studied sy...

Creep brings forth considerable influences on both static and dynamic behaviours of concrete structures. This paper intends to deepen the investigation on the creep influence on structural dynamic performance, evaluating their relationship from the view of reliability. The influencing mechanism of concrete creep on structural dynamic behaviour is first stated. Integration of the structural creep analysis by the Model B3 and the age-adjusted effective modulus method with the stochastic seismic analysis by the pseudo-excitation method is then proposed. Based on the creep-influenced structural static and stochastic seismic behaviours, formulations for the dynamic reliability with the consideration of creep effect are derived using the first-passage failure criterion and Poisson crossing assumption. A systematic numerical simulation is conducted on a long-span concrete filled steel tube arch bridge, considering (1) the creep influence on concrete mechanical properties and structural configuration and internal forces; (2) the dimensionality, wave passage effect and incoherence effect of random ground motions; and (3) the uncertainties existing in the structure and creep behaviour. Critical conclusions are drawn and it is recommended to consider the long-term effect of dead loads in seismic design to ensure structural seismic safety.

A large number of highway bridges have been constructed in China since 1980s. Most of the aging bridges are in need of strengthening, which will lead to consuming big amounts of material and energy resources, producing air emissions and solid waste. This paper made a life cycle assessment for a highway bridge with four different strengthening plans by using Eco-indicator 99 to figure a total environmental impact score of the bridge. Based on analyzing the life cycle assessment (LCA) investigations of bridges, the adopted LCA method for the highway bridge tracks materials and energy resources through the various stages of the bridge life cycle including production, transportation, construction, strengthening, and demolition, considering the impact of vehicle detours during strengthening construction, to calculate environmental impact for ecosystem quality, human health, energy, and resources. This is done for four strengthening schemes, which are traditionally compared based only on the basis of economic cost. In order to account for the variability of critical input variables, a Monte Carlo simulation was performed to estimate the variability of environmental scores associated with the transportation distance, the average fuel consumption for each vehicle, detouring distance, the structure closure period, and maintenance times. Ten thousand iterations were conducted based on previous studies. The analysis shows that the maintenance phase alone contributes about 66 % of the total environmental impact (including detouring stage 50 %, repaving bridge deck 12 %, strengthening 4 %), followed by material production stage (approximately 40 %). Of the four strengthening plans, plan 1 and plan 3 have relatively greater contributions in terms of environmental damage while the cost budgets are much lower. On the contrary, plan 2 and plan 4 have lower environmental burdens but cost much more. Sensitivity analysis shows that the damage to resources and ecosystem quality are more sensitive to the variation of parameters. A life cycle assessment for a highway bridge in China with four different strengthening plans is conducted by using Eco-indicator 99 to figure a total environmental impact score of the bridge. It determines that the maintenance phase contributes the most to the environment deterioration. This study also shows that the energy consumptions and pollutant emissions related to traffic disruption during maintenance operations should not be excluded. Regarding the strengthening plans, it can be concluded that the environmental impact of bonding carbon fiber-reinforced polymer is fewer than that of bonding steel plates.

In order to classify typical Chinese tea varieties, Fourier transform infrared spectroscopy (FTIR) of tea polysaccharides (TPS) was used as an accurate and economical method. Partial least squares (PLS) modeling method along with a self-organizing map (SOM) neural network method was utilized due to the diversity and heterozygosis between teas. FTIR spectra results of tea extracts after spectra preprocessing were used as input data for PLS and SOM multivariate statistical analyses respectively. The predicted correlation coefficient of optimization PLS model was 0.9994, and root mean square error of calibration and cross-validation (RMSECV) was 0.03285. The features of PLS can be visualized in principal component (PC) space, contributing to discover correlation between different classes of spectra samples. After that, a data matrix consisted of the scores on the selected 3PCs computed by principle component analysis (PCA) and the characteristic spectrum data was used as inputs for training of SOM neural network. Compared with the PLS linear technique's recognition rate of 67% only, the correct recognition rate of the PLS-SOM as a non-linear classification algorithm to differentiate types of tea reaches up to 100%. And the models become reliable and provide a reasonable clustering of tea varieties.

Surface functionalization with stimuli-responsive materials can turn an ordinary material into a smart one that shows adaptive properties upon external stimuli. In this study, an electrospun regenerated cellulose (RC) nanofibrous membrane was firstly prepared; subsequently, poly(N-isopropylacrylamide) (PNIPAAm), a thermo-responsive polymer, was surface grafted to form the polymer chains/brushes on the surface of RC nanofibers via the surface-initiated atom transfer radical polymerization (SI-ATRP) method. Thereafter, the PNIPAAm-modified RC nanofibrous membrane was investigated for its temperature-responsive surface wettability at temperatures below/above the lower critical solution temperature (LCST). Furthermore, the nature of the hydrophilic/hydrophobic transitions of the modified nanofibrous membrane was also investigated through the water up-take and release experiment at various temperatures. Especially, as responses to different temperatures, the PNIPAAm-grafted nanofibrous membrane exhibits switchable super-lyophilic/super-lyophobic properties at a water–oil–solid three-phase interface. With the large surface area and switchable surface wettability, the as-prepared PNIPAAm-grafted nanofibrous membrane exhibits excellent properties of controllable oil/water separation, and possesses great potential towards both wastewater treatment and oil purification.

