bluuebunny/crossref_metadata_2025 huggingface dataset:
Transformation of donor‐derived bone marrow precursors into host microglia during autoimmune CNS inflammation and during the retrograde response to axotomy
Authors: Flügel Alexander , Bradl Monika , Kreutzberg Georg W. , Graeber Manuel B.
Published: August 2002

Macrophages in the brain can have a triple source. They may originate from recently blood‐derived precursors, from the largely resident perivascular cell population (perivascular macrophages and related cells), and from intrinsic parenchymal as well as perivascular microglia. Although continuous exchange of part of the perivascular cell population with bone marrow‐derived precursors is now accepted, the turnover of adult parenchymal microglia has remained enigmatic. Using bone‐marrow chimeras carrying an unexpressed marker gene and carbon labeling of peripheral monocyte/macrophages in a combined model of facial nerve axotomy and transfer experimental autoimmune encephalitis, we demonstrate for the first time that there is an easy to induce exchange between parenchymal central nervous system (CNS) microglia and the macrophage precursor cell pool of the bone marrow. Furthermore, very low level infiltration of the CNS parenchyma by recently bone marrow‐derived microglia could be observed after simple peripheral nerve axotomy that is followed by neuronal regeneration. Thus, microglial cells can be considered wanderers between the peripheral immune system and the CNS where they may act as a “Trojan horse” in infections. The fact that recently bone marrow‐derived parenchymal microglia fully integrate into a regenerating brain nucleus' architecture encourages entirely new approaches for delivering genes into the adult CNS. J. Neurosci. Res. 66:74–82, 2001. © 2001 Wiley‐Liss, Inc.
Neurotoxicant‐induced elevation of adrenomedullin expression in hippocampus and glia cultures
Authors: Jahnke G.D. , Brunssen S. , Maier W.E. , Harry G.J.
Published: August 2002

Adrenomedullin (AM), a vasoactive peptide first isolated from pheochromocytoma, has been reported to be present in neurons in the central nervous system and in tumors of neural and glial origin. In this study, we investigated AM expression both in the hippocampus and in glial cell cultures using a chemical‐induced model of injury. An acute intraperitoneal injection of the organometal trimethyltin (TMT) results in neurodegeneration of the hippocampal CA3–4 pyramidal cell layer. Within 4 days of injection, sparse, punctate staining for AM and lectin was evident in the CA3–4 region; by 10 days, a minimal level of CA3–4 neuronal degeneration was evident, with an increase in glial fibrillary acidic protein (GFAP)‐positive astrocytes throughout the hippocampus. Degeneration progressed in severity until 30 days post‐TMT, with distinct positive immunoreactivity for AM in the CA4 region. mRNA levels for tumor necrosis factor (TNF)‐α, interleukin (IL)‐1α, GFAP, and AM in the hippocampus were increased over control levels within 4 days following TMT. In cultured glial cells, a 6 hr exposure to TMT (10 μM) produced a morphological response of the cells and increased immunoreactivity for vimentin, GFAP, and AM. mRNA levels for TNFα, IL‐1α, GFAP, vimentin, and AM were elevated within 3–6 hr of exposure. In culture, neutralizing antibodies to IL‐1α and TNFα were effective in inhibiting the TMT‐induced elevation of AM mRNA. These data suggest an interaction between the proinflammatory cytokines and glia response in the regulation of AM in response to injury. J. Neurosci. Res. 66:464–474, 2001. Published 2001 Wiley‐Liss, Inc.
Disaggregating climatic trends by classification of circulation patterns
Authors: Huth Radan
Published: August 2002

The trends in occurrence frequencies of circulation types over Europe and in nine climate variables in the Czech Republic conditioned by the types are examined for period 1949–1980. The circulation types are determined by an objective procedure from daily 500 hPa heights. Both in summer and winter, anticyclonic types have become more frequent at the expense of cyclonic types. The circulation changes are shown to be unrelated to the trends in surface climate elements in summer, whereas in winter, trends in circulation explain a part of the observed warming and strengthening of southerly winds.

The trends in climate elements are not uniform among circulation types. In summer, the trend pattern consisting of decreasing maximum and daily mean temperatures, daily temperature range (DTR) and sunshine duration, and increasing cloudiness and relative humidity is observed under the cyclonic types and the types with a well‐pronounced jet, but is missing under types with a blocking anticyclone over Europe. Two possible mechanisms causing this trend pattern are proposed: increasing cloudiness, and a process responsible for the reduction of sunshine without a concurrent increase of cloudiness. The latter mechanism can possibly be identified with increasing aerosol concentrations. In winter, the degree of warming is governed by changes in zonal wind. The mechanism of change in DTR seems to vary with elevation: at the lowland station (Prague‐Klementinum), the increase in DTR is related to the warming trend, and consequently with zonal wind changes, while at the mountain station (Milešovka), the increase in DTR reflects the increase in precipitating clouds.

