bluuebunny/crossref_metadata_2025 huggingface dataset:
Differential regulation of neurotrophin expression in basal forebrain astrocytes by neuronal signals
Authors: Wu Hai , Friedman Wilma J. , Dreyfus Cheryl F.
Published: March 2004

Nerve growth factor (NGF), brain‐derived neurotrophic factor (BDNF), and neurotrophin‐3 (NT3) promote the function and/or survival of basal forebrain (BF) cholinergic neurons in vivo and in culture. The neurotrophin source is commonly thought to be targets of cholinergic neurons and the possibility that local glial sources support cholinergic neurons has not been well examined. These sources, however, may be critical to BF neurons before or even after they reach their targets. We investigated neurotrophin expression in BF astrocytes and its regulation by neural signals. Solution hybridization and immunocytochemical assays revealed that NGF, BDNF, and NT3 mRNA and proteins were expressed in cultured BF astrocytes. To investigate roles of neuronal signals in neurotrophin regulation, effects of K+, glutamate, and the cholinergic agonist carbachol were examined. These stimuli affected neurotrophin expression differentially. KCl increased BDNF mRNA but did not alter NGF or NT3 mRNA. The effect was blocked by nifedipine, suggesting that it was mediated by L‐type voltage‐dependent calcium currents. Carbachol also increased BDNF mRNA levels without changing NGF or NT3. Effects were blocked by the muscarinic antagonist, atropine. In contrast, glutamate increased both NGF and BDNF mRNA. NT3 mRNA again was unaffected. The metabotropic agonist trans‐(1S,3R)‐1‐amino‐1,3‐cyclopentanedicarboxylic acid (trans‐ACPD) reproduced glutamate effects, whereas kainate or N‐methyl‐D‐aspartate (NMDA) plus glycine did not. Lack of antagonism by ionotropic antagonists and blockade of glutamate effects by metabotropic antagonists confirmed metabotropic mediation. We suggest that BF astrocytes are local sources of neurotrophins for BF cholinergic neurons during development and are regulated differentially by specific neuronal signals. Critical neuronal‐glial interactions may underlie basal forebrain function. © 2004 Wiley‐Liss, Inc.
Development of a model of seizure‐induced hippocampal injury with features of programmed cell death in the BALB/c mouse
Authors: Shinoda Sachiko , Araki Tomohiro , Lan Jing‐Quan , Schindler Clara K. , Simon Roger P. , Taki Waro , Henshall David C.
Published: March 2004

Although mice are amenable to gene knockout, they have not been exploited in the setting of seizure‐induced neurodegeneration due to the resistance to injury of key mouse strains. We refined and developed models of seizure‐induced neuronal death in the C57BL/6 and BALB/c strains by focally evoking seizures using intra‐amygdala kainic acid. Seizures in adult male BALB/c mice, or C57BL/6 mice as reference, caused ipsilateral death of CA1 and CA3 neurons within the hippocampus. Termination of seizures by lorazepam was more effective than diazepam in both strains, largely restricting neuronal loss to the CA3 sector. Electroencephalography (EEG) recordings defined injurious and non‐injurious seizure patterns, which could not be separated adequately by behavioral observation alone. Degenerating neurons in the hippocampus were positive for DNA fragmentation and approximately a third of these exhibited morphologic features of programmed cell death. Western blot analysis revealed the cleavage of caspase‐8 after seizures in both strains. These data refine our C57BL/6 model and establish a companion model of focally evoked limbic seizures in the BALB/c mouse that provides further evidence for activation of programmed cell death after seizures. © 2004 Wiley‐Liss, Inc.
Analysis of key Anglo‐Saxon manuscripts (8–11th centuries) in the British Library: pigment identification by Raman microscopy
Authors: Brown Katherine L. , Clark Robin J. H.
Published: March 2004

Seven important and valuable Anglo‐Saxon manuscripts of the 8–11th centuries and held at the British Library, London, were analysed by Raman microscopy in order to establish and compare their palettes. They are the Vespasian Psalter (Cotton MS Vespasian A1), Harley MS 7653, the Royal Prayer Book (Royal MS 2 A xx), the Royal Bible (Royal MS 1E vi), the Eadui Psalter (Arundel MS 155), the Grimbald Gospels (Add. MS 34890) and the Psychomachia by Prudentius (Cotton Cleopatra C viii). The overall palette of the manuscripts studied includes carbon, indigo, lazurite, orpiment, red lead, red ochre, verdigris, vergaut and white lead. Lazurite appears not to have been used until 920 AD and vermilion until the 12th century. Chalk and gypsum appear occasionally, probably as extenders, with gold and sometimes silver used to illuminate the most expensive manuscripts. Raman microscopy proves to be a very effective technique for the identification of inorganic pigments on manuscripts, and is much more reliable than optical microscopy. Copyright © 2004 John Wiley & Sons, Ltd.
Non‐destructive Raman study of the glazing technique in lustre potteries and faience (9–14th centuries): silver ions, nanoclusters, microstructure and processing
Authors: Colomban Philippe , Truong Catherine
Published: March 2004