To make further studies on the difference of cis-nitenpyram analogues, a series of cis-nitenpyram compounds containing a flexible amido segment anchored on tetrahydropyrimidine ring was designed and synthesized. Preliminary bioassays indicate that all the analogues exhibit a mortality of 100% at 100 mg/L, and the analogue 4d shows the best activity against Nilaparvata lugens and Myzus persicae, with a mortality of 100% at 4 mg/L (LC50=0.172 mg/L). The structure activity relationship studies show that insecticidal activities of the analogues are affected by the kinds and size of substituent R. In addition, the molecular docking simulations reveal that compouds 4 with a flexible amido segment on tetrahydropyrimidine ring show their different binding affinities for the nicotinic acetylcholine receptor(nAChR) of insect and compoud 4d shows stronger hydrogen-bonding with nAChR, which may provide the structure-activity relationship observed in vitro.

A novel and sensitive electrochemical sensor for bisphenol A (BPA) determination based on carbon black supporting ferroferric oxide nanoparticles (Fe 3 O 4 NPs-CB) was developed. The Fe 3 O 4 NPs-CB nanocomposite fabricated on the glassy carbon electrode (GCE) demonstrated a high electrocatalytic activity towards the oxidation of BPA. The oxidation overpotentials of BPA decreased significantly and the peak current increased greatly compared with those of Fe 3 O 4 NPs- or CB-modified or bare GCE. Differential pulse voltammetry (DPV) was used as a sensitive analytical method for the determination of BPA, and a much wider linear dynamic range of BPA determination was found between 0.1 nM and 50 μM. The limit of detection (LOD) for BPA was found down to 0.031 nM based on S / N = 3. Fabricated Fe 3 O 4 NPs-CB nanocomposite on GCE displayed several outstanding properties such as good stability, high sensitivity and remarkable repeatability. The described sensor has been used for the determination of BPA in water samples with good recovery, ranging from 93.2% to 104.1%. Additionally, the migration of BPA from PC drinking bottles was evaluated by using water to simulate migration into aqueous and acidic foods.

Damping as a material property plays an important role in decreasing dynamic response of structures. However, very little is known about the evaluation and application of the actual damping of Fiber Reinforced Polymer Confined Reinforced Concrete (FRP-C RC) material which is widely adopted in civil engineering at present. This paper first proposes a stress-dependent damping model for FRP-C RC material using a validated Finite Element Model (FEM), then based on this damping-stress relation, an iterative scheme is developed for the computations of the non-linear damping and dynamic response of FRP-C RC columns at any given harmonic exciting frequency. Numerical results show that at resonance, a considerable increase of the loss factor of the FRP-C RC columns effectively reduces the dynamic response of the columns, and the columns with lower concrete strength, FRP volume ratio and axial compression ratio or higher longitudinal reinforcement ratio have stronger damping values, and can relatively reduce the resonant response.

Low add-on technologies have attracted more and more attention due to the shortage of water resources. In order to explore the mechanism of low add-on technologies, the states of water and the pore properties (pore size distribution, total pore volume, specific surface area, and the average of pore radius) of cotton fibers were investigated over a wide moisture range by using differential scanning calorimetry (DSC) based on the Gibbs–Thomson effect. A simple model of cotton fiber with various moisture ratios was given. Larger pores changed in size with the change of moisture ratio prior to smaller pores in both wetting and drying of cotton fibers. The information obtained could be used to explain the results of dyeing processes. Low add-on technology (wet pick-up 30–40%) was a favorable choice for surface treatment. Excellent surface performance of fabric could be obtained, and large amounts of water and energy could be saved by low add-on technology.

The foam dyeing of cotton fabric with CI Reactive Red 120 has been studied as a low-add-on technology. The foamability of different types of foaming agent and the stability of foam stabilisers were compared. Factors influencing foam dyeing, including wet pick-up, fixation agent, foam stabiliser, and blow ratio, were evaluated by colour strength and dye fixation rate. Wet pick-up, fixation agent, and foam stabiliser were found to be the main factors in the foam dyeing process. The comparative build-up properties, dyeing properties, and total consumption between foam dyeing and conventional dyeing were assessed. The results indicate that, in foam dyeing, the dyestuff has a better build-up property, the dyed fabric has excellent wash and rub fastness, and large amounts of water and energy are saved. Moreover, foam dyeing requires smaller dosages of chemical agents and reduces the difficulty of effluent treatment.

Nanosized particles can exhibit unexpected properties different from those of the original bulk material. The basic premise is that properties can dramatically change when a substance's size is reduced to the nanometre range. The applications of nanoparticles, e.g. carbon black or some finishing agents in the textile industry, have a long tradition but are in fact not part of nanotechnology. A typical feature of nanotechnology in textiles is to use nanoparticles with some systematic arrangements. In this manuscript, the main features of nanotechnology are summarized. A core part is devoted to the description of the nanoparticle behaviour arising from their small dimensions. The problem of nanoparticle stabilization is denoted. Selected applications of nanoparticles in the textile field are reviewed.

