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Motion sickness (MS) is a common physiological response to real or virtual motion. The purpose of this study was to investigate the effects of transcutaneous electrical acustimulation (TEA) on MS and the underlying mechanisms in healthy subjects.

The organosilicon hydrophobic impregnants is applied on concrete to prevent rebar corrosion with its water repellent property which can prevent the intrusion of chloride and other harmful media. On-site the parameters of organosilicon hydrophobic impregnants of controlling quality consist of resistance to chloride penetration, water absorption of concrete and impregnating depth of organosilicon hydrophobic impregnants. The status of test methods of these parameters is summarized and their advantages and disadvantages are briefly reviewed. Finally some ideas are presented about shortcomings of test methods.

The garage body is designed with steel structure, the mechanical part comprises a frame, a transmission track vehicle guide system, the external tooth slewing ring and elevator The control unit using PLC, sensor and the host computer, control the whole process of vehicle access.

Finite Difference Time Domain method(FDTD) is used to study the resonance properties of E-type nano antenna in this paper. According to the result of numerical simulation,the size and location of ledge part made a great influence on the resonance properties of holistic nano antenna while major rectangle part is invariant.The electronic field distribution, enhancement factor and corresponding resonance frequency of E-type nano antennas with invariant major rectangle part and different ledge parts are calculated through FDTD method,comparing with rectangle nano antenna without ledge part, E-type nano antenna has a great promotiom in electronic field enhancement at about 100 times of the excite electronic field intensity while regular rectangle nano antenna can achieve about 30times only.The resonance frequency is relate to the ledge part ,by changing the size and location of ledge part,resonant frequency can be adjusted between 340Thz and 400Thz,at the meantime, the field enhancement almost unchanged. After a glass substrate is added under the E-type nano antenna with constant size,the electronic field intensification factor improved significantly and the electronic field spread over the area around the ledge part rather than the junction of glass and metal.The horizontal position of ledge part has an effect on holistic resonance properties.When the ledge part located in the middle, the electronic field intensification factor of three ledge parts rised to 240 times at the same time,and distinct double resonance peak appeared.When the ledge part moved to the edge, the electronic field enhancement around the ledge parts on the sides weaken and middle ledge part rised to 350 times,double resonance peak disappeared.

The influence of curved surface on the method of polychromatic speckle autocorrelation measuring surface roughness is studied by introducing the curvature radius of surface. The rough surface, and the dichromatic speckle patterns, and trichromatic speckle patterns are simulated, and the effects of different radius of curved surface on speckle patterns and speckle elongation ratio are discussed. The results show that the larger curvature radius is, the larger speckle elongation becomes, and the smaller the deviation of measured surface roughness is. Therefore, influence of curvature of rough surface on measurement precision should be taken into consideration during measuring process.

The strong field enhancement of a new type of rectangle plasmonic optic nano-antenna with two protrusions in the middle gap is studied by the comparison with two another common rectangle structures using CST software. The intensity of the new type presented in the paper is about 2.5 times more than its common counterpart, up to about 60V/m in the center of antenna, and the position of peak shifts to visible region (406THz) from infrared region (382THz). Further more, the resonant magnitude in the region of corners of protrusions in the middle gap is somewhat larger than that in center region of antenna, and the resonant frequencies all are controlled in the visible range, about 410THz,the results indicate that the protrusions have a good effect on the performance of antenna. Moreover, when a glass substrate is used, the maximum of field magnitude is about 3 times lager than the same structure without substrate, up to 214 V/m, and the resonant frequency red-shifts to about 359THz, which demonstrates that the substrate plays a important role in the excitation of stronger enhancement. The type presented in the paper has a certain reference for the fabrication of high-quality optical nano-antennas and solar cells etc.

In this paper dipole type optical antenna and V type optical antenna are designed using gold and glass substrates, we compared their resonance properties by finite-difference time-domain (FDTD) method, calculated and analyzed their distribution and field enhancement effects contrastively. The results showed that in the same projected length, the resonant frequency of dipole type optical antenna was higher than the V type optical antenna, while the resonance enhancement factor was lower than the V type optical antenna. These have certain reference significance for researching characteristics of nanoantenna based on surface plasma.

