ESCA Research Articles

A Review of Diffusion and Interfacial Reactions in Sandwich Thin-Film Couples

In this paper different techniques for sandwich thin film production, characterization and interfacial reactions have been reviewed in order to understand the kinetic behaviour in the above systems. The contact and composite resistance measurements are the indirect methods for this purpose, while X-ray diffraction studies (XRD), Transmission electron microscopy (TEM), Scanning electron microscopy (SEM), Rutherford backscattering (RBS), Auger electron spectroscopy (AES), secondary ion mass spectrometry (SIMS), ion sputtering spectrometry (ISS), X-ray photoelectron spectroscopy (XPS) which is also referred to as electron spectroscopy for chemical analysis (ESCA) and atomic force microscopy (AFM) are some of the direct methods. Trends indicate that interfacial reactions start at room temperature.

ESCA Analysis of Doped Hydrogenated a-GexSi1-x Thin Films

A polycrystalline GexSi1-x alloy has been prepared. Its structure and composition have been determined using various standard surface techniques. Hydrogenated a-GexSi1-x thin films (a-GexSi1-x:H) were deposited on glass substrates by a thermal evaporation method. These thin films were fabricated under different deposition conditions, such as Ge content (x = 0–1) and atomic percentage of Al (p-type) and As (n-type) dopants (0.5%–3.5%). The element (Si and Ge) concentration of the prepared alloy and films were determined by atomic absorption spectroscopy (AAS) and energy-dispersive spectroscopy EDS. The structures and chemical compositions of these films were investigated using X-ray diffraction analysis (XRD) and electron spectroscopy for chemical analysis (ESCA), respectively. Fourier transform infrared spectroscopy (FTIR) was used to monitor the effect of hydrogenation on these thin films prepared under various deposition conditions.

Removal of trichloroethylene by zerovalent iron/activated carbon derived from agricultural wastes

Activated carbon (AC) and zerovalent iron (ZVI) have been widely used in the adsorption and dehalogenation process, respectively, for the removal of organic compounds in environmental treatments. This study aims to prepare ZVI/AC derived from an agricultural waste, coir pith, through simple one-step pyrolysis. The effect of activation temperature and time on the surface area, iron content, and zerovalent iron ratio of ZVI/AC was systemically investigated. The results indicated that the activation of AC by FeSO4 significantly increased surface area of AC and distributed elemental iron over the AC. The X-ray diffraction (XRD), electron spectroscopy for chemical analysis (ESCA), and X-ray absorption near edge structure (XANES) spectra of ZVI/AC revealed that zerovalent iron was present. As compared to AC without FeSO4 activation, ZVI/AC increased the trichloroethylene removal rate constant by 7 times. The dechlorination ability of ZVI/AC was dominated by the zerovalent iron content. We have shown that lab-made ZVI/AC from coir pith can effectively adsorb and dehalogenate the chlorinated compounds in water.

Thermosensitive PHEMA microcarriers: ATRP synthesis, characterization, and usabilities in cell cultures

In this study, we developed a novel microcarrier to enhance the production of anchorage-dependent mammalian cells in large scale by preserving them from the effects of shear forces and to enhance their removal from the surface without using proteolytic enzymes and chelating agents. This ‘thermosensitive microcarrier’ was synthesized by the grafting thermoresponsive molecule, N-isopropylacrylamide (NIPAAm), to the crosslinked poly(2-hydroxyethyl methacrylate) (PHEMA) beads by surface-initiated atom transfer radical polymerization. NIPAAm was polymerized on bromine-activated beads’ surfaces to prepare PHEMA-g-PNIPAAm microcarriers. Then, they were chemically characterized by attenuated total reflectance Fourier transform infrared and electron spectroscopy for chemical analysis. Surface morphologies were further investigated by scanning electron microscope and atomic force microscopy techniques. The results of characterization studies confirmed that PNIPAAm was successfully grafted onto PHEMA beads by the means of atom transfer radical polymerization reaction. The cellular activities of PHEMA-g-PNIPAAm microcarriers were evaluated at static and dynamic culture conditions by using two types of cell lines with different morphology, i.e. L929 mouse fibroblasts and HS2 epithelial human keratinocytes. The microcarriers exhibited better cell adhesion and proliferation characteristics for both cell lines. Although their thermally induced cell detachment efficiencies are lower than that of trypsinization, thermally harvested cells preserved their surface morphologies and proliferation characteristics.