A new potential damping model for the dynamic analysis of systems is called exponential damping. This article shows that the finite element model updated method for the systems with exponential damping can accurately predict not only the natural frequencies but also the frequency response functions (FRFs) of the systems. A complex mode procedure for identifying the exponential damping model and its applicability and limitations is presented. A new iterative method for relaxation factor, which is simple, direct, and compatible with conventional modal testing procedures is proposed. The proposed method and several related issues are illustrated by numerical examples. Combined with the FRFs-based model updating method, the finite element model with such nonviscous damping is updated.

Material damping affects the dynamic behaviors of engineering structures considerably, but up to till now little research is maintained on influence factors of material damping. Based on the damping-stress function of steel, the material damping of steel beams is obtained by calculating the stress distribution of the beams with an analytical method. Some key influence factors of the material damping, such as boundary condition, amplitude and frequency of excitation, load position as well as the cross-sectional dimension of a steel beam are analyzed respectively. The calculated results show that even in elastic scope, material damping does not remain constant but varies with these influence factors. Although boundary condition affects material damping to some extent, such influence can be neglected when the maximum stress amplitude of the beam is less than the fatigue limit of steel. Exciting frequency, load position and cross-section dimension have great effects on the material damping of the beam which maintain the similar changing trend under different boundary conditions respectively.

Utilization of CdSe nanoparticle suspension for latent fingermarks on a multitude of non-porous and semi-porous surfaces has been demonstrated in this paper. Whether it is dark or light, the color of adhesives has no effect on the results of developing, because of the strong fluorescence excited by irradiation with UV LEDs. Enough contrast could be obtained for imaging. As an effective stabilizer for suspension which is commonly used in fingermark developing, Tween 20 with different concentration was also applied for better results. However, it did not work for nanometer-sized particles, which have already been stable in suspension. To broaden the scope of its application, different excitation systems were adopted. Well-contrast images could be obtained when 365 nm UV light, 440 nm blue light and daylight were applied. TiO2 SPR (small particle reagent) and gentian violet were used to compare with CdSe nanoparticle suspension under daylight. The results indicated that it produced significantly less background development and better contrast.

At present, the global energy consumption of transport sectors is about one third of the total energy consumption of the world, such a proportion in China accounts for about 20%. Over the past decades, with the continuous development of China's economy, China's energy consumption increases rapidly, China became the world's biggest energy consumer in the year of 2009. Meanwhile, China's transport energy consumption grows greatly, and the proportion of the transport terminal energy consumption is expanding considerably. Recently, a number of theoretical methods and technical schemes focusing on China's transport energy consumption and saving were reported. In this paper, by reviewing the existing reports, we discuss and analyze the current status of China's transport energy consumption including four different transport sectors: road, railway, waterway and civil aviation, and outline the trend of China's transport energy consumption and the four sectors. In addition, the technology status of China's energy saving in road, railway and waterway transport as well as civil aviation and their development direction are also presented. Here by analyzing the major development barriers of the technology and policy of China's transport energy saving, some related policy suggestions are proposed.

With the rapid economic growth and the improvement of people's living standards, China's building energy consumption has kept rising during the past 15 years. Under the effort of the Chinese government and the society, China's building energy efficiency has made certain achievements. However, the implementation of building energy efficiency in China is still far from its potential. Based on the analysis of the existing policies implemented in China, the article concluded that the most essential and the most effective ways to promote building energy efficiency is the government's involvement as well as economic and financial incentives. In addition, the main barriers in the process of promoting building energy efficiency in China are identified in six aspects. It has been found that the legal system and administrative issues constitute major barriers, and the lack of financial incentives and the mismatching of market mechanism also hamper the promotion of building energy efficiency. Finally, in view of the existing policies and barriers analysis, three corresponding policy proposals are presented.

