bluuebunny/crossref_metadata_2025_split huggingface dataset:
Design of a 9 GHz CMOS low noise amplifier using gain‐enhanced technique
Authors: Wang Sen 
Published: January 2011

AbstractIn this article, a 9 GHz low noise amplifier (LNA) using gain‐enhanced technique is presented. The compact and high‐gain LNA with cascode topology is implemented in a standard 0.18‐μm CMOS process. The gain‐enhanced technique consists of two inductors in the common gate (CG) stage of the cascode configuration. The first inductor at the source terminal in the CG stage eliminates the parasitic effects caused by the parasitic capacitances of transistors at high frequencies. Moreover, the second inductor at the gate terminal in the CG stage achieves a negative resistance making a high gain characteristic of the amplifier. Finally, the measured small signal gain, noise figure and inputP1dBat 9 GHz are 16.5 dB, 4.5 dB, and −15 dBm, respectively. The chip size of the compact LNA is 0.48 mm × 0.8 mm including all testing pads. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:479–481, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25778
A K‐band balanced subharmonically pumped image rejection mixer using 0.15‐μm GaAs pHEMT technology
Authors: Ke Po‐Yu , Chiu Hsien‐Chin , Kuo Che‐Yu , Fu Jeffrey S. , Chiang Yi‐Chyun 
Published: January 2011

AbstractThis work presents a K‐band balance single side‐band subharmonically pumped image rejection diode mixer (SHIRM).It uses lumped elements and three‐conductor‐line quadrature couplers and is fabricated in a 0.15‐μm GaAs process. The SHIRM is realized in size reduction by using two antiparallel diode pairs for frequency mixing. The three‐conductor‐line bending coupler is 55% reduction in size compared to the nonbending one for radio frequency port, and lumped elements realization is 62% smaller in size than the quarter‐wavelength line for local oscillator port. The proposed circuit with a symmetric layout provides good matches on amplitude and phase performances. The measured results exhibit a minimum conversion loss of 13 dB, a maximum image rejection ratio of 19 dB. All ports isolations are better than 10 dB. The chip area is only 1.5 × 1 mm2. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:485–488, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25781
Candelabra shaped microstrip antenna for ultra‐wideband applications
Authors: Haraty Mohammad Reza , Momeni Seyed Majid Seyed , Sadeghzadeh R. A. 
Published: January 2011

AbstractThis article presents the results of a novel and compact microstrip antenna having a candelabra geometry, which exhibits ultra‐wideband (UWB) performance when excited using coplanar waveguide feed. The proposed antenna exhibits an impedance bandwidth of 138% from 2.3 to 12.7 GHz, exceeding Federal Communication Commission's ultra‐wideband frequency range with a return‐loss performanceS11= −10 dB. The antenna radiates omnidirectionally in theH‐plane and bidirectionally inE‐plane. Details of the antenna's design and simulation results are presented and validated with practical measurements. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:669–672, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25783
Four‐channel incoherent mimo transmission over 4.4‐km MM fiber
Authors: Kowalczyk Marcin , Siuzdak Jerzy 
Published: January 2011

AbstractThe article presents realization of four‐channel incoherent MIMO system operating over GI MM fiber with 50‐μm core. The quality of the received channels was good. The selection of the carrier frequency has little impact on the system operation. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:502–506, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25791
Low‐phase noise oscillator using spurline resonator for I‐band applications
Authors: Shrestha B. , Kim N. Y. 
Published: January 2011

AbstractThis letter presents two compact L‐type spurline and meander spurline resonators and their application to low‐phase noise oscillators. These resonators have a bandstop characteristic that can be used in the series feedback oscillator topology. Both miniaturized resonators consist of a defected L‐type spurline and a meander spurline with inductive characteristics and a loaded stub with capacitive characteristics. The structure of resonators reduces the required the circuit area as well as the cost. The oscillators, using the spurline and the meander spurline resonators, show excellent phase noise performances of −96.23 dBc/Hz and −103.23 dBc at a 100 kHz offset from the carrier frequency of 9.0 GHz and 9.2 GHz with an output power of 14.47 dBm and 15.23 dBm, respectively. The later oscillator exhibited better phase noise characteristics due to the high Q value of the defected meander spurline resonator. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:543–547, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25803
Gain‐enhanced linearly tapered slot antenna with half‐circular slotted side edges
Authors: In Dae‐Myoung , Pyo Seongmin , Lee Min‐Jae , Kim Young‐Sik 
Published: January 2011