The changes in DTR are related much more to mid‐tropospheric circulation than to cloud cover in summer, whereas in winter, cloud cover plays a more important role in affecting DTR trends. Copyright © 2001 Royal Meteorological Society
A space–time model for seasonal hurricane prediction
Authors: Jagger Thomas H. , Niu Xufeng , Elsner James B.
Published: August 2002

A space–time count process model is explained and applied to annual North Atlantic hurricane activity. The model uses the best‐track data set of historical hurricane positions and intensities, together with climate variables, to determine local space–time coefficients of a right‐truncated Poisson process. The truncated Poisson space–time autoregressive (TPSTAR) model is motivated by first examining a time‐series model for the entire domain. Then a Poisson generalized linear model is considered that uses grid boxes within the domain and adds offset factors for latitude and longitude. A natural extension is then made that includes instantaneous local and autoregressive coupling between the grids. A final version of the model is found by backward selection of the predictors based on values of Bayesian and Akiake information criteria. The final model has five nearest neighbours and statistically significant couplings. Hindcasts are performed on the hurricane seasons from 1994 to 1997. Results show that, on average, model forecast probabilities are larger in regions in which hurricanes occurred. Quantitative skill assessment indicates some useful skill above climatology—currently the default leading candidate. The TPSTAR model could be a valuable guidance product when issuing seasonal hurricane forecasts. Copyright © 2002 Royal Meteorological Society.
Polarized resonance Raman dispersion spectroscopy on metalporphyrins
Authors: SCHWEITZER-STENNER REINHARD
Published: August 2002

Resonance Raman spectroscopy is an ideal tool to investigate the structural properties of chromophores embedded in complex (biological) environments. This holds particularly for metalporphyrins which serve as prosthetic group in various proteins. Resonance Raman dispersion spectroscopy involves the measurement of resonance excitation and depolarization ratios of a large number of Raman lines at various excitation energies covering the spectral region of the chromophore's optical absorption bands. Thus, one obtains resonance excitation profiles and the depolarization ratio dispersion of these bands. While the former contains information about the structure of excited electronic states involved in the Raman scattering process, the latter reflects asymmetric perturbations which lower the porphyrin macrocycle symmetry from ideal D4h. The article introduces and compares different quantum mechanical approaches designed to quantitatively analyze both resonance excitation and the relationship between symmetry lowering and depolarization ratio dispersion.
Probing the reactivity of the radiation sensitizer motexafin gadolinium (Xcytrin®) and a series of lanthanide(III) analogues in the presence of both hydroxyl radicals and aqueous electrons
Authors: SESSLER JONATHAN L. , TVERMOES NICOLAI A. , GULDI DIRK M. , MODY TARAK D.
Published: August 2002

The competition of the radiation sensitizer motexafin gadolinium (Xcytrin®, gadolinium(III) texaphyrin) and several other water-soluble metallotexaphyrin complexes with N,N,N',N'-tetramethyl-p-phenylenediamine (TMPD) for solvated electrons and hydroxyl radicals was studied using pulse radiolysis and by steady-state γ-radiolysis. It was found that the one-electron reduced forms ( M - Tex ·+) of the Gd(III) , Eu(III) , Dy(III) , Yb(III) , and Cd(II) texaphyrin complexes, after an initial reaction with hydrated electrons, do not compete with TMPD for hydroxyl radicals formed under pulse radiolytic conditions. By contrast, the reduced Y(III) , In(III) , Tm(III) , and Lu(III) texaphyrin complexes do. These differences in competitive reactivity toward . OH are rationalized in terms of the relative rates of protonation of the various singly reduced texaphyrins. In the case of Gd - Tex 2+ in particular, the one-electron reduced product, Gd - Tex ·+, protonates rapidly, producing a redox-inactive species that does not react appreciably with . OH . By contrast, the one-electron reduced product from, e.g., Lu - Tex 2+ (motexafin lutetium), does. These results may explain, at least in part, why the Gd(III) texaphyrin functions as a radiation sensitizer in vivo, while the analogous Lu(III) complex does not.
Attitudes in the Danish tourism industry to the roles of business and government in sustainable tourism
Authors: Bramwell Bill , Alletorp Lone
Published: August 2002

The introduction of more sustainable forms of tourism in a country is likely to be the result of a combination of government regulations and other interventions and businesses making their own decisions in response to the market. This paper examines attitudes among senior managers in the Danish tourism industry to where prime responsibility lies for promoting sustainable tourism practices. The opinions of these senior industry managers are also reported on incentives and obstacles to the adoption of sustainable tourism practices, on external assistance that may encourage the introduction of these practices, and whether there should be more government regulations to encourage their adoption. Industry attitudes in Denmark to these issues are of particular interest because of the relative prominence of environmental issues in the country. Copyright © 2001 John Wiley & Sons, Ltd.
Soil chemical quality changes and implications for fertilizer management after 11 years of no‐tillage wheat production systems in semiarid Morocco
Authors: Mrabet R. , Ibno‐Namr K. , Bessam F. , Saber N.
Published: August 2002

A long‐term experiment comparing no‐till with conventional tillage systems across five rotations was evaluated 11 years after initiation. The objectives of the present paper are (1) to report differences in soil chemical properties (namely soil organic matter, total nitrogen, phosphorus, potassium and pH) that have resulted by converting from conventional to no‐till under contrasting cropping systems and (2) to draw tentative conclusions and recommendations on fertility status and fertilizer use and management. Soil in the no‐till system had increased surface soil organic C levels relative to conventional tillage regardless of rotation. In addition, depending on the rotation, the N and P content of the soil improved with no‐till compared with conventional tillage. In other words, no‐till has helped to retain soil organic matter (SOM), conserved more N, and resulted in increased extractable P and exchangeable K concentrations in the upper root‐zone. Hence, wheat produced in a no‐till system may receive more nutrients from decomposition of SOM and acidification of the seed zone. It is possible that lesser amounts of fertilizer nutrients will be needed because of the greater efficiency of nutrient cycling in no‐till systems relative to conventional systems. Copyright © 2001 John Wiley & Sons, Ltd.
Low‐power helium: Neon laser irradiation enhances production of vascular endothelial growth factor and promotes growth of endothelial cells in vitro
Authors: Kipshidze Nicholas , Nikolaychik Victor , Keelan Michael H. , Shankar Latha Raja , Khanna Ashwani , Kornowski Ran , Leon Martin , Moses Jeffrey
Published: August 2002

