经腹联合经阴道彩超在评估凶险型前置胎盘合并胎盘植入中的应用价值

本文对经腹联合经阴道彩超在评估凶险型前置胎盘(PPP)合并胎盘植入中的应用价值进行了探讨。选取我院2017年6月~2019年6月PPP患者172例,所有患者均给予经腹彩超、经阴道彩超检查,以产后病理结果为对照,分析经腹彩超、经阴道彩超,以及二者联合,对PPP合并胎盘植入的评估价值。产后病理结果显示,172例PPP患者中,有合并胎盘植入患者120例(69.77%)、无合并胎盘植入患者52例(30.23%)。对PPP合并胎盘植入的敏感度、特异度、准确度进行评估,结果显示,经腹彩超其值分别为76.67%、73.08%、75.58%,经阴道彩超分别为83.33%、80.77%、82.56%,经腹联合经阴道彩超则分别为96.67%、96.15%、96.51%,二者联合明显高于经腹彩超、经阴道彩超,差异有统计学意义(P<0.05)。证实经腹、经阴道彩超是评估PPP合并胎盘植入的有效检查方法,且二者联合的评估价值更高,值得临床推广。     

Ion implantation into collagen-coated surfaces for the development of small diameter artificial grafts

Ion implantation into collagen (Type I) coated inner surfaces of test tubes with a length of 50 mm and an inner diameter of 2 and 3 mm were performed to develop hybrid type small diameter artificial vascular grafts. To obtain information about the cellular response and chemical and physical structure of those collagen surfaces, several experiments such as platelets adhesion test, endothelial cell culture, analysis of amino acids and animal study were performed. He(+) ion implanted collagen coated specimen exhibited cell attachment and inhibit platelet adhesion. From these results, it was assumed that He(+) ions broke the ligands that correspond to platelet, and the ligands that correspond to endothelial cell adhesion still existed after ion implantation. It was suggested that platelets and cell attachment could be control individually by ion implantation into collagen.     

Ion implantation doping and electrical properties of high-temperature ladder polymers

We report the first ion implantation doping studies on high-temperature ladder polymers and show that insulting films of the benzimidazobenzophenanthroline-type ladder polymer (BBL) can be doped by boron, argon, and krypton implantation to conductivities as high as 224 S/cm at a dose of 4.0 × 10¹⁶/cm² while retaining the excellent mechanical properties of the pristine films. Effects of dose (ions/cm²) and beam current density (microamps/cm²) on electrical conductivity at fixed ion energies are reported. The temperature dependence of the conductivity indicates that the implanted ladder polymer films are semiconductors. Spatially selective implantation, creating regions of conducting lines in an insulating matrix, which suggests microelectronic device applications of the ladder polymers, is demonstrated.     

Influence of channeling effects on ion distribution and damage profiles during high energy ion implantation in Si

Nitrogen implantation has been performed in silicon [001] crystals in carefully controlled alignment conditions. The channeling effects are clearly evident when implanting in [001] and [011] directions at energies ranging from 0.6 to 1.4 MeV. Both ion distribution and damage profiles are strongly influenced by channeling effects during ion implantation. The angular region around the [001] direction has been also investigated by implanting at small angles with respect to the axis. The same kind of study has been performed by implanting at different angles with respect to the planar (011) direction. The ion distributions (investigated by SIMS) show a strong dependence upon the alignment conditions. Moreover in high energy ion implantation, the lattice damage is located deep inside the crystal, leaving the surface layer almost unperturbed. The channeling effects on the damage production have been investigated by double crystal diffraction (DCD) in the low-dose regime and by RBS-channeling experiments (after implantation at doses greater than 1 × 10¹⁵ cm^–2) and for different ion alignment conditions.A big increase in the ion ranges and a strong reduction in the lattice damage is evident when implanting along major crystal axes. No saturatíon of the lattice damage and of the channelled component of the beam has been detected if the implantation is performed parallel to the [011] axis.     