Effect of family visit nursing intervention on self-nursing ability and quality of life of patients with coronary heart disease

Objective To discuss the effect of family visit nursing intervention on self-nursing ability and quality of life of patients with coronary heart disease,so as to provide basis for community rehabilitation nursing.Methods 60 patients with CHD were randomly divided into the study group (32patients) and the control group (28patients) by flipping the coin.The control group received self-management,care from family tender and general nursing guidance when seeing a doctor,while the study group received family visit nursing intervention carried out by specialized nursing staff once a month for 6 months.ESCA and SF-36 were used to evaluate nursing effect in both groups before and after intervention.Results There was no statistically significant difference of ESCA and SF-36 scores between two groups before intervention (P ＞ 0.05).But after intervention,the score of ESCA and SF-36 was (137.56 ± 17.32),(66.29 ± 6.31) in the study group,(114.21 ± 16.10),(59.52 ± 5.62) in the control group,and the differences were statistically significant (t =5.38,4.36,respectively; P ＜0.01).All dimensions in ESCA and SF-36 had statistically significant differences between two groups after intervention (P ＜ 0.01).Conclusions Family visit nursing intervention can improve self-nursing ability and quality of life of patients with coronary heart disease,which has positive effect for home rehabilitation of community patients with CHD. Key words: Coronary heart disease ; Community; Family visit; Nursing intervention; Self-nursing ability; Quality of life

Sol–gel immobilized enzymatic glucose biosensor on gold interdigitated array (IDA) microelectrode

An enzymatic glucose biosensor with good sensitivity, selectivity and stability employing interdigitated array microelectrode (IDA μ-electrode) was reported. IDA μ-electrode was prepared by photolithography method with its surface immobilized with a layer of glucose oxidase (GOx), entrapped in a three-dimensional network composed of chitosan and tetraethyl orthosilicate sol–gel. The surface of the as-prepared IDA μ-electrode was characterized by scanning electron microscope, electron spectroscopy for chemical analysis, and atomic force microscopy. The experimental parameters for the best glucose sensing performance were optimized according to the loading of GOx, the applied voltages, the concentration of mediator, and the pH for glucose detection. The resulted biosensor exhibited a good response to glucose with a wide linear range from 0 to 35 mM and a low detection limit of 1 mM. The glucose sensor also showed a short response time (within 5 s) that the fast response was reflected by the small Michaelis–Menten constant (KM app) with a value of 2.94 mM. The reported glucose biosensor exhibited good sensitivity (8.74 μA/mM.cm2), reproducibility, and stability.

Creation of biofunctionalized plasma polymerized allylamine gradients

ABSTRACTA chemical gradient possessing gradual change of amine concentration for every 100 carbon atoms (NHx/100 C) from 4.03 to 1.98 was prepared by plasma polymerization of allylamine on polypropylene films. Electron spectroscopy for chemical analysis and water contact angle (WCA) measurements revealed that the nitrogen incorporation resulted in the amine functionality (CN binding) and, therefore, the formation of the wettability gradient. The gradient showed the WCAs varied from 15° to 90° as the change of amine concentration on the gradient from the nitrogen rich end to the nitrogen deprived end. Furthermore, the interactions between the gradient with mammalian cells revealed that more than twofold cell density was found at the nitrogen rich end when compared with the nitrogen deprived end. Plasma polymerization was demonstrated as an effective method to create controllable chemical gradient and the obtained allylamine gradient was useful for biomaterial applications. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2013, 51, 1361–1367

Influence of carbon fiber’s surface state on interlaminar shear properties of CFRP laminate

In order to investigate the influence of carbon fiber’s surface state on the interlaminar shear properties of carbon fiber-reinforced plastic (CFRP) laminate, the carbon fiber’s surface state was modified by thermal treatment at elevated temperatures. The interlaminar shear strength (ILSS) of CFRP laminates reinforced with treated fibers was measured by means of short-beam shear test, and the surface state of fiber was characterized by Electron Spectroscopy for Chemical Analysis (ESCA) analysis to reveal the dominate factor for controlling the ILSS. Combining the ILSS measurement with the ESCA analysis, the results indicated that: (1) the ILSS is strongly dependent on the oxygen-containing functional groups on the surface of carbon fiber; (2) the fiber treated at 600 °C has the highest oxygen-containing functional groups that lead to the highest ILSS of CFRP; and (3) at temperatures beyond 600 °C, the oxygen-containing functional groups decrease with increasing the heat treatment temperature, resulting in a low ILSS of CFRP laminates. Furthermore, from the microstructure observation, it was found that the CFRP mainly failed in the mode of multi-interlaminar shear. The multi-interlaminar shear failure in the CFRP laminates with low ILSS is more severe due to a weak fiber-matrix interface.

