bluuebunny/crossref_metadata_2025_split huggingface dataset:
Automated compensation of light attenuation in confocal microscopy by exact histogram specification
Authors: Stanciu Stefan G. , Stanciu George A. , Coltuc Dinu 
Published: September 2009

AbstractConfocal laser scanning microscopy (CLSM) enables us to capture images representing optical sections on the volume of a specimen. The images acquired from different layers have a different contrast: the images obtained from the deeper layers of the specimen will have a lower contrast with respect to the images obtained from the topmost layers. The main reasons responsible for the effects described above are light absorption and scattering by the atoms and molecules contained in the volume through which the light passes. Also light attenuation can be caused by the inclination of the observed surface. In the case of the surfaces that have a steep inclination, the reflected light will have a different direction than the one of the detector. We propose a technique of digital image processing that can be used to compensate the effects of light attenuation based on histogram operations. We process the image series obtained by CLSM by exact histogram specification and equalization. In this case, a strict ordering among pixels must be induced in order to achieve the exact histogram modeling. The processed images will end up having exactly the specified histogram and not a histogram with a shape that just resembles to the specified one, as in the case of classical histogram specification algorithms. Experimental results and theoretical aspects of the induced ordering are discussed, as well as a comparison between several histogram modeling techniques with respect to the processing of image series obtained by confocal microscopy. Microsc. Res. Tech., 2010. © 2009 Wiley‐Liss, Inc.
MRT letter: Recovering weak‐textured surfaces using image focus
Authors: Muhammad Mannan Saeed , Choi Tae‐Sun 
Published: September 2009

AbstractIn nature, objects have partially weak texture and their shape reconstruction using focus based passive methods like shape from focus (SFF), is difficult. This article presents a new SFF algorithm which can compute precise depth of dense as well as weak textured objects. Segmentation is applied to discard wrong depth estimate and then later interpolating them from accurate depth values of their neighbors. The performance of the proposed method is tested, using different image sequences of synthetic and real objects, with varying textures. Microsc. Res. Tech., 2009. © 2009 Wiley‐Liss, Inc.
The toxic effect of ketamine on SH‐SY5Y neuroblastoma cell line and human neuron
Authors: Mak Ying T. , Lam Wai P. , Lü Lanhai , Wong Yeuk W. , Yew David T. 
Published: September 2009

AbstractKetamine used as an injectable anesthetic in human and animal medicine is also a recreational drug used primarily by young adults often at all night dance parties in nightclubs. The percentage of ketamine users has grown very fast in the last 5 years worldwide. However, this leads to the serious question of the long‐term adverse effects of ketamine on our nervous system, particularly the brain, because ketamine as an NMDA antagonist could cause neurons to commit apoptosis. Our study therefore aimed to find out the chronic effect of ketamine on neuron using prolonged incubation (48 h) of neuronal cells with ketamine in culture. Our results showed that differentiated neuronal cells were prone to the toxicity of ketamine but probably less susceptible than undifferentiated neuronal cells and fibroblasts. This suggested that the ketamine abuse would be harmful to many other organs as well as the brain. Our results also confirmed that the toxicity of ketamine is related to apoptosis via the Bax/Bcl‐2 ratio pathway and caspase‐3 in the differentiated neuronal cells. Therefore, long‐term ketamine treated cell or animal models should be sought to study this multiorgan effects of ketamine. Microsc. Res. Tech., 2010. © 2009 Wiley‐Liss, Inc.
Differences between nanoscale structural and electrical properties of AZO:N and AZO used in polymer light‐emitting diodes
Authors: Chen Sy‐Hann , Yu Chang‐Feng 
Published: September 2009

AbstractConducting atomic force microscopy and scanning surface potential microscopy were adopted to investigate the nanoscale surface electrical properties of N‐doped aluminum zinc oxide (AZO:N) films that were prepared by pulsed laser deposition (PLD) at various substrate temperatures. Experimental results demonstrated that when the substrate temperature is 150°C and the N2O background pressure is 150 mTorr, the N‐dopant concentration on the surface is optimal. In addition, the root‐mean‐square roughness value of the film surface, the low contact current (<400 nA) conducting region as a percentage of the total area, and the mean work function value are 1.43 nm, 96.9%, and 4.88 eV, respectively, all of which are better than those of the optimal AZO film made by PLD. This result indicates that N‐doped AZO films are better for use as window materials in polymer light‐emitting diodes. Microsc. Res. Tech., 2010. © 2009 Wiley‐Liss, Inc.
The ultrastructure of malpighian tubules and the chemical composition of the cocoon of Aeolothrips intermedius Bagnall (Thysanoptera)
Authors: Conti Barbara , Berti Francesco , Mercati David , Giusti Fabiola , Dallai Romano 
Published: September 2009