The strong local property of surface plasmon polaritons can break through the diffraction limit, and reduce the propagation of corner scattering on nanoscale. The nanoantenna structure based on the plasmon resonant effect can collect the light energy effectively, and the local field enhancement effects of the structure have extensive application prospect. The field distribution and field enhancement effects of optical antenna under nanoscale are calculated with finite-difference time-domain (FDTD) method. Several different structures of nanooptical antenna are studied, and their enhancement properties are compared in this paper.

Based on the method of polychromatic speckle autocorrelation measuring surface roughness, this paper discussed the influence of the combination of different wavelengths on speckle patterns and speckle elongation ratio when rough surface and polychromatic speckle patterns were simulated. The results show that the smaller the difference of wavelengths combination is, the further peak of the speckle elongation ratio is from the speckle field centre, for the same surface roughness. And the wider area of speckle elongation effects extends. Therefore, influence of combination of wavelengths on measurement precision should be taken into consideration during measuring process.

Applying autocorrelation method to process laser speckle patterns, the relation between surface roughness and speckle elongation and correlation length of autocorrelation function can be obtained, and the measured surface roughness can be achieved based on this relation. One-dimension autocorrelation and two-dimension autocorrelation function are used, Moreover, surface roughness is evaluated by speckle elongation and correlation length of autocorrelation function. Aspect ratio of speckle granular represents speckle elongation ratio, which eliminates effects of speckle granular average size on measurement results compared to other methods using before. It has high reliability and efficiency in surface roughness measurement evaluation.

Based on the equations of motion and rheological theory of abrasive flow in the slit, effect between wall slip and grinding has been analyzed and grinding flow model of abrasive flow has been built in this paper. Wall pressure, wall shear stress, wall slip and the grinding force equation of abrasive flow were derived using the model. What is important, the effects of relevant factors were analyzed. The results show that wall slip is one of the necessary conditions that in abrasive flow machining, and show that main factors influencing wall slip are viscosity coefficient , grinding coefficient of abrasive flow, and the first normal stress difference. In the meantime, the results also show that grinding force in slit wall is proportional to the entrance pressure of slit. That is to say that the grinding force of per unit length in flow direction increasing dramatically with decreasing slit height.

In this article, a novel strong interaction by forming complex between bovine serum albumin (BSA) and copper ion was utilized for the preparation of molecular imprinted hydrogel in aqueous solution. Results show that the inclusion of copper ion in preparation can bridge the template BSA and functional monomers together and improve the imprinting effect compared to the polymer made without copper ion added. High selectivity factor and large adsorption capacity are also observed for the obtained BSA-imprinted hydrogel.

In this paper we discuss the temperature dependence and its effect on surface roughness. In abrasive flow machining (AFM) process the temperature of media rises drastically due to procedure of being sheared. To examine the effect of media temperature on surface roughness, an experiment system with the functions of controlling, measuring and recording temperature is set up. The variable trend of media temperature is revealed during AFM. Experiments are performed at different temperatures. Experimental results show that the media at high temperature results in less improvement in surface roughness. Therefore the media can have good machining performance in the first few cycles and the media temperature rise rapidly. Finally we conclude that the best workable temperature should be below 25 °C during the AFM.

This letter used the molecular imprinting technology to build up the microenvironment around co-monomer hemin to mimic the cytochrome P450 catalyzing the epoxidation of styrene. The results showed that the conversion rates of products were obviously enhanced by molecularly imprinted polymers, compared to free hemin solution, using three kinds of oxidants. The used axial ligand in polymers synthesis also improved the total conversion rates.

A highly selective immunoaffinity column was obtained by coupling anti‐papaverine polyclonal antibodies to CNBr‐activated Sepharose 4B. It was found that the coupling efficiency and performance of the immunoaffinity column were greatly improved by prolonging the coupling reaction time from 3 h at 20°C with shaking to incubation overnight at 4°C after the 3 h shaking reaction. The pH and ionic strength were observed to be the most important factors that influence the binding of papaverine to the immunoaffinity column. Using 0.01 mol/L phosphate buffered saline (PBS, pH 8.3) and methanol‐water (80 : 20, v/v) as the loading and eluting solutions, respectively, papaverine was first retained on the column and then quantitatively eluted out with a mean recovery of 86% at a loading concentration of 1 μg/mL. When applied to real samples of pericarpium papaveris and food products, the established immunoaffinity column showed high efficiency in removing the matrix interferences in the samples and satisfactory recovery results were obtained. The method was useful for extraction and purification of papaverine from related samples.