Direct observation of charge transfer region at interfaces in graphene devices

Nanoscale spectromicroscopic characterizing technique is indispensable for realization of future high-speed graphene transistors. Highly spatially resolved soft X-ray photoelectron microscopy measurements have been performed using our “3D nano-ESCA” (three-dimensional nanoscale electron spectroscopy for chemical analysis) equipment in order to investigate the local electronic states at interfaces in a graphene device structure. We have succeeded in detecting a charge transfer region at the graphene/metal-electrode interface, which extends over ∼500 nm with the energy difference of 60 meV. Moreover, a nondestructive depth profiling reveals the chemical properties of the graphene/SiO2-substrate interface.

Characterization of Carbon Nanofibers/ ZrO2 Ceramic Matrix Composite

Carbon micro/nanofibers prepared by catalytic chemical vapor deposition have been characterized in the form of powders and in the form of filaments, intercorporated in the matrix of ZrO2. Scanning electron microscopy, transmission electron microscopy, high resolution electron microscopy, electron spectroscopy for chemical analysis and Raman spectroscopy have been used. The outer diameter of the fibers varied from 50 nm to 600 nm with an average diameter of 120 nm, length from several micrometers to several tens of micrometers and inner diameters from 20 nm to 230 nm. Two types of fibers have been identified; cylindrical which consists of a distinct graphite layers parallel to the fiber axes and bamboo - shaped fibers with walls which are built from domains with different orientations of graphite layers. The fibers contain 99.05 at.% carbon and 0.95 at.% oxygen with a binding energy of O (1s) electrons of 532.7 e V which corresponds to carbon in C-O bonds. In the first-order Raman spectra, the position of the band G was found at 1600 cm-1 and D at 1282 cm-1. The CNFs in ZrO2 + CNFs composite have been relatively well dispersed, however clusters of CNFs together with porosity are present as a result of the difficulty of dispersing, too. TEM and HREM revealed that the CNFs are usually located at the grain boundaries of ZrO2 in the form of undamaged nanofibers or disordered graphite.

Study on the present situation and the influential factors of self-care ability among elderly hypertensive patients in Hengyang community

Objective To explore the present situation of self-care ability among elderly hypertensive patients in the community and its influential factors.Methods 310 elderly hypertensive patients in Hengyang community were studied with a demographic questionnaire,ESCA and SSRS.Results The total mean scores of self-care ability were (105.43±19.25).68.71％ of the elderly hypertensive patients were at medium level and 29.35％ of them were at high level.Statistically significant relations were found between self-care ability and the following condition factors:education level,marital status,monthly income,obtaining health education status,social support,subjective support,availability,objective support and the severity of hypertension.There were no significant relations with sex and occupations.The results of multiple regression showed that the main factors ranged from high to low including the severity of hypertension,education level,monthly income,subjective support,obtaining health education status and marital status.Conclusions Community health nurses should aim directly at the influential factors,take effective measures and improve their self-care ability. Key words: Hypertension; The elderly; Self-care ability; Social support

Study on the correlation between self-care ability and health behavior in gynecologic patients receiving chemotherapy

Objective To discuss the status of self-care ability and health behavior in gynecologic patients receiving chemotherapy,and analyze their correlation.Methods ESCA and HPL were used to investigate 90 cases of gynecologic patients receiving chemotherapy and analyze the correlation.Results The score of self-care ability was (112.17 ± 17.46),health behavior was (123.21 ± 20.23),and there was a positive correlation between the self-care ability and health behavior in gynecologic patients receiving chemotherapy (r =0.275-0.705,P ＜ 0.05).Conclusions Nurses should take effective nursing measures to improve self-care ability of gynecologic patients receiving chemotherapy,so as to promote them take health behaviors to reduce tumor recurrence and improve cancer survivors' quality of life. Key words: Genitalis tumor, female; Health behavior; Self-care ability ; Chemotherapy ; Correlation research