The oldest known nanotechnology dates back to the fabrication of the first lustre potteries. A lustre is a thin film formed just below the surface of medieval Islamic glazed potteries which contains silver and/or copper in the metallic and ionic form. Raman studies of the lustre films of different ceramics excavated from Fustât (near Cairo, Egypt, 11–12th century) or from the Silk Road (Termez, 13–14th centuries) showed that they associate many layers of different compositions (with or without cassiterite). Energy‐dispersive spectroscopic analysis shows that all studied glazes are Ca‐ (and K)‐rich, nearly free of Al silicates, with some addition of lead. Comparison is made with a copy of three‐colour Tang ceramics made in Bassorah or Baghdad, in the 9th century, which is among the first known ‘faiences’, i.e. ceramics enamelled with an Sn‐containing glaze. Surprisingly, Sn is not present in the form of a cassiterite (SnO2) precipitate but as a Ca,K‐rich salt. Composition analysis and Raman spectra show that all glazes have been processed with similar technology. The distribution of elemental Ag and Cu is very heterogeneous in the lustre decor. The main Raman signature (50–100 cm−1 peaks) of the lustre film is assigned to Ag+ ions. The additional low‐wavenumber features could be due to the Ag0 [or (Agn)m+] nanocluster modes. It is clear that the lustre colour arises from the combination of iridescence (diffraction) and absorption/diffusion. Raman criteria are proposed for a sample classification as a function of processing (cassiterite content, processing temperature). The glazing technique is discussed on the basis of experimental evidence and ancient potters' reports. Exothermic burning of acetate residus is proposed as the key step for the preparation of polychrome lustre. Copyright © 2004 John Wiley & Sons, Ltd.
Three English manuscripts post‐1066 AD: pigment identification and palette comparisons by Raman microscopy
Authors: Brown Katherine L. , Clark Robin J. H.
Published: March 2004

Three distinguished English manuscripts post‐1066 AD, viz. Add. Ms 42555, the Abingdon Apocalypse, Add. Ms 24686, the Alphonso Psalter, and Harley Ms 7026, the Lovell Lectionary, were analysed by Raman microscopy in order to establish the identities of the pigments used in each case. Palette comparisons were made with those of earlier Anglo‐Saxon manuscripts. The palette of the Abingdon Apocalypse contains carbon, chalk, indigo, lazurite, orpiment, red lead, verdigris, vermilion and white lead. The palette of the Alphonso Psalter is closely similar, one notable difference being that azurite replaces indigo; this identification by Raman microscopy of azurite indicates the earliest established usage of this pigment (ca 1300 AD) on an English manuscript. The palette of the Lovell Lectionary does not include chalk, indigo or red lead, but notably does include lead tin yellow type I in its later parts, which date from ca 1450 AD, indicating the earliest established usage of this pigment on an English manuscript. Copyright © 2004 John Wiley & Sons, Ltd.
Stem cell therapy of the liver— Fusion or fiction?
Authors: Dahlke Marc H. , Popp Felix C. , Larsen Stephen , Schlitt Hans J. , Rasko John E.J.
Published: March 2004

Various stem cell populations have been described in distinct models of liver regeneration. This review provides an overview of these different stem cell populations aimed at unifying diverse views of liver stem cell biology. Embryonic stem cells, hemopoietic stem cells, mesenchymal stem cells, liver-derived hepatic stem cells, bone marrow-derived hepatic stem cells, and mature hepatocytes (as cells with stemlike properties) are considered separately. In so doing, we seek to clarify the nomenclature of putative liver stem cell types. Experiments that address the question of cellular fusion versus transdifferentiation as explanations for observed liver regeneration are highlighted. This review concludes with a series of open questions that should be addressed in the context of clinical liver disease before attempts at human therapeutic interventions. (Liver Transpl 2004;10:471-479.)
Centrilobular necrosis after orthotopic liver transplantation: Association with acute cellular rejection and impact on outcome
Authors: Hassoun Ziad , Shah Vijay , Lohse Christine M. , Pankratz Shane V. , Petrovic Lydia M.
Published: March 2004

Several studies have linked centrilobular necrosis (CN) to acute cellular rejection (ACR) following liver transplantation. However, it may be difficult to establish the diagnosis of ACR when the classic portal features are absent. The aim of the present study was to identify specific features that would help to recognize ACR in biopsies with CN. One hundred and forty liver biopsies with CN were identified from 97 patients who underwent liver transplantation. The following histopathologic features were assessed: CN, steatosis, lobular inflammation, cholestasis, endothelialitis, and fibrosis. CN was graded semiquantitatively. A number of clinical and biochemical parameters were also recorded. Biopsies with CN were assessed for the presence or absence of ACR and divided into two groups accordingly. The associations of the biochemical, pathologic, and clinical features with ACR were assessed using a multivariate logistic regression model. The outcomes of patients with and without rejection were compared using the Cox proportional hazards regression model. Seventy-four biopsies (52.9%) showed evidence of ACR, and 52 patients (53.6%) had evidence of ACR at the first biopsy with CN. The multivariate analysis showed the presence of cholestasis, lobular inflammation, the ALT level, and time since liver transplantation to be independent predictors of the presence of ACR in biopsies with CN. Patients with ACR on their first biopsy with CN were significantly more likely to experience graft loss compared with patients without ACR. In conclusion, the presence of cholestasis and lobular inflammation on biopsies with CN appeared helpful in predicting its association with ACR. (Liver Transpl 2004;10:480-487.)
Ischemic preconditioning and intermittent clamping improve murine hepatic microcirculation and Kupffer cell function after ischemic injury
Authors: Vajdová Katarína , Heinrich Stefan , Tian Yinghua , Graf Rolf , Clavien Pierre-Alain
Published: March 2004