AbstractIn this article, a new linearly tapered slot antenna (LTSA) with half‐circular slots (HCSs) embedded on both edge‐sides is proposed for improving antenna gain. The side lobe levels of the LTSA are lowered as these HCSs may alter the surface current intensities on both edge‐sides. As the half‐circular size is increased, the 3‐dB beamwidths of the proposed antenna are decreased in E‐ and H‐plane, respectively. The measured gain is improved in a whole Ku‐band (12.4–18.5 GHz), and it has a maximum gain of 14.8 dB at the design frequency of 15 GHz. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:686–688, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25818
Erratum: To compact branch‐line couplers using parallel high‐impedance transmission lines
Authors: Khalaj‐Amirhosseini Mohammad , Yazdani Mohsen 
Published: January 2011

AbstractOriginally published Microwave Opt Technol Lett 52: 1996–1999, 2010. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:700–700, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25843(Original article DOI 10.1002/mop.25369)
Magnetic resonance microimaging of human skin vasculature in vivo at 3 Tesla
Authors: Laistler Elmar , Loewe Robert , Moser Ewald 
Published: January 2011

AbstractMRI can be used to investigate human skin microvasculature in vivo, provided adequate spatial resolution. Therefore, the sensitivity of the experiment has to be optimized to achieve sufficient signal‐to‐noise ratio (SNR) within reasonable measurement time to minimize motion artifacts, improve patient comfort and save costs. In this work, the high sensitivity of a 15 mm surface coil and the signal strength of a 3 Tesla scanner, together with a three‐dimensional gradient echo sequence and post‐processing have been combined to obtain high SNR. Images of human skin with isotropic spatial resolution of 100 μm were acquired within 10 min and the cutaneous vasculature could be visualized in 3D [Correction made here after initial online publication.], based on three averaged scans. The presented method can be used for diagnosis and, due to its non‐invasiveness, treatment monitoring of vascular pathologies in the skin, such as inflammation, vascular malformation, or neoangiogenesis in superficial tumors. Magn Reson Med, 2011. © 2011 Wiley‐Liss, Inc.
Combining phase images from multi‐channel RF coils using 3D phase offset maps derived from a dual‐echo scan
Authors: Robinson Simon , Grabner Günther , Witoszynskyj Stephan , Trattnig Siegfried 
Published: January 2011

AbstractA method is presented for the combination of phase images from multi‐channel RF coils in the absence of a volume reference coil. It is based on the subtraction of 3D phase offset maps from the phase data from each coil. Phase offset maps are weighted combinations of phase measurements at two echo times. Multi‐Channel Phase Combination using measured 3D phase offsets (MCPC‐3D) offers a conceptually and computationally simple solution to the calculation of combined phase images. The dual‐echo data required for the phase maps can be intrinsic to the high‐resorlution gradient‐echo scan to be reconstructed (MCPC‐3D‐I). Alternatively, a separate, fast, low‐resolution dual‐echo scan can be used (MCPC‐3D‐II). Both variants are shown to give near perfect phase matching, yielding images with high SNR throughout and high GM‐WM contrast. MCPC‐3D is compared with other reference‐free phase image crombination methods; high‐pass phase filtering, phase difference imaging, and matching using constant offsets (MCPC‐C). Multi‐Channel Phase Combination using measured 3D phase offsets method does not need an overlap between the signals from individual coils and can be used with parallel imaging, making it ideally suited to multi‐channel coils with a large number of elements, and to high and ultra‐high field systems. Magn Reson Med, 2011. © 2011 Wiley‐Liss, Inc.
Enhancement effects of hepatic dynamic MR imaging at 3.0 T and 1.5 T using gadoxetic acid in a phantom study: comparison with gadopentetate dimeglumine
Authors: Morita Kosuke , Namimoto Tomohiro , Awai Kazuo , Komi Masanori , Hashida Masahiro , Tsuji Takashi , Hirai Toshinori , Yamashita Yasuyuki 
Published: January 2011

