bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rostral brain axonal injury in congenital central hypoventilation syndrome
Authors: Kumar Rajesh , Macey Paul M. , Woo Mary A. , Harper Ronald M. 
Published: March 2010

AbstractBrain injury underlying the state‐related loss of ventilatory drive, autonomic, cognitive, and affective deficits in congenital central hypoventilation syndrome (CCHS) patients appears throughout the brain, as demonstrated by magnetic resonance (MR) T2 relaxometry and mean diffusivity studies. However, neither MR measure is optimal to describe types of axonal injury essential for assessing neural interactions responsible for CCHS characteristics. To evaluate axonal integrity and partition the nature of tissue damage (axonal vs. myelin injury) in CCHS, we measured water diffusion parallel (axial diffusivity) and perpendicular (radial diffusivity) to rostral brain fibers, indicative of axonal and myelin changes, respectively, with diffusion tensor imaging (DTI). We performed DTI in 12 CCHS (age 18.5 ± 4.9 years, 7 male) and 30 control (17.7 ± 4.6 years, 18 male) subjects, using a 3.0‐Tesla MR imaging scanner. Axial and radial diffusivity maps were calculated, spatially normalized, smoothed, and compared between groups (analysis of covariance; covariates, age and gender). Significantly increased radial diffusivity, primarily indicative of myelin injury, emerged in fibers of the corona radiata, internal capsule, corpus callosum, hippocampus through the fornix, cingulum bundle, and temporal and parietal lobes. Increased axial diffusivity, suggestive of axonal injury, appeared in fibers of the internal capsule, thalamus, corona radiata, and occipital and temporal lobes. Multiple brain regions showed both higher axial and radial diffusivity, indicative of loss of tissue integrity with a combination of myelin and axonal injury, including basal ganglia, bed nucleus, and limbic, occipital, and temporal areas. The processes underlying injury are unclear, but likely stem from both hypoxic and developmental processes. © 2010 Wiley‐Liss, Inc.
μ‐Opioid receptor knockout mice are insensitive to methamphetamine‐induced behavioral sensitization
Authors: Shen Xine , Purser Chris , Tien Lu‐Tai , Chiu Chi‐Tso , Paul Ian A. , Baker Rodney , Loh Horace H. , Ho Ing K. , Ma Tangeng 
Published: March 2010

AbstractRepeated administration of psychostimulants to rodents can lead to behavioral sensitization. Previous studies, using nonspecific opioid receptor (OR) antagonists, revealed that ORs were involved in modulation of behavioral sensitization to methamphetamine (METH). However, the contribution of OR subtypes remains unclear. In the present study, using μ‐OR knockout mice, we examined the role of μ‐OR in the development of METH sensitization. Mice received daily intraperitoneal injection of drug or saline for 7 consecutive days to initiate sensitization. To express sensitization, animals received one injection of drug (the same as for initiation) or saline on day 11. Animal locomotor activity and stereotypy were monitored during the periods of initiation and expression of sensitization. Also, the concentrations of METH and its active metabolite amphetamine in the blood were measured after single and repeated administrations of METH. METH promoted significant locomotor hyperactivity at low doses and stereotyped behaviors at relative high doses (2.5 mg/kg and above). Repeated administration of METH led to the initiation and expression of behavioral sensitization in wild‐type mice. METH‐induced behavioral responses were attenuated in the μ‐OR knockout mice. Haloperidol (a dopamine receptor antagonist) showed a more potent effect in counteracting METH‐induced stereotypy in the μ‐OR knockout mice. Saline did not induce behavioral sensitization in either genotype. No significant difference was observed in disposition of METH and amphetamine between the two genotypes. Our study indicated that the μ‐opioid system is involved in modulating the development of behavioral sensitization to METH. © 2010 Wiley‐Liss, Inc.
Impaired neurogenesis is an early event in the etiology of familial Alzheimer's disease in transgenic mice
Authors: Demars Michael , Hu Yuan‐Shih , Gadadhar Archana , Lazarov Orly 
Published: March 2010