High-energy ion implantation of polymers: Poly(vinylidene fluoride)

Poly(vinylidene fluoride) films were implanted with high-energy (up to 6 MeV) He, C, O, and Ni ions and characterized using DSC, FTIR, and solubility measurements. None of the ions were energetic enough to penetrate the polymer film completely. The effects of ion energy, fluence, and ion type were studied individually. The implantation process lowered the crystallinity, induced crosslinking, and produced carbonyl groups on the polymer. The ion energy (in the range 0.4–4.5 MeV for He ions) had the most drastic effect, the radiation damage was found to increase with decreasing energy. The sample implanted with 0.4 MeV He ions lost 81% of its initial crystallinity and was only 24% soluble, even though the incident ions have a range of only 2.7 μm in this case. The other samples retained most of their initial crystallinity but still were substantially cross-linked. The results can be qualitatively explained by assuming that hydrogen free radicals, produced during implantation, can diffuse throughout the sample and react, resulting in crystallinity and solubility losses beyond the ion deceleration region.     

X-ray imaging during plasma-source ion implantation

Plasma source ion implantation (PSII) is a technique for modifying stafaces that places the object to he modified directly into a plasma and then negatively pulse biases the object so as to implant positive ions. If the voltage is high enough, X-rays can he generated by electrons that are also accelerated by the pulse. This work describes techniques for imaging and characterizing the X-rays A pinhole camera was used to image the X-rays being emitted as electrons collided with surfaces in the chamber. The images show that X-rays are generated at the chamber walls and near the target. The time dependence of these X-rays during each pulse was examined using a PIN diode X-ray detector. Then, using another X-ray sensor and pulseheight analyzer, the spectra of the emitted X-rays was determined. The object is to relate the X-ray intensity and spectrum to the temporal and spatial values of the implantation dose so that it may he used as a process monitor and a control sensor.     

Investigation of the stability of glass-ceramic composites containing CeTi2O6 and CaZrTi2O7 after ion implantation

Glass-ceramic composite materials have been investigated for nuclear waste sequestration applications due to their ability to incorporate large amounts of radioactive waste elements. A key property that needs to be understood when developing nuclear waste sequestration materials is how the structure of the material responds to radioactive decay of nuclear waste elements, which can be simulated by high energy ion implantation. Borosilicate glass-ceramic composites containing brannerite-type (CeTi₂O₆) or zirconolite-type (CaZrTi₂O₇) oxides were synthesized at different annealing temperatures and investigated after being implanted with high-energy Au ions to mimic radiation induced structural damage. Backscattered electron (BSE) images were collected to investigate the interaction of the brannerite crystallites with the glass matrix before and after implantation and showed that the morphology of the crystallites in the composite materials were not affected by radiation damage. Surface sensitive Ti K-edge glancing angle XANES spectra collected from the implanted composite materials showed that the structures of the CeTi₂O₆ and CaZrTi₂O₇ ceramics were damaged as a result of implantation; however, analysis of Si L_2,3-edge XANES spectra indicated that the glass matrix was not affected by ion implantation.     

Effect of Nb,Ti, and W ion implantation on surface properties and cell compatibility of silicon carbide

Silicon carbide is considered as a bio-inert semiconductor material; consequently, it has been proposed for potential applications in human body implantation. In this study, we study the effect of implanting different metal ions on the surface properties of silicon carbide single crystal. The valence states of the elements and the surface roughness of implanted SiC were studied using X-ray photoelectron spectroscopy and atomic force microscope, respectively. Osteoblastic MG-63 cells were utilized to characterize the cytocompatibility of ion implanted SiC. The results show that after Nb ion implantation on the SiC surface, it mainly exists in the form of Nb–C bond, Nb–O bond, and a small amount of metallic niobium. The titanium implanted on SiC primarily forms Ti-C bond and Ti-O bond. The tungsten implanted on SiC mostly presents as metallic tungsten and W–O bond. The roughness of silicon carbide single crystal is improved by ion implantation of all three metal ions. Ion implantation of titanium and niobium can improve the cell compatibility and hydrophilicity of silicon carbide, whereas ion implantation of tungsten reduces the cell compatibility and hydrophilicity of silicon carbide.     

Boron implantation in Si: Channeling effects studied by SIMS and simulation

The axial channeling behaviour of boron implants in <100>, <110> and <111> silicon wafers is investigated by SIMS. Large differences of channeling characteristics such as channeled projected range (the projected range of channeled ions or channeling peak) and the fraction of channeled to implanted ions are observed among the three major crystal orientations. Within the critical angle, the channeling behaviour is very sensitive to the incidence beam angle with respect to crystal orientations. SIMS measurements are performed at different positions along several critical directions over a whole wafer. Well channeled profiles with an incidence beam angle to crystal orientations of 0 ° are obtained for each ion implantation energy and orientation. The results are used to test various models of ion implantation by simulation. A 3-parameter model for electronic stopping power of boron in silicon was proposed.     

