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Sustainable Porous Scaffolds with Retained Lignin as An Effective Light-absorbing Material for Efficient Photothermal Energy Conversion. SMALL METHODS 2023; 7:e2300913. [PMID: 37717229 DOI: 10.1002/smtd.202300913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 09/05/2023] [Indexed: 09/19/2023]
Abstract
Organic phase change materials (PCMs) are promising to utilize thermal energy from solar radiation for photothermal energy conversion. However, the issues of poor photo absorption and liquid leakage greatly restrict their practical application. Herein, a sustainable porous scaffold comprising periodate oxidized wood (POW) as the supporting material and in situ retains lignin as the light-absorber dopant are demonstrated. The π-π stacking ability of lignin molecules endows the retained lignin with efficient photonic energy harvesting characteristics for fast thermal conductivity to reach a higher maximal energy storage volume. The inherently porous structure of the POW scaffold enables excellent shape-stability, which bypasses the liquid leakage problem. The resulting POW/PCM composites exhibit superior comprehensive performance, including enhanced light absorption capacity, high photothermal conversion efficiency (≈86.7%), and high latent heat of 151 J g-1 . Furthermore, the POW/PCM composites also possess the ability to maintain a relatively constant indoor temperature when fixed atop the model house roof, showing great potential for their practical applications in the thermal regulation of intelligent buildings. This work not only paves a new way to obtain sustainable and effective porous scaffolds for sufficient photothermal energy conversion but also provides more possibilities for their practical application in the future.
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2
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Spectroscopic Investigation of the Impact of Cold Plasma Treatment at Atmospheric Pressure on Sucrose and Glucose. Foods 2022; 11:foods11182786. [PMID: 36140914 PMCID: PMC9497776 DOI: 10.3390/foods11182786] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 08/26/2022] [Accepted: 09/06/2022] [Indexed: 11/16/2022] Open
Abstract
When exposing food and feedstuff to cold atmospheric pressure plasmas (CAPP), e.g., for decontamination purposes, possible unwanted effects on the contained nutrients might occur. In the present study, we thus concentrated on CAPP-induced degrading effects on different sugars, namely glucose and sucrose. The treatments were performed using admixtures of argon and synthetic air over durations of up to 12min. Continuous degradation of sucrose and glucose was determined using ATR-FTIR and XPS analyses. OH stretching bands showed notable broadening in the ATR-FTIR spectra, which possibly indicates reduced crystallinity of the sugars caused by the CAPP treatment. In the fingerprint regions, most bands, especially the more intense C-O bands, showed decreases in peak heights. In addition, two new bands occurred after CAPP treatment. The bands were detectable in the range between 1800 and 1600cm−1 and potentially can be assigned to C=C and, after comparison with the results of the XPS measurements, O-C=O bindings. The XPS measurements also showed that the O-C=O bonds probably originated from earlier C-O bonds.
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Dynamically Tunable All-Weather Daytime Cellulose Aerogel Radiative Supercooler for Energy-Saving Building. NANO LETTERS 2022; 22:4106-4114. [PMID: 35510868 DOI: 10.1021/acs.nanolett.2c00844] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
A passive cooling strategy without any electricity input has shown a significant impact on overall energy consumption globally. However, designing tunable daytime radiative cooler to meet requirement of different weather conditions is still a big challenge, especially in hot, humid regions. Here, a novel type of tunable, thermally insulating and compressible cellulose nanocrystal (CNC) aerogel coolers is prepared via chemical cross-linking and unidirectional freeze casting process. Such aerogel coolers can achieve a subambient temperature drop of 9.2 °C under direct sunlight and promisingly reached the reduction of ∼7.4 °C even in hot, moist, and fickle extreme surroundings. The tunable cooling performance can be realized via controlling the compression ratio of shape-malleable aerogel coolers. Furthermore, energy consumption modeling of using such aerogel coolers in buildings in China shows 35.4% reduction of cooling energy. This work can pave the way toward designing high-performance, thermal-regulating materials for energy consumption savings.