Introduction In this paper, the authors presented a case of acrylamide poisoning in a middle-aged woman who had underwent unsuccessful cosmetic surgery six years earlier. The victim was told that the product that had been injected into her face was Restylane®, which mainly contained sodium hyaluronate and was the first and only Food and Drug Administration (FDA)-approved dermal filler for lip enhancement in the USA for more than 20years. Widespread facial infections occurred several years post-injection; finally, the victim had to undergo removal surgery. Acrylamide poisoning was strongly suspected based on the victim's clinical manifestation. The product that had been injected into the victim's face was probably polyacrylamide hydrogel-based product, which had been prohibited by the State Food and Drug Administration (SFDA) in China in 2006. To confirm this suspicion, a systematical method was established to differentiate varieties of cosmetic surgery products and identify residential acrylamide. Methods The removed objects, original products and a certified reference sample of Restylane® were collected for examination. A direct microscopic examination was applied as a rapid screening method. Fourier transform infrared (FTIR) microspectroscopy analysis was subsequently performed to distinguish the main components from each sample. Automated solid phase extraction, ultra high performance liquid chromatography (SPE UHPLC) analysis was ultimately utilised and optimised to detect the residual acrylamide. Chromatographic separation was achieved on an ACQUITY UHPLC HSS T3 column. The mobile phase consisted of 0.01% aqueous formic acid solution and acetonitrile. The tunable UV (TUV) detection wavelength was at 202nm. Results The microscopic examination indicated that different samples had different morphological characteristics, depending on their main components. The FTIR spectrum showed that different polymers could be distinguished according to the CO stretching vibration (1655cm −1 ), NH bending vibration (1540cm −1 ) and CO stretching vibration (1078 and 1045cm −1 ). The UHPLC results demonstrated that the calibration curve was linear in the range of 0.5–20.0μg/mL, with a correlation coefficient of 0.999. The average recoveries of the method were 99–107% with an RSD of 1.6–6.3%. The detection limit was 0.1μg/mL (S/N=3). The analytical time was 6min per sample. Acrylamide was detected in the allegedly Restylane® injection. Conclusions This systematical method provides a rapid, accurate and sensitive determination of polyacrylamide and residual acrylamide. The microscopic and FTIR spectroscopic examinations help to verify the existence of polyacrylamide quickly and easily. The optimised SPE UHPLC-TUV method offers a simpler and more sensitive approach to confirm the amount of acrylamide, comparing to the methods in the literature.

Uniform and well-dispersed photoluminescent semiconductor CdSe (Cadmium selenium) QDs (Quantum dots) were in-situ prepared by taking G4.0-NH2PAMAM(polyamidoamine) dendrimers as inner templates in water and methanol respectively. The prepared solutions containing photoluminescent semiconductor CdSe QDs were utilized for detection of unfumed oil fingerprints on tinfoil. The results show that unfumed latent fingerprints treated with prepared CdSe/PAMAM nanocomposites both displayed yellow emission and the latent fingerprints were detected clearly, while treated with CdSe/PAMAM composites in water manifested stronger emission compared with those treated with CdSe/PAMAM composites in methanol; Also, the veins of fingerprints treated with CdSe/PAMAM nanocomposites in methanol became slim because of the dissolution of methanol to oil components in fingerprints.

Two kinds of new immunogens and coating antigens had been designed and synthesised by methods of lively ester (DCC) and carbodiimide (EDC), respectively. Preliminary immunosorbent assays indicated that the two target conjugates presented good inhibition ratio against the haptens of cypermethrin in vivo. The results showed that the best efficient titres of anti-cypermethrin rabbit serum in methods of DCC and EDC were 1:32000 and 1:64000, the IC50 of them were 18.907µg/L and 16.877µg/L against the haptens of cypermethrin, respectively. The data indicated that the anti-cypermethrin antibodies in method of EDC had higher sensitivity and higher selectivity than the anti-cypermethrin antibodies in method of DCC. Thus, we can synthesise antigens and anti-bodies with method of EDC. The antibodies of high quality can be effectively used in the field of the rapid detection of pyrethroid pesticide residues in the research of the reagent strips.

In this paper, frequency-domain analysis of linear exponentially damped systems subjected to arbitrary initial conditions is studied. The standard Discrete Fourier Transform (DFT) procedure combined with Fast Fourier Transform (FFT) algorithms is applied to compute dynamic responses, after transforming the original motion equations subjected to non-zero initial conditions into new ones with completely null initial conditions by using the pseudo-force approach. A multi-degree-of-freedom (MDOF) system and a continuum system with exponential damping are considered as the illustrative problems. The accuracy of the proposed method is evaluated by comparing the results with those obtained from Simulink based on the state-space method.

Chitooligosaccharides (COSs) is a kind of polysaccharide scaffolds used to enhance cartilage repair during treatments involving bone marrow stimulation, angiogenesis and osteogenesis increase in vivo. Capabilities of COSs in promoting the proliferation and differentiation of hematopoietic stem cells/hematopoietic progenitor cells were mainly explored in the paper. The results showed that a high concentration of COSs significantly proliferate the mice marrow cells and induced CD34+ cells into megakaryocyte progenitor cells. However, COSs could not enhance the proliferation of CD19+ and CD4+ and promote CD34+ cells to differentiate into lymphoid progenitor cells. It suggested that COSs can promote hematopoietic stem/progenitor cells hyperplasia, and the mechanism may be that COSs promote stromal cell secretion of hematopoietic growth factors.

High performance gel permeation chromatography (HPGPC), ultraviolet-visible spectra (UV), infrared absorption spectra (IR) and ion chromatography (IC) techniques were used in fingerprint analysis of tea polysaccharides (TPS). Multi-fingerprint was applied to assess TPS consistency and to discriminate other polysaccharides in order to achieve the quality control of TPS. The experimental data for spectrogram and chromatogram were used for similarity calculation, included angle cosine method and correlation coefficient method. The results showed that the UV absorption spectra, IR absorption spectra and IC of 22 batches of TPS had a high degree of similarity, respectively, and the similar indexes were up to 0.9985 and 0.9475. Other five polysaccharides were compared with the referential fingerprint, which had an obvious difference. It could conclude that some differences were really existed between TPS and other polysaccharides; and multi-fingerprint is a more useful means to control the quality of TPS than one simple fingerprint. This analytical method is highly rapid, effective, visual and accurate for polysaccharides research.