Background and Objective

Numerous reports suggest that low‐power laser irradiation (LPLI) is capable of affecting cellular processes in the absence of significant thermal effect. The objective of the present study was to determine the effect of LPLI on secretion of vascular endothelial growth factor (VEGF) and proliferation of human endothelial cells (EC) in vitro.

Study Design/Materials and Methods

Cell cultures were irradiated with single different doses of LPLI (Laser irradiance from 0.10 to 6.3 J/cm2) by using a He:Ne continuous wave laser (632 nm). VEGF secretion by smooth muscle cells (SMC) and fibroblasts was quantified by sandwich enzyme immunoassay technique. The endothelial cell proliferation was measured by Alamar Blue assay. VEGF and transforming growth factor beta (TGF‐β) expression by cardiomyocytes was studied by reverse transcription‐polymerase chain reaction (RT‐PCR).

Results

We observed that (1) LPLI of vascular and cardiac cells results in a statistically significant increase of VEGF secretion in culture (1.6‐fold for SMC and fibroblasts and 7‐fold for cardiomyocytes) and is dose dependent (maximal effect was observed with LPLI irradiance of 0.5 J/cm2 for SMC, 2.1 J/cm2 for fibroblasts and 1.05 J/cm2 for cardiomyocytes). (2) Significant stimulation of endothelial cell growth was obtained with LPLI‐treated conditioned medium of SMC (maximal increase was observed with LPLI conditioned medium with irradiance of 1.05 J/cm2 for SMC and 2.1 J/cm2 for fibroblasts.

Conclusions

Our studies demonstrate that low‐power laser irradiation increases production of VEGF by SMC, fibroblasts, and cardiac myocytes and stimulates EC growth in culture. These data may have significant importance leading to the establishment of new methods for endoluminal postangioplasty vascular repair and myocardial photoangiogenesis. Lasers Surg. Med. 28:355–364, 2001. © 2001 Wiley‐Liss, Inc.
Risk reduction and real estate portfolio size
Authors: Byrne Peter J. , Lee Stephen
Published: August 2002

There is remarkably little empirical evidence of the advantages of increased size on risk levels in real estate portfolios based on actual portfolios. This paper improves this by examining the portfolio risk of a large sample of actual real estate data in the UK over the period from 1981 to 1996. The results show that real estate portfolios of larger sizes tend, on average, to have lower risks than smaller sized portfolios and, more importantly, that portfolios with only a few assets can have very high or very low risk. For fund managers to be confident that their portfolio will have a risk level like the average, they need to hold portfolios of a considerably greater size than they might expect, or can sensibly acquire. Previous studies suggesting that only 20–40 properties are needed to reduce the risk of a property portfolio down to the market level are a significant underestimate. The actual figure is likely to be 400–500 properties, well above that of even the largest fund in the UK. Size alone does not necessarily lead to a reduction in portfolio risk. Other factors are of greater importance. Copyright © 2001 John Wiley & Sons, Ltd.
Latent demand and the browsing shopper
Authors: Earl Peter E , Potts Jason
Published: August 2002

This article explores ways of making sense of unplanned purchases on shopping expeditions without seeing shopping as lacking any systematic foundations or reflecting some kind of pathology. The analysis employs both introspection and inputs from cognitive science and focuses on shifts from planned search to browsing in response to promotional cues encountered whilst navigating malls that are designed to promote browsing behaviour. Browsing is examined both in terms of its socio‐psychological foundations and with respect to a variety of kinds of latent demand. The economic psychology of attention is examined as are a variety of factors that bring browsing processes to a close. The paper concludes with a discussion of the significance of the analysis in terms of the path dependence of economic systems. Copyright © 2000 John Wiley & Sons, Ltd.
The political economy of gambling regulation
Authors: Sauer Raymond D.
Published: August 2002

This paper presents an interest group model of gambling regulation and applies it to major changes in the regulation of US gambling markets. Gambling markets are among the most restricted and politicized markets in the American economy, yet economists interested in the economics of regulation have paid them little attention. Applying the economic theory of regulation to gambling markets can lead to greater understanding of current public policy. In addition, this application may shed light on the discipline itself, as to its ability to explain recurrent fluctuations in the extent of regulatory intervention over long periods of time. Broadly speaking, the interest group model is consistent with changes in the extent of regulation, including the recent period of liberalization and consequent growth in gambling. Copyright © 2001 John Wiley & Sons, Ltd.
Latah in Jakarta, Indonesia
Authors: Tanner Caroline M. , Chamberland Jerry
Published: August 2002

OBJECTIVE:

To investigate the characteristics of latah in modern Indonesia; to determine whether contemporary latah resembles the syndrome described in the nineteenth century; to compare the syndrome of latah to other disorders featuring tics or exaggerated startle responses.