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4
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Light sheet fluorescence microscopy for the investigation of blood-sucking arthropods dyed via artificial membrane feeding. Parasit Vectors 2022; 15:52. [PMID: 35151358 PMCID: PMC8841056 DOI: 10.1186/s13071-022-05157-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Accepted: 01/08/2022] [Indexed: 12/02/2022] Open
Abstract
Physical methods to control pest arthropods are increasing in importance, but detailed knowledge of the effects of some of these methods on the target organisms is lacking. The aim of this study was to use light sheet fluorescence microscopy (LSFM) in anatomical studies of blood-sucking arthropods in vivo to assess the suitability of this method to investigate the morphological structures of arthropods and changes in these structures over time, using the human louse Pediculus humanus (Phthiraptera: Pediculidae) as sample organism. Plasma treatment was used as an example of a procedure employed to control arthropods. The lice were prepared using an artificial membrane feeding method involving the ingestion of human blood alone and human blood with an added fluorescent dye in vitro. It was shown that such staining leads to a notable enhancement of the imaging contrast with respect to unstained whole lice and internal organs that can normally not be viewed by transmission microscopy but which become visible by this approach. Some lice were subjected to plasma treatment to inflict damage to the organisms, which were then compared to untreated lice. Using LSFM, a change in morphology due to plasma treatment was observed. These results demonstrate that fluorescence staining coupled with LSFM represents a powerful and straightforward method enabling the investigation of the morphology—including anatomy—of blood-sucking lice and other arthropods.
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Methods to Characterize Electrospun Scaffold Morphology: A Critical Review. Polymers (Basel) 2022; 14:polym14030467. [PMID: 35160457 PMCID: PMC8839183 DOI: 10.3390/polym14030467] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 01/06/2022] [Accepted: 01/19/2022] [Indexed: 12/10/2022] Open
Abstract
Electrospun scaffolds can imitate the hierarchical structures present in the extracellular matrix, representing one of the main concerns of modern tissue engineering. They are characterized in order to evaluate their capability to support cells or to provide guidelines for reproducibility. The issues with widely used methods for morphological characterization are discussed in order to provide insight into a desirable methodology for electrospun scaffold characterization. Reported methods include imaging and physical measurements. Characterization methods harbor inherent limitations and benefits, and these are discussed and presented in a comprehensive selection matrix to provide researchers with the adequate tools and insights required to characterize their electrospun scaffolds. It is shown that imaging methods present the most benefits, with drawbacks being limited to required costs and expertise. By making use of more appropriate characterization, researchers will avoid measurements that do not represent their scaffolds and perhaps might discover that they can extract more characteristics from their scaffold at no further cost.
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How Fiber Surface Topography Affects Interactions between Cells and Electrospun Scaffolds: A Systematic Review. Polymers (Basel) 2022; 14:polym14010209. [PMID: 35012232 PMCID: PMC8747153 DOI: 10.3390/polym14010209] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 12/22/2021] [Accepted: 12/29/2021] [Indexed: 01/02/2023] Open
Abstract
Electrospun scaffolds have a 3D fibrous structure that attempts to imitate the extracellular matrix in order to be able to host cells. It has been reported in the literature that controlling fiber surface topography produces varying results regarding cell–scaffold interactions. This review analyzes the relevant literature concerning in vitro studies to provide a better understanding of the effect that controlling fiber surface topography has on cell–scaffold interactions. A systematic approach following PRISMA, GRADE, PICO, and other standard methodological frameworks for systematic reviews was used. Different topographic interventions and their effects on cell–scaffold interactions were analyzed. Results indicate that nanopores and roughness on fiber surfaces seem to improve proliferation and adhesion of cells. The quality of the evidence is different for each studied cell–scaffold interaction, and for each studied morphological attribute. The evidence points to improvements in cell–scaffold interactions on most morphologically complex fiber surfaces. The discussion includes an in-depth evaluation of the indirectness of the evidence, as well as the potentially involved publication bias. Insights and suggestions about dose-dependency relationship, as well as the effect on particular cell and polymer types, are presented. It is concluded that topographical alterations to the fiber surface should be further studied, since results so far are promising.
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Curriculum „Palliative nephrologische Betreuung“. DER NEPHROLOGE 2021; 16:380-385. [PMID: 34603535 PMCID: PMC8475426 DOI: 10.1007/s11560-021-00536-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Accepted: 09/01/2021] [Indexed: 12/02/2022]
Abstract
Palliativmedizinische Aspekte wie Dialysevorenthalt und -abbruch, Einleitung einer konservativen Therapie sowie kooperative Betreuung am Lebensende sind zunehmend Teil der nephrologischen Regelversorgung geworden. Die entsprechende Wissensvermittlung palliativmedizinischer Grundsätze fehlt bislang in Aus- und Weiterbildung. In diesem Konsensuspapier wird für das nephrologische Team eine strukturierte kurrikuläre Weiterbildung zu den Grundprinzipien einer palliativen Betreuung vorgeschlagen.