AbstractFormation of new neurons in the adult brain takes place in the subventricular zone and in the subgranule layer of the dentate gyrus throughout life. Neurogenesis is thought to play a role in hippocampus‐ and olfaction‐dependent learning and memory. However, whether impairments in neurogenesis take place in learning and memory disorders, such as Alzheimer's disease, is yet to be established. Importantly, it remains to be elucidated whether neurogenic impairments play a role in the course of the disease or are the result of extensive neuropathology. We now report that transgenic mice harboring familial Alzheimer's disease‐linked mutant APPswe/PS1ΔE9 exhibit severe impairments in neurogenesis that are evident as early as 2 months of age. These mice exhibit a significant reduction in the proliferation of neural progenitor cells and their neuronal differentiation. Interestingly, levels of hyperphosphorylated tau, the cytotoxic precursor of the Alzheimer's disease hallmark neurofibrillary tangles, are particularly high in the neurogenic niches. Isolation of neural progenitor cells in culture reveals that APPswe/PS1ΔE9‐expressing neurospheres exhibit impaired proliferation and tau hyperphosphorylation compared with wildtype neurospheres isolated from nontransgenic littermates. This study suggests that impaired neurogenesis is an early critical event in the course of Alzheimer's disease that may underlie memory impairments, at least in part, and exacerbate neuronal vulnerability in the hippocampal formation and olfaction circuits. Furthermore, impaired neurogenesis is the result of both intrinsic pathology in neural progenitor cells and extrinsic neuropathology in the neurogenic niches. Finally, hyperphosphorylation of the microtubule‐associated protein tau, a critical player in cell proliferation, neuronal maturation, and axonal transport, is a major contributor to impaired neurogenesis in Alzheimer's disease. © 2010 Wiley‐Liss, Inc.
Characterization of sialylated and fucosylated glycopeptides of β2‐glycoprotein I by a combination of HILIC LC and MALDI MS/MS
Authors: Kondo Akira , Thaysen‐Andersen Morten , Hjernø Karin , Jensen Ole N. 
Published: March 2010

AbstractCharacterization of low microgram levels of glycoprotein remains a challenge due to extensive heterogeneity of the conjugated N‐glycans at each individual glycosylation site. We present an optimized, sensitive workflow for glycopeptide isolation and characterization that exploits the complementary features of RP (Poros R2) and hydrophilic (zwitter‐ionic hydrophilic interaction chromatography) chromatographic resins. The glycopeptide analysis workflow was applied to human β2‐glycoprotein I (β2‐GPI, apolipoprotein H), which contains multiple N‐glycosylation sites. Conditions for rapid proteolytic digestion of β2‐GPI using low‐specificity proteases were optimized to detect β2‐GPI glycopeptides by MS. We demonstrate the importance of ensuring sufficient column capacity of both hydrophobic and hydrophilic stationary phases for optimal glycoprofiling by MS. The enriched glycopeptides were characterized using MALDI quadrupole TOF MS/MS. A total of 23 glycan structures, including sialylated bi‐ and tri‐antennary complex type glycans, were characterized at three N‐glycosylation sites, namely Asn‐143, Asn‐174 and Asn‐234, of β2‐GPI. Further exploration of the complementary nature of RP and HILIC stationary phases for glycopeptide isolation prior to MS analysis may eventually enable systematic analysis of complex glycoprotein samples in functional proteomic research and advance our understanding of the biological role of protein glycosylation.
Determination of melamine in milk powder using zwitterionic HILIC stationary phase with UV detection
Authors: Nkem Ihunegbo Felicia , Tesfalidet Solomon , Jiang Wen 
Published: March 2010

AbstractA hydrophilic interaction liquid chromatography‐UV method was developed for the determination of melamine in milk powder. Sulfobetaine type zwitterionic hydrophilic interaction liquid chromatography stationary phase was used to achieve straightforward separation of melamine in milk powder without any sample derivatization or addition of ion‐pair reagent. The sample preparation was simple and fast with the steps of acetonitrile/perchloric acid extraction‐centrifugation‐filtration. No SPE or other pre‐concentration procedure was required. By using large volume sample injection and choosing low UV wavelength (210 nm), the LOD and LOQ were 0.005 and 0.015 μg/mL for melamine standards, and 0.02 and 0.06 μg/mL for the spiked milk extracts. The LOD and LOQ of the latter correspond to 0.95 and 2.2 μg/g melamine in the milk powder. The correlation coefficients for melamine standard, pre‐spiked milk extracts and post‐spiked milk extracts in the range of 0–0.5 μg/mL were 0.9978, 0.9976 and 0.9995, respectively. This newly developed method is sensitive and cost effective, therefore, suitable for screening of melamine in tainted milk products.
Hyposmia in progressive supranuclear palsy
Authors: Silveira‐Moriyama Laura , Hughes Graham , Church Alistair , Ayling Hilary , Williams David R. , Petrie Aviva , Holton Janice , Revesz Tamas , Kingsbury Ann , Morris Huw R. , Burn David J. , Lees Andrew J. 
Published: March 2010

