Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0432222 (SEM)
 47,337 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The purpose of the present study was to assess the value of utilizing SEM in the examination of bite marks in foodstuffs. Six students, whose front teeth showed no conspicuous irregularities, were asked to bite off a part of some selected foodstuff consisting of butter, cheese, Norwegian brown sweet cheese, apples, carrots, bananas, chocolate and chewing gum. The texture and the varying stickiness of the foodstuffs seemed to be of significance as far as the details of the bite marks were concerned. In butter, chewing gum and Norwegian brown sweet cheese, fine details were discerned, thus justifying the use of SEM. Both scratch marks of the front teeth and impression marks of the incisal edges were studied. Only the latter revealed details of value for the identification by means of the SEM. Often small enamel defects were found at the incisal edge of the front teeth. These defects showed a great number of individually characteristic details. Where dentin was exposed at the incisal edge, further characteristic details could also be found. Thus, the use of SEM seemed to be of value in special cases as a supplement to conventional investigation methods.
 ...
PMID:Scanning electron microscopy in the investigation of bite marks in foodstuffs. 122 79

Itch is a major symptom of skin disease and remains poorly studied. We have used limb-worn digital accelerometers, and infrared video of patients as a gold standard, on children with atopic dermatitis and control subjects in their own homes at night. Video analysis shows that nocturnal scratching and restlessness are more complex than we first thought, with many movements that potentially damage the skin not conforming to stereotypical scratch movements. Children with atopic dermatitis spent a mean of 46 minutes less time motionless or sleeping at night than control subjects (468 +/- 3 [SEM] vs 422 +/- 37 [SEM], P<.001). Children with atopic dermatitis showed 2 to 3 times as much scratching or restlessness activity as control subjects, with little overlap between groups (P<.01). Scratching and restlessness were highly correlated with each other (0.94, P<.01). Accelerometer scores were highly correlated with video results (rho>0.02, P<.01, for scratching, restlessness, and sleeping time). Individual limb scores were highly correlated with each other (rho approximately 0.87-0.98), suggesting that little information would be lost if only 1 limb was measured. There was little relation between parental assessment of scratch and objective measured scratch. Accelerometers provide a useful and practical way of assessing scratching at night in the patient's own home and could be used as an objective measure of disease activity both in clinical trials and in everyday clinical practice.
 ...
PMID:The development of an objective method for measuring scratch in children with atopic dermatitis suitable for clinical use. 1469 62

In the last years different types of surface modifications were developed with the aim of improving the osteointegration ability of titanium alloys. The chemical composition, crystallographic structure and morphology of a surface layer can be modified in order to obtain a better interaction between the implant, the cells and the organic fluids. The final goal is to obtain a more efficient bone growth also in critical clinical cases. In the present paper were reported several data about the characterization of the Ti-6Al-7Nb alloy treated by two innovative surface treatments. They consist of blasting, followed by a two step chemical etching and heat treatment performed in air or in vacuum. TEM, XRD and SEM investigations were performed in order to assess the structure and morphology of the modified surfaces. The surface chemical composition was investigated by XPS ad AES analyses. The ability to interact with physiological fluids was tested by immersion of the treated materials in an acellular simulated body fluid (SBF). Metal ion concentration analyses of the fluid and SEM observations of the samples were performed after different times of soaking. The mechanical characterization involved scratch and fatigue tests. The surface of treated samples shows chemical, structural and morphological modifications. The passivation pre-treatment has influence on the surface modification. The treated samples evidenced a quite low metal ion release and interact with SBF solution, showing a moderate bioactivity. A relevant decrease in fatigue strength was observed on modified samples.
 ...
PMID:Characterization of surface modified Ti-6Al-7Nb alloy. 1580 74

Ocular trauma and disorders that lead to corneal blindness account for over 2 million new cases of monocular blindness every year. A popular ocular surface reconstruction therapy, amniotic membrane transplantation, has been shown to aid corneal wound repair. However, the success rates of the procedure are variable. Here, we proposed to bioengineer a novel synthetic material that would serve as a biomimetic corneal bandage. The PLGA-PEG-PLGA triblock copolymer was synthesised via ring-opening polymerisation. Thermoreversible gelation behaviour was investigated at different polymer concentrations (23%, 30%, 35%, 40%, 45%, w/v) at temperatures ranging between 5 and 60 degrees C. Viscoelastic properties were studied in dynamic mechanical analysis with 1 degrees C/min temperature ramp. Cryo-SEM revealed a porous hydrogel with interconnecting networks. No adverse cytotoxicity was observed with an in vitro scratch-wound assay and in in vivo biocompatibility tests. We have demonstrated that the PLGA-PEG-PLGA hydrogel possessed a suitable gelling profile and, for the first time, the biocompatibility properties for this application as a potential bandage for corneal wound repair.
 ...
PMID:A thermoreversible hydrogel as a biosynthetic bandage for corneal wound repair. 1797 17