AbstractThe secretory activity of the two branched malpighian tubules (MTs) of the second‐instar larva in Aeolothrips intermedius is described. MTs of adult thrips have the typical ultrastructure of excretory epithelium with apical microvilli containing long mitochondria and a rich system of basal membrane infoldings. In the second‐instar larva just before pupation, the ultrastructure of MT epithelial cells is dramatically different, and there are numerous huge Golgi systems in the cytoplasm. These cells are involved in an intense secretory activity to produce an electron‐dense product which is released into the MTs lumen. This secretion is extruded from the hindgut and used by the second‐instar larva to build an elaborate protective cocoon for pupation. Electron‐spray‐ionization mass spectrometry analysis of the cocoon revealed the presence of a β‐N‐acetyl‐glucosamine, the main component of chitin, which is also present in the cocoons of Neuroptera and some Coleoptera. J. Morphol., 2010. © 2009 Wiley‐Liss, Inc.
Sensitivity analysis of lossy nonuniform multiconductor transmission lines based on the Lax‐Wendroff technique
Authors: Dou Lei , Dou Jiao 
Published: September 2009

AbstractThis paper applies the Lax‐Wendroff technique, usually used in fluid dynamics, to transmission line sensitivity analysis. A second‐order‐accurate Lax‐Wendroff difference scheme for sensitivity analysis of both uniform and nonuniform transmission lines is derived. Based on this scheme, a new method for analyzing multiconductor transmission line sensitivity, which does not need to be decoupled, is presented by combining with matrix operations. Using numerical experiments, the proposed method is compared with the characteristic method and the fast Fourier transform approach. With the presented method, the sensitivity of a nonlinear circuit including nonuniform multiconductor transmission lines is analyzed and the results are verified by the HSPICE perturbation method. The proposed method can be applied to either linear or nonlinear circuits, which include lossy nonuniform multiconductor transmission lines and is proved to be efficient. Copyright © 2009 John Wiley & Sons, Ltd.
Careers as tournaments: The impact of sex and gendered organizational culture preferences on MBAs' income attainment
Authors: O'Neill Olivia A. , O'Reilly Charles A. 
Published: September 2009

AbstractDrawing on gender role theory and tournament theory, we examined the effects of sex and organizational culture preferences on the incomes of MBA graduates over an 8‐year period. We found that masculine culture preferences led to higher income 4 years after graduation and, in contrast to previous research, the effect was stronger for women. By 8 years after graduation, however, men's rate of income increase was significantly higher than women's, an effect that was mediated by hours worked per week. These findings clarify some of the conflicting results of previous research on the effects of gender roles on women's careers and suggest that a tournament‐like aspect of careers may account for higher incomes in organizations. Copyright © 2009 John Wiley & Sons, Ltd.
N‐acetylcysteine prevents nitric oxide‐induced chondrocyte apoptosis and cartilage degeneration in an experimental model of osteoarthritis
Authors: Nakagawa Shuji , Arai Yuji , Mazda Osam , Kishida Tsunao , Takahashi Kenji A. , Sakao Kei , Saito Masazumi , Honjo Kuniaki , Imanishi Jiro , Kubo Toshikazu 
Published: September 2009