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Self-Compounded Nanocomposites: toward Multifunctional Membranes with Superior Mechanical, Gas/Oil Barrier, UV-Shielding, and Photothermal Conversion Properties. ACS APPLIED MATERIALS & INTERFACES 2021; 13:28668-28678. [PMID: 34110125 DOI: 10.1021/acsami.1c06376] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Nanocomposites combine multiple favorable properties to achieve intriguing functionalities, but the formation of nanocomposites with only one constituent with the inclusion of multiple superior properties is still not known. Herein, novel self-compounded nanocomposite membranes from one single polymer-cellulose cinnamate (CCi)-with multiple outstanding properties are reported. The self-compounded membranes contain two distinct morphologies as CCi nanoparticles (CCi-NPs) and a CCi polymer matrix, while CCi-NPs are either firmly embedded in the CCi matrix or fused with adjacent CCi-NPs. The unique self-compounded nanostructure endows the membranes with a tensile strength of 94 MPa and Young's modulus of 3.1 GPa. The water vapor permeability, oxygen permeability, and oil permeability reach as low as (0.94 ± 0.03) × 10-11 g m-1 s-1 Pa-1, (8.48 ± 2.39) ×10-13 cm3·cm/cm2·s·cmHg, and 0.008 ± 0.003 g mm m-2 day-1, respectively. Moreover, self-compounded CCi nanocomposite membranes also demonstrate UV-shielding and photothermal conversion properties. UVB and UVC light are entirely blocked, while UVA light is partly blocked. The temperature increases from room temperature to 120 °C within 1 min under UV irradiation. In addition, CCi membranes also show remarkable thermal and humidity resistance. Based on these outstanding properties, CCi membranes are applied as food packaging materials. This work offers a new avenue to construct nanocomposites with multiple superior properties from one constituent, which is promising for diverse applications.
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9
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Structural Colors by Synergistic Birefringence and Surface Plasmon Resonance. ACS NANO 2020; 14:16832-16839. [PMID: 33290653 DOI: 10.1021/acsnano.0c05599] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
One-dimensional nanomaterials including cellulose nanocrystals (CNCs) and gold nanorods (GNRs) are widely used in optical materials due to their respective inherent features: birefringence with accompanying light retardation and surface plasmon resonance (SPR). Herein, we successfully combine these properties of both nanorods to generate synergistic and readily tunable structural colors in hybrid composite polymer films. CNCs and GNRs are embedded either in the same or in separate films after unidirectional alignment in dynamic hydrogels. By synergistically leveraging CNCs and GNRs with diverse amounts in hybrid films or stacked separate films, wide-ranging structural colors are obtained, far beyond those from films solely with aligned CNCs or GNRs. Higher GNR contents enhance light absorption at 520 nm with promoted magenta colors, while more CNCs affect the overall phase retardation with light absorption between 400 and 700 nm between crossed polarizers. Moreover, adjusting the angles between films solely with CNCs or GNRs via a stacking/rotating technique successively manipulates colors with flexible film combinations. By rotating the films with aligned GNRs (0-180°), light absorption can traverse from ∼500 to 650 nm. Thus, tuning the adjustable synergism of birefringence of CNCs and SPR of GNRs provides great potential for structural colors, which enlightens inspirations for designing functional optical materials.
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10
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In Situ Investigation of the Formation Kinematics of Plasma-Generated Silver Nanoparticles. NANOMATERIALS 2020; 10:nano10030555. [PMID: 32204519 PMCID: PMC7153378 DOI: 10.3390/nano10030555] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 03/09/2020] [Accepted: 03/15/2020] [Indexed: 02/07/2023]
Abstract
In this publication, it is shown how to synthesize silver nanoparticles from silver cations out of aqueous solutions by the use of an atmospheric pressure plasma source. The use of an atmospheric pressure plasma leads to a very fast reduction of silver ions in extensive solvent volumes. In order to investigate the nanoparticle synthesis process, ultraviolet/visible (UV/VIS) absorption spectra were recorded in situ. By using transmission electron microscopy and by the analysis of UV/VIS spectra, the kinetics of silver nanoparticle formation by plasma influence can be seen in more detail. For example, there are two different sections visible in the synthesis during the plasma exposure process. The first section of the synthesis is characterized by a linear formation of small spherical particles of nearly constant size. The second section is predominated by saturation effects. Here, particle faults are increasingly formed, induced by changes in the particle shape and the fusion of those particles. The plasma exposure time, therefore, determines the shape and size distribution of the nanoparticles.