AbstractTo identify the optimum sequence at gadoxetic acid enhanced hepatic dynamic magnetic resonance imaging in the arterial phase, we studied phantoms that contained gadoxetic acid or gadopentetate dimeglumine diluted in human blood. We obtained magnetic resonance images at 3.0 T and 1.5 T with one vendor (Siemens) using 3D‐gradient echo (GRE)‐, 2D‐fast low angle shot (FLASH)‐, and turbo spin echo sequences. Contrast ratio was highest for 3D‐GRE; at both 3.0 T and 1.5 T it was superior when the contrast agent was gadoxetic acid. With both gadoxetic acid and gadopentetate dimeglumine, contrast ratio peaked at around 5‐and 2 mmol/L on 3D‐GRE‐ and 2D‐FLASH images, respectively. Compared with gadopentetate dimeglumine, at 3.0 T, the peak contrast ratio of gadoxetic acid was 14.1% better on 3D‐GRE images and 14.0% better on 2D‐FLASH images; at 1.5 T it was 16.4% better on 3D‐GRE‐ and 5.7% better on 2D‐FLASH images. With respect to the magnetic field strength, at 3.0 T the peak contrast ratio of gadoxetic acid was 6.0% better than at 1.5 T on 3D‐GRE images and 49.5% better on 2D‐FLASH images; it was 8.5% better on 3D‐GRE‐ and 44.6% better on 2D‐FLASH images than when the contrast agent was gadopentetate dimeglumine. Thus, gadoxetic acid yielded better enhancement on 3D‐GRE images acquired at 3.0 T than at 1.5 T and enhancement was better than that obtained with gadopentetate dimeglumine at the same concentration. Magn Reson Med 66:213–218, 2011. © 2011 Wiley‐Liss, Inc.
Effects of electrical stimulation on neuromuscular junction morphology in the aging rat tongue
Authors: Johnson Aaron M. , Connor Nadine P. 
Published: January 2011

AbstractAlterations in neuromuscular junction (NMJ) structure in cranial muscles may contribute to age‐related deficits in critical sensorimotor actions such as swallowing. Neuromuscular electrical stimulation (NMES) is used in swallowing therapy, but it is unclear how NMJ structure is affected or if NMJ morphology is best measured in two or three dimensions. Two‐ and three‐dimensional measurements of NMJ morphology in the genioglossus muscle were compared in rats that had undergone 8 weeks of hypoglossal nerve stimulation vs. untreated controls. The relationship between motor endplate volume and nerve terminal volume had a mean positive slope in 90% of the young adult controls, but it was positive in only 50% of the old controls; 89% of NMES old rats had a positive slope. NMJ measurements were more accurate when measured in three dimensions. In the NMJ, aging and NMES are associated with changes in the pre‐ and post‐synaptic relationship. Muscle Nerve 43: 203–211, 2011
Time‐course of changes in the myonuclear domain during denervation in young‐adult and old rat gastrocnemius muscle
Authors: van der Meer Sander F.T. , Jaspers Richard T. , Jones David A. , Degens Hans 
Published: January 2011

AbstractIf myonuclear loss initiates muscle wasting, it should precede the loss of muscle mass. As aging affects muscle plasticity, the time‐course of muscle atrophy during disuse may differ between young and old animals. To investigate this, gastrocnemius muscles of 5‐ and 25‐month‐old rats were exposed to 1, 2, or 4 weeks of denervation, whereas the contralateral gastrocnemius muscles served as controls. Muscle fibers of each type responded similarly to 4 weeks of denervation. For both ages most of the atrophy (36%; P < 0.001) occurred in the first 2 weeks. In young‐adult muscles, the myonuclear number remained constant, but in old muscles it decreased to below control level after 4 weeks of denervation (P < 0.05). Despite this differential response, myonuclear domain size decreased similarly at both ages (P < 0.001). In both young‐adult and old rats, denervation‐induced atrophy was not preceded by a loss of myonuclei. Muscle Nerve 43: 212–222, 2011
Spinal reflex excitability and homosynaptic depression after a bout of whole‐body vibration
Authors: Kipp Kristof , Johnson Samuel T. , Doeringer Jeffrey R. , Hoffman Mark A. 
Published: January 2011

AbstractAlthough whole‐body vibration (WBV) affects neuromuscular performance, it remains unclear whether the effects are due to spinal reflex potentiation or inhibition, or differ between muscle groups. This study aimed to identify the effect of WBV on measures of spinal reflex excitability (H‐reflex) and homosynaptic depression (HD) in the soleus (SOL) and medial gastrocnemius (MG) muscles. H‐reflex and HD measurements were made in the SOL and MG muscle of 20 participants before and after a bout of WBV. H‐reflex and HD were measured every 15 seconds for 10 minutes post‐WBV and averaged at 1‐minute increments. H‐reflex amplitude was depressed for the first minute post‐vibration, whereas the effect of HD was reduced for the first 2 minutes post‐vibration. WBV significantly decreases spinal reflex excitability and HD, but it does so transiently and independent of muscle group. Muscle Nerve 43: 259–262, 2011
Impaired respiratory function in mdx and mdx/utrn+/− mice
Authors: Huang Ping , Cheng Georgiana , Lu Haiyan , Aronica Mark , Ransohoff Richard M. , Zhou Lan 
Published: January 2011