The aim of this study was to evaluate whether the protective effect of intermittent clamping and ischemic preconditioning is related to an improved hepatic microcirculation after ischemia/reperfusion injury. Male C57BL/6 mice were subjected to 75 or 120 min of hepatic ischemia and 1 or 3 hours of reperfusion. The effects of continuous ischemia, intermittent clamping, and ischemic preconditioning before prolonged ischemia on sinusoidal perfusion, leukocyte-endothelial interactions, and Kupffer cell phagocytic activity were analyzed by intravital fluorescence microscopy. Kupffer cell activation was measured by tissue levels of tumor necrosis factor (TNF)-α, and the integrity of sinusoidal endothelial cells and Kupffer cells were evaluated by electron microscopy. Continuous ischemia resulted in decreased sinusoidal perfusion rate and phagocytic activity of Kupffer cell, increased leukocyte-endothelial interactions and TNF-α levels. Both protective strategies improved sinusoidal perfusion, leukocyte-endothelial interactions and phagocytic activity of Kupffer cells after 75-minutes of ischemia, and intermittent clamping also after 120 minutes ischemia. TNF-α release was significantly reduced and sinusoidal wall integrity was preserved by both protective procedures. In conclusion, both strategies are protective against ischemia/reperfusion injury by maintaining hepatic microcirculation and decreasing Kupffer cell activation for clinically relevant ischemic periods, and intermittent clamping appears superior for prolonged ischemia. (Liver Transpl 2004;10:520-528.)
Hepatopulmonary syndrome after living donor liver transplantation and deceased donor liver transplantation: A single-center experience†
Authors: Carey Elizabeth J. , Douglas David D. , Balan Vijayan , Vargas Hugo E. , Byrne Thomas J. , Moss Adyr A. , Mulligan David C.
Published: March 2004

Hepatopulmonary syndrome (HPS) is a progressive, debilitating complication of end-stage liver disease. In contrast to the well-established reversal of HPS after deceased donor liver transplantation (DDLT), little has been written about the natural course of HPS after the newer procedure of living donor liver transplantation (LDLT). We describe HPS in a small series of 4 liver transplant recipients (2 DDLT; 2 LDLT) at a single center. Before transplantation, these 4 patients had a mean shunt fraction of 23.6 ± 14.3% and a mean Pao2 of 58.5 ± 11.3 mm Hg. All 4 patients used supplemental oxygen before transplantation. Sixteen weeks after transplantation, all 4 patients had normalized or improved shunt fraction and Pao2. These patients regained normal pulmonary function within a few months, despite the period of hepatic regeneration after LDLT. In conclusion, both DDLT and LDLT are associated with rapid and dramatic reversal of HPS. (Liver Transpl 2004;10:529-533.)
Refinement of venous reconstruction using cryopreserved veins in right liver grafts
Authors: Sugawara Yasuhiko , Makuuchi Masatoshi , Akamatsu Nobuhisa , Kishi Yoji , Niiya Takashi , Kaneko Junichi , Imamura Hiroshi , Kokudo Norihiro
Published: March 2004

Short and direct vein anastomosis is generally performed in living donor liver transplantation using a right liver graft. The graft will regenerate, however, and might thus compress the anastomosis. We formulated a strategy for outflow reconstruction in right liver graft. When reconstruction of multiple short hepatic veins was necessary, a cryopreserved inferior vena cava graft was anastomosed with the hepatic veins of the graft in a basin. When there were no major short hepatic veins in the graft, a rectangular-shaped vein graft was used to make a single orifice using the middle and right hepatic veins in the graft. When there were no tributaries of the middle hepatic vein to be reconstructed, a diamond-shaped vein patch was anastomosed on the anterior wall of the right hepatic vein orifice of the graft. These techniques were satisfactorily applied in 40 patients with no torsion or tension at the anastomotic site of the hepatic venous reconstruction or other complications in outflow. The present strategy seemed to be technically feasible for outflow reconstruction in a right liver graft. (Liver Transpl 2004;10:541-547.)
Circles of inclusion
Authors: Hesselbein Frances
Published: March 2004

Achieving new levels of engagement, inquiry, performance, and results.
Leading a virtuous‐spiral organization
Authors: Lawler Edward E.
Published: March 2004

Creating an environment where both individuals and the organization achieve more and more of their goals.
How leadership networks strengthen people and organizations
Authors: Giovagnoli Melissa , Stover David R.
Published: March 2004

Leadership networking is rapidly gaining recognition as a critical tool for organizational success.
Pressure effects on the inhomogeneities of environmentally sensitive polymer gels
Authors: Shibayama Mitsuhiro , Takata Shinichi , Nakamoto Chikanobu
Published: March 2004

The effects of pressure at gel preparation on the inhomogeneities were investigated by small‐angle neutron scattering. Poly(N‐isopropylacrylamide) (PNIPA) gels, known as thermosensitive polymer gels undergoing volume transition, were prepared at various pressures ranging from 0.1 to 300 MPa. The scattering intensity increased with increasing Pprep, up to 200 MPa, then decreased by further increase in Pprep. The degree of inhomogeneities evaluated by the ratio of the static and dynamic correlators exhibited a similar behavior to that of the ensemble average light scattered intensity, E. The physical meaning of the gel inhomogeneities is discussed from the viewpoint of swelling thermodynamics. It will be shown that the increase in the swelling degree is due not to an increase in the miscibility of PNIPA with water but to the increase in inhomogeneities.
Unresolved issues in the preparation and characterization of thermoresponsive microgels
Authors: Pelton Robert
Published: March 2004