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11
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Investigation of Non-Uniformity of Classically-Polished Fused Silica Surfaces via Laser-Induced Breakdown Spectroscopy. EPJ WEB OF CONFERENCES 2019. [DOI: 10.1051/epjconf/201921508003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
In this contribution, the surface uniformity of classically-manufactured fused silica windows was investigated via laser-induced breakdown spectroscopy. It is shown that for all investigated samples a comparatively high aluminium content was found at the edge of the surface with respect to its centre. This contamination can be attributed to residues from lapping and polishing agents and leads to a mentionable non-uniformity of the surface in terms of chemical composition and optical properties, respectively.
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12
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Increasing the Laser-Induced Damage Threshold of Optical Components by Atmospheric Pressure Plasma Surface Finishing. EPJ WEB OF CONFERENCES 2019. [DOI: 10.1051/epjconf/201921501003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
In this contribution, a plasma-based approach for finishing optics surfaces is introduced. Experiments were performed on classically manufactured zinc crown glass and sapphire. It is shown that the use of direct dielectric barrier discharge plasma at atmospheric pressure allows the removal of surface-adherent carbonaceous contaminations that were induced by classical manufacturing. Moreover, the use of such plasma leads to a certain decrease in surface roughness. Both effects, surface cleaning and smoothing finally increase the laser-induced damage threshold of optical components.
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13
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DGP-AG Nichttumorpatienten: Frühe palliative Versorgung von Menschen mit Nichttumorerkrankungen. ZEITSCHRIFT FUR PALLIATIVMEDIZIN 2018. [DOI: 10.1055/a-0659-9493] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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14
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Palliativversorgung von Menschen mit neurologischen Erkrankungen – Neuro Palliative Care. Palliat Care 2018. [DOI: 10.1007/978-3-662-56151-5_16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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15
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Ideal radiation source for plasma spectroscopy generated by laser ablation. Phys Rev E 2017; 96:053210. [PMID: 29347637 DOI: 10.1103/physreve.96.053210] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Indexed: 11/07/2022]
Abstract
Laboratory plasmas inherently exhibit temperature and density gradients leading to complex investigations. We show that plasmas generated by laser ablation can constitute a robust exception to this. Supported by emission features not observed with other sources, we achieve plasmas of various compositions which are both uniform and in local thermodynamic equilibrium. These properties characterize an ideal radiation source opening multiple perspectives in plasma spectroscopy. The finding also constitutes a breakthrough in the analytical field as fast analyses of complex materials become possible.
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16
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Investigation of nonuniform surface properties of classically manufactured fused silica windows. APPLIED OPTICS 2017; 56:7427-7434. [PMID: 29048065 DOI: 10.1364/ao.56.007427] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Accepted: 08/15/2017] [Indexed: 06/07/2023]
Abstract
We report on investigations of the spatial variations of contamination, roughness, and index of refraction of classically manufactured polished fused silica surfaces. Therefore, laser-induced breakdown spectroscopy was used to probe surface and subsurface impurities via the detection of aluminum. Measurements at different positions on the surface of the cylindrical fused silica windows evidenced an almost contamination-free center region, whereas a relatively large contamination area was found close to the edge. In-depth measurements verify the presence of aluminum atoms in the bulk until a depth of several tens of microns for the edge region. In addition, atomic force microscopic measurements show that the surface roughness is larger in the center region compared to the edge. Further, the index of refraction increases from the center region towards the edge as measured via ellipsometry. The results indicate a nonuniform impact of the grinding, lapping, and polishing tools on the surface. The findings turn out to be of specific interest for different applications, particularly for the realization of large-scale high-performance coatings.