AbstractMuscle fibrosis is a prominent pathological feature that directly causes muscle dysfunction in Duchenne muscular dystrophy (DMD). The DMD mouse models, mdx mice and mdx mice with haploinsufficiency of the utrophin gene (mdx/utrn+/−), display progressive diaphragm fibrosis. We performed unrestrained whole‐body plethysmography (WBP) in mdx and mdx/utrn+/− mice, and compared them with wild‐type controls. Respiratory function gauged by respiratory frequency, tidal volume, minute volume, peak inspiratory flow, and peak expiratory flow was significantly impaired in the mdx mice. Consistent with more severe diaphragm fibrosis in the mdx/utrn+/− mice, respiratory impairment was worse than in mdx mice at 6 months. WBP is useful for monitoring in vivo respiratory function of mdx and mdx/utrn+/− mice, and it may serve as an outcome measurement for therapies that target diaphragm fibrosis. The mdx/utrn+/− mouse model may be better than the mdx model for testing antifibrotic therapies, especially at the severe stage. Muscle Nerve 43: 263–267, 2011
Acute superficial sensory neuropathy with generalized anhidrosis, anosmia, and ageusia
Authors: Miyazaki Yu , Koike Haruki , Ito Mizuki , Atsuta Naoki , Watanabe Hirohisa , Katsuno Masahisa , Kusunoki Susumu , Sobue Gen 
Published: January 2011

AbstractWe report a 53‐year‐old woman with an unusual presentation characterized by acute onset of generalized sensory symptoms associated with anhidrosis, anosmia, ageusia, and elevated titers of anti–GalNAc‐GD1a antibodies. After intravenous immunoglobulin therapy, a remarkable improvement in the pain and temperature sensation was noted in her face, trunk, and extremities. The impaired pain and temperature sensation remained distributed along cranial and spinal dermatomes in a non–length‐dependent manner, suggesting that the ganglionopathy affected small neurons. Muscle Nerve 43:287–289, 2011
Physiological properties of malignant tumours
Authors: Vaupel P. 
Published: January 2011

AbstractIt is generally accepted that tumour microcirculation, blood flow, oxygen and nutrient supply, tissue pH distribution, and the bioenergetic status—factors which are usually closely linked and which define the so‐called metabolic microenvironment—can markedly influence the therapeutic response of malignant tumours to conventional irradiation, chemotherapy, other non‐surgical treatment modalities, and the cell proliferation activity within the tumours. Currently available information on the parameters defining the metabolic micromilieu in human tumours is presented in this paper. According to these data, significant variations in these relevant factors are likely to occur between different locations within a tumour, and between tumours of the same grading and clinical staging. Therefore, evaluation of the metabolic microenvironment in individual tumours before therapy and a corresponding ‘fine‐tuning’ of treatment protocols for individual patients may result in an improved tumour response to treatment.
Phospholipid metabolites as indicators of cancer cell function
Authors: Ruiz‐Cabello Jesús , Cohen Jack S. 
Published: January 2011

AbstractNMR methods are being applied to study phospholipid metabolism of cancer cells by monitoring the resonances which appear in the31P spectrum. This review, aside from considering the applicability of NMR to this specific pathway, raises the question of whether the phospholipid metabolite peaks observed by MR are indicators of cancer cell function or tumor response to treatment. After assessing the results from many investigations, it is concluded that there is no clear correlation and that a combination of techniques, includingin vitroand extract studies, will be necessary for a more comprehensive evaluation of thein vivodata.
On the interpretation of proton NMR spectra from brain tumours in vivo and in vitro
Authors: Bruhn H. , Michaelis T. , Merboldt K. D. , Hänicke W. , Gyngell M. L. , Hamburger C. , Frahm J. 
Published: January 2011

AbstractLocalized proton NMR spectroscopy in vivo allows focal studies of cerebral metabolites in both man and laboratory animals from image‐defined regions as small as 1 mL or 64 μL, respectively. Although brain tumours lead to remarkable spectral alterations relative to normal brain, a number of problems may compromise the interpretation of the results. Potential complications arise from the chosen experimental conditions (method, TE, size and location of volume of interest), from regional metabolic heterogeneity in and around tumours, from differences between human tumours and animal models, and from discrepancies between in vivo and in vitro findings. Strategies and pitfalls are illustrated with use of selected examples from primary brain tumours, a rat tumour model and perchloric acid extracts of resected specimens.
In vivoandex vivomagnetic resonance spectroscopy as applied to pharmacokinetic studies with anticancer agents: a review
Authors: Newell David R. , Maxwell Ross J. , Golding Bernard T. 
Published: January 2011