Abstract. A simple and novel flow injection method for the determination of gaseous SO₂ is described based on gas permeation denuder (GPD) online sampling and preconcentration. The GPD is easily prepared with poly(vinylidene) difluoride microporous membrane as gas permeable material and two Perspex blocks with smooth and flat interface and rectangular engraved channels of mirror image. The sample gas is on one side of the membrane and phosphate buffer of pH 7.0 as the absorbing solution is on the other side. Gaseous SO₂ permeates partially through the gas permeable membrane and dissolves in the absorbing solution. After preconcentration for 5.0 or 8.0 min, the solution is injected into the flow of 5.0×10^-4 mol L^-1 5,5'-dithiobis(2,2'-dinitrobenzoic acid) (DTNB) in 0.025 mol L^-1 phosphate buffer. The resulting product formed between DTNB and absorbed SO₂ is spectrophotometrically monitored at 410 nm with a charge coupled device (CCD) fiber optic spectrometer. The calibration graphs for preconcentration of 5.0 and 8.0 min are linear up to 4.0 and 3.2 mg m^-3 with detection limits of 50 and 35 µg m^-3, respectively. The corresponding analysis speeds are 8.5 and 6 samples h^-1. The method is selective and just suffer from interference of hydrogen sulfide at higher than 1% of SO₂ level (in m/V) with an error >+10%. The assay just uses cheap and common membrane and reagents and shows potential application in the monitoring of atmospheric SO₂.

Polymer capable of specific binding to Cu2+‐2, 2′‐dipyridyl complex was prepared by molecular imprinting technology. The binding specificity of the polymer to the template (Cu2+‐2, 2′‐dipyridyl complex) was investigated by cyclic voltammetric scanning using the carbon paste electrode modified by polymer particles in phosphate buffer solution. Factors that influence rebinding of the imprinted polymer were explored. The results demonstrated that cyclic voltammetry was an efficient approach to explore interactions between template and imprinted polymers. Copyright © 2002 John Wiley & Sons, Ltd.

Molecularly imprinted polymers (MIPs) using p‐hydroxybenzoic acid (p‐HB), p‐hydroxyphenylacetic acid (p‐HPA) and p‐hydroxyphenylpropionic acid (p‐HPPA) as templates were synthesized. The performance of the templates and their analogues on polymer‐based high performance liquid chromatography (HPLC) columns was studied. The imprinting effect of the MIP using p‐HB as template is more obvious than that of MIP using either p‐HPA or p‐HPPA as template, and the mixture of p‐HB and p‐HPA can be well separated on the MIP using p‐HB as template, but not on the blank. Interestingly, the recognition of MIP (p‐HB as the template) to p‐HB showed a synergistic effect. The retention factor of p‐HB is not the sum of those of phenol and benzoic acid. We also found that the imprinting effect decreased when increasing the concentration of acetic acid in mobile phase. The possible reason is that acetic acid molecules occupied the binding sites of the polymer, thereby decreasing the concentration of binding sites. Furthermore, polymers, which showed specificity to 3,4‐dihydroxybenzoic acid, can be prepared with p‐HB as template. It is thus possible to synthesize a specific polymer for a compound that is either expensive or unstable by using a structurally similar compound as template. Copyright © 2001 John Wiley & Sons, Ltd.