The preparation and properties of colloidal thermal responsive microgels based on poly(N‐isopropylacrylamide) are described with an emphasis on the unresolved issues which will impair commercial implementation. The main difficulties are: 1) removal of sol, surfactants and other impurities; 2) obtaining colloidally stable particles less than 50 nm in diameter; 3) synthesis of concentrated, colloidally stable microgel dispersions; 4) accurate measurement of water content; and, 5) control of microgel particle morphology.
Thermoreversible gelation strongly coupled to polymer conformational transition
Authors: Tanaka Fumihiko
Published: March 2004

Thermoreversible gelation of polymers driven by the coil‐to‐helix transition in chain conformation is theoretically studied. For pairwise association of single helices, there are three fundamental types of self‐assemblies as a result of competition between helix growth and helix association: Type I network (random coils connected by paired short helices), Type II network (helices connected by short random coils) and pairing (pairs of long helices without branching). Two distinct phase diagrams showing sol/gel transition and coil/helix transition are derived for weak and strong association.
Synthesis, characterization and stimuli‐sensitive properties of novel linear and crosslinked polybetaines based on acrylic acid and ethyl 3‐aminocrotonate
Authors: Kudaibergenov Sarkyt E. , Didukh Alexander G. , Zhumadilova Gulmira T. , Koizhaiganova Raushan B. , Bimendina Larisa A. , Jung‐Gyun Noh , Geckeler Kurt E.
Published: March 2004

Novel linear and crosslinked polybetaines based on acrylic acid (AA) and ethyl 3‐aminocrotonate (CRO) have been synthesized by a Michael addition reaction followed by radical polymerization. The polymerization of AA and CRO was carried out in bulk, water and organic solvents. The dependence of polymer yield on the molar ratio of monomers and water content was found. Primary attention was paid to linear and crosslinked polybetaines synthesized at equimolar ratio of monomers in the feed. The composition and structure of linear polybetaines was determined by elemental analysis, potentiometric titration, FTIR and NMR spectroscopy. The isoelectric points of linear and crosslinked polybetaines determined by electrophoresis, viscometry and swelling experiments corresponded to pH 2.0‐2.2. The stimuli‐sensitive properties of amphoteric gels were studied as a function of pH, ionic strength, water‐organic solvent mixture, electric, and combined electric and magnetic fields. Appearance of pH gradient within the polyampholyte gel matrix under the externally imposed DC electric field was observed.
Superabsorbent polymer of poly[acrylamide‐co‐(acrylic acid)] by foamed polymerization. I. synthesis and water swelling properties
Authors: Kiatkamjornwong Suda , Wongwatthanasatien Rattana
Published: March 2004

Superabsorbent polymers of acrylamide and acrylic acid were synthesized by foamed polymerization, initiated by ammonium persulfate and N, N, N′, N′‐tetramethylenediamine. The crosslinking agent N, N′‐methylenebisacrylamide, the foaming agent sodium bicarbonate, and a foam stabilizer, a triblock copolymer of polyoxyethylene/polyoxypropylene/polyoxyethylene, were used in the polymerization. The superabsorbent polymer synthesized with an acrylamide/(acrylic acid) ratio of 1:9 by mole at 250 rpm and 45°C for 30 min of polymerization time produced the highest water absorption of 2300 times its dried weight. This article describes the synthetic method and measurements of water absorption.
Let it be: Salvage of exposed hemodialysis grafts with fasciocutaneous island flaps
Authors: Isenberg J. Scott
Published: March 2004

Contaminated and exposed prosthetic implants have traditionally required surgical explantation. This has been standard treatment, particularly for implants in the central circulation or those bridging major vascular structures, such as hemodialysis grafts. We present our experience in salvaging exposed hemodialysis grafts utilizing regional fascio‐ and septo‐cutaneous flaps. In 5 of 6 cases, graft salvage was achieved, obviating the need for explantation and de novo insertion at another location. In selected instances of hemodialysis graft exposure, wound coverage and graft function can be obtained with regionally based flaps. © 2004 Wiley‐Liss, Inc.
Wideband and high‐gain triple‐offsets‐fed ring‐slot antenna backed by a ground plane
Authors: Jang Yong‐Woong , Arai Hiroyuki
Published: March 2004

The triple‐offsets‐fed ring‐slot antenna backed by a ground plane with large bandwidth and high gain is presented experimentally in this paper. The return loss, radiation pattern, and antenna gain of this configuration are presented. Although the use of a high relative permittivity (εr = 4.3) substrate usually restricts the operation bandwidth, the radiation resistance has a low value, as well. The measured impedance bandwidth is approximately 94.3% (−10 dB ≥ S11). The measured gain of the proposed antenna backed by a ground plane is better than approximately 6 dBi throughout the bandwidth. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 161–163, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20079
PILOT: A fast algorithm for enhanced 3D parasitic capacitance extraction efficiency
Authors: Gope Dipanjan , Jandhyala Vikram
Published: March 2004