BACKGROUND:

Latah, described centuries ago in Malay people, is characterized by an exaggerated motor startle response, often with associated involuntary vocalizations, echolalia, echopraxia, and forced obedience. Modern latah has not been systematically studied.

DESIGN AND METHODS:

Persons with latah living in Jakarta, Indonesia, were investigated using a standardized, videotaped protocol.

RESULTS:

Fifteen women were studied. All had exaggerated startle to touch, and 10 to frightening words. Echolalia was seen in 10, echopraxia in 11, and forced obedience in 13. The startle response did not habituate, but instead worsened in response to repeated stimuli. Startle and associated symptoms were only partially suppressible in fewer than half.

CONCLUSION:

Modern latah resembles that described over a century ago. Latah resembles other disorders with exaggerated startle response, but is clinically distinct from Tourette's Syndrome. © 2001 Movement Disorder Society.
Co‐Occurrence of infantile epileptic seizures and childhood paroxysmal choreoathetosis in one family: Clinical, EEG, and SPECT characterization of episodic events
Authors: Thiriaux Anne , de St Martin Anne , Vercueil Laurent , Battaglia Fabrice , Armspach Jean‐Paul , Hirsch Edouard , Marescaux Christian , Namer Izzie J.
Published: August 2002

The co‐occurrence of infantile convulsions and childhood paroxysmal choreoathetosis (ICCA syndrome) has recently been reported in several families. The pattern of familial clustering observed is consistent with a single locus mutation which has been mapped onto the pericentromeric region of chromosome 16. We studied the main clinical, electroencephalogram (EEG), and single photon emission computed tomography (SPECT) characteristics of episodic events in a new family presenting clinical features similar to that described in the ICCA syndrome. In the first year of life, a mother and her two daughters suffered from rare afebrile seizures lasting from 30 seconds to 15 minutes. Ictal EEG recording in one daughter at 7 months of age showed bilateral polyspikes with a posterior predominance. In the three patients, epileptic seizures regressed within a few weeks, and never reoccurred. At the age of 7 and 12 years, respectively, the two daughters presented daily brief (20 seconds to 1 minute) involuntary choreoathetotic episodes. In 10 of these attacks, EEG did not show any epileptiform abnormalities. In both sisters, an ictal SPECT was performed during a choreoathetotic episode. Subtracting the ictal SPECT from the interictal SPECT coregistered to magnetic resonance imaging (MRI) revealed significant modifications in the local cerebral perfusion in the sensorimotor cortex, the supplementary motor areas, and pallidum. Carbamazepine completely suppressed paroxysmal dyskinesias. These observations, together with literature data, suggest that in this syndrome, depending on brain maturation, the same genetic abnormality may result in different paroxysmal neurological symptoms. © 2001 Movement Disorder Society.
Irresistible onset of sleep during acute levodopa challenge in a patient with multiple system atrophy (MSA): Placebo‐controlled, polysomnographic case report
Authors: Högl Birgit , Seppi Klaus , Brandauer Elisabeth , Wenning Gregor , Poewe Werner
Published: August 2002

A 67‐year‐old male patient with clinically probable multiple system atrophy developed severe reproducible sleepiness and irresistible onset of sleep during an acute levodopa (L‐dopa) challenge. In a placebo‐controlled, double‐blind study of acuteL‐dopa challenge, videopolysomnography revealed multiple episodes of non‐rapid eye movement sleep 60 minutes afterL‐dopa and none following placebo. These observations suggest the irresistible sleep can also be induced byL‐dopa and also in patients with atypical parkinsonism. © 2001 Movement Disorder Society.
Recent strategies in the development of new human cytomegalovirus inhibitors
Authors: Martinez Ana , Castro Ana , Gil Carmen , Perez Concepcion
Published: August 2002

Human cytomegalovirus (HCMV) is one of the most common opportunistic infections in immunucompromised individuals, such as AIDS patients and organ transplant recipients, and is the most frequent congenital viral infection in humans. Despite a reduction of the incidence of AIDS‐related opportunistic infections in patients under highly active antiretroviral treatment, attention should be paid to the HCMV risk factor in these individuals. Furthermore, HCMV may have an important role in atherosclerosis. Existing antiviral treatments for the HCMV infection suffer from poor bioavailability, toxicity, and limited effectiveness, mainly due to the development of drug resistance. Fortunately there are novel and potentially very effective new compounds undergoing pre‐clinical and clinical evaluation. This review provides an overview in the last five years of new HCMV inhibitors (chemical structures, SAR, and new mechanisms of action) with the aim to provide new clues for the development of future drugs against this opportunistic virus. © 2001 John Wiley & Sons, Inc. Med Res Rev, 21, No. 3, 227–244, 2001
Economic impact of a specialist outreach team in residential and nursing home settings
Authors: Richardson Gerald , Davies Linda , South Belinda , Proctor Rebekah , Burns Prof Alistair , Powell Hilary Stratton , Tarrier Prof Nicholas , Faragher Brian
Published: August 2002

Background: The results of a randomized controlled trial have indicated that a training and educational programme for staff in nursing or residential homes may result in reductions in levels of depression and levels of cognitive impairment for residents presenting with an active management problem. The training and educational intervention consisted of members of a hospital outreach team who presented a series of 1 hour seminars on topics which staff had indicated would improve their knowledge and skills.