Ti-TiC-TiC/diamond-like carbon (DLC) gradient nano-composite films have been prepared on NiTi alloy substrates by the technique of plasma immersion ion implantation and deposition (PIIID) combined with plasma-enhanced chemical vapor deposition (PECVD). The influence of negative bias voltage applied to the substrate (from -100 V to -500 V) on the chemical structure, microstructure, mechanical properties and corrosion resistance was investigated by Raman spectrum, x-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), x-ray diffraction (XRD), friction coefficient test, scratch test, nano-indentation test and anodic polarization experiments. The Raman spectrum and XPS results showed that the doped films kept an amorphous DLC structure. TEM observation revealed that nanometer TiC particles were surrounded by the amorphous DLC. With the increase of bias voltage, the ratio of sp(2)/sp(3) first decreased, reaching a minimum value at -200 V, and then increased. The nano-indentation results showed that the hardness of the Ti-TiC-TiC/DLC gradient films reached the maximum value at -200 V when TiC particles reached the maximum content in the films. The friction coefficient test and scratch test indicated that Ti-TiC-TiC/DLC gradient films had a low friction coefficient and high bonding strength with the NiTi substrates. Combined with anodic polarization curves and SEM observation, it was found that the corrosion resistance of the Ti-TiC-TiC/DLC gradient films was much better than that of the bare NiTi alloy.
 ...
PMID:Ti-TiC-TiC/DLC gradient nano-composite film on a biomedical NiTi alloy. 1902

This study investigated the effect of board type (unmodified vs. MAPE modified) on the surface quality and thickness swelling-water absorption properties of recycled high density polyethylene (HDPE) based wood plastic composites. Additionally, two commercially available coatings (cellulosic coating and polyurethane lacquer coating) were also applied to composite surfaces and their adhesion strength, abrasion and scratch resistance, and gloss values were determined. This study showed that modification of the composites with MAPE coupling agent increased the surface smoothness and reduced the water absorption and thickness swelling of the panels. Abrasion resistance of the composites was also improved through MAPE modification. Regardless of board type, higher scratch resistance and gloss values were observed for polyurethane lacquer coated samples compared to those of cellulosic varnish coated ones. Improvement of adhesion strength was also seen on SEM micrographs.
 ...
PMID:Some properties of composite panels made from wood flour and recycled polyethylene. 1933 92

In this study a spontaneously formed corneal epithelial cell line, namely HCE-S, was established and characterised. The cell line was karyotyped and corneal epithelial maker expression of the cell line was assessed by immunostaining and semi-quantitative RT-PCR. The morphological characteristics were investigated using SEM and TEM analyses. The functional response to EGF in terms of cell proliferation, wound healing and cell migration was tested using Alamar Blue, scratch wound and colony dispersion assays, respectively. The cells were maintained in culture for more than 100 divisions and 35 passages suggesting that an immortalised cell line had been established. HCE-S, has maintained an epithelial morphology and has not phenotypicaly changed through passages. SEM and TEM microscopy showed morphological similarities to primary corneal epithelial cells. HCE-S expressed a battery of characteristic markers of primary corneal epithelial cells including cytokeratin 3 and PAX 6 as well as the basal cell integrins beta1 and alpha9 and the putative corneal stem cell marker ABCG2. HCE-S cells were responsive to exogenous EGF as shown by proliferation, migration and scratch wound assays. HCE-S can be cultured in a simple DMEM and only serum-based media which gives them an advantage against available corneal epithelial cell lines. This fact, along with the often limited availability and variability of primary corneal epithelial cells and the similarities of the cell line with primary cell characteristics suggest that HCE-S could be a useful tool for the study of corneal epithelial cell biology, ocular surface toxicity studies and pharmacological testing.
 ...
PMID:Characterisation and functional features of a spontaneously immortalised human corneal epithelial cell line with progenitor-like characteristics. 1969 83