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17
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Impact of assisting atmospheric pressure plasma on the formation of micro- and nanoparticles during picosecond-laser ablation of titanium. APPLIED OPTICS 2017; 56:3365-3371. [PMID: 28430259 DOI: 10.1364/ao.56.003365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
In this work, we investigated the generation of particles during pure laser and plasma-assisted laser ablation of titanium. Experiments were performed using a NIR picosecond laser at a wavelength of 1030 nm and a pulse duration of 8 ps. For plasma-assisted ablation, an atmospheric pressure dielectric barrier discharge plasma was applied where the process gas was argon. Quantitative particle distributions at sizes from 10 nm to 10 μm were determined. In addition, we evaluated the amount of ablated material via laser scanning microscopy. The ablated volume was significantly increased by a factor of 2 to 3 in the case of plasma-assisted ablation, depending on the applied laser dose. It is shown that the increase in particle volume and number of particles was lower than the ablated volume. However, when applying plasma simultaneously, the generation of small nanoparticles increases notably by a factor of up to 6.63 at a laser dose of 0.7 kJ/mm2 for particles with a mean diameter of 10 nm. The results suggest that even smaller particles than measurable are generated. Hence, plasma-assisted laser ablation could enhance the process efficiency, reduce the particle agglomeration, and give rise to an increase in generation of nanoparticles at the same time.
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Increase in nanosecond laser-induced damage threshold of sapphire windows by means of direct dielectric barrier discharge plasma treatment. OPTICS LETTERS 2017; 42:49-52. [PMID: 28059175 DOI: 10.1364/ol.42.000049] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
In this Letter we present a novel approach for increasing the nanosecond laser-induced damage threshold (LIDT) of sapphire windows. It is shown that after direct dielectric barrier discharge plasma treatment at atmospheric pressure for 90 s the LIDT is increased by a factor of 1.5 with respect to untreated samples. Several possible underlying mechanisms are introduced. For instance, organic contaminants and residues from polishing agents were removed by the plasma as ascertained by XPS measurements.
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Low-temperature atmospheric pressure argon plasma treatment and hybrid laser-plasma ablation of barite crown and heavy flint glass. APPLIED OPTICS 2012; 51:3847-3852. [PMID: 22695664 DOI: 10.1364/ao.51.003847] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2012] [Accepted: 04/27/2012] [Indexed: 06/01/2023]
Abstract
We report on atmospheric pressure argon plasma-based surface treatment and hybrid laser-plasma ablation of barite crown glass N-BaK4 and heavy flint glass SF5. By pure plasma treatment, a significant surface smoothing, as well as an increase in both the surface energy and the strength of the investigated glass surfaces, was achieved. It was shown that for both glasses, hybrid laser plasma ablation allows an increase in the ablation depth by a factor of 2.1 with respect to pure laser ablation. The ablated volume was increased by an averaged factor of 1.5 for N-BaK4 and 3.7 for SF5.
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Near-surface modification of optical properties of fused silica by low-temperature hydrogenous atmospheric pressure plasma. OPTICS LETTERS 2012; 37:566-568. [PMID: 22344108 DOI: 10.1364/ol.37.000566] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
In this Letter, we report on the near-surface modification of fused silica by applying a hydrogenous atmospheric pressure plasma jet at ambient temperature. A significant decrease in UV-transmission due to this plasma treatment was observed. By the use of secondary ion mass spectroscopy, the composition of the plasma-modified glass surface was investigated. It was found that the plasma treatment led to a reduction of a 100 nm thick SiO2 layer to SiOx of gradual depth-dependent composition. For this plasma-induced layer, depth-resolved characteristic optical parameters, such as index of refraction and dispersion, were determined. Further, a significant plasma-induced increase of the concentration of hydrogen in the bulk material was measured. The decrease in transmission is explained by the plasma-induced near-surface formation of SiOx on the one hand and the diffusion of hydrogen into the bulk material on the other hand.
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21
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Efficient versatile-repetition-rate picosecond source for material processing applications. APPLIED OPTICS 2008; 47:967-974. [PMID: 18311268 DOI: 10.1364/ao.47.000967] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
We report on the development of an efficient and simple picosecond diode-pumped solid-state laser source with a versatile repetition rate (typically 1 Hz-1 MHz) for material processing applications. The laser source is based on a 4 MHz repetition rate mode-locked oscillator and a passive 3D multipass amplifier both based on Nd:YVO(4) crystals. Micromachining experiments were performed to study the influence of pulse energy on the machining quality for Al, Cu, paper, and glass.