Aims of the study: The aim of this study was to present an exploratory analysis of the impact on costs associated with providing an old age psychiatry outreach team giving training and education for staff in nursing and residential homes.

Method: For the economic study, a societal perspective was employed. Measures of resource use and costs to the health service, social and community services and the nursing and residential homes were analysed for 120 residents from 12 nursing or residential homes, as part of a randomized controlled trial to assess a training package provided in residential and nursing homes. Cost estimates were based on estimates from generalized estimated equations. To allow for clustering effects within homes, the unit of randomization was the home as opposed to the individual. To ensure models were correctly specified, several tests including the Ramsey RESET test were employed.

Results: There were no significant differences in the total cost per person in the homes that received the intervention and the control homes. This study has shown that the additional cost of providing the specialist outreach team was likely to be covered by reductions in the use of other resources such as GP visits to nursing and residential homes. Therefore, though the study had limitations, it appeared that improved care could be provided at little or no extra cost.

Implications for Health Care Provision and Use: The evidence presented suggests that the specialist outreach team was unlikely to add to the total cost of caring for residents in nursing and residential homes. This finding combined with the benefits in terms of lower levels of depression and cognitive impairment suggested that the intervention was good value for money. The intervention should be considered for use in other nursing and residential homes. © 2000 John Wiley & Sons, Ltd.
Surgery for ischemic pain and Raynaud's' phenomenon in scleroderma: A description of treatment protocol and evaluation of results
Authors: Tomaino Matthew M. , Goitz Robert J. , Medsger Thomas A.
Published: August 2002

Although the literature suggests that palmar sympathectomy (PS) with or without vascular reconstruction may improve ischemic digital pain, fingertip ulceration, and cold intolerance in patients with scleroderma, the question regarding long‐term efficacy still remains. This retrospective study of six patients (eight hands) operated on between 1995 and 1997 evaluates both early (6 months) and long‐term (average, 2.5 years) outcome after PS in combination with decompression arteriolysis of the radial and ulnar arteries proximal to the wrist. When preoperative digital blood flow was inadequate based on noninvasive vascular studies and major inflow occlusion was present, vascular reconstruction was also performed when feasible. At early review, significant improvement in ischemic digital pain and moderate improvement in cold intolerance resulted in eight hands, and at final follow‐up, this was sustained in seven hands. Preoperatively, digital ulcerations were present in six hands. After digital debridement and/or amputation, all wounds healed, but in one patient with bilateral disease who continued to smoke, ulcerations recurred without the need for subsequent surgery. Five of six patients were no longer dependent on narcotic analgesics, but use of vasodilator medication did not change. Five of six patients claimed significant improvement in the quality of life after surgery and reported that they would undergo the surgery again. PS in combination with radial and ulnar arteriolysis appears to be efficacious at both early and long‐term review. When major inflow occlusion exists and digital blood flow is compromised, vascular reconstruction is recommended if possible. We review our treatment protocol in this complex population of patients. © 2001 Wiley‐Liss, Inc. Microsurgery 21:75–79 2001
An osteomyocutaneous transplantation model on the rat
Authors: Liao Tai‐Ching , Yeh Lih‐Seng , Chu Rea‐Min , Hou Sheng‐Mou
Published: August 2002

To replace the complex and time‐consuming procedure of limb transplantation, we developed a new osteomyocutaneous model that excluded the function but retained all the tissue components of the limb. Ten vascularized grafts from five donor hindlimbs were contralaterally transplanted to 10 syngeneic recipients' inguinal region. The graft of this model is composed of complete tibia and fibula and partial muscle and skin of the crus. The operative time was 145.3 ± 9.1 minutes with the harvesting time of 49.7 ± 5.8 minutes and the warm ischemia time of 65.4 ± 6.0 minutes. The transplantation procedure of this model takes significantly less time and is less stressful to the animals than the previous whole limb transplantation model. This model is suitable for the studies of limb or composite tissue transplantation if functional recovery is not the main concern. © 2001 Wiley‐Liss, Inc. MICROSURGERY 21:329–332 2001
Junctions of waveguides with capacitance gap
Authors: Komarov Vyacheslav V.
Published: August 2002

The finite‐difference time‐domain method and approximate analytical algorithm are applied for the analysis of junctions of a rectangular T‐septum waveguide and microwave devices on a single‐ridge waveguide. Both approaches demonstrate good agreement at ISM frequencies of 915 MHz and 2.45 GHz when simple junctions of two waveguides with different cross sections are analyzed. Junctions of various waveguides with a capacitance gap may be successfully employed for the design of transitions between such structures and conventional transmission lines. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 31: 368–371, 2001.
A broadband microstrip antenna array for LMDS applications
Authors: Oh Soonsoo , Seo Seongho , Yoon Mikyoung , Oh Changyoul , Kim Eungbae , Kim Youngsik
Published: August 2002

In this paper, a broadband 20×20 microstrip antenna array is presented. Once a rectangular microstrip patch antenna with parasitic patches as an element antenna has been optimized at 24.2–26.7 GHz, a parallel‐series feed network with minimum feed lengths can be utilized to combine element antennas. From simulation and measurement, the array antenna yields relatively high gains of 26.0–30 dB and narrow 3 dB beamwidths of 4.5–5.1° in theH‐plane and 4.1–7.1° in theE‐plane, respectively, in an LMDS band. © 2002 John Wiley & Sons, Inc. Microwave Opt Technol Lett 32: 35–37, 2002.
Investigation of ground bounce effect on PCBs
Authors: Fung L. C. , Leung S. W. , Wan Lixi , Siu Y. M. , Chan K. H.
Published: August 2002