High-energy ion implantation of polymers: Poly(ethylene terephthalate)

The effect of high-energy ion implantation of oxygen into a thin film of poly(ethylene terephthalate) (PET) was studied by Fourier transform infrared spectroscopy and differential scanning calorimetry (DSC). Mylar samples 13 μm thick were implanted with 6-MeV oxygen ions at fluences ranging from 5 × 10¹² to 2 × 10¹⁴ ions/cm². The DSC data showed a substantial loss of crystallinity, even at the lowest fluence, which extended deeper into the polymer film than the predicted range for oxygen deceleration in PET. Solubility measurements indicated the presence of cross-linking, especially at the highest fluence, but bands due to cross-linking could not be detected in the infrared. The trans/gauche ratio for the glycol group conformation was measured by a pair of conformationally sensitive infrared bands. Surprisingly, the conformation of the glycol segments did not change appreciably with increasing fluence, although crystallinity decreased and degree of cross-linking increased. The implications these results have on possible mechanisms of chemical and physical alterations of the polymer structure by ion implantation are discussed.     

Modification of polyether ether ketone by low-temperature plasma and ion implantation method for use in medicine and biology

Russian Chemical Bulletin - The review concerns modification of polyether ether ketone (PEEK) using low-temperature plasma and ion implantation and presents the results of studies on the surface...     

Monte Carlo simulation of ion implantation into solids as a tool for the characterization of surface analytical reference materials

The physical and chemical prerequisites of ion implantation and their translation into a Monte Carlo calculation simulating the implantation process of high energy ions (300 keV) are described; calculations are extended to high dose implantation (up to 1×10¹⁸ ions cm^–2) taking into consideration various effects such as matrix change during implantation, cascade mixing, sputter erosion and relaxation of the target material.To check the suitability of such calculations for a characterization of implanted samples, the results of the calculations are compared with those obtained experimentally from implanted samples. As an example,P ⁺ is implanted into polycrystalline Al at various doses (110×10¹⁷ p ⁺ cm^–2), and depth profiles are taken by AES/Ar⁺-sputtering.The calculated and measured results agree better than 10% for both the depth and the concentration scale.     

Simple and biocompatible micropatterning of multiple cell types on a polymer substrate by using ion implantation

A noncytotoxic procedure for the spatial organization of multiple cell types remains as a major challenge in tissue engineering. In this study, a simple and biocompatible micropatterning method of multiple cell types on a polymer surface is developed by using ion implantation. The cell-resistant Pluronic surface can be converted into a cell-adhesive one by ion implantation. In addition, cells show different behaviors on the ion-implanted Pluronic surface. Thus this process enables the micropatterning of two different cell types on a polymer substrate. The micropatterns of the Pluronic were formed on a polystyrene surface. Primary cells adhered to the spaces of the bare polystyrene regions separated by the implanted Pluronic patterns. Secondary cells then adhered onto the implanted Pluronic patterns, resulting in micropatterns of two different cells on the polystyrene surface.     

Stem cell implantation for osteonecrosis of the femoral head

What is the most effective treatment for the early stages of osteonecrosis of the femoral head? We assessed multiple drilling and stem cell implantation to treat the early stages of osteonecrosis of the femoral head. We report the clinical and radiological results of stem cell implantation and core decompression. In total, 128 patients (190 hips) who had undergone surgery were divided into two groups based on which treatment they had received: (1) multiple drilling and stem cell implantation or (2) core decompression, curettage and a bone graft. The clinical and radiographic results of the two groups were compared. At 5-year follow-up, in the stem cell implantation group, 64.3% (27/42) of the patients with Stage IIa disease, 56.7% (21/37) of the patients with Stage IIb disease and 42.9% (21/49) of the patients with Stage III disease had undergone no additional surgery. In the conventional core decompression group, 64.3% (9/14) of the patients with Stage IIa disease, 55.6% (5/9) of the patients with Stage IIb disease and 37.5% (3/8) of the patients with Stage III disease had undergone no additional surgery. Success rates were higher in patients with Ficat Stage I or II lesions than in those with Stage III lesions. There were no statistically significant differences between the groups in terms of success rate or in the clinical and radiographic results of the two methods. Essentially the same results were found with stem cell implantation as with the conventional method of core decompression.     