Integral‐equation methodologies applied to extract parasitics for board, package, and on‐chip structures involve solving a dense system of equations. In this paper, we present an improved matrix‐compression technique for fast iterative solution of such dense systems, which applies QR decomposition on multilevel oct‐tree‐based interaction sub‐matrices. The regular‐tree structure of the fast‐multipole method and the rank‐revealing QR‐based matrix‐compression scheme are combined in order to achieve superior time and memory efficiency. As is demonstrated by the numerical‐simulation results presented herein, the new algorithm is found to be faster and more memory efficient than both existing QR‐based methods and FastCap. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 169–173, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20083
Analysis of photonic band‐gap (PBG) structures using the FDTD method
Authors: Tong Ming‐Sze , Cheng Min , Lu Yilong , Chen Yinchao , Krozer Viktor , Vahldieck Rüdiger
Published: March 2004

In this paper, a number of photonic band‐gap (PBG) structures, which are formed by periodic circuit elements printed on transmission‐line circuits, are studied by using a well‐known numerical method, the finite‐difference time‐domain (FDTD) method. The results validate the band‐stop filter behavior of these structures, and the computed results generally match well with ones published in the literature. It is also found that the FDTD method is a robust, versatile, and powerful numerical technique to perform such numerical studies. The proposed PBG filter structures may be applied in microwave and communication systems. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 173–177, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20084
Azimuthally symmetric long‐period fiber gratings fabricated with CO2laser
Authors: Oh S. T. , Han W. T. , Paek U. C. , Chung Y.
Published: March 2004

Two methods for fabrication of azimuthally symmetric long‐period fiber gratings (LPFGs) with CO2laser are presented. These methods are based on symmetric exposure of the laser beam and rotation of the fiber, and the measured polarization‐dependent losses (PDL) are comparable to that of the normal fiber. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 188–190, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20088
A widebeam microstrip antenna for intelligent transport system application
Authors: Yin Ying‐Zeng , Zhao Yong‐Jiu , Liu Qi‐Zhong
Published: March 2004

A wide‐beam and middle‐gain microstrip antenna for the intelligent transport system (ITS) is demonstrated experimentally and numerically. The results show that a −3‐dB beam width of 105°, a middle gain of 10 dBi, and a bandwidth of about 12% for VSWR less than 2:1 are obtained. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 200–202, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20092
A method for the determination of a distributed FET noise model based on matched‐source noise‐figure measurements
Authors: Maya M. C. , Lázaro A. , Pradell L.
Published: March 2004

A new method for the determination of a distributed FET noise model is presented. It is based on the extraction of the intrinsic noise‐correlation matrix of an elemental section of the device from the device's noise figure, measured for only one source‐impedance state at a number of frequency points. Experimental results up to 40 GHz are given. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 221–225, 2004; 2004; Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/mop.20099
Scattering analysis for a circular to rectangular T‐junction
Authors: Hwang Keum C. , Eom Hyo J.
Published: March 2004

The reflection and transmission characteristics of a circular‐to‐rectangular single T‐junction are analyzed. The techniques of Fourier transform and mode matching are used for the analysis. An approximate dominant‐mode solution is derived in a closed form. Computations show that our result is numerically efficient and accurate, and thus will be useful for practical application. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 231–234, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20102
Dielectric response of matter with cubic, circular‐cylindrical, and spherical microstructure
Authors: Sihvola Ari , Venermo Jukka , Ylä‐Oijala Pasi
Published: March 2004

The effect of the microstructure of heterogeneous matter on its macroscopic dielectric properties is studied. The basic polarizable elements are allowed to be either homogeneous spheres (which is the classical Lorenz–Lorentz case), cubes, or circular cylinders. Accurate numerical estimates are given for the polarizability of these shapes as functions of the permittivity, and these are applied to estimate the effective permittivity of mixtures where such scatterers are embedded in a background medium. Physical interpretations are given for the behaviour of the dielectric response of these various inclusions. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 245–248, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20106
Compact hairpin‐shaped duplexer using a BMT substrate with high dielectric constant
Authors: Hyung Kwon Koo , Han Sang‐Min , Nahm Shan , Kim Min Han , Kim Young‐Sik
Published: March 2004

In this paper, a compact planar microwave duplexer on a high‐dielectric substrate is proposed. As Ba(Mg1/3Ta2/3)O3 (BMT) has good dielectric performances with a high‐dielectric constant of εr = 23, it is suitable for application on printed circuit boards for compact‐size circuits. The BMT substrate is fabricated using a tape‐casting process; then, metal patterns are screen‐printed upon it and silver pasted. An open‐loop ring‐type duplexer is designed and implemented on the BMT substrate. A size reduction of about 80% is achieved without any degrading duplexer performances, compared with the same one fabricated on a commercial substrate (εr = 6.15). © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 251–253, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20108
Broadband printed π‐shaped monopole antenna for WLAN operation
Authors: Su Saou‐Wen , Wu Chih‐Hsien , Chen Wen‐Shyang , Wong Kin‐Lu
Published: March 2004

A broadband printed π‐shaped monopole antenna is presented. The antenna is easily achieved by adding two short vertical strips (one is a feeding strip and one is a short‐circuiting strip) to a long horizontal strip, forming into a π shape with a low profile. This antenna can generate a wide bandwidth (about 29%) formed by two separate, but closely spaced, resonant modes. A prototype well suited for covering the 5.2/5.8‐GHz WLAN bands and operating as an internal antenna for a wireless device is demonstrated. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 269–270, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20113
Noise wave modeling of microwave transistors based on neural networks
Authors: Marković Vera , Pronić Olivera , Marinković Zlatica
Published: March 2004