In this paper, a “local wave” concept using the generalized 2‐D transmission‐line equation (GTLE) to model the ground bounce (GB) effect in PCBs is described. The model is then used to characterize the GB effect in PCBs for both the power/ground and the trace/ground configuration. Simulation results for both configurations are presented. © 2002 John Wiley & Sons, Inc. Microwave Opt Technol Lett 32: 259–264, 2002.
A dual‐band planar inverted‐F patch antenna with a branch‐line slit
Authors: Hsiao Fu‐Ren , Chen Hong‐Twu , Chiou Tzung‐Wern , Lee Gwo‐Yun , Wong Kin‐Lu
Published: August 2002

By embedding a branch‐line slit in the radiating patch of a planar inverted‐F patch antenna, novel 900 and 1800 MHz dual‐band operation is obtained. The embedded branch‐line slit has two branch slits (one long folded slit and one short bent slit) protruding from the main slit which has an open end at the patch boundary. The main slit and the long folded branch slit together strongly meander the excited patch surface currents starting from the feed to the portion of the patch encircled by the folded branch slit, which leads to a significant reduction in the required dimensions for the proposed antenna. In addition, the two operating frequencies have wavelengths corresponding to about 4.0 and 2.0 times the length of the above‐mentioned meandered patch surface current path. The short bent branch slit, on the other hand, mainly serves as a tuning slit for achieving good impedance matching of the two operating frequencies. The proposed antenna and experimental results are described in detail in this paper. © 2002 John Wiley & Sons, Inc. Microwave Opt Technol Lett 32: 310–312, 2002.
Dual‐band multilayer ceramic microwave bandpass filter for applications in wireless communication
Authors: Huang Cheng‐Liang , Pan Chung‐Lone
Published: August 2002

A dielectric multilayer dual‐band filter is realized by using a stepped‐impedance resonator (SIR). The input/output ports of the filter are formed with transmission lines directly tapped to the resonators. The admittance matrix for the equivalent circuit of the filter has been derived and transformed to the scattering matrix to initially determine the required spec. Losses and other EM effects are taken into account to further modify the actual dimension of the designed filter. The designed structures are simulated using an IE3D simulator. The response of the fabricated filter is measured using an HP8757D network analyzer. Sample results of the filter performances demonstrate responses, in good agreement with the computer simulations. © 2002 John Wiley & Sons, Inc. Microwave Opt Technol Lett 32: 327–329, 2002.
A single‐feed TM21‐mode circular patch antenna with circular polarization
Authors: Du Biao , Yung Edward Kai‐Ning
Published: August 2002

A single‐feed TM21‐mode circular patch antenna with circular polarization (CP) is proposed and investigated. The operating condition for CP in the antenna is theoretically determined and experimentally validated. An impedance bandwidth of 10% (SWR ≤ 2) and an axial ratio bandwidth of >2% (≤3 dB) have been obtained. The radiation patterns are stable over the operating band. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 33: 154–156, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10262
AM–PM conversion introduced by MESFET and HBT
Authors: Jardón‐Aguilar H. , Aguilar‐Torrentera J.
Published: August 2002

The AM–PM conversion introduced by microwave transistors was researched using the approach of the AM–PM conversion as a phase statement of compression and desensitization. As proven in this article, the presented approach permits developing high linear amplifiers optimizing their AM–PM conversion instead of optimizing the intermodulation distortion, as it is usually accomplished. The effect of frequencies and amplitudes of input signals, load resistance, and bias condition on the AM–PM conversion introduced by MESFET and HBT amplifiers are reported. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 33: 319–321, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10307
A compact Ku‐band monopulse horn
Authors: Zhang H. Z. , Granet C. , Sprey M. A.
Published: August 2002

The design, manufacture, and testing of a compact Ku‐band monopulse horn is described, with an emphasis on an effort to maximize the return loss of the sum, azimuth, and elevation channels. The results show that the multimode monopulse horn has the required radiation patterns and acceptable return loss for its narrowband operation requirement. The bandwidth is found to be limited by the difficulty of matching the three channels simultaneously. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 34: 9–13, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10357
Experimental comparison of DSF‐ and SOA‐based optical phase conjugator performance in ASE‐limited microwave optical links
Authors: Ramos Francisco , Marti Javier
Published: August 2002

Optical phase conjugators (OPCs) based on either a dispersion‐shifted fiber (DSF) or a semiconductor optical amplifier (SOA) have been experimentally compared in terms of electrical carrier‐to‐noise ratios and conversion losses in microwave optical links. The experimental results show that the SOA‐based OPC enables using more efficient electrical modulation formats than the DSF‐based OPC due to less influence of the ASE noise. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 29: 31–33, 2001.
Experimental investigation of a sampled grating with a chirp in the sampling period
Authors: Chen Xiang‐Fei , Li Xu‐Hui , Xia Li , Xie Shi‐Zhong , Fan Chong‐Cheng , Wang Jian‐Ping
Published: August 2002