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22
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Palliative Care für Patienten mit fortgeschrittener Demenz. ZEITSCHRIFT FUR PALLIATIVMEDIZIN 2007. [DOI: 10.1055/s-2007-970876] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Rudolf Lemkes Bedeutung für die Entwicklung der Kinderneuropsychiatrie in Jena. DER NERVENARZT 2007; 78:706, 708-12. [PMID: 17323060 DOI: 10.1007/s00115-006-2239-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Child and adolescent psychiatry has a long tradition in Jena, Germany, and goes back to the psychiatrists Theodor Ziehen and Wilhelm Strohmayer. It seems that Rudolf Lemke (1906-1957) eminently promoted the development of child and adolescent psychiatry after World War II. A versatile scientist, Lemke had many publications in psychiatric and neurologic fields. His significance to the development of the specialty of child and adolescent psychiatry is reflected not only by his publications but also by his work as a clinician and liaison psychiatrist in the Johannes Trueper School in Jena. He founded an independent psychiatric unit for the treatment of children which allowed treatment separated from adults.
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Stable mode-locked operation of a low repetition rate diode-pumped Nd:GdVO4 laser by combining quadratic polarisation switching and a semiconductor saturable absorber mirror. OPTICS EXPRESS 2006; 14:7093-7098. [PMID: 19529080 DOI: 10.1364/oe.14.007093] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
In this paper, we present the mode-locked operation of an ultra-robustly stabilised Nd:GdVO(4) laser with low repetition rate by combining quadratic polarisation switching and a semiconductor saturable absorber mirror (SESAM). In addition, similar experiment was also done with Nd:YVO(4). For Nd:GdVO(4), 16-ps pulses at 1063 nm with a repetition rate of 3.95 MHz have been obtained for a laser average output power of 1.4 W. For Nd:YVO(4), the performance was 2.5 W of average power for 15-ps pulses at 1064 nm. Moreover, we demonstrate experimentally the advantage of combining these two passive mode locking techniques in terms of stability ranges. We show how the dual mode-locking technique is crucial to obtain a stable and long-term mode-locked regime in our case of a diode-pumped Nd:GdVO(4) laser operating at low repetition rate and more generally how this dual mode-locking technique improves the stability range of the mode-locked operation giving more flexibility on different parameters.
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Verminderung von Technologie�ngsten in der psychosomatischen Rehabilitation?Konzepte und Ergebnisse zu einem Computertraining f�r �ltere Arbeitnehmer*. Z Gerontol Geriatr 2004; 37:221-30. [PMID: 15224243 DOI: 10.1007/s00391-004-0184-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2002] [Accepted: 09/12/2003] [Indexed: 11/29/2022]
Abstract
A computer training program was developed specifically oriented toward middle-aged employees, their learning needs and their computer-related fears. This program was based on a pilot study showing a high degree of stresses associated with the introduction of computer technology at the workplace in this age group (50-59 years). A survey of 623 patients confirmed that these persons experienced technological change predominantly as disadvantageous or threatening. Based on 114 patients, concepts and results of the computer training are presented. Participation reduced avoidance behaviors, fears and increased interest and initiative based both on the patients' and their trainers' perspectives.
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26
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Modification of a choledochoscope for extraction of difficult biliary stones. Am Surg 2001; 67:630-2. [PMID: 11450775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
Cholelithiasis is a common problem in the United States, affecting 10 to 15 per cent of the population. Although only one per cent of these patients have intrahepatic gallstones their discovery intraoperatively may present a technical challenge for the surgeon. This paper describes a simple method for dislodging difficult intrahepatic biliary stones: modification of a rigid choledochoscope to permit use of a biliary Fogarty catheter and Segura basket under direct visualization.
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Abstract
BACKGROUND Thrombospondin-1 (TSP-1) is important in platelet adhesion and aggregation, inflammation, cell to cell interaction, angiogenesis, and smooth muscle cell (SMC) proliferation. TSP-1 expression increases rapidly with injury. Therefore, we hypothesize that TSP-1 may play a role in the development of intimal hyperplasia (IH). The purpose of this study is to examine the interaction between cholesterol and TSP-1 on SMC proliferation and to quantitatively assess TSP-1 expression in an established model of IH, with and without underlying cholesterol-induced atherosclerosis. MATERIALS AND METHODS In vitro, rabbit aortic SMC culture studies were performed to see the effect of TSP-1 antibodies on PDGF and, separately, cholesterol-induced SMC proliferation. In vivo, 23 rabbits were fed either a regular or a high-cholesterol diet. Hypercholesterolemia was confirmed by measurement of serum levels. Subsets underwent intraluminal aortic injury. Aortas were harvested 8-10 weeks later. Arterial wall TSP-1 was evaluated immunohistochemically and quantified by computer image analysis. RESULTS In vitro, TSP-1 antibodies were able to inhibit PDGF and cholesterol-induced SMC proliferation (P < 0.05). In vivo, TSP-1 was found predominantly in the extracellular matrix in the rabbit aorta. IH was uniformly seen status-post angioplasty. Hyperplasia was more prominent in samples from hypercholesterolemic animals. ANOVA and Student's t test analyses demonstrated significantly more TSP-1 in the high-cholesterol/angioplasty group than in all other groups (P = 0.0006 vs regular diet/no angioplasty group). CONCLUSIONS These data are consistent with the hypothesis that TSP-1 contributes to the development of IH. This study suggests that injured arteries in hypercholesterolemic atherosclerotic rabbits overexpress TSP-1.