The noise modeling of microwave FETs based on the noise‐wave representation of a transistor‐intrinsic circuit is considered. Frequency‐dependent noise‐wave temperatures are introduced as empirical model parameters and modeled using neural networks. In this way, online optimization in a circuit simulator is shifted to offline training of neural networks. An example of transistor‐noise modeling for one specified component is shown. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 294–297, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20120
Improving the linearity‐efficiency trade‐off in FET power amplifiers using large‐signal IMD sweet spots
Authors: Malaver Emigdio , García José Angel , Tazón Antonio , Mediavilla Angel
Published: March 2004

In this paper, a device‐level bias‐adaptation technique for improving the linearity‐efficiency trade‐off in Class‐B FET power amplifiers is introduced. The proposed approach uses the low‐current large‐signal intermodulation distortion sweet spot that appears below the VGS pinch‐off voltage as the bias point. A detailed characterization of the sweet‐spot evolution shows that a dynamic dual‐bias adjustment could guarantee, under strong input‐power level variations, low in‐band intermodulation distortion while the amplifier remains working around its highest efficiency value. The proposed technique is validated using an IS‐95 QPSK signal. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 327–331, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20132
Differential development of rabbit embryos derived from parthenogenesis and nuclear transfer
Authors: Liu Ji‐Long , Sung Li‐Ying , Du Fuliang , Julian Marina , Jiang Shie , Barber Michele , Xu Jie , Tian X. Cindy , Yang Xiangzhong
Published: March 2004

Parthenogenetic development (PA) is often used as a model to investigate activation protocols for nuclear transfer (NT) embryos. The objective of this study was to compare the development, as well as the dynamics of the nuclear materials and microtubules of PA and NT embryos following similar activation treatment. Our results demonstrate that, during parthenogenesis, activation through either electrical pulses or chemical stimulation alone resulted in low cleavage rates and compromised development. A combination of two sets of electrical pulses and a 2‐h‐exposure to chemical activation medium (5 μg/ml cycloheximide (CHX) and 2 mM 6‐dimethylaminopurine (6‐DMAP) in KSOM+0.1% BSA) could effectively activate rabbit oocytes, and resulted in a 99% (n = 73) cleavage rate with greater than 60% (n = 73) developing to blastocysts at day 4. However, the same activation protocol following NT resulted in only 65–72% of oocytes cleaved (depending on donor cell type), with less than 20% developing to the blastocyst stage. The differences observed between NT and PA embryos subjected to the same activation protocol were also evident in terms of the time required for their development to the blastocyst stage, as well as the cell numbers present in blastocysts at day 6. Furthermore, laser confocal microscopy revealed that pronuclear formation in the NT embryos was delayed by comparison to that in the parthenotes. In conclusion, our study suggests that an effective protocol for parthenogenesis cannot promise a comparable outcome for NT embryos. Mol. Reprod. Dev. 68: 58–64, 2004. © 2004 Wiley‐Liss, Inc.
Incidence of apoptosis in clone embryos and improved development by the treatment of donor somatic cells with putative apoptosis inhibitors
Authors: Park E.S. , Hwang W.S. , Jang G. , Cho J.K. , Kang S.K. , Lee B.C. , Han J.Y. , Lim J.M.
Published: March 2004

This study was conducted to promote in vitro‐development of clone embryos by the treatment of donor somatic cells with hemoglobin (Hb) and/or β‐mercaptoethanol (ME), based on the analysis of apoptosis after somatic cell nuclear transfer (SCNT). Prospective, randomized study was conducted and, in vitro‐matured bovine oocytes and fetal fibroblasts were provided for SCNT. In the first series of experiment, embryo apoptosis after SCNT was monitored by a terminal deoxynucleotidyl transferase‐mediated d‐UTP nick end‐labeling assay. As results, apoptosis occurred more (P < 0.05) frequently after SCNT than after in vitro‐fertilization (IVF) of control treatment. Subsequently, donor somatic cells treated with Hb (1 μg/ml) and/or ME (10 μM) were provided for SCNT. Either Hb or ME greatly reduced apoptosis (0.083 ± 0.006 vs. 0.058–0.068 ± 0.005), while combined treatment did not. ME was more promotive than Hb; significant increases were found in morula compaction (86%), cell numbers of blastocyst (131.3 ± 1.3 cells/blastocyst), and inner cell mass (31.9 ± 0.8 cells/blastocyst) cell, and the ratio of inner cell mass to trophectodermal cell numbers (0.24 ± 0.01). In conclusion, the treatment of donor somatic cells with ME or Hb could reduce apoptosis after SCNT, resulting improved preimplantation development. Mol. Reprod. Dev. 68: 65–71, 2004. © 2004 Wiley‐Liss, Inc.
Differential growth, cell proliferation, and apoptosis of mouse embryo in various culture media and in coculture
Authors: Xu Jia‐Sen , Chan Samuel Ting‐Hon , Lee Will W.M. , Lee Kai‐Fai , Yeung William S.B.
Published: March 2004