AbstractPrevious studies suggested that olfaction is normal in progressive supranuclear palsy (PSP). We applied the University of Pennsylvania Smell Identification Test (UPSIT) to 36 patients with PSP who scored more than 18 on the Mini Mental State Examination (MMSE), 140 patients with nondemented Parkinson's disease (PD) and 126 controls. Mean UPSIT scores in PSP were lower than in controls (P < 0.001) but higher than in PD (P < 0.001) after adjusting for age, gender, and smoking history. For patients with PSP, UPSIT scores correlated with MMSE (r = 0.44, P = 0.006) but not disease duration (P = 0.6), motor subscale of the Unified Parkinson's Disease Rating Scale (P = 0.2), or Frontal Assessment Battery (P = 0.5). The brains of six of the patients with PSP were examined postmortem and all revealed neurofibrillary tangles and tau accumulation in the rhinencephalon, although only three had hyposmia. Further prospective studies including patients with early PSP and PSP‐P with postmortem confirmation might help clarify if smell tests could be useful when the differential diagnosis lies between PD and PSP. © 2010 Movement Disorder Society
Design, Synthesis, and Evaluation of Antineoplastic Activity of Novel Carbocyclic Nucleosides
Authors: Helguera Aliuska M. , Rodríguez‐Borges J. E. , Caamaño Olga , García‐Mera Xerardo , González Maykel Pérez , Cordeiro M. Natália D. S. 
Published: March 2010

AbstractCancer is the leading cause of death among men and women under age 85. Every year, millions of individuals are diagnosed with cancer. But finding new drugs is a complex, expensive, and very time‐consuming task. Over the past decade, the cancer research community has begun to address the in silico modeling approaches, such as Quantitative Structure‐Activity Relationships (QSAR), as an important alternative tool for targeting potential anticancer drugs. With the compilation of a large dataset of nucleosides synthesized in our laboratories, or elsewhere, and tested in a single cytotoxic assay under the same experimental conditions, we recognized a unique opportunity to attempt to build predictive QSAR models. Early efforts with 2D classification models built from part of this dataset were very encouraging. Here we report a further detailed evaluation of classification models to flag potential anticancer activities derived from a variety of 3D molecular representations. A quantitative 3D‐model model that discriminates anticancer compounds from the inactive ones was attained, which allowed the correct classification of 82 % of compounds in such a large and diverse dataset, with only 5 % of false inactives and 11 % of false actives. The model developed here was then used to select and design a new series of nucleosides, by classifying beforehand them as active/inactive anticancer compounds. From the compounds so designed, 22 were synthesized and evaluated for their inhibitory effects on the proliferation of murine leukemia cells (L1210/0), of which 86 % were well‐classified as active or inactive, and only two were false actives, corroborating the good predictive ability of the present discriminant model. The results of this study thus provide a valuable tool for the design of novel potent anticancer nucleoside analogues.
Structure‐Activity Relationship Studies of a Number of α1‐Adrenoceptor Antagonists and Antiarrhythmic Agents
Authors: Nowaczyk Alicja , Przybylski Rafał , Kulig Katarzyna , Malawska Barbara 
Published: March 2010