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[14C]Methylamine accumulation in cultured human skin fibroblasts--a biochemical test for lysosomal storage and lysosomal diseases. Clin Chim Acta 1994; 227:121-33. [PMID: 7955409 DOI: 10.1016/0009-8981(94)90141-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Incorporation of the lysosomotropic amine [14C]methylamine by fibroblasts cultured from patients with lysosomal storage diseases and from controls was used to estimate the size of the lysosomal compartment. All cell lines from patients with infantile and juvenile forms of mucopolysaccharidoses, mucolipidoses and oligosacharidoses showed markedly increased radioactivity compared with the normal range of controls. In cells from patients with sphingolipidoses and adult forms of storage diseases, however, methylamine accumulation was not significantly increased. Experimentally induced lysosomal storage by enzyme inhibitors (leupeptin, suramin) also caused increased methylamine accumulation. When the lysosomal pH was determined with fluorescein isothiocyanate-dextran, it was in the range of normal controls (pH 4.7-5.0) in patients cells. Thus, [14C]methylamine accumulation should depend on the volume rather than differences in acidity of the lysosomal compartment and be a measure of its eventual pathological enlargement. We conclude that the determination of [14C]methylamine accumulation in fibroblasts provides a valuable tool in the screening for a variety of lysosomal storage disorders.
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[Recall service--when, next and regular!]. QUINTESSENZ JOURNAL 1987; 17:49-52. [PMID: 3473553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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30
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Abstract
The present study using the results of the postmortem examination of twenty-four children, who had infantile spasms (West-Syndrome), gives a view of the aetiology and course of the West-Syndrome. According to the time of occurrence of the lesions three groups could be established: one group of six cases with only embryofetal lesions, one group of ten cases with combined embryofetal and peri/postnatal lesions and one group of eight cases with only peri/postnatal lesions. It is significant, that the time of onset of infantile spasms depends on time of manifestation of lesions. In the groups with combined embryofetal and peri/postnatal lesions the seizures were manifested at the same time as in the cases with isolated embryofetal lesions. Even in the group with combined lesions, microdysgenesis was interpreted as being embryofetal. These embryofetal lesions, as opposed to the peri/postnatal lesions thus appear to dominate and thereby to be pathoplastic. From this correlation two thirds of the cases of infantile spasms can be regarded as fetal epilepsies. The question is open if the infantile spasms which are manifested later on and develop mostly a Lennox-Syndrome indeed should be classified as a separate group together with the isolated peri/postnatal lesions.
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Histopathological findings in adrenoleukodystrophy autopsy report of a boy aged 11 years and 11 months. ACTA NEUROPATHOLOGICA. SUPPLEMENTUM 1981; 7:215-8. [PMID: 6939238 DOI: 10.1007/978-3-642-81553-9_64] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Clinical and pathohistological findings of a boy who died of adrenoleukodystrophy at the age of 11 years and 11 months are reported. Special features are the advanced diffuse demyelination of cerebral and cerebellar white matter as well as the "burnt-out" stage of myelin breakdown with fibrous gliosis. The leukodystrophic process is accompanied by secondary loss of axons with marked atrophy of grey matter in the whole of the brain stem, dentates and cerebellar cortex of the Purkinje cell type. The degeneration of nerve fibres is considered as a complex mechanism, which is not restricted to the Wallerian type. -- Only free cholesterol was shown by histochemical tests in the preserved myelin sheaths. Free and esterified cholesterol was found in the adrenal cortical cells. The lack of detectable cholesteryl esters in the sparse sudanophilic macrophages was unexpected. This finding may be attributed to the sensitivity of the histochemical method or to interference by achromogenic 7-ketocholesterol.
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