Improvement of biofouling resistance on bacterial cellulose membranes

Bacterial cellulose possesses excellent biocompatibility and mechanical strength that show great potentials for biomaterial applications. In this study, the surface modifications of bacterial cellulose (BC) membranes were facilitated using either simple coating or chemical grafting methods. The surface coating method is to simply immobilize BC membranes with poly(ethylene glycol) (PEG) solutions of concentration from 1 to 10%, followed by post-treatment with argon (Ar) plasma. The chemical method involved grafting mPEG (monofunctional methyl ether PEG) on BCs. The outcomes of surface modifications were characterized by surface chemical compositions (electron spectroscopy for chemical analysis (ESCA), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), thermogravimetry analysis (TGA), and surface morphology (atomic force microscopy (AFM) and scanning electron microscopy (SEM)). The effects of resistance to biofouling were verified by quantifying the adsorption of proteins and mammalian cells. The results showed that the PEG coating on BCs improved the resistance to cell adhesion by more than 30%. On the other hand, the specific chemical grafting resulted in a particularly high resistance to biofouling that the density of adherent cells reduced by more than 70% when compared to that on pristine BC. We have demonstrated that the two proposed methods were effective for the preparation of bioinert BC membranes with great potentials for applications in biomaterials and tissue engineering.

Effect of processing variables and bulk composition on the surface composition of spray dried powders of a model food system

The surface compositions of food powders created from spray drying solutions containing various ratios of sodium caseinate, maltodextrin and soya oil have been analysed by Electron Spectroscopy for Chemical Analysis. The results show significant enrichment of oil at the surface of particles compared to the bulk phase and, when the non-oil components only are considered, a significant surface enrichment of sodium caseinate also. The degree of surface enrichment of both oil and sodium caseinate was found to increase with decreasing bulk levels of the respective components. Surface enrichment of oil was also affected by processing conditions (emulsion drop size and drying temperature), but surface enrichment of sodium caseinate was relatively insensitive to these. The presence of “pock marks” on the particle surfaces strongly suggests that the surface oil was caused by rupturing of emulsion droplets at the surface as the surrounding matrix contracts and hardens.

PNIPAAm-grafted thermoresponsive microcarriers: Surface-initiated ATRP synthesis and characterization

In this study, we developed novel thermoresponsive microcarriers as a powerful tool for cell culture and tissue engineering applications. For this purpose, two types of commercially available spherical microparticles (approximately 100μm in diameter), dextran-based Sephadex® and vinyl acetate-based VA-OH (Biosynth®), were used and themoresponsive poly(N-isopropylacrylamide) (PNIPAAm) was grafted to the beads' surfaces by surface-initiated atom transfer radical polymerization (SI-ATRP). Initially, hydroxyl groups of microbeads were reacted with 2-bromopropionyl bromide to form ATRP macroinitiator. Then, NIPAAm was successfully polymerized from the initiator attached microbeads by ATRP with CuBr/2,2′-dipyridyl, catalyst complex. Furthermore, grafted and ungrafted microbeads were characterized by attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy, scanning electron microscope (SEM), atomic force microscopy (AFM) and electron spectroscopy for chemical analysis (ESCA). The results of characterization studies confirmed that PNIPAAm was successfully grafted onto both dextran and vinyl acetate-based beads by means of ATRP reaction and thus, grafted microbeads gained thermoresponsive characteristics which will be evaluated for cell harvesting in further studies.

Mode of action studies of a new desensitizing mouthwash containing 0.8% arginine, PVM/MA copolymer, pyrophosphates, and 0.05% sodium fluoride

ObjectiveThe mode of action of an arginine mouthwash using the Pro-Argin™ Mouthwash Technology, containing 0.8% arginine, PVM/MA copolymer, pyrophosphates and 0.05% sodium fluoride, has been proposed and confirmed as occlusion using a variety of in vitro techniques. MethodsQuantitative and qualitative laboratory techniques were employed to investigate the mode of action of the new arginine mouthwash. Confocal laser scanning microscopy (CSLM) and atomic force microscopy (AFM) investigated a hydrated layer on dentine surface. Electron spectroscopy for chemical analysis (ESCA), secondary ion mass spectroscopy (SIMS) and near-infrared spectroscopy (NIR) provided information about its chemical nature. ResultsCLSM was used to observe the formation of a hydrated layer on exposed dentine tubules upon application of the arginine mouthwash. Fluorescence studies confirmed penetration of the hydrated layer in the inner walls of the dentinal tubules. The AFM investigation confirmed the affinity of the arginine mouthwash for the dentine surface, supporting its adhesive nature. NIR showed the deposition of arginine after several mouthwash applications, and ESCA/SIMS detected the presence of phosphate groups and organic acid groups, indicating the deposition of copolymer and pyrophosphates along with arginine. ConclusionThe studies presented in this paper support occlusion of the dentine surface upon the deposition of an arginine-rich layer together with copolymer and phosphate ions from an alcohol-free mouthwash containing 0.8% arginine, PVM/MA copolymer, pyrophosphates and 0.05% sodium fluoride.