AbstractWe investigated whether N‐acetylcysteine (NAC), a precursor of glutathione, could protect rabbit articular chondrocytes against nitric oxide (NO)‐induced apoptosis and could prevent cartilage destruction in an experimental model of osteoarthritis (OA) in rats. Isolated chondrocytes were treated with various concentrations of NAC (0–2 mM). Apoptosis was induced by 0.75 mM sodium nitroprusside (SNP) dehydrate, which produces NO. Cell viability was assessed by MTT assay, while apoptosis was evaluated by Hoechst 33342 and TUNEL staining. Intracellular reactive oxygen species (ROS) and glutathione levels were measured, and expression of p53 and caspase‐3 were determined by Western blotting. To determine whether intraarticular injection of NAC prevents cartilage destruction in vivo, cartilage samples of an OA model were subjected to H&E, Safranin O, and TUNEL staining. NAC prevented NO‐induced apoptosis, ROS overproduction, p53 up‐regulation, and caspase‐3 activation. The protective effects of NAC were significantly blocked by buthionine sulfoximine, a glutathione synthetase inhibitor, indicating that the apoptosis‐preventing activity of NAC was mediated by glutathione. Using a rat model of experimentally induced OA, we found that NAC also significantly prevented cartilage destruction and chondrocyte apoptosis in vivo. These results indicate that NAC inhibits NO‐induced apoptosis of chondrocytes through glutathione in vitro, and inhibits chondrocyte apoptosis and articular cartilage degeneration in vivo. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:156–163, 2010
Relative contributions of mechanical degradation, enzymatic degradation, and repair of the extracellular matrix on the response of tendons when subjected to under‐ and over‐ mechanical stimulations in vitro
Authors: Cousineau‐Pelletier Paule , Langelier Eve 
Published: September 2009

AbstractTendon response to mechanical loading results in either homeostasis, improvement, or degeneration of tissue condition. In an effort to better understand the development of tendinopathies, this study investigated the mechanical and structural responses of tendons subjected to under‐ and over‐stimulations (1.2% and 1.8% strain respectively, 1 Hz). The objective was to examine three sub‐processes of tendon response: mechanical degradation, enzymatic degradation, and repair of the extracellular matrix. We subjected rat tail tendons to a 10‐day stimulation protocol with four periods of 6 h each day: 30 min of stimulation and 5 h 30 min of rest. To investigate the contribution of the three sub‐processes, we controlled the contribution of the cells through variations in the nutrient and protease inhibitor content in the in vitro solutions. Using nondestructive cyclic tests, we evaluated the daily changes in the peak stress. To assess structural changes, we carried out microscopic analyses at the end of the study period. We observed that the relative contributions of the sub‐processes differed according to the stimulation amplitude. With over‐stimulation of tendons immersed in DMEM, we succeeded in reducing enzymatic degradation and increasing peak stress. In under‐stimulation, the addition of protease inhibitors was required to obtain the same result. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:204–210, 2010
Decrease in particle‐induced osteolysis in ovariectomized mice
Authors: Nich Christophe , Marchadier Arnaud , Sedel Laurent , Petite Hervé , Vidal Catherine , Hamadouche Moussa 
Published: September 2009

AbstractPostmenopausal osteoporosis is a common disorder that results from increased osteoclastic activity caused by estrogen deficiency. Whether postmenopausal bone remodeling can alter the response to particulate debris is unknown. The purpose of this study was to evaluate the bone response to polyethylene particles in an ovariectomized murine model. Polyethylene particles were implanted onto the calvaria of seven control mice and seven ovariectomized (OVX) mice, as compared with calvaria from sham‐operated and OVX mice. Calvaria were harvested after 14 days. Skulls were analyzed with a high‐resolution micro‐CT and by histomorphometry after staining with Stevenel blue and picrofuschine, and for tartrate‐specific alkaline phosphatase. As assessed by micro‐CT, particle implantation induced a significant decrease in bone thickness in control mice, while bone thickness remained stable in OVX mice. In particle‐implanted animals, the osteoclast number was 2.84 ± 0.3 in control mice and 1.74 ± 0.22 in OVX mice. Mean bone loss was −12% ± 1.9% in control mice and −4.7% ± 1.7% in OVX animals. The reduction of osteolytic response suggests that ovariectomy may have a protective role against particle‐induced bone resorption. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:178–183, 2010
Use of thermo‐Raman spectroscopy and chemometric analysis to identify dehydration steps of hydrated inorganic samples—application to copper sulfate pentahydrate
Authors: Widjaja Effendi , Chong Hui Heng , Tjahjono Martin 
Published: September 2009