AbstractThe potential role of MRS in studying the pharmacokinetics of anticancer drugs is reviewed.In vivoandex vivoMRS has been used extensively in studies with fluoropyrimidines. Results from preclinical models have demonstrated that biochemical modulation of 5‐fluorouracil metabolism can be demonstrated by MRS. The more general potential of MRS is illustrated by studies with the antifolate CB3988 (C2‐desamino‐C2‐methyl‐N10‐propargyl‐2′‐trifluoromethyl‐5,8‐dideazafolic acid). Studies in mice and rats have shown that hepatobiliary clearance and renal elimination can be measured non‐invasively by MRS. Comparison of half‐lives derived from MRS and high performance liquid chromatography data gave reasonable agreement. In addition, MRI was used to localize drug‐derived material within the abdominal cavity. The application ofex vivoMRS is illustrated by studies on the urinary excretion of platinum complexes.1H‐MRS has been used to demonstrate the presence of the cyclobutanedicarboxylate leaving group, both free and platinum bound, in the urine of patients treated with carboplatin. With iproplatin195Pt NMR has been used to demonstratein vivoreduction of this Pt(IV) complex to Pt(II) complexes. Finally, the application of MRS to the study of the molecular pharmacology of alkylating agents (a nitrogen mustard andN‐methyl‐N‐nitrosourea) is discussed.
1H NMR spectroscopy of subcutaneous tumors in mice: Preliminary studies of effects of growth, chemotherapy and blood flow reduction
Authors: Shungu Dikoma C. , Bhujwalla Zaver M. , Wehrle Janna P. , Glickson Jerry D. 
Published: January 2011

AbstractThis study evaluates a number of methods for obtaining 1H NMR spectra with adequate suppression of lipid and water resonances in two subcutaneously implanted transplantable tumor models (RIF‐1 and EMT6/SF). Spin‐echo spectra with long TEs (270 ms; water suppressed by presaturation) eliminated lipid resonances from 1H spectra of RIF‐1 and decreased lipid contamination in spectra of EMT6/SF; however, spectral sensitivity was substantially reduced. A shorter TE (135 ms) increased sensitivity but did not result in adequate suppression of the lipid peaks. In RIF‐1, but not EMT6/SF, adequate lipid suppression was achieved by: (i) spatially selective presaturation of lipid, which in this tumor (but not in EMT6/SF) was localized in a thin region along the periphery of the tumor, followed by a 1‐D spin‐echo chemical shift imaging pulse sequence (TE = 135 ms); and (ii) 2‐D spin‐echo chemical shift imaging (TE = 270 ms; ∼2 × 2 × 9 mm3 voxels). Preliminary 1H studies of the RIF‐1 tumor indicate that: (i) there are no significant changes in metabolite levels relative to tumor water during 4 days of untreated tumor growth; (ii) tumor response to chemotherapy with 5‐fluorouracil results in a decrease in intensity of all metabolite 1H resonances relative to tumor water, with total choline decreasing the most and lactate the least; and (iii) acute tumor blood flow reduction induced by administration of hydralazine results in doubling of the lactate intensity relative to water. These experiments demonstrate that in vivo 1H spectroscopy is feasible in at least one commonly employed subcutaneous tumor model (RIF‐1) and that this nucleus holds considerable promise for clinical and experimental studies of tumors.
Studies of human tumors by MRS: A review
Authors: Negendank William 
Published: January 2011

AbstractThe literature describing 31P, 1H, 13C, 23Na and 19F MRS in vivo in human cancers is reviewed. Cancers have typical metabolic characteristics in 31P and 1H MRS including high levels of phospholipid metabolites and a cellular pH more alkaline than normal. These alone are not specific for cancer but are diagnostic in appropriate clinical settings. Some metabolic characteristics appear to be prognostic indices and correlation with treatment response is emerging as an important potentially cost‐effective use of MRS in oncology. 19F MRS examines pharmacokinetics of 5‐fluorouracil and by demonstrating its retention predicts response of a cancer to treatment. Current needs include improvement of diagnostic specificity by use of techniques like multivoxel MRS, proton decoupling of 31P, short echo time and fat‐suppressed 1H MRS, 13C MRS direct or via 1H‐observe, and statistical analysis of multiple spectral features. Trials in large populations in well defined clinical settings are needed to determine if MRS can provide independent prognostic indices useful in cancer management.