In this letter, a sampled Bragg grating (SBG) with a chirp in the sampling period (CSP) is fabricated and experimentally investigated for the first time. Its spectrum response shows that the effective chirp in the grating period (CGP) varies among stopbands, which is consistent with the previous theoretical predictions. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 29: 128–130, 2001.
Wideband and noncontact characterization of the complex permittivity of liquids
Authors: Jose K. A. , Varadan V. K. , Varadan V. V.
Published: August 2002

The noncontact evaluation and characterization of liquids, especially chemically active reagents, is a problem for many industries, and currently there is no method available to characterize such liquid samples. In this paper, we present the results of the noncontact measurement and characterization of liquids and powders using a free‐space system. It is already established that the characterization of solids and nonuniform samples is possible using the spot‐focused free‐space measurement system from 5 to 110 GHz. Since the measured 3 dB spot size of the focused beam is 4.37 cm×3.2 cm at 9.1 GHz, only small samples are required, and the inaccuracies in free‐space measurement due to diffraction were minimized for samples of three times the spot size. The far‐field focusing ability of the horn‐lens antennas is helpful in designing a simple and noncontact wideband measurement system for the characterization of liquids. This noncontact method has the advantage of characterizing samples in high‐ and low‐temperature environments, which should find wide applications in industry forin situmaterial characterization. This method is readily applicable to monitoring the curing of polymers and gels, as well as thick‐film coating characterization in the wet state. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 30: 75–79, 2001.
Two integrated stacked shorted patch antennas for DCS/WLAN dual‐band operations
Authors: Wu Jian‐Yi , Wong Kin‐Lu
Published: August 2002

A new design of two stacked shorted patch antennas integrated on the same microwave substrate for DCS and WLAN dual‐band operations is presented. The two antennas together occupy a small area of 19×28.5 mm2, and the heights for the DCS and WLAN antennas are 10 and 5.2 mm, respectively. Details of the measured antenna performances are presented. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 30: 134–136, 2001.
A model for crosstalk prediction in PCB layout
Authors: Fung L. C. , Leung S. W. , Wan Lixi
Published: August 2002

A new model based on dyadic Green's functions for the fast and efficient prediction of crosstalk between traces in PCBs is presented here. The model is simple to set up, is capable of dealing with PCBs that have many traces, and gives accurate results. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 30: 142–144, 2001.
Analysis of similar behaviors of planar and linear arrays
Authors: Li Jian‐Ying , Li Le‐Wei , Ooi Ban‐Leong , Kooi Pang‐Shyan , Leong Mook‐Seng
Published: August 2002

In this paper, the method of moments is employed to analyze both planar and linear finite phased arrays of radiating slots fed by rectangular waveguides. The equivalent magnetic currents and active patterns due to these elements of phased arrays are discussed in detail. The relationship between linear and planar arrays is analyzed, and some similar behaviors are realized. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 30: 196–199, 2001.
Accurate modeling of shorted microstrip patch antennas using the locally conformal FDTD method
Authors: Cui Jun‐Hai , Zhong Shun‐Shi , Yu Chun
Published: August 2002

An accurate analysis of shorted microstrip patch antennas is presented based on the use of the locally conformal finite‐difference time‐domain (CFDTD) method. This approach enables the positions and dimensions of the probe and the shorting pin to be chosen independently. The calculated result is compared with the measured result, and good agreement is observed. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 30: 216–218, 2001.
A wideband subharmonically injection‐locked frequency synthesizer for LMDS
Authors: Xue Quan
Published: August 2002

A low‐cost wideband subharmonically injection‐locked frequency synthesizer for local multipoint distribution system (LMDS) down‐converter applications is introduced in this letter. This synthesizer consists of a 2.0 GHz PLL synthesizer, and is a general‐purpose bipolar transistor VCO at 5.8 GHz. The 5.8 GHz VCO is not only subharmonically injection locked by a 2.0 GHz PLL synthesizer, but also, the varactor diode's voltage is adaptively controlled by the 2.0 GHz PLL controlling voltage via a suitable converter at the same time. In this way, real‐time wideband locking can be attained. When third subharmonically injection locked, the output power of the synthesizer is more than 7.5 dBm, with a bandwidth of more than 25%. At 5.8 GHz, the power is 8.5 dBm, and the phase noise is −93 dBc/Hz at an offset frequency of 100 kHz. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 30: 310–312, 2001.
CAD of cylindrical dielectric resonator filters by a 3‐D finite‐element segmentation method
Authors: García Jesús , Rubio Jesús , Montejo‐Garai Jose Ramón , Zapata Juan
Published: August 2002

A procedure for dielectric‐loaded filter design on a step‐by‐step basis is presented. A full‐wave 3‐D finite‐element segmentation method is used. The structure is segmented into blocks whose generalized scattering matrix is computed, using analytical solutions when possible. The filter is linked and tuned in a full analytical procedure. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 31: 71–75, 2001.
A hybrid GMT–PO method for calculating the NDC of the irregular edge of a semi‐infinite circular cylinder
Authors: Bao Xiu Long , Zhang Wen Xun
Published: August 2002

In this paper, the GMT–PO hybrid method accompanied by the iterative technique is applied successfully to calculate 3‐D numerical diffraction coefficients (3‐D NDC) of the irregular circular‐cylinder edge. The computed RCS of the circular cylinder with 3‐D NDC of the irregular edge is in good agreement with the measured data from the reference. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 31: 108–110, 2001.
Synthesis and multinuclear magnetic resonance investigation of some 1,3‐selenazole and 1,3‐selenazoline derivatives
Authors: Duddeck Helmut , Bradenahl Ralf , Stefaniak Lech , Jazwinski Jaroslaw , Kamienski Bohdan
Published: August 2002