It is challenging to explore a unified solution for the treatment of oily wastewater from complex sources. Thus, membrane materials with flexible separation schemes are highly desired. Herein, we fabricated a smart membrane by electrospinning TiO2 doped polyvinylidene fluoride (PVDF) nanofibers. The as-formed beads-on-string structure and hierarchical roughness of the nanofibers contribute to its superwetting/resisting property to liquids, which is desirable in oil/water separation. Switched simply by UV (or sunlight) irradiation and heating treatment, the smart membrane can realize reversible separation of oil/water mixtures by selectively allowing water or oil to pass through alone. Most importantly, the as-prepared nanofiber membrane possesses outstanding antifouling and self-cleaning performance resulting from the photocatalytic property of TiO2, which has practical significance in saving solvents and recycling materials. This work provides a route for fabricating cost-effective, easily scaled up, and recyclable membranes for on-demand oil/water separation in versatile situations, which can be of great usage in the new green separation technology.

The thermal decomposition approach, reverse micro-emulsion system and surface modification technique had been successfully used to synthesis single magnetic core Fe3O4@Organic Layer@SiO2–NH2 complex microspheres. The magnetization of the magnetic microspheres core could be easily tuned between 28 and 56 emu/g by adjusting the amount of 2-mercaptobarbituric acid. It was found that the Organic Layer to some extent had a protective effect on avoiding Fe3O4 being oxidized into Fe2O3. Each Fe3O4@Organic Layer microsphere could be coated uniformly by about 30 nm of silica shell. The average diameter of the Fe3O4@Organic Layer@SiO2 composites was about 538 nm. The saturation magnetization of the Fe3O4@Organic Layer@SiO2 complex microspheres was 12.5% less than magnetic microspheres cores. The Fe3O4@Organic Layer@SiO2–NH2 composites possessed a huge application potentiality in specificity enriching and separating biological samples.

PP/POSS and PP/SiO2 composite non-woven fabrics filled with polyhedral oligomeric silsesquioxanes (POSS) and SiO2 respectively using a convenient blending method were prepared through melt-blown process with corona charging. The morphology of the composite fibers and the distribution of POSS and SiO2 nanoparticles in PP matrix were investigated by field-emission scanning electron microscope (FSEM) and transmission electron microscope (TEM), respectively. POSS and SiO2 can act as nucleating agent and accelerate the crystallization process during nonisothermal cooling. The shear storage modulus G′, loss modulus G″, and complex viscosity η* of non-woven fabric reduce when 1 wt % POSS was added and increase for PP5/POSS composite non-woven fabric compared with pure PP non-woven fabrics. However, all G′, G″ and η* of PP/SiO2 non-woven fabric decrease with increasing SiO2 content owing to plasticization by SiO2. Both stress and elongation at break of the PP/POSS melt-blown non-woven fabrics are improved compared with PP non-woven fabrics, however decrease when SiO2 was added, as compared to the neat PP non-woven fabric. The onset temperature of decomposition for both the PP/POSS and PP/SiO2 composite non-woven fabrics is higher (5–10 °C) than pure PP and char content is increased with increasing POSS and SiO2.

This article mainly focused on the hypoglycemic effects of green tea flower polysaccharides (TFPS) and their possible mechanisms about regulating concentration of blood glucose. An alloxan-induced Sprague–Dawley (SD) rat model was used to observe the change in blood glucose. Inhibition rate of α-amylase and α-glucosidase, and antioxidant ability of TFPS were also tested to explain the possible mechanism. The results showed that TFPS could reduce blood glucose in alloxan-treated rats. TFPS had strong hydrogen donor ability and could protect cell membrane from overoxidation. TFPS could also inhibit the activity of α-amylase and α-glucosidase in vitro. But the inhibition of α-amylase by TFPS was comparatively low. It suggested that TFPS could protect against rapid blood glucose rise in alloxan-induced SD rats. The possible mechanism was that TFPS not only could donate hydrogen to protect SD rats from oxidative damage, but also inhibit digestive enzymes activities.

article i nfo The aim of this study was to verify that the combination of Fourier transform infrared microspectroscopy and scanning electron microscope / energy dispersive X-ray mapping could be applied to line intersection prob- lems. The spectral data of red seal ink, laser toner and their intersections, such as peak location and peak in- tensity, were described. Relative peak height ratios of different chemical components in intersecting lines were used to distinguish the sequences. Energy dispersive X-ray mapping characteristics of intersecting areas were also detailed. The results show that both the laser toner and the seal ink appear on the surface of intersections, regardless of the sequence. The distribution of the two inks on the surface is influenced not only by the sequence of heterogeneous lines but also by diffusion. Fourier transform infrared microspec- troscopy and scanning electron microscope/energy dispersive X-ray mapping are able to explore the chem- ical components and the corresponding elemental distribution in the intersections. The combination of these two techniques has provided a reliable method for sequencing intersecting lines of red seal ink and laser toner, and more importantly, this method may be a basis for sequencing superimposed lines from other writing instruments.