Surface hardness changes induced by O-, Ca- or P-ion implantation into titanium

Titanium or titanium alloys are very attractive biomedical materials. Biocompatible elements of oxygen, calcium and phosphorus were implanted into titanium and changes of surface hardness were measured using an ultra micro indenter (UMIS-2000). A multiple load-partial unload procedure that can reveal a hardness versus depth profile was adopted. Depth profiles of concentration of implanted ions were obtained by SIMS measurement. For O and P implantation, it is observed that the hardness increases with the increases in the dose. O implantation produced the largest increase in hardness, up to 2.2 times higher than the unimplanted titanium. On the other hand, Ca implantation produced only a small increase in the hardness that was independent of the ion dose. The surface oxide layer of a Ca implanted titanium sample was much thicker than the unimplanted samples or those implanted with O and P ions. The depth of maximum hardness increases with increasing energy of implanted ions. The depths of the maximum hardness occur at indentation depths of one-third to one-eighth of the mean ranges of implanted ions.     

In situ ion implantation for quantification in secondary-ion mass spectrometry

Summary The primary ion beam column of a secondary ion mass spectrometer has been used to produce an internal quantification standard via in situ ion implantation. Subsequent depth profile analysis has been done in the instrument after switching to another primary projectile. In this way, the interfacial oxygen concentration between an amorphous and crystalline Si layer and the hydrogen content ( 30 at %) in a 48 nm amorphous carbon layer on a silicon substrate have been determined. The use, in the latter case, of deuterium as an in situ implant exemplifies that minor isotopes can be employed for the quantification in secondary-ion mass spectrometry of components with high concentrations while achieving an accuracy of better than ±50%

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In-situ-Ionenimplantation für quantitative Bestimmungen in der Sekundärionen-Massenspektrometrie

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Work performed at Institut für Grenzflächenforschung und Vakuumphysik, Kernforschungsanlage Jülich     

Effect of N5+ ion implantation on optical and gas sensing properties of WO3 films

In this paper we report the optical and gas sensing behaviours of tungsten oxide (WO₃) films, implanted with 45‐keV N^{5 +} ions of different fluences in the range 1 × 10¹⁵ to 1 × 10¹⁷ cm^–2. The film with fluence 1 × 10¹⁵ cm^–2 shows the most intense PL spectrum with two prominent peaks near UV and blue regions. The morphological changes because of ion implantation are also investigated by atomic force microscopy. Because of implantation the gas sensitivity of the film, in exposure of methane, is found to increase with reasonably fast response and recovery times. With the increase of the concentration of methane, the sensors show better result. Present work also includes the effect of N^{5 +} ion implantation on the structural property of WO₃ films. Copyright © 2015 John Wiley & Sons, Ltd.     

Molecular ion implantation in silicon

¹⁵N₂ ⁺ molecular ions were implanted with 10keV (j=10 A/cm²) under high vacuum conditions close to room temperature in 100 silicon (c-Si) to study the¹³N depth distributions, particularly the dependence of peak concentration and dose on the ion fluence. The analysis were performed by the resonant nuclear reaction¹⁵N(p, )¹²C(NRA). A maximum peak concentration of 65 at.% was measured. Thin stoichiometric silicon nitride layers with a thickness of approx. 20 nm (15 at.% nitrogen at the specimen surface) were produced by this low-energy implantation of¹⁵N₂ ⁺ ions with an ion fluence of 1.5·10¹⁷ ions/cm². NRA analysis of 38 keV¹⁵N₂ ⁺ and 19keV¹⁵N⁺ ion implantations were performed to compare the¹⁵N depth distributions. No significant changes in the depth distributions are measured, that means, the molecular¹⁵N₂ ⁺ ions are already disintegrated passing the very first atomic layers of the sample during implantation. Non-Rutherford RBS with⁴He⁺ ions and 3.45 MeV was performed in order to confirm the results obtained by NRA.Dedicated to Professor Dr. rer.nat. Dr. h.c. Hubertus Nickel on the occasion of his 65th birthday