Molecularly imprinted polymers (MIPs) using p-hydroxybenzoic acid (p-HB), p-hydroxyphenylacetic acid (p-HPA) and p-hydroxyphenylpropionic acid (p-HPPA) as templates were synthesized. The performance of the templates and their analogues on polymer-based high performance liquid chromatography (HPLC) columns was studied. The imprinting effect of the MIP using p-HB as template is more obvious than that of MIP using either p-HPA or p-HPPA as template, and the mixture of p-HB and p-HPA can be well separated on the MIP using p-HB as template, but not on the blank. Interestingly, the recognition of MIP (p-HB as the template) to p-HB showed a synergistic effect. The retention factor of p-HB is not the sum of those of phenol and benzoic acid. We also found that the imprinting effect decreased when increasing the concentration of acetic acid in mobile phase. The possible reason is that acetic acid molecules occupied the binding sites of the polymer, thereby decreasing the concentration of binding sites. Furthermore, polymers, which showed specificity to 3,4-dihydroxybenzoic acid, can be prepared with p-HB as template. It is thus possible to synthesize a specific polymer for a compound that is either expensive or unstable by using a structurally similar compound as template. Copyright © 2001 John Wiley & Sons, Ltd.

Imprinted polymers were prepared for nicotinamide and its positional isomers. The influence of porogenic solvent and functional monomer on recognition properties of the polymer was compared. The results indicated that two functional groups, the heterocyclic nitrogen and the amide group, in the nicotinamide or isonicotinamide molecule have a synergistic effect in binding to the polymer. The polymers prepared with nicotinamide and isonicotinamide can be used as HPLC stationary phase for the separation of positional isomers of nicotinamide or isonicotinamide, while the polymer prepared with picolinamide showed no specificity toward the template. The mechanisms for the differences in recognition are discussed. In addition to the retention of polymers to their templates the polymers also displayed excellent retention to nicotinic acid and isonicotinic acid, compounds structurally similar to the template. This dual recognition property of the polymer may be useful in circumstances where the preparation of a polymer for a specific template may be problematic because of poor stability or solubility. Copyright © 2001 John Wiley & Sons, Ltd. Abbreviations used: AIBN 2,2'-azo-bis-iso-butyronitrile EGDMA ethylene glycol dimethacrylate HPLC high performance liquid chromatography MAA methacrylic acid MIPs molecular imprinted polymers NAM nicotinamide.

The reactivity of a series of phenolic lignin diphenylmethane (DPM) model dimers has been examined in soda and kraft cooks, in an attempt to understand the role of lignin condensation in the alkaline delignification process. These condensed dimers were shown to be rather stable in alkali in the absence of O2 even at elevated temperatures. In contrast, they were sensitive to traces of O2 present in air, and the degradation mechanism involved was shown to be different from that occurring under mild alkali-O2 conditions.

AbstractA sensitive fluorometric method is described For selective determination of cytosine in nucleobases. The method is based on chemical derivatization of cytosine by triethylamine/chloroacetonitrile. The effects of solvent, reaction temperature, reaction time and concentration of reagents on the efficiency of the reaction were studied. A good linear relationship between fluorescence intensities and cytosine concentrations in the range of 2.0–800 ng/mt was observed. The detection limit for cytosine is 0.6 ng/ml (S/N=3). The relative standard deviations (7 replicates) for measurements of 50 and 500 ng/ml cytosine were 2.1 and 2.5%, respectively.

N,N′-Dicyanomethyl-o-phenylenediamine was synthesized with a 90% yield by a reaction ofo-phenylenediamine with chloroacetonitrile in triethylamine. Our experimental results showed that it was the effective fluorogenic substrate for horseradish peroxidase (HRP) and hemin. TheKmfor the HRP system was 48 μM,and that for hemin was 1.3 μM.Properties of the substrate were evaluated from the detection limits of enzymes and H2O2. The linear ranges for the determination of HRP and hemin were 21–150 pMand 2–20 nM,respectively. The linear range for the determination of H2O2using HRP or hemin was 18–140 and 60–1000 nM,respectively. The structural elucidation of the fluorescent product using NMR and mass spectral techniques was proposed to be 1,2-dihydro-2-imido-imidazo[1,2-a] quinoxaline. Based on the product structure and earlier reports, the possible reaction mechanism of HRP and the substrate was also proposed, i.e., two steps for ring closures, one step of isomerization, and a final step of oxidative dehydrogenation.