Sequential culture and coculture are two methods of improving the development of preimplantation embryos in vitro. Direct comparison of the efficiency of these methods is limited. Proliferation and apoptosis determine the total number of blastomere in preimplantation embryo, which is a sensitive parameter for evaluation of the development of embryo in vitro. In this study, we compared the proliferation and apoptosis of mouse embryo in different culture media, including CZB, KSOM, MTF, G1.2/G2.2 sequential culture media, and in human oviductal cell coculture. Sequential culture using G1.2/G2.2 was superior to KSOM, MTF, and CZB/CZB + G with respect to the formation of 3–4 cell embryos, morula, and blastocyst. G1.2/G2.2 cultured blastocyst had significantly more proliferating blastomeres and higher total cell number per blastocyst than those cultured in KSOM or CZB/CZB + G. Compared to embryos cultured in G1.2/G2.2, embryos cocultured in G1.2/G2.2 hatched more frequently. Cocultured blastocysts also had significantly higher percentage of proliferating cell and lower percentage of apoptotic cell per blastocyst than those cultured in G1.2/G2.2. It was concluded that G1.2/G2.2 facilitated the proliferation of blastomere whilst human oviductal cell coculture suppressed apoptosis in addition to stimulating proliferation of blastomere. Mol. Reprod. Dev. 68: 72–80, 2004. © 2004 Wiley‐Liss, Inc.
Effects of scrotal heating on sperm surface protein PH‐20 expression in sheep
Authors: Fleming Jean S. , Yu Fu , McDonald Robin M. , Meyers Stuart A. , Montgomery Grant W. , Smith John F. , Nicholson Helen D.
Published: March 2004

Sperm surface protein PH‐20 expression was studied during spermatogenesis in pubertal and adult sheep, using molecular and histological methods. The effects of 24 hr of insulation raising scrotal temperatures to 39°C on PH‐20 expression in ejaculated sheep sperm were also determined. A 282 nt cDNA fragment of ovine PH‐20 was identified in total RNA extracts of sheep testes, which exhibited 76% identity at the nucleotide level with the equivalent region of the human sequence. Ovine PH‐20 mRNA and immunoreactivity were identified only in adult ram testis and not in peri‐pubertal ram testis tubules lacking round spermatids, nor in adult sheep brain, pituitary, heart, spleen, lung, liver, kidney, epididymis, or ovary. Ovine PH‐20 protein was distributed predominantly on the postacrosomal membrane and was also present on the anterior membrane of the sperm head in fresh, unheated sheep semen. Scrotal heating caused a significant, transient decrease in the percentage of PH‐20 immunoreactive sperm, but did not change the pattern of PH‐20 staining on the sperm head. The results strongly suggest that ovine PH‐20 is postmeiotically expressed in haploid germ cells in sheep testis and is arrayed on the membrane of the mature ovine spermatozoon. Scrotal heating appears to have few effects on PH‐20 expression and distribution on ejaculated sperm. Mol. Reprod. Dev. 68: 103–114, 2004. © 2004 Wiley‐Liss, Inc.
Nuclear and cytoskeletal alterations of in vitro matured porcine oocytes under hyperthermia
Authors: Ju Jyh‐Cherng , Tseng Jung‐Kai
Published: March 2004

The effects of heat shock (HS) on the nucleus and cytoskeleton of in vitro matured pig oocytes were examined in this study. Porcine cumulus–oocyte complexes (COCs) were aspirated from 3 to 6 mm diameter follicles and subjected to standard in vitro maturation (IVM) procedures for 42 hr. In Experiment 1, IVM‐derived oocytes were then randomly allocated to different HS treatments at 41.5°C for 0 (control, C0h, n = 101), 1 (HS1h, n = 113), 2 (HS2h, n = 104), and 4 hr (HS4h, n = 111), respectively. An additional control group of oocytes was cultured for 4 hr without HS (C4h, n = 93). Immunocytochemical staining was performed using anti‐tubulins and FITC‐conjugated mouse IgG for microtubule (MT) labeling. The chromatin and microfilaments (MFs) were stained using Hoechst 33342 and rhodamine–phalloidin, respectively. In the severe HS (4 hr), the chromosomes of the MII oocytes became an aggregated chromatin structure and separated into groups. The spindle MTs were completely depolymerized or formed MT arrays. The relative fluorescence intensity (RFI) or amount of the MF structures including transzona processes (TZPs), vitelline ring (VR), and pericytoplasmic MF, were changed in various degrees. The reversibility of these alterations in the chromatin and the cytoskeleton depended on the duration of the HS. In general, abnormalities in the chromosomes, spindle MTs and the percentages of oocytes with pericytoplasmic MTs increased with length of HS treatment. The size of the spindle and the RFI of MFs in the HS oocytes were also altered. The significant changes in the nucleus and the cytoskeleton in porcine oocytes after HS may be associated with reduced development under hyperthermia and, perhaps, with the low pregnancy rates in domestic species during hot seasons. Mol. Reprod. Dev. 68: 125–133, 2004. © 2004 Wiley‐Liss, Inc.
Expression of 11 members of the BCL‐2 family of apoptosis regulatory molecules during human preimplantation embryo development and fragmentation
Authors: Metcalfe Anthony D. , Hunter Helen R. , Bloor Debra J. , Lieberman Brian A. , Picton Helen M. , Leese Henry J. , Kimber Susan J. , Brison Daniel R.
Published: March 2004