In this paper, the well known oscillation criteria due to Hille and Nehari for second-order linear differential equations will be generalized and extended to the third-order nonlinear dynamic equation (r"2(t)((r"1(t)x^@D(t))^@D)^@c)^@D+q(t)f(x(t))=0 on time scale T, where @c>=1 is a ratio of odd positive integers. Our results are essentially new even for third-order differential and difference equations, i.e., when T=R and T=N. Two examples of dynamic equations on different time scales are given to show the applications of our main results.

Yields of tea flower polysaccharides (TFPS) were investigated by ethanol fractional precipitation and stepwise precipitation and the monosaccharide composition of TFPS was investigated by ion chromatography(IC). Furthermore, a preliminary study on bioactivities of TFPS was discussed. The result indicated that the molecular weight distribution of TFPS was wide. Results of ethanol fractional precipitation and stepwise precipitation suggested that most of polysaccharides were precipitated when the final concentration of ethanol was adjusted to 30% (v/v). TFPS contained acid polysaccharides and it was composed of rhamnose, arabinose, galactose, glucose, xylose, mannose, GalA, and GluA with a molar ratio of 4.95:11.57:11.89:4.26:1.31:1.98:8.41:1.0. Furthermore, TFPS exhibited strong inhibitory effect on α-glucosidase and proliferation effect on lymphocytes.

To develop an efficient water-collecting surface that integrates both fast water-capturing and easy drainage properties is of high current interest for addressing global water issues. In this work, a superhydrophobic surface was fabricated on cotton fabric via manipulation of both the surface roughness and surface energy. This was followed by a subsequent spray coating of TiO2 nanosol that created light-induced superhydrophilic bumps with a unique raised structure as a result of the interfacial tension of the TiO2 nanosol sprayed on the superhydrophobic fiber surface. These raised TiO2 bumps induce both a wettability gradient and a shape gradient, synergistically accelerating water coalescence and water collection. The in-depth study revealed that the quantity and the distribution of the TiO2 had a significant impact on the final water collection efficiency. This inexpensive and facilely fabricated fabric biomimicks the desert beetle's back and spider silk, which are capable of fog harvesting without additional energy consumption.

a b s t r a c t In this paper, the composition and biological activities of polysaccharides from tea seed (TSPS) obtained by water extraction were investigated. The properties and chemical compositions of TSPS were analyzed with HPGPC, IC, and IR methods. The results showed that TSPS consisted of three kinds of polysaccharides with the molecular weight of 500 kDa, 130 kDa, and 5 kDa. TSPS consisted of rhamnose, xylose, arabinose, glucose and galactose, GalA, GulA, with a molar ratio of 4.9:1.7:11.1:27.2:14.0:3.4:1, sugar backbone of TSPS might consist of glucose, but branched chain may consist of rhamnose, xylose, arabinose, and galactose. The IR spectrum of TSPS revealed the typical characteristics of polysaccharides and protein. TSPS significantly inhibited the growth of K562 cells, especially, at the concentration of 50 g/ml; the inhibition activity of TSPS was the highest with an inhibition ratio beyond 38.44 ± 2.22% (P < 0.01). TSPS with high concentrations (100, 200 and 400 g/ml) had higher proliferation effect on lymphocyte. Results of these studies demonstrated that the polysaccharide had a potential application as natural antitumor drugs.

A new method for the determination of tea polysaccharide (TPS) in green tea (Camellia sinensis) leaves has been developed. The method was based on the enhancement of resonance light scattering (RLS) of TPS in the presence of cetylpyridinium chloride (CPC)-NaOH system. Under the optimum conditions, the RLS intensity of CPC was greatly enhanced by adding TPS. The maximum peak of the enhanced RLS spectra was located at 484.02 nm. The enhanced RLS intensity was proportional to the concentration of TPS in the range of 2.0-20 μg/ml. It showed that the new method and phenol-sulfuric acid method give some equivalent results by measuring the standard compounds. The recoveries of the two methods were 96.39-103.7% (novel method) and 100.15-103.65% (phenol-sulfuric acid method), respectively. However, it showed that the two methods were different to some extent. The new method offered a limit of detection (LOD) of 0.047 μg/ml, whereas the phenol-sulfuric acid method gives a LOD of 1.54 μg/ml. Interfered experiment demonstrated that the new method had highly selectivity, and was more suitable for the determination of TPS than phenol-sulfuric method. Stability test showed that new method had good stability. Moreover, the proposed method owns the advantages of easy operation, rapidity and practicability, which suggested that the proposed method could be satisfactorily applied to the determination of TPS in green tea.