A procedure for the simultaneous time-resolved fluoroimmunoassay for phenobarbital and phenytoin, based on the use of europium- and samarium-labeled haptens, has been investigated. These lanthanide ions are bound to the haptens by means of the anhydride of diethylenetriaminepentaacetic acid. The antibody is immobilized onto immunoplate in which samples are assayed in competitive immunoassay. After the immunoreactions and dissociation with a fluorescence enhancement solution, the fluorescence intensity is measured. The detection limits of the assay are, respectively, 20 ng/ml for phenobarbital and 50 ng/ml for phenytoin. Results obtained with the proposed methods correlate well (CV <10%). The inter-reactions between phenobarbital, phenytoin, and their antibodies are studied.

Specially designed wood blocks from Norway spruce were used to study the nature of the fracture surfaces developed in shear using a tensile tester. In the case of the control (water-soaked blocks), the fracture in the latewood takes place mainly in the S1 layer while in the earlywood the fracture occurs across the double cell wall. After dilute alkali treatment, some earlywood cells also fracture in the S1 layer. For sulfite-treated samples, on the other hand, both earlywood and latewood fracture in the middle lamella.

The interaction of the La3+-morin complex with DNA has been examined using fluorescence and absorption spectroscopic as well as viscosity measurement methods. The fluorescence intensity of La3+-morin complex could be highly enhanced by DNA. In the presence of DNA the absorption wavelength or fluorescence excitation wavelength showed a red shift of 43 – 45 nm, while the emission wavelength remained unchanged, consistent with groove binding of fluorescent dye with DNA. In contrast to intercalators, the complex showed an enhanced stacking effect, based on a viscometer measurement, on base pairs of DNA. The presence of both NaCl and phosphate showed a strong quenching effect on the fluorescence of the ternary system. This is also in favor of groove binding. Thus, groove binding rather than intercalation of the complex to DNA was suggested. Binding of the complex into a DNA narrow minor groove imposed constrains on free motion of the complex. Therefore, the non-radioactive deactivation of the excited state of the complex was inhibited and fluorescence enhancement was observed. The enhancement effect of DNA on the fluorescence of La3+-morin complex was used for a quantitative and selective determination of double-stranded DNA. The detction limit was 20 ng/ml.

The fluorescence enhancement of terbium(III) by nucleotides (AMP, ADP, ATP, GMP, GDP, GTP) and polyhomonucleotides [poly(A), poly(G), poly(C), poly(U)] in the presence of phenanthroline (phen) was studied. Investigation of the composition of the terbium(III)/ANP(AMP, ADP, ATP)/phen complexes and conditions of optimization suggest a 1:2 molar ratio of terbium(III) and phen for the ternary complexes. The results showed that the presence of phen enhanced the net fluorescence of terbium(III)/ANP, poly(A), poly(C) or poly(U) from several fold to more than one-hundred fold, while it has little effect on the fluorescence of terbium(III)/GNP(GMP, GDP and GTP) or the poly(G) system. The possibility of spectrofluorimetric measurements of these compounds were studied under optimal conditions (pH 7.0 in tris-HCl buffer; Ex=298 nm, Em=543.5 nm). The detection limits were 2.0×10-7, 6.0×10-7 and 1.0×10-6 mol/l for AMP, ADP and ATP, respectively. The relative standard deviations (6 replicates) were within 2.0% in the middle of the linear range.

A new fluorescent reaction of DNA with chloroacetic acid in the presence of triethylamine is proposed, and the reaction conditions have been optimized. Based on this fluorescent reaction, a sensitive fluorometric method is described for the determination of DNA and the selective determination of cytosine and dCMP. The detection limits for DNA, cytosine and dCMP were 6.0, 0.4 and 1.4 ng/ml, respectively.

To mimic the peroxidase activity of horseradish peroxidase (HRP), hemin was chemically attached, through its carbon–carbon double bond, to N,N′-methylenebisacrylamide (MBA)-cross-linked N- isopropylacrylamide (NIPAAm) hydrogel to form a hemin-based mimetic enzyme [poly(NIPAAm)/MBA/hemin]. The newly synthesised mimetic enzyme exhibits a lower critical solution temperature (LCST) of 39.5 °C in neutral solution. It precipitates out of the aqueous solution as the temperature is raised to and above the LCST and redissolves when it is cooled below the LCST. This behavior is reversible. The characteristics of this mimetic enzyme were systematically studied with H2O2 as oxidizing agent and p-hydroxyphenylacetic acid as fluorogenic substrate. The results showed that it may be used as a novel substitute for peroxidase. The mimetic enzyme showed an optimum reaction pH of about 9.8, which is lower than that in hemin-catalyzed reaction systems where the optimum reaction pH is about 11. The activity of the mimetic enzyme is higher than that of hemin. The LCST behavior of the newly developed mimetic enzyme made its preparation, purification and further chemical modification easier and faster. The detection limits for H2O2 and poly(NIPAAm)/MBA/hemin are 1.5×10–8 and 2.5×10–9 mol l–1, respectively.