AbstractIn situ thermo‐Raman spectroscopy (TRS) measurements were performed in order to investigate solid‐phase transformation of the copper sulfate pentahydrate from room temperature up to 300 °C. Band‐target entropy minimization (BTEM), a blind‐source separation algorithm, was employed in order to identify and reconstruct the pure component spectra of the species involved in the dehydration process. In spite of low signal‐to‐noise ratio and elevated baseline spectral data, BTEM was successfully utilized to identify and reconstruct four pure component spectra of copper sulfate pentahydrate, trihydrate, monohydrate, and anhydrate, which were formed during this thermally induced process. Subsequent mapping of these four pure component spectral estimates back onto the preprocessed spectra yielded the relative concentrations of each individual species. Finally, the transition temperatures of each dehydration step could be unambiguously deduced from the obtained concentration profile. The current study shows that combined thermo‐Raman spectroscopy and chemometric analysis provides an effective tool to determine the dehydration temperatures as well as to identify the structures of each individual species involved in a solid‐phase dehydration process. Copyright © 2009 John Wiley & Sons, Ltd.
Raman and infrared spectra, conformational stability, ab initio calculations and vibrational assignment of dimethylsilylisocyanate
Authors: Guirgis Gamil A. , Zhou Sarah Xiaohua , Durig James R. 
Published: September 2009

AbstractThe Raman (3200‐30 cm−1) and/or infrared spectra (3500 to 400 cm−1) of gaseous, liquid and solid dimethylsilylisocyanate, (CH3)2 Si(H)NCO, have been recorded. The MP2(full) calculations, employing a variety of basis sets with and without diffusion functions, have been used to predict the structural parameters, conformational stability, vibrational fundamental wavenumbers, Raman activities, depolarization values and infrared intensities to support the vibrational assignment. The low wavenumber Raman spectrum of the gas with a significant number of Q‐branches for the SiNC(O) bend is consistent with an essentially linear SiNCO moiety. The ab initio calculations supported this conclusion as all possible orientations of the NCO moiety lead to nearly the same energy. This result is at variance with the conclusion from the electron diffraction study that the heavy atom skeleton was bent with an angle of 152(5)° with one stable cis conformer. It is believed that this reported angle difference from 180° is due to the shrinkage effect. The SiH distance of 1.486 Å has been obtained from the isolated SiH stretching wavenumber. From the adjustment of the ab initio MP2(full)/6‐311+G(d,p) predicted structural parameters, a proposed structure is reported, which is expected to give rotational constants within a few megahertz of the actual ones. These experimental and theoretical results are compared with the corresponding quantities of similar molecules. Copyright © 2009 John Wiley & Sons, Ltd.
Electromagnetic field enhancement in TERS configurations
Authors: Yang Zhilin , Aizpurua Javier , Xu Hongxing 
Published: September 2009

AbstractWe use three‐dimensional finite‐difference time domain (3D‐FDTD) simulations to investigate the field enhancement properties of tip‐enhanced Raman scattering (TERS) in order to find optimal geometric parameters of the metal tip and the metal substrate under certain excitation wavelengths with side illumination. The simulation results show that plasmon coupling effects between the metal tip and the metal substrate play the key role in TERS enhancement, and the enhancement drops dramatically as the distance between the tip and the substrate increases. The spatial resolution of TERS is mainly dependent on the radius of curvature of the tip end. A sharp tip with a small radius can dramatically increase the spatial resolution of TERS. Increasing the tip–substrate distance or changing the metallic substrate into a dielectric substrate lowers the spatial resolution. The TERS enhancement dependence on the incident angle and polarization, the size of tip, as well as the composition of the substrate is also discussed in detail. Copyright © 2009 John Wiley & Sons, Ltd.
A complete Raman mapping of phase transitions in Si under indentation
Authors: Das C. R. , Hsu H. C. , Dhara S. , Bhaduri A. K. , Raj B. , Chen L. C. , Chen K. H. , Albert S. K. , Ray A. , Tzeng Y. 
Published: September 2009

AbstractCrystalline Si substrates are studied for pressure‐induced phase transformation under indentation at room temperature (RT) using a Berkovich tip. Raman spectroscopy, as a nondestructive tool, is used for the identification of the transformed phases. Raman lines as well as area mapping are used for locating the phases in the indented region. Calculation of pressure contours in the indented region is used for understanding the phase distribution. We report here a comprehensive study of all the phases of Si, reported so far, leading to possible understanding of material properties useful for possible electromechanical applications. As a major finding, distribution of the amorphous phase in the indented region deviates from the conventional wisdom of being in the central region alone. We present phase mapping results for both Si(100) and Si(111) substrates. Copyright © 2009 John Wiley & Sons, Ltd.
Characterisation of FXTAS related isolated intranuclear protein inclusions using laser tweezers Raman spectroscopy
Authors: Moritz Tobias J. , Brunberg James A. , Krol Denise M. , Wachsmann‐Hogiu Sebastian , Lane Stephen M. , Chan James W. 
Published: September 2009