Carbon based films can combine the properties of solid lubricating graphite structure and hard diamond crystal structure, i.e., high hardness, chemical inertness, high thermal conductivity and optical transparency without the crystalline structure of diamond. Issues of fundamental importance associated with nanocarbon coatings are reducing stress, improving adhesion and compatibility with substrates. In this work new nanocomposite coatings with improved toughness based in nanocrystalline phases of metals and ceramics embedded in amorphous carbon matrix are being developed within the frame of a research project: nc-MeNxCy/a-C(Me) with Me = Mo, Si, Al, Ti, etc. Carbide forming metal/carbon (Me/C) composite films with Me = Mo, W or Ti possess appropriate properties to overcome the limitation of pure DLC films. These novel coating architectures will be adopted with the objective to decrease residual stress, improve adherence and fracture toughness, obtain low friction coefficient and high wear-resistance. Nanocomposite DLC's films were deposited by hybrid technique using a PVD-Physically Vapor Deposition (magnetron sputtering) and Plasma Enhanced Chemical Vapor Deposition (PECVD), by the use of CH4 gas. The parameters varied were: deposition time, substrate temperature (180 degrees C) and dopant (Si + Mo) of the amorphous carbon matrix. All the depositions were made on silicon wafers and steel substrates precoated with a silicon inter-layer. The characterisation of the film's physico-mechanical properties will be presented in order to understand the influence of the deposition parameters and metal content used within the a-C matrix in the thin film properties. Film microstructure and film hybridization state was characterized by Raman Spectroscopy. In order to characterize morphology SEM and AFM will be used. Film composition was measured by Energy-Dispersive X-ray analysis (EDS) and by X-ray photoelectron spectroscopy (XPS). The contact angle for the produced DLC's on silicon substrates were also measured. Thin film adherence was studied by micro-scratch test. Residual stresses in the produced coatings will be analysed by bending technique.
 ...
PMID:Nanocomposite metal amorphous-carbon thin films deposited by hybrid PVD and PECVD technique. 1991 9

The abrasion response of cross sectional areas of enamel was studied by sliding a rounded diamond conical nano-indenter tip across the surface. The nano-indenter tip (radius approximately 1,200 nm) was scanned over a specific squared area with a load of 400 microN. Two different environments were chosen: Hank's balanced salt solution (HBSS) and atmospheric laboratory condition. SEM (Scanning Electron Microscopy) and AFM (Atomic Force Microscopy) were used to characterize the final abraded areas. In addition, single scratches with linear incremented load were performed. The normal load and displacement data were utilized in a complementary manner to support the proposed deformation mechanisms. Greater orientation dependence for the case of the single scratches in relation to the abrasion tests was found. The latter results are discussed in terms of plastic deformation effects. The abrasion mechanisms were found to be the same for both wet and dry measurements and similar to that described in a previous study (Guidoni et al., Wear 266:60-68, 2009; Guidoni, Nano-scale mechanical and tribological properties of mineralized tissues. PhD. Montan University Leoben, Leoben, Austria, 2008). However, scratch deformation under fluid measurements shows greater recovery effects and abrasion resistance.
 ...
PMID:Nano-scale sliding contact deformation behaviour of enamel under wet and dry conditions. 2014 79

Three type of photocatalytic composite films, MPC500SGF-MC, ANPSGF-MC and P25SGF-MC, have been synthesized by a modified sol-gel method using different particle size of TiO2 nanopowder MPC500, ANP and P25, respectively. Methyl cellulose (MC) was added as a template to the sol for stress reduction which improved not only the amount of crystalline material immobilized on the support, but also the nanosize of the films calcined at 500 degrees C. The physicochemical properties, including surface morphology, crystallinity, crystal size and adhesion on glass substrate, of the three types of films were investigated by SEM, XRD and the scratch test. The photocatalytic activities of the films were compared using methyl orange (MO) as a model organic contaminant in water. The results on photocatalytic degradation of MO showed that the increase in photocatalytic activity for P25SGF-MC, compared with that of MPC500SGF-MC and ANPSGF-MC composite films. The optimum degradation conditions of MO solution are determined. This study proves that particle size of starting TiO2 material is important for the preparation of nanostructured TiO2 composite film with enhanced photocatalytic activity and excellent adhesion on the glass substrate.
 ...
PMID:Comparison of physicochemical properties of three nanostructure composite TiO2 films and their photocatalytic properties. 2035 72


1 2 3 4 5 6 Next >>