AbstractArylpiperazines represent one of the most studied classes of α1‐adrenoceptor (α1‐AR) antagonists. Currently, α1‐AR antagonists are useful in the treatment of benign prostatic hyperplasia, lower urinary tract symptoms or cardiac arrhythmia. The activity of various derivatives of 1‐[3‐(4‐arylpiperazin‐1‐yl)propyl]pyrrolidin‐2‐one as α1‐adrenergic receptor antagonists and antiarrhythmic (AA) agents was described using the qualitative inverse Structure Activity Relationship (SAR) model. The three‐dimensional structures of the pyrrolidin‐2‐one derivatives in the basic form were obtained using AM1 semi‐empirical quantum chemical calculations. All the molecules were geometry‐optimized until the root‐mean‐square (RMS) gradient value was smaller than 10−6a.u. Single‐point energy (SPE) calculations were performed at the DFT/B3LYP level of theory using the 6‐31G** basis set. The main focus of this inverse SAR study is to find which features cause enhancing of antiarrhythmic properties between subtly different types of activity (α1‐adrenoreceptor antagonists and antiarrhythmic activities). Our SAR study involves the charge distribution in the plane of the pharmacophore model for α1‐AR. Suitable maps of the electrostatic potential were plotted based on the electronic and nuclear charge distribution obtained from the energy calculations. The results of this modelling study indicate that if the terminal arylpiperazine moiety is surrounded by regions of negative electrostatic potential, then the antiarrhythmic activity is blocked.
Equivalence of space‐fed microstrip antenna array with horn antenna
Authors: Bhide Rahul , Kumar Girish 
Published: March 2010

AbstractEquivalence between space‐fed microstrip antenna arrays and horn antenna is established. A method is proposed to determine the array height from the fed microstrip antenna and correction of phase error across the array aperture. A 25‐element array with elements arranged in a 5 × 5 rectangular grid is designed. Simulated and measured results are presented. Space‐fed arrays are easy to fabricate, have less weight, high gain, and low side lobe levels. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1180–1183, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25092
A new time domain solution for the multiple diffraction of spherical waves by an array of nonperfectly conducting wedges for UWB signals
Authors: Liu Peng , Long Yunliang 
Published: March 2010

AbstractA time domain (TD) solution for the analysis of multiple diffraction of spherical waves after an array of nonperfectly conducting wedges with different interior angles is presented.The proposed TD solution is based on the representation of the inverse Laplace transform of the corresponding frequency domain solution in closed form, as it is given by a hybrid of the uniform theory of diffraction (UTD)‐physic optics (PO) solution. The new formulation, validated with the results from technical literature, does not need to incorporate the TD version of the higher‐order diffraction coefficients and allows for the calculation of large number of wedges. It has the major advantage in terms of the mathematical complexity and computation efficiency when compared with other TD solutions. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1006–1008, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25094
Circular‐slotted microstrip antenna for GPS
Authors: Sun Xu‐Bao 
Published: March 2010

AbstractTo meet the required precision and reliability for global positioning systems, a probe‐feed dual‐band circularly polarized (CP) microstrip antenna is proposed.This new microstrip antenna design uses a circular patch that is printed on a two‐layer substrate consisting of an FR4 dielectric layer and a foam layer, and cutting a crossed‐slot and an open ring‐slot in the circular patch. When compared with the conventional dual‐band CP antenna with two patches among substrate materials, not only is the performance of the antenna improved but also its fabrication becomes easier. The simulated and measured results indicate the validity of the design. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 999–1000, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25095
Printed wide‐slot antenna with high polarization purity for wideband applications
Authors: Naser‐Moghadasi Mohammad , Bayderkhani Reza , Dadashzadeh Gholamreza , Virdee Bal S. 
Published: March 2010

AbstractThis article describes a novel compact wideband slot antenna comprising of an E‐shaped patch that is excited with a trident‐shaped microstrip feed‐line structure. The antenna design exhibits a very wide operating bandwidth of over 163% with S11 < −10 dB in the frequency range 2–19.95 GHz. The antenna's radiation characteristics are stable across the 2–12 GHz band. The proposed antenna exhibits high polarization purity with cross‐polarization level that is well below −50 dB. A comprehensive parametric study was performed on the antenna to fully understand the effects of various antenna parameters that enable optimization of the antenna's performance. This antenna easily fulfills the requirements for ultra‐wideband wireless communication systems as specified by federal communication commission over the designated band 3.1–10.6 GHz. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1001–1006, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25096
An efficient time‐domain method analysis of quasiperiodic structures by a finite‐element tearing and interconnecting algorithm
Authors: Du L. , Chen R. S. , Ye Z.B. , Yang Y. 
Published: March 2010