Apoptosis during preimplantation development has received much interest because of its potential role in eliminating defective cells. Although development in humans is characterised by a high degree of genetic abnormality, little is known of the regulation of apoptosis in embryos. By PolyA PCR we analysed expression of 11 BCL‐2 genes in individual human embryos representative of normal development and in severely fragmented embryos. We demonstrate constitutive expression of BAX in virtually all embryos at all stages of development, and variable expression of BCL2, BCL‐XL, BCL‐W, MCL‐1 BAK, BAD, BOKL, BID, BIK, and BCL‐XS. The frequency of expression of pro‐ and anti‐apoptotic BCL‐2 members was similar throughout development, except at the two‐cell stage where pro‐apoptotic genes predominated. Protein expression was confirmed for BCL‐2, MCL‐1, BCL‐X, BAX, BAD, and activated caspase 3. BCL‐2 protein was associated with mitochondria but expressed inconsistently in the blastocyst inner cell mass. Consistent differences between morphologically intact and fragmented embryos included the expression of BAK in fragmented but not intact four‐cell embryos. Our study addresses the importance of examining single human embryos representative of the viable population for a large number of genes, in order to establish meaningful expression profiles and provide information on overlapping function in a large gene family. Mol. Reprod. Dev. 68: 35–50, 2004. © 2004 Wiley‐Liss, Inc.
“I couldn't think that far”: Infertile women's decision making about multifetal reduction
Authors: Collopy Kate Sullivan
Published: March 2004

In this phenomenological study women's experiences regarding their decisions to undergo or forgo multifetal reduction of their higher‐order multiple pregnancies were explored. Seven women who had conceived higher‐order multiple pregnancies as the result of in vitro fertilization were interviewed. Four participants accepted reduction, whereas three participants declined. Three themes were discerned: (a) the presence of infertility as a barrier to contemplating hyperfertility; (b) multiple‐birth pregnancy as yet another form of loss for infertile women; and (c) the lasting effects of having made the decision. © 2004 Wiley Periodicals, Inc. Res Nurs Health 27:75–86, 2004
Modeling health insurance expansions: Effects of alternate approaches
Authors: Remler Dahlia K. , Zivin Joshua Graff , Glied Sherry A.
Published: March 2004

Estimates of the costs and consequences of many types of public policy proposals play an important role in the
development and adoption of particular policy programs. Estimates of the same, or similar, policies that employ
different modeling approaches can yield widely divergent results. Such divergence often undermines effective
policymaking. These problems are particularly prominent for health insurance expansion programs. Concern focuses on
predictions of the numbers of individuals who will be insured and the costs of the proposals. Several different
simulation‐modeling approaches are used to predict these effects, making the predictions difficult to
compare. This paper categorizes and describes the different approaches used; explains the conceptual and
theoretical relationships between the methods; demonstrates empirically an example of the (quite
restrictive) conditions under which all approaches can yield quantitatively identical predictions; and
empirically demonstrates conditions under which the approaches diverge and the quantitative extent of that
divergence. All modeling approaches implicitly make assumptions about functional form that impose restrictions on
unobservable heterogeneity. Those assumptions can dramatically affect the quantitative predictions made. © 2004
by the Association for Public Policy Analysis and Management.
Identification of human whole saliva protein components using proteomics
Authors: Vitorino Rui , Lobo Maria João C. , Ferrer‐Correira António J. , Dubin Joshua R. , Tomer Kenneth B. , Domingues Pedro M. , Amado Francisco M. L.
Published: March 2004

The determination of salivary biomarkers as a means of monitoring general health and for the early diagnosis of disease is of increasing interest in clinical research. Based on the linkage between salivary proteins and systemic diseases, the aim of this work was the identification of saliva proteins using proteomics. Salivary proteins were separated using two‐dimensional (2‐D) gel electrophoresis over a pH range between 3–10, digested, and then analyzed by matrix assisted laser desorption/ionization‐time of flight (MALDI‐TOF)‐TOF mass spectrometry (MS) and tandem mass spectrometry (MS/MS). Proteins were identified using automated MS and MS/MS data acquisition. The resulting data were searched against a protein database using an internal Mascot search routine. Ninety spots give identifications with high statistical reliability. Of the identified proteins, 11 were separated and identified in saliva for the first time using proteomics tools. Moreover, three proteins that have not been previously identified in saliva, PLUNC, cystatin A, and cystatin B were identified.
Reversible labeling of cysteine‐containing peptides allows their specific chromatographic isolation for non‐gel proteome studies
Authors: Gevaert Kris , Ghesquière Bart , Staes An , Martens Lennart , Van Damme Jozef , Thomas Grégoire R. , Vandekerckhove Joël
Published: March 2004

We report upon a novel procedure to specifically isolate cysteine‐containing peptides from a complex peptide mixture. Cysteines are converted to hydrophobic residues by mixed disulfide formation with Ellman's reagent. Proteins are subsequently digested with trypsin and the generated peptide mixture is a first time fractionated by reverse‐phase high‐performance liquid chromatography. Cysteinyl‐peptides are isolated out of each primary fraction by a reduction step followed by a secondary peptide separation on the same column, performed under identical conditions as for the primary separation. The reducing agent removes the covalently attached group from the cysteine side chain, making cysteine‐peptides more hydrophilic and, thereby, such peptides can be specifically collected during the secondary separation and are finally used to identify their precursor proteins using automated liquid chromatography tandem mass spectrometry. We show that this procedure efficiently isolates cysteine‐peptides, making the sample mixture less complex for further analysis. This method was applied for the analysis of the proteomes of human platelets and enriched human plasma. In both proteomes, a significant number of low abundance proteins were identified next to extremely abundant ones. A dynamic range for protein identification spanning 4–5 orders of magnitude is demonstrated.