Effective virtual screening relies on our ability to make accurate prediction of protein-ligand binding, which remains a great challenge. In this work, utilizing the molecular-mechanics Poisson-Boltzmann (or Generalized Born) surface area approach, we have evaluated the binding affinity of a set of 156 ligands to seven families of proteins, trypsin β, thrombin α, cyclin-dependent kinase (CDK), cAMP-dependent kinase (PKA), urokinase-type plasminogen activator, β-glucosidase A, and coagulation factor Xa. The effect of protein dielectric constant in the implicit-solvent model on the binding free energy calculation is shown to be important. The statistical correlations between the binding energy calculated from the implicit-solvent approach and experimental free energy are in the range of 0.56-0.79 across all the families. This performance is better than that of typical docking programs especially given that the latter is directly trained using known binding data whereas the molecular mechanics is based on general physical parameters. Estimation of entropic contribution remains the barrier to accurate free energy calculation. We show that the traditional rigid rotor harmonic oscillator approximation is unable to improve the binding free energy prediction. Inclusion of conformational restriction seems to be promising but requires further investigation. On the other hand, our preliminary study suggests that implicit-solvent based alchemical perturbation, which offers explicit sampling of configuration entropy, can be a viable approach to significantly improve the prediction of binding free energy. Overall, the molecular mechanics approach has the potential for medium to high-throughput computational drug discovery.

Long-term properties of concrete affect structures in many respects, not excepting dynamic behaviors. This paper investigates the influence of concrete creep on the dynamic behaviors of concrete filled steel tube (CFT) arch bridges, by means of combining the analytical method for the creep of axially compressed CFT members, which is based on Model B3 for concrete creep, with the finite element model of CFT arch bridges. By this approach, the changes of the stress and strain of each element in the bridge with time can be obtained and then transformed into damping and stiffness matrices in the dynamic equation involved in the finite element model at different times. A numerical example of a long-span half- through CFT arch bridge shows that creep influences the natural vibration characteristics and seismic responses of the bridge considerably, especially in the early age. In addition, parameter analysis demonstrates that concrete composition, compressive strength and steel ratio have an obvious effect on the seismic response of the CFT arch bridge.

This paper presents an experimental work on the long-term deformation properties of four FRP-wrapped concrete columns (FWCCs) with low-volume fly ash (FA) as admixture, and a theoretical study on the creep of FWCCs with or without FA in the concrete mix. Theoretically, considering the creep of concrete under triaxial stresses and the interaction between concrete core and fiber reinforced polymer (FRP) wraps, an analytical model, based on the Model B3 or modified Model B3 for the creep of concrete without or with FA, and the power law for the creep of FRP, is developed to study the creep of FWCC. Validations against creep data from literatures and the experimental results in this paper show the model works well. Additionally, the influences of various parameters on the creep of FWCC are investigated. The creep of FWCC with FA is shown to be less than that of FWCC without FA. And the composition and compressive strength of concrete are demonstrated to affect the creep of FWCC obviously.

In this paper, the crude polysaccharides from the flowers of tea plant (Camellia sinensis) (TFPS) extracted with hot water were fractionated on a DEAE Sepharose FF chromatography to get TFPS1 with a yield of 18%. The properties and chemical compositions of TFPS1 were analyzed with GC, HPGPC, IC, IR methods and its morphology was observed with atomic force microscopy (AFM). The results showed that TFPS1 was a neutral glycoprotein conjugate with a molecular weight 500 kDa. The alanine, threonine, glycine, valine, serine, histidine, glutamic acid, histidine and tyrosine were found in TFPS1 and the total content was 2.03%. TFPS1 was consisted of rhamnose, arabinose, mannose, glucose and galactose, with a mole ratio of 1.0:2.9:0.5:1.3:3.3. Sugar backbone of TFPS1 may consist of glucose and galactose, but branched chain may consist of arabinose, galactose and rhamnose. The IR spectrum of TFPS1 revealed the typical characteristics of polysaccharides and protein. TFPS1 was spherical particle structure with a diameter of 50–70 nm.

A chitosan-degrading fungus, BSF114, was isolated from soil. The culture preparation showed strong chitosanolytic enzyme activity at optimum pH 4.0 and optimum temperature of 60 degrees C after 36-40 h fermentation. The rapid decreased viscosity of chitosan solutions at early stage of reaction suggested an endo-type cleavage of the polymeric chitosan chains. To identify the isolated fungus, molecular biological and morphological methods were used. The fungal internal transcribed spacer (ITS) region 1 was amplified, sequenced, and then compared with related sequences in the GenBank database using BLAST. The phylogenetic relationships were then analyzed, and the results showed that the fungus belongs to Aspergillus fumigatus. Morphological observations were also used to confirm the above conclusion. The chitooligosaccharides (COS) obtained through hydrolyzing the colloidal chitosan showed A. fumigatus BSF114 is suitable for degrading chitosan and producing chitooligosaccharides on a large scale. High concentrations of the COS (1000 and 500 microg/mL) significantly proliferated mice marrow cells.