The 1H, 13C, 15N and 77Se NMR data of various annelated 1,3‐selenazoles and ‐1,3‐selenazolines are discussed in terms of tautomerism, configurational and conformational preference as well as HOMO–LUMO transition energies. The interpretations are corroborated by semi‐empirical calculations. Divergencies in solution‐ and solid‐state 77Se NMR data are discussed. Copyright © 2001 John Wiley & Sons, Ltd.
Comparison by restriction fragment differential display RT‐PCR of gene expression pattern in bovine oocytes matured in the presence or absence of fetal calf serum
Authors: Rzucidlo S. Jacek , Gibbons John , Stice Steven L.
Published: August 2002

A novel restriction fragment differential display (RFDD) RT‐PCR has been used to compare patterns of mRNA expression in bovine oocytes matured in vitro in the presence (10%) or absence of fetal calf serum (FCS). Total RNA extracted from matured and denuded oocytes was processed using display Profile kit (Display System Biotech). RFDD RT‐PCR products were separated on 6% polyacrylamide gel and analyzed using a Storm 860 scanner. Selected bands representing potentially differentially expressed fragments were excised from the gel and re‐amplified. Re‐amplified fragments with size matched to the original fragment were cloned into the TA vector and sequenced. Initially, 10 and 15 differentially expressed fragments were isolated from oocytes matured in the presence and absence of FCS, respectively. Eight out of 10 and 10 out of 15 fragments were re‐amplified successfully as evidenced bysize similarity to the original fragments. Finally, the size of six inserts sequenced from each group matched the size of corresponding original as well as re‐amplified fragments. Sequence comparison search revealed similarity of some isolated fragments to 18s ribosomal RNA, bovine apolipoprotein A‐I, bovine mitochondrion DNA, human CGI‐79 mRNA, human Ab1‐interactor protein, and bovine satellite DNA. The other sequenced fragments may represent novel genes. We showed that RFDD RT‐PCR can be effectively applied to contrast gene expression pattern in bovine oocytes and that presence or absence of FCS during maturation interval affects gene expression pattern in matured bovine oocytes. Mol. Reprod. Dev. 59:90–96, 2001. © 2001 Wiley‐Liss, Inc.
Protamine 1: Protamine 2 stoichiometry in the sperm of eutherian mammals*
Authors: Corzett Michele , Mazrimas Joe , Balhorn Rod
Published: August 2002

We have compared the relative proportion of protamine 1 (P1) and protamine 2 (P2) bound to DNA in the sperm of a variety of eutherian mammals to obtain insight into how these two proteins interact in sperm chromatin. Gel electrophoresis (combined with microdensitometry) and high performance liquid chromatography (HPLC) were used to determine the content of the two protamines, and the identity of each protein was confirmed by amino‐terminal sequencing or amino acid analysis. The sperm of all species examined contained P1, but P2 was found to be present only in certain species. Unlike the fixed ratio of core histones that package DNA into nucleosomes in all somatic cells, the proportion of P2 present in mature sperm was found to be continuously variable from 0 to nearly 80%. These results show that P1 and P2 do not interact with each other or DNA to form a discrete complex or subunit structure that is dependent upon particular P1/P2 stoichiometries. Data obtained from a number of closely and distantly related species also indicate that while the P2 content of sperm chromatin is allowed to vary over a wide range during the course of evolution, the relative proportion of P1 and P2 are tightly regulated within a genus. Mol. Reprod. Dev. 61:519–527, 2002. © 2002 Wiley‐Liss, Inc.
In silico mining of EST databases for novel pre‐implantation embryo‐specific zinc finger protein genes*
Authors: Choo Kong‐Bung , Chen Huang‐Hui , Cheng Winston T.K. , Chang Hung‐Shue , Wang Manni
Published: August 2002

Progress in the understanding of early mammalian embryo development has been severely hampered by scarcity of study materials. To circumvent such a constraint, we have developed a strategy that involves a combination of in silico mining of new genes from expressed sequence tags (EST) databases and rapid determination of expression profiles of the dbEST‐derived genes using a PCR‐based assay and a panel of cDNA libraries derived from different developmental stages and somatic tissues. We demonstrate that in a random sample of 49 independent dbEST‐derived zinc finger protein genes mined from a mouse embryonic 2‐cell cDNA library, more than three‐quarters of these genes are novel. Examination of characteristics of the human orthologues derived from these mouse genes reveals that many of them are associated with human malignancies. Expression studies have further led to the identification of three novel genes that are exclusively expressed in mouse embryos before or up to the 8‐cell stage. Two of the genes, designated 2czf45 and 2czf48 (2czf for 2‐cell zinc finger), are zinc finger protein genes coding for a RBCC protein with a RFP domain and a protein with three C2H2 fingers, respectively. The third gene, designated 2cpoz56, codes for a protein with a POZ domain that is often associated with zinc finger proteins. These three genes are candidate genes for regulatory or other functions in early embryogenesis. The strategy described in this report should generally be applicable to rapid and large‐scale mining of other classes of rare genes involved in other biological and pathological processes. Mol. Reprod. Dev. 59:249–255, 2001. © 2001 Wiley‐Liss, Inc.