AbstractWe report the analysis of the vibrational modes of intranuclear protein inclusions isolated from the brain of human subjects with the Fragile X‐associated tremor/ataxia syndrome (FXTAS). In this preliminary study, Raman spectra of optically trapped inclusions were measured and analysed to determine protein composition and structure. Our main findings are as follows: (1) The spectra of protein inclusions are characteristic of H2A and H2B histones, which correlate with previous mass spectrometry (MS) studies; (2) Tyrosine is present in its OH form and exposed at the protein surface; (3) Zn and to a lesser extent Cu bound to histidine side chains are detected in the inclusions; (4) The tryptophan side‐chain torsion angle is calculated to be 102°; (5) Several potential spectroscopic markers for the inclusions of FXTAS are identified. These results show the capability of using laser tweezers Raman spectroscopy to identify protein inclusions in a non‐perturbative way and to gain further insight into the pathogenesis and progression of FXTAS in human subjects and in experimental models of this disorder. Copyright © 2009 John Wiley & Sons, Ltd.
Raman spectroscopy of synthetic, geological and biological vaterite: a Raman spectroscopic study
Authors: Wehrmeister U. , Soldati A. L. , Jacob D. E. , Häger T. , Hofmeister W. 
Published: September 2009

AbstractRaman spectroscopy was used to study vaterite samples of biological, geological and synthetic origin. The Raman band positions and the full width at half‐maximum (FWHM) of the lattice modes and the internal modes of the carbonate ion of all specimens show no significant differences between vaterites of different origin. With increasing Mg concentrations, synthetic vaterite samples show increasing FWHM in the region of the lattice modes and the three ν1 bands, whereas no change in luminescence was detected. In contrast, in situ measurements of vaterite areas in freshwater cultured pearls (FWCPs) by laser ablation inductively coupled plasma mass spectrometry (LA‐ICP‐MS) together with the Raman spectra obtained at the same points show that the luminescence intensity in biological samples is affected by the magnesium content. The Raman spectroscopic features of vaterite and parisite‐(Ce) are compared, and their similarities suggest that the structure of vaterite contains at least three crystallographically independent carbonate groups and similar carbonate group layers. A band at 263 cm−1 is observed for the first time in this study, whereas it could be demonstrated that bands previously reported at 130 and 190 cm−1 do not belong to vaterite. Copyright © 2009 John Wiley & Sons, Ltd.
Local field enhancement of an infinite conical metal tip illuminated by a focused beam
Authors: Zhang Weihua , Cui Xudong , Martin Olivier J. F. 
Published: September 2009

AbstractWe present a systematic numerical investigation of conical metal tips which are commonly used in tip‐enhanced Raman spectroscopy (TERS). Different from previous studies, we focus on how the tip length and the illumination condition influence the local field enhancement at the tip apex, and provide a useful reference for real experiments. In particular, we show that the type of illumination has a dramatic influence on the field enhancement: a localized illumination spot—as used in experiments—producing a very different response than a plane wave illumination—as usually used in previous models. Also, the effect of the different geometrical parameters, such as the sharpness of the tip apex and the cone angle, provides guidance to optimize the tip design. Finally, we investigate the influence of the substrate and compare numerical data with results deduced from a simplified model, finding good agreement. This brings new insights into the enhancement mechanism of TERS. Copyright © 2009 John Wiley & Sons, Ltd.
Detection of small amounts of H2O in CO2‐rich fluid inclusions using Raman spectroscopy
Authors: Berkesi Márta , Hidas Károly , Guzmics Tibor , Dubessy Jean , Bodnar Robert J. , Szabó Csaba , Vajna Balázs , Tsunogae Toshiaki 
Published: September 2009

AbstractRaman spectroscopic analysis at low (−100 °C) or high (100–200 °C) temperature is shown to be effective for detecting small amounts of H2O in CO2‐rich fluid inclusions from the deep lithosphere, which have previously been thought to be water‐free. Copyright © 2009 John Wiley & Sons, Ltd.