The purpose of our work was to develop a simple and efficient analytical method for simultaneous determination of different species of organic phosphorus pesticides from plasma sample by using automated solid phase extraction (SPE) and gas chromatography/pulsed flame photometric detector (GC/PFPD) as a diagnostic tool. Firstly, the developed extraction method was validated using 5 certified reference materials; then, it was applied to plasma sample. Such factors as the category and volume of wash and elution solvent were examined separately. Among these factors, the category of elution solvent is most important. Hexane-acetone (50:50, v/v) seems to be the best choice for it. The eluent was evaporated on a nitrogen stream at room temperature and redissolved by acetone. 1microL of aliquots was chromatographed on GC/PFPD. Response versus the amount of pesticides injected ranging from 0.05 to 2ng showed a good linearity. The detection limits were 0.01ng for dimethoate, 0.03ng for methyl-parathion and malathion, 0.04ng for terbufos and 0.02ng for parathion. Extraction recoveries range from 84.3% to 109.1%.This extraction method for multispecies analysis incorporates many benefits in terms of speed, low solvent use, accuracy of measurement, sensitivity, relative simplicity, as well as the time saving and convenience of multiple species measurement through sample preparation and analysis as an integrated step.

Four flavones (flavone, 7-hydroxyflavone, chrysin, and baicalein) sharing the same B- and C-ring structure but a different numbers of hydroxyl groups on the A-ring were studied for their affinities for BSA and HSA. The hydroxylation on ring A of flavones increased the binding constants (K(a)) and the number of binding sites (n) between flavones and serum albumins. The affinities of 7-hydroxyflavone for BSA and HSA were about 800 times and 40 times higher than that of flavone, respectively. It appears that the optimal number of hydroxyl groups introduced to the ring A of flavones is one. As more hydroxyl groups were introduced to positions at C-5, C-6, and/or C-7 of flavones, the affinities for serum albumins decrease. The critical energy transfer distances (R(0)) between the hydroxylated flavones (1-3 OH on the ring A) and serum albumins decreased with the increasing affinities for serum albumins.

A direct procedure for the determination of total polysaccharides (TPS) in Camellia sinensis was set up based on the modified phenol-sulfuric acid method. The monosaccharide composition of TPS was analyzed by GC. Based on the results of GC, model monosaccharide mixtures were made which provided an adequate standard for this procedure. Through single-factor and orthogonal (L934) experiments, the experimental conditions such as the volume of phenol, the volume of concentrated sulfuric acid, the reaction time, and the incubation temperature, were optimized. The highest sensitivity of absorbance was obtained when the volume of concentrated sulfuric acid, the volume of phenol (6%), and the incubation temperature were 2.5 ml, 0.2 ml, and 50?C, respectively. Under optimum conditions, the prepared samples were determined satisfactorily, with the recovery from 100.2% to 103.7%, and a relative standard deviation (RSD) of 2.1%. Overall, the modified method is easily operated, rapid, sensitive and accurate. A similar procedure can be applied to the determination of other plant polysaccharides as well. .

The effects of different extraction methods on the composition and bioactivity of tea flower polysaccharides (TFPS) were investigated. Traditional water extraction (TWE), microwave-assisted water extraction (MAE), and ultrasound-assisted water extraction (UAE) were compared to extract TFPS. TWE was found to be the optimal method with highest yield of TFPS and highest neutral and acid saccharides contents in TFPS. TFPS obtained by TWE mainly consisted of two kinds of polysaccharides with the molecular weight of 31 kDa and 5000 Da. TFPS obtained by MAE and UAE generally had very low inhibitory effects on α-glucosidase. TFPS (2 mg/mL) obtained by TWE exhibited a strong inhibitory effect on α-glucosidase with the inhibitory rate of 83.3%. TFPS obtained by TWE had stronger proliferation effect on lymphocyte at the concentration of 3.0 μg/mL than that of tea leave polysaccharides (TPS).

There are several models by means of quenching fluorescence of BSA to determine the binding parameters. The binding parameters obtained from different models are quite different from each other. Which model is suitable to study the interaction between trans-resveratrol and BSA? Herein, twelve models based fluorescence quenching of BSA were compared. The number of binding sites increasing with increased binding constant for similar compounds binding to BSA maybe one approach to resolve this question. For example, here eleven flavonoids were tested to illustrate that the double logarithm regression curve is suitable to study binding polyphenols to BSA.

Many emerging interfacial technologies, such as self-cleaning surfaces, oil/water separation, water collection, and microfluidics, are essentially liquid manipulation processes. In this regard, micro-nanostructures of the living organisms are highly preferable, by virtue of the evolutionary pressure and the adaptation to the specific environments, to inspire the optimization of man-made interfaces. With the increasing demands of modern life, research, and industry, intelligent materials with stimuli-responsive liquid manipulation functions have gained substantial attention from interfacial scientists. This review introduces the recent progress in the development of stimuli-responsive liquid-manipulating materials with bioinspired structures and surface chemistry according to two classified manipulation modes: (i) smart manipulation of liquid wetting behaviors, including lyophobic/lyophilic and superlyophobic/superlyophilic, and (ii) smart manipulation of liquid motion behaviors, including coalescence, transportation, rolling/adhesion, and sliding/pinning. At the beginning of the presentation of each classification, the theoretical basis and the sources of inspiration are introduced comprehensively to ensure a better understanding. This review mainly focuses on the mechanisms, fabrication, and applications of the state-of-the-art works related to smart and biomimetic liquid-manipulating materials. Finally, conclusions and future prospects are provided, and the remaining problems and promising breakthroughs in fabricating large-scale, cost-effective, and efficient smart liquid-manipulating materials are outlined.