수산화인회석과 인산삼칼슘 및 1형 콜라젠 혼합골의 전자빔 조사 효과

Purpose: The aim of this study is to evaluate the effect and potential of electron beam (E-beam) irradiation treatment to the synthetic bony mixtures composed of hydroxyapatite (HA; Bongros<TEX>$^{(R)}$</TEX>, Bio@ Co., Korea) and tricalcium phosphate (<TEX>${\beta}$</TEX>-TCP, Sigma-Aldrich Co., USA), mixed at various ratios and of type I collagen (Rat tail, BD Biosciences Co., Sweden) as an organic matrix. Methods: We used 1.0~2.0 MeV linear accelerator and 2.0 MeV superconductive linear accelerator (power 100 KW, pressure 115 kPa, temperature <TEX>$-30{\sim}120^{\circ}C$</TEX>, sensor sensitivity 0.1~1.2 mV/kPa, generating power sensitivity 44.75 mV/kPa, supply voltage <TEX>$5{\pm}0.25$</TEX> V) with different irradiation dose, such as 1, 30 and 60 kGy. Structural changes in this synthetic bone material were studied in vitro, by scanning electron microscopy (SEM), elementary analysis and field emission scanning electron microscope (FE-SEM), attenuated total reflection (ATR), and electron spectroscopy for chemical analysis (ESCA). Results: The large particular size of HA was changed after E-beam irradiation, to which small particle of TCP was engaged with organic collagen components in SEM findings. Conclusion: The important new in vitro data to be applicable as the substitutes of artificial bone materials in dental and medical fields will be able to be summarized.

The Anti-Inflammatory Effects of Tetrandrine-Loading Poly(L-Lactic Acid) Film &lt;i&gt;In Vitro&lt;/i&gt;

In the present study, the anti-inflammatory effects of tetrandrine-loading poly (L-lactic acid) (PLLA) films were investigated in vitro. The surface characteristics of blank PLLA film and tetrandrine-loading PLLA films were examined by electron spectroscopy for chemical analysis (ESCA). The ESCA data suggested that the tetrandrine-loading PLLA films became enriched with nitrogen atoms. The MTT assay was applied to evaluate the cytotoxicity of PLLA films with RAW264.7 cells. Production of nitric oxide (NO) was measured by the Griess colorimetric method. The gene expression levels of inducible nitric oxide synthase (iNOS) and IL-6 were detected by quantitative real-time reverse-transcription polymerase chain reaction (real-time RT-PCR). These results suggested that the anti-inflammatory effects of tetrandrine-loading PLLA films might be the results from modulating the NO/iNOS pathway and inhibiting the mRNA expression of iNOS and IL-6 in activated macrophages.

三次元走査型光電子顕微鏡 （3D nano-ESCA）

We have developed a scanning photoelectron microscope system with the capability of depth profiling in electron spectroscopy for chemical analysis (ESCA). We call this system “3D nano-ESCA.” The system has been installed at the University-of-Tokyo Materials Science Outstation beamline, BL07LSU, at SPring-8. A total spatial resolution is achieved to be better than 70 nm. A photoelectron analyzer with an acceptance angle of 60 degrees enables us to obtain the angular dependence of the photoelectron spectra for the depth-profile analysis without rotating the sample. In this article, we introduce the capability of the 3D nano-ESCA system and recent research activities on high-k gate insulator, graphene, and metal-nanowire devices using the 3D nano-ESCA system.

Control of the molecular density in a chemically adsorbed thiophene system monolayer

Chemically absorbed monolayers (CAM) of thienyl functionalized n-alkyltrichlorosilane 11-(3-thienyl) undecyltrichlorosilane (TUTS) have been prepared with two methods which are the standard technique (TUTS-STD) and the twice adsorption method (TUTS-TAM). The existence of TUTS-CAM was confirmed with water contact angle measurements, calculation of thickness with ellipsometry, fourier transform infrared reflection adsorption spectroscopy (FTIR-RAS). Here are described is the comparison of TUTS-STD and TUTS-TAM characterized by using Electron Spectroscopy for Chemical Analysis (ESCA) and ultraviolet visible (UV-vis) absorption spectroscopy. TUTS-TAM showed more densely packing than TUTS-STD by these measurements. Moreover, these TUTS-CAM polymerized by chemical oxidative polymerization and UV-Vis absorption spectra was measured to confirm the conjugated bond length of the polymerized thienyl groups. UV-vis spectra of the polymerized TUTS-CAM showed a new broad absorbance band at longer wavelength than 700nm.