The influence of sulfidity in kraft pulping of Norway spruce chips on the characteristics of residual lignin has been examined at two levels 25 and 40%. Comparing with the reference kraft cook at similar kappa number, the high sulfidity pulp lignin displayed a significantly lower phenolic hydroxyl group content, and a lower response to O2 delignification, but it gave a slightly higher yield of nitrobenzene oxidation products, and was more responsive to a neutral sulfite treatment.

A series of phenolic lignin-model dimers of the guaiacyl diphenylmethane (DPM) type has been shown to be quite reactive under mild alkali-O2 conditions (0.5 N NaOH, 55°C) giving significant amounts of monomeric products. The reactivity of these dimers varies significantly and decreases in the order of α-5, 5,5', α-6, and α-1 types. Interestingly, the oxidative cleavages of these DPM units, except the α-6 type, all gave the benzyl alcohol products e.g. vanillyl alcohol.

Periodate oxidation, because of its high selectivity in the degradation of free-phenolic units, has been used along with the combined phenyl nucleus exchange and nitrobenzene oxidation techniques to estimate the distribution of phenolic hydroxyl groups in hardwood lignins. Analyses of the aspen and white birch wood lignin in situ indicate that the percentage of uncon-densed structures having a phenolic hydroxyl group was considerably higher for guaiacyl (∼20%) than for syringyl (-5%) units. Thus, the total phenolic hydroxyl groups of hardwood lignins are largely associated with the guaiacyl propane units.

Oxidation of woodmeals with an excess of aqueous sodium periodate solution at 4°C released an amount of methanol approximately equivalent to the phenolic hydroxyl content of the lignin as determined by the aminolysis method. The periodate and aminolysis methods gave very comparable data for Norway spruce and aspen woodmeal samples.

A new fluorometric immunoassay for methotrexate (MTX) was developed using the mimetic enzyme Mn(III)-tetrakis(sulfophenyl) porphine (Mn-TPPS4) as a labelling reagent to catalyze the fluorescence reaction of 4-hydroxyphenylacetic acid (HPA) and hydrogen peroxide. In the competitive assay MTX (antigen) from human serum and Mn-TPPS4 labelled MTX competitively react with antibody (anti-MTX) coated on a polystyrene 40-well plate. The Mn-TPPS4 in the bound fraction, after the separation from the free fractions, was determined by measuring the fluorescence intensity between HPA and H2O2 catalyzed by bound Mn-TPPS4 and MTX conjugate, which was anti-proportional to the concentration of MTX in the serum. MTX can be determined between 0.5 and 10 µg/well with a detection limit of 100 ng/well.

Etiology determination of neurodevelopmental disabilities (NDDs) currently remains a worldwide common challenge on child health. We herein reported the etiology distribution feature in a cohort of 285 Chinese patients with NDDs. Although concrete NDD etiologies in 48.4% of the total patients could not be identified, genetic diseases (with the proportion of 35.8% in the total cases) including inborn errors of metabolism (IEM) and congenital dysmorphic diseases, constituted the commonest etiology category for NDDs in this study. The two key experimental technologies in pediatric metabolomics, gas chromatography-mass spectrometry (GC-MS), and tandem mass spectrometry (MS-MS), proved to be substantially helpful for the exploration of the NDD etiologies in this clinical investigation. The findings in this paper provided latest epidemiologic information on the etiology distribution of NDDs in Chinese, and the syndromic NDDs caused by citrin deficiency and the novel chromosomal karyotype, respectively, further expanded the etiology spectrum of NDDs.