AbstractBased on the finite‐element approximation and nonoverlapping domain decomposition, an efficient tearing and interconnecting algorithm of the finite‐element time‐domain method is presented. Using edge‐based finite element, the method divides the computation domain into several nonoverlapping subdomains and computes electric fields in each subdomain by solving the vector curl–curl wave equation. Adjacent subdomains are related to each other by Dirichlet and Neumann boundary condition. By use of the repetition of the quasiperiod structures, the method further reduces the memory requirement and CPU time. The time‐dependent formulation employs an unconditional stable time‐integration method based on the Newmark‐beta method. An anisotropic perfectly matched layers absorbing material terminated by the first‐order boundary condition is applied for the truncation of lattices. Numerical results demonstrate that our proposed method is extremely efficient for the time‐domain analysis of the quasiperiodic structures, such as electromagnetic band gap structures.© 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1072–1078, 2010; Published online in Wiley InterScience (www.interscience. wiley.com). DOI 10.1002/mop.25100
Wireless network based on radio‐over‐fiber with optical carrier reuse by fiber grating
Authors: Yiying Gu , Shanfeng Li , Xin Luo , Xiuyou Han , Mingshan Zhao 
Published: March 2010

AbstractThis article presents a vector signal transmission architecture for wireless network based on radio‐over‐fiber system. Partly double sideband carrier suppressed modulation scheme was used to generate optical frequency doubled microwave while the same optical carrier was reused via a fiber grating for up‐link transmission in base station (BS). The 5 GHz microwave carrying 1 Mbps 8PSK‐vector signal was up‐converted to 10 GHz in BS with the vector signal conversion from 8PSK to QPSK. Also, a 50 GHz millimeter‐wave was generated that can be seen from the optical spectra. Such a system shows simple configuration and is cost‐efficient. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1145–1148, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25103
KTN ferroelectrics‐based microwave tunable phase shifter
Authors: Zhang Ling Yan , Laur Vincent , Pothier Arnaud , Simon Quentin , Laurent Paul , Martin Noham , Guilloux‐Viry Maryline , Tanné Gérard 
Published: March 2010

AbstractThis letter presents the design, fabrication, and measurement of a KTa1‐xNbxO3‐ (KTN‐) based phase shifter. This loaded‐line phase shifter has insertion losses of about 7.36 dB at zero bias and 10 GHz, a return loss greater than 12 dB over the frequency range 1–16 GHz and a relatively high differential phase shift of about 88° for a 120 V DC bias at 10 GHz. The enhancement of performances observed by comparison with those presented by the KTN‐based phase shifters positions KTN materials as a serious alternative to Ba1‐xSrxTiO3 ones for microwave agility applications. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1148–1150, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25104
Efficient DRW antenna for quasi‐optics feed in W‐band imaging radiometer system
Authors: Kim Won‐Gyum , Thakur Jay Prakash , Kim Yong‐Hoon 
Published: March 2010

AbstractModification in tapered dielectric rod waveguide antenna is achieved by the implementation of step change in width in metallic waveguide transition. The proposed antenna has circular symmetric radiation pattern and gain about 15.3 dB with improved return loss and side lobes level at W‐band. It has 10 dB beamwidth 53.2° and 48.6° in the E‐ and H‐plane. Proposed antenna can be used for a millimeter wave quasi‐optics feed array design in W‐band imaging radiometer design. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1221–1223, 2010; Published online in Wiley InterScience (www. interscience.wiley.com). DOI 10.1002/mop.25107
An incomplete factorization preconditioner based on shifted Laplace operators for FEM analysis of microwave structures
Authors: Zhu J. , Ping X. W. , Chen R. S. , Fan Z.H. , Ding D. Z. 
Published: March 2010

AbstractIn this article, the tangential vector finite element method combined with the high‐order basis functions is applied for the analysis of electromagnetic problems based on Helmholtz equations. Different from conventional preconditioners, the preconditioner presented in this article is derived based on the shifted Laplace operator, and the diagonally perturbed incomplete factorization is used to approximate the inverse of this operator. Numerical experiments demonstrate that the proposed preconditioner can significantly speed up the iterative convergence of conjugate gradient method for several electromagnetic structures. